U.S. patent application number 16/609831 was filed with the patent office on 2020-02-27 for flaskless mold machine.
This patent application is currently assigned to SINTOKOGIO, LTD.. The applicant listed for this patent is SINTOKOGIO, LTD.. Invention is credited to Yutaka HADANO, Koichi SAKAGUCHI, Tokiya TERABE.
Application Number | 20200061696 16/609831 |
Document ID | / |
Family ID | 64104688 |
Filed Date | 2020-02-27 |
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United States Patent
Application |
20200061696 |
Kind Code |
A1 |
TERABE; Tokiya ; et
al. |
February 27, 2020 |
FLASKLESS MOLD MACHINE
Abstract
A flaskless molding machine includes: an upper flask; a lower
flask; an upper sand tank; an upper plate attached to a lower end
of the upper sand tank; a first lower sand tank; a second lower
sand tank storing mold sand supplied from the first lower sand
tank; a lower plate attached to an upper end of the second lower
sand tank, with at least one supply port being formed, the supply
port allowing the second lower sand tank to communicate with an
inside of the lower flask; at least one pressure detector detecting
a pressure of at least one tank among the upper sand tank, the
first lower sand tank and the second lower sand tank; and a control
unit connected to the pressure detector and obtaining a detection
result of the at least one pressure detector.
Inventors: |
TERABE; Tokiya;
(Toyokawa-shi, Aichi, JP) ; SAKAGUCHI; Koichi;
(Toyokawa-shi, Aichi, JP) ; HADANO; Yutaka;
(Toyokawa-shi, Aichi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SINTOKOGIO, LTD. |
Nagoya-shi, Aichi |
|
JP |
|
|
Assignee: |
SINTOKOGIO, LTD.
Nagoya-shi, Aichi
JP
|
Family ID: |
64104688 |
Appl. No.: |
16/609831 |
Filed: |
April 26, 2018 |
PCT Filed: |
April 26, 2018 |
PCT NO: |
PCT/JP2018/017056 |
371 Date: |
October 31, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22C 15/28 20130101;
B22C 15/02 20130101; B22C 15/24 20130101; B22C 15/26 20130101 |
International
Class: |
B22C 15/24 20060101
B22C015/24; B22C 15/28 20060101 B22C015/28; B22C 15/26 20060101
B22C015/26; B22C 15/02 20060101 B22C015/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 12, 2017 |
JP |
2017-095852 |
Claims
1. A flaskless molding machine forming a flaskless upper mold and
lower mold, comprising: an upper flask; a lower flask disposed
below the upper flask and capable of clamping a match plate with
the upper flask; an upper sand tank disposed above the upper flask,
communicating with a compressed air source, being open at a lower
end thereof, and internally storing mold sand; an upper plate
attached to a lower end of the upper sand tank, with at least one
supply port being formed in the upper plate, the supply port
allowing the upper sand tank to communicate with an inside of the
upper flask; a first lower sand tank communicating with a
compressed air source, internally storing mold sand, and having a
first communication port for discharging the stored mold sand; a
second lower sand tank disposed below the lower flask, being open
at an upper end thereof, having a second communication port capable
of communicating with the first communication port of the first
lower sand tank, and storing the mold sand supplied from the first
lower sand tank and to be supplied into the lower flask; a lower
plate attached to an upper end of the second lower sand tank, with
at least one supply port being formed in the lower plate, the
supply port allowing the second lower sand tank to communicate with
an inside of the lower flask; at least one pressure detector
detecting a pressure of at least one tank among the upper sand
tank, the first lower sand tank and the second lower sand tank; and
a control unit connected to the pressure detector and obtaining a
detection result of the at least one pressure detector.
2. The flaskless molding machine according to claim 1, further
comprising: a drive unit moving the second lower sand tank in a
vertical direction, and allowing the upper plate and the lower
plate to perform squeezing; and an adjustment drive unit moving the
first lower sand tank in the vertical direction.
3. The flaskless molding machine according to claim 1, wherein the
upper sand tank includes a storage chamber storing the mold sand,
and at least one supply chamber provided on a side of the storage
chamber and communicating with the compressed air source, and the
at least one pressure detector detects a pressure of the at least
one supply chamber of the upper sand tank.
4. The flaskless molding machine according to claim 3, wherein the
at least one supply chamber of the upper sand tank includes a first
supply chamber disposed nearer to an upper end than a center of the
upper sand tank, and a second supply chamber disposed nearer to a
lower end than the center of the upper sand tank, and the at least
one pressure detector includes a first pressure detector detecting
a pressure of the first supply chamber, and a second pressure
detector detecting a pressure of the second supply chamber.
5. The flaskless molding machine according to claim 3, wherein the
storage chamber of the upper sand tank includes, on an inner
surface thereof, a first permeation member having a plurality of
pores allowing compressed air to pass, and the at least one supply
chamber of the upper sand tank communicates with the storage
chamber of the upper sand tank via the first permeation member.
6. The flaskless molding machine according to claim 1, wherein the
first lower sand tank includes a storage chamber storing the mold
sand, and at least one supply chamber provided on a side of the
storage chamber and communicating with the compressed air source,
and the at least one pressure detector detects a pressure of the at
least one supply chamber of the first lower sand tank.
7. The flaskless molding machine according to claim 6, wherein the
at least one supply chamber of the first lower sand tank includes a
third supply chamber disposed at a center of the first lower sand
tank, a fourth supply chamber disposed nearer to an upper end than
the center of the first lower sand tank, and a fifth supply chamber
disposed nearer to a lower end than the center of the first lower
sand tank, and the at least one pressure detector includes a third
pressure detector detecting a pressure of the third supply chamber,
a fourth pressure detector detecting a pressure of the fourth
supply chamber, and a fifth pressure detector detecting a pressure
of the fifth supply chamber.
8. The flaskless molding machine according to claim 7, wherein the
storage chamber of the first lower sand tank includes, on an inner
surface thereof, a second permeation member having a plurality of
pores allowing compressed air to pass, and the third supply chamber
and the fourth supply chamber communicate with the storage chamber
of the first lower sand tank via the second permeation member.
9. The flaskless molding machine according to claim 7, wherein the
fifth supply chamber is disposed at a curved lower end of the first
lower sand tank, and communicates with the storage chamber of the
first lower sand tank via a plurality of ventholes.
10. The flaskless molding machine according to claim 1, wherein the
second lower sand tank includes a storage chamber storing the mold
sand, and at least one supply chamber provided at a bottom of the
storage chamber and communicating with the compressed air source,
and the at least one pressure detector detects a pressure of the at
least one supply chamber of the second lower sand tank.
11. The flaskless molding machine according to claim 10, wherein
the at least one supply chamber of the second lower sand tank
communicates with the storage chamber of the second lower sand tank
via a plurality of ventholes.
12. The flaskless molding machine according to claim 1, further
comprising a display unit connected to the control unit and
displaying a detection result of the at least one pressure
detector.
13. The flaskless molding machine according to claim 12, wherein
the control unit causes the display unit to display, as the
detection result, a graph indicating a relationship between a
pressure and a time.
14. The flaskless molding machine according to claim 12, wherein
the control unit causes the display unit to display a setting
screen for setting an aeration setting pressure and a time.
15. The flaskless molding machine according to claim 12, further
comprising a storage unit storing a detection result of the at
least one pressure detector, and the control unit causes the
display unit to display the detection result stored in the storage
unit, and a detection result detected this time, in a manner
allowing comparison.
16. The flaskless molding machine according to claim 1, wherein the
control unit includes a communication unit transmitting a detection
result of the at least one pressure detector via a communication
network.
17. The flaskless molding machine according to claim 5, further
comprising a display unit connected to the control unit and
displaying the detection result of the at least one pressure
detector, wherein the control unit causes the display unit to
display the detection result of the at least one pressure detector
of the upper sand tank and a preset threshold in a manner allowing
comparison.
18. The flaskless molding machine according to claim 8, further
comprising a display unit connected to the control unit and
displaying the detection result of the at least one pressure
detector, wherein the control unit causes the display unit to
display the pressure detected by the third pressure detector or the
fourth pressure detector, and a preset threshold, in a manner
allowing comparison.
19. The flaskless molding machine according to claim 1, wherein at
least one control valve openable and closable according to a
control signal is provided between each of the upper sand tank, the
first lower sand tank and the second lower sand tank, and the
compressed air source, and the control unit outputs the control
signal to the at least one control valve, based on the detection
result of the at least one pressure detector.
20. The flaskless molding machine according to claim 19, wherein
when air is discharged from the upper sand tank, the first lower
sand tank and the second lower sand tank, the control unit outputs
the control signal in such a way as to open the at least one
control valve, based on the detection result of the at least one
pressure detector.
21. The flaskless molding machine according to claim 19, wherein
when air is discharged from the upper sand tank, the first lower
sand tank and the second lower sand tank, and the pressure detected
by the at least one pressure detector is not equal to or less than
a predetermined threshold, the control unit outputs warning
information.
22. The flaskless molding machine according to claim 19, wherein
the control valve corresponding to the upper sand tank is disposed
on a side of the upper sand tank, and the control valve
corresponding to the first lower sand tank is disposed on a side of
the first lower sand tank.
23. The flaskless molding machine according to claim 1, wherein in
an aeration process, when a maximum pressure detected by the
pressure detector in a predetermined aeration time period does not
reach a predetermined threshold, the control unit extends the
aeration time period, and when the maximum pressure detected by the
at least one pressure detector does not reach the predetermined
threshold after the extension, the control unit outputs warning
information.
Description
TECHNICAL FIELD
[0001] This disclosure relates to a flaskless molding machine.
BACKGROUND ART
[0002] Patent Literature 1 discloses a flaskless molding machine
that forms a flaskless type mold that does not have any flask. This
molding machine includes: a pair of an upper flask and a lower
flask that clamp a match plate where a model is disposed; a supply
mechanism that supplies mold sand; and a squeeze mechanism that
compresses the mold sand. The molding machine moves the lower flask
close to the upper flask, and causes the upper flask and the lower
flask to clamp the match plate. In this state, the molding machine
operates the supply mechanism, thereby supplying mold sand into
upper and lower molding spaces formed by the upper flask and the
lower flask. The molding machine operates the squeeze mechanism,
thereby compressing the mold sand in the upper and lower molding
spaces. Through the process described above, an upper mold and a
lower mold are simultaneously formed.
[0003] The supply mechanism of the molding machine supplies the
mold sand to the upper and lower molding spaces using compressed
air. The supply mechanism includes an upper sand tank that
communicates with a compressed air source and stores mold sand, and
an upper blow head that is disposed above the upper flask and
statically communicates with the upper sand tank. The compressed
air blown from the compressed air source supplies the upper blow
head with the mold sand stored in the upper sand tank, and supplies
the mold sand at the upper blow head to the upper molding space
defined by the upper flask. Likewise, the supply mechanism includes
a lower sand tank that communicates with the compressed air source
and stores mold sand, and a lower blow head that is disposed below
the lower flask, moves vertically, and communicates with the lower
sand tank at a predetermined position. The compressed air blown
from the compressed air source supplies the lower blow head with
the mold sand stored in the lower sand tank, and supplies the mold
sand at the lower blow head to the lower flask.
[0004] The squeeze mechanism of the flaskless molding machine
includes an upper squeeze cylinder and a lower squeeze cylinder
that vertically face each other. The upper squeeze cylinder applies
a downward pressure to the mold sand in the upper molding space,
and the lower squeeze cylinder applies an upward pressure to the
mold sand in the lower molding space. Accordingly, the hardness of
the mold sand is increased.
CITATION LIST
[0005] Patent Document [0006] Patent Document 1: Japanese
Unexamined Patent Publication No. S54-51930
SUMMARY OF INVENTION
Technical Problem
[0007] As with the flaskless molding machine described in Patent
Document 1, the apparatus that supplies mold sand into the molding
spaces using compressed air possibly causes sand clogging in the
sand tanks. However, the flaskless molding machine described in
Patent Document 1 cannot grasp the situations in the sand tanks.
Such sand clogging affects the moldability of the molds and the
quality of a casting product. In this technical field, a flaskless
molding machine that foams excellent molds and casting products is
desired.
Solution to Problem
[0008] A flaskless molding machine according to one aspect of this
disclosure is a flaskless molding machine forming flaskless upper
mold and lower mold, comprising: an upper flask; a lower flask
disposed below the upper flask and capable of clamping a match
plate with the upper flask; an upper sand tank disposed above the
upper flask, communicating with a compressed air source, being open
at a lower end thereof, and internally storing mold sand; an upper
plate attached to a lower end of the upper sand tank, with at least
one supply port being formed in the upper plate, the supply port
allowing the upper sand tank to communicate with an inside of the
upper flask; a first lower sand tank communicating with a
compressed air source, internally storing mold sand, and having a
first communication port for discharging the stored mold sand; a
second lower sand tank disposed below the lower flask, being open
at an upper end thereof, having a second communication port capable
of communicating with the first communication port of the first
lower sand tank, and storing the mold sand supplied from the first
lower sand tank and to be supplied into the lower flask; a lower
plate attached to an upper end of the second lower sand tank, with
at least one supply port being formed in the lower plate, the
supply port allowing the second lower sand tank to communicate with
an inside of the lower flask; at least one pressure detector
detecting a pressure of at least one tank among the upper sand
tank, the first lower sand tank and the second lower sand tank; and
a control unit connected to the pressure detector and obtaining a
detection result of the at least one pressure detector.
[0009] In this flaskless molding machine, the pressure of at least
one tank among the upper sand tank, the first lower sand tank and
the second lower sand tank is detected by at least one pressure
detector. The detection result of at least one pressure detector is
then obtained by the control device. As described above, the
situations in the sand tanks are obtained by obtaining the
pressures in the tanks. As a result, excellent molds and casting
products can be obtained.
[0010] In one embodiment, the flaskless molding machine may further
include: a drive unit moving the second lower sand tank in a
vertical direction, and allowing the upper plate and the lower
plate to perform squeezing; and an adjustment drive unit moving the
first lower sand tank in the vertical direction. In such a
configuration, in the apparatus where the squeeze process is
performed by the second lower sand tank moving in the vertical
direction, the situations in the sand tanks can be appropriately
grasped.
[0011] In one embodiment, the upper sand tank may include a storage
chamber storing the mold sand, and at least one supply chamber
provided on a side of the storage chamber and communicating with
the compressed air source. At least one pressure detector may
detect a pressure of the at least one supply chamber of the upper
sand tank. In such a configuration, the apparatus can utilize the
supply chamber for supplying compressed air in order to arrange the
pressure detector.
[0012] In one embodiment, at least one supply chamber of the upper
sand tank may include a first supply chamber disposed nearer to an
upper end than a center of the upper sand tank, and a second supply
chamber disposed nearer to a lower end than the center of the upper
sand tank. The at least one pressure detector may include a first
pressure detector detecting a pressure of the first supply chamber,
and a second pressure detector detecting a pressure of the second
supply chamber. In such a configuration, the upper and lower
pressures of the upper sand tank, that is, the entire pressures of
the upper sand tank are detected. Accordingly, the apparatus can
grasp the pressure deviation dependent on the detection position of
the upper sand tank.
[0013] In one embodiment, the storage chamber of the upper sand
tank may include, on an inner surface thereof, a first permeation
member having a plurality of pores allowing compressed air to pass.
The at least one supply chamber of the upper sand tank may
communicate with the storage chamber of the upper sand tank via the
first permeation member. According to such a configuration, the
apparatus can detect clogging at the first permeation member.
[0014] In one embodiment, the first lower sand tank may include a
storage chamber storing the mold sand, and at least one supply
chamber provided on a side of the storage chamber and communicating
with the compressed air source. The at least one pressure detector
may detect a pressure of the at least one supply chamber of the
first lower sand tank. In such a configuration, the apparatus can
utilize the supply chamber for supplying compressed air in order to
arrange the pressure detector.
[0015] In one embodiment, the at least one supply chamber of the
first lower sand tank may include a third supply chamber disposed
at a center of the first lower sand tank, a fourth supply chamber
disposed nearer to an upper end than the center of the first lower
sand tank, and a fifth supply chamber disposed nearer to a lower
end than the center of the first lower sand tank. The at least one
pressure detector may include a third pressure detector detecting a
pressure of the third supply chamber, a fourth pressure detector
detecting a pressure of the fourth supply chamber, and a fifth
pressure detector detecting a pressure of the fifth supply chamber.
In such a configuration, the upper and lower pressures of the first
lower sand tank, that is, the entire pressures of the first lower
sand tank are detected. Accordingly, the apparatus can grasp the
pressure deviation dependent on the detection position of the first
lower sand tank.
[0016] In one embodiment, the storage chamber of the first lower
sand tank may include, on an inner surface thereof, a second
permeation member having a plurality of pores allowing compressed
air to pass. The third supply chamber and the fourth supply chamber
may communicate with the storage chamber of the first lower sand
tank via the second permeation member. According to such a
configuration, the apparatus can detect clogging at the second
permeation member.
[0017] In one embodiment, the fifth supply chamber may be disposed
at a curved lower end of the first lower sand tank, and communicate
with the storage chamber of the first lower sand tank via a
plurality of ventholes. In such a configuration, the apparatus can
detect the pressure at the lower end of the first lower sand tank
where clogging at the permeation member tends to occur. At the
curved lower end of the first lower sand tank, owing to the shape
thereof, the abrasion of the permeation member disposed in the
storage chamber tends to be larger than that at another arrangement
position. According to the apparatus, in the storage chamber at the
curved lower end of the first lower sand tank, the plurality of
ventholes instead of the permeation member are adopted.
Accordingly, at the curved lower end of the first lower sand tank,
occurrence of clogging at the permeation member can be avoided.
[0018] In one embodiment, the second lower sand tank may include a
storage chamber storing the mold sand, and at least one supply
chamber provided at a bottom of the storage chamber and
communicating with the compressed air source. The at least one
pressure detector may detect a pressure of the at least one supply
chamber of the second lower sand tank. In such a configuration, the
apparatus can utilize the supply chamber for supplying compressed
air in order to arrange the pressure detector.
[0019] In one embodiment, the at least one supply chamber of the
second lower sand tank communicates with the storage chamber of the
second lower sand tank via a plurality of ventholes. In the second
lower sand tank, the mold sand flows from bottom to up and is
supplied into the lower flask. Accordingly, the abrasion of the
permeation member disposed in the storage chamber in the second
lower sand tank tends to be higher than abrasions of the other
tanks. According to the apparatus, in the storage chamber of the
second lower sand tank, the plurality of ventholes are adopted
instead of the permeation member. Accordingly, in the second lower
sand tank, occurrence of clogging at the permeation member can be
avoided.
[0020] In one embodiment, the flaskless molding machine may further
include a display unit connected to the control unit and displaying
a detection result of the at least one pressure detector. According
to such a configuration, the apparatus can notify the operator of
the detection result of the pressure detector.
[0021] In one embodiment, the control unit may cause the display
unit to display, as the detection result, a graph indicating a
relationship between a pressure and a time. According to such a
configuration, the apparatus can notify the operator of the time
dependence of the pressure.
[0022] In one embodiment, the control unit may cause the display
unit to display a setting screen for setting an aeration setting
pressure and a time. According to such a configuration, the
apparatus can assist a setting operation by the operator.
[0023] In one embodiment, the flaskless molding machine may further
include a storage unit storing a detection result of the at least
one pressure detector. The control unit may cause the display unit
to display the detection result stored in the storage unit, and a
detection result detected this time, in a manner allowing
comparison. In such a configuration, the apparatus may notify the
operator of the difference between the previous detection result
and the detection result this time.
[0024] In one embodiment, the control unit may include a
communication unit transmitting a detection result of the at least
one pressure detector via a communication network. In such a
configuration, the apparatus can transmit the detection results of
the pressure detectors to an external computer or the like without
intervention of a physical storage medium.
[0025] In one embodiment, the flaskless molding machine may further
include a display unit connected to the control unit and displaying
a detection result of the at least one pressure detector. The
control unit may cause the display unit to display the detection
result of the at least one pressure detector of the upper sand tank
and a preset threshold in a manner allowing comparison. In this
case, the apparatus can allow the operator to predict clogging at
the first permeation member.
[0026] In one embodiment, the flaskless molding machine may further
include a display unit connected to the control unit and displaying
a detection result of the at least one pressure detector. The
control unit may cause the display unit to display the pressure
detected by the third pressure detector or the fourth pressure
detector, and a preset threshold, in a manner allowing comparison.
In this case, the apparatus can allow the operator to predict
clogging at the second permeation member.
[0027] In one embodiment, at least one control valve openable and
closable according to a control signal may be provided between each
of the upper sand tank, the first lower sand tank and the second
lower sand tank, and the compressed air source. The control unit
may output the control signal to the at least one control valve,
based on the detection result of the at least one pressure
detector. In such a configuration, the apparatus can perform
feedback control about the pressure, for example. Accordingly, the
apparatus can appropriately control the flow of the mold sand in
the tank.
[0028] In one embodiment, when air is discharged from the upper
sand tank, the first lower sand tank and the second lower sand
tank, the control unit may output the control signal in such a way
as to open the at least one control valve, based on the detection
result of the at least one pressure detector. In such a
configuration, the apparatus can prevent the mold sand from
reversely flowing from the storage chamber to the supply
chamber.
[0029] In one embodiment, when air is discharged from the upper
sand tank, the first lower sand tank and the second lower sand
tank, and the pressure detected by the at least one pressure
detector is not equal to or less than a predetermined threshold,
the control unit may output warning information. According to such
a configuration, the apparatus can warn the operator about presence
of a failure in a discharge system.
[0030] In one embodiment, the control valve corresponding to the
upper sand tank may be disposed on a side of the upper sand tank,
and the control valve corresponding to the first lower sand tank
may be disposed on a side of the first lower sand tank. In such a
configuration, the distance from the tank to the corresponding
control valve becomes short. Accordingly, the apparatus can improve
the response of supply with compressed air.
[0031] In one embodiment, in an aeration process, when a maximum
pressure detected by the pressure detector in a predetermined
aeration time period does not reach a predetermined threshold, the
control unit may extend the aeration time period. When the maximum
pressure detected by the at least one pressure detector does not
reach the predetermined threshold after the extension, the control
unit may output warning information. In such a configuration, when
the maximum pressure does not reach the predetermined threshold,
the apparatus can automatically perform the additional aeration.
Furthermore, when the situation is not improved even by the
additional aeration, the apparatus may issue the warning to the
operator.
Advantageous Effects of Invention
[0032] According to the various aspects and embodiments of this
disclosure, a flaskless molding machine that forms excellent molds
and casting products is provided.
BRIEF DESCRIPTION OF DRAWINGS
[0033] FIG. 1 is a perspective view on a front side of a flaskless
molding machine according to one embodiment.
[0034] FIG. 2 is a front view of the flaskless molding machine
according to one embodiment.
[0035] FIG. 3 is a schematic diagram on a left side of the
flaskless molding machine according to one embodiment.
[0036] FIG. 4 is a schematic diagram on the left side of the
flaskless molding machine in an aeration process.
[0037] FIG. 5 is a schematic diagram on a left side of a compressed
air supply structure related to an upper sand tank.
[0038] FIG. 6 is a schematic diagram on the back of the compressed
air supply structure related to the upper sand tank.
[0039] FIG. 7 is a schematic diagram on the upper surface side of
the compressed air supply structure related to the upper sand
tank.
[0040] FIG. 8 is a schematic diagram on a left side of the
compressed air supply structure related to a first lower sand tank
and a second lower sand tank.
[0041] FIG. 9 is a schematic diagram on the back of the compressed
air supply structure related to the first lower sand tank and the
second lower sand tank.
[0042] FIG. 10 is a partially enlarged view of a lower portion of
the apparatus in FIG. 8.
[0043] FIG. 11 is a sectional view of an inspection door.
[0044] FIG. 12 shows an example of connection of a third pressure
detector.
[0045] FIG. 13 is a flowchart illustrating a molding process of the
flaskless molding machine according to one embodiment.
[0046] FIG. 14 is a functional block diagram of the flaskless
molding machine according to one embodiment.
[0047] FIG. 15 shows an example of a graph of a control signal for
an electro-pneumatic proportional valve and detection results of
the pressure detectors.
[0048] FIG. 16 shows an example of a graph indicating the detection
result of the pressure detector and a threshold.
[0049] FIG. 17 shows an example of comparison between a
preliminarily stored detection result and a detection result this
time.
[0050] FIG. 18 shows screen examples displayed by a display
unit.
DESCRIPTION OF EMBODIMENTS
[0051] Hereinafter, embodiments are described with reference to the
drawings. The identical or corresponding portions in the diagrams
are assigned identical signs, and redundant description is omitted.
Hereinafter, the horizontal directions are assumed as X-axis and
Y-axis directions, and the vertical direction (upward and downward
direction) is assumed as a Z-axis direction.
[0052] [Overview of Flaskless Molding Machine]
[0053] FIG. 1 is a perspective view on a front side of a flaskless
molding machine according to one embodiment. A flaskless molding
machine 1 is a molding machine that forms a flaskless upper mold
and lower mold. As shown in FIG. 1, the flaskless molding machine 1
includes a molding unit A1, and a conveyance unit A2. In the
molding unit A1, an upper flask and a lower flask that have box
shapes and are movable in the vertical direction (Z-axis direction)
are disposed. The conveyance unit A2 introduces a match plate where
models are arranged, to the molding unit A1. The upper flask and
the lower flask of the molding unit A1 are moved to be close to
each other, and clamp the match plate. The inside of the upper
flask and the inside of the lower flask are filled with mold sand.
The mold sand filled in the upper flask and the lower flask are
pressurized in the vertical direction by a squeeze mechanism
included in the molding unit A1, and the upper mold and the lower
mold are simultaneously formed. Subsequently, an upper mold and a
lower mold are removed from the upper flask and the lower flask,
respectively, and are conveyed to the outside of the machine. As
described above, the flaskless molding machine 1 forms the
flaskless upper mold and lower mold.
[0054] [Frame Structure]
[0055] FIG. 2 is a front view of the flaskless molding machine 1
according to one embodiment. FIG. 3 is a schematic diagram on the
left side of the flaskless molding machine according to one
embodiment. As shown in FIGS. 2 and 3, the flaskless molding
machine 1 includes an upper frame 10, a lower frame 11, and four
guides 12 that connect the upper frame 10 and the lower frame 11.
As for the guides 12, their upper ends are connected to the upper
frame 10, and their lower ends are connected to the lower frame 11.
The frame of the molding unit A1 described above is made up of the
upper frame 10, the lower frame 11 and the four guides 12.
[0056] On a side of the frame of the molding unit A1 (in the
negative direction on the X-axis), a support frame 13 (FIG. 2) of
the conveyance unit A2 is disposed. Furthermore, on a side of the
frame of the molding unit A1 (the positive direction on the
Y-axis), a support frame 14 (FIG. 3) extending in the vertical
direction is disposed. The support frame 14 supports a first lower
sand tank described later.
[0057] [Upper Flask and Lower Flask]
[0058] The flaskless molding machine 1 includes an upper flask 15.
The upper flask 15 is a box-shaped frame where the upper end and
the lower end are open. The upper flask 15 is movably attached to
the four guides 12. The upper flask 15 is supported by an upper
flask cylinder 16 attached to the upper frame 10, and vertically
moves along the guides 12 according to the operation of the upper
flask cylinder 16.
[0059] The flaskless molding machine 1 includes a lower flask 17
disposed below the upper flask 15. The lower flask 17 is a
box-shaped frame where the upper end and the lower end are open.
The lower flask 17 is movably attached to the four guides 12. The
lower flask 17 is supported by two lower flask cylinders 18 (FIG.
2) attached to the upper frame 10, and vertically moves along the
guides 12 according to the operation of the lower flask cylinders
18. Hereinafter, a region encircled by the guides 12 is also called
a formation position.
[0060] A match plate 19 (FIG. 2) is introduced between the upper
flask 15 and the lower flask 17, from the conveyance unit A2. The
match plate 19 is a plate-shaped member with models being disposed
on both the surfaces thereof, and moves to and fro between the
upper flask 15 and the lower flask 17. According to a specific
example, the support frame 13 of the conveyance unit A2 includes
rails toward a formation position, a conveyance plate 20 having
rollers disposed on the rails, and a conveyance cylinder 21 that
operates the conveyance plate 20. The match plate 19 is disposed on
the conveyance plate 20, and is disposed at the formation position
between the upper flask 15 and the lower flask 17 by the operation
of the conveyance cylinder 21. The upper flask 15 and the lower
flask 17 can clamp the disposed match plate 19, in the vertical
direction. Hereinafter, a region on the support frame 13 is also
called a retracted position.
[0061] [Sand Tank]
[0062] The flaskless molding machine 1 includes an upper sand tank
22 disposed above the upper flask 15. The upper sand tank 22 is
attached to the upper frame 10. More specifically, the upper sand
tank 22 is statically fixed to the upper frame 10. The upper sand
tank 22 includes a storage chamber S1 that internally stores mold
sand to be supplied to the upper flask 15. The upper sand tank 22
is open at its upper end and lower end. The upper end of the upper
sand tank 22 is provided with a slide gate 23 that slides a
plate-shaped shield member in the horizontal direction (the
positive and negative directions on the X-axis). The upper sand
tank 22 is configured so that its upper end can be opened and
closed by the operation of the slide gate 23. A mold sand loading
chute 24 that loads mold sand is fixedly disposed above the upper
sand tank 22. The mold sand loading chute 24 is described later.
When the slide gate 23 is in an open state, the mold sand is
supplied through the mold sand loading chute 24 to the upper sand
tank 22.
[0063] The lower end of the upper sand tank 22 is open, and an
upper plate 25 (FIG. 3) is attached to the opening at the lower
end. The upper plate 25 is a plate-shaped member, and has at least
one supply port through which the upper sand tank 22 and the inside
of the upper flask 15 communicate with each other. The mold sand in
the upper sand tank 22 is supplied through the supply port of the
upper plate 25 into the upper flask 15. The upper plate 25 has a
size substantially identical to the size of the opening of the
upper flask 15. The upper flask 15 moves in the upward direction,
thereby causing the upper plate 25 to enter the inside of the upper
flask 15. The upper flask 15 moves in the downward direction,
thereby retracting the upper plate 25 from the upper flask 15. As
described above, the upper plate 25 is configured to be capable of
entering and being retracted from the inside of the upper flask 15.
The details of the upper plate 25 are described later.
[0064] The upper sand tank 22 communicates with a compressed air
source (not shown). According to a specific example, the upper sand
tank 22 communicates with pipes 80 to 83 (FIGS. 2 and 5 to 7) for
supplying compressed air, and communicates with the compressed air
source through the pipes 80 to 83. The pipes 80 to 83 are provided
with electro-pneumatic proportional valves 90 to 93 (examples of
control valves in FIGS. 2 and 5 to 7). The electro-pneumatic
proportional valve 92 not only switches supply and stop of
compressed air but also automatically adjusts the valve opening
degree according to the pressure on the output side. Accordingly,
the compressed air at a predetermined pressure is supplied to the
upper sand tank 22. When the slide gate 23 is in a closed state,
compressed air is blown into the upper sand tank 22. The mold sand
in the upper sand tank 22 is supplied, together with the compressed
air, through the supply port of the upper plate 25 into the upper
flask 15. Details of a compressed air supply mechanism are
described later.
[0065] The storage chamber S1 of the upper sand tank 22 includes,
on its inner surface, a first permeation member 22a (FIG. 3) having
a plurality of pores that allow the compressed air to pass.
Accordingly, the compressed air is supplied through the entire
surface of the first permeation member 22a to the entire storage
chamber S1, thereby improving the fluidity of the mold sand. The
first permeation member 22a may be formed of a porous material. The
upper sand tank 22 communicates with a pipe 29 (FIG. 2) for
discharging the compressed air. The compressed air passes through
the first permeation member 22a when being discharged through the
pipe 29. The first permeation member 22a does not allow the mold
sand to pass but allows the compressed air to pass. Consequently,
the mold sand can be prevented from being discharged to the outside
of the upper sand tank 22.
[0066] The flaskless molding machine 1 includes a lower sand tank
that stores mold sand to be supplied into the lower flask 17.
According to an example, the lower sand tank is divided into a
first lower sand tank 30 (FIG. 3) and a second lower sand tank 31
(FIG. 3). The first lower sand tank 30 is disposed on a side of the
upper sand tank 22. The first lower sand tank 30 includes a storage
chamber S2 that internally stores mold sand to be supplied to the
lower flask 17.
[0067] The first lower sand tank 30 is supported by the support
frame 14, and is movably attached to a vertically extending guide
12A (FIG. 1) provided for the support frame 14. More specifically,
the first lower sand tank 30 is supported by a lower tank cylinder
(adjustment drive unit) 32 (FIG. 3) attached to the upper frame 10,
and vertically moves along the guide 12A according to the operation
of the lower tank cylinder 32.
[0068] The first lower sand tank 30 is open at its upper end. The
first lower sand tank 30 is provided with a slide gate 33 (FIG. 3)
that slides a plate-shaped shield member in the horizontal
direction (the positive and negative directions on the X-axis), at
the upper end. The first lower sand tank 30 is configured so that
its upper end can be opened and closed by the operation of the
slide gate 33. A hopper 34 (FIG. 3) for loading mold sand is
fixedly disposed above the first lower sand tank 30. The
communication relationship between the hopper 34 and the mold sand
loading chute 24 is described later. When the slide gate 33 is in
an open state, the mold sand is supplied through the hopper 34 to
the first lower sand tank 30.
[0069] The first lower sand tank 30 is bent at its lower end in the
horizontal direction (the negative direction on the Y-axis), and,
at its distal end, a first communication port 35 (FIG. 3) for
discharging the stored mold sand is formed. The first communication
port 35 is configured so that this port can communicate with an
after-mentioned second communication port of the second lower sand
tank 31 at a predetermined height (communication position). The
mold sand is supplied through the first communication port 35 to
the second lower sand tank 31. The distal end of the first lower
sand tank 30 is provided with a first block plate 36 (FIG. 3) that
extends in the vertical direction. When an after-mentioned second
communication port of the second lower sand tank 31 is not at a
communication position, this port is shielded by the first block
plate 36.
[0070] The first lower sand tank 30 communicates with the
compressed air source (not shown). According to a specific example,
the first lower sand tank 30 communicates with pipes 84 to 87 (FIG.
9) for supplying compressed air, and communicates with the
compressed air source through the pipes 84 to 87. The pipes 84 to
87 are provided with electro-pneumatic proportional valves 94 to 97
(FIG. 9). Accordingly, the compressed air at a predetermined
pressure is supplied to the first lower sand tank 30. When the
slide gate 33 is in the closed state and the after-mentioned second
communication port of the second lower sand tank 31 is at the
communication position, the compressed air is supplied into the
first lower sand tank 30. The mold sand in the first lower sand
tank 30 is supplied, together with the compressed air, through the
first communication port 35 into the second lower sand tank 31.
Details of the compressed air supply mechanism are described
later.
[0071] The storage chamber S2 of the first lower sand tank 30 is
provided, on its inner surface, with a second permeation member 30a
(FIG. 3) having a plurality of pores that allow the compressed air
to pass. Accordingly, the compressed air is supplied through the
entire surface of the second permeation member 30a to the entire
storage chamber S2, thereby improving the fluidity of the mold
sand. The second permeation member 30a may be formed of a porous
material. The first lower sand tank 30 communicates, at its side,
with a pipe (not shown) for discharging the compressed air. The
compressed air passes through the second permeation member 30a when
being discharged through the pipe. The second permeation member 30a
does not allow the mold sand to pass but allows the compressed air
to pass. Consequently, the mold sand can be prevented from being
discharged to the outside of the first lower sand tank 30.
[0072] The second lower sand tank 31 is disposed below the lower
flask 17. The second lower sand tank 31 includes a storage chamber
S3 that internally stores mold sand to be supplied to the lower
flask 17. The second lower sand tank 31 is movably attached to the
four guides 12, and is supported in a vertically movable manner by
a vertically extending squeeze cylinder (drive unit) 37.
[0073] At a side portion of the second lower sand tank 31, a second
communication port 38 (FIG. 3) that can communicate with the first
communication port 35 of the first lower sand tank is formed. The
second communication port 38 is configured so that this port can
communicate with the first communication port 35 of the first lower
sand tank 30 at a predetermined height (communication position).
The communication position has a height at which the first
communication port 35 and the second communication port 38
communicate with each other and, more specifically, is a position
at which the first communication port 35 and the second
communication port 38 are disposed concentrically with each other.
The first communication port 35 and the second communication port
38 communicate with each other on a communication plane along the
vertical direction.
[0074] The first lower sand tank 30 and the second lower sand tank
31 are in a state of communicating with each other through
communication between the first communication port 35 and the
second communication port 38 being at the predetermined
communication position. The mold sand is supplied through the first
communication port 35 and the second communication port 38 from the
first lower sand tank 30 to the second lower sand tank 31. The
second communication port 38 of the second lower sand tank 31 is
provided with a vertically extending second block plate 39 (FIG.
3). The opposite sides of the first communication port 35 of the
first lower sand tank 30 are provided with guide rails (not shown)
that guide a second block plate 39. The second block plate 39 is
guided by the guide rails, thereby allowing the first communication
port 35 and the second communication port 38 to be guided to the
communication position without being inclined from each other. When
the first communication port 35 of the first lower sand tank 30 is
not at the communication position, this port is shielded by the
second block plate 39.
[0075] It should be noted that the flaskless molding machine 1 may
include a sealing mechanism that hermetically seals the
communication planes of the first communication port 35 and the
second communication port 38. For example, the sealing mechanism is
provided on the first communication port 35 side.
[0076] The upper end of the second lower sand tank 31 is open, and
a lower plate 40 (FIG. 3) is attached to the opening at the upper
end. The lower plate 40 is a plate-shaped member, and has at least
one supply port through which the second lower sand tank 31 and the
inside of the lower flask 17 communicate with each other. The mold
sand in the second lower sand tank 31 is supplied through the
supply port of the lower plate 40 and an after-mentioned lower
filling frame into the lower flask 17.
[0077] [Lower Filling Frame]
[0078] The flaskless molding machine 1 includes, for example, a
lower filling frame 41. The lower filling frame 41 is disposed
below the lower flask 17. The lower filling frame 41 is a
box-shaped frame where the upper end and the lower end are open.
The opening at the upper end of the lower filling frame 41
communicates with the opening at the lower end of the lower flask
17. The lower filling frame 41 is configured so that its inside can
accommodate the second lower sand tank 31. The lower filling frame
41 is supported in a vertically movable manner by a lower filling
frame cylinder 42 fixed to the second lower sand tank 31. The lower
plate 40 has a size substantially identical to each of the sizes of
openings of the lower filling frame 41 and the lower flask 17. A
position where the vertically movable lower filling frame 41
internally accommodates the second lower sand tank 31 and the lower
plate 40 is an original position (initial position), and serves as
a descending end. The lower filling frame 41 moves in the upward
direction, thereby retracting the lower plate 40 from the lower
filling frame 41. The lower filling frame 41 having moved in the
upward direction is moved in the downward direction, thereby
allowing the lower plate 40 to enter the inside of the lower
filling frame 41. As described above, the lower plate 40 is
configured to be capable of entering and being retracted from the
inside of the lower filling frame 41 (movable to and fro). The
flaskless molding machine 1 can reduce the stroke of the lower
flask 17 by comprising the lower filling frame 41. Consequently,
the flaskless molding machine having a lower machine height can be
achieved in comparison with a case of not comprising the lower
filling frame 41. Furthermore, as the flaskless molding machine 1
can reduce the stroke of the lower flask 17 by comprising the lower
filling frame 41, the molding time of the pair of the upper mold
and the lower mold can be reduced.
[0079] It should be noted that the flaskless molding machine 1 does
not necessarily include the lower filling frame 41. In this case,
the lower plate 40 is configured to be capable of entering and
being retracted from the inside of the lower flask 17 (movable to
and fro). The descending end of the vertically movable lower flask
17 is the original position (initial position). That is, the lower
plate 40 enters the inside of the lower flask 17 by moving in the
upward direction relatively more than the lower flask 17 moving in
the upward direction. The lower plate 40 is retracted from the
lower flask 17 by moving in the downward direction relatively more
than the lower flask 17.
[0080] [Molding Space and Squeeze]
[0081] The molding space (upper molding space) of the upper mold is
formed by the upper plate 25, the upper flask 15 and the match
plate 19. The molding space (lower molding space) of the lower mold
is formed by the lower plate 40, the lower flask 17 and the match
plate 19. The upper molding space and the lower molding space are
formed when the upper flask cylinder 16, the lower flask cylinders
18 and the squeeze cylinder 37 are operated and the upper flask 15
and the lower flask 17 clamp the match plate at a predetermined
height. In a case where the flaskless molding machine 1 includes
the lower filling frame 41, the lower molding space may be formed
by the lower plate 40, the lower flask 17, the lower filling frame
41 and the match plate 19.
[0082] The upper molding space is filled with the mold sand stored
in the upper sand tank 22, through the upper plate 25. The lower
molding space is filled with the mold sand stored in the second
lower sand tank 31, through the lower plate 40. Compressed air is
used for filling. A process of filling the upper molding space and
the lower molding space with the mold sand while causing the mold
sand to flow using the compressed air is called aeration. FIG. 4 is
a schematic diagram on the left side of the flaskless molding
machine in the aeration process. As shown in FIG. 4, when the upper
flask 15 and the lower flask 17 clamp the match plate 19 at a
predetermined height, the mold sand is supplied by the compressed
air into the molding space.
[0083] The CB of the mold sand with which the upper molding space
and the lower molding space are filled may be set in a range from
30% to 42%. The compressive strength of the mold sand with which
the upper molding space and the lower molding space are filled may
be set in a range from 8 to 15 N/cm.sup.2. It should be noted that
as the thickness of the mold to be formed is changed according to
the model shape and the CB (compactability) of the mold sand, the
height of a target of the second lower sand tank 31 is changed
according to the thickness of the mold. That is, the height of the
second communication port 38 of the second lower sand tank 31 is
changed. At this time, the height of the first communication port
35 of the first lower sand tank 30 is adjusted to be at the
communication position of the second communication port 38 of the
second lower sand tank 31 by the lower tank cylinder 32. Such
adjustment can be achieved by an after-mentioned control device 50
(FIG. 3).
[0084] In a state where the upper molding space and the lower
molding space are filled with the mold sand, the squeeze cylinder
37 performs squeezing with the upper plate 25 and the lower plate
40 by moving the second lower sand tank 31 upward. Accordingly, a
pressure is applied to the mold sand in the upper molding space,
and the upper mold is formed. At the same time, a pressure is
applied to the mold sand in the lower molding space, and the lower
mold is formed.
[0085] [Mold Sand Loading Chute]
[0086] The mold sand loading chute 24 is open at the upper end, and
is bifurcated at the lower end. The upper end is provided with a
switch damper 43. The switch damper 43 changes its inclination
direction so that the mold sand can fall to any one of the
bifurcated lower end portions. One lower end portion of the mold
sand loading chute 24 is fixed to the upper portion of the upper
sand tank 22, and the other lower end portion of the mold sand
loading chute 24 is accommodated in the hopper 34 and is not fixed.
Since the lower end portion on the first lower sand tank 30 side is
not fixed as described above, the lower tank cylinder 32 can
control the height of the first communication port 35 of the first
lower sand tank 30 independently from the upper sand tank 22.
[0087] [Compressed Air Supply Structure]
[0088] The upper sand tank 22, the first lower sand tank 30 and the
second lower sand tank 31 each include at least one supply chamber
that communicates with the compressed air source. "Communicate(s)"
means connection allowing air to pass through. The supply chamber
may be disposed in such a way as to surround the storage chamber.
The storage chamber and the supply chamber communicate with each
other through a through-hole. Compressed air is blown from the
compressed air source into the supply chamber, and is blown from
the supply chamber into the storage chamber through the permeation
members or ventholes.
[0089] Hereinafter, the compressed air supply structure at each
tank is described. First, the compressed air supply structure at
the upper sand tank 22 is described. FIG. 5 is a schematic diagram
on the left side of the compressed air supply structure related to
the upper sand tank. FIG. 6 is a schematic diagram on the back of
the compressed air supply structure related to the upper sand tank.
FIG. 7 is a schematic diagram on the upper surface side of the
compressed air supply structure related to the upper sand tank.
[0090] As shown in FIGS. 5 to 7, the upper sand tank 22 includes a
first supply chamber S4 disposed nearer to the upper end than the
center of the upper sand tank 22, and a second supply chamber S5
disposed nearer to the lower end than the center of the upper sand
tank 22, for example. The center of the upper sand tank 22 is the
center of the upper sand tank 22 in the axial direction. The first
supply chamber S4 and the second supply chamber S5 are disposed on
a side of the storage chamber S1. The first supply chamber S4 and
the second supply chamber S5 are spaces provided in such a way as
to surround the storage chamber S1. The first supply chamber S4 is
defined between a side wall 22b of the storage chamber S1 and a
pipe member 22c provided outside of the side wall 22b of the
storage chamber S1. The second supply chamber S5 is defined between
the side wall 22b of the storage chamber S1 and a pipe member 22d
provided outside of the side wall 22b of the storage chamber
S1.
[0091] The pipes 80 and 83 communicate with the first supply
chamber S4. The pipes 80 and 83 are connected at the positions of
the pipe member 22c opposite to each other. The pipes 80 and 83
communicate with a main pipe 100 that communicates with the
compressed air source. The pipe 80 is provided with an
electro-pneumatic proportional valve 90. The pipe 83 is provided
with an electro-pneumatic proportional valve 93. The
electro-pneumatic proportional valves 90 and 93 are disposed on a
side of the upper sand tank 22. The electro-pneumatic proportional
valves are valves that are connected to the after-mentioned control
device 50, and open and close on the basis of a control signal of
the control device 50. The first supply chamber S4 communicates
with the storage chamber S1 via a through-hole (not shown). When
the electro-pneumatic proportional valves 90 and 93 are opened, the
compressed air flows from the main pipe 100 through the pipes 80
and 83 and is supplied into the first supply chamber S4. The
compressed air is blown from the first supply chamber S4 through
the through-hole and the first permeation member 22a into the
storage chamber S1. It should be noted that a plurality of
through-holes may be formed in the side wall 22b of the storage
chamber S1. For example, the plurality of through-holes may be
formed in such a way as to surround the storage chamber S1. In this
case, the compressed air is allowed to be uniformly blown toward
the storage chamber S1 in the circumferential directions.
[0092] The pipes 81 and 82 communicate with the second supply
chamber S5. The pipes 81 and 82 communicate with one side of the
pipe member 22d. The pipes 81 and 82 communicate with the main pipe
100 that communicates with the compressed air source. The pipe 81
is provided with the electro-pneumatic proportional valve 91. The
pipe 82 is provided with the electro-pneumatic proportional valve
92. The electro-pneumatic proportional valves 91 and 92 are
disposed on a side of the upper sand tank 22. The second supply
chamber S5 communicates with the storage chamber S1 via a
through-hole (not shown). When the electro-pneumatic proportional
valves 91 and 92 are opened, the compressed air flows from the main
pipe 100 through the pipes 81 and 82 and is supplied into the
second supply chamber S5.
[0093] The compressed air is blown from the second supply chamber
S5 through the through-hole and the first permeation member 22a
into the storage chamber S1. It should be noted that a plurality of
through-holes may be formed in the side wall 22b of the storage
chamber S1. For example, the plurality of through-holes may be
formed in such a way as to surround the storage chamber S1. In this
case, the compressed air is allowed to be uniformly blown toward
the storage chamber S1 in the circumferential directions.
[0094] Next, the compressed air supply structure at the first lower
sand tank 30 and the second lower sand tank 31 is described. FIG. 8
is a schematic diagram on a left side of the compressed air supply
structure related to the first lower sand tank and the second lower
sand tank. FIG. 9 is a schematic diagram on the back of the
compressed air supply structure related to the first lower sand
tank and the second lower sand tank. FIG. 10 is a partially
enlarged view of a lower portion of the apparatus in FIG. 8.
[0095] As shown in FIGS. 8 to 10, the first lower sand tank 30
includes a third supply chamber S6 disposed at the center of the
first lower sand tank 30, a fourth supply chamber S7 disposed
nearer to the upper end than the center of the first lower sand
tank 30, and a fifth supply chamber S8 disposed nearer to the lower
end than the center of the first lower sand tank 30. The center of
the first lower sand tank 30 is the center of the first lower sand
tank 30 in the axial direction. The third supply chamber S6 and the
fourth supply chamber S7 are disposed on a side of the storage
chamber S2. The fifth supply chamber S8 is provided at a curved
lower end of the first lower sand tank 30.
[0096] The third supply chamber S6 and the fourth supply chamber S7
are spaces provided in such a way as to surround the storage
chamber S2. The third supply chamber S6 is defined between a side
wall 30c of the storage chamber S2 and a pipe member 30d provided
outside of the side wall 30c of the storage chamber S2. The fourth
supply chamber S7 is defined between the side wall 30c of the
storage chamber S2 and a pipe member 30g provided outside of the
side wall 30c of the storage chamber S2.
[0097] The pipe 84a communicates with the third supply chamber S6.
The pipe 84a communicates with one side of the pipe member 30d. The
pipe 84a communicates with the main pipe 100 that communicates with
the compressed air source via the pipe 84. The pipe 84 is provided
with an electro-pneumatic proportional valve 94. The
electro-pneumatic proportional valve 94 is disposed on a side of
the first lower sand tank 30. The third supply chamber S6
communicates with the storage chamber S2 via a through-hole (not
shown). When the electro-pneumatic proportional valve 94 is opened,
the compressed air flows from the main pipe 100 through the pipes
84 and 84a and is supplied into the third supply chamber S6. The
compressed air is blown from the third supply chamber S6 through
the through-hole and the second permeation member 30a into the
storage chamber S2. It should be noted that a plurality of
through-holes may be formed in the side wall 30c of the storage
chamber S2. For example, the plurality of through-holes may be
formed in such a way as to surround the storage chamber S2. In this
case, the compressed air is allowed to be uniformly blown toward
the storage chamber S2 in the circumferential directions.
[0098] A pipe 84b communicates with the fourth supply chamber S7.
The pipe 84b communicates with one side of the pipe member 30g. The
pipe 84b communicates with the main pipe 100 that communicates with
the compressed air source via the pipe 84. The pipe 84 is provided
with the electro-pneumatic proportional valve 94. That is, the
electro-pneumatic proportional valve 94 controls the flow rates of
both the pipes 84a and 84b. The electro-pneumatic proportional
valve 94 is disposed on a side of the first lower sand tank 30. The
fourth supply chamber S7 communicates with the storage chamber S2
via a through-hole (not shown). When the electro-pneumatic
proportional valve 94 is opened, the compressed air flows from the
main pipe 100 through the pipes 84 and 84b and is supplied into the
fourth supply chamber S7. The compressed air is blown from the
fourth supply chamber S7 through the through-hole and the second
permeation member 30a into the storage chamber S2. It should be
noted that a plurality of through-holes may be formed in the side
wall 30c of the storage chamber S2. For example, the plurality of
through-holes may be formed in such a way as to surround the
storage chamber S2. In this case, the compressed air is allowed to
be uniformly blown toward the storage chamber S2 in the
circumferential directions.
[0099] The fifth supply chamber S8 is formed in an inspection door
70. The inspection door 70 is a door that is opened and closed
during maintenance of the first lower sand tank 30. FIG. 11 is a
sectional view of the inspection door. As shown in FIG. 11, the
inspection door 70 is a hollow member in which the fifth supply
chamber S8 is defined. A supply port 70b that communicates with a
pipe 85 for supplying compressed air is formed on an outer side
surface 70a of the inspection door 70. Through-holes 70d for
supplying compressed air into the storage chamber S2 are formed on
an inner surface side 70c of the inspection door 70. The number of
formed through-holes 70d may be one or more. Ventholes 70e where
slits are formed are fit in the through-holes 70d.
[0100] As shown in FIGS. 8 to 10, the pipe 85 communicates with the
fifth supply chamber S8. The pipe 85 communicates with the supply
port 70b. The pipe 85 communicates with the main pipe 100 that
communicates with the compressed air source. The pipe 85 is
provided with the electro-pneumatic proportional valve 95. The
electro-pneumatic proportional valve 95 is disposed on a side of
the first lower sand tank 30. The fifth supply chamber S8
communicates with the storage chamber S2 via the plurality of
ventholes 70e. When the electro-pneumatic proportional valve 95 is
opened, the compressed air flows from the main pipe 100 through the
pipe 85 and is supplied into the fifth supply chamber S8. The
compressed air is blown from the fifth supply chamber S8 through
the plurality of ventholes 70e into the storage chamber S2.
[0101] The second permeation member 30a does not intervene at the
flow path from the fifth supply chamber S8 to the storage chamber
S2. At the curved lower end of the first lower sand tank 30, owing
to the shape thereof, the abrasion of the permeation member
disposed in the storage chamber S2 tends to be larger than that at
another arrangement position. Accordingly, in the storage chamber
S2 at the curved lower end of the first lower sand tank 30, the
plurality of ventholes 70e instead of the second permeation member
30a are adopted. Consequently, at the bent lower end of the first
lower sand tank 30, clogging of the permeation member is prevented
from occurring.
[0102] The second lower sand tank 31 includes, for example, a sixth
supply chamber S9 and a seventh supply chamber S10 that are
disposed at a bottom of the storage chamber S3. The sixth supply
chamber S9 is defined in a pipe member 71. The pipe member 71 is
disposed at a bottom of the second communication port 38 of the
second lower sand tank 31. At the pipe member 71, a supply port 71a
that communicates with a pipe for supplying compressed air, and
through-holes 71b for supplying compressed air into the storage
chamber S3 are formed. The number of formed through-holes 71b may
be one or more. Ventholes (not shown) where slits are formed are
fit in the through-holes 71b. At the pipe member 72, a supply port
72a that communicates with a pipe for supplying compressed air, and
through-holes 72b for supplying compressed air into the storage
chamber S3 are formed. The number of formed through-holes 72b may
be one or more. Ventholes (not shown) where slits are formed are
fit in the through-holes 72b.
[0103] A pipe 86 communicates with the sixth supply chamber S9. The
pipe 86 communicates with the supply port 71a. The pipe 86
communicates with the main pipe 100 that communicates with the
compressed air source. The pipe 86 is provided with the
electro-pneumatic proportional valve 96. The sixth supply chamber
S9 communicates with the storage chamber S3 via a plurality of
ventholes. When the electro-pneumatic proportional valve 96 is
opened, the compressed air flows from the main pipe 100 through the
pipe 86 and is supplied into the sixth supply chamber S9. The
compressed air is blown from the sixth supply chamber S9 through
the plurality of ventholes into the storage chamber S3.
[0104] A pipe 87 communicates with the seventh supply chamber S10.
The pipe 87 communicates with the supply port 72a. The pipe 87
communicates with the main pipe 100 that communicates with the
compressed air source. The pipe 87 is provided with the
electro-pneumatic proportional valve 97. The seventh supply chamber
S10 communicates with the storage chamber S3 via a plurality of
ventholes. When the electro-pneumatic proportional valve 97 is
opened, the compressed air flows from the main pipe 100 through the
pipe 87 and is supplied into the seventh supply chamber S10. The
compressed air is blown from the seventh supply chamber S10 through
the plurality of ventholes into the storage chamber S3.
[0105] Any permeation member does not intervene at the flow path
from the sixth supply chamber S9 and the seventh supply chamber S10
to the storage chamber S2. In the second lower sand tank 31, the
abrasion of the permeation member disposed in the storage chamber
tends to be higher than the abrasions of the other tanks.
Accordingly, in the storage chamber S3 of the second lower sand
tank 31, the plurality of ventholes are adopted instead of the
permeation member. Consequently, in the second lower sand tank 31,
clogging of the permeation member is prevented from occurring.
[0106] [Pressure Detectors]
[0107] The flaskless molding machine 1 may include at least one
pressure detector. At least one pressure detector detects the
pressure of at least one tank among the upper sand tank 22, the
first lower sand tank 30 and the second lower sand tank 31. The
pressure detector includes, for example, a main body, a diaphragm
that is stored in the main body and is deformed by the pressure,
and a strain gauge that outputs a signal according to the
deformation of the diaphragm. The pressure detector may include a
display (e.g., an LED (Light Emitting Diode) display) or the like
on the main body. Any of various methods may be adopted as a method
of attaching the pressure detector. For example, attachment may be
made onto a side wall of the storage chamber. Alternatively,
attachment may be made onto a side wall of a space that
communicates with the storage chamber.
[0108] Hereinafter, the arrangement of the pressure detector at
each tank is described. First, the arrangement of the pressure
detector at the upper sand tank 22 is described. As shown in FIG.
3, the upper sand tank 22 is provided with a first pressure
detector 61 and a second pressure detector 62. The first pressure
detector 61 detects the pressure of the first supply chamber S4.
The second pressure detector 62 detects the pressure of the second
supply chamber S5. As described above, at the upper sand tank 22,
the pressure in a space (the first supply chamber S4 and the second
supply chamber S5) that is outside of the storage chamber S1 and
communicates with the storage chamber S1 via the first permeation
member 22a is detected.
[0109] Next, the arrangement of the pressure detector at the first
lower sand tank 30 is described. As shown in FIG. 3, the first
lower sand tank 30 is provided with a third pressure detector 63, a
fourth pressure detector 64 and a fifth pressure detector 65. The
third pressure detector 63 detects the pressure in the third supply
chamber S6 and the fourth supply chamber S7. The fourth pressure
detector 64 detects the pressure in the storage chamber S2. The
fifth pressure detector 65 detects the pressure in the fifth supply
chamber S8. As described above, at the first lower sand tank 30,
the pressure in the storage chamber S2 is directly detected, while
the pressure in a space (the third supply chamber S6, the fourth
supply chamber S7 and the fifth supply chamber S8) that is outside
of the storage chamber S2 and communicates with the storage chamber
S2 via the second permeation member 30a is detected. It should be
noted that the pressure in the storage chamber S2 detected by the
fourth pressure detector 64 is used as a reference pressure for
preventing a reverse flow during discharge, which is described
later.
[0110] Next, the arrangement of the pressure detector at the second
lower sand tank 31 is described. As shown in FIG. 3, the second
lower sand tank 31 is provided with a sixth pressure detector 66.
The sixth pressure detector 66 detects the pressure in the storage
chamber S3. It should be noted that the sixth pressure detector 66
may detect the pressure in a space that is outside of the storage
chamber S3 and communicates with the storage chamber S3 via a vent
or the like.
[0111] [Details of Attachment of Pressure Detectors]
[0112] The arrangement of the pressure detectors (the first
pressure detector 61 to the third pressure detector 63 and the
fifth pressure detector 65) that detect the pressures outside of
the storage chambers is described. The forms of connection of these
pressure detectors are the same. Accordingly, the third pressure
detector 63 is typified and described. FIG. 12 shows an example of
connection of the third pressure detector. As shown in FIG. 12, on
the inner side of the side wall 30c of the first lower sand tank
30, the second permeation member 30a is attached via rubber members
30f. In the side wall 30c, a through-hole 30e is formed. The pipe
member 30d defining the third supply chamber S6 is attached to the
outside of the side wall 30c at a position corresponding to the
through-hole 30e. The third supply chamber S6 communicates with the
storage chamber S2 via the through-hole 30e and the second
permeation member 30a. The third supply chamber S6 is provided with
a communication port (not shown) through which compressed air is
supplied. The compressed air supplied through the communication
port passes through the through-hole 30e and the second permeation
member 30a, and is supplied into the storage chamber S2 of the
first lower sand tank 30. As described above, the first pressure
detector 61 to the third pressure detector 63 and the fifth
pressure detector 65 detect the pressures of spaces that are
outside of the storage chambers and communicate with the storage
chambers via the permeation members.
[0113] [Control Device]
[0114] The flaskless molding machine 1 may include a control device
50 (an example of a control unit). The control device 50 is a
computer that includes a control unit such as a processor, a
storage unit such as a memory, an input and output unit such as an
input device and a display device, and a communication unit such as
a network card, and controls each of units of the flaskless molding
machine 1, for example, a mold sand supply system, a compressed air
supply system, a drive system, a power source system and the like.
The control device 50 allows an operator to perform a command input
operation and the like in order to manage the flaskless molding
machine 1, using the input device, and can cause the display device
to visualize and display the operation situations of the flaskless
molding machine 1. Furthermore, the storage unit of the control
device 50 stores a control program for allowing the processor to
control various processes to be executed by the flaskless molding
machine 1, and a program for causing each configuration unit of the
flaskless molding machine 1 to execute processes according to a
molding condition.
[0115] The control device 50 is connected to the first pressure
detector 61 to the sixth pressure detector 66, and obtains a
detection result of at least one of the pressure detectors. Control
based on the pressure detection result is described later.
[0116] [Molding Process]
[0117] An overview of a molding process according to this
embodiment is described. FIG. 13 is a flowchart illustrating the
molding process of the flaskless molding machine according to one
embodiment. The molding process shown in FIG. 13 is a process of
molding a pair of the upper mold and the lower mold. The molding
process shown in FIG. 13 is automatically activated with a
condition that the attitude of the flaskless molding machine 1 is
the original position (initial position). When the attitude of the
flaskless molding machine 1 is not at the original position, this
machine is manually operated to be moved to the original position.
When an automatic activation button is pressed with the attitude
(original position) of the flaskless molding machine 1 shown in
FIG. 3, the molding process shown in FIG. 13 is started.
[0118] When the molding process is started, a shuttle-in process
(S12) is performed first. In the shuttle-in process, the conveyance
cylinder 21 moves the conveyance plate 20 mounted with the match
plate 19 to a molding position.
[0119] Next, a flask setting process (S14) is performed. In the
flask setting process, the upper flask cylinder 16, the lower flask
cylinders 18 (FIG. 2), the lower filling frame cylinder 42 and the
squeeze cylinder 37 are elongated and contracted in conformity with
the thicknesses of the molds to be formed. Accordingly, the upper
flask 15 is moved to the predetermined position, and the lower
flask 17 comes into contact with the match plate 19, and
subsequently, the lower flask 17 mounted with the match plate 19 is
moved to the predetermined position, thereby achieving a state
where the match plate 19 is clamped between the upper flask 15 and
the lower flask 17. The second lower sand tank 31 and the lower
filling frame 41 then rise, and the lower filling frame 41 comes
into contact with the lower flask 17. The lower tank cylinder 32 is
elongated and contracted to move the first lower sand tank 30 in
the vertical direction, thereby achieving a state where the height
of the first communication port 35 of the first lower sand tank 30
coincides with the height of the second communication port 38 of
the second lower sand tank 31. At this time, the upper molding
space and the lower molding space are in a state (height)
determined by the control device 50.
[0120] Next, an aeration process (S16) is performed. As shown in
FIG. 4, in the aeration process, the sealing mechanism seals the
first communication port 35 of the first lower sand tank 30 and the
second communication port 38 of the second lower sand tank 31. The
slide gate 23 of the upper sand tank 22 and the slide gate 33 of
the first lower sand tank 30 are then closed, and compressed air is
supplied by the compressed air source and the electro-pneumatic
proportional valves 90 to 97 into the upper sand tank 22, the first
lower sand tank 30 and the second lower sand tank 31. Accordingly,
the upper molding space and the lower molding space are filled with
the mold sand while the mold sand is allowed to flow. For example,
if the set pressure and time are satisfied, the aeration process is
finished. It should be noted that after the aeration process is
completed, a discharge process for the upper sand tank 22, the
first lower sand tank 30 and the second lower sand tank 31 is
performed.
[0121] Next, a squeeze process (S18) is performed. In the squeeze
process, the sealing mechanism having been operated in the aeration
process (S16) releases the sealing, and the squeeze cylinder 37 is
further elongated, thereby further raising the second lower sand
tank 31. Accordingly, the lower plate 40 attached to the second
lower sand tank 31 enters the inside of the lower filling frame 41
and compresses the mold sand in the lower molding space, while the
upper plate 25 enters the inside of the upper flask 15 and
compresses the mold sand in the upper molding space. In a case
where the squeeze cylinder 37 is controlled by an oil-hydraulic
circuit, the squeeze process is finished when the oil pressure of
the oil-hydraulic circuit can be determined to be the same as the
set oil pressure, for example. In a case where during the squeeze
process, the upper flask cylinder 16, the lower flask cylinders 18
and the lower filling frame cylinder 42 are controlled by the
oil-hydraulic circuit, each cylinder is set as a free circuit.
Accordingly, each cylinder yields to the squeeze force and is
contracted.
[0122] Next, a model release process (S20) is performed. In the
model release process, the lower filling frame cylinder 42 is
contracted to lower the lower filling frame 41. Subsequently, the
squeeze cylinder 37 is contracted and lowers the second lower sand
tank 31, and subsequently lowers the lower flask 17 mounted with
the match plate 19 and the conveyance plate 20. The model is then
released from the upper flask 15. When the lower flask 17 is
lowered to a fixed unit (not shown), the match plate 19 and the
conveyance plate 20 are supported by the fixed unit. Accordingly,
the model is released from the lower flask 17.
[0123] Next, a shuttle-out process (S22) is performed. In the
shuttle-out process, the conveyance cylinder 21 is contracted,
thereby moving the conveyance plate 20 to the retracted position. A
core is disposed in the upper flask 15 or the lower flask 17 if
necessary.
[0124] Next, a flask alignment process (S24) is performed. In the
flask alignment process, the lower flask cylinders 18 are
contracted and the squeeze cylinder 37 is elongated, thereby
raising the lower flask 17 and the second lower sand tank 31 to
align the flask.
[0125] Next, the flask release process (S26) is performed. In the
flask release process, the upper flask cylinder 16 and the lower
flask cylinders 18 are contracted, thereby raising the upper flask
15 and the lower flask 17 to the raised ends to release the
flask.
[0126] Next, a first flask separating process (S28) is performed.
In the first flask separating process, in a state where the mold is
mounted on the lower plate 40 of the second lower sand tank 31, the
squeeze cylinder 37 is contracted to lower the second lower sand
tank 31. At this time, the lower flask cylinders 18 are elongated
to lower the lower flask 17, and the mold is stopped at a position
of not interfering with conveyance of the mold.
[0127] Next, a mold extrusion process (S30) is performed. In the
mold extrusion process, an extrusion cylinder 48 (see FIG. 2) is
elongated, thereby conveying the upper mold and the lower mold to
the outside of the machine (e.g., a molding line).
[0128] Next, a second flask separating process (S32) is performed.
In the second flask separating process, the lower flask cylinders
18 are elongated to return the lower flask 17 to the original
position.
[0129] As described above, the process of forming the pair of the
upper mold and the lower mold is thus finished,
[0130] [Detection of Pressures in Sand Tanks]
[0131] FIG. 14 is a functional block diagram of the flaskless
molding machine according to one embodiment. As shown in FIG. 14,
the flaskless molding machine 1 includes the first pressure
detector 61 to the sixth pressure detector 66, the control device
50, a display unit 67, and the electro-pneumatic proportional
valves 90 to 97.
[0132] The control device 50 is connected to the first pressure
detector 61 to the sixth pressure detector 66, and can obtain a
detection result. The detection result is information about the
pressure output from at least one pressure detector among the first
pressure detector 61 to the sixth pressure detector 66.
[0133] The control device 50 includes an operation unit 51, a
communication unit 52, and a storage unit 53. The operation unit 51
is a configuration element that performs various operations related
to pressure control, and is achieved by a processor, a memory and
the like. The communication unit 52 is a configuration element that
transmits information to the outside of the apparatus, and is
achieved by a network card and the like.
[0134] The communication unit 52 processes data in conformity with
a communication standard on the basis of an instruction by the
operation unit 51, and outputs the data to the communication
network 68. The communication network 68 may be of wireless
communication or wired communication. The storage unit 53 is a
configuration element that stores data, and is achieved by a memory
and the like.
[0135] The display unit 67 is a device that can display information
in a viewable state. The display unit 67 is a display device, for
example. The display unit 67 may be fixed to the apparatus, or
separated from the apparatus. The display unit 67 displays the
detection result of at least one pressure detector on the basis of
the control signal from the control device 50. The display unit 67
may display warning information on the basis of the control signal
from the control device 50. The display unit 67 may be a touch
panel that accepts an input operation by an operator. The display
unit 67 may output the input operation by the operator to the
control device 50.
[0136] Hereinafter, a control process by the control device 50 is
described in association with each configuration element. [First
data display process]
[0137] A first data display process is a process of causing the
display unit 67 to display results detected by the first pressure
detector 61 to the sixth pressure detector 66 during execution of
the molding process in FIG. 13. The display timing may be in the
middle of the molding process, or after the molding process. The
operation unit 51 of the control device 50 causes the display unit
67 to display a graph representing the relationship between the
pressure and time, as the detection result of the first pressure
detector 61 to the sixth pressure detector 66. The operation unit
51 may cause the display unit 67 to display control information on
the electro-pneumatic proportional valves 90 to 97, together with
the detection result. The control information is information about
control signals for the electro-pneumatic proportional valve. For
example, the control signals for the electro-pneumatic proportional
valves are signals obtained by converting control signals into
pressures on the basis of a predetermined calculation expression.
Such conversion is executed by the operation unit 51. The operation
unit 51 of the control device 50 causes the display unit 67 to
display the control information and the detection result in a
manner allowing comparison. For example, the operation unit 51 of
the control device 50 displays, on the screen, the control
information and the detection result at the same timing. For
example, the operation unit 51 displays comparison target data
items on the same graph in an overlaid manner. The operation unit
51 may display the comparison target data items as separate graphs
on the same screen. It should be noted that the manner allowing
comparison is not limited to a case where the comparison target
data items are displayed on the screen at the same timing. The
comparison target data items may be alternately displayed on the
screen.
[0138] FIG. 15 shows an example of a graph of the control signal
for the electro-pneumatic proportional valve and the detection
results of the pressure detectors. The graph shown in FIG. 15
indicates the detection result at the upper sand tank 22. The
abscissa is the time. The ordinate is the pressure. In FIG. 15, the
control signal for the electro-pneumatic proportional valve is
converted into the pressure and is indicated by a broken line. That
is, the broken line in the diagram is a target pressure. A time
period from the rise to the fall of the waveform of the broken line
is an aeration time period T1. In FIG. 15, the detection results
are indicated by solid lines. A thick solid line is the detection
result of the first pressure detector 61. A thin solid line is the
detection result of the second pressure detector 62. The operator
or the like can check the validity of the control on the basis of
the graph shown in FIG. 15.
[0139] For example, in the graph shown in FIG. 15, in an early
stage of the aeration time period T1, the pressure in the upper
sand tank 22 increases. As indicated by timing E1 in the diagram,
the increase in pressure temporarily stops. It is believed that the
stop of increase in pressure occurs because mold sand flows in the
upper sand tank 22. Subsequently, as indicated by timing E2 in the
diagram, the pressure restarts to increase. It is believed that the
reascending in pressure occurs because the filling with the mold
sand is completed. After the time elapses from the timing E2, the
pressure slightly increases to a constant value. The operator or
the like can verify the length of the aeration time period T1 on
the basis of the graph shown in FIG. 15. The operator or the like
can set the length of the aeration time period T1 through an
after-mentioned setting screen. For example, the operator or the
like may adjust the aeration time period T1 so that the finish
timing of the aeration time period T1 can approach the timing E2.
The operator or the like may adjust the aeration time period T1 so
that the finish timing of the aeration time period T1 can approach
timing after lapse of a margin time period T2 from the timing E2.
The margin time period T2 is a value defined on the basis of actual
measurement. The margin time period T2 may be a value appropriately
set by the operator or the like. Such adjustment can reduce the
cycle time, and optimize the amount of air to be consumed.
[0140] [Second Data Display Process]
[0141] A second data display process is a process of causing the
display unit 67 to display results detected by the first pressure
detector 61 to the sixth pressure detector 66. The display timing
is timing when clogging of the first permeation member 22a or the
second permeation member 30a is checked, and is a maintenance time,
for example. The operation unit 51 of the control device 50 causes
the display unit 67 to display a graph representing the
relationship between the pressure and time, as the detection result
of at least one of the first pressure detector 61 to the third
pressure detector 63, for example. The first pressure detector 61
to the third pressure detector 63 communicate with the storage
chambers via the first permeation member 22a or the second
permeation member 30a. Consequently, from the detection result of
the pressures of the first pressure detector 61 to the third
pressure detector 63, the clogging of the first permeation member
22a or the second permeation member 30a can be detected.
[0142] The clogging of the permeation member is determined by the
operator or the like. To assist the determination by the operator
or the like, a threshold may be displayed together with the
detection result of the pressure. For example, the operation unit
51 of the control device 50 causes the display unit 67 to display
the detection result of at least one pressure detector (the first
pressure detector 61, the second pressure detector 62) at the upper
sand tank 22 and a preset threshold in a manner allowing
comparison. Alternatively, the operation unit 51 causes the display
unit 67 to display the pressure detected by the third pressure
detector 63 at the first lower sand tank 30 and a preset threshold
in a manner allowing comparison. The preset threshold may be stored
in the storage unit 53. For example, a value obtained by
subtracting a predetermined value from an observed abnormal value
may be set as the threshold and be stored in the storage unit 53.
The control device 50 may obtain the threshold via a touch panel or
the like, and store the threshold in the storage unit 53. The
operation unit 51 may cause the display unit 67 to display control
information on the electro-pneumatic proportional valves 90 to 94,
together with the detection result. The control information is
information about control signals for the electro-pneumatic
proportional valve. For example, the control signals for the
electro-pneumatic proportional valves are signals obtained by
converting control signals into pressures on the basis of a
predetermined calculation expression. Such conversion is executed
by the operation unit 51.
[0143] FIG. 16 shows an example of a graph indicating the detection
result of the pressure detector and the threshold. The graph shown
in FIG. 16 indicates the detection result at the upper sand tank
22. The abscissa is the time. The ordinate is the pressure. In FIG.
16, a thick solid line is the abnormal value, a broken line is the
threshold, and a thin solid line is the detection result of the
pressure detector. When clogging occurs in the first permeation
member 22a, the pressure increases and exceeds the threshold. The
operator or the like can check the presence or absence of clogging
of the permeation member on the basis of the graph shown in FIG.
16.
[0144] [Third Data Display Process]
[0145] A third data display process is a process of causing the
display unit 67 to display results detected by the first pressure
detector 61 to the sixth pressure detector 66 during execution of
the molding process in FIG. 13. The display timing may be in the
middle of the molding process, or after the molding process. The
operation unit 51 of the control device 50 causes the display unit
67 to display a graph representing the relationship between the
pressure and time, as the detection result of the first pressure
detector 61 to the sixth pressure detector 66. The operation unit
51 may cause the display unit 67 to display control information on
the electro-pneumatic proportional valves 90 to 97, together with
the detection result. The control information is information about
control signals for the electro-pneumatic proportional valve. For
example, the control signals for the electro-pneumatic proportional
valves are signals obtained by converting control signals into
pressures on the basis of a predetermined calculation expression.
Such conversion is executed by the operation unit 51.
[0146] The operation unit 51 of the control device 50 stores the
detection results of the first pressure detector 61 to the sixth
pressure detector 66 in the storage unit 53 at predetermined
timing. The operation unit 51 then causes the display unit 67 to
display the stored detection results and the detection results this
time in a manner allowing comparison. For example, the operation
unit 51 refers to the storage unit 53, obtains the preliminarily
stored detection results, and obtains the detection results this
time from the first pressure detector 61 to the sixth pressure
detector 66. The operation unit 51 then displays, on the screen,
the preliminarily stored detection results and the detection
results this time at the same timing. For example, the operation
unit 51 displays comparison target data items on the same graph in
an overlaid manner. The operation unit 51 may display the
comparison target data items as separate graphs on the same screen.
It should be noted that the manner allowing comparison is not
limited to a case where the comparison target data items are
displayed on the screen at the same timing. The comparison target
data items may be alternately displayed on the screen.
[0147] FIG. 17 shows an example of comparison between the
preliminarily stored detection result and the detection results
this time. The graphs shown in FIG. 17 indicate the detection
results at the upper sand tank 22. The abscissa is the time. The
ordinate is the pressure. A screen example (A) is a screen where a
graph G1 of the preliminarily stored detection result is displayed.
A screen example (B) is a screen where the graph G1 of the
preliminarily stored detection result and a graph G2 of a detection
result this time are displayed in an overlaid manner. The operator
or the like can check the presence or absence of the difference
from the previous process on the basis of the graph shown in FIG.
17.
[0148] [Setting Screen Display Process]
[0149] The operation unit 51 causes the display unit 67 to display
a setting screen, as an example of the setting process. The setting
screen is a screen for setting the aeration setting pressure and
the time. The operation unit 51 then sets the aeration setting
pressure and time on the basis of the operator's input information
accepted through an input unit (not shown). For example, the
operation unit 51 sets the aeration time period, the pressure, the
threshold and the like. The setting is to store a target value in
the storage unit 53, for example.
[0150] FIG. 18 shows screen examples displayed by the display unit.
A screen example (A) is an example of a setting screen for setting
the aeration time period. Icons IC1 for accepting an input
operation for page transition are displayed at an upper portion of
the screen example (A). Icons IC2 for accepting an input operation
for calling applications or various functions are displayed at a
lower portion of the screen. Setting targets and setting items are
displayed at the center of the screen. An example of the setting
target is the electro-pneumatic proportional valve. On the screen
example (A), the electro-pneumatic proportional valves 90 and 93
and the electro-pneumatic proportional valves 90 and 93 are
respectively displayed as objects OB1 and OB2. Examples of the
setting items are aeration time periods and pressures. On the
screen example (A), the aeration time periods and the pressures are
displayed as objects OB3 to OB5. Objects OB3 to OB5 are items that
can be input by the operator or the like.
[0151] Examples of the setting items are aeration time periods and
pressures in an additional process. The additional process is not
executed when the aeration process is normal. The additional
process is a process executed to extend the aeration time period
before the aeration process is determined to be abnormal. The
details of the additional process are described later. On the
screen example (A), the aeration time period and the pressure in
the additional process are displayed as an object OB6. An object
OB6 is an item that can be input by the operator or the like.
Setting items acceptable at the object OB6 are setting values for
the additional aeration. The operator or the like can perform
setting related to aeration by inputting values in the objects OB3
to OB6.
[0152] [Warning Process]
[0153] The control device 50 issues a warning when detecting an
abnormality. The warning is notification about the abnormality to
the operator or the like. The control device 50 displays, on the
display unit 67, a screen related to the warning as an example of
the warning process. The control device 50 may output an alarm
through a speaker, not shown, instead of the warning through
display or together with the warning though the display.
[0154] One abnormality assumed in the flaskless molding machine
through use of compressed air is a blow abnormality. The blow
abnormality is "a phenomenon where a site without mold sand due to
partial clogging at each supply port of the lower plate 40 occurs
and the site serves as a path of the compressed air." At the site
without mold sand, the air resistance is low. Accordingly, the
compressed air is blown only through the site. Accordingly, if the
blow abnormality occurs, the pressure does not increase. The
control device 50 extends the aeration time period when normal
filling with mold sand is not performed in the aeration process
(additional process). That is, the control device 50 outputs the
control signal to at least one electro-pneumatic proportional valve
on the basis of the detection results of the first pressure
detector 61 to the sixth pressure detector 66. In a more specific
example, when the maximum pressure detected by the pressure
detector in the aeration time period T.sub.1 in the aeration
process does not reach a predetermined threshold, the control
device 50 determines that normal filling with mold sand is not
finished. The predetermined threshold is stored in the storage unit
53, for example. The control device 50 outputs the control signal
to the electro-pneumatic proportional valve on the basis of the
value set using the screen example (A) in FIG. 18, for example (the
additional process of extending the aeration time period).
[0155] When the blow abnormality is resolved by the additional
process, that is, when the maximum pressure detected by the
pressure detector in the additional aeration time period reaches
the predetermined threshold, the control device 50 determines that
the process of filling with mold sand is normal and does not issue
a warning. On the contrary, when the maximum pressure detected by
the pressure detector in the additional aeration time period does
not reach the predetermined threshold, the control device 50 issues
warning information. The warning information is data related to a
warning, is screen data when being output to the display unit 67,
and is alarm data when being output to a speaker or the like. The
control device 50 may stop the operation of the flaskless molding
machine 1 when outputting the warning information. The screen
example (B) in FIG. 18 is an example of the warning. The control
device 50 causes the display unit 67 to display the content of the
abnormality, the operation state of the flaskless molding machine
1, a countermeasure (handling method), a recovery (recovery method)
or the like.
[0156] After the aeration time period T1 elapses, the control
device 50 performs the discharge process. In the discharge process,
the compressed air in the upper sand tank 22 is discharged and the
pressure gradually decreases. If sand clogging is at a discharge
mechanism, the reduction in pressure becomes sluggish in a
discharge process time period T3 as indicated by a graph G3 in the
screen example (B) in FIG. 17, for example. If the pressure
detected by at least one pressure detector is not equal to or less
than the predetermined threshold after lapse of a predetermined
time period in a case of air discharge from the upper sand tank 22,
the first lower sand tank 30 and the second lower sand tank 31, the
control device 50 issues the warning information. Accordingly, the
operator or the like can recognize a discharge abnormality.
[0157] It should be noted that the control device 50 may output the
control signal so that at least one electro-pneumatic proportional
valve is opened on the basis of the detection result of at least
one pressure detector in the discharge process. According to such
operation, the pressure in the supply chamber increases.
Consequently, a reverse flow from a filling chamber to the supply
chamber is prevented. The reverse flow of mold sand tends to occur
at the sites where vents are disposed, that is, at the supply
chambers S8 to S10. In the discharge process, the control device 50
outputs the control signal so that the electro-pneumatic
proportional valves 95 to 97 can be opened, on the basis of the
pressure detected by the fourth pressure detector 64, which serves
as the reference. The control device 50 may open the
electro-pneumatic proportional valves 95 to 97 in such a way as to
achieve a higher pressure than the pressure detected by the fourth
pressure detector 64 by a predetermined value (feedback
process).
[0158] As described above, in the flaskless molding machine 1
according to this embodiment, the pressures in the upper sand tank
22, the first lower sand tank 30 and the second lower sand tank 31
are detected by the first pressure detector 61 to the sixth
pressure detector 66. The detection results of the first pressure
detector 61 to the sixth pressure detector 66 are then obtained by
the control device 50. As described above, according to the
flaskless molding machine 1, the situations in the sand tanks are
obtained by obtaining the pressures in the tanks. As a result,
excellent molds and casting products can be obtained.
[0159] According to the flaskless molding machine 1, in a case
where the squeeze process is performed by the second lower sand
tank moving in the vertical direction, the situations in the sand
tanks can be appropriately grasped.
[0160] According to the flaskless molding machine 1, due to the
arrangement of the first pressure detector 61 to the sixth pressure
detector 66, the supply chambers S4 to S10 for supplying compressed
air can be utilized. The flaskless molding machine 1 is not
required to be provided with a through-hole or the like for
pressure detection at the storage chambers S1 to S3, which store
the mold sand. According to the flaskless molding machine 1, the
effects of the arrangement of the first pressure detector 61 to the
sixth pressure detector 66 on the molding process can be small.
[0161] According to the flaskless molding machine 1, the upper and
lower pressures of the upper sand tank 22, that is, the entire
pressures of the upper sand tank 22, are detected. Consequently,
the pressure deviation dependent on the detection positions at the
upper sand tank 22 can be grasped. According to the flaskless
molding machine 1, the upper and lower pressures of the first lower
sand tank 30, that is, the entire pressures of the first lower sand
tank 30, are detected. Consequently, the pressure deviation
dependent on the detection positions at the first lower sand tank
30 can be grasped.
[0162] According to the flaskless molding machine 1, clogging at
the first permeation member 22a and the second permeation member
30a can be detected. According to the flaskless molding machine 1,
in the storage chamber S2 at the curved lower end of the first
lower sand tank 30 or in the second lower sand tank 31, the
plurality of ventholes instead of the permeation members are
adopted. According to the flaskless molding machine 1, at the site
where clogging at the permeation member tends to occur, occurrence
of clogging at the permeation member can be avoided.
[0163] According to the flaskless molding machine 1, the detection
results of the first pressure detector 61 to the sixth pressure
detector 66 can be notified to the operator. According to the
flaskless molding machine 1, the time dependence of the pressure
can be notified to the operator. According to the flaskless molding
machine 1, a setting operation by the operator can be assisted by
displaying the setting screen on the display unit 67. According to
the flaskless molding machine 1, the difference between the
preliminarily stored detection result and the detection result this
time can be notified to the operator. According to the flaskless
molding machine 1, the detection results of the first pressure
detector 61 to the sixth pressure detector 66 can be transmitted to
an external computer or the like without intervention of a physical
storage medium.
[0164] According to the flaskless molding machine 1, the display
unit can be caused to display the detection results of the pressure
detectors and the preset threshold in the manner allowing
comparison. In this case, the operator is allowed to predict
clogging at the first permeation member 22a or the second
permeation member 30a.
[0165] According to the flaskless molding machine 1, the control
signals for the electro-pneumatic proportional valves can be output
on the basis of the detection results of the pressure detectors.
Consequently, the feedback control can be performed, for example.
For example, in the flaskless molding machine 1, during discharge,
on the basis of the detection result of the third pressure detector
63, the control signals are output in such a way as to open the
electro-pneumatic proportional valves 95 to 97. According to the
flaskless molding machine 1, the flow of the mold sand in the tanks
can be appropriately controlled. More specifically, the flaskless
molding machine 1 can prevent the mold sand from reversely flowing
from the storage chambers S2 and S3 to the supply chambers S8 to
S10.
[0166] According to the flaskless molding machine 1, the operator
can be warned about presence of a failure in a discharge system.
According to the flaskless molding machine 1, the electro-pneumatic
proportional valves 90 to 97 are disposed on the sides of the sand
tanks. Consequently, the response of supply with compressed air can
be improved.
[0167] According to the flaskless molding machine 1, when the
maximum pressure does not reach the predetermined threshold, the
additional aeration can be automatically performed. Further
according to the flaskless molding machine 1, when the situation is
not improved even by the additional aeration, the warning can be
issued to the operator.
[0168] It should be noted that the embodiment described above is an
example of the flaskless molding machine according to this
disclosure. The flaskless molding machine according to this
disclosure is not limited to the flaskless molding machine 1
according to the embodiment, and may be what is achieved by
modifying the flaskless molding machine 1 according to the
embodiment or by application to another machine in a range without
changing the gist described in each claim.
[0169] For example, in the embodiment described above, the example
where the upper sand tank 22 is fixed to the upper frame 10 is
described. Alternatively, the upper sand tank 22 may be configured
to be movable. The number of sand tanks of the molding machine is
not necessarily three, and may be one, two, or four or more.
REFERENCE SIGNS LIST
[0170] 1 . . . Flaskless molding machine, 12 . . . Guide, 15 . . .
Upper flask, 16 . . . Upper flask cylinder, 17 . . . Lower flask,
18 . . . Lower flask cylinder, 19 . . . Match plate, 22 . . . Upper
sand tank, 25 . . . Upper plate, 22a . . . First permeation member,
30a . . . Second permeation member, 30 . . . First lower sand tank,
31 . . . Second lower sand tank, 32 . . . Lower tank cylinder, 35 .
. . First communication port, 36 . . . First block plate, 37 . . .
Squeeze cylinder, 38 . . . Second communication port, 39 . . .
Second block plate, 40 . . . Lower plate, 41 . . . Lower filling
frame, 42 . . . Lower filling frame cylinder, 50 . . . Control
device, 51 . . . Operation unit, 52 . . . Communication unit, 53 .
. . Storage unit, 61 . . . First pressure detector, 62 . . . Second
pressure detector, 63 . . . Third pressure detector, 64 . . .
Fourth pressure detector, 65 . . . Fifth pressure detector, 67 . .
. Display unit, 68 . . . Communication network, 90 to 97 . . .
Electro-pneumatic proportional valve.
* * * * *