U.S. patent application number 15/027411 was filed with the patent office on 2016-09-01 for mold-cooling system and mold-cooling method.
The applicant listed for this patent is Kabushikikisha Matsui Seisakusho. Invention is credited to Jun KUDAMATSU, Motoharu SHIMIZU.
Application Number | 20160250685 15/027411 |
Document ID | / |
Family ID | 52812995 |
Filed Date | 2016-09-01 |
United States Patent
Application |
20160250685 |
Kind Code |
A1 |
SHIMIZU; Motoharu ; et
al. |
September 1, 2016 |
Mold-Cooling System and Mold-Cooling Method
Abstract
A mold-cooling system for cooling a heated mold by supplying
cooling medium from a cooling medium supply source to a medium flow
path provided for a mold. The mold-cooling system is characterized
in that a discharge side path connected to an outlet side of the
medium flow path of the mold is communicated with a heat exchanger
condensing the cooling medium gasified and discharged from the
medium flow path.
Inventors: |
SHIMIZU; Motoharu; (Osaka,
JP) ; KUDAMATSU; Jun; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kabushikikisha Matsui Seisakusho |
Osaka-shi, Osaka |
|
JP |
|
|
Family ID: |
52812995 |
Appl. No.: |
15/027411 |
Filed: |
October 3, 2014 |
PCT Filed: |
October 3, 2014 |
PCT NO: |
PCT/JP2014/076514 |
371 Date: |
April 5, 2016 |
Current U.S.
Class: |
164/128 |
Current CPC
Class: |
B29C 35/007 20130101;
B22D 45/00 20130101; B22D 30/00 20130101; B22D 17/2218 20130101;
B22D 46/00 20130101; B22C 9/065 20130101 |
International
Class: |
B22D 30/00 20060101
B22D030/00; B22D 46/00 20060101 B22D046/00; B22C 9/06 20060101
B22C009/06; B22D 45/00 20060101 B22D045/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2013 |
JP |
2013-210178 |
Claims
1. A mold-cooling system for cooling a heated mold by supplying
cooling medium from a cooling medium supply source to a medium flow
path provided for a mold, wherein a discharge side path connected
to an outlet side of the medium flow path of the mold is
communicated with a heat exchanger condensing cooling medium
gasified and discharged from the medium flow path.
2. The mold-cooling system according to claim 1, wherein a path
supplying steam from a steam source or air from an air source is
connected to a supply side path connected to an inlet side of the
medium flow path of the mold from the cooling medium supply source,
and wherein the mold-cooling system comprises a control portion
controlling supply of steam or air and supply of cooling medium,
and supplying cooling medium to the medium flow path of the mold
after supplying steam or air to the medium flow path of the
mold.
3. The mold-cooling system according to claim 1, wherein the path
supplying steam from the steam source or air from the air source is
connected to the supply side path connected to the inlet side of
the medium flow path of the mold from the cooling medium supply
source, and wherein the mold-cooling system comprises the control
portion controlling the supply of steam or air and the supply of
cooling medium, and supplying steam or air to the medium flow path
of the mold after supplying cooling medium to the medium flow path
of the mold.
4. The mold-cooling system according to claim 1, wherein the
discharge side path on a downstream side of the heat exchanger is
provided with a backflow prevention portion preventing
backflow.
5. The mold-cooling method for cooling a heated mold by supplying
cooling medium to a medium flow path provided for a mold, wherein a
discharge side path connected to an outlet side of the medium flow
path of the mold is communicated with a heat exchanger, and cooling
medium gasified and discharged from the medium flow path is
condensed in the heat exchanger.
6. The mold-cooling method according to claim 5, wherein cooling
medium is supplied to the medium flow path of the mold after
executing a precooling step in which steam or air is supplied to
the medium flow path of the mold.
7. The mold-cooling method according to claim 5, wherein a second
cooling step in which steam or air is supplied to the medium flow
path of the mold is performed after executing a first cooling step
in which cooling medium is supplied to the medium flow path of the
mold.
8. The mold-cooling system according to claim 2, wherein the
control portion controls the supply of steam or air and the supply
of cooling medium, and supplies steam or air to the medium flow
path of the mold after supplying cooling medium to the medium flow
path of the mold.
9. The mold-cooling system according to claim 2, wherein the
discharge side path on a downstream side of the heat exchanger is
provided with a backflow prevention portion preventing
backflow.
10. The mold-cooling system according to claim 3, wherein the
discharge side path on a downstream side of the heat exchanger is
provided with a backflow prevention portion preventing
backflow.
11. The mold-cooling system according to claim 8, wherein the
discharge side path on a downstream side of the heat exchanger is
provided with a backflow prevention portion preventing
backflow.
12. The mold-cooling method according to claim 6, wherein a second
cooling step in which steam or air is supplied to the medium flow
path of the mold is performed after executing a first cooling step
in which cooling medium is supplied to the medium flow path of the
mold.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present invention relates to a mold-cooling system and a
mold-cooling method for cooling a heated mold.
[0003] 2. Description of the Related Art
[0004] For cooling a heated mold, a mold-cooling system (a
mold-cooling apparatus) supplying cooling medium such as cooling
water to a medium flow path provided for a mold has been known
conventionally. In the above-mentioned mold-cooling system, there
has been a problem that cooling medium supplied to the medium flow
path of the mold heated to a high temperature gasifies in the
medium flow path and the vapor is discharged. Patent Literature 1
below, for instance, discloses a temperature-control device for the
mold constituted in such a manner that a conduit pipe for supplying
liquid at ordinary temperatures and a drain pipe are connected to a
liquid circulating passage constituted by connecting a liquid
passage of the mold with that of a temperature controller, and the
conduit pipe for liquid supply and the drain pipe are connected by
a throttle passage, thereby supplying the ordinary temperature
liquid passing through the throttle passage to the drain pipe and
suppressing generation of the vapor.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 2002-52538
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0006] Recently, due to large size of articles to be molded,
diversification of molding material or the like, a system for
cooling the mold at a high temperature approximately from 150
degrees Celsius to 300 degrees Celsius is desired. In such a
cooling system, when cooling medium is fed into the medium flow
path of the mold, the cooling medium instantly gasifies and
pressure increases in the medium flow path of the mold; also
accompanied with relatively large heat capacity of the mold, it is
difficult to feed cooling medium into the medium flow path of the
mold from a supply source side of cooling medium, cooling time is
prolonged, and a pump of high discharge pressure is required. As
shown in Patent Literature 1, for instance, condensation by
supplying liquid to a path on a discharge side of the mold is also
possible; similar to a medium feeding side, it is difficult to
supply liquid due to the increase in pressure, and the pump of high
discharge pressure is required.
[0007] In view of the above-mentioned problems, an object of the
present invention is to provide a mold-cooling system and a
mold-cooling method which suppress discharge of gasified cooling
medium and enhance cooling efficiency.
Means of Solving the Problems
[0008] In order to achieve the above-mentioned object, in a
mold-cooling system of the present invention for cooling a heated
mold by supplying cooling medium from a cooling medium supply
source to a medium flow path provided for a mold, a discharge side
path connected to an outlet side of the medium flow path of the
mold can be communicated with a heat exchanger condensing the
cooling medium gasified and discharged from the medium flow
path.
[0009] In the present invention, a path supplying steam from a
steam source or air from an air source can be connected to a supply
side path connected to an inlet side of the medium flow path of the
mold from the cooling medium supply source, and the mold-cooling
system can include a control portion controlling supply of the
steam or the air and supply of the cooling medium, and supplying
the cooling medium to the medium flow path of the mold after
supplying the steam or the air to the medium flow path of the
mold.
[0010] In the present invention, the path supplying steam from the
steam source or air from the air source can be connected to the
supply side path connected to the inlet side of the medium flow
path of the mold from the cooling medium supply source, and the
mold-cooling system can include the control portion controlling the
supply of the steam or the air and the supply of the cooling
medium, and supplying the steam or the air to the medium flow path
of the mold after supplying the cooling medium to the medium flow
path of the mold.
[0011] In the present invention, the discharge side path on a
downstream side of the heat exchanger can be provided with a
backflow prevention portion preventing backflow.
[0012] In order to achieve the above-mentioned object, in a
mold-cooling method of the present invention for cooling the heated
mold by supplying cooling medium to the medium flow path provided
for the mold, the discharge side path connected to the outlet side
of the medium flow path of the mold is communicated with the heat
exchanger, and the cooling medium gasified and discharged from the
medium flow path is condensed in the heat exchanger.
[0013] In the present invention, the cooling medium can be supplied
to the medium flow path of the mold after executing a precooling
step in which steam or air is supplied to the medium flow path of
the mold.
[0014] In the present invention, a second cooling step in which
steam or air is supplied to the medium flow path of the mold can be
performed after executing a first cooling step in which the cooling
medium is supplied to the medium flow path of the mold.
Effects of the Invention
[0015] The mold-cooling system and the mold-cooling method of the
present invention, constituted as mentioned above, suppress
discharge of gasified cooling medium and enhance the cooling
efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a system configuration diagram which schematically
shows one example of the mold-cooling system in one embodiment of
the present invention.
[0017] FIG. 2 is a schematic time chart which shows one example of
basic operation executed in the mold-cooling system.
[0018] FIG. 3 is the system configuration diagram which
schematically shows one example of the mold-cooling system in
another embodiment of the present invention.
[0019] FIG. 4 is the schematic time chart which shows one example
of basic operation executed in the mold-cooling system.
[0020] FIG. 5 is the system configuration diagram which
schematically shows one example of the mold-cooling system in still
another embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0021] An embodiment of the present invention is explained below
with reference to the drawings. In FIG. 1, FIG. 3, and FIG. 5, pipe
lines (pipe arrangement), i.e. paths through which medium, or the
like passes, are schematically shown in a solid line.
[0022] The schematic time charts in FIG. 2 and FIG. 4
diagrammatically show ON and OFF operations, opening and closing
operations or the like of respective devices.
[0023] FIG. 1 and FIG. 2 illustrate a mold-cooling system in a
first embodiment and a mold-cooling method carried out with the
mold-cooling system.
[0024] A mold-cooling system 1 in the embodiment is constituted for
cooling a heated mold 2 in such a manner that cooling medium from a
cooling medium supply source 10 is supplied to a medium flow path 4
provided for the mold 2. As shown in FIG. 1, the mold-cooling
system 1 is constituted in such a manner that a discharge side path
15 connected to an outlet 5 side of the medium flow path 4 of the
mold 2 is communicated with a heat exchanger 20 condensing gasified
cooling medium discharged from the medium flow path 4.
[0025] In the embodiment, the mold-cooling system 1 is a mold
heating-cooling system 1 which performs heating in addition to
cooling of the mold 2.
[0026] The mold 2 is, for instance, constituted with a fixed mold
and a movable mold; the fixed mold and the movable mold are
respectively provided with the medium flow paths 4, 4 for
circulating cooling medium. A supply side path 13 (a medium feeding
path) is connected to inlets 3, 3 (medium feeding connection ports)
side of the medium flow paths 4, 4. The discharge side path 15 (a
medium returning path) is connected to outlets 5, 5 (medium
returning connection ports) side of the medium flow paths 4, 4.
[0027] The supply side path 13 and the inlets 3, 3 of the medium
flow paths 4, 4 can be connected by a manifold portion which
divides a single supply side path 13 into plurality or by flexible
piping members, such as a hose or a tube which is connected to a
plurality of connection ports of the manifold portion.
[0028] The discharge side path 15 and the outlets 5, 5 of the
medium flow paths 4, 4 can be substantially similarly connected by
a manifold portion which branches a single discharge side path 15
into plurality or by flexible piping members, such as a hose or a
tube which is connected to a plurality of connection ports of the
manifold portion.
[0029] The mold 2 is provided with a temperature sensor 6 as a
detection means for detecting the temperature of the mold 2. The
temperature sensor 6 can be constituted so as to detect the
temperature of medium (cooling medium) on the outlet 5 side, a
vicinity region of the outlet 5 of the medium flow path 4, a
downstream vicinity region of the outlet 5, or the like. The mold 2
is provided with a mold heater 7 as a heating means for heating the
mold 2. The figure shows an example in which the mold heaters 7, 7
are respectively embedded in the fixed mold and the movable mold of
the mold 2.
[0030] A target heating temperature (a set heating temperature,
referring to FIG. 2) of the mold 2 heated by the mold heater 7 as
the heating means can be appropriately set according to the size or
the shape of an article to be molded, the type of molding material
or the like and in view of improving fill ability of molten
material or transfer property (transfer rate) of a cavity face to
the article to be molded. When the article to be molded is
relatively large in size, the target heating temperature can be set
relatively high, for instance approximately from 150 degrees
Celsius to 300 degrees Celsius or approximately from 200 degrees
Celsius to 300 degrees Celsius.
[0031] A target cooling temperature (a set cooling temperature,
referring to FIG. 2) of the mold 2 cooled by cooling medium from
the cooling medium supply source 10, to be mentioned below, can be
also appropriately set from a similar point of view as mentioned
above, from the point of view of capable of solidifying molten
material and shortening a molding cycle, or the like. The target
cooling temperature can be set lower than the target heating
temperature. However, when the target cooling temperature is too
low, accompanied with large heat capacity of the mold 2, time for
cooling down to the target temperature and time for heating up to
the target temperature in a next step are likely to be prolonged.
From the above-mentioned view or the like, the target cooling
temperature can be, for instance, approximately from 100 degrees
Celsius to 200 degrees Celsius or approximately from 150 degrees
Celsius to 200 degrees Celsius. When the target heating temperature
is set relatively high as mentioned above, the target cooling
temperature can be set lower than the target heating temperature
approximately by 40 degrees Celsius to 120 degrees Celsius.
[0032] A molding machine of the mold 2 can be an injection molding
machine or the like in which synthetic resin, i.e. material molten
by a cylinder or the like, is injected from a nozzle or the like
and filled into a cavity or the like formed by the fixed mold and
the movable mold of the mold 2, thereafter the article is molded
successively. Other molding machines such as a compression molding
machine can be adopted. Molding material can be fiber-reinforced
synthetic resin material or the like, i.e. synthetic resin material
containing reinforced-fiber such as carbon fiber or glass
fiber.
[0033] The heating means for the mold 2 is not limited to the mold
heater 7 mentioned above; it can be a heating medium supply source
which supplies heating medium to the medium flow path provided for
the mold 2. In such a case, the heating medium can be fed into the
cooling medium flow path, or an aspect can be such that the heating
medium is fed into the medium flow path exclusively for the heating
medium. Other kinds of heating means can be adopted. Furthermore,
heating of the mold 2 can be performed by autothermal of molten
material injected into the cavity of the mold 2.
[0034] As for the cooling medium supply source 10, appropriate
supply sources can be adopted according to types of cooling medium,
required temperatures of cooling medium, the target cooling
temperature or the like. For instance, the cooling medium supply
source 10 can be constituted with a storage portion (a tank) which
stores cooling medium, and with a cooling medium supply pump 11
(referring to FIG. 2) which supplies (feeds) cooling medium stored
in the storage portion towards a mold 2 side. In such a case,
temperature can be appropriately controlled by a cooler such as a
chiller so that cooling medium stored in the storage portion is
maintained at the predetermined temperature.
[0035] Cooling medium supplied from the cooling medium supply
source 10 is liquid on a supply side and is water (clean water) in
the embodiment; alcohol including ethanol, or other cooling medium
can be adopted. Cooling medium of which boiling point at ordinary
pressures is equal to or less than 100 degrees Celsius can be
adopted.
[0036] The temperature of cooling medium supplied from the cooling
medium supply source 10 can be set at ordinary temperatures or can
be, for instance, approximately from 5 degrees Celsius to 90
degrees Celsius or approximately from 10 degrees Celsius to 50
degrees Celsius. The cooling medium supply source 10 is not limited
to the one as mentioned above and can have a storage portion in
which temperature control is not performed. The cooling medium
supply source can be a cooling tower or the like installed in a
plant or the like, or can be a water supply system (industrial
water works, water works).
[0037] In the embodiment, the mold heating-cooling system 1 is
constituted in such a manner that paths 18, 19 respectively
supplying steam from a steam source 8 and air from an air source 9
are connected to supply side paths 12, 13 connected to an inlet 3
side of the medium flow path 4 of the mold 2 from the cooling
medium supply source 10.
[0038] The steam source 8 can be a boiler or the like which heats
and vaporizes, or gasifies liquid (preferably liquid of the same
kind as cooling medium supplied to the medium flow path 4 of the
mold 2 from the cooling medium supply source 10) with a heat
source.
[0039] The steam supply path 18 which supplies steam from the steam
source 8 is provided with a steam valve 18a such as a solenoid
valve which supplies or cuts off steam from the steam source 8. One
end of the steam supply path 18 is connected to the steam source 8
and the other end is connected to the supply side path 13 by an
appropriate coupling or the like. The temperature of steam supplied
from the steam source 8 can be appropriately set according to the
above-mentioned target cooling temperature, for instance,
substantially the same temperature as or lower than the
above-mentioned target cooling temperature.
[0040] The air source 9 can be constituted in such a manner that
the atmosphere or the like is sent by a blower; it can be a
compression air source of a gas tank or the like which stores gas
(high-pressure gas) compressed by a compression machine such as a
compressor through an aftercooler, a drain separator, a dryer, or
the like.
[0041] The air supply path 19 which supplies air from the air
source 9 is provided with an air valve 19a such as a solenoid valve
which supplies or cuts off air from the air source 9. One end of
the air supply path 19 is connected to the air source 9 and the
other end of the air supply path 19 is connected to the supply side
path 13 by an appropriate coupling or the like.
[0042] The supply side paths 12, 13 which connect the cooling
medium supply source 10 with the inlet 3 of the medium flow path 4
of the mold 2 are constituted with an upstream supply side path 12
(a cooling medium supply source 10 side) further than a connecting
portion, as mentioned above, of the steam supply path 18 and the
air supply path 19, and with a downstream supply side path 13 (the
mold 2 side) further than the connecting portion.
[0043] The upstream supply side path 12 of the supply side paths
12, 13 is provided with a cooling medium valve 12a such as a
solenoid valve which supplies or cuts off cooling medium from the
cooling medium supply source 10. The cooling medium supply pump 11
as mentioned above is disposed at the upstream supply side path 12.
The upstream supply side path 12, the above-mentioned storage
portion or the like is provided with the detection means such as a
temperature sensor which detects the temperature of cooling medium
fed into the medium flow path 4 of the mold 2; based on the
detection value of the detection means, temperature can be
controlled by the above-mentioned cooler or the like so that the
temperature of cooling medium becomes the predetermined
temperature.
[0044] The heat exchanger 20, in which cooling medium fed through
the discharge side path 15 connected to the outlet 5 of the medium
flow path 4 of the mold 2 is high-temperature fluid, is
communicated with a cooling path 14 into which low-temperature
fluid which cools and condenses the high-temperature fluid is fed.
The discharge side path 15 and the cooling path 14 can be
respectively connected to a fluid passage on a high-temperature
side and a fluid passage on a low-temperature side of the heat
exchanger 20.
[0045] In the heat exchanger 20, cooling medium gasified through
the medium flow path 4 of the mold 2 heated to a high temperature
is heat-absorbed by low-temperature fluid which is fed through the
cooling path 14, cooled condensed, and liquefied.
[0046] In the embodiment, the cooling path 14 is constituted to
feed cooling medium supplied from the cooling medium supply source
10 into the fluid passage on the low-temperature side of the heat
exchanger 20. Namely, the cooling medium supply source 10 which
supplies cooling medium to the medium flow path 4 of the mold 2 is
constituted so as to be also used as the supply source which
supplies cooling medium to the fluid passage on the low-temperature
side of the heat exchanger 20. As mentioned above, the constitution
is further simplified as compared with a case in which the cooling
medium supply source for the heat exchanger 20 is separately
provided.
[0047] The cooling path 14 is connected by an appropriate coupling
or the like on the upstream side further than a region for which
the cooling medium valve 12a of the upstream supply side path 12 is
provided. In other words, the upstream supply side path 12 is
divided into the supply side path 12 heading toward the mold 2 side
and the cooling path 14 heading toward a heat exchanger 20 side on
the upstream side further than the region for which the cooling
medium valve 12a is provided.
[0048] The cooling path 14 is provided with a heat exchanger
cooling valve 14a such as a solenoid valve which supplies or cuts
off cooling medium from the cooling medium supply source 10. The
cooling path 14 is connected to a medium returning side of the
cooling medium supply source 10.
[0049] In the embodiment, the discharge side path 15 (on a
downstream side of the heat exchanger 20) connected to the outlet 5
of the medium flow path 4 of the mold 2 and passing through the
heat exchanger 20 is connected on the medium returning side of the
cooling medium supply source 10. Namely, cooling medium supplied to
the medium flow path 4 of the mold 2 is circulated in a closed-loop
manner with the cooling medium supply source 10. As constituted
above, impurities are unlikely to be mixed and quality control of
cooling medium is easily performed.
[0050] The figure shows an example in which the discharge side path
15 on the downstream side of the heat exchanger 20 is connected to
the cooling path 14 on the downstream side of the heat exchanger 20
in a confluent manner.
[0051] In the embodiment, the discharge side path 15 on the
downstream side of the heat exchanger 20 is provided with a
backflow prevention portion 16 for preventing backflow.
[0052] The backflow prevention portion 16 in the embodiment is a
backflow prevention valve (a non-return valve, a check valve) which
permits a fluid flow from the heat exchanger 20 side into the
cooling medium supply source 10 side and blocks a fluid flow from
the cooling medium supply source 10 side into the heat exchanger 20
side. By adopting such a backflow prevention valve as the backflow
prevention portion 16, an opening and closing control or the like
becomes unnecessary on discharging (returning the medium) and
backflow is prevented by a simple control, as compared with the
conventional one provided with an opening and closing valve or the
like as the backflow prevention portion.
[0053] As for the above-mentioned heat exchanger 20, heat
exchangers of various types such as a double pipe heat exchanger, a
plate heat exchanger, a shell and tube heat exchanger, and a cross
fin heat exchanger can be adopted. While the figure shows the heat
exchanger 20 of a parallel flow type, heat exchangers of a counter
flow type, a cross flow type or the like can be used.
[0054] The discharge side path 15 on the downstream side of the
heat exchanger 20 (the discharge side path 15 on an upstream side
further than the backflow prevention portion 16) can be
appropriately provided with a steam trap or the like if
necessary.
[0055] While the figure shows an embodiment in which opening and
closing valves (ON and OFF valves) are respectively provided to
open and close the upstream supply side path 12, the cooling path
14, the steam supply path 18, and the air supply path 19, all or
some of the above-mentioned valves can be constituted by a
multiport and multi-position type changeover valve or the like.
[0056] The mold heating-cooling system 1 has a control panel 21
including a control portion 22 which controls the mold heater 7,
the cooling medium supply pump 11, and the valves 12a, 14a, 18a,
19a.
[0057] The control panel 21 has the control portion 22 such as a
CPU, a display operation portion 24, and a memory portion 23, which
are respectively connected by signal lines. The display operation
portion 24 constitutes a display portion and an operation portion
for setting up, inputting or displaying. The memory portion 23 is
constituted by various memories and stores information about
conditions and values inputted and set up by an operation of the
display operation portion 24, various programs such as a control
program for executing respective operations mentioned below,
various predetermined operation conditions, various data tables or
the like.
[0058] The control portion 22 has a timing means such as a clock
timer, and an arithmetic processing portion and is connected to the
mold heater 7, the cooling medium supply pump 11, and the valves
12a, 14a, 18a, 19a through the signal line or the like for
controlling. The control portion 22 is also connected to the
temperature sensor 6 of the mold 2 through the signal line or the
like.
[0059] In the embodiment, the control portion 22 is constituted to
control the supply of steam or air and also the supply of cooling
medium.
[0060] In the embodiment, as shown in FIG. 2, the control portion
22 is constituted to control so as to supply cooling medium to the
medium flow path 4 of the mold 2 after supplying steam to the
medium flow path 4 of the mold 2.
[0061] In the embodiment, as shown in FIG. 2, the control portion
22 is constituted to control and supply air to the medium flow path
4 of the mold 2 after supplying cooling medium to the medium flow
path 4 of the mold 2.
[0062] The mold-cooling apparatus constituting the mold
heating-cooling system 1 could be the one having opening and
closing valves 12a, 14a, 18a, 19a disposed at the above-mentioned
paths 12, 14, 18, 19, the backflow prevention portion 16, the heat
exchanger 20, and the control panel 21 as shown in two-dot chain
lines of FIG. 1. Furthermore, the above apparatus could be the one
having at least one of the steam source 8, the air source 9, and
the cooling medium supply source 10. In addition, the above
apparatus could be a mold heating-cooling apparatus which further
has the heating means 7 for heating the mold 2.
[0063] In the mold heating-cooling system 1 in the embodiment
constituted as above, the mold 2 is heated when the mold heater 7
is activated. The mold heater 7 can be such that energization
control such as a PID control is performed by the control portion
22 in order that the temperature of the mold 2 becomes the
predetermined target heating temperature based on a measurement
temperature signal (a detection temperature) of the temperature
sensor 6 of the mold 2. The above-mentioned target heating
temperature can be inputted and set up through the display
operation portion 24.
[0064] When the cooling medium supply pump 11 is activated and the
cooling medium valve 12a is opened, cooling medium from the cooling
medium supply source 10 is supplied (supplied in circulation in the
embodiment) to the medium flow path 4 of the mold 2.
[0065] When the cooling medium supply pump 11 is activated and the
heat exchanger cooling valve 14a is opened, cooling medium from the
cooling medium supply source 10 is supplied to the fluid passage on
the low-temperature side of the heat exchanger 20. The opening and
closing control of the above-mentioned heat exchanger cooling valve
14a, such as the PID control, can be performed by the control
portion 22 in order that the temperature of returned cooling medium
becomes the predetermined target temperature based on the
measurement temperature signal (the detection temperature) of the
temperature sensor. The temperature sensor detects the temperature
on the downstream side of the heat exchanger 20 of the discharge
side path 15 which is communicated with the fluid passage on the
high-temperature side of the heat exchanger 20. The above-mentioned
target temperature can be inputted and set up through the display
operation portion 24.
[0066] When the steam valve 18a is opened, steam from the steam
source 8 is supplied to the medium flow path 4 of the mold 2.
[0067] When the air valve 19a is opened, air from the air source 9
is supplied to the medium flow path 4 of the mold 2.
[0068] One example of a mold heating-cooling method (the
mold-cooling method) is explained based on FIG. 2 as one example of
basic operation executed in the mold heating-cooling system 1 in
the embodiment constituted as above.
[0069] In a graph of FIG. 2, a horizontal axis is a time axis, a
vertical axis is the detection temperature of the temperature
sensor 6, and its transition is schematically shown.
[0070] First, the mold heater 7 is activated and a preheating step
can be executed to preheat the mold 2 substantially at ordinary
temperatures approximately to the target cooling temperature. A
standby state is obtained when the preheating step is executed as
above.
[0071] In the molding machine of the mold 2 not shown in the
figure, molten material such as resin is injected and filled into
the cavity provided for the mold 2 in a closed condition, and
pressure is appropriately kept; when molten material is solidified,
the mold is opened, and the article is demolded. In such a series
of molding steps, the mold heating-cooling system 1 in the
embodiment is used for executing a mold heating step in order that
the solidification of molten material is retarded and filling is
smoothly performed. After molten material is filled into the
cavity, the mold heating-cooling system 1 in the embodiment is used
for executing a mold cooling step for rapidly solidifying molten
material. The mold heating step and the mold cooling step which are
executed by the mold heating-cooling system 1 can be executed
(started and stopped) together with a molding operation of the
molding machine, for instance, based on a mold closing signal, an
injection signal, a pressure keeping signal, a mold opening signal
of the molding machine.
[0072] When preheating is performed as mentioned above and a signal
on a molding machine side or another heating start signal is
received in the standby state, a heating step for heating the mold
2 is executed and the mold 2 is heated to the predetermined target
heating temperature. The heating step can be finished when the
signal on the molding machine side or another heat finish signal is
received, or can be finished after reaching the target heating
temperature and the elapse of predetermined time.
[0073] When the heating step is finished and the predetermined time
elapses or the signal on the molding machine side or another
cooling start signal is received, a cooling step for cooling the
mold 2 is executed and the mold 2 is cooled to the predetermined
target cooling temperature. The target cooling temperature can be
inputted and set up through the display operation portion 24.
[0074] In the embodiment, since the heat exchanger cooling valve
14a which supplies or cuts off low-temperature medium (cooling
medium) is provided for the fluid passage on the low-temperature
side of the heat exchanger 20, the opening and closing control of
the heat exchanger cooling valve 14a is performed during the
cooling step. As in a second and a third embodiments mentioned
below, in such an aspect without the heat exchanger cooling valve
14a, the low-temperature medium (cooling medium) can be constantly
supplied to the fluid passage on the low-temperature side of the
heat exchanger 20.
[0075] In the example of the operation, the precooling step in
which steam is supplied to the medium flow path 4 is executed
before cooling medium is supplied to the medium flow path 4. In
other words, in such a state that the cooling medium valve 12a is
closed, the steam valve 18a is opened and steam is supplied to the
medium flow path 4. When steam is supplied as mentioned above, due
to its contact to an inner circumferential face of the medium flow
path 4, the heat is absorbed, precooling is performed, and steam is
condensed in the heat exchanger 20. Thereby, pressure drops in the
respective paths, i.e. the supply side path 13, the medium flow
path 4, and the discharge side path 15. Namely, steam and cooling
medium which is adhered to the inner circumferential face of the
medium flow path 4 are gasified, successively condensed and
liquefied in the heat exchanger 20, thereby the pressure in the
respective paths sharply drops also accompanied with the backflow
prevention portion 16 provided.
[0076] The above-mentioned precooling step can be executed in such
a manner that the supply side path 13, the medium flow path 4, and
the discharge side path 15 are almost filled with steam. The
precooling step can be executed until the predetermined time
elapses or until a measurement pressure signal (detection pressure)
of a detection means which detects the pressure in the paths such
as a pressure sensor provided for any of the supply side path 13,
the medium flow path 4, and the discharge side path 15 falls below
the predetermined pressure (a threshold value). In other words,
when the pressure falls below the predetermined pressure, supply of
steam can be switched into supply of cooling medium. The
predetermined pressure, for instance, can be at which the next
supply of cooling medium is possible; it can also be appropriately
set according to capacity (discharge pressure) or the like of the
cooling medium supply pump 11. The predetermined pressure can be
inputted and set up through the display operation portion 24.
[0077] In the precooling step, steam can be mixed with a small
amount of cooling medium and supplied, or air can be supplied
instead of steam. In such a case, air can be mixed with a small
amount of cooling medium or steam and supplied.
[0078] After the above precooling step, a main cooling step in
which cooling medium is supplied to the medium flow path 4 of the
mold 2 is executed. In other words, when the cooling medium supply
pump 11 is activated, and the steam valve 18a is closed, the
cooling medium valve 12a is opened. The figure shows an example in
which, considering rise time or the like, the cooling medium supply
pump 11 is activated earlier than an opening of the cooling medium
valve 12a.
[0079] In the example of the operation, after a first cooling step
constituted by the main cooling step, a second cooling step in
which air is supplied to the medium flow path 4 of the mold 2 is
executed. In other words, when the cooling medium valve 12a is
closed, and the air valve 19a is opened, air is supplied to the
medium flow path 4. On closing the cooling medium valve 12a, the
cooling medium supply pump 11 can be stopped. An aspect can be such
that a bypass path which connects the supply side path 12 with the
discharge side path 15 (the cooling path 14 in the figure) is
provided, a bypass valve provided for the bypass path is conversely
opened and closed relative to the opening and the closing of the
cooling medium valve 12a, thereby generally activating the cooling
medium supply pump 11 constantly.
[0080] The first cooling step and the second cooling step can be
respectively executed until the predetermined time elapses in such
a manner that cooling medium in the medium flow path 4 is generally
discharged (purged) by executing the second cooling step and
without excessive cooling or the like; in other words, the
temperature does not greatly fall below the target cooling
temperature on finishing the cooling step. Based on the detection
temperature of the temperature sensor 6, the first cooling step can
be switched into the second cooling step and the second cooling
step can be finished; in other words, the air valve 19a can be
closed. In the second cooling step, in place of or in addition to
air, a small amount of cooling medium can be intermittently
supplied or steam can be supplied as in an example of an operation
in the second embodiment mentioned below. In such a case in which
steam is supplied, a small amount of cooling medium can be
intermittently supplied in addition to steam. When steam or a small
amount of cooling medium is supplied as mentioned above, the supply
can be appropriately controlled in such a manner that the total
amount in the medium flow path 4 almost gasifies and the medium in
the medium flow path 4 almost does not remain at the end of the
second cooling step. For instance, heat quantity released from an
inner wall face of the medium flow path 4 is calculated based on
capacity of the medium flow path 4, mold temperatures before and
after filling of molten material such as resin; it can be
experimentally or empirically determined based on the heat
quantity, gasification heat quantity of the medium, the target
cooling temperature, or the like. Since gasification occurs in a
mold opening or a demolding step, a relatively small amount of
remaining medium can be allowed.
[0081] After the cooling step, in the mold 2, the mold opening and
the demolding of the molded article are appropriately executed, and
the heating step and the cooling step are repeatedly executed.
[0082] The heating step in which the mold 2 is heated and the
cooling step in which the mold 2 is cooled, executed as mentioned
above, improve transfer property (transfer rate) of the cavity face
to the molded article and shorten the molding cycle.
[0083] The mold-cooling system 1 (the mold heating-cooling system)
in the embodiment and the mold-cooling method (the mold
heating-cooling method) which is executed by the mold-cooling
system 1 constituted as mentioned above enhance cooling efficiency
while suppressing discharge of gasified cooling medium.
[0084] In other words, the discharge side path 15 connected to the
outlet 5 side of the medium flow path 4 of the mold 2 is
communicated with the heat exchanger 20 condensing gasified cooling
medium discharged from the medium flow path 4. Accordingly,
gasified cooling medium is condensed in the heat exchanger 20 and
discharge of gasified cooling medium is suppressed. By condensing
in the heat exchanger 20, pressure raised by gasification of
cooling medium drops. Thereby, cooling medium is easily fed into
the medium flow path 4, cooling time is shortened, and cooling
efficiency is enhanced.
[0085] In the embodiment, the discharge side path 15 on the
downstream side of the heat exchanger 20 is constituted so as to
return the medium to the cooling medium supply source 10, i.e. so
as to circulate cooling medium. Accordingly, deposition of silica,
scale, or the like into the medium flow path 4 of the mold 2 or the
like contained in cooling medium by gasification of cooling medium
decreases as compared with the conventional one constituted in such
a manner that cooling medium is not circulated; new cooling medium
is supplied and discharged. Thereby, the maintenance or the like of
the medium flow path 4 is less frequently required.
[0086] In the embodiment, the discharge side path 15 on the
downstream side of the heat exchanger 20 is provided with the
backflow prevention portion 16 for preventing backflow.
Accordingly, when gasified cooling medium is condensed in the heat
exchanger 20, the pressure in the paths is more effectively
dropped. Thereby, cooling medium is more easily fed into the medium
flow path 4, cooling time is shortened, and cooling efficiency is
extremely enhanced.
[0087] The backflow prevention portion 16 is not limited to the
backflow prevention valve as in the figure and can be the opening
and closing valve or the like of which opening and closing are
controlled by the control portion 22. In such a case, an aspect can
be such that, when a pressure drop, associated with condensation in
the heat exchanger 20, is detected by the pressure sensor or the
like, or a temperature detected by the temperature sensor or the
like falls below the predetermined value, the opening and closing
valve is opened and liquefied cooling medium is discharged
(returned).
[0088] As in the above-mentioned embodiment, the constitution can
be such that the control portion 22 is provided to control the
supply of steam or air and the supply of cooling medium and to
supply cooling medium to the medium flow path 4 of the mold 2 after
supplying steam or air to the medium flow path 4 of the mold 2. In
other words, cooling medium can be supplied to the medium flow path
4 of the mold 2 after the precooling step in which steam or air is
supplied to the medium flow path 4 of the mold 2. As constituted
above, the mold 2 is precooled by steam or air and cooling medium
is more easily fed into the medium flow path 4 thereafter. In other
words, the heat of the medium flow path 4 of the mold 2 is absorbed
by the medium gasified by mixing the medium with steam or air. The
above gasified medium is condensed in the heat exchanger 20 and the
pressure drops, thereby more easily feeding cooling medium into the
medium flow path 4.
[0089] As in the above-mentioned embodiment, the constitution can
be such that the control portion 22 is provided to control the
supply of steam or air and the supply of cooling medium and to
supply steam or air to the medium flow path 4 of the mold 2 after
supplying cooling medium to the medium flow path 4 of the mold 2.
In other words, after the first cooling step in which cooling
medium is supplied to the medium flow path 4 of the mold 2, the
second cooling step in which steam or air is supplied to the medium
flow path 4 of the mold 2 can be executed. As constituted above,
cooling medium remained in the medium flow path 4 of the mold 2 is
purged, the heat is absorbed by contacting the medium flow path 4,
and the mold 2 is cooled. Thereby, the remaining medium in the
medium flow path 4 of the mold 2 decreases and heating is
effectively performed.
[0090] One example of the mold-cooling system in another embodiment
of the present invention and one example of the mold-cooling method
executed with the example of the mold-cooling system in another
embodiment of the present invention are explained.
[0091] FIG. 3 and FIG. 4 illustrate the mold-cooling system in the
second embodiment and the mold-cooling method executed with the
mold-cooling system in the second embodiment. Differences from the
first embodiment are mainly explained and common constitutions are
allotted with the same reference numerals and their explanation is
omitted or briefly explained. And an explanation of common
operations with the example of the operation mentioned above is
omitted or briefly explained.
[0092] Also in the embodiment, a mold-cooling system 1A is a mold
heating-cooling system 1A which performs heating in addition to
cooling of the mold 2.
[0093] The embodiment mainly differs from the above-mentioned first
embodiment in that the steam supply path 18 supplying steam from
the steam source 8 is not connected to the supply side path 13, the
cooling path 14 communicated with the fluid passage on the
low-temperature side of the heat exchanger 20 is not provided with
the heat exchanger cooling valve 14a, and the discharge side path
15 on the downstream side of the heat exchanger 20 is not provided
with the backflow prevention portion 16.
[0094] In the embodiment, the supply amount of cooling medium from
the cooling medium supply source 10 is able to be regulated. In the
figure, the upstream supply side path 12 connected to a medium
feeding side of the cooling medium supply source 10 is provided
with a small flow path 12b in a parallel manner; the small flow
path 12b is provided with a valve for a small amount of cooling
medium 12c which supplies or cuts off cooling medium. In other
words, when the cooling medium valve 12a provided for the upstream
supply side path 12, i.e. a main path, is closed and the valve for
a small amount of cooling medium 12c of the small flow path 12b is
opened, a relatively small flow amount of cooling medium is
supplied. The valve for a small amount of cooling medium 12c is
connected to the control portion 22 through the signal line or the
like similar to the other valves and the opening and closing
control is performed by the control portion 22.
[0095] In place of the above, an aspect can be such that a flow
amount control valve or the like capable of controlling an opening
degree is provided as the cooling medium valve 12a.
[0096] One example of the mold heating-cooling method (the
mold-cooling method) as one example of basic operation executed in
the mold heating-cooling system 1A in the embodiment constituted as
above is explained based on FIG. 4.
[0097] Also in a graph of FIG. 4, the horizontal axis is the time
axis, the vertical axis is the detection temperature of the
temperature sensor 6, and its transition is schematically shown the
same as above.
[0098] First, the preheating step can be executed and the heating
step can be executed in the same manner as above.
[0099] After that, the cooling step which cools the mold 2 can be
executed.
[0100] In the example of the operation, cooling medium is supplied
to the medium flow path 4 of the mold 2 without executing the
precooling step in which steam or air is supplied to the medium
flow path 4 of the mold 2. In other words, when the cooling medium
supply pump 11 is activated and the cooling medium valve 12a is
opened, cooling medium from the cooling medium supply source 10 is
supplied to the medium flow path 4 of the mold 2. The figure shows,
the same as above, an example in which the cooling medium supply
pump 11 is activated earlier than the opening of the cooling medium
valve 12a , considering the rise time or the like.
[0101] In the example of the operation, after the first cooling
step constituted by the main cooling step, the second cooling step
in which a small flow amount of cooling medium and air are
intermittently supplied to the medium flow path 4 of the mold 2 is
executed. In the example of the operation, the cooling medium valve
12a is closed; the valve for a small amount of cooling medium 12c
is intermittently opened; the small flow amount of cooling medium
is intermittently supplied to the medium flow path 4 of the mold 2;
and after that, the air valve 19a is intermittently opened and air
is intermittently supplied to the medium flow path 4 of the mold 2.
When the valve for a small amount of cooling medium 12c is closed,
the cooling medium supply pump 11 can be stopped. In place of the
above aspect, an aspect in the second cooling step can be such that
air valve 19a is intermittently opened and air is intermittently
supplied to the medium flow path 4 of the mold 2; and after that,
the valve for a small amount of cooling medium 12c is
intermittently opened and the small flow amount of cooling medium
is intermittently supplied to the medium flow path 4 of the mold 2.
And further after that, the air valve 19a can be intermittently
opened and air can be intermittently supplied to the medium flow
path 4 of the mold 2. Or an aspect can be such that the valve for a
small amount of cooling medium 12c and the air valve 19a are
alternately opened, and the small flow amount of cooling medium and
air are alternately supplied to the medium flow path 4 of the mold
2.
[0102] In the example of the operation, when the detection value of
the temperature sensor 6 as mentioned above falls below the
predetermined threshold value (a switching threshold value), the
first cooling step is switched into the second cooling step. The
setting of the switching threshold value and the execution control
of the second cooling step can be appropriately performed in such a
manner that, the same as above, cooling medium in the medium flow
path 4 is almost discharged (purged) by executing the second
cooling step and excessive cooling or the like is not caused; in
other words, the temperature does not greatly fall below the target
cooling temperature at the end of the cooling step. The
above-mentioned switching threshold value can be inputted and set
up through the display operation portion 24. In the above-mentioned
second cooling step, steam can be supplied in place of or in
addition to air as mentioned above.
[0103] Also in the example of the operation, the precooling step as
mentioned above can be executed.
[0104] Also in the example of the operation, after the cooling
step, in the mold 2, the mold opening and the demolding of the
molded article are appropriately executed, and the heating step and
the cooling step are repeatedly executed.
[0105] Also in the mold-cooling system 1A (the mold heating-cooling
system) in the embodiment and the mold-cooling method (the mold
heating-cooling method) which is executed by the above system, an
effect substantially similar to the above-mentioned first
embodiment and the example of the operation in the first embodiment
is obtained.
[0106] One example of the mold-cooling system in still another
embodiment of the present invention and one example of the
mold-cooling method which is executed by the example of the
mold-cooling system in still another embodiment of the present
invention are explained below.
[0107] FIG. 5 illustrates the mold-cooling system in the third
embodiment and the mold-cooling method which is executed by the
mold-cooling system in the third embodiment.
[0108] Differences from the above-mentioned respective embodiments
are mainly explained and common constitutions are allotted with the
same reference numerals and their explanation is omitted or briefly
explained.
[0109] Also in the embodiment, a mold-cooling system 1B is a mold
heating-cooling system 1B which performs heating in addition to
cooling of the mold 2.
[0110] In the embodiment, a cooling path 14A which supplies cooling
medium to a fluid passage on a low-temperature side of a heat
exchanger 20A is not communicated with the cooling medium supply
source 10 which supplies cooling medium to the medium flow path 4
of the mold 2 but is communicated with a cooling medium supply
source 17 for the heat exchanger 20A. As constituted above, the
cooling medium supply source 17 can be a cooling tower or the like
installed in the plant or the like and the cooling medium supply
source 10 can be the storage portion or the like in which
temperature control is not performed, thereby simplifying the
constitution of the cooling medium supply source 10.
[0111] Also in the mold heating-cooling system 1B in the
embodiment, operation (the mold heating-cooling method (the
mold-cooling method)) substantially similar to those in the
above-mentioned respective embodiments is executed; an effect
substantially similar to those in the above-mentioned respective
embodiments is obtained.
[0112] The heat exchanger 20, 20A is not limited to such an aspect
in which cooling is performed by feeding cooling medium into the
fluid passage on the low-temperature side; for instance, gasified
cooling medium which is fed into the fluid passage on the
high-temperature side can be condensed by cooling with a fan or the
like, i.e. an air cooling type.
[0113] The above-mentioned constitutions, operations, or the like
which are different from each other can be appropriately recombined
or combined, or appropriately modified as needed.
[0114] In the above-mentioned respective embodiments, while an
aspect is shown that the discharge side path 15 on the downstream
side of the heat exchanger 20, 20A is connected to the medium
returning side of the cooling medium supply source 10 and cooling
medium is circulated, an aspect can be such that the discharge side
path 15 on the downstream side of the heat exchanger 20, 20A is not
connected to the medium returning side of the cooling medium supply
source 10 and cooling medium is discharged as drain.
[0115] In the above-mentioned respective embodiments, the mold
heating-cooling system 1, 1A, 1B which performs heating in addition
to cooling of the mold 2 is shown but can be the mold-cooling
system 1, 1A, 1B which performs cooling of the mold 2. In such a
case, a mold-heating system (a mold-heating apparatus) which is
controlled separately from the mold-cooling system 1, 1A, 1B and
performs heating of the mold 2 can be provided.
[0116] In the above-mentioned respective examples of the operation,
an example in which, after the first cooling step in which cooling
medium is supplied to the medium flow path 4 of the mold 2, the
second cooling step in which steam or air is supplied to the medium
flow path 4 of the mold 2 is shown; however the second cooling step
can be omitted. In such a case, the cooling step can be such that
the precooling step as mentioned above is executed and then the
main cooling step is executed, or furthermore only the main cooling
step is executed. In other words, in order that the pressure is
dropped, cooling medium is effectively supplied, and cooling is
performed, the discharge side path 15 connected to the outlet 5
side of the medium flow path 4 of the mold 2 can be communicated
with the heat exchanger 20, 20A and gasified cooling medium
discharged from the medium flow path 4 can be condensed in the heat
exchanger 20, 20A.
DESCRIPTION OF THE REFERENCE NUMERAL
[0117] 1, 1A, 1B mold heating-cooling system (mold-cooling
system)
[0118] 2 mold
[0119] 3 inlet
[0120] 4 medium flow path
[0121] 5 outlet
[0122] 8 steam source
[0123] 9 air source
[0124] 10 cooling medium supply source
[0125] 12,13 supply side path
[0126] 15 discharge side path
[0127] 16 backflow prevention portion
[0128] 18 steam supply path
[0129] 19 air supply path
[0130] 20, 20A heat exchanger
[0131] 22 control portion
* * * * *