U.S. patent application number 14/118977 was filed with the patent office on 2014-05-22 for hot-pressing apparatus.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is Junji Asano, Kenji Komura. Invention is credited to Junji Asano, Kenji Komura.
Application Number | 20140137619 14/118977 |
Document ID | / |
Family ID | 47216801 |
Filed Date | 2014-05-22 |
United States Patent
Application |
20140137619 |
Kind Code |
A1 |
Asano; Junji ; et
al. |
May 22, 2014 |
HOT-PRESSING APPARATUS
Abstract
Disclosed is a hot-pressing apparatus capable of quenching a
workpiece at a sufficient cooling rate. The hot-pressing apparatus
performs a hot-press forming of a workpiece using a lower die and
an upper die, in which a cooling channel and a cooling channel, and
a plurality of gas-introduction paths and a plurality of
gas-introduction paths through which heat-conducting gas flows are
provided in the lower die and the upper die. The plurality of
gas-introduction paths penetrate through the dies. The hot-press
forming is performed while the heat-conducting gas is supplied to
the areas between the dies and the workpiece from the plurality of
gas-introduction paths opening on the forming surfaces of the
dies.
Inventors: |
Asano; Junji; (Toyota-shi,
JP) ; Komura; Kenji; (Toyota-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Asano; Junji
Komura; Kenji |
Toyota-shi
Toyota-shi |
|
JP
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi, Aichi
JP
|
Family ID: |
47216801 |
Appl. No.: |
14/118977 |
Filed: |
May 26, 2011 |
PCT Filed: |
May 26, 2011 |
PCT NO: |
PCT/JP2011/062124 |
371 Date: |
January 31, 2014 |
Current U.S.
Class: |
72/38 |
Current CPC
Class: |
C21D 7/13 20130101; B21D
22/208 20130101; B21D 37/16 20130101; B21D 22/21 20130101; C21D
1/673 20130101; B21D 24/16 20130101 |
Class at
Publication: |
72/38 |
International
Class: |
B21D 37/16 20060101
B21D037/16 |
Claims
1. A hot-pressing apparatus comprising a lower die having a lower
forming surface, and an upper die having an upper forming surface
facing the lower forming surface, which performs a hot-press
forming in which the lower die and the upper die press a heated
workpiece arranged therebetween, and at the same time, the forming
surfaces of the lower die and the upper die are kept in contact
with a surface of the workpiece to cool the workpiece, wherein the
lower die and/or the upper die comprises: a cooling channel through
which a cooling medium flows; and a plurality of gas-introduction
paths through which heat-conducting gas flows, the plurality of
gas-introduction paths penetrate through the lower die and/or the
upper die from the forming surface thereof to a surface other than
that forming surface so as to run in the vicinity of the cooling
channel, and open on the forming surface of the lower die and/or
the upper die so as to coincide in position with gaps formed by
deformation of the pressed workpiece between the workpiece and the
lower die and/or the upper die where the plurality of
gas-introduction paths are formed, and the hot-press forming is
performed while the heat-conducting gas is supplied to an area
between the workpiece and the lower die and/or the upper die from
the plurality of gas-introduction paths.
2-3. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a hot-pressing apparatus
which presses and cools a heated workpiece at the same time.
BACKGROUND ART
[0002] Conventionally, a hot-pressing apparatus is widely known
which causes a die to press a workpiece, such as a steel plate,
heated to above a temperature at which an austenite structure
appears, and at the same time, quenches the workpiece by bring the
die into contact with the workpiece.
[0003] A technique on the hot-pressing apparatus is publicly known
which enables the die to suitably cool the workpiece during the
quenching by providing water channels through which cooling water
to cool the die flows in the die (for example, see Patent
Literature 1).
[0004] However, since the pressed workpiece deforms because of
spring back, uneven thickness thereof and the like, a gap is formed
between the workpiece and the die during the quenching.
Consequently, a contact area between the surface of the workpiece
and the forming surface of the die decreases during the quenching,
which causes a problem that some parts in the workpiece are not
cooled at a sufficient cooling rate (e.g. 30 [.degree. C./sec] and
above), and hardness of some parts in the workpiece is smaller than
a predetermined value.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: JP 2006-326620 A
SUMMARY OF INVENTION
Problem to Be Solved By the Invention
[0006] The objective of the present invention is to provide a
hot-pressing apparatus capable of quenching a workpiece at a
sufficient cooling rate.
Means for Solving the Problem
[0007] The first embodiment of the present invention is a
hot-pressing apparatus including a lower die having a lower forming
surface, and an upper die having an upper forming surface facing
the lower forming surface, which performs a hot-press forming in
which the lower die and the upper die press a heated workpiece
arranged therebetween, and at the same time, the forming surfaces
of the lower die and the upper die are kept in contact with a
surface of the workpiece to cool the workpiece. The lower die
and/or the upper die includes a cooling channel through which a
cooling medium flows, and a plurality of gas-introduction paths
through which heat-conducting gas flows. The plurality of
gas-introduction paths penetrate through the lower die and/or the
upper die from the forming surface thereof to a surface other than
that forming surface. The hot-press forming is performed while the
heat-conducting gas is supplied to an area between the workpiece
and the lower die and/or the upper die from the plurality of
gas-introduction paths opening on the forming surface of the lower
die and/or the upper die.
[0008] Advantageously, the plurality of gas-introduction paths are
formed to run in the vicinity of the cooling channel.
[0009] Preferably, the plurality of gas-introduction paths open on
the forming surface of the lower die and/or the upper die so as to
coincide in position with gaps formed by deformation of the pressed
workpiece between the workpiece and the lower die and/or the upper
die where the plurality of gas-introduction paths are formed.
Effects of the Invention
[0010] The present invention makes it possible to quench a
workpiece at a sufficient cooling rate, and to prevent hardness of
some parts in the workpiece from being smaller than a predetermined
value.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 illustrates a hot-pressing apparatus according to an
embodiment of the present invention.
[0012] FIG. 2 illustrates the hot-pressing apparatus in which an
upper die moves to the bottom dead center when pressing a
workpiece.
[0013] FIG. 3 illustrates the hot-pressing apparatus in which the
upper die is at the bottom dead center when pressing the
workpiece.
DESCRIPTION OF EMBODIMENTS
[0014] With reference to FIGS. 1 to 3, described below is a
hot-pressing apparatus 1 as an embodiment of a hot-pressing
apparatus according to the present invention.
[0015] The hot-pressing apparatus 1 performs hot-press forming of a
workpiece W.
[0016] The workpiece W is a steel plate to be pressed by the
hot-pressing apparatus 1, and is heated to above a temperature at
which an austenite structure appears by ohmic heating and the
like.
[0017] For convenience, a top-bottom direction in FIG. 1 is defined
as a top-bottom direction of the hot-pressing apparatus 1, and a
right-left direction in FIG. 1 is defined as a right-left direction
of the hot-pressing apparatus 1. In addition, this side in FIG. 1
is defined as a front side of the hot-pressing apparatus 1, and the
far side in FIG. 1 is defined as a rear side of the hot-pressing
apparatus 1, thereby a front-rear direction of the hot-pressing
apparatus 1 being defined.
[0018] As shown in FIG. 1, the hot-pressing apparatus 1 includes a
lower die 10, an upper die 20, two lateral gas-feeders 30, a lower
gas-feeder 40, and an upper gas-feeder 50.
[0019] The lower die 10 and the upper die 20 are arranged so that
the forming surfaces thereof are opposed to each other. The upper
die 20 is brought close to the lower die 10 by a hydraulic cylinder
and the like to move to the bottom dead center. Thereby, the lower
die 10 and the upper die 20 press the workpiece W arranged
therebetween to form the workpiece W into what is called a hat
shape. At the same time, the lower die 10 and the upper die 20 keep
the forming surfaces thereof in contact with the surface of the
workpiece W to cool the workpiece W. Consequently, the workpiece W
as a product is produced.
[0020] The lower die 10 corresponds to the upper die 20. The lower
die 10 has a protrusion 11 which protrudes upward from the forming
surface (the upper surface) thereof.
[0021] The protrusion 11 protrudes upward from the forming surface
of the lower die 10. The protrusion 11 is continuously formed in
the front-rear direction in the intermediate part (the
substantially middle part), in the right-left direction, of the
forming surface of the lower die 10.
[0022] The lower die 10 has a top surface 10a extending in the
right-left direction at the uppermost part of the protrusion 11,
two lateral surfaces 10b extending downward from both the ends of
the top surface 10a in the right-left direction, and two base
surfaces 10c extending outward in the right-left direction from the
bottom ends of the lateral surfaces 10b, and these surfaces act as
what is called a hat-shaped forming surface of the lower die
10.
[0023] The lower die 10 has a cooling channel 12, a plurality of
gas-introduction paths 13, a plurality of gas-introduction paths
14, and a plurality of gas-introduction paths 15 which are provided
inside the lower die 10.
[0024] The cooling channel 12 is a channel through which a cooling
medium such as water flows, and is provided in the lower die 10 to
cool the forming surface of the lower die 10. The cooling channel
12 is configured so that the cooling medium flows into the lower
die 10 through the lower surface of the right part of the lower die
10, and then flows to the outside of the lower die 10 through the
lower surface of the left part of the lower die 10 after flowing
inside the lower die 10 in the front-rear direction and the
right-left direction (see the white-painted arrows in FIG. 1). Note
that a predetermined pump (not shown) enables the cooling medium to
flow in the lower die 10. After the cooling medium cools the
forming surface of the lower die 10 and flows to the outside of the
lower die 10, the cooling medium is cooled and flows into the lower
die 10 again. Thus, the cooling medium constantly circulates in the
lower die 10.
[0025] The gas-introduction path 13, the gas-introduction path 14
and the gas-introduction path 15 are paths through which helium gas
flows which is inert gas (hereinafter referred to as
"heat-conducting gas") with thermal conductivity extremely higher
than that of air. The gas-introduction path 13, the
gas-introduction path 14 and the gas-introduction path 15 are bored
through the lower die 10 in the top-bottom direction from the
forming surface to the lower surface of the lower die 10, and are
formed to run the vicinity of the cooling channel 12. The
gas-introduction path 13, the gas-introduction path 14 and the
gas-introduction path 15 open on the middle of the top surface 10a
in the right-left direction, on the part of the left base surface
10c in the vicinity of the left lateral surface 10b, and on the
part of the right base surface 10c in the vicinity of the right
lateral surface 10b, respectively. Note that, although not shown,
each of the plurality of gas-introduction paths 13, the plurality
of gas-introduction paths 14 and the plurality of gas-introduction
paths 15 are formed in the lower die 10 at predetermined intervals
in the front-rear direction.
[0026] As mentioned above, in the lower die 10, the plurality of
gas-introduction paths 13, the plurality of gas-introduction paths
14 and the plurality of gas-introduction paths 15 are formed on
three places in total: the middle of the top surface 10a in the
right-left direction, and the parts of the base surfaces 10c in the
vicinities of the lateral surfaces 10b.
[0027] Note that each of the openings, which open on the forming
surface of the lower die 10, of the plurality of gas-introduction
paths 13, the plurality of gas-introduction paths 14 and the
plurality of gas-introduction paths 15 formed in the lower die 10
has such an inner diameter that the openings have no negative
influence on the press working of the workpiece W (that the press
working of the workpiece W is performed similarly to a conventional
press working thereof).
[0028] The upper die 20 corresponds to the lower die 10. The upper
die 20 has a recess 21 in which the forming surface (the lower
surface) of the upper die 20 dents upward along the shape of the
protrusion 11.
[0029] The recess 21 is formed so that the forming surface of the
upper die 20 dents upward. The recess 21 is continuously formed in
the front-rear direction in the intermediate part (the
substantially middle part), in the right-left direction, of the
forming surface of the upper die 20.
[0030] The upper die 20 has a bottom surface 20a extending in the
right-left direction at the uppermost part of the recess 21, two
lateral surfaces 20b extending downward from both the ends of the
bottom surface 20a in the right-left direction, and two base
surfaces 20c extending outward in the right-left direction from the
bottom ends of the lateral surfaces 20b, and these surfaces act as
what is called a hat-shaped forming surface of the upper die
20.
[0031] The upper die 20 has a cooling channel 22, a plurality of
gas-introduction paths 23, a plurality of gas-introduction paths
24, a plurality of gas-introduction paths 25, and a plurality of
gas-introduction paths 26 which are arranged inside the upper die
20.
[0032] The cooling channel 22 is a channel through which the
cooling medium such as water flows, and is provided in the upper
die 20 to cool the forming surface of the upper die 20. The cooling
channel 22 is configured so that the cooling medium flows into the
upper die 20 through the upper surface of the right part of the
upper die 20, and then flows to the outside of the upper die 20
through the upper surface of the left part of the upper die 20
after flowing inside the upper die 20 in the front-rear direction
and the right-left direction (see the white-painted arrows in FIG.
1). Note that a predetermined pump (not shown) enables the cooling
medium to flow in the upper die 20. After the cooling medium cools
the forming surface of the upper die 20 and flows to the outside of
the upper die 20, the cooling medium is cooled and flows into the
upper die 20 again. Thus, the cooling medium constantly circulates
in the upper die 20.
[0033] The gas-introduction path 23, the gas-introduction path 24,
the gas-introduction path 25 and the gas-introduction path 26 are
paths through which the helium gas as the heat-conducting gas
flows. The gas-introduction path 23, the gas-introduction path 24,
the gas-introduction path 25 and the gas-introduction path 26 are
bored through the upper die 20 in the top-bottom direction from the
forming surface to the upper surface of the upper die 20, and are
formed to run the vicinity of the cooling channel 22. The
gas-introduction path 23, the gas-introduction path 24, the
gas-introduction path 25 and the gas-introduction path 26 open on
the part of the bottom surface 20a in the vicinity of the left
lateral surface 20b, on the part of the bottom surface 20a in the
vicinity of the right lateral surface 20b, the part of the left
base surface 20c in the vicinity of the left lateral surface 20b,
and the part of the right base surface 20c in the vicinity of the
right lateral surface 20b, respectively. Note that, although not
shown, each of the plurality of gas-introduction paths 23, the
plurality of gas-introduction paths 24, the plurality of
gas-introduction paths 25 and the plurality of gas-introduction
paths 26 are formed in the upper die 20 at predetermined intervals
in the front-rear direction.
[0034] As mentioned above, in the upper die 20, the plurality of
gas-introduction paths 23, the plurality of gas-introduction paths
24, the plurality of gas-introduction paths 25 and the plurality of
gas-introduction paths 26 are formed on four places in total: the
parts of the bottom surface 20a in the vicinities of the lateral
surfaces 20b, and the parts of the base surfaces 20c in the
vicinities of the lateral surfaces 20b.
[0035] Note that each of the openings, which open on the forming
surface of the upper die 20, of the plurality of gas-introduction
paths 23, the plurality of gas-introduction paths 24, the plurality
of gas-introduction paths 25 and the plurality of gas-introduction
paths 26 formed in the upper die 20 has such an inner diameter that
the openings have no negative influence on the press working of the
workpiece W (that the press working of the workpiece W is performed
similarly to a conventional press working thereof).
[0036] The lateral gas-feeders 30 are devices for feeding the
helium gas as the heat-conducting gas to an area between the lower
die 10 and the upper die 20 (to an area between the workpiece W and
the lower die 10, and an area between the workpiece W and the upper
die 20). The lateral gas-feeders 30 discharge the helium gas as the
heat-conducting gas stored in a predetermined container (not shown)
into the area between the lower die 10 and the upper die 20. The
lateral gas-feeders 30 are arranged to the left and the right of
the lower die 10 in the vicinities of the base surfaces 10c of the
lower die 10 so as to discharge the helium gas as the
heat-conducting gas into the space between the lower die 10 and the
upper die 20 from the outside of the lower die 10 and the upper die
20 when the upper die 20 arrives at the bottom dead center (see
FIG. 3). Note that, although not shown, each of the lateral
gas-feeders 30 has a plurality of nozzles from which the helium gas
as the heat-conducting gas discharges, and the plurality of nozzles
are arranged at predetermined intervals in the front-rear
direction.
[0037] The lower gas-feeder 40 is a device for feeding the helium
gas as the heat-conducting gas to an area between the workpiece W
and the lower die 10. Specifically, the lower gas-feeder 40 causes
the helium gas as the heat-conducting gas stored in a predetermined
container (not shown) to flow into the plurality of
gas-introduction paths 13, the plurality of gas-introduction paths
14 and the plurality of gas-introduction paths 15 formed in the
lower die 10 from the openings on the lower surface of the lower
die 10, and to spout from the openings on the forming surface of
the lower die 10.
[0038] The upper gas-feeder 50 is a device for feeding the helium
gas as the heat-conducting gas to an area between the workpiece W
and the upper die 20. Specifically, the upper gas-feeder 50 causes
the helium gas as the heat-conducting gas stored in a predetermined
container (not shown) to flow into the plurality of
gas-introduction paths 23, the plurality of gas-introduction paths
24, the plurality of gas-introduction paths 25 and the plurality of
gas-introduction paths 26 formed in the upper die 20 from the
openings on the upper surface of the upper die 20, and to spout
from the openings on the forming surface of the upper die 20.
[0039] Described below is behavior of the hot-pressing apparatus 1
configured as mentioned above during the hot-press forming of the
workpiece W.
[0040] As shown in FIG. 2, the upper die 20 moves toward the lower
die 10 to press the workpiece W. Then, before the upper die 20
arrives at the bottom dead center, the lateral gas-feeders 30 feed
the helium gas as the heat-conducting gas to the area between the
lower die 10 and the upper die 20, the lower gas-feeder 40 feeds
the helium gas as the heat-conducting gas to the area between the
workpiece W and the lower die 10, and the upper gas-feeder 50 feeds
the helium gas as the heat-conducting gas to the area between the
workpiece W and the upper die 20.
[0041] Note that black-painted arrows in FIG. 2 show directions in
which the helium gas as the heat-conducting gas discharges.
[0042] As shown in FIG. 3, until the upper die 20 arrives at the
bottom dead center, the lateral gas-feeders 30, the lower
gas-feeder 40 and the upper gas-feeder 50 continue to feed the
helium gas as the heat-conducting gas. Thus, the upper die 20 is
kept at the bottom dead center in the state where the helium gas as
the heat-conducting gas fills the area between the workpiece W and
the lower die 10, and the area between the workpiece W and the
upper die 20.
[0043] Note that timing when the lateral gas-feeders 30, the lower
gas-feeder 40 and the upper gas-feeder 50 feed the helium gas as
the heat-conducting gas is not limited as long as the helium gas as
the heat-conducting gas fills the area between the workpiece W and
the lower die 10, and the area between the workpiece W and the
upper die 20 when the upper die 20 is kept at the bottom dead
center.
[0044] Since the pressed workpiece W slightly deforms because of
spring back and the like, gaps are formed between the lower die 10
and the upper die 20.
[0045] However, when the lower die 10 and the upper die 20 cool the
workpiece W, the helium gas with thermal conductivity extremely
higher than that of air fills the area between the workpiece W and
the lower die 10, and the area between the workpiece W and the
upper die 20. This makes it possible to quench even a part of the
workpiece W separate from the forming surface of the lower die 10
or the forming surface of the upper die 20 at a sufficient cooling
rate (e.g. 30 [.degree. C./sec] and above).
[0046] Therefore, it is possible to prevent hardness of some parts
in the workpiece W from being smaller than a predetermined
value.
[0047] Moreover, it is possible to control oxidation of the lower
die 10 and the upper die 20 to a minimum because the helium gas is
inert gas difficult to undergo chemical reactions.
[0048] Hydrogen gas with thermal conductivity comparable to that of
the helium gas may be given as the heat-conducting gas according to
the present invention in addition to the helium gas. However, it is
preferable that the helium gas which is inert gas is adopted
because the hydrogen gas is easy to undergo chemical reactions.
[0049] On the other hand, nitrogen gas, argon gas and the like may
be given as inert gas. However, these gases are excluded because
each of these gases has thermal conductivity comparable to that of
air.
[0050] As mentioned previously, the plurality of gas-introduction
paths 13, the plurality of gas-introduction paths 14 and the
plurality of gas-introduction paths 15 are formed in the lower die
10, and the plurality of gas-introduction paths 23, the plurality
of gas-introduction paths 24, the plurality of gas-introduction
paths 25 and the plurality of gas-introduction paths 26 are formed
in the upper die 20.
[0051] Thus, when the helium gas as the heat-conducting gas
discharged from the lower gas-feeder 40 flows through the plurality
of gas-introduction paths 13, the plurality of gas-introduction
paths 14 and the plurality of gas-introduction paths 15, the lower
die 10 cooled by the cooling channel 12 cools the helium gas. In
addition, when the helium gas as the heat-conducting gas discharged
from the upper gas-feeder 50 flows through the plurality of
gas-introduction paths 23, the plurality of gas-introduction paths
24, the plurality of gas-introduction paths 25 and the plurality of
gas-introduction paths 26, the upper die 20 cooled by the cooling
channel 22 cools the helium gas.
[0052] Therefore, the helium gas as the heat-conducting gas can be
cooled without using a device for cooling the helium gas as the
heat-conducting gas, and the helium gas as the heat-conducting gas
can quickly remove heat of the workpiece W when the workpiece W is
quenched.
[0053] The plurality of gas-introduction paths 13, the plurality of
gas-introduction paths 14 and the plurality of gas-introduction
paths 15 are formed to run the vicinity of the cooling channel 12,
and the plurality of gas-introduction paths 23, the plurality of
gas-introduction paths 24, the plurality of gas-introduction paths
25 and the plurality of gas-introduction paths 26 are formed to run
the vicinity of the cooling channel 22.
[0054] Thus, when the helium gas as the heat-conducting gas
discharged from the lower gas-feeder 40 flows through the plurality
of gas-introduction paths 13, the plurality of gas-introduction
paths 14 and the plurality of gas-introduction paths 15, the helium
gas is cooled by the cooling channel 12. In addition, when the
helium gas as the heat-conducting gas discharged from the upper
gas-feeder 50 flows through the plurality of gas-introduction paths
23, the plurality of gas-introduction paths 24, the plurality of
gas-introduction paths 25 and the plurality of gas-introduction
paths 26, the helium gas is cooled by the cooling channel 22.
[0055] Therefore, the helium gas as the heat-conducting gas can
more quickly remove heat of the workpiece W when the workpiece W is
quenched.
[0056] It is desirable that the gas-introduction path 13, the
gas-introduction path 14 and the gas-introduction path 15 are
formed so as to have as many parts in the vicinity of the cooling
channel 12 as possible. In addition, it is desirable that the
gas-introduction path 23, the gas-introduction path 24, the
gas-introduction path 25 and the gas-introduction path 26 are
formed so as to have as many parts in the vicinity of the cooling
channel 22 as possible.
[0057] The plurality of gas-introduction paths 13, the plurality of
gas-introduction paths 14 and the plurality of gas-introduction
paths 15 are formed to open on the forming surface of the lower die
10, and the plurality of gas-introduction paths 23, the plurality
of gas-introduction paths 24, the plurality of gas-introduction
paths 25 and the plurality of gas-introduction paths 26 are formed
to open on the forming surface of the upper die 20.
[0058] Thus, the helium gas as the heat-conducting gas discharged
from the lower gas-feeder 40 can spout from the openings on the
forming surface of the lower die 10, and the helium gas as the
heat-conducting gas discharged from the upper gas-feeder 50 can
spout from the openings on the forming surface of the upper die
20.
[0059] Therefore, the helium gas as the heat-conducting gas can
efficiently be supplied to the area between the workpiece W and the
lower die 10, and the area between the workpiece W and the upper
die 20 without the helium gas diffusing to the atmosphere, compared
with the case where the helium gas is supplied from a place, for
example, situated sideward of the workpiece W.
[0060] The plurality of gas-introduction paths 13, the plurality of
gas-introduction paths 14 and the plurality of gas-introduction
paths 15 are formed on the middle of the top surface 10a in the
right-left direction, and on the parts of the base surfaces 10c in
the vicinities of the lateral surfaces 10b. In addition, the
plurality of gas-introduction paths 23, the plurality of
gas-introduction paths 24, the plurality of gas-introduction paths
25 and the plurality of gas-introduction paths 26 are formed on the
parts of the bottom surface 20a in the vicinities of the lateral
surfaces 20b, and on the parts of the base surfaces 20c in the
vicinities of the lateral surfaces 20b. In other words, as shown in
FIG. 3, the plurality of gas-introduction paths 13, the plurality
of gas-introduction paths 14 and the plurality of gas-introduction
paths 15 open on the forming surface of the lower die 10 so as to
coincide in position with the gaps between the pressed workpiece W
and the lower die 10. In addition, the plurality of
gas-introduction paths 23, the plurality of gas-introduction paths
24, the plurality of gas-introduction paths 25 and the plurality of
gas-introduction paths 26 open on the forming surface of the upper
die 20 so as to coincide in position with the gaps between the
pressed workpiece W and the upper die 20.
[0061] This makes it possible to efficiently supply the helium gas
as the heat-conducting gas to the area between the workpiece W and
the lower die 10, and the area between the workpiece W and the
upper die 20, and to fill the area between the workpiece W and the
lower die 10, and the area between the workpiece W and the upper
die 20 with the helium gas in a small mount.
[0062] Therefore, it is possible to control consumption of the
helium gas as the heat-conducting gas to a minimum, and to reduce
costs.
[0063] Note that positions of the gaps between the workpiece W and
the lower die 10, and the gaps between the workpiece W and the
upper die 20 can be grasped in advance because deformation
characteristics of the pressed workpiece W can be acquired through
experiment and the like.
[0064] In the present embodiment, each of the lower die 10 and the
upper die 20 is provided with a cooling channel and a plurality of
gas-introduction paths, but one of the lower die 10 and the upper
die 20 may be provided with the cooling channel and the plurality
of gas-introduction paths.
[0065] Moreover, in the present embodiment, the lower die 10 and
the upper die 20 have shapes to form the workpiece W into the hat
shape, but the shapes thereof are not limited thereto. The present
invention may be applied to a hot-pressing apparatus including a
lower die and an upper die with other shapes.
[0066] In the present embodiment, a gas-feeder according to the
present invention consists of the lateral gas-feeders 30, the lower
gas-feeder 40 and the upper gas-feeder 50, but these may be
configured as one gas-feeder.
INDUSTRIAL APPLICABILITY
[0067] The present invention is applied to a hot-pressing apparatus
which presses and cools a heated workpiece at the same time.
REFERENCE SIGNS LIST
[0068] 1: hot-pressing apparatus [0069] 10: lower die [0070] 12:
cooling channel [0071] 13, 14, 15: gas-introduction path [0072] 20:
upper die [0073] 22: cooling channel [0074] 23, 24, 25, 26:
gas-introduction path [0075] 30: lateral gas-feeder [0076] 40:
lower gas-feeder [0077] 50: upper gas-feeder
* * * * *