Mold apparatus and method for hot press forming

Abstract

To enable a press forming section to be provided with high precision at a portion of a plate-shaped workpiece material composed of thermoplastic synthetic resin and the like.SOLUTION: A hot press forming mold apparatus 1 comprises first and second dies 2, 3 for performing hot press forming on a workpiece 110 mounted on a press brake 101, positioned relatively to each other, and stacked to form a plate-like shape. A workpiece mounting section 5, where the workpiece is mounted, is provided on the side of the first die facing the overlapping surface with the second die. A press forming section 8, which forms a press-formed portion on the workpiece mounted in the workpiece mounting section, is provided between the first die and the second die. Furthermore, a sheath heater 106 and a temperature controller 107 are provided to control and heat the heating temperature of the workpiece supported between the superimposed first and second dies.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a die apparatus and a method for hot press molding that are useful for hot press molding of plate-shaped workpieces, particularly plate-shaped workpieces made of thermoplastic synthetic resins. [Background technology]

[0002] BACKGROUND ART Hot press molding has been used as a method for obtaining molded articles by imparting a predetermined shape to synthetic resin sheets or other synthetic resin plate-like members (Patent Document 1).

[0003] Also, a method has been proposed in which a synthetic resin material such as carbon fiber reinforced plastic (CFRP) is subjected to press working to obtain a flat plate-shaped molded product (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-154409 [Patent Document 2] Japanese Patent Publication No. 2022-104168 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally proposed hot press molding methods and the devices used for these molding methods transfer the shape of a molding die onto the entire plate-like workpiece, or flatten the entire workpiece, making it difficult to impart a predetermined shape to a portion of the workpiece.

[0006] Therefore, the technical object of the present invention is to provide a mold device for hot press molding and a hot press molding method that make it possible to provide a press-molded portion in a part of a plate-shaped workpiece made of thermoplastic synthetic resin.

[0007] Another technical object of the present invention is to provide a mold device for hot press molding and a hot press molding method that enable a press-molded portion to be formed with high precision in a part of a plate-shaped workpiece made of a thermoplastic synthetic resin or the like.

[0008] Furthermore, a technical object of the present invention is to provide a mold device for hot press molding and a hot press molding method that enable press-molded portions of various shapes to be formed in a portion of a plate-shaped workpiece made of a thermoplastic synthetic resin or the like.

[0009] Furthermore, the technical problems of the present invention will become more apparent from the embodiments described below with reference to the drawings. [Means for solving the problem]

[0010] The present invention, proposed to solve the technical problems described above, is a mold device for hot press molding, comprising first and second molds that are attached to a press device and positioned and stacked on each other to perform hot press molding on a plate-shaped workpiece, wherein a workpiece mounting section on which the workpiece is mounted is provided on the side of the first mold where it mates with the second mold, and a press molding means is provided between the first mold and the second mold for forming a press-molded section in the workpiece mounted on the workpiece mounting section, and further a heating temperature control means is provided for controlling the heating temperature of the workpiece supported between the first mold and the second mold which are stacked on each other.

[0011] The press molding means is composed of a press die provided on one of the first and second dies, and a press die receiving portion for supporting the press die provided on the other of the first and second dies.

[0012] The press molding means is composed of a press die provided on one of the first and second dies, and a press die receiving portion provided on the other of the first and second dies into which the press die fits.

[0013] In the present invention, it is desirable that the workpiece mounting portion be provided with a burr absorbing portion that absorbs burrs that occur on the workpiece that has been heat-press molded between the first and second dies.

[0014] The heating temperature control means heats the first die and heats the workpiece supported between the first die and the second die.

[0015] The first mold is also composed of a formwork that forms a workpiece mounting portion onto which the workpiece is mounted, and a bottom plate that is superimposed on one side of the formwork, forms the bottom of the workpiece mounting portion, and has a stamping die receiving portion that supports the workpiece to be hot-pressed by a stamping die provided in the second mold.

[0016] Furthermore, the present invention provides a hot press molding method for hot press molding a plate-shaped workpiece using a mold device that is attached to a press device and has a first mold and a second mold that are positioned and overlapped with each other, and that also has a heating means, wherein the plate-shaped workpiece is attached to a workpiece attachment portion provided on the side of the first mold where it will be overlapped with the second mold, and then the second mold is overlapped on the first mold, and then the workpiece attached to the workpiece attachment portion is heated together with the first and second molds by the heating means, and while the workpiece is heated, the second mold is pressed against the first mold, and the workpiece is hot press molded by a press molding means provided between the first mold and the second mold to form a press-molded portion.

[0017] In the present invention, the workpiece to be hot-press molded is made of a thermoplastic synthetic resin, and is characterized by being heated to a temperature below the melting point and above the glass transition point, and then hot-press molded.

[0018] The press molding means used in the present invention has a press mold provided on one of the first and second dies, and a press mold receiving portion for supporting the press mold provided on the other of the first and second dies, and is characterized in that the press mold and the press mold receiving portion pressurize and compress a portion of the heated workpiece to form a press-molded portion in the workpiece.

[0019] The press molding means comprises a press die provided on one of the first and second dies and a press die receiving portion into which the press die is fitted, provided on the other of the first and second dies, and is characterized in that the press die is fitted into the press die receiving portion and a press-molded portion onto which the molding protrusion is transferred is molded into the heated workpiece. [Effects of the Invention]

[0020] The present invention makes it possible to form a press-formed portion with high precision in a part of a plate-shaped workpiece by hot press molding, and further makes it possible to provide press-formed portions of various shapes. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a side view showing a schematic configuration of a press brake equipped with a die device according to an embodiment of the present invention. [Figure 2] 1 is an exploded perspective view showing a mold device according to an embodiment of the present invention. [Figure 3] 1 is a plan view showing a first mold that constitutes a mold device according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Figure 5] FIG. 3 is a plan view showing a second mold that constitutes a mold device according to the present embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 2 is a cross-sectional view showing a state in which the first mold and the second mold are superimposed. [Figure 8]1 is a cross-sectional view of a die assembly showing a state in which a part of a workpiece is compressed and plastically deformed. FIG. [Figure 9] FIG. 2 is a perspective view showing a workpiece that has been hot-press molded and has a press-molded portion formed thereon. [Figure 10] FIG. 10 is an exploded perspective view showing a mold device according to another embodiment of the present invention. [Figure 11] FIG. 10 is a plan view showing a first mold of a mold device according to another embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 10 is a cross-sectional view showing a second mold of a mold device according to another embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing a state in which a first mold and a second mold of a mold device according to another embodiment are superimposed. [Figure 15] FIG. 10 is a cross-sectional view showing a state in which a workpiece is press-formed by a die device according to another embodiment. [Figure 16] FIG. 10 is a perspective view showing another example of a workpiece that has been hot-press molded to form a press-molded portion. [Figure 17] FIG. 10 is a perspective view showing a mold apparatus according to still another embodiment of the present invention. [Figure 18] 18 is a perspective view showing a first mold that constitutes the mold device shown in FIG. 17. FIG. [Figure 19] 18 is a cross-sectional view showing a state in which the first mold and the second mold of the mold device shown in FIG. 17 are superimposed. FIG. [Figure 20] 18 is a cross-sectional view showing a state in which a workpiece is subjected to hot press molding by the mold device shown in FIG. 17. FIG. [Figure 21] 18 is a perspective view showing a workpiece on which a press-formed portion is formed by the die device shown in FIG. 17. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The mold device according to this embodiment includes a first mold and a second mold that are positioned and superimposed on each other to perform hot press molding on a plate-shaped workpiece.

[0023] As shown in FIG. 1, a first die 2 and a second die 3 constituting a die apparatus 1 according to this embodiment are mounted on a press brake 101 as a press apparatus when used.

[0024] A press brake 101 to which the die device 1 according to this embodiment is attached includes an apparatus frame 102 constituting the apparatus main body, with a fixed table 103 fixedly disposed below the apparatus frame 102 and a movable table 104 disposed above the apparatus frame 102 so as to face the fixed table 103. The movable table 104 is connected to a hydraulic cylinder 105 disposed in the apparatus frame 102, and is moved vertically toward and away from the fixed table 103 by driving the hydraulic cylinder 105.

[0025] In this embodiment, a first mold 2 is mounted on a fixed table 103, and a second mold 3 is mounted on the movable table 104 on the surface thereof facing the fixed table 103. The second mold 3 moves toward and away from the first mold 2 mounted on the fixed table 103 as the movable table 104 moves. The second mold 3 operates together with the movable table 104 and is placed near and overlapped with the first mold 2, thereby subjecting a flat, plate-like workpiece 110 made of thermoplastic synthetic resin and supported by the first mold 2 to hot press molding.

[0026] The workpiece 110 to be press-molded by the mold apparatus 1 according to this embodiment is a thin plate-like member made of polycarbonate resin, which is a thermoplastic resin. This workpiece 110 is formed into a rectangular frame by cutting out the center of a rectangular thin plate-like member. In this embodiment, one side 111 of this rectangular frame-like workpiece 110 is heat-press molded.

[0027] In this embodiment, the fixed table 103 on which the first mold 2 is mounted is provided with a heating means for heating the workpiece 110 to be hot-molded. A sheathed heater 106 is used as the heating means. The sheathed heater 106 is mounted on the fixed table 103. The sheathed heater 106 heats the first mold 2 mounted on the fixed table 103. By heating the first mold 2, the workpiece 110 supported by the first mold 2 and the second mold 3 placed on top of the first mold 2 are heated.

[0028] A temperature controller 107 is connected to the sheathed heater 106, and the heating temperature is controlled. A temperature sensor 108 is provided on the first mold 2 to detect the temperature of the workpiece 110 supported by this first mold 2. The sheathed heater 106 is controlled to a predetermined heating temperature by the temperature controller 107, which is controlled by the detection output of the temperature sensor 108. The workpiece 110 is heated to a predetermined heating temperature between the glass transition point and the melting point, at which plasticity is imparted, by the sheathed heater 106, whose heating temperature is controlled to a predetermined temperature.

[0029] The sheathed heater 106 for heating the workpiece 110 may be attached to the first mold 2. As the heating means, a sheet-shaped heater may be used instead of the sheathed heater 106. The sheet-shaped heater may be bonded to the outer peripheral surface of the second mold 2.

[0030] The first mold 2 constituting the mold apparatus 1 according to this embodiment is formed in a flat plate shape using a stainless steel plate, as shown in FIGS. 2 and 3 . In this embodiment, the first mold 2 is formed in a rectangular shape, as shown in FIG. 3 . A concave workpiece mounting portion 5 is formed in the center of the first mold 2 on the side where it mates with the second mold 3, as shown in FIGS. 3 and 4 . The workpiece mounting portion 5 is formed in a concave shape with a size approximately equal to the outer shape of the workpiece 110 so as to support the workpiece 110 and prevent it from shifting position during press forming. In this embodiment, the flat bottom of the workpiece mounting portion 5 serves as a first press support portion 6 when hot press forming the thin workpiece 110.

[0031] The second die 3, which is positioned and superimposed on the first die 2, is formed in a flat plate shape using a stainless steel plate, similar to the first die 2, as shown in Fig. 2. In this embodiment, the second die 3 is formed in the same rectangular shape as the first die 2, as shown in Fig. 5. The superimposing surface 3a of the second die 3, which faces the first die 2, serves as a second press support portion 7 that supports the workpiece 110 placed on the workpiece support portion 5 together with the first press support surface 6 formed on the first die 2.

[0032] In the mold device 1 according to this embodiment, a press molding section 8 is formed between the first mold 2 and the second mold 3, which performs thermal press molding on a portion of the workpiece 110 supported under pressure between the first press support section 6 and the second press support section 7, as described below.

[0033] In this embodiment, as shown in FIG. 2, the press-forming section 8 is composed of a plurality of press dies 9, 9 provided in the second mold 3 and press-die support parts 10, 10 configured in the first mold 2. In this embodiment, the press dies 9, 9 configuring the press-forming section 8 are formed to protrude from the second press support part 7 formed as a flat surface on the second mold 3, as shown in FIGS. 2 and 5. These press dies 9, 9 are formed in a shape corresponding to the press-formed part to be formed in a part of the workpiece 110. The press-die support parts 10, 10 are support surfaces that support the press dies 9, 9 when the second mold 3 is superimposed on the first mold 2 to hot-press-form the press-formed part on the workpiece 110, and are configured by a partial area of ​​the first press support part 6 formed as a flat surface.

[0034] In this embodiment, a positioning mechanism 11 constituting a positioning means for determining the overlapping position of the first mold 2 and the second mold 3 when hot press molding a press-molded portion on the workpiece 110 is provided between the first mold 2 and the second mold 3. This positioning mechanism 11 is composed of positioning pins 12 erected in each corner of the first mold 2, and positioning holes 13 formed as through-holes in each corner of the second mold 3.

[0035] In this embodiment, the workpiece support portion 5 is provided with concave burr absorbing portions 14 that absorb burrs that occur on the workpiece 110 that has been hot-press molded between the first and second molds 2 and 3. As shown in Fig. 3, the burr absorbing portions 14 are located on opposing sides in the long side direction of the workpiece support portion 5, and are formed by cutting out the surface of the first mold 2 on which the workpiece support portion 5 is formed.

[0036] Next, a process of performing hot press molding on a plate-shaped workpiece 110 made of a thermoplastic synthetic resin using the mold device 1 having the above-described configuration will be described.

[0037] In this embodiment, to perform hot press molding on the workpiece 110 described above, the first die 2 is attached to the fixed table 103 of the press brake 101, and the second die 3 is attached to the movable table 104.

[0038] 3, a workpiece 110 formed in a rectangular frame shape is placed in the workpiece mounting portion 5 of the first mold 2 mounted on the fixed table 103. In this embodiment, the workpiece 110 has a thickness D2 that is greater than the depth D1 of the workpiece support portion 5, as shown in FIG.

[0039] With the workpiece 110 placed on the first die 2, the movable table 104 is driven to move the second die 3 toward the first die 2 and place it on top of the first die 2 as shown in FIG. 7. At this time, the positioning holes 13 engage with the positioning pins 12, and the overlapping positions of the first and second dies 2 and 3 are determined. When the first and second dies 2 and 3 are positioned and placed one on top of the other, the workpiece 110 placed on the workpiece mounting section 5 is supported in a pressurized state between the first press support section 6 and the second press support section 7.

[0040] The workpiece 110 is supported between the first mold 2 and the second mold 3, and is heated together with the first and second molds 2 and 3 by energizing the sheathed heater 106 to generate heat. At this time, the workpiece 110, which is made of a thermoplastic resin, is heated to a predetermined temperature above the glass transition point and below the melting point at which plasticity is imparted. At this time, the heat generation temperature of the sheathed heater 106 is controlled by a temperature controller 107, and the workpiece 110 is heated to the predetermined temperature. Furthermore, the heat generation temperature of the sheathed heater 106 is controlled by the temperature controller 107 based on the detection output of a temperature sensor 108 provided in the first mold 2 that detects the temperature of the workpiece 110, and the sheathed heater 106 maintains the state in which the workpiece 110 is heated to the predetermined temperature.

[0041] A workpiece 110 is held between the first and second molds 2 and 3 and heated to a temperature at which thermoplasticity is imparted. The movable table 104 is then driven to press the second mold 3 against the first mold 2. With the second mold 3 pressed against the first mold 2, the workpiece 110 supported between the first press support 6 and the second press support 7 is press-formed by the press-forming unit 8. That is, when the second mold 3 is pressed against the first mold 2, the press dies 9 constituting the press-forming unit 8 compress and plastically deform a portion of the workpiece 110 against the press-die support dies 10, as shown in FIG. 8 . This hot press forming results in a press-formed portion 112, to which the shape of the forming protrusions 9 has been transferred, being formed in a portion of the workpiece 110.

[0042] In this embodiment, when the workpiece 110 is press-formed and plastically deformed, burrs 113 may be generated. These burrs 113 are absorbed by the burr absorbing portion 14 provided in the workpiece mounting portion 5.

[0043] After press-forming the workpiece 110, the heating of the sheath heater 106 is stopped, the first and second dies 2, 3 are allowed to radiate heat, and the workpiece 110 is cooled to a temperature below the glass transition point. Next, the hydraulic cylinder 105 is driven to perform die opening, which separates the second die 3 attached to the movable table 104 from the first die 2. Once die opening is complete, the workpiece 110 is removed from the first die 2. This removal completes the press-forming of the workpiece 110.

[0044] After the press forming is performed and the workpiece 110 is removed from the die device 1, any burrs 113 generated on the workpiece 110 are appropriately cut off and removed.

[0045] By using the mold apparatus 1 according to this embodiment, it is possible to form a press-molded portion 112 with high precision on one side 111 of a workpiece 110 formed by cutting out a thin sheet-like plate made of thermoplastic synthetic resin into a rectangular frame shape, as shown in Fig. 9. In particular, it is possible to provide the press-molded portion 112 on a part of the workpiece 110 while maintaining the flat plate-like state of the workpiece 110.

[0046] Next, a description will be given of a mold apparatus 21 according to another embodiment of the present invention. This mold apparatus 21 makes it possible to form a press-molded portion in a part of a workpiece 210 made of a flat plate-like thermoplastic synthetic resin, the press-molded portion having a larger deformation amount than the press-molded portion 112 molded by the mold apparatus 1 according to the above-described embodiment.

[0047] Like the die device 1, the die device 21 according to this embodiment is also mounted on a press brake 101 as a press device shown in FIG. 1 when used.

[0048] The mold device 21 of this embodiment, like the mold device 1 described above, is equipped with a first mold 22 and a second mold 23 that perform thermal press molding on a workpiece 210 that is positioned and stacked on top of each other to form a plate-like shape.

[0049] As shown in FIG. 10 , the first die 22 mounted on the fixed table 103 of the press brake 101 is formed from a stainless steel plate in the shape of a flat rectangular plate. A concave workpiece mounting portion 25 is formed in the center of the first die 22 on the side where it mates with the second die 23, as shown in FIGS. 10 and 11 . The workpiece mounting portion 25 is formed in a concave shape with a size substantially equal to the outer shape of the workpiece 210 so as to support the workpiece 210 and prevent it from shifting during press forming. In this embodiment, the flat bottom of the workpiece support portion 25 serves as a first press support portion 26 when hot press forming the thin workpiece 210.

[0050] The second die 23 attached to the movable table 104 of the press brake 101 is formed in the same flat plate shape using a stainless steel plate as the first die 22, as shown in Fig. 10. In this embodiment, the second die 23 is formed in the same rectangular shape as the first die 22, as shown in Fig. 10. The mating surface of the second die 23 facing the first die 22 is a second press support part 27 that supports the workpiece 210 placed on the workpiece support part 25 together with a first press support surface 26 formed on the first die 22.

[0051] In the mold device 21 according to this embodiment, press molding sections 28, 28 are formed between the first mold 22 and the second mold 23, which perform thermal press molding on a portion of the workpiece 210 supported under pressure between the first press support section 26 and the second press support section 27, as described below.

[0052] In this embodiment, the press molding sections 28, 28 are composed of a plurality of press dies 29, 29 provided in the second mold 23 and press die receiving sections 30, 30 into which the press dies 29, 29 formed in the first mold 22 fit, as shown in Figure 10.

[0053] In this embodiment, as shown in Figures 10 and 13, the press dies 29, 29 are formed to protrude from the second press support portion 27, which is formed as a flat surface on the second die 23. These press dies 29, 29 are formed in a shape corresponding to the press-formed portion to be formed in a part of the workpiece 210. Then, press die receiving portions 30, 30 which constitute the press-formed portion 28, 28 together with the press dies 29, 29, are formed in the bottom of the workpiece mounting portion 25 formed in the first die 21, as shown in Figures 10 and 11. These press die receiving portions 30, 30 are formed as fitting holes into which the press dies 29, 29 fit, as shown in Figure 12.

[0054] In this embodiment, similarly to the previous embodiment, a positioning mechanism 31 constituting a positioning means for determining the overlapping position when hot-pressing a press-molded portion on the workpiece 210 is provided between the first mold 22 and the second mold 23. This positioning mechanism 31 is composed of positioning pins 32 erected in each corner of the first mold 22, and positioning holes 33 formed as through-holes in each corner of the second mold 23.

[0055] In this embodiment, the workpiece support portion 25 is provided with concave burr absorbing portions 34 that absorb burrs that occur on the workpiece 210 that has been hot-press molded between the first and second molds 22, 23. As shown in Figures 10 and 11, the burr absorbing portions 34 are located on opposing sides in the long side direction of the workpiece mounting portion 25, and are formed by cutting out the surface of the first mold 32 on which the workpiece support portion 25 is formed.

[0056] Next, a process of hot press molding a plate-shaped workpiece 210 made of a thermoplastic synthetic resin using the mold device 21 having the above-described configuration will be described.

[0057] In this embodiment, to perform thermal press molding on the workpiece 210, the first mold 22 is attached to the fixed table 103 of the press brake 101, and the second mold 23 is attached to the movable table 104, as in the previously described embodiment.

[0058] 10 and 11, a workpiece 210 formed in the shape of a rectangular plate is placed on the workpiece mounting portion 25 of the first mold 22 mounted on the fixed table 103. In this embodiment, the workpiece 210 has a thickness D4 that is slightly larger than the depth D3 of the workpiece support portion 25, as shown in FIG.

[0059] With the workpiece 210 placed on the first die 22, the movable table 104 is driven to move the second die 23 toward the first die 22 and place it on the first die 22 as shown in Fig. 14. At this time, the positioning holes 33 engage with the positioning pins 32, and the overlapping positions of the first and second dies 22, 23 are determined. When the first and second dies 22, 23 are positioned and placed on top of each other, the workpiece 210 placed on the workpiece support part 25 is supported in a pressurized state between the first press support part 26 and the second press support part 27.

[0060] The workpiece 210 is supported between the first mold 22 and the second mold 23, and is heated together with the first and second molds 22, 23 by energizing the sheathed heater 106 to generate heat. The workpiece 210, made of a thermoplastic resin, is heated to a predetermined temperature above the glass transition point and below the melting point at which plasticity is imparted. At this time, the temperature of the sheathed heater 106 is controlled by the temperature controller 107, and the workpiece 210 is heated to the predetermined temperature. The temperature of the sheathed heater 106 is controlled by the temperature controller 105, which is controlled by the detection output of a temperature sensor 108 provided in the first mold 2 that detects the temperature of the workpiece 110, and the workpiece 210 is maintained in a state where it is heated to the predetermined temperature.

[0061] The workpiece 210 is held between the first and second dies 22, 23 and heated to a temperature at which thermoplasticity is imparted, and then the movable table 104 is driven to press the second die 23 against the first die 22. When the second die 23 is pressed against the first die 22, the press dies 29, 29 press a portion of the workpiece 210 into the press die receiving portions 30, 30. The workpiece 210 is plastically deformed by being pressed into the press die receiving portions 30, 30 by the press dies 29, 29, and a press-molded portion 212 having a convex shape following the press-molding protrusions 29, 29 is formed, as shown in Figures 15 and 16 .

[0062] In this embodiment, burrs may be generated when the workpiece 210 is press-formed and plastically deformed. These burrs are absorbed by the burr absorbing portion 24 provided in the workpiece mounting portion 25.

[0063] After the workpiece 210 has been press-molded, the heating of the sheath heater 106 is stopped, the first and second dies 22, 23 are allowed to radiate heat, and the workpiece 210 is cooled to a temperature below the glass transition point. Next, the hydraulic cylinder 105 is driven to perform die opening, in which the second die 23 attached to the movable table 104 is separated from the first die 22. Once die opening has been completed, the workpiece 210 is removed from the first die 22. This removal completes the hot press molding of the workpiece 110.

[0064] After the workpiece 110 has been subjected to the heat press molding and removed from the mold device 21, any burrs that may have formed on the workpiece 110 are appropriately cut off and removed.

[0065] By using the mold device 21 according to this embodiment, a concave press-molded portion 212 can be formed in a thin plate-like workpiece 210 made of thermoplastic synthetic resin, as shown in Figures 15 and 16. In particular, the concave press-molded portion 212 can be provided in a part of the flat plate-like workpiece 210 while maintaining the flat plate-like state of the workpiece 210.

[0066] Further, a further embodiment of the present invention will be described, which makes it possible to form a press-molded portion with high precision in a part of a plate-like workpiece to which thermoplasticity is imparted.

[0067] Like the die assemblies 1 and 21, the die assembly 41 according to this embodiment is also mounted on a press brake 101 serving as a press apparatus shown in FIG.

[0068] The mold device 41 of this embodiment, like the mold devices 1 and 21 described above, is equipped with a first mold 42 and a second mold 43 that perform thermal press molding on a workpiece 310 that is positioned and stacked on top of each other to form a plate-like shape.

[0069] As shown in FIG. 17, the first mold 42 mounted on the fixed table 103 of the press brake 101 comprises a rectangular formwork 44 and a rectangular bottom plate 45 that is superimposed on one side of the formwork 44. Here, as shown in FIG. 18, the formwork 44 is integrated by engaging positioning pins 47 embedded in each corner of the bottom plate 45 with positioning holes 48 formed in each corner. The area surrounded by the formwork 44, one side of which is closed by the bottom plate 45, serves as a workpiece mounting section 46. This workpiece mounting section 46 is formed to have a size substantially equal to the outer shape of the workpiece 310 so that it can support the workpiece 310 and prevent it from shifting during press forming. In this embodiment, the bottom of the workpiece mounting section 46, closed by the bottom plate 45, serves as a first press support section 50 when hot press forming the thin workpiece 310.

[0070] On the other hand, the second die 43 attached to the movable table 104 of the press brake 101 is formed into a flat plate shape using a stainless steel plate, as shown in Fig. 17. In this embodiment, the second die 43 is formed into the same rectangular shape as the first die 42, as shown in Fig. 17. The mating surface of the second die 43 facing the first die 42 is a second press support part 51 that supports the workpiece 310 placed in the workpiece attachment part 46 together with the first press support part 50 formed on the first die 42.

[0071] In the mold device 41 according to this embodiment, a press molding section 52 is formed between the first mold 42 and the second mold 43, which performs thermal press molding on a portion of the workpiece 310 supported under pressure between the first press support section 50 and the second press support section 51, as described below.

[0072] In this embodiment, as shown in FIGS. 17, 19, and 20, the press-molding section 52 is composed of a press die 53 provided in the second mold 43 and a press die receiving portion 54 configured in the first mold 42. In this embodiment, the press die 53 configuring the press-molding section 52 is formed to protrude from a second press support portion 51 formed as a flat surface on the second mold 43, as shown in FIG. 17. The press die 53 is formed in a shape corresponding to the press-molded portion to be formed in a part of the workpiece 310. In this embodiment, the press die 53 is formed in a rectangular convex shape, but may be formed in any other appropriate shape, such as a cylindrical shape or a polygonal shape. In addition, in this embodiment, the press die 53 is formed at a position where the hot-press-molded portion will be formed in the workpiece 310 attached to the workpiece attachment portion 49.

[0073] The press die receiving portion 54 is a support surface that supports the press die 53 when the second die 43 is superimposed on the first die 42 and the press-molded portion is hot-press molded into the workpiece 310, and is composed of a partial area of ​​the first press support portion 50 formed as a flat surface.

[0074] In this embodiment, a positioning mechanism 59 constituting a positioning means for determining the overlapping positions of the first mold 42 and the second mold 43 when hot-press-forming a press-molded portion into the workpiece 310 is provided between the first mold 42 and the second mold 43. The positioning mechanism 59 is composed of positioning pins 47 planted in each corner of the bottom plate 45 constituting the first mold 42, and positioning holes 56 formed as through-holes in each corner of the second mold 43. The positioning pins 47 pass through positioning holes 48 formed in the mold frame 44 and engage with the positioning holes 56 in the second mold 43, thereby integrating the first mold 42 and the second mold 43.

[0075] In this embodiment, the workpiece mounting portion 46 is provided with a plurality of recessed burr absorbing portions 57 that absorb burrs that occur on the workpiece 310 that has been hot-press molded between the first and second molds 42, 43. As shown in Fig. 17, these burr absorbing portions 57 are formed on each of the opposing inner peripheral sides of the formwork 44 that constitutes the workpiece mounting portion 46. These burr absorbing portions 57 are formed by cutting out part of the inner peripheral surface of the formwork 44.

[0076] Next, a process of hot press molding a plate-shaped workpiece 310 made of a thermoplastic synthetic resin using the mold device 41 having the above-described configuration will be described.

[0077] In this embodiment, to perform thermal press molding on the workpiece 310, the first mold 42 is attached to the fixed table 103 of the press brake 101, and the second mold 43 is attached to the movable table 104, as in the previously described embodiment.

[0078] 18, a workpiece 310 formed in the shape of a rectangular plate is placed in the workpiece mounting portion 46 of the first mold 42 mounted on the fixed table 103. In this embodiment, the workpiece 310 has a thickness D6 that is slightly larger than the depth D5 of the mold frame 44 that constitutes the workpiece mounting portion 46, as shown in FIG.

[0079] Next, with the workpiece 310 placed in the first die 42, the movable table 104 is driven to move the second die 43 toward the first die 42 and place it on top of the first die 42, as shown in Figure 19. At this time, the positioning holes 56 of the second die 43 engage with the positioning pins 47, and the overlapping positions of the first and second dies 42, 43 are determined. When the first and second dies 42, 43 are positioned and overlapped, the workpiece 310 placed on the workpiece mounting section 46 is supported in a pressurized state between the first press support part 50 and the second press support part 51.

[0080] The workpiece 310 is supported between the first mold 42 and the second mold 43, and is heated together with the first and second molds 42, 43 by energizing the sheathed heater 106 to generate heat. The workpiece 310, made of a thermoplastic resin, is heated to a predetermined temperature above the glass transition point and below the melting point at which plasticity is imparted. At this time, the temperature of the sheathed heater 106 is controlled by the temperature controller 107, and the workpiece 310 is heated to the predetermined temperature. The temperature of the sheathed heater 106 is controlled by the temperature controller 107 based on the detection output of a temperature sensor 108 provided in the first mold 2 that detects the temperature of the workpiece 310, and the sheathed heater 106 maintains its heated state at the predetermined temperature.

[0081] The workpiece 310 is held between the first and second dies 42, 43 and heated to a temperature at which thermoplasticity is imparted, and then the movable table 104 is driven to press the second die 43 against the first die 42. When the second die 43 is pressed against the first die 42, the press die 53 presses a portion of the workpiece 310 against the press die receiving portion 54. The workpiece 310 is compressed and plastically deformed by being pressed against the press die receiving portion 54 by the press die 53, and a press-molded portion 312 having a convex shape conforming to the press-molding protrusion 53 is formed, as shown in FIG. 20 .

[0082] In this embodiment, when the workpiece 310 is press-formed and plastically deformed, burrs may occur on the periphery of the workpiece 310. These burrs are absorbed by the burr absorbing portion 57 provided in the workpiece mounting portion 46.

[0083] After the workpiece 310 has been press-molded, the heating of the sheathed heater 106 is stopped, the first and second dies 42, 43 are allowed to radiate heat, and the workpiece 310 is cooled to a temperature below the glass transition point. Next, the hydraulic cylinder 105 is driven to perform die opening, in which the second die 43 attached to the movable table 104 is separated from the first die 42. Once die opening has been completed, the workpiece 310 is removed from the first die 42. This removal marks the end of the hot press molding of the workpiece 310.

[0084] After the workpiece 310 has been subjected to the heat press molding and removed from the mold device 41, any burrs that may have formed on the workpiece 310 are appropriately cut off and removed.

[0085] By using the mold device 41 according to this embodiment, it is possible to form a convex press-formed portion 312 on the inner periphery of a thin plate-like workpiece 310 made of thermoplastic synthetic resin, as shown in Fig. 21. In particular, it is possible to provide the convex press-formed portion 312 on part of the inner periphery of the plate-like workpiece 310 while maintaining the flat plate-like state of the workpiece 310.

[0086] In the above-described embodiment, an example has been given in which hot press molding is performed on a workpiece made of a thermoplastic synthetic resin. However, by forming the first and second molds from stainless steel plate, the present invention can also be used for press molding of a thin plate workpiece made of aluminum, magnesium, copper, lead, tin, or other alloys that can be thermally deformed at low temperatures of 600°C or less. [Explanation of symbols]

[0087] 1 die device, 2 first die, 3 second die, 5 workpiece mounting section, 6 first press support section, 7 second press support section, 8 press forming section, 9 press die, 10 press die support section, 11 positioning mechanism, 14 burr storage section, 101 press brake, 103 fixed table, 104 movable table, 106 sheath heater, 107 temperature controller, 108 temperature sensor, 110 workpiece

Claims

1. A die device for hot press molding, comprising first and second dies that are attached to a press device and that perform hot press molding on a plate-shaped workpiece that is positioned and stacked on top of each other, a workpiece mounting portion on which the workpiece is mounted is provided on a mating surface side of the first mold with the second mold; a press-forming means for forming a press-formed portion on a workpiece attached to the workpiece attachment portion is provided between the first die and the second die; Furthermore, a heating temperature control means is provided for controlling and heating the heating temperature of the workpiece supported between the first die and the second die which are superposed on each other. A mold device for hot press molding characterized by the above.

2. 2. A mold device for hot press molding according to claim 1, characterized in that the press molding means comprises a press die provided on one of the first and second molds, and a press die receiving portion for supporting the press die provided on the other of the first and second molds.

3. 2. A mold device for hot press molding according to claim 1, characterized in that the press molding means comprises a press die provided on one of the first and second molds and a press die receiving portion provided on the other of the first and second molds into which the press die fits.

4. 2. A mold device for hot press molding according to claim 1, characterized in that the workpiece mounting portion is provided with a burr absorption portion that absorbs burrs that occur on the workpiece that has been hot press molded between the first and second molds.

5. The mold device for hot press molding according to any one of claims 1 to 4, characterized in that the heating temperature control means heats the first mold and heats the workpiece supported between the first mold and the second mold.

6. 2. A mold device for heat pressing according to claim 1, characterized in that the first mold comprises a mold frame constituting a workpiece mounting portion on which the workpiece is mounted, and a bottom plate having a pressing die disposed on one side of the mold frame, constituting the bottom of the workpiece mounting portion, and supporting the workpiece to be heat pressed by a pressing die provided in the second mold.

7. A hot press molding method for hot press molding a plate-shaped workpiece using a mold device that is attached to a press device and includes a first mold and a second mold that are positioned and superimposed on each other, and also includes a heating means, the method comprising: A plate-shaped workpiece is attached to a workpiece attachment portion provided on a mating surface side of the first mold with the second mold; Then, the second mold is placed on the first mold, Thereafter, the workpiece mounted on the workpiece mounting portion is heated together with the first and second dies by the heating means; While the workpiece is heated, the second mold is pressed against the first mold, and the workpiece is subjected to hot press molding by a press molding means provided between the first mold and the second mold to form a press-molded portion. A hot press molding method characterized by the above.

8. 8. The hot press molding method according to claim 7, wherein the workpiece is made of a thermoplastic synthetic resin and is heated to a temperature below its melting point and above its glass transition point.

9. the press molding means has a pressing die provided in one of the first and second dies, and a pressing die receiving portion for supporting the pressing die provided in the other of the first and second dies, 9. The hot press molding method according to claim 7, wherein a portion of the heated workpiece is compressed by the press die and the press die support, thereby forming a press-molded portion in the workpiece.

10. the press molding means comprises a press die provided in one of the first and second dies, and a press die receiving portion provided in the other of the first and second dies, into which the press die is fitted; 9. The hot press molding method according to claim 7, wherein the press die is fitted into the press die receiving portion, and a press-molded portion onto which the press die is transferred is molded into the heated workpiece.

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