Press forming apparatus and method for manufacturing press-formed articles

Abstract

To provide a press molding apparatus, etc., capable of, in press molding of fiber-reinforced composite material, shortening a heating and cooling cycle and fabricating a high-quality press-molded body even without a separate preheater.SOLUTION: A press molding apparatus (1) comprises a fixed mold (2) and a movable mold (3). The fixed mold (2) includes a fixed mold base part (21) and a fixed mold middle part (22) disposed sandwiching a fixed mold gap (2s) along with the fixed mold base part (21), and the movable mold (3) includes a movable mold base part (31) and a movable mold middle part (32) disposed sandwiching a movable mold gap (3s) along with the movable mold base part (31).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a press molding apparatus and a method for manufacturing a press molded body using a composite material such as a composite material. In particular, it relates to a press molding apparatus for a composite material having a press molding temperature of 150 ° C or higher.

Background Art

[0002] Conventionally, composite materials alternative to metal materials have been developed as materials for forming automotive parts, electric motorcycles, separators for EV hydrogen engines, aircraft members, drone parts, prosthetic legs, etc. In particular, in recent years, composite materials using thermoplastic resins or thermosetting resins have attracted attention because they can be mass-produced by press molding and can handle complex shapes.

[0003] Examples of composite materials using resins for press molding include GMT (glass mat reinforced thermoplastic), carbon fiber reinforced composite materials, natural fiber reinforced composite materials, aramid fiber reinforced composite materials, and the like. For the molding of these composite materials, press molding methods such as those disclosed in Patent Document 1 are disclosed. By the way, the press molding temperature of composite materials is as high as 150 ° C or higher; there has been a problem that the cycle of heating and cooling becomes long, the production efficiency is low, and the production cost is high.

[0004] In addition, in order to manufacture a high-quality press molded body, it is desirable to preheat the material of the press molded body before setting it in the press molding apparatus (Patent Document 2, etc.). However, depending on the shape of the material and the type of fibers contained in the composite material, etc., there are those for which preheating is difficult (non-woven fabrics, chopped materials, etc.), and those for which, even if preheating is possible, it is difficult to set the preheated material in the mold. Therefore, there has been a problem that a high-quality press molded body cannot be obtained without preheating.

[0005] Furthermore, when the upper and lower molds are closed as a whole along guide pins or the like (in the case of fully closing the molds), there has been a problem that it is difficult to adjust the guide pins, that is, to position the parts of the molds and the press molded body.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-112827 [Patent Document 2] International Publication No. 2018 / 003433 [Overview of the project] [Problems that the invention aims to solve]

[0007] In view of the above circumstances, the present invention aims to provide a press molding apparatus that shortens the heating and cooling cycle in press molding of composite materials and can produce high-quality press-molded articles without the need for a separate preheating device. Here, "high-quality press-molded articles" refer to articles in which the composite material fibers and resin are sufficiently mixed, resulting in minimal fiber exposure on the surface of the press-molded article, or articles that are molded with high precision even if their shape is complex (including bosses, ribs, thin-walled sections, undercuts, etc.) or if there are issues with the homogeneity of the material. [Means for solving the problem]

[0008] The press molding apparatus (1) for press molding a press-formed composite material of the present invention comprises a fixed mold (2) and a movable mold (3). The fixed mold (2) has a fixed mold base (21) and a fixed mold intermediate portion (22) provided together with the fixed mold base (21) and sandwiching the fixed mold gap (2s). The movable mold (3) has a movable mold base (31) and a movable mold intermediate portion (32) provided together with the movable mold base (31) and sandwiching the movable mold gap (3s). The fixed mold intermediate portion (22) and the movable mold intermediate portion (32) are arranged to face each other so as to be in contact with each other, the fixed mold base portion (21) has a fixed mold base cooling channel (211), the movable mold base portion (31) has a movable mold base cooling channel (311), the fixed mold intermediate portion (22) has a fixed mold intermediate heating and cooling channel (221) on the side facing the fixed mold gap (2s), and on the side away from the fixed mold gap (2s), the movable mold (3) has a fixed mold intermediate heater (222) on one side, the movable mold intermediate (32) has a movable mold intermediate heating / cooling channel (321) on the side of the movable mold gap (3s), and on the side away from the movable mold gap (3s) and on the side of the fixed mold (2) has a movable mold intermediate heater (322), and during preheating and heating, heating fluid flows until it reaches a predetermined temperature, and during cooling, cooling fluid flows, and the movable In the intermediate heating and cooling channel (321) of the mold, heating fluid flows until a predetermined temperature is reached during preheating and heating, and cooling fluid flows during cooling. The gaps between the fixed mold (2s) and the movable mold (3s) are adjustable in width, and the gaps can be made zero to eliminate the gaps, allowing the fixed mold base (21) and the intermediate part of the fixed mold (22) to come into contact with each other, and the movable mold base (31) and the intermediate part of the movable mold (32) to come into contact with each other.

[0009] The method for manufacturing a press-formed composite material using the above-described press molding apparatus (1) of the present invention comprises steps A, B, C, D, E, and F, wherein step A is a step of preheating the fixed die intermediate section (22) and the movable die intermediate section (32), configured to have a fixed die gap (2s) and a movable die gap (3s), and the fixed die intermediate section (22) and the movable die intermediate section (32) are brought into contact in a die intermediate closing state, and cooling fluid is flowed through the fixed die base cooling channel (211) and the movable die base cooling channel (311), and the fixed die intermediate section Step B is a step in which heating fluid is flowed through the heat cooling channel (221) and the movable mold intermediate heating and cooling channel (321), and the fixed mold intermediate heater (222) and the movable mold intermediate heater (322) are turned ON to heat, and Step B is a step in which the material for the press molded body is applied to the movable mold (3), and is configured to have the fixed mold gap (2s) and the movable mold gap (3s), and the mold is opened so that the fixed mold intermediate part (22) and the movable mold intermediate part (32) are not in contact, and the fixed mold base cooling channel (211) and the movable mold base cooling channel (311) Step C is a step in which a cooling fluid is flowed through the fixed mold intermediate heating and cooling passage (221) and the movable mold intermediate heating and cooling passage (321), the fixed mold intermediate heater (222) and the movable mold intermediate heater (322) are turned ON to heat, and the material of the press-molded body is applied to the movable mold (3) side, Step C is a step in which the material of the press-molded body is heated, and is configured to have the fixed mold gap (2s) and the movable mold gap (3s), and the mold is closed in an intermediate state in which the fixed mold intermediate (22) and the movable mold intermediate (32) are in contact, Step D is a step of heating by flowing cooling fluid through the fixed mold base cooling channel (211) and the movable mold base cooling channel (311), flowing heating fluid through the fixed mold intermediate heating and cooling channel (221) and the movable mold intermediate heating and cooling channel (321), and turning on the fixed mold intermediate heater (222) and the movable mold intermediate heater (322). Step D is a step of pressing the press-formed body by making the gap width between the fixed mold gap (2s) and the movable mold gap (3s) zero and eliminating the gap, and bringing the fixed mold intermediate part (22) and the movable mold intermediate part (32) into contact.Step E is a process in which the fixed mold base (21) and the fixed mold intermediate section (22) are brought into contact with each other, the movable mold base (31) and the movable mold intermediate section (32) are brought into contact, cooling fluid is flowed through the fixed mold base cooling channel (211) and the movable mold base cooling channel (311), heating fluid is flowed through the fixed mold intermediate section heating and cooling channel (221) and the movable mold intermediate section heating and cooling channel (321), and the fixed mold intermediate section heater (222) and the movable mold intermediate section heater (322) are turned ON. Step E is a process in which the fixed mold intermediate section (22) and the movable mold This is a step to cool the intermediate section (32) and the press-molded body, by making the gap width between the fixed die gap (2s) and the movable die gap (3s) zero to eliminate the gap, bringing the fixed die intermediate section (22) and the movable die intermediate section (32) into contact, and closing the mold so that the fixed die base (21) and the fixed die intermediate section (22) are in contact with each other, and the movable die base (31) and the movable die intermediate section (32) are in contact with each other, and cooling fluid is flowed through the fixed die base cooling channel (211) and the movable die base cooling channel (311), and the fixed die intermediate section heating and cooling channel (221 Step F is a step in which cooling fluid is flowed through the heating and cooling channel (321) of the movable mold intermediate section, and the heater (222) of the fixed mold intermediate section and the heater (322) of the movable mold intermediate section are turned OFF, and Step F is a step in which the press molded body is removed, configured to have a gap (2s) between the fixed mold and the gap (3s) between the movable mold, the mold is opened so that the intermediate section (22) of the fixed mold and the intermediate section (32) are not in contact, cooling fluid is flowed through the cooling channel (211) of the fixed mold base and the cooling channel (311) of the movable mold base, and the intermediate section (32) of the fixed mold The process involves flowing cooling fluid through the heating / cooling channel (221) and the intermediate heating / cooling channel (321) of the movable mold, turning off the intermediate heater (222) of the fixed mold and the intermediate heater (322) of the movable mold, and removing the press-formed body from the movable mold (3). The heating or cooling fluid flowing through the intermediate heating / cooling channel (221) of the fixed mold and the intermediate heating / cooling channel (321) is stopped once the intermediate heating / cooling channel (221) of the fixed mold and the intermediate heating / cooling channel (321) reach a predetermined temperature. [Effects of the Invention]

[0010] The press molding apparatus of the present invention shortens the heating and cooling cycle of press molding and provides a press molding apparatus that can produce high-quality press molded products without the need for a separate preheating device. Even materials that are difficult to preheat (such as nonwoven fabrics and chopped materials) or materials that are difficult to set into the mold after preheating can be press-molded. Furthermore, there is less exposure of fibers and other materials on the surface of the press-molded body, and even press-molded bodies with complex shapes can be molded with high precision. Because the heating and cooling cycles of press molding can be shortened, and positioning is easier during pressing, the manufacturing efficiency of press-molded products can be improved while simultaneously suppressing manufacturing costs. Furthermore, by bringing the intermediate section of the fixed mold and the intermediate section of the movable mold into contact, and by heating the material of the press-molded body while the entire upper and lower molds are not closed (intermediate mold closing), positioning of the mold components and the press-molded body becomes easier compared to when the molds are fully closed. [Brief explanation of the drawing]

[0011] [Figure 1] This is an example of a press molding apparatus of the present invention, showing the case where the fixed die intermediate section and the movable die intermediate section are not in contact (die open state). [Figure 2] This is an example of a press molding apparatus of the present invention, showing the case where the fixed die intermediate section and the movable die intermediate section are in contact (die intermediate closing state). [Figure 3] This is an example of a press molding apparatus of the present invention, showing the case where the fixed die intermediate section and the movable die intermediate section, the fixed die base and the fixed die intermediate section, and the movable die base and the movable die intermediate section are in contact (die closed state). [Figure 4] This graph shows the change in temperature over time when a press molding machine is heated from 50°C to 150°C while the die is open. [Figure 5] This graph shows the change in temperature over time when a press molding machine is heated from 50°C to 220°C while the die is open. [Figure 6] A graph showing the change in temperature over time when the press molding apparatus is heated from 50°C to 300°C in the mold-open state. [Figure 7] A graph showing the change in temperature over time when the press molding apparatus is heated from 50°C to 150°C in the mold-partially-closed state. [Figure 8] A graph showing the change in temperature over time when the press molding apparatus is heated from 50°C to 220°C in the mold-partially-closed state. [[ID=X]] [Figure 9] A graph showing the change in temperature over time when the press molding apparatus is heated from 50°C to 300°C in the mold-partially-closed state. [Figure 10] A graph showing the change in temperature over time when steam is passed through the fixed mold intermediate heating / cooling channels and the movable mold intermediate heating / cooling channels of the press molding apparatus. [Figure 11] Examples of press molded articles manufactured by the press molding apparatus of the present invention. Figures 11(a) and (b) are 3D image pictures, and Figures 11(c) and (d) are photographs. [Figure 12] An example of the press molding apparatus of the present invention is shown. Figure 12(a) is a picture of the mold-open state and Figure 12(b) is a photograph of the mold-partially-closed state. [[ID=X]]

Embodiments for Carrying Out the Invention

[0012] The press molding apparatus and the method for manufacturing a press molded article of the present invention will be described below with reference to Figures 1 to 12 and the like. Reference numerals will be used for the description, but the present invention is not limited by the reference numerals.

[0013] (Press Molding Apparatus) The press molding apparatus 1 of the present invention is for press molding a press molded article of a composite material such as a fiber reinforced composite material.

[0014] When the composite material is a fiber reinforced composite material, it contains fibers and the like and a synthetic resin.

[0015] It should be noted that there seems to be an error in the original text where the tag [[ID=X]] is used without a proper definition. I have left it as is in the translation for the sake of maintaining the integrity of the original content. If this is a misprint, please correct it in the original text for a more accurate translation.Examples of fibers include glass fibers, carbon fibers, natural fibers, and aramid fibers contained in GMT (glass mat reinforced thermoplastic). In addition, metal fibers such as aluminum, organic fibers such as graphite fibers, PBO (poly(p-phenylenebenzobisoxazole)), polyphenylene sulfide, polyester, acrylic, nylon, and polyethylene, and inorganic fibers such as silicon carbide and silicon nitride can also be used.

[0016] Examples of synthetic resins include polypropylene resin, a thermoplastic resin. Other thermoplastic resins that can be used include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and liquid crystal polyester; polyolefins such as polyethylene (PE) and polybutylene; polyarylene sulfides such as polyoxymethylene (POM), polyamide (PA), and polyphenylene sulfide (PPS); fluoropolymers such as polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethernitrile (PEN), and polytetrafluoroethylene; and crystalline resins such as liquid crystal polymer (LCP). In addition to styrene-based resins, amorphous resins such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene ether (PPE), thermoplastic polyimide (PI), polyamide-imide (PAI), polyetherimide (PEI), polysulfone (PSU), polyethersulfone, and polyarylate (PAR) can be used. Other thermoplastic resins can be selected from phenolic resins, phenoxy resins, and thermoplastic elastomers such as polystyrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, polyisoprene-based, fluoropolymer-based, and acrylonitrile-based resins, as well as copolymers and modified versions thereof.

[0017] Furthermore, as synthetic resins, thermosetting resins such as phenolic resin (PF), epoxy resin (MF), alkyd resin, silicone resin, polyurethane (PUP), thermosetting polyimide, melamine resin, and urea resin can be used.

[0018] The reinforcing fiber content in the fiber-reinforced composite material (before press molding) can be appropriately set within a range of approximately 20% to 75% by mass. In order to mold a product with high physical strength, it is also possible to set the reinforcing fiber content in the fiber-reinforced composite material to 50% or more by mass, or even 60% or more by mass.

[0019] Composite materials include fiber-reinforced composites, as well as those containing super engineering plastics and synthetic resins.

[0020] (Fixed molds and movable molds) As shown in Figures 1 and 2, the press molding apparatus 1 comprises a fixed mold 2 and a movable mold 3 facing each other. Specifically, the intermediate portion 22 of the fixed mold and the intermediate portion 32 of the movable mold are arranged to face each other so as to be able to contact each other.

[0021] (Fixed mold) The fixed mold 2 has a fixed mold base 21 and a fixed mold intermediate portion 22 that is provided together with the fixed mold base 21, sandwiching the fixed mold gap 2s.

[0022] The material for the fixed mold base 21 is preferably carbon steel such as S45C. The size of the fixed mold base 21 depends on the size of the press-formed body, but an example is approximately 50cm x 70cm x 10cm thick. Various types of carbon steel are used as materials for the intermediate section 22 of the fixed mold, and pre-hardened steel such as PXA30 (manufactured by Daido Steel Co., Ltd., carbon steel) is frequently used from the perspective of mirror finish quality and hardness. The size of the fixed die intermediate section 22 depends on the size of the press-formed body, but an example is approximately 40cm x 50cm x 9cm thick.

[0023] A fixed mold gap 2s is provided between the fixed mold base 21 and the fixed mold intermediate portion 22. The fixed mold gap 2s provides a heat insulating effect by trapping air between the fixed mold base 21 and the fixed mold intermediate portion 22. The fixed mold gap 2s is provided by attaching a fixed mold elastic body 23, such as a spring or coil, to the side of the fixed mold base 21 and / or the side of the fixed mold intermediate portion 22. It is preferable that the fixed mold elastic body 23 be attached to the side of the fixed mold base 21, through which the cooling fluid always flows. The width of the fixed mold gap 2s (the distance between the fixed mold base 21 and the fixed mold intermediate part 22) is typically 0 mm to 10 mm, with 0 mm to 6 mm being more preferable. When thermal insulation is desired, a range of 4 mm to 6 mm is preferable. If it exceeds 10 mm, positioning the mold components tends to become difficult. The gap 2s between the fixed molds can be adjusted using a fixed mold elastic body 23 such as a spring or coil and a thickness adjustment bolt. When a certain amount of pressing force is applied between the fixed mold 2 and the movable mold 3, the gap 2s becomes 0 mm, the gap disappears, and the fixed mold base 21 and the fixed mold intermediate part 22 come into contact with each other (see Figure 3).

[0024] A fixed mold insert 24 can be provided on the side of the fixed mold intermediate section 22 opposite to the fixed mold base section 21. The fixed mold insert 24, together with the movable mold insert 34 described later, is used to combine with the molded body mold 4 to form the flat section, side wall, and undercut section.

[0025] The intermediate section 22 of the fixed mold can be equipped with a thermocouple 25 for measuring the mold temperature.

[0026] The fixed mold base 21 is provided with a fixed mold base cooling channel 211 through which a cooling fluid constantly flows during operation. The cooling fluid can be any substance that can act as a cooling medium, but chilled water is an example. An example of a fixed mold base cooling channel 211 is a configuration in which 24 tubes with a diameter of 11 mm (12 tubes in two rows) are arranged within the plane of the fixed mold base 21. In this case, the velocity of the cooling fluid depends on the tube diameter, the desired cooling temperature, the area of ​​the press-formed body, etc., but from the viewpoint of cooling efficiency, it is preferable to set it to be turbulent rather than laminar.

[0027] The intermediate section 22 of the fixed mold is provided with a heating / cooling channel 221 for the intermediate section of the fixed mold, on the side of the gap 2s between the fixed molds, through which a heating fluid or a cooling fluid flows. During preheating and heating, a heating fluid can flow through the heating / cooling channel 221 until it reaches a predetermined temperature, and during cooling, a cooling fluid can flow through it.

[0028] The heating fluid can be any medium that can act as a heating agent, but examples include hot water, hot oil, and steam. The cooling fluid can be any medium that can act as a cooling agent, but examples include cold water, etc. An example of the heating and cooling channel 221 in the intermediate section of the fixed mold is a configuration in which 10 tubes with a diameter of 11 mm are arranged (10 in one stage) on the side of the fixed mold gap 2s in the intermediate section 22 of the fixed mold. When the heating fluid is steam, the flow rate is adjusted by pressure. The velocity of the cooling fluid depends on the pipe diameter, the desired cooling temperature, the area of ​​the press-formed body, etc., but from the viewpoint of cooling efficiency, it is preferable to set it to be turbulent rather than laminar.

[0029] The fixed mold intermediate section 22 is provided with a fixed mold intermediate section heater 222 on the side away from the fixed mold gap 2s and on the side of the movable mold 3. The fixed mold intermediate section heater 222 can be any heater capable of the desired heating, but an example configuration is to arrange 12 heaters (12 in one stage) with a length of 400 mm, a diameter of Φ8 mm, 10A, 220V, and 2000W in the plane of the fixed mold intermediate section 22 on the side away from the fixed mold gap 2s. In addition, an example configuration is to make a hole in the fixed mold intermediate section 22 at the position of the fixed mold intermediate section heater 222 and place the fixed mold intermediate section heater 222 inside it.

[0030] (Movable mold) The movable mold 3 has a movable mold base 31 and a movable mold intermediate portion 32 which is provided together with the movable mold base 31, sandwiching the movable mold gap 3s.

[0031] Various types of carbon steel are used as examples of the material for the movable mold base 31, with carbon steel of material S45C, which is recognized as a carbon steel for machine structures according to JIS standards, being preferred. The size of the movable mold base 31 is exemplified as approximately 50 cm x 70 cm x 10 cm thick. Various types of carbon steel are used as materials for the movable mold intermediate section 32, and pre-hardened steel such as PXA30 (manufactured by Daido Steel Co., Ltd., carbon steel) is frequently used from the perspective of mirror finish quality and hardness. The size of the movable mold intermediate section 32 depends on the size of the press-formed body, but an example is approximately 40cm x 50cm x 9cm thick.

[0032] A movable mold gap 3s is provided between the movable mold base 31 and the movable mold intermediate portion 32. The movable mold gap 3s provides a heat insulating effect by trapping air between the movable mold base 31 and the movable mold intermediate portion 32. The movable mold gap 3s is provided by attaching a movable mold elastic body 33, such as a spring or coil, to the side of the movable mold base 31 and / or the side of the movable mold intermediate portion 32. It is preferable that the movable mold elastic body 33 be attached to the side of the movable mold base 31, through which cooling fluid always flows. The width of the movable mold gap 3s (the distance between the movable mold base 31 and the movable mold intermediate part 32) is typically 0 mm to 10 mm, with 0 mm to 6 mm being more preferable. When thermal insulation is desired, a range of 4 mm to 6 mm is preferable. If it exceeds 10 mm, positioning the mold components tends to become difficult. The gap 3s between the movable molds can be adjusted using a movable mold elastic body 33 such as a spring or coil and a thickness adjustment bolt. When a certain amount of pressing force is applied between the fixed mold 2 and the movable mold 3, the gap 3s becomes 0 mm, the gap disappears, and the movable mold base 31 and the movable mold intermediate part 32 come into contact with each other (see Figure 3).

[0033] A movable mold insert 34 can be provided on the side of the movable mold intermediate section 32 opposite to the movable mold base section 31. The movable mold insert 34, together with the fixed mold insert 24, is used to combine with the molded body mold 4 to form the flat section, side wall, and undercut section.

[0034] The movable mold base 31 is provided with a movable mold base cooling channel 311 through which a cooling fluid constantly flows during operation. The cooling fluid can be any fluid that can act as a cooling medium, but chilled water is an example. An example of the cooling channel 311 for the movable mold base is a configuration in which 24 tubes with a diameter of 11 mm (12 tubes in two rows) are arranged within the plane of the movable mold base 31. In this case, the velocity of the cooling fluid depends on the tube diameter, the desired cooling temperature, the area of ​​the press-formed body, etc., but from the viewpoint of cooling efficiency, it is preferable to set it to be turbulent rather than laminar.

[0035] The movable mold intermediate section 32 is provided with a movable mold intermediate heating / cooling channel 321 on the side of the movable mold gap 3s, through which a heating fluid or cooling fluid flows. During preheating and heating, a heating fluid can flow through the movable mold intermediate heating / cooling channel 321 until it reaches a predetermined temperature, and during cooling, a cooling fluid can flow through it.

[0036] The heating fluid can be any medium that can act as a heating agent, but examples include hot water, hot oil, and steam. The cooling fluid can be any medium that can act as a cooling agent, but examples include cold water, etc. An example of the heating and cooling channel 321 in the intermediate section of the movable mold is a configuration in which 10 tubes with a diameter of 11 mm are arranged (10 in one stage) on the side of the movable mold gap 3s in the intermediate section 32 of the movable mold. When the heating fluid is steam, the flow rate is adjusted by pressure. The velocity of the cooling fluid depends on the pipe diameter, the desired cooling temperature, the area of ​​the press-molded body, etc., but from the viewpoint of cooling efficiency, it is preferable to set it to be turbulent rather than laminar.

[0037] (Fixed mold intermediate section and movable mold intermediate section) The fixed mold intermediate section 22 and the movable mold intermediate section 32 are positioned to face each other and be able to contact each other. In the "mold intermediate closing" and "mold closing" states described later, the fixed mold intermediate section 22 and the movable mold intermediate section 32 are in contact, and in the "mold open" state, the fixed mold intermediate section 22 and the movable mold intermediate section 32 are not in contact and face each other with a predetermined distance between them.

[0038] (Method for manufacturing press-formed products) The press-molded article of the present invention comprises steps A, B, C, D, E, and F.

[0039] Step A is a step of preheating the fixed mold intermediate section 22 and the movable mold intermediate section 32. Step A is performed in a state of intermediate mold closing, where the fixed mold intermediate section 22 and the movable mold intermediate section 32 are in contact, with the fixed mold gap 2s and the movable mold gap 3s being configured. Cooling fluid is flowed through the fixed mold base cooling channel 211 and the movable mold base cooling channel 311, heating fluid is flowed through the fixed mold intermediate section heating cooling channel 221 and the movable mold intermediate section heating cooling channel 321, and the fixed mold intermediate section heater 222 and the movable mold intermediate section heater 322 are turned ON to heat. Because it has a fixed mold gap 2s and a movable mold gap 3s, the fixed mold base 21 and the movable mold base 31 do not rise in temperature excessively due to the heat insulation effect. Furthermore, even if cooling fluid is flowed through the fixed mold base 21 and the movable mold base 31 to maintain the shape stability of the device, the heat insulation effect does not reduce the heating efficiency of the fixed mold intermediate section 22 and the movable mold intermediate section 32 excessively.

[0040] Step B is the process of applying the press-formed material to the movable die 3. Step B is performed with the die open so that there is a fixed die gap 2s and a movable die gap 3s, and the fixed die intermediate section 22 and the movable die intermediate section 32 are not in contact. Cooling fluid is flowed through the fixed die base cooling channel 211 and the movable die base cooling channel 311, heating fluid is flowed through the fixed die intermediate section heating cooling channel 221 and the movable die intermediate section heating cooling channel 321, and the fixed die intermediate section heater 222 and the movable die intermediate section heater 322 are turned ON to heat. In this state, the press-formed material is applied to the movable die intermediate section 32 side of the movable die 3.

[0041] Step C is a step in which the material of the press-formed body is heated. Step C is performed in a state of intermediate die closing, where the fixed die intermediate section 22 and the movable die intermediate section 32 are in contact, with the fixed die gap 2s and the movable die gap 3s configured to have an intermediate die gap 2s and the movable die intermediate section 32. Cooling fluid is flowed through the fixed die base cooling channel 211 and the movable die base cooling channel 311, heating fluid is flowed through the fixed die intermediate section heating cooling channel 221 and the movable die intermediate section heating cooling channel 321, and the fixed die intermediate section heater 222 and the movable die intermediate section heater 322 are turned ON to heat the body. Since the material of a press-molded product is a composite of materials with different properties, such as fibers and synthetic resin, it is desirable to ensure that the synthetic resin is sufficiently impregnated into the fibers before press molding, and that there is little difference in the softness of the synthetic resin and the degree of impregnation into the fibers depending on the location of the press-molded product (near the center or near the edge, thick or thin parts, etc.). For this reason, steps B and C are performed after step A.

[0042] Step D is the process of pressing the press-formed body. Step D is performed in a closed state where the gap width between the fixed die gap 2s and the movable die gap 3s is reduced to 0, the fixed die intermediate part 22 and the movable die intermediate part 32 are brought into contact, and the fixed die base 21 and the fixed die intermediate part 22 are brought into contact with each other, and the movable die base 31 and the movable die intermediate part 32 are brought into contact with each other. Cooling fluid is flowed through the fixed die base cooling channel 211 and the movable die base cooling channel 311, heating fluid is flowed through the fixed die intermediate heating and cooling channel 221 and the movable die intermediate heating and cooling channel 321, and the fixed die intermediate heater 222 and the movable die intermediate heater 322 are turned ON. Furthermore, in processes A, B, C, and D, if water (steam) is used as the heating fluid and the predetermined temperature is higher than 150°C, it is desirable to stop supplying the heating fluid when the heating fluid reaches approximately 140°C to 150°C. If the supply is stopped, it is desirable to purge the fixed mold base cooling channel 211 and the movable mold base cooling channel 311 in preparation for the next cooling process.

[0043] Step E is a process for cooling the fixed die intermediate section 22, the movable die intermediate section 32, and the press-formed body. Step E is performed in a closed die state, where the width of the gap between the fixed die gap 2s and the movable die gap 3s is set to 0 to eliminate the gap, the fixed die intermediate section 22 and the movable die intermediate section 32 are brought into contact, and the fixed die base 21 and the fixed die intermediate section 22 are in contact with each other, and the movable die base 31 and the movable die intermediate section 32 are in contact with each other. Cooling fluid is flowed through the fixed die base cooling channel 211 and the movable die base cooling channel 311, cooling fluid is flowed through the fixed die intermediate section heating and cooling channel 221 and the movable die intermediate section heating and cooling channel 321, and the fixed die intermediate section heater 222 and the movable die intermediate section heater 322 are turned OFF. By eliminating the gaps between the fixed mold gap 2s and the movable mold gap 3s by setting their widths to zero, the cooling fluid flowing through the fixed mold base cooling channel 211 and the movable mold base cooling channel 311 can also contribute to cooling, thereby improving cooling efficiency. Furthermore, in step E, it is desirable to stop supplying the cooling fluid once the predetermined temperature is reached.

[0044] Step F is the process of removing the press-formed body. Step F is configured to have a fixed die gap 2s and a movable die gap 3s, and is performed with the die open so that the intermediate part of the fixed die 22 and the intermediate part of the movable die 32 are not in contact. Cooling fluid is flowed through the fixed die base cooling channel 211 and the movable die base cooling channel 311, and cooling fluid is flowed through the fixed die intermediate heating and cooling channel 221 and the movable die intermediate heating and cooling channel 321, the fixed die intermediate heater 222 and the movable die intermediate heater 322 are turned OFF, and the press-formed body is removed from the movable die 3.

[0045] As described above, one of the main features of the press molding apparatus and press molding method of the present invention is that when heating by the fixed die intermediate section 22 and the movable die intermediate section 32, the heater is placed on the press molding product side, the heating and cooling passage is placed on the die base side to flow the heating fluid, and the fixed die base 21 and the movable die base 31 are insulated by the fixed die gap 2s and the movable die gap 3s, respectively. Furthermore, when cooling, the width of the fixed die gap 2s and the movable die gap 3s is set to 0, bringing the fixed die base 21 and the fixed die intermediate section 22 into contact with each other, and the movable die base 31 and the movable die intermediate section 32 into contact with each other, so that the cooling fluid flowing through the fixed die base cooling passage 211 and the movable die base cooling passage 311 can also contribute to cooling. Due to these features, it is possible to shorten the heating and cooling cycle and obtain a high-quality press molding even with complex shapes or composite materials unsuitable for preheating.

[0046] (Evaluation test of heating using heaters and heating fluids) Using the press molding apparatus of the present invention, the heating time using a heater and steam (heating fluid) until a predetermined temperature is reached was evaluated. Similarly, the heating time using only a conventional heater was evaluated, and the reduction in time was verified.

[0047] The evaluation was performed with the mold open and partially closed, measuring the time it took to reach 150°C from 50°C, 220°C from 50°C, and 300°C from 50°C. Steam supply was stopped when the mold temperature reached 140°C, compressed air was purged for 10 seconds, and the valve was closed. The evaluation results are shown in Figures 4 to 9 and Table 1. For reference, the heating time using steam alone was measured with the mold open and with the mold partially closed, and is shown in Figure 10.

[0048] [Table 1]

[0049] Figures 4 to 9 and Table 1 show that the time reduction can be significantly shortened, from 34 to 101 seconds when the mold is open, and from 53 to 115 seconds when the mold is partially closed. Since the steam is stopped when the mold temperature reaches 140°C, when heating from 50°C to 220°C or from 50°C to 300°C, a time reduction of 1 to 2 minutes is observed even though heating is done solely by heaters once the temperature exceeds 140°C. Furthermore, Figure 10 shows that when heating to 150°C using only steam, the heating time is 1155 seconds in the open state and 917 seconds in the partially closed state, which is 6.7 times and 5.3 times longer, respectively, compared to when using only heaters (172 seconds from Figure 4 and 173 seconds from Figure 7). From the above, it was found that while steam alone has lower heating efficiency compared to heater alone, heating with steam in combination with a heater in the initial stages of heating significantly reduces the heating time and also improves the efficiency of heater heating in the later stages when the steam supply is stopped. In particular, the thermal efficiency can be further improved by positioning the heater on the press-molded body side and the steam flow path on the opposite side from the press-molded body.

[0050] On the other hand, during cooling, cooling fluid flows through the heating and cooling channel 221 in the middle section of the fixed mold and the heating and cooling channel 321 in the middle section of the movable mold, thus shortening the cooling time.

[0051] Figure 11 shows an example of a press-molded body (a composite material of polyamide resin and carbon fiber nonwoven fabric, 320 mm x 230 mm) manufactured using the press molding apparatus of the present invention. Figure 11(a) is a 3D image of the back side, Figure 11(b) is a 3D image of the front side, Figure 11(c) is a photograph of the back side, and Figure 11(d) is a photograph of the front side. In this way, even with uneven surfaces, ribs, and areas of varying thickness, high-quality press-formed products can be obtained.

[0052] Figure 12 shows an example of the press molding apparatus of the present invention. Figure 12(a) shows the die open state, and Figure 12(b) shows the die partially closed state, with a fixed die gap 2s and a movable die gap 3s.

[0053] In this specification, the upper part of the press molding apparatus is described as a "fixed mold" and the lower part as a "movable mold," but the upper part may be a movable mold and the lower part a fixed mold. Alternatively, both the upper and lower parts may be movable molds. [Explanation of Symbols]

[0054] 1. Press forming machine 2 Fixed mold 21 Fixed mold base 211 Fixed mold base cooling channel 22 Fixed mold intermediate section 221 Fixed mold intermediate heating and cooling channel 222 Fixed mold intermediate heater 23 Fixed mold elastic body 24 Fixed mold insert 25 Thermocouples 2s Fixed mold gap 3. Movable mold 31 Movable mold base 311 Cooling channel for movable mold base 32 Movable mold intermediate section 321 Heating and cooling channel in the middle section of the movable mold 322 Movable mold intermediate heater 33 Movable mold elastic body 34 Movable mold insert 3s movable mold gap 4. Molded body mold 5 Drive Unit

Claims

[Claim 1] A method for manufacturing a press-formed body of a composite material using a press-forming apparatus (1), The aforementioned press forming apparatus (1) It comprises a fixed mold (2) and a movable mold (3), The fixed mold (2) has a fixed mold base (21) and a fixed mold intermediate portion (22) which is provided together with the fixed mold base (21) and sandwiching the fixed mold gap (2s), The movable mold (3) has a movable mold base (31) and a movable mold intermediate portion (32) provided together with the movable mold base (31) and sandwiching the movable mold gap (3s), The fixed mold intermediate portion (22) and the movable mold intermediate portion (32) are arranged to face each other so as to be able to contact each other. The fixed mold base (21) has a fixed mold base cooling channel (211), The movable mold base (31) has a movable mold base cooling channel (311), The fixed mold intermediate section (22) has a fixed mold intermediate section heating and cooling channel (221) on the side of the fixed mold gap (2s), and a fixed mold intermediate section heater (222) on the side away from the fixed mold gap (2s) and on the side of the movable mold (3). The movable mold intermediate section (32) has a movable mold intermediate section heating and cooling channel (321) on the side facing the movable mold gap (3s), and a movable mold intermediate section heater (322) on the side away from the movable mold gap (3s) and facing the fixed mold (2). In the aforementioned heating and cooling channel (221) of the intermediate section of the fixed mold, heating fluid flows until a predetermined temperature is reached during preheating and heating, and cooling fluid flows during cooling. In the aforementioned heating and cooling channel (321) of the movable mold intermediate section, heating fluid flows until a predetermined temperature is reached during preheating and heating, and cooling fluid flows during cooling. The gap between the fixed mold (2s) and the gap between the movable mold (3s) is adjustable in width, and by setting the gap width to zero, the gap can be eliminated, allowing the fixed mold base (21) and the fixed mold intermediate portion (22) to come into contact with each other, and the movable mold base (31) and the movable mold intermediate portion (32) to come into contact with each other. The manufacturing method includes steps A, B, C, D, E, and F. Step A is a preheating step in which the fixed mold intermediate section (22) and the movable mold intermediate section (32) are configured to have a fixed mold gap (2s) and a movable mold gap (3s), the fixed mold intermediate section (22) and the movable mold intermediate section (32) are brought into contact in a mold intermediate closing state, cooling fluid is flowed through the fixed mold base cooling channel (211) and the movable mold base cooling channel (311), heating fluid is flowed through the fixed mold intermediate section heating and cooling channel (221) and the movable mold intermediate section heating and cooling channel (321), and the fixed mold intermediate section heater (222) and the movable mold intermediate section heater (322) are turned ON. Step B is a step of applying the material for the press-formed body to the movable mold (3), configured to have a fixed mold gap (2s) and a movable mold gap (3s), opening the mold so that the intermediate part of the fixed mold (22) and the intermediate part of the movable mold (32) are not in contact, flowing cooling fluid through the cooling channel of the base of the fixed mold (211) and the cooling channel of the base of the movable mold (311), flowing heating fluid through the heating and cooling channel of the intermediate part of the fixed mold (221) and the heating and cooling channel of the intermediate part of the movable mold (321), turning on the heater of the intermediate part of the fixed mold (222) and the heater of the intermediate part of the movable mold (322) to heat, and applying the material for the press-formed body to the movable mold (3). Step C is a step of heating the material of the press-formed body, and is configured to have a fixed die gap (2s) and a movable die gap (3s), and is set to a state of die intermediate closing in which the fixed die intermediate part (22) and the movable die intermediate part (32) are in contact, cooling fluid is flowed through the fixed die base cooling channel (211) and the movable die base cooling channel (311), heating fluid is flowed through the fixed die intermediate heating and cooling channel (221) and the movable die intermediate heating and cooling channel (321), and the fixed die intermediate heater (222) and the movable die intermediate heater (322) are turned ON to heat the material. Step D is a step of pressing the press-formed body, wherein the width of the gap between the fixed die (2s) and the movable die (3s) is reduced to zero to eliminate the gap, the intermediate part of the fixed die (22) and the intermediate part of the movable die (32) are brought into contact, the fixed die base (21) and the intermediate part of the fixed die (22) are brought into contact with each other, and the movable die base (31) and the intermediate part of the movable die (32) are brought into contact with each other to form a die-closed state, cooling fluid is flowed through the cooling channel of the fixed die base (211) and the cooling channel of the movable die base (311), heating fluid is flowed through the heating and cooling channel of the intermediate part of the fixed die (221) and the heating and cooling channel of the intermediate part of the movable die (321), and the heater of the intermediate part of the fixed die (222) and the heater of the intermediate part of the movable die (322) are turned ON. Step E is a step of cooling the fixed die intermediate section (22), the movable die intermediate section (32), and the press-molded body, and is a step of eliminating the gaps between the fixed die gap (2s) and the movable die gap (3s) by making the gap width zero, bringing the fixed die intermediate section (22) and the movable die intermediate section (32) into contact, bringing the fixed die base (21) and the fixed die intermediate section (22) into contact with each other, and bringing the movable die base (31) and the movable die intermediate section (32) into contact with each other to create a die-closed state, flowing cooling fluid through the fixed die base cooling channel (211) and the movable die base cooling channel (311), flowing cooling fluid through the fixed die intermediate section heating and cooling channel (221) and the movable die intermediate section heating and cooling channel (321), and turning off the fixed die intermediate section heater (222) and the movable die intermediate section heater (322). Step F is a step of removing the press-formed body, and is configured to have a fixed die gap (2s) and a movable die gap (3s), the die is opened so that the intermediate part of the fixed die (22) and the intermediate part of the movable die (32) are not in contact, cooling fluid is flowed through the cooling channel of the base of the fixed die (211) and the cooling channel of the base of the movable die (311), cooling fluid is flowed through the heating and cooling channel of the intermediate part of the fixed die (221) and the heating and cooling channel of the intermediate part of the movable die (321), the heater of the intermediate part of the fixed die (222) and the heater of the intermediate part of the movable die (322) are turned OFF, and the press-formed body is removed from the movable die (3). A method for manufacturing a press-formed article, characterized in that the supply of heating fluid or cooling fluid flowing through the intermediate heating / cooling channel (221) of the fixed mold and the intermediate heating / cooling channel (321) of the movable mold is stopped when the intermediate heating / cooling channel (221) of the fixed mold and the intermediate heating / cooling channel (321) of the movable mold reach a predetermined temperature.

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