JP7799170B2 - Manufacturing method of the structure - Google Patents

Description

The present invention relates to a method for manufacturing a structure.

Patent Document 1 discloses a method for manufacturing a resin structure using a mold and an outer frame arranged around the mold. The outer frame in Patent Document 1 moves forward so as to protrude from the mold, and comes into contact with a hanging resin sheet, allowing it to adsorb the resin sheet. When this outer frame adsorbs the resin sheet, the space (cavity) between the resin sheet and the mold becomes a closed space. Therefore, by reducing the pressure in this space, it is possible to shape the resin sheet into the mold.

Japanese Patent Application Laid-Open No. 2018-122462

The outer frame needs to be retracted to a certain extent from its advanced position in order to properly shape the resin sheet into the mold. Depending on the amount of retraction of the outer frame and the shape of the mold, it may be difficult for the resin sheet to conform to the mold surface, causing the resin sheet to peel off from the mold surface or outer frame, resulting in molding defects.

The present invention was made in consideration of these circumstances, and aims to provide a method for manufacturing a structure that can reduce molding defects.

According to the present invention, there is provided a method for manufacturing a structure using a mold and an outer frame, comprising a hanging process, a suction process, and a shaping process. In the hanging process, a molten resin sheet is hung down from the front of the mold. The mold has a cavity portion, a pinch-off portion, and a chamfered portion. The chamfered portion is provided between the outer frame and the pinch-off portion and is formed so that the distance between the hanging resin sheet and the resin sheet increases in the direction from the pinch-off portion toward the outer frame. In the suction process, the outer frame is advanced to suction the resin sheet with the outer frame, forming a closed space between the outer frame, the resin sheet, and the mold. The outer frame is disposed around the mold and is configured to be able to suction the resin sheet. In the shaping process, the outer frame is retracted and the closed space is depressurized to shape the resin sheet in the cavity portion. As the outer frame retracts, the resin sheet moves with the outer frame and is positioned along the chamfered portion.

In the present invention, the mold is equipped with a chamfered portion, so when the resin sheet moves together with the outer frame during the shaping process, the resin sheet is smoothly positioned along the chamfered portion. This prevents the resin sheet from peeling off from the mold or outer frame, and avoids molding defects.

Various embodiments of the present invention will be exemplified below.
Preferably, a method is provided wherein the chamfer comprises a tapered surface.
Preferably, a method is provided in which the inclination angle of the tapered surface is 60 degrees or less.
Preferably, in the shaping step, the outer frame is retracted to the position of the rear end of the chamfered portion.
Preferably, in the shaping step, a recession distance of the outer frame is 30 mm or more and 80 mm or less.
Preferably, the manufacturing method further uses a movable part, and further includes a molding process, the mold has first and second split molds, the movable part is configured to move relative to the first split mold and cut a portion of the resin sheet, and is attached to the periphery of the first split mold, the second split mold has the chamfered portion, and the outer frame is arranged around the second split mold, and in the molding process, the first and second split molds are closed, and when the molding process is completed, at least a portion of the movable part is arranged closer to the outer frame than the position of the front end of the chamfered portion.
Preferably, the chamfered portion has a width in the opening and closing direction of the mold of 10 mm or more and 63 mm or less.
Preferably, the chamfered portion has a width in a direction from the pinch-off portion toward the outer frame of 5.7 mm or more and 70 mm or less.

Fig. 1A is a perspective view of a resin panel 1. Fig. 1B is a perspective view of a core material 3. FIG. 2 is a front view showing the configuration of the molding machine 10 (the first and second split molds 21 and 22, the outer frame 31, the core material 3, etc. are shown in cross section). FIG. 3 is a perspective view of the first and second split molds 21, 22 and outer frames 31, 32, showing the state in which the first and second split molds 21, 22 are open. FIG. 4 is an enlarged view of area A shown in FIG. Fig. 5 is a perspective view of the first and second split molds 21, 22 and outer frames 31, 32 as viewed from a different direction than Fig. 3. In Figs. 9 to 15, the first and second split molds 21, 22, etc. are shown as end faces cut along a horizontal plane passing through the upper and lower points P1 shown in Fig. 5. In Figs. 7 and 8, the first and second split molds 21, 22, etc. are shown as end faces cut along a vertical plane passing through the upper and lower points P2 shown in Fig. 5. 6A to 6C are front views showing the operation of the movable part 23 when the first cutting step is performed. FIG. 7 shows a state in which the skin material attachment step has been completed and the hanging step is being carried out. FIG. 8 shows the state in which the adsorption step is being carried out. FIG. 9 is a horizontal end view of the first and second split molds 21, 22, etc. shown in FIG. Fig. 10 is an enlarged view of area A shown in Fig. 9. In Fig. 10, dashed lines L1 and L5 correspond to the position of the rear end portion 22ab, dashed lines L2 and L4 correspond to the position of the front end portion 22af, and dashed line L3 corresponds to the position of the front end face of the outer frame 32. FIG. 11 shows the state after the shaping step has been carried out. FIG. 12 shows the state after the core material welding step has been carried out. FIG. 13 shows the state after the molding step has been carried out. Fig. 14 is an enlarged view of the main parts of the first and second split molds 21, 22, etc. shown in Fig. 13. In Fig. 14, dashed line T1 corresponds to the position of the front end surface of the outer frame 32, dashed line T2 corresponds to the position of the front end surface of the suction portion 23g, and dashed line T3 corresponds to the position of the opposing surface portion 23a. Fig. 15 shows the state after the first cutting step is performed, in which the movable part 23 moves away from the first separate mold 21, and the outer flash part 5bc2 is cut off from the inner flash part 5bc1. FIG. 16 shows a front view of the molded body 5 . FIG. 17 is a front view schematically showing a state in which the outer burr portion 5bc2 of the molded body 5 shown in FIG. 13 has been cut from the inner burr portion 5bc1 by carrying out the first cutting step.

The following describes embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. Furthermore, each feature can be an independent invention.

1. Resin Panel 1 As shown in FIG. 1, a resin panel 1 (an example of a "structure") according to one embodiment of the present invention is a panel covered with a resin molded body 2 that is substantially rectangular in plan view.

As shown in Fig. 1, the resin panel 1 includes a hollow resin molded body 2 and a core material 3, with the core material 3 disposed within the resin molded body 2. A skin material 4 is attached to one side of the resin molded body 2 so as to extend to a parting line PL. The skin material 4 is, for example, a nonwoven fabric, and is molded integrally with the resin molded body 2 during molding.
Both surfaces of the core material 3 are in close contact with the resin molded body 2. The core material 3 is made up of base bodies 3a and 3b and a reinforcing member 3c that connects them. The reinforcing member 3c is a long, thin member with a uniform cross-sectional shape. The base bodies 3a and 3b are made of, for example, foam.

2. Manufacturing Method of Resin Panel 1 2-1 Description of Manufacturing Apparatus As shown in FIG. 2, in the manufacturing method according to the embodiment, a molding machine 10 and an insertion device 19 are used to form the molded body 5 shown in FIG. 16. As shown in FIGS. 2 and 3, the molding machine 10 includes a pair of sheet-forming devices 14, molds (first and second split molds 21, 22), outer frames 31, 32, and a movable unit 23. Although not shown, the molding machine 10 also includes a drive device that operates to move the movable unit 23 away from the first split mold 21, as shown in FIGS. 6A to 6C. This drive device can move the upper portion of the movable unit 23 and then move the lower portion of the movable unit 23, as shown in FIGS. 6B and 6C, allowing for smooth tearing of flash (part of the resin sheet).

2-1-1 Configuration of Sheet Forming Apparatus 14 As shown in Fig. 2, the sheet forming apparatus 14 includes a hopper 12, an extruder 13, an accumulator 17, and a T-die 18. The extruder 13 and the accumulator 17 are connected via a connecting pipe 15. The accumulator 17 and the T-die 18 are connected via a connecting pipe 16. Each component will be described in detail below.

<Hopper 12, Extruder 13>
The hopper 12 is used to feed the raw resin 11 into the cylinder 13a of the extruder 13. The form of the raw resin 11 is not particularly limited, but is typically pelletized. The raw resin is, for example, a thermoplastic resin such as polyolefin. Examples of polyolefin include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof. The raw resin 11 may also include recycled raw materials produced by crushing flash using a crusher. After being fed from the hopper 12 into the cylinder 13a, the raw resin 11 is heated and melted into a molten resin within the cylinder 13a. The raw resin 11 is then transported toward the tip of the cylinder 13a by the rotation of a screw disposed within the cylinder 13a. The screw is disposed within the cylinder 13a and conveys the molten resin while kneading it with its rotation. A gear device is provided at the base end of the screw, which rotates the screw.

<Accumulator 17, T-die 18>
The raw resin is extruded from the resin extrusion port of the cylinder 13a and injected into the accumulator 17 through the connecting pipe 15. The accumulator 17 includes a cylinder 17a and a piston 17b that can slide inside the cylinder 17a, and the molten resin 11a can be stored in the cylinder 17a. After a predetermined amount of the molten resin 11a has been stored in the cylinder 17a, the piston 17b is moved, whereby the molten resin 11a is extruded through the connecting pipe 16 and slid down from a slit provided in the T-die 18, forming molten resin sheets p1 and p2.

2-1-2 Mold (first and second split molds 21, 22) and outer frames 31, 32
As shown in Fig. 7, resin sheets p1, p2 are introduced between first and second split molds 21, 22. The first and second split molds 21, 22 are separable at a parting surface that abuts when the molds are closed, and a molded body 5 (see Fig. 16) is formed by the first and second split molds 21, 22. That is, in the molding process, the molded body 5 is formed using a pair of separable first and second split molds 21, 22. In addition, in the embodiment, a skin relief space sp (see Figs. 14 and 15) is formed between the first and second split molds 21, 22. An end of the skin material 4 is placed in the skin relief space sp during molding.

<First split mold 21>
As shown in FIG. 5 , the first split mold 21 includes a main body 21a1, a pair of first outer portions 21a2, and an end surface 21a3 (see FIG. 15 ). A cavity portion CVT is formed in the main body 21a1. When the first and second split molds 21, 22 are closed, the cavity portion CVT is a closed space formed between the first and second split molds 21, 22, where the molded body is molded. The first outer portions 21a2 are connected to the lateral ends (left and right ends) of the main body 21a1. The lateral width direction is a direction perpendicular to the opening and closing direction of the first and second split molds 21, 22 and perpendicular to the up-down direction. The end surface 21a3 forms a surface against which the movable portion 23 abuts. In this embodiment, the end surface 21a3 is formed on a side surface of the first outer portion 21a2.

The first separate mold 21 is provided with a number of vacuum suction holes hl (see Figure 10), which allow the resin sheet p1 to be vacuum-suctioned and shaped to fit the inner surface 21b of the first separate mold 21. As shown in Figure 5, the inner surface 21b faces the cavity portion cvt.

As shown in FIG. 5, the first separate mold 21 has a pinch-off portion 21d, which is arranged to surround the cavity portion CVT. The pinch-off portion 21d is a protrusion formed to protrude from the first separate mold 21 side toward the second separate mold 22 side. As shown in FIG. 10, the pinch-off portion 21d has an inner pinch-off portion 21d1 and an outer pinch-off portion 21d2. The inner pinch-off portion 21d1 and the outer pinch-off portion 21d2 are formed in the first outer portion 21a2.

The inner pinch-off portion 21d1 is provided so as to face the cavity portion CVT. The inner pinch-off portion 21d1 is formed in a shape that corresponds to the shape of the resin panel 1. Specifically, in this embodiment, the inner pinch-off portion 21d1 has a flat top surface. Also, in this embodiment, the inner pinch-off portion 21d1 extends in a bent straight line.

The outer pinch-off portion 21d2 is located farther from the cavity portion CVT than the inner pinch-off portion 21d1. The outer pinch-off portion 21d2 is formed to match the shape of the movable portion 23. Specifically, the outer pinch-off portion 21d2 is formed to match the shape of the engaging portion 23d of the movable portion 23 (see Figures 5 to 6C), which is closest to the first separate mold 21 (hereinafter referred to as the closest engaging portion 23d). Specifically, when the first separate mold 21 and the movable portion 23 are viewed in plan, the outer pinch-off portion 21d2 is formed to follow the closest engaging portion 23d. This prevents the cutting line of the burr from becoming distorted and makes it easier to cut the burr.

As shown in FIG. 5 , the first split mold 21 has a pair of suction sections 21A. The suction sections 21A are provided at the top and bottom of the first split mold 21, respectively. The upper and lower suction sections 21A are connected to the top and bottom ends of the main body section 21a1, respectively. The suction sections 21A are formed to protrude from the first split mold 21 side toward the second split mold 22 side. As a result, when the first split mold 21 advances, the suction sections 21A contact the resin sheet p1 before the pinch-off section 21d. A suction hole 21B is formed in the front end surface of the suction section 21A, and the suction section 21A can adsorb the resin sheet p1 by sucking air through the suction hole 21B. As shown in FIG. 5 , the suction section 21A has an inclined surface 21C, which facilitates the resin sheet p1 to conform to the surface of the first split mold 21 when the resin sheet p1 is shaped by the first split mold 21.

As shown in Figure 2, the first split mold 21 has a male protrusion 21e. The male protrusion 21e is located opposite a female protrusion 19c (described below) of the insertion device 19. The male protrusion 21e slides relative to the first split mold 21 and can be received in a hole (not shown) within the first split mold 21.

<Second split mold 22>
As shown in FIGS. 3 and 4 , the second split mold 22 includes a main body portion 22a1, a pair of second outer portions 22a2, a pair of opposing portions 22a3, and four chamfered portions 22a4. A cavity portion CVT is formed in the main body portion 22a1. The second outer portions 22a2 are connected to the widthwise ends (left and right ends) of the main body portion 22a1. Each opposing portion 22a3 is connected to a widthwise end of each second outer portion 22a2. The opposing portions 22a3 are disposed to face the engaging portion 23d of the movable portion 23. Each opposing portion 22a3 is formed with a flat surface and is connected to one of the upper and lower chamfered portions 22a4 and the left and right chamfered portions 22a4.

The chamfered portion 22a4 is formed on the periphery of the second split mold 22. In this embodiment, the second split mold 22 has a rectangular shape in plan view, and accordingly, the chamfered portion 22a4 is provided on each of the four sides of the second split mold 22. Each chamfered portion 22a4 has a front end 22af and a rear end 22a. The front end 22af is the portion of the chamfered portion 22a4 closest to the first split mold 21 in the mold opening/closing direction. The rear end 22ab is the portion of the chamfered portion 22a4 farthest from the first split mold 21 in the mold opening/closing direction.

The left and right chamfered portions 22a4 are provided between the outer frame 32 and the pinch-off portion (outer pinch-off portion 22d2). When the left and right chamfered portions 22a4 are viewed while the resin sheet p2 is hanging down, the left and right chamfered portions 22a4 are formed so that the distance between them and the hanging resin sheet p2 increases in the direction from the outer pinch-off portion 22d2 toward the outer frame 32. In this embodiment, the chamfered portions 22a4 are formed with tapered surfaces (inclined surfaces). Specifically, the tapered surfaces (inclined surfaces) of the chamfered portions 22a4 are formed from the front end portion 22af to the rear end portion 22ab. Note that the chamfered portions 22a4 do not have suction holes for adsorbing the resin sheet p2.

As shown in FIG. 10, the inclination angle θ of the tapered surface of the chamfered portion 22a4 is preferably greater than 0 degrees and less than or equal to 60 degrees. Specifically, the inclination angle θ (degrees) can be, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 degrees. The inclination angle θ can also be defined within a range between any two of the values exemplified here (for example, greater than or equal to 5 degrees and less than or equal to 60 degrees).

As shown in Figure 10, the width w1 of the chamfered portion 22a4 in the mold opening/closing direction is preferably 10 mm or more and 63 mm or less. Specifically, for example, the width w1 (mm) can be 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, or 63 mm, or can be defined within a range between any two of the values exemplified here.

As shown in FIG. 10, the width w2 of the chamfered portion 22a4 in the direction from the pinch-off portion 22d toward the outer frames 31 and 32 is preferably 5.7 mm or more and 70 mm or less. More preferably, the width w2 is 12 mm or more and 40 mm or less. Specifically, for example, the width w2 (mm) can be 5.7, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, or 70 mm, or can be defined within a range between any two of the numerical values exemplified here.

In this embodiment, the second split mold 22 has a total of four chamfered portions 22a4 (upper and lower chamfered portions 22a4 and left and right chamfered portions 22a4). The configurations of these chamfered portions 22a4 (inclination angle θ, width w1, width w2) may be the same or different, as long as they satisfy the above-mentioned numerical values or numerical ranges. For example, the upper and lower chamfered portions 22a4 may have the same configuration, and the left and right chamfered portions 22a4 may have the same configuration, but the configurations of the upper and lower chamfered portions 22a4 and the left and right chamfered portions 22a4 may be different.

The second split mold 22 is provided with a number of vacuum suction holes hl (see Figure 10), which allow the resin sheet p2 to be vacuum-suctioned and shaped to fit the inner surface 22b of the second split mold 22. The inner surface 22b faces the cavity portion cvt.

The second separate mold 22 has a pinch-off portion 22d, which is arranged to surround the cavity portion CVT. The pinch-off portion 22d is a protrusion formed to protrude from the second separate mold 22 side toward the first separate mold 21 side. The pinch-off portion 22d has an inner pinch-off portion 22d1 and an outer pinch-off portion 22d2. The inner pinch-off portion 22d1 and the outer pinch-off portion 22d2 are formed in the second outer portion 22a2.

The inner pinch-off portion 22d1 and the outer pinch-off portion 22d2 have the same configuration as the inner pinch-off portion 21d1 and the outer pinch-off portion 21d2. The inner pinch-off portion 22d1 is arranged to face the cavity portion CVT. The inner pinch-off portion 22d1 is formed in a shape that corresponds to the shape of the resin panel 1. Specifically, the top surface of the inner pinch-off portion 22d1 is flat. Furthermore, the inner pinch-off portion 22d1 extends in a bent, linear fashion.

The outer pinch-off portion 22d2 is located farther from the cavity portion CVT than the inner pinch-off portion 22d1. Like the outer pinch-off portion 21d2, the outer pinch-off portion 22d2 is formed in a shape that matches the shape of the movable portion 23.

<Outer frames 31, 32>
As shown in Figures 3 and 4, the outer frames 31, 32 are arranged around the second split mold 22. Specifically, the outer frame 31 is attached to the upper and lower parts of the second split mold 22, respectively, and the outer frame 32 is attached to the left and right sides of the second split mold 22, respectively. The outer frames 31, 32 are configured to be movable parallel to the opening and closing direction of the mold. In other words, the outer frames 31, 32 are configured to be able to move forward and backward in the opening and closing direction of the mold. Suction holes 31a, 32a are formed in the front end surfaces of the outer frames 31, 32, respectively, and the outer frames 31, 32 are able to adsorb the resin sheet p2 by sucking air through the suction holes 31a, 32a.

The outer frames 31, 32 move forward when adsorbing the resin sheet p2, but then, in this embodiment, the outer frames 31, 32 move backward. By moving backward, the resin sheet p2 is properly shaped in the second split mold 22, and interference between the outer frames 31, 32 and the first split mold 21 or the movable part 23 is prevented when the first and second split molds 21, 22 are closed.

Here, as shown in Figure 10, the outer frame 32 recedes to the position of the rear end 22ab of the chamfered portion 22a4. The same applies to the outer frame 31. The receding distance w3 of the outer frames 31, 32 is 30 mm or more and 80 mm or less. Specific examples of the receding distance w3 (mm) of the outer frames 31, 32 are 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, and 80, and can also be defined within a range between any two of the numerical values exemplified here.

As shown in Figure 14, when the outer frame 32 and the suction portion 23g are closest to each other (at the completion of the molding process), it is preferable that the distance t1 between the front end surface of the outer frame 32 and the front end surface of the suction portion 23g be 5 mm or more. Specifically, the distance t1 (mm) can be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 mm, and can also be defined within a range between any two of the values exemplified here. The same applies to the outer frame 31 and the suction portion 21A. In other words, the distance between the front end surface of the outer frame 31 and the front end surface of the suction portion 21A can also be defined in the same way as the distance t1 described above.

<Skin material relief space sp>
The skin escape space SP shown in FIGS. 14 and 15 is a space where excess skin material 4 is placed. The end of the skin material 4 is placed in the skin escape space SP. The skin escape space SP is the space between the first outer portion 21a2 and the second outer portion 22a2, and is also the space between the inner pinch-off portion 21d1 and the inner pinch-off portion 22d1 and the outer pinch-off portion 21d2 and the outer pinch-off portion 22d2. The skin material 4 used during molding is larger than the size of the cavity portion CVT. Therefore, excess skin material 4 is generated during molding. The excess skin material 4 is removed by an operator in a subsequent process. Although the raw resin 11 constituting the flash portion can be reused, if the excess skin material 4 adheres to the resin sheet P1 corresponding to the raw resin 11, it may adhere firmly, making it difficult to peel the skin material 4 from the resin sheet P1. If the flash cannot be removed, the flash will have to be discarded, making it impossible to reuse the resin. Therefore, in this embodiment, a skin escape space sp is formed in the first and second split molds 21 and 22.

2-1-3 Configuration of the Movable Part 23 The movable part 23 has the function of engaging with and cutting off burrs. As shown in FIGS. 6A to 6C, the movable part 23 is provided so as to be movable relative to the first separate mold 21. As shown in FIG. 6B, the movable part 23 is attached to the side of the first outer part 21a2 of the first separate mold 21. As shown in FIG. 15, the movable part 23 includes an opposing surface part 23a, an abutting surface part 23b, a suction part 23c, an engaging part 23d, a seal member 23e, and a suction part 23g.

The opposing surface portion 23a is provided to face the opposing portion 22a3 of the second separate mold 22. Multiple engagement portions 23d are formed on the opposing surface portion 23a.

The abutting surface portion 23b is formed so that it can abut against the end surface portion 21a3 of the first split mold 21. The abutting surface portion 23b is formed to fit the end surface portion 21a3. Therefore, when air is decompressed and sucked through the vacuum suction hole hl while the abutting surface portion 23b is abutted against the end surface portion 21a3, it is possible to prevent air from flowing between the abutting surface portion 23b and the end surface portion 21a3 into the area where the resin is being molded. Furthermore, the sealing member 23e is attached to the abutting surface portion 23b. Specifically, a groove is formed in the abutting surface portion 23b, and the sealing member 23e is attached within the groove. This effectively prevents air from flowing between the abutting surface portion 23b and the end surface portion 21a3 into the area where the resin is being molded. The areas where the resin is shaped include, for example, the inside of the cavity portion CVT, the gap between the flash portion and the surface of the engagement portion 23d, etc.

The suction portion 23c is a hole formed in the opposing surface portion 23a, and opens into the area where the engagement portion 23d is formed. Air is sucked under reduced pressure through the suction portion 23c, forming the burr portion (outer burr portion 5bc2) into the engagement portion 23d. This allows the burr portion (outer burr portion 5bc2) to be more securely caught on the movable portion 23, preventing the burr portion from slipping relative to the movable portion 23 when the movable portion 23 is driven. As a result, in this embodiment, when the movable portion 23 is driven, the burr portion properly follows the movable portion 23, making it possible to more reliably cut the burr portion.

The engaging portion 23d has the function of engaging with flash portions. The engaging portion 23d is a protrusion formed to protrude toward the second split mold 22. Because multiple engaging portions 23d are formed on the opposing surface portion 23a, the opposing surface portion 23a has an uneven formation area for the engaging portions 23d. Note that in the embodiment, the suction portion 23c is described as opening in the area between two adjacent engaging portions 23d on the opposing surface portion 23a, but this is not limited to this. The suction portion 23c may also open on the surface of the engaging portion 23d.

The suction portion 23g is provided on the end side of the movable portion 23 in the moving direction (the direction in which the movable portion 23 moves from the state shown in FIG. 6A to the state shown in FIG. 6C). The suction portion 23g is formed to protrude from the movable portion 23 toward the outer frame 32. As a result, when the movable portion 23 advances together with the first separate mold 21, the front end surface of the suction portion 23g contacts the resin sheet p1 before the engagement portion 23d. Note that in this embodiment, the position of the front end surface of the suction portion 23g coincides with the position of the front end surface of the suction portion 21A of the first separate mold 21. A suction hole 23g1 is formed in the front end surface of the suction portion 23g, allowing the suction portion 23g to adsorb the resin sheet p1 by sucking air through the suction hole 23g1. As shown in FIG. 10, the suction portion 23g has an inclined surface 23g2, which facilitates the resin sheet p1 to conform to the surface of the movable portion 23 when the resin sheet p1 is shaped into the movable portion 23. The inclined surface 23g2 is connected to the opposing surface portion 23a.

As shown in Figure 14, the protrusion amount t2 of the suction portion 23g (the distance between the position of the front end surface of the suction portion 23g and the position of the opposing surface portion 23a in the mold opening/closing direction) is preferably 15 mm or more. Specific examples of the protrusion amount t2 (mm) are 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30, and it can also be defined as a range between any two of the numerical values exemplified here.

2-1-4 Insertion device 19
The insertion device 19 is configured to be movable by a drive mechanism (not shown). As shown in Fig. 2, the insertion device 19 includes a base 19a, a suction pad 19b, and a female protrusion 19c. Each member is held by the base 19a. The suction pad 9b is used to suction and hold the core material 3. The female protrusion 19c is capable of holding the skin material 4 and is used to attach the skin material 4 to the first split mold 21.

2-2 Molded body 5
The resin panel 1 is obtained by removing flash from a molded body 5 (see FIG. 16 ) described below. That is, the molded body 5 is a molded body in a state after being molded in a mold but before flash is removed.

As shown in Figure 16, the molded body 5 is constructed by connecting the molded body main body 5a and the large burr portion 5b via a cutting line 5c that surrounds the molded body main body 5a. The cutting line 5c corresponds to the portion crushed by the pinch-off portions 21d and 22d. By cutting the molded body 5 along the cutting line 5c around the entire circumference of the molded body main body 5a, the molded body 5 can be separated into the molded body main body 5a and the large burr portion 5b.

16 and 17, the molded body main body 5a is composed of a portion (molded product 5d) corresponding to the resin panel 1 described above, and a small flash portion 5e and an inner flash portion 5bc1 connected to that portion. In other words, the resin panel 1 can be obtained by removing the small flash portion 5e and the inner flash portion 5bc1 from the molded body main body 5a.
The large burr portion 5b is composed of an upper burr portion 5bu located at the top of the molded body main body 5a, a lower burr portion 5bb located at the bottom of the molded body main body 5a, and an outer burr portion 5bc2 located between the upper burr portion 5bu and the lower burr portion 5bb. The outer burr portion 5bc2 is connected to the inner burr portion 5bc1 before being cut into the movable portion 23.

As shown in FIG. 13, the inner burr portion 5bc1 is composed of resin sheets p1 and p2 and a skin material 4. On the other hand, the outer burr portion 5bc2 is composed of resin sheets p1 and p2. In other words, the outer burr portion 5bc2 does not include a skin material 4. In other words, the skin material 4 is positioned so that its end is located between the inner pinch-off portions 21d1 and 22d1 and the outer pinch-off portions 21d2 and 22d2.

The cutting lines 5c include a left line 5cl, a right line 5cr, an upper line 5cu, and a lower line 5cb. The left line 5cl, the right line 5cr, the upper line 5cu, and the lower line 5cb are located on the left, right, upper, and lower sides, respectively, of the molded body main body 5a when the molded body 5 is viewed from the mold closing direction of the second split mold 22.

In this embodiment, a first cutting process is performed in which the molded body 5 is cut along the right line 5cr and the left line 5cl using the first and second split molds 21, 22 and the movable part 23. Then, after the molded body 5 is removed from the first and second split molds 21, 22, a second cutting process is performed in which the molded body 5 is cut along the remainder of the cutting line 5c (i.e., the upper line 5cu and the lower line 5cb).

The molded body main body 5a is composed of a molded product 5d (corresponding to the resin panel 1), a small flash 5e, and an inner flash 5bc1 connected via a parting line 5f. In other words, the molded body main body 5a includes the molded product 5d, the small flash 5e, the inner flash 5bc1, and a portion of the parting line 5f (left line 5fl and right line 5fr). Therefore, by cutting the molded body main body 5a along the parting line 5f around the entire periphery of the molded product 5d, the small flash 5e and the inner flash 5bc1 can be separated from the molded product 5d.

The parting line 5f includes a left line 5fl, a right line 5fr, an upper line 5fu, and a lower line 5fb. The left line 5fl, right line 5fr, upper line 5fu, and lower line 5fb are located on the left, right, upper, and lower sides, respectively, of the molded body main body 5a when the molded body 5 is viewed from the mold closing direction of the second split mold 22.

In the embodiment, a lower line 5cb of the cutting line 5c overlaps with a lower line 5fb of the parting line 5f.
The upper line 5cu of the cutting line 5c is provided adjacent to the upper side of the upper line 5fu of the parting line 5f, so that the molded product 5d and the small flash portion 5e are connected via the upper line 5fu.
Furthermore, the left line 5cl and the right line 5cr of the cutting line 5c are provided at positions adjacent to the sides of the left line 5fl and the right line 5fr of the parting line 5f, respectively, so that the molded product 5d and the inner flash portion 5bc1 are connected via the left line 5cl and the right line 5cr.

The upper line 5fu of the parting line 5f is non-linear. Therefore, for example, an operator may need to use a cutter to cut the molded body 5 along the upper line 5fu. Therefore, in this embodiment, a linear upper line 5cu is provided adjacent to the upper side of the upper line 5fu. In addition, in this embodiment, the lower line 5fb of the parting line 5f is also linear. Such a linear line can be cut using a cutter from a burr cutting device. In this way, after the left line 5cl and right line 5cr are cut, the upper line 5cu and lower line 5cb are cut, and the molded body main body 5a is separated from the large burr 5b.

2-3 Explanation of each step of the manufacturing method The manufacturing method of the resin panel 1 of this embodiment includes a skin material attachment step, a hanging step, an adsorption step, a shaping step, a core material welding step, a molding step, a first cutting step, a molded body removal step, a second cutting step, and a post-process.

2-3-1 Skin Material Attachment Step In the skin material attachment step, the skin material 4 is attached to the first separate mold 21. Specifically, the female projections 19c are inserted in advance into through holes formed in the skin material 4, and the skin material 4 is held by the insertion device 19, as shown in Fig. 2. In the skin material attachment step, the female projections 19c and the male projections 21e are brought into opposition to each other, and then the two are engaged. In this state, the skin material 4 is moved to the male projections 21e by pushing it toward the male projections 21e. As a result, the skin material 4 is attached to the first separate mold 21, as shown in Fig. 9.

7, in the hanging process, the resin sheets p1 and p2 extruded from the T-die 18 are hung between the first and second split molds 21 and 22. The resin sheet p1 is hung between the core material 3 and the skin material 4. The resin sheet p2 is hung between the insertion device 19 and the second split mold 22. In this embodiment, direct vacuum forming is performed using the resin sheets p1 and p2 extruded from the T-die 18 as they are, so the resin sheets p1 and p2 are not cooled to room temperature and solidified before molding, and the solidified resin sheets p1 and p2 are not heated before molding.

2-3-3 Suction Process In the suction process, as shown in FIGS. 8 to 10 , the first split mold 21 and the movable part 23 advance together, and the suction part 23g comes into contact with the resin sheet p1. The resin sheet p1 is then sucked onto the front end surface of the suction part 23g by the suction action of the suction holes 23g1 of the suction part 23g. Note that because the first split mold 21 also advances in the same way, the upper and lower suction parts 21A also come into contact with the resin sheet p1, as shown in FIG. 8 . The resin sheet p1 is then sucked onto the front end surface of the suction part 21A by the suction action of the suction holes 21B of the suction part 21A. As a result, a sealed space SD1 is formed between the resin sheet p1, the first split mold 21, and the movable part 23, as shown in FIG. 10 .

Furthermore, as shown in Figures 8 to 10, the outer frame 32 moves forward and comes into contact with the resin sheet p2. The resin sheet p2 is then adsorbed to the front end surface of the outer frame 32 by the suction action of the suction holes 32a in the outer frame 32. As shown in Figure 8, the outer frame 31 also moves forward in a similar manner. The resin sheet p2 is then adsorbed to the front end surface of the outer frame 31 by the suction action of the suction holes 31a in the outer frame 31. As a result, a sealed space SD1 is formed between the resin sheet p2, the second split mold 22, and the outer frames 31, 32, as shown in Figure 10.

2-3-4 Shaping process As shown in FIG. 11, in the shaping process, the air in the sealed spaces SD1, SD2 is vacuum-suctioned through the vacuum suction holes h1 of the first and second split molds 21, 22 and the suction section 23c of the movable section 23, and the resin sheets p1, p2 are shaped into the first and second split molds 21, 22 and the movable section 23.
In the shaping step, the outer frames 31, 32 that were advanced in the suction step are retracted. Specifically, the outer frames 31, 32 are retracted until the positions of the front end faces of the outer frames 31, 32 are aligned with the rear end portions 22ab of the chamfered portions 22a4.

As the outer frames 31, 32 retract, the resin sheet p2 is shaped to fit the surface of the second split mold 22. Because the second split mold 22 is equipped with a chamfered portion 22a4, when the resin sheet p1 moves together with the outer frames 31, 32, the resin sheet p1 is smoothly positioned along the chamfered portion 22a4. This prevents the resin sheet p1 from peeling off from the second split mold 22 or the outer frames 31, 32, avoiding molding defects.

For example, if the second split mold 22 does not have a chamfered portion 22a4 and has a right-angled corner, when the outer frames 31, 32 retract beyond the position of the corner, the resin sheet p1 will stretch so as to bend at a right angle from the corner. However, depending on the physical properties of the resin sheet p1, the resin sheet p1 may not be able to properly follow the retraction of the outer frames 31, 32, causing the corner and its surrounding area to separate (peel off) from the outer frames 31, 32 and the second split mold 22. In other words, the resin sheet p1 is forcibly stretched at the corner, preventing the resin sheet p1 from properly following the retraction of the outer frames 31, 32, causing the resin sheet p1 to peel off from the outer frames 31, 32 and the second split mold 22. In such cases, the resin sheet p1 will not be properly decompressed and shaped, leading to leakage from the sealed space SD1.

However, in the embodiment, since the second split mold 22 has a chamfered portion 22a4, when the outer frames 31, 32 retreat and the resin sheet p1 moves together with the outer frames 31, 32, the resin sheet p1 follows along the chamfered portion 22a4, thereby preventing peeling from the second split mold 22.
It is also possible to improve the followability of the resin sheet p1 by slowing down the retreat speed of the outer frames 31, 32, but this method has the disadvantage of not only lengthening the molding time for the molded body 5 but also placing restrictions on the manufacturing conditions for other processes. However, in the manufacturing method according to the embodiment, there is no need to slow down the retreat speed of the outer frames 31, 32, and it is possible to avoid a lengthening of the molding time for the molded body 5 and also to avoid placing restrictions on the manufacturing conditions.

The timing at which the decompression suction begins and the timing at which the outer frames 31, 32 begin to retract may be simultaneous or may be offset.

The timing for shaping the resin sheets p1 and p2 may be staggered. For example, the resin sheet p2 may be shaped after the core material welding process, or during the mold clamping process. The pressure in the suction section 23c may be reduced after the molding process, which will be described later.

2-3-5 Core Material Welding Process In the core material welding process, the core material 3 is welded to the resin sheet p1. As shown in Figures 11 and 12, the inserting device 19 has attached the skin material 4 to the first split mold 21, so the core material 3 remains in the inserting device 19. In this state, the inserting device 19 is moved toward the resin sheet p1, thereby welding the core material 3 to the resin sheet p1. After the core material 3 is welded to the resin sheet p1, the inserting device 19 is moved to a position outside the movement locus of the first and second split molds 21, 22.

The timing for placing the core material 3 between the resin sheets p1 and p2 is not limited, and it may be placed between the resin sheets p1 and p2 during the hanging process or shaping process. Alternatively, the core material 3 may be welded to the resin sheet p2 first.

In the molding step, the first and second split molds 21 and 22 are closed. As a result, the resin sheets p1 and p2 are crushed and welded at the locations corresponding to the pinch-off portions 21 d and 22 d, and the molded body 5 shown in FIG.
When the molding process is completed, at least a part of the movable part 23 (in this embodiment, the suction part 23g) is positioned closer to the outer frame 32 than the front end 22af of the chamfered part 22a4. Although not shown, the same is true for the suction part 21A, which is positioned closer to the outer frame 31 than the front end 22af of the chamfered part 22a4. In the shaping process, the outer frames 31 and 32 are appropriately retracted, thereby avoiding contact between the members.

2-3-8 First Cutting Step The molded body main body 5a is housed within the first and second split molds 21, 22, and the large flash portion 5b is engaged with the engaging portion 23d provided on the movable portion 23 of the first split mold 21. In this state, when the upper side of the movable portion 23 is tilted away from the main body portion 22a1, the molded body 5 begins to tear from the top along the left line 5cl and the right line 5cr of the cutting line 5c. Next, when the movable portion 23 is moved so that the lower side of the movable portion 23 is separated from the first split mold 21, the tearing of the molded body 5 progresses downward, and the first cutting step is completed (see FIG. 17 ).

2-3-9 Molded Body Removal Process In the molded body removal process, the first and second split molds 21, 22 are opened while a clamping device (not shown) clamps the burr portion, such as the upper burr portion 5bu. The molded body 5 is then transported by the clamping device to a desired location for the next process. As shown in FIG. 17 , the molded body 5 is cut along the left line 5cl and the right line 5cr of the cutting line 5c. Meanwhile, the molded body 5 is not cut along the upper line 5cu and the lower line 5cb of the cutting line 5c. If the molded body 5 were cut along either the upper line 5cu or the lower line 5cb, the molded body main body 5a would be prone to shaking relative to the large burr portion 5b, making it difficult to handle. However, in this embodiment, the molded body 5 is cut only along the left line 5cl and the right line 5cr at this point, making the molded body 5 easy to handle.

2-3-10 Second Cutting Step In the second cutting step, the molded body 5 is cut along the upper line 5cu and the lower line 5cb to separate the molded body 5 into the molded body main body 5a and the large burr portion 5b. In the second cutting step, for example, a cutting device that can recognize the positions of the upper line 5cu and the lower line 5cb and automatically cut the cutting lines can be used.

2-3-11 Post-Process In the post-process, the small flash portion 5e and the inner flash portion 5bc1 are removed to obtain the resin panel 1. This process can be performed by an operator.

3. Other Embodiments The chamfered portion 22a4 is not limited to a tapered surface. It may have any shape as long as the distance between the chamfered portion 22a4 and the resin sheet P2 increases in the direction from the outer pinch-off portion 22d2 toward the outer frame 32. For example, the chamfered portion 22a4 may be formed of multiple tapered surfaces (multiple inclined surfaces) with different inclinations.
In addition, in the embodiment, the tapered surface of the chamfered portion 22a4 is formed in a flat shape, but it may be formed in a curved shape, or a flat portion and a curved portion may be combined.
Furthermore, if the distance between the chamfered portion 22a4 and the resin sheet P2 increases in the direction from the outer pinch-off portion 22d2 toward the outer frame 32, the chamfered portion 22a4 may have one or more step portions (portions formed in a stepped shape).

In the embodiment, the second split mold 22 is described as having four chamfered portions 22a4, but this is not limited to this. For example, the second split mold 22 may have only left and right chamfered portions 22a4 and no top and bottom chamfered portions 22a4, or vice versa. Furthermore, the second split mold 22 may be configured to have only one of the four top, bottom, left and right chamfered portions 22a4.

In the embodiment, the molding machine 10 is described as having a movable part 23, but this is not limited to this and it may not have a movable part 23.

In the embodiment, an example has been described in which a pair of movable parts 23 are arranged on the left and right sides of the first split mold 21, but this is not limited to this. In addition to the movable parts 23 on the left and right sides of the first split mold 21, a movable part 23 may be arranged below the first split mold 21. Furthermore, instead of the movable parts 23 on the left and right sides of the first split mold 21, a movable part 23 may be arranged below the one-split mold 21.

DESCRIPTION OF SYMBOLS 1: Resin panel 2: Resin molded body 3: Core material 3a: Base body 3a1: Recess 3b: Base body 3b1: Recess 3c: Reinforcing member 3c1: Upper wall 3c11: Protrusion 3c2: Lower wall 3c21: Protrusion 3c3: Pillar portion 4: Skin material 5: Molded body 5a: Molded body main body 5b: Large flash portion 5bb: Lower flash portion 5bc1: Inner flash portion 5bc2: Outer flash portion 5bu: Upper flash portion 5c: Cutting line 5cb: Lower line 5cl: Left line 5cr: Right line 5cu: Upper line 5d: Molded product 5e: Small flash portion 5f: Parting line 5fb: Lower line 5fl: Left line 5fr: Right line 5fu: Upper line 9a: Base 9b: Suction pad 10: Molding machine 11 : Raw material resin 11a : Molten resin 12 : Hopper 13 : Extruder 13a : Cylinder 14 : Sheet forming device 15 : Connecting pipe 16 : Connecting pipe 17 : Accumulator 17a : Cylinder 17b : Piston 18 : T-die 19 : Insertion device 19a : Base 19b : Suction pad 19c : Female projection 21 : First split mold 21A : Suction portion 21B : Suction hole 21C : Inclined surface 21a1 : Main body 21a2 : First outer portion 21a3 : End surface 21b : Inner surface 21d : Pinch-off portion 21d1 : Inner pinch-off portion 21d2 : Outer pinch-off portion 21e : Male projection 22 : Second split mold 22a : Rear end portion 22a1 : Main body 22a2 : Second outer portion 22a3 : opposing portion 22a4 : chamfered portion 22ab : rear end portion 22af : front end portion 22b : inner surface 22d : pinch-off portion 22d1 : inner pinch-off portion 22d2 : outer pinch-off portion 23 : movable portion 23a : opposing surface portion 23b : abutting surface portion 23c : suction portion 23d : engaging portion 23e : sealing member 23g : suction portion 23g1 : suction hole 23g2 : inclined surface 31 : outer frame 31a : suction hole 32 : outer frame 32a : suction hole PL : parting line SD1 : sealed space SD2 : sealed space cvt : cavity portion hl : decompression suction hole p1 : resin sheet p2 : resin sheet sp : space t1 : distance t2 : protrusion amount w3 : setback distance θ : inclination angle

Claims (8)

A method for manufacturing a structure using a mold and an outer frame,
The method includes a drooping step, an adsorption step, and a shaping step,
In the hanging step, a molten resin sheet is hung down on the front surface of the mold,
the mold has a cavity portion, a pinch-off portion, and a chamfered portion;
the chamfered portion is provided between the outer frame and the pinch-off portion, and is formed so that a gap between the chamfered portion and the hanging-down resin sheet increases in a direction from the pinch-off portion toward the outer frame,
In the suction step, the outer frame is moved forward to suction the resin sheet with the outer frame, thereby forming a closed space between the outer frame, the resin sheet, and the mold;
the outer frame is disposed around the mold and is configured to be able to adsorb the resin sheet;
In the shaping step, the outer frame is retracted and the closed space is decompressed to shape the resin sheet in the cavity portion,
In the shaping step, the outer frame retracts to a position on the rear end side of the chamfered portion as viewed from the front end of the chamfered portion,
The method, wherein the resin sheet moves together with the outer frame as the outer frame retracts, and is positioned along the chamfered portion. 10. The method of claim 1,
The method, wherein the chamfer comprises a tapered surface. 3. The method of claim 2,
The method wherein the inclination angle of the tapered surface is 60 degrees or less. The method according to any one of claims 1 to 3,
In the shaping step, the outer frame retracts to the position of the rear end of the chamfered portion. The method according to any one of claims 1 to 4,
A method in which, in the shaping step, the recession distance of the outer frame is 30 mm or more and 80 mm or less. The method according to any one of claims 1 to 5,
The manufacturing method further includes a movable part and further includes a molding step;
The mold has first and second split molds,
the movable part is configured to move relative to the first separate mold to cut a portion of the resin sheet, and is attached to the periphery of the first separate mold;
the second split mold has the chamfered portion, and the outer frame is disposed around the second split mold;
In the molding step, the first and second split molds are closed, and when the molding step is completed, at least a part of the movable part is positioned closer to the outer frame than the position of the front end of the chamfered part. The method according to any one of claims 1 to 6,
The method, wherein the chamfered portion has a width in the opening and closing direction of the mold of 10 mm or more and 63 mm or less. The method according to any one of claims 1 to 7,
The method, wherein the chamfered portion has a width in a direction from the pinch-off portion toward the outer frame of 5.7 mm or more and 70 mm or less.