Manufacturing method for resin molding

Abstract

To provide a resin molding bent to be limited in an influence to the resin molding and difficult to give press traces, press damages or the like even when a plastic deformation load to the resin molding during bending is great.SOLUTION: A method for manufacturing a resin molding comprises: a step of setting at least a bending-scheduled part of a resin molding M in a longitudinal direction on a die 1 via a core material 3 made of a blank different from the resin molding M; a step of lowering a punch 2 lifted with respect to the die 1 and applying a bending load of a size enough to give plastic deformation to the resin molding M to the bending-scheduled part of the resin molding M via the core material 3; and a step of removing the core material 3 from the bent resin molding. The core material 3 is divided into a die side core material 31 against which the die 1 abuts and a punch side core material 32 against which the punch 2 abuts. Abutting of the die 1 and the punch 2 against the bending-scheduled part of the resin molding M is prevented by holding the bending-scheduled part of the resin molding M between the die side core material 31 and the punch side core material 32.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for producing a resin molding, and particularly to a method for producing a resin molding to be attached to a flange around an opening of a vehicle such as an automobile door or back door. [Background Art]

[0002] Resin moldings attached to flanges around openings of vehicles such as automobile doors and back doors are manufactured by extrusion-molding resin. Extruded molded products have a linear shape, and are classified into those that are attached in a linear shape and those that are attached in a bent shape. After extrusion molding, bending is performed in accordance with the shape of the periphery of the opening of the vehicle such as the automobile door or back door to which the molding is attached. As a method for producing a resin molding having a bent shape, a method has been proposed in which a core material is set on a portion to be bent of a linear belt molding heated by a heating device, and a bending load is applied by a die and a punch to the set material of the linear belt molding core material to perform bending processing (see, for example, Patent Document 1). [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2015-157437 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in the method for producing a resin molding described in Patent Document 1 mentioned above, bending is performed by directly pressing the resin molding with a punch to apply a plastic deformation load. Therefore, when the plastic deformation load increases, there is a problem that the cross-sectional framework of the resin molding is deformed.

[0005] Furthermore, if the shape of the punch used to apply the plastic deformation load by pressing from above to ensure uniformity is the same as the cross-sectional shape of the resin molding, then in areas where the contact area between the two is small, indentations and scratches may occur, resulting in a poor appearance and compromising the marketability of the product.

[0006] In particular, in the case of resin inner belt moldings installed on the interior side of automobiles, since door trim covers are usually installed on the inside of the door panel, the cross-sectional structure (cross-sectional shape) of the resin inner belt molding is more complex than that of the resin outer belt molding, and the cross-sectional area is also larger, making it difficult to manufacture in a way that satisfies the performance and appearance quality required for automobiles.

[0007] Therefore, the present invention has been made in view of these problems, and aims to provide a method for manufacturing a resin molding that, even when a large plastic deformation load is applied to the resin molding during bending, has little effect on the cross-sectional structure of the resin molding, and is less likely to cause indentations or scratches. [Means for solving the problem]

[0008] To solve the aforementioned problems, the present invention provides a method for manufacturing a resin molding, comprising the steps of: covering the portion of the resin molding to be bent with a core material made of a different material, and setting the resin molding on the curved surface of a die curved according to the bending of the portion to be bent via the core material; lowering a punch toward the die, so that the die and the punch press against the portion of the resin molding to be bent via the core material, thereby causing plastic deformation of the portion to be bent and performing bending; and removing the core material from the resin molding after the bending is complete. The resin molding comprises a resin molding body that is attached to the flange portion of a vehicle door or the like, and a lip portion that is provided so as to protrude from the resin molding body and rubs against the vehicle's glass. The aforementioned core material is The die-side core material that the die contacts and the punch-side core material that the punch contacts It is composed of parts, When the resin molding is sandwiched and covered by the die-side core material and the punch-side core material, the upper part of the lip portion is open. It is characterized by the following: Furthermore, in the resin molding manufacturing method according to the present invention, the die-side core material has a die contact portion against which the die abuts, a die-side resin molding body pressing portion provided with an uneven surface corresponding to the shape of the resin molding body, a die-side lip portion lower protective wall portion that protrudes from the die-side resin molding body pressing portion by a length greater than or equal to the lateral protrusion length of the lip portion, and a die-side lip portion tip protective wall vertical portion that rises from the end of the die-side lip portion lower protective wall portion opposite to the die-side resin molding body pressing portion and extends by a length greater than or equal to the height of the lip portion, while the punch-side core material has a die contact portion against which the punch abuts The punch contact portion and the resin molding body pressing portion have an uneven surface corresponding to the shape of the resin molding body and sandwich and press the resin molding body between the die-side resin molding body pressing portion to plastically deform it. The punch contact portion and the punch-side resin molding body pressing portion are provided between the punch contact portion and the punch-side resin molding body pressing portion and face the vertical portion of the tip protective wall of the die-side lip portion, and the upper protective vertical wall portion of the punch-side lip portion extends above the height of the lip portion so that the upper surface of the lip portion does not come into contact with the punch-side pressing portion of the punch, and the punch descends and presses the resin molding through the core material against the die. curved surface Another feature is that when pressing and plastically deforming the resin molding, the punch is configured so as not to come into contact with the lip portion of the resin molding. Furthermore, in the method for manufacturing resin molding according to the present invention, the resin molding is sandwiched between the die-side core material and the punch-side core material. Covered with Furthermore, the height of the vertical portion of the protective wall at the tip of the die-side lip portion in the die-side core material and the height of the punch contact portion in the punch-side core material are formed such that they are higher than the height of the tip of the lip portion even when the lip portion is erected from the resin molding body of the resin molding. [Effects of the Invention]

[0009] In the method for manufacturing resin molding according to the present invention, the portion of the resin molding to be bent is divided and covered with a core material, which is then set on a die. The die and the punch press the portion of the resin molding to be bent through the core material, thereby causing plastic deformation of the portion of the resin molding to be bent and performing the bending process. Therefore, when bending the portion of the resin molding to be curved using a die and punch, the punch and die can be prevented from directly contacting the resin molding body. As a result, even when a large plastic deformation load is applied to the resin molding, the impact on the cross-sectional structure of the resin molding is reduced, and indentations and scratches are less likely to occur, making it possible to manufacture bent resin molding with good appearance quality. [Brief explanation of the drawing]

[0010] [Figure 1] (a) to (c) are diagrams showing a simplified representation of the linear resin molding after extrusion molding, a diagram showing an example of a door panel fitted with a resin molding manufactured by the resin molding manufacturing method according to the present invention, and a diagram showing a simplified representation of the resin molding manufactured by the resin molding manufacturing method according to the present invention. [Figure 2] This is an enlarged cross-sectional view of a key part showing an example of a resin molding manufactured by the resin molding manufacturing method according to the present invention, attached to a door panel. [Figure 3] This is a front view showing the state immediately before the portion of a straight-shaped resin molding intended to be bent, using a core material, is sandwiched between a die and a punch in the manufacturing method of resin molding according to the present invention. [Figure 4] This is a cross-sectional view along line AA in Figure 3. [Figure 5] This is a front view showing the state in which a straight-shaped resin molding is bent by sandwiching the portion to be bent between a die and a punch with a core material in place, in a method for manufacturing resin molding according to the present invention. [Figure 6] (a) to (c) are cross-sectional views showing the die-side core material and punch-side core material combined, respectively, which constitute the core material used in the resin molding manufacturing method according to the present invention. [Figure 7] This is a cross-sectional view showing the core material according to the present invention set in the portion of the resin molding that is to be bent. [Figure 8] Table 1 shows the bending amount measurement results for 10 test specimens, each bent to a target of 90 mm, using the resin molding manufacturing method according to an embodiment of the present invention. [Figure 9] Table 2 shows the wrap amounts (deflection amounts) of the upper and lower lips relative to the door glass at the lip portion of a test specimen bent by the resin molding manufacturing method according to an embodiment of the present invention. [Figure 10] (a) and (b) are each diagrams showing cross-sectional shapes of test specimens of resin moldings having other cross-sectional shapes manufactured by bending processing via the resin molding manufacturing method according to an embodiment of the present invention. [Figure 11] Table 3 shows bending evaluation results of the test specimens shown in FIG. 10(a) and (b) bent by the resin molding manufacturing method (same punch and die) according to an embodiment of the present invention. [Figure 12] It is a diagram showing a modified example of the core material used in the resin molding manufacturing method according to an embodiment of the present invention, wherein the core material is provided with slits at predetermined intervals in the transverse direction thereof. MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the resin molding manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiments described below are merely examples of the present invention, and the present invention is not limited to the following embodiments, and can be appropriately modified within the scope of the technical idea of the present invention.

[0012] The resin molding M before being subjected to bending processing by the resin molding manufacturing method according to an embodiment of the present invention has a linear shape as shown in FIG. 1(a). Since the boundary between the mounting position P on the door panel 42 of an automobile door 4 and the door glass 41 as shown in FIG. 1(b) is sometimes curved, a linear-shaped resin molding M cannot be mounted reliably and neatly.

[0013] For this reason, the linearly shaped resin molding M after extrusion molding is bent in accordance with the curved shape of the mounting position P on the door panel 42 as shown in FIG. 1(c).

[0014] The resin molding M attached to the doors 4 of such automobiles includes resin outer belt moldings installed on the outside of the vehicle and resin inner belt moldings installed on the inside of the vehicle. In the case of resin inner belt moldings, as shown in Figure 2, a door trim cover 43 is installed on the inside of the door panel 42, so the cross-sectional shape is often more complex than that of resin outer belt moldings.

[0015] (Cross-sectional structure of resin molding M) The resin molding M of the resin inner belt molding shown in Figure 2 is typically constructed with a resin molding body M1 that has an S-shaped cross-section due to the formation of irregularities by an inner upright portion M11, a central upright portion M12, a lip-side upright portion M13, an upper wall portion M14, and a lower wall portion M15, so as to cover both sides and the tip of the flange portion 42a of the vehicle door panel 42 and the flange portion 43a of the door trim cover 43, and has a plurality of lip portions M21, M22, etc. (here, for example, two) that protrude from the lip-side upright portion M13 on the door glass 41 side toward the door glass 41 and rub against the door glass 41.

[0016] Here, the lip portions M21 and M22 must always maintain contact even when the door glass 41 moves up and down. For this reason, the lip portion connecting ends M21a and M22a, which are the connection points with the resin molding body M1, are formed to be thinner (narrower) than the central part of the lip portions M21 and M22 so that the lip portions M21 and M22 can move freely relative to the resin molding body M1, and the lip portion tips M21b and M22b, which are the tips of the lip portions M21 and M22, are also formed in a tapered shape. Note that in Figure 2, the resin molding M is provided with two lip portions M21 and M22, but it is also fine to provide one, or of course, three or more.

[0017] (Die 1 composition) As shown in Figures 3 to 5, the die 1 is located below the punch 2 and consists of a die base 11 that is installed on a stable floor surface, die-side vertical wall sections 12, 12 that are erected on the die base 11 at intervals equal to the width of the core material 3 that covers the portion of the resin molding M to be bent, and a die-side pressing section 13 that is provided between the inner walls of the die-side vertical wall sections 12, 12 and has a die-side curved surface 13a that is curved to match the portion of the resin molding M to be bent. A die-side curved groove section 14 is provided between the inner walls of the die-side vertical wall sections 12, 12 and the die-side curved surface 13a into which the resin molding M covered with the core material 3 is pressed.

[0018] (Composition of Punch 2) As shown in Figures 3 to 5, the punch 2 has a punch-side pressing portion 22 on the lower surface of the punch base portion 21, which has a punch-side curved surface 22a that is curved according to the curved surface of the portion of the resin molding M to be bent. The punch base portion 21 is attached to a lifting mechanism (not shown) and is configured to move up and down. The punch 2 applies a plastic deformation load that causes the portion of the resin molding M to be bent to be plastically deformed by pressing the portion of the resin molding M to be bent from above with the punch-side curved surface 22a via the core material 3, and sandwiching it between the die-side pressing portion 13 of the die 1 and the die-side curved surface 13a, thereby causing the portion of the resin molding M to be plastically deformed.

[0019] In this embodiment, the portion of the resin molding M that is to be bent is covered with a core material 3 consisting of a die-side core material 31 and a punch-side core material 32, as described later. Then, as shown in Figure 5, a plastic deformation load is applied by sandwiching the core material between the punch-side curved surface 22a of the punch-side pressing portion 22 and the die-side curved surface 13a of the die-side pressing portion 13 via the die-side core material 31 and the punch-side core material 32, so that the punch-side curved surface 22a and the die-side curved surface 13a do not directly contact the resin molding M.

[0020] (Composition of core material 3) As shown in Figures 4, 6(a) to 6(c), and 7, the core material 3 is divided into a die-side core material 31 that the die 1 contacts and a punch-side core material 32 that the punch 2 contacts.

[0021] The materials of the die-side core material 31 and punch-side core material 32 that constitute the core material 3 are preferably materials that elastically deform under the plastic deformation load of the punch 2 but can be restored to their original shape without plastic deformation. In the embodiment of the present invention, for example, UPE (ultra-high molecular weight polyethylene) is used. Furthermore, since the core material 3 can be bent if its wall thickness is 0.5 to 6.0 mm, it is formed to have a wall thickness of 0.5 to 6.0 mm.

[0022] (Die-side core material 31) As shown in Figures 6(a) and (c), the die-side core material 31 includes a die contact portion 31a that contacts the die-side curved surface 13a of the die 1 (see Figures 3 to 5), a die-side resin molding body pressing portion 31b which has an uneven surface corresponding to the shape of the resin molding body M1, a die-side lip portion lower protective wall portion 31c which is provided to protrude horizontally from the die-side resin molding body pressing portion 31b by a length greater than the lateral protrusion length of the lip portions M21 and M22 and protects the lip portions M21 and M22 from being pressed, as shown in Figure 7 which will be described later, and a die-side lip portion tip protective wall vertical portion 31d which rises from the end of the die-side lip portion lower protective wall portion 31c opposite to the die-side resin molding body pressing portion 31b, does not contact the tips of the lip portions M21 and M22, and extends upward by a length greater than the height of the upper lip portion (upper lip portion) M21.

[0023] Here, the die-side lip lower protective wall portion 31c has a die-side lip lower protective wall high portion 31c1 which is the same height as the die-side resin molding body pressing portion 31, and a die-side lip lower protective wall low portion 31c2 which is one step lower than the die-side lip lower protective wall high portion 31c1, and the height of the die-side lip tip protective wall vertical portion 31d is formed to be lower than the height of the die-side resin molding body pressing portion 31b. Furthermore, in the present invention, instead of providing a lower portion 31c2 of the lower protective wall of the lower protective wall of the die side lip which is lower than the higher portion 31c1 of the lower protective wall of the lower protective wall of the die side lip, the lower protective wall portion 31c of the die side lip may be inclined such that the height of the vertical portion 31d of the tip protective wall of the die side lip is lower than the height of the pressing portion 31b of the resin molding body on the die side, or the lower protective wall portion 31c of the die side lip may be configured to be horizontally flush without providing the higher portion 31c1 and the lower protective wall 31c2 of the lower protective wall of the die side lip.

[0024] The reason for providing a lower protective wall portion 31c2 on the die side lip portion lower protective wall portion 31c, which is lower than the height of the die side resin molding body pressing portion 31b, is that when a plastic deformation load is applied to the resin molding body M1 sandwiched between the die side core material 31 and the punch side core material 32, and the tips of the lip portions M21 and M22 deform in such a way that they tilt due to the deformation of the resin molding body M, the lower surface of the lower lip portion M22 will not come into contact with the die side lip portion lower protective wall portion 31c as much as possible, so as not to cause indentations or scratches.

[0025] (Punch side core material 32) The punch-side core material 32 has a punch contact portion 32a that contacts the punch-side curved surface 22a (see Figures 3 to 5) of the punch-side pressing portion 22 of the punch 2, as shown in Figures 6(a), (b), etc., and a punch-side resin molding body pressing portion 32b which has an uneven surface corresponding to the shape of the resin molding body M1 and presses and plastically deforms the resin molding body M1 by sandwiching it between the die-side resin molding body pressing portion 31b and the punch contact portion 32a and the punch-side resin molding body pressing portion 32b, and the vertical portion 31d of the die-side lip tip protective wall of the die-side core material 31. The upper lip portion (upper lip portion) M21 has a vertical protective wall portion 32c that rises from the punch-side resin molding body pressing portion 32b toward the punch contact portion 32a, and is positioned to prevent the upper surfaces of the lip portions M21 and M22 from contacting the punch-side pressing portion 22 of the punch 2. When combined with the die-side core material 31, it is configured to form a lip portion accommodating space 33 with the upper part of the die-side lip portion lower protective wall portion 31c of the die-side core material 31 open, as shown in Figures 6(a) and 7.

[0026] In other words, as shown in Figure 7, when the die-side core material 31 and the punch-side core material 32 are attached to the portion of the resin molding M that is to be bent, the resin molding body M1 is sandwiched between the die-side resin molding body pressing portion 31b of the die-side core material 31 and the punch-side resin molding body pressing portion 32b of the punch-side core material 32. However, the lip portions M21 and M22 are housed in the lip portion housing space 33 so that they can move freely without coming into contact with the die-side core material 31 and the punch-side core material 32. Even when the lip portions M21 and M22 move freely, the lip portion M21 is configured not to come into contact with the punch-side curved surface 22a of the punch 2 (see Figure 5, etc.).

[0027] Therefore, even when a plastic deformation load is applied to the resin molding body M1 via the die-side resin molding body pressing portion 31b and the punch-side resin molding body pressing portion 32b by the die 1 and the punch 2, and the lip portions M21 and M22 stand upright in the vertical direction due to the deformation of the resin molding body M1, the height of the upper end of the vertical portion 31d of the die-side lip portion tip protective wall on the die-side core material 31 and the height of the punch contact portion 32a of the punch-side core material 32 are formed to be higher than the tip of the upper lip portion (upper lip portion) M21.

[0028] Specifically, for the die-side core member 31, as shown in FIG. 7, let H1 be the length of the upper lip portion (upper lip) M21, and H2 be the height from the lower end of the lip-side standing portion M13 of the resin molding main body M1 (see FIG. 2) to the connecting end M21a of the upper lip portion (upper lip) M21. The height h1 from the lower die-side lip protection wall high portion 31c1 to the upper end of the vertical die-side lip tip protection wall portion 31d is set such that even when the upper lip portion (upper lip) M21 stands up vertically from the state shown in FIG. 7, the tip of the upper lip portion (upper lip) M21 does not contact the punch-side curved surface 22a of the punch 2 (see FIGS. 3 to 5). Therefore, the height h1 of the upper punch-side lip protection vertical wall portion 32c is determined so that at least the relationship (H1+H2)<h1 is satisfied.

[0029] Furthermore, for the punch-side core member 32, as shown in FIG. 7, let h2 be the length of the upper punch-side lip protection vertical wall portion 32c, and H3 be the height from the connecting end M21a of the upper lip portion (upper lip) M21 to the upper end of the lip-side standing portion M13 of the resin molding main body M1 (see FIG. 2). The length h2 of the upper punch-side lip protection vertical wall portion 32c is determined such that even when the upper lip portion (upper lip) M21 stands up vertically from the state shown in FIG. 7, the tip of the upper lip portion (upper lip) M21 does not contact the punch-side curved surface 22a of the punch 2 (see FIGS. 3 to 5), so that at least the relationship (H1+H2)<(H2+H3+h2), that is, H1<(H3+h2) is satisfied.

[0030] Furthermore, in the present embodiment, in addition to satisfying the above two relationships, when the die-side core member 31 and the punch-side core member 32 are attached to the portion to be bent of the resin molding M, as shown in FIG. 7, the height of the vertical die-side lip tip protection wall portion 31d of the die-side core member 31 matches the height of the punch contact portion 32a of the punch-side core member 32. Therefore, the heights of the die-side core member 31 and the punch-side core member 32 are determined so that the relationship h1=(H2+H3+h2) is satisfied.

[0031] <Method for manufacturing resin molding according to embodiment of the present invention> Next, a method for manufacturing resin molding according to an embodiment of the present invention will be described.

[0032] (Heat treatment of resin molding M) As shown in Figure 1(a), the linear resin molding M after extrusion is heat-treated before bending by die 1 and punch 2 to avoid impairing product performance and appearance quality.

[0033] The heat treatment before applying the bending load that causes plastic deformation involves sending a straight-shaped resin molding M into a heating furnace (not shown) set to a predetermined temperature, for example, 100°C to 130°C, using methods such as air heating, electromagnetic waves, or hot water.

[0034] In this case, the heat treatment of the resin molding M is performed only on the portion to be bent. Furthermore, even for the resin molding M in the portion to be bent, it is sufficient to heat treat only the resin molding body M1, which is the skeletal part of the resin molding M, and it is not necessarily required to heat treat the lip portions M21 and M22. However, it is preferable to heat treat the entire resin molding M in the portion to be bent, including not only the resin molding body M1 but also the lip portions M21 and M22.

[0035] Here, the set temperature during the heat treatment varies depending on the amount of bending required for the part of the resin molding M that is to be bent. For example, if the target bending amount is 90 mm, a suitable setting temperature for the heating furnace would be around 100°C to 130°C. However, if the bending amount of the resin molding M is small, the heat treatment of the resin molding M may be omitted.

[0036] (The heat-treated resin molding M is set into the core material 3.) Next, the core material 3 is set onto the heat-treated linear resin molding M as described above. Specifically, the heat-treated linear resin molding M is placed on top of the die-side core material 31, and then the punch-side core material 32 is placed over it.

[0037] As shown in Figure 7, the resin molding body M1 is then set in a manner in which it is sandwiched from above and below by the die-side resin molding body pressing portion 31b of the die-side core material 31, which has an uneven surface corresponding to the uneven shape of its lower surface, and the punch-side resin molding body pressing portion 32b of the punch-side core material 32.

[0038] In contrast, the lip portions M21 and M22 are housed in an open lip portion housing space 33 formed by the die-side core material 31 and the punch-side core material 32, as shown in Figures 6(a) and 7, and are set so as not to come into contact with the die-side resin molding body pressing portion 31b of the die-side core material 31 and the punch-side resin molding body pressing portion 32b of the punch-side core material 32.

[0039] (The resin molding M, which is set on the core material 3, is set on die 1 and pressed with punch 2.) As described above, the resin molding M sandwiched between the die-side core material 31 and the punch-side core material 32 is set in the die 1, the upper surface of the set punch-side core material 32 is pressed by the punch 2, and the punch-side pressing portion 22 of the punch 2 pushes the portion of the resin molding M that is to be bent, covered by the die-side core material 31 and the punch-side core material 32, into the die-side curved groove portion 14 of the die 1 (see Figures 3 and 4, etc.), and the die-side curved surface 13a and the punch-side curved surface 22a press the resin molding M via the die-side core material 31 and the punch-side core material 32 with a plastic deformation load, and this pressed state is maintained for a certain period of time.

[0040] Here, the duration for which a plastic deformation load is applied to the resin molding M also varies depending on the amount of bending required for the portion of the resin molding M that is to be bent. For example, if the target bending amount to be processed is 90 mm, then a suitable duration for applying a plastic deformation load to the portion of the resin molding M that is to be bent, which is covered by the die-side core material 31 and the punch-side core material 32 within the die-side curved groove 14 of the die 1, is approximately 80 to 100 seconds.

[0041] Once the pressing of the resin molding M with a plastic deformation load for a certain period of time on the part to be bent is complete, the punch 2 is raised, and then the resin molding M covered with the die-side core material 31 and the punch-side core material 32 is removed from the die 1, and then the die-side core material 31 and the punch-side core material 32 are removed from the resin molding M, and the resin molding M that has been bent with a plastic deformation load is removed.

[0042] As a result, the resin molding M is pressed by the die 1 and punch 2 within the die-side curved groove 14 of the die 1 with a plastic deformation load, and since this pressing state continues for a predetermined time of about 80 to 100 seconds, it undergoes plastic deformation and is bent.

[0043] In contrast, the die-side core material 31 and punch-side core material 32 of the core material 3, which were pressed by the die 1 and punch 2 with a plastic deformation load within the die-side curved groove 14 of the die 1, are formed from a material such as UPE (ultra-high molecular weight polyethylene), and are therefore restored to their original straight shape by the elasticity of the core material 3 itself and reused.

[0044] <Evaluation of the example (test sample) manufactured by the resin molding manufacturing method of the embodiment> Next, we will describe the evaluation of an example (test product) manufactured by bending a core material 3 that has been divided into a die-side core material 31 and a punch-side core material 32 using the resin molding manufacturing method of the embodiment of the present invention.

[0045] (Evaluation of bending amount and return amount) Figure 8 shows the measurement results of the bending amount of test samples No. 1 to No. 10, which were bent to a target bending amount of 90 mm using the resin molding manufacturing method of the embodiment of the present invention. Table 1 shows the bending amount after 1 hour (1h), the bending amount after 3 days, the bending amount after 5 days, the return amount after 5 days, and the deformation amount relative to the target bending amount of 90 mm, respectively.

[0046] For example, in the case of test sample No. 1, as shown in Table 1 in Figure 8, the amount of bending after 1 hour (1h) was 93.5 mm, the amount of bending after 3 days was 91.4 mm, the amount of bending after 5 days was 91.1 mm, the average amount of return after 5 days was 2.4 mm, and the average amount of deformation relative to the target bending amount of 90 mm was 1.1 mm.

[0047] As a result, the average values ​​for test samples No. 1 to No. 10 were as shown in Table 1 in Figure 8: the average bending amount after 1 hour (1h) was 93.8 mm, the average bending amount after 3 days was 91.6 mm, the average bending amount after 5 days was 91.3 mm, the average return amount after 5 days was 2.5 mm, and the average deformation amount relative to the target bending amount of 90 mm was 1.3 mm.

[0048] Furthermore, the maximum values ​​(max) were 96.5 mm for the bending amount after 1 hour (1h), 94.3 mm after 3 days, 94.0 mm after 5 days, 3.1 mm for the average return amount after 5 days, and 4.0 mm for the deformation amount relative to the target bending amount of 90 mm. The minimum values ​​(min) were 91.9 mm, 89.9 mm, 89.4 mm, 1.9 mm, and -0.6 mm, respectively. The variance (δ) and median (MEDIAN) are shown in Table 1 of Figure 8.

[0049] As a result, from the measurement of the bending amount of test samples No. 1 to No. 10, it was found that by adopting a separate structure in which the core material 3 is divided into a die-side core material 31 and a punch-side core material 32, the bending amount was processed with an average of +1.3 mm, a maximum of 4.0 mm, and a minimum of -0.6 mm compared to the target value of 90 mm, with small variations between test samples.

[0050] (Lip section M21, M22 shape overlap amount and evaluation) Figure 9 is Table 2, which shows the measurement results of the overlap amount of the shape of the upper lip portion (upper lip portion) M21 and lower lip portion (lower lip portion) M22 of the resin molding M of test samples No. 1 to No. 10, which were bent to a target bending amount of 90 mm by the resin molding manufacturing method of the embodiment of the present invention, with respect to the door glass 41.

[0051] As shown in Table 2 of Figure 9, for the upper lip portion M21, the overlap amounts of the shape with respect to the door glass 41 were +6.41 mm, +5.51 mm, +5.78 mm, and +4.76 mm at 0 mm, 300 mm, 600 mm, and 730 mm from the tip of the upper lip portion M21, respectively. On the other hand, for the lower lip portion M22, the overlap amounts of the shape with respect to the door glass 41 were +2.96 mm, +2.45 mm, +2.45 mm, and +2.53 mm at 0 mm, 300 mm, 600 mm, and 730 mm from the tip of the lower lip portion M22, respectively.

[0052] As a result, both the upper lip portion M21 and the lower lip portion M22 exceeded the minimum tolerance distance of 0 mm at which the lip portions M21 and M22 of the resin molding M come into contact with the door glass 41 at all positions of 0 mm, 300 mm, 600 mm, and 730 mm from the tips of their respective lip portions M21 and M22. This proves that the resin molding M manufactured by bending using the core material 3 divided into a die-side core material 31 and a punch-side core material 32 according to the resin molding manufacturing method of the embodiment of the present invention can ensure sufficient overlap with the door glass 41 of the automobile door 4 even when the upper lip portion M21 and the lower lip portion M22 come into contact with the door glass 41, and thus it was found that there is no impact on product performance.

[0053] Furthermore, when the resin moldings M' and M'' with the cross-sectional shapes shown in Figures 10(a) and (b), which were manufactured by bending the core material 3 divided into die-side core material 31 and punch-side core material 32 in the manufacturing method of the resin molding according to the embodiment of the present invention, were similarly subjected to a bending test with a bending amount of 90 mm and an appearance inspection, as shown in Table 3 in Figure 11, there was no change in appearance quality in the upper lip portion M21 and the lower lip portion M22, and no indentations or scratches were found.

[0054] As a result, although there were some differences in bending conditions between the resin moldings M' and M'' with the cross-sectional shapes shown in Figures 10(a) and (b) due to cross-sectional area, cross-sectional framework (cross-sectional shape), etc., no other significant differences were found in the evaluation.

[0055] <Summary of the method for manufacturing resin molding according to the embodiment of the present invention> As described above, the method for manufacturing a resin molding according to the embodiment of the present invention comprises the steps of: setting the resin molding M on a die 1 having a die-side curved groove portion 14 via a core material 3 made of a different material from the resin molding M, at least the portion of the resin molding M to be bent in the longitudinal direction; lowering a punch 2 that moves up and down to press the portion of the resin molding M to be bent against the die-side curved groove portion 14 of the die 1 via the core material 3 and applying a bending load of a magnitude that causes plastic deformation to the portion of the resin molding M to be bent; and removing the core material 3 from the resin molding M after the bending process is completed. The core material 3 is divided into a punch-side core material 32 that the punch 2 contacts and a die-side core material 31 that the die 1 contacts.

[0056] Therefore, when a plastic deformation load is applied to the portion of the resin molding M to be bent by the die 1 and punch 2, the die 1 and punch 2 do not directly contact the resin molding M. As a result, even when a large plastic deformation load is applied to the portion of the resin molding M to be bent, the impact on the resin molding M is reduced, and it becomes less likely to cause indentations or scratches on the resin molding M, making it possible to manufacture a bent resin molding M with good appearance quality.

[0057] Furthermore, in the resin molding manufacturing method of the embodiment of the present invention, the die-side core material 31 has a die contact portion 31a that the die-side curved surface 13a of the die 1 abuts against, a die-side resin molding body pressing portion 31b that has an uneven surface corresponding to the shape of the resin molding body M1, a die-side lip portion lower protective wall portion 31c that protrudes horizontally from the die-side resin molding body pressing portion 31b by a length greater than or equal to the lateral protrusion length of the lip portions M21 and M22, and a die-side lip portion tip protective wall vertical portion 31d that rises from the end of the die-side lip portion lower protective wall portion 31c opposite to the die-side resin molding body pressing portion 31b, does not contact the tips of the lip portions M21 and M22, and extends upward by a length greater than or equal to the height of the upper lip portion (upper lip portion) M21, and the punch-side core material 32 has a punch contact portion 32a that the punch-side curved surface 22a of the punch-side pressing portion 22 of the punch 2 abuts against, and the shape of the resin molding body M1 The punch-side resin molding body pressing portion 32b is provided with corresponding uneven surfaces and presses and plastically deforms the resin molding body M1 between itself and the die-side resin molding body pressing portion 31b. The punch-side resin molding body pressing portion 32b is provided between the punch contact portion 32a and the punch-side resin molding body pressing portion 32b and faces the vertical portion 31d of the die-side lip portion tip protective wall of the die-side core material 31. The punch-side lip portion upper protective vertical wall portion 32c is provided so as to prevent the upper surfaces of the lip portions M21 and M22 from contacting the punch-side pressing portion 22 of the punch 2, and is positioned at a height greater than or equal to the height of the upper lip portion (upper lip portion) M21, rising from the punch-side resin molding body pressing portion 32b toward the punch contact portion 32a. When the die-side core material 31 and the punch-side core material 32 are combined, the configuration is such that a lip portion accommodating space portion 33 is formed by opening the area above the die-side lip portion lower protective wall portion 31c of the die-side core material 31, as shown in Figures 6(a) and 7.

[0058] Therefore, when the die 1 and punch 2 apply a plastic deformation load to the portion of the resin molding M that is to be bent, the plastic deformation load is applied only to the resin molding body M1 of the portion of the resin molding M that is to be bent, via the die-side resin molding body pressing portion 31b and the punch-side resin molding body pressing portion 32b. The lip portions M21 and M22 are housed in the lip portion housing space 33 surrounded by the die-side lip portion lower protective wall portion 31c, the die-side lip portion tip protective wall vertical portion 31d, and the punch-side lip portion upper protective vertical wall portion 32c, and no plastic deformation load is applied by the die-side core material 31 and the punch-side core material 32. As a result, the die 1 and punch 2 do not directly contact the resin molding M, making it difficult to inflict indentations or scratches on the resin molding M. Furthermore, the load on the lip connecting ends M21a and M22a, which are thinner (narrower) than the central part of the lip portions M21 and M22 and connected to the resin molding body M1, is reduced, and defects such as the lip connecting ends M21a and M22a being cut are reliably prevented. Thus, it is possible to manufacture a bent resin molding M with good appearance quality.

[0059] In particular, in the resin molding manufacturing method of the embodiment of the present invention, the punch-side core material 32 is not located above the lip portion housing space 33, and is left open.

[0060] Therefore, the volume of the punch-side core material 32 can be reduced, thereby lowering costs. Furthermore, if a lid-like punch-side core material 32 were to be provided above the lip portion housing space 33, it would become like a thin plate lid, weakening its strength and increasing the possibility of damage due to repeated application of plastic deformation loads to the punch-side core material 32. By leaving the top of the lip portion housing space 33 open and not providing a punch-side core material 32, the durability of the punch-side core material 32 can be improved, further reducing costs.

[0061] In the above description of the embodiment, the die-side contact portion 31 with the die 1 in the die-side core material 31 and the punch-side contact portion 32a with the punch 2 in the punch-side core material 32 that constitute the core material 3 were described as being configured in a planar manner. However, if the amount of bending, i.e., the curvature, of the portion of the resin molding M that is to be bent is large, the die-side core material 31 and the punch-side core material 32 that constitute the core material 3 may be damaged, or may not be restored to their original shape due to repeated plastic deformation loads.

[0062] Therefore, if the amount of bending in the planned bending portion of the core material 3 is large, depending on the curvature of the straight section and the virtual curvature section, it is preferable to incorporate slits extending in the short direction at predetermined intervals in the longitudinal direction of the core material 3, as shown in Figure 12, and the pitch (spacing) of the slits may be changed depending on the cross-sectional shape and bending ratio. In the example shown in Figure 12, if the core material 3 has a total length of 500 mm in its longitudinal direction, slits S are provided at 3 mm intervals.

[0063] Furthermore, in the description of this embodiment, as shown in Figures 6 and 7, the punch-side core material 32 constituting the core material 3 was described as being configured so that the upper part of the lip portion housing space 33 is open and the punch-side core material 32 is not provided. However, the present invention is not limited to this, and of course, a portion is provided in the punch-side core material 32 that extends horizontally from the upper end of the punch-side lip portion upper protective vertical wall portion 32c to the upper end of the die-side lip portion tip protective wall vertical portion 31d, and that closes the lip portion housing space 33, facing the die-side lip portion lower protective wall portion 31c, so that the punch 2 does not come into contact with the resin molding M.

[0064] Furthermore, in this description of the embodiment, the core material 3 was described as being divided into two parts: the die-side core material 31 and the punch-side core material 32. However, the core material 3 can of course be divided into three or more parts. Moreover, even when divided into two parts, such as the die-side core material 31 and the punch-side core material 32, the division can be made horizontally rather than vertically, so that, for example, the lower surface of each of the two divided core materials abuts against the die 1, and the upper surface of each of the two divided core materials abuts against the bunch 2. [Explanation of Symbols]

[0065] 1 die 11 Die base section 12. Vertical wall section on the die side 13. Die-side pressing section 13a Die-side curved surface 14 Die-side curved groove 2 punches 21 Punch base section 22 Punch-side pressing section 22a Curved surface on the punch side 3 Core material 31 Die-side core material 31a Die contact portion 31b Die-side resin molding body pressing part 31c Die-side lip section lower protective wall section 31c1 Die-side lip section lower protective wall high section 31c2 Lower protective wall of the die-side lip section 31d Vertical part of the protective wall at the tip of the die-side lip section 32 Punch-side core material 32a Punch contact area 32b Punch-side resin molding body pressing section 32c Upper protective vertical wall section of the punch-side lip 33 Lip section housing space 4-door 41 Door glass 42 Door Panel 42a Flange section 43 Door trim cover 43a Flange section M,M',M” Resin molding M1, M1', M1” Resin molding body M11 Inner upright part M12 central installation part M13 Lip-side erection section M14 Upper wall M15 Lower wall part M21, M21', M21” Upper lip section M22, M22', M22” Lower lip section M21a, M22a Lip section connecting end M21b, M22b Lip tip

Claims

1. The steps include: covering the portion of the resin molding to be bent with a core material made of a different material, and setting the resin molding on the curved surface of a die that is curved according to the bending of the portion to be bent, via the core material; The steps include lowering the punch toward the die, and pressing the die and the punch against the portion of the resin molding to be bent via the core material, thereby causing plastic deformation of the portion of the resin molding to be bent and performing the bending process, The process includes the step of removing the core material from the resin molding after the bending process is completed, The resin molding comprises a resin molding body that is attached to the flange portion of a vehicle door or the like, and a lip portion that is provided so as to protrude from the resin molding body and rubs against the vehicle's glass. A method for manufacturing a resin molding, characterized in that the core material is divided into a die-side core material that the die contacts and a punch-side core material that the punch contacts, and when the resin molding is sandwiched and covered by the die-side core material and the punch-side core material, the area above the lip portion is open.

2. In the method for manufacturing resin molding according to claim 1, The die-side core material is The die contact portion that the die contacts, A die-side resin molding body pressing portion is provided with an uneven surface corresponding to the shape of the resin molding body, A protective wall portion below the lip portion on the die side is provided, which protrudes from the pressing portion of the resin molding body on the die side by a length greater than or equal to the lateral protrusion length of the lip portion, The die-side lip portion lower protective wall portion has a vertical portion of the die-side lip portion tip protective wall that rises from the end opposite to the die-side resin molding body pressing portion and extends to a height greater than or equal to the height of the lip portion, The punch-side core material is, The punch contact portion that the punch contacts, A punch-side resin molding body pressing portion is provided with an uneven surface corresponding to the shape of the resin molding body, and presses and plastically deforms the resin molding body by sandwiching it between the die-side resin molding body pressing portion and the punch-side resin molding body pressing portion. The punch-side lip portion has an upper protective vertical wall portion that extends above the height of the lip portion, provided between the punch contact portion and the punch-side resin molding body pressing portion, and facing the vertical portion of the die-side lip portion tip protective wall, so that the upper surface of the lip portion does not come into contact with the punch-side pressing portion of the punch. A method for manufacturing a resin molding, characterized in that when the punch descends and presses the resin molding through the core material against the curved surface of the die to cause plastic deformation, the punch is configured not to come into contact with the lip portion of the resin molding.

3. In the method for manufacturing resin molding according to claim 1 or claim 2, A method for manufacturing a resin molding, characterized in that when the resin molding is sandwiched and covered by the die-side core material and the punch-side core material, the height of the vertical portion of the protective wall at the tip of the die-side lip portion in the die-side core material and the height of the punch contact portion in the punch-side core material are formed to be higher than the height of the tip of the lip portion even when the lip portion of the resin molding is raised from the resin molding body.

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