Manufacturing method for resin molded products

Abstract

To provide a method for manufacturing resin molded products that can improve productivity. [Solution] The method for manufacturing the lamp housing 11 includes a mold opening step P4, wherein parts of the sides 61, 71 of the first mold portion 60 and the second mold portion 70 of the mold 52 define a first recess 54, a part of the side 61 includes a first inclined surface 61s, and a part of the side 71 includes a second inclined surface 71s, and the mold opening step P4 includes a first moving step P41 which moves the first mold portion 60 to the opposite side from the mold 51 side relative to the lamp housing 11, and a second moving step P42 which moves the second mold portion 70 to the lamp housing 11 in the same direction as the movement direction of the first mold portion 60 from the timing when the first inclined surface 61s is located on the side of the first mold portion 60 in the direction of movement of the first mold portion 60 from the tip of the first protrusion 30 and the first protrusion 30 and the first mold portion 60 overlap.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a resin molded product.

Background Art

[0002] In some resin molded products, a protruding portion may be provided. Patent Document 1 below discloses a mold device for manufacturing a resin molded product having a protruding portion.

[0003] The mold device of Patent Document 1 below includes a pair of molds. In a mold-closed state where the pair of molds are closed, a cavity into which molten resin is filled is formed between the pair of molds. In one of the molds, a recess is formed whose internal space is part of the cavity and whose depth direction is along the mold-opening direction. One of the molds includes a first mold part and a second mold part having a side surface facing the side surface of the first mold part. In the closed state, a part of the side surfaces of the first mold part and the second mold part are separated from each other to define the above-mentioned recess. Also, a part of the side surface of the first mold part is substantially parallel to the mold-opening direction from the opening side to the bottom side of the recess, and a part of the side surface of the second mold part includes an inclined surface that inclines from the opening side to the bottom side toward the opposite side of the above-mentioned side surface side of the first mold part.

[0004] According to this mold device, a resin molded product including a protruding portion having side surfaces facing each other corresponding to the recess is formed. Also, one side surface of the protruding portion is a substantially flat surface, and the other side surface of the protruding portion includes an inclined surface that inclines from the tip toward the opposite side of the one side surface side. Therefore, a convex portion that protrudes in a direction perpendicular to the protruding direction of the protruding portion is formed on this other side surface, and the convex portion is pressed against the inclined surface of the second mold part when the second mold part moves from the bottom side to the opening side of the recess. That is, this convex portion is an undercut portion.

[0005] In the mold apparatus described in Patent Document 1, when the pair of molds are opened, the resin molded product is attached to one of the molds. After the resin molded product is released from the first mold section, it is then released from the second mold section. Specifically, the resin molded product and the second mold section are moved in a direction parallel to the mold opening direction relative to the first mold section, so that the protruding portion of the resin molded product and the first mold section do not overlap in a direction perpendicular to the mold opening direction. As a result, a space is formed on the side opposite to the side of the second mold section with respect to the protruding portion. In this state, the second mold section is moved relative to the resin molded product in the same direction as the movement of the first mold section relative to the resin molded product. As described above, a convex portion is provided on the other side of the protruding portion. As a result, the convex portion is pressed by the inclined surface of the second mold section on the side opposite to the side of the second mold section, but because the above-mentioned space is formed, the second mold section can move relative to the resin molded product with the protruding portion flexed and positioned in the above-mentioned space. Therefore, the stress applied to the protruding part can be reduced, and the tearing of the protruding part is suppressed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 08-203302 [Overview of the project] [Problems that the invention aims to solve]

[0007] There is a need to improve productivity when manufacturing resin molded products including protrusions with undercut portions using a mold device such as the mold device described in Patent Document 1 above.

[0008] Therefore, the present invention aims to provide a method for manufacturing resin molded products that can improve productivity. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a method for manufacturing a resin molded product comprising: a clamping step of clamping a pair of molds; a filling step of filling a cavity formed between the clamped pair of molds with molten resin; a cooling step of cooling the molten resin filled in the cavity to form a resin molded product; and an opening step of opening the pair of molds to remove the resin molded product, wherein one of the molds includes a first mold portion and a second mold portion having a side surface facing the side surface of the first mold portion, and in the clamped state, at least a portion of the side surfaces of the first mold portion and the second mold portion are separated from each other to define a recess which is part of the cavity, and the side surface of the first mold portion is inclined toward the side surface of the second mold portion toward the bottom side of the recess The second mold portion includes a first inclined surface that defines a part of the recess, the side surface of the second mold portion includes a second inclined surface that slopes toward the opposite side of the first mold portion toward the bottom side from the opening side and defines another part of the recess, and the mold opening step is characterized by including a first moving step of moving the first mold portion toward the opposite side of the other mold portion relative to the resin molded product, and a second moving step of moving the second mold portion toward the resin molded product in the same direction as the moving direction, from a timing when at least a part of the first inclined surface is located toward the tip of a protrusion of the resin molded product formed by the cooling of the molten resin that has filled the recess, toward the resin molded product, and the protrusion and the first mold portion overlap in a direction perpendicular to the mold opening direction.

[0010] The protrusion corresponding to the recess has a surface that abuts against the first bevel on the side surface of the first mold part and slopes toward the side surface of the second mold part toward the tip, and a surface that abuts against the second bevel on the side surface of the second mold part and slopes toward the opposite side toward the tip toward the side of the first mold part. The portion including the surface that abuts against the second bevel is an undercut portion. In the first movement step, the first mold part moves relative to the resin molded product, creating a space between the first bevel of the first mold part and the surface of the protrusion that was in contact with the first bevel. Then, in the second movement step, the second mold part moves relative to the resin molded product, and the second bevel presses the protrusion toward the side surface of the first mold part. At the timing when the movement of the second mold part begins, at least a part of the first bevel is located on the side of the first mold part that is moving relative to the resin molded product, beyond the tip of the protrusion of the resin molded product. Therefore, the portion of the protrusion from the surface that abutted against the first bevel to the tip is exposed in the above space. Therefore, the protruding portion can bend to the side of the first mold portion so that the above-mentioned portion moves into the above-mentioned space, and the second mold portion can move while bending the protruding portion in this manner. For this reason, the stress applied to the protruding portion can be reduced, similar to the method for manufacturing resin molded products described in Patent Document 1. Furthermore, at the timing when the movement of the second mold portion begins, the protruding portion and the first mold portion overlap in a direction perpendicular to the mold opening direction. For this reason, compared to the case where the first mold portion is moved relative to the resin molded product until the protruding portion and the first mold portion do not overlap in a direction perpendicular to the mold opening direction, and then the second mold portion is moved relative to the resin molded product, the time required to remove the resin molded product can be shortened, and productivity can be improved.

[0011] At the aforementioned timing, it is preferable that the entire first slope is located on the side of the direction of movement from the tip of the protrusion.

[0012] With this configuration, the space formed between the protrusion and the first mold section at the timing when the second mold section starts moving can be made larger compared to the case where the first inclined surface overlaps with the protrusion in a direction perpendicular to the mold opening direction at the timing described above. For this reason, with this configuration, in the second moving step, the portion of the protrusion from the surface that was in contact with the first inclined surface to the tip can be made less likely to come into contact with the first mold section, and the stress applied to the protrusion can be reduced.

[0013] At the aforementioned timing, it is preferable that the entire protruding portion and the first mold portion are separated.

[0014] With this configuration, in the second moving step, the protrusion is less likely to come into contact with the first mold portion, and the stress applied to the protrusion can be reduced.

[0015] In the first moving step, the movement of the first mold part relative to the resin molded product may be interrupted at the timing, and the movement of the first mold part relative to the resin molded product in the first moving step may be resumed before the distance the second mold part moves relative to the resin molded product becomes equal to or greater than the distance the first mold part moves relative to the resin molded product up to the timing.

[0016] The movement speed of the first mold part relative to the resin molded product in the first movement step may be the same as the movement speed of the second mold part relative to the resin molded product in the second movement step. [Effects of the Invention]

[0017] As described above, the present invention provides a method for manufacturing resin molded products that can improve productivity. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a schematic side view showing a vehicle lighting fixture including a resin molded product according to an embodiment of the present invention. [Figure 2] Figure 2 is an enlarged view of the area including the first and second protrusions in Figure 1. [Figure 3] FIG. 3 is a perspective view showing the first protrusion and the second protrusion. [Figure 4] FIG. 4 is a diagram schematically showing a mold apparatus used for manufacturing the lamp housing of the embodiment. [Figure 5] FIG. 5 is an enlarged view of a portion including the first recess and the second recess in FIG. 4. [Figure 6] FIG. 6 is a view of the first recess and the second recess as seen along the mold opening direction. [Figure 7] FIG. 7 is a flowchart showing the steps of a method for manufacturing a lamp housing in the embodiment. [Figure 8] FIG. 8 is a view showing the mold apparatus after the filling step. [Figure 9] FIG. 9 is an enlarged view showing a part of the mold apparatus during the first moving step. [Figure 10] FIG. 10 is a view showing the mold apparatus during the second moving step in the same manner as FIG. 9. [Figure 11] FIG. 11 is a view showing the mold apparatus during the second moving step of the modified example in the same manner as FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, preferred embodiments of a method for manufacturing a resin molded product according to the present invention will be described in detail with reference to the drawings. The embodiments illustrated below are for facilitating the understanding of the present invention and are not for limiting the interpretation of the present invention. The present invention can be changed and improved within the scope of the claims without departing from the gist thereof. In the drawings referred to below, for the sake of easy understanding, the dimensions of each member may be shown changed. Also, in the drawings, for the sake of easy viewing, reference numerals may be attached only to a part of the similar components, and some reference numerals may be omitted.

[0020] Figure 1 is a schematic side view showing a vehicle lighting fixture including a resin molded product according to this embodiment. The vehicle lighting fixture 1 of this embodiment is a headlight for an automobile. As shown in Figure 1, the vehicle lighting fixture 1 of this embodiment mainly comprises a housing 10 and a lighting unit LU. Note that in Figure 1, the housing 10 is shown in a vertical cross-section.

[0021] The housing 10 of this embodiment has a lamp housing 11 made of resin molded product and a front cover 12. In this embodiment, the lamp housing 11 has a cylindrical peripheral wall portion 21 extending in the front-rear direction and a bottom wall portion 22 that closes the opening on the rear side of the peripheral wall portion 21. The peripheral wall portion 21 and the bottom wall portion 22 are integral, and the lamp housing 11 is formed in a box shape with an opening at the front. Note that the two members being integral means that the two members are made of the same material and there is no joint between the two members. The peripheral wall portion 21 is inclined outward toward the front, and the outer diameter and inner diameter of the peripheral wall portion 21 are larger toward the front. The bottom wall portion 22 is a plate-shaped member that extends in the vertical direction, which is generally perpendicular to the extending direction of the peripheral wall portion 21. The bottom wall portion 22 has a first projection 30 and a second projection 40 that project toward the front and are integral with the bottom wall portion 22. The width of the first protrusion 30 and the second protrusion 40 in the protruding direction is greater than the maximum width in the direction perpendicular to the protruding direction.

[0022] Figure 2 is an enlarged view of the portion including the first protrusion 30 and the second protrusion 40 in Figure 1. Figure 3 is a perspective view showing the first protrusion 30 and the second protrusion 40, and Figure 3 also shows a part of the bottom wall 22. As shown in Figures 2 and 3, in this embodiment, the first protrusion 30 is a plate-like member that extends in the front-rear and left-right directions, and the width of the first protrusion 30 in the left-right direction is generally constant in the front-rear direction and is narrower than the width of the first protrusion 30 in the front-rear direction. The thickness of the first protrusion 30 is thinner towards the front end, which is the tip. The first protrusion 30 also has a base portion 31 that extends generally horizontally forward from the bottom wall 22, an inclined portion 32 that slopes downward toward the front from the front end of the base portion 31, and a tip portion 33 that slopes upward toward the front from the front end of the inclined portion 32.

[0023] In this embodiment, the second projection 40 is located below the first projection 30, and the first projection 30 and the second projection 40 are spaced apart and arranged vertically. The second projection 40 has a first vertical wall portion 41 and a second vertical wall portion 42. The first vertical wall portion 41 is a plate-like member that protrudes forward from the bottom wall portion 22 and whose main surface extends vertically. The thickness of the first vertical wall portion 41 is thinner towards the front end, which is the tip. The front end of the first vertical wall portion 41 is located in front of the front end of the first projection 30. The side surface 41s of the first vertical wall portion 41 on the side of the first projection 30 includes a base surface 41sa that is slightly inclined downward toward the front, and an inclined surface 41sb that is inclined downward toward the front from the front end of the base surface 41sa. The base surface 41sa is opposite to the base portion 31, the inclined portion 32 of the first projection 30, and the portion on the inclined portion 32 side of the tip portion 33. The distance between the base surface 41sa and the base 31 of the first projection 30 is wider than the distance between the base surface 41sa and the inclined portion 32. The distance between the base surface 41sa and the inclined portion 32 narrows as it extends forward, and the distance between the base surface 41sa and the tip portion 33 widens as it extends forward. The rear portion of the inclined surface 41sb faces the portion of the tip portion 33 of the first projection 30 that is opposite to the inclined portion 32, and the distance between the inclined surface 41sb and the inclined portion 32 widens as it extends forward.

[0024] The second vertical wall portion 42 is a plate-like member that protrudes forward from the bottom wall portion 22, with its main surface extending in the left-right direction. The second vertical wall portion 42 is located below the first vertical wall portion 41, on the opposite side from the first projection portion 30. The lower end of the first vertical wall portion 41 is connected to the left-right central part of the second vertical wall portion 42, and the first vertical wall portion 41 and the second vertical wall portion 42 are integral. The shape of the second projection portion 40 in a cross-section perpendicular to its projection direction is generally an inverted T shape. The width in the left-right direction at the front end of the second vertical wall portion 42 narrows toward the front, while the width in the left-right direction at the rear of the second vertical wall portion 42 is generally constant in the front-rear direction and is narrower than the width in the left-right direction of the first projection portion 30.

[0025] A cable CA, electrically connected to the luminaire unit LU, is sandwiched between the first protrusion 30 and the second protrusion 40 in this configuration. Specifically, the cable CA is sandwiched between the base 31 and the inclined portion 32 of the first protrusion 30 and the first vertical wall portion 41 of the second protrusion 40. Since the minimum distance between the inclined portion 32 and the first vertical wall portion 41 is smaller than the diameter of the cable CA, the cable CA is less likely to fall out from between the first protrusion 30 and the second protrusion 40.

[0026] Examples of materials that make up the lamp housing 11 include polyethylene, polypropylene, polycarbonate, polystyrene, ABS resin, acrylic resin, polyethylene terephthalate, polyacetal, and polyamide.

[0027] Returning to Figure 1, the front cover 12 is a light-transmitting plate-shaped member and is fixed to the peripheral wall portion 21 of the lamp housing 11 so as to close the opening on the front side of the peripheral wall portion 21. In this way, a housing space R is formed in the housing 10, surrounded by the lamp housing 11 and the front cover 12, and the luminaire unit LU is placed in this housing space R.

[0028] The luminaire unit LU of this embodiment includes a light source (not shown) and emits light from the light source forward in a manner that results in a low beam light distribution. The low beam emitted from the luminaire unit LU is projected onto the front of the vehicle via the front cover 12. The luminaire unit LU may be equipped with a reflector, projection lens, etc., to ensure that the light from the light source has a low beam light distribution. For example, an LED (Light Emitting Diode) can be used as the light source. Furthermore, the light emitted by the luminaire unit LU is not limited and may be, for example, a high beam. The luminaire unit LU may also be capable of changing the light distribution pattern of the emitted light.

[0029] Next, the mold apparatus used in the manufacture of the lamp housing 11 of this embodiment will be described.

[0030] Figure 4 is a schematic diagram showing a mold apparatus 50 used in the manufacture of the lamp housing 11 of this embodiment. As shown in Figure 4, the mold apparatus 50 mainly comprises a pair of molds 51 and 52.

[0031] In this embodiment, mold 51 is a fixed mold, and mold 52 is a movable mold that can move in a clamping direction D1 approaching mold 51 and in an opening direction D2 away from mold 51. When mold 52 is pressed against mold 51 and molds 51 and 52 are joined together in a clamped state, a cavity 53, which is a space corresponding to the lamp housing 11, is formed between the pair of molds 51 and 52. In other words, irregularities are formed on the surface 51s of mold 51 facing mold 52 and the surface 52s of mold 52 facing mold 51, so that the cavity 53 is formed in the clamped state. Specifically, recesses 51a are formed on the surface 51s of mold 51 that define the outer peripheral surface of the peripheral wall portion 21 and the rear surface of the bottom wall portion 22, which are the outer surfaces of the lamp housing 11. Convex portions 52a are formed on the surface 52s of mold 52 that define the inner peripheral surface of the peripheral wall portion 21 and the front surface of the bottom wall portion 22, which are the inner surfaces of the lamp housing 11. The protrusion 52a is provided with a first recess 54 and a second recess 55 spaced apart, and the depth direction of the first recess 54 and the second recess 55 is aligned with the mold opening direction D2. Furthermore, the depth of the first recess 54 and the second recess 55 is greater than the maximum width in the direction perpendicular to the depth direction.

[0032] Figure 5 is an enlarged view of the area including the first recess 54 and the second recess 55 in Figure 4. Figure 6 is a view of the first recess 54 and the second recess 55 along the mold opening direction D2. As shown in Figures 5 and 6, the internal space of the first recess 54 is part of the cavity 53, and the shape of the surface defining the first recess 54 corresponds to the overall surface shape of the first projection 30. The first recess 54 includes an opening side portion 54a corresponding to the base portion 31 of the first projection 30, an inclined portion 54b corresponding to the inclined portion 32 of the first projection 30, and a bottom side portion 54c corresponding to the tip portion 33 of the first projection 30. The opening side portion 54a is a section that extends from the opening 54h of the first recess 54 in a direction generally parallel to the mold opening direction D2. The inclined portion 54b is a section that extends from the end of the opening side portion 54a opposite to the opening 54h side toward the bottom 54d side of the first recess 54 in a direction nonparallel to the mold opening direction D2, and is inclined toward the second recess 55 side toward the bottom 54d side. The bottom side portion 54c includes the bottom 54d of the first recess 54 and is a section that extends from the end of the inclined portion 54b on the bottom 54d side in a direction nonparallel to the extending direction of the inclined portion 54b, and is inclined toward the opposite side of the second recess 55 side toward the bottom 54d side.

[0033] The internal space of the second recess 55 is another part of the cavity 53, and the shape of the surface defining the second recess 55 corresponds to the overall surface shape of the second projection 40. The second recess 55 includes a first portion 55a corresponding to the first vertical wall portion 41 of the second projection 40 and a second portion 55b corresponding to the second vertical wall portion 42, with the first portion 55a and the second portion 55b being in communication with each other.

[0034] Returning to Figure 4, the mold 51 has a runner 56 formed therein, which is a flow channel for molten resin, and one end of the runner 56 is in communication with the cavity 53. The mold 52 also includes a first mold section 60 and a second mold section 70.

[0035] As shown in Figures 4 to 6, the first mold portion 60 of this embodiment is a rectangular prism-shaped member extending in a direction generally parallel to the mold opening direction D2, and the second mold portion 70 has a through hole 70h formed therein that penetrates the second mold portion 70 in a direction parallel to the mold opening direction D2. The first mold portion 60 is inserted into the through hole 70h. The outer shape of the through hole 70h is rectangular. Therefore, the second mold portion 70 has four sides 71 that define the through hole 70h. Each of the four sides 61 of the first mold portion 60 faces a side 71 of the second mold portion 70. Of the sides 61, 71 of the first mold portion 60 and the second mold portion 70 that face each other, parts of one pair of sides 61, 71 are separated from each other and define the entirety of the first recess 54. Other parts of these sides 61, 71 are in contact with each other. Furthermore, there is almost no gap between the other sides 61 and 71. In the following, when we simply refer to the sides 61 and 71, we are referring to the sides 61 and 71 that are partially separated from each other and define the first recess 54.

[0036] The surface 72 that connects to the edge of the opening on the mold 51 side of the through hole 70h in the second mold section 70 and the surface 62 that connects to a part of the edge 54he of the opening 54h of the first recess 54 in the first mold section 60 are generally flush, and surfaces 62 and 72 are exposed to the cavity 53.

[0037] Furthermore, a second recess 55 is formed in the second mold section 70. As described above, the inclined portion 54b of the first recess 54 is inclined toward the second recess 55 from the opening 54h side toward the bottom 54d side. For this reason, the inclined portion 54b extends in a direction nonparallel to the mold opening direction D2 from the opening 54h side toward the bottom 54d side, and is inclined toward the side surface 71 of the second mold section 70 from the opening 54h side toward the bottom 54d side. Such an inclined portion 54b is the space between the first inclined surface 61s in a part of the side surface 61 of the first mold section 60 and the second inclined surface 71s in another part of the side surface 71 of the second mold section 70. The first inclined surface 61s is an inclined surface that is inclined toward the side surface 71 of the second mold section 70 from the opening 54h side toward the bottom 54d side of the first recess 54. The second inclined surface 71s is an inclined surface that slopes from the opening 54h side of the first recess 54 toward the bottom 54d side, away from the side surface 61 side of the first mold section 60. In other words, a portion of the side surface 61 of the first mold section 60 includes the first inclined surface 61s that slopes toward the side surface 71 side of the second mold section 70 toward the opening 54h side of the first recess 54 toward the bottom 54d side, defining a portion of the first recess 54. Furthermore, a portion of the side surface 71 of the second mold section 70 includes the second inclined surface 71s that slopes toward the side surface 61 side of the first mold section 60 toward the opening 54h side of the first recess 54 toward the bottom 54d side, away from the side surface 61 side of the first mold section 60, defining another portion of the first recess 54. The second inclined surface 71s overlaps with the first inclined surface 61s in a direction perpendicular to the mold opening direction D2. Furthermore, the width of the first inclined surface 61s in the direction parallel to the mold opening direction D2 is approximately the same as the width of the second inclined surface 71s in the direction parallel to the mold opening direction D2. Also, the inclination angle of the first inclined surface 61s with respect to the direction parallel to the mold opening direction D2 is approximately the same as the inclination angle of the second inclined surface 71s with respect to the direction parallel to the mold opening direction D2.

[0038] In this embodiment, the first mold section 60 and the second mold section 70 are individually movable in the clamping direction D1 and the opening direction D2. In the clamped state, the first mold section 60 does not move relative to the second mold section 70, and the first mold section 60 and the second mold section 70 are fixed to each other so as to define the first recess 54.

[0039] Examples of materials that constitute the mold 51, the first mold section 60, and the second mold section 70 include metals such as steel, Burlington steel, and stainless steel.

[0040] Next, the manufacturing method of the lamp housing 11 in this embodiment will be described.

[0041] Figure 7 is a flowchart showing the steps for manufacturing the lamp housing 11 in this embodiment. As shown in Figure 7, the manufacturing method for the lamp housing 11 in this embodiment mainly comprises a mold clamping step P1, a filling step P2, a cooling step P3, and a mold opening step P4.

[0042] <Mold clamping process P1> This process involves moving the mold 52 toward the mold 51 in the mold apparatus 50 shown in Figure 4, pressing the mold 52 against the mold 51, and bringing the mold 51 and mold 52 into a clamped state. When the mold 51 and mold 52 are joined together, a cavity 53 corresponding to the lamp housing 11 is formed between the mold 51 and mold 52. As described above, in this clamped state, the first mold section 60 and the second mold section 70 are fixed to each other, and parts of the sides 61 and 71 of the first mold section 60 and the second mold section 70 are separated from each other, defining the first recess 54.

[0043] <Filling process P2> This process involves filling the cavity 53 formed by the clamping process P1 with molten resin that will become the lamp housing 11. Figure 8 shows the mold apparatus 50 after this process. In this embodiment, molten resin 57 is injected into a runner 56 that communicates with the cavity 53 by an injection unit (not shown). The molten resin 57 injected into the runner 56 flows through the runner 56 and is injected into the cavity 53. In this way, the molten resin 57 is injected into the cavity 53 and the cavity 53 is filled with molten resin 57 to a predetermined pressure. The pressure of the molten resin 57 is adjusted, for example, by the amount of molten resin 57 injected from the injection unit.

[0044] <Cooling process P3> This step involves cooling the molten resin 57 filled in the cavity 53. In this embodiment, the molten resin 57 is cooled by cooling the molds 51 and 52 with outside air. The lamp housing 11 is formed by cooling and solidifying the molten resin 57. The method of cooling the molten resin 57 is not limited.

[0045] Here, the first projection 30 of the lamp housing 11 corresponds to the first recess 54, and the inclined portion 32 of the first projection 30 corresponds to the inclined portion 54b of the first recess 54. This inclined portion 54b is inclined toward the side surface 71 of the second mold portion 70 from the opening 54h side toward the bottom 54d side. Therefore, the inclined portion 32 is inclined toward the side surface 71 of the second mold portion 70 from the root side toward the tip side of the first projection 30. The surface of the inclined portion 32 toward the side surface 61 of the first mold portion 60 abuts against the first inclined surface 61s, and the surface of the inclined portion 32 toward the side surface 71 of the second mold portion 70 abuts against the second inclined surface 71s. The inclined portion 32 is sandwiched between the first inclined surface 61s and the second inclined surface 71s.

[0046] <Mold opening process P4> This process involves opening the pair of molds 51 and 52 to remove the lamp housing 11 from the mold device 50. As shown in Figure 7, this process includes a first moving step P41 and a second moving step P42.

[0047] <1st movement process P41> This step involves moving the first mold section 60 to the opposite side of the mold 51 relative to the lamp housing 11. Figure 9 is an enlarged view of a part of the mold apparatus 50 during this step. As described above, the inclined portion 32 of the first protrusion 30, which is sandwiched between the first inclined surface 61s and the second inclined surface 71s, is inclined toward the side surface 71 of the second mold section 70 from the base side to the tip side of the first protrusion 30. Therefore, as shown in Figure 9, in this embodiment, by moving the first mold section 60 to the opposite side of the mold 51, that is, by moving the first mold section 60 in the mold opening direction D2, the first inclined surface 61s separates from the first protrusion 30. This movement of the first mold section 60 creates a space SP between the first inclined surface 61s and the surface 32s1 of the first protrusion 30 that was in contact with the first inclined surface 61s.

[0048] In this embodiment, at least a portion of the first inclined surface 61s is located on the side of the first mold portion 60 that moves relative to the lamp housing 11, beyond the tip of the first protrusion 30, and the movement of the first mold portion 60 is interrupted at the timing when the first protrusion 30 and the first mold portion 60 overlap in a direction perpendicular to the mold opening direction D2. Figure 9 shows the state of the mold device 50 at this timing. In this embodiment, at this timing, the entire first inclined surface 61s is located on the side of the first mold portion 60 that moves relative to the lamp housing 11, beyond the tip of the first protrusion 30, and the entire first protrusion 30 and the first mold portion 60 are separated. Also, in a direction perpendicular to the mold opening direction D2, the inclined portion 32 and tip portion 33 of the first protrusion 30 overlap with the first mold portion 60, but the base portion 31 of the first protrusion 30 does not overlap with the first mold portion 60. Furthermore, the first inclined plane 61s does not overlap with the second inclined plane 71s in a direction perpendicular to the mold opening direction D2. Also, by this time, the first mold section 60 has moved a distance PD relative to the ramp housing 11. The movement of the first mold section 60 will resume, but this resumption will be described later.

[0049] <Second movement process P42> This process begins after the start of the first movement process P41, when at least a portion of the first inclined surface 61s is located on the side of the first mold section 60 that is moving relative to the lamp housing 11, and when the first protrusion 30 and the first mold section 60 overlap in a direction perpendicular to the mold opening direction D2. In this embodiment, it is started when the state of the mold device 50 is as shown in Figure 9. In other words, it is started at the timing when the movement of the first mold section 60 is interrupted. Alternatively, the second mold section 70 may be moved relative to the lamp housing 11 after a predetermined period has elapsed from the timing when the movement of the first mold section 60 is interrupted.

[0050] In this process, the second mold section 70 is moved relative to the lamp housing 11. The direction of movement of the second mold section 70 relative to the lamp housing 11 is the same as the direction of movement of the first mold section 60 relative to the lamp housing 11, and is toward the opposite side from the mold 51. Figure 10 is a diagram showing the mold apparatus 50 during this process, similar to Figure 9. As shown in Figure 10, in this embodiment, the second mold section 70 is moved in the mold opening direction D2. At this time, the lamp housing 11 becomes attached to the mold 51 due to frictional force, and the second mold section 70 moves relative to the lamp housing 11 toward the opposite side from the mold 51.

[0051] As described above, the inclined portion 32 of the first projection 30 has a surface 32s1 and a surface 32s2. Surface 32s1 abuts against the first inclined surface 61s of the first mold portion 60 and tilts toward the side surface 71 of the second mold portion 70 toward the tip, while surface 32s2 abuts against the second inclined surface 71s on the side surface 71 of the second mold portion 70 and tilts toward the opposite side toward the side surface 61 of the first mold portion 60 toward the tip. As a result, when the second mold portion 70 moves in the mold opening direction D2, the second inclined surface 71s presses against surface 32s2 which is in contact with the second inclined surface 71s. Therefore, the portion of the first protrusion 30 including surface 32s2 is an undercut portion. Here, as described above, when the first mold portion 60 moves relative to the lamp housing 11 by the first movement step P41, a space SP is formed between the first inclined surface 61s of the first mold portion 60 and surface 32s1 of the first protrusion 30 that was in contact with the first inclined surface 61s. Then, in the second movement step P42, the second inclined surface 71s presses the first protrusion 30 against the side surface 61 of the first mold section 60 in order to move the second mold section 70 relative to the lamp housing 11. At the timing when the movement of the second mold section 70 begins, at least a part of the first inclined surface 61s is positioned on the side of the first mold section 60 in the direction of movement relative to the lamp housing 11, beyond the tip of the first protrusion 30. As a result, the portion of the first protrusion 30 from the surface 32s1 that was in contact with the first inclined surface 61s to the tip is exposed to the space SP. As a result, the first protrusion 30 can bend toward the side surface 61 of the first mold section 60 so that the above portion moves toward the space SP, and the second mold section 70 moves while bending the first protrusion 30 in this manner. In this embodiment, at the timing when the movement of the second mold section 70 begins, the entire first protrusion 30 and the first mold section 60 are separated, and the entire first protrusion 30 bends toward the side surface 61 of the first mold section 60.

[0052] Next, the resumption of movement of the first mold section 60 will be described. In this embodiment, the movement of the first mold section 60 relative to the lamp housing 11 is resumed in the first movement step P41 before the movement distance of the second mold section 70 relative to the lamp housing 11 becomes greater than or equal to the movement distance PD of the first mold section 60 relative to the lamp housing 11 up to the timing when the movement of the first mold section 60 is interrupted. Here, Figure 10 shows the mold apparatus 50 at the timing when the movement of the first mold section 60 is resumed. At this timing, the second inclined surface 71s does not overlap with the first inclined surface 61s in the direction perpendicular to the mold opening direction D2, but overlaps with the tip of the first protrusion 30. Note that at this timing, the second inclined surface 71s does not have to overlap with the first protrusion 30 in the direction perpendicular to the mold opening direction D2, and it may overlap with the first inclined surface 61s in the direction perpendicular to the mold opening direction D2.

[0053] In this embodiment, the movement speed of the first mold section 60 relative to the lamp housing 11 in the first movement step P41 is the same as the movement speed of the second mold section 70 relative to the lamp housing 11 in the second movement step P42. Therefore, after the movement of the first mold section 60 is resumed, the first mold section 60 and the second mold section 70 move together in the mold opening direction D2. Note that the movement speed of the first mold section 60 relative to the lamp housing 11 in the first movement step P41 may be different from the movement speed of the second mold section 70 relative to the lamp housing 11 in the second movement step P42. Note that the movement speed of the first mold section 60 before interrupting its movement may be slower, faster, or the same as the movement speed of the first mold section 60 after its movement is resumed.

[0054] As the second mold section 70 moves from the tip of the first protruding section 30 to the opposite side of the mold 51, the deflection of the inclined section 32 is eliminated. In this embodiment, the movement of the first mold section 60 and the second mold section 70 stops when the distance between the second mold section 70 and the mold 51 is greater than the width D2 in the mold opening direction of the lamp housing 11. In other words, the first movement process P41 and the second movement process P42 are completed in this state. Then, the lamp housing 11 is ejected from the mold 51 and removed from the mold device 50 by ejector pins (not shown) provided on the mold 51, which push the lamp housing 11 toward the mold 52. In this way, the lamp housing 11 is manufactured by the mold device 50.

[0055] As described above, the manufacturing method for the lamp housing 11 as a resin molded product of this embodiment comprises a mold clamping step P1, a filling step P2, a cooling step P3, and a mold opening step P4. The mold clamping step P1 is a step of clamping a pair of molds 51 and 52 together. The filling step P2 is a step of filling a cavity 53 formed between the clamped pair of molds 51 and 52 with molten resin 57. The cooling step P3 is a step of cooling the molten resin 57 filled in the cavity 53 to form the lamp housing 11. The mold opening step P4 is a step of opening the pair of molds 51 and 52 to remove the lamp housing 11. The mold 52 includes a first mold portion 60 and a second mold portion 70 having a side surface 71 facing the side surface 61 of the first mold portion 60. In the clamped state, portions of the sides 61, 71 of the first mold section 60 and the second mold section 70 separate from each other to define a first recess 54, which is part of the cavity 53. A portion of the side 61 of the first mold section 60 includes a first inclined surface 61s that slopes toward the side 71 of the second mold section 70 toward the bottom 54d of the first recess 54, defining a portion of the first recess 54. A portion of the side 71 of the second mold section 70 includes a second inclined surface 71s that slopes toward the opposite side of the side 61 of the first mold section 60 toward the bottom 54d, defining another portion of the first recess 54. The mold opening process P4 includes a first moving process P41 and a second moving process P42. The first moving process P41 is a process of moving the first mold section 60 toward the opposite side of the mold 51 relative to the lamp housing 11. The second moving step P42 is started when at least a portion of the first inclined surface 61s is located on the side of the moving direction of the first mold part 60 relative to the lamp housing 11 from the tip of the first protrusion 30 of the lamp housing 11, which is formed by the cooling of molten resin 57 that has filled the first recess 54, and when the first protrusion 30 and the first mold part 60 overlap in a direction perpendicular to the mold opening direction D2. In the second moving step P42, the second mold part 70 is moved relative to the lamp housing 11 in the same direction as the moving direction of the first mold part 60 relative to the lamp housing 11.

[0056] In the manufacturing method of this embodiment, as described above, the portion of the first protrusion 30 that includes the surface 32s2 that abuts against the second inclined surface 71s is an undercut portion. Furthermore, the first moving step P41 creates a space SP between the first inclined surface 61s of the first mold portion 60 and the surface 32s1 of the first protrusion 30 that was in contact with the first inclined surface 61s, and the second moving step P42 causes the second inclined surface 71s to press the first protrusion 30 towards the side surface 61 of the first mold portion 60. At the timing when the movement of the second mold portion 70 begins, at least a portion of the first inclined surface 61s is positioned on the side of the movement direction of the first mold portion 60 relative to the lamp housing 11, from the tip of the first protrusion 30. Therefore, the portion of the first protrusion 30 from the surface 32s1 that was in contact with the first inclined surface 61s to the tip is exposed to the space SP. Therefore, the first protrusion 30 can bend toward the side surface 61 of the first mold section 60 so that the above-mentioned portion moves into space SP, and the second mold section 70 can move while bending the first protrusion 30 in this manner. As a result, the stress applied to the first protrusion 30 can be reduced. Furthermore, in the manufacturing method of this embodiment, at the timing when the movement of the second mold section 70 begins, the first protrusion 30 and the first mold section 60 overlap in a direction perpendicular to the mold opening direction. As a result, compared to the case in which the first mold section 60 is moved relative to the lamp housing 11 until the first protrusion 30 and the first mold section 60 do not overlap in a direction perpendicular to the mold opening direction D2, before the second mold section 70 is moved relative to the lamp housing 11, the time required to remove the lamp housing 11 can be shortened, and productivity can be improved.

[0057] Furthermore, in the manufacturing method of this embodiment, at the timing described above, the entire first inclined surface 61s is located on the side of the movement direction of the first mold portion 60 relative to the lamp housing 11, beyond the tip of the first protrusion 30. Therefore, compared to the case where the first inclined surface 61s overlaps with the first protrusion 30 in a direction perpendicular to the mold opening direction D2 at the timing described above, the space SP formed between the first protrusion 30 and the first mold portion 60 at the start of the second movement step P42 can be made larger. Therefore, in the second movement step P42, the portion of the first protrusion 30 from the surface 32s1 that was in contact with the first inclined surface 61s to the tip can be made less likely to come into contact with the first mold portion 60, and the stress applied to the first protrusion 30 can be reduced. Note that at the timing described above, the first protrusion 30 and the first inclined surface 61s may overlap in a direction perpendicular to the mold opening direction.

[0058] Furthermore, in the manufacturing method of this embodiment, at the timing described above, the entire first protrusion 30 and the first mold portion 60 are separated. Therefore, in the second moving step P42, the first protrusion 30 is less likely to come into contact with the first mold portion 60, and the stress applied to the first protrusion 30 can be reduced. However, at the timing described above, a part of the first protrusion 30 may be in contact with the first mold portion 60.

[0059] Although the present invention has been described above with reference to the above embodiments, the present invention is not limited thereto.

[0060] For example, in the above embodiment, the first movement process P41 was interrupted at the timing of starting the second movement process P42, and the first movement process P41 was restarted before the movement distance of the second mold part 70 relative to the lamp housing 11 became greater than or equal to the movement distance PD of the first mold part 60 relative to the lamp housing 11 up to the above timing. However, it is not necessary to interrupt the first movement process P41.

[0061] Furthermore, in the above embodiment, the first mold section 60 was moved in the mold opening direction D2 in the first moving step P41, and the second mold section 70 was moved in the mold opening direction D2 in the second moving step P42. However, in the first moving step P41, the first mold section 60 only needs to be moved to the opposite side of the lamp housing 11 from the mold 51 side. Also, in the second moving step P42, at least a part of the first inclined surface 61s is located on the side of the lamp housing 11 that is in the direction of movement of the first mold section 60 relative to the lamp housing 11, and from the timing when the first protrusion 30 and the first mold section 60 overlap in a direction perpendicular to the mold opening direction D2, the second mold section 70 only needs to be moved in the same direction as the movement of the first mold section 60 relative to the lamp housing 11. The following describes a modified method for manufacturing the lamp housing 11. Note that components that are the same as or equivalent to those in the above embodiment are given the same reference numerals unless otherwise specified, and redundant descriptions are omitted.

[0062] In this modified example, the mold 51 of the mold device 50 is a movable mold, and the mold 52 is a fixed mold. Also, the clamping direction D1 in this example is the same direction as the mold opening direction D2 in the above embodiment, and the mold opening direction D2 in this example is the same direction as the clamping direction D1 in the above embodiment. Furthermore, the first mold section 60 is movable in the direction away from the mold 51 relative to the second mold section 70, that is, in the clamping direction D1. The steps of the manufacturing method for the lamp housing 11 in this modified example are the same as the steps of the manufacturing method in the above embodiment, but the operations in the first moving step P41 and the second moving step P42 mainly differ from the operations in the first moving step P41 and the second moving step P42 in the above embodiment. For this reason, the first moving step P41 and the second moving step P42 will be described with reference to Figure 7.

[0063] <1st movement process P41> In this modified version, the first mold section 60 is moved to the opposite side of the mold 51 by moving it in the clamping direction D1, which is the opposite direction to the mold opening direction D2. The movement of the first mold section 60 is stopped when it has moved a distance PD. As a result, the mold apparatus 50 is in the same state as the mold apparatus 50 shown in Figure 9. Therefore, as in the above embodiment, the movement of the first mold section 60 creates a space SP between the first inclined surface 61s and the surface 32s1 of the first protruding section 30 that was in contact with the first inclined surface 61s.

[0064] <Second movement process P42> Figure 11 shows the mold apparatus 50 during the process of this modified example in the same manner as in Figure 9. In this modified example, in the state shown in Figure 9, the mold 51 is moved in the mold opening direction D2. At this time, the ramp housing 11 becomes attached to the mold 51 due to frictional force. As a result, as shown in Figure 11, the first mold section 60 and the second mold section 70 move toward the opposite side from the mold 51 side relative to the ramp housing 11. As a result, similar to the above embodiment, the second inclined surface 71s presses the first protrusion 30 toward the side surface 61 of the first mold section 60. At the timing when the movement of the second mold section 70 begins, the first protrusion 30 and the first mold section 60 overlap in a direction perpendicular to the mold opening direction D2. Also at this timing, at least a part of the first inclined surface 61s is located toward the direction of movement of the first mold section 60 relative to the ramp housing 11, beyond the tip of the first protrusion 30 of the ramp housing 11. Therefore, the portion of the first protrusion 30 from the surface 32s1 that was in contact with the first inclined surface 61s to the tip is exposed to space SP. As a result, the first protrusion 30 can bend toward the side surface 61 of the first mold portion 60 so that the above portion moves toward space SP, and the second mold portion 70 moves while bending the first protrusion 30 in this manner. In addition, the first mold portion 60 moves toward the opposite side of the mold 51 relative to the lamp housing 11. In other words, the movement of the mold 51 in the mold opening direction D2 restarts the first movement process P41 and starts the second movement process P42.

[0065] In this modified example, the movement of the mold 51 stops when the distance between the second mold section 70 and the mold 51 is greater than the width of the lamp housing 11 in the mold opening direction D2. In other words, the first movement step P41 and the second movement step P42 are completed in this state. Then, as in the above embodiment, the lamp housing 11 is released from the mold 51 and removed from the mold device 50.

[0066] Even with this modified example, the time required to remove the lamp housing 11 can be shortened and productivity can be improved in the same manner as in the above embodiment.

[0067] Furthermore, in the above embodiment, the lamp housing 11 was attached to the mold 51 when the mold was opened. However, the lamp housing 11 may be attached to the mold 52. In this case, for example, in the above modified example, the mold 52 is provided with ejector pins that push the lamp housing 11 toward the mold 51. Then, the mold 51 is moved toward the mold opening direction D2 until the distance between the mold 51 and the mold 52 becomes greater than the width of the lamp housing 11 toward the mold opening direction D2. Thus, the first moving step P41 is performed. Next, the lamp housing 11 is pushed toward the mold 51 toward the mold 51 toward the mold opening direction D2 by these ejector pins. In this way, the first mold part 60 and the second mold part 70 move toward the opposite side of the mold 51 toward the lamp housing 11. In other words, the second moving step P42 is performed together with the first moving step P41.

[0068] Furthermore, in the above embodiment, a mold 52 comprising a rectangular prism-shaped first mold portion and a second mold portion 70 into which a rectangular through hole 70h into which the first mold portion 60 is inserted is formed was described as an example. However, the configuration of the mold 52 is not limited as long as the mold 52 includes a first mold portion 60 and a second mold portion 70 having a side surface 71 facing the side surface 61 of the first mold portion 60, and in the clamped state, at least parts of the side surfaces 61, 71 are separated from each other to define a first recess 54 which is part of the cavity 53, and a part of the side surface 61 includes a first inclined surface 61s that slopes toward the side surface 71 toward the bottom 54d side of the first recess 54 and defines a part of the first recess 54, and a part of the side surface 71 includes a second inclined surface 71s that slopes toward the opposite side of the side surface 61 toward the bottom 54d side of the first recess 54 and defines another part of the first recess 54. For example, the first mold portion 60 may be a triangular prism-shaped member, and the second mold portion 70 may have a triangular through-hole 70h into which the first mold portion 60 is inserted. The first protrusion 30 only needs to have a surface 32s1 that abuts against the first inclined surface 61s and a surface 32s2 that abuts against the second inclined surface 71s before the mold opening process P4.

[0069] Furthermore, in the above embodiment, the first inclined surface 61s and the second inclined surface 71s overlapped each other in a direction perpendicular to the mold opening direction D2 when the mold was clamped, but they do not have to overlap. For example, the first inclined surface 61s may be located on the bottom 54d side of the first recess 54 than the second inclined surface 71s, or the second inclined surface 71s may be located on the bottom 54d side of the first recess 54 than the first inclined surface 61s. The former configuration makes it easier to shorten the period from the start of the first movement process P41 to the start of the second movement process P42 compared to the latter configuration. Also, the latter configuration makes it easier to shorten the period during which the first protrusion 30 is deflected in the second movement process P42. In addition, at least one of the first inclined surface 61s and the second inclined surface 71s may be connected to the edge 54he of the opening 54h. Furthermore, when the first inclined surface 61s connects to the edge 54he, the second movement step P42 is started at a timing when a portion of the first inclined surface 61s is located on the side of the movement direction of the first mold portion 60 relative to the lamp housing 11, beyond the tip of the first protrusion 30.

[0070] Furthermore, in the above embodiment, the width of the first inclined surface 61s in the direction parallel to the mold opening direction D2 was approximately the same as the width of the second inclined surface 71s in the direction parallel to the mold opening direction D2. However, the width of the first inclined surface 61s in the direction parallel to the mold opening direction D2 may be wider than the width of the second inclined surface 71s in the direction parallel to the mold opening direction D2, and the width of the second inclined surface 71s in the direction parallel to the mold opening direction D2 may be wider than the width of the first inclined surface 61s in the direction parallel to the mold opening direction D2. With the former configuration, compared to the latter configuration, at least a part of the first inclined surface 61s is located on the side of the movement direction of the first mold portion 60 relative to the ramp housing 11 from the tip of the first protrusion 30, and it is easier to lengthen the period during which the first protrusion 30 and the first mold portion 60 overlap in the direction perpendicular to the mold opening direction D2. Therefore, the former configuration makes it easier to improve the degree of freedom in the timing of starting the second movement process P42 compared to the latter configuration. Also, the latter configuration makes it easier to reduce the increase in stress per unit time applied to the first protrusion 30 due to the movement of the second mold part 70 relative to the lamp housing 11 compared to the former configuration. In other words, it makes it easier to suppress a rapid increase in the stress applied to the first protrusion 30.

[0071] Furthermore, in the above embodiment, the inclination angle of the first inclined surface 61s with respect to the direction parallel to the mold opening direction D2 was approximately the same as the inclination angle of the second inclined surface 71s with respect to the direction parallel to the mold opening direction D2. However, the inclination angle of the first inclined surface 61s with respect to the direction parallel to the mold opening direction D2 may be smaller than the inclination angle of the second inclined surface 71s with respect to the direction parallel to the mold opening direction D2, and the inclination angle of the second inclined surface 71s with respect to the direction parallel to the mold opening direction D2 may be smaller than the inclination angle of the first inclined surface 61s with respect to the direction parallel to the mold opening direction D2. With the former configuration, compared to the latter configuration, at least a part of the first inclined surface 61s is located on the side of the movement direction of the first mold portion 60 relative to the ramp housing 11 from the tip of the first protrusion 30, and it is easier to lengthen the period during which the first protrusion 30 and the first mold portion 60 overlap in the direction perpendicular to the mold opening direction D2. Therefore, the former configuration makes it easier to improve the degree of freedom in the timing of starting the second movement process P42 compared to the latter configuration. Also, the latter configuration makes it easier to reduce the increase in stress per unit time applied to the first protrusion 30 due to the movement of the second mold part 70 relative to the lamp housing 11 compared to the former configuration. In other words, it makes it easier to suppress a rapid increase in the stress applied to the first protrusion 30.

[0072] Furthermore, in the above embodiment, a lamp housing 11 having a first protrusion 30 and a second protrusion 40 capable of holding a cable CA was described as an example of a resin molded product formed by the mold device 50. However, the resin molded product formed by the mold device 50 is not limited as long as it has protrusions. For example, in the above embodiment, a lamp housing 11 having a first protrusion 30 and a second protrusion 40 protruding toward the housing space R side was described as an example. However, the first protrusion 30 and the second protrusion 40 may protrude toward the rear side from the housing space R side, for example from the bottom wall portion 22. In this case, for example, a first recess 54 and a second recess 55 are formed in the mold 51 of the mold device 50, and the mold 51 is composed of a first mold portion 60 and a second mold portion 70. Also, the second protrusion 40 may consist only of the first vertical wall portion 41 without including the second vertical wall portion 42, and the second recess 55 of the mold 52 may consist only of the first portion 55a. Furthermore, the lamp housing 11 does not necessarily have to include the second projection 40, and the mold 52 may not have the second recess 55 formed therein. Also, a recess, which is another part of the cavity 53, may be formed in the first mold portion 60, spaced apart from the first recess 54. [Industrial applicability]

[0073] According to the present invention, a method for manufacturing resin molded products that can improve productivity is provided, and this method can be used in fields such as resin molding. [Explanation of Symbols]

[0074] 11. Lamp housing (resin molded product) 30...1st protrusion (protrusion) 50... Mold equipment 51, 52... Mold 53... Cavity 54...First recess (recess) 60...First Mold Department 61... Side view 61s...First slope 70...2nd Mold Department 71...side view 71s...Second slope P1···Xingdi Project P2··· Filling Project P3 Cooling Engineering P4··· Opening Project P41···First Moving Project P42···Second Moving Project

Claims

1. The clamping process involves clamping a pair of molds together, A filling step of filling the cavity formed between the clamped pair of molds with molten resin, A cooling step in which the molten resin filled in the cavity is cooled to form a resin molded product, A mold opening step involves opening the pair of molds and removing the resin molded product, Equipped with, The mold, on the other hand, includes a first mold portion and a second mold portion having a side surface facing the side surface of the first mold portion. In the clamped state, at least a portion of the side surfaces of the first mold portion and the second mold portion are separated from each other, defining a recess that is part of the cavity, The side surface of the first mold portion includes a first inclined surface that slopes toward the side surface of the second mold portion toward the bottom side of the recess from the opening side of the recess and defines a part of the recess. The side surface of the second mold portion includes a second inclined surface that slopes from the opening side toward the bottom side toward the opposite side of the first mold portion and defines another part of the recess, The mold opening process is as follows: A first moving step involves moving the first mold portion of the resin molded product to the opposite side of the other mold portion, A second movement step involves moving the second mold portion relative to the resin molded product in the same direction as the movement direction, starting from a timing when the protrusion of the resin molded product, formed by the cooling of the molten resin filling the recess, is located on the side of the movement direction of the first mold portion relative to the resin molded product from the tip of the protrusion of the resin molded product, and the protrusion and the first mold portion overlap in a direction perpendicular to the mold opening direction. including A method for manufacturing a resin molded product characterized by the following:

2. At the aforementioned timing, the entire first slope is located on the side of the direction of movement from the tip of the protrusion. A method for manufacturing a resin molded product according to feature 1.

3. At the aforementioned timing, the entire protruding portion and the first mold portion are separated. A method for manufacturing a resin molded product according to feature 1.

4. In the first movement step, at the timing, the movement of the first mold part relative to the resin molded product is interrupted. Before the distance the second mold portion moves relative to the resin molded product exceeds the distance the first mold portion moves relative to the resin molded product up to the aforementioned timing, the movement of the first mold portion relative to the resin molded product in the first movement step is restarted. A method for manufacturing a resin molded product according to feature 1.

5. The movement speed of the first mold part relative to the resin molded product in the first movement step is the same as the movement speed of the second mold part relative to the resin molded product in the second movement step. A method for manufacturing a resin molded article according to any one of claims 1 to 3.

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