Molding method of inner panel

Abstract

To prevent in an inner panel a peripheral part around a nut of a reinforcement panel from deforming when a panel body is molded.SOLUTION: Molding of an inner panel (10) uses an injection molding die (200) in which a slide die (214) is embedded in a core die (210). The slide die can advance and retract in a direction (Da) perpendicular to a welded face (56) of a nut (51) of a reinforcement panel (50A) in a position corresponding to a rear side of the nut and is located in an escape part (215) arranged in a peripheral part around a core-type nut in an advanced state. A molding method of the inner panel includes: mold clamping the injection molding die; bringing a cavity die (220) into contact with a part corresponding to the nut in a surface of the reinforcement panel; supporting the part corresponding to the escape part in a rear face of the reinforcement panel with a rear face of the nut by the slide die advanced after the mold clamping of the injection molding die; and in that state injecting molten resin (R) into a cavity (230).SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a method for forming an inner panel. [Background technology]

[0002] It has been known for some time that a resin inner panel is used in a vehicle back door. In order to ensure rigidity, a metal reinforcing panel made of a steel plate or the like is inserted into the inner panel. Such an inner panel is molded by insert molding (see, for example, Patent Document 1). In insert molding, the reinforcing panel is set in an injection molding die so as to be located within a cavity, and in this state, the die is clamped to form a cavity, and molten resin is injected into the cavity to mold a resin panel body integrally with the reinforcing panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-260724 A Summary of the Invention [Problem to be solved by the invention]

[0004] A hinge that is connected to the vehicle body is attached to the inner panel. The hinge is fastened to a portion of the inner panel where the reinforcing panel is provided. The reinforcing panel is exposed on the back side at the hinge attachment portion where the hinge of the inner panel is attached. A nut for fastening the hinge is welded to the exposed back portion of the reinforcing panel.

[0005] When the opening and closing direction of the injection molding die used to mold such an inner panel is different from the perpendicular direction of the welded surface of the nut on the reinforcing panel, the core die in which the reinforcing panel is set is provided with a relief portion corresponding to the periphery of the nut to avoid interference with the nut welded to the reinforcing panel. In other words, the portion of the reinforcing panel corresponding to the relief portion is not supported by the core die.

[0006] Therefore, the reinforcing panel may be deformed at the portion corresponding to the relief portion due to the pressure of the molten resin during molding of the inner panel. If the reinforcing panel is deformed around the nut, the position of the nut will be displaced, and the positional accuracy of the hinge will be deteriorated. This is particularly problematic when a relatively thin reinforcing panel is used to reduce the weight of the back door.

[0007] An object of the present invention is to suppress deformation of a peripheral portion of a nut of a reinforcing panel in an inner panel constituting a vehicle back door during molding of a panel body. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention uses an injection molding die in which a slide die is incorporated into a core die, and the relief portion provided in the core die is filled with the slide die.

[0009] Specifically, the first invention is directed to a method for molding an inner panel. The method for molding an inner panel of the first invention is a method for molding an inner panel having a hinge mounting portion to which a hinge is attached, a metal reinforcing panel inserted so as to be exposed on the back side at the hinge mounting portion, and a nut for mounting the hinge welded to the exposed back side of the reinforcing panel. In the method for molding an inner panel, an injection molding die is used that includes a core die to which the reinforcing panel to which the nut has already been welded is set, and a cavity die that forms a cavity between the reinforcing panel by clamping the core die. The opening and closing direction of the injection molding die in which the core die and the cavity die approach or move away from each other is different from the perpendicular direction of the welding surface of the reinforcing panel to which the nut is welded. The core die has a relief portion around the nut that does not come into contact with the back side of the reinforcing panel. A slide die is assembled at a position on the core die corresponding to the back side of the nut. The slide die is movable back and forth in a direction perpendicular to the welding surface and is positioned in the relief portion when advanced.

[0010] In the method for molding an inner panel of the first invention, after the reinforcing panel is set in the core mold, the injection molding mold is closed and the cavity mold is abutted against the portion on the surface of the reinforcing panel corresponding to the nut, and the slide mold is advanced before or after the injection molding mold is closed to support the portion on the back surface of the reinforcing panel corresponding to the escape portion and the back surface of the nut, and molten resin is injected into the cavity of the injection molding mold in the closed state to fill it and then hardened, thereby molding a resin panel body integral with the reinforcing panel, and after the slide mold is retracted, the injection molding mold is opened and the inner panel formed by integrating the reinforcing panel and the panel body is demolded.

[0011] A second invention is a molding method for an inner panel according to the first invention, in which the slide mold has an elastic body that abuts against the back surface of the nut. In the molding method for an inner panel according to the second invention, the slide mold is advanced after the injection molding die is clamped, thereby pressing the elastic body against the back surface of the nut.

[0012] A third invention is a method for molding an inner panel according to the first or second invention, wherein a radial gap between the nut and a portion of the sliding mold located in the escape portion is 2 mm or less. Effect of the Invention

[0013] According to the first invention, an injection mold in which a slide mold is incorporated in a core mold is used. The slide mold can advance and retreat in a direction perpendicular to the surface of the welding surface of the nut of the reinforcing panel at a position corresponding to the back side of the nut, and when advanced, it is located in an escape portion provided in the periphery of the nut of the core mold. In the molding method of the inner panel, the injection mold is clamped to bring the cavity mold into contact with a portion of the surface of the reinforcing panel corresponding to the nut, and the slide mold advanced before or after clamping the injection mold supports a portion of the back surface of the reinforcing panel corresponding to the escape portion and the back surface of the nut, and in this state, molten resin is injected into the cavity. In this way, when the cavity is filled with molten resin, the range in which the back surface is not supported by the periphery of the nut of the reinforcing panel can be reduced. This makes it possible to suppress deformation of the peripheral portion of the nut of the reinforcing panel during molding of the panel body.

[0014] According to the second invention, the slide mold is advanced after the injection molding mold is clamped, and the elastic body provided in the slide mold is pressed against the nut. In this way, the nut is pressed by the elastic body in the direction perpendicular to the welding surface, so that the set position of the reinforcing panel does not shift. Then, the nut is urged toward the cavity mold by the repulsive force of the elastic body, and the part of the surface of the reinforcing panel corresponding to the nut is closely attached to the cavity mold. This makes it possible to prevent the molten resin from entering the front side of the welded part of the nut of the reinforcing panel. This is advantageous in preventing the welded part of the nut of the reinforcing panel from being deformed.

[0015] According to the third invention, in the injection molding die, the gap between the nut and the portion located in the relief portion of the slide die is 2 mm or less in the radial direction of the nut. If the gap is 2 mm or less, even if a lightweight and inexpensive pressed iron plate having a thickness of, for example, about 0.5 mm to 0.6 mm is used as the reinforcing panel, the peripheral portion of the nut of the reinforcing panel can be suitably prevented from being deformed during molding of the panel body. [Brief description of the drawings]

[0016] [Figure 1]FIG. 1 is a perspective view of a vehicle back door. [Diagram 2] FIG. 2 is an exploded perspective view of the vehicle back door. [Diagram 3] FIG. 3 is a rear view illustrating a schematic configuration of the inner panel. [Figure 4] FIG. 4 is a rear view illustrating a main part of the inner panel. [Diagram 5] FIG. 5 is a perspective view illustrating a main part of the inner panel surrounded by V in FIG. [Figure 6] 6 is a cross-sectional view of a main part of the inner panel taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view of a main part of the inner panel taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view of a main part of the inner panel surrounded by VIII in FIG. [Figure 9] FIG. 9 is a view showing an example of a main part of the inner panel with the hinge attached, as viewed from a direction indicated by an arrow IX in FIG. [Figure 10] FIG. 10 is a cross-sectional view showing how an inner reinforcement is set in an injection molding die in a molding process of an inner panel. [Figure 11] FIG. 11 is a cross-sectional view showing a state in which the injection mold is clamped in the molding process of the inner panel. [Figure 12] FIG. 12 is a cross-sectional view showing a state in which a slide die is advanced in an injection molding die in a molding process of an inner panel. [Figure 13] FIG. 13 is a cross-sectional view showing a state in which molten resin is injected into a cavity of an injection mold in a molding process of an inner panel. [Figure 14] FIG. 14 is a cross-sectional view showing how the injection mold is opened in the molding process of the inner panel to remove the molded product, that is, the inner panel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an exemplary embodiment will be described in detail with reference to the drawings. In the following embodiment, for convenience of explanation, the front side in the vehicle longitudinal direction will be referred to as "front", the rear side will be referred to as "rear", the left side in the vehicle width direction facing the front of the vehicle will be referred to as "left", the right side will be referred to as "right", the upper side in the vehicle height direction will be referred to as "upper", and the lower side will be referred to as "lower". In addition, the back door according to this embodiment will be described assuming a posture with the rear opening of the vehicle closed, unless otherwise specified with respect to the open / closed state.

[0018] <<Embodiment>> The vehicle back door 1 of this embodiment is a flip-up type back door. The upper end of this back door 1 is connected to the upper edge of a rear opening provided in the vehicle body of a hatchback vehicle via a pair of hinges 100. The back door 1 opens and closes the rear opening by rotating in the vertical direction around a rotation axis formed by the pair of hinges 100 and extending in the vehicle width direction.

[0019] -Backdoor configuration- 1 and 2, the back door 1 mainly comprises a door body 5 and a plurality of lamp units 90. A window section 7 is provided in the upper half of the door body 5. The door body 5 is configured by joining an inner panel 10 and an outer panel 60 in a mutually opposing state, and includes a window panel 80 forming the window section 7.

[0020] A damper stay 110 is provided between the door main body 5 and both left and right side portions of the rear opening of the vehicle body. One end of the damper stay 110 is attached to the upper end on both the left and right sides of the rear opening of the vehicle body. The other end of the damper stay 110 is attached to the middle of the edge of the door main body 5 in the left and right direction.

[0021] When the back door 1 is opened, the damper stay 110 biases the door body 5 in the opening direction from a predetermined position. The opening action of the back door 1 is assisted by the biasing force of the damper stay 110. Note that, for the sake of convenience, only the right damper stay 110 is shown in Fig. 2, but a pair of left and right damper stays 110 are connected to the back door 1.

[0022] The lamp units 90 include a high mount stop lamp unit 92 and a rear lamp unit 94. The rear lamp unit 94 includes a tail lamp and a rear blinker. For convenience, only the left rear lamp unit 94 is shown in FIG. 2, but the back door 1 is provided with a pair of left and right rear lamp units 94.

[0023] <Inner panel> The inner panel 10 is a single resin panel, and is combined with the outer panel 60 and the window panel 80 to form the back door 1. As shown in FIG. 3, a window opening 11 is formed in the upper half of the inner panel 10. The window opening 11 is a substantially trapezoidal opening extending in the left-right direction. The inner panel 10 includes a resin panel main body 40 having the window opening 11, and a metal reinforcing panel 50 (indicated by dot hatching in FIGS. 3 to 5) inserted into the panel main body 40.

[0024] The panel body 40 is integrally formed with the reinforcing panel 50 by injection molding. The panel body 40 is made of, for example, a thermoplastic resin containing a fiber reinforcement material. Specifically, the panel body 40 is made of a material such as glass fiber-reinforced polypropylene (PP-GF), carbon fiber-reinforced polypropylene (PP-CF), or cellulose nanofiber-reinforced polypropylene (PP-CNF).

[0025] A pair of upper reinforcement 50A and lower reinforcement 50B are inserted into the reinforcing panel 50. The upper reinforcement 50A and the lower reinforcement 50B are made of an iron plate made of iron (Fe) or stainless steel (SUS), or a galvanized iron plate. The thickness of the upper reinforcement 50A and the lower reinforcement 50B is relatively thin, for example, 0.5 mm to 0.8 mm.

[0026] The upper portion of the window frame portion 12 that forms the outer periphery of the window opening 11 in the panel body 40 constitutes an upper frame portion 13 extending in the left-right direction. The upper frame portion 13 forms the ceiling portion of the door body 5. Furthermore, the left and right portions of the window frame portion 12 each constitute a pillar portion 14 extending in the up-down direction. The pillar portion 14 is formed in a concave shape that opens toward the rear. The portion of the inner panel 10 below the window opening 11 (hereinafter simply referred to as the lower portion) constitutes the lower portion of the door body 5.

[0027] An inner standing wall 16 is provided on the peripheral portion of the window opening 11 in the inner panel 10. The inner standing wall 16 rises rearward toward the outer panel 60. An inner joint piece 18 is provided at the rear end of the inner standing wall 16. The inner joint piece 18 protrudes inwardly into the window opening 11. Furthermore, an outer standing wall 20 is provided on the outer periphery of the inner panel 10. The outer standing wall 20 rises rearward toward the outer panel 60. An outer joint piece 22 is provided at the rear end of the outer standing wall 20. The outer joint piece 22 protrudes toward the outer periphery of the inner panel 10.

[0028] The inner panel 10 has a pair of hinge mounting portions 24. The pair of hinge mounting portions 24 are provided on the outer standing wall 20 of the upper frame portion 13. The outer standing wall 20 on which the pair of hinge mounting portions 24 are provided extends vertically and horizontally, and constitutes a rear portion of the upper frame portion 13 of the inner panel 10. The pair of hinge mounting portions 24 are formed at positions spaced apart from each other on both sides in the left-right direction. A metal hinge 100 is fixed from the front to each hinge mounting portion 24 using a first bolt 108 (see FIG. 2).

[0029] A stay attachment portion 25 is provided on the outer wall portion in the vehicle width direction of the lower end of each pillar portion 14. One side end of a damper stay 110 is connected to the stay attachment portion 25 from the outside in the vehicle width direction using a second bolt 112 so as to be able to swing freely (see FIG. 2). A pair of upper reinforcements 50A are provided integrally on both the left and right sides of the inner panel 10 by insert molding.

[0030] Each upper reinforcement 50A is formed roughly in an L shape, and is inserted from both left and right sides of the upper frame portion 13 of the window frame portion 12 of the panel main body 40 along the pillar portion 14. Each upper reinforcement 50A extends from the hinge mounting portion 24 to the stay mounting portion 25, and constitutes the hinge mounting portion 24 and the stay mounting portion 25 together with the panel main body 40.

[0031] An upper service hole 26 is formed in the inner standing wall 16 of the upper frame portion 13 of the inner panel 10. The upper service hole 26 is a work opening used for connecting a harness to the high mounted stop lamp unit 92, maintenance work, and the like. The inner standing wall 16 in which the upper service hole 26 is formed extends in the front-rear and left-right directions, and is formed so that its thickness direction corresponds to the top and bottom.

[0032] The upper service hole 26 is formed in the left-right center of the inner standing wall 16 of the upper frame portion 13. Although not shown, the peripheral portion of the upper service hole 26 in the inner panel 10 is formed so that the underside is recessed upward. A cover member 84 (shown in FIG. 2) is fitted from below into the recess in the peripheral portion of the upper service hole 26. The upper service hole 26 is closed by this cover member 84.

[0033] The upper frame portion 13 of the inner panel 10 is further provided with a plurality of reinforcing ribs 28. The multiple reinforcing ribs 28 are positioned at intervals from one another in the left-right direction. Each reinforcing rib 28 protrudes toward the upper panel 62 and extends linearly in the front-rear direction. The tip of each of these reinforcing ribs 28 is located near the rear surface of the upper panel 62. When the upper panel 62 bends downward, it comes into contact with and is supported by the reinforcing ribs 28. This restricts the upper panel 62 from bending downward.

[0034] Of the multiple reinforcing ribs 28, some (three in this example) reinforcing ribs 28 located in the middle in the left-right direction are formed so as to straddle upper service hole 26. Reinforcing ribs 28 are also formed on both left and right edge portions of upper service hole 26. Each of reinforcing ribs 28 formed on both left and right edge portions of upper service hole 26 corresponds to a recess in the peripheral portion of upper service hole 26, and is positioned so as to overlap cover member 84.

[0035] A latch mounting portion 29 is provided on the lower edge of the lower part of the inner panel 10. A latch (not shown) is attached to the latch mounting portion 29. The latch cooperates with a striker provided on the lower edge of the rear opening of the vehicle body to form a locking mechanism that locks the back door 1 in the closed state. A lower reinforcement 50B is provided integrally with the latch mounting portion 29 by insert molding.

[0036] A parts mounting portion 30 is provided in the upper central portion of the lower part of the inner panel 10. A lamp for illuminating the license plate, a knob mechanism, and the like are attached to the parts mounting portion 30. A lower service hole 31 is formed below the parts mounting portion 30 of the inner panel 10. The lower service hole 31 is an opening used for latch installation work, maintenance work, and the like.

[0037] A recess that is recessed toward the front and protrudes toward the rear is formed in a portion of the inner panel 10 that includes the component mounting portion 30. The lower service hole 31 is formed in an inner portion of the recess. The opening of the recess is closed from the front side by a cover trim 86. This inner panel 10 employs a band-shaped holding structure that holds the upper reinforcement 50A in a manner that partially exposes it on the back side.

[0038] As shown in Fig. 4, the band-shaped holding structure is provided in the portion of the inner panel 10 where the upper reinforcement 50A is inserted, that is, in the portion extending from both the left and right sides of the upper frame portion 13 to a position below the pillar portion 14. The band-shaped holding structure is constituted by a plurality of band-shaped resin portions 43. The upper reinforcement 50A is positioned biased toward the back surface side of the inner panel 10. As shown in Figs. 4 to 7, the panel main body 40 has a front resin layer 41 and a plurality of band-shaped resin portions 43 in the portion where the upper reinforcement 50A is inserted.

[0039] The front-side resin layer 41 covers substantially the entire front surface side of the upper reinforcement 50A. The plurality of strip-shaped resin parts 43 are provided on the back surface side of the upper reinforcement 50A. Each of the plurality of strip-shaped resin parts 43 extends in a strip shape having a flat cross-sectional shape, and contacts the back surface of the upper reinforcement 50A on one side surface in the thickness direction. Each strip-shaped resin part 43 is connected to the front-side resin layer 41 at least at both ends. The upper reinforcement 50A is held to the panel main body 40 by the plurality of strip-shaped resin parts 43.

[0040] The multiple strip-shaped resin parts 43 are integrally formed to form a net part 45. The net part 45 covers the back surface side of the upper reinforcement 50A in a net-like manner. Through holes (not shown) are formed in the upper reinforcement 50A at locations corresponding to the intersections of the strip-shaped resin parts 43. The net part 45 and the front-side resin layer 41 are connected via the through holes. The upper reinforcement 50A is partially exposed on the back surface side from the panel main body 40 at the mesh parts of the net part 45. In addition, the back side of the outer edge part located on the upper frame part 13 of the upper reinforcement 50A is covered by the panel main body 40.

[0041] A portion of the upper reinforcement 50A corresponding to the hinge mounting portion 24 and a portion corresponding to the stay mounting portion 25 are exposed on the back surface side from the panel main body 40. A pair of first nuts 51 for mounting the hinge 100 are welded to the exposed portions corresponding to the hinge mounting portion 24 on the back surface of the upper reinforcement 50A. In addition, a second nut 52 for fastening the damper stay 110 is welded to the exposed portions corresponding to the stay mounting portion 25 on the back surface of the upper reinforcement 50A.

[0042] 5, reinforcing ribs 28 are provided on the back surface of each strip-shaped resin portion 43 provided on the upper frame portion 13 of the inner panel 10. Of the multiple reinforcing ribs 28, all of the reinforcing ribs 28 located in the portion where the upper reinforcement 50A is inserted are formed integrally with the strip-shaped resin portion 43. Each of the reinforcing ribs 28 is connected to the outer periphery of the upper reinforcement 50A in the panel main body 40, specifically, to the inner standing wall 16.

[0043] <Outer panel> 2, the outer panel 60 is divided into two parts, an upper panel 62 and a lower panel 64.

[0044] The upper panel 62 and the lower panel 64 are each a resin panel. The upper panel 62 and the lower panel 64 are formed by injection molding. The material used for the upper panel 62 and the lower panel 64 may be synthetic resin such as talc-containing polypropylene (PP-T) or a mixture of ethylene propylene diene methylene rubber (EPDM).

[0045] The upper panel 62 is provided to face the upper frame portion 13 of the inner panel 10. The upper panel 62 forms the ceiling portion of the door body 5 and constitutes a spoiler portion 66 protruding rearward. A lamp unit attachment portion 67 is provided at the rear end portion of the spoiler portion 66. A high mount stop lamp unit 92 is attached to the lamp unit attachment portion 67. A lower panel portion of the upper panel 62 that constitutes the lower portion of the spoiler portion 66 is folded back diagonally downward and rearward at the front side to constitute an upper joint piece 69.

[0046] An outer edge portion of the upper panel 62 is joined to the inner panel 10 using an adhesive. Specifically, a front edge portion of the upper panel 62 is adhered to the outer joint piece 22 of the inner panel 10. An upper joint piece 69 constituting a lower edge portion of the upper panel 62 is adhered to the inner joint piece 18 of the inner panel 10. An internal space is formed between the upper panel 62 and the inner panel 10 joined in this manner.

[0047] The lower panel 64 is provided to face the lower part of the inner panel 10. A lamp unit mounting portion 67 is provided on both left and right sides of the lower panel 64. A rear lamp unit 94 is attached to the lamp unit mounting portion 67. For example, the rear lamp unit 94 is fastened together at multiple points from the front to the outer joint piece 22 of the inner panel 10 and the lower panel 64 using fasteners 96 such as nuts.

[0048] A plate mounting portion 70 is provided in the center of the lower panel 64. A license plate (number plate) (not shown) is attached to the plate mounting portion 70. A lower joint piece 72 is provided at the upper edge of the lower panel 64. The lower joint piece 72 is located forward via a step portion that extends in the front-to-rear direction. The lower joint piece 72 extends over the entire upper edge of the lower panel 64 in the left-to-right direction.

[0049] The outer edge portion of the lower panel 64 is joined to the inner panel 10 using an adhesive. Specifically, the lower joint piece 72 constituting the upper edge portion of the lower panel 64 is adhered to the inner joint piece 18 of the inner panel 10. The left and right edge portions and the lower edge portion of the lower panel 64 are adhered to the outer joint piece 22 of the inner panel 10. An internal space is formed between the lower panel 64 and the inner panel 10 joined in this manner.

[0050] <Window Panel> The window panel 80 is a horizontally long panel extending across both the left and right ends of the back door 1. The window panel 80 is disposed between the upper panel 62 and the lower panel 64 to close the window opening 11 of the inner panel 10 and cover the opening of the pillar portion 14 of the inner panel 10. The window panel 80 is made of transparent resin such as polycarbonate (PC) or glass. Although not shown, a concealing layer made of black ceramics or the like is provided on the outer periphery of the window panel 80 to conceal the joint portion with the outer panel 60.

[0051] An outer edge portion of the window panel 80 is joined to the outer panel 60 and the inner panel 10 using an adhesive. Specifically, an upper edge portion of the window panel 80 is adhered to an upper joint piece 69 of the upper panel 62. A lower edge portion of the window panel 80 is adhered to a lower joint piece 72 of the lower panel 64. Both left and right edge portions of the window panel 80 are adhered to outer joint pieces 22 between the upper panel 62 and the lower panel 64 of the inner panel 10. An internal space is formed between the window panel 80 and the pillar portion 14 of the inner panel 10 joined in this manner.

[0052] A harness that supplies power to lamp units 90 such as a high mount stop lamp unit 92 and a rear lamp unit 94 is laid in the internal space between the above-mentioned outer panel 60 and window panel 80 and the inner panel 10. The harness is led into the internal space from an opening 37 formed in the outer standing wall 20 at the upper edge of the inner panel 10 through a grommet (not shown).

[0053] <Inner panel hinge mounting section and surrounding structure> 6, each upper reinforcement 50A is inserted so as to be exposed on the back side at the hinge mounting portion 24. A pair of insertion holes 54 is formed in a portion of the upper reinforcement 50A corresponding to the hinge mounting portion 24. The pair of first nuts 51 are welded to the exposed back side of the upper reinforcement 50A with the screw holes corresponding to the insertion holes 54, respectively.

[0054] A surface-perpendicular direction Da of a welding surface 56 to which the first nut 51 of the upper reinforcement 50A is welded differs from a protruding direction of the reinforcing rib 28. The protruding direction of the reinforcing rib 28 corresponds to an opening / closing direction Db of an injection molding die 200 that molds the inner panel 10. The front resin layer 41 is not provided in a portion of the front surface of the upper reinforcement 50A that corresponds to the first nut 51. That is, a peripheral portion of the insertion hole 54 on the front surface of the upper reinforcement 50A is exposed from the front resin layer 41.

[0055] The front resin layer 41 is formed up to the edge of a portion of the front surface of the upper reinforcement 50A that corresponds to the first nut 51. A recess 58 is formed in the portion of the front resin layer 41 that corresponds to the first nut 51, the recess 58 having a bottom surface at the periphery of the insertion hole 54 of the upper reinforcement 50A. As shown in FIG. 8, an annular collar 106 is disposed in this recess 58. The collar 106 is a metal member. A pair of first bolts 108 that attach the hinge 100 are each fixed to the upper reinforcement 50A by using the collar 106.

[0056] As shown in FIG. 9, the hinge 100 includes a first hinge member 101 and a second hinge member 102. The first hinge member 101 is a metal part having a bent shape with a central portion protruding rearward. Both side portions in the left-right direction of the first hinge member 101 each constitute a flat fastened portion 103. An attachment hole 104 is formed in the fastened portion 103. The second hinge member 102 is a metal part provided with a weld bolt 105 to be fastened to the vehicle body. The second hinge member 102 is connected to the protruding portion of the first hinge member 101 so as to be able to swing freely around an axis extending in the left-right direction.

[0057] 8, each fastened portion 103 of the hinge 100 is applied to the surface of the inner panel 10 so that the mounting holes 104 correspond to holes of the collars 106 disposed in the recesses 58 of the front resin layer 41. A pair of first bolts 108 are inserted through the mounting holes 104 of the corresponding fastened portions 103 of the hinge 100, the collars 106, and the insertion holes 54 of the upper reinforcement 50A, and are fastened to the first nuts 51. Each fastened portion 103 of the hinge 100 is sandwiched between the head of the first bolt 108 and the collars 106. In this manner, the hinge 100 is attached to the hinge attachment portion 24 of the inner panel 10.

[0058] -Inner panel molding method- The inner panel 10 of this embodiment is molded using an injection molding die 200 shown in FIG.

[0059] <Injection mold> The injection molding die 200 includes a core die 210 and a cavity die 220. The core die 210 has a first molding surface 212 that molds the back surface of the inner panel 10. The cavity die 220 has a second molding surface 222 that molds the front surface of the inner panel 10. The core die 210 and the cavity die 220 are clamped together to form a cavity 230 between them for molding the panel main body 40. The cavity 230 is a space having a shape corresponding to the panel main body 40.

[0060] A plurality of magnets (not shown) are incorporated in the core mold 210. A plurality of magnets are provided in each of a portion of the core mold 210 where the upper reinforcement 50A is set and a portion where the lower reinforcement 50B is set. A plurality of gates (not shown) are formed in the second molding surface 222 of the cavity mold 220. The gates are inlets for injecting the molten resin R, which is the raw material of the panel main body 40, into the cavity 230. A plurality of gates are set on the outer periphery and inner periphery of the cavity 230 at intervals from each other.

[0061] The cavity mold 220 is further provided with resin flow paths (not shown) such as hot runners and sprues that communicate with each gate. Needle valves that control the opening and closing of each gate are provided in the resin flow paths. The resin flow paths open to the outer surface of the cavity mold 220. The openings of the resin flow paths communicate with a nozzle of a resin molding machine (not shown).

[0062] The resin injector injects heated and softened molten resin R from a nozzle into the injection molding die 200. The molten resin R is a thermoplastic resin in a molten state. The molten resin R injected from the resin injector is sent to each gate through a resin flow passage. The injection timing of the molten resin R from each gate to the cavity 230 is controlled by opening and closing a needle valve.

[0063] The opening / closing direction Db of the injection molding die 200 in which the core die 210 and the cavity die 220 approach or move away from each other differs from the perpendicular direction Da of the welding surface 56 to which the first nut 51 of the upper reinforcement 50A is welded. For this reason, the core die 210 has a relief portion 215 that does not come into contact with the back surface of the upper reinforcement 50A around the first nut 51 to avoid interference with the first nut 51 welded to the upper reinforcement 50A.

[0064] A slide die 214 is assembled into the core die 210 at a position corresponding to the rear side of the first nut 51. The slide die 214 is movable forward and backward in a direction perpendicular to the surface Da of the welding surface 56 of the upper reinforcement 50A. The slide die 214 has a filling portion 216 and an elastic body 218. The filling portion 216 is a portion that fills the relief portion 215 of the core die 210. The filling portion 216 is located in the relief portion 215 when the slide die 214 is advanced, and is retracted from the relief portion 215 when the slide die 214 is retracted.

[0065] A gap g (shown in FIG. 12) between the first nut 51 and the filling portion 216 located in the relief portion 215 of the slide mold 214 in the radial direction of the first nut 51 is designed to be 2 mm or less. The elastic body 218 is provided at the end of the slide mold 214 on the advancing side corresponding to the back side of the first nut 51. A recess 219 is formed at the end of the slide mold 214 on the advancing side. The elastic body 218 is fitted and fixed in the recess 219, and is disposed so as to come into contact with the back side of the first nut 51 when the slide mold 214 advances. The elastic body 218 is made of, for example, rubber such as silicone rubber or an elastomer.

[0066] <Inner panel molding process> The method for molding the inner panel 10 includes a setting step, a mold clamping step, an injection molding step, and a demolding step.

[0067] First, in the setting process, a pair of upper reinforcement 50A and lower reinforcement 50B to which a first nut 51 and a second nut 52 have been welded are set in an injection molding die 200 in an open state in which a core die 210 and a cavity die 220 are separated from each other, as shown in Fig. 10. At this time, each of the upper reinforcement 50A and the lower reinforcement 50B is attracted and held by the magnetic force of a plurality of magnets, and is in a state in which the back surface of each of the upper reinforcement 50A and the lower reinforcement 50B is in contact with the core die 210.

[0068] At this time, the slide mold 214 is retracted. With the slide mold 214 in the retracted position, when the upper reinforcement 50A is set in the core mold 210, the first nut 51 does not interfere with the filling portion 216 of the slide mold 214 and does not interfere with the setting operation of the upper reinforcement 50A. In addition, by retracting the slide mold 214, it is possible to prevent the upper reinforcement 50A from hitting the elastic body 218 and floating from the core mold 210, making it impossible to set the upper reinforcement 50A stably. Furthermore, when the injection molding mold 200 is clamped as described below, the first nut 51 is pushed by the elastic body 218 in a direction different from the perpendicular direction Da of the welding surface 56, so that it is possible to prevent the setting position of the upper reinforcement 50A from being shifted.

[0069] In the mold clamping process that follows, as shown in Fig. 11, the core mold 210 is brought close to the cavity mold 220 to close the injection molding mold 200, and then the injection molding mold 200 is clamped up to clamp the mold. This forms a cavity 230 inside the injection molding mold 200. Also, the cavity mold 220 is brought into contact with a portion of the surface of the upper reinforcement 50A that corresponds to the first nut 51. At this time, the needle valves of all the gates are kept in a closed state.

[0070] Then, after the injection molding die 200 is clamped, the slide die 214 is advanced. In this way, as shown in Fig. 12, the slide die 214 supports a portion of the back surface of the upper reinforcement 50A corresponding to the relief portion 215 and the back surface of the first nut 51. The portion of the back surface of the upper reinforcement 50A corresponding to the relief portion 215 is supported by a filling portion 216 of the slide die 214. The back surface of the first nut 51 is supported by an elastic body 218.

[0071] At this time, as the slide die 214 advances, the first nut 51 is pressed by the elastic body 218 in the direction perpendicular to the surface Da of the welding surface 56, so that the set position of the upper reinforcement 50A is unlikely to shift. Also, the elastic body 218 is elastically deformed by being pressed against the first nut 51, so that there is little effect on the advancing operation of the slide die 214. Furthermore, as the first nut 51 is pressed by the elastic body 218, the welded portion of the first nut 51 of the upper reinforcement 50A is uniformly pressed against the cavity die 220 in the direction perpendicular to the surface.

[0072] In the subsequent injection molding process, injection of molten resin R is started from the nozzle of the resin injector. At the same time, needle valves corresponding to each gate are opened at a predetermined timing, and the molten resin R sent from the resin injector is injected from each gate into the cavity 230. Then, as shown in Fig. 13, the molten resin R injected from each gate is spread throughout the entire cavity 230. When the entire cavity 230 is filled with the molten resin R, injection of the molten resin R from the resin injector is terminated, and all gates are closed.

[0073] Then, cooling of the injection molding die 200 is started. The molten resin R filled in the cavity 230 is solidified by cooling of the injection molding die 200. By solidifying the molten resin R in the cavity 230 in this manner, the panel main body 40 is molded integrally with the pair of upper reinforcement 50A and lower reinforcement 50B.

[0074] 14, in the demolding process performed thereafter, the injection molding die 200 is opened and the core die 210 is separated from the cavity die 220. Furthermore, an ejector pin (not shown) provided on the core die 210 is caused to protrude from the first molding surface 212, thereby releasing the inner panel 10 in which the pair of upper reinforcements 50A and lower reinforcements 50B and the panel main body 40 are integrated, from the first molding surface 212 of the core die 210, and the inner panel 10 is demolded from the injection molding die 200. Thereafter, post-processing such as cutting off gate residue attached to the inner panel 10 is performed.

[0075] In this manner, the inner panel 10 can be formed.

[0076] -Features of the embodiment- In the molding method of the inner panel 10 of this embodiment, an injection molding die 200 in which a slide die 214 is incorporated in a core die 210 is used. The slide die 214 can advance and retreat in a direction perpendicular to the surface Da of the welding surface 56 of the first nut 51 of the upper reinforcement 50A at a position corresponding to the back side of the first nut 51, and in the advanced state, is located in an escape portion 215 provided in the periphery of the nut of the core die 210. In the molding method of the inner panel 10, the injection molding die 200 is clamped to bring the cavity die 220 into contact with a portion of the surface of the upper reinforcement 50A corresponding to the first nut 51, and the slide die 214 advanced after clamping the injection molding die 200 supports a portion of the back side of the upper reinforcement 50A corresponding to the escape portion 215 and the back side of the first nut 51, and in this state, molten resin R is injected into the cavity 230. This makes it possible to reduce the area where the back surface is not supported by the periphery of the first nut 51 of the upper reinforcement 50A when the molten resin R is filled into the cavity 230. This makes it possible to suppress deformation of the periphery of the first nut 51 of the upper reinforcement 50A when the panel main body 40 is molded.

[0077] In the molding method of the inner panel 10 of this embodiment, the slide die 214 is advanced after the injection molding die 200 is clamped, so that the elastic body 218 provided in the slide die 214 is pressed against the first nut 51. In this way, the first nut 51 is pressed by the elastic body 218 in the direction perpendicular to the surface Da of the welding surface 56, so that the upper reinforcement 50A does not deviate from the set position. Then, the first nut 51 is urged toward the cavity die 220 by the repulsive force of the elastic body 218, and the part of the surface of the upper reinforcement 50A corresponding to the first nut 51 is closely attached to the cavity die 220. This makes it possible to suppress the molten resin R from entering the front side of the welding part of the first nut 51 of the upper reinforcement 50A. This is advantageous in suppressing deformation of the welding part of the first nut 51 of the upper reinforcement 50A.

[0078] In the molding method of the inner panel 10 of this embodiment, in the injection molding die 200, a gap g in the radial direction of the first nut 51 between the first nut 51 and a portion located at the escape portion 215 of the slide die 214 is 2 mm or less. If the gap g is 2 mm or less, even if a lightweight and inexpensive pressed iron plate having a thickness of about 0.5 mm to 0.6 mm is used as the upper reinforcement 50A, deformation of the peripheral portion of the first nut 51 of the upper reinforcement 50A during molding of the panel main body 40 can be suitably suppressed.

[0079] Other Embodiments In the above embodiment, a pair of upper reinforcements 50A are inserted from both the left and right sides of the upper frame portion 13 of the inner panel 10 along the pillar portions 14, but this is not limiting. The upper reinforcement 50A may be an integrated upper reinforcement 50A connected along the upper frame portion 13, rather than a pair separated on the left and right.

[0080] In the above embodiment, the injection molding die 200 in which the elastic body 218 that abuts against the back surface of the first nut 51 is provided on the slide die 214 is used, but this is not limited to the above. The slide die 214 does not have to be provided with the elastic body 218. In this case, the slide die 214 may be advanced after the injection molding die 200 is closed, or may be advanced before the injection molding die 200 is closed.

[0081] In the above embodiment, the outer panel 60 is configured with two separate bodies, the upper panel 62 and the lower panel 64, but this is not limited thereto. The outer panel 60 may be configured as a single panel. Also, although the window panel 80 is described as a panel separate from the outer panel 60, it may be integrated with the outer panel 60, that is, it may be configured as a part of the outer panel 60.

[0082] As described above, a preferred embodiment has been described as an example of the present invention. However, the present invention is not limited to this, and can be applied to embodiments in which appropriate changes, substitutions, additions, omissions, etc. are made. It will be understood by those skilled in the art that various further modifications are possible for the above embodiment without departing from the spirit of the present invention, and that such modifications also fall within the scope of the technology disclosed herein.

[0083] Note that the descriptions "first," "second," etc., mentioned above are merely used to distinguish the words to which they are attached, and do not limit the number or order of the words. Also, the description "~" in the numerical ranges mentioned above means a range that includes the numerical values ​​before and after it. In other words, if X and Y are substituted for numerical values, then the description "X~Y" indicates a range of "greater than or equal to X and less than or equal to Y." [Industrial Applicability]

[0084] INDUSTRIAL APPLICABILITY As described above, the present invention is useful as a method for forming an inner panel. [Explanation of symbols]

[0085] Da: perpendicular to the weld surface Db Injection mold opening and closing direction g Gap R Molten resin 10 Inner Panel 24 Hinge mounting part 40 Panel body 50 Reinforcement Panel 51 First Nut (Nut) 56 Welding Mask 100 Hinge 200 injection mold 210 Core Type 214 Slide type 215 Relief 218 Elastic Body 220 Cavity type 230 Cavity

Claims

1. A method for forming an inner panel (10) having a hinge mounting portion (24) to which a hinge (200) is attached, a metal reinforcing panel (50) is inserted at the hinge mounting portion (24) so ​​as to be exposed on the back side, and a nut (51) for mounting the hinge (100) is welded to the exposed back side of the reinforcing panel (50), comprising: an injection molding die (200) including a core die (210) in which the reinforcing panel (50) to which the nut (51) has been welded is set, and a cavity die (220) that is clamped to the core die (210) to form a cavity (230) between the core die (210) and the reinforcing panel (50); an opening / closing direction (Db) of the injection molding die (200) in which the core die (210) and the cavity die (220) approach or move away from each other is different from a surface perpendicular direction (Da) of a welding surface (56) to which the nut (51) of the reinforcing panel (50) is welded; the core mold (210) has a relief portion (215) that does not come into contact with the back surface of the reinforcing panel (50) around the periphery of the nut (51), a slide die (214) that can advance and retreat in a direction perpendicular to the welding surface (56) and that is positioned in the relief portion (56) when advanced is incorporated in the core die (210) at a position corresponding to the back side of the nut (51); After the reinforcing panel (50) is set in the core mold (210), the injection molding mold (200) is closed to bring the cavity mold (220) into contact with a portion of the surface of the reinforcing panel (50) corresponding to the nut (51), and the slide mold (214) is advanced before or after the injection molding mold (200) is closed to support a portion of the back surface of the reinforcing panel (50) corresponding to the relief portion (56) and the back surface of the nut (51); a molten resin (R) is injected into the cavity (230) of the injection molding die (200) in a clamped state, filled therein, and then solidified to form a resin panel body (40) integrally with the reinforcing panel (50); After the slide mold (214) is retracted, the injection molding mold (200) is opened, and the inner panel (10) formed by integrating the reinforcing panel (50) and the panel body (40) is demolded. A method for forming an inner panel comprising the steps of:

2. In the method for forming an inner panel according to claim 1, The slide die (214) has an elastic body (218) that comes into contact with a back surface of the nut (51), After the injection molding die (200) is clamped, the slide die (214) is advanced to press the elastic body (218) against the back surface of the nut (51). A method for forming an inner panel comprising the steps of:

3. In the method for forming an inner panel according to claim 1 or 2, A gap (g) between the nut (51) and a portion of the slide die (214) located in the relief portion (56) is 2 mm or less in a radial direction of the nut (51). A method for forming an inner panel comprising the steps of:

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