Method for manufacturing vehicle door inner panel and vehicle door inner panel

Abstract

The invention provides a method for manufacturing a vehicle door inner panel and the vehicle door inner panel, which can ensure the mechanical strength in a side frame which is a thinner area of a window frame and extends along the vertical direction. A method for manufacturing a door inner panel including a side frame extending in the vertical direction and integrally molded from a composite material X including reinforcing fibers dispersed in the in-plane direction and an injection molded material Y, the method including the following steps (1)-(4): (1) a step for disposing the composite material X on a molding fixed mold; (2) a step for lowering the molding moving die and bringing the molding moving die into contact with the composite material X; (3) a step for injecting the injection molding material (Y) into the molding die; and (4) pressing the composite material (X) and the injection-molded material (Y) in a molding die to integrally mold the vehicle door inner panel.

Description

Technical Field

[0001] The invention relates to a method for manufacturing an inner door panel for automobiles and the inner door panel. The inner door panel has two side frames extending in the up-down direction and a window opening located between the two side frames and is integrally formed of a composite material and an injection molding material. Background Art

[0002] The door inner panel for automobiles refers to the door panel on the interior side of the door panels constituting the door. Conventional door inner panels are manufactured using thin cold-rolled steel sheets, and various measures have been taken to ensure strength and rigidity.

[0003] Composite materials using reinforcing fibers such as carbon fiber and glass fiber as reinforcing materials have high tensile strength, high tensile elastic modulus, and low linear expansion coefficient, so they have excellent dimensional stability, and are also excellent in heat resistance, chemical resistance, fatigue resistance, wear resistance, electromagnetic wave shielding, and X-ray transmittance. Therefore, composite materials are widely used in automobiles, sports and leisure, aerospace, general industrial uses, etc.

[0004] Patent Document 1 describes a method of manufacturing a rear door inner panel by integrally molding two types of reinforced plastics, wherein the reinforced plastics forming both sides of the window frame portion have relatively high mechanical strength.

[0005] Patent Document 2 describes a rear door inner panel, which uses prepreg to form a reinforcement portion, and forms other portions using sheet molding compound. Generally speaking, prepreg is a sheet substrate formed by impregnating resin into continuous fibers aligned in one direction. In prepreg, since the continuous fibers are aligned in one direction, the target properties cannot be exerted when the configuration of the prepreg is slightly deviated. Therefore, when using prepreg for molding, extremely strict configuration of the prepreg and prevention of positional deviation are required.

[0006] Patent Document 3 describes a method of manufacturing a molded body by placing a plate-like material in a molding die and then injecting an injection material into the molding die.

[0007] Patent document 4 describes a method for providing a method for manufacturing an injection molded product that contains a plurality of sheets at a lower cost. In patent document 4, a plurality of reinforcing component resin-impregnated sheets having holes are arranged, a movable mold is moved to close the mold, and resin is injected to fill the spaces between the reinforcing component resin-impregnated sheets with resin.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: International Publication No. 2015 / 091448

[0011] Patent Document 2: Japanese Patent Application Publication No. 2019-10910

[0012] Patent Document 3: International Publication No. 2020 / 196076

[0013] Patent Document 4: Japanese Patent Application Publication No. 2020-179549 Summary of the invention

[0014] Technical problem that the invention aims to solve

[0015] However, when the rear door inner panel is formed by continuous injection molding of two reinforced plastics, it is difficult to control the fiber orientation in the two side frames extending in the vertical direction. In addition, the injection molding material is a mixed material, so the fiber length is short, and the strength required for the two side frames cannot be obtained by injection molding material alone.

[0016] In general, prepregs contain continuous fibers, but even if the prepregs are slightly misaligned during molding (even if there is a misalignment of several mm), it is difficult to obtain the target physical properties. Therefore, measures are required to prevent the prepregs from being misaligned.

[0017] In Patent Document 3, no research is conducted as a door inner panel.

[0018] Patent document 4 does not conduct any research on the use of the sheet as an inner door panel. Moreover, in the method of patent document 4, a sheet impregnated with polypropylene resin is used as a resin-impregnated sheet for a reinforcing component. In the case of a material in which reinforcing fibers are continuously oriented in a specific direction, such as a plain woven fabric, if there is a slight deviation (even if only a few mm) in the configuration when the injection material is injected and press-formed, it is difficult to obtain the target physical properties. Therefore, it is necessary to take measures to prevent the resin-impregnated sheet for the reinforcing component from being offset. In particular, when it is desired to impregnate the resin between multiple reinforcing components, the process becomes too complicated.

[0019] An object of the present invention is to provide a method for manufacturing a door inner panel and a door inner panel capable of ensuring mechanical strength even in a narrow region of the door inner panel serving as a window frame, that is, a side frame extending in the vertical direction.

[0020] Technical solutions to the problem

[0021] <1>

[0022] A method for manufacturing a vehicle door inner panel, wherein:

[0023] The door inner panel includes a side frame extending in the up-down direction and is integrally formed of a composite material X and an injection molding material Y, the composite material X containing reinforcing fibers dispersed in an in-plane direction,

[0024] The manufacturing method comprises the following steps (1) to (4):

[0025] (1) a step of placing the composite material X on a forming fixed die of a forming die;

[0026] (2) a step of lowering a movable forming mold of the forming mold to bring the movable forming mold into contact with the composite material X;

[0027] (3) a step of injecting the injection molding material Y into the molding die;

[0028] (4) A step of pressing the composite material X and the injection molding material Y in a molding die to integrally mold the door inner panel.

[0029] <2>

[0030] according to <1> The method for manufacturing the inner door panel, wherein:

[0031] The molding die has an area for arranging the composite material X at a position corresponding to the side frame.

[0032] A first gate is provided in a region where the composite material X is arranged, and the first gate is used to inject the injection molding material Y into the molding die.

[0033] <3>

[0034] According to the claim <1> or <2> The method for manufacturing the inner door panel, wherein:

[0035] The composite material X is brought into contact with the cavity wall surface of the molding die to form a surface layer including an X portion formed of the composite material X.

[0036] <4>

[0037] According to the claim <3> The method for manufacturing the inner door panel, wherein:

[0038] The surface layer including the X portion is formed on a surface of the door inner panel that is disposed on the vehicle inner side.

[0039] <5>

[0040] According to the claim <3> The method for manufacturing the inner door panel, wherein:

[0041] The surface layer including the X portion is formed on a surface of the door inner panel disposed on the vehicle outer side.

[0042] <6>

[0043] According to the claim <1> to <5> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0044] The forming die has:

[0045] a first gate for injecting the injection molding material Y into the molding die at a region where the composite material X is arranged; and

[0046] a second gate for injecting the injection molding material Y into the molding die in a region other than a region where the composite material X is arranged,

[0047] The number n1 of the first gates and the number n2 of the second gates satisfy n1>n2≥0.

[0048] <7>

[0049] According to the claim <1> to <5> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0050] The forming die has:

[0051] a first gate for injecting the injection molding material Y into a region of the molding die where the composite material X is disposed; and

[0052] a second gate for injecting the injection molding material Y into a region other than a region in the molding die where the composite material X is disposed,

[0053] The discharge amount V1 of the injection molding material Y discharged from the first gate and the discharge amount V2 of the injection molding material Y discharged from the second gate satisfy V1>V2≥0.

[0054] <8>

[0055] According to the claim <1> or <2> The method for manufacturing the inner door panel, wherein:

[0056] The injection molding material Y is brought into contact with the cavity wall surface of the molding die to form a surface layer including a Y portion molded by the injection molding material Y.

[0057] <9>

[0058] According to the claim <1> , <2> , <8> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0059] The forming die has:

[0060] a first gate for injecting the injection molding material Y into a region of the molding die where the composite material X is disposed; and

[0061] a second gate for injecting the injection molding material Y into a region other than a region in the molding die where the composite material X is disposed,

[0062] The number n1 of the first gates and the number n2 of the second gates satisfy 0<n1<n2.

[0063] <10>

[0064] According to the claim <1> , <2> , <8> or <9> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0065] The forming die has:

[0066] a first gate for injecting the injection molding material Y into the molding die at a region where the composite material X is arranged; and

[0067] a second gate for injecting the injection molding material Y into the molding die in a region other than a region where the composite material X is arranged,

[0068] A discharge amount V1 of the injection molding material Y discharged from the first gate and a discharge amount V2 of the injection molding material Y discharged from the second gate satisfy 0<V1<V2.

[0069] <11>

[0070] According to the claim <1> to <10> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0071] The surface of the side frame that becomes the inner side of the vehicle is the interior design portion of the vehicle.

[0072] In the step (4), the texture shape provided on the inner wall surface of the cavity of the molding die is transferred to the interior design part.

[0073] <12>

[0074] According to the claim <1> to <11> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0075] At least one of the movable forming mold and the fixed forming mold has a hole forming member for forming a hole in the door inner panel.

[0076] In the step before the step (1), a hole Xa is provided in the composite material X,

[0077] In the step (1), the composite material X is disposed in a molding die so that the hole Xa corresponds to the hole forming member.

[0078] <13>

[0079] According to the claim <12> The method for manufacturing the inner door panel, wherein:

[0080] The holes Xa are provided in the composite material X at a portion corresponding to the upper portion of the side frame and at a portion corresponding to the lower portion of the side frame.

[0081] <14>

[0082] According to the claim <1> to <13> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0083] In the step (3), the injection molding material Y is kneaded before injection, and a gap is provided between the movable molding die and the fixed molding die to fill the injection molding material Y.

[0084] <15>

[0085] According to the claim <1> The method for manufacturing the inner door panel, wherein:

[0086] The composite material X comprises reinforcing fibers A having a weight-average fiber length LwA of 1 mm or more and 100 mm or less,

[0087] The injection molding material Y includes reinforcing fibers B whose weight average fiber length LwB is smaller than LwA,

[0088] The mechanical strength of the reinforcement portion formed of the composite material X is higher than the mechanical strength of the main body portion formed of the injection molding material Y.

[0089] <16>

[0090] According to the claim <1> to <15> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0091] The door inner panel is a rear door inner panel.

[0092] <17>

[0093] According to the claim <16> The method for manufacturing the inner door panel, wherein:

[0094] Prior to the step (2), a component for connecting with the hinge is arranged in the region connected with the hinge, and the component is insert-molded together with the composite material X and the injection molding material Y.

[0095] <18>

[0096] According to the claim <16> The method for manufacturing the inner door panel, wherein:

[0097] Prior to the step (2), a component for connecting with the trunk lock is arranged in the region where the trunk lock is mounted, and the component is insert-molded together with the composite material X and the injection molding material Y.

[0098] <19>

[0099] According to the claim <16> to <18> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0100] The door inner panel has:

[0101] lower half;

[0102] a pair of side frames extending upward from an upper left end and an upper right end of the lower half; and

[0103] a beam portion connecting upper ends of the pair of side frames to each other,

[0104] The injection molding material Y is used to manufacture the central portion and the lower half of the beam portion.

[0105] <20>

[0106] According to the claim <17> or <18> The method for manufacturing the inner door panel is characterized in that:

[0107] The fitting is a metal fastener having a bolt insert,

[0108] The door inner panel has a hole at a position corresponding to the bolt insertion portion.

[0109] <21>

[0110] According to the claim <20> The method for manufacturing the inner door panel, wherein:

[0111] A hole is provided in the Y portion formed by the injection molding material Y at a position corresponding to the bolt insertion portion.

[0112] <22>

[0113] According to the claim <20> or <21> The method for manufacturing the inner door panel, wherein:

[0114] The fitting is in contact with the Y portion molded from the injection molding material Y.

[0115] <23>

[0116] According to the claim <20> or <21> The method for manufacturing the inner door panel, wherein:

[0117] The accessory does not contact the X portion formed by the composite material X.

[0118] <24>

[0119] According to the claim <20> to <23> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0120] The door inner panel has a rib within 30 mm from the fitting.

[0121] <25>

[0122] According to the claim <20> or <21> The method for manufacturing the inner door panel, wherein:

[0123] The door inner panel has a thickness uneven portion at a position within 30 mm from the accessory.

[0124] <26>

[0125] According to the claim <20> to <25> The method for manufacturing a rear door inner panel as described in any one of the preceding claims, wherein:

[0126] In the step (4), a hole is provided at a position corresponding to the bolt insertion portion.

[0127] <27>

[0128] According to the claim <20> to <22> or <25> The method for manufacturing a door inner panel as described in any one of the above, wherein:

[0129] At least one of the movable forming die and the fixed forming die has a hole forming member for forming a hole at a position corresponding to the bolt insertion portion.

[0130] In the step before the step (1), a hole Xa is provided in the composite material X,

[0131] In the step (1), the composite material X is arranged in a molding die so that the hole Xa corresponds to the hole forming member.

[0132] In the step (4), a hole is provided at a position corresponding to the bolt insertion portion by the hole forming member.

[0133] <28>

[0134] A vehicle door inner panel, comprising:

[0135] lower half;

[0136] a pair of side frames extending upward from an upper left end and an upper right end of the lower half; and

[0137] a beam portion connecting upper ends of the pair of side frames to each other,

[0138] The pair of side frames includes: an X portion formed of a composite material X containing reinforcing fibers dispersed in an in-plane direction; and a Y portion formed of an injection molding material Y,

[0139] The central portion of the beam portion and the lower half portion include the Y portion molded from the injection molding material Y.

[0140] Effects of the Invention

[0141] The door inner panel of the present invention uses the composite material X in which the reinforcing fibers are dispersed in the in-plane direction, so even if the composite material X flows slightly during molding, the basic mechanical properties do not change significantly. Therefore, when manufacturing the door inner panel for an automobile having a window opening, even in the narrow area that becomes the window frame, that is, the two side frames extending in the vertical direction of the vehicle across the window opening, the target mechanical strength can be easily obtained by using the composite material X. In addition, compared with the case where continuous fibers such as plain weave are used as the composite material, the shape following property is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0142] Figure 1 It is a schematic diagram of the door inner panel 1 according to the embodiment of the present invention.

[0143] Figure 2 yes Figure 1 A sectional view of the inner door panel 1 taken along the II-II direction.

[0144] Figure 3 It means in Figure 2 2 is a cross-sectional view showing a state where the bracket 101 is mounted on the vehicle inner side of the beam portion 2.

[0145] Figure 4 yes Figure 1 A cross-sectional view of the inner door panel 1 taken along the line IV-IV.

[0146] Figure 5 It means in Figure 4 sectional view showing a state where the bracket 111 is mounted on the vehicle inner side of the side frame 3L.

[0147] Figure 6 yes Figure 1 A cross-sectional view of the inner door panel 1 taken along the line VI-VI.

[0148] Figure 7 It means in Figure 6 A cross-sectional view showing a state in which the bracket 121 is mounted on the vehicle inner side of the lower half 4 .

[0149] Figure 8 1 is a diagram showing a state where the composite material X is arranged on the fixed molding die 201 .

[0150] Fig. 9 1 and 2 , which are views showing a state in which the movable forming die 301 is brought close to the fixed forming die 201 and the movable forming die 301 is brought into contact with the composite material X. FIG.

[0151] Fig.10 1 and 2 are diagrams showing a state in which an injection molding material Y is injected into the molding die from a gate 203 provided in a molding fixed die 201 .

[0152] Fig.11 This is a diagram showing a state where the composite material X and the injection molding material Y are pressed and integrally molded in a molding die.

[0153] Fig.12 1 and 2 are diagrams showing a state in which the composite material X is arranged on the upper portion of the molding fixed die 201 in a state in which the hole forming member 205 is inserted into the hole Xa.

[0154] Fig.13 It is a top view of the forming fixed mold 201.

[0155] Fig.14 It is a top view of the molding fixed die 201A involved in the second embodiment.

[0156] Fig.15 It is a horizontal cross-sectional view showing the fixed forming mold 201B and the movable forming mold 301B which are provided so as to be openable and closable in the horizontal direction.

[0157] Fig.16 It is a perspective view showing a box-shaped molded body 400 .

[0158] Fig.17 It is a top view of the composite material showing the shape after pattern cutting.

[0159] Fig.18 1 is a front view of a molding and fixing die 201C showing a state in which the composite material X after pattern cutting is fixed by a fixing member 210C.

[0160] Fig.19 1 is a horizontal cross-sectional view showing a fixed forming mold 201C and a movable forming mold 301C that fix the composite material X via a fixing member 210C. DETAILED DESCRIPTION

[0161] [First embodiment]

[0162] Hereinafter, a first embodiment of the present invention will be described in detail.

[0163] [Door inner panel]

[0164] Figure 1 1 is a schematic diagram of a door inner panel 1 according to an embodiment of the present invention. The door inner panel 1 includes a beam portion 2, a pair of side frames 3L, 3R, and a lower half portion 4. The pair of side frames 3L, 3R extend upward from the upper left end and the upper right end of the lower half portion 4, and the upper ends of the side frames 3L, 3R are connected to each other via the beam portion 2.

[0165] The portion surrounded by the beam portion 2, the side frames 3L, 3R, and the lower half 4 is a window opening 5. The side frames 3L, 3R extend in the vertical direction of the vehicle portion across the window opening 5, and form a so-called window frame.

[0166] The vehicle door inner panel 1 of the present invention is preferably a rear door inner panel.

[0167] The rear door may include a door inner panel 1 located on the vehicle inner side, that is, the front side of the vehicle, and a door outer panel located on the vehicle outer side, that is, the rear side of the vehicle. The door outer panel may also be a resin panel.

[0168] In addition, an interior trim panel may be provided at a position closer to the vehicle interior than the door inner panel 1 .

[0169] Hereinafter, the “rear door inner panel” may also be simply referred to as the “door inner panel”.

[0170] The rear door equipped with the door inner panel 1 of the present invention can be, for example, a rear door that is opened and closed vertically or horizontally, and is provided at the rear end of the automobile body. The rear door is connected to the vehicle body by a hinge so that it can be opened and closed in the vertical direction or the horizontal direction. In the case where the rear door is opened and closed in the vertical direction, a hinge is provided at the upper end of the rear door. The rear door swings in the vertical direction or the horizontal direction with the hinge as a fulcrum to open and close the opening of the vehicle body.

[0171] The door inner panel 1 includes a hinge fastening portion 6 for connecting with a hinge. When the rear door is opened and closed in the up-down direction, the hinge fastening portion 6 is preferably present at the upper end portion of the door inner panel 1.

[0172] When the rear door is opened and closed in the up and down direction, one end of a rod-shaped spring built-in shock absorber is installed on the left and right sides of the rear end of the vehicle body, and the other end of the shock absorber is connected to the end edges of the door inner panel of the rear door in the vehicle width direction through the shock absorber stay, so that the rear door can be opened and closed while being applied by the shock absorber. The shock absorber stay is a fastener of the shock absorber, and the shock absorber prevents the rear door from closing unexpectedly.

[0173] The damper fastening portion 7 is preferably provided at the portion of the door inner panel 1 to which the damper stay is attached. The damper stay is preferably fastened and fixed to the damper fastening portion 7, thereby fixing the damper to the door inner panel 1.

[0174] Various functional parts can also be installed on the door inner panel 1, or installation spaces for electrical components can be set. For example, installation parts for functional parts such as door locks, window regulators, inside handles, door armrests, door interior panels, weather strips, door opening limit rod seats, speakers, switches for electric remote control rearview mirrors, switches for electric windows, and other electrical components can be set at appropriate positions on the door inner panel 1.

[0175] The trunk lock 8 may also be mounted on the door inner panel 1. Figure 1 In the embodiment, a trunk lock 8 is provided at the lower end center of the lower half 4.

[0176] The door inner panel 1 of the present invention has a resin panel using a composite material X and an injection molding material Y as molding materials. The composite material X is disposed at least on the side frames 3L and 3R, and the injection molding material Y is integrally molded with the composite material X to form the door inner panel.

[0177] The central portion and the lower half 4 of the beam portion 2 are preferably made of injection molded material Y.

[0178] The composite material X forms a reinforcement portion of the door inner panel 1. The mechanical strength of the reinforcement portion is higher than that of the main body portion formed of the injection molded material Y.

[0179] The door inner panel 1 may also include integrally formed parts 91 to 93 (see FIG. 1 ) as described below, in addition to the resin panel. Figures 2 to 7 ).

[0180] The composite material X includes reinforcing fibers and a matrix resin. In the composite material X, the reinforcing fibers are dispersed in the matrix resin in the in-plane direction. By using the composite material X in which the reinforcing fibers are dispersed in the in-plane direction, even if the composite material X deviates from the target position during molding, it will not have a significant effect on the physical properties of the molded resin panel. Therefore, the manufacturing process can be simplified, and the quality of the obtained molded body (door inner panel 1) can be stabilized.

[0181] Hereinafter, the "door inner panel" or the "rear door inner panel" may be referred to as a "molded body".

[0182] The accessory 91 may be installed at the hinge fastening portion 6 of the door inner panel 1. In addition, the accessory 92 may be installed at the damper fastening portion 7. The above-mentioned accessories may be provided integrally with the resin panel of the rear door inner panel 1 by insert molding. Insert molding refers to a molding method in which resin is injected around the accessory inserted into the molding die to integrate the accessory with the resin. The insert molding method is not particularly limited.

[0183] [Cross-sectional shape of resin panel]

[0184] The cross-sectional shape of the resin panel is not particularly limited. The resin panel preferably has at least one planar portion. The cross-sectional shape may include a T-shaped, L-shaped, C-shaped, cap-shaped (hat-shaped), and three-dimensional shapes including these, and may also have a concave-convex shape (e.g., ribs, bosses, etc.).

[0185] The resin panel preferably has a shape including a portion having a hat-shaped cross-sectional shape.

[0186] Figure 2 yes Figure 1 A cross-sectional view of the door inner panel 1 taken along the II-II direction. Figure 2 As shown, the beam portion 2 includes an inner wall 21 disposed on the inner side of the vehicle, outer walls 22T and 22B disposed on the outer side of the vehicle, a connecting wall 23T connecting the inner wall 21 and the outer wall 22T, and a connecting wall 23B connecting the inner wall 21 and the outer wall 22B. The connecting wall 23T is connected to the upper end of the inner wall 21, and the outer wall 22T is connected to the upper end of the connecting wall 23T. In addition, the connecting wall 23B is connected to the lower end of the inner wall 21, and the outer wall 22B is connected to the lower end of the connecting wall 23B.

[0187] like Figure 2 As shown, a fitting 91 is provided integrally with the connecting wall 23T. The fitting 91 is preferably provided integrally with the connecting wall 23T by insert molding. A bolt insertion hole 91a (bolt insertion portion) is provided in the fitting 91. In addition, it is preferred to provide a hole 23a at a position corresponding to the bolt insertion hole 91a of the connecting wall 23T.

[0188] The beam portion 2 may further include a rib 24 that connects the connecting walls 23T and 23B. The rib 24 is preferably provided at a distance of 30 mm or less from the fitting 91. On the other hand, the rib 24 may be provided at a position more than 30 mm away from the fitting 91. The rib 24 may be provided using the composite material X, or the rib 44 may be provided using the injection molding material Y.

[0189] Figure 3 It means in Figure 2 A cross-sectional view of a state where a bracket 101 is installed on the inner side of the beam portion 2 of the vehicle. Figure 3As shown, the bolt 102 is inserted through the fitting 91 and the bracket 101, and the nut 103 is fastened to the bolt 102, thereby mounting the bracket 101 on the beam portion 2. By mounting the hinge on the bracket 101, the hinge can be mounted on the door inner panel 1. Figure 3 As shown, the bolt 102 is preferably inserted into the bracket 101 and the fitting 91 from the inside of the vehicle and fastened to the nut 103 from the outside of the vehicle.

[0190] By using the metal fittings 91 at the portion connected to the hinge, it is possible to ensure strength.

[0191] It is preferred that the bracket 101 only contacts the fitting 91 in a surface-to-surface manner and does not contact the resin panel. By making only the metals of the fitting 91 and the bracket 101 contact each other in a surface-to-surface manner, the stability of the fastening is improved. The area S1 of the contact surface of the bracket 101 with the fitting 91 is preferably smaller than the area S2 of the portion of the fitting 91 exposed from the resin panel. By making S1 < S2, even if the fitting 91 embedded in the resin panel contacts the bracket 101 in a surface-to-surface manner, the resin panel will not be sandwiched between the fitting 91 and the bracket 101, and the fastening strength can be stabilized.

[0192] In addition, it is preferable that the portion of the resin panel that contacts the fitting 91 is formed of the molding material Y alone.

[0193] Figure 4 yes Figure 1 A cross-sectional view of the door inner panel 1 taken along the IV-IV direction. Figure 4 As shown, the side frame 3L includes an inner wall 31 disposed on the inner side of the vehicle, outer walls 32R and 32L disposed on the outer side of the vehicle, a connecting wall 33R connecting the inner wall 31 and the outer wall 32R, and a connecting wall 33L connecting the inner wall 31 and the outer wall 32L. The connecting wall 33R is connected to the right end of the inner wall 31, and the outer wall 32R is connected to the right end of the connecting wall 33R. In addition, the connecting wall 33L is connected to the left end of the inner wall 31, and the outer wall 32L is connected to the left end of the connecting wall 33L.

[0194] like Figure 4 As shown, a fitting 92 is provided integrally with the connecting wall 33R. The fitting 92 is preferably provided integrally with the connecting wall 33R by insert molding. A bolt insertion hole 92a (bolt insertion portion) is provided in the fitting 92. In addition, it is preferred to provide a hole 33a at a position corresponding to the bolt insertion hole 92a of the connecting wall 33R.

[0195] The side frame 3L may further include a rib 34 that connects the connecting walls 33R and 33L. The rib 34 is preferably provided at a distance of 30 mm or less from the fitting 92. On the other hand, the rib 34 may be provided at a position more than 30 mm away from the fitting 92. The rib 34 may be provided using the composite material X or the injection molding material Y.

[0196] Figure 5 It means in Figure 4 A cross-sectional view of a state where the bracket 111 is installed on the vehicle inner side of the side frame 3L. Figure 5 As shown in FIG. 1 , the bolt 112 is inserted through the fitting 92 and the bracket 111, and the nut 113 is fastened to the bolt 112, thereby mounting the bracket 111 on the side frame 3L. By mounting the shock absorber stay on the bracket 111, the shock absorber can be mounted on the door inner panel 1. Figure 5 As shown, the bolt 112 is preferably inserted into the bracket 111 and the fitting 92 from the inside of the vehicle and fastened to the nut 113 from the outside of the vehicle.

[0197] By using the fittings 92 at the portion connected to the shock absorber, it is possible to ensure strength.

[0198] The bracket 111 is preferably in surface contact only with the fitting 92 and not in contact with the resin panel. By making only the metals of the fitting 92 and the bracket 111 in surface contact with each other, the stability of the fastening is improved. The area S1 of the contact surface of the bracket 111 with the fitting 92 is preferably smaller than the area S2 of the part of the fitting 92 exposed from the resin panel. By making S1 < S2, even if the fitting 92 embedded in the resin panel is in surface contact with the bracket 111, the resin panel will not be sandwiched between the fitting 92 and the bracket 111, and the fastening strength can be stabilized.

[0199] In addition, it is preferable that the portion of the resin panel that contacts the fitting 92 is formed of the molding material Y alone.

[0200] The side frame 3R has a shape that is substantially bilaterally symmetrical with the side frame 3L, and therefore illustration of the cross-sectional shape is omitted.

[0201] Figure 6 yes Figure 1 A cross-sectional view of the inner door panel 1 taken along the VI-VI direction. Figure 6As shown, the lower half 4 has an inner wall 41 disposed on the inner side of the vehicle, outer walls 42T and 42B disposed on the outer side of the vehicle, a connecting wall 43T connecting the inner wall 41 and the outer wall 42T, and a connecting wall 43B connecting the inner wall 41 and the outer wall 42B. The connecting wall 43T is connected to the upper end of the inner wall 41, and the outer wall 42T is connected to the upper end of the connecting wall 43T. In addition, the connecting wall 43B is connected to the lower end of the inner wall 41, and the outer wall 42B is connected to the lower end of the connecting wall 43B.

[0202] like Figure 6 As shown, a fitting 93 is provided integrally with the connecting wall 43B. The fitting 93 is preferably provided integrally with the connecting wall 43B by insert molding. A bolt insertion hole 93a (bolt insertion portion) is provided in the fitting 93. In addition, it is preferred to provide a hole 43a at a position corresponding to the bolt insertion hole 93a of the connecting wall 43B.

[0203] The lower half 4 may further include a rib 44 that connects the connecting walls 43T and 43B. The rib 44 is preferably provided at a distance of 30 mm or less from the fitting 93. On the other hand, the rib 44 may be provided at a position more than 30 mm away from the fitting 93. The rib 44 may be provided using the composite material X or the injection molding material Y.

[0204] Figure 7 It means in Figure 6 A cross-sectional view of the state where the bracket 121 is installed on the inner side of the vehicle of the lower half 4. Figure 7 As shown, the bolt 122 is inserted through the fitting 93 and the bracket 121, and the nut 123 is fastened to the bolt 122, thereby mounting the bracket 121 on the lower half 4. By mounting the trunk lock 8 on the bracket 121, the trunk lock 8 can be mounted on the door inner panel 1. Figure 7 As shown, the bolt 122 is preferably inserted into the bracket 121 and the fitting 93 from the inside of the vehicle and fastened to the nut 123 from the outside of the vehicle.

[0205] By using the fitting 93 at the portion connected to the trunk lock 8, it is possible to ensure strength.

[0206] Preferably, the bracket 121 is in surface contact only with the fitting 93 and not in contact with the resin panel. By making only the metals of the fitting 93 and the bracket 121 in surface contact with each other, the stability of the fastening is improved. The area S1 of the contact surface of the bracket 121 with the fitting 93 is preferably smaller than the area S2 of the portion of the fitting 93 exposed from the resin panel. By making S1 < S2, even if the fitting 93 embedded in the resin panel is in surface contact with the bracket 121, the resin panel will not be sandwiched between the fitting 93 and the bracket 121, and the fastening strength can be stabilized.

[0207] In addition, it is preferable that the portion of the resin panel that contacts the fitting 93 is formed of the molding material Y alone.

[0208] The resin panel of the door inner panel 1 may also include a thickness uneven portion. That is, the resin panel may also include a thickness uneven structure. For example, the thickness of the resin panel corresponding to the hinge fastening portion 6, the shock absorber fastening portion 7, and the trunk lock 8 may be thicker than the thickness of the resin panel of other portions of the rear door inner panel 1.

[0209] When the accessories 91 to 93 are used, the uneven thickness portion of the door inner panel may be located within 30 mm from the accessories 91 to 93. In other words, the periphery of the accessories 91 to 93 may have an uneven thickness structure. In addition, it is preferred that when the accessories 91 to 93 are covered with the Y portion, the uneven thickness structure is provided so that the portion within 30 mm from the accessories 91 to 93 is thicker than other portions by using the thickness of the X portion and the thickness of the Y portion. It is more preferred that the uneven thickness portion of the rear door inner panel is provided at a location within 20 mm from the accessories 91 to 93.

[0210] On the other hand, the uneven thickness portion may be present at a position 30 mm or more away from the attachments 91 to 93 .

[0211] In the case where the resin panel has a non-uniform thickness structure (a portion with non-constant thickness), the Y portion preferably contributes to the non-uniform thickness structure. This is because the composite material X used to make the X portion is preferably plate-shaped, so it is preferred to make the non-plate-shaped Y portion by injection molding material Y. By using injection molding material Y, it is easy to manufacture the rear door inner panel with a non-uniform thickness structure.

[0212] For example, when manufacturing a door inner panel having a thickness uneven structure in which the thickness gradually changes from 2 mm to 3 mm, the thickness uneven structure can be formed by placing a 1 mm thick composite material X on a molding die and injecting an injection molding material Y into the remaining 1 mm to 2 mm area.

[0213] When a sheet molding compound (sometimes referred to as SMC) containing reinforcing fibers is used as the composite material X and the fitting 91 is covered while the composite material X is molded, the X portion can contribute to the uneven thickness structure.

[0214] Hereinafter, the composite material X and the injection molding material Y will be described in more detail.

[0215] [Reinforcement Fiber]

[0216] In the present specification, the reinforcing fiber is preferably at least one selected from the group consisting of carbon fiber, aramid fiber, and glass fiber. More preferably, the reinforcing fiber is carbon fiber or glass fiber.

[0217] More specifically, the reinforcing fibers contained in the composite material X are preferably carbon fibers or glass fibers. The reinforcing fibers contained in the injection molding material Y are preferably carbon fibers or glass fibers.

[0218] [Carbon Fiber]

[0219] 1. Carbon fiber overall

[0220] As the carbon fiber used in the present invention, polyacrylonitrile (PAN) carbon fiber, petroleum coal pitch carbon fiber, rayon carbon fiber, cellulose carbon fiber, lignin carbon fiber, phenolic carbon fiber, etc. are generally known, but in the present invention, any one of them can be preferably used. Among them, in the present invention, polyacrylonitrile (PAN) carbon fiber is preferably used from the aspect of excellent tensile strength. As PAN carbon fiber, for example, carbon fiber "Tenax" (registered trademark) STS40-24KS (average fiber diameter 7 μm) manufactured by Teijin Co., Ltd. can be used.

[0221] 2. Carbon fiber sizing agent

[0222] The carbon fiber used in the present invention may have a sizing agent attached to the surface. When using carbon fiber with a sizing agent attached, the type of the sizing agent can be appropriately selected according to the type of carbon fiber and the type of resin used in the composite material X or the injection molding material Y, and is not particularly limited.

[0223] [Fiberglass]

[0224] The case where the reinforcing fiber used in the present invention is glass fiber will be described.

[0225] 1. Glass fiber overall

[0226] The glass fiber used in the present invention may be any glass fiber as long as it is generally called glass fiber. The glass composition of A glass, C glass, E glass, etc. specified in JIS R3140:2006 is not particularly limited, and may contain components such as TiO2, SO3, P2O5, etc. as required. As the glass fiber, for example, glass fiber E-glass RS240QR-483 (count: 2400g / 1000m) manufactured by Nitto Bosho Co., Ltd. may be used.

[0227] 2. Sizing agent for glass fiber

[0228] The glass fiber used in the present invention may have a sizing agent attached to the surface. When using a glass fiber with a sizing agent attached, the type of the sizing agent can be appropriately selected according to the type of glass fiber and the type of resin, and is not particularly limited. The glass fiber can preferably be pre-treated with a coupling agent known in the past such as an organosilane compound, an organotitanium compound, an organoborane compound, and an epoxy compound.

[0229] [Dispersion in the in-plane direction]

[0230] The reinforcing fibers contained in the composite material X of the present invention are dispersed in the in-plane direction.

[0231] The reinforcing fibers are dispersed in the in-plane direction, which means that the fiber axes of the reinforcing fibers are dispersed so as to face the in-plane direction. The angle formed between the fiber axes of the reinforcing fibers and the in-plane direction is preferably 45° or less.

[0232] 1. In-plane direction

[0233] The composite material X is preferably a plate-shaped material. The in-plane direction refers to any direction parallel to a plane perpendicular to the plate thickness direction of the composite material X.

[0234] 2.2 Random dispersion along two dimensions

[0235] The reinforcing fibers are preferably randomly dispersed in two-dimensional directions in the in-plane direction of the composite material X. When the composite material X is press-formed without flowing, the morphology of the reinforcing fibers is substantially maintained before and after forming, and therefore the reinforcing fibers contained in the X portion of the door inner panel (formed body) obtained by forming the forming material are also preferably randomly dispersed in two dimensions in the in-plane direction.

[0236] Here, two-dimensional random dispersion means that the reinforcing fibers are not oriented in a specific direction such as one direction in the in-plane direction of the composite material X or the X portion, but are randomly oriented, and are arranged in the sheet surface without showing a specific directionality as a whole. The composite material X (or the X portion of the molded body) obtained using the two-dimensionally randomly dispersed discontinuous fibers does not have anisotropy in the plane, but is substantially isotropic.

[0237] In addition, the two-dimensional random orientation degree is evaluated by finding the ratio of the tensile modulus in two mutually orthogonal directions. For any direction of the composite material (or the X portion of the formed body), and the direction orthogonal thereto, if the ratio (Eδ) obtained by dividing the larger value of the values ​​of the tensile modulus measured separately by the smaller value is 5 or less, more preferably 2 or less, and further preferably 1.5 or less, it can be evaluated as a two-dimensional random dispersion of the reinforcing fibers. Since the X portion of the door inner panel 1 is a curved surface, as an evaluation method for the two-dimensional random dispersion in the in-plane direction, the door inner panel 1 can be heated to a softening temperature or above and restored to a flat plate shape and cured after only the X portion is taken out. Then, if a test piece is cut out from the X portion restored to a flat plate shape and the tensile modulus is obtained, the random dispersion state in the two-dimensional direction can be confirmed.

[0238] [Fiber length of reinforcing fibers contained in portion X]

[0239] The composite material X preferably includes reinforcing fibers A having a weight-average fiber length LwA.

[0240] Since the weight average fiber length of the composite material X does not change before and after molding, the weight average fiber length LwA of the reinforcing fibers contained in the X portion can be found by examining the weight average fiber length of the reinforcing fibers contained in the composite material X.

[0241] The weight average fiber length of the reinforcing fiber A contained in the X part is preferably 1 mm or more, more preferably 3 mm or more. The weight average fiber length of the reinforcing fiber A contained in the X part is more preferably 3 mm or more and 100 mm or less. The weight average fiber length LwA of the reinforcing fiber A is more preferably 3 mm or more and 80 mm or less, and more preferably 5 mm or more and 60 mm or less. If LwA is 100 mm or less, when the composite material X is press-formed and manufactured, the fluidity of the material is not easy to reduce, and it is easy to be made into a fiber reinforced resin part in a desired shape. In addition, when LwA is 1 mm or more, the mechanical strength of the obtained fiber reinforced resin part is not easy to reduce, so it is preferred.

[0242] The weight average fiber length and number average fiber length of the reinforcing fibers are determined by the following equations (1) and (2).

[0243] [Fiber length of reinforcing fibers contained in the Y portion]

[0244] The injection molding material Y preferably contains reinforcing fibers B having a weight average fiber length LwB, and LwB < LwA. Thus, the mechanical strength of the reinforcement portion formed by the composite material X can be higher than the mechanical strength of the main body portion formed by the injection molding material Y. The composite material X forms two side frames extending in the vertical direction of the window opening. This area is usually narrower in width than other parts and requires higher strength than other parts (for example, a part made only of the injection molding material Y).

[0245] In the "step (3) of injecting the injection molding material Y into the molding die" described later, the injection molding material Y is the material immediately before injection, and when there is a kneading step before injection, the kneaded material is referred to as the injection molding material Y. Since the weight average fiber length does not change after kneading, if the weight average fiber length of the reinforcing fibers contained in the Y portion is examined, the weight average fiber length LwB of the reinforcing fibers contained in the injection molding material Y can be known.

[0246] The weight average fiber length LwB of the reinforcing fiber B is preferably less than 3mm. The weight average fiber length LwB is more preferably 0.01mm or more and less than 3mm. The lower limit is preferably 0.01mm or more, more preferably 0.05mm or more, and more preferably 0.1mm or more. If the weight average fiber length LwB is 0.01mm or more, mechanical strength can be ensured. On the other hand, the upper limit of the weight average fiber length LwB is preferably less than 3mm, more preferably less than 2mm, and more preferably less than 1mm. If the weight average fiber length LwB is less than 1.0mm, it is easy to manufacture the injection molding material Y by mixing. In the case of injection, there is a mixing step, and after sufficient mixing step, the weight average fiber length of the reinforcing fiber is usually less than 1mm.

[0247] The weight average fiber length and number average fiber length of the reinforcing fibers are determined by the following equations (1) and (2).

[0248] [Number average fiber length Ln and weight average fiber length Lw]

[0249] Generally speaking, if the fiber length of each reinforcing fiber is L i , the number average fiber length Ln and the weight average fiber length Lw are calculated by the following formulas (1) and (2). In addition, the units of the number average fiber length Ln and the weight average fiber length Lw are mm.

[0250] [Number 1]

[0251]

[0252] Here, "I" represents the number of reinforcing fibers measured.

[0253] When the fiber length is constant, the number average fiber length and the weight average fiber length are the same value. For example, the reinforcing fibers can be extracted from the door inner panel by performing a heating treatment at about 500° C. for 1 hour to remove the resin in a furnace.

[0254] The number average fiber length Ln and the weight average fiber length Lw can be measured by, for example, measuring the fiber lengths L1 to L2 of 100 fibers (I=100) randomly extracted from the door inner panel using a vernier caliper or the like. 100The value was measured in units of 1 mm and was determined based on equations (1) and (2).

[0255] In the case of containing short fibers that cannot be measured with a vernier caliper, after removing the resin, the obtained reinforcing fibers are put into water added with a surfactant, and fully stirred by ultrasonic vibration. The dispersion of the stirred reinforcing fibers is randomly selected with a measuring spoon to obtain an evaluation sample, and the length of 3000 reinforcing fibers (I=3000) is measured using an image analyzer Luzex AP manufactured by NIRECO. The measured values ​​of fiber length L1 to L 3000 The number average fiber length Ln and the weight average fiber length Lw can be calculated in the same manner as in the above-mentioned formulas (1) and (2).

[0256] [Volume Ratio of Reinforcement Fibers in X and Y Parts]

[0257] The reinforcing fiber volume ratio (Vf) of each of the X portion and the Y portion can be calculated by the following formula (3).

[0258] The reinforcing fiber volume ratio is not particularly limited, but the reinforcing fiber volume ratio (Vf) is preferably 10 Vol% to 60 Vol%, more preferably 20 Vol% to 50 Vol%, and further preferably 25 Vol% to 45 Vol%.

[0259] Reinforcement fiber volume ratio (Vf) = 100 × reinforcement fiber volume / (reinforcement fiber volume + resin volume) Formula (3)

[0260] In the present invention, the volume ratio Vfb of the reinforcing fibers in the Y part and the volume ratio Vfa of the carbon fibers in the X part preferably satisfy the relationship of Vfa≥Vfb in the manufacturing process. For example, in the case where the material obtained by crushing the scraps recovered from the manufacturing process and the product is used as the injection molding material Y, or the Y part is manufactured by crushing the scraps and using them as the injection molding material Y further added with a thermoplastic resin, there are many cases where Vfa>Vfb. That is, if a manufacturing method such as Vfa≥Vfb is adopted, the scraps remaining after cutting out the X part can be efficiently utilized, or the material can be easily recycled.

[0261] Vfa is preferably 20 Vol% to 45 Vol%, more preferably 25 Vol% to 40 Vol%.

[0262] Vfb is preferably 1 Vol% to 40 Vol%, more preferably 5 Vol% to 30 Vol%, further preferably 10 Vol% to 25 Vol%.

[0263] [Analysis of reinforcing fiber volume ratio (Vf)]

[0264] The analysis of the reinforcing fiber volume ratio is not limited, and can be measured as follows.

[0265] The sample was cut from the X or Y part, and the resin was burned off in a furnace at 500°C for 1 hour. The mass of the sample before and after the treatment was weighed to calculate the mass of the reinforcing fiber and the resin. Next, the volume ratio of the reinforcing fiber to the resin was calculated using the specific gravity of each component.

[0266] Vf = 100 × reinforcing fiber volume / (reinforcing fiber volume + resin volume)

[0267] [Resin]

[0268] The matrix resin contained in the composite material X and the resin contained in the injection molding material Y may be thermosetting or thermoplastic.

[0269] 1. Thermoplastic resin

[0270] 1.1 Overview

[0271] When the resin used is a thermoplastic resin, its type is not particularly limited, and a resin having a desired softening point or melting point can be appropriately selected and used. As the thermoplastic resin, a thermoplastic resin having a softening point in the range of 180° C. to 350° C. is generally used, but is not limited thereto.

[0272] Examples of the thermoplastic resin include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyether nitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic polyurethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0273] The thermoplastic resin used in the resin panel of the door inner panel 1 of the present invention may be only one kind or two or more kinds. As a method of using two or more thermoplastic resins in combination, for example, a method of using thermoplastic resins having different softening points or melting points in combination, a method of using thermoplastic resins having different average molecular weights in combination, etc. can be cited, but it is not limited thereto.

[0274] When a thermoplastic resin is used, a polyolefin resin is more preferably used, and a polypropylene resin is further preferably used.

[0275] 1.2 Composite material X and injection molding material Y resin

[0276] The resin contained in the injection molding material Y is preferably a thermoplastic resin. When the resin contained in the X portion is a thermoplastic resin, the resin contained in the composite material X and the injection molding material Y is more preferably the same thermoplastic resin.

[0277] 2. Thermosetting resin

[0278] The resin contained in the composite material X may also be a thermosetting resin. In this case, a sheet molding compound using reinforcing fibers may be used as the composite material X. Since the sheet molding compound has high moldability, even a complex shape can be easily molded. The flowability and shapeability of the sheet molding compound are higher than those of continuous fibers, and ribs and protrusions can be easily formed.

[0279] [Other reagents]

[0280] The resin used in the composite material X and the injection molding material Y may contain additives such as various fibrous or non-fibrous fillers of organic fibers or inorganic fibers, flame retardants, UV resistant agents, stabilizers, release agents, pigments, softeners, plasticizers, surfactants, etc., within the scope that does not impair the purpose of the present invention.

[0281] [Preferred combinations of resin and fiber]

[0282] [fiber]

[0283] The reinforcing fibers A contained in the composite material X are glass fibers and / or carbon fibers, and the reinforcing fibers B contained in the injection molding material Y are preferably glass fibers.

[0284] Carbon fibers may be partially used as the reinforcing fibers A contained in the composite material X, and glass fibers may be used in the other parts. The part where carbon fibers are partially used is preferably the periphery of the hole Xa described later, and is preferably used for reinforcement and fastening.

[0285] [Resin]

[0286] The resin contained in the composite material X may be a thermoplastic resin or a thermosetting resin, and the resin contained in the injection molding material Y may be a thermoplastic resin or a thermosetting resin. Alternatively, the injection molding material Y may contain a thermoplastic resin, and the composite material X may use a thermosetting sheet molding compound.

[0287] The volume Va of the composite material X used and the volume Vb of the injection molding material Y used preferably satisfy the relationship Vb ≥ Va. Va:Vb is preferably 10:90 to 50:50, more preferably 20:80 to 40:60.

[0288] When Va:Vb is 10:90 to 50:50, the side frames 3L and 3R extending in the vertical direction of the window opening 5 can be formed of the composite material X, and the remaining portion can be formed of the door inner panel 1 using the injection molding material Y with high fluidity.

[0289] [Part X and Part Y]

[0290] After molding, the composite material X preferably forms an X portion. Similarly, after molding, the injection molding material Y preferably forms a Y portion.

[0291] [Side frame]

[0292] 1. Method 1

[0293] The door inner panel 1 of the present invention has: a surface layer forming the inner side of the vehicle and a surface layer forming the outer side of the vehicle. Here, the surface layer is a layer formed by cooling and solidifying the molding material (composite material X, injection molding material Y) by contacting the molding material with the cavity wall of the molding mold.

[0294] In both side frames 3L and 3R, it is preferable that at least a part of one surface layer has an X portion.

[0295] In the composite material X, the reinforcing fibers are dispersed in the in-plane direction. Therefore, when the composite material X becomes the X portion, the reinforcing fibers dispersed in the in-plane direction are visible, which is beautiful as a design surface.

[0296] More preferably, the surface layer having the X portion is provided on the surface of the door inner panel 1 that becomes the vehicle inner side. More preferably, the surface of the two side frames 3L and 3R extending in the vertical direction of the window opening 5 that becomes the vehicle inner side is more preferably the vehicle interior design portion. It is further preferred that the texture shape designed on the inner wall surface of the cavity of the forming movable mold or the forming fixed mold is transferred to the interior design portion. The surface formed by the Y portion of the surface of the door inner panel 1 that becomes the vehicle inner side, except for the surface of the side frames 3L and 3R that becomes the vehicle inner side, can also be covered with an interior panel.

[0297] The single surface layer where the X portion is observed may be the vehicle outer side surface of the door inner panel 1. In this case, most of the vehicle inner side surface of the door inner panel 1 becomes the Y portion, so that the appearance design of the door inner panel 1 observed from the vehicle inner side can have a unified look.

[0298] [Manufacturing method]

[0299] Next, a method for manufacturing the door inner panel 1 will be described. In the present embodiment, a plate-shaped composite material X is used, and an injection molding material Y is caused to flow and extend in the in-plane direction of the composite material X, thereby manufacturing the door inner panel 1.

[0300] The method for manufacturing the door inner panel 1 by press forming comprises the following steps (1) to (4):

[0301] (1) placing the composite material X in the cavity of a forming fixed mold;

[0302] (2) a step of bringing the movable forming die close to the fixed forming die so that the movable forming die contacts the composite material X;

[0303] (3) A step of injecting the injection molding material Y into the molding die;

[0304] (4) A step of pressing the composite material X and the injection molding material Y in a molding die to integrally mold the door inner panel 1.

[0305] When the resin contained in the composite material X or the injection molding material Y is a thermoplastic resin, cold press molding is preferably used.

[0306] The following description will focus on cold press forming, but the composite material X and the injection molding material Y may also be integrally formed by hot press forming.

[0307] The method for manufacturing the door inner panel 1 by cold forming comprises the following steps (0) to (4):

[0308] (0) heating the composite material X to a first preset temperature;

[0309] (1) placing the composite material X in the cavity of a forming fixed mold;

[0310] (2) a step of bringing the movable forming die close to the fixed forming die so that the movable forming die contacts the composite material X;

[0311] (3) A step of injecting the injection molding material Y into the molding die;

[0312] (4) A step of pressing the composite material X and the injection molding material Y in a molding die to integrally mold the door inner panel 1.

[0313] (0) Step of heating the composite material X to a first predetermined temperature

[0314] The composite material X is preferably preheated to a first predetermined temperature. When the thermoplastic resin contained in the composite material X is crystalline, the first predetermined temperature is a temperature that is higher than the melting point and lower than the decomposition temperature of the thermoplastic resin. When the thermoplastic resin contained in the composite material X is amorphous, the first predetermined temperature is a temperature that is higher than the glass transition temperature and lower than the decomposition temperature of the thermoplastic resin.

[0315] (1) Process of placing the composite material X in the cavity of the molding fixed mold

[0316] like Figure 8 As shown, the composite material X is arranged on the molding fixed die 201. When the door inner panel is a rear door inner panel, at least one composite material X is arranged at each position corresponding to the two side frames 3L and 3R.

[0317] The step of placing the composite material X on the molding fixed die can be performed using a conventionally known method.

[0318] Furthermore, the composite material X may be pre-shaped along the forming die and arranged in the forming fixed die.

[0319] In the case of cold press forming, the temperature of the forming fixed mold 201 is adjusted to a second predetermined temperature. When the thermoplastic resin contained in the composite material X is crystalline, the second predetermined temperature is a temperature lower than the melting point of the thermoplastic resin. When the thermoplastic resin contained in the composite material X is amorphous, the second predetermined temperature is a temperature lower than the glass transition temperature of the thermoplastic resin.

[0320] In this way, by adjusting the temperature of the composite material X and the forming mold, cold pressing can be appropriately performed.

[0321] (2) A step of bringing the movable forming die close to the fixed forming die so that the movable forming die comes into contact with the composite material X

[0322] Then, if Fig. 9 As shown, the movable forming mold 301 is brought close to the fixed forming mold 201 so that the movable forming mold 301 is in contact with the composite material X.

[0323] (3) Step of injecting the injection molding material Y into the molding die

[0324] Then, if Fig.10 As shown, the injection molding material Y is injected into the molding die from the gate 203 provided in the molding fixed mold 201. It should be noted that the timing of injecting the injection molding material Y may be just before the pressure is applied to a part of the composite material X from the molding movable mold 301, or just after the pressure is applied to a part of the composite material X.

[0325] In order to prevent the composite material X from being displaced in the mold, the injection molding material Y is preferably injected immediately after the pressure is applied, while being in contact with at least a portion of the composite material X. The method of injecting the injection molding material Y into the mold is not particularly limited, and a conventionally known method can be used.

[0326] At this time, the composite material X is pressed against the movable molding die 301 by the pressure of the injection molding material Y.

[0327] The injection molding material Y is a kneaded material, and is preferably filled with the injection material by providing a gap between the fixed molding die 201 and the movable molding die 301. By pressing the injection molding material Y after filling it into the molding die, positional deviation of the composite material X can be suppressed.

[0328] When the thermoplastic resin contained in the injection molding material Y is crystalline, the injection molding material Y when put into the molding die is preferably heated to a temperature above the melting point and below the decomposition temperature of the thermoplastic resin. When the thermoplastic resin is amorphous, the injection molding material Y when put into the molding die is preferably heated to a temperature above the glass transition temperature and below the decomposition temperature of the thermoplastic resin.

[0329] In order to provide a gap between the fixed molding die 201 and the movable molding die 301 to fill the injection molding material Y, it is sufficient to temporarily stop approaching the movable molding die 301 before completely closing the molding die. The position where the movable molding die is stopped is preferably after the movable molding die 301 contacts the composite material X. By contacting the composite material X with the movable molding die 301 to suppress the movement of the composite material X, it is possible to suppress positional deviation of the composite material X during pressing.

[0330] (4) Step of pressing the composite material X and the injection molding material Y in a molding die to integrally mold the door inner panel 1

[0331] Then, if Fig.11 As shown, the composite material X and the injection molding material Y are pressed and integrally molded in a molding die. The molding pressure is not particularly limited, but is preferably less than 20 MPa, more preferably less than 10 MPa, relative to the projection area of ​​the molding die cavity.

[0332] At this time, the composite material X is cooled by contacting with the cavity wall surface of the molding movable mold 301, so the X portion formed by solidifying the composite material X forms a part of the surface layer. In addition, if a texture shape is provided on the cavity wall surface of the molding fixed mold 201 or the molding movable mold 301, the texture shape is transferred to the surface layer of the door inner panel 1. After molding, the composite material X forms the X portion, and the injection molding material Y forms the Y portion, and the X portion and the Y portion constitute the door inner panel 1.

[0333] Thereafter, the integrally formed door inner panel 1 is taken out from the forming die.

[0334] In this way, since the X portion and the Y portion are integrally formed, the bonding strength between the X portion and the Y portion is excellent.

[0335] Furthermore, since the easily flowable injection molding material Y is injected and pressed while the plate-shaped composite material X is arranged in the molding die, a door inner panel having a complex shape such as ribs or bosses can be manufactured.

[0336] Furthermore, various steps may be added between the above steps (0) to (4).

[0337] Alternatively, vacuum press forming may be performed in which the above steps are performed under vacuum.

[0338] In the above, a method for manufacturing the door inner panel 1 by cold press forming is described, but hot press forming can also be used to manufacture the door inner panel 1. In this case, step (0) is not required. For example, when a thermosetting sheet molding compound (SMC) is used as the composite material X, it is sufficient to set the forming mold to the curing temperature of the SMC.

[0339] [Insert molding]

[0340] In addition to pre-adding the composite material X in the molding die, accessories 91 to 93 are also pre-arranged, and then the injection molding material Y is injected into the molding die and pressed, thereby manufacturing a door inner panel with integrated accessories in one molding process, with excellent productivity.

[0341] When insert molding is performed on the accessories 91 to 93, it is preferred that the accessories 91 to 93 are arranged in the molding fixed mold in advance before step (2) and fixed to the molding fixed mold 201 in a manner that does not move during the pressing step. It is preferred that the accessories 91 to 93 are clamped in the molding fixed mold 201 in advance and the molded body (door inner panel) is separated from the molding mold using a slide core at the same time as the molding is completed.

[0342] [Accessories placement location]

[0343] At least one of the accessories 91 to 93 is preferably covered by the Y portion. For example, the accessories 91 to 93 are preliminarily arranged in a molding die, and an injection molding material Y is injected into the molding die and placed in the molding die, whereby the injection molding material Y covers the accessories 91 to 93, and after molding, the accessories 91 to 93 are covered by the Y portion. In this case, the X portion is integrally formed with the accessories 91 to 93 via the Y portion.

[0344] In addition, it is preferred that the X portion does not contact at least one of the accessories 91 to 93. For example, during insert molding, the composite material X and the accessories 91 to 93 are pre-arranged in the molding die without contacting each other, and then the injection molding material Y is injected into the molding die and placed into the molding die. By injecting the injection molding material Y, the accessories 91 to 93 are covered by the Y portion. If this manufacturing method is used, it will lead to a reduction in manufacturing man-hours. Moreover, by setting a design in which the accessories 91 to 93 are covered by the Y portion and the accessories 91 to 93 do not contact the X portion, the welding generated by the contact between the composite material X and the injection molding material Y does not exist around the metal fastener. That is, the accessories 91 to 93 are covered by the Y portion, and it is more preferred that there is no welding generated by the Y portion on the contact surface with the accessories 91 to 93. In addition, when the X portion is not in contact with the accessories 91 to 93, it is preferred to contact with the Y portion.

[0345] like Figure 2 , Figure 4 , Figure 6 As described above, when the bolt insertion holes 91a to 93a are provided in the fittings 91 to 93, it is preferable to provide the holes 23a, 33a, 43a at positions corresponding to the bolt insertion holes 91a to 93a of the resin panel on which the fittings 91 to 93 are insert-molded.

[0346] When the holes 23a, 33a, 43a are provided in the X portion, the holes Xa may be provided in advance at positions corresponding to the holes 23a, 33a, 43a of the composite material X before step (1). A hole forming member is provided at a position corresponding to the hole Xa of the composite material X in the molding die, and after the hole forming member is inserted into the hole Xa of the composite material X, when the molding of the composite material X is completed, the holes 23a, 33a, 43a can be made in the X portion.

[0347] In order to prevent the composite material X from being displaced during molding, it is preferred that at least one of the fixed molding die or the movable molding die be provided with a hole forming member for forming a hole Xa in the composite material X.

[0348] In the step before step (1), a hole Xa is provided in the composite material X,

[0349] In step (1), the composite material X is placed in the molding die with the hole forming member inserted into the hole Xa.

[0350] For example, in step (1), if Fig.12 As shown in FIG. 1 , a hole forming member 205 is provided in the forming fixed die 201, and the composite material X is arranged on the upper part of the forming fixed die 201 in a state where the hole forming member 205 is inserted into the hole Xa. The hole forming member 205 is provided by arranging a pin in the forming fixed die 201, and is sometimes referred to as a core pin. In addition, the projection area of ​​the hole Xa is larger than the projection area of ​​the hole forming member 205.

[0351] Thereafter, by performing steps (2) to (4), the door inner panel 1 can be molded while preventing the composite material X from being displaced during molding.

[0352] In addition, as the hole Xa provided in the composite material X, a hole other than the holes 23a, 33a, and 43a corresponding to the bolt insertion holes 91a to 93a may be provided.

[0353] If the hole Xa is large enough, the injection molding material Y passes through the hole Xa. Therefore, when the surface layer including the Y portion is provided on both surfaces of the door inner panel 1, it is preferable that the hole Xa is large enough.

[0354] The forming die in which the hole forming member 205 is provided may be either a male or female forming die, but when using a composite material X that is preheated and in a softened state, it is preferably provided in the forming die on the side where the composite material X is arranged in order to facilitate the supply of the composite material X. In addition, depending on the situation, the hole forming member may be provided in both male and female forming dies in such a manner that the distal end surfaces of the hole forming member are in contact with each other when the dies are closed.

[0355] When the composite material X with a thickness of t is arranged in the forming fixed mold 201, the average distance Lf between the inner wall surface of the hole Xa of the composite material X and the hole forming component 205 is preferably 0<Lf<10t. This means that when the thickness t of the composite material X is thick, the flow distance of the composite material X can be extended. For example, when the thickness of the composite material X is 2.5 mm, the average distance Lf can be 0<Lf<25 mm. The distance between the inner wall surface of the hole Xa of the composite material X and the hole forming component is, for example, as shown in 805 of 12), which is the distance L from the inner wall surface of the hole Xa to the hole forming component 205. The average distance Lf is the average of L even if the shapes of the hole forming component 205 and the hole Xa are indefinite or the configuration positions are deviated.

[0356] The hole Xa is preferably provided at a portion disposed at the upper portion and the lower portion of the composite material X. The portions where the hole Xa is formed are preferably provided at two or more locations for one composite material X. By providing the hole Xa at two or more locations in the composite material X, positional deviation of the composite material X can be appropriately suppressed.

[0357] For example, the hole Xa may be provided at a position corresponding to the holes 23a and 33a. Here, the hole 23a is provided at a position arranged at the upper portion of the side frames 3L and 3R, and the hole 33a is provided at a position arranged at the lower portion. Alternatively, the hole Xa may be provided at a different position not corresponding to the holes 23a and 33a.

[0358] On the other hand, a hole may be provided in the Y portion as the hole 23a, 33a, 43a provided in the door inner panel 1. In the case of insert molding in which the injection molding material Y is injected into the molding die and inserted into the molding die, if the molding die is designed in advance to provide the hole 23a, 33a, 43a, the hole 23a, 33a, 43a can be made in the Y portion at the moment when the injection molding material Y is flowed in and molding is completed.

[0359] In addition, holes corresponding to the holes 23a, 33a, and 43a may be provided in both the X portion and the Y portion, or holes may be provided in both the X portion and the Y portion at positions not corresponding to the holes 23a, 33a, and 43a.

[0360] Since the holes 23a, 33a, and 43a are provided while the X portion and the Y portion are integrally formed, the holes 23a, 33a, and 43a can be easily provided. If the holes 23a, 33a, and 43a are provided by integral molding, the manufacturing process can be simplified.

[0361] Alternatively, after the press forming in (4) is completed, the holes 23a, 33a, and 43a may be provided by secondary processing.

[0362] [Gate location]

[0363] In order to manufacture the door inner panel 1 in which the X portion is observed in at least a portion of the surface layer, it is preferable to provide a gate for injecting the injection molding material Y in a region where the composite material X is arranged. Figure 8 to Figure 11 In the embodiment, the example in which the gate 203 is provided at the position where the composite material X is arranged in the molding fixed mold 201 is described, but a gate for injecting the injection molding material Y may be provided at the position where the composite material X is arranged in the molding movable mold 301. In this case, the composite material X is pressed against the molding fixed mold 201 by the pressure of the molding material Y. Since the gap between the composite material X and the cavity wall surface of the molding movable mold is blocked, it is possible to suppress the injection molding material Y from entering between the composite material X and the cavity wall surface of the molding movable mold.

[0364] Fig.13 201 is a top view of the forming fixed mold. Fig.13 As shown, the upper surface of the forming fixed die 201 is provided with: a region 2A corresponding to the shape of the beam portion 2, a region 3LA corresponding to the shape of the side frame 3L, a region 3RA corresponding to the shape of the side frame 3R, and a region 4A corresponding to the shape of the lower half 4. In addition, a region XA corresponding to the composite material X, a region 6A corresponding to the hinge fastening portion 6, a region 7A corresponding to the damper fastening portion 7, and a region 8A corresponding to the region where the trunk lock 8 is arranged are indicated by dotted lines.

[0365] There is no particular limitation on the position of providing the gate for injecting the injection molding material Y. For example, the gate for injecting the injection molding material Y may be provided in a region (2A, 4A) other than the region XA where the composite material X is arranged.

[0366] [Number of gates]

[0367] In order to manufacture the door inner panel 1 in which the X portion is observed in at least a portion of the surface layer, the number of gates preferably satisfies n1>n2≥0.

[0368] n1 is the number of first gates provided in the region (XA) where the composite material X is arranged when the cavity of the molding die is viewed from above;

[0369] n2 is the number of second gates provided in a region other than the region where the composite material X is arranged when the cavity of the molding die is viewed from above.

[0370] For example, in Fig.13 In the example shown, one gate 202 is provided in the region 2A, eight gates 203 are provided in the region XA, and three gates 204 are provided in the region 4A. The gate 203 is a first gate provided in the region XA, and the gates 202 and 204 are second gates provided in regions other than the region XA. In this case, n1=8, n2=4, and n1>n2≥0 is satisfied.

[0371] In this way, when n1>n2≥0 is satisfied, the injection molding material Y injected from the gate 203 presses the composite material X against the inner wall of the cavity of the molding movable mold, and the injection molding material Y also expands to the area outside the area XA, thereby preventing the injection molding material Y injected from the gates 202 and 204 from entering between the composite material X and the wall surface of the cavity of the molding movable mold.

[0372] In addition, Fig.13 In the above, the case where the gates 202 to 204 for injecting the injection molding material Y are provided in the molding fixed mold 201 is described, but the gate for injecting the injection molding material Y may also be provided in the molding movable mold 301. Even in this case, by satisfying n1>n2≥0, the gap between the composite material X and the cavity wall surface of the molding fixed mold 201 is blocked, so that the injection molding material Y can be suppressed from entering between the composite material X and the cavity wall surface of the molding fixed mold 201.

[0373] [Gate discharge volume]

[0374] In order to manufacture the two-sided frame in which the X portion is observed in at least a portion of the single-sided surface layer, the discharge amount of the injection molding material Y from the gate for injecting the injection molding material Y preferably satisfies V1>V2≥0. Where:

[0375] V1 is the discharge amount of the injection molding material Y discharged from the first gate (203) provided in the area (XA) where the composite material X is arranged when the cavity of the molding die is viewed from above;

[0376] V2 is the discharge amount of the injection molding material Y discharged from the second gate (202, 204) provided in the area (2A, 4A) other than the area where the composite material X is arranged when the cavity of the molding die is viewed from above.

[0377] For example, in Fig.13In the example shown, one gate 202 is provided in the region 2A, eight gates 203 are provided in the region XA, and three gates are provided in the region 4A. At this time, if the total amount of the injection molding material Y discharged from the gate 203 is set to V1, and the total amount of the injection molding material Y discharged from the gates 202 and 204 is set to V2, it is preferable to satisfy V1>V2≥0. The injection molding material Y injected from the gate 203 presses the composite material X against the inner wall of the cavity of the molding movable mold, and the injection molding material Y also spreads to the area outside the region XA. The discharge amount V1 of the injection molding material Y injected from the gate 203 is larger than the discharge amount V2 of the injection molding material Y injected from the gates 202 and 204, so the injection molding material Y injected from the gates 202 and 204 does not reach the composite material X, and can be suppressed from entering between the cavity walls of the molding movable mold.

[0378] [Second embodiment]

[0379] Next, a second embodiment of the present invention will be described. In addition, descriptions of the same structures as those of the first embodiment will be omitted.

[0380] In the second embodiment, the surface layers of both sides of the side frames 3L and 3R may also include a Y portion in at least a portion. By forming the surface layer on the vehicle inner side and the vehicle outer side of the door inner panel 1 by the Y portion, the appearance of the door inner panel 1 observed from the vehicle inner side and the appearance observed from the vehicle outer side can be made uniform.

[0381] Fig.14 FIG. 2 is a top view of a molding fixed mold 201A according to the second embodiment. Fig.13 The same structures are denoted by the same reference numerals and description thereof will be omitted.

[0382] [Number of gates]

[0383] In order to make the surface layers of both surfaces of the side frames 3L and 3R have the Y portion in at least a part, the injection molding material Y may be allowed to enter between the composite material X and the cavity wall surface of the molding die.

[0384] In this case, the number of gates for injecting the injection molding material Y preferably satisfies 0<n1<n2. Where:

[0385] n1 is the number of first gates provided in the region (XA) where the composite material X is arranged when the cavity of the molding die is viewed from above;

[0386] n2 is the number of second gates provided in a region other than the region where the composite material X is arranged when the cavity of the molding die is viewed from above.

[0387] For example, in Fig.14In the example shown, three gates 202 are provided in the region 2A, six gates 203 are provided in the region XA, and five gates 204 are provided in the region 4A. The gate 203 is a first gate provided in the region XA, and the gates 202 and 204 are second gates provided in a region other than the region XA. In this case, n1=6, n2=8, and 0<n1<n2 is satisfied.

[0388] When 0<n1<n2 is satisfied, the injection molding material Y injected from the gates 202 and 204 spreads to the region XA where the composite material X is arranged, so that the injection molding material Y can be urged to enter between the composite material X and the cavity wall of the molding movable mold.

[0389] [Discharge amount from gate]

[0390] In order to make at least a part of the surface layer of both surfaces of the side frames 3L and 3R have the Y portion, the discharge amount discharged from the gate for injecting the injection molding material Y preferably satisfies 0<V1<V2.

[0391] V1 is the discharge amount of the injection molding material Y discharged from the first gate provided in the region (XA) where the composite material X is arranged when the cavity of the molding die is viewed from above;

[0392] V2 is the discharge amount of the injection molding material Y discharged from the second gate provided in a region other than the region (XA) where the composite material X is arranged when the cavity of the molding die is viewed from above.

[0393] For example, in Fig.14 In the example shown, three gates 202 are provided in the region 2A, six gates 203 are provided in the region XA, and five gates are provided in the region 4A. At this time, if the total amount of the injection molding material Y discharged from the gate 203 is set to V1, and the total amount of the injection molding material Y discharged from the gates 202 and 204 is set to V2, it is preferable to satisfy 0<V1<V2. When 0<V1<V2 is satisfied, the injection molding material Y injected from the gates 202 and 204 spreads to the region XA where the composite material X is arranged, so that the injection molding material Y can be caused to enter between the composite material X and the cavity wall of the molding movable mold.

[0394] [Opening and closing direction of the molding die]

[0395] 1. Up and down direction

[0396] In the present invention, the opening and closing direction of the forming mold is not particularly limited, but the forming fixed mold is the forming lower mold, the forming movable mold is the forming upper mold, and the forming upper mold moves up and down toward the forming lower mold, thereby opening and closing the forming mold.

[0397] 2. Horizontal direction

[0398] On the other hand, a molded body may be manufactured by moving the movable molding die in the horizontal direction toward the fixed molding die and opening and closing the mold.

[0399] When a molded body is produced by moving the movable molding die in the horizontal direction to open and close it, it is preferred that at least two fixing members are provided to fix the composite material X to the fixed molding die.

[0400] Fig.15 201B and the movable forming mold 301B are horizontally sectional views showing the fixed forming mold 201B and the movable forming mold 301B which are arranged to be openable and closable in the horizontal direction. Fig.15 In the embodiment, a plurality of fixing members 210 are provided to fix the composite material X to the forming fixed die 201B. The plurality of fixing members 210 are preferably located at different positions in the horizontal direction. By arranging the plurality of fixing members 210 at different positions in the horizontal direction of the forming fixed die 201B, it is possible to prevent the position of the composite material X from being offset relative to the forming fixed die 201B. The fixing members 210 may also be arranged at different positions in the height direction. Three or more fixing members 210 may also be arranged at different positions in the height direction and the horizontal direction.

[0401] Furthermore, a hole 310 for inserting the fixing member 210 may be provided at a position of the movable molding die 301B facing the fixing member 210 .

[0402] 3. Fixed mold and mobile mold

[0403] Depending on the type of forming mold, the fixed mold may move. If the fixed mold is assumed to move, the forming mold with a relatively short moving distance is regarded as the fixed mold, and the forming mold with a relatively large moving distance is regarded as the moving mold.

[0404] [Pattern cutting]

[0405] The composite material X may also be a shape cut out by pattern cutting. Pattern cutting refers to cutting the composite material into a target shape in advance according to the shape of the formed body. It is not a simple shape such as a square or a rectangle. For example, Fig.16 As shown, in the case of manufacturing a box-shaped molded body 400, as shown in Fig.17 As shown in FIG. 1 , the composite material X may be formed into a shape in which a margin is added to the portion constituting the expanded view of the box. Fig.17 In the embodiment, four side portions 402 are provided around a portion 401 which is a bottom surface of a rectangular box, and margins 403 are provided at portions which are joined when forming adjacent side portions 402. Fig.17In the embodiment, the margin 403 is provided only in one of the two adjacent side portions 402 , but the margin 403 may be provided in both sides.

[0406] The resin contained in the composite material X is a thermoplastic resin. When cold pressing is used as the molding method, the composite material X is particularly preferably a composite material X in a shape cut by pattern cutting. In the case of cold pressing, the resin begins to solidify from the moment the molding fixed mold contacts the composite material X, so the fluidity during molding is lower than that of thermosetting resins. Therefore, if it is cut into a target shape in advance, it is easy to produce a molded body of the target shape. The pattern cutting shape is preferably a shape developed by a computer through inverse molding analysis based on the three-dimensional shape of the manufactured pressed molded body.

[0407] [Pattern cutting and fixing parts]

[0408] When the composite material X is cut into a shape by pattern cutting and a molded body is manufactured by moving the movable molding die horizontally toward the fixed molding die to open and close, the composite material X is preferably fixed by a plurality of fixing members provided in the fixed molding die.

[0409] Fig.18 2 is a front view showing a molding fixed mold 201C in a state where the composite material X after pattern cutting is fixed by a fixing member 210C. Fig.18 As shown, for example, in a portion 401 of the bottom surface of a rectangular box, the composite material X is fixed to a forming fixed mold 201C by fixing members 210C at a plurality of locations separated in the horizontal direction.

[0410] Fig.19 It is a horizontal cross-sectional view showing a fixed forming mold 201C and a movable forming mold 301C that fix the composite material X by a fixing member 210C. Fig.19 When the composite material X is opened and closed with the plate surface in the vertical direction (with the left and right direction), Fig.19 In this case, when the composite material X cut by the pattern is used, the composite material may sag in an undesirable direction compared to a composite material of a simple shape such as a square or a rectangle. Therefore, by using the fixing member 210C to properly fix the composite material X to the forming fixed mold 201C, it is possible to properly prevent the composite material X from sagging in an undesirable direction.

[0411] exist Fig.18 In the embodiment, the composite material X may be pre-shaped so that the portion 402 to be the side surface and the margin 403 above the portion 401 to be the bottom surface fixed to the forming fixed mold 201C by the fixing member 210C are not moved to the forming movable mold 301C (see Fig.19 ) side, but tilted toward the forming fixed mold 201C side in advance.

[0412] [Injection and design properties from fixed mold]

[0413] Injection from a fixed mold and design properties are described below. The step (3) of injecting the injection molding material Y into the molding mold includes the step of injecting the injection molding material Y between the molding fixed mold and the molding movable mold. The injection molding material Y is preferably injected from the molding fixed mold. Compared with injecting the injection molding material Y from the molding movable mold, injecting from the molding fixed mold is less complicated in terms of equipment and is therefore preferred.

[0414] 1. Formation of the design surface

[0415] When the injection molding material Y is injected from the molding fixed mold, it is preferable to form the design surface by the molding movable mold. This is because the trace of the injection gate remains on the surface of the molded body formed by the molding fixed mold, while on the other hand, the trace of the injection gate does not remain on the surface formed by the movable mold. In this case, by conducting the following research on the composite material X or the molding movable mold, the design of the molded body can be improved.

[0416] 2. Composite materials and design surfaces

[0417] When injection is performed from a fixed mold, it is preferred to fill the injection molding material between the movable mold and the composite material X. By filling the injection molding material between the movable mold and the composite material X, the fibers contained in the composite material can be hidden. By filling the injection molding material between the movable mold and the composite material X, a surface layer is formed.

[0418] The thickness of the surface layer is preferably 50 μm or more and 300 μm or less, and preferably 70 μm or more and 200 μm or less.

[0419] 2.1 Flow hole

[0420] When the design surface is formed by the movable molding die, the injection molding material Y is filled between the movable molding die and the composite material X, for example, Fig.15As shown in FIG. 1 , it is preferable to provide at least one flow hole X1 for the injection molding material Y to pass through the composite material X, and the injection molding material Y injected from the gate 203 of the molding fixed mold 201B flows through the flow hole X1, and is injected between the composite material X and the molding movable mold 301B. By allowing the injection molding material Y injected from the molding fixed mold 201B to pass through the flow hole X1, the injection molding material Y can enter between the composite material X and the molding movable mold 301B. At this time, it is preferable to provide the gate 203 in the region where the composite material X is arranged in the molding fixed mold 201B.

[0421] 2.2 Configuration of resin sheet

[0422] When the design surface is formed by the forming movable die, it is preferred to arrange a resin sheet between the composite material X arranged in the forming fixed die and the forming movable die. If the resin sheet does not contain fibers, the transferability of the forming mold mirror surface of the forming movable die is good, so it is preferred. By providing the resin sheet, it is possible to easily form a design surface on the formed body. The resin sheet and the composite material X may be stacked and arranged in the forming fixed die, or the resin sheet may be stacked on the composite material X after the composite material X is arranged in the forming fixed die.

[0423] 2.3 Texture

[0424] When the design surface of the molded body is formed by the forming movable mold, the design surface may also have a texture shape formed by the forming movable mold. By transferring the mold surface of the forming movable mold to form the texture shape on the molded body, the reinforcing fibers contained in the composite material can be made inconspicuous, thereby improving the design. In order to make the texture shape of the mold surface of the forming movable mold easily transferred to the composite material X, a resin-rich layer may be provided on the surface of the composite material X, or a resin sheet may be provided between the forming movable mold and the composite material X when the composite material X is arranged in the forming fixed mold.

[0425] This application claims priority based on Japanese Patent Application No. 2022-149322 filed on September 20, 2022 and Japanese Patent Application No. 2022-196925 filed on December 9, 2022.

[0426] Description of Reference Numerals

[0427] 1: Door inner panel

[0428] 2: Beam

[0429] 3L, 3R: Side frame

[0430] 4: Lower half

[0431] 5: Window opening

[0432] 6: Hinge fastening part

[0433] 7: Shock absorber fastening part

[0434] 8: Trunk lock

[0435] 91, 92, 93: Accessories

[0436] 201, 201A, 201B, 201C: Forming fixed mold

[0437] 202, 203, 204: Gate

[0438] 205: Hole forming component

[0439] 210, 210C: Fixed parts

[0440] 301, 301B, 301C: Forming moving die

Claims

1. A method for manufacturing a door inner panel, characterized in that: The door inner panel includes a side frame extending in the up-down direction and is integrally formed of a composite material X and an injection molding material Y, wherein the composite material X includes reinforcing fibers dispersed in an in-plane direction. The manufacturing method comprises the following steps (1) to (4): (1) a step of placing the composite material X on a forming fixed die of a forming die; (2) a step of lowering a movable forming mold of the forming mold to bring the movable forming mold into contact with the composite material X; (3) a step of injecting the injection molding material Y into the molding die; (4) A step of pressing the composite material X and the injection molding material Y in a molding die to integrally mold the door inner panel.

2. The method for manufacturing a door inner panel according to claim 1, characterized in that: The molding die has an area for arranging the composite material X at a position corresponding to the side frame. A first gate is provided in a region where the composite material X is arranged, and the first gate is used to inject the injection molding material Y into the molding die.

3. The method for manufacturing a door inner panel according to claim 1 or 2, characterized in that: The composite material X is brought into contact with the cavity wall surface of the molding die to form a surface layer including an X portion formed of the composite material X.

4. The method for manufacturing a door inner panel according to claim 3, characterized in that: The surface layer including the X portion is formed on a surface of the door inner panel that is disposed on the vehicle inner side.

5. The method for manufacturing a door inner panel according to claim 3, characterized in that: The surface layer including the X portion is formed on a surface of the door inner panel disposed on the vehicle outer side.

6. The method for manufacturing a door inner panel according to any one of claims 1 to 5, characterized in that: The forming die has: a first gate, the first gate being used to inject the injection molding material Y into the molding die in an area where the composite material X is arranged; as well as a second gate for injecting the injection molding material Y into the molding die in a region other than a region where the composite material X is arranged, The number n1 of the first gates and the number n2 of the second gates satisfy n1>n2≥0.

7. The method for manufacturing a door inner panel according to any one of claims 1 to 5, characterized in that: The forming die has: a first gate, the first gate being used to inject the injection molding material Y into a region of the molding die where the composite material X is disposed; as well as a second gate for injecting the injection molding material Y into a region other than a region in the molding die where the composite material X is disposed, The discharge amount V1 of the injection molding material Y discharged from the first gate and the discharge amount V2 of the injection molding material Y discharged from the second gate satisfy V1>V2≥0.

8. The method for manufacturing a door inner panel according to claim 1 or 2, characterized in that: The injection molding material Y is brought into contact with the cavity wall surface of the molding die to form a surface layer including a Y portion molded by the injection molding material Y.

9. The method for manufacturing a door inner panel according to any one of claims 1, 2 or 8, characterized in that: The forming die has: a first gate, the first gate being used to inject the injection molding material Y into a region of the molding die where the composite material X is disposed; as well as a second gate for injecting the injection molding material Y into a region other than a region in the molding die where the composite material X is disposed, The number n1 of the first gates and the number n2 of the second gates satisfy 0<n1<n2.

10. The method for manufacturing a door inner panel according to any one of claims 1, 2, 8 or 9, characterized in that: The forming die has: a first gate, the first gate being used to inject the injection molding material Y into the molding die in an area where the composite material X is arranged; as well as a second gate for injecting the injection molding material Y into the molding die in a region other than a region where the composite material X is arranged, A discharge amount V1 of the injection molding material Y discharged from the first gate and a discharge amount V2 of the injection molding material Y discharged from the second gate satisfy 0<V1<V2.

11. The method for manufacturing a door inner panel according to any one of claims 1 to 10, characterized in that: The surface of the side frame that becomes the inner side of the vehicle is the interior design portion of the vehicle. In the step (4), the texture shape provided on the inner wall surface of the cavity of the molding die is transferred to the interior design part.

12. The method for manufacturing a vehicle door inner panel according to any one of claims 1 to 11, characterized in that: At least one of the movable forming mold and the fixed forming mold has a hole forming member for forming a hole in the door inner panel. In the step before the step (1), a hole Xa is provided in the composite material X, In the step (1), the composite material X is disposed in a molding die so that the hole Xa corresponds to the hole forming member.

13. The method for manufacturing a vehicle door inner panel according to claim 12, characterized in that: The holes Xa are provided in the composite material X at a portion corresponding to the upper portion of the side frame and at a portion corresponding to the lower portion of the side frame.

14. The method for manufacturing a door inner panel according to any one of claims 1 to 13, characterized in that: In the step (3), the injection molding material Y is kneaded before injection, and a gap is provided between the movable molding die and the fixed molding die to fill the injection molding material Y.

15. The method for manufacturing a door inner panel according to claim 1, characterized in that: The composite material X comprises reinforcing fibers A having a weight-average fiber length LwA of 1 mm or more and 100 mm or less, The injection molding material Y includes reinforcing fibers B whose weight average fiber length LwB is smaller than LwA, The mechanical strength of the reinforcement portion formed of the composite material X is higher than the mechanical strength of the main body portion formed of the injection molding material Y.

16. The method for manufacturing a door inner panel according to any one of claims 1 to 15, characterized in that: The door inner panel is a rear door inner panel.

17. The method for manufacturing a vehicle door inner panel according to claim 16, characterized in that: Prior to the step (2), a component for connecting with the hinge is arranged in the region connected with the hinge, and the component is insert-molded together with the composite material X and the injection molding material Y.

18. The method for manufacturing a vehicle door inner panel according to claim 16, characterized in that: Prior to the step (2), a component for connecting with the trunk lock is arranged in the region where the trunk lock is mounted, and the component is insert-molded together with the composite material X and the injection molding material Y.

19. The method for manufacturing a door inner panel according to any one of claims 16 to 18, characterized in that: The door inner panel has: lower half; a pair of side frames extending upward from an upper left end and an upper right end of the lower half; and a beam portion connecting upper ends of the pair of side frames to each other, The injection molding material Y is used to manufacture the central portion and the lower half of the beam portion.

20. The method for manufacturing a door inner panel according to claim 17 or 18, characterized in that: The fitting is a metal fastener having a bolt insert, The door inner panel has a hole at a position corresponding to the bolt insertion portion.

21. The method for manufacturing a vehicle door inner panel according to claim 20, characterized in that: A hole is provided in the Y portion formed by the injection molding material Y at a position corresponding to the bolt insertion portion.

22. The method for manufacturing a vehicle door inner panel according to claim 20 or 21, characterized in that: The fitting is in contact with the Y portion molded from the injection molding material Y.

23. The method for manufacturing a door inner panel according to claim 20 or 21, characterized in that: The accessory does not contact the X portion formed by the composite material X.

24. The method for manufacturing a door inner panel according to any one of claims 20 to 23, characterized in that: The door inner panel has a rib within 30 mm from the fitting.

25. The method for manufacturing a vehicle door inner panel according to claim 20 or 21, characterized in that: The door inner panel has a thickness uneven portion at a position within 30 mm from the accessory.

26. The method for manufacturing a door inner panel according to any one of claims 20 to 25, characterized in that: In the step (4), a hole is provided at a position corresponding to the bolt insertion portion.

27. The method for manufacturing a door inner panel according to any one of claims 20 to 22 or 25, characterized in that: At least one of the movable forming die and the fixed forming die has a hole forming member for forming a hole at a position corresponding to the bolt insertion portion. In the step before the step (1), a hole Xa is provided in the composite material X, In the step (1), the composite material X is arranged in a molding die so that the hole Xa corresponds to the hole forming member. In the step (4), a hole is provided at a position corresponding to the bolt insertion portion by the hole forming member.

28. A vehicle door inner panel, characterized in that: have: lower half; a pair of side frames extending upward from an upper left end and an upper right end of the lower half; and a beam portion connecting upper ends of the pair of side frames to each other, The pair of side frames includes: an X portion formed of a composite material X containing reinforcing fibers dispersed in an in-plane direction; and a Y portion formed of an injection molding material Y, The central portion of the beam portion and the lower half portion include the Y portion molded from the injection molding material Y.

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