JP2021116056A - Back door for vehicle and method for molding inner panel - Google Patents

Abstract

To provide a back door for a vehicle which reduces thermal expansion and contraction in a longitudinal direction of a lower part of an inner panel, and suppresses deformation due to heat in the lower part of the inner panel.SOLUTION: A back door (1) includes an inner panel (3) and an outer panel (7) which are joined to each other. The inner panel is formed with an opening (11) for window. The inner panel is an injection molding which is composed of a thermoplastic resin (R) containing a fiber reinforcement material (Fb). The inner panel lower part (3b) that is a part lower than the opening for window in the inner panel has a laterally long division wall part (39) which is divided in a vertical direction by a slit-like opening (37) extending in the longitudinal direction and extends in the longitudinal direction.SELECTED DRAWING: Figure 2

Description

The technique of the present disclosure relates to a method for molding a vehicle back door and an inner panel.

Conventionally, as a vehicle back door that replaces a sheet metal back door, a resin back door that is advantageous for reducing the weight of the vehicle and has a high degree of freedom in modeling has been known. The resin back door has a structure in which an inner panel located inside the vehicle and an outer panel located outside the vehicle are joined to support the outer panel having a good surface appearance with a rigid inner panel. As the material of the inner panel, a thermoplastic resin containing a fiber reinforcing material is used in order to have the body rigidity required for the comfort and running performance of the vehicle (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-230723

Since the resin inner panel described above is formed by injection molding in which a resin melted by heating is injected into a mold and cooled and solidified, deformation due to thermal expansion and contraction can occur. The degree of thermal expansion and contraction that causes the inner panel to be deformed depends on the orientation state of the fiber reinforcing material contained in the resin forming the inner panel. The orientation of the fiber reinforcing material tends to be aligned in the direction in which the resin injected from the gate flows in the mold for molding the inner panel. Thermal expansion and contraction of the inner panel is unlikely to occur in the direction in which the fiber reinforcement is oriented.

The lower part of the inner panel, which is the lower part of the inner panel below the window opening, constitutes a relatively wide surface in the vertical and horizontal directions. Therefore, at the time of molding the inner panel, in the cavity portion forming the lower part of the inner panel of the mold, the flows of the resins injected from the plurality of gates are not fixed in one direction and interfere with each other, so that the fiber reinforcing material is oriented. It will be in a random direction. When the orientation of the fiber reinforcing material at the lower part of the inner panel is in a random direction, the thermal expansion and contraction of the lower part of the inner panel becomes relatively large in the left-right direction which is the longitudinal direction.

The technique of the present disclosure has been made in view of these points, and an object thereof is to reduce thermal expansion and contraction of the lower part of the inner panel in the left-right direction in a vehicle back door, and to reduce the thermal expansion and contraction of the lower part of the inner panel. The purpose is to suppress deformation due to heat.

In order to achieve the above object, in the technique of the present disclosure, the structure of the lower part of the inner panel is devised so that the resin flow at the time of molding the panel is determined in the left-right direction.

Specifically, the technology of the present disclosure is intended for vehicle backdoors. In this vehicle back door, an inner panel located inside the vehicle and an outer panel located outside the vehicle are joined to form a window opening in the inner panel.

The first aspect of the present disclosure is a vehicle back door in which the inner panel is an injection-molded product made of a thermoplastic resin containing a fiber reinforcing material. A slit-shaped opening extending in the left-right direction was formed in the lower part of the inner panel below the window opening of the inner panel, and the lower part of the inner panel was divided in the vertical direction by the slit-shaped opening. It has a horizontally long split wall that extends in the left-right direction.

A second aspect of the present disclosure is that the vehicle back door of the first aspect is provided with a concave portion at the lower part of the inner panel, which is recessed from the inside of the vehicle toward the outer panel side and is covered with a cover panel from the inside of the vehicle. It is a back door for. The slit-shaped opening is formed in the bottom wall of the concave portion. The horizontally long divided wall portion constitutes the bottom wall of the concave portion.

In the third aspect of the present disclosure, in the vehicle back door of the second aspect, the outer standing walls rising to the outer panel side are spaced apart from the side wall of the concave portion in the left-right direction at both side ends of the lower part of the inner panel in the left-right direction. It is a back door for vehicles provided in the above. At the lower part of the inner panel, a bridge-shaped portion that connects the side wall of the concave portion and the outer standing wall in the left-right direction is provided.

A fourth aspect of the present disclosure is the vehicle backdoor of the third aspect, in which the bridge-shaped portion is arranged in a horizontal line with the dividing wall portion in the horizontal direction.

In the fifth aspect of the present disclosure, in any one of the vehicle back doors of the first to fourth aspects, a work opening opened rearward is formed at the lower part of the inner panel separately from the slit-shaped opening. It is a back door for vehicles.

A sixth aspect of the present disclosure is the vehicle backdoor of the fifth aspect, wherein the lower part of the inner panel has a plurality of divided wall portions. The plurality of divided wall portions include a first divided wall portion in which a work opening is formed and a second divided wall portion in which a work opening is not formed, which are adjacent to each other in the vertical direction. Vertical walls extending in the vertical direction and the front-rear direction are provided at each end of the first division wall portion on the work opening side in the left-right direction. The vertical wall is connected to the second divided wall portion and constitutes an opening having a work opening.

The technique of the present disclosure also covers a method of molding an inner panel of a vehicle back door. The inner panel molded by this molding method is an inner panel in which a window opening is formed. A slit-shaped opening extending in the left-right direction is formed in the lower part of the inner panel, which is a portion of the inner panel below the window opening. The lower part of the inner panel has a horizontally long divided wall portion extending in the left-right direction, which is divided in the vertical direction by the slit-shaped opening. A work opening opened rearward is formed in the lower part of the inner panel separately from the opening.

A seventh aspect of the present disclosure is a portion in which a cavity for molding an inner panel is formed inside the molding die by closing the molding die, and a peripheral portion of the inner panel work port is formed in the cavity. Inner panel molding in which a side gate for supplying molten resin is formed from a portion corresponding to the inside of the work opening, and molten resin containing a fiber reinforcing material is injected from the side gate into the cavity. The method.

According to the vehicle back door of the first aspect, since the lower portion of the inner panel has a horizontally long divided wall portion extending in the horizontal direction, which is divided in the vertical direction by a slit-shaped opening, the inner panel is formed. At times, in the cavity portion where the split wall portion of the mold is formed, the flow of the resin injected from the gate is determined in the left-right direction, and the fiber reinforcing material contained in the resin is oriented in the left-right direction. As a result, thermal expansion and contraction of the lower part of the inner panel in the left-right direction can be reduced, and deformation of the lower part of the inner panel due to heat can be suppressed.

According to the vehicle back door of the second aspect, the horizontally long split wall portion constitutes the bottom wall of the concave portion provided at the lower part of the inner panel and recessed from the inside of the vehicle toward the outer panel side, and the concave portion is the vehicle. Since it is covered with the cover panel from the inside, the slit-shaped opening and the divided wall portion are concealed by the cover panel. This makes it possible to prevent the appearance of the vehicle back door from being impaired due to the slit-shaped opening and the split wall portion provided in the inner panel.

According to the vehicle back door of the third aspect, a bridge-shaped portion for connecting the side wall of the concave portion and the outer standing wall in the left-right direction is provided at the lower portion of the inner panel, so that when the inner panel is molded, the inner panel is formed. In the cavity portion where the bridge shape portion of the mold is formed, the flow of the resin injected from the gate is determined in the longitudinal direction of the bridge shape portion, and the fiber reinforcing material contained in the resin is oriented in the longitudinal direction of the bridge shape portion. .. As a result, thermal expansion and contraction of the lower part of the inner panel in the left-right direction can be reduced at both left and right ends between the concave portion and the outer standing wall. As a result, the deformation of the lower part of the inner panel due to heat can be suppressed in the entire left-right direction.

According to the vehicle back door of the fourth aspect, since the bridge shape portion and the dividing wall portion are arranged in a straight line in the horizontal direction, when thermal expansion or contraction occurs in the lower part of the inner panel, those bridges are formed. The shape part and the dividing wall part are stretched in a straight line in the horizontal direction and are hard to bend. As a result, deformation of the lower part of the inner panel due to heat can be suitably suppressed in the left-right direction.

According to the vehicle back door of the fifth aspect, a work opening opened rearward is formed at the lower part of the inner panel separately from the slit-shaped opening. Therefore, the work opening is used as a hand space for a wiper device or a latch. Equipment parts such as can be easily maintained.

According to the vehicle back door of the sixth aspect, a work opening is formed in the first division wall portion, and vertical walls provided at each end on the work opening side in the left-right direction of the first division wall portion are formed. Since the opening is formed by being connected to the second dividing wall, the rigidity of the periphery thereof can be increased even if a work opening is provided. Further, the second divided wall portion in which the work opening is not formed is advantageous for reducing thermal expansion and contraction of the lower portion of the inner panel in the left-right direction.

According to the inner panel molding method of the seventh aspect, the cavity formed inside the mold in the closed mold corresponds to the inside of the work opening with respect to the portion where the peripheral portion of the inner panel work opening is molded. Since the molten resin containing the fiber reinforcing material is injected from the side gate from the part where the fiber reinforcing material is formed, the orientation of the fiber reinforcing material is stable from the vicinity of the gate as compared with the case where the molten resin is injected into the cavity by the direct gate. do. This is advantageous in reducing thermal expansion and contraction of the lower part of the inner panel in the left-right direction.

FIG. 1 is an exploded perspective view of a vehicle back door according to the first embodiment. FIG. 2 is a perspective view of the inner panel constituting the vehicle back door according to the first embodiment as viewed from the rear side. FIG. 3 is a perspective view of the inner panel constituting the vehicle back door according to the first embodiment as viewed from the front side. FIG. 4 is a cross-sectional view of the inner panel at the location taken along the line IV-IV of FIG. FIG. 5 is a cross-sectional view of the inner panel at the location taken along the line VV of FIG. FIG. 6 is a cross-sectional view of the inner panel at the location along the VI-VI line of FIG. FIG. 7 is a cross-sectional view of the inner panel at the location taken along the line VII-VII of FIG. FIG. 8 is a schematic view showing the orientation state of the fiber reinforcing material of the inner panel constituting the vehicle back door according to the first embodiment together with the position of the gate of the mold at the time of molding the inner panel. FIG. 9 is a cross-sectional view of the inner panel molding apparatus according to the first embodiment. FIG. 10 is a perspective view conceptually showing a direct gate set at the lower part of the inner panel together with the inner panel according to the first embodiment. FIG. 11 is a perspective view of the inner panel constituting the vehicle back door according to the second embodiment as viewed from the rear side. FIG. 12 is a perspective view of the inner panel constituting the vehicle back door according to the second embodiment as viewed from the front side. FIG. 13 is a cross-sectional view of the inner panel at the location taken along the line XIII-XIII of FIG. FIG. 14 is a cross-sectional view of the inner panel at the location taken along the line XIV-XIV of FIG. FIG. 15 is a cross-sectional view of the inner panel molding apparatus according to the second embodiment. FIG. 16 is a perspective view showing the position of the side gate set around the work opening together with the inner panel according to the second embodiment. FIG. 17 is a conceptual diagram showing the orientation state of the fiber reinforced material when the molten resin containing the fiber reinforced material is injected by the side gate. FIG. 18 is a conceptual diagram showing the orientation state of the fiber reinforced material when the molten resin containing the fiber reinforced material is injected by the direct gate. FIG. 19 is a perspective view conceptually showing the position of the side gate set around the work opening of the inner panel according to the modified example of the second embodiment. FIG. 20 is a perspective view conceptually showing the position of the side gate set around the work opening of the inner panel according to the modified example of the second embodiment.

Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. In the following embodiments, for convenience of explanation, the front side in the vehicle front-rear direction is referred to as "front" and the rear side is referred to as "rear". The upper side in the vehicle height direction is called "upper" and the lower side is called "lower". Further, the back door according to this embodiment will be described on the premise of a posture in which the back door opening at the rear of the vehicle is closed, unless the open / closed state is specifically stated.

<< First Embodiment >>
-Outline configuration of back door-
FIG. 1 is an exploded perspective view of the vehicle back door 1 according to the first embodiment. FIG. 2 is a perspective view of the inner panel 3 constituting the vehicle back door 1 according to the first embodiment as viewed from the rear side. FIG. 3 is a perspective view of the inner panel 3 according to the first embodiment as viewed from the front side. FIG. 4 is a cross-sectional view of the inner panel 3 at the location taken along the line IV-IV of FIG. FIG. 5 is a cross-sectional view of the inner panel 3 at the location taken along the line VV of FIG. FIG. 6 is a cross-sectional view of the inner panel 3 at a location taken along the line VI-VI of FIG. FIG. 7 is a cross-sectional view of the inner panel 3 at the location taken along the line VII-VII of FIG.

The vehicle back door 1 shown in FIG. 1 is a vertical opening / closing type back door that opens / closes a back door opening provided at the rearward position of a hatchback vehicle. As shown in FIG. 1, the back door 1 mainly includes an inner panel 3 and a cover panel 5 located on the inside (front side) of the vehicle, and an outer panel 7 and a window panel 9 located on the outside (rear side) of the vehicle. Be prepared.

<Structure of inner panel>
The inner panel 3 is a single resin panel, which is an injection-molded product formed by injection molding. The inner panel 3 is made of a thermoplastic resin R containing a fiber reinforcing material Fb. Examples of the material of the inner panel 3 include polypropylene containing glass fiber (PP-GF: Polypropylene Glass fiber) as a fiber reinforcing material, polypropylene containing carbon fiber (PP-CF: Polypropylene Carbon Fiber) as a fiber reinforcing material, and fiber. Polypropylene containing cellulose nanofibers (PP-CNF: Polypropylene Cellulose Nanofiber) is used as a reinforcing material.

As shown in FIG. 2, a substantially trapezoidal window opening 11 extending in the vehicle width direction is formed in the upper half of the inner panel 3. In the inner panel 3, the peripheral portion of the window opening 11 includes an inner standing wall 13 that rises rearward toward the outer panel 7, and an inner side that protrudes inward from the rear end of the inner standing wall 13. A joint piece 15 is provided. Further, the outer peripheral edge portion of the inner panel 3 is provided with an outer standing wall 17 that rises rearward toward the outer panel 7 side and an outer joining piece 19 that protrudes from the rear end of the outer standing wall 17 toward the outer peripheral side. There is.

A pair of hinge mounting portions 21 having a recessed front side and protruding rearward are provided on both left and right sides in the vehicle width direction in the inner panel upper portion 3a, which is a portion of the inner panel 3 above the window opening 11. It is provided. An opening / closing hinge (not shown) connected to the vehicle body is fixed to the hinge mounting portion 21 from the front with fasteners such as bolts. The back door 1 is attached to the vehicle body body so as to be openable and closable by the hinge attachment portions 21. A plurality of reinforcing ribs 23 are further provided on the inner panel upper portion 3a in order to increase the rigidity in the front-rear and up-down directions.

In the inner panel lower portion 3b, which is a portion of the inner panel 3 below the window opening 11, a latch attachment portion 25 for attaching a latch (not shown) is provided on the outer standing wall 17 constituting the lower end portion. Has been done. The latch is a device that detachably engages with a striker provided at the lower edge of the back door opening in the vehicle body, and locks the back door 1 to the vehicle body in a closed state in cooperation with the striker. Configure a locking device. Further, the lower portion 3b of the inner panel is provided with a substantially rectangular concave portion 27 that is recessed rearward from the inside of the vehicle toward the outer panel 7 side.

<Cover panel configuration>
As shown in FIGS. 4 and 5, the cover panel 5 is fitted into the opening of the concave portion 27 in the lower portion 3b of the inner panel to cover the opening of the concave portion 27 from the inside of the vehicle. Although not shown in detail, the cover panel 5 is attached to the concave portion 27 or its peripheral portion of the inner panel lower portion 3b by a fitting structure or claw engagement. The bottom wall 27b of the concave portion 27 is concealed by the cover panel 5.

<Outer panel configuration>
The outer panel 7 is a single resin panel, which is an injection-molded product formed by injection molding. As the material of the outer panel 7, polypropylene containing talc (PP-T: Polypropylene Talc) or a synthetic resin obtained by mixing polypropylene containing talc (PP-T) and ethylene propylene diene methylene rubber (EPDM: Ethylene Propylene Diene Monomer). Is used.

A substantially trapezoidal window opening 29 extending in the vehicle width direction is formed in the upper half of the outer panel 7. The window opening 29 of the outer panel 7 corresponds to the window opening 29 of the inner panel 3 in the front-rear direction. The outer peripheral edge portion of the outer panel 7 is bonded to the outer bonding piece 19 of the inner panel 3 by using an adhesive 31. The peripheral edge of the window opening 29 of the outer panel 7 is joined to the inner joining piece 15 of the inner panel 3 by using an adhesive 31. A fitting portion 33 recessed forward toward the inner panel 3 side is provided in the peripheral portion of the window opening 29 in the outer panel 7. The fitting portions 33 are open to both sides of the inner panel 3 in the left-right direction.

<Window panel configuration>
The window panel 9 is a horizontally long panel that extends over the left and right ends of the back door 1 in the vehicle width direction. The window panel 9 is fitted into the fitting portion 33 of the outer panel 7 from the rear, and closes the window openings 11 and 29 of the inner panel 3 and the outer panel 7. The window panel 9 is joined to the fitting portion 33 of the outer panel 7 by using an adhesive 31. The window panel 9 is made of a transparent resin such as polycarbonate (PC), glass, or the like. Although not shown, a concealing layer made of black ceramics or the like is provided on the outer peripheral portion of the window panel 9 in order to conceal the joint portion with the outer panel 7.

-Detailed configuration at the bottom of the inner panel-
As shown in FIGS. 2 to 7, the lower portion 3b of the inner panel is provided with a substantially rectangular concave portion 27 as described above. The concave portion 27 is provided in most of the lower portion 3b of the inner panel. The bottom wall 27b of the concave portion 27 is provided with a plurality of convex strips 35 protruding forward (two in the examples shown in FIGS. 1 to 5). The plurality of convex portions 35 extend over both side walls of the concave portion 27 in the left-right direction, and are arranged at intervals from each other in the up-down direction. The bottom wall 27b of the concave portion 27 has a concave-convex shape in a vertical cross section due to the provision of the plurality of convex portions 35.

A plurality of slit-shaped openings 37 extending in the left-right direction are formed on the bottom wall 27b of the concave portion 27. Specifically, the openings 37 are formed on the wall portions on both sides in the vertical direction of each convex portion 35, and are divided into left and right sides by each wall portion. The opening 37 is opened on both the upper and lower sides, and is opened forward toward the opening of the concave portion 27. At least one of these plurality of openings 37 also serves as an opening for mounting for attaching the latch to the latch mounting portion 25 or for wiring a harness or the like, or for maintenance for maintaining the wiper device or the latch. ing.

The inner panel lower portion 3b has a plurality of horizontally long divided wall portions 39 extending in the left-right direction, which are divided in the vertical direction by the plurality of openings 37. The divided wall portion 39 is a portion of the inner panel lower portion 3b corresponding to both sides of the opening 37 in the vertical direction, and constitutes the bottom wall 27b of the concave portion 27. Specifically, the plurality of divided wall portions 39 include a front side wall portion 39f located between the openings 37 among the protruding end portions forming a surface facing the front of the convex portion 35, and a bottom wall 27b of the concave portion 27. Of these, the portion where the convex portion 35 is not provided is the rear side wall portion 39r corresponding to the opening 37 in the vertical direction.

A center connecting portion 41 for partitioning a pair of openings 37 in the left-right direction is provided on each wall portion on both sides of each of the plurality of ridge portions 35 in the vertical direction. The center connecting portion 41 extends in the front-rear direction and connects the central portion in the left-right direction at the protruding end portion of the convex portion 35 and both side portions of the bottom wall 27b of the concave portion 27 in the vertical direction of the convex portion 35. ing. Both ends of the convex portion 35 in the left-right direction are integrated with the side wall 27s in the left-right direction of the concave portion 27 and both side portions of the bottom wall 27b of the concave portion 27 in the vertical direction of the convex portion 35. It is connected.

At both left and right ends of the inner panel lower portion 3b in the left-right direction, outer standing walls 17 are provided at intervals in the left-right direction from the side wall 27s of the concave portion 27. Of the lower part 3b of the inner panel, the side walls on both sides of the concave portion 27 in the left-right direction, the outer standing wall 17, and the portion between the two walls 17, 27 form a groove-shaped portion 43 that opens rearward toward the outer panel 7 side. It is configured. Such a groove-shaped portion 43 is also provided between the lower side wall 27s of the concave portion 27 and the outer standing wall 17, and also between the upper side wall 27s of the concave portion 27 and the inner standing wall 13.

A bridge-shaped portion 45 is provided for each rear side wall portion 39r in each of the groove-shaped portions 43 on both sides of the inner panel lower portion 3b in the left-right direction. The bridge-shaped portion 45 connects the side wall 27s of the concave portion 27 and the outer standing wall 17 so as to bridge in the left-right direction. The bridge-shaped portion 45 is formed in a strip shape so as to be connected to the rear side wall portion 39r at a position corresponding to the rear side wall portion 39r in the left-right direction. The width of the bridge-shaped portion 45 in the vertical direction is equivalent to the width of the rear side wall portion 39r in the vertical direction. The bridge-shaped portion 45 is arranged in a straight line with the rear side wall portion 39r in the horizontal direction.

FIG. 8 is a schematic view showing the orientation state of the fiber reinforcing material Fb of the inner panel 3 according to the first embodiment together with the positions of the gates G1, G2, and G3 of the molding apparatus at the time of molding the inner panel 3.

As shown in FIG. 8, the fiber reinforcing material Fb contained in the thermoplastic resin R forming the inner panel 3 is substantially oriented in the left-right direction in the upper portion 3a of the inner panel, and is in the left-right direction of the window opening 11 of the inner panel 3. The parts constituting both sides of the above are generally oriented in the vertical direction. Then, in the lower part 3b of the inner panel, the fiber reinforcing material Fb is generally oriented in the left-right direction. In particular, in the portion of each of the divided wall portions 39 excluding the portion corresponding to the vertical direction of the center connecting portion 41 and the bridge-shaped portion 45, the orientation state of the fiber reinforcing material Fb is aligned in the left-right direction.

-Inner panel molding method-
FIG. 9 is a cross-sectional view of the molding apparatus 101 of the inner panel 3 according to the first embodiment. FIG. 10 is a perspective view conceptually showing a second gate G2 (direct gate DG) set in the lower part 3b of the inner panel together with the inner panel 3 according to the first embodiment.

For molding the inner panel 3 according to the first embodiment, for example, the molding apparatus 101 shown in FIG. 9 is used. The molding apparatus 101 includes a molding die 103 including a fixed mold 105 and a movable mold 107 as a mold, an injection machine (not shown), and a control unit 109. The molding apparatus 101 closes the fixed mold 105 and the movable mold 107 to form a cavity 111 between them, and injects the molten thermoplastic resin R sent from the injection machine into the cavity 111. It has become.

The fixed mold 105 is attached to the fixed plate 115 via the spacer block 113. The fixed mold 105 has a molding surface 105a for molding the surface (front side surface) of the inner panel 3. A plurality of gates G1, G2, and G3 for injecting the thermoplastic resin R into the cavity 111 are formed on the molding surface 105a of the fixed mold 105. The plurality of gates G1, G2, and G3 are, for example, the first gate G1, the second gate G2, and the third gate G3 shown in FIG.

The first gate G1 is provided on both the upper and lower sides of the cavity 111 forming the central portion of the inner panel upper portion 3a in the left-right direction. The first gate G1 is a side gate. The second gate G2 is provided on both the upper and lower sides of the lower portion 3b of the inner panel that forms the central portion in the left-right direction, and the front side of each front side wall portion 39f that forms the central portion in the left-right direction. The former second gate G2 is a side gate. On the other hand, the latter second gate G2 is a direct gate as shown in FIG. The third gate G3 is provided on both the left and right sides of the portion forming the inner panel lower portion 3b. The third gate G3 is a side gate.

The fixed type 105 is further provided with a hot runner 117 communicating with each of the gates G1, G2, and G3, and a sprue 119 communicating with the hot runner 117. The hot runner 117 extends from each gate G1, G2, G3 via the gate runner 121 or directly from the gate G2 in the mold opening direction, and extends so as to be orthogonal to the branch portion 117a, and is the opposite of the branch portion 117a. It has a connecting portion 117b that connects the ends on the gates G1, G2, and G3 sides to each other. A needle 123 is housed in each branch portion 117a of the hot runner 121. In the spacer block 113 on the fixed mold 105 side, accommodation holes 125 are formed in the mold opening direction corresponding to each needle 123. Each accommodating hole 125 accommodates a solenoid 127 that advances and retreats the needle 123. Each gate G1, G2, G3 opens and closes by the advance / retreat operation of the needle 123. The sprue 119 extends from the connecting portion 117b of the hot runner 117 in the mold opening direction. The sprue 119 penetrates the spacer block 113 and the fixing plate 115 on the fixed mold 105 side and communicates with the nozzle 129 of the injection machine.

The movable type 107 is attached to the movable plate 134 via a spacer block 133 having a storage chamber 131. An ejector plate 137 provided with an ejector pin 135 is accommodated in the accommodation chamber 131. The ejector plate 137 moves forward and backward in conjunction with the opening / closing operation of the molding die 103. The movable type 107 has a molding surface 107a for molding the back surface (rear side surface) of the inner panel 3. The movable mold 107 is formed with a plurality of through holes 139 penetrating in the mold opening direction. The ejector pin 135 is housed in each through hole 139.

The control unit 109 is connected to each of a plurality of solenoids 127 provided on the fixed type 105. The control unit 109 draws the thermoplastic resin R from the first gate G1, the second gate G2, and the third gate G3 in a state where the fixed mold 105 and the movable mold 107 are closed and the cavity 111 is formed between them. Control the timing of injection.

In order to mold the inner panel 3, first, in the molding apparatus 101, the fixed mold 105 and the movable mold 107 are closed to form a cavity 111 for molding the inner panel 3, and the cavity 111 is melted. The first gate G1, the second gate G2, and the third gate G3, which are side gates for supplying the thermoplastic resin R in the state, are formed. At this time, the needles 123 corresponding to all the gates G1, G2 and G3 are advanced to close each gate G1, G2 and G3, and the tips of all the ejector pins 135 are substantially the same as the molding surface 107a of the movable mold 107. It is retracted so that it becomes a surface.

Then, the injection of the molten thermoplastic resin R is started from the nozzle 129 of the injection machine. The thermoplastic resin R contains a fiber reinforcing material Fb. Subsequently, by retracting the needle 123 corresponding to each gate G1, G2, G3, each gate G1, G2, G3 is opened at a predetermined timing, and the thermoplastic resin R sent from the injection machine is used for each gate G1, G2. , G3 is injected into the cavity 111.

The plurality of gates G1, G2, and G3 are opened in the order of the first gate G1, the second gate G2, and the third gate G3, and the thermoplastic resin R is injected into the cavity 111 in that order. The timing of opening the second gate G2 and the third gate G3 is such that the resin R injected from the second gate G2 into the cavity 111 and the resin R injected from the third gate G3 into the cavity 111 are in the lower part 3b of the inner panel. It is preferable that the concave portion 27 is adjusted so as to join at a portion forming the side wall 27s or an outer standing wall 17 in the left-right direction.

When the thermoplastic resin R is injected into the cavity 111 from the plurality of gates G1, G2, G3, the resin R flows through the cavity and spreads to fill the entire cavity 111. At this time, the orientation state of the fiber reinforcing material Fb contained in the thermoplastic resin R tends to be aligned in the direction in which the resin R flows. In the cavity 111, since the thermoplastic resin R flows in the left-right direction at the portion where the divided wall portion 39 and the bridge-shaped portion 45 are formed, the fiber reinforcing material Fb contained in the resin R is oriented in the left-right direction. As a result, the orientation states of the fiber reinforcing members Fb contained in the split wall portion 39 and the bridge shape portion 45 are aligned in the left-right direction.

When the entire cavity 111 is filled with the thermoplastic resin R, cooling of the molding die 103 is started. Then, the injection of the thermoplastic resin R from the nozzle 129 is completed, and the needles 123 corresponding to all the gates G1, G2 and G3 are advanced to close each gate G1, G2 and G3. The thermoplastic resin R filled in the cavity 111 is solidified by cooling the molding die 103. The inner panel 3 is formed into the cavity 111 by solidifying the thermoplastic resin R. Next, the movable mold 107 is moved in the mold opening direction, and the tip of each ejector pin 135 is projected from the molding surface 107a of the movable mold 107 by advancing the ejector plate 137, and the inner panel 3 is moved to the molding surface of the movable mold 107. It is separated from 107a, and the inner panel 3 is taken out from the molding die 103. After that, post-treatment such as excision of the gate residue attached to the inner panel 3 is performed.

As described above, the inner panel 3 can be molded by using the molding apparatus 101.

-Effect of the first embodiment-
According to the back door 1 of the present embodiment, the inner panel 3b has a horizontally long divided wall portion 39 extending in the left-right direction, which is divided in the vertical direction by the slit-shaped opening 37. In the cavity portion where the divided wall portion 39 of the molding apparatus is molded, the flow of the resin R injected from the gates G1, G2, and G3 is determined in the left-right direction, and the fiber reinforcing material Fb contained in the resin R is determined. Is oriented in the left-right direction. As a result, thermal expansion and contraction of the inner panel lower portion 3b in the left-right direction can be reduced, and deformation of the inner panel lower portion 3b due to heat can be suppressed. As a result, the gap forming the parting line between the back door 1 and the peripheral edge of the back door opening of the vehicle body can be narrowed, and the appearance of the vehicle can be improved.

According to the back door 1 of the present embodiment, the horizontally long split wall portion 39 constitutes the bottom wall 27b of the concave portion 27 provided in the lower portion 3b of the inner panel and is recessed from the inside of the vehicle toward the outer panel 7 side, and is concave. Since the portion 27 is covered with the cover panel 5 from the inside of the vehicle, the slit-shaped opening 37 and the divided wall portion 39 are concealed by the cover panel 5. As a result, it is possible to prevent the appearance of the back door 1 from being impaired due to the slit-shaped opening 37 and the split wall portion 39 being provided in the inner panel 3.

According to the back door 1 of the present embodiment, the lower portion 3b of the inner panel is provided with a bridge-shaped portion 45 for connecting the side wall 27s of the concave portion 27 and the outer standing wall 17 in the left-right direction. At the time of molding, in the cavity portion where the bridge-shaped portion 45 of the molding apparatus is molded, the flow of the resin R injected from the gates G1, G2 and G3 is determined in the longitudinal direction of the bridge-shaped portion 45 and is contained in the resin R. The fiber reinforcing material Fb is oriented in the longitudinal direction of the bridge shape portion 45. As a result, the thermal expansion and contraction of the inner panel lower portion 3b in the left-right direction can be reduced at both the left and right ends between the concave portion 27 and the outer standing wall 17. As a result, the deformation of the lower part 3b of the inner panel due to heat can be suppressed over the entire area in the left-right direction.

According to the back door 1 of the present embodiment, since the bridge-shaped portion 45 and the dividing wall portion 39 are arranged in a straight line in the horizontal direction, when thermal expansion or contraction occurs in the inner panel lower portion 3b, they are arranged. The bridge-shaped portion 45 and the dividing wall portion 39 are stretched in a straight line in the horizontal direction and are difficult to bend. As a result, deformation of the lower part 3b of the inner panel due to heat can be suitably suppressed in the left-right direction.

<< Second Embodiment >>
The vehicle back door 1 of the second embodiment has a different configuration of the inner panel lower portion 3b from that of the first embodiment. In this embodiment, the vehicle back door 1 is configured in the same manner as in the first embodiment, except that the configuration of the inner panel lower portion 3b is different from that in the first embodiment.

FIG. 11 is a perspective view of the inner panel 3 constituting the vehicle back door 1 according to the second embodiment as viewed from the rear side. FIG. 12 is a perspective view of the inner panel 3 constituting the vehicle back door 1 according to the second embodiment as viewed from the front side. FIG. 13 is a cross-sectional view of the inner panel 3 at the location taken along the line XIII-XIII of FIG. FIG. 14 is a cross-sectional view of the inner panel 3 at a location taken along the line XIV-XIV of FIG.

In the vehicle back door 1 according to the first embodiment, at least one of the plurality of openings 37 formed in a slit shape in the lower portion 3b of the inner panel also serves as an opening for maintenance of the wiper device and the latch. And said. On the other hand, as shown in FIGS. 11 to 14, in the vehicle back door 1 according to the present embodiment, the inner panel lower portion 3b has a work opening 51 opened rearward and a slit-shaped opening 37. It is formed separately.

The work port 51 is formed in one of the plurality of dividing wall portions 39. The work port 51 is formed in the middle of the dividing wall portion 39 in the left-right direction. The dividing wall portion 39 on which the work opening 51 is formed is divided in the left-right direction with the work opening 51 as a boundary. It is preferable that the work opening 51 is not formed in at least one dividing wall portion 39. This is because when the dividing wall portion 39 is divided in the left-right direction, the effect of reducing the thermal expansion and contraction of the inner panel lower portion 3b in the left-right direction by the dividing wall portion 39 is reduced.

In the present embodiment, the work port 51 is formed only on the front side wall portion 39f located on the lower side. That is, the plurality of divided wall portions 39 include a lower front side wall portion 39f in which the work opening 51 is formed and other divided wall portions 39 (upper front side wall portion 39f and rear side wall portion) in which the work opening 51 is not formed. Part 39r) and is included. The lower front side wall portion 39f is divided by the work opening 51 in the middle in the left-right direction. Here, the front side wall portion 39f corresponds to the first divided wall portion, and the other divided wall portions 39f and 39r correspond to the second divided wall portion.

A pair of vertical walls 53 are provided at each end of the lower front side wall portion 39f on the work port 51 side in the left-right direction. The pair of vertical walls 53 extend in the vertical direction and the front-rear direction, respectively, and face each other in the left-right direction. Each vertical wall 53 is connected to each rear side wall portion 39r located on both sides in the vertical direction with respect to the lower front side wall portion 39f, and has a slit shape that divides the front side wall portion 39f and each rear side wall portion 39r. The end of the opening 37 on the work opening 51 side is closed. Both vertical walls 53 form an opening 55 having a work opening 51.

The configuration of the inner panel lower portion 3b of the present embodiment is the same as that of the first embodiment except that such an opening 55 is formed.

-Inner panel molding method-
FIG. 15 is a cross-sectional view of the molding apparatus 101 of the inner panel 3 according to the second embodiment. FIG. 16 is a perspective view showing the positions of the second gate G2 (side gate) set around the work opening 51 together with the inner panel 3 according to the second embodiment.

For molding the inner panel 3 according to the second embodiment, for example, the molding apparatus 101 shown in FIG. 15 is used. The configuration of the molding apparatus 101 is the same as that of the molding apparatus 101 for molding the inner panel 3 according to the first embodiment, except for the second gate G2. In the molding apparatus 101, the second gate G2 is provided on both the upper and lower sides of the lower portion 3b of the inner panel that forms the central portion in the left-right direction and the portion that forms the peripheral portion of the work opening 51. All of these second gates G2 are side gates.

As shown in FIG. 16, the second gate G2 of the portion for forming the peripheral portion of the work opening 51 is provided at both ends of the gate runner 121 extending in the vertical direction at a portion corresponding to the inside of the opening 55. .. Of these two second gates G2, the upper second gate G2 opens at a portion of the molding surfaces 105a and 107a in the molding die 103 that forms the lower side surface of the rear side wall portion 39r located above the opening 55. do. On the other hand, the lower second gate G2 opens to a portion of the molding surfaces 105a and 107a in the molding die 103 where the upper side surface of the rear side wall portion 39r located below the opening 55 is molded.

The inner panel 3 according to the second embodiment is molded by the same procedure as when molding the inner panel 3 according to the first embodiment using the molding apparatus 101. That is, by closing the molding die 103, a cavity 111 for molding the inner panel 3 is formed inside the molding die 103, and a side gate for supplying the molten thermoplastic resin R to the cavity 111. The first gate G1, the second gate G2, and the third gate G3 are formed, and the fiber reinforcing material Fb is contained in the cavity 111 from the first gate G1, the second gate G2, and the third gate G3 in a molten state. The thermoplastic resin R is injected at a predetermined timing. As a result, the cavity 111 is filled with the thermoplastic resin R, and the thermoplastic resin R is cooled and solidified in the molding die 103 to form the inner panel 3.

FIG. 17 is a conceptual diagram showing the orientation state of the fiber reinforced material Fb when the thermoplastic resin R containing the fiber reinforced material Fb is injected by the side gate SG. FIG. 18 is a conceptual diagram showing the orientation state of the fiber reinforced material Fb when the thermoplastic resin R containing the fiber reinforced material Fb is injected by the direct gate DG.

In the injection of the thermoplastic resin R by the direct gate DG, the gate cross-sectional area is relatively large. Therefore, as shown in FIG. 18, the orientation state of the fiber reinforcing material Fb contained in the thermoplastic resin R around the gate DG is different from that of the first portion P1 on the one surface side close to the gate DG in the inner panel 3. , The third site P3 on the other surface side away from the gate DG and the second site P2 between the first site P1 and the third site P3 exhibit different aspects. Further, in the second portion P2 and the third portion P3, the orientation of the fiber reinforcing material Fb is not determined and tends to vary easily. Here, the first part P1, the second part P2, and the third part P3 are the positions of the respective parts when the peripheral part of the gate in the inner panel 3 is divided into three equal parts in the thickness direction.

On the other hand, in the injection of the thermoplastic resin R by the side gate SG, the gate cross-sectional area is relatively small. When the gate cross-sectional area is relatively small, the orientation of the fiber reinforcing material Fb is aligned to some extent in the process of the thermoplastic resin R passing through the gate SG. Therefore, as shown in FIG. 17, the orientation state of the fiber reinforcing material Fb contained in the thermoplastic resin R around the gate SG is the first portion P1 on one surface side and the other surface in the inner panel 3. The third site P3 on the side and the second site P2 between the first site P1 and the third site P3 exhibit a similar aspect. When the side gate SG is used in this way, the orientation of the fiber reinforcing material Fb contained in the thermoplastic resin R is stabilized.

-Effect of the second embodiment-
According to the back door 1 of the present embodiment, a work opening 51 opened rearward is formed in the lower portion 3b of the inner panel separately from the slit-shaped opening 37. Therefore, the work opening 51 is used as a hand space for the wiper device. Maintenance of equipment parts such as and latches can be facilitated.

According to the back door 1 of the present embodiment, a work port 51 is formed on the lower front side wall portion 39f, and a vertical wall 53 provided at each end on the work port 51 side in the left-right direction of the front side wall portion 39f. However, since the opening 55 is formed by connecting with the rear side wall portions 39r on both the upper and lower sides, the rigidity of the periphery thereof can be increased even if the work opening 51 is provided. Further, the divided wall portions 39f and 39r in which the work port 51 is not formed are advantageous in reducing thermal expansion and contraction of the inner panel lower portion 3b in the left-right direction.

According to the molding method of the inner panel 3 of the present embodiment, the working port is formed with respect to the portion of the cavity 111 formed inside the molding die 103 in the closed mold state where the peripheral portion of the working port 51 of the inner panel 3 is molded. Since the molten thermoplastic resin R containing the fiber reinforcing material Fb is injected from the portion corresponding to the inside of the 51 by the second gate G2 which is the side gate SD, the thermoplastic resin R is injected into the cavity 111 by the direct gate DG. The orientation of the fiber reinforcing material Fb is more stable from the vicinity of the second gate G2 as compared with the case of injecting into. This is advantageous for reducing thermal expansion and contraction of the inner panel lower portion 3b in the left-right direction.

<< Modified example of the second embodiment >>
FIG. 19 is a perspective view conceptually showing the position of the second gate G2 (side gate) set around the work port 51 of the inner panel 3 according to the modified example of the second embodiment. FIG. 20 is a perspective view conceptually showing the position of the second gate G2 (side gate) set around the work port 51 of the inner panel 3 according to the modified example of the second embodiment.

In the molding die 103 of the inner panel 3 in the second embodiment, the second gate G2 at the portion where the peripheral portion of the work port 51 is molded is located on both the upper and lower sides of the opening 55 on the molding surfaces 105a and 107a. It is assumed that the side wall portion 39r is opened at a portion where the side surfaces facing each other are formed. However, as shown in FIG. 19, the second gate G2 extends a portion corresponding to the inside of the opening portion 55 in the left-right direction. It may be provided at both ends of the. In this case, the two second gates G2 are opened in the molding surfaces 105a and 107a of the molding die 103 at the portions where the vertical walls 53 located on the left and right sides of the opening 55 are molded.

Further, as shown in FIG. 20, the second gate G2 may be provided at each end of the gate runner 121 extending in a cross shape in the vertical direction and the horizontal direction at a portion corresponding to the inside of the opening 55. .. In this case, the second gates G2 provided at both ends of the gate runner 121 extending in the left-right direction are formed by a pair of rear side wall portions 39r located on both upper and lower sides of the opening 55 on the molding surfaces 105a and 107a of the molding die 103. Each side surface facing each other is opened to a portion to be molded. The second gates G2 provided at both ends of the gate runner 121 extending in the vertical direction are opened at the portions of the molding surfaces 105a and 107a of the molding die 103 where the vertical walls 53 located on the left and right sides of the opening 55 are formed. do.

As described above, a preferred embodiment has been described as an example of the technique of the present disclosure. However, the technique of the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. are made as appropriate. In addition, the components described in the attached drawings and the detailed description may include components that are not essential for solving the problem. Therefore, it should not be immediately determined that those non-essential components are essential by the fact that those non-essential components are described in the accompanying drawings and detailed description.

For example, in the above embodiment, an example is shown in which there are two convex portions 35 provided on the bottom wall 27b of the concave portion 27, but the technique of the present disclosure is not limited to this. The number of ridges 35 may be one, or three or more.

In the above embodiment, the bridge-shaped portion 45 connecting the side wall 27s of the concave portion 27 and the outer standing wall 17 is arranged in a horizontal direction in line with the rear side wall portion 39r. Not limited to. The bridge-shaped portion 45 may be arranged so as to be displaced in the vertical direction with respect to the rear side wall portion 39r, or may extend in an oblique direction with respect to the vertical and horizontal directions. Further, the bridge shape portion 45 is preferably provided as in the above embodiment, but may not be provided.

In the above embodiment, the bottom wall 27b of the concave portion 27 has a concave-convex shape in a vertical cross section, but the technique of the present disclosure is not limited to this. The bottom wall 27b of the concave portion 27 may have another shape such as a flat plate as long as it has a horizontally long divided wall portion 39 divided in the vertical direction by a slit-shaped opening 37 extending in the left-right direction. ..

In the above embodiment, the outer panel 7 is a single resin panel, but the technique of the present disclosure is not limited to this. The outer panel 7 may be divided into an upper panel facing the inner panel upper portion 3a and a lower panel facing the inner panel lower portion 3b. Further, although the window panel 9 is a panel separate from the outer panel 7, it may be integrated with the outer panel 7, that is, it may be composed of a part of the outer panel 7.

As described above, the technique of the present disclosure is useful for a vehicle back door in which an inner panel made of a thermoplastic resin containing a fiber reinforcing material supports an outer panel.

Fb Fiber Reinforcement R Thermoplastic Resin 1 Back Door 3 Inner Panel 3a Inner Panel Upper 3b Inner Panel Lower 5 Cover Panel 7 Outer Panel 9 Window Panel 11 Window Opening 13 Inner Standing Wall 15 Inner Joint Piece 17 Outer Standing Wall 19 Outer Joint Piece 21 Hinge mounting part 23 Reinforcing rib 25 Latch mounting part 27 Concave part 27b Bottom wall of concave part 27s Side wall of concave part 29 Window opening 31 Adhesive 33 Fitting part 35 Convex part 37 Opening 39 Divided wall part 39f Front side wall part (Split wall)
39r rear side wall (split wall)
41 Center connection 43 Groove 45 Bridge shape 51 Work port 53 Vertical wall 55 Opening

Claims (7)

A vehicle back door in which an inner panel (3) located inside the vehicle and an outer panel (7) located outside the vehicle are joined to form a window opening (11) in the inner panel (3).
The inner panel (3) is an injection-molded product made of a thermoplastic resin (R) containing a fiber reinforcing material (Fb).
A slit-shaped opening (37) extending in the left-right direction is formed in the lower part (3b) of the inner panel, which is a portion of the inner panel (3) below the window opening (11).
The lower portion (3b) of the inner panel is a vehicle back door characterized by having a horizontally long divided wall portion (39) extending in the left-right direction, which is divided in the vertical direction by the opening (37). In the vehicle back door according to claim 1.
The lower portion (3b) of the inner panel is provided with a concave portion (27) that is recessed from the inside of the vehicle toward the outer panel (7) and is covered with the cover panel (5) from the inside of the vehicle.
The opening (37) is formed in the bottom wall (27b) of the concave portion (27).
The divided wall portion (39) is a back door for a vehicle, which comprises a bottom wall (27b) of the concave portion (27). In the vehicle back door according to claim 2.
At both left and right ends of the inner panel lower portion (3b) in the left-right direction, an outer standing wall (17) rising to the outer panel (7) side is spaced from the side wall (27s) of the concave portion (27) in the left-right direction. Opened up,
A vehicle characterized in that a bridge-shaped portion (45) connecting the side wall (27s) of the concave portion (27) and the outer standing wall (17) is provided on the lower portion (3b) of the inner panel. For backdoor. In the vehicle back door according to claim 3.
The vehicle back door is characterized in that the bridge-shaped portion (45) is arranged in a horizontal line with the divided wall portion (39) in the horizontal direction. In the vehicle back door according to any one of claims 1 to 4.
A vehicle back door characterized in that a work opening (51) opened rearward is formed at the lower portion (3b) of the inner panel separately from the slit-shaped opening (37). In the vehicle back door according to claim 5.
The lower part (3b) of the inner panel has a plurality of the divided wall portions (39).
The plurality of divided wall portions (39) are adjacent to each other in the vertical direction, the first divided wall portion (39) in which the work port (51) is formed and the first division wall portion (39) in which the work port (51) is not formed. Including the two-divided wall part (39)
Vertical walls (53) extending in the vertical direction and the front-rear direction are provided at each end on the work port (51) side in the left-right direction of the first division wall portion (39).
A vehicle back door characterized in that the vertical wall (53) is connected to the second divided wall portion (39) and constitutes an opening (55) having the work port (51). A window opening (11) is formed, and a slit-shaped opening (37) extending in the left-right direction is formed in the lower portion (3b) of the inner panel, which is a portion below the window opening (11), and the inner panel is formed. The lower portion (3b) has a horizontally long split wall portion (39) extending in the horizontal direction, which is divided in the vertical direction by the opening (37), and a work opening opened rearward in the lower portion (3b) of the inner panel. (51) is a method of forming an inner panel of a vehicle back door, which is formed separately from the opening (37).
By closing the molding die (103), a cavity (111) for molding the inner panel (3) is formed inside the molding die (103), and the inner of the cavity (111) is formed. A side gate (SG) for supplying a molten resin (R) from a portion corresponding to the inside of the work opening (51) with respect to a portion of the panel (3) to be molded around the work opening (51). ) Is formed, and a molten resin (R) containing a fiber reinforcing material (Fb) is injected from the side gate (SG) into the cavity (111).

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