JP7685906B2 - Vehicle back door - Google Patents

Description

The present invention relates to a vehicle back door.

Patent Document 1 discloses a plastic vehicle back door configured as a hatchback. This back door is configured with a pair of left and right skeletal structures including a pair of back door side portions, a pair of connecting portions, and a pair of beads. Each connecting portion is provided on the back door side portion. The cross-sectional shape of the back door side portion and the connecting portion is a U-shape that opens to the rear of the vehicle. The pair of beads each extend diagonally upward from both the left and right sides of the lock mechanism attachment portion to the connecting portion. The skeletal structure is continuous from a pair of hinge attachment portions provided at the top of the back door to the lock mechanism attachment portion provided at the bottom of the back door.

JP 2018-012500 A

In a hatchback-type back door as disclosed in Patent Document 1, rubber abutments provided on both left and right ends of the lower end of the door body are abutted against the vehicle body when the rear opening of the vehicle body is closed. This causes a repulsive force of the abutments to act on the lower part of the back door. Also, when closing the back door from an open state, the user presses down on the lower part of the back door. In this case, the closing force is often applied by placing a hand on either the left or right side of the lower part of the back door. When the repulsive force or closing force of the abutments acts on either the left or right side of the lower part of the back door in this way, there is a risk of deformation of the door body.

The purpose of the present invention is to prevent the door body from being deformed by forces acting on the bottom of the back door.

In order to achieve the above objective, the present invention has devised a structure for the inner panel that, when an external force is applied to the lower part of either the left or right side of the back door, transmits the external force in the left-right direction and disperses it.

Specifically, the first invention is a vehicle back door that is formed by joining a resin inner panel and a resin outer panel facing each other and has a door body with a window provided in the upper half. The upper end of the door body is connected to the vehicle body via a hinge, and the rear opening of the vehicle body is opened and closed by vertical rotation around the hinge. Abutments are provided at both left and right ends of the lower end of the door body that come into contact with the vehicle body when the door body closes the rear opening of the vehicle body.

In the vehicle back door of the first invention, an outer peripheral skeletal structure having a stepped cross section is formed on the outer peripheral portion of the inner panel. A curved arch-shaped lower skeletal structure is provided on the inner panel below the window portion so as to protrude upward from a lower edge portion of the outer peripheral skeletal structure that extends to the lower end of the door body. The central portion of the lower skeletal structure is positioned above and spaced from the lower edge portion of the outer peripheral skeletal structure, and both end portions of the lower skeletal structure are connected to both end portions of the lower edge portion of the outer peripheral skeletal structure.

The second invention is a vehicle back door according to the first invention, in which the lower framework structure has a hollow convex bead-shaped portion protruding toward the outer panel and a rib-shaped portion formed continuous with the bead-shaped portion. Both end portions of the lower framework structure are formed by the rib-shaped portion and overlap the outer peripheral framework structure.

The third invention is a vehicle back door according to the first or second invention, in which the upper portion of the lower edge portion of the outer peripheral skeletal structure is formed by a step-forming wall having a width in the front-rear direction. A concave recess portion is provided between the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure, the step-forming wall being recessed upward. The top surface portion of the recess portion is formed by a wall constituting the lower skeletal structure.

The fourth invention is a vehicle back door according to any one of the first to third inventions, in which a plurality of contact ribs protruding toward the outer panel are provided on a portion of the inner panel between the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure. The plurality of contact ribs each extend in the vertical direction and are spaced apart from each other in the horizontal direction. Both ends of the contact rib are connected to the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure. The tip of the contact rib is located near the rear surface of the outer panel.

The fifth invention is a vehicle back door according to the fourth invention, in which the upper portion of the lower edge portion of the outer peripheral skeletal structure is formed by a step-forming wall having a width in the front-rear direction. A concave recess portion is provided between the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure, the step-forming wall being recessed upward. The contact rib is connected to a wall that constitutes the rear portion of the recess portion.

The sixth invention is a vehicle back door according to any one of the first to fifth inventions, in which the lower frame structure extends through the center of each divided area obtained by dividing the portion of the door body below the window in the left-right direction, and has a partial adhesive portion at each central area of the divided area. The inner panel is bonded to the outer panel at the partial adhesive portion.

In the first invention, a peripheral skeletal structure is formed on the outer periphery of the inner panel. The peripheral skeletal structure has a stepped cross-sectional shape, which increases the rigidity of the inner panel. An arch-shaped lower skeletal structure is provided in the portion of the inner panel below the window portion. The central portion of the lower skeletal structure is positioned above and spaced from the lower edge portion of the peripheral skeletal structure, and both end portions are connected to both end portions of the lower edge portion of the peripheral skeletal structure. When the repulsive force of the contact portion or the closing force acts on either the left or right side of the lower part of the back door, this lower skeletal structure transmits and disperses these forces in the left and right directions at the lower part of the back door. This makes it possible to suppress deformation of the door body due to forces acting on the lower part of the back door.

In the second invention, both end portions of the lower skeletal structure that are connected to both end portions of the lower edge of the outer skeletal structure are formed by rib-shaped portions. If both end portions of the lower skeletal structure are formed by bead-shaped portions, the shape of the outer skeletal structure would be destroyed by the bead-shaped portions, weakening the rigidity of the outer skeletal structure, and therefore they cannot be provided overlapping the outer skeletal structure. In contrast, if both end portions of the lower skeletal structure are formed by rib-shaped portions, these end portions can exist without destroying the shape of the outer skeletal structure, and therefore can be provided overlapping the outer skeletal structure. This is advantageous in dispersing the repulsive force or closing force of the contact portion acting on either the left or right side of the lower part of the back door in the lower part of the back door.

In the third invention, a concave recess is provided between the lower edge portion of the outer peripheral frame structure and the lower frame structure by recessing the step-forming wall constituting the upper portion of the lower edge portion of the outer peripheral frame structure upward. The portion of the inner panel between the lower edge portion of the outer peripheral frame structure and the lower frame structure is reinforced by the three-dimensional shape of the recess. This increases the rigidity of the lower portion of the door body.

In the fourth invention, a plurality of support ribs are provided in the portion of the inner panel between the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure. The portion of the inner panel between the lower edge portion of the outer peripheral skeletal structure and the lower skeletal structure is connected and reinforced by the plurality of support ribs. This ensures the rigidity of the support ribs themselves. This also increases the rigidity of the lower portion of the door body.

In addition, when closing the back door from an open state, a downward force is applied to the bottom of the back door, which can cause the outer panel to deform and bend towards the inner panel. When such deformation occurs in the outer panel, the deformed portion of the outer panel is received by the rigid contact rib, which prevents further deformation. Here, because the tip of the contact rib is located near the back surface of the outer panel, the amount of deformation of the outer panel can be reduced. This reduces the so-called squishy feeling that occurs when the outer panel is deformed and warped.

In the fifth invention, the contact rib is connected to the wall that constitutes the rear portion of the recess. With this, even if sink marks occur on the surface of the inner panel due to the provision of the contact rib, the sink marks are present on the inner surface of the recess and are therefore hidden from the inside of the vehicle by the wall that constitutes the front portion of the recess. Therefore, it is possible to prevent the appearance of the door body from being marred by sink marks that occur due to the provision of the contact rib.

In the sixth invention, the inner panel and the outer panel are bonded to each other at the center of each divided area that divides the lower part of the door body in the left-right direction, by a partial adhesive part of the lower framework structure. If the inner panel and the outer panel are not bonded to each other at the center of each divided area, when a downward force is applied to one of the left and right sides of the lower part of the back door when closing it from an open state, the outer panel will be displaced toward the inner panel in one divided area to which the downward force is applied, and will be twisted and deformed so as to be displaced away from the inner panel in the other divided area.

In contrast, when the inner panel and the outer panel are bonded at the partial adhesive portion of the lower frame structure, twisting deformation of the outer panel can be suppressed. The outer panel is used to form the exterior appearance of the vehicle body and does not contribute significantly to the rigidity of the door body, but by preventing the outer panel from easily displacing away from the inner panel, the outer panel can be made to contribute favorably to increasing the rigidity of the door body.

FIG. 2 is a perspective view of a vehicle back door. FIG. 2 is an exploded perspective view of the vehicle back door. FIG. 4 is a cross-sectional view of the back door taken along a line IV-IV in FIG. 3 . 4 is a cross-sectional view of the back door at a location corresponding to line VV in FIG. 3. 6 is a cross-sectional view of the back door taken along a line VI-VI in FIG. 3 . FIG. 7 is a cross-sectional view of the back door taken along a line corresponding to VII-VII in FIG. FIG. 8 is a cross-sectional view of the back door taken along a line corresponding to line VIII-VIII in FIG. 3 . 9 is a cross-sectional view of the back door taken along a line corresponding to line IX-IX in FIG. 3. 4 is a cross-sectional view of the back door taken along a line corresponding to XX in FIG. 3. 10 is a cross-sectional view of the back door taken along a line corresponding to line XI-XI in FIG. 3. FIG. 2 is a perspective view showing a main part of an inner panel.

An exemplary embodiment will be described in detail below with reference to the drawings. In the following embodiment, for ease of explanation, the front side in the longitudinal direction of the vehicle will be referred to as "front" and the rear side as "rear", the left side in the vehicle width direction facing the front of the vehicle will be referred to as "left" and the right side as "right", the upper side in the vehicle height direction will be referred to as "upper" and the lower side as "lower". In addition, unless otherwise specified as to whether the back door according to this embodiment is open or closed, the description will be given assuming a position with the rear opening of the vehicle closed.

The vehicle back door 1 of this embodiment is a back door that opens and closes from above and below. This back door 1 opens and closes a rear opening provided in the body of a hatchback vehicle by rotating it in the vertical direction. As shown in Figures 1 and 2, the back door 1 mainly comprises a door body 5 and a plurality of lamp units 90.

A window section 7 is provided in the upper half of the door body 5. Abutments 8 are provided at both left and right ends of the lower end of the door body 5, which come into contact with the vehicle body when the door body 5 closes the rear opening of the vehicle body. The door body 5 is made up of an inner panel 10 and an outer panel 60 joined together in a mutually opposing state, and includes a window panel 80 that forms the window section 7.

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

<Inner Panel>
The inner panel 10 is a one-piece resin panel. The inner panel 10 is molded, for example, by injection molding. The inner panel 10 is made of, for example, a thermoplastic resin containing a fiber reinforcement material. The material of the inner panel 10 may be polypropylene with glass fiber (PP-GF: Polypropylene Glass Fiber), polypropylene with carbon fiber (PP-GF: Polypropylene Carbon Fiber), polypropylene with cellulose nanofiber (PP-CNF: Polypropylene Cellulose Nanofiber), or the like.

As shown in FIG. 3, a window opening 12 is formed in the upper half of the inner panel 10. The window opening 12 is a generally trapezoidal opening extending in the left-right direction. The portion of the inner panel 10 above the window opening 12 (hereinafter simply referred to as the upper portion) forms the ceiling portion 9 of the door body 5. The portions of the inner panel 10 located on both the left and right sides of the window opening 12 form concave pillar portions 14 that open toward the rear. The portion of the inner panel 10 below the window opening 12 (hereinafter simply referred to as the lower portion) forms the lower portion of the door body 5.

An inner standing wall 16 is provided on the peripheral portion of the window opening 12 in the inner panel 10. The inner standing wall 16 rises rearward toward the outer panel 60. An inner joint piece 18 is provided at the rear end of the inner standing wall 16. The inner joint piece 18 protrudes inwardly into the window opening 12. Furthermore, an outer standing wall 20 is provided on the outer peripheral edge of the inner panel 10. The outer standing wall 20 rises rearward toward the outer panel 60. An outer joint piece 22 is provided at the rear end of the outer standing wall 20. The outer joint piece 22 protrudes toward the outer peripheral side of the inner panel 10.

A pair of hinge mounting parts 24 are provided on the outer standing wall 20 at the upper part of the inner panel 10. The outer standing wall 20 provided with the pair of hinge mounting parts 24 extends up, down, left and right, and forms the rear end portion at the upper part of the inner panel 10. The pair of hinge mounting parts 24 are formed at positions spaced apart from each other on both the left and right sides. As shown in FIG. 5, a hinge part 100 that is connected to the vehicle body is fixed from the front to the hinge mounting part 24 using a fastener 102 such as a bolt.

The upper end of the door body 5 is connected to the vehicle body via a pair of hinge parts 100 so that it can be opened and closed. The back door 1 rotates vertically around the hinge parts 100. Metallic upper reinforcements 25 are integrally provided on both the left and right sides of the inner panel 10 by insert molding. Each upper reinforcement 25 extends from the hinge mounting portion 24 of the inner panel 10 through the pillar portion 14 to a portion where a back door damper (not shown) is connected.

As shown in Figures 3 and 4, an upper service hole 26 is formed in the inner standing wall 16 at the top of the inner panel 10. The upper service hole 26 is a work opening that is used for connecting a harness to the high mount stop lamp unit 92, maintenance work, and the like. The inner standing wall 16 in which the upper service hole 26 is formed extends in the front-rear and left-right directions, and is formed so that the thickness direction corresponds to the top and bottom.

The upper service hole 26 is formed in the left-right central portion of the inner standing wall 16. The peripheral portion of the upper service hole 26 in the inner panel 10 is recessed upward. The cover member 84 is fitted into the recess 36 in the peripheral portion of the upper service hole 26 to close the upper service hole 26. The upper service hole 26 is closed from below by the cover member 84.

A number of support ribs 28 are further provided on the upper part of the inner panel 10. The support ribs 28 are arranged at intervals from one another in the left-right direction. Each support rib 28 protrudes toward the upper panel 62 and extends linearly in the front-rear direction. The tip of each of these support ribs 28 is located near the rear surface of the upper panel 62. When the upper panel 62 bends downward, it abuts against the support ribs 28 and is supported. This restricts the downward bending of the upper panel 62.

Of the multiple support ribs 28, some (three in this example) located in the middle in the left-right direction are formed to straddle the upper service hole 26. The upper service hole 26 is divided by the support ribs 28. Support ribs 28 are also formed on the edges on both the left and right sides of the upper service hole 26. Each support rib 28 formed on the edges on both the left and right sides of the upper service hole 26 corresponds to a recess 36 on the peripheral portion of the upper service hole 26, and is positioned so as to overlap the cover member 84.

As shown in FIG. 3, a latch mounting portion 29 is provided on the lower edge of the lower part of the inner panel 10. As shown in FIG. 10, a latch 34 is attached to the latch mounting portion 29. This latch 34 cooperates with a striker provided on the lower edge of the rear opening of the vehicle body to form a locking mechanism that locks the back door 1 in the closed state. A metal lower reinforcement 36 is integrally provided on the latch mounting portion 29 by insert molding.

As shown in FIG. 3, a parts mounting portion 30 is provided in the upper central portion of the lower part of the inner panel 10. A lamp for illuminating the license plate, a knob mechanism, and the like are attached to the parts mounting portion 30. A lower service hole 31 is formed below the parts mounting portion 30 of the inner panel 10. The lower service hole 31 is an opening used for installing the latch 34, performing maintenance work, and the like.

A stopper mounting portion 32 is formed on each of both left and right end portions of the lower end of the inner panel 10 (strictly speaking, the second wall 43 described below). A mounting hole 33 is formed in the stopper mounting portion 32. As shown in FIG. 8, a rubber stopper member 85 is inserted into the mounting hole 33 and attached to the stopper mounting portion 32. The stopper member 85 is exposed to the outside of the door body 5 and constitutes the abutment portion 8. The stopper member 85 serves to cushion the impact when the back door 1 is closed from an open state.

As shown in Figures 7 to 11, a recess 34 is formed in the portion of the inner panel 10 including the part mounting portion 30, recessed at the front and protruding to the rear. The lower service hole 31 is formed inside the recess 34. The opening of the recess 34 is closed from the front by a cover trim 86. As a structure for reinforcing the rigidity of the inner panel 10, a peripheral skeletal structure 40 is formed on the outer periphery of the inner panel 10. In addition, a lower skeletal structure 50 is formed on the lower part of the inner panel 10. The peripheral skeletal structure 40 and the lower skeletal structure 50 are connected to each other.

<Outer panel>
1 and 2, the outer panel 60 is divided into two parts, an upper panel and an lower panel. The outer panel 60 is composed of an upper panel 62 and a lower panel 64. The upper panel 62 and the lower panel 64 are each made of resin. The upper panel 62 and the lower panel 64 are molded, for example, by injection molding. The material used for the upper panel 62 and the lower panel 64 may be synthetic resin such as talc-containing polypropylene (PP-T: Polypropylene Talc) or a mixture of ethylene propylene diene methylene rubber (EPDM: Ethylene Propylene Diene Monomer).

As shown in FIG. 4, the upper panel 62 faces the upper part of the inner panel 10. The upper panel 62 forms the ceiling portion 9 of the door body 5 and constitutes a spoiler portion 66 that protrudes rearward. A lamp unit mounting portion 67 is provided at the rear end portion of the spoiler portion 66. A high mount stop lamp unit 92 is attached to the lamp unit mounting portion 67. The lower panel portion of the upper panel 62 that constitutes the lower portion of the spoiler portion 66 is folded back diagonally downward at the front side to constitute an upper joint piece 69.

As shown in Figures 4 and 5, the outer edge portion of the upper panel 62 is joined to the inner panel 10 using adhesive 75. Specifically, the front edge portion of the upper panel 62 is adhered to the outer joint piece 22 of the inner panel 10. The upper joint piece 69 constituting the lower edge portion of the upper panel 62 is adhered to the inner joint piece 18 of the inner panel 10. An internal space S is formed between the upper panel 62 and the inner panel 10 joined in this manner.

The lower panel 64 faces the lower part of the inner panel 10. Lamp unit mounting parts 68 are provided on both the left and right sides of the lower panel 64. A rear lamp unit 94 is attached to the lamp unit mounting parts 68. For example, the rear lamp unit 94 is fastened together at multiple points from the front to the outer joint piece 22 of the inner panel 10 and the lower panel 64 using fasteners 96 such as nuts.

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

The outer edge portion of the lower panel 64 is joined to the inner panel 10 using adhesive 75. Specifically, the lower joint piece 72 constituting the upper edge portion of the lower panel 64 is adhered to the inner joint piece 18 of the inner panel 10. The left and right edge portions and the lower edge portion of the lower panel 64 are adhered to the outer joint piece 22 of the inner panel 10. An internal space S is formed between the lower panel 64 and the inner panel 10 joined in this manner.

The window panel 80 is a horizontally long panel that extends across both the left and right ends of the back door 1. The window panel 80 is disposed between the upper panel 62 and the lower panel 64 to close the window opening 12 of the inner panel 10 and cover the opening of the pillar portion 14 of the inner panel 10. The window panel 80 is made of transparent resin such as polycarbonate (PC) or glass. Although not shown, a concealing layer made of black ceramics or the like is provided on the outer periphery of the window panel 80 to conceal the joint with the outer panel 60.

The outer edge portion of the window panel 80 is joined to the outer panel 60 and the inner panel 10 using adhesive 75. Specifically, the upper edge portion of the window panel 80 is adhered to the upper joint piece 69 of the upper panel 62. The lower edge portion of the window panel 80 is adhered to the lower joint piece 72 of the lower panel 64. Both left and right edge portions of the window panel 80 are adhered to the outer joint pieces 22 between the upper panel 62 and the lower panel 64 of the inner panel 10. An internal space S is formed between the window panel 80 joined in this manner and the pillar portion 14 of the inner panel 10.

A harness 98 that supplies power to lamp units 90 such as a high-mounted stop lamp unit 92 and a rear lamp unit 94 is laid in the internal space S between the outer panel 60 and the window panel 80 and the inner panel 10. The harness 98 is pulled into the internal space S through a grommet 38 from an opening 37 formed in the outer standing wall 20 at the top of the inner panel 10.

<Outer peripheral frame structure>
The peripheral skeletal structure 40 is provided over the entire peripheral portion of the inner panel 10. The peripheral skeletal structure 40 is formed into a stepped cross section by combining a plurality of step-forming walls 41. As shown in Figures 4 to 11, the peripheral skeletal structure 40 has a first wall 42, a second wall 43, and a third wall 44 as the step-forming walls 41. The first wall 42, the second wall 43, and the third wall 44 are formed continuously in this order from the outer periphery side of the inner panel 10 toward the window opening 12 side.

The first wall 42 constitutes the outer standing wall 20. The first wall 42 at the upper part of the inner panel 10 extends vertically and horizontally, with a thickness direction corresponding to the front-to-rear direction (see Figures 4 and 5). The first walls 42 at both the left and right sides of the inner panel 10 extend vertically and vertically, with a thickness direction corresponding to the left-to-right direction (see Figures 6 and 7). The first wall 42 at the lower part of the inner panel 10 extends vertically and horizontally, with a thickness direction corresponding to the up-to-down direction (see Figures 9 to 11).

The second wall 43 is connected at an angle to the end of the first wall 42 located on the vehicle interior side. The second wall 43 at the upper part of the inner panel 10 extends in the front-rear and left-right directions, with its thickness direction corresponding to the up-down direction (see Figures 4 and 5). The second wall 43 at the upper part of the inner panel 10 itself has a stepped cross section. The second walls 43 at both the left and right sides and the lower part of the inner panel 10 extend in the front-rear and left-right directions, with its thickness direction corresponding to the front-rear direction (see Figures 6, 7, and 9 to 11).

The third wall 44 is connected at an angle to the end of the second wall 43 on the window opening 12 side. The third wall 44 at the upper part of the inner panel 10 extends vertically and is provided opposite the first wall 42 in the front-to-rear direction (see Figures 4 and 5). The third walls 44 at both the left and right sides of the inner panel 10 extend vertically and front-to-rear and are provided opposite the first wall 42 in the left-to-right direction (see Figures 6 and 7). The third wall 44 at the lower part of the inner panel 10 extends vertically and front-to-rear and is provided opposite the first wall 42 in the top-to-bottom direction (see Figures 9 to 11).

As shown in Figures 9 to 11, the upper portion of the lower edge portion of the outer peripheral skeletal structure 40 that extends to the lower end of the door body 5 is formed by a third wall 44 at the lower part of the inner panel 10. This third wall 44 has a width in the front-to-rear direction. A pair of recesses 45 are provided between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50. The recesses 45 are located on both the left and right sides of the lower service hole 31. The recesses 45 are formed in a concave shape by recessing the third wall 44 at the lower part of the inner panel 10 upward.

The recess 45 is a hollow portion that protrudes rearward and opens downward. The recess 45 has a rear wall 46 and a front wall 47. The rear wall 46 constitutes the rear portion of the recess 45. The front wall 47 constitutes the front portion of the recess 45. The rear wall 46 and the front wall 47 face each other in the front-to-rear direction. The front wall 47 is provided with a support protrusion 48 that supports the cover trim 86 and reinforces the recess 45. The top surface portion 49 of the recess 45 is formed by the lower wall 54 that constitutes the lower framework structure 50.

<Lower frame structure>
3, the lower skeleton structure 50 is formed in a curved arch shape below the component mounting portion 30 of the inner panel 10 so as to extend upward from the lower side of the outer peripheral skeleton structure 40. The central portion of the lower skeleton structure 50 is positioned above and spaced apart from the lower side of the outer peripheral skeleton structure 40. Both end portions of the lower skeleton structure 50 are connected to both end portions of the lower side of the outer peripheral skeleton structure 40.

As also shown in Figures 8 to 11, the lower framework structure 50 has a bead-shaped portion 51 and a rib-shaped portion 55. The bead-shaped portion 51 extends in the left-right direction in the central area of the lower part of the inner panel 10. The bead-shaped portion 51 has a hollow convex shape that protrudes toward the lower panel 64. The bead-shaped portion 51 has an upper wall 52, a rear wall 53, and a lower wall 54. The upper wall 52, rear wall 53, and lower wall 54 are formed continuously in this order from top to bottom.

The upper wall 52 constitutes the upper portion of the bead-shaped portion 51. The upper wall 52 extends in the front-rear and left-right directions, and is provided so that its thickness direction corresponds to the up-down direction. The rear wall 53 constitutes the rear portion of the bead-shaped portion 51. The rear wall 53 is connected to the rear end of the upper wall 52 at an angle. The rear wall 53 extends in the up-down and left-right directions, and is provided so that its thickness direction corresponds to the front-rear direction. The lower wall 54 constitutes the lower portion of the bead-shaped portion. The lower wall is connected to the lower end of the rear wall at an angle. The lower wall 54 extends in the front-rear and left-right directions, and is provided so that it faces the upper wall 52 in the up-down direction.

The rib-shaped portions 55 are provided in pairs on both the left and right ends of the bead-shaped portion 51. Each of the pair of rib-shaped portions 55 is formed continuous with the bead-shaped portion 51. As shown in FIG. 12, both end portions of the lower frame structure 50 are formed by the rib-shaped portions 55. The rib-shaped portions 55 have a plurality of reinforcing ribs 56a (three reinforcing ribs 56a in this example). Each of the multiple reinforcing ribs 56a protrudes toward the lower panel 64 and extends linearly from the bead-shaped portion 51 toward the stopper mounting portion 32.

Each reinforcing rib 56a constituting the rib-shaped portion 55 is connected to the first wall 42, the second wall 43, and the third wall 44. In this way, both end portions of the lower skeletal structure portion 50 overlap with the outer skeletal structure portion 40 without destroying the shape of the outer skeletal structure portion 40. In addition, the multiple reinforcing ribs 56a are connected together by another reinforcing rib 56b provided to separate the bead-shaped portion 51 and the stopper mounting portion 32.

The bead-shaped portion 51 of the lower framework structure 50 extends through the center of each divided area RA, LA that divides the portion of the door body 5 below the window portion 7 into two in the left-right direction. The bead-shaped portion 51 has a pair of partial adhesive portions 57. The partial adhesive portions 57 are provided at both ends of the bead-shaped portion 51 in the left-right direction and are formed by the rear wall 53. The partial adhesive portions 57 are located in the center of each of the divided areas RA, LA. The inner panel 10 is bonded to the lower panel 64 at each of the partial adhesive portions 57 using adhesive 75.

A number of contact ribs 58 are provided in the portion of the inner panel 10 between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50. The contact ribs 58 are arranged at intervals from one another in the left-right direction. Each contact rib 58 protrudes toward the lower panel 64 and extends linearly in the up-down direction. The tip of each contact rib 58 is located near the rear surface of the lower panel 64. When the lower panel 64 bends forward, it comes into contact with and is supported by the contact rib 58. This restricts the forward bending of the lower panel 64.

The reinforcing ribs 56a constituting the rib-shaped portion 55 described above also play a role in restricting forward deflection of the lower panel 64, similar to the contact ribs 58. Reinforcing ribs 59 are provided in the vertical middle of some of the contact ribs 58. The reinforcing ribs 59 protrude on both the left and right sides of the contact rib 58 and extend over the entire height of the contact rib 58. The front end portion of the reinforcing rib 59 is connected to the bent portion of the inner panel 10, specifically the connection portion between the first wall 42 and the second wall 43 (see Figures 9 and 11).

Both ends of each contact rib 58 are connected to the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50. That is, the lower end of each contact rib 58 is connected to the first wall 42, the second wall 43, and the third wall 44 that form the lower edge portion of the outer peripheral skeletal structure 40. The upper end of each contact rib 58 is connected to the lower wall 54 of the lower skeletal structure 50. Some of the contact ribs 58 are provided in a portion of the inner panel 10 that corresponds to the recess portion 45. The base portion of the contact rib 58 is connected to the front wall 47 of the recess portion 45.

-Features of the embodiment-
In the back door 1 of this embodiment, a peripheral skeleton structure 40 is formed on the outer peripheral portion of the inner panel 10. The peripheral skeleton structure 40 has a stepped cross section, which increases the rigidity of the inner panel 10. An arch-shaped lower skeleton structure 50 is provided on the portion of the inner panel 10 below the window portion 7. In the lower skeleton structure 50, the center portion is located above the lower edge portion of the peripheral skeleton structure 40 with a gap therebetween, and both end portions are connected to both end portions of the lower edge portion of the peripheral skeleton structure 40. When the repulsive force or closing force of the abutment portion 8 acts on one of the left and right sides of the lower portion of the back door 1, the lower skeleton structure 50 transmits and disperses the force in the left and right directions at the lower portion of the back door 1. This makes it possible to suppress deformation of the door body 5 due to the force acting on the lower portion of the back door 1.

In the back door 1 of this embodiment, the lower skeletal structure 50 has both end portions connected to both end portions at the lower edge of the outer peripheral skeletal structure 40, which are formed by rib-shaped portions 55. If both end portions of the lower skeletal structure 50 are formed by bead-shaped portions 51, the shape of the outer peripheral skeletal structure 40 would be destroyed by the bead-shaped portions 51, which would weaken the rigidity of the outer peripheral skeletal structure 40, and therefore they cannot be provided overlapping the outer peripheral skeletal structure 40. In contrast, if both end portions of the lower skeletal structure 50 are formed by rib-shaped portions 55, these end portions can exist without destroying the shape of the outer peripheral skeletal structure 40, and therefore can be provided overlapping the outer peripheral skeletal structure 40. This is advantageous in dispersing the repulsive force or closing force of the contact portion 8 acting on either the left or right side of the lower part of the back door 1 at the lower part of the back door 1.

In the back door 1 of this embodiment, a concave recess 45 is provided between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50 by recessing the third wall 44 that constitutes the upper portion of the lower edge portion of the outer peripheral skeletal structure 40 upward. The portion of the inner panel 10 between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50 is reinforced by the three-dimensional shape of the recess 45. This increases the rigidity of the lower portion of the door body 5.

In the back door 1 of this embodiment, multiple support ribs 58 are provided in the portion of the inner panel 10 between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50. The portion of the inner panel 10 between the lower edge portion of the outer peripheral skeletal structure 40 and the lower skeletal structure 50 is connected and reinforced by the multiple support ribs 58. This ensures the rigidity of the support ribs 58 themselves. This also increases the rigidity of the lower portion of the door body 5.

In addition, when the back door 1 is closed from an open state, if a force is applied to push down on the bottom of the back door 1, the lower panel 64 may be deformed so that it bends toward the inner panel 10. When such deformation occurs in the lower panel 64, the deformed portion of the lower panel 64 is received by the rigid stop rib 58, restricting further deformation. Here, because the tip of the stop rib 58 is located near the back surface of the lower panel 64, the amount of deformation of the lower panel 64 can be reduced. This reduces the so-called squishy feeling that occurs when the lower panel 64 is deformed so as to warp.

In the back door 1 of this embodiment, the contact rib 58 is connected to the rear wall 53 of the recess 45. With this, even if the provision of the contact rib 58 causes a sink mark to appear on the surface of the inner panel 10, the sink mark is present on the inner surface of the recess 45 and is therefore hidden from the inside of the vehicle by the front wall 47 of the recess 45. Therefore, the provision of the contact rib 58 can prevent the appearance of the door body 5 from being marred by the sink mark.

In the back door 1 of this embodiment, the inner panel 10 and the outer panel 60 are bonded to each other at the central portion of each divided area Ra, RL that divides the lower part of the door body 5 in the left-right direction by the partial adhesive portion 57 of the lower framework structure 50. According to this, when the back door 1 is closed from the open state, as shown by the solid arrow in FIG. 1, a downward force applied to one side of the lower part of the back door 1 displaces the lower panel 64 in one divided area (divided area RA in the example shown in FIG. 1) in a direction toward the inner panel 10 (direction indicated by the virtual arrow), and in the other divided area (divided area LA in the example shown in FIG. 1) in a direction away from the inner panel 10 (direction indicated by the virtual arrow). This can suppress the occurrence of twisting deformation. As a result, the lower panel 64 can be favorably contributed to increasing the rigidity of the door body 5.

As described above, a preferred embodiment has been described as an example of the present invention. However, the present invention is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. It will be understood by those skilled in the art that the above-described embodiment is an example, that various further modifications are possible for each of the components, and that such modifications also fall within the scope of the present invention.

For example, the above embodiment may be configured as follows:

In the above embodiment, the peripheral skeletal structure 40 has three step-forming walls 41 (first wall 42, second wall 43, and third wall 44), but is not limited to this. The peripheral skeletal structure 40 may be composed of two step-forming walls 41, or may be composed of three or more step-forming walls 41. The peripheral skeletal structure 40 may adopt other structures that increase the rigidity of the inner panel 10 as long as they are provided in a cross-sectional shape.

In the above embodiment, the lower skeletal structure 50 has a bead-shaped portion 51 and a rib-shaped portion 55, but this is not limited thereto. The lower skeletal structure 50 may be composed of only the bead-shaped portion 51, or may be composed of only the rib-shaped portion 55. The lower skeletal structure 50 may adopt other structures that increase the rigidity of the inner panel 10, so long as it is formed in a curved arch shape that protrudes upward from the lower edge portion of the outer peripheral skeletal structure 40.

In the above embodiment, the outer panel 60 is configured as two separate bodies, the upper panel 62 and the lower panel 64, but this is not limited thereto. The outer panel 60 may be configured as a single panel.

As described above, the present invention is useful for vehicle back doors.

REFERENCE SIGNS LIST 1 back door 5 door body 7 window portion 8 abutment portion 10 inner panel 40 peripheral frame structure portion 44 third wall (step-forming wall)
45 Recessed portion 49 Top surface portion 50 Lower frame structure portion 51 Bead-shaped portion 54 Lower wall 55 Rib-shaped portion 57 Partially bonded portion 58 Contact rib 60 Outer panel 100 Hinge part RA, LA Divided area

Claims (4)

The door is provided with a door body (5) which is formed by joining a resin inner panel (10) and a resin outer panel (60) facing each other and has a window portion (7) provided in an upper half portion thereof;
The upper end of the door body (5) is connected to the vehicle body via a hinge part (100), and the door body opens and closes a rear opening of the vehicle body by vertical rotation about the hinge part (100).
A back door for a vehicle, the back door being provided at both ends in the left-right direction of a lower end of the door body (5) with abutment portions (8) that come into contact with a vehicle body when the door body (5) closes a rear opening of the vehicle body,
A peripheral frame structure (40) having a stepped cross section is formed on the peripheral portion of the inner panel (10),
a lower skeleton structure portion (50) having an arch shape curved so as to protrude upward from a lower edge portion of the outer peripheral skeleton structure portion (40) that extends to a lower end portion of the door body (5) is provided in a portion of the inner panel (10) below the window portion (7);
a central portion of the lower skeletal structure (50) is located above and spaced from the lower side portion of the outer skeletal structure (40), and both end portions of the lower skeletal structure (50) are connected to both end portions of the lower side portion of the outer skeletal structure (40);
the lower framework structure (50) has a hollow convex bead-shaped portion (51) protruding toward the outer panel (60) and a rib-shaped portion (55) formed continuously with the bead-shaped portion (51),
Both end portions of the lower skeleton structure (50) are formed by the rib-shaped portions (55) and overlap with the outer peripheral skeleton structure (40).
A vehicle back door. The door is provided with a door body (5) which is formed by joining a resin inner panel (10) and a resin outer panel (60) facing each other and has a window portion (7) provided in an upper half portion thereof;
The upper end of the door body (5) is connected to the vehicle body via a hinge part (100), and the door body opens and closes a rear opening of the vehicle body by vertical rotation about the hinge part (100).
A back door for a vehicle, the back door being provided at both ends in the left-right direction of a lower end of the door body (5) with abutment portions (8) that come into contact with a vehicle body when the door body (5) closes a rear opening of the vehicle body,
A peripheral frame structure (40) having a stepped cross section is formed on the peripheral portion of the inner panel (10),
a lower skeleton structure portion (50) having an arch shape curved so as to protrude upward from a lower edge portion of the outer peripheral skeleton structure portion (40) that extends to a lower end portion of the door body (5) is provided in a portion of the inner panel (10) below the window portion (7);
a central portion of the lower skeletal structure (50) is located above and spaced from the lower side portion of the outer skeletal structure (40), and both end portions of the lower skeletal structure (50) are connected to both end portions of the lower side portion of the outer skeletal structure (40);
an upper portion of the lower side portion of the outer circumferential skeletal structure (40) is formed by a step-forming wall (44) having a width in the front-rear direction,
a recess (45) formed by recessing the step-forming wall (44) upward is provided between the lower side portion of the outer peripheral skeleton structure (40) and the lower skeleton structure (50);
A vehicle back door, wherein a top surface portion (49) of the recess portion (45) is formed by a wall (54) constituting the lower framework structure (50). The door is provided with a door body (5) which is formed by joining a resin inner panel (10) and a resin outer panel (60) facing each other and has a window portion (7) provided in an upper half portion thereof;
The upper end of the door body (5) is connected to the vehicle body via a hinge part (100), and the door body opens and closes a rear opening of the vehicle body by vertical rotation about the hinge part (100).
A back door for a vehicle, the back door being provided at both ends in the left-right direction of a lower end of the door body (5) with abutment portions (8) that come into contact with a vehicle body when the door body (5) closes a rear opening of the vehicle body,
A peripheral frame structure (40) having a stepped cross section is formed on the peripheral portion of the inner panel (10),
a lower skeleton structure portion (50) having an arch shape curved so as to protrude upward from a lower edge portion of the outer peripheral skeleton structure portion (40) that extends to a lower end portion of the door body (5) is provided in a portion of the inner panel (10) below the window portion (7);
a central portion of the lower skeletal structure (50) is located above and spaced from the lower side portion of the outer skeletal structure (40), and both end portions of the lower skeletal structure (50) are connected to both end portions of the lower side portion of the outer skeletal structure (40);
a plurality of contact ribs (58) protruding toward the outer panel (60) are provided in a portion of the inner panel (10) between the lower side portion of the outer peripheral skeleton structure (40) and the lower skeleton structure (50);
The plurality of contact ribs (58) each extend in the up-down direction and are arranged at intervals in the left-right direction.
Both ends of the contact rib (58) are connected to the lower side portion of the outer peripheral skeleton structure (40) and the lower skeleton structure (50),
a tip end of the contact rib (58) is located near the rear surface of the outer panel (60);
an upper portion of the lower side portion of the outer circumferential skeletal structure (40) is formed by a step-forming wall (44) having a width in the front-rear direction,
a recess (45) formed by recessing the step-forming wall (44) upward is provided between the lower side portion of the outer peripheral skeleton structure (40) and the lower skeleton structure (50);
The back door for a vehicle, wherein the contact rib (58) is connected to a wall (46) constituting a rear portion of the recessed portion (45). The vehicle back door according to any one of claims 1 to 3 ,
The lower framework structure (50) has a hollow convex bead-shaped portion (51) protruding toward the outer panel (60),
the bead-shaped portion (51) extends through a central portion of each divided region (RA, LA) obtained by dividing a portion of the door body (5) below the window portion (7) in the left-right direction into two, and has a partial adhesive portion (57) in each central portion of the divided region (RA, LA);
The inner panel (10) is bonded to the outer panel (60) at the partial adhesive portion (57).

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