Back door

Abstract

[Problem] To provide a back door that suppresses bending behavior due to vibration of a vehicle. [Solution] A back door device 10 (back door) includes: a back door body including an inner panel 20 positioned on the vehicle interior side and an outer panel 30 positioned on the vehicle exterior side; back door glass 40 disposed in a window opening 31 (opening) formed in the back door body; and a joining part 60 for joining the back door body and the periphery of the back door glass. The back door body has a fragile portion having rigidity lower than that of the other portions. In the joining part, the joining strength of a joining portion at the position corresponding to the fragile portion is higher than the joining strength of the other joining portions.

Description

back door

[0001] The present invention relates to a back door.

[0002] A flip-up type tailgate device is known as one of the doors provided on the rear of a vehicle (see Patent Document 1). Patent Document 1 discloses a tailgate device having a resin inner panel, an outer panel, and a tailgate glass. The tailgate glass is bonded to the outer panel with a single adhesive.

[0003] Publication No. 2021-116056

[0004] The closed cross section formed by the inner panel and the outer panel is made relatively small to maintain the space inside the vehicle cabin. In the back door devices used in SUVs (Sport Utility Vehicles), etc., the closed cross section is made small to take into account various design factors such as ensuring the space inside the vehicle and the vehicle design, resulting in areas with low rigidity. As a result, the areas with low rigidity become weak parts and may bend due to vehicle vibrations, which may cause low sound absorption.

[0005] Therefore, an object of the present invention is to provide a back door that is prevented from bending due to vibrations of the vehicle.

[0006] In order to achieve the above-mentioned object, one aspect of the present invention provides a tailgate having a tailgate body including an inner panel located on the inside of the vehicle and an outer panel located on the outside of the vehicle, a tailgate glass placed in an opening formed in the tailgate body, and a joint that joins the tailgate body to the periphery of the tailgate glass, wherein the tailgate body has a weak part that is less rigid than other parts, and the joint strength of the joint at a position corresponding to the weak part is higher than the joint strength of other joints.

[0007] This configuration makes it possible to reinforce the weak portion at a location with low rigidity, thereby reducing vibration and deflection of the back door when vehicle vibrations are input to the back door. This makes it possible to provide a back door that is less likely to bend due to vehicle vibrations.

[0008] 2. A side view schematically showing a flip-up type back door device. 3. A rear view of the back door glass as seen from the rear of the vehicle. 4. A cross-sectional view along line 3-3 in FIG. 2. 5. A cross-sectional view along line 5-5 in FIG. 4.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown here are merely examples for embodying the technical concept of the present invention and are not intended to limit the present invention. Therefore, all other embodiments, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included within the scope and spirit of the present invention, as well as within the scope of the inventions set forth in the claims and their equivalents.

[0010] In addition, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically with the scale, aspect ratio, shape, etc. appropriately changed from the actual product, but these are merely examples and do not limit the interpretation of the present invention.

[0011] In this specification, ordinal numbers such as "first" and "second" may be used. However, unless otherwise specified, these ordinal numbers are used to identify components for the sake of convenience, and do not specify the number or order.

[0012] 1 and 2 show a flip-up type tailgate device 10 used in an SUV or the like. As also shown in FIGS. 3, 4, and 5, the tailgate device 10 has an inner panel 20 located on the vehicle interior side, an outer panel 30 located on the vehicle exterior side, and a tailgate glass 40 placed in a window opening 31 (corresponding to an opening) formed in the outer panel 30. A structure including the inner panel 20 and the outer panel 30 is referred to as a tailgate body. The inner panel 20 is formed, for example, from a composite material of PP resin (polypropylene) and glass fiber reinforced resin, and the outer panel 30 is formed, for example, from PP resin (polypropylene).

[0013] As shown in Figures 3, 4, and 5, the inner panel 20 and the outer panel 30 have a shape with a closed cross section 50 extending in the left-right direction of the vehicle at the front portion of the back door glass 40. As shown in Figures 3 and 4, when the door is closed, the closed cross section 50 is formed higher in the vehicle height direction than a head lining 51 that forms the ceiling surface. The rear visibility is determined by the head lining 51. Reference numeral 52 denotes a line indicating the rear visibility.

[0014] As shown in FIG. 1 , the back door device 10 includes a first panel portion 11 located at the rear of the vehicle and standing substantially upright, and a second panel portion 12 extending obliquely from the first panel portion 11 toward the front of the vehicle. The first panel portion 11 includes a striker 13 for a door lock device at its lower end in the vehicle height direction. The second panel portion 12 includes a hinge portion 14 at its front end toward the front of the vehicle. The back door glass 40 is joined to an outer panel 30 of the second panel portion 12. The closed cross section 50 formed by the inner panel 20 and the outer panel 30 is relatively small to maintain the space within the vehicle cabin. The closed cross section 50 of the first panel portion 11 is relatively large. The closed cross section 50 of the second panel portion 12 gradually becomes smaller toward the front of the vehicle. Reference numeral 15 in FIG. 1 denotes an arrow indicating the size of the closed cross section 50 at each portion.

[0015] 2, the back door device 10 has a joint 60 that joins the outer panel 30 and the periphery of the back door glass 40. In a rear view of the back door glass 40 seen from behind the vehicle, the joint 60 has an upper edge 61 located above in the vehicle height direction, a lower edge 62 located below in the vehicle height direction, and left and right side edge portions 63, 64 located in the left-right direction of the vehicle. In the back door device 10, the joint strength of the upper edge portion 61 is greater than the joint strength of the left and right side edge portions 63, 64.

[0016] The outer panel 30 can be joined to the periphery of the back door glass 40 by known methods such as bolt fastening or adhesive bonding. Differences in the joint strength between the top edge portion 61 and the left and right side edge portions 63, 64 can be created by, for example, varying the number and spacing of fastening bolts, varying the tightening torque, or varying the area of ​​adhesive application. Differences in joint strength can also be created by using different adhesives with different tensile adhesive strengths, peel adhesive strengths, etc.

[0017] As described above, the joint strength of the upper edge portion 61 of the joint 60 is higher than the joint strength of the left and right side edge portions 63, 64. This configuration increases the rigidity of the upper edge portion 61 compared to the left and right side edge portions 63, 64. This reduces vibration and deflection originating from the upper end of the tailgate glass 40 when vehicle vibrations are input to the tailgate device 10. As shown in FIG. 1 , in the tailgate device 10, the closed cross section 50 formed by the inner panel 20 and the outer panel 30 is relatively small at the upper edge portion 61 of the joint 60, making the portion indicated by reference numeral 16 prone to becoming a weak portion. This weak portion is located at a position corresponding to the side edge portions 63, 64 of the tailgate body, at a position at or a predetermined distance (e.g., 30 cm) below the vehicle height equal to the upper portion of the inner circumferential edge 31 a of the window opening 31 (described later). By setting the joint strength of the upper edge 61 of the joint 60 higher than the joint strength of the left and right side edge portions 63, 64, it is possible to compensate for the rigidity of the portion where the closed cross section 50 is small.

[0018] In addition, in the present embodiment, the weakened portion is described as being at a position where the thickness of the closed cross section formed by the inner panel 20 and the outer panel 30 in a side view is minimum, but the weakened portion may be formed by, for example, the area, shape, or plate thickness of the closed cross section. In addition, in the present embodiment, the weakened portion has lower rigidity than other portions against inputs in the vertical direction of the vehicle.

[0019] As shown in FIG. 2 , the upper edge portion 61 of the joint 60 includes a first upper edge portion 61a extending in the vehicle transverse direction and a second upper edge portion 61b positioned rearward of the first upper edge portion 61a and extending in the vehicle transverse direction. Both the first upper edge portion 61a and the second upper edge portion 61b are formed with adhesive, with the first upper edge portion 61a being a first adhesive and the second upper edge portion 61b being a second adhesive. This configuration allows for adhesively bonded portions between the highly rigid back door glass 40 and the outer panel 30 at two locations (two rows) in the vehicle transverse direction. This allows for a wider bonded surface, further enhancing the rigidity of the portion with a small closed cross section 50. Furthermore, adhesives are preferable to bolt fastening because they allow for continuous fixation.

[0020] We have described the first upper edge portion 61a extending in the left-right direction of the vehicle and the second upper edge portion 61b positioned rearward of the vehicle from the first upper edge portion 61a and extending in the left-right direction of the vehicle, but the first adhesive may be arranged along the periphery of the vehicle's tailgate glass 40, and the second adhesive may be arranged along the first adhesive.

[0021] As shown in Figures 3 and 4, the inner panel 20 and the outer panel 30 are joined via a first joint portion 71a and a second joint portion 71b. Both the first joint portion 71a and the second joint portion 71b are formed with an adhesive. The upper position of the second joint portion 71b is lowered as far rearward and downward in the vehicle height direction as possible without obstructing the rearward visibility 52. ​​As shown in Figure 2, the second joint portion 71b is positioned so as to surround the window opening 31 with a closed curve.

[0022] As shown in Figure 2, the bottom edge 62 and the left and right side edge portions 63, 64 of the joint 60 are all made of adhesive. The first top edge portion 61a, the left and right side edge portions 63, 64, and the bottom edge portion 62 are arranged to surround the window opening 31 with a closed curve. This configuration prevents water from entering the inside of the back door glass 40, thereby reducing the risk of watertightness problems caused by water droplets.

[0023] As shown in Figure 2, the distance L1 between the first upper edge portion 61a (first adhesive) and the second upper edge portion 61b (second adhesive) along the vehicle longitudinal direction is greater than the distance L2 between the second upper edge portion 61b and the inner peripheral edge 31a of the window opening 31 along the vehicle longitudinal direction. With this configuration, the second upper edge portion 61b is positioned near the inner peripheral edge 31a of the window opening 31. This further enhances the rigidity of the portion with a small closed cross section 50. Note that along the vehicle longitudinal direction includes the extending direction of the outer panel 30 at the joint.

[0024] As shown in FIG. 2 , the second upper edge portion 61b has an extension portion 61c that continues to the end portion in the vehicle's left-right direction. The extension portion 61c extends to the curved portion 41 at both ends of the back door glass 40 in the vehicle's left-right direction. With this configuration, the second upper edge portion 61b can increase the bonding surface three-dimensionally. This increases the rigidity of the portion where the closed cross section 50 is small. Furthermore, part or all of the extension portion 61c may extend in the vehicle's fore-and-aft direction. This further increases the rigidity of the portion where the closed cross section 50 is small. Note that "along the vehicle's fore-and-aft direction" includes the extension direction of the outer panel 30 at the joint (extension portion).

[0025] As shown in FIGS. 2 and 4 , the back door device 10 further includes a plurality of reinforcing ribs 80 disposed within the closed cross section 50 and extending in the vehicle longitudinal direction. As shown in FIG. 5 , the reinforcing ribs 80 are vertical ribs extending from the inner panel 20 in the vehicle height direction. The upper end of the reinforcing rib 80 has a flange portion 81 extending substantially parallel to the inner surface of the outer panel 30. The outer panel 30 and the flange portion 81 of the reinforcing rib 80 are joined via an adhesive 82. In a side view of the vehicle (or a cross section of the vehicle) viewed from the left-right direction of the vehicle, the first upper edge portion 61 a and the second upper edge portion 61 b ​​are positioned corresponding to the positions of the reinforcing ribs 80. This configuration allows the first upper edge portion 61 a and the second upper edge portion 61 b ​​to overlap the portion reinforced by the reinforcing ribs 80. This further improves the rigidity of the upper portion of the back door device 10.

[0026] The reinforcing rib 80 has a through hole in the center for passing a harness or the like through. Although the reinforcing rib 80 is shown as being formed separately from the inner panel 20, the reinforcing rib 80 can be molded from resin integrally with the inner panel 20. The reinforcing rib 80 can also be provided on the inner surface of the outer panel 30.

[0027] As shown in Figure 4, the reinforcing rib 80 has a generally triangular shape that matches the inner shape of the closed cross section 50. In a side view of the vehicle (or the vehicle cross section) viewed from the left-right direction of the vehicle, the second upper edge portion 61b is located at a position corresponding to the rear end 83 of the reinforcing rib 80. With this configuration, the reinforcing rib 80 is located above the headlining 51, and can support the outer panel 30 as far rearward as possible. This allows the back door device 10 to further improve rigidity without obstructing the rearward visibility 52.

[0028] The above disclosure discloses a means for increasing the rigidity of the upper edge portion 61 as a joint at a position corresponding to the weak portion, since the weak portion is located higher in the vehicle height direction to ensure a larger interior space. However, when the weak portion is located higher in the vehicle height direction of the back door device 10, a means for increasing the rigidity may be applied to the side edge portions 63, 64 of the vehicle, in a region close to the upper edge portion 61 (above the side edge portions 63, 64), as a joint at a position corresponding to the weak portion, rather than to the upper edge portion 61. Furthermore, the means may be applied to both the upper edge portion 61 and the upper side edge portions 63, 64. It goes without saying that a certain degree of effect can also be achieved by applying a similar measure to the lower edge portion 62 or the left and right side edge portions 63, 64 in a region close to the lower edge portion 62 (below the side edge portions 63, 64).

[0029] Furthermore, it is desirable that the means for increasing rigidity be provided at a position corresponding to the position of the weak portion. In addition to the above example, for example, if the weak portion is located lower in the vehicle height direction of the back door device 10, means for increasing rigidity may be applied to the lower edge portion 62 as a joint at a position corresponding to the weak portion. Furthermore, means for increasing rigidity may be applied not only to the lower edge portion 62 but also to the side edge portions 63, 64 of the vehicle, in a region close to the lower edge portion 62 (below the side edge portions 63, 64) as a joint at a position corresponding to the weak portion. Furthermore, means for increasing rigidity may be applied to both the lower edge portion 62 and below the side edge portions 63, 64.

[0030] The above describes an embodiment of the present invention, but the present invention is not limited to the configurations described in the above embodiment, and can be modified as appropriate based on the claims.

[0031] The following embodiments are also included within the scope of the present invention: a back door device 10 according to any one of claims 2 to 6 having the features of claim 7; and a back door device 10 according to any one of claims 3 to 6 having the features of claim 8.

[0032] 10 Back door device (back door) 11 First panel portion 12 Second panel portion 13 Striker 14 Hinge portion 20 Inner panel 30 Outer panel (back door main body including inner panel 20 and back door panel 30) 31 Window opening (opening) 31a Inner peripheral edge 40 Back door glass 41 Curved portion 50 Closed cross section 51 Headlining 52 Rear visibility 60 Joint portion 61 Upper edge portion 61a First upper edge portion (first adhesive) 61b Second upper edge portion (second adhesive) 61c Extension portion 62 Lower edge portion 63 Left side edge portion 64 Right side edge portion 71a First joint portion 71b Second joint portion 80 Reinforcing rib 81 Flange portion 82 Adhesive 83 Rear end portion

Claims

1. A back door including an inner panel located on the inner side of the vehicle and an outer panel located on the outer side of the vehicle, a back door glass disposed in an opening formed in the back door body, and a joint portion joining the back door body and the periphery of the back door glass, wherein the back door body has a vulnerable portion with lower rigidity than other portions, and the joint strength of the joint portion at a position corresponding to the vulnerable portion is higher than the joint strength of other joint portions.

2. The back door according to claim 1, wherein the joint portion at a position corresponding to the vulnerable portion has a first adhesive extending along the periphery of the back door glass and a second adhesive disposed on the opening side of the first adhesive and extending along the first adhesive.

3. In a rear view of the vehicle, the joint portion has an upper side portion located above in the vehicle height direction, a lower side portion located below in the vehicle height direction, and left and right side portions located in the vehicle left-right direction, and the first adhesive is a continuous adhesive spanning the upper side portion, the lower side portion, and the side portions in the joint portion.

4. The back door according to claim 2, wherein the interval along the vehicle front-rear direction between the first adhesive and the second adhesive is larger than the interval along the vehicle front-rear direction between the second adhesive and the inner peripheral end of the opening.

5. The back door according to claim 2, wherein the second adhesive has an extension portion that is continuous at the ends in the vehicle left-right direction and extends to the curved portions at both ends in the vehicle left-right direction of the back door glass.

6. The back door according to claim 5, wherein a part or all of the extension portion extends in a direction along the vehicle front-rear direction.

7. In a rear view of the vehicle, the joint portion has an upper side portion located above in the vehicle height direction, a lower side portion located below in the vehicle height direction, and left and right side portions located in the vehicle left-right direction, the vulnerable portion is disposed at a position corresponding to the side portion, and the joint portion at a position corresponding to the vulnerable portion is the upper side portion when the vulnerable portion is located above in the vehicle height direction in the side portion, and the lower side portion when the vulnerable portion is located below in the vehicle height direction in the side portion.

8. In a rear view of the vehicle, the joint portion has an upper side portion located above in the vehicle height direction, a lower side portion located below in the vehicle height direction, and left and right side portions located in the vehicle left-right direction. The weak portion is located at a position corresponding to the side portion and is disposed above the side portion in the vehicle height direction. The joint portion at the position corresponding to the weak portion is the upper side portion. The back door body has a shape having a closed cross section extending in the vehicle left-right direction at a front portion of the back door glass in the vehicle front direction. The back door body further has a plurality of reinforcing ribs disposed in the closed cross section and extending in the vehicle front-rear direction. In a side view of the vehicle, the first adhesive and the second adhesive are disposed corresponding to the position of the reinforcing rib. The back door according to claim 2, characterized in that.

9. In the side view of the vehicle, the closed cross section is disposed at the same height in the vehicle height direction as the position of the headlining forming the ceiling surface or above the position of the headlining in the vehicle height direction. The second adhesive is disposed corresponding to the position of the rear end portion of the reinforcing rib. The back door according to claim 8, characterized in that.

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