Resin back door inner

Abstract

To provide a rein back door inner capable of suppressing heat creep displacement due to deadweight and a load from a peripheral component in a state of being attached to a body of an automobile.SOLUTION: A resin back door inner 10 has a panel shape and forms a back door of an automobile together with a back door outer. In an outer peripheral portion of a weather strip contact groove 17 provided in the resin back door inner 10, a bead 18 extending from a hinge attachment seating surface 15 to a stopper rubber attachment seating surface 16 is provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a plastic back door inner, and more particularly to a technique for suppressing deformation of a plastic back door inner due to thermal creep. [Background technology]

[0002] In recent years, as part of efforts to reduce environmental impact by improving fuel efficiency in vehicle tailgates such as automobiles, at least one of the tailgate outer and tailgate inner components that make up the tailgate has been formed from resin, which is lighter than metal (see, for example, Patent Document 1).

[0003] Similarly, in order to improve fuel efficiency by reducing weight, attempts have been made to provide reinforcing members at predetermined positions such as on the back door inner panel (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-124346 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-148463 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the tailgate inner panel is made of resin as described above, it is necessary to consider not only simple rigidity (strength) but also rigidity against thermal creep. With a resin tailgate inner panel, there is a concern that its weight (its own weight) and the load from surrounding parts may cause significant thermal creep even under normal usage conditions (for example, when the vehicle is parked outdoors for a long time in the scorching sun of midsummer). When thermal creep occurs, the tailgate inner panel stretches downward due to its own weight and the load from surrounding parts. Depending on the amount of creep, this may interfere with the body, making it impossible to open or close the tailgate.

[0006] In this case, it is possible to provide a reinforcing structure to suppress thermal creep, but since there is still insufficient knowledge about thermal creep deformation due to the weight of this type of resin molded product and the load from surrounding parts, it is currently difficult to provide an appropriate reinforcing structure.

[0007] In view of the above circumstances, the technical problem to be solved in this specification is to provide a plastic tailgate inner that can suppress thermal creep deformation due to its own weight and loads from surrounding parts when attached to the body of an automobile. [Means for solving the problem]

[0008] The above-mentioned problems are solved by the resin back door inner of the present invention. That is, this back door inner is a panel-shaped resin back door inner that, together with the back door outer, constitutes the back door of an automobile, and is characterized in that a bead is provided on the outer periphery of the weatherstrip abutment groove, extending from the hinge mounting seat surface toward the stopper rubber mounting seat surface.

[0009] The inventors analyzed the thermal creep deformation of a plastic tailgate inner panel due to its own weight and loads from surrounding components, and verified the deformation behavior. As a result, they found that stress concentration occurs at the connection between the top and side sections of the tailgate inner panel, particularly near the hinge mounting surface, causing forward bending deformation starting from this stress concentration point. Furthermore, they found that this bending deformation triggers thermal creep deformation. In light of these findings, the present invention provides a bead extending from the hinge mounting surface toward the stopper rubber mounting surface on the outer periphery of the weatherstrip abutment groove of the tailgate inner panel. The provision of this bead eliminates or alleviates the stress concentration that occurs near the hinge mounting surface in conventional structures. Furthermore, the provision of this bead improves the rigidity of the tailgate inner panel against forward bending deformation. As a result of the above-mentioned action, the resin tailgate inner of the present invention can suppress forward bending deformation starting from the vicinity of the hinge mounting seat during thermal creep, thereby making it possible to prevent or suppress as much as possible the downward extension deformation (thermal creep deformation) that occurs as a trigger of this bending deformation.

[0010] In the resin back door inner according to the present invention, the surface of the bead may be smoothly connected to the hinge mounting seat surface via a convex curved surface.

[0011] In the case where a bead is provided on the back door inner as described above, if there is a step or corner between the longitudinal end of the bead and the hinge mounting surface, this step or corner may become a starting point for stress concentration, and the stress dispersion effect of providing the bead may not be fully exerted. In contrast, in the back door inner of the present invention, by smoothly connecting the surface of the bead with the hinge mounting surface, it is possible to avoid stress concentration at the boundary between the bead surface and the hinge mounting surface and to enjoy the desired effect (stress dispersion effect) of providing the bead.

[0012] In the resin back door inner according to the present invention, the bead may be provided over the entire area from the hinge mounting seat surface to the stopper rubber mounting seat surface.

[0013] As described above, one of the effects of providing the bead according to the present invention is to avoid stress concentration occurring near the hinge mounting surface. In view of this, by providing the bead as long and continuously as possible, the stress described above is made lower and more uniform (dispersed). Therefore, with this configuration, it is possible to more reliably prevent forward bending deformation due to stress concentration. [Effects of the Invention]

[0014] As described above, the resin back door inner according to the present invention can suppress thermal creep deformation due to its own weight and the load from surrounding parts when attached to the body of an automobile. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of a main portion of a resin back door inner according to an embodiment of the present invention. [Figure 2] 2 is a side view of a main part of the back door inner shown in FIG. 1. [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A resin back door inner according to one embodiment of the present invention will now be described with reference to the accompanying drawings.

[0017] 1 shows a perspective view of a main part of a back door inner 10 according to one embodiment of the present invention. The back door inner 10 is made of resin and constitutes a back door for an automobile together with a back door outer (not shown). The back door inner 10 and the back door outer are fixed to each other by, for example, adhesive.

[0018] 1, the back door inner panel 10 includes a window glass opening 11, an upper edge portion 12 that extends in the width direction and defines the upper side of the window glass opening 11, side edge portions 13 that extend in the vertical direction and define both the left and right sides of the window glass opening 11, and a lower edge portion 14 that defines the lower side of the window glass opening 11. Hinge mounting bearing surfaces 15 are provided on both widthwise ends of the upper edge portion 12, and a stopper rubber mounting bearing surface 16 is provided on the lower ends of the side edge portions 13.

[0019] Meanwhile, weatherstrip abutment grooves 17, against which a weatherstrip (not shown) abuts, are provided around the periphery of the window glass opening 11, from the upper edge 12 to the side edge 13, and further from the side edge 13 to the lower edge 14. In this case, the hinge mounting seat surface 15 is located above a portion 17a of the weatherstrip abutment groove 17 that is provided at the upper edge 12. The stopper rubber mounting seat surface 16 is located outside (outside in the width direction) a portion 17b of the weatherstrip abutment groove 17 that is provided at the side edge 13.

[0020] When the back door inner panel 10 has the above-described configuration, a bead 18 extending from the hinge mounting seat surface 15 toward the stopper rubber mounting seat surface 16 is provided on the outer periphery of the weatherstrip abutment groove 17 .

[0021] In this embodiment, as shown in FIG. 2, a surface 18a of the bead 18 on the front side of the vehicle body is smoothly connected to the hinge mounting seat surface 15 via a convex curved surface 19.

[0022] In this embodiment, the bead 18 is provided over the entire area from the hinge mounting seat surface 15 to the stopper rubber mounting seat surface 16. In this case as well, the surface 18a of the bead 18 is smoothly connected to the stopper rubber mounting seat surface 16.

[0023] Here, the longitudinal dimension of the bead 18 is greater than the longitudinal dimension of the outer peripheral portion 20 (shown by the two-dot chain line in FIG. 2) of the weatherstrip abutment groove 17 in the absence of the bead 18.

[0024] The shape of the bead 18 and the height at which it protrudes forward can be determined as desired, but for example, as shown in Figure 3, the protruding height of the bead 18, i.e., the fore-and-aft position of the surface 18a of the bead 18, may be set so that the distance t between the bead 18 and the opposing body side surface 2a (shown by a two-dot chain line in Figure 3) is as uniform as possible over the entire longitudinal area of ​​the bead 18.

[0025] As described above, in the plastic back door inner 10 according to this embodiment, a bead 18 extending from the hinge mounting seat 15 toward the stopper rubber mounting seat 16 is provided on the outer periphery of the weatherstrip abutment groove 17 provided in the back door inner 10. By providing the bead 18 in this manner, stress concentration that occurs near the hinge mounting seat 15 in conventional structures due to the weight of the back door inner 10 and loads from surrounding components when the back door inner 10 is attached to the vehicle body is eliminated or alleviated. Furthermore, providing the bead 18 improves the rigidity of the back door inner 10 against forward bending deformation. As a result of the above-described actions, the plastic back door inner 10 according to this embodiment can suppress forward bending deformation from the vicinity of the hinge mounting seat 15 as a base point during thermal creep, thereby making it possible to prevent or suppress, as much as possible, downward extension deformation (thermal creep deformation) triggered by this bending deformation.

[0026] Furthermore, as in this embodiment, by smoothly connecting the surface 18a of the bead 18 to the hinge mounting seat 15 via the convex curved surface 19, it is possible to avoid stress concentration at the boundary between the surface 18a of the bead 18 and the hinge mounting seat 15, and to enjoy the desired effect (stress dispersion effect) of providing the bead 18.

[0027] Although one embodiment of the present invention has been described above, the resin back door inner according to the present invention can also have configurations other than those described above within the scope of the invention. [Explanation of symbols]

[0028] 2a Surface (body side) 10 Resin back door inner 11 Window Glass Openings 12 Upper edge 13 Side edge 14 Lower edge 15 Hinge mounting surface 16 Stopper rubber mounting surface 17, 17a, 17b Weatherstrip contact groove 18 Beads 18a surface 19 Convex curved surface 20 Outer area t interval

Claims

[Claim 1] A panel-shaped resin back door inner that, together with a back door outer, constitutes a back door of an automobile. A resin back door inner is provided with a bead extending from the hinge mounting seat surface toward the stopper rubber mounting seat surface on the outer periphery of the weatherstrip abutment groove.

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