JP4693519B2 - back door - Google Patents

Description

  The present invention relates to an automobile back door.

2. Description of the Related Art Conventionally, a back door for an automobile is widely used in which an inner panel made of a glass fiber reinforced resin molded product and an outer panel made of a resin molded product are joined together by an adhesive. Glass fiber reinforced resin molded products have higher specific rigidity than steel plate products (high bending rigidity can be secured even with light weight), complex shapes that are difficult to process with steel plate products can be formed relatively easily, and mold costs are low Therefore, there are advantages such as being suitable for small-volume production.
JP 2000-247148 A

  An important characteristic required for the back door is safety performance at the time of a rear collision, that is, prevention of breakage of the back door.

  In the conventional back door, the steel plate reinforcing member is attached to the inner panel or the outer panel so as to ensure safety at the time of rear collision. However, in this structure, the plate thickness of the steel plate is increased in order to ensure safety at the time of a rear collision, and furthermore, a large number of steel plate reinforcing members are fixed with mounting screws, increasing the weight of the back door, This is a factor of cost increase.

  Further, Patent Document 1 discloses a structure in which a reinforcing material is provided on the outer surface of the window frame portion of the inner member. However, in this structure, the reinforcing material is exposed, and thus the appearance of the back door is impaired. There's a problem.

  An object of the present invention is to ensure high appearance quality of a back door, suppress an increase in weight and cost of the back door, and suppress damage to the back door at the time of a rear collision.

  The invention according to claim 1 is a first reinforcing member formed to be extendable in a back door that is formed in a hollow shape by an inner panel and an outer panel, and that is openably and closably attached to a back door frame portion at the rear of the vehicle body. Are disposed along these panels between the inner panel and the outer panel, and both ends of the first reinforcing member are fixed to at least one of the inner panel and the outer panel. Backdoor characterized by.

  The invention according to claim 2 is the back door according to claim 1, wherein the first reinforcing member is a corrugated steel sheet.

  According to a third aspect of the present invention, in the back door according to the first or second aspect, the first door is provided with a window frame portion that is formed across the inner panel and the outer panel and holds the window panel. The member is characterized in that the extending and contracting direction extends along the vertical direction at the left and right side portions of the window frame portion.

  According to a fourth aspect of the present invention, in the back door according to the third aspect, a second reinforcing member provided on the inner panel for reinforcing a hinge mounting portion formed on an upper portion of the inner panel; A third reinforcing member provided on the inner panel below the second reinforcing member and below the window frame portion to reinforce the inner panel, and an upper end portion of the first reinforcing member Is fixed to the inner panel via the second reinforcing member, while the lower end of the first reinforcing member is fixed to the inner panel via the third reinforcing member It is characterized by.

  The invention according to claim 5 is the back door according to claim 2, wherein the first reinforcing member has a width in a range of 5 mm to 30 mm, a thickness in a range of 0.5 mm to 2.0 mm, The maximum amount of stretchable deformation is in the range of 100 mm to 250 mm.

  According to the present invention, the first reinforcing member formed to be extendable is disposed along these panels between the inner panel and the outer panel, and both ends of the first reinforcing member are the inner panel. Since it is fixed to at least one of the outer panel and the outer panel, it ensures high appearance quality of the back door, suppresses the back door weight increase and costs, and prevents damage to the back door at the time of rear collision. it can.

  An embodiment of the present invention will be described based on the drawings with reference to FIGS. This embodiment is an application example to a back door attached to the rear part of a wagon car that is an automobile.

  FIG. 1 is a perspective view showing a rear portion of an automobile provided with a back door of the present embodiment. As shown in FIG. 1, a back door 3 is attached to a back door frame 2 a formed at the rear of a vehicle body 2 of an automobile 1 so as to be opened and closed. A back door opening (not shown) is formed in the back door frame portion 2a. The back door opening is opened by opening the back door 3, and the back door opening is closed by closing the back door 3.

  A rear glass 4 which is a window panel is incorporated in the upper part of the back door 3, and a concave license plate mounting part 5 is formed in the lower part thereof. The back door 3 is rotatably provided with respect to the vehicle body 2 by a hinge 6 (see FIG. 2) attached to the upper portion of the back door 3. The back door 3 is locked to the vehicle body 2 by engaging a door side lock portion and a vehicle body side lock portion (both not shown) constituting the lock mechanism. Here, the top and bottom in the back door 3 are the top and bottom when the back door 3 is closed.

  FIG. 2 is a longitudinal side view showing a side portion of the back door 3. FIG. 2 shows an AA cross section in FIG. As shown in FIG. 2, the back door 3 includes an inner panel 11 and an outer panel 12 that are opposed to each other in the vehicle front-rear direction, and edges of the inner panel 11 and the outer panel 12 are joined by an adhesive 13. Is formed in a hollow shape.

  The material of the inner panel 11 is, for example, glass fiber reinforced resin, and the material of the outer panel 12 is, for example, resin.

  A hinge attachment portion 13 to which the hinge 6 is attached is formed on the upper portion of the inner panel 11.

  Further, a window frame portion 14 that holds the entire periphery of the rear glass 4 is formed over the inner panel 11 and the outer panel 12 at the upper portion of the back door 3. An opening (not shown) is formed in the window frame portion 14, and the opening is closed by the rear glass 4.

  Inside the left and right side portions 14a and 14b of the window frame portion 14, a first reinforcing member 15 is provided so as to extend in the vertical direction. Specifically, the first reinforcing member 15 is disposed along the panels 11 and 12 at a position spaced from the panels 11 and 12 between the inner panel 11 and the outer panel 12.

  The first reinforcing member 15 is formed in a bellows shape and can be expanded and contracted. Specifically, the first reinforcing member 15 is a corrugated steel sheet in which triangular corrugations are repeatedly and continuously formed in the vertical direction, and is formed in a long shape that is long in the vertical direction. Therefore, the expansion / contraction direction, which is the direction in which the bellows shape of the first reinforcing member 15 expands / contracts, is the vertical direction. The corrugated steel sheet is formed of, for example, a cold rolled steel sheet that has been subjected to a rust prevention treatment. The first reinforcing member 15 is stretched so that the triangular waveform is flattened by being pulled with a load greater than a predetermined size in a direction in which the upper end 15a and the lower end 15b, which are both ends thereof, are separated from each other. Plastic deformation.

  Here, the first reinforcing member 15 has a width in a range of 5 mm to 30 mm, a thickness in a range of 0.5 mm to 2.0 mm, and a maximum deformable elongation in a range of 100 mm to 250 mm. It is desirable that the maximum amount of stretchable deformation is 150 mm to 200 mm.

  The upper end portion 15 a of the first reinforcing member 15 is fixed to the inner panel 11 via the second reinforcing member 16, while the lower end portion 15 b of the first reinforcing member 15 is fixed to the third reinforcing member 17. It is being fixed to the inner panel 11 via.

  The second reinforcing member 16 is provided on the inner surface of the inner panel 11 along the hinge mounting portion 13 formed on the upper portion of the inner panel 11 and reinforces the hinge mounting portion 13. An upper end portion 15 a of the first reinforcing member 15 is fixed to the second reinforcing member 16 with a screw 18.

  The third reinforcing member 17 is provided below the second reinforcing member 16 and extends in the left-right direction below the window frame portion 14. The lower end portion 15 b of the first reinforcing member 15 is fixed to the third reinforcing member 17 with a screw 18.

  Next, the deformation of the back door 3 when the rear portion of the automobile 1 collides with an obstacle will be described with reference to FIG. Here, FIG. 3 is a longitudinal sectional side view showing a deformed state of the back door 3 at the time of a rear collision. As shown in FIG. 3, when the rear part of the automobile 1 collides with an obstacle and the lower part of the back door 3 is pushed and bent forward, the first reinforcing member 15 has its upper end part 15a as a fixed side. A load is input in a direction in which the lower end portion 15b is pulled diagonally forward and downward. When the tensile load is equal to or greater than a predetermined magnitude, the first reinforcing member 15 is stretched and plastically deformed by the tensile load to absorb the input load and suppress the breakage of the back door 3. When the tensile load is smaller than the prescribed size, the first reinforcing member 15 is elastically deformed by the tensile load to absorb the input load and suppress the breakage of the back door 3. Accordingly, a part of the components of the back door 3 is prevented from being separated from other components of the back door 3. Here, since the first reinforcing member 15 is formed in a bellows shape, the first reinforcing member has a larger amount of elongation than the case where the first reinforcing member is a flat steel plate. Therefore, damage to the back door 3 can be further suppressed as compared with the case of a flat steel plate.

  As described above, in the present embodiment, the first reinforcing member 15 formed to be stretchable is disposed along the panels 11 and 12 between the inner panel 11 and the outer panel 12. At the same time, the upper and lower end portions 15a and 15b, which are both ends of the first reinforcing member 15, are fixed to at least one of the inner panel 11 and the outer panel 12, thereby causing damage to the back door 3 at the time of rear collision. Can be suppressed. And in this structure, since only the upper end part 15a and the lower end part 15b of the 1st reinforcement member 15 are being fixed to inner panel 11, compared with the case where the intermediate part of a reinforcement member, etc. are also fixed to inner panel 11, An increase in weight and cost of the back door 3 are suppressed. In addition, since the first reinforcing member 15 is provided between the inner panel 11 and the outer panel 12, the first reinforcing member 15 is not exposed to the outside of the back door 3. That is, according to the present embodiment, it is possible to ensure high appearance quality of the back door 3 and suppress an increase in weight and cost of the back door 3 and suppress damage of the back door 3 at the time of a rear collision.

  Further, in the present embodiment, the first reinforcing member 15 is formed by extending the expansion / contraction direction along the vertical direction at the left and right side portions 14a and 14b of the window frame portion 14, thereby The reinforcement member 15 reinforces the window frame portion 14 and suppresses deformation of the window frame portion 14, thereby suppressing deformation of the entire back door 3.

  Moreover, in this Embodiment, since the hinge attachment part 13 is reinforced by the 2nd reinforcement member 16, damage to the hinge attachment part 13 is suppressed. Moreover, since the inner panel 11 at the lower part of the window frame part 14 is reinforced by the third reinforcing member 17, damage to the lower part of the window frame part 14 is suppressed.

  In the present embodiment, the first reinforcing member 15 has a width in the range of 5 mm to 30 mm, a thickness in the range of 0.5 mm to 2.0 mm, and a maximum deformable elongation of 100 mm to By being within the range of 250 mm, the deployment length of the first reinforcing member 15 can be sufficiently taken when a load is applied in the tensile direction to the first reinforcing member 15 in a collision, and the first reinforcing member 15 can be taken. The increase in weight can be suppressed.

  The present invention is not limited to this embodiment, and various other embodiments can be adopted without departing from the gist of the present invention.

  For example, in the present embodiment, an example has been described in which the upper end 15a and the lower end 15b, which are both ends of the first reinforcing member 15, are fixed to the inner panel 11, but the present invention is not limited to this. The upper end portion 15 a and the lower end portion 15 b of the reinforcing member 15 may be fixed to at least one of the inner panel 11 and the outer panel 12. That is, the upper end 15a and the lower end 15b of the first reinforcing member 15 may be fixed to the outer panel 12, or one end 15a or 15b is fixed to the inner panel 11 and the other end 15b or 15 a may be fixed to the outer panel 12.

  In the present embodiment, the upper and lower end portions 15a and 15b of the first reinforcing member 15 are fixed to the inner panel 11 by the second reinforcing member 16 and the third reinforcing member 17, but the first reinforcing member The fixing members that fix the upper and lower end portions 15a, 15b of the 15 to the inner panel 11 or the outer panel 12 are not limited thereto. Further, in the present embodiment, the fixing members (second reinforcing member, third reinforcing member) for fixing the upper and lower end portions 15a, 15b of the first reinforcing member 15 to the inner panel 11 or the outer panel 12 are the first. Although an example in which the reinforcing member 15 is a separate part has been described, the fixing member may be formed integrally with the first reinforcing member 15.

  Next, a first reinforcing member 15 and a comparative reinforcing member (hereinafter referred to as a comparative product) that can maintain the locked state of the door lock mechanism in a rear collision experiment under a predetermined condition are manufactured, and the weight and A cost comparison was made. The comparative product was a flat plate member made of a steel plate, and was fixed to the boss formed on the inner panel 11 with a tapping screw. The weight and cost (index) of the first reinforcing member 15 and the comparative product are shown in FIG.

  As shown in FIG. 4, in this comparison, the weight of the first reinforcing member 15 was 1.5 kg, whereas the weight of the comparative product was 2.7 kg. Further, when the cost (index) of the comparative product is 100, the cost (index) of the first reinforcing member 15 is 80. Thus, the first reinforcing member 15 of the present invention is for maintaining the locked state of the door lock mechanism in the rear surface collision experiment under a predetermined condition, that is, for preventing the back door 3 from being damaged. The increase in weight and cost can be suppressed as compared with the conventional reinforcing member.

It is a perspective view which shows the rear part of a motor vehicle provided with the back door of one Embodiment of this invention. It is a vertical side view which shows the side part of a back door. It is a vertical side view which shows the deformation | transformation state of the back door at the time of a rear surface collision. It is explanatory drawing which shows the comparison result of the weight and cost of the Example and comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Car body 2a Back door frame part 3 Back door 11 Inner panel 12 Outer panel 13 Hinge attachment part 14 Window frame part 14a Side part of window frame part 14b Side part of window frame part 15 1st reinforcement member 15a 1st reinforcement member Upper end portion 15b Lower end portion of first reinforcing member 16 Second reinforcing member 17 Third reinforcing member

Claims (1)

In the back door which is formed in a hollow shape by the inner panel and the outer panel, and is attached to the back door frame part at the rear part of the vehicle body so as to be freely opened and closed.
A first reinforcing member formed to be extendable is disposed along these panels between the inner panel and the outer panel, and both end portions of the first reinforcing member are disposed between the inner panel and the outer panel. And fixed to at least one of the
The first reinforcing member is a corrugated steel plate,
A window frame portion that is formed across the inner panel and the outer panel and holds the window panel,
The first reinforcing member is extended so that the expansion / contraction direction is along the vertical direction at the left and right side portions of the window frame portion,
A second reinforcing member provided on the inner panel for reinforcing a hinge mounting portion formed on an upper portion of the inner panel; and a lower portion of the window frame portion below the second reinforcing member. A third reinforcing member that is provided on the inner panel and reinforces the inner panel;
The upper end portion of the first reinforcing member is fixed to the inner panel via the second reinforcing member, while the lower end portion of the first reinforcing member is interposed via the third reinforcing member. A back door fixed to the inner panel .

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