JP2012066654A - Lower back structure for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lower back structure for an automobile which can enhance rigidity and strength of an extended part of an inner panel without causing problems such as increase in weight of a vehicle body and costs.SOLUTION: A bead 14 is formed in the extended part 10c of the inner panel 10. The bead 14 includes: a first bead part 14a facing flange parts (rear end parts) 3a-3c at a rear end of a rear side member 3 from a rear side of a vehicle; a second bead part 14b following the first bead part 14a and extending in the vehicle width direction; and a third bead part 14c following the second bead part 14b and extending within a closed cross section part 12.

Description

  The present invention relates to a lower back structure for an automobile provided with a lower back panel disposed in a rear end portion of a vehicle body and extending in the vehicle width direction.

  In general, a lower back panel of an automobile has a structure in which an inner panel and an outer panel form a closed cross section, and an extension that extends further downward from the lower edge of the outer panel is formed on the inner panel. And the rear-end part of the rear side member extended in the vehicle front-back direction is couple | bonded with an extension part (for example, refer patent document 1).

  By the way, since the extension portion of the inner panel is a single plate, it is necessary to increase the rigidity and strength of the extension portion with respect to the input from the rear side member. For example, it is conceivable to increase the thickness of the inner panel or arrange a separate rein hose in the extension.

JP 2002-331963 A

  However, in the conventional structure in which the thickness of the inner panel is increased or the separate rein hose is disposed, there is a problem that the weight of the vehicle body increases and the cost increases. In particular, it is a structure that is difficult to adopt in a small automobile where weight reduction and cost reduction are strongly desired, and there is room for studying a new structure for achieving weight reduction and cost reduction.

  The present invention has been made in view of the above-described conventional circumstances, and provides a lower back structure for an automobile that can increase the rigidity and strength of an extension portion of an inner panel without causing problems such as an increase in vehicle weight and cost. It is an issue.

  The present invention provides a lower back having a closed cross-section formed by joining an inner panel and an outer panel, and an extension formed integrally with the inner panel so as to extend below a lower edge of the outer panel. A lower back structure of an automobile in which a panel is disposed at a rear end portion of a vehicle body so as to extend in a vehicle width direction, and a rear end portion of a rear side member extending in a vehicle front-rear direction is coupled to the extension portion. A first bead portion facing the rear end portion of the rear side member, a second bead portion extending in the vehicle width direction following the first bead portion, and the closed bead portion following the second bead portion. A bead having a third bead portion extending in the direction is formed.

  According to the lower back structure according to the present invention, the bead formed in the extension portion of the inner panel includes the first bead portion facing the rear end portion of the rear side member, and the first bead portion extending in the vehicle width direction following the first bead portion. Since it has two bead parts and a third bead part that extends into the closed cross section following the second bead part, without increasing the thickness of the inner panel or providing a separate rein hose The rigidity of the extension part of the inner panel can be increased. As a result, the input from the rear side member can be distributed and transmitted to the closed cross-sectional portion of the lower back panel via the bead of the extension portion, thereby meeting the demand for light weight and low cost of the small vehicle.

It is a rear view of the lower back panel of the motor vehicle by Example 1 of this invention. It is sectional drawing (II-II sectional view taken on the line of FIG. 1) of the said lower back panel. FIG. 3 is a sectional view of the lower back panel (a sectional view taken along line III-III in FIG. 1). It is a perspective view of the inner panel of the said lower back panel.

  1 to 4 are views for explaining a lower back structure of an automobile according to a first embodiment of the present invention. In the description of this embodiment, front and rear and left and right mean front and rear and left and right when viewed in the forward direction from the rear of the vehicle, unless otherwise specified.

  In the figure, reference numeral 1 denotes a lower back portion of an automobile, which is disposed at a rear end portion of the vehicle body and extends in the vehicle width direction, and left and right rear side members 3, 3 extending in the vehicle front-rear direction. And a rear floor panel 4 disposed on the upper surface of the left and right rear side members 3. A back door opening edge is formed by the upper edge 2 ′ of the lower back panel 2.

  Wheel houses 5 and 5 are disposed at the left and right ends of the lower back panel 2 so as to cover the rear wheels (not shown), and rear fenders 6 and 6 are disposed outside the left and right wheel houses 5. Is arranged. The rear floor panel 4 is formed with a spare tire storage recess 4a bulging downward.

  The lower back panel 2 has a closed cross section 12 and an extension 10c. The closed cross-sectional portion 12 is formed by joining the upper flange portions 10a and 11a and the lower flange portions 10b and 11b of the inner panel 10 and the outer panel 11 each having a substantially cross-sectional hat shape by spot welding, and in the vehicle width direction. A closed section structure of a rectangular tube shape extending in the direction is formed.

  The inner panel 10 is divided into a vehicle width direction center portion 10 'and a left and right side portion 10' ', and the center portion 10' and the left and right side portions 10 '' are joined together by welding. It has become. Further, rear lamp mounting recesses 11d are formed on the left and right sides of the outer panel 11, respectively.

  The extension portion 10c is formed integrally with the lower flange portion 10b of the inner panel 10 so as to extend further downward than the lower flange portion 11b of the outer panel 11.

  Left and right flange portions 3a and 3b and a lower flange portion 3c formed at the rear ends of the left and right rear side members 3 are joined to the extension portion 10c by spot welding (see the crosses in FIG. 1). .

  The left and right extension portions 10c of the inner panel 10 are integrally formed with a bulge 14 that protrudes toward the rear of the vehicle. The bead 14 has a substantially semicircular cross section over its entire length.

The bead 14 includes a first bead portion 14a facing the left and right flange portions 3a and 3b and the lower flange portion 3c formed at the rear end portion of the rear side member 3 from the rear of the vehicle, and the first bead portion 14a. The first bead portion 14a has a second bead portion 14b extending in the vehicle width direction and a third bead portion 14c extending into the closed cross section 12 following the second bead portion 14b. When viewed, it is bent so as to form a substantially square shape passing between the right flange portion 3b and the lower flange portion 3c from between the left flange portion 3a and the lower flange portion 3c. This prevents the first bead portion 14a from interfering with the spot hitting point between the flange portion of the rear side member 3 and the extension portion 10c of the inner panel 10, and the rear side member 3 and the inner panel 10 are spot welded. It is definitely connected.

  The second bead portion 14b extends substantially linearly outward in the vehicle width direction following the first bead portion 14a.

  The third bead portion 14c extends in an upward curved manner following the second bead portion 14b, and passes through the lower wall portion 10e of the inner panel 10 following the extension portion 10c, and the middle of the vertical wall portion 10f in the vertical direction. (See FIGS. 3 and 4).

  In addition, a relief portion 11e is formed at the portion of the lower flange portion 11b of the outer panel 11 corresponding to the third bead portion 14c so as to surround the third bead portion 14c.

  According to the present embodiment, the wide bead 14 having a convex shape is formed on the extended portion 10 c of the inner panel 10, and the bead 14 is opposed to the flange portions 3 a to 3 c of the rear side member 3. 14a, a second bead portion 14b extending in the vehicle width direction following the first bead portion 14a, and a third bead portion 14c extending into the closed cross-sectional portion 12 following the second bead portion 14b. Therefore, the rigidity of the extension 10c of the inner panel 10 can be increased without increasing the thickness of the inner panel or providing a separate rein hose as in the prior art. As a result, the input from the rear side member 3 is distributed and transmitted to the closed cross section 12 of the lower back panel 2 via the bead 14 of the extension 10c, which meets the demand for weight reduction and cost reduction of a small vehicle. be able to.

  In this embodiment, the bead 14 extends from the rear end portion of the rear side member 3 in the vehicle width direction, and then is bent upward so as to extend into the closed cross section 12 of the inner panel 10. The rigidity of can be further increased.

  In the above embodiment, the first bead portion 14a is disposed so as to oppose the rear end portion of the rear side member 3. However, as shown by the two-dot chain line in FIGS. Subsequently, an extended bead portion 14 d extending upward may be formed in 14 a, and the extended bead portion 14 d may be arranged to extend into the closed cross-sectional portion 12. In this case, the extended bead portion 14d and the third bead portion 14c are coupled to the closed cross-sectional portion 12 with a gap in the vehicle width direction, and the rigidity of the extended portion 10c can be further increased. At the same time, it is possible to more reliably distribute the input.

2 Lower back panel 3 Rear side members 3a to 3c Flange (rear end)
DESCRIPTION OF SYMBOLS 10 Inner panel 10c Extension part 11 Outer panel 12 Closed cross-section part 14 Bead 14a 1st bead part 14b 2nd bead part 14c 3rd bead part

Claims (1)

A lower back panel having a closed cross-section formed by joining an inner panel and an outer panel, and an extension formed integrally with the inner panel so as to extend below a lower edge of the outer panel. Arranged at the rear end to extend in the vehicle width direction,
A lower back structure of an automobile in which a rear end member of a rear side member extending in the vehicle longitudinal direction is coupled to the extension portion,
The extended portion of the inner panel includes a first bead portion facing the rear end portion of the rear side member, a second bead portion extending in the vehicle width direction following the first bead portion, and the second bead portion. And forming a bead having a third bead portion extending into the closed cross section.

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