JP3287749B2 - Automobile cross member structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross member structure of an automobile provided between center pillars on both sides in a vehicle width direction on a front floor.

[0002]

2. Description of the Related Art As shown in FIG. 5, when a side collision occurs in the riding state of FIG. A, a cross-sectional force is generated in this kind of cross member 10, and the center pillar 3 penetrates (FIG. B).
Further, even after the cross-sectional force on the cross member 10 reaches the peak, the upper part of the center pillar 3 which is weak in strength enters, and the impact on the chest of the occupant 9 increases (FIG. C). The cross member 10 has a function of protecting the occupant from an impact by suppressing the penetration amount of the lower part of the center pillar at the time of a side collision, but in order to enhance the effect, a cross-section of the cross member is increased or a bulkhead is added inside the cross member. And so on.

[0003]

However, if such reinforcement is performed, on the other hand, the approach of the lower part of the center pillar is reduced, and the tip of the center pillar falls near the upper part, so that the amount of intrusion increases. Therefore, reinforcement near the upper part of the center pillar is also required.

SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to provide a cross member structure of an automobile which can suppress the amount of bite at the upper portion of the center pillar without reinforcing the body structure at the time of a side collision. I do.

[0005]

In order to achieve this object, according to the present invention, according to the present invention, a cross member structure of a vehicle provided in a vehicle width direction on a front floor between center pillars on both sides in the vehicle width direction. In the above, the cross member main body having a hat-shaped cross section whose flange at the lower end is welded to the front floor is terminated with a gap in the rocker immediately below the center pillar, and the gap overlaps with the outer surface of the end portion of the cross member main body. A sub-cross member having a U-shaped cross section having an idling portion connected so as to allow idling in the width direction is provided, and the wall surface is located at a position retreated by an idling stroke from an end position of the cross member body and an end position of the sub cross member. And a sub-cross member portion closer to the end than the idle portion is welded to the front floor or the rocker.

When a side collision occurs, a collision force is applied to the rocker and the front floor portion, which are the lower portion of the center pillar, due to the sub-cross member running idle, so that the sub cross member deforms and enters, and the amount of intrusion in the upper portion is reduced. . Furthermore, when a collision force is applied and both walls of the cross member collide with each other, idle running ends and stress is generated in the cross member. At this point, the collision force is attenuated, and the penetration of the upper portion of the center pillar after that is reduced. According to the second aspect, the same effect is obtained when the sub cross member is overlapped on the inner surface of the end portion of the cross member main body.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cross member structure of an automobile according to an embodiment of the present invention will be described with reference to FIGS. 1
Reference numeral 0 denotes a cross member disposed between the center pillar 3 erected on the rocker 2 and the tunnel section 4 on the front floor 1 in the vehicle width direction. The cross member has a hat-shaped cross-member body 11 terminated with a gap in the rocker 2 immediately below the center pillar 3, and the gap overlaps the end portion of the cross-member body 11 in the gap so that the cross member can run in the vehicle width direction. And a sub-cross member 15 having a U-shaped cross section and having an idle portion A connected to the sub-cross member 15.

The cross member body 11 is welded to the front floor 1 at a flange 11a at a lower end thereof. A wall surface 11b is formed at the end position of the cross member main body 11. Such a cross member with a free running section is provided separately or on the opposite side of the tunnel section 4.

As shown in FIGS. 3 and 4, the sub-cross member 15 has a U-shaped cross-section main body 16 having a flange portion 16a formed at an end portion, and a cross-section shape having a wall surface 17b formed at a start end. And a core portion 17 having a flange portion 17a formed at the end portion is inserted. The sub cross member 15 is formed by superimposing a sub cross member main body 16 on a core portion 17 in which a flange portion 17a is welded to the rocker panel 2, and
6a is fixed by overlapping and welding. In this state, the portion on the starting end side of the position of the wall surface 17b of the sub cross member 15 forms the idle running portion A. The free running portion partially overlaps the outer surface of the end portion of the cross member body 11 and is connected in a contact state, and the wall surface 17b is
Occupies a position retracted by the idle running stroke B from

When a side collision occurs as shown in FIG. 5, a collision force is applied to the rocker 2 and the front floor 1 as shown in FIG. The rocker 2 and the front floor 1 are deformed and invade while narrowly running idle. This allows
The lower part of the center pillar 3 intrudes as compared with the lower part of the center pillar 3 (D in the figure), and the amount of intrusion of the upper part of the center pillar 3 decreases. Further, the wall members 17b and 11b collide with each other, and thereafter, stress is generated in the cross member 10. At that point, the collision force is attenuated, and the amount of penetration of the upper part of the center pillar 3 is suppressed (FIG. E).

Incidentally, instead of the above-described embodiment, the idle running portion overlaps the inner surface of the end portion of the cross member body in a contact state,
The wall surface may be formed at a position retracted inward by the idle running stroke from the start position of the sub-cross member and the start position of the inserted sub-cross member in the cross member body.

[0012]

According to the present invention, the strength of the front cross member against a side collision is delayed and caused to act, thereby causing stress deformation on the rocker and the front floor, thereby suppressing an increase in the amount of penetration of the upper portion of the center pillar. It becomes possible. Since the idle running stroke at which the cross member starts to operate can be set by setting the wall surface position, it is possible to appropriately set the penetration amount of the center pillar with respect to the assumed collision force.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cross member structure of an automobile according to an embodiment of the present invention.

FIG. 2 is a perspective view of the cross member main body.

FIG. 3 is an exploded perspective view of a sub cross member of the cross member.

FIG. 4 is a sectional view of the cross member.

FIG. 5 is a cross-sectional view for explaining the operation of the cross member structure in comparison with that of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front floor 2 Rocker 3 Center pillar 10 Cross member 11 Cross member main body 11b, 17b Wall 15 Sub cross member

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-277227 (JP, A) JP-A-7-61374 (JP, A) JP-A-5-262264 (JP, A) JP-A-4- 87888 (JP, A) Japanese Utility Model 1-90676 (JP, U) Japanese Utility Model 58-149259 (JP, U) Japanese Utility Model Utility Model 3-107286 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B62D 25/20 B62D 25/04

Claims (2)

(57) [Claims] 1. A cross member body of a cross section in which a lower end flange is welded to a front floor in a cross member structure of an automobile provided on a front floor between center pillars on both sides in a vehicle width direction. The rocker immediately below the center pillar is terminated with a gap, and the gap has a U-shaped cross-section having an idling portion that overlaps with the outer surface of the end portion of the cross member body and is connected in an idling manner in the vehicle width direction. A sub-cross member is provided, and a wall surface is formed at an end position of the cross member main body and at a position retreated by the idle running stroke from the end position of the sub-cross member, and the sub-cross closer to the end than the idle portion is formed. A cross member structure for an automobile, wherein a member portion is welded to the front floor or the rocker. 2. A cross-member structure of a vehicle provided in a vehicle width direction on a front floor between center pillars on both sides in the vehicle width direction, wherein a flange portion at a lower end portion is welded to the front floor. The main body is terminated by placing a gap on a rocker immediately below the center pillar with a gap, and a U-shaped cross section having an idling portion that overlaps the inner surface of the end portion of the cross member main body and is connected to the cross member so that it can run idly in the vehicle width direction. And a wall formed at a starting end position of the sub cross member and a position retracted by the idle running stroke from the starting end position in the cross member main body, and the sub cross member closer to the end than the idle running portion is formed. A cross member structure for an automobile, wherein a cross member portion is welded to the front floor or the rocker.