JP3311797B2 - Lower body structure of car - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower vehicle body structure capable of securing the strength of a vehicle body of an automobile and preventing the steering from moving into a vehicle compartment at the time of a frontal collision.

[0002]

2. Description of the Related Art As a conventional vehicle body structure, for example, one disclosed in Japanese Utility Model Laid-Open Publication No. Sho 59-151782 includes a vertical wall portion that separates an engine room and a vehicle compartment located at a front portion and a vehicle interior side. A dash lower panel comprising an inclined transition portion,
A floor panel having a tunnel portion protruding toward the passenger compartment and extending in the vehicle front-rear direction at a center portion in the vehicle width direction, a transition portion inclined upward and joined to a dash lower panel, and provided on the lower surface on both sides of the floor panel. A bead portion extending in the width direction of the vehicle body at a position substantially corresponding to the bent portion of the front frame of the tunnel portion, so that the tunnel portion stretches at the time of a frontal collision. And the compression load applied to the floor panel becomes substantially uniform, thereby suppressing the occurrence of local bending deformation and the like.

[0003]

However, generally, a steering column and an instrument panel are supported by a steering support member extending in the vehicle width direction on the back side of the instrument panel. A mechanism is provided that contracts in the axial direction of the front steering column of the vehicle body when receiving a load in the front-rear direction. However, in the above-described conventional vehicle body structure, when the dash panel portion is deformed in the vehicle interior direction during a frontal collision. In addition, there is a problem that the steering column may be moved to the rear of the vehicle body, and the steering wheel may not be sufficiently retracted toward the instrument panel.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the rigidity of a dash panel portion in the longitudinal direction of a vehicle body and to enable a steering wheel to move forward from the interior of a vehicle body when a load is applied in the longitudinal direction of the vehicle body. Is to provide a structure.

[0005]

In order to achieve the above object, a lower body structure of an automobile according to the present invention is provided as a lower half of a dash panel erected at the forefront of a passenger compartment, and has a vertical wall portion. A dash lower cross member extending in the vehicle width direction is provided on the back surface of the dash lower panel having a transition portion connected to the floor panel and extending from the lower end thereof, and an intermediate portion of the dash lower cross member is extended rearward of the vehicle body. A lower body structure that forms a closed cross-section at the upper part of the tunnel by mounting a center stay that supports a steering support member above the closed cross-section, and between the center stay mounting portion and the dash lower panel vertical wall portion. , The front and rear direction of the vehicle having the closed cross-section and a bead extending in the vehicle width direction.
And a fragile part that absorbs the impact force acting on the dash panel. Can be moved. The closed cross-section is formed by a dash lower panel, a dash lower cross member, a tunnel reinforcement, and a front floor panel. Formed and acts on the front side of the vehicle body beyond the joint in the vehicle front- rear direction.
The provision of the weak portion for absorbing the force can provide a further effect. Also, it acts in the front-rear direction of the vehicle body.
By providing the fragile portion for absorbing the impact force to the dash lower panel and the dash lower cross member, the shock absorbing ability of the fragile portion is increased.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS.
A main tunnel portion 11 having a substantially inverted inverted cross-sectional shape and having a downward opening and extending in the vehicle front-rear direction is formed at an intermediate portion in the vehicle width direction of a front floor panel (hereinafter simply referred to as a floor panel) 1. The dash lower panel 2 includes a vertical wall portion 2a,
A transition portion 2b whose lower end is inclined rearward of the vehicle body;
and a floor portion 2c extending horizontally rearward from the vehicle body b, and is formed higher and higher than the main tunnel portion 11 over the transition portion 2b and the floor portion 2c, and the front end of the main tunnel 11 is fitted. A tunnel end portion 21 extends rearward of the vehicle body, and a bead portion (fragile portion) 22 having at least one bead extending in the vehicle width direction is provided on an upper surface of the tunnel end portion 21.

As shown in FIG. 3, the dash lower cross member 3 provided on the back surface of the dash lower panel 2, that is, on the outer side surface of the vehicle compartment, has a vertical plate portion 3a and a horizontal plate portion 3b having flanges 3af and 3bf at the edges, respectively. The flange portions 3af, 3bf are fixed to the back surface of the transition portion 2b of the dash lower panel 2, and extend the horizontal plate portion 3b toward the rear of the vehicle body at an intermediate position in the vehicle width direction. Tunnel end 21 coincides with tunnel end 21 of lower panel 2.
A longer partition wall 30 is provided, and the partition wall 30 is inserted into the tunnel end 21 to partition the inside of the tunnel end 21 up and down, thereby forming a closed cross section 32 at an upper portion inside the tunnel end 21. In addition, the height of the partition wall 30 of the dash lower cross member 3 is matched with the height of the upper wall of the main tunnel portion 11, and at least one partition wall 30 is located at a position forward of the rear end of the tunnel end 21 of the partition wall 30. A bead portion (fragile portion) 33 having a bead extending in the vehicle width direction is provided.

With the above structure, the strength of the dash lower cross member 3 is increased, and the strength of the tunnel portion is also increased. The load in the vehicle longitudinal direction can be absorbed by the tunnel portion. The burden on the side frame 4 is reduced.

A front end of the floor panel 1 is connected and fixed to a rear end of the floor portion 2c of the dash lower panel 2, a side wall of the main tunnel portion 11 is a side wall of the tunnel end portion 21, and an upper wall of the main tunnel portion 11 is a dash lower cross member. 3 partition wall 30
Is connected to the rear end. The two ends of the front end of the upper wall of the main tunnel portion 11 are cut off from the side walls and cut upward to form a connection bracket 12, and the upper end of the connection bracket 12 is connected to the rear end of the upper end of the tunnel end 21 for connection. The rear end of the partition wall 30 of the dash lower cross member 3 is connected to the lower end of the bracket 12.

A downwardly opening tunnel reinforcement 5 having a substantially inverted concave cross section is provided with a lower opening fitted in the upper part of the main tunnel portion 11, and a front end 53 of an upper wall of the tunnel reinforcement 5 is provided. Is connected to the rear end of the upper wall of the tunnel end 21, and the front end of the floor panel 1, the rear end of the tunnel end 21 of the dash lower panel 2, and the front end 53 of the upper wall of the tunnel reinforcement 5 are overlapped. Join together. The lower ends 52 of both side walls of the tunnel reinforcement 5 are joined to both upper ends of the main tunnel portion 11 to form a closed section 50 on the upper surface of the main tunnel portion 11, and the steering support member 10 is mounted on the upper surface of the closed section 50. The supporting center stay 9 is erected (see FIG. 2).

The cross member 7 is formed to have a substantially inverted concave cross section and includes a horizontal portion 71 extending in the vehicle width direction along the upper surface of the floor panel 1 and a rising portion 72 extending over the main tunnel portion 11. The entire length in the vehicle width direction is joined to the floor panel 1 by a flange 73 at the lower opening edge, and both ends are connected to the inner side surface of a side sill 8 extending in the front-rear direction on both side edges of the vehicle body.

The flange 54 at the rear end of the upper wall of the tunnel reinforcement 5 is connected to the rising portion 7 of the cross member 7.
2, a substantially rectangular recess 55 is formed at the rear of the tunnel reinforcement 5, and the bottom surface of the recess 55 is joined to the front flange 73 at the lower opening edge of the rising portion 72. With this configuration, the main tunnel portion 11
And the strength in the vehicle body width direction can be secured. Reference numeral 31 denotes a work hole provided in the partition wall 30, 5
Reference numeral 1 denotes a working hole provided on the upper surface of the front part of the tunnel reinforcement 5.

According to the above configuration, the center stay 10
Between the mounting portion and the vertical wall portion 2a of the dash lower panel 2,
By providing a closed cross-section and a fragile portion with a bead or the like extending in the width direction of the vehicle body, the stiffness of the dash panel in the vehicle front-rear direction is improved, and the steering wheel is mounted on the vehicle when receiving a load in the vehicle front-rear direction. It can be prevented from moving indoors. The closed cross section is formed by a front floor panel 1, a dash lower panel 2, a dash lower cross member 3, and a tunnel reinforcement 5, and the dash lower panel 2, the tunnel reinforcement 5, and the front floor panel 1 A further effect can be obtained by forming the sheets by laminating them and joining them together, and providing the above-mentioned fragile portion on the front side of the vehicle body with respect to the joints. In addition, the fragile portion is connected to the tunnel end 21 of the dash lower panel 2 and the partition wall 3 of the dash lower cross member 3.
By providing 0, the shock absorbing capacity of the fragile portion is increased.

[0014]

Since the present invention is configured as described above, it has the following effects. A closed cross-section and a fragile part are provided between the center stay mounting part and the dash lower panel vertical wall part to improve the rigidity of the dash panel part in the vehicle longitudinal direction and to receive the load in the vehicle longitudinal direction. In this case, the steering wheel can be prevented from moving into the vehicle interior. The closed cross-section is formed by a dash lower panel, a dash lower cross member, a tunnel reinforcement, and a front floor panel, and is formed by combining three dash lower panels, a tunnel reinforcement, and a front floor panel, By providing the above-mentioned fragile portion on the front side of the vehicle body with respect to the connecting portion, a further effect can be obtained. Further, by providing the fragile portion on the dash lower panel and the dash lower cross member, the shock absorbing ability of the fragile portion increases.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a front part of a vehicle compartment of a vehicle according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a dash lower cross member according to the present invention.

[Explanation of symbols]

1 floor panel, 2 dash lower panel, 3 dash lower cross member 4 front side frame, 5 tunnel reinforcement, 7 cross member, 8 side sill, 9
Center stay, steering support member

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A 3-126778 (JP, U) JP-A 2-103882 (JP, U) JP-A 1-158283 (JP, U) JP-A 3- 25083 (JP, U) Actually open sho 59-151782 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 25/20

Claims (3)

(57) [Claims] 1. A dash lower cross member extending in a vehicle width direction is provided on a back surface of a dash lower panel having a vertical wall portion and a transition portion extending from a lower end thereof, and an intermediate portion of the dash lower cross member is extended rearward of the vehicle body. A lower body structure in which a closed cross section is formed at an upper portion of a tunnel, a center stay for supporting a steering support member is mounted above the closed cross section, and the center stay mounting portion and a dash lower panel vertical wall portion are provided between the center stay mounting portion and the dash lower panel vertical wall portion. Closed section and body longitudinal direction
A lower body structure of an automobile, comprising a fragile portion for absorbing an acting impact force . 2. The closed cross-section includes a dash lower panel, a dash lower cross member, a tunnel reinforcement, and a front floor panel, and three dash lower panels, a tunnel reinforcement, and a front floor panel are provided. The impact force acting in the front-rear direction of the vehicle body on the front side of the vehicle body relative to the connection portion is formed.
The lower vehicle body structure of an automobile according to claim 1, further comprising a fragile portion that absorbs . 3. Absorbing the impact force acting in the longitudinal direction of the vehicle body.
The lower vehicle body structure according to claim 1, wherein the fragile portion to be accommodated is provided in the dash lower panel and the dash lower cross member.