JPH09272466A - Lower part vehicle body structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the efficiency of absorbing impact force upon collision without lowering the rigidity of the front part of a tunnel part in the longitudinal direction of a vehicle. SOLUTION: Tunnel reinforcements 32, 34 are arranged in a tunnel part of a lower dash panel 14 along the longitudinal direction of a vehicle. Beads 40, 32 serving as a reinforcing means are formed at opposite side wall surfaces 30B, 30C of the front part 30d of the tunnel part, extending oblique downward from the front end upper part. The rear end parts 40A, 40A of the beads 40, 42 are extended downward from the front end parts 32G, 34G of the tunnel reinforcements 32, 34.

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 of a vehicle, and more particularly to a lower vehicle body structure of a vehicle in which a reinforcing member is provided in a tunnel portion formed in a vehicle body floor portion.

[0002]

2. Description of the Related Art Conventionally, as an example of a lower vehicle body structure of a vehicle in which a reinforcing member is arranged in a tunnel portion formed on a floor portion of a vehicle body, a structure disclosed in Japanese Patent Laid-Open No. 6-144299 is known.

As shown in FIG. 8, in the lower body structure of this vehicle, a dash lower cross member 72 extending in the vehicle width direction is provided on the back surface of a dash lower panel 70 having a vertical wall portion 70A and a transition portion 70B. A central portion in the vehicle width direction of the dash lower cross member 72 is extended rearward of the vehicle to form a closed cross-section portion 74 at an upper portion of the tunnel portion. A dash lower panel 70, a dash lower cross member 72, a tunnel reinforcement 76, and a front floor panel 78 form a closed cross section 80 behind the closed cross section 74, and a steering support member 82 is supported above the closed cross section 80. A center stay 84 is attached to the dash lower panel 70 and the tunnel reinforcement 76.
And weakened portions 88 and 90 provided with one or more beads on the vehicle front side with respect to the joining portion 86 formed by overlapping and joining three front floor panels 78 to the tunnel end portion 92 and the partition wall 94, The impact force at the time of collision can be absorbed by the fragile portions 88 and 90 formed in the front portion of the tunnel.

[0004]

However, in the lower body structure of this vehicle, the fragile portions 88 and 90 due to the beads are formed.
However, the rigidity of the front part of the tunnel part in the front-rear direction of the vehicle decreases, and it is difficult to support a high load at the front part of the tunnel part.

In view of the above facts, the present invention has an object to obtain a lower vehicle body structure of a vehicle capable of efficiently absorbing the impact force at the time of a collision without lowering the rigidity of the front portion of the tunnel portion in the vehicle front-rear direction. is there.

[0006]

According to a first aspect of the present invention, there is provided a reinforcing member at the upper portion of a tunnel portion formed on a floor portion of a vehicle body for reinforcing a portion from a position separated from a front end of the tunnel portion by a predetermined distance to a rear portion. In the lower body structure of the arranged vehicle,
Reinforcing means is provided along the vehicle front-rear direction without being connected to the reinforcing member at the front portion of the tunnel portion, and the rear portion of the reinforcing means and the front portion of the reinforcing member are overlapped in the vehicle front-rear direction. It has a feature.

Therefore, when an impact force to the rear of the vehicle acts on the tunnel portion, a part of this impact force is transmitted to the rear by the reinforcing means at the front portion of the tunnel portion. For this reason, a tensile load acts between the rear part of the reinforcing means that overlaps in the vehicle front-rear direction and the front part of the reinforcing member that reinforces the upper part of the tunnel, and the front part of the tunnel part sits behind the vehicle while giving a high load. Bend and absorb the impact force.

According to a second aspect of the present invention, in the lower body structure for a vehicle according to the first aspect, the reinforcing means is provided on both left and right wall surfaces of the front portion of the tunnel portion and obliquely downward from the upper front end of the tunnel portion. It is characterized in that it is provided toward.

Therefore, when an impact force to the rear of the vehicle acts on the tunnel portion, a part of this impact force is transmitted to the rear by the reinforcing means provided on both left and right wall surfaces at the front portion of the tunnel portion. Therefore, a tensile load acts between the lower rear end of the reinforcing means that overlaps in the vehicle front-rear direction and the front portion of the reinforcing member that reinforces the tunnel upper portion, and the front portion of the tunnel portion produces a high load and the rear portion of the vehicle Buckle to absorb the impact force.

According to a third aspect of the present invention, in the lower body structure for a vehicle according to the first aspect, the reinforcing means is provided on an upper wall surface of a front portion of the tunnel portion, and is directed rearward from a front end portion of the tunnel portion. It is characterized in that the rear part is inserted between the front end parts branched to the left and right of the reinforcing member.

Therefore, when an impact force to the rear of the vehicle acts on the tunnel portion, a part of this impact force is reinforced on the upper wall surface of the front portion of the tunnel portion from the front end portion of the tunnel portion toward the rear. It is transmitted to the rear by means. Therefore, a tensile load acts between the rear portion of the reinforcing means that overlaps in the vehicle front-rear direction and the front end portions of the reinforcing member that are branched to the left and right, and the front portion of the tunnel portion produces a high load while sitting behind the vehicle. Bend and absorb the impact force.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a lower vehicle body structure for a vehicle according to the present invention will be described with reference to FIGS.

In the drawings, an arrow FR indicates a forward direction of the vehicle, and an arrow UP indicates an upward direction of the vehicle. As shown in FIG. 3, in the vehicle body front portion 10 of the first embodiment, a pair of left and right front side members 12 are arranged near lower portions on both ends in the vehicle width direction along the vehicle body front-rear direction. These front side members 12 have a closed cross-sectional structure extending in the front-rear direction of the vehicle body, and a rear end portion of the front side member 12 partitions the engine room and the vehicle compartment and forms a front portion of the vehicle body floor. It is welded to the lower panel 14. Further, an inclined portion 12A extending toward the vehicle body lower rear side along the dash lower panel 14 is formed at the rear end portion of the front side member 12, and the lower end portion of the inclined portion 12A is located at the rear of the vehicle body. It is extended toward and is made into the horizontal part 12B.

The cross-sectional shapes of the inclined portion 12A and the horizontal portion 12B of the front side member 12 viewed from the longitudinal direction are as follows.
The dash lower panel 14 is formed in a U-shape with the opening facing the side, and the left and right flanges formed at the opening end are welded to the dash lower panel 14, respectively. Therefore, the inclined portion 12A and the horizontal portion 12B of the front side member 12 together with the dash lower panel 14 form a closed cross section extending in the vehicle front-rear direction in a plan view.

A dash cross member 20 is inserted along the vehicle width direction between the rear portions 12C, which are the upper ends of the inclined portions 12A of the left and right front side members 12, and the dash cross member 20 is disposed on the left and right front sides. The rear parts of the member 12 are connected to each other along the vehicle width direction. The cross-sectional shape of the dash cross member 20 as viewed in the longitudinal direction is a U-shape with the opening facing the vehicle rear side, and the upper and lower flanges formed at the opening end are welded to the dash lower panel 14, respectively. ing. Therefore, the dash cross member 20 and the dash lower panel 14 form a closed cross-section portion that connects the left and right front side members 12.

Rear part 1 of the left and right front side members 12
A pillar brace 24 is inserted substantially horizontally between 2C and the front pillar 22 as a skeletal member, and the pillar brace 24 connects the rear portion 12C of the left and right front side members 12 and the front pillar 22. .

Therefore, the front side member 12, the dash cross member 20, and the pillar brace 24 form a substantially Y-shaped structure in a plan view. This abbreviation Y
The dash cross member 20 and the pillar brace 24 constitute two bifurcated portions of the character structure, and a part of the impact force applied to the front side member 12 is generated in the axial direction of the dash cross member 20 and the pillar brace 24. It is configured to receive by supporting power.

A tunnel portion 30 bulging upward is formed in the vehicle width direction central portion of the dash lower panel 14 forming the vehicle body floor portion along the vehicle front-rear direction.

As shown in FIG. 2, the tunnel section 30 has a trapezoidal cross section as viewed from the front of the vehicle body. The tunnel section 30 has a trapezoidal shape with its opening facing downward, and has an upper wall surface 30A and left and right side wall surfaces 30B.
Tunnel reinforcements 32 and 34 as reinforcing members are provided at the corners of 30C along the vehicle front-rear direction. These tunnel reinforcements 32 and 34 extend from a predetermined position of the front portion 30D of the tunnel portion 30 to a rear portion thereof, and the front portion 30 of the tunnel portion 30 is provided.
It is reinforced from the predetermined position of D to the rear part.

The tunnel reinforcement 32 has an upper wall surface 32 which is parallel to the upper wall surface 30A of the tunnel portion 30.
A, the lower wall surface 32B, and the side wall surface 30B of the tunnel portion 30
The outer wall surface 32C and the inner wall surface 32D that are parallel to each other, and the flange 32 formed at the end of the lower wall surface 32B.
E and the flange 32 formed at the end of the inner wall surface 32D
F is the side wall surface 30B of the tunnel portion 30 and the upper wall surface 30A.
It is welded to and. Therefore, the tunnel reinforcement 32 and the tunnel portion 30 form a closed cross-section portion 36 extending in the vehicle front-rear direction.

Similarly, the tunnel reinforcement 3
Reference numeral 4 denotes an upper wall surface 34A and a lower wall surface 34B that are parallel to the upper wall surface 30A of the tunnel portion 30, and an outer wall surface 34C and an inner wall surface 42 that are parallel to the side wall surface 30C of the tunnel portion 30.
A flange 34E formed at the end of the lower wall surface 34B and a flange 34F formed at the end of the inner wall surface 34D are welded to the side wall surface 30C and the upper wall surface 30A of the tunnel portion 30. ing. Therefore, the tunnel reinforcement 34 and the tunnel portion 30 form a closed cross-section portion 38 extending in the vehicle front-rear direction.

As shown in FIG. 1, the bead 40 as a reinforcing means is provided on both side wall surfaces 30B and 30C of the front portion 30D of the tunnel portion 30 obliquely downward from the upper front end.
42 are formed, and the rear end portions 4 of the beads 40 and 42 are formed.
0A and 42A are tunnel reinforcement 3 respectively
It reaches below the front ends 32G and 34G of the two and 34. That is, the rear end portions 40A and 42A of the beads 40 and 42 are connected to the front ends 32 of the tunnel reinforcements 32 and 34, respectively.
G and 34G overlap in the vehicle front-rear direction.

Next, the operation of the first embodiment will be described.
In the first embodiment, when an impact force from the front of the vehicle body is applied to the front side member 12, a part of this impact force is supported by the dash cross member 20 and the pillar brace 24. As a result, a part of the impact force is added to the tunnel portion 30 via the dash cross member 20. At this time, a part of the impact force is applied to the beads 40, 42 provided on both side wall surfaces 30B, 30C of the front portion 30D of the tunnel portion 30.
When applied to the upper portions of the front ends 40B, 42B of the, the impact force is transmitted rearward by the beads 40, 42. For this reason,
Beads 40 and 4 overlapping in the vehicle front-rear direction
A tensile load (arrow F in FIG. 1) acts between the rear end portions 40A and 42A of the second tunnel and the front ends 32G and 34G of the tunnel reinforcements 32 and 34, and the front portion 30D of the tunnel portion 30 outputs a high load. Buckles to the rear of the vehicle and absorbs impact force.

Therefore, the lower vehicle body structure of the vehicle of the first embodiment can efficiently absorb the impact force at the time of collision without reducing the rigidity of the front portion 30D of the tunnel portion 30 in the vehicle front-rear direction.

Further, in the lower vehicle body structure of the vehicle of the first embodiment, since the reinforcing means is composed of the beads 40 and 42, it is not necessary to provide another member, and the number of parts can be reduced.

In the lower vehicle body structure of the vehicle of the first embodiment, the reinforcing means is composed of the beads 40 and 42, but instead of the beads, as shown in FIG. 4, it is a member separate from the tunnel portion 30. The reinforcements 44 and 46 as reinforcing means may be joined to both side wall portions 30B and 30C of the front portion 30D of the tunnel portion 30.

Next, the second lower body structure of the vehicle of the present invention
The embodiment will be described with reference to FIGS.

The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 5, in the second embodiment, the upper flange 20A and the lower flange 20B provided at the open end of the dash cross member 20 are joined to the vehicle front side surface 14A of the dash lower panel 14. . The position of the lower wall portion 20C of the dash cross member 20 is set at substantially the same height as the upper wall surface 30A of the tunnel portion 30,
On the upper wall surface 30A of the tunnel portion 30, a front reinforcement 52 as a reinforcing means is provided from the front end portion of the tunnel portion 30 toward the rear.

The front reinforcement 52 has a front portion and a lower portion opened, and a U-shaped flange 54 is formed at the front edge portion. The flange 54 is joined to the vehicle rear side surface 14B of the dash lower panel 14, and the upper portion 54A of the flange 54 sandwiches the dash lower panel 14 and the upper flange 20A of the dash cross member 20.
Is facing.

As shown in FIG. 6, the front reinforcement 52 is gradually reduced in width toward the rear and has a substantially triangular shape in a plan view, and is formed at the lower end edge of the front reinforcement 52. A substantially V-shaped flange 56 is joined to the upper wall surface 30A of the tunnel portion 30.

The tunnel reinforcement 58 as a reinforcing member extends from a predetermined position of the front portion 30D of the tunnel portion 30 to a rear portion thereof, and the front portion 3 of the tunnel portion 30.
It is reinforced from the predetermined position of 0D to the rear part.

As shown in FIG. 5, in the tunnel reinforcement 58, a convex portion 58A along the vehicle front-rear direction is formed at a portion facing the corners of the upper wall surface 30A of the tunnel portion 30 and the left and right side wall surfaces 30B and 30C. , 58B are formed. Convex portion 58A of tunnel reinforcement 58
The base portion 58C between the convex portion 58B and the convex portion 58B is the tunnel portion 30.
Is joined to the upper wall surface 30A, and the lower portions of the left and right side portions 58D and 58E of the tunnel reinforcement 58 are
It is joined to the left and right side wall surfaces 30B and 30C of the tunnel portion 30. Therefore, the tunnel reinforcement 58
And the tunnel portion 30 form a pair of left and right closed cross-section portions 60, 62 extending in the vehicle front-rear direction.

The front portion 58F of the tunnel reinforcement 58 has a V-shaped notch 64 having an opening facing the front of the vehicle.
Is formed, and the rear end portion 52A of the front reinforcement 52 is inserted into the notch 64. That is, the rear end portion 52A of the front reinforcement 52
Overlaps the front portion 58F of the tunnel reinforcement 58 in the vehicle front-rear direction.

Incidentally, the tunnel reinforcement 58
In the front portion 58F, the convex portions 58A and 58B are gradually narrowed toward the front.

Next, the operation of the second embodiment will be described.
In the second embodiment, when an impact force from the front of the vehicle body is applied to the front side member 12, a part of this impact force is supported by the dash cross member 20 and the pillar brace 24. As a result, a part of the impact force is added to the tunnel portion 30 via the dash cross member 20. At this time, if a part of the impact force is applied to the front portion of the front reinforcement 52 provided on the upper wall surface 30A of the front portion 30D of the tunnel portion 30, the impact force is transmitted rearward by the front reinforcement 52. It Therefore, the rear end portion 52A of the front reinforcement 52 that overlaps in the vehicle front-rear direction and the front portion 58F that is branched to the left and right of the tunnel reinforcement 58.
A tensile load (arrow F in FIG. 6) acts on each of the tip portions of the.

As a result, as shown in FIG. 7, the front reinforcement 52 has the front portion 3 of the tunnel portion 30.
While 0D is exerting a high load, it is retracted while buckling to the rear of the vehicle and stopped at a position close to the tunnel reinforcement 58.

Therefore, in the second embodiment, the front portion 30D of the tunnel portion 30 buckles under a constant load, and after the impact at the time of collision is absorbed, the deformation is stopped. It is possible to achieve both a high shock absorption amount and a small vehicle body deformation amount without reducing the rigidity in the front-rear direction.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included within the scope of the present invention. It is clear to a person skilled in the art that is possible.

[0040]

According to the first aspect of the present invention, a reinforcing member is provided on the upper portion of the tunnel portion formed on the floor of the vehicle body to reinforce the portion from a predetermined distance from the front end of the tunnel portion to the rear portion. In the lower body structure of a vehicle, reinforcing means is provided along the vehicle front-rear direction in the front part of the tunnel portion without connecting to the reinforcing member, and the rear part of the reinforcing means and the front part of the reinforcing member are overlapped in the vehicle front-rear direction. Therefore, there is an excellent effect that the impact force at the time of collision can be efficiently absorbed without reducing the rigidity of the front portion of the tunnel portion in the vehicle front-rear direction.

According to a second aspect of the present invention, in the vehicle body structure according to the first aspect, the reinforcing means is provided on both left and right wall surfaces of the front portion of the tunnel portion and extends obliquely downward from the upper front end of the tunnel portion. Since it is provided, it has an excellent effect that the impact force at the time of collision can be efficiently absorbed on the left and right wall surfaces of the front part of the tunnel part without reducing the rigidity of the front part of the tunnel part in the vehicle front-rear direction. .

The present invention according to claim 3 is the vehicle body structure for a vehicle according to claim 1, wherein the reinforcing means is provided on the upper wall surface of the front portion of the tunnel portion from the front end portion of the tunnel portion toward the rear. Since the rear portion is inserted between the left and right front end portions of the reinforcing member, without lowering the rigidity of the front portion of the tunnel portion in the vehicle front-rear direction, on the upper wall surface of the front portion of the tunnel portion, It has an excellent effect that the impact force at the time of collision can be efficiently absorbed.

[Brief description of drawings]

FIG. 1 is a perspective view of a lower vehicle body structure of a vehicle according to a first embodiment of the present invention as seen obliquely from the front of the vehicle.

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

FIG. 3 is a perspective view of the front portion of the vehicle body to which the lower vehicle body structure according to the first embodiment of the present invention is applied, as seen obliquely from the front of the vehicle.

FIG. 4 is a perspective view showing a lower vehicle body structure of a vehicle according to a modified example of the first embodiment of the present invention, as viewed obliquely from the front of the vehicle.

FIG. 5 is a perspective view showing a lower vehicle body structure of a vehicle according to a second embodiment of the present invention as seen obliquely from the rear of the vehicle.

FIG. 6 is a plan view showing a lower body structure of a vehicle according to a second embodiment of the present invention.

FIG. 7 is an operation explanatory view of the lower vehicle body structure of the vehicle according to the second embodiment of the present invention.

FIG. 8 is a side sectional view showing a lower vehicle body structure of a vehicle according to a conventional embodiment.

[Explanation of symbols]

 14 Dash lower panel 30 Tunnel part 30A Upper wall surface of tunnel part 30B Side wall surface of tunnel part 30C Side wall surface of tunnel part 32 Tunnel reinforcement (reinforcing member) 34 Tunnel reinforcement (reinforcing member) 40 Bead (reinforcing means) 42 Bead (reinforcing) Means) 44 Reinforcement (Reinforcement Means) 46 Reinforcement (Reinforcement Means) 52 Front Reinforcement (Reinforcement Means) 58 Tunnel Reinforcement (Reinforcement Member)

Claims (3)

[Claims] 1. A lower vehicle body structure for a vehicle, wherein a reinforcing member for reinforcing a portion from a front end of the tunnel portion to a rear portion is provided on an upper portion of the tunnel portion formed on a floor portion of the vehicle body. Reinforcing means is provided along the vehicle front-rear direction without being connected to the reinforcing member at the front of the portion, and the rear portion of the reinforcing means and the front portion of the reinforcing member are overlapped in the vehicle front-rear direction. The lower body structure of the vehicle. 2. The vehicle according to claim 1, wherein the reinforcing means is provided on both left and right wall surfaces of a front portion of the tunnel portion and obliquely downward from an upper front end of the tunnel portion. Lower body structure. 3. The reinforcing means is provided on an upper wall surface of a front portion of the tunnel portion from a front end portion of the tunnel portion toward the rear, and a rear portion of the front end portion branched to the left and right of the reinforcing member. It is inserted in between, The claim 1 characterized by the above-mentioned.
The lower body structure of the vehicle described.