JPH06171551A - Automotive lower car body structure - Google Patents

Abstract

PURPOSE:To prevent a cross member installation part from being pushed up while backward movement of the front part of a floor panel is properly regulated when collision of an automobile occurs. CONSTITUTION:The lower car body structure of an automobile comprises a front panel 1 to which a tunnel part 5 extending longitudinally in a car body is formed; a cross member 2 installed in the car width direction in a manner to cross the tunnel part 5; and a pair of right and left front floor frames 3 installed on the under surface of the floor panel 1. A joining flange part arranged on the rear end part of the front frame arm 3 is positioned between a front flange part 12 arranged on the lower end part of a front wall plate 8 of which the cross member 2 consists and a rear flange part 13 arranged on the lower end part of a rear wall part 9.

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 an automobile provided with a floor panel constituting a floor portion of a vehicle body.

[0002]

2. Description of the Related Art Conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. 57-65181, a tunnel portion extending in the front-rear direction is formed in a floor panel of a vehicle body, and a cross member is arranged between left and right side sills. The cross member is installed near the installation portion of the occupant's seat so as to intersect with the tunnel portion, whereby the installation portion of the occupant's seat is reinforced. Further, a pair of left and right front floor frames (side members) are installed on the lower surface of the floor panel to reinforce the front portion of the floor panel.

Further, as shown in FIG. 6, a joint flange portion provided at the rear end portion of the front floor frame 41 is provided in order to prevent the passenger compartment from being adversely affected by the impact load applied at the time of collision of the automobile. 42 and a joining flange portion 44 provided at the rear end portion of the cross member 43 are arranged so as to face each other, and the joining flange portions 42 and 44 and the floor panel 45 are overlapped and joined together. Is being done.

[0004]

When the joining flange portion of the front floor frame and the joining flange portion of the cross member are integrally joined as described above, the front floor frame is constructed by the front floor frame when the vehicle collides. There is an advantage that the front portion of the supported floor panel can be restricted from retracting at the installation portion of the cross member. However, on the other hand, when a large load is applied at the time of collision of an automobile, there is a problem that the installation member for the cross member and the occupant seat is deformed and retracted by being pushed by the front floor frame.

Further, when the front end of the vehicle body is deformed so as to descend, and a reaction force exerts a moment for raising the rear end of the front floor frame, it is pressed against the rear end of the front floor frame. There is a problem that the installation portion of the cross member may be deformed so as to be pushed up.

The present invention has been made in order to solve the above-mentioned problems, and the installation portion of the cross member is pushed up while properly controlling the rearward movement of the front portion of the floor panel in the event of an automobile collision. It is an object of the present invention to provide a lower body structure of an automobile capable of preventing

[0007]

The invention according to claim 1 is
A floor panel in which a tunnel portion extending in the front-rear direction of the vehicle body is formed, a cross member installed in the vehicle width direction so as to intersect the tunnel portion, and a pair of left and right front floor frames installed on the lower surface of the floor panel. In a lower body structure of an automobile having a front floor frame between a front flange portion provided at a lower end portion of a front wall plate forming the cross member and a rear flange portion provided at a lower end portion of a rear wall plate. The rear end is located.

According to a second aspect of the present invention, a reinforcing member extending in the vehicle width direction is installed in the cross member, and a joint portion of the reinforcing member to the floor panel is joined to a joint flange provided at a rear end portion of the front floor frame. It is installed at a position facing the section.

According to a third aspect of the present invention, a cross member is arranged so as to connect the left and right side sills, and a mounting portion for an occupant seat is provided on the upper wall of the cross member. The outer end of the installed reinforcing member is joined to the side sill, and the inner end of the reinforcing member is positioned below the mounting portion of the occupant seat.

[0010]

According to the invention described in claim 1, a gap is formed between the rear end portion of the front floor frame and the rear flange portion of the cross member, and the gap portion absorbs the impact at the time of collision. A buffer area for

According to the second aspect of the present invention, the joint portion of the reinforcing member disposed in the cross member and the joint flange portion provided at the rear end portion of the front floor frame are interposed by the floor panel. The front end of the front floor frame and the rear end of the front member of the cross member are joined together as a result of the clearance. It will be stably supported.

According to the third aspect of the present invention, the cross member is reinforced in the vehicle width direction by the reinforcing member arranged in the cross member, and the mounting portion of the passenger seat is reinforced by the reinforcing member. Will be done.

[0013]

1 to 3 show an embodiment of a lower body structure of an automobile according to the present invention. This lower vehicle body structure includes a floor panel 1 that forms the bottom of a vehicle compartment, a cross member 2 that is installed on the upper surface of the floor panel 1 and extends in the vehicle width direction, and a front and rear of the vehicle body that is installed on the lower surface of the floor panel 1. Front floor frame 3 extending in the direction, and a pair of left and right side sills 4 arranged on the sides of the floor panel 1.
And have.

A tunnel portion 5 extending in the front-rear direction of the vehicle body is formed in the center portion of the floor panel 1, and a cross member 2 extending in the vehicle width direction is arranged so as to intersect with the tunnel portion 5. The cross member 2 is normally N
o. It is called a two-cross member and is arranged in the installation portion of the passenger seat (front seat). The cross member 2 is composed of a pair of left and right side members 6 arranged between the left and right side sills 4, and a central portion 7 connecting the both side members 6 to each other above the tunnel portion 5. ing.

The side member 6 includes a pair of front and rear wall plates 8 and 9.
And a top plate 10 provided on the upper end thereof are formed in a U-shaped cross section, and a mounting hole 11 for a seat bracket (not shown) for supporting the front part of the occupant seat is formed in the top plate 10. Has been done. The front flange portion 12 provided at the lower end portion of the front wall plate 8 and the rear flange portion 13 provided at the lower end portion of the rear wall plate 9 are joined to the upper surface of the floor panel 1, and The inner flange portion 14 provided at the inner end portion of the square member 6 is joined to the side wall surface of the tunnel portion 5 so that the cross member 2 is installed so as to intersect the tunnel portion 5.

Further, in the side member 6 of the cross member 2, the occupant's seat including the mounting hole 11 disposed between the installation portion of the side sill 4 and the installation portion of the front floor frame 3 is provided. A reinforcing member including a cross member gusset 15 that reinforces the installation portion, and a reinforcement 16 that is disposed between the top plate 10 and the floor panel 1 and reinforces the inner portion of the mounting hole 11 are provided. ing.

The cross member gusset 15 has an upper wall 17 joined to the lower surface of the top plate 10 of the side member 6 and a pair of side walls 18 joined to the inner surfaces of the front and rear wall plates 8 and 9.
And has a U-shaped cross section. Further, the cross member gusset 15 has a joint portion 18 formed at the outer end portion of the upper wall 17 which is sandwiched and joined between the inner end portion of the side sill 4 and the outer end portion of the side member 6. In addition, an end plate 20 having a joint flange portion 19 joined to the floor panel 1 is provided at the inner end portion. The joint flange portion 19 provided on the inner end portion of the cross member gusset 15 is joined to the upper surface of the floor panel 1 below the mounting hole 11.

Further, the reinforcement 16 is
An upper flange portion 21 joined to the lower surface of the top plate 10 of the cross member 2, a lower flange portion 22 joined to the upper surface of the floor panel 1, and the cross member provided between the flange portions 21 and 22. 2 has a main body 23 that constitutes a node that divides the inside of the unit 2 into left and right.

The front floor frame 3 is installed between the side sill 4 and the tunnel portion 5 so as to extend rearward from the front end portion of the floor panel 1. The front floor frame 3 has a pair of left and right side plates 2.
4, 25 and a bottom plate 26 provided at the lower ends of the side plates 24, 25 are formed in a U-shape in cross section. The upper ends of the side plates 24, 25 are joined to the lower surface of the floor panel 1. Joint flange portions 27 and 28 are provided.

At the rear end portion of the front floor frame 3, as shown in FIG. 3, front and rear flange portions 1 provided at the lower ends of both wall plates 8 and 9 constituting the cross member 2.
Between 2 and 13, a rear wall plate 30 having a joint flange portion 29 joined to the lower surface of the floor panel 1 is provided. The rear end of the side plate 25 located on the inner side of the front floor frame 3 faces the end plate 20 provided at the inner end of the cross member gusset 15, as shown in FIGS. 2 and 3. This end plate 2 is installed at the position
The joint flange portion 19 of No. 0 and the joint flange portion 28 of the side plate 25 are integrally joined via the floor panel 1.

In the lower vehicle body structure having the cross member 2 for reinforcing the installation portion of the occupant seat and the front floor frame 3 for reinforcing the front portion of the floor panel as described above, the rear end portion of the front lower frame 3 Is located at the installation portion of the cross member 2, it is possible to effectively prevent the front portion of the floor panel 1 supported by the front floor frame 3 from retracting in the event of an automobile collision by the cross member 2.

Since the rear wall plate 30 provided at the rear end portion of the front floor frame 3 is arranged between the front side flange portion 12 and the rear side flange portion 13 of the cross member 2, the rear wall plate 30 acts when the vehicle collides. Depending on the impact load applied, the installation portion of the cross member 2 is pushed back by the front floor frame 3, or the cross member 2 and the occupant seat placed thereon are deformed so as to be pushed up. Can be prevented.

That is, since the rear end portion of the front floor frame 3 and the rear side flange portion 13 of the cross member 2 are separated from each other to provide a gap serving as a buffer area therebetween, the front floor frame 3 is retracted. When a large load or a moment load for raising the rear end portion of the front floor frame 3 is applied, the load is absorbed in the buffer area, whereby the cross member 2 is installed in conjunction with the front floor frame 3. The deformation of the part can be effectively suppressed.

Further, as described above, the reinforcing member including the cross member gusset 15 is provided in the cross member 2, and the joint flange portion 19 provided at the inner end portion thereof is provided at the rear end portion of the front floor frame 3. When the flange portions 19 and 28 are arranged so as to be opposed to each other and the flange portions 19 and 28 are integrally joined via the floor panel 1, the rear end portion of the front floor frame 3 is It can be supported by the cross member gusset 15.

Therefore, the load transmitted from the front portion of the vehicle body through the front floor frame 3 is dispersed and supported by both the cross member 2 and the cross member gusset 15, and local deformation of the lower vehicle body is suppressed. can do. Further, by supporting the load acting at the time of a side collision of the automobile by both the cross member 2 and the cross member gusset 15, the deformation of the lower vehicle body can be suppressed.

In the above embodiment, the joint portion 18 provided on the outer end portion of the cross member gusset 15 is joined to the inner end portion of the side sill 4 and the joint portion 18 provided on the inner end portion of the cross member gusset 15. Since the flange portion 19 is arranged below the mounting portion of the occupant seat including the mounting hole 11, the mounting portion of the occupant seat can be effectively reinforced by the cross member gusset 15. Further, there is an advantage that the mounting hole 11 can be used as a working hole when the joint portion 19 is spot-welded and mounted to the floor panel 1.

Further, as shown in the above-mentioned embodiment, when a reinforcement 16 for connecting the top plate 10 and the floor panel 1 is arranged inside the mounting hole 11 to form a node, The inner portion of the mounting portion of the occupant seat can be effectively reinforced with a simple structure, and the deformation of the cross member 21 due to torsion can be suppressed by the reinforcement 16.

As shown in FIGS. 4 and 5, a covering member 31 is installed to cover the rear surface of the connecting portion between the tunnel portion 5 and the cross member 2, and the covering member 31 and the side wall portion of the tunnel portion 5 are provided. You may make it form the closed cross section 32 with the floor panel 1, and in this case, with a simple structure,
It is possible to sufficiently secure the connecting strength between the tunnel portion 5 and the cross member 2. By adopting a configuration in which the rear end portion of the covering member 31 is extended to the installation portion of the seat bracket 33 that supports the rear portion of the occupant seat,
By the closed cross section 32 and the cross member 2, the installation portion of the seat bracket 33 can be reinforced and its supporting strength can be increased.

[0029]

As described above, the present invention provides a lower vehicle body structure constructed such that a front member of a floor panel supported by a front floor frame is prevented from retracting by a cross member when a vehicle crashes. Since the rear end portion of the front floor frame is arranged between the front flange portion and the rear flange portion of the cross member, the front floor frame is pushed back by the front floor frame in response to the impact load applied at the time of a collision of the vehicle. It is possible to prevent the cross member and the occupant seat installed on the cross member from being deformed by being pushed up.
Therefore, there is an advantage that it is possible to effectively prevent the vehicle compartment from being adversely affected while appropriately absorbing the impact load at the time of a collision.

A reinforcing member extending in the vehicle width direction is installed in the cross member, and a joint portion of the reinforcing member to the floor panel is joined to the floor panel integrally with a joint portion provided at a rear end portion of the front floor frame. In such a case, the reinforcing member can reinforce the cross member and the rear end portion of the front floor frame.

Therefore, the load transmitted from the front portion of the vehicle body through the front floor frame at the time of a head-on collision of the vehicle is dispersed and supported by both the cross member and the cross member gusset, and the lower vehicle body is locally deformed. It is possible to suppress the deformation of the lower vehicle body by supporting both the cross member and the cross member gusset with the load that acts on the side collision of the vehicle.

In addition, a cross member is arranged so as to connect the left and right side sills, and a mounting portion for an occupant seat is provided on the upper wall of the cross member, so that a reinforcing member installed inside the cross member is provided. When the outer end portion is joined to the side sill and the inner end portion of the reinforcing member is positioned below the mounting portion of the occupant seat, the mounting portion of the occupant seat is effectively reinforced by the reinforcing member. It has the advantage that it can be reinforced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a lower body structure of an automobile according to the present invention.

FIG. 2 is a front sectional view showing a main part of the lower vehicle body structure.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view showing an installation portion of a seat bracket.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

1 floor panel 2 cross member 3 front floor frame 4 side sill 5 tunnel part 8 front wall plate 9 rear wall plate 11 mounting hole (mounting part) 15 cross member gusset (reinforcing member) 29 joint flange part (rear end part of front floor frame) )

Claims (3)

[Claims] 1. A floor panel in which a tunnel portion extending in the front-rear direction of the vehicle body is formed, a cross member installed in the vehicle width direction so as to intersect with the tunnel portion, and a pair of left and right installed on the lower surface of the floor panel. In a lower body structure of an automobile having a front floor frame of, a front flange portion provided at a lower end portion of a front wall plate forming the cross member and a rear flange portion provided at a lower end portion of a rear wall plate. A lower body structure of an automobile, characterized in that a rear end portion of a front floor frame is located between them. 2. A reinforcing member extending in the vehicle width direction is installed in the cross member, and a joint portion of the reinforcing member to the floor panel is located at a position facing a joint flange portion provided at a rear end portion of the front floor frame. The lower body structure of the automobile according to claim 1, wherein the lower body structure is installed. 3. A cross member is disposed so as to connect the left and right side sills, and an occupant seat mounting portion is provided on an upper wall of the cross member, and a reinforcing member installed inside the cross member. The outer end portion is joined to the side sill, and the inner end portion of the reinforcing member is located below the attachment portion of the occupant seat.
The lower body structure of the described vehicle.