JP2005161975A - Lower structure of vehicle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower structure of a vehicle body capable of enhancing the rigidity without propagating any vibration unnecessary for an occupant. <P>SOLUTION: The lower structure of the vehicle body comprises a floor panel 2 in which a tunnel part 1 extending in the longitudinal direction of the vehicle body is formed substantially in the center of the vehicle width direction, first cross members 10 and 12 extending in the vehicle width direction at the position separate from a bulkhead backward of the vehicle body to reinforce the floor panel, a second cross member 20 extending in the vehicle width direction at the position backward of the first cross members to reinforce the floor panel, and a pair of right and left tunnel side members 30 mounted on the floor panel so as to extend along the tunnel part on both sides of the vehicle width direction of the tunnel part between the first and second cross members. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle body lower structure, and more particularly, to a vehicle body lower structure including a tunnel side member that reinforces a tunnel portion formed in a floor panel.

2. Description of the Related Art As a lower body structure of an automobile, a structure in which a tunnel panel that extends in the longitudinal direction of a vehicle body and through which a drive shaft passes is formed on a floor panel is used. In such a vehicle body lower structure, a structure in which a reinforcing member extending in the longitudinal direction of the vehicle body is disposed in the vicinity of the tunnel portion may be employed in order to reinforce the tunnel portion.
For example, a vehicle body floor structure has been proposed in which a tunnel side member extending along a tunnel portion is attached to a floor panel to improve the rigidity of a vehicle floor structure (see, for example, Patent Document 1).

JP-A-5-193526

  In this prior art structure, the tunnel side member extends over its entire length in parallel with the tunnel portion. Therefore, since the front end portion of the tunnel side member is located in the vicinity of the engine, vibration from the engine or the like is easily transmitted to the tunnel side member. Since the seat bracket for fixing the seat to the floor panel is disposed in the vicinity of the tunnel side member, in the above-described structure, the vibration transmitted from the engine or the like transmitted to the tunnel side member passes through the seat bracket as an unpleasant vibration to the passenger. There was a problem that passenger comfort was lost.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a vehicle body lower structure capable of improving rigidity without transmitting unnecessary vibration to an occupant.

  According to the present invention, a tunnel panel extending in the vehicle longitudinal direction is formed at a substantially central position in the vehicle width direction, and the floor panel extends in the vehicle width direction at a position spaced from the bulkhead to the vehicle body rear side to reinforce the floor panel. A vehicle width of the tunnel portion between the cross member, a second cross member extending in the vehicle width direction at a rear position of the first cross member and reinforcing the floor panel, and between the first cross member and the second cross member There is provided a vehicle body lower structure comprising a pair of left and right tunnel side members attached to the floor panel so as to extend along both sides in the direction along the tunnel portion.

According to such a configuration, the front end of the tunnel side member that reinforces the tunnel portion is disposed on the rear side of the first cross member disposed on the rear side of the bulkhead that divides the engine room. Vibration from the engine or the like is not easily transmitted to the side member. Furthermore, since the length of the tunnel side member is shortened, weight reduction is achieved. On the other hand, the rigidity required for the floor panel is secured by the tunnel side member, the first cross member before and after the tunnel side member, and the second cross member.
In particular, when combined with a configuration in which a seat is disposed at a position between the first cross member and the second cross member, such as a two-theta open car, the rigidity of the floor portion where the seat abuts is locally increased. . Further, when combined with such a configuration, the rear end of the tunnel side member is disposed at a position close to the rear suspension, so that road surface information such as vibration from the rear suspension is easily transmitted to the tunnel side member.

According to the other preferable aspect of this invention, the said tunnel side member is arrange | positioned in the boundary part vicinity of the tunnel part of the said floor panel, and the plane part located in the outer side.
According to such a configuration, the tunnel portion can be effectively reinforced by the tunnel side member.

According to another preferred aspect of the present invention, a seat bracket is attached to the floor panel on both sides of the tunnel portion, and the seat bracket is disposed so as to at least partially overlap the tunnel side member in the vertical direction. Yes.
According to such a configuration, although the mounting rigidity of the seat is improved by the tunnel side member, vibration from the engine or the like is difficult to be input to the tunnel side member, so vibration unpleasant for the occupant is hardly transmitted to the seat.

According to another preferred aspect of the present invention, the front portion of the seat bracket is disposed so as to overlap the front end portion of the tunnel side member in the vertical direction, and the rear portion of the seat bracket is the rear end of the tunnel side member. It is arranged so as to overlap the part in the vertical direction.
According to such a configuration, since the seat is fixed to the floor panel at the position of the end of the tunnel side member, the seat mounting rigidity is further increased.

According to another preferred aspect of the present invention, the front end of the tunnel side member is disposed so as to overlap the first cross member in the vertical direction.
According to such a configuration, the rigidity of the center position of the floor panel in the longitudinal direction of the vehicle body is increased. Further, the input to the tunnel side member is distributed to the left and right of the vehicle body through the first cross member.

According to the other preferable aspect of this invention, the connection member which connects the right and left open ends of the said tunnel part is provided.
According to such a configuration, the so-called opening where the side walls of the tunnel portion fall toward each other can be suppressed, and the rigidity of the floor panel can be improved in the vicinity of the connecting member.
According to the other preferable aspect of this invention, the said connection member is equipped with the X-type member.

  According to another preferred aspect of the present invention, a kick-up portion extending obliquely upward is provided at a rear portion of the floor panel, and the second cross member is connected to the floor panel at the kick-up portion. Is reinforced.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle body lower part structure which can improve rigidity, without transmitting an unnecessary vibration to a passenger | crew is provided.

Hereinafter, a vehicle body lower part structure according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. This embodiment is an example in which the lower body structure of the present invention is applied to the lower body structure of a two-seater passenger car (sports car).
FIG. 1 is a perspective view of a lower body structure according to an embodiment of the present invention cut at a seat rear end position of a seat and viewed from an obliquely upper position on the vehicle rear side, and FIG. FIG. 3 is a bottom view of the vehicle body lower structure in FIG. 1. FIG. 4 is a perspective view of the floor panel of the vehicle body lower structure of FIGS. 1 to 3 as viewed from an obliquely upper position in front of the vehicle body.

  As shown in FIGS. 1 and 2, the vehicle body lower structure of the present embodiment includes a floor panel 2 in which a tunnel portion 1 that protrudes upward in a convex shape is formed. The tunnel portion 1 extends in the longitudinal direction of the vehicle body at a substantially central position in the vehicle width direction of the left and right seats 4, 4. The tunnel portion 1 opens downward, and a drive shaft (not shown) is disposed inside. In the present embodiment, the floor panel 2 forms substantially flat portions 6 on both sides of the tunnel portion 1.

As shown in FIG. 3, the vehicle body lower structure of the present embodiment has a pair of left and right first pairs arranged so as to extend in the vehicle width direction at positions spaced apart from the bulkhead 8 separating the engine room to the rear of the vehicle body. Cross members 10 and 12 are provided.
Each of the first cross members 10 and 12 is a member obtained by bending an elongated plate-like portion into a substantially U-shaped cross section, and forms a closed cross section with the upper side surface of the floor panel 1 so as to form a closed cross section. Is mounted at a substantially central position in the longitudinal direction of the vehicle body on the passenger compartment side (FIG. 4). The left first cross member 10 connects the left outer wall of the tunnel portion 1 and the left side sill 14, and the right first cross member 12 connects the right outer wall of the tunnel portion 1 and the right side sill 16. Yes.

As shown in FIG. 4, the rear end of the floor panel 1 of the present embodiment is connected to a kick-up portion 18 that extends substantially vertically toward a diagonally upward direction. The kick-up portion 18 is formed by a separate plate member connected to the rear end of the floor panel 1. A second cross member 20 arranged so as to extend in the vehicle width direction is attached to the rear side of the upper end portion of the kick-up portion 18.
Specifically, the second cross member 20 extends upward from the rear ends of the side sills 14 and 16, and is attached between the connecting members 26 and 28 connected to the front ends of the rear side frames 22 and 24. . Further, the second cross member 20 is also connected to the rear surface of the kick-up portion 18. Thus, the 2nd cross member 20 is connected with the floor panel 2 via the kick-up part 18 and the connection members 26 and 28, and reinforces this. A suspension cross member (not shown) connected to the rear suspension is attached to the rear side frames 22 and 24.

  A pair of tunnel side members 30 that reinforce the tunnel portion 1 are attached to both side edges of the tunnel portion 1. The tunnel side member 30 is a member obtained by bending a rectangular plate-like member into a substantially U shape, and the back side of the floor panel 2 so as to form a closed cross section with the back surface (lower side surface) of the floor panel 2. Installed on. Each tunnel side member 30 is attached to the boundary region between the tunnel portion 1 and the flat portion 6 so as to extend along the tunnel portion 1.

  In the present embodiment, the tunnel side member 30 is arranged such that the front end overlaps with the first cross members 10, 12 in the vertical direction and the rear end is forward of the second cross member 20. Therefore, in the vehicle body lower structure of the present embodiment, the tunnel side member 30 is disposed between the first cross members 10, 12 and the second cross member 20. As a result, in this embodiment, the front end of the tunnel side member 30 is disposed at a position away from the engine.

  As shown in FIG. 1, left and right rear seat brackets 32 for connecting the seat 4 to the floor panel 2 are attached to the front side surface of the floor panel 2 below the rear portion of the seat 4. Rear seat mounting members 34 and 36 (not shown in FIG. 4) are connected to positions (FIG. 4) indicated by crosses 34 'and 36' on the seat brackets 32, respectively. A rear portion of a seat rail connected to the seat 4 is attached to the attachment members 34 and 36. The rear seat bracket 32 (the rear portion of the seat bracket) inward in the vehicle width direction is disposed so as to overlap the rear end portion of the tunnel side member 30 in the vertical direction.

In the present embodiment, both end portions of the left and right first cross members 10 and 12 extending in the vehicle width direction also serve as front seat brackets, and the left and right first cross members 10 and 12 have both end portions. Front side seat attachment members (not shown) are connected to the positions indicated by crosses 35 ′ and 37 ′ (FIG. 4). And the front part of a seat rail is connected with this front side seat attachment member.
As described above, since the front end portion of the tunnel side member 30 is disposed at a position overlapping the first cross members 10 and 12 in the vertical direction, the front seat bracket (the first cross member 10, 12 in the vehicle width direction inner end portion, that is, the front portion of the seat bracket) overlaps with the front end portion of the tunnel side member 30 in the vertical direction.

  With the arrangement as described above, in the present embodiment, the front seat bracket 32a that fixes the front end portion of the seat rail 36 on the inner side in the vehicle width direction is the front end portion of the tunnel side member 30 and the inner side in the vehicle width direction. The rear seat bracket 32b for fixing the rear end portion of the seat rail 28 is disposed so as to overlap the rear end portion of the tunnel side member 30 in the vertical direction.

Furthermore, the vehicle body lower structure of the present embodiment includes a connecting member 38 that covers the tunnel portion 1 from the back side of the floor panel 2 and connects the left and right open ends of the tunnel portion 1. The connecting member 38 has a shape in which an X-shaped inner member 38b is disposed in a rectangular outer frame 38a.
In the present embodiment, as shown in FIGS. 3 and 2, the length of the connecting member 30 in the longitudinal direction of the vehicle body is set substantially equal to the length of the tunnel side member 30 in the longitudinal direction of the vehicle body. The connecting members 38 are fixed at the front and rear end portions of the left and right tunnel side members 30 attached to the back surface of the floor panel 2 on both sides of the tunnel portion 1 to connect the left and right tunnel side members 30. doing.

According to the vehicle body lower structure of the present embodiment configured as described above, the tunnel side member has a structure extending toward the rear of the vehicle body from a position spaced rearward from the bulkhead. Transmission to the seat via the side member is suppressed.
On the other hand, the rear end of the tunnel side member is connected to a second cross member that connects the left and right rear side frames via a kick-up portion. Since a suspension cross member is connected to the rear side frame, vibration from the rear suspension or the like is transmitted to the seat via the kick-up portion, the tunnel side member, or the like.
Therefore, in the configuration of the above-described embodiment, it is possible to provide the occupant with vibration (road surface information) from the rear suspension while eliminating unpleasant vibration from the engine or the like.

  Further, since the tunnel side member, the seat bracket, and the connecting member are arranged so as to overlap in the vertical direction, the seat mounting rigidity and the floor panel rigidity are improved. Furthermore, since the length of the tunnel side member is shortened, the floor structure is lightweight.

The present invention is not limited to the above-described embodiments, and various changes or modifications can be made within the scope of the technical matters described in the claims.
In the above embodiment, the rear part of the floor panel is a kick-up part, and the second cross member is connected in the vicinity of the upper end of the kick-up part. However, the present invention includes a kick-up part at the rear part. The present invention is also applicable to a vehicle body lower structure having no floor panel.
In such a configuration, it is preferable that the second cross member is divided into a tunnel portion like the first cross member, and is arranged at a position overlapping the rear end portion of the tunnel side member in the vertical direction.

It is the perspective view which cut the body lower part structure of one embodiment of the present invention in the seat surface rear end position of the seat, and was seen from the slanting upper position on the vehicle rear side. It is the perspective view which looked at FIG. 1 from the diagonally lower position of the vehicle rear side. It is a top view of the vehicle body lower part structure of FIG. It is a typical side view of the vehicle body lower part structure of FIG.

Explanation of symbols

1: Tunnel portion 2: Floor panel 4: Seat 6: Flat portion 8: Bulkhead 10, 12: First cross member 14: Left side sill 16: Right side sill 18: Kick-up portion 20: Second cross member 30: Tunnel side Member 38: connecting member

Claims (8)

A floor panel in which the tunnel portion extending in the longitudinal direction of the vehicle body is formed at the approximate center in the vehicle width direction;
A first cross member that extends in the vehicle width direction at a position separated from the bulkhead rearward of the vehicle body and reinforces the floor panel;
A second cross member extending in the vehicle width direction at a rear position of the first cross member and reinforcing the floor panel;
A pair of left and right tunnel side members attached to the floor panel so as to extend along both sides of the tunnel portion in the vehicle width direction between the first cross member and the second cross member. ing,
The underbody structure characterized by that. The tunnel side member is disposed in the vicinity of the boundary portion between the tunnel portion of the floor panel and the flat portion located outside thereof.
The vehicle body lower structure according to claim 1. A seat bracket is attached to the floor panel on both sides of the tunnel portion, and the seat bracket is disposed so that at least a portion thereof overlaps the tunnel side member in the vertical direction.
The vehicle body lower part structure according to claim 1 or 2. The front portion of the seat bracket is disposed so as to overlap the front end portion of the tunnel side member in the vertical direction, and
The rear portion of the seat bracket is disposed so as to overlap the rear end portion of the tunnel side member in the vertical direction.
The vehicle body lower structure according to claim 3. The front end of the tunnel side member is disposed so as to overlap the first cross member in the vertical direction.
The vehicle body lower part structure according to any one of claims 1 to 4. A connecting member that connects the left and right open ends of the tunnel portion is provided,
The vehicle body lower part structure according to any one of claims 1 to 5. The connecting member includes an X-shaped member;
The vehicle body lower structure according to claim 6. A kick-up portion extending obliquely upward is provided at the rear of the floor panel,
The second cross member is connected to the floor panel at the kick-up portion and reinforces the floor panel.
The vehicle body lower part structure according to any one of claims 1 to 7.

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