JPH04300792A - Lower body structure for automobile - Google Patents

Abstract

PURPOSE:To improve the rigidity of a floor panel of a mount supporting part and its peripheral part by effectively utilizing front and rear cross members in a body in which the floor panel is mounted and supported with chasis frames. CONSTITUTION:Front and rear side cross members 2 and 3 are welded to a floor panel 1 composing a body flood part so as to form a closed cross section in company with the floor panel 1. The rear side cross member 3 is composed of a main part 3a extending in a vehicle width direction, and connecting parts 3b extending from both the sides of the main part 3a to a body fore-and-aft direction. The front end parts of both the connecting parts 3b are welded to the front side cross member 2 respectively, and this connects the front and rear cross members 2 and 3. The floor panel 1 is mounted and supported with chasis frames 4 at the linked part of the front and rear cross members 2 and 3. The rigidity of the floor panel of a mount supporting part and its peripheral part is improved with the front and rear cross members 2 and 3 mutually linked.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a lower body structure of an automobile,
In particular, the present invention relates to a mount support portion in a vehicle body in which the body of the vehicle is mounted and supported by a chassis frame, and the vehicle body structure around the mount support portion.

0002

[Prior Art] An automobile body has an integral structure in which the body and chassis frame are integrally formed, and a chassis frame that is separate from the body. The vehicle body has a structure for attaching (
Hereinafter, the chassis frame supporting the body via the mount in this manner will be referred to as "mount support."

[0003] In the case of a car body in which the chassis frame mounts and supports the body, the mount support part on the body side receives external forces such as thrusting, torsion, and vibration while driving, so this mount support part must have bending and torsional strength. It is necessary to BACKGROUND ART Conventionally, there is a vehicle body in which a body-side mount support portion is provided on a floor panel, and a chassis frame mounts and supports the floor panel.

0004

As described above, when the chassis frame mounts and supports the floor panel, the floor panel is formed of a thin steel plate and therefore does not have sufficient strength as a mount support. Therefore, as disclosed in, for example, Japanese Utility Model Application Publication No. 60-173473, it is conceivable to join a cross member to the floor panel so that the chassis frame mounts and supports the floor panel at this joint.

However, generally, a plurality of such cross members are arranged on the front panel so as to extend independently in the vehicle width direction, and they are said to increase the surface rigidity of the entire floor panel. Although it is effective in terms of
When viewed as a mount support as described above, the rigidity of the mount support was not sufficient, as the floor panel around the mount support was bent due to thrusting up while driving.

In view of the above-mentioned problems, the present invention effectively utilizes cross members disposed at the front and rear of a vehicle body in which a chassis frame mounts and supports a floor panel, thereby increasing the rigidity of the mount support portion and the surrounding floor panel. The object of the present invention is to provide a lower body structure for an automobile that can improve the performance.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the lower body structure of an automobile according to the present invention includes a floor panel constituting the floor of the vehicle body, and a front and rear panel extending in the vehicle width direction joined to the floor panel. It comprises a pair of cross members and a chassis frame provided below the floor panel, and at least one of the pair of cross members has a main part extending in the vehicle width direction, and a connecting part extending in the longitudinal direction of the vehicle body and connected to the other cross member, ◆The floor panel is mounted to the chassis frame at the connecting part where the pair of cross members are connected. It is characterized by being supported.

Furthermore, in order to solve the above problem, the lower body structure of an automobile according to the present invention includes, in addition to the above structure, a pair of said communication parts extending from the vicinity of both ends of said main part. You can also do it. Moreover, this also allows the fuel tank to be placed in a position surrounded by the pair of cross members.

[0009]

[Operations and Effects] As described above, in the lower body structure of an automobile according to the present invention, at least the cross member of the pair of front and rear cross members extending in the vehicle width direction joined to the floor panel is the main part extending in the vehicle width direction. A chassis frame that extends from this main part in the longitudinal direction of the vehicle and is connected to the other cross member, and is provided below the floor panel at the connection part where both cross members are connected. is what mounts and supports this floor panel.

[0010] Forces such as thrusting up that are applied from the chassis frame to the mount support portion during driving are transmitted to and supported by the front and rear cross members, respectively, thereby suppressing the deflection of the floor panel around the mount support portion due to thrusting. be able to. As described above, the lower body structure of an automobile according to the present invention interconnects the front and rear cross members, which were conventionally used independently, and makes effective use of these cross members, thereby increasing the mount support portion and its The rigidity of the floor panel in the peripheral area can be improved.

[0011] Furthermore, if a pair of the connecting parts are provided extending from the vicinity of both ends of the main part, the pair of front and rear cross members can be more firmly connected, so that the mount support part and its surrounding parts can be connected more firmly. The rigidity of the floor panel can be further improved. Additionally, by placing the fuel tank in a position surrounded by a pair of front and rear cross members, the fuel tank is protected by the front and rear cross members, which prevents the fuel tank from being damaged in the event of a collision. .

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the lower body structure of an automobile according to the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view schematically showing the overall structure of a lower body structure of an automobile according to an embodiment of the present invention, and FIGS. 2 and 3 are views schematically showing partial structures thereof. 2 is a sectional view taken along the line II-II in FIG. 1, FIG. 3 is a sectional view taken along the line III-III in FIG. 1, FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. Figure 6 is a diagram showing the structure of a pair of front and rear cross members; Figure (a) is an external perspective view of the rear cross member, Figure (b) is an external perspective view of the front cross member, and Figure 6
FIG. 2 is an external perspective view showing the configuration of a connecting portion of a pair of front and rear cross members.

As shown in FIG. 1, the lower body structure of the automobile of this embodiment relates to the rear part of the car body, and includes a floor panel 1 constituting the floor part of the rear part of the car body, and is connected to the floor panel 1, respectively. It includes a front cross member 2 and a rear cross member 3 extending in the width direction, and a chassis frame 4 (only a portion shown) extending in the longitudinal direction of the vehicle body below the floor panel 1.

The floor panel 1 is composed of a lower part 1a, a rising part 1b, and an upper part 1b, and has a tunnel part 5 in the center part in the vehicle width direction that bulges inward of the passenger compartment and extends in the longitudinal direction of the vehicle body. In addition, both end edges in the vehicle width direction are connected to the inner panel 6b of the side sill 6 extending in the longitudinal direction of the vehicle body, where the outer panel 6a and the inner panel 6b form a closed cross section at the lower section 1a and the rising section 1b, and at the upper section. 1c
Here, they are each welded to a wheel house 7 that accommodates a rear wheel (not shown).

As shown in FIG. 5(a), the rear cross member 3 has a U-shaped cross section, and includes a main portion 3a extending in the vehicle width direction, and a main portion 3a extending in the longitudinal direction of the vehicle from both sides of the main portion 3a. A communication section 3b is provided. Further, a flange 3c is formed on the upper part of the main part 3a and the communication part 3b, and connection flanges 3d and 3e are formed on the front end of the communication part 3b, respectively. On the other hand, as shown in FIG. 5(b), the front cross member 2 is formed to have an L-shaped cross section, and is displaced in the longitudinal direction of the vehicle body at an intermediate portion in the vehicle width direction. and flanges 2a, 2b and 2c on its top, front and both ends.
are formed respectively.

As shown in FIG. 1, the upper flange 2a of the front cross member 2 is attached to the upper part 1c of the floor panel 1.
The front flange 2b is welded to the rising portion 1b of the floor panel 1, and the flanges 2c at both ends are welded to the inner panels 6b of the side sills 6 on both sides, so that the front cross member 2 is welded together with the floor panel 1. It forms a closed cross section. On the other hand, the upper flange 3c of the rear cross member 3 is welded to the upper part 1c of the floor panel 1, and the rear cross member 3 and the floor panel 1 form a closed cross section. Further, as shown in FIG. 6, connecting flanges 3d and 3 formed at the front end of the connecting portion 3b of the rear cross member 3
e is welded to the front flange 2 so as to connect the front and rear cross members 2 and 3. As a result, a space surrounded by the front and rear cross members 2 and 3 is formed below the upper part 1c of the floor panel 1.
As shown in FIGS. 1 and 2, this space includes a fuel tank 8.
is located.

As shown in FIGS. 3 and 4, at the connecting portion where the front cross member 2 and the rear cross member 3 are connected, the floor panel 1 is connected via a mount bracket 9, a rubber mount 10, and a chassis bracket 11. It is mounted and supported by the chassis frame 4. As clearly shown in FIG. 4, the upper surface part 9a of the mount bracket 9 is connected to the connecting flange 3e formed at the front end of the connecting part 3b of the rear cross member 3, and the front part 9b is connected to the rising part 1b of the floor panel 1. are welded to each. Further, as shown in FIG. 3, the end of the chassis bracket 11 is attached to the chassis frame 4.
is welded to. As clearly shown in FIG. 4, the front cross member 2 and the chassis bracket 11 are connected to each other via the flange 3e of the rear cross member 3, the upper surface 9a of the mount bracket 9, and the rubber mount 10.
and are connected by a nut 13. As described above, in this embodiment, the cross-sectional structure of the part where the upper part of the rubber mount 10 comes into contact has a three-layer structure consisting of the upper surface part 9a of the mount bracket 9, the flange 3e of the rear cross member 3, and the front cross member 2. As a result, the rigidity of this portion is increased so that it has sufficient resistance against pushing up from the chassis frame 4 while driving.

Further, as shown in FIGS. 1 and 2, a rear seat 14 is provided in the upper section 1c of the floor panel 1. This rear seat 14 is bolted to the floor panel 1, and as shown in FIG.
The end of the seat belt 15 is bolted to the joint between the upper section 1c of the floor panel 1 and the rear cross member 3. As a result, in this embodiment, the force acting on the seat belt 15 during a car collision is transmitted to and supported by the rear cross member 3, front cross member 2, and side sill 6, thereby increasing safety.

Although the lower body structure of an automobile according to the present invention has been described above based on one embodiment, the lower body structure of an automobile according to the present invention is not limited to this embodiment.

For example, although the embodiment described above relates to the structure of the rear body of an automobile, the present invention can be applied not only to the rear body but also to the front and middle parts of the body.

Furthermore, in the embodiment described above, the connecting portion 3b of the rear cross member 3 is formed to extend from both ends of the main portion 3a, but the connecting portion 3b is formed to extend from the middle portion of the main portion 3a. It is also possible to provide such a configuration, and the shapes of the front and rear cross members 2 and 3 can also be changed as appropriate.

Furthermore, the configuration of the mount support portion can be changed as appropriate depending on the vehicle body, such as by mounting and supporting the chassis frame 4 without using the chassis bracket 11.

[Brief explanation of drawings]

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

FIG. 2 is a sectional view taken along line II-II in FIG. 1, schematically showing a partial configuration of a lower body structure of an automobile according to an embodiment of the present invention;

FIG. 3 is III- in FIG. 1 schematically showing a partial configuration of a lower body structure of an automobile according to an embodiment of the present invention;
III Line sectional view

FIG. 4 shows IV-IV in FIG. 3 showing the configuration of a mount support portion of a lower vehicle body structure of an automobile according to an embodiment of the present invention.
Enlarged cross-sectional view

FIG. 5 is an external perspective view showing the structure of a pair of front and rear cross members of the lower body structure of an automobile according to an embodiment of the present invention.

FIG. 6 is an external perspective view showing the configuration of a connecting portion between a pair of front and rear cross members of a lower vehicle body structure of an automobile according to an embodiment of the present invention;

[Explanation of symbols]

1 Floor panel 2, 3 Cross member 3a Main part 3b Liaison Department 4 Chassis frame 8 Fuel tank

Claims (2)

[Claims] [Claim 1] A floor panel constituting a vehicle body floor;
Front and rear 1 extending in the vehicle width direction connected to this floor panel
It includes a pair of cross members and a chassis frame provided below the floor panel, and at least one cross member of the pair of cross members has a main part extending in the vehicle width direction, and a main part extending from the main part. a connecting portion extending in the longitudinal direction of the vehicle body and connected to the other cross member, and the floor panel is mounted and supported by the chassis frame at the connecting portion where the pair of cross members are connected. An automobile lower body structure characterized by: 2. A pair of communication portions are provided extending from near both ends of the main portion, and a fuel tank is disposed at a position surrounded by the pair of cross members. The lower body structure of a motor vehicle according to claim 1.