JPH06321138A - Vehicle body structure of automobile - Google Patents

Abstract

PURPOSE:To form easily the structure of a vehicle body having a complex shape and at the same time absorb effectively impact energy that acts on at the time of collision. CONSTITUTION:In the case of the vehicle body structure of an automobile having a side frame 2 that is provided on the lower surface of a floor panel 1 and extends in the longitudinal direction of a vehicle body, at least part of the side frame 2 is formed of a cast material consisting of a light alloy material or the like, and at the same time a floor panel 1 provided on the upper surface of the side frame 2 is formed of an expanded material consisting of a light alloy material or the like, and the vehicle body is constituted by joining these integrally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure for an automobile having a pair of left and right side frames arranged on the lower surface of a floor panel.

[0002]

2. Description of the Related Art A conventional body structure generally has a monocoque structure in which exterior members such as side panels and roof panels are integrally formed with a body frame. This monocoque structure has an advantage that the structure can be simplified by integrating the exterior member and the vehicle body frame, and at the same time, the energy of impact at the time of collision can be effectively absorbed, but the structure can be made common. Difficult and
There is a problem that the design change that changes the shape cannot be easily performed.

Further, as disclosed in, for example, Japanese Unexamined Patent Publication No. 62-88674, a first skeleton structure which constitutes a floor portion and a second skeleton structure which defines a passenger space and the like are respectively made of a light alloy. It has been practiced to easily form a highly rigid and highly accurate vehicle body by casting and integrally joining these.

[0004]

When the entire skeletal structure constituting the vehicle body is made of a light alloy casting material as described above, the light alloy casting material is more likely to be used than the wrought material. Since the toughness is low, the absorbed amount of impact energy that acts at the time of collision tends to be insufficient. It should be noted that by forming the frame material with a wrought material made of a light alloy, it may be possible to effectively absorb the impact energy at the time of collision, but in this case, the wrought material is used. Since it is difficult to form a complicated shape, there is a problem in that it is difficult to provide a connecting portion for the cross member or change the plate thickness of the frame material as necessary.

The present invention has been made in order to solve the above-mentioned problems, and can easily form a vehicle body structure having a complicated shape and can effectively absorb the impact energy that acts at the time of a collision. It is intended to provide a structure.

[0006]

The invention according to claim 1 is
In a vehicle body structure of an automobile having a floor panel and a side frame disposed below the floor panel and extending in the front-rear direction of the vehicle body, at least a part of the side frame is formed of a casting material, and an upper surface of the side frame is covered. The floor panel thus installed is formed by wrought material.

According to a second aspect of the present invention, in a vehicle body structure of an automobile having a side frame disposed on the lower surface of the floor panel and extending in the front-rear direction of the vehicle body, the side frame is divided into a front frame member and a rear frame member. One of them is made of a cast material and the other is made of a wrought material.

According to the third aspect of the present invention, a connecting portion for connecting the end of the frame material made of the cast material to the casing is provided at the end of the frame material made of the cast material.

[0009]

According to the invention described in claim 1, the side frame having a complicated shape is easily formed by the cast material, and the impact resistance of the vehicle body is secured by the floor panel made of the wrought material. become.

According to the second aspect of the present invention, of the front frame material or the rear frame material forming the side frame, a portion having a complicated shape such as a connecting portion of the cross member is formed by a casting material. Thus, excellent moldability can be obtained. Further, since the wrought material forms a portion of the both frame members to which a large impact load is input at the time of collision, the impact load at the time of collision is effectively absorbed.

According to the third aspect of the invention, the frame material made of the cast material and the frame material made of the wrought material are easily and firmly fixed at the connecting portion.

[0012]

FIG. 1 shows an embodiment of the vehicle body structure of an automobile according to the present invention. This vehicle body structure includes a floor panel 1 forming a floor surface of a rear vehicle body, a pair of left and right side frames 2 arranged below the floor panel 1 and extending in the front-rear direction of the vehicle body, and left and right side frames 2. It has a cross member 3 connected to each other at an intermediate portion.

The floor panel 1 is formed by a wrought material obtained by pressing or rolling a light alloy extruded material such as an aluminum alloy or a magnesium alloy. The side frame 2 and the cross member 3 are integrally formed from a cast material made of a light alloy such as an aluminum alloy or a magnesium alloy. The side frame 2 includes a front portion 4 connected to a rear end portion of a side sill (not shown), an intermediate portion 5 that extends from the rear end portion toward the inside of the vehicle body while extending rearward, and a rear end portion. It is composed of a rear portion 6 extending to the rear side of the vehicle body, and these are integrally cast.

The front portion 4 of the side frame 2 has a bottom plate 7
And an L-shaped section 9 having an inner plate 8 and the bottom plate 7
Has a U-shaped section 10 projecting from the front end of the. As shown in FIG. 2, a pair of projecting pieces 11 are provided on the lower surface of the bottom plate 7 so as to be opposed to each other. The both projecting pieces 11 form a suspension supporting portion for supporting the end 12 of the suspension member. There is.

The intermediate portion 5 of the side frame 2 is also provided.
Is a pair of left and right side plates 1 facing each other, as shown in FIG.
It is formed in a U-shaped cross section having 3, 3 and a bottom plate 15 connecting the lower end portions of the side plates 13, 14. The flange portion 16 provided on the upper end portion of the inner side plate 13 is joined to the lower surface of the floor panel 1 by means such as bolting or welding, and the upper end portion of the outer side plate 14 and the floor panel 1 are joined together. By joining the outer end of the vehicle body by welding or the like, a closed cross section 17 extending in the front-rear direction of the vehicle body is formed by the floor panel 1 and the intermediate portion 5 of the side frame 2.

As shown in FIG. 4, the rear portion 6 of the side frame 2 is formed in a U-shaped section having a pair of left and right side plates 18 and 19 and a bottom plate 20, and is provided at the upper ends of the side plates 18 and 19. The flange portion 21 is joined to the lower surface of the floor panel 1 by means such as welding so that a closed cross section 22 extending in the front-rear direction of the vehicle body is formed. Further, a pair of left and right tie-down hook mounting portions 23 are provided at predetermined positions on the lower surface of the bottom plate 20, and the base end portion of the tie-down hook 24 is welded to the inner wall surface of the mounting portion 23 by means such as welding. It is fixed.

As shown in FIG. 1, a bulging portion 25 having a screw hole into which a mounting bolt for a silencer (not shown) is screwed is provided at a predetermined position on the side plate 19 constituting the rear portion 6 of the side frame 2. Has been formed. Also, the side frame 2
The rear end portion is closed by an end plate 26.

The cross member 3 is formed in a U-shaped cross section, which is composed of a pair of front and rear side plates 27, 28 facing each other and a bottom plate 29 connecting the lower end portions thereof, and the outer end portion thereof is the side frame 2. Is integrally connected to the inner wall surface of the intermediate portion 5. Then, the flange portion 30 provided on the upper end portions of the side plates 27 and 28 is joined to the lower surface of the floor panel 1 by means such as welding so that a closed cross section extending in the vehicle width direction is formed. There is.

By joining the floor panel 1 made of wrought material made of light alloy to the upper surface of the side frame 2 made of cast material made of light alloy as described above, a closed cross section 17 extending in the longitudinal direction of the vehicle body, Since it is configured to form 22, the side portion of the rear vehicle body can be effectively reinforced with a simple configuration. That is, since the side frame 2 is formed of a cast material and the plate thickness of each part is easily set,
Side frame 2 according to the magnitude of the load acting
By setting the plate thickness of (1) to an appropriate value, it is possible to sufficiently secure the strength of the required portion without installing a reinforcement or the like.

Further, by bonding the floor panel 1 made of a wrought material having high toughness to the upper surface of the side frame 2, the insufficient toughness of the side frame 2 made of a cast material can be compensated by the floor panel 1. Therefore, it is possible to effectively absorb the impact load applied at the time of the collision of the automobile and to sufficiently secure the rigidity against the torsion load applied during the traveling.

Further, by using the side frame 2 and the cross member 3 which are integrally formed of the above-mentioned cast material as a common component in various vehicle bodies, the mass productivity can be improved and the floor made of the wrought material can be improved. The design of the vehicle body structure can be easily changed by changing the shape of the panel 1.

Further, since the floor panel 1 exposed to the outside in the trunk room of the rear vehicle body is formed of the above-mentioned wrought material, there is no need for complicated surface finishing.
The appearance of the rear vehicle body can be maintained in a good state. Then, the side frame 2 having a complicated shape, in which the projecting piece 11 constituting the suspension support portion, the mounting portion 23 of the tie-down hook 24, the bulging portion 25 serving as the mounting portion of the silencer, and the like are formed, is formed of a cast material. Since it is configured as described above, the above-mentioned parts can be easily formed without performing complicated shaving, etc., and thereby the manufacturing cost of the vehicle body can be kept low.

Further, as shown in the above embodiment, when the side frame 2 is cast from a light alloy material such as an aluminum material, the weight of the vehicle body can be effectively reduced and die casting can be performed. There is an advantage that the surface texture of the sub-frame 2 can be formed well.
Further, when the floor panel 1 joined to the upper surface of the side frame 2 is formed of a light alloy wrought material, both members can be easily integrated.

In the above embodiment, the pair of left and right side members 2 and the cross member 3 are integrally formed by casting, but the cross member 3 is made of wrought material or cast material. After they are formed separately, they may be integrally joined by means such as welding. Further, as shown in FIG. 5, a reinforcing rib 31 is integrally provided at the joint between the side frame 2 and the cross member 3 so that the joint strength between the side frame 2 and the cross member 3 is improved. You may

Further, as shown in FIG. 6, the front frame member 32 consisting of the front portion 4 and the intermediate portion 5 of the side frame 2 and the cross member 3 are integrally formed by casting and the rear portion of the side frame 2 is formed. The rear frame member 33 composed of 6 may be formed as a separate member by a wrought material. According to this configuration, when the automobile is rear-end hit, the impact load input from the rear end of the vehicle body is effectively absorbed by the rear frame member 33 made of the wrought material, so Front frame material 3
It is possible to effectively prevent 2 from being affected by the impact load.

The front frame member 3 of the side frame 2
When casting 2 is performed, the casting is performed with the rear frame material 33 of the side frame 2 previously formed by the wrought material set in the mold, so that the front frame material as shown in FIG. At the rear end of 32, the end of the rear frame member 33 may be cast-in to form a connecting portion 34 that connects both frame members.

In the case of the above construction, the front frame member 32 and the rear frame member 3 of the side frame 2 are formed.
The frame members 32 and 33 can be easily and firmly connected to each other as compared with the case of connecting 3 to each other by means such as welding or bolting. Further, both frame members 32, 33
In order to increase the connection strength of the rear frame member 33,
A curved portion 35 having an arc shape is formed at the end of the curved portion 35.
It is desirable that the above-mentioned connecting part 34 be cast and wrapped. Further, as shown in FIG. 8, in a state where the rear end of the front frame member 32 made of a cast material and the front end of the rear frame member 33 are butted against each other, they may be joined together by welding or bolting. You may comprise.

In the above embodiment, the vehicle body structure having the rear side frame 2 provided on the rear vehicle body has been described, but the vehicle body structure having the front side frame provided on the front vehicle body is also described. The configuration of the invention can be adopted. In this case, while effectively absorbing the impact load that acts at the time of a frontal collision of the vehicle,
In order to ensure the formability of the side frame, it is desirable that the front frame forming the front side frame is formed of a wrought material and the rear frame material disposed behind the front frame is formed of a cast material. .

[0029]

As described above, according to the present invention, since the side frame at least a part of which is made of cast material is installed on the lower surface of the floor panel made of wrought material, it is made of cast material. By setting the plate thickness of each part of the side frame to an appropriate value in accordance with the magnitude of the load acting, it is possible to sufficiently secure the strength of the necessary portion without installing a reinforcement or the like. Further, since the floor panel is made of the wrought material having high toughness, there is an advantage that the insufficient toughness of the side frame made of the cast material is compensated by the floor panel and the impact load acting at the time of collision of the automobile can be effectively absorbed. .

Further, since the floor panel exposed to the outside in the trunk room of the rear vehicle body is formed of the wrought material, the appearance of the rear vehicle body can be maintained in a good condition without complicated surface finishing. And
Since the side frame having a complicated shape having the protrusions constituting the suspension support portion, the attachment portion of the tie-down hook, and the bulge portion serving as the attachment portion of the silencer can be easily formed by casting, the manufacturing cost thereof can be reduced. It can be kept cheap.

According to the construction in which one of the front frame material and the rear frame material of the side frame is made of the cast material and the other is made of the wrought material, the impact load input at the time of the collision of the automobile. Can be effectively absorbed by a frame material made of wrought material, and a frame material having a complicated shape including a joint portion of a cross member can be easily and properly formed by a cast material. .

According to the constitution in which the rear end portion of the frame material made of the cast material is provided with the connecting portion for connecting both frame materials by casting the end portion of the frame material made of the wrought material, When casting and forming the frame material, the ends of the frame material made of wrought material are automatically integrated, compared to the case where both frame materials are connected by means such as welding or bolting. The connection work can be easily performed.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

4 is a cross-sectional view taken along the line CC of FIG.

FIG. 5 is a partial explanatory view showing another embodiment of the vehicle body structure.

FIG. 6 is a partial explanatory view showing still another embodiment of the vehicle body structure.

7 is a cross-sectional view taken along the line DD of FIG.

FIG. 8 is a cross-sectional view showing another example of the connecting portion between the front frame and the rear frame.

[Explanation of symbols]

 1 Floor Panel 2 Side Frame 4 Front Side Frame (Front Frame Material) 5 Middle Side Frame (Front Frame Material) 6 Rear Side Frame (Rear Frame Material) 32 Front Frame Material 33 Rear Frame Material 34 Connection

Front page continued (72) Inventor Hiroshi Shinagawa No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Nohisa Miwa No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (3)

[Claims] 1. A vehicle body structure for an automobile having a floor panel and a side frame disposed below the floor panel and extending in the front-rear direction of the vehicle body, wherein at least a part of the side frame is formed of a cast material, and the side frame is formed. A vehicle body structure, wherein a floor panel installed so as to cover an upper surface of a frame is formed of a wrought material. 2. A vehicle body structure of an automobile having a side frame disposed on a lower surface of a floor panel and extending in a front-rear direction of a vehicle body, wherein the side frame is divided into a front frame material and a rear frame material, and one of them is cast. A vehicle body structure, characterized in that it is made of a material and the other is made of a wrought material. 3. The automobile according to claim 2, wherein a connecting portion is provided at an end of the frame material made of the cast material to connect the end of the frame material made of the wrought material by casting. Body structure.