GB2260296A

GB2260296A - Floor construction for the body of a motor vehicle

Info

Publication number: GB2260296A
Application number: GB9219920A
Authority: GB
Inventors: Minoru Araki
Original assignee: Suzuki Motor Corp
Current assignee: Suzuki Motor Corp
Priority date: 1991-10-09
Filing date: 1992-09-21
Publication date: 1993-04-14
Anticipated expiration: 2012-09-21
Also published as: JPH0597065A; GB9219920D0; GB2260296B; JP3180924B2; DE4233832C2; DE4233832A1

Abstract

A floor construction for the body of a motor vehicle has a longitudinally extending tunnel side member 5 provided on both lateral surfaces of a floor tunnel. Upper and lower reinforcement members 6a, 6b are fixed between the tunnel side members 5. <IMAGE>

Description

-1DESCRIPTION FLOOR CONSTRUCTION FOR THE BODY OF AN AUTOMOBILE

The present invention relates to a floor construction for the body of an automobile.

Conventionally, as a floor construction for the body of an automobile. the structures shown in Figs. and 8 of the accompanying drawings have been used. Referring to Fig. 7, a floor tunnel 72 is provided at the centre of a floor panel 71. A propeller shaft, exhaust gas pipe and the like may be disposed in the interior of this floor tunnel 72 depending on the type of the automobile. Normally, the floor tunnel 72 provides only a small reinforcing effect against bending or torsion of the vehicle body. Therefore, as shown in Fig. 8, floor side members 74 are sometimes provided between the side sills 73 and the floor tunnel 72 to increase strength.

However, in the foregoing conventional construction, since the floor side members 74 are provided on the lower surface of the floor, it is necessary to make the level of the floor higher, with the result that the centre of gravity of the vehicle can become high. Therefore, it is not suitable for a sports car or the like, in which the centre of gravity must be low. In addition, in view of the need to provide the floor side members 74 beneath the lower 7 -2surface of the floor, the cross-sectional area of the floor side members 74 must be made small while, in order to keep its strength, it is necessary to increase the sheet thickness, which has caused its weight to be increased.

With a view to overcoming the foregoing problems. the present invention provides a floor construction for the body of an automobile in which a tunnel side member extending in the direction of the vehicle body is provided at both lateral sides of the floor tunnel, between which at least one reinforcement is fixed.

According to the floor construction embodying the present invention, it is not necessary to provide the floor side member or the like or the lower surface of the floor to lower the floor surface. As a result. the position of the seat or the centre of gravity can be lowered. Therefore, it is suitable for a sports car or the like which calls for a lowered centre of gravity. In addition, a member constituting the foregoing reinforced construction allows its crosssectional area to be increased within the floor tunnel, and it is not necessary to increase the sheet thickness in order to keep the strength and so avoids an increase of weight. Accordingly, the entire vehicle body can be achieved using a thin steel plate providing an excellent performance when adopted to lg -3such a car type as an opencar to the like, which calls for reinforcement of the construction.

Further, an ideal performance free of nodes and small in displacement caused by bending and torsion can be achieved and, with regard to the travelling performance, excellent steering and stability can be achieved.

The present invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which; Fig. 1 is a lateral view schematically illustrating an automobile suitable for receiving a floor construction according to the present invention; Fig. 2 is a plan view schematically illustrating the automobile suitable for receiving the floor construction according to the present invention; Fig. 3 is a plan view for explaining a specific embodiment of the floor construction according to the present invention; Fig. 4 is a cross-sectional view taken along line A-A of Fig. 3; Fig. 5 is a graphic view illustrating the characteristic of the strength of the floor construction according to the illustrated embodiment of the present invention; Fig. 6 is a partial cross-sectional view of -4another embodiment of the present invention; Fig. 7 is a cross-sectional view for explaining a conventional floor construction; and Fig. 8 is a cross-sectional view for explaining another conventional floor construction.

Figs. 1 to 4 illustrate a targa top type opencar 1 (a type which can be fully open) suitable for receiving a floor construction according to the present invention, in which 2 denotes a floor tunnel. 3 a floor panel, 4 a side sill, 5 a tunnel side member and 6a, 6b an upper and a lower reinforcement, respectively.

The foregoing floor tunnel 2 is connected to a dash cross member 7 at the front end, and to a bulkhead lower cross member 8 at the rear end. Further, the floor tunnel 2 is connected to a seat riser member 8 at the centre. Still further, the foregoing dash cross member 7 is connected to a front end member 11 via a front side member 10. In addition, the foregoing bulkhead cross member 8 is connected to a rear side member 12.

The foregoing dash cross member 7, bulkhead lower cross member 8 and seat riser member 9 are each connected to the side sill 4 at the opposite side leading to the floor tunnel 2.

The tunnel side member 5 extends in the p -5longitudinal direction of the car body and, as shown in Fig. 4, is provided on both sides of the lower portion of the floor tunnel 2 to form a boxed shape in cross section. Between both tunnel side members 5, the foregoing upper and lower reinforcements 6a, 6b are fastened by means of bolts to thereby form a closed cross section within the floor tunnel 2 to increase the strength and the rigidity.

Fig. 5 illustrates features peculiar to the floor construction according to the foregoing embodiment.

Characteristic view of the bending rigidity This is shown assuming that loads W1, W2 act between the wheel bases. It can be seen that there is a considerable difference between the maximum bending displacements (torsions a, b of the car body). Further, if the front side member and the reinforcement are provided, no node (which forms a weak point) can occur in terms of strength at the front (D) and rear (E) ends of the floor of the car body. otherwise, such a node can occur.

Characteristic view of the torsional rigidity This shows the displacement caused by a torsional angle when a torsional torque T1 acts on the front wheel portion with the rear wheel portion as the supporting end. Also in this figure, when the front side member and the reinforcement are provided, the -6displacement (a) is small, and no node (which forms a weak point) can occur in terms of strength at the front end (D) and rear end (E) of the floor. Otherwise. the displacement (p) is great and the node also occurs.

As apparent from Fig. 5, in this embodiment, the displacement is small in regard to the bending as well as the torsion, and an ideal characteristic free of any node can be achieved. Therefore, with an FR car (Front engine and Rear drive) as shown in Fig. 4, in which the propeller shaft 13 or exhaust gas pipe 14 is provided within the floor tunnel 2, the effect exerted on these parts can be made small. Incidentally, the present structure can be applied to the construction of a car body using the floor tunnel as the reinforcing member as in an FF car (Front engine and Front drive), MR car (Midship car) or RR car (Rear engine and Rear drive). let alone the FR car.

Although the present invention has been explained with reference to the foregoing embodiment, it is not necessarily restricted'thereto. For example, although the foregoing reinforcements 6a, 6b are fixed by bolts, they may be fixed by welding entirely or partially. In addition, these reinforcements 6a, 6b may be used on either one of the upper and lower portions depending on the conditions associated with the maintenance or evacuation heat and the like.

1 ---Rj, The tunnel side member is not restricted to the boxed shape in cross section. but may be a flat member 15, as shown in Fig. 6.

Claims

1. A floor construction for the body of an automobile in which a tunnel side member extending in the direction of the body is provided on both lateral sides of a floor tunnel and at least one reinforcement is fixed between the tunnel side member.

2. A floor construction as claimed in claim 1, in which there are two of said reinforcements, namely an upper reinforcement and a lower reinforcement, both of which are disposed between and fixed to the tunnel side members.

3. A floor construction for the body of an automobile in which a tunnel side member extending in the direction of the body is provided on both lateral surfaces of a floor tunnel, and either one of an upper or lower reinforcement is fixed between the tunnel side members.

4. A floor construction for the body of an automobile, substantially as hereinbefore described, with reference to and as illustrated in any of Figures 1 to 6 of the accompanying drawings.

P