GB1580276A

GB1580276A - Motor vehicle

Info

Publication number: GB1580276A
Application number: GB1392078A
Authority: GB
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1977-04-22
Filing date: 1978-04-10
Publication date: 1980-12-03
Also published as: FR2387835B1; AU3502478A; DE2717942C3; DE2717942B2; DE7712746U1; DE2717942A1; FR2387835A1

Description

(54) MOTOR VEHICLE (71) We, GENERAL MOTORS CORPORATION, a Company incorporated under the laws of the State of Delaware, in the United States of America, of Grand Boulevard, in the City of Detroit, State of Michigan, in the United States of America do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a motor vehicle having an under-body structure including a floor portion and a longitudinally extending tunnel portion which protrudes upwardly from said floor portion and forms a channel-shaped reinforcing member for the under-body structure .

A tunnel portion of this kind makes it possible to place certain components, particularly the drive shaft of the vehicle and the exhaust pipe of the vehicle, underneath the vehicle without having to raise the floor portion of the vehicle in order to attain the necessary ground clearance for said components.

In passenger vehicles, particularly passenger vehicles having five seating places, a tunnel portion which protrudes upwardly of the floor to a substantial extent forms an obstacle for a passenger sitting in the middle of the rear seat of the passenger vehicle, since his available space is severely limited. A substantially high tunnel portion also tends to make the passenger space look smaller than it actually is.

A motor vehicle according to the present invention comprises a motor vehicle having an under-body structure including a floor portion and a longitudinally extending tunnel portion which protrudes upwardly from said floor portion, has an inverted channel-shaped crosssection, and has side walls connected together by a ceiling portion, the base of each side wall extending below said floor portion along at least a section of said tunnel portion; with said base along said section being shaped into an upwardly-extending beaded configuration adjacent a juncture thereof with said floor portion so that along said section the internal height of said tunnel portion exceeds the height of said tunnel portion relative to said floor portion.

Preferably the beaded configuration at the base of each side wall extends substantially the length of the tunnel portion. Where the tunnel portion is an integral part of the floor portion of the under-body structure, the beaded configuration at the base of each side wall is integral with the adjacent floor portion and is formed therein by subjecting said under-body structure to a drawing operation. The depth of the beaded configuration is dependent upon the overall width of the beaded configuration and the ductility of the material of the under body structure.

In motor vehicles having integral under body structures incoporating a system of beaded reinforcing ribs formed therein, the beaded configuration at the base of each side wall of the tunnel portion can form part of such a system of reinforcing ribs.

The beaded configuration at the base of each side wall of the tunnel portion may remain of a substantially uniform depth over the length of said beaded configuration, or, alternatively, the beaded configuration may vary in depth. Where the under-body structure includes an integral raised portion extending across said floor portion transversely to said tunnel portion, it is advantageous to extend the bead configuration at the base of each side wall across said integral raised formation in order to retain the internal height of said tunnel portion substantially unchanged and to provide valuable reinforcement of the under-body adjacent said raised portion.

The appended claims define the scope of the invention claimed. The invention and how it may be performed are hereinafter particularly described with reference to the accompanying drawings, in which: Figure 1 is a side elevation of a motor vehicle; Figure 2 is a section through the underbody of the vehicle taken along the line Il-Il in Figure 1; Figure 3 is a plan view of a portion of the under-body of the vehicle; and Figure 4 is a longitudinal section through a portion of a motor vehicle, from a more schematic aspect.

In Figure 1, the front part of a motor vehicle is designated by reference numeral 2, the passenger compartment by the reference numeral 4, and the rear part of the vehicle by the reference numeral 6. Underneath a door 8, there runs an entry sill 10 having a cross-section as shown in Figure 2. The two entry sills 10 each form a kind of side member of an under-body 12 and are adjoined to one another by the floor portion 14 of the vehicle. This floor portion 14 extends towards the middle of the vehicle and merges into a tunnel portion 16 of the underbody 12.

The tunnel portion 16, also known as the propeller-shaft tunnel, consists of side-walls 18 and an upper ceiling part 20, so that the whole assembly in cross-section is of a trapeziumshape. The cross-section of the tunnel portion 16 may be different however, and need not necessarily have such a symmetrical shape. Over its length, the cross-sectional shape of the tunnel portion 16 may be varied, if desired. As will be seen from Figure 2, the walls 18 are continued downwards to below the level of the floor portion 14 so as to form a beaded configuration 22 at the point of transition of each respective side wall 18 into the floor portion 14. In Figure 2, the conventional configuration of the tunnel portion is indicated in dashed lines. Because of the beaded configurations 22, the tunnel portion 16, that is, its upper ceiling part 20, is lowered relative to the floor portion 14 by an amount equivalent to the depth of the beaded configurations 22. This will be apparent by comparing the tunnel portion drawn in continuous lines with the conventional tunnel portion indicated in dashed lines. Nevertheless, the effective internal height of the tunnel portion 16 is retained.

The depth of the beaded configurations 22 is limited primarily by the ductility of the material of the under-body 12. The amount of lowering h of the tunnel portion 16 relative to the floor portion 14 will normally be at least 10 mm. This decrease in relative height creates a conspicuous optical impression of decreased heights in the tunnel portion 16. The depth of the beaded configurations 22 also depends on the shape of the configurations, particularly with respect to the overall width thereof. The beaded configurations 22 may extend over the entire length of the tunnel portion 16.

Reference numeral 24 designates an exhaust pipe of the vehicle in Figure 2, and reference numeral 26 denotes the road surface under the motor vehicle. The distance a between the road surface 26 and the floor portion 14 will remain uninfluenced by the measures adopted for forming the beaded configurations, because the floor portion 14 is normally provided with a system of similar beaded configurations, channels or ribs which contribute towards vibration dampening and stiffening of the floor portion 14. As shown in Figure 3, such a system of floor reinforcement consists of several channels 30 forming a rectangle. In the upper half of Figure 3, the beaded configuration 22, extends continuously over the entire length of the tunnel portion 16, whilst in the lower half of Figure 3, it will be seen that the beaded configuration 22 extends from the front of the vehicle only as far as a transverse seat girder 32 in order to ensure that the buckling strength of the tunnel portion 16 is sufficient in this region. The buckling strength of the tunnel portion 16 can be achieved in some manner other than by the indrawn transverse girder, if desired, for example, by making use of parts of the vehicle which are present in any case.

The beaded configurations 22 not only contribute towards raising the capacity of the tunnel portion 16, but they also increase the compressive strength and buckling resistance of tunnel portion 16. The beaded configurations 22 therefore also contribute towards stiffening the passenger compartment 4 of the vehicle against stress applied longitudinally of the vehicle. Consequently, the beaded configurations 22 provide such additional stiffness even when they only extend over a length of the passenger compartment as far as the transverse girder 32. In Figure 3, the rear seat is designated by reference numeral 34.

In Figure 3, the transverse girder 32 is a separate profiled component connected to the floor portion 14, and is joined to the tunnel portion 16. However, according to Figure 4, the transverse girder may also be formed as a raised portion 36 which is formed in the floor portion 14 and on which a rear end support 40 of a front tilting seat 42 slides.

Due to the presence of the raised portion 36, the effective height of the tunnel portion 16 at this point is diminished. At this point on the floor portion, the deeper course of the beaded configurations 22 is indicated in dash lines and is designated by the reference numeral 44. It is, of course, also possible to vary the depth of the beaded configuration along the length of the tunnel portion 16, even when the height of the tunnel portion 16 relative to the floor portion 14 remains the same.

In Figure 4, reference numeral 46 designates the front panel and reference numeral 48 the steering wheel of the vehicle. In front of the rear seat 34, a heel support 50 is mounted on the floor portion 14. Of course the beaded configurations 22 can also be produced by mechanical deformation techniques other than by drawing techniques.

Claims

WHAT WE CLAIM IS:

1. A motor vehicle having an under-body structure including a floor portion and a longitudinally extending tunnel portion which protrudes upwardly from said floor portion, has an inverted channel-shaped cross-section and has side walls conected together by a ceiling portion, the base of each side wall extending below said floor portion along at least a section of said tunnel portion, with said base along said section being shaped into an upwardlyextending beaded configuration adjacent a juncture thereof with said floor portion so that along said section the internal height of said tunnel portion exceeds the external height of said tunnel portion relative to said floor portion.

2. A motor vehicle according to Claim 1, in which the beaded configuration at the base of each side wall extends substantially the length of the tunnel portion.

3. A motor vehicle according to Claim 1 or 2, in which the beaded configuration forms part of a system of beaded reinforcing ribs formed in the under-body structure.

4. A motor vehicle according to any one of the preceding claims, in which the beaded configuration at the base of each side wall is integral with the adjacent floor portion and is formed therein by subjecting said under-body structure to a drawing operation.

5. A motor vehicle according to any one of the preceding claims, in which the beaded configuration at the base of each side wall is of a substantially uniform depth over the length of said beaded configuration.

6. A motor vehicle according to any one of the preceding claims, in which the under-body structure includes an integral raised portion extending across said floor portion transversely to said tunnel portion, and the beaded configuration at the base of each side wall extends across said integral raised portion.

7. A motor vehicle having an under-body structure substantially as hereinbefore particularly described and as shown in Figures 1 to 4 of the accompanying drawings.