GB2266282A - Motor vehicle - Google Patents

Abstract

A motor vehicle having aerodynamically designed struts projecting laterally from the chassis beams (13) or body and on the outer end of which the wheels of the vehicle are supported by simplified suspension means (53). The invention is directed principally at open wheel race cars and the aerodynamically design struts replace the traditional wishbone type suspensions and separate aerofoils or wings. <IMAGE>

Description

IMPROVED MOTOR VEHICLE This invention relates to an improved construction of motor vehicle. The invention is particularly designed for incorporation in an open wheel type of vehicle, e.g. a Formula Three or Formula One type of racing vehicle, although it could be incorporated in other types of motor vehicle.

One of the fundamental design principles incorporated in all current open wheel race cars, and many other marques of competition cars, is the provision of aerofoils (wings) fitted to the front and rear of the car. These wings provide the reverse aerodynamic effect to that of an aeroplane wing. Instead of creating lift, the profiles of the aerofoils are such that they provide a strong down force. This effectively increases the co-efficient of friction between the tyres and the road surface. It also provides additional adhesion against lateral "G" forces in high speed corners. Wings do increase frontal area, which necessitates the need for extra horsepower. This concept was first introduced in the mid-1960's and is now used on all open wheel race cars, and on other cars as well.

All current race car designs also use a conventional type of twin strut suspension on all four wheels. This in general terms is in the form of an upper and lower "wishbone" made of fabricated steel. These "wishbones" are affixed to the chassis by pivoted attachments, and to the wheels by an upright, cast from metal which houses the hub.

This arrangement provides vertical movement of the wheel.

The vertical movement of the four wheels is controlled by one or more coil springs of varying ratings. The sudden vertical movement of the wheels is dampened by the use of a gas, or hydraulic type shock absorber unit. This design configuration has been used in motor sport for over 50 years. However, it has a large number of parts, and is therefore an expensive part of the car. It is also well known that it has many unreliable characteristics, the principal one being the possibility of mechanical failure.

Furthermore, when the wheels move in an upwards (vertical) direction, they follow an arc, and consequently the tyre does not sit consistently flat on the road surface. This causes excessive, and uneven, tyre wear. This can be partially corrected by camber changes, but it is not the solution to what is a main design fault.

The present invention seeks to overcome the disadvantages associated with current vehicles which incorporate aerofoils and/or wishbone type suspension systems.

According to the broadest aspect of the present invention, we provide a motor vehicle chassis on which at least three wheels are supported, at least two of the wheels being supported on respective struts extending laterally from the chassis, and including aerofoil means associated with these struts.

Preferably, the struts are themselves designed as aerofoils.

Also according to the present invention, we provide a motor vehicle having a driver compartment, an engine, transmission means, four wheels, and a chassis, wherein the wheels are supported on respective single struts which are extensions of the chassis, each strut being designed as an aerofoil.

Preferably, each wheel is supported on its strut by resilient means, such as small coil springs or rubber mountings.

The struts may be bolted onto the chassis. Preferably the chassis is provided with four strut beams where the respective struts are to be bolted to it, these beams being locatable in recesses in the inner face of the respective struts. Bolts may be passed through the beams to engage captive nuts in the struts.

Preferably, each front wheel is supported in its respective front strut by a single upright shaft about which the respective wheel can pivot for steering the vehicle.

Preferably, each rear wheel is supported in its respective rear strut by a mount held in position by two spaced upright shafts, and drive to each rear wheel is from a half shaft extending through a tunnel extending along the length of the rear strut.

The invention is now described by way of example with reference to the accompanying schematic drawings, in which: FIGURE 1 is a plan view of an open wheel vehicle in which the invention is incorporated; FIGURE 2 is an enlarged plan view of a front strut; FIGURE 3 is a vertical section through a front strut; FIGURE 4 is a longitudinal section through a front strut; FIGURE 5 is a plan view of a rear strut, and FIGURE 6 is a partial transverse section through a rear strut.

FIGURE 7 is a front elevation of an alternative design of vehicle.

Referring to the drawings, Figure 1 shows an open wheel race car, e.g. of Formula One or Formula Three type.

The car has a monocoque chassis shown generally at 1 to which bodywork 3 has been fitted. The car has a cockpit or driver compartment 4, fuel area 5, engine compartment with engine 6, gearbox 8, forming part of the transmission, a rear chassis beam 9, and front chassis beam 12 to which a nose 14 is fitted.

Current state of the art race cars are fitted with front and rear wings, and complicated suspension systems incorporating wishbone struts and shock absorbers. In accordance with this invention, these are not required, and the car has a pair of aerodynamically designed front struts 15,17 which support respective front wheels 19,21 and a pair of aerodynamically designed rear struts 23,25 which support respective rear wheels 27,29. These struts 15, 17, 23, 25 provide the necessary down force when the car is in motion.

While it is envisaged that the struts 15,17,23,25 could be formed as an integral part of the chassis 1, they are shown as being rigidly connected thereto, so as effectively to form part of the chassis. At the front of the vehicle, two front chassis beams 31,33 are provided, which locate in respective mating recesses 35 in the front struts, each strut otherwise being shaped on its inner face 36 to match the car's body shape. Each strut 15,17 is bolted to beam 31 or 33 in any known manner, e.g. by means of studs (not shown) passing through the beams 31,33 and engaging captive nuts (not shown) in the strut.

As can be seen from Figures 2 and 3, each front strut has at its outer end an upstand 37, in the outer face of which a clevis is formed by upper and lower arms 39,41.

Vertically aligned apertures 43,45 are provided in the arms 39,41 by means of which a steerable wheel mount 47 is supported on the strut 17. The mount 47 has a pair of inwardly extending arms 48 and is supported in the clevis by an upright axle 50, suitable bearings 52 being provided between the arms 48 and the axle 50. Coil springs 53 extend between the supper clevis arm 39 and upper mount arm 48, and between the lower clevis arm 41 and lower mount arm 48.

These springs 53 provide the suspension for the vehicle, and by changing the springs, so the suspension characteristics of the vehicle can be altered. It will of course be appreciated that rubber blocks could be used instead of the coil springs 53.

The wheel mount 47 is steered through a suitable steering linkage (not shown), e.g. connected to bracket 54 and a wheel axle 55 is supported in the mount 47 by suitable bearings (not shown), the axle supporting a hub 57, on which a wheel (not shown) is supported largely in known manner.

Suitable skirts 51 are provided on the underside of the strut 17. These are only shown in Figure 3.

The strut may be made of metal but is preferably formed of a structural synthetic resinous material which has a large strength/weight ratio.

The struts serve the dual purpose of acting as suspension supports for the front wheels, and as replacements for the traditional front wings of the car.

Accordingly, the struts have an aerodynamic shape which provides a downward force on the car, the strength of which is dependent upon the forward speed of the car.

Referring now to Figure 4, this shows the crosssectional shape of a front strut in the vicinity of the chassis beam recess 35, the leading edge L of the strut being "roundly" pointed, and the trailing edge being straight. It will be appreciated that different strut profiles will be required for different race circuits.

The rear struts 23,25 are identical to each other and like the front struts, may be integral with the chassis 1, but are preferably connected to the chassis 1 with the aid of rear chassis beams 59 which engage in mating recess 61.

They are secured in place in any suitable manner, e.g. with studs (not shown) engaging captive nuts 63. At its outer end, each rear strut 23,25 is bifurcated (see figure 6) so as to provide a pair of vertically spaced horizontally extending arms 65,67 defining a clevis, which is considerably wider than that on the outer end of each front strut (see Figure 5). Two fore and aft spaced pairs of aligned apertures 69,71 are formed in the arms, in which apertures, two wheel mount support shafts 73,75 are located, which support a rear wheel mount 77. The mount 77 has two vertically spaced inwardly extending arms 79 having apertures therein, and through which the shafts 63,75 extend, there being two coil springs extending between arm 65 and upper arm 79, and arm 67 and lower arm 79, so as resiliently to support the wheel mount 77.As with the front struts, springs 81 may be changed, depending on the stiffness of the suspension required, or replaced with rubber mounting blocks. The two shafts 73,75 ensure that each wheel mount can only move vertically. The mount 77 rotatably supports a wheel hub 83, largely in known manner through a suitable bearing arrangement 85, and the wheel is driven via a drive or half shaft shown schematically at 87.

A tunnel 89 extends centrally through each rear strut, this tunnel being sufficiently large to accommodate the drive shaft 87, which is driven from an output 91 on the side of the gearbox 8.

In the construction shown in Figure 7, like parts are identified with the same reference numerals as in Figures 16, but followed by the letter a. As in the embodiment of Figures 1-6, the race car is provided with aerodynamically designed front and rear struts 15a,17a; 23a,25a, on the outer ends of which the wheels are supported by simplified suspensions, these struts replacing the traditional wishbone type suspensions and separate front and rear wings on current race cars.

Tyres are mounted on the respective wheel hubs in known manner.

It will be appreciated that by replacing wishbone type suspensions and traditional wings with the aerodynamic struts of the present invention, vehicle weight and frontal area can be reduced. Hence, less power is required to reach a given speed. Also, the struts optical vertical position on the car can be selected at will.

It will also be appreciated that the car's suspension system is very considerably simplified, and there are far less parts to break. Also, by not requiring twin wishbone suspensions (parallelogram linkages which cause the wheels they support to move in an arc) it is possible to reduce tyre wear, since the simple suspension of this invention ensures that all the tyres of the car stay flat on the road surface.

It will of course be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Claims (14)

CLAIMS:

1. A motor vehicle chassis on which at least three wheels are supported, at least two of the wheels being supported on respective struts extending laterally from the chassis, and including aerofoil means associated with these struts.

2. A chassis as claimed in claim 1 wherein the struts are themselves designed as aerofoils.

3. A motor vehicle having a driver compartment, an engine, transmission means, four wheels, and a chassis, wherein the wheels are supported on respective single struts which are extensions of the chassis, each strut being designed as an aerofoil.

4. The invention as claimed in claim 1, 2 or 3 wherein each wheel is supported on its strut by resilient means.

5. The invention as claimed in claim 4 wherein the resilient means comprises two coil springs.

6. The invention as claimed in any one of claims 1-5 wherein the struts are bolted onto the chassis.

7. The invention as claimed in any one of claims 1-6 wherein, for each strut, the chassis is provided with a strut beam to which the respective strut is bolted.

8. The invention as claimed in claim 7 wherein each strut beam is locatable in a recess in the inner face of its respective strut.

9. The invention as claimed in claim 7 or 8 wherein bolts are passed through each beam to engage captive nuts in the respective strut.

10. The invention claimed in claim 3 or any one of claims 4-9 when dependent on claim 3 wherein each front wheel is supported in its respective front strut by a single upright shaft about which the respective wheel can pivot for steering the vehicle.

11. The invention as claimed in any one of the preceding claims wherein each rear wheel is supported in its respective rear strut by a mount held in position by two spaced upright shafts.

12. The invention claimed in claim 11 wherein drive to each rear wheel is from a half shaft extending through a tunnel extending along the length of the rear strut.

13. A chassis for a vehicle, substantially as hereinbefore described with reference to the accompanying drawings.

14. A vehicle, substantially as hereinbefore described with reference to the accompanying drawings.