GB2348400A

GB2348400A - An aerodynamic road vehicle

Info

Publication number: GB2348400A
Application number: GB9907333A
Authority: GB
Inventors: Valerian Dare-Bryan
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-31
Filing date: 1999-03-31
Publication date: 2000-10-04
Anticipated expiration: 2019-03-31
Also published as: GB9907333D0; GB2348400B

Abstract

An aerodynamic road vehicle, usually a goods vehicle is formed with air guidance surfaces which extend downwards from the chassis to each side of the vehicle. The surfaces are for guiding air flow over the lower region of the vehicle at the level of the wheels (10) during travel. The air guidance surfaces are formed in two parts of which an upper part (16) is relatively rigid and supported by the chassis. A lower part (22) is secured along its upper edge to the lower edge of the upper part and is formed of flexible material. This arrangement means that over the more exposed areas the guidance surfaces can resist damage whilst still maintaining improved aerodynamic properties.

Description

AERODYNAMIC VEHICLE This invention relates to aerodynamic vehicles and, in particular, but not exclusively to load carrying commercial vehicles.

It has been proposed to improve the aerodynamic qualities of commercial vehicles by providing surfaces at the sides of such vehicles located around the level of the wheels by which the air flow at the sides of the vehicle is caused to pass over those surfaces to improve the aerodynamic qualities of such vehicles.

In providing air guidance surfaces to improve the aerodynamic qualities of commercial vehicles it has been found that constraints exist in achieving the best aerodynamic benefits.

This may be due for the need for such vehicles to be docked during loading and unloading in docking stations at which the surfaces may be damage. Damage may also occur for other reasons.

An object of the invention is to provide aerodynamic surfaces for commercial vehicles giving improved aerodynamic qualities without increasing the liability to damage.

According to the invention an aerodynamic road vehicle comprises a frame acting as a chassis and a load supporting structure of the vehicle, wheels on which the vehicle is supported, and air guidance surfaces depending downwards from the frame to each of the sides of the vehicle and for guiding air flow at the lower part of the sides of the vehicle at the level of the wheels during travel, the air guidance surfaces each being formed of two parts, an upper part which is relatively rigid and is supported by the frame, and a lower part secured along its upper edge towards the level of the lower edge of the upper part, and being formed of flexible resilient material to extend downwards from the upper part and with its lower edge spaced from ground level.

Preferably the upper part is formed of plastics material in sheet form, suitable material being fibre reinforced plastics. The lower part may be formed of rubber sheet, conveniently reinforced rubber sheet.

The upper part may extend downwards for a distance of between 500-1000mm towards the ground and the lower part may extend downwards from the lower edge of the upper part for a distance of some 100-300mm. The lower edge of the lower part may lie at a distance of some 100-200mm from the ground surface.

Conveniently the upper edge of the lower part is secured by fixing means mounted towards the lower edge of the upper part.

The lower part may be stepped inwardly from the associated upper part over at least part of its length with the vertical plane of the upper part lying generally parallel to the vertical plane of the lower part. In one arrangement a support for the lower edge of the upper part, which is located inwardly of the respective guidance surface, also provides means for securing the upper edge of the lower part.

The flexibility of the lower part may be such as to enable it to readily bend and resume its original shape upon engagement of an object. However the material of the lower part should be such that the lower part does not move significantly in the lateral direction during normal use of the vehicle. If necessary the lower edge of the lower part may be weighted to inhibit such movement.

Further features of the invention will appear from the following description of an embodiment of the invention given by way of example only and with reference to the drawings, in which: Fig 1 is a side elevation of an articulated trailer to which the invention has been applied, and Fig 2 is a vertical section on the line 2-2 in Fig 1.

Referring to the drawings, the illustrated vehicle is an articulated trailer intended for attachment to a tractor vehicle in conventional manner. In this case the vehicle has two sets of wheels 10 to each side of the vehicle. The front end of the vehicle 11 is fitted with a coupling (not shown) of conventional form by which the trailer is attached releasably to the tractor. A parking leg 12 is located reanvardly of the coupling to support the vehicle towards each side of the vehicle when it is disconnected from the tractor.

The vehicle can be of any suitable construction for load carrying purposes constituting a frame 13 supporting the wheels 10 and providing a load carrying platform which may differ according to the use to which the vehicle is to be put. The lower edge of the frame 13 at the sides of the vehicle is generally at a level 14 above the wheels and the vehicle container extends above this level usually forming a rectangular box (not shown) in which the load is located.

Mounted on the frame 13 and extending downwards from the level 14 to each side of the vehicle are provided air guidance members 16 extending between a region adjacent the parking legs 12 to the rearmost part of the vehicle. The air guidance members 16 may be of generally conventional form including sheet material, usually of fibre reinforced plastics, fixed to mounting members 17, part of one of which is seen in Fig 2. The mounting members 17 seen in Fig 2 include longitudinally extending beams carried by vertically extending members 18 secured to the frame 13. The horizontal mounting members 17 are secured towards the lower edge of the members 16. The air guidance members 16 present outwardly facing air guidance surfaces for improving air flow over the region of the vehicle below the level 14.

At the leading end of the members 16, adjacent the leg 12, at each side of the vehicle, the members 16 are radiused at 18 to tum inwards so that an inwardly directed portion lies transverse to the longitudinal direction of the vehicle, in known manner.

From the forward end 18 of the air guidance members 16 the members extend rearwards at the sides of the vehicle and parallel to the longitudinal direction. In approaching the wheels 10 the members 16 are shaped to expose the wheels 10, there being an intermediate portion 18A of the members 16 which lies between the two sets of wheels. To the rear of the reanvard wheel set of wheels the members 16 extend towards the rear of the vehicle but in this region are tapered inwardly at 18B of the sides of the vehicle. Moreover along the lower edge of the members 16 in this region 18B the edge is inclined upwardly, as shown. At the lower edge the air guidance member is formed with a shaped outwardly-directed portion 19 which, at its rearward end, is located adjacent a cross-bar 20 which conventionally extends across the rear of the vehicle.

In the arrangement shown the depth of the air guidance members 16 between the level 14 and their lower edge is benveen 500-1000mm, but this depends on the vehicle concemed and the purpose to which it is to be put.

Extending downwardly below the lower edge of each of the air guidance members 16 is provided a further, flexible air guidance member 22 which extend downwards towards the ground level G on which the vehicle is located. The flexible members 22 extend from the rear of the radiused portion 18 of the air guidance members 16, up to the forward set of wheels 10. A further length of the flexible air guidance member 22 extends from the rear of the rearward set of wheels 10 to the rearward part of the vehicle. The flexible air guidance member 22 extend some 100-300mm below the lower edge of the air guidance members 16.

The lower edges of the flexible air guidance members 22 are spaced some 100-200mm from ground level G.

As seen in Fig 2 the flexible air guidance members 22 are each supported at their upper edges by a securing arrangement which, as illustrated, comprises angle members 23 fixed by bolts 24 to the mounting members 17. Further bolts 25 and mounting strips 26 secure the upper ends of the members 22 to the angle members 23, the bolts 25 being provided at spaced intervals along the angle members 23. As will be seen from Fig 2 this arrangement steps the flexible members 22 inwards from the side of the vehicle with respect to the air guidance members 16. The flexible members 22 lie with the planes of the outer air guidance surfaces generally vertical and parallel to the members 16.

Over the rearward part of the vehicle the flexible members 22 may not taper inwardly in the same manner as the tapering members 16 in the region 18B, being secured to the outwardly stepped part 19 of the members 16 in this region.

It is preferred that the flexible members 22 are formed of reinforced rubberised sheet but other materials can be used which can give the required flexibility and resilience to enable the members 22 to flex when encountering an obstruction whilst maintaining sufficient weight and strength to prevent the members 22 from undue lateral movement during normal vehicle travel. The sheet may be 3-lOmm thick. Reinforced rubber sheet provides this requirement but flexible plastics material may also be suitable. Rubberised canvas may also be employed. On encountering an obstruction it is intended that the members 22 should flex and resume their initial shape after flexing whilst not being damaged significantly. The members 22 thereby provide air guidance below the level of the more rigid air guidance members 16 and improve the aerodynamic qualities of the vehicle over a greater height beneath the level 14.

Sheet material of the members 22 may employ rubber of different hardness according to the application. Reinforcement rods or strips may be incorporated into the sheet for added stiffness. This may be particularly relevant when the members are of significant height.

Although there is shown in the drawings the use of the air guidance members 16 and 22 on an articulated trailer vehicle they may also find application on rigid vehicles in which the main frame of the vehicle includes an integral tractor and load carrying unit. In this case the air guidance members 16 and 22 extend from close to the rear of the cab part of the vehicle and to the rearward end of the vehicle.

Claims

Claims 1. An aerodynamic road vehicle which comprises a frame acting as a chassis and a load supporting structure of the vehicle, wheels on which the vehicle is supported, and air guidance surfaces depending downwards from the frame to each of the sides of the vehicle and for guiding air flow at the lower part of the sides of the vehicle at the level of the wheels during travel, the air guidance surfaces each being formed of two parts, an upper part which is relatively rigid and is supported by the frame, and a lower part secured along its upper edge towards the lower edge of the upper part and being formed of flexible resilient material to extend downwards from the upper part and with its lower edge spaced from ground level.
2. A vehicle according to claim 1 wherein said upper part is formed of plastics material in sheet form.
3. A vehicle according to claim 1 or 2 wherein said lower part is formed of rubber sheet.
4. A vehicle according to any one of the preceding claims wherein said upper part extends downwards for a distance of between 500-1000 mm towards the ground and the lower part extends downwards from the lower edge of the upper part for a distance of between 100-300 mm.
5. A vehicle according to any one of the preceding claims wherein the lower edge of said lower part lies at a distance of between 100-200 mm from the ground surface.
6. A vehicle according to any one of the preceding claims wherein the upper edge of said lower part is secured by fixing means mounted towards the lower edge of said upper part.
7. A vehicle according to any one the preceding claims wherein said lower part is stepped inwardly from said upper part over at least part of its length with the plane of said upper part lying generally parallel to the plane of said lower part.
8. A vehicle according to any one of the preceding claims comprising a support for the lower edge of said upper part, which support is located inwardly of the respective guidance surface, the support also providing means for securing the upper edge of said lower part.
9. A vehicle according to any one of the preceding claims wherein said lower part has a flexibility such that it may bend out of the plane of the guidance surface and will resume its original shape after bending.
10. A vehicle according to any one of the preceding claims wherein the material of said lower part is supported such that said lower part will not move significantly in a direction transverse to the guidance surface during normal use of the vehicle.
11. An aerodynamic road vehicle substantially as described with reference to the drawings.