GB2459186A

GB2459186A - An air deflection device

Info

Publication number: GB2459186A
Application number: GB0906376A
Authority: GB
Inventors: John Cartwright
Original assignee: Cartwright & Sons S
Current assignee: Cartwright & Sons S
Priority date: 2008-04-15
Filing date: 2009-04-14
Publication date: 2009-10-21
Also published as: GB0806807D0; GB0906376D0

Abstract

An air deflection device, for a load carrying body 3 behind a cab 2, the device comprising a fairing 6 mountable to the cab and having an airflow surface to deflect airflow relative to the body, and means 20 for adjusting position of the fairing on the cab relative to the body, characterised by the provision of a detector arrangement (not shown) adapted to provide an indication of attainment of an adjusted height of the fairing which has a predetermined relationship with the height of the trailer body and to provide there from within the cab a notification of said height. The airflow surface may be formed in parts movable relative to each other. The air deflection may comprise a supplementary aerodynamic structure via which the fairing is mountable on the cab whereby the said supplementary aerodynamic structure comprises additional airflow surfaces. The movement of the air deflection device may comprise both horizontal and vertical components.

Description

* VEHICLE FAIIJNG This invention relates to an air deflection device, incorporating an aerodynamic fairing, for a load-carrying road vehicle.

For load-carrying road vehicles which have a load-carrying body behind a cab, it is known to provide a fairing on top of the cab to facilitate streamlined airflow over the leading end of the body. Advantageously, this can reduce fuel consumption.

Typically the fairing takes the form of a moulded shell, made from glass fibre reinforced resin, with an upwardly convex curved surface.

In practice, load-carrying bodies having different heights are commonly used.

For optimum efficiency, this requires fairings also having different heights.

This can be accommodated by manufacturing fairings with the different heights. This is however expensive, and also can be inconvenient, particularly in relation to trailer vehicles where different bodies may be used with the same traction unit cab. It is also possible to use a manually adjustable fairing whereby the height of the fairing can be adjusted to suit the body with which it is used. However, it can be complicated and inconvenient to implement correct manual adjustment to attain desired aerodynamic properties and reliance on special equipment and/or skilled personnel may be necessary. * * *

An object of the present invention is to provide an inexpensive cab fairing S...

.: 20 which can be adapted, accurately and conveniently, to suit different sizes, and *:. particularly different heights of load-carrying bodies.

* :. According to one aspect of the invention therefore there is provided an air deflection device, for a load-carrying vehicle having a load-carrying body behind a cab, the device comprising a fairing mountable on the cab and having an airflow surface to deflect airflow relative to the body, and means for adjusting the position of the fairing on the cab relative to the body, characterised by the provision of a detector arrangement adapted to provide an indication of attainment of a predetermined fairing adjustment position.

With this arrangement the position of the fairing can be adjusted to accommodate different body characteristics and the detector arrangement can facilitate attainment of a desired adjustment without necessarily requiring expensive equipment or skilled personnel.

The airflow surface of the fairing may be shaped, particularly so as to be outwardly displaced away from the cab. This displacement may be provided by a curvature in two or three dimensions andlor a multi-faced arrangement. The shaping of the airflow surface may be such that the fairing displacement increases from a leading end region to a trailing end region. The leading end region may taper to an edge.

In one embodiment the airflow surface has a central face and connected side faces extending transversely in a common direction from the central face. Thus, the fairing may be generally wedge shaped particularly with a curved said central face, which may be generally rectangular, and generally triangular side faces which may be ..* planar or which may be outwardly curved. Curved transitions may be provided *...

between the central face and the side faces.

*:. Conveniently the fairing may be a shell or open box structure which may be * moulded or vacuum-formed from plastics or reinforced resin, particularly glass-fibre * * reinforced resin, or recyclable plastic.

The airflow surface is preferably a smooth continuous imperforate surface. It may be formed in one piece or as an integral construction with fixed dimensions.

Alternatively it may be formed in two or more parts movable relative to each other e.g. as telescopic or hinged parts whereby the shape andlor size of the surface can be changed.

Adjustment of the fairing may involve bodily movement thereof by pivoting andlor by displacement or sliding along a linear or other path. Alternatively or additionally adjustment may involve displacement or sliding movement of one or more parts of the fairing relative to one or more other parts thereof, along a linear or other path, e.g. corresponding to movement of the aforesaid telescopic or hinged parts of the airflow surface.

The fairing may be mountable on the cab via one or more supplementary aerodynamic structures forming part of the airflow deflection device whereby the (or each) such supplementary structure provides an additional airflow surface which coacts, and may be generally continuous with, the airflow surface of the fairing.

The airflow surface of the (or each) supplementary structure may have a central face and connected side faces extending transversely in a common direction from the central face. Other features of the (or each) supplementary structure may be as described above in relation to the fairing.

Where the fairing is a shell-or open box-structure as described above this may * *** * 20 be arranged to fit over the (or each) supplementary structure in nested configuration.

Where there are multiple supplementary structures one or more of these may be of *** * shell or open box structure as mentioned above so that two or more such :*::; supplementary structures fit one over another in nested configuration. Other arrangements whereby the fairing and the (or each) supplementary structure are in close proximity, but are not necessarily nested, may also be used.

With a nested or other close-proximity arrangement as aforesaid, provision may be made for movement of the fairing relative to the (or each) supplementary structure andlor movement of the supplementary structures relative to each other. In this way it is possible to achieve generally smooth continuous airflow over the cab even when the fairing has been moved to a position significantly displaced away from the cab, in so far as the airflow surface of the fairing is generally aligned and forms a smooth continuation with the airflow surface of the (Or each) supplementary structure.

The airflow surface of the fairing, and where appropriate of the (or each) supplementary structure, is preferably curved or otherwise displaced upwardly away from the cab, and the adjustment movement of the fairing, and where appropriate of the (or each) supplementary structure, may be upwards whereby different body heights can be accommodated. Movement of the fairing may have vertical and horizontal components e.g. so that the fairing moves upwardly and rearwardly to maintain an advantageous aerodynamic profile or angle. This may be achieved by provision of a guide arrangement, such as a guide track or slot in combination with a link member which engages the guide track or slot to be constrained to follow a path defined by the track or slot. One of the track or slot and the link member may be * ..* * * * connected to the fairing, the other being connected to a fixed structure on the cab, S...

such as the aforesaid supplementary structure.

Movement of the fairing, and of any movable said supplementary structure, *:*. may be effected by a suitable powered device such as a pneumatic or hydraulic *: . actuator. Alternatively or additionally, a manual actuator such as a hand pump or the like may be used.

* With regard to the detector arrangement, this may comprise any suitable proximity or ranging arrangement operable between the vehicle body and the fairing whereby for example an infrared or ultrasonic beam from the fairing is directed at the body and detects when the body is no longer horizontally aligned with an extremity of the fairing. It may also be possible to program the detector arrangement with different predetermined body dimensions whereby the detector arrangement gives an indication when it has moved to a position corresponding to such dimensions.

The indication may be in the form of an alerting signal of a visual andlor audible nature. Alternatively or additionally it may comprise an activated control function. Thus, the indication may involve termination or limitation of adjustment movement when the required position has been reached. Alternatively or additionally the indication may comprise a read out or other audible andlor visual notification of an actual detected parameter or dimension of the body. In particular, it may give the height of the body, as a digital display or by actuation of one of a range of lamps or other indicators representing different heights or height ranges. This height indication advantageously can alert a driver to the height of the body to assist in negotiation of low bridges or the like.

*:::: Thus, and in accordance with a second aspect of the invention, which may have any or all of the features of the first aspect, there is provided an air deflection device, for a load-carrying vehicle having a load-carrying body behind a cab, the *:. device comprising a fairing mountable on the cab and having an airflow surface to *: * deflect airflow relative to the body, and means for adjusting the position of the fairing on the cab relative to the body, characterised by the provision of a detector arrangement adapted to provide an indication of attainment of an adjusted height of * the fairing which has a predetermined relationship with the height of the trailer body, and to provide therefrom within the cab a notification of said height.

The air deflection device may be applied to an integrated cab of a load-carrying road vehicle having an integral body, or the cab of a separate traction unit used with a trailer body.

The device may be attached to the cab, particularly the roof of the cab in any suitable permanent or detachable manner.

The fairing may have therein an aperture or channel to direct an airstrearn towards the vehicle body, and an air-driven electrical generator may be mounted on the body in the path of this airstream whereby electrical power can be generated e.g. for the purpose of charging a storage battery or batteries on the trailer.

Thus and in accordance with a third aspect of the present invention, which may have any or all of the features of the second and third aspects, there is provided an air deflection device, for a load-carrying vehicle having a load-carrying body behind a cab, the device comprising a fairing mountable on the cab and having an airflow surface to deflect airflow relative to the body, characterised by the provision of an air-directing configuration adapted to direct an airstream towards the vehicle * : body, an air-driven electrical generator being provided for mounting on the vehicle body so as to be operated by the airstream to generate electric power.

* ** * * :* 20 The invention will now be described further by way of example only and with reference to the accompanying drawings in which:- *: * Figures 1 and 2 are side views of a load carrying road trailer vehicle fitted with one form of an air deflection device according to the invention, in different configurations; * Figures 3 to 6 are perspective views showing the air deflection device in different positions; and Figure 7 is a schematic perspective view.

Referring to Figure 1, this shows a load-carrying road vehicle having a traction unit I with a cab 2, and a trailer body 3. The trailer body 3 has a vertical front end waIl 4 which projects above the roof 5 of the cab 2.

In order to improve aerodynamic efficiency and thereby improve fuel consumption an air deflecting fairing 6 is mounted on top of the cab roofS.

This fairing 6, as described in more detail hereinafter, consists of an upwardly curved structure having a vertical displacement above the cab roof 5 which increases from a leading end 7 of the fairing 6 to a trailing end 8 thereof, the fairing 6 thereby being generally wedge shaped.

Figure 1 shows the fairing 6 used with a conventional European standard single deck trailer body 3 having a height of 4m, that is, such that the uppermost extremity of the roof 9 of the body 3 is 4in above the road surface 10.

The uppermost extremity 11 of the fairing 6, which is at the trailing end 8 thereof, is level with the roof 9 of the body 3.

As shown in Figure 3, the fairing 6 is a shell-or open box-structure made from ****** glass fibre-reinforced resin. This structure has a generally rectangular central wall 12 .: 20 which is upwardly convexly curved in two dimensions from a straight, horizontal *:. leading edge 13 to the extremity 11 which is a straight, horizontal trailing edge. At each opposite side there is an integral downwardly extending generally triangular, generally flat side wall 14 with a straight horizontal bottom edge 15 arid a straight vertical rear edge 16, and a convexly curved top edge 17. There is a smoothly curved S transition 18 between the central wall 12 and each side wall 14. The fairing structure 6 is thereby generally wedge shaped.

The structure 6 is mounted on top of and over a supplementary structure 19 which is fixed to the cab roof 5. This supplementary structure 19 is generally of like shape to the structure 6. That is, it is generally wedge shaped with a curved top wall 1 2a and generally triangular generally flat side walls 1 4a. The width is slightly smaller so that the supplementary structure 19 can fit in nested configuration within the confines of the structure 6. Any other suitable close-proximity arrangement, not necessarily a nested arrangement, may also be used. The structure 6 is supported on the supplementary structure 19 via a hydraulic ram 20 and a guide slider arrangement described below. The ram 20 is connected between the centre of the trailing edge 11 of the structure 6, and a batten 21 fixed on the cab rood 5 and extending transversely thereacross. The ram 20 is connected to the batten 21 via a pivot joint and a cut out is provided in the centre of the trailing edge ila of the supplementary structure 19 to allow passage therethrough of the ram 20.

As shown in Figure 4, the guide slider arrangement comprises a link member 22 at each side of the leading edge region 13 of the structure 6 which is fixed to the adjacent curved transition 18 and engages a slot 23 which runs along the corresponding curved transition 23a of the supplementary structure 19. The link * S member 22 is retained relative to the supplementary structure 19 but is free to slide along the slot 23.

*: * With this arrangement, actuation of the ram 20 to cause this to extend causes *: * the trailing edge 11 of the structure 6 to move upwardly relative to the supplementary structure 19. At the same time, the guide slider arrangement constrains the structure 6 * to move rearwardly relative to the supplementary structure 19 whilst it is displaced upwardly. The ram 20 pivots about the batten 21 to accommodate this. The structure thereby moves from the position of Figure 3 to that of Figures 5 and 6.

Figure 1 shows the arrangement with the ram 20 fully contracted as in Figure 3, whereby the leading edge 13 of the structure 6 is generally level with the leading edge 13 a of the supplementary structure and the bottom edges 15 of the side walls 14 of the structure 6 are close to the bottom edges 1 5a of the supplementary structure 19. An air flow surface is thereby defined by the central wall 12 of the structure 6, and the side walls 14 of the structure 6 which are generally continuous with the lower regions of the side walls 14a of the supplementary structure 19. In this position the trailing edge 11 of the central wall 12 of the structure 6 is level with the roof 9 of the trailer body 3 When travelling, air can thereby flow smoothly over the roof 9 of the trailer body 3 and also round the sides thereof Figure 2 shows the arrangement with the ram 20 extended so that the trailing edge 11 of the central wall 12 of the structure is level with the roof 9a of a standard UK double deck trailer which is 4.9m above the road surface 10.

The ram 20 is extended to an extent necessary to attain coincidence of heights :. of the trailer body roof 9a arid the trailing edge 11 of the central wall 12 of the structure 6.

The correct extension of the ram 20 is achieved with the assistance of a detector arrangement (not shown) comprising a transmitter/detector incorporated in the structure 6 immediately beneath the trailing edge 11 of the central wall 12. The * : . transmitter/detector which may be ultrasonic receives a reflected beam from the front end wall 4a of the trailer body 3a. This generates a signal which is processed with connected circuitry within the cab 2. The circuitry is connected to a control device for the ram 20 and to display devices and to operating controls within the cab 2. Thus, on an automatic basis, after operating a manual start control in the cab, or automatically after the trailer body 3a is connected to the unit 1, the ram 20 is connected to hydraulic supply from the cab and the structure 6 is elevated until the detector arrangement determines that the structure 6 is at the required height as indicated by the absence of a reflected beam from the trailer body front wall 3a. Actuation of the ram 20 is maintained to maintain the structure 6 in its correct elevated position.

On changing the trailer body 3a for a body of different height, such as the single deck body 3 of Figure 1, the structure 6 can be lowered or raised automatically to be of the correct height for alignment with the roof 9 of the new trailer body 3.

The detector arrangement has a display within the cab which gives a read-out of the actual height of the trailing edge 11 of the central wall 12 of the structure. The driver is thereby made aware of the height of the trailer body 3 which is of assistance in negotiating low bridges and the like.

With the above described embodiment the fairing position is automatically accurately adjusted to give optimum aerodynamic characteristics appropriate to the height of the trailer body.

Figure 7 shows a modified embodiment. The air deflection device is identical * 20 with that described with reference to Figures 1 to 6, and the same reference numerals * are used for the same features, except for the following: * Instead of the continuous, imperforate central wall 12 of Figures 1 to 6, the *: . wall 12 has a central aperture 24 in its upper region which has an open-ended duct or funnel 25 attached therearound. The duct or funnel 25 provides an airflow conduit -11 -whereby air flowing into the aperture 24, when the vehicle is moving, is directed horizontally at the upper region of the front wall 4 of the vehicle body 3.

A conventional wind turbine 26 with connected electrical generator is mounted on the front wall in the path of the airflow. This generates electricity which is used, via appropriate control circuitry, to charge two storage batteries 27 carried in the vehicle body 3. These batteries 27 are used to power electric trailer functions.

With conventional trailer systems the batteries 27 are charged by connection via a charging lead to a power output of the traction unit 1. It can happen that a driver forgets to plug in the lead when the trailer 3 is linked to the traction unit 1 which gives rise to problems of flat batteries. The above described air turbine arrangement automatically effects charging and thereby problems of flat batteries can be avoided.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments which are described by way of example only. Thus, for example, instead of using an air turbine electrical generator associated with the fairing for charging the batteries, any other automatic arrangement may be used. That is, an air turbine generator or similar wind operated device may be provided separately from the fairing.

Also, in addition to the double acting ram 20, there may be one or more S. gas stays between the fairing parts 6, 19 to provide a more positive displacement and * S. S : 20 to make the arrangement less prone to rattles and jarring e.g. when driving over S.. I pot holes or other uneven road surfaces. Typically there may be two gas stays which : may exert a force of around 40kg which would be overcome by the greater force * * when the double acting ram 20 powers inwards and retracts the fairing 6.

Claims

-12 -S CLAIMS1. An air deflection device, for a load-carrying vehicle having a load-carrying body behind a cab, the device comprising a fairing mountable on the cab and having an airflow surface to deflect airflow relative to the body, and means for adjusting the position of the fairing on the cab relative to the body, characterised by the provision of a detector arrangement adapted to provide an indication of attainment of a predetermined fairing adjustment position.
2. A device according to claim 1 wherein the fairing is shaped so as to be outwardly displaced away from the cab.
3. A device according to claim 2 wherein the fairing displacement increases from a leading end region to a trailing end region.
4. A device according to claim 3 wherein the leading end region tapers to an edge.
5. A device according to claim 3 or 4 wherein the airflow surface has a central face and connected side faces extending transversely in a common direction from the central face.
6. A device according to claim 5 wherein the central face is curved.
7. A device according to any one of claims 3 to 6 wherein the airflow surface is * : formed in parts movable relative to each other. *..
8. A device according to any one of claims I to 7 wherein the fairing is bodily .: * movable for effecting said adjustment.
9. A device according to any one of claims 1 to 8 wherein the fairing has parts :::: movable relative to each other for effecting said adjustment.
10. A device according to any one of claims 1 to 9 including one or more -13 -supplementary aerodynamic structures via which the fairing is mountable on the cab, the (or each) said supplementary structure having an additional airflow surface which coacts with the airflow surface of the fairing.
11. A device according to claim 10 wherein the (or each) supplementary aerodynamic structure is shaped so as to be displaced away from the cab with the displacement thereof increasing from a leading end region to a trailing end region and wherein the (or each) supplementary aerodynamic structure has a central face and connected side faces extending transversely in a common direction from the central face.
12. A device according to claim 11 wherein the leading end region of the (or each) supplementary aerodynamic structure tapers to an edge.
13. A device according to claim 11 or 12 wherein the central face of the (or each) supplementary aerodynamic structure is curved.
14. A device according to any one of claims 11 to 13 wherein the fairing arid the (or each) supplementary aerodynamic structure are formed as open box-structures and the fairing is arranged to fit over the (or each) supplementary aerodynamic structure in nested configuration.
15. A device according to claim 14 wherein the fairing and the (or each) **p .. : supplementary structure are movable relative to each other with the airflow *SS. 0 ** 20 surface of the fairing generally aligned and forming a smooth continuation with the additional airflow surface of the (or each) supplementary S..* aerodynamic structure.
16. A device according to claim 8 or any claim dependent thereon wherein the said movement has vertical and horizontal components thereto so that the -14 -fairing moves upwardly and rearwardly.
17. A device according to claim 16 wherein a guide arrangement is provided for guiding movement of the fairing, said guide arrangement comprising a track or slot in combination with a link member which follows the track or slot.
18. A device according to any one of claims I to 17 wherein said means for adjusting the positioning of the fairing comprises a powered device.
19. A device according to any one of claims 1 to 18 wherein the detector arrangement comprises a proximity or ranging arrangement operable between the vehicle body and the fairing.
20. A device according to claim 19 wherein the detector arrangement gives an indication when the body is no longer horizontally aligned with an extremity of the fairing.
21. A device according to claim 19 or 20 wherein the detector arrangement is programmed with different predetermined body dimensions whereby the indication is given when the fairing is at a position corresponding to such a dimension.
22. A device according to any one of claims 1 to 21 wherein the said indication is in the form of an alerting signal.

* .
23. A device according to any one of claims 1 to 22 wherein the said indication is *.S.in the form of an activated control function. * **

:.: **
24. A device according to claim 23 wherein the indication involves termination or * ** S * limitation of positional adjustment of the fairing.
25. A device according to any one of claims 1 to 24 wherein the indication comprises a notification of an actual detected parameter of the vehicle body.

-15 -
26. A device according to claim 25 wherein the parameter is the body height.
27. An air deflection device, for a load-carrying vehicle having a load-carrying body behind a cab, the device comprising a fairing mountable on the cab and having an airflow surface to deflect airflow relative to the body, and means for adjusting the position of the fairing on the cab relative to the body, characterised by the provision of a detector arrangement adapted to provide an indication of attainment of an adjusted height of the fairing which has a predetermined relationship with the height of the trailer body, and to provide therefrom within the cab a notification of said height,
28. A device according to claim 27 which is also a device according to any one of claims 1 to 24.
29. A device according to any one of claims 1 to 28 applied to an integrated cab of a load-carrying road vehicle having an integral body.
30. A device according to any one of claims 1 to 28 applied to the cab of a traction unit for use with a separate trailer body.
31. A device according to claim 29 or 30 wherein the fairing has therein an aperture or channel to direct an airstream towards the vehicle body, and an air-driven electrical generator is mounted on the body in the path of this * *** .. : airstream for generation of electrical power. **S.
32. An air deflection device for a lcad-canying vehicle having a load-carrying body behind a cab, the device comprising a fairing mountable on the cab and having an airflow surface to deflect airflow relative to the body, characterised ** S by the provision of an air-directing configuration adapted to direct an airstream towards the vehicle body, an air-driven electrical generator being * provided for mounting on the vehicle body so as to be operated by the airstream to generate electric power.
33. A device according to claim 32 which is also a device according to any one of claims 1 to 26.
34. An air deflection device according to claim 1, or claim 27 or claim 31 substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. * * * ** S *.* . S * **S * * 55 * S * *** S * *S.S ** * * S S * .5 SS 5 * S * * *S