GB2438184A

GB2438184A - Hybrid electric vehicle

Info

Publication number: GB2438184A
Application number: GB0608035A
Authority: GB
Inventors: Angelo Fanourakis
Original assignee: GKN Autostructures Ltd
Current assignee: Autostructures UK Ltd
Priority date: 2006-04-25
Filing date: 2006-04-25
Publication date: 2007-11-21
Also published as: GB0608035D0

Abstract

A vehicle includes a body, first ground engaging wheels (22 see fig 1) at or towards one end of the body and second ground engaging wheels (30 see fig 1) at or towards a second end of the body, one of the first and second ground engaging wheels (22, 30), typically the front wheels (22), being drivable by an engine and the other (30) being drivable by at least one electric motor 35. The chassis 12, motor 35, a battery 40 and mounting cradles 38, 42 may be configured to allow a low floor (20 see fig 1) for a cargo carrying space. A controller 46 coordinates drive to the front and/or rear wheels of the vehicle and controls the motor 35 to operate as an electrical generator when appropriate.

Description

Vehicle

Description of Invention

This invention relates to a vehicle and more particularly but not exclusively to a so called hybrid drive vehicle which has both an engine and an electric motor capable of imparting drive.

Hybrid passenger carrying vehicles are known in which drive to ground wheels may be imparted by either the engine or the motor, depending upon operating conditions. A controller controls the vehicle in response to driver controls, to select either engine drive, when the motor may function as an electrical generator to recover energy from the vehicle's motor to re-charge a vehicle battery which otherwise provides power to drive the electric motor, or electric motor drive when the engine may idle or be de-actuated.

Generally, the motor is preferentially used for imparting drive in cities where minimal pollution is desirable.

The invention has been derived particularly but not exclusively for application to light commercial vehicles which may have large payloads which if driven by a battery powered electric motor may quickly drain the battery of its charge.

Such vehicles therefore have particular operating requirements. Moreover, such vehicles have particular geometrical requirements too, as it is desirable SI.. . 25 for such vehicles to have a substantially unobstructed cargo carrying space, whereas typical hybrid drive vehicles tend not to have this primary consideration in their design. S..

According to the invention we provide a vehicle which includes a body, first ground engaging wheels at or towards one end of the body and second ground engaging wheels at or towards a second end of the body, one of the first and second ground engaging wheels being drivable by an engine and the other of the first and second ground engaging wheels being drivable by at least one electrical motor.

It has been found that a vehicle, in which the first and second ground engaging wheels are driven respectively by the engine and the motor, is an ideal arrangement for a light commercial vehicle.

The vehicle may include a first transmission for transmitting drive from the engine to the first ground engaging wheels and a second transmission for transmitting drive from the electrical motor to the second ground engaging wheels.

The first transmission may include a gearbox. The first ground engaging wheels may be carried on an axle which is driven from the gearbox but preferably the vehicle includes a suspension module which carries the or each of the first wheels, with there being a drive shaft to each of the one wheels, from the gearbox.

The second ground engaging wheels may be barried on an axle. In one embodiment, the axle may be driven by the electrical motor, for example though a propeller shaft and differential of the second transmission. In another example the electric motor may drive the axle directly i.e. the axle may be a :. live axle in which case the motor may be an integral part of an axle and differential assembly, or the vehicle may include a suspension module which S...

carries the or each of the second ground engaging wheels, with there being a drive shaft from the electrical motor to each of the second wheels. In yet another example, each of the second ground engaging wheels may be driven by a respective electric motor.

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* 5: 30 In a preferred embodiment the first ground engaging wheels are at or towards an end of the body which is at the front of the vehicle in the normal direction of travel of the vehicle and the first ground engaging wheels are driven by the engine and the second ground engaging wheels are driven by the electrical motor. However, if desired the first ground engaging wheels may be at or towards the end of the body which is at the rear of the vehicle in the normal direction of travel of the vehicle.

In each case the vehicle may include a chassis having a pair of chassis members which extend between the first and second ends of the body. Where the first pair of ground engaging wheels are provided at or towards the front of the vehicle, and particularly but not exclusively where the engine drives the first pair of ground engaging wheels through drive shafts from a gearbox to each of the wheels, the chassis may carry the engine at or adjacent the one end of the body, i.e. locally of the suspension module, and for example, at least partially above the chassis members.

Thus the chassis may include a sub-frame member to mount the engine, which extends between the pair of chassis members.

Where the second pair of ground engaging wheels are provided at or towards the rear of the vehicle, and particularly where the second ground engaging wheels are carried on an axle driven by the electrical motor though a propeller shaft, the electrical motor may be mounted by the chassis between the first :. and second ground engaging wheels, preferably nearer the second ground :..::: engaging wheels than the first ground engaging wheels. For example, the S...

electric motor may be carried by a cradle secured below the pair of chassis members.

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Thus the motor is provided at a low position so as not to extend upwards substantially of the chassis. This is a particularly efficient design where the vehicle is a load carrying vehicle, such as a light commercial vehicle, where the load carrying space provided by the body i.e. a space above the chassis is preferably maxim ised or at least unobstructed, for load carrying capability.

The invention may though be utilised for other kinds of vehicle, or even to off-road working machines with vehicular function, in which case throughout this specification, references to "vehicle" and the like should be construed to include such machines.

The vehicle may include a battery for providing power to the electric motor, which battery may be mounted by the chassis, for example by a cradle which is secured beneath the chassis, so as not substantially to obstruct the space above the chassis. The battery may be re-chargeable by the operation of the engine, for example though an electrical generator driven by the engine.

However the electric motor may be able to function as an electrical generator, driven by motion of the vehicle, to recover energy and to re-charge the battery.

In each case the drives to the first and second ground engaging wheels may be mechanically separate. Thus the vehicle may include a controller to control and co-ordinate the drive to each of the first and second ground engaging wheels, for example to ensure that the neither of the first and second ground engaging wheels are driven at a different speed to the other of the first and :. second ground engaging wheels, and to operate the electric motor as an * S..

5. electrical generator when appropriate. *S*.

The controller may be mounted by the chassis, for example only, between the pair of chassis members, where these are provided. S. ** * S

Desirably, at least in a first operating mode, which typically may be driver selected for driving the vehicle where both the first and second ground engaging wheels are required to be driven, e.g. off road, the controller controls the motor to drive the second ground engaging wheels in dependence upon the state of drive imparted to the first ground engaging wheels for example in response to driver controls and/or driving conditions. Thus the vehicle may include ground engaging wheel speed sensors to sense at least the rotational speed of the first ground engaging wheels driven from the engine and to provide input to the controller, and depending upon other inputs too, such as the state of one or more driver operated controls, e.g. the accelerator and/or brake, the controller may control the electric motor to provide appropriate drive to the second ground engaging wheels.

In a second preferably driver selectable operating mode, the controller may operate the motor to impart drive to the second pair of ground engaging wheels when drive is not being imparted to the first ground engaging wheels, for example for city travelling. Thus pollution from the engine exhaust may be minimised in cities. The engine may idle when the second operating mode is selected, or may be de-actuated altogether, but in each case, the controller may be operable to actuate the engine to assist the motor in driving the vehicle where required, for example on a steep hill, and/or when the battery is nearIy discharged.

In a third preferably driver selectable operating mode, the controller may control the motor not to provide drive to the second ground engaging wheels, :. but the motor may still function as a generator to re-charge the battery, which third operating mode may be used for example, for on-road inter city travel.

Embodiments of the invention will now be described with reference to the accompanying drawings in which:-* S * * *:*. FIGURE 1 is an illustrative side view of a vehicle in accordance with the invention; FIGURE 2 is an underside illustrative and perspective view of a chassis of the vehicle of figure 1.

Referring to the drawings a vehicle 10 has a body 11, carried on a chassis 12.

In this example, the vehicle 10 is a light load-carrying commercial vehicle 10 which includes a driver's cab 14 at or towards a front 15 of the vehicle 10, from which cab 14 a driver may operate the vehicle 10, and a load carrying space 16 behind the cab 14 and extending towards a rear end 18 of the vehicle 10. The load carrying space 16 includes a floor 20 on which a load may be carried.

The vehicle has first, in this example front, ground engaging wheels 22, being a pair of wheels carried by a front suspension module 23, which is suspended beneath a pair of chassis members 24, 25 of the chassis 12, which chassis members 24, 25 extend between the front 15 and rear 18 ends of the vehicle 10. In figure 2, a pair of suspension struts 26, 27 are illustrated supporting the suspension module 23. The chassis 12 carries an engine (not seen but the location for which is generally indicated at E) generally above the pair of chassis members 24, 25 so as to extend in the main, upwardly of the chassis 12, the engine being located generally above the suspension module 23.

Desirably the engine has an integral or directly connected gear box, with a transmission including drive shafts from the gear box extending to the wheels 22 to impart drive from the engine to the front wheels 22. * *..

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The vehicle includes second, rear, ground engaging wheels 30 which in this example are carried on an axle 32 and are drivable via the axle 32 by an electric motor 35 via a transmission which includes a propeller shaft 36 which connects the motor 35 to a differential 37 of the axle 32. The motor 35 is S * * *:: carried by a cradle 38 which is secured to the undersides of each of the chassis members 24, 25 so that the motor 35 does not extend upwardly substantially of the chassis 12, for example to obstruct the load-carrying space 16.

A battery 40 to provide power to drive the motor 35 is carried by a cradle 42 too, the battery cradle 42 also being secured to the undersides of the pair of chassis members 24, 25, so that the battery 40 does not extend upwardly substantially of the chassis 12, for example to obstruct the load-carrying space 16.

The axle 32 carrying the rear wheels 30 is suspended from the body 11, for example by a pair of leaf springs, one at each side of the body 11, which springs are indicated at 44, 45 in figure 2.

A controller 46 is provided for controlling at least the electric motor 35 as hereinafter described. The controller 46 is provided as a modular unit 46 carried between the pair of chassis members 24, 25 and operatively connected to a data bus (not seen) to which the motor 35 and battery 40 are also operatively connected, as well as sensors, operator controls and other devices as hereinafter indicated.

Other features of the vehicle 10 which are shown include an exhaust system for conveying, cooling and cleaning exhaust gases from the engine (E) to :. an exhaust outlet pipe 51, which exhaust system 50 is located generally below and slung from at least one of the pair of chassis members 24, 25, a fuel tank S...

53 which is carried between the pair of chassis members 24, 25 for maximum protection in the event of accidental vehicle impact, a support bar 54 which extends crosswise between the pair of chassis members 24, 25 for supporting a bumper 55 or a loading device for example, at the rear 18 of the vehicle 10.

The vehicle 10 is operable in a plurality of different operating modes, to suit different driving conditions. Desirably, the operating modes are selectable by a driver of the vehicle 10 from within the cab 14, but sensed conditions may give rise to the automatic changing of operating condition.

The vehicle 10 is operable in a first operating mode where both the front engine driven wheels 22 are required to be driven, e.g. off road. In this operating mode, the controller 46 controls the motor 35 to drive the rear ground engaging wheels 30 in dependence upon the state of drive imparted to the front ground engaging wheels 22 in response to driver controls.

To co-ordinate the engine drive to the front wheels 22 and the motor 35 drive to the rear wheels 30, the vehicle 10 may include ground engaging wheel speed sensors to sense at least the rotational speed of the front ground engaging wheels 22 driven from the engine and to provide input via the data bus, to the controller 46. Depending upon such inputs, and other inputs too, such as the state of one or more driver operated controls, e.g. the accelerator and/or brake which may be sensed by appropriate control sensors in the cab 14 for example, which control sensors may be operatively connected to the data bus, the controller 46 controls the electric motor 35 to provide appropriate drive to the rear ground engaging wheels 30, e.g. to ensu(e that the rear wheels 30 are not driven at a faster or slower speed that the wheel-to-road speed.

:. In a second driver selectable operating mode, the controller 46 operates the motor 35 to impart drive to the rear 30 pair of ground engaging wheels whilst S...

drive is not being imparted to the front ground engaging wheels 22. Such an operating mode is particularly suited, or example, for city travelling, to minimise pollution from the engine exhaust in built-up areas. S. ** * S *

. : The engine 35 may idle when the second operating mode is selected, or may * 30 be de-actuated altogether, but in each case, the controller 46 may be operable automatically to actuate the engine to assist the motor 35 in driving the vehicle where required, for example on a steep hill, and/or when the battery 40 is nearly discharged.

If required, when motor 35 drive only is required, a clutch in the transmission between the engine and the front wheels 22 (not shown) may be disengaged, fully to isolate engine drive from the front wheels, or the transmission may otherwise be disengaged.

In a third selectable operating mode, the controller 46 may control the motor 35 not to provide drive to the rear ground engaging wheels 30, but the motor may still function as a generator to re-charge the battery 40, which third operating mode may be used for example, for on-road inter city travel.

Various modifications are possible without departing from the scope of the invention. For examples only, the front wheels 22 could be carried by a driven axle like rear axle 32, if required, and/or the rear wheels 30 may be carried on a suspension module (or independent suspension modules) if required.

Although in the example described the second ground engaging wheels 30 are carried on an axle 32 which is driven by the (or at least one) electrical motor 35 though a propeller shaft 36 and differential 37, in another example the electric motor or motors 35 may drive the axle 32 directly i.e. the axle 32 :. may be a live axle in which case the motor or motors 35 may be integral with an axle and differential assembly. * I..

In yet another example the vehicle 10 may include a suspension module which carries the or each of the second ground engaging wheels 30, with there being a drive shaft from the electrical motor or motors to each of the * * * second wheels.

*. .: 30 Thus the second ground engaging wheels 30 may be carried on a dead beam (non-driven/live axle), with drive to each of the second ground engaging wheels 30 being superimposed on the dead beam to achieve electric drive to the second ground engaging wheels 30.

In still yet another example, each of the second ground engaging wheels 30 may be driven by a respective electric motor, each such motor being controllable by the controller 46. For example a motor may be incorporated into each hub carrying the respective ground engaging wheel 30, or there may be a transmission member to transmit drive from each motor to its respective ground engaging wheel 30. With this architecture, no differential would be required as the motors may be driven at differential speeds by the controller 46 as required.

In another embodiment, instead of the rear wheels 30 being drivable by the electric motor 35 and the front wheels 22 by the engine, this may be reversed with the engine driving the rear wheels 30 and the motor 35 the front wheels 22. In that case, the engine may be mounted at or towards the rear end 18 of the vehicle 10 instead or at or towards the front end 15 as in the example shown, and the motor 35 may be more appropriately carried by the chassis 12, still between the front 22 and rear 30 wheels, but nearer the front wheels 22 rather than nearer the rear wheels 30 as shown in the example illustrated. * I * *..

**I... The controller 46 may be mounted in alternative appropriate positions to that laSs illustrated and described, preferably so as not to obstruct the load space 16, and such that the controller 46 can readily be connected to the vehicle data bus. S. ** * S

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Although the invention has been described in relation to a light commercial vehicle 10, the invention may be applied to other vehicle kinds.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof. S. * S * a.. a a.. S * *S.. S. * $ * SI. IS. a I. ** a S *

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Claims

CLAIMS

1. A vehicle which includes a body, first ground engaging wheels at or towards one end of the body and second ground engaging wheels at or towards a second end of the body, one of the first and second ground engaging wheels being drivable by an engine and the other of the first and second ground engaging wheels being drivable by an electrical motor.

2. A vehicle according to claim 1 wherein the vehicle includes a first transmission for transmitting drive from the engine to the first ground engaging wheels and a second transmission for transmitting drive from the electrical motor to the second ground engaging wheels.

3. A vehicle according to claim 2 wherein the first transmission includes a gearbox.

4. A vehicle according to claim 3 wherein there is provided a suspension module which carries the or each of the first ground engaging wheels, with there being a drive shaft to each of the one wheels, from the gearbox.

5. A vehicle according to any one of the preceding claims wherein the second ground engaging wheels are carried on an axle. * I

:.::; 6. A vehicle according to claim 5 wherein the axle is driven by the S...

electrical motor though a propeller shaft and differential of the second transmission. I..

7. A vehicle according to claimS wherein the electric motor drives the axle S. * directly.

8. A vehicle according to any one of the preceding claims wherein the first ground engaging wheels are at or towards an end of the body which is at the front of the vehicle in the normal direction of travel of the vehicle and the first ground engaging wheels are driven by the engine and the second ground engaging wheels are driven by the at least one electrical motor.

9. A vehicle according to any one of the preceding claims wherein the vehicle includes a chassis having a pair of chassis members which extend between the first and second ends of the body.

10. A vehicle according to claim 9 wherein the chassis carries the engine at or adjacent the one end of the body at least partially above the chassis members.

11. A vehicle according to claim 10 wherein the chassis includes a sub-frame member to mount the engine, which extends between the pair of chassis members.

12. A vehicle according to any one of claims 9 to 11 wherein the electrical motor is mounted by the chassis between the first and second ground engaging wheels.

13. A vehicle according to claim 12 where appendent to claim 6 wherein :.::: the motor is mounted nearer the second ground engaging wheels than the first * *..

ground engaging wheels.

14. A vehicle according to claim 12 or claim 13 wherein the electric motor is carried by a cradle secured below the pair of chassis members. * $ S * S

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* *: 30 15. A vehicle according to claim 14 wherein the motor is provided at a low position so as not to extend upwards substantially of the chassis.

16. A vehicle according to any one of the preceding claims wherein the vehicle includes a battery for providing power to the electric motor.

17. A vehicle according to claim 16 wherein the battery mounted by the chassis, in a cradle which is secured beneath the chassis.

18. A vehicle according to claim 16 or claim 17 wherein the battery is re-chargeable by the operation of the engine.

19. A vehicle according to claim 18 wherein the battery is rechargeable though an electrical generator driven by the engine.

20. A vehicle according to any one of claims 16 to 19 wherein the electric motor is able to function as an electrical generator, driven by motion of the vehicle, to recover energy and to re-charge the battery.

21. A vehicle according to any one of the preceding claims wherein the drives to the first and second ground engaging wheels are mechanically separate, there being a controller to control and co- ordinate the drive to each of the first and second ground engaging wheels, and to operate the electric motor as an electrical generator when appropriate. a

22. A vehicle according to claim 21 wherein the controller is mounted by the chassis.

23. A vehicle according to claim 21 or claim 22 wherein the vehicle is operable in a first operating mode when both the first and second ground a.. engaging wheels are required to be driven, the controller controlling the motor to drive the second ground engaging wheels in dependence upon the state of drive imparted to the first ground engaging wheels.

24. A vehicle according to claim 23 wherein the vehicle includes ground engaging wheel speed sensors to sense at least the rotational speed of the first ground engaging wheels driven from the engine and to provide input to the controller which in response, controls the electric motor to provide appropriate drive to the second ground engaging wheels.

25. A vehicle according to any one of claims 21 to 24 wherein the vehicle is operable in a second operating mode in which the controller operates the motor to impart drive to the second pair of ground engaging wheels when drive is not being imparted to the first ground engaging wheels.

26. A vehicle according to claim 25 wherein the engine idles when the second operating mode is selected, or is de-actuated altogether, and the controller is operable to actuate the engine to assist the motor in driving the vehicle where required.

27. A vehicle according to any one of claims 21 to 26 wherein the vehicle is operable in a third operating mode in which the controller controls the motor not to provide drive to the second ground engaging wheels.

28. A vehicle according to claim 27 wherein when operating in the third :* operating mode, the motor functions as a generator to re-charge the battery. Si'

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I q, * 29. A vehicle according to any one of claims 23 to 28 wherein the or at least one of the operating modes is selectable by a vehicle driver. *55

30. A vehicle substantially as hereinbefore described with reference to I I * and/or as shown in the accompanying drawings.

31. Any novel feature or novel combination of features described herein and/or as shown in the accompanying drawings. a. * . a *i * a a.. * 4s I a a'.

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