GB2329166A

GB2329166A - Vehicles with interchangeable tools

Info

Publication number: GB2329166A
Application number: GB9800863A
Authority: GB
Inventors: Torben Juul; James A Stone; Jonathan C Booty; Peter C D Todd; Lloyd Taylor; Wilhelm Goellner; Manfred Maiers
Original assignee: Sauer Sundstrand GmbH and Co; Danfoss AS; PERKINS TECHNOLOGY Ltd
Current assignee: Sauer Sundstrand GmbH and Co; Danfoss AS; PERKINS TECHNOLOGY Ltd
Priority date: 1998-01-15
Filing date: 1998-01-15
Publication date: 1999-03-17
Also published as: GB9800863D0

Abstract

A vehicle comprises a power system (10, 14) for propelling the vehicle and manipulating an interchangeable tool (8) mounted on the vehicle, first operator controls (11) to control the propulsion of the vehicle, second operator controls (16) to control the manipulation of the interchangeable tool. A vehicle control system (18) is connected between the first (11) and second (16) operator controls and the power system (10, 14) and varies the response of the power system (10, 14) to at least the second operator controls (16) according to the nature of the tool (8) mounted on the vehicle. The variation of response may include limitation of the orientation or height of a tool or the speed of the vehicle. The weight of the tool and any load carried thereby may also be used as a parameter. The vehicle may be a telescopic material handler. Each tool may contain a transponder to convey its nature to the control system.

Description

VEHICLES WITH INTERCHANGEABLE TOOLS This invention relates to vehicles with interchangeable tools.

An example of a known vehicle with interchangeable tools is a telescopic material handler in the form of a four-wheeled vehicle provided with a manoeuvrable telescopic boom located, in this instance, behind a cab for the operator. A diesel engine is used to drive the wheels and the pump of a hydraulic system provided for manoeuvring the boom to manipulate a tool mounted on the distal end thereof.

It is an object of the invention to enable the safety and performance of such a vehicle to be improved.

The present invention provides a vehicle comprising: power system means for propelling the vehicle and manipulating an interchangeable tool mounted on the vehicle, first operator controls for use by an operator to control the propulsion of the vehicle, second operator controls for use by the operator to control the manipulation of the interchangeable tool, and a vehicle control system connected between the first and second operator controls and the power system means, wherein the vehicle control system is arranged to modify the response of the power system means to at least the second operator controls according to the nature of the tool mounted on the vehicle.

By this means, it is possible to take into account the characteristics of particular tools and modify the response of the second power system to the second operator controls to ensure that they are used more safely and performance is more effective.

Most advantageously, the vehicle control system is arranged to modify the response of the power system means to both the first and second operator controls according to the nature of the tool mounted on the vehicle. This feature is appropriate when the tools are such as to require the performance of the vehicle to be adapted to the nature of the tool, for example, to prevent the operator from driving too fast when transporting personnel in a personnel carrier. It is, however, of considerable advantage since not only can it ensure that safety laws regarding speed of movement are complied but also it enables an improvement in the efficiency of operation of the vehicle to be obtained.

The power system means may comprises a first power system and a second power system. The first power system could be used to propel the vehicle and the second power system to manipulate the tool but a preferred arrangement is one in which the first power system is arranged to drive the second power system, the second power system being a hydraulic power system.

The first power system may be an internal combustion engine, for example, a diesel engine, arranged to drive one or more pumps of the hydraulic power system.

Preferably, the vehicle control system defines a plurality of sets of limits for operating parameters of the second hydraulic system, each set relating to a respective particular type of tool. That has the advantage that the appropriate set of limits (which may consist of only a single limit) simply has to be selected on identification of the tool to be used.

It is especially preferred that each set of limits is formed of first and second subsets of limits, the first subset containing limits that are always enforced and cannot be overridden by the operator and the second subset containing limits that are normally enforced but can be overridden by the operator. That has the advantage that the first subset can comprise limits that are required by law and/or are absolutely essential to safety. For certain tools, however, there may be reasons for making either the first or the second subset an empty subset.

Preferably, means are provided to warn the operator that an overridable limit has been reached. That has the advantage that the operator is made aware that a limit has been imposed and that he can override it if he chooses.

Advantageously, a tool-discriminating sensor is provided on the vehicle and the vehicle control system is arranged to select the appropriate set of limits according to the tool detected by the sensor. By this means, the selection of the appropriate set of limits can be achieved automatically on mounting a tool on the vehicle.

Advantageously, the tool-discriminating sensor operates without making physical contact with the tool.

Such a non-contact or remote sensor will be relatively insensitive to the effects of dirt and rough handling.

The tool-discriminating sensor may includes one or more inductive sensors.

If desired, the transmitter element on the or each tool comprises a transponder. By this means, an active response from the tool to interrogation by sensor can be achieved, which is a certain means of identifying the tool in question.

Instead of defining a plurality of limits in the vehicle control system, the or each tool may be arranged to transmit to the vehicle control system a set of limits for operating parameters of the second power system, the set relating to the respective particular type of tool. That has the advantage that the vehicle control system does not have to store sets of limits relating to all possible tools that might be used.

Some or all of each set of limits may be stored in a rewritable form. By this means, the opportunity may be given to the operator to define some limits of his own choice for a particular tool. Legal and essential safety limits can, however, be stored in a read only form when only some of the limits are rewritable.

Again, the or each set of limits may be formed of first and second subsets of limits, the first subset containing limits that are always enforced and cannot be overridden by the operator and the second subset containing limits that are normally enforced but can be overridden by the operator.

Means may be provided to warn the operator that an overridable limit has been reached are provided.

The or each tool may includes a transmitter element arranged to transmit to the vehicle control system without physical contact.

One or more inductive sensors may be provided to receive the transmitted limits.

Preferably, the transmitter element comprises a transponder.

Advantageously, means are provided to determine the loading of the vehicle and to modify the response of the second power system to the second operator controls according to the loading of the vehicle. By this means, limits relating to safe loading can readily be enforced.

The means provided to determine the loading of the vehicle may comprise a strain gauge mounted on a rear axle of the vehicle. That is a very simple way of determining the loading of the vehicle.

The vehicle may be a wheeled vehicle. The invention is, however, also applicable to vehicles which have moving tracks instead of wheels such as crawler vehicles.

The vehicle may be a telescopic material handler (sometimes known as a telehandler). Alternatively, the vehicle could be a fork lift vehicle or a wheeled loader, for example.

A vehicle constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawing, in which: Fig. 1 is a diagrammatic side elevation of the vehicle; Fig. 2 is a block diagram of power systems of the vehicle, and Fig. 3 is a diagrammatic illustration of an inductive sensing system.

Referring to the accompanying drawing, a wheeled vehicle in the form of a telescopic material handler 1 is shown in Figure 1. The telescopic material handler has four wheels 2, a driver's cab 4, and a telescopic boom 6, to the distal end of which an interchangeable tool 8 can be attached.

As shown in Figure 2, the telescopic material handler 1 has a first power system 10 in the form of a diesel engine for driving pumps of a second, hydraulic, power system 14. First operator controls 11 including a steering wheel 12 are provided in the cab 4 for use by an operator of the vehicle to drive the telescopic material handler as regards propulsion and steering.

The second, hydraulic, power system 14 is provided for driving the wheels 2 of the vehicle, for operating the steering, and for manipulating the boom 6 and the interchangeable tool 8. For this purpose, various hydraulic motors, and piston and cylinder arrangements (not shown) are provided and arranged in a known manner.

Second operator controls 16 are provided in the cab 4 for use by the operator to control the second power system 14, a vehicle control system 18, including a microprocessor (not shown) and memory circuits (not shown) being connected between the first operator controls 11 and the second operator controls 16, and the second power system 14. The vehicle control system 18 is arranged to modify the response of the second power system 14 to both the first operator controls 11 and the second operator controls 16 according to the nature of the tool 8 mounted on the vehicle.

The vehicle control system 18 defines a plurality of sets of limits for operating parameters of the hydraulic power system 14, each set relating to a respective particular type of tool 8. Each set of limits is formed of first and second subsets of limits, the first subset containing limits, if any, that must be and are always enforced and cannot be overridden by the operator and the second subset containing limits, if any, that are normally enforced but can be overridden by the operator. Examples are given below: i. subset of limits always enforced

I tool Darameter limit platform from horizontal loading low limit, much less than loading at which vehicle might tip over speed of moderate boom movement vehicle speed very slow diesel low engine speed bucket emptying allowable degree of position closeness to cab loading highest safe limit without danger of the vehicle's tipping over fork safe load always ON lndlcatlon

forward acceleration: (i) boom lowered high limit (ii) boom raised low limit reverse low limit acceleration sweeper/ maximum oil limit corresponding concrete flow to tool to the tool mixer ii. subset of limits normally enforced but overridable

tool arameter limit personnel speed of slow platform movement bucket speed of moderate movement fork movement pre-set rate steering pre-set response aggressive or gentle l

auto slow return speed diesel low engine speed An alarm and operator interface 20 is provided to warn the operator that an overridable limit has been reached are provided. The alarm can, for example, including a warning buzzer and means to halt the operation of the vehicle until the operator turns an override key. A display panel can be provided to indicate the nature of the limit that has been reached, for example, "LIMIT OF VEHICLE SPEED", "LIMIT OF BOOM MOVEMENT", and "LIMIT OF ENGINE LOADING" could be displayed.

A tool-discriminating sensor 22 is provided at the distal end of the boom 6 and the vehicle control system 18 is arranged to select the appropriate set of limits according to the particular tool 8 detected by the sensor 22.

There is a non-contact interface 23 between the tool-discriminating sensor 22 and a corresponding element 24 on the tool. Figure 3 shows an example of three inductive coupling elements 26, 28, 30 responding to a ferro-magnetic tooth 32 on the tool element 24. As shown in Figure 3, the tooth 32 is centrally placed so that the correspondingly placed inductive element 28 responds with a logic "1" whereas the other two inductive elements 26 and 30 give logic "0". Other tools would have one or more teeth differently placed to give rise to different logical combinations in the sensor 22.

A strain gauge 26 (Figure 2) is mounted on a rear axle of the telescopic material handler 1 so that the vehicle control system 18 can compare actual loading with a stored limit for loading. An example of the known use of a strain gauges for load sensing is to be found in European patent specification 0 466 046.

In an alternative arrangement (not shown), the or each tool 8 has a transponder for transmitting to the vehicle control system its own set of limits for operating parameters of the second power system 14. That is, the limits are stored in the transponder and transferred to the vehicle control system 18. Thus, the vehicle control system 18 does not, in this case, have to store a plurality of sets of limits and select between them according to the tool attached to the telescopic material handler. In this case, the transponder can include a EEPROM so that some or all of each set of limits can be rewritten.

The invention is not limited in its application to telescopic material handlers but may be applied to many other types of vehicle especially those in which a hydraulic power system is used to manipulate a tool.

Other types of sensor can be used instead of that described, for example, an optical sensor.

Claims

C L A I M S:

1. A vehicle comprising: power system means for propelling the vehicle and manipulating an interchangeable tool mounted on the vehicle, first operator controls for use by an operator to control the propulsion of the vehicle, second operator controls for use by the operator to control the manipulation of the interchangeable tool, and a vehicle control system connected between the first and second operator controls and the power system means, wherein the vehicle control system is arranged to modify the response of the power system means to at least the second operator controls according to the nature of the tool mounted on the vehicle.

2. A vehicle as claimed in claim 1, wherein the vehicle control system is arranged to modify the response of the power system means to both the first and second operator controls according to the nature of the tool mounted on the vehicle.

3. A vehicle as claimed in claim 1 or claim 2, wherein the power system means comprises a first power system and a second power system.

4. A vehicle as claimed in claim 3, wherein the first power system is arranged to drive the second power system, the second power system being a hydraulic power system.

5. A vehicle as claimed in claim 4, wherein the first power system is an internal combustion engine arranged to drive one or more pumps of the hydraulic power system.

6. A vehicle as claimed in claim 5, wherein the internal combustion engine is a diesel engine.

7. A vehicle as claimed in any one of claims 3 to 6, wherein the second power system is arranged both to propel the vehicle and manipulate said interchangeable tool mounted on the vehicle.

8. A vehicle as claimed in any one of claims 3 to 7, wherein the vehicle control system is arranged to modify the response of both the first and second power systems to each of the first and second operator controls.

9. A vehicle as claimed in any preceding claim, wherein the vehicle control system defines a plurality of sets of limits for operating parameters of the second hydraulic system, each set relating to a respective particular type of tool.

10. A vehicle as claimed in claim 9, wherein each set of limits is formed of first and second subsets of limits, the first subset containing limits that are always enforced and cannot be overridden by the operator and the second subset containing limits that are normally enforced but can be overridden by the operator.

11. A vehicle as claimed in claim 10, wherein means are provided to warn the operator that an overridable limit has been reached are provided.

12. A vehicle as claimed in any one of claims 9 to 11, wherein a tool-discriminating sensor is provided on the vehicle and the vehicle control system is arranged to select the appropriate set of limits according to the tool detected by the sensor.

13. A vehicle as claimed in claim 12, wherein the tool-discriminating sensor operates without making physical contact with the tool.

14. A vehicle as claimed in claim 13, wherein the tool-discriminating sensor includes one or more inductive sensors.

15. A vehicle as claimed in claim 13 or claim 14 in combination with at least one interchangeable tool, wherein the or each tool includes a transponder to communicate with the tool-discriminating sensor.

16. A vehicle as claimed in any one of claims 1 to 8 in combination with at least one interchangeable tool, wherein the or each tool is arranged to transmit to the vehicle control system a set of limits for operating parameters of the second power system, the set relating to the respective particular type of tool.

17. A vehicle as claimed in claim 16, wherein some or all of each set of limits is stored in a rewritable form.

18. A vehicle as claimed in claim 16 or 17, wherein the or each set of limits is formed of first and second subsets of limits, the first subset containing limits that are always enforced and cannot be overridden by the operator and the second subset containing limits that are normally enforced but can be overridden by the operator.

19. A vehicle as claimed in claim 18, wherein means are provided to warn the operator that an overridable limit has been reached are provided.

20. A vehicle as claimed in any one of claims 16 to 19, wherein the or each tool includes a transmitter element arranged to transmit to the vehicle control system without physical contact.

21. A vehicle as claimed in claim 20, wherein one or more inductive sensors are provided to receive the transmitted limits.

22. A vehicle as claimed in claim 20 or claim 21, wherein the transmitter element comprises a transponder.

23. A vehicle as claimed in any preceding claim, wherein means are provided to determine the loading of the vehicle and to modify the response of the power system means to the second operator controls according to the loading of the vehicle.

24. A vehicle as claimed in claim 23, wherein the means provided to determine the loading of the vehicle comprise a strain gauge mounted on a rear axle of the vehicle.

25. A vehicle as claimed in any preceding claim, wherein the vehicle is a wheeled vehicle.

26. A vehicle as claimed in any preceding claim, wherein the vehicle is a telescopic material handler.

27. A vehicle substantially as herein described with reference to, and as illustrated by, the accompanying drawings.