AU2004100084A4 - A manual control and diagnostic aid for automatic electronic air suspension - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION

PATENT

A manual control and diagnostic aid for automatic Electronic Air Suspension The following statement is a full description of this invention, including the best method of performing it known to me: A manual control and diagnostic aid for automatic Electronic Air Suspension Technical Field The present invention relates to a manual control unit and diagnostic aid for the Range Rover automatic Electronic Air Suspension system.

Background to the Invention Since the early 1990s Land Rover has manufactured their Range Rover vehicles with an automatic Electronic Air Suspension system.

Owners and drivers of these vehicles have experienced problems with the operation of their Electronic Air Suspension systems. Many have been left with their suspension 'locked' by the automatic control unit on one setting or 'on the bump stops'. In the first instance the vehicle suspension setting can be 'locked' at an inappropriate height for the driving conditions with the inherent instability this brings when the vehicle is traversing a slope, cornering or driving on the highway. In the second instance 'on the bump stops' it leaves the vehicle with virtually no suspension travel and only a minimum of ground clearance under the vehicle. This makes for a very rough ride when driving on road and makes it difficult or impossible to negotiate rough terrain when driving off road, always with the possibility of damage to the vehicle.

In order to return the Electronic Air Suspension system to fully automatic operation fault diagnosis and repairs have to be made and then a specialized proprietary diagnostic computer is required to erase the fault memory inside of the air suspension automatic control unit. Someone to carry out the diagnostics, spare parts and a proprietary diagnostic computer are usually not readily available when and where the automatic air suspension control system malfunctions.

Accordingly, it is an object of the present invention to provide for manual control, and aid fault diagnostics, of the various functions of the Electronic Air Suspension system in a Range Rover vehicle to allow the vehicle to proceed with appropriate ground clearance. It can also provide the user with input data from the various vehicle systems and output signals to the various vehicle systems to test their operation for fault diagnostic purposes.

Summary of the invention The present invention is to provide an air suspension manual control unit and diagnostic aid, for Range Rover motor vehicles, to manually control vehicle height, including a logic processor, sensor inputs for receiving signals indicative of various vehicle parameters to said logic processor, visual and audible displays, a means for sending control signals both manually and from the logic processor to air suspension control and other vehicle devices including at least, but not limited to, the air compressor, valve block and its driver unit, lights and warnings; At any time or when a Range Rover Electronic Air Suspension control unit no longer automatically controls the suspension height of the vehicle the operator has the option, with the use of this invention, of manual control of the vehicles suspension height.

Brief Description of the Drawings The invention will now be described with reference to the following drawings in which: Figure 1 is a system Circuit Diagram showing the Manual Control Unit (MCU) and the circuitry of the Power and Control connections to the vehicles wiring.

Figure 2 is a system Circuit Diagram showing the Manual Control Unit (MCU) and the circuitry of the Input and Output connections to the vehicle wiring.

Detailed Description of the Invention As an aid to the description of this invention a copy of the United States Patent Number 5,452,919 is enclosed. Being the Rover Group Limited Patent for the "Suspension System for a Vehicle" and contains a description of the air suspension system and its automatic operation.

It will be appreciated that the following description relates to a particular, preferred implementation. Alternative components, devices and approaches may be used within the general scope of the present invention.

Figure 1 This Circuit Diagram shows the Power and Control connections that the Manual Control Unit (MCU) has with the wiring and components in the vehicle.

These connections provide at terminal number: 1 12 volt power 18 earth 16 input from the air compressor motor overheat sensor 13 input from the stored air supply pressure switch 8 output to drive the air compressor relay that operates the air compressor and the air operated solenoid valve 11 output to the valve block driver to operate the left rear valve 28 output to the valve block driver to operate the right rear valve output to the valve block driver to operate the left front valve 27 output to the valve block driver to operate the right front valve 26 output to the valve block driver to operate the inlet valve 9 output to the valve block driver to operate the exhaust valve Taken with all of the connections above, the MCU can: 1. With the ignition switched on the MCU has voltage supplied to terminal 1. This together with the permanent earth connection at terminal 18 provide the necessary power to operate the MCU and control the air suspension.

2. With a 'cold' input from the air compressor overheat sensor, a 'low pressure' input from the pressure switch and with the compressor switch on the MCU in the 'run' position the MCU logic processor allows the operation of the air compressor until either or both of the inputs change.

3. When the air reservoir is fully charged the pressure switch signals the MCU to turn off the air compressor. When the pressure lowers in the air tank the pressure switch will again signal the MCU to run the compressor to refill the air tank. If the air compressor runs for an extended time it may get hot enough for the overheat sensor to signal the MCU to stop the compressor to let it cool down.

4. Emergency bypass switches are included in the MCU to enable the operation of these parts of the system if there is a failure of either the pressure switch, the overheat sensor or their associated wiring.

The MCU contains switches to operate each of the solenoid valves in the valve block that channel the air through the air suspension system. With the correct use of these switches it is possible to add and remove air from the air suspension bags in each of the four corners of the vehicle.

Figure 2 This Circuit Diagram shows the Input and Output connections to the vehicle wiring that the Manual Control Unit (MCU) has with the Range Rover Electronic Air Suspension wiring and components in the vehicle.

These connections provide at terminals number: 4, 5, 22, and 23 inputs from the four corner height sensors.

12 input for engine RPM input for Road Speed 31 input for foot brake applied signal 34 input for door open signal 14 input for handbrake on and transmission in neutral signal input from inhibit switch 33 input from lower switch 32 input from raise switch 17 35 inputloutput for diagnostic port output for raise lamp 7 output for lower lamp 19 output for warning lamp relay 2, 3, 20 21 power output to the four corner height sensors 6 earth for the warning lamp relay 24 earth for the four corner height sensors 29 earth for the raise, lower and inhibit switches Taken with all of the connections in figure 1, the MCU can: 1. Supply regulated power out of terminals 2, 3, 20 21, earth at terminal 24, and receives inputs at terminals 4, 5, 22, and 23 to collect, process and display height data from the four corner height sensors. This height data may be used to maintain a manually set height adjustment, provide a warning if either a height sensor malfunctions or if a height cannot be maintained.

2. Input, process and display sensor data for engine RPM from terminal 12. This engine running signal can be used to cause or inhibit certain air suspension functions unless the engine is running. Such as to stop the operation of the air compressor to prevent draining the vehicle battery 3. Input, process and display sensor data for Road Speed from terminal 30. This road speed signal can be used to cause or inhibit certain air suspension functions unless or until the vehicle is moving. Such as to cause or inhibit height changes while the vehicle is moving.

4. Input, process and display the input for the foot brake applied signal from terminal 31. This foot brake signal can be used to cause or inhibit certain air suspension functions unless or until the foot brake is applied. Such as to inhibit height changes while the foot brake is applied.

5. Input, process and display the input for the door open signal from terminal 34.

This door open signal can be used to cause or inhibit certain air suspension functions unless or until a door is open. Such as to inhibit height changes while a door is open.

6. Input, process and display the input for the handbrake on and the transmission in neutral signals from terminal 14. This handbrake on and the transmission in neutral signal can be used to cause or inhibit certain air suspension functions unless or until the handbrake is on and/or the transmission is in neutral. Such as to allow height changes except while a door is open and the engine is not running.

7. Input, process and display the input from the inhibit switch from terminal 15. This inhibit signal can be used to cause or inhibit certain air suspension functions unless or until the inhibit switch is depressed.

8. Input, process and display the input from the lower switch from terminal 33. This lower signal can be used to cause or inhibit certain air suspension functions unless or until the lower switch is depressed. Such as to allow height changes except while a door is open and the engine is not running.

9. Input, process and display the input from the raise switch from terminal 32. This raise signal can be used to cause or inhibit certain air suspension functions unless or until the raise switch is depressed. Such as to allow height changes except while a door is open and the engine is not running.

Output at terminal 25 to illuminate the raise lamp.

11. Output at terminal 7 to illuminate the lower lamp.

12. Output at terminal 19 to operate the warning lamp relay.

13. Supply earth for the warning lamp relay at terminal 6.

14. Supply earth for the raise, lower and inhibit switches at terminal 29.

It will be appreciated that the above description has been given in relation to a preferred embodiment only, and is not meant to be limited to the specifics of the disclosure which may vary in many ways as would be understood by the person skilled in the art, within the scope of the present invention.

Claims (3)

1. An air suspension manual control unit and diagnostic aid, for Range Rover motor vehicles, to manually control vehicle height, including a logic processor, sensor inputs for receiving signals indicative of various vehicle parameters to said logic processor, visual and audible displays, a means for sending control signals both manually and from the logic processor to air suspension control and other vehicle devices.

2. An air suspension manual control unit and diagnostic aid according to claim 1, wherein when a driver manually sends control signals to selectively operate said air suspension control devices in order to manually adjust the height of said vehicle, said driver gathers the sensor inputs selected from the groups comprising connections in figure 1 and/or figure 2 and height data.

3. An air suspension manual control unit and diagnostic aid according to claim 1, wherein said system further includes means to provide a notification to the driver in the event that some or all of the data determined by said logic processor are exceeded in order that the driver may bring the vehicle back within the manually adjusted height criteria.