Patent ID: 6266590
Filing Date: 2001-07-24
Classification: B60G

Abstract:
In an improved pneumatic suspension leveling system for a vehicle with pneumatic suspension leveling elements assigned to vehicle wheels and axles, and with a compressor and central pressure accumulator for pressurizing and storing air to be selectively supplied to the pneumatic suspension leveling elements, and with an air pressure sensor which senses and air pressure level (Pz) in the central pressure accumulator and which generates a signal value (Sz) correlated to the air pressure level therein, and an electronic control device for receiving and processing the signal value (Sz) for initiating a charging of the central accumulator with compressed air from the compressor when the signal value (Sz) reaches a predetermined lower threshold signal value (Szu) and for terminating charging of the central accumulator when the signal value (Sz) reaches a predetermined upper threshold signal value (Szo), the improved system comprising: an ambient air pressure compensator including an ambient pressure sensor (25) for detecting the atmospheric air pressure level (Pu) about the vehicle; said ambient pressure sensor (25) generating and transmitting a signal value (Su) corresponding to the atmospheric air pressure level to the electronic control unit (11) for processing to produce a change in the upper threshold signal value (Szo); the functional relationship between the upper threshold signal value (Szo) and the signal value (Su) of the ambient pressure sensor (25) for terminating compressor operation is selected so that an upper cutoff pressure (Pzo) in the pressure accumulator (9) corresponding to the upper threshold signal value (Szo) rises with increasing ambient air pressures (Pu) and decreases with decreasing ambient air pressures (Pu); the functional relationship between the upper threshold signal value (SzO) and the signal value (Su) of the ambient pressure sensor (25) is selected so that the corresponding upper cutoff pressure (Pzo) corresponding to the upper threshold signal value (Szo) varies in the central accumulator (9) proportionally to the ambient air pressure (Pu).