Lift axle control unit for a motor vehicle

Abstract

The invention refers to a lift axle control unit (1) for a lift axle suspension system (30) of a vehicle (1000), said lift axle control unit (1) comprising at least: an electronic control unit (4) receiving at least a first electric input signal (S1) and a position indicating signal (S4), at least one supply input port (100) to be connected to a pressure reservoir (2), a first delivery port (220) to be connected to at least one suspension bellow (14) and a second delivery port (250) to be connected to at least one lift bellow (16), a load detection valve (3) being connectable to load variable parts (1010) of said vehicle (1000) and delivering an pressure output signal (p3) in dependence of an axle load of the vehicle (1000), a first relay valve (6) connected to said first delivery port (220) for feeding said suspension bellow (14), a second relay valve (7) connected to said second delivery port (250) for feeding at least one lift bellow (16), a solenoid valve (5) for receiving an electric control signal (S5) from said electronic control unit (4) and for connecting said load detection valve (3) to said first and second relay valve (6, 7) or separating it from said first and second relay valve (6, 7) in dependence of said electric control signal (S5).

Description

technical field [0001] The invention relates to a lift axle control unit to be used in a lift axle suspension system of a commercial vehicle, furthermore to a lift axle suspension system comprising such a lift axle control unit and to a vehicle, in particular A commercial vehicle including such a lift axle suspension system. Background technique [0002] Lift axle suspension systems for commercial vehicles typically include suspension bellows (like other axles) for damping and for adjusting the distribution of axle loads between the axles, and one or more Bellows are lifted to free the wheels of the lift axle from the ground; pneumatic valves for controlling these bellows are also provided. [0003] Lift axle suspension systems in commercial vehicles are capable of the following functions: [0004] - automatically raises or lowers the lift axle depending on the vehicle load state, [0005] - For better traction and maneuverability of the vehicle, over-slack to raise the l...

AI Technical Summary

Problems solved by technology

[0010] One disadvantage of these prior art lift shaft control valves is the high cost of manufacture due to the separate cast valve bodies for the individual valves (lift shaft control valve and relay valve) and the pipe connection

[0011] Another disadvantage of the known technology is that the separate exhaust ports of the valve have to be individually protected from water and dust

[0012] Another disadvantage of the known technology is the direct execution of the control of the external relay valve connected to the suspension bellows, without damping

More air consumption due to frequent discharge of air from the suspension bellows when the vehicle passes over bumpy road conditions

[0013] Another disadvantage of the lift shaft control valves of the known art can be seen from the fact that load detection is performed by means of a double throw pressure switch

[0016] The drawbacks of this system are still the complexity of its design and the cost of manufacturing

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