초록 ▼

To improve the operating and spring characteristics of the utility vehicle it is proposed that the mechanical and hydraulic components be designed for a spring suspension under maximum load of the axle body. The valve circuit is configured and controlled in such a way that in the accumulators an ade

To improve the operating and spring characteristics of the utility vehicle it is proposed that the mechanical and hydraulic components be designed for a spring suspension under maximum load of the axle body. The valve circuit is configured and controlled in such a way that in the accumulators an adequate pressure is constantly maintained in order to make possible a spring suspension of the axle body under all load and operating conditions of the vehicle.

대표청구항 ▼

[ We claim:] [1.] A hydro-pneumatic suspension system for a front axle of a vehicle, having a pair of hydraulic cylinders, coupled between a chassis of the vehicle and an axle body, each cylinder having a rod end chamber and a piston end chamber, each rod end chamber being connected to a rod end acc

[ We claim:] [1.] A hydro-pneumatic suspension system for a front axle of a vehicle, having a pair of hydraulic cylinders, coupled between a chassis of the vehicle and an axle body, each cylinder having a rod end chamber and a piston end chamber, each rod end chamber being connected to a rod end accumulator and to a valve circuit fed by a hydraulic pump, the valve circuit controlling a position of the chassis relative to the axle body, and controlling fluid pressure in the accumulator as a function of load on the axle body, the improvement wherein:the suspension system include components which are designed to resiliently suspend the chassis under all loads expected to be applied to the axle body;a position sensor senses a position of the chassis relative to the axle and generates a position signal representative thereof;the valve circuit maintains a pressure in the accumulator sufficient to resiliently suspend the axle body under all load and operating conditions, the valve circuit comprising a pair of electromagnetically controlled level control valves, each level control valve having a first port communicated with the hydraulic pump and a second port communicated with a reservoir, one of the level control valves having a third port communicated with the rod end chamber via a first pilot controlled check valve, the other level control valve having a third port communicated with the piston end chamber via a second pilot controlled check valve, each check valve preventing fluid backflow out of the corresponding rod end chamber and piston end chamber; anda control unit controls the valve circuit as a function of the position signal.