| 摘要 |
A hydraulic circuit for raising and lowering a load arm on a work machine is adapted to provide a ride control function which will cushion shocks through the load arm as the machine traverses rough terrain. The circuit includes a hydraulic ram (16) that moves the load arm and a first hydraulic accumulator (36) connected to a first chamber (22) of a hydraulic ram (16). The accumulator (36) provides a cushionings effect to the ram (16) when the ride control function is engaged. The accumulator (36) is located between a first control valve (10) and a load hold valve (28) of the circuit so that the load hold valve (28) will hold the ram (16) in position should there be any sudden pressure drop in or adjacent the accumulator (36). The accumulator (36) can also be connected to a control surface of the load hold valve (28) via a valve 42 to simultaneously open the valve (28) and cushion the ram (16).The control surface of the load hold valve (28) is also connectable or not to a second chamber (24) of the cylinder (16) via a control valve (34). A second dedicated accumulator (38) can also be introduced for this purpose if desired. |
