公开(公告)号：US3990520A

公开(公告)日：1976-11-09

申请号：US601660

申请日：1975-08-04

申请人： James Allan Koch ,  Richard Treichel ,  Benjamin Michael Witte

发明人： James Allan Koch ,  Richard Treichel ,  Benjamin Michael Witte

IPC分类号： A01B63/112

CPC分类号： A01B63/112

摘要： The lower draft link of a tractor three-point hitch includes a sensor to sense draft loads imposed on the draft link by an earth-working implement. Variations in the draft load cause variations in the pressure of the fluid in the sensor from a preselected pressure. A pilot-operated, load control valve is connected to the sensor and is shiftable in response to pressure above and below the preselected pressure to actuate a control mechanism. The control mechanism actuates a direction control valve for directing fluid to and from a hydraulic lift cylinder for respectively raising and lowering the draft link to adjust the implement so as to maintain the preselected pressure and thus maintain the desired draft load.

摘要翻译： 拖拉机三点牵引车的下部牵引连杆包括传感器，用于感测由地面作业工具施加在牵引连杆上的载荷。 牵引载荷的变化会导致传感器中的流体压力与预选压力的变化。 先导操作的负载控制阀连接到传感器，并且响应于高于和低于预选压力的压力而移动以致动控制机构。 控制机构致动一个方向控制阀，用于将流体引导到液压提升缸，用于分别升高和降低牵引连杆，以调节工具，以保持预选的压力，从而保持所需的牵伸载荷。