A HYDRAULIC CONTROL SYSTEM FOR WORK VEHICLES

摘要

A hydraulic control system (1) for work vehicles including a control unit (2) to control the steering wheels of a vehicle via a cylinder (3) and a priority valve (4) which by means of a first load-sensing system (LS1) controls the pressure fluid flow to the control unit (2) and to a subsequent proportional valve group (9a-9c). By means of a second load-sensing system (LS2) the proportional valve group (9a-9c) controls the pressure fluid flow to secondary hydraulic motors (10) or work cylinders (11, 12) to control the work tools of the vehicle. The control system (1) also includes an open-centre valve connection (6) and a fixed displacement pump (8). The first load-sensing system (LS1) is connected with a second load-sensing system (LS2), whereby drop-off of the pressure fluid flow to the control unit (2) is avoided at simultaneous operation of the latter and of one or several of the proportional valves (9a-9c) as it is the case with known control systems. Hereby a control system is provided which is particularly agreeable to operate for the driver of the work vehicle.