The throttle system overcomes the load pressure by the pressure of the oil return throttle. Its speed regulation characteristics are affected by the load pressure and the flow of the oil pump. The stem formation of the oil pipeline cylinder starts is related to the load pressure and the pump flow: the higher the load pressure, the smaller the pump flow, the larger the valve stem stroke, the smaller the speed regulation area. The speed regulating stroke of flow is large and the operation performance is good when the load is light. The flow adjustment stroke is small and the operation performance is poor when heavy load is in use. The speed adjustment and control are unstable, the valve rod control stroke is unchanged, and the cylinder speed will change with the change of load and pump flow.
Due to the reasons of throttle system, there are some shortcomings and shortcomings
1. the load pressure of excavator is unstable and randomly changing, and the flow of hydraulic pump is changing constantly, so its speed regulation performance is very unstable and difficult to operate.
2. when one pump supplies multiple actuators to act simultaneously, because the hydraulic oil flows to the actuator with light load, it is necessary to throttle the control valve rod of the actuator with light load. Because the load of each actuator is changing at all times, the flow rate should be reasonably distributed so as to realize the required cooperation
It's hard to control the complex action of seeking.
3. it is not easy to meet the requirements of various working conditions of hydraulic excavator and realize ideal compound action.
