带DA阀的液压泵功能分析及系统调试

为更好地使用和调试DA阀的泵控系统，确保DA控制系统在工程机械上运用的灵活性，做到不同工况设备都能自动处在最佳状态工作，通过分析DA阀和DA泵的构造原理及测试曲线，论证DA泵的3个主要功能： 1）发动机转速控制排量功能，即操纵发动机油门踏板就可以改变泵的排量，从而改变车速的自动驾驶功能； 2）恒功率功能，即通过调节并锁定泵的设定，使泵有稳定的功率输出，以适应原动机的功率； 3）压力切断功能，即当泵的压力达到设定的最大极限压力时，控制泵的排量接近为0，以防发动机因负载过大而熄火。通过对具体设备液压系统主要参数的设定和调试，给出DA泵系统的调试方法与调试过程，以实现DA泵转矩与发动机转矩的最佳匹配，减小发动机功率损耗和防止发动机因负载过大而熄火，同时也减轻操作者的疲劳和负担。

Function Analysis and System Debugging of Hydraulic Pump with DA Valve

In order to study the pump control system of DA valve in detail, ensure the flexibility of DA control system in application of engineering machinery, and guarantee the best working state of the equipment in different working conditions, the structural principle and test curve of DA valve and DA pump are analyzed. The main functions of DA pump are demonstrated as follows: (1) The function of displacement control by engine speed, i.e. the automatic driving function can change the pump displacement by manipulating the engine accelerator pedal, thus changes the speed. (2) Then function of power constant, i.e. the stable power output of pump can be guaranteed by adjusting and locking the pump setting to adapt to the prime mover power. (3) The function of pressure cut off, i.e. the pump displacement is closed to zero when the pump pressure reaches the set maximum limit pressure to prevent the engine from flaking out due to overload. Through the setting and debugging of main parameters of hydraulic system of specific equipment, the debugging method and process of DA pump system are given, so as to achieve the best match between DA pump torque and engine torque, reduce the engine power loss, prevent the engine from flaking out due to overload, and reduce the fatigue and burden of operators.