The purpose of main pump control is to improve the operation efficiency of excavator and save fuel at the same time. When the excavator is working, the electromagnetic proportional reducing valve on the main pump controls the output flow of the main pump according to the input current signal to meet the speed and power requirements of different working conditions.
(1) Mode s: when this mode is selected, is the input current of the electromagnetic proportional reducing valve? The output torque of the main pump is about 90% of the rated torque of the engine.
(2) Mode l: when this mode is selected, the input current of the electromagnetic proportional reducing valve is, 1, and the output torque of the main pump is about 70% of the rated torque of the engine. The initial value of I1 is constant.
(3) When f and I modes are selected, the engine speed is 1200R / min, and the control of the main pump is the same as that of L mode. Select mode F and mode I, the excavator will walk alone (the upper pressure switch is in off position and the travel pressure switch is in on position), and the control of the main pump is the same as that of mode s.
(5) When h mode is selected, the output power of the engine can be used to the greatest extent by changing the input current of the electromagnetic proportional reducing valve of the main pump. When h mode is selected, the current is 495ma. When mode s is selected, the current is (305 ± 20) MA.
