SMALL DISPLACEMENT START CONTROL LOOP FOR MAIN PUMP AND CONTROL METHOD THEREOF

摘要

A small displacement start control loop for a main pump and a control method thereof. The control loop comprises a controller (1) and a hydraulic loop (2). The hydraulic loop (2) comprises a first solenoid valve (21), a second solenoid valve (22), a first shuttle valve (23), a second shuttle valve (24) and a main pump assembly (25). An electrical control terminal of the first solenoid valve (21) and an electrical control terminal of the second solenoid valve (22) are connected to the controller (1), respectively. An input end of the first solenoid valve (21) and an input end of the second solenoid valve (22) are connected to a pilot pump of the main pump assembly (25), respectively. An output end of the first solenoid valve (21) and an output end of the second solenoid valve (22) are connected to the input end of the first shuttle valve (23) and the input end of the second shuttle valve (24), respectively. An output end of the first shuttle valve (23) and an output end of the second shuttle valve (24) are connected to the flow control oil outlet of the main pump assembly (25), respectively. The small displacement start control loop for a main pump and a control method thereof implement the minimum displacement control for the main pump and effectively avoid the difficulty in starting the engine of an excavator in a cold environment.