A valve-pump combined multi-mode hydraulic control system and control method thereof

Abstract

The invention relates to a valve-pump combined multi-mode hydraulic control system and a control method thereof. The multi-mode hydraulic system comprises a pump control motor main loop, a valve control branch circuit, a mode switching unit and a control unit, wherein the valve control branch circuit is connected with the pump control motor main loop in parallel through the mode switching unit. The control method is characterized in that a controller has two layers of control strategies, wherein the first layer of control strategy is a mode selection strategy, and the system can be in variousworking modes such as the valve control mode, pump control mode and valve-pump combined control mode by controlling the mode switching unit; and the second layer of control strategy is a flow controlstrategy, one circuit is used for controlling the displacement of a proportional variable pump so as to adjust the flow in the pump control mode, the other circuit is used for controlling an opening of a proportional reversing valve so as to adjust the flow in the valve control mode, and finally, the rotating speed of a hydraulic motor is controlled through a closed loop. The valve-pump combined multi-mode hydraulic control system can be used for hydraulic power devices with obvious speed regulation processes, such as a hydraulic elevator and an engineering machinery rotary table, different working modes are adopted in different speed regulation stages, so that the comprehensive speed regulation performance of the system is improved.

Description

technical field [0001] The invention relates to the field of hydraulic transmission and control, in particular to a valve-pump combined multi-mode hydraulic control system and a control method thereof. Background technique [0002] There are two basic types of traditional hydraulic control systems: valve control and pump control. Among them, the valve control system has fast dynamic response but low efficiency, which is suitable for occasions with small and medium power and high requirements for dynamic response; the pump control system has high efficiency, but Slow dynamic response, suitable for occasions with high power and low speed requirements. The valve-pump joint control system combines the advantages of the valve control system and the pump control system, and can be used in occasions with high power and fast dynamic response. However, the existing valve-pump joint control system has a single control mode, cannot work in multiple working modes, and cannot change the...

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Problems solved by technology

[0003] In order to overcome the problem that the current valve-pump joint control system cannot work in multiple modes, the present invention provides a valve-pump joint multi-mode hydraulic control system and its control method. The system can work in valve control, pump control, valve-pump Combined control of multiple working modes

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