Abstract: Existing multi way valves have problems such as difficulty in controlling large flow and low pressure losses, and poor dynamic characteristics. The inlet and outlet of the multi way valve are coupled, resulting in large pressure loss at the valve port and low system freedom. The existing multi way valve is difficult to meet the requirements of high-end hosts for maneuverability, energy conservation, intelligence, and load adaptability. Therefore, based on the advantages of high flow control characteristics of cartridge valves and good slide valve micromotion performance, a new configuration is innovatively proposed. This new configuration is to connect two flow amplification proportional cartridge valves in series at the inlet and outlet of the reversing spool valve, and further develop a series spool valve port independently controlled multi way valve. The two cartridge valves can be designed as flow control or pressure control functions based on control requirements. The valve has a high degree of freedom in the system and has a high potential for intellectualization. In order to achieve high-precision redundant control of flow and pressure, a series two-stage displacement closed-loop+parallel flow/pressure closed-loop control strategy is designed. The characteristics of the valve under three operating modes of position, flow, and pressure were studied through simulation. Further, a sample valve was trial-produced. A test rig was built to test the pressure loss characteristics, displacement hysteresis, flow control characteristics, dynamic response characteristics, and steady-state load characteristics. The results show that the rated flow rate of the sample valve reaches 300 L/min,and the displacement hysteresis of the main valve is <1%; Main valve step response <35 ms, with high dynamic characteristics;Maximum flow deviation <5%, high flow control accuracy.

Key words: multi-way valve, independent metering control, steady state characteristics, dynamic characteristics