A Non-Leakage Pressure Compensated Electromagnetic Proportional Valve

Abstract

The invention discloses a no-leakage pressure compensation electromagnetic proportional valve. A valve body is provided with a P port and T port; a valve sleeve is assembled at the upper part of the valve body; a proportional electromagnet is assembled at the upper part of the valve sleeve; a static iron core, a movable iron core and a first spring are arranged in the proportional electromagnet; apilot valve element is arranged in the center of the movable iron core; a main valve element is arranged at the upper part of the valve body; a control cavity is formed above the main valve element in the valve sleeve; the main valve element is provided with a first runner hole and a second runner hole; a first damping hole is formed in the first runner hole; a second damping hole is formed in the second runner hole; the lower end of the pilot valve element cooperates with the second damping hole; a pressure compensation valve element is arranged at the lower part of the valve body, and is provided with a throttling hole; a screw plug is arranged at the lower end of the valve body; a sensitive cavity is formed in the valve body, and communicates with the P port through an oil leading hole; when the pressure compensation valve element is positioned in an upper limit position, a flow passing cavity communicates with the T port through the throttling hole; and a damping ring is arrangedin the sensitive cavity for changing the damping magnitudes of oil flowing in and flowing outside the sensitive cavity. The no-leakage pressure compensation electromagnetic proportional valve has theadvantages of reasonable and compact structure, capability of buffering the pressure fluctuation of the T port and high response speed.

Description

technical field [0001] The invention relates to the technical field of hydraulic valve manufacturing, in particular to a non-leakage pressure compensation electromagnetic proportional valve. Background technique [0002] In recent years, proportional control valves have been used more and more in lifting equipment such as truck-mounted cranes, aerial work vehicles, tractor rotary plows, and electric forklifts. In the load lifting hydraulic system, the proportional directional valve is usually used to reduce the load. Generally, the lowering speed is adjusted through the opening of the proportional directional valve, but in the case of large load changes, the speed will be fast and slow, causing the system unstable. Moreover, these proportional reversing valves are all in the form of slide valves. When closing or stopping the load, the load cannot be kept at a certain position and will slide down, and the pressure in the cavity cannot be well maintained when pressure mainten...

AI Technical Summary

Problems solved by technology

[0004] (1) Since the oil guide hole of the pressure compensator is located on the front side of the sealing line, when the coil is not powered, the sensitive chamber of the pressure compensator has no pressure, so the pressure compensator is in the position of the valve under the force of the second spring. When the coil is fully opened, when a certain voltage is given to the coil, the opening of the main spool is relatively rapid. When the throttle groove of the main spool has been opened, the pressure in the sensitive chamber of the pressure compensator has not been fully established. When the pressure compensator is still in the fully open state, there is no pressure compensation function, which will cause the instantaneous flow impact of the opening, which will vibrate the mechanical equipment and affect the safe use

[0005] (2) The rear end of the second spring in the pressure compensator is installed on the spring seat, so that the oil of the main valve core will flow out through the flow hole on the spring seat, in order to ensure that the flow capacity does not exceed the flow rate of the main valve core Influenced by the adjustment, the spring seat is usually designed to be large to ensure the flow area of ​​the flow hole, which will cause the overall valve diameter to be too large and not compact

[0006] (3) There is no damping part in the pressure compensator, and the oil directly enters the load sensitive chamber, so when the outlet pressure fluctuates, the opening of the pressure compensator will appear suddenly large and small, resulting in unstable flow and vibration of the equipment

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