Electric valve with rotating speed closed-loop control function and control method

Abstract

An electric valve with a rotating speed closed-loop control function is used for a flow adjusting circuit in the process industry. An electric valve body is composed of a DC brushless motor, a cylindrical gear speed reducer, a worm and gear mechanism, a valve rod, a valve element, a valve body and a limiting switch. A peripheral control circuit is composed of a single-chip microcomputer development board, a DC brushless motor driver, a photoelectric isolated converter and connecting wires. An output shaft of the DC brushless motor is fixedly connected with the head end of a reduction gearbox.The tail end of the reduction gearbox is fixedly connected with a worm. The worm is meshed with a worm gear. The worm gear is in rigid connection with the valve rod. The valve rod is in rigid fixed connection with the valve element. The rotating speed closed-loop control can be realized, the valve element works strictly according to a five-section S-shaped positioning curve, and the positioning precision is effectively improved.

Description

technical field [0001] The invention belongs to an electric valve capable of realizing the closed-loop control of the rotational speed, and in particular relates to a new type of electric regulating valve improved on the basis of the hardware unit of a domestic common ZJKV type electric valve. Background technique [0002] The domestic ordinary ZJKV electric valve is an important actuator responsible for flow regulation in the process industry, and its positioning accuracy plays a decisive role in maintaining the accuracy of fluid flow. Domestic electric valves are driven by three-phase asynchronous motors, with a positioning accuracy of only 80 to 100 steps. For angular stroke valves of 0 to 90°, 100 steps means that each operation step makes the spool rotate 0.9°, and the spool The angle of rotation is completely determined by the power-on time. There is no drive torque control. The actuator body is an open-loop control system, which cannot be adapted to the precise ratio ...

AI Technical Summary

Problems solved by technology

Domestic electric valves are driven by three-phase asynchronous motors, with a positioning accuracy of only 80 to 100 steps. For angular stroke valves of 0 to 90°, 100 steps means that each operation step makes the spool rotate 0.9°, and the spool The angle of rotation is completely determined by the power-on time. There is no drive torque control. The actuator body is an open-loop control system, which cannot be adapted to the precise ratio of the flow of two materials. It will be difficult to meet the medium and high flow control requirements of the future development of the process industry. Accuracy requirements

In contrast, the electric valves produced by foreign Metro and BTG companies have an accuracy of 15,000 to 20,000 steps, and are only used in special occasions that require high precision. Between 180,000 and 200,000 yuan, many domestic companies are discouraged

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