Double-acting conversion units for valve positioners

Abstract

The invention provides a double-acting conversion unit for a valve positioner. The double-acting conversion unit is simple in structure and is arranged in a single-plate way. An exhaust valve seat and an intake valve seat are of respectively a plate type structure and are arranged in a laminated way; and axes of the intake valve and the exhaust valve are respectively perpendicular to the plate surface of the valve seat. The double-acting conversion unit is simple in integral structure, low in mechanical processing cost and easy in part assembly. A rubber valve core for sealing is supported on a metal framework, so that the rigidity of the rubber valve core is enhanced; and in addition, rubber is not directly stressed to the spring, so that the valve core is not easy to deform, the sealing effect for a long time can be ensured and the effective work pressure can be effectively improved simultaneously. The rubber valve core and an annular lug boss of the sealed end surface of the valve seat form linear sealing, so that the sealing reliability is improved.

Description

technical field [0001] The invention relates to the technical field of automatic control, in particular to an I / P conversion unit of a valve positioner. Background technique [0002] With the improvement of the function of the intelligent valve positioner, the original I / P conversion unit using the electromagnetic coil can no longer meet the requirements of intelligent valve positioner, low power consumption and high frequency. At present, the I / P conversion unit of the intelligent valve positioner uses a piezoelectric valve to replace the electromagnetic coil control requirement. [0003] In the control system, if the air source input and output ports of the I / P conversion unit leak, it will cause the valve positioning to oscillate continuously, resulting in the instability of the conveying medium in the control pipeline, affecting the quality of the product or causing danger. Therefore, the air source input and output ports of the piezoelectric valve type I / P conversion u...

AI Technical Summary

Problems solved by technology

[0006] 1. The rubber valve core and rubber sealing sheet are subject to spring force for a long time, which is easy to deform and affect the sealing effect;

[0007] 2. Because the rigidity of the rubber valve core is not easy to grasp, the further increase of the working pressure of the product is limited;

[0009] 4. When the pressure of the chamber is low, the seal is prone to leakage;

[0010] 5. The requirements for the compression spring are high, the spring force is too large, it is not easy to open when it is opened, the spring force is too small, and it is easy to leak when it is cut off

[0011] In addition, the structure of the existing conversion unit is complicated, and it is difficult to process and assemble

[0012] Due to the above deficiencies, it is necessary to further improve the I / P conversion unit of the valve positioner, simplify the structure of the conversion unit, and at the same time overcome the insufficient rigidity of the valve core in the conversion unit and the deficiencies of easy deformation, and improve the input and output ports of the gas source. The reliability of the seal

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