Pilot-operated type control valve

Abstract

The invention discloses a pilot-operated type control valve. The pilot-operated type control valve comprises a main valve and a pilot valve. The main valve comprises a main valve seat with a valve cavity and a piston arranged inside the main valve seat. The piston divides the valve cavity into an upper cavity and a lower cavity and can axially move along the valve cavity so as to open or close a main valve port. The side portion of the periphery of the main valve seat is connected with a cross connection pipe communicated with the lower cavity, and the bottom of the main valve seat is connected with a vertical connection pipe communicated with the main valve port. The sealing face of the piston and the main valve port is higher than the axial center line of the cross connection pipe. In this way, the sealing face of the main valve port is higher than the horizontal center line where cold media flow into; transverse impact force on the piston can be reduced when work pressure of the cold media fluctuates; the piston is prevented from being impacted and inclined; the sealing performance of the main valve port is ensured; abrasion and abnormal noise of related parts are also avoided.

Description

technical field [0001] The invention relates to the technical field of fluid control components, in particular to a pilot control valve. Background technique [0002] Please refer to figure 1 , figure 1 It is a schematic diagram of the structure of the pilot control valve commonly used at present. [0003] like figure 1 As shown, the pilot control valve includes a main valve 10 and a pilot valve 20 arranged on the upper side of the main valve 10 . [0004] The main valve 10 includes a main valve seat 11 with a bottom through hole and a main valve seat core 12 sealed and fixed on the bottom through hole. The main valve seat core 12 is provided with a main valve port, and the main valve seat 11 is provided with a The valve cavity moves axially to open or close the piston 13 of the main valve port; the cross section of the piston 13 is in an inverted convex shape, that is, the piston 13 includes a large diameter portion 131 and a small diameter portion 132, and the lower en...

AI Technical Summary

Problems solved by technology

[0013] First, the small-diameter portion 132 of the piston 13 faces the refrigerant inflow center. When the working pressure of the refrigerant fluctuates, it will generate a relatively large lateral impact force on the small-diameter portion 132 of the piston 13, causing the small-diameter portion 132 to shift, causing the valve Poor sealing between the needle 133 and the main valve port, and the impact and tilt of the piston 13 will also cause wear and abnormal noise of other related parts;

[0014] Second, the coaxiality between the pilot valve core 24 and the pilot valve port needs to be ensured, while the pilot valve core 24 is guided by the transition seat 16, and the pilot valve port and the piston 13 are integrated, so that the transition seat 16 and the piston 13 need to ensure coaxiality degree, but the coaxiality between the transition seat 16 and the piston 13 needs to be assembled multiple times to ensure that the coaxial error accumulates, which seriously affects the internal leakage performance of the product

Images