Piston type four-way reversing valve

Abstract

The invention discloses a piston type four-way reversing valve and belongs to a valve for changing the flow direction of a refrigeration working substance, and the existing four-way reversing valve has a defect that after shutdown, an oil film can be easily cleaned by the refrigerating fluid so as to cause the lack of the lubricating oil and then cause that the piston is deadlocked. The piston type four-way reversing valve mainly consists of a main valve and a pilot valve, wherein the pilot valve is communicated with the cavity of the main valve through an air duct; the main valve comprises a valve body, a piston arranged in the valve body and two end covers arranged on the two ends of the valve body; four valve ports are arranged on the valve body, the piston is formed by connecting two components, which have I-shaped view patterns and are rotated to be vertical to each other, into a whole, a lubrication sleeve is arranged between the internal surface of the valve body and the piston, and the lubrication sleeve is fixedly connected with the valve body; through holes which correspond to valve ports and are communicated with the valve ports are arranged on the sleeve body of the lubrication sleeve, a plurality of oil holes are arranged on the internal surface of the sleeve body, and a solid lubricating material can be embedded in the oil holes; and the solid lubricating material without oil can lubricate the piston, the piston is ensure to move in the valve body flexibly and can not be deadlocked, and the service life is prolonged.

Description

technical field [0001] The invention belongs to a valve for changing the flow direction of refrigerant in a refrigeration system, in particular to a piston type four-way reversing valve. Background technique [0002] Large-capacity four-way reversing valves are generally used in heat pump air conditioners. The usual large-capacity piston-type four-way reversing valve is composed of a pilot valve and a main valve. The main valve includes a steel valve body, a ductile iron piston located in the valve body, and two end covers arranged at both ends of the valve body. The valve of the main valve The body, the piston and the end cover form two left and right cavities. The pilot valve communicates with the cavity of the main valve through the air guide tube. There are valves on the air guide tube respectively, and there is a drain that can be closed between the valve and the main valve cavity. Pneumatic device; the piston mainly uses the system pressure difference inside the four-...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the defects of the aforementioned four-way reversing valve that the oil film is easily washed away by the refrigerant after shutdown, resulting in lack of lubricating oil and causing the piston to be stuck, and to provide a piston that can ensure the flexible movement of the piston in the valve body. Type four-way reversing valve

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