Method for welding expansion valve

Abstract

The invention provides a method for welding an expansion valve. The method is used for welding an air box head of the expansion valve; an air box cover is butted with an air box seat; the thickness surface of the air box cover and that of the air box seat form a first annular; an outer surface formed through intersection of the air box cover and the first annular surface is a second annular surface; an outer surface formed through intersection of the air box seat and the first annular surface is a third annular surface; the air box cover and the air box seat are clamped in the middle through a firs tool and a second tool; the edges of the outer sides of the annular surface of the first tool and the second annular surface align; the edges of the outer sides of the annular surface of the second tool and the third annular surface align; a welding tool of which the density of energy output by a welding energy source is more than 10<4>W / cm<2> is used to weld a connectingpart between the air box cover and the air box seat, thereby solving the problem of deformation of the air box head after the air box head is heated for a long time in the welding process, in particular to the problem of the failure of the expansion valve because a film is heated and crystal grains grow up.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a welding method for an expansion valve. Background technique [0002] A commonly used expansion valve includes a valve body, a valve core and an air box head, wherein the air box head includes an air box cover, an air box seat, a diaphragm and a transmission plate, and one side of the diaphragm is formed by the diaphragm and the air box cover. In the medium chamber, the transmission plate is located on the other side of the diaphragm and is in an active state. When working, the cold medium flows through the valve port, and the air box head feels the superheat at the outlet of the evaporator, which causes the medium in the medium chamber to expand or contract to act on the diaphragm, and then the diaphragm transmits the force to the transmission rod through the transmission plate. The movement of the transmission rod pushes the valve core to move near the valve port to change t...

AI Technical Summary

Problems solved by technology

[0006] The problem to be solved by the present invention is that the gas box head is heated and deformed for a long time during the welding process, and the heated grain of the diaphragm grows, which causes the expansion valve to fail.

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