Soldered seal structure of power head part for thermal expansion valve

Abstract

This invention is related to a brazing and sealing structure of dynamic head component of thermal expansion valve. The dynamic head component is consists of a stopper and a cavity which used to accommodate the thermal-sensitive medium. The cavity has holes in its ektexine and the medium can be added into the cavity through the holes. The stopper is used to plug the holes so the medium is sealed in the cavity. Its characteristics are placing brazing filler metal between the stopper and the ektexine and brazing to form a seal, so the thermal-sensitive medium is sealed in the cavity reliably. The program uses the method of brazing to put brazing filler metal between the stopper and ektexine, and melting down the brazing filler metal using the thermal resistance, and make the filler infiltrated into the stopper and the ektexine and realize the connection of the two parts. It is not only helpful for ensuring the seal and preventing the outer wall from being corrupted, but it also can resist the pressure effectively that produced by the heat expansion of the medium, and it is helpful for molding in one time in process.

Description

【Technical field】 [0001] The invention relates to a thermal expansion valve suitable for an air-conditioning system, especially a structure for sealing a heat-sensitive medium in an accommodating cavity by sealing a filling hole of a power head (also called an air box head) with a plug. 【Background technique】 [0002] The existing thermal expansion valve suitable for air-conditioning systems is clearly recorded in the invention patent specification with the notification number CN 1058779C. The structure in the cavity is described in detail, and the analysis and induction of the prior art in this document are as follows: ①Project welding is performed between the edge around the hole and the conical surface of the plug, because a concave part is formed around the convex welding part, so Water accumulation (condensation water, etc.) is likely to occur in the concave part, and there is a problem of corroding the outer wall of the cover; ② The plug is tack welded by projection we...

AI Technical Summary

Problems solved by technology

However, since the projection welding is directly connected together by melting the contact parts of two connected parts through resistance heat, the smaller the contact area of ​​the two parts, the greater the resistance heat generated per unit area, and the better the welding effect. The opposite is the opposite; therefore, the above solution sacrifices the welding quality per unit area while achieving multiple welding positions, which is undesirable to seal the heat-sensitive medium in the containing chamber with a plug, unless the welding energy is increased ; Moreover, the "cavity" pointed out in the CN 1058779C No. invention patent description will be formed between multiple welding positions to cause internal corrosion problems

[0004] On a deeper level, due to the heat expansion of the sealed heat-sensitive medium during welding, the pressure increases, which is very unfavorable for the relatively small welding part (0.2-1.5mm) formed by projection welding; based on the characteristics of projection welding, It is unavoidable to form a concave part around the projection welding part. Therefore, to prevent the outer wall from corroding, it is necessary to cover the projection welding part with anti-corrosion materials, which is difficult to realize in one process.

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