Overall heat treatment method for coil assembly with double metal strips and coil assembly

Abstract

The invention discloses an overall heat treatment method for a coil assembly with double metal strips. The method comprises the following steps: (a) performing heat treatment on double metal strips, fixedly connecting the double metal strips with wiring terminals of the coils by virtue of spot welding, and forming a coil assembly of the coils and the double metal strips welded with the coils; (b) arranging the coil assembly serving as an overall workpiece to be subjected to heat treatment in a high-temperature ageing box; (c) heating the high-temperature ageing box, wherein the highest temperature is lower than 130 DEG C, and the heating speed range is from 0.2 DEG C per minute to 10 DEG C per minute; (d) closing the power supply of the high-temperature ageing box, and preserving the temperature for a period of time; and (e) opening the door of the high-temperature ageing box, so that the overall workpiece is cooled to normal temperature in air along with furnace cooling, and taking out the workpiece. The coil assembly manufactured by the method comprises coils and double metal strips which are wound on a coil framework, and the double metal strips and the wiring terminals of the coils are fixedly welded and connected together. The coils and the double metal strips are integrally subjected to heat treatment, so that the production efficiency can be effectively improved, the manufacturing cost is reduced, and the finished product repair rate is obviously reduced.

Description

technical field [0001] The invention relates to a heat treatment method for electrical components, in particular to an overall heat treatment method for a coil component with bimetallic strips, and also relates to a coil component with bimetallic strips manufactured by the method. Background technique [0002] Coil components with bimetal strips are widely used components, such as low-voltage circuit breakers, which are commonly used to achieve instantaneous tripping and delayed tripping. Coil assemblies with bimetal strips generally include an induction coil wound on the bobbin of the coil and a bimetal strip connected by spot welding to terminals of the coil. As we all know, the bimetal sheet of the coil assembly is a temperature-sensitive element, which bends and changes with the change of its heating temperature, and requires a functional relationship between its temperature change and bending change (ie, the temperature bending characteristic ) is stable, and it is als...

AI Technical Summary

Problems solved by technology

However, in the process of connecting the coil and the bimetal by spot welding, due to the high temperature of the spot welding, heat and force must be applied to the bimetal, which will change the internal stress of the bimetal, resulting in The temperature bending characteristics of the bimetal sheet change, so that the temperature curvature of the bimetal sheet will be inconsistent, which greatly deteriorates the consistency of the temperature bending characteristics

The existing way to solve this problem is to select good consistency and put it on the same product, but due to the limited means of identifying consistency, it will still cause the following two problems: one is that this selection must invest a large amount of man-hours , which restricts production efficiency and increases manufacturing costs; second, it is still inevitable that there will be poor consistency, resulting in a high repair rate of finished products and serious waste problems

And because it is generally believed that the bimetallic sheet has been overheated before spot welding, there is no need to process it again. Therefore, existing manufacturers have not thought of needing to process it again.

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