Spring-elastic measuring element comprising a flat connecting element that can be welded

Abstract

The invention relates to a spring-loaded elastic measuring element (1), in particular for thermometers, pressure switches or pressure gauges, comprising a curved measuring tube (3), a base body (2) and a connection element for the measuring device (10). For fully automatic welding and improved heat-affected zone, the connection between the measuring tube (3) and the base body (2) and between the measuring tube (3) and the joint element (10) is indirectly via a weldable connecting element (11 , 12) Realize. As a result, the risk of contamination of the measuring system can be significantly reduced, and the formation of corrosion and vibration cracks can be significantly reduced through the use of a small heat-affected zone. A connecting element (11, 12) can also be made integral with the measuring tube (3) by flaring or crimping the measuring tube (3). Welds can be formed by laser welding or electron beam welding and the invention allows welding of Cr-Ni steel with copper.

Description

technical field [0001] The invention relates to a spring-type elastic measuring element, especially for thermometers, pressure switches or pressure gauges, comprising a curved or helical measuring tube, which is connected at one end to a base and at the other end to a measuring device The joint element connection is especially welded. Background technique [0002] For pressure- or temperature-sensitive measuring instruments, an elastic spring element made of thin-walled material can be used which deforms under the prevailing pressure. For this reason, the measuring element is generally formed in an arc shape and one end is connected to a solid base, and the other end is connected to the measuring device through a connecting rod, so that through the deformation that occurs, a small force is applied to the measuring device through the connecting rod. This thrust generated during the rotary movement is transmitted via the measuring device to the indicating device. In this cas...

AI Technical Summary

Problems solved by technology

Since the measuring springs of the different measuring ranges have different dimensions, large gaps cannot be avoided for this purpose, which prevents perfect gas-tight mechanical welding without wire supply

Furthermore, it should be emphasized that due to the high heat penetration for welding the measuring cell to the base body, the resulting oxide layer penetrates into the weld seam zone as far as the measuring system, wherein otherwise insignificant heat penetration results in structures in the heat-affected zone change, the strength and corrosion

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