Stop for sealing a housing of an exhaust gas sensor, exhaust gas sensor, and exhaust gas sensor production

Abstract

The invention relates to a stop for sealing a housing (11) of an exhaust gas sensor. The stop (1) has at least one axial through-channel (25) for the passage of a connection cable (21), and the stop has a main part (24) which has a fluoroelastomer. The invention is characterized in that the stop (1) has at least one outer seal (36, 38) which is arranged radially on the outside of the stop (1) and which has at least one thermoplastically processable fluoropolymer-containing material with a melting point or melting range between 170 DEG C and 320 DEG C.

Description

technical field [0001] The invention relates to an exhaust gas sensor. Such an exhaust gas sensor comprises a housing in which an electrochemically active sensor element, for example ceramic, is located. Furthermore, such an exhaust gas sensor comprises a plug which seals the housing and through which at least one connecting cable is led out of the housing or into the housing. Background technique [0002] On the one hand, high leak-tightness requirements are placed on the plug and on the interaction of the plug with the housing. The high degree of tightness prevents the penetration of harmful, for example corrosion-causing liquids and gases into the interior of the exhaust gas sensor very effectively and permanently. In order to achieve this tightness, it is especially required for the plug to have sufficient elasticity. Due to the high exhaust gas temperatures to which the exhaust gas sensor is subjected, on the other hand only materials with a correspondingly high heat...

AI Technical Summary

Problems solved by technology

However, if the exhaust gas sensor is subjected to excessively high temperatures for an impermissibly long period of time, in particular due to the diffusion of plasticized constituents from the fluoroelastomer and / or due to other changes in the properties of the elastomer The embrittlement of the material occurs due to the mechanism, resulting in a decrease in elasticity

Due to the thus reduced sealing effect of the fluoroelastomer plug, undesired liquids and gases, for example causing corrosion, can penetrate into the interior of the exhaust gas sensor and have a negative effect on its function.

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