Abstract:

As the contact surface of the safety type railway signal relay is often corroded by contaminants during use,the contact reliability is reduced.So,this paper selects a batch of railway signal relays that have been in service for about 10 years for operation tests.The distribution characteristics and discrete degree of contact pressure drop were analyzed,and the topographic features and pollutant components of the corresponding contact surface were analyzed and extracted.The results show that,for those contats whose contact pressure drop first fluctuates and then stabilizes,the discrete peaks of random failure,and the interquartile range are larger,and some large dust particles and corrosive deposits adhere to the elliptical contact area;While for those contaets whose pressure drop presents continuously fluctuating,the discrete peaks and interquartile distances of random failures are small,and the micro-morphology of the elliptical contact area contains more minute corrosives and dust particles.By extracting the contact failure characteristics of long-term service relays,it provides a theoretical basis for the reliability design,use and maintenance of relay products.

Key words: relay, contact failure, randomness, reliability, interquartile range