Research On Quality Consistency Design And Key Process Control Technology Of Electromagnetic Relay

Electromagnetic relay is a key element in the whole machine system,and its working reliability can directly determine whether the machine system can execute orders as expected.Among domestic reliable electromagnetic relays,those applied to aerospace field represent the highest design and manufacturing levels at home,but they are still plagued with such problems as uncontr olled quality uniformity in same batch when compared with foreign counterparts.The root cause is existing relay products within our country are mostly designed and manufactured either based on experience or referring to similar products in overseas countr ies.There are no systematic and effective design approaches.What's more,the design process is not analyzed by being combined with actual production process features so that theoretical design deviates from actual manufacturing.This paper takes into account the actual engineering application cases,systematically analyzes related research achievements both at home and abroad,investigates into the approximate modeling and simulation technology,design of experiments(DOE)of typical failure modes,tolerance optimization design,critical procedure determination ways,critical process control and uniformity evaluation approaches,and develops the way of controlling the electromagnetic relay uniformity from design to engineering application.To improve both accuracy and efficiency of theoretical design,actual process features are combined in the early stage of design to form a mechanical parameter designing approach on the basis of process features and mature engineering practices.The static and dynamic output characteristics of the contact system and electromagnetic system are analyzed through finite element emulation analysis.Based on this,the present paper studies the radial basis function neural network model based on rival penalized competitive learnin g(RPCL)and particle swarm optimization(PSO),and thus solves the problems concerning selection of such parameters as number and width of central points in the aforesaid neural network model.Then,the typical dynamic characteristics from approximate mod eling are compared with that from finite element approach to testify the accuracy of the approximate model.In order to enhance the reliability of electromagnetic relay,its typical failure mechanism and performance optimization methods are studied through rated life experiment.Based on orthogonal test design through,optimal plans are determined for those critical factors such as contact gap and pressure and overrun.Later,the control scopes of those impact factors are figured out through tolerance desig n approach.The study covers the failure mechanism of relay in medium current test,internal atmosphere control methods.Moreover,DOE is employed to determine the process control parameters such as baking temperature,time and vacuum degree that can effectively eliminate the organic atmosphere within the relay.This can help to solve carbon precipitation on the contact surface after medium current test.The relay failure mechanism during thermal shock test is also analyzed,and it is found that the major factors influencing failure are surface roughness of gild contact as well as closed contact pressure.On this basis,grinding treatment and vibratory impulse gilding solutions are proposed to effectively reduce the adhesive strength of gild contact surface under temperature shock and finally bring down the reject ratio of relays under thermal shock condition.In order to improve the quality consistency of electromagnetic relays,the operating voltage is determined as the output characteristic parameter to characterize the consistency of electromagnetic relays.At the same time,in order to ensure that the quality consistency design of electromagnetic relay is guaranteed in the manufacturing process,the consistency evaluation method based on Monte Carlo idea and fast calculation model of relay is studied.In view of the inconsistency of operating voltage,tolerance design and tolerance allocation are carried out for the key design parameters of electromagnetic relay.Combined with process characteristics and finite element simulation,the influence of spot welding,laser welding,riveting and other processes on the resistance characteristic curve is analyzed.On this basis,the control points of riveting process are put forward to reduce the design errors caused by production process in the process of consistent design.To strengthen the quality uniformity of electromagnetic relay,the output characteristic parameter representing its uniformity is determined as the operation voltage.In the meanwhile,in order to guarantee the quality uniformity of electromagnetic relay in manufacturing process,the uniformity evaluation approach based on Monte Carlo thought and relay-specific fast calculation model is analyzed.In view of the inconsistence in operation voltage,those key parameters for electromagnetic relay design are put to undergo tolerance design and distribution.Furthermore,process characteristics and finite element emulation are combined to analyze the effects of such processes as spot welding,laser weldi ng and riveting assembly on the characteristic curve of attracting force and propose some controlling essentials for riveting assembly process so as to reduce the design error arising from the production process during consistent design.To make sure the manufactured products can attain uniformity design requirements,fault tree and tolerance design contribution rate are employed to screen the key factors and determine corresponding key procedures.The process features and procedures of key procedures are taken into consideration in studying the major reasons behind uncontrolled uniformity in component dimensions which are determined as acid pickling and plating,those two procedures are optimized.At the same time,the assembly process of spot welding,riv eting and adjustment is optimized from the aspects of equipment improvement and fixture optimization.All those improvements contribute to the final significantly enhanced quality uniformity of the relays.This research is a improvement to the quality consi stency design and key process control technology of electromagnetic relays.It can be applied to improve the quality consistency of batch electromagnetic relays and the feasibility of product manufacturing process.The related methods and technical achieve ments can also be applied to the design of other types of electromagnetic relays.