The temperature rise to a certain extent restricts the miniaturization and lightweight development of automobile relays.It is particularly important to analyze the temperature field of automobile relays to improve their heat resistance.The computational fluid dynamics(CFD)simulation tool based on heat conduction differential equations,fluid motion control equations,and radiation heat transfer equations is used to propose a temperature field simulation method for automobile relays based on fluid structure coupling.Using the proposed method the temperature field distribution of a certain automobile relay under different environmental temperatures and load current levels are obtained.The proportion of heat dissipation through conduction,convection,and radiation is calculated.the heat dissipation law of the relay and coil under different environmental temperatures and load current levels is analyzed,which can lay a foundation for the subsequent thermal design and temperature rise optimization of automobile relays.

The permanent magnet (PM) is the key part of the relay. This paper aims to solve the problem of the uneven magnetization for the PM with nonlinear demagnetization curve after magnetizing and demagnetizing. A method partitioning the PM along the magnetization direction and the vertical direction of magnetization according to the condition of the specific magnetization of the PM was presented. By this method, the demagnetization model of the PM was built, the state of the PM magnetization was simulated under the demagnetizing magnetic intensity, and the recoil line and its initial point of each partition of the PM were obtained. Then the characteristic of the recoil line of each partition was used as its magnetic characteristic for the equivalent model of the PM to calculate the static torque characteristics under the demagnetizing magnetic field. Finally, the static torque characteristics of simulation and experiment were compared and the validity of the equivalent model presented was verified.

Aiming at clapper relay in the form of movable spring riveting with armature,the mechanical virtual prototype model of clapper relay was built by virtual prototype technology.By orthogonal experimental design method,the influence of the bending angle of movable spring to reaction force characteristics was analyzed to determine the key angles for normally closed contact force,final reaction force and revolution axis force.The validity of the model was verified by comparing with measuring results.This work can provide guidance in the process of reaction force system design and manufacture for this kind of relay.

The fast and accurate computation of the static and dynamic characteristics is the foundation of design and optimization of electromagnetic (EM) relay. This paper, considering the advantages of both the magnetic equivalent circuit (MEC) method and the finite element method (FEM) for the EM system computation, proposes an algorithm of output space-mapping (OSM) based on the compensation factor (CF). This algorithm, based on the differentiability of CF function about dimensional parameters, can attain the fast and accurate computation of the static and dynamic characteristics of the EM relay, when the dimensional parameters vary within their ranges, respectively. The comparison of the static attraction torque and dynamic characteristics computing by the OSM algorithm and FEM shows that the OSM algorithm is reliable.

Ambient temperature is an important factor influencing contact erosion of electromagnetic relay. In this paper, based on results of 1×105 cycle operations with the same load under different temperatures (room temperature: +20℃, high temperature: +125℃), the erosion of contacts and the data of tests are analyzed, and the reasons of different contact erosions and different results of tests under the two ambient temperatures are given. Then, the static and dynamic model of electromagnetic relay is built; some parameters under the influence of different contact erosions are calculated and analyzed. Finally, the different failure modes of contacts are predicted under the two ambient temperatures, and some measures of prevention and improvement are given.

Electromagnetic system (EMS) is the important part of electromagnetic relay (EMR). Considering the contradiction of efficiency and accuracy of solving EMS, a method integrating advantages of magnetic equivalent circuit (MEC) method and finite element method (FEM) was presented to quickly calculate the dynamic characteristics of EMR. The fast calculation of dynamic characteristics of EMR could be accomplished by this method, when dimension parameters of EMS varied. The accuracy of solutions using the proposed method was verified by comparing with the results of FEM. Moreover, adopting geometry dimensions as design variables, taking increasing the contacts’ breaking velocity and decreasing closing velocity as goals, the EMS was optimized by genetic algorithm (GA), and the optimized results were finally given.

Permanent-magnet(PM) is the key part of the relay.Aiming at the problem of the non-uniform magnetization for the PM with nonlinear demagnetization curve after charging magnetism and demagnetizing,a method partitioning the PM along the magnetization direction and the vertical direction of magnetization according to the condition of the specific magnetization of the PM was presented.Using this method,the demagnetization model of the PM was built,the state of the PM magnetization was simulated under one demagnetizing magnetic field intensity,and the recoil line and its initial point of each partition of the PM were obtained.Then the characteristic of the recoil line of each partition was used as its material for the equivalent model of the PM to calculate the static force(torque) characteristics under the demagnetizing magnetic field.Finally,the static torque characteristics of simulation and experiment were compared and the validity of the equivalent model presented was verified.

The cooperative characteristics of electromagnetic relay's attraction torque and reaction torque are the key property to ensure its reliability, and it is important to attain better cooperative characteristics by analyzing and optimizing relay's electromagnetic system and mechanical system. From the standpoint of changing reaction torque of mechanical system, in this paper, adjusted parameters (armature's maximum angular displacement αarm_max, initial return spring's force Finiti_return_spring, normally closed (NC) contacts' force FNC_contacts, contacts' gap δgap, and normally opened (NO) contacts' over travel δNO_contacts) were adopted as design variables, and objective function was provided for with the purpose of increasing breaking velocities of both NC contacts and NO contacts. Finally, genetic algorithm (GA) was used to attain optimization of the objective function. Accuracy of calculation for the relay's dynamic characteristics was verified by experiment.

On the stage of electromagnetic relay's being adjusted, the technical control of adjusted parameters directly affects relays' characteristics of reaction force, and changes the match of attractive force and reaction force. It eventually influences the breaking velocity of relay's contacts. And the change of contacts' breaking velocity has a great effect on relays' electrical lifespan. Taking adjusted parameters (including armature's maximum angular displacement, initial return spring's force, normally closed contacts' force, contacts' gap and normally open contacts' over travel) as factors and breaking velocities as targets, this paper does the orthogonal experimental design of five factors and four levels, analyzes and investigates the key adjusted parameters influencing breaking velocities. The research results indicate that α_(arm_max),δ_(gap) and δ_(NO_(_contacts)) are the key factors affecting breaking velocity of NC contacts, δ_(NO_(_contacts)) is the key factor affecting breaking velocity of NO contacts. Then, based on the above work, optimum method of adjusted parameters is presented.

Electromagnetic relay is a widely used apparatus which usually works in a magnetic disturbance environment. To evaluate its electromagnetic compatibility (EMC) in a static magnetic field, dynamic characteristics of a clapper relay in a uniform static magnetic field situation based on the finite element method (FEM) is studied. Influences of the magnetic field on dynamic parameters (delay time, pick-up time, end pressure, and final velocity) as well as a situation in which the relay cannot function normally are analyzed. Simulation reveals that the external magnetic field which weakens the relay’s air-gap field has a greater influence on the relay’s dynamic parameters than the one strengthening the field. The validity of the simulation is verified by measured results of coil current and armature displacement.

FLUX3D was employed to model the aerospace electromagnetic relay with finite element method (FEM) for solving static and dynamic characteristics. The characteristics of a clap-type relay were calculated by this new method, and the validity of this method has been confirmed by comparing with experiments. The accuracy and efficiency of this method makes it possible to optimize the electromagnetic system of electromagnetic relay.

The significance of virtual prototyping technology on relay and the necessity of development of the mechanical virtual prototype system of electromagnetic relay are discussed.A parameterized mechanical system model of relay is set up adopting the software package ADAMS which is based on the theory of multi-body dynamics and the finite element analyzed software ANSYS.As the data source of mechanical system driving force,the magnetic force is calculated by the electromagnetic field finite element calculated software FLUX and driving force can be loaded on by the dll document which is developed by fortran language.The customer interface is established and the calling of every software and parameter delivery are realized by the C++ Builder.This simulation system has been applied in the optimization of a certain model relay.The model is confirmed by the experiments on current dynamic characteristic of relay.The performance of mechanical system of relay is advanced by modifying the parameters of model.

With the advantage of small volume, low power consumption, quickly switch, and high stability, the micro-electro-mechanical relay may bridge the performance and economic gaps between conventional electromagnetic relay and solid state relay. Analysis of three-dimensional magnetic field is the foundation work for optimum design of electromagnetic system. In this paper the magnetic distribution character of micro-electro-mechanical relay was analyzed by applying Biot-Savart law and integral equation method(IEM). The results of IEM and FEM show the method which used in analyzing three-dimensional stationary magnetic field for Micro-electro-mechanical relay is feasible. The revised schemes were designed basing on the original model features, and central planer coil structure was preferable by analyzing electromagnetic attraction force of movable contact. The optimum design was realized associated with the relationship among coil turns, exciting current and electromagnetic attraction force. The conclusions are valuable in theory and practice to design Micro-electro-mechanical relay.

To obtain object of establishing the virtual prototype of military hermetic electromagnetic relay, the CAD system for military hermetic electromanetic relay based on UG platform was developed. This system possesses many functions such as parameterized modeling, automatic assembling, checking interference of assembly, engineering drawing output etc.. This CAD system facilitates the relay designer to do relay initial virtual design, provides models for following simulation of military hermetic electromagnetic relay in virtual environment, lays a foundation for perfect relay’s virtual prototype technique.

Micro-electro-mechanical system technology offers great promise in addressing the need for smaller electromechanical relays, and may bridge the performance and economic gaps between conventional electromechanical technology and solid state devices. It is necessary for electromagnetic field analysis during design process of micro-electro-mechanical relay. Planar coil and magnetic plate structures were modeled by using finite element method in this paper. Furthermore the open domain magnetic field views of micro-electro-mechanical relay with different structures were compared. And the electromagnetic attraction force of movable contacts in MEMS relay was analyzed, thus can not only simplify the fabrication procedure, but also develop the working performance of products. The results of the analysis can be useful for designers to develop optimal magnetic structure of micro-electro-mechanical relays.