The Installation Process Of Rail Stress Sensor And Research Of Dedicated Spot Welding Equipment

With the rapid development of the national railway construction, theapplication of continuous welded rail (CWR) is gradually increasing. Stress sensorplays an important role in the detection of stress changes and deformation of CWR.In the stress detection system of CWR, a novel installation technology of stresssensor requires the sensor’s bracket with the thickness of150μm directly fix on therail waist. Such rigid fixation can guarantee the accurate flow of the stress.As an important part of the welding disciplines, resistance welding technologyhas got an unprecedented development with the progress of new materials, newtechnology, computer technology and power electronic technology.In this paper, based on the installation of stress sensor, to design a portablemicro-electronic energy storage spot welding machine which suits for fieldoperation. It also introduced the structural principle and test results. The maincontent and works are as follows:1. Study the stress generation of CWR and the stress detection methods; list theadvantages and disadvantages of various detection methods. Focus research onresistance strain sensor detection methods, as well as the traditional installationprocess of this kind of sensor. Put forward the spot welding installation process.2. Research basic principle and theory of spot welding machine, invertertechnology were summarized, design desktop storage spot welding machine andportable micro energy storage spot welding machine. Desktop spot welding machineusing thyristor to improve charging and discharging circuit of the charge rate andenergy conversion rate. Focus on the design principle of portable micro energystorage spot welding machine, resolve the problem of charge adaptive control usingthe large capacitor to store energy with PWM, reduce the heat loss of limitingresistance charge and impact of high pulse current to capacitor. Solve the problem ofthousands of amperes of current electronic switch discharge.3. Solder joints were tested at room temperature tensile using tensile testingmachine, including tear and tensile test experiment, the effect was good. Comparedwith similar spot welding machine from the United States, the results showed thatthe spot welding machine in this paper get greater output power, continuous worklonger, higher joint strength. Portable micro energy storage spot welding machine is completely divorcedfrom the mains to meet field conditions. It realized resistance spot welding withhardware circuit, effectively solve the problem of outdoor passive sensor spotwelding installation process, also got good welding results. Further expand the rangeof applications of spot welding machine, has some theoretical significance andpractical value.