| The band-saw flash butt welder is a special machine for flash butt welding of band saw blades.Mainly used for welding of bimetal band saw blades and high speed steel band saw blades.Its function is to weld a complete strip saw into a circular ring,and the finished product can be used with the band sawing machine.Based on the domestic UBN-8 flash butt welding machine and the BAS320 flash butt welding machine produced by foreign iDEAL company,the operation process and flash process characteristics of the two kinds of machine welding mechanisms are analyzed.The welding mechanism covers three flash butt welding processes: flash,upset and annealing.A high-speed photography instrument is used to photograph the cam running process in the flash feed mechanism,and the timing relationship between the flash process and the cam operation is analyzed.Especially for the analysis of the forging time and the forging stroke.At the same time,the tensile test machine is used to carry out the force test on the disc spring in the upsetting and pressurizing mechanism,and the working principle of the annealing mechanism is analyzed.The Hall current sensor,true value converter,oscilloscope and other equipment are used to sample the two main electrical parameters of the welding voltage and welding current in the flash welding process.Again,high-speed photography was used to capture the slow image of weld area during flash.Combined with the collected waveform data,the influence of electrical parameters on the flash process is analyzed,and the trend of dynamic resistance in flash butt welding process is analyzed.Taking STM32 development board as the core of control,a flash butt welding parameter detection system is assisted by Lab VIEW software.The system can detect the main welding parameters during flash butt welding,including welding voltage,welding current,forging pressure,flash displacement,flash speed and so on.After testing,the acquisition system has strong anti-interference ability,and can effectively collect all welding parameters and save data.By using orthogonal design method,the welding parameters of two kinds of AC welder in welding a certain band saw are optimized.The hardness and microstructure of the welded samples were analyzed,and the differences between the two were compared.A high frequency DC power supply is developed to replace the AC transformer in the UBN-8 machine to feed the machine in order to solve the problem that the flash exists intermittently at the welding seam and the heat affected area is concentrated.The welding tests were successfully carried out through debugging,and all the welded samples met the qualification standard after torsion test.The high-speed images showed that the DC welding has the advantages of short flash blasting and uniform heat affected zone.The test successfully verified the feasibility of DC flash butt welding,which is of great significance for further research in this field. |
