Key Manufacturing Technologies Of Solenoid Valve Injector For Car

The structural of electromagnetic valve injector in gasoline engine was designed, by adopting a ball valve structure to the injector , the weight of coupling valve was greatly reduced, so the injector can open faster under a lesser electromagnetic force. The materials of fuel injector components were investigated and choiced. The performance of these materials must meet some require of work, such as better welding properties,good anti-fatigue properties and good corrosion resistance propertiesDetailed experimental study was made on the laser welding process of the injector, and getting the best welding process., The best welding seam can be got when the welding parameters are as follow: current:110A~120A, pulse duration:1.8~2.0ms, pulse frequency:60HZ, welding speed:600mm/min, clearance between focal point:-1mm.the microstructure property of welding seam was analysed. The main organization of welding seam are austenitic dendrite and equiaxed crystal. On the weld border, crystallization direction of dendrite is perpendicular to fusion line, point to fusion center. Dendrite crystallization direction become unsystematic in the middle of the fusion line, and equiaxed crystal began to emerge. Some weld grain characteristics show significantly layered phenomenon. The characteristics of stratification phenomenon have been explained through laser welding overlapping and flow characteristics of liquid pool metal. As the power density of pulse peak increased, Weld prone to produce pores, surface depression, cracks and other defects.In order to make fuel injector establish a preferable magnetic field, the heat treatment was done to improve the magnetic properties of the injector conjugate flake. When the heating preservation temperature is between 0℃to 1000℃,and the holding time is 3 hours .The grain size of 1J50 become lager along with the improve of heating preservation temperature.But The grain size no longer become lager when the heating preservation temperature beyond 1100℃.The best process parameters are as follow: improve the temperature at the rate 300℃/h, and the heating preservation temperature is 3 hours .When the temperature is down to 350℃at cooling rate 200℃/h,the samples get fast-cooling by opening the gate of furnace.After heat treatment, material grain obviously grown up than the untreated state, but with the insulation temperature increases, the grain growth was not obvious. After heat treatment, sensitivity of material react to magnetic field was stronger, in a smaller magnetic field strength situation, materials magnetic induction can be quickly reached capacity, and the saturation magnetic induction intensity has significantly improved. After the heat treatment, the inductance of magnetic properties increased significantly too.A detail analysis on the open process of injector valve has been carried out, a calculation model of time to open the mathematical has been established, a software programmed with VB was developed to calculate the time to open. Analysis on the impaction of various factors on the fuel injector opening time has been carried out based on this Software.