Research And Manufacture Of The Spindle Automatic Tightening Equipment

This project was sponsored by a company and the results would beused to improve the assembly line. The article focuses on the automatictightening for the shut-off valve.Firstly the paper proposed the overall design plan of the tighteningequipment, the each part architecture and software design of the tighteningequipment. The device is composed of control unit, drive unit, rotation unit and gasunit. The control unit can coordinate drive unit, measure the torque and the angle. Thedrive unit can realize screws tight automatically. Rotation unit can automatic rotateturntable based on the control unit. Gas unit can provide power output for thepneumatic cylinder.Then, the design of control unit, drive unit and rotation unit is explainedin detail. the control program of control unit is based on PLC, achievedreal-time display through the touch-screen, and it is communicated with driveunit through the serial port. The drive unit is consisted of servo system,reduction gear and torque sensor. The role of the rotary unit is achieving theautomatic rotation of the turntable based on the instruction of the control unit.Finally, according to the merits of relative coupling control,Fuzzy-PID is used in multi-motor synchronization control, realized the nutstightening at the same time. According to a large number of experimentsand analysis, the final torque accuracy met the requirements.