A Gyroscope Cordless Screwdriver Development

Electric screwdriver is one of the power tools used on assembly operation,its main function is to turn screws with slotted heads to achieve assembly or disassembly of workpieces connection.Rotation direction switching and speed adjustment of current electric screwdrivers are performed by forward and reverse speed switches.When being used in a small and narrow workplace in the cases of frequent changing turning direction,current screwdrivers working efficiency will be lower because it need the operator to grip and switch the forward and reverse direction at the same time.The purpose of this thesis is to develop a cordless screwdriver controlled by a gyroscope sensor,which can automatically perform the rotation direction switching and speed adjustment by sensing the operator's twist direction and range,and to develop a new handle switch models to suit different workplaces.This thesis includes the following main contents:(1)General scheme analysis and design.Executed product definition and function requirements analysis,presented four transmission plans for the mechanical design,completed analysis of the motor selection and gyroscope control system,worked out the product general layout design.(2)Mechanical transmission system design.Executed feasibility analysis of the transmission plans and confirmed to use planetary gear mechanism.There are 6 kinds of planetary gears plans which were analyzed.Completed design and calculation of the final planetary gear plan.Completed the torque adjustment device structure analysis and design.Developed the handle grip mode switching device.(3)Electronic control system design.Completed all circuit design of micro-processing chips,MEMS gyroscope and H-bridge driver of motor.Completed strategy control design for the rotation direction switching and the speed adjustment and programing flow mode.Finally qualified the electronic control system by testing the PCB module sample.(4)Built all parts and assembly 3D model and engineering drawing design by using CATIA software,and then built a rapid working prototype.Finally,this thesis is validated that this gyroscope screwdriver design is feasible by performance test and user research.There are important practical significance and reference value for power tools design and innovation.