A method for controlling the output torque of an electric impact wrench

Abstract

A method for controlling the output torque of an electric impact wrench. Aiming at the thread pair to be twisted and the characteristics of the workpiece, the relationship data table of speed-torque, speed-impact times-torque, thread pair specification-current and thread pair type-current relationship data table is established through experiments; The processor calculates the motor speed and impact times corresponding to the preset torque by using the relational data table and the calculation basis selected by the user according to the preset torque. When the torque control accuracy is selected as the priority, the low speed is preferentially selected from various effective combinations and high impact times, use the relational data table to look up the table to calculate the corresponding output torque value; the microprocessor looks up the table according to the preset current relational data table and calculates and determines the current corresponding to the screw pair selected by the user when tightening the idle stroke Or the current change rate threshold, control the motor to run at a preset speed and constant speed, judge the start time of the impact action and count down the preset number of impacts, and turn off the brushless motor when the count is reduced to zero, so that the output torque of the electric impact wrench is accurate and controllable .

Description

technical field [0001] The invention relates to torque control of an electric impact wrench, in particular to a method for controlling the output torque of a torque-controllable lithium battery impact wrench with a networking function. Background technique [0002] The thread pair connection is widely used in various mechanical structures, and is the most commonly used connection method at present. Its essence is to reliably connect two or more components together by controlling the axial preload to an appropriate range. Since the axial pretightening force is an internal force, it is currently impossible to directly control the pretightening force to assemble the thread pair, and controlling the torque applied is the main method in the screwing process of the mechanical structure thread pair at present. [0003] The impact wrench has the advantages of large output torque, small size, light weight, low energy consumption, small reaction torque, and low price, which make it w...

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Problems solved by technology

This is not mentioned in the disclosed technical solution of the invention, and the invention cannot achieve this technically, and the accuracy of torque control is difficult to guarantee

[0006] The products, technologies and standards imported from abroad generally have clear requirements for thread pair assembly torque, which also forces Chinese enterprises to pay attention to the impact of assembly quality on the overall quality, reliability and safety of products. The current electric impact wrench generally has a pair of control The configuration of torsion parameters is not flexible enough to adapt to the precise control of torsion control and high operating efficiency under various torsion conditions. It has not yet realized the application of intelligence and the Internet of Things, and cannot satisfy the whole process monitoring and control of the torsion operation process. Job data traceability

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