A torque control method for an intelligent electric torque wrench

Abstract

The invention discloses an intelligent electric torque wrench, a torque control system and a control method thereof, and belongs to the technical field of electric torque wrenches. The torque control method comprises the steps that firstly, an operating mode is selected in a keyboard input module, and in other words, a needed torque value is determined; secondly, a microprocessor module calls a corresponding power value according to the torque-power relation; thirdly, a normally open contact of a mechanical switch is pressed down, a closing singal is transmitted to the microprocessor module, the microprocessor module drives a power control module, and a motor drives a wrench output shaft to rotate according to the power; fourthly, a voltage sensor collects voltage signals of a power source for carrying out power compensation on the microprocessor module; fifthly, a current sensor collects the working current change of the motor, and when the current reaches to the current value, corresponding to the power, stored in the microprocessor module, the power control module is turned off, and the motor is stopped. The antijamming capability is high, and the control precision of output torque of the wrench is improved.

Description

technical field [0001] The present invention relates to the technical field of electric torque wrench, and more specifically, relates to an intelligent electric torque wrench, a torque control system and a control method thereof. Background technique [0002] Electric torque wrench is usually used in occasions where bolts or nuts are disassembled and assembled with high torque and high precision of tightening torque. Electric torque wrenches in the prior art can be divided into two types: current speed type and dynamic torque sensor type. The current speed electric torque wrench judges the torque value according to the current value and speed change of the motor during the bolt tightening process, and the motor stops working when it reaches the predetermined value. The dynamic torque sensor type electric torque wrench is equipped with a torque sensor on the output shaft of the wrench to detect the change of the torque value. When the predetermined torque is reached, the mot...

AI Technical Summary

Problems solved by technology

The controller in this application selects the current working range suitable for the electric wrench according to the preset torque value, and controls the conduction angle of the thyristor to control the current delivered to the wrench motor in the current working range. This torque control unreliable method

[0005] In addition, in the process of tightening the nut, due to the influence of the change of the friction force of the threaded connection pair, the influence of many factors such as the use environment, the tightening torque value will be different, which requires timely torque calibration of the wrench. At present, the electric torque wrench The calibration of the wrench is usually performed by professionals in the manufacturing and assembly plant, so that the torque calibration cannot be performed in time during the actual use of the wrench, and the exact torque value of the wrench cannot be grasped.

To sum up, the torque control of the existing electric torque wrench fluctuates greatly and does not have the function of torque calibration

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