Electric impact wrench with current PID control

Abstract

The invention discloses an electric impact wrench with current PID control. The electric impact wrench comprises a power supply, a driving motor, a planetary gear reducer, an impact mechanism and a control system, wherein the wrench is connected with the planetary gear reducer through the driving motor to drive the impact mechanism to fasten a bolt, the control system comprises a single-chip microcomputer, a motor driving module, a sensor detection module and a key control module, a relation model of the current of the driving motor of the wrench and the output torque is built in the single-chip microcomputer, the relation model and a relation curve are adopted to pre-store corresponding current values corresponding to different torque values into a database, after a preset torque value isgiven, a current sensor is controlled to detect an actual measurement value of the current of the motor to enable the actual measurement value to reach the pre-stored value, and after the preset torque value is reached, the bolt fastening operation is stopped. According to the wrench, through monitoring of the current of the motor in real time and combination of double closed-loop PID control ofthe rotating speed and the current, fixed torque output of the electric impact wrench is achieved, and higher assembling precision is obtained.

Description

technical field [0001] The invention belongs to the technical field of electric torque wrench, in particular to an electric impact wrench controlled by current PID. Background technique [0002] The impact type electric torque wrench refers to a type of wrench with a rotating belt tangential impact mechanism. Due to its advantages of high work efficiency, small reaction torque and low energy consumption, it plays an important role in thread assembly. However, its assembly torque is usually determined by the operator's hand feeling of holding the wrench and observation of the sleeve rotation to determine whether the required torque is reached. In this case, there is a large accuracy error in the assembly torque. Due to the complex working principle of the electric impact wrench, there are many parts involved in the work, which makes it difficult to analyze the principle and accurately model it. How to realize the constant torque control of electric impact wrench is the key p...

AI Technical Summary

Problems solved by technology

When the electric impact wrench tightens different types of bolts, it is necessary to avoid the deformation and damage of the bolts caused by "overtightening" due to excessive torque, or the bolts loosening and falling off due to "undertightening" due to too small torque

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