Numerical-control constant-torque electric spanner

Abstract

The invention relates to a handheld-type electric-control constant-torque electric spanner. The numerical-control constant-torque electric spanner comprises a shell, a bushing, an elastic shaft, a reduction mechanism and a motor, wherein an output shaft of the motor is connected with the input end of the reduction mechanism in a transmission way, the output end of the reduction mechanism is connected with the elastic shaft, the other end of the elastic shaft is fixedly connected with the bushing, and the numerical-control constant-torque electric spanner also comprises an electric control system, wherein the electric control system comprises a sensor, a main control unit, a storage device, a keystroke circuit, a display unit and a relay drive circuit, the sensor is a strain foil, and the sensor is stuck onto the elastic shaft. The strain foil is directly stuck onto the elastic shaft, a way for directly measuring the torque is adopted, the rotation of the motor is controlled through the electric control system, and high constant-torque screwing precision is realized.

Description

technical field [0001] The invention relates to a portable power tool for tightening or loosening screws or nuts, in particular to a hand-held electric wrench with constant torque. Background technique [0002] In recent years, with the enlargement of structures, high-strength bolts have been used more and more widely. High-strength bolts are mainly used in steel structure engineering to connect the connection points of steel structural steel plates. The correct tightening of high-strength bolts is very important. When high-strength bolts are tightened, only when the pre-tightening force required by the design is reached, can the set fastening strength and fatigue life be guaranteed, so as to exert the due performance of its fasteners. Fastening connection. At present, domestic and foreign standards strictly stipulate the technical indicators of torque and pre-tightening force of high-strength bolts. The final pre-tightening force of high-strength bolts cannot be directly m...

AI Technical Summary

Problems solved by technology

At present, domestic and foreign standards strictly stipulate the technical indicators of torque and pre-tightening force of high-strength bolts. The final pre-tightening force of high-strength bolts cannot be directly measured at present. Only high-precision constant-torque electric wrench can be used to ensure the final tightening of high-strength bolts. The torque reaches the set requirement

The existing constant torque electric wrench mostly uses motor current feedback to measure the torque value of the electric wrench. This method is an indirect measurement, and is affected by factors such as voltage, and the measurement and control accuracy is low.

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