Detection system and control method for bolts and their pretightening force

Abstract

The invention provides a bolt and a detection system and control method for pretightening force of the bolt. The control method comprises the steps that a strain gage is pasted on the outer surface of a polish rod section of the bolt; a first through hole is formed in a bolt head; a guide wire penetrates through the first through hole to enable the strain gage and a measurement mechanism to be electrically connected; the bolt is pre-tightened to enable the measurement mechanism to obtain the axial strain epsilon of the strain gage, and the pretightening force F of the bolt is controlled according to the relation expression of the axial strain epsilon and the pretightening force F to achieve mounting. Through the mode, the bolt, the detection system and the control method can precisely control the pretightening force of the bolt, and the connecting safety of the bolt can be improved.

Description

technical field [0001] The invention relates to the technical field of mechanical connections, in particular to a detection system and control method for bolts and their pretightening force. Background technique [0002] The connection with bolts as connecting parts is the most common detachable connection, and the preload is an important performance index that needs to be measured during the tightening process of bolts. Appropriate pre-tightening force can improve the reliability of the bolted connection and the fatigue strength of the bolt, and it can improve the airtightness of the connection with tightness requirements. However, excessive pre-tightening force will lead to overload of the bolts and connected parts, which can easily lead to safety accidents. Therefore, it is necessary to strictly control the pre-tightening force of the bolts during assembly. [0003] In the prior art, the pretightening force is generally controlled by the torque method, which is based on ...

AI Technical Summary

Problems solved by technology

However, using this torque method requires a large number of experiments before assembly to determine the value of the anti-torsion coefficient K, and the friction between the bolt and the connected parts is different due to the different lubrication conditions, even for the same batch of the same size For bolts, the error range of the value of the torsion coefficient K is also large, so that the precise control of the pretightening force of the bolts cannot be realized, which can easily lead to safety accidents.

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