Intelligent gasket with anti-loosening function for monitoring bolt fastening state and monitoring method

Abstract

The invention relates to an intelligent gasket with an anti-loosening function for monitoring a bolt fastening state and a monitoring method. The intelligent gasket comprises a metal upper piece, an insulating piece, a monitoring piece, a hyperelastic piece and a metal lower piece, the metal upper piece and the metal lower piece not only bear and prevent scratches, but also play a role in sealing protection, and the insulating piece and the hyperelastic piece are both made of insulating materials. And the monitoring circuit is not conducted with the metal upper piece and the metal lower piece. According to the requirements of different tightening torques, the structure and material parameters of the internal monitoring piece and the hyperelastic piece are adjusted, the good elastic recovery capacity of the hyperelastic piece is used for enabling the metal contact of the monitoring piece to make contact with or be separated from the metal lower piece when the bolt pre-tightening force changes, and the on-off state change of an internal monitoring circuit is achieved; and therefore, the connection state of the bolt is represented. Compared with a grating type, piezoelectric sensing type or resistance strain gauge type intelligent fastener, the intelligent gasket is low in cost and high in reliability, not only has an anti-loosening function, but also can effectively monitor the bolt fastening state to prevent connection failure.

Description

technical field [0001] The invention belongs to the technical field of fastener connection state monitoring, in particular to an intelligent washer and a monitoring method for monitoring the fastening state of bolts with an anti-loosening function. Background technique [0002] As the most commonly used fasteners in industrial sites, bolts are widely used in key equipment in aerospace, marine turbines, bridge construction, chemical equipment, new energy and other fields. Due to its simple structure, unified standard, high reliability, and easy assembly and maintenance, bolted connection has become the main connection method at present. Under the action of variable load, vibration and impact, or when the working temperature changes greatly, the bolt connection may lead to stress relaxation and local deformation of the connection part, which will lead to loose connection and cause the reduction or even loss of the pre-tightening force of the bolt, resulting in the failure of t...

AI Technical Summary

Problems solved by technology

[0003] At present, the monitoring methods for bolt failure are mainly divided into the following types: image detection method based on visual recognition, which judges whether the bolt is loose by monitoring the geometric characteristics such as nut angle and bolt deformation. Generally speaking, this method has low precision and poor reliability. The external environment is limited, so there are not many applications; based on the strain-type and fiber-optic vibration sensor method, the bolt looseness is judged by detecting and analyzing the elastic wave generated after the bolt is excited by vibration. Vibration, and the elastic wave signals generated are quite different, so it needs to be analyzed separately, with poor versatility and high cost, it is difficult to be widely used; based on the piezoelectric and strain-type pressure sensor method, the bolt is directly detected by the pressure sensor The pre-tightening force is used to judge whether the bolt is loose. This method is complicated to install, high in cost, and is easily interfered by the external environment, so its application is limited.

Therefore, the intelligent monitoring of bolted connection status has been unable to be promoted on a large scale

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