A Gasket Type Pressure Sensor Used to Detect Bolt Pretightening Force

Abstract

The invention relates to a gasket-type pressure sensor for detecting the pretightening force of bolts, which comprises an upper cover and a casing, the upper cover is embedded in the top of the casing, and a first The elastic body, the upper pole plate, the second elastic body, the first elastic body, the upper pole plate and the second elastic body are respectively provided with second circular holes of the same size, and the upper pole plate is connected with an AC for measuring the capacitance value. The measuring instrument, the upper cover and the casing together constitute the lower plate, and there is no contact between the upper plate and the lower plate. When the first elastic body and / or the second elastic body are compressed and deformed, the upper plate and the lower plate The distance between the plates changes, so that the capacitance value generated between the upper plate and the lower plate changes, and the pre-tightening force of the bolt is detected according to the change of the capacitance value. Compared with the prior art, the present invention uses the elastic body and the parallel plate capacitor as the basic electromechanical conversion structure, and combines with the AC measuring instrument to detect the bolt pretightening force accurately in real time.

Description

technical field [0001] The invention relates to the technical field of pressure sensors, in particular to a gasket type pressure sensor for detecting the pretightening force of bolts. Background technique [0002] High-strength bolts are widely used in industrial fields such as civil construction and mechanical installation. The pre-tightening force of high-strength bolts usually reaches more than ten tons or even twenty tons, and the load is huge. Therefore, the safety requirements for fastening joints are all Relatively high, when using bolts as key fasteners, it is usually necessary to accurately detect and control the axial stress of the bolts, that is, the bolt pretightening force, to ensure the safety and reliability of the connection. [0003] The traditional bolt pretightening force measurement methods include torque wrench and ultrasonic force measurement method. Among them, the axial force measured by the torque wrench is not reliable. First, the torque wrench itse...

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Problems solved by technology

[0003] The traditional bolt pretightening force measurement methods include torque wrench and ultrasonic force measurement method. Among them, the axial force measured by the torque wrench is not reliable. First, the torque wrench itself needs regular calibration and maintenance. Secondly, it is easy to Affected by other factors; the use of ultrasonic testing to detect the axial stress of bolts has great limitations, and is not suitable for vacuum environments, high-temperature environments, and complex mechanical structures. Therefore, bolt monitoring sensors are often used to detect bolt pretightening force at present. , but when the existing bolt detection sensors are applied to high-strength bolts with a pre-tightening force of more than ten tons, the measurement accuracy is low, and it is difficult to achieve real-time detection, so it is impossible to detect the abnormal situation of the bolt pre-tightening force in time. prone to safety accidents

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