Piezoelectric intelligent material based bolt pre-tightening force sensor

Abstract

The invention relates to a piezoelectric intelligent material based bolt pre-tightening force sensor. According to the technical scheme, an upper gasket (1) and a lower gasket (7) of the bolt pre-tightening force sensor are fixed together back to back through a left positioning pin (13) and a right positioning pin (14); the front side of the upper gasket (1) is provided with a first annular groove concentrically; a wire leading hole is machined between the circumferential surface of the upper gasket (1) and the first annular groove; a first insulating layer (2) is brushed at the bottom of the first annular groove; a first upper electrode (5) and a first lower electrode (6) are pasted on the upper plane and the lower plane of a first annular piezoelectric ceramic (4) correspondingly to form a first annular piezoelectric ceramic assembly which is pasted on the first insulating layer (2) arranged at the bottom of the first annular groove; a first insulating sealant (3) is filled between the first annular piezoelectric ceramic assembly and the first annular groove; a first insulating sealant (3) is coated on the upper plane of the first annular piezoelectric ceramic assembly. The piezoelectric intelligent material based bolt pre-tightening force sensor has the advantages of being strong in universality, simple in structure, long in service life and low in cost.

Description

technical field [0001] The invention belongs to the technical field of bolt pretightening force sensors. In particular, it relates to a bolt pretightening force sensor based on piezoelectric smart materials. Background technique [0002] Bolt connection is widely used in various equipment and structures in machinery, chemical industry, transportation, electric power, aviation and civil engineering industries. On the one hand, it is used to connect detachable parts, and on the other hand, it is used to transfer loads between parts. It is axial preload, and the size of its preload is directly related to the reliability and safety of the entire equipment or structure. [0003] In engineering, the torque wrench method is often used to control the tightening force of bolts, and the electric resistance strain gauge method is used to measure the axial force of bolts. The torque wrench method is difficult to accurately measure and control the axial force of the bolt due to the unc...

AI Technical Summary

Problems solved by technology

The torque wrench method is difficult to accurately measure and control the axial force of the bolt due to the uncertainty of the friction between the nut and the component and the thread; the electric resistance strain gauge method uses a standard resistance strain gauge, and the resistance strain gauge is pasted on the bolt. In general, the axial force of the bolt is obtained by measuring the axial strain of the bolt. Although this method has high measurement accuracy, it is difficult to be applied in many places where the bolt is used due to the limitation of the bolt installation form and working conditions.

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