Pre-tightening structure for inhibiting high-temperature relaxation of piezoelectric element and pre-tightening method thereof

Abstract

The invention discloses a pre-tightening structure for inhibiting high-temperature relaxation of a piezoelectric element and a pre-tightening method thereof.The pre-tightening structure comprises a fixed platform, a stud is arranged on the fixed platform, and the stud is sequentially sleeved with a first insulator, the piezoelectric element, a second insulator, an outer cone compensation body and an inner cone compensation body from bottom to top; the upper end of the stud is matched with a pre-tightening nut used for pressing the inner cone compensation body, the upper end of the outer cone compensation body is provided with a first annular conical surface, and the lower end of the inner cone compensation body is provided with a second annular conical surface matched with the first annular conical surface; according to the scheme, the first annular conical surface and the second annular conical surface relatively slide due to the radial expansion difference and drive the inner cone compensation body to move upwards, so that the size in the height direction is increased; the size increasing amount can be used as the pre-tightening compensation amount generated by the difference of the thermal expansion amount of the piezoelectric element and the stud in the height direction at the working temperature, and therefore the phenomenon that the piezoelectric element is loosened on the pre-tightening structure at the high temperature is restrained.

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