SU1250956A1 - Sensing element of piezoelectric accelerometer - Google Patents

Abstract

The invention relates to measuring motion parameters, in particular, vibration and shock acceleration sensors. The aim of the invention is to increase the dynamic accuracy of the vibration acceleration measurements. The device contains an elastic disk 1 with a central 2 and peripheral 3 protrusions, over which an elastic reinforcement plate 4 with a piezoelectric transducer 5 is placed. In the presence of vibration acceleration on the elastic disk 1, alternating forces act on the side of the inertial element from the parts 6 and 7 causing a change in the bending of the elastic plate 4 the reinforcement of the piezoelectric converter 5, on the electrodes of which there are charges corresponding to the magnitude and sign of the measured acceleration. During deformation of the damping element, forces appear that reduce the resonance peak and dynamic errors of the device. Relations between the heights of the central and peripheral protrusions of the elastic disk and the size of the piezoelectric transducer, 2 Il, are given. S (L B B to sd o soe aul

Description

The invention relates to the measurement of motion parameters, in particular to sensors of vibration and shock accelerations.

The aim of the invention is to improve the dynamic accuracy of the acceleration measurement.

FIG. 1 and 2 a simplified structural diagram of the sensitive element of a piezoelectric accelerometer is shown.

The device contains an elastic disk 1 with a central 2 and peripheral 3 protrusions, a plate of elastic reinforcement 4, a piezoelectric transducer 5 mounted on the plate 4, for example, using glue, and located along the perimeter of the disk

Part of the inertial element

each of which consists, for convenience of assembly, of two parts 6 and 7 interconnected by, for example, a screw 8. Parts of the inertial element are placed in the material of the damping element 9. In the case of the piezoelectric accelerometer, the sensitive element is mounted on the leg 0, to which screwed in

II through insulating washer 12.

In order to achieve the maximum range of measured accelerations, the difference in heights between the central and peripheral protrusions of the elastic disk and the dimensions of the FBE and the elastic reinforcement plate are related by:

.

E., a-b „,,.

B.a l ei.all-nji bn, c h.do-yau

m ,, w ..

45

de, 06-0.12 - the estimated coefficient;

 Cn is the radius of the piezoelectric transducer and the elastic reinforcement plate;

- thickness of piezoelectric transducer and elastic reinforcement plate i

p.e n., are Young's moduli and Poisson’s ratios of materials of a piezoelectric transducer and an elastic sub50 plate

mounting accordingly;

0

five

0 5

ABOUT

0

five

6 |, is the limit of the mechanical strength of the material of the piezoelectric transducer under compression.

Such a constructive solution provides a uniform axisymmetric bending of the piezoelectric element and, as a result, a significant margin of its dynamic strength.

The device works as follows.

If there is a measured vibration acceleration along the axis of symmetry of the sensing element, oscillations of the inertial element relative to the accelerometer case occur. At the same time, alternating vultures act on the elastic disk 1 from the side of the parts 6 and 7 of the inertial element, causing axisymmetric bending of the disk 1 and changing the bending of the elastic reinforcement plate 4 of the piezoelectric transducer 5 through their protrusions through the protrusions 3. Charges appear on the electrodes of the piezoelectric transducer corresponding to the magnitude and sign of the measured acceleration. The material of the damping element 9 with oscillations of the inertial element is deformed by its parts 6 and 7 and creates opposing forces proportional to the speed of movement of the inertial element and reducing the resonant peak and the dynamic errors of the accelerometer as a whole.

Claims (1)

Invention Formula A sensory element of a piezoelectric accelerometer, containing an inertial element, an elastic disk with uniformly high protrusions uniformly distributed along its periphery, an elastic reinforcement plate with a piezoelectric transducer fixed on it, and a damping element, different in that it is vibrated to measure the vibration accuracy of vibration. an elastic reinforcement is located between the piezoelectric transducer and the peripheral protrusions, and the elastic disk is provided with a central ring ndricheskim protrusion whose height is less uneven peripheral protrusions by an amount iVi, selected from ratios of J.lL 1L -Ar uLill: Ji)  Ё ;; b; B -IE; / T -) where, 06-0,12 - the calculation coefficient;  - radius of the piezoelectric transducer and the elastic reinforcement plate J - thickness of the piezoelectric transducer and the elastic reinforcement plate, .} and .., .l 6. Young's moduli and Poisson’s ratios of piezoelectric transducer materials and elastic reinforcement plates; limit of mechanical strength of a piezoelectric converter material under compression, at the same time, the damping element is located on the periphery of the elastic disk and contains inside itself evenly distributed and installed on both parts of the elastic disk part of the inertial element - 20 mt. Editor M.Kelemes Compiled by K.Lukomsky Tehred M.Hodanich Order 4404/40 Circulation 778 Subscription VNIISH State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35 Raushsk nab., d, 4/5 Production and printing company, Uzhgorod, st. Project, 4 Figg Proof-reader I.Erdeyi