SU1527527A1 - Piezoelectric sensor of pulsed pressure - Google Patents

Abstract

The invention relates to a measurement technique, in particular, to devices for recording pulse pressures and forces in solids and is aimed at improving the accuracy and convenience of operation. The device contains an elastic element 1 in the form of a rod with a conical protrusion 2, a groove 3, a screw 4 and a tightening nut 5, as well as a force-transmitting element 6 coaxially to the rod 6 in the form of a tube with a supporting flange 7. The piezo sensing element 8 is fixed inside the groove 3 on its near in relation to the pressure source of the plane and has a damper 9. The electrical terminals 11 are laid in the bore 12. With the help of the nut 5, a gapless connection of the rod and the tube with the part is carried out. The screening of parasitic vibrations is carried out by an air gap between the rod and the tube, as well as by a protective gasket 10. It is possible to move the sensor along the height to select the most informative measurement zone. 1 il.

Description

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The piezoelectric sensing element 8 is fixed inside the groove 3 at its proximal to the pressure source plane and has a damper 9. The electrical terminals 11 are laid in the bore 12. With the help of a nut 5, a gapless connection of the rod and

tube with detail. The screening of parasitic oscillations is achieved by an air rejection between the rod and the pipes -. It is possible to move the sensor along the height to select the most informative measurement zone. 2 Il.

The invention relates to measuring and control technology, in particular, devices for recording pulse pressures in solids of finite size, for example, inside metal parts of machines and mechanisms.

The aim of the invention is to improve the measurement accuracy and ease of operation.

Figure 1 shows the construction of the proposed sensor; figure 2 - section aa in figure 1 ..

The piezoelectric sensor contains an elastic element 1 in the form of a cylindrical rod with a conical protrusion 2 from the side of the longitudinal groove 3 and a screw 4 with a tightening nut 5 on the opposite side, the power supply element 6 in the form of a tube with slots along the generatrix on one side (one ) and the supporting flange 7 on the other, the piezoelectric element 8, attached to the inner plane of the elastic element 1 close to the pressure source, the damper 9, made. in the form of a visco-elastic compound with a high value of the coefficient of the penetra- tion of the acoustic signal embedded in the groove 3. The sensor is mounted on the protective gasket 10 and has electrical outlets 11 brought out through the opening 12 in the elastic element 1.

To install the sensor into the measured body, a cylindrical hole is made in it, the axis of which is perpendicular to the direction of propagation of the pressure impulse (impact), and the plane of the piezo-sensitive element 8 is also oriented perpendicular to the direction of impact. The sensor is fixed by rotating the nut 5 on the screw 4. When the nut is applied to the supporting flange 7, the elastic element 1 is axially moved to press its conical protrusion along the force-generating element 6 which forms the inner surface of the cone.

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deforming, snaps to the surface of a cylindrical bore made in the measured solid.

Thus, the elastic element 1 is connected to the measured body without a gap through the force-transmitting element 6 along a circle lying in the plane P.

The sensor works in the following way.

A shock wave (pressure impulse) in a solid body through a power-transmitting element 6 along the plane P bends the cantilevers of the elastic element 1, to one of which a piezo-sensitive element 8 is attached, generating a charge proportional to the magnitude of the impulse, pressure. The shock wave components outside the plane P do not deform the elastic element 1 due to the absence of acoustic contact with it, since there is an air gap and a rubber gasket 10 between the rod and the tube.

At the same time, the deformation wave passing through the segment console, the piezoelectric element 8, the damper 9, reaches the cylindrical and conical surface of the elastic element, decomposes into shear waves and decays.

To select the most informative measurement zone, the sensor can be moved along the height of the hole by loosening and tightening the nut 5.

The design of the sensor also ensures its quick change.

Claims (1)

The proposed sensor makes it possible to increase the measurement accuracy by means of a gapless connection of it with the measured part and to eliminate the influence on the measurement results of parasitic oscillations, which makes it possible to measure pulse pressures and, therefore, pro- to conduct technical diagnostics of parts and assemblies of mechanisms and machines, during their operation in the mode of shock loads. Invention Formula A piezoelectric pulse pressure sensor containing elastic and 5152752 elements, as well as a piezoelectric element with a damper, characterized in that, in order to increase accuracy and ease of operation, the elastic element is made in the form of a rod, equipped with a screw with a nut at one end and a conical protrusion at the other end, having the groove along the axis in which the piezoelectric element is fixed, and the power-transmitting element is made in the form of a tube with a supporting flange and slots along the generatrix, which is located coaxially with a gap relative to the rod and has a diameter not exceeding the diameter of the base of the conical protrusion. FIG. 2