Preparation method of piezoelectric sensor assembly

Abstract

The invention discloses a preparation method of a piezoelectric sensor assembly. The method comprises the steps that 1) powder of a metal material of a low melting point is pressed by a die or metal of a low melting point is melted and then casted by a die to form interior and exterior low-melting-point metal layers; 2) a metal tool of certain thickness is sleeved with the bottom of a sleeve rod of a pedestal; 3) the interior low-melting-point metal layer, a piezoelectric component and the exterior low-melting-point metal layer are placed surrounding the sleeve rod successively on the tool, and a mass block is sleeved with the sleeve rod; 4) the pedestal, the tool on the pedestal as well as the interior low-melting-point metal layer, the piezoelectric component, the exterior low-melting-point metal layer and the mass block on the tool are placed in an electric furnace or a box type furnace as a whole for insulation; 5) the pedestal, the tool, as well as the interior low-melting-point metal layer, the piezoelectric component, the exterior low-melting-point metal layer and the mass block on the tool are cooled with the furnace or directly taken out and cooled naturally to a temperature lower than the melting point of the metal material; and6) the metal tool is removed from the pedestal, and the required piezoelectric sensor assembly is obtained. According to the invention, the sensor performance is improved, the technical conditions and cost of preparation are lowered, and the production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of sensors and transducers, in particular to a method for preparing piezoelectric sensor components used in vibration testing, monitoring and monitoring. Background technique [0002] Piezoelectric sensors work based on the piezoelectric effect of piezoelectric materials. Due to their high sensitivity, wide operating temperature range, and good stability, they have broad applications in the measurement, monitoring, and monitoring of speed, acceleration, pressure, vibration, and shock. application prospects. [0003] At present, the use of piezoelectric sensors mainly adopts nut locking, epoxy resin bonding and clamping rings to install piezoelectric elements and mass blocks on the base, such as figure 1 In the shown positive end compression piezoelectric sensor assembly, a sleeve rod 102 is formed in the middle of the base 10, the piezoelectric element 13 and the mass block 14 are stacked sequentially and p...

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Problems solved by technology

[0004] The assembly made by the above-mentioned method of nut locking and clamping ring can fasten the piezoelectric element 13 and the mass block 14 on the base 10 at one time, because there is a prestress, the mass block 14, the piezoelectric element 13 and the base There is almost no gap between the fixed parts of the seat 10, and at the same time, the mass block 14 and the base 10 are used as conductive electrodes, which can effectively avoid abnormal sensitivity output of the sensor. The application of stress will make the high d 33 and d 15 The performance of the piezoelectric element with a lower value will deteriorate, which will lead to a decrease in sensor sensitivity and poor stability. At the same time, the clamp ring 17 is a very special metal material, which is not suitable for actual large-scale production.

[0005] The assembly made by the method of fixing the piezoelectric element 13 and the mass 14 on the base 10 with epoxy resin and conductive glue requires very skilled operators to operate under a microscope to prevent the process of coating epoxy resin Defects affect the quality of components, and the coating can only be completed in two steps, so the piezoelectric sensor component has low production efficiency and high cost

In addition, epoxy resin and conductive glue are applied, resulting in a large size gap between the mass block, piezoelectric element and the fixed part of the base, which affects the sensitivity output of the sensor, and the sensitivity value is difficult to control, especially due to mass block, piezoelectric element Inconsistent thermal expansion coefficients among components, bases, and organic substances lead to thermal stress, and the use of mass 14 and base 10 as conductive electrodes in components can easily lead to large deviations in sensitivity output

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