Development Of Piezoelectric Film Three-Dimensional Force Sensor And Research On Its Calibration Technology

Bearing rolling elements are an important part of the bearing.The accuracy and performance of the bearing rolling elements directly determine the performance and service life of the final product.Cold heading is used as the first process of steel ball processing.Cold heading plays an extremely important role in the entire production process of steel balls.The lack of defect detection capability in the cold heading process has become a bottleneck restricting the development of the steel ball billet industry.The quality of the cold heading of the steel ball is closely related to the value of the three-dimensional force.The load cell currently used has the limitation that it can only realize one-way heavy load measurement.The force sensor cannot fully meet the requirements for three-dimensional force measurement in cold heading force measurement.Piezoelectric quartz is brittle.The piezoelectric coefficient of piezoelectric ceramics is too large.Piezoelectric quartz and piezoelectric ceramics are not suitable for cold heading occasions.PVDF piezoelectric film sensor has the advantages of high sensitivity,high natural frequency,and good dynamic response characteristics.PVDF piezoelectric film sensor is one of the most suitable sensors for dynamic measurement of impact force.How to realize the dynamic measurement of the three-dimensional force based on the piezoelectric film is a technical problem in the real-time monitoring and research of the quality of cold forming of steel balls.Therefore,the development of piezoelectric thin-film three-dimensional force sensor and its key technology research have been launched.Aiming at the problems of heavy load,strong impact force and dynamic measurement,the structure design of the piezoelectric film three-dimensional force sensor with high linearity,high natural frequency,high sensitivity and high stiffness based on the piezoelectric effect has been completed.The principle of three-dimensional force measurement of PVDF piezoelectric film,the layout analysis of force-sensitive components and the principle of parallel load sharing of sensors are combined.Combination of theoretical analysis and ANSYS simulation analysis.The schematic design of the piezoelectric film three-dimensional force sensor is completed.Based on the mechanism modeling method,the static and dynamic mathematical models of the piezoelectric film three-dimensional force sensor are established.The sensor's force-to-electricity conversion law,charge sensitivity and natural frequency calculation formula are derived.After using MATLAB software to calculate and analyze the influence law of each structural parameter of the sensor on its static and dynamic performance is obtained.Using ANSYS software,the sensor is subjected to static simulation analysis.The structural parameters of the sensor are determined by orthogonal experiments.The charge sensitivity of the sensor under the action of three-dimensional force is obtained.The sensor was subjected to modal analysis and response analysis.The natural frequency of the sensor is obtained.Combining theoretical derivation and simulation analysis results,the optimal design of the sensor is completed.The static and dynamic performance of the sensor is improved.Finally,a dynamic sensor calibration device is designed and manufactured based on the principle of negative step response.Completed the manufacture of piezoelectric film three-dimensional force sensor.The sensitivity and nonlinearity of the sensor are obtained by static calibration experiments.The repeatability of the sensor is obtained through the impact test.The natural frequency of the sensor is obtained by dynamically calibrating the experiment.