| It is pointed out that the accuracy of the force exerted by the force source device of overlap-type force standard machine and the maintaining period of the force value depend on the minimum displacement and the control accuracy which may be realized on the machine. The present force devices restrict the accuracy and performance of force standard machine, because of the natural defects of their structure and working principle. On the basis of analysis on the working principle of overlap-type force standard machine, the authors have proposed and established a theory and a method by making use of the piezoelectric converse effect to produce a controllable precise deformation directly on the transmission system of force standard machine to control the force. A force source device and its corresponding controller have been developed by using piezoelectric ceramics. Theoretical analysis and experimental results have proved that the use of piezoelectric ceramics and its control technique as the force source device and controller of overlap-type force standard machine has made the force source to get the advantage of high accuracy, good performance, low-cost and automation.1.Introducing the classification,the characteristics,the application and the currentdevelopment status and trends at home and abroad of the piezoelectricmicro-displacement device.Piezoelectric actuators use electromechanical couplingeffect which is the reverse piezoelectric effect or electrostrictive effects to producemicro-displacement.Using electromechanical coupling effects,high resolution canbe achieved,and the speed of electromechanical coupling effects is very quick,heatexchange with the outside world could not be considered to be similar to theadiabatic process,there is no heat.We use the micro-displacement effects ofelectromechanical coupling,and only need control the applied voltage,can beeasily migrated to achieve even higher accuracy.2.Introducing the general basic kNowledge of piezoelectric ceramics,and weanalyse the theory of the piezoelectric micro-displacement technology with grandloading capacity,and deduct the role of the principle.Using piezoelectric actuatorsto achieve the precision displacement is widely used.In these applications,thedrive to overcome the load is often smaller.The text researches output tohigh-thrust,the main purpose of overcoming the big load piezoelectric actuatortechnology and its applications.The research of making a big load of piezoelectricceramics is unique in the world,This has been done by the force of 3 MN.3.We do some test for the selected compression strength of the piezoelectricceramics in order to better control and apply piezoelectric ceramics.Piezoelectricdevices in the process of use should be under a lot of pressure,and havedeformed.so we should estimate its compressive strength before the use to betterdesign completed,and it will not be dug up at work.We control the output of forceby controlling precision displacement,so deformation test is necessary.4.We do some test for the application of piezoelectric devices in the large load stacking strength,and we introduce the superposition principle of the compositionand work of the Building-up Force Standard Machine.The building-up ForceStandard Machine as a standard power metering equipment,due to low prices, efficient and user-friendly features,is widely welcomed by load sensor manufacturers and force workers.In this paper,we study the use of piezoelectric ceramic piezoelectric effect in the value of stacking strength and control aircraft,in order to enhance the value of such a force measurement equipment,improve the power accuracy,efficiency of production,and to reduce production costs and achieve automation.These are the key elements of the thesis.It proves that the technology is very valuable by the theoretical analysis and practical application of the technology ofthe piezoelectric actuator with grand loading capacity,and there may be output larger force,so there is the need for further research. |
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