Research On Matching Characteristics Of Ultrasonic Power Supply

In the process of ultrasonic machining, the matching circuit needs to be set up between the ultrasonic power and ultrasonic vibration system. The main purpose of the matching circuit is tuned and variable resistance, it play a quite important role. The effect of matching performance of ultrasonic power supply not only decides whether the whole vibration system can operate efficiently, also can control the technical performance of the whole equipment, even affect the service life of the ultrasonic power supply and the devices of ultrasonic vibration system.However, because of various external factors and the reason of itself of ultrasonic vibration system, matching circuit can not tune resonance state and transform the impedance. So it will reduce the output power and the efficiency of vibration system. In order to solve this situation, the purpose of this study is to optimize matching circuit and create new ways of matching.Matching circuit is divided into static matching circuit and dynamic matching circuit. For static matching circuit, the research choose T-type matching circuit, because of its convenient adjustment and three adjustable electrical parameters. The current research about T-type network only stay in the adjustment of the structure and function level, but it did not explain how to select the values of each electrical parameter correctly. In general, the electrical parameter of T-type is decided by the parameters of transducer itself. Then due to the connection problem of vibration rod, amplitude transformer, and the support frame, the analysis show that dynamic resistor R1will be changed strongly when piezoelectric transducer is connected with the ultrasonic vibration system. At the same time, dynamic resistor R, is the most important factors to determine the T-type matching circuit. Therefore, only taking the transducer into consideration and ignoring other device of vibration system will make that the initial matching circuit can’t make a good effect. This will make the vibration system in a state of mismatch before applying the dynamic load. In addition, for the dynamic matching circuit, when the load is added at the ultrasonic vibration system, vibration system will be mismatch due to strongly variable load. So through the study of static matching and dynamic matching, the research implement improving matching characteristics of ultrasonic power supply.The main research content is as follows:(1) Introduce the rise of the ultrasonic machining technology and ultrasonic power and the development of the current state of the world. Separately introduce the three stages of development of ultrasonic power supply and the current problems existing in the ultrasonic power supply in the circuit matching, and then put forward methods to solve the problem.(2) Introduce the working principle of ultrasonic power and the working process of the internal modules. In preparation for the analysis of matching circuits and ultrasonic vibration system, select each module circuit of the ultrasonic power correctly by the characteristics of ultrasonic power supply used for this experiment.(3) According to the performance of the piezoelectric transducer and ultrasonic horns, using of force-electrical equivalent model, derivate the equivalent circuit of piezoelectric transducer and impedance circle diagram. Analysis the electrical parameters of transducer equivalent circuit and the vibration frequency when the transducer is in resonance.(4) For matching problem of inaccurate in static matching circuit, considering the relevant reasons of the dynamic resistance caused by the other device of vibration system, use the two matching circuit condition and the relationship between Rj and the parameters, resize the value of electricity parameter of T-type matching circuit.(5) Using the Multiuse software to simulate and analysis the working process of the internal main circuit of ultrasonic power supply, verify the simulation result is consistent with the theoretical calculation. Simulate and analysis optimized T-type match circuit to verify the matching effect when resistor R1change.(6) When the load of Vibration system change strongly, use impedance analyzer to actual measurement the change of the parameters of the equivalent circuit. Make the optimized T-type matching circuit and dynamic tuning matching circuit connected with the ultrasonic vibration system to verify the actual matching effect.