Views: 5 Author: Site Editor Publish Time: 2019-05-22 Origin: Site
In a multi-frequency ultrasonic cleaner system, the ultrasonic cleaning transducer is one of the key components. It must have two resonant frequencies and the impedance near its resonance point should be close to achieve the best conversion of electricity and sound.
The sandwich type piezoelectric ceramic transducer has many resonance frequencies, that is, fundamental frequency vibration, primary harmonic frequency, secondary harmonic frequency, and the like. According to the design theory of the ultrasonic composite sandwich composite transducer, by appropriately changing the structural mode of the transducer, it can work both at the fundamental frequency and at the first harmonic, that is, the dual-frequency transducer. There are two vibration modes of the dual-frequency transducer, the fundamental frequency vibration is half wavelength, and there is one node in the transducer; and the harmonic vibration is a full-wavelength structure, and the transducer has two nodes.
The two vibration modes have different node positions. According to the research on the influence of the position of the ceramic in the transducer of the ultrasonic cleaner on the performance of the transducer, the piezoelectric ceramic piece is preferably placed near the vibration node of the transducer. Therefore, if the conventional sandwich transducer mode is to put the piezoelectric ceramic wafers together, for the half-wavelength vibration mode, the ceramic wafer may be near its vibration node; for the full-wavelength vibration mode, the ceramic wafer will deviate from its vibration node. To reduce the power capacity of the transducer.
In order to meet the positional alignment requirements of the piezoelectric ceramic wafers in two different vibration modes, the piezo ring crystal wafers are divided into two groups, and the distance between the metal members is separated/appropriate by 0, so that the transducer is in two different vibration modes. The piezoelectric ceramic wafer is basically in the vicinity of the vibration node, and its structural form is as shown in FIG. The front cover of the ultrasonic cleaner is made of metal aluminum, which increases the radiation surface, increases the radiation resistance (C water.S), and reduces the mechanical quality factor Q; the rear cover and the middle "electrode" have low internal power consumption and fatigue resistance. Heavy metal 45. Steel with good performance, high rigidity and certain toughness, which is made by special high temperature modulation.
Most of the energy is radiated from the front cover. The fundamental frequency of the dual-frequency ultrasonic cleaner parts transducer is measured by the cw-1232 frequency characteristic measuring instrument produced by Suzhou Chaowei Electronics Co., Ltd., f1=29.2 kHz, and the first harmonic frequency f2=52.1 kHz. 9 dual-frequency ultrasonic cleaner transducers with the same frequency characteristics were bonded to the bottom of the 300mmx300mmx180mm stainless steel cleaning tank, so that the 9 dual-frequency transducers and the cleaning tank form a complex frequency conversion resonance system, and the complex is measured. The fundamental frequency of the frequency-shifting vibration system is f1-1=27.6 kHz, and the first harmonic is f2-2=47.1 kHz.
