Ultrasonic transducers are widely used. According to the application industries, they are divided into industry, agriculture, transportation, life, medical treatment and military. According to the realized functions, it is divided into ultrasonic processing, ultrasonic cleaning, ultrasonic detection, detection, monitoring, telemetry, remote control, etc.; according to the working environment, it is divided into liquid, gas, biological body, etc.; according to the nature, it is divided into power ultrasonic, detection ultrasonic, ultrasonic imaging, etc. .
Piezoelectric ceramic transformer
The piezoelectric ceramic transformer uses the piezoelectric effect of the polarized piezoelectric body to achieve voltage output. The input part is driven by a sinusoidal voltage signal and vibrates through the inverse piezoelectric effect. The vibration wave is mechanically coupled to the output part through the input and output parts, and the output part generates electric charge through the positive piezoelectric effect to realize the electric energy of the piezoelectric body. -Mechanical energy-two transformations of electrical energy to obtain the highest output voltage at the resonance frequency of the piezoelectric transformer. Compared with electromagnetic transformers, this has the advantages of small size, light weight, high power density, high efficiency, resistance to breakdown, high temperature resistance, no fear of burning, no electromagnetic interference and electromagnetic noise, and simple structure, easy production, and easy mass production. In some areas, it has become an ideal substitute for electromagnetic transformers. This type of transformer is used in switching converters, notebook computers, neon lamp drivers, etc.
Ultrasonic motors use the stator as a transducer, use the inverse piezoelectric effect of the piezoelectric crystal to make the motor stator vibrate at an ultrasonic frequency, and then rely on the friction between the stator and the rotor to transfer energy and drive the rotor to rotate. Small size, large torque, high resolution, simple structure, direct drive, no brake mechanism, no bearing mechanism, these advantages are beneficial to the miniaturization of the device. It is widely used in the fields of optical instruments, lasers, semiconductor microelectronics processes, precision machinery and instruments, robotics, medicine and biological engineering.
The mechanism is to use physical effects such as cavitation, radiation pressure, and acoustic flow when ultrasonic waves propagate in the cleaning liquid to peel off the machinery generated by the dirt on the cleaning parts, and at the same time, it can promote the chemical reaction between the cleaning liquid and the dirt to achieve Purpose of cleaning objects. The frequency used can be selected from 10 to 500 kHz according to the size and purpose of the cleaning object, generally 20 to 50 kHz. As the frequency increases, Langevin vibrators, longitudinal vibrators, thickness vibrators, etc. can be used. In terms of miniaturization, there are also radial and flexural vibrations using disc vibrators. It has been widely used in various industries, agriculture, household equipment, electronics, automobiles, rubber, printing, airplanes, food, hospitals, and medical research.
There are two types of ultrasonic welding: ultrasonic metal welding and ultrasonic plastic welding. Among them, ultrasonic plastic welding technology has been widely used. It uses the ultrasonic vibration generated by the transducer to transmit the ultrasonic vibration energy to the welding area through the upper weldment. Due to the large acoustic resistance of the welding area, that is, the junction of the two weldments, local high temperature will be generated to melt the plastic, and the welding work will be completed under the action of contact pressure. Ultrasonic plastic welding can facilitate welding of parts that cannot be welded by other welding methods. In addition, it also saves expensive mold costs for plastic products, shortens processing time, improves production efficiency, and is economical, fast, and reliable.
The fine abrasive is applied to the workpiece with a certain static pressure together with the tool, and the same shape as the tool can be processed. During processing, the transducer needs to produce an amplitude of 15-40 microns at a frequency of 15-40kHz. Ultrasonic tools make the abrasive on the surface of the workpiece continuously impact with considerable impact force, destroy the ultrasonic radiation part, and break the material to achieve the purpose of removing the material. Ultrasonic processing is mainly used in the processing of brittle and hard materials such as gems, jade, marble, agate, and cemented carbide, as well as the processing of special-shaped holes and fine deep holes. In addition, when vibration is added to ordinary cutting tools, it can also improve accuracy and efficiency.
Ultrasound weight loss
Using the cavitation effect and micro-mechanical vibration, the excess fat cells under the human epidermis are crushed, emulsified and excreted to achieve the purpose of weight loss and shaping. This is a new technology developed in the 1990s internationally. Zocchi from Italy used ultrasonic degreasing for the bed for the first time and was successful, setting a precedent for plastic surgery and beauty. Ultrasonic fat removal technology has developed rapidly at home and abroad.
Irradiating plant seeds with appropriate frequency and intensity of ultrasonic waves can increase the germination rate of seeds, reduce the rate of mildew, promote the growth of seeds, and increase the growth rate of plants. According to information, ultrasound can increase the growth rate of some plant seeds by 2 to 3 times.
Blood Pressure Monitor
Using the pressure of the receiving blood vessel, when the airbag compresses the blood vessel, because the applied pressure is higher than the vasodilation pressure, the pressure of the blood vessel cannot be felt; and when the airbag is gradually deflated, the pressure on the blood vessel will decrease to a certain value. When the pressure of the two reaches a balance, the pressure of the blood vessel can be felt at this time. This pressure is the systolic pressure of the heart. The indicator signal is sent through the amplifier to give the blood pressure value. Because the electronic sphygmomanometer eliminates the stethoscope, the labor intensity of medical staff can be reduced.