Ultrasonic transducer is the core component of welding machine, which is mainly composed of vibrator and amplitude modulator. Its function is to drive the whole transducer resonance through the simple harmonic vibration of vibrator itself under the excitation of electric signal, so as to convert electric energy into mechanical energy. The transducer vibrator adopts sandwich structure, which is composed of pre-stressed bolts to clamp the front and rear driving blocks, piezoelectric wafers and electrode pieces. The front drive block and the amplitude modulator are assembled by connecting screws.

 

When the voltage is applied at the two poles of the piezoelectric chip, the piezoelectric chip will deform in the thickness direction (i.e. the axial direction of the transducer) due to the inverse piezoelectric effect of the piezoelectric ceramic material. The deformation will stretch and compress repeatedly under the action of the alternating current, so as to convert the electrical energy into mechanical energy. Under the action of alternating current, the oscillator periodically stretches and compresses at the resonant frequency, which also drives the amplitude modulator to resonance. In this way, the oscillator and the amplitude modulator become a simple harmonic vibration unit respectively. The oscillator is excited by the electric signal, and then the amplitude modulator is excited, and the two resonate. When each resonant cell outputs axial amplitude, radial deformation occurs periodically. The axial deformation is the largest at both ends of the cell, and the radial deformation is the smallest, while the position of the middle node is opposite. The structure gain of the resonant unit is proportional to the mass ratio of the two ends of the node. The amplitude of the ultrasonic transducer depends on the structure gain of the oscillator and the amplitude modulator, as well as the applied voltage. The larger the amplitude is, the higher the voltage is, and the higher the output power is.

It can be divided into industry, agriculture, transportation, life, medical and military industries. According to the function, it can be divided into ultrasonic processing, ultrasonic cleaning, ultrasonic detection, detection, monitoring, telemetry, remote control, etc.; according to the working environment, it can be divided into liquid, gas, organism, etc.; according to the nature, it can be divided into power ultrasonic, detection ultrasonic, ultrasonic imaging, etc.