Working principle and structure of handheld ultrasonic welding machine

Handheld ultrasonic welding machineIn the ultrasonic welding process, the handheld ultrasonic welding machine can increase the amplitude of this high-frequency vibration wave through an amplifier, and then load it to the upper mold. Through the upper mold, the strengthened high-frequency vibration wave will act on the product Therefore, the instantaneous high-frequency vibration between products can not generate high heat, so as to achieve the purpose of product integration.
The handheld ultrasonic welding machine is composed of a high-frequency current transformer, a piezoelectric transformer, an amplitude modulator, an electrode arm or a sound rod.
1. High frequency current converter
The main function of the high frequency current converter is to convert the input low frequency current into the output high frequency current. Its frequency range is the same as the ultrasonic frequency range. Ultrasonic welding usually uses an output frequency of 20kHz.
2. Piezoelectric converter
The function of the piezoelectric transformer is to convert electrical energy into mechanical vibration energy under the condition of constant frequency. It is usually done by piezoelectric or inverter. It uses asymmetric crystals, such as natural quartz plates, synthetic lithium titanate plates or barium plates, etc. In an alternating electric field, as the frequency of the current changes, mechanical deformation or size shrinkage at the same frequency occurs, also known as piezoelectric effect. Using the piezoelectric effect of this chip, high-frequency electrical energy can be converted into ultrasonic energy.
3. Amplitude modulator
The expansion or contraction of piezoelectric materials under the action of AC voltage produces high-frequency vibration, but the amplitude is not large, about (0.01-0.02MM). This is obviously not enough to produce a good welding effect, so an amplitude modulator is used on a handheld ultrasonic welding machine to increase the amplitude. This is a half-wave resonator made of aluminum or titanium.
4. Electrode arm or sonic rod
Electrode arm or sonic rod, also known as ultrasonic mold, is a tool that transfers energy to plastic products to be welded, usually made of alloys such as aluminum and titanium. Its function is to transmit high-frequency vibration and pressure to the welding part of the part as the amplitude of the end of the electrode arm increases. The typical amplitude range is (0.05-0.12) mm. The design of the electrode arm is a complicated matter. In addition to the shape of the product to be welded, it must be consistent with the shape. At the same time, the frequency of the product must be matched with the handheld ultrasonic welder. In order to ensure the smooth progress of the welding process, the electrode arm is generally designed and manufactured by a handheld ultrasonic welding machine manufacturer or an acoustic research institution.