Development trend of ultrasonic welding technology
1. Improving welding productivity is an important driving force for the development of welding technology. There are two ways to improve productivity: firstly improve the welding deposition rate, such as three-wire submerged arc welding, the process parameters are 220A/33V and 1400A40V1100A45V respectively. The groove section is small, the baffle or liner is arranged behind, and the 50~60mm steel plate can be welded and formed at one time. The welding speed can reach 0.4m/min or more, and the deposition rate is more than 100 times compared with the electrode arc welding. The second way is to reduce the section of the groove and the metal cladding. The outstanding achievement in the past decade is the narrow gap welding. Narrow gap welding is based on gas shielded welding. It is welded by monofilament, double wire and triple wire. No matter the thickness of the joint, the joint form can be used. For example, the thickness of the steel plate is 50~300mm, and the gap can be designed to be about 13mm. The amount of deposited metal required is reduced by several times and tens of times, thereby greatly increasing productivity. The main technical key of narrow-span welding is to see how to ensure the penetration of both sides and ensure that the arc center is automatically tracked and on the center line of the groove. For this reason, various countries have developed various solutions, so a variety of narrow gap welding has emerged. law. For electron beam welding, plasma welding, and laser welding, butt joints can be used without opening, so it is a more ideal narrow gap welding method, which is one of the reasons why it is widely valued. The newly developed laser arc hybrid welding method can improve the welding speed, such as 5mm steel plate or aluminum plate, the welding speed can reach 2~3m/min, and the good forming and quality are obtained, and the welding deformation is small.
2. Improve the mechanization of the preparatory workshop, and the level of automation is the key development direction of the world's advanced industrial regions. In order to improve the production efficiency and quality of the welded structure, there are certain limitations in starting from the welding process. Therefore, countries around the world pay special attention to the technical transformation of the workshop. The main processes in the preparation workshop include material transportation, material surface degreasing, sand blasting, protective lacquering; steel scribe line, cutting, opening; component assembly and spotting. The above processes have been mechanized and automated in modern factories. The advantage is not only to increase the productivity of the product, but more importantly to improve the quality of the product.
3, the welding process is automated, intelligent is an important direction to improve the quality of welding quality and solve the harsh working conditions.
4. The development of emerging industries continues to advance the advancement of welding technology. Welding technology has been in existence for more than 100 years since its invention, and it can meet almost all the needs of the production and manufacture of all important products in the industry. But the development of new industries still forces welding technology to move forward. The development of the microelectronics industry has promoted the development of micro-joining processes and equipment; and the development of ceramic materials and composite materials has promoted vacuum brazing and vacuum diffusion welding. The development of aerospace technology will also promote the development of space welding technology.
5. The research and development of heat sources is the fundamental driving force for the development of welding processes. The welding process uses almost all the heat sources available in the world, including flame, arc, electric resistance, ultrasonic, friction, plasma, electron beam, laser beam, microwave, etc. (Our company mainly uses arc welding and resistance welding for automatic welding equipment. Main), the emergence of every kind of heat source in history is accompanied by the emergence of new welding processes. However, the development and research of welding heat sources has not been terminated.
6. Energy-saving technology is a common concern. It is well known that welding consumes a lot of energy. For example, electrode arc welding is about 10KVA, each submerged arc welding machine is 90KVA, and the resistance welding machine can be as high as thousands KVA. Many new technologies It appears to achieve this energy saving goal. In resistance spot welding, using the development of electronic technology, changing the AC spot welder into a secondary rectifier spot welder can increase the power factor of the welder and reduce the welder capacity. The 1000KVA spot welder can be reduced to 200KVA. Throw can achieve the same welding effect. In the past decade, the emergence of inverter welding machine is another successful example. It can reduce the weight of the welding machine and improve the control performance of the power factor of the welding machine. It has been widely used in production.
Ultrasonic spot welding machine plastic welding principle is to generate 20KHz (or 15KHz) high-voltage, high-frequency signal by the generator, through the conversion system, the signal is converted into high-frequency mechanical vibration, applied to the workpiece of plastic products, through the surface of the workpiece and The friction between the molecules increases the temperature transmitted to the interface. When the temperature reaches the melting point of the workpiece itself, the workpiece interface is rapidly melted, and then filled in the gap between the interfaces. When the vibration stops, the workpiece is simultaneously cooled under a certain pressure. Shaped to achieve the perfect weld.