The full-automatic ultrasonic cleaning machine mainly depends on the ultrasonic cavitation, which is affected by the technological parameters and the physical properties of the cleaning solution, and clear cleaning process parameters. The effect of ultrasonic cleaning is affected by vibration frequency, power, and cleaning fluid. In general, the vibration frequency of ultrasonic cleaning is 20-120khz, the lower frequency of noise, shorter wavelength, and more concentrated energy, are generally used in small and precise parts cleaning. In the case of high frequency, the wavelength is shortened, the cavitation effect is weakened, and the cleaning efficiency is lower. For some parts with more errors and complex shapes, they can be cleaned in a way with a higher power, which requires good power control. If the power is too high, although the cleaning effect can be improved, because of the strong cavitation, the precision of the workpiece will have a certain impact. At the same time, the ultrasonic cleaning operation is affected by the temperature and physical characteristics of the cleaning fluid, the cleaning fluid level should be higher than the transducer vibration level, and height control at 100mm is the best. In the selection of cleaning solution, the corrosion effect on the workpiece and the cleaning tank body should be considered.
Analysis of process parameters of automatic ultrasonic cleaning machine
The first is the frequency of ultrasonic vibration. In ultrasonic cleaning, cavitation is the most important link, the vibration frequency of sound waves has a great impact on it, we should pay attention to the choice of vibration frequency range, in general, the vibration frequency of ultrasonic cleaning is controlled at 20-80kHz. The cavitation threshold has a certain influence on the ultrasonic frequency, and the frequency is proportional to the cavitation threshold. The lower the frequency of ultrasound, the more likely the liquid cavitation, and the greater the intensity of production, the operation is also relatively strong, and usually difficult to clean the dirt in the application. High power ultrasonic direction is a strong, relatively short wavelength, generally used in high Surface finish parts cleaning, deep holes, gaps, and other surprise workpiece cleaning. At the same time, the frequency can not be too high, so that the wavelength is becoming shorter, but weaken the cavitation, so that the cleaning efficiency is reduced. If there is a certain standing wave field in the cleaning tank, because of the uneven analysis of sound pressure, the workpiece can not be effectively cleaned. Therefore, the shape of the cleaning tank should be suitable for the characteristics of the reverberation field, with the help of dual-frequency, multi-frequency, and other ways to avoid the appearance of cleaning blind area.
The second is ultrasonic power density. To improve the efficiency of ultrasonic cleaning, high-density ultrasonic power is usually used, especially for the parts with heavy oil, complicated shape, and deep hole, and the cleaning trough with high-density regeneration is adopted. At the same time, the high power density side of the work to avoid corrosion, especially with the coating, high Surface finish, and aluminum alloy parts. If the ultrasonic power is too large, the sound wave in the liquid is too high, the bubble is too much, and it is difficult to radiate the whole cylinder block, affecting the cleaning effect.
Third, is the temperature of the cleaning solution. In the process of workpiece cleaning, it is necessary to destroy the adhesion of pollutants on the surface of the workpiece, which can be overcome by heat energy, improve the activity of the temperature-enhanced cleaning medium, reduce the surface tension of the medium, and enhance the cleaning efficiency. Although the temperature can reduce the adhesion and improve the cleaning effect, the higher the temperature is not the better. Combined with the different properties of the cleaning fluid medium, the best effect and cavitation effect have certain restrictions on the temperature, for example, the optimum temperature of a water-based cleaning solution is 35 ~ 60 °C. In addition, the temperature can also affect the medium vapor pressure, surface tension, viscosity, and density, if the temperature reaches the boiling point will make cavitation effect fails.
Fourth, is the choice of cleaning fluid. The cleaning of radioactive filter elements usually uses acid and alkali as the cleaning agent, its cost is relatively controllable, and the effect is obvious. According to the different materials of the filter element, the process environment is different, and the composition of the radioactive material adhered to the surface is also different. It is one of the main factors to ensure the cleaning efficiency by selecting the proper cleaning agent. Fifth is ultrasonic cleaning time. If the cleaning time is too long, it will affect the cleaning efficiency and even cause cavitation corrosion on the surface of the workpiece. Generally speaking, for some of the surfaces of sinter material with more serious parts for cleaning, you can appropriately increase the cleaning time, for the surface is smooth, sinter material lighter parts, need to control the cleaning time.
Compared with the traditional soaking, brushing, and high-pressure cleaning technology, the automatic ultrasonic cleaning machine has the characteristics of high speed, high precision, consistency, less waste liquid, and so on. Ultrasonic energy can penetrate very small gaps and small holes, ultrasonic, wave cleaning with blind holes, deep holes, bending holes, cracks, and other relatively complex small and medium-sized workpiece cleaning, with very good cleaning accuracy and efficiency, for some small and medium-sized parts, can be placed in a special box for cleaning several one-time, plus the role of cleaning fluid, can effectively improve the cleaning speed and efficiency, reduce the amount of manual work. As long as we choose the appropriate process parameters, cleaning can achieve twice the result with half the effort.
