Study And Control Of Noise On The Impact Wrench

Currently, pneumatic tools are widely applied in manufacturing industry, especially in the fields of mechanical and automobile assembly workshop or repair place. Pneumatic tools is one of the most commonly used tools. While facilitating the manufacture industry, it also brings many adverse effects. In many adverse effects, noise is one of the most prominent .It is more and more significant to reduce the noise of muffler in such a harmonious society. The noise of the pneumatic tools belong to air dynamic noise, so the most common way to reduce the noise is designing a appropriate muffler. In this paper, According to the features of the pneumatic tools noise and pneumatic tools themselves using, we designed a new type of interfere muffler which use a few strands of airflow collide with each other reducing the energy. The muffler overcomes many faults of traditional muffler, such as narrow noise elimination frequency scope and high cost. It also provide in certain extend theory basis for further design of interfere muffler.The primary work of this paper are :1. Using ND2 Precision sound-level meter to measure noise and obtaining the dB value. Analyzing the frequency spectrum by using noise equipment and software spectrum analysis of the Oriental vibration testing vibration of the institute in order to obtain the noise width and frequency. Based on the mechanism of noise, we can find out primary noise resource.2. According to the research of the current situation of domestic and foreign muffler, combined with the actual conditions of factory, we make a reasonable noise reduction plan and design a new type of muffler. Such muffler not only has good noise elimination quantity, but also with good aerodynamics.3. Compared the noise value and rotate speed change with or without muffler to determine the effect of noise elimination and aerodynamics.4. Using finite element software on muffler conduct modal analysis in order to obtain the 1-10 step Inherent frequencies and modal shapes of muffler. If Inherent frequencies of muffler nearby the peak frequency of noise. It will have resonating in the noise peak place, so, the noise elimination effect would be affected .In order to avoid resonance, the muffler structure should be optimized.5. Designed a experiment model to measure the change of torch for muffler by using strain gauge as sensor...