Vibration Reduction Research Of Construction Machinery's Cab

As customers pay more and more attention to the comfort of construction equipments, vibration of construction equipments has become increasingly concerned. Vibration shortens the use life of products. Integrated with the project 'Ergonomic Simulation and Application Research of Construction machine's Cab', this paper studies the vibration sources, engine's mounting system, vibration reduction of cab and seat's dynamic comfort in depth, which could close the gap between domestic and foreign products, improve market competitive strength of domestic construction machine companies. This paper provides guiding significance for construction machine companies to develop products with high reliability and performance independently.According to all kind of vibration problems, this paper summarizes many domestic and foreign research literature, and models the dynamics of vibration-reduction system of construction machinery, then finds the design methods of reducing vibration by the combination of theory with practice:Based on the vibration theory of engine, experimentally analyze the quadratic vibration amplitude variation of the engine with increasing speed, and find the main cause of severe vibration. Based on the result of analysis, we find that engine's stiffness and damp parameters match inappropriately and make the mounting system resonating; inappropriate layout of mounting system makes tipping moment huge, the vibration is severe in x direction.Based on decoupling and striking center theory of engine's mounting system, design reasonable layout and locations of engine's mounting system, and choose the engine's absorber with appropriate stiffness and damp, which will reduce the vibration response of engine and frame and improve the reliability of the engine and its attachments. After effective measures, the vibration of the engine is reduced obviously in all directions (especially in x direction), resonance of the engine is avoided by choosing the absorbers with low stiffness and high damp. Based on modal analysis theory, test the modes of the cab, get the natural frequencies and modes of the cab to analyze the local weak area of the cab's structure, and find that the natural frequencies of cab's mounting system should lower than 47 Hz. Contrast three kinds of cab's absorbers by test and find silicone oil shock absorbers have good effect of vibration reduction overall. Due to the property of big damp in low frequencies and small stiffness in high frequencies, ameliorate the cab's vibration response in the progress of running.According to domestic and international criterions about comfort design of cab, quantitative evaluate vibration-reduction effects and dynamic comfort of different bands seats. The test indicate that weighted values of acceleration of three different seats are in the range of discomfort in the progress of running and loading; seat B has good effect of vibration reduction in vertical direction. By using vibration-reduction design of this paper, the test verification shows that the vibration of cab, frame, engine is reduced obviously and reliability and dynamic comfort is improved effectively.