Research On Cab Noise Control Of Hydraulic Excavator

With rapid development of the construction machinery industry and people’s awareness of environmental protection, requirements for engineering machinery noise and vibration control become more and more stringent. Engineering machinery cab noise has a great influence on the physical and mental health of the operators, and also reduces work efficiency. So the cab noise control becomes an important aspect of engineering machinery noise control domains. In order to guide noise control effectively, enhance the overall level of the product and improve international competitiveness of our country’s engineering machinery products, research on cab noise control is of great practical significance.This paper conducts a research on the cab noise control based on a practical engineering application background of Hydraulic excavator cab vibration and noise reduction program. The main research contents of the cab noise control involve cab ear noise characteristics analysis, cab body structure sound insulation properties research, evaluating the role of sound insulation measures in noise control, engine vibration isolation improvement and structural vibration characteristics optimization. In this paper, cab noise control is structure-borne noise and airborne noise control-oriented.By using the method of spectrum analysis and one-third octave analysis, cab ear noise characteristics is analyzed clearly. And contribution of each octave noise to the overall octave sound pressure level is obtained. Then the main noise control frequency range is determined. At the same time, the paper conducts analysis of cab structure sound insulation characteristics and the role of sound insulation measures in noise control.The paper evaluates the engine damping characteristics of shock absorber by employing vibration transmission rate in Time-frequency domain, and then puts forward improvement program. By optimizing the engine vibration isolation and reducing vibration transmission, structure-borne sound which is an ingredient of the cab noise reduces to a certain degree, so cab noise is controlled.The vibration characteristics of structure play great roles in the structure-borne noise propagation control. The paper analyzes the vibration characteristics of the main structural component-upper frame by modal analysis method, the weak link of the upper frame is obtained, and then improvement measures are proposed. By optimizing the vibration characteristics of machine, noise and vibration characteristics of the cab body structure is improved and optimized, and cab noise values reduced.