Vibration And Noise Analysis And Improvement Of Variable Cutting Mower

With the development of society and the improvement of people’s living standards,environmental greening had been paid more and more attention by people,and lawn mowers had become a common greening tool in life.However,the vibration and noise generated by the lawn mower greatly affects people’s living environment and physical health.Therefore,In this paper,the Wei Bang variable cutting mower was taken as the research object,and the vibration and noise of the mower were analyzed and improved.First of all,the reason for the vibration noise generated by the lawn mower were analyzed.The relationship between the vibration and noise of the mower and the structure and working principle of the mower were expounded.The model of the mowing mechanism and the belt drive system model were established.The vibration analysis was carried out,and the mower cutter shell was analyzed.Vibration noise generated under these excitations.Secondly,the local vibration test analysis of the lawn mower was carried out.The local vibration test was carried out on the handle when the maximum speed of the mower was 2800 r/min and the load status was no load and load.According to the test results,the reason why the vibration acceleration of the handle was large when the lawn mower was empty was analyzed.Using the maximum test point of the load acceleration,the cumulative time of the daily vibration exposure of the vibrating white finger of the exposed person was calculated to be 7.6 years,and the influence of the mower vibration on the human body was analyzed.Then,the mower was subjected to noise test analysis.The mower was tested for noise when the maximum speed of the mower was 2800 r/min and the load status was no load and load.The test results show that the noise of the mower at no load and load was 91.5 dB and 88 dB,respectively,and the reason why the lawn mower was noisy when it was no load was analyzed.The surface vibration method was used to identify the main noise source of the lawn mower as the secondary cutter-head,followed by the main cutter-head,and verified the accuracy of the surface vibration method.Finally,the measures of vibration and noise reduction of the lawn mower were proposed.The noise control measures of the variable cutting mower were proposed from three aspects: sound source,propagation route and receiver.The vibration speed of the mower and the main cutter was analyzed.According to the analysis results,the sub-cutter was added.The ribs,the main cutter-head added the skirt structure and the vibration isolation using the rubber gasket,and the modal analysis was verified by the improved scheme.Under the load condition of the lawn mower,the vibration and noise test of the improved cutter-head structure was carried out.The test results show that the radiated noise of the modified sub-cutter was reduced by 4.3 dB,the radiated noise of the main cutter was reduced by 3.8 dB,and the noise of the lawn mower was reduced by 5.8 dB(6.5%),the analysis shows that the improved scheme had a certain effect of vibration reduction and noise reduction.