| High breaking rate of sugarcane is one of the main problems to be solved by domestic sugarcane harvesters at present,which seriously affects the yield of sugarcane in the next year.Therefore,this paper takes the small sugarcane harvester logistics frame as the research object to explore how to control the vibration of the logistics frame and reduce the transmission of the vibration of the logistics frame,so as to achieve the goal of reducing the amount of vibration of sugarcane cutting so as to reduce the breaking rate.This paper is mainly divided into the following parts for research:1)The static analysis and modal analysis are carried out on the logistics frame model,the safety performance of the structure is checked by the static analysis,the dynamic performance of the logistics frame is evaluated by the modal analysis,and the modal shapes of each order are analyzed,and verified by the test.The analysis results show that the connection between the rear end of the logistics frame and the beam is the main weak position,the maximum deformation is at the rear end of the logistics frame,and the vibration amplitude reaches 3.619 mm.The vibration peak at 50 Hz reached 5.4m/s2.At medium and high frequencies,the vibration peak and peak group also appeared at 150 Hz,320Hz and 400 Hz,respectively.The reason for the increase in the amplitude of the tool rest was found.The structure of logistics frame is optimized and analyzed.Four reinforcement bars are added in the weak position of the rear part of logistics frame to improve the stiffness of logistics frame.The overall deformation is controlled,reduced to 1.457 mm,reduced to 59.7%.The third mode is raised from 50 Hz to 74 Hz,avoiding the second order of excitation frequency of 25 Hz,which achieves better optimization effect.2)Vibration isolation control of logistics shelf is carried out.According to the connection characteristics of each system component of the prototype model and based on the theory of vibration control method,the vibration isolation mechanism is designed.Considering the factors of vibration isolation material,connection mode,stiffness and damping of the vibration isolator,the vibration isolation mechanism is designed to achieve the ultimate purpose of vibration isolation and meet the need of cutting tool holder up and down.The vibration transmission path of the vibration isolation mechanism was simulated.Taking the tool holder as the response point,the displacement response of the tool holder before and after vibration isolation was reduced from 0.735 mm to 0.395 mm,which decreased by 46%.This shows that the vibration isolation mechanism has a good vibration isolation effect on the sugarcane harvester.3)The vibration isolation mechanism was tested,and the vibration isolation mechanism was evaluated by the vibration isolation evaluation index.According to the design drawings of vibration isolation mechanism,it was processed and installed on the sugarcane harvester.The road excitation and engine excitation were simulated on the experimental platform,and the factors of different rubber layers were compared.Finally,the optimum scheme was determined as adding a layer of rubber,the thickness of rubber was 10 mm,the vibration reduction before and after vibration isolation was 4.62m/s2,59.3% and the vibration isolation rate was 7.81 d.B,which accords with the evaluation index of vibration isolation;the vibration isolation system is tested and analyzed by multi-factor orthogonal test.The results show that the RMS value of the tool holder is reduced from 6.98m/s2 to 3.04m/s2,which is 56.4%.The amplitude of Z direction is reduced from 0.9mm to 0.33 mm,which is 63.3%.The test results show that the vibration amplitude of Z direction has been reduced to different degrees.The attenuation further verifies that the vibration isolation mechanism has an effective vibration isolation effect on the small sugarcane harvester. |
