农业工程学报2017，Vol.33Issue(9)：53-60,8.DOI:10.11975/j.issn.1002-6819.2017.09.007
4SY-2.9型油菜割晒机机架振动分析及改进
Vibration analysis and improvement for frame of 4SY-2.9 typed rape windrower
摘要
Abstract
In China, the rape harvesting mechanization level is low and traditional manual harvesting is so poor, so it is necessary to develop rape windrower to improve productivity and reduce cost. The pros and cons of the frame design play an important role on the comfort and working reliability of the windrower machine manipulation. The frame of 4SY-2.9 typed rape windrower is the base and bears the load of whole assembly, and during the rape windrower working, the exciting vibrations from cutter and the conveyor belt spring tooth will cause the rape windrower to vibrate. Because those excitation frequencies were closed to or overlapped the natural frequencies of the rape windrower, the frame of 4SY-2.9 typed rape windrower will produce resonance seriously. To improve the quality of laying, reducing the vibration amplitude of the frame of rape windrower is a feasible way, and the finite element method will solve this problem by using structural modal analysis to get the dynamic characteristics of the frame structure. In order to solve the problem of the large amplitude of the rack caused by the random exciting force produced by the movement of various parts of the machine, in this paper, we modeled the rack and imported the model in ANSYS Workbench to work out the frequency and vibration mode of the rack under the free modal, and we verified the accuracy of the finite element model through the contrast of the modal test and the simulation analysis results. It was found that the relative error between the 2 results was in a reasonable range, so the rationality of frame modal analysis was verified. Based on the analysis of the characteristics of the external excitation frequency of the frame and the simulation results, the design scheme was put forward, which was increasing the frame arch structure, and the simulation experiment on the pipe thickness and installation position of arch was carried out. The optimized rack's first-order modal frequency was adjusted to 15.339 Hz, so that it avoided the excitation frequency of the conveyor belt spring tooth and the cutter effectively which could cause the frame resonance. Through the finite element statistics analysis on the optimized model of the frame, the result showed that the strength of the frame met the requirements. Windrower on no-load condition collected acceleration time-domain signal of the biggest deformation point of longitudinal beam, and obtained the fast fourier transform power spectral analysis diagram under the condition with and without the installation of the arch. The test results showed that the amplitude alongX direction at the largest peak point of test point decreased by 71.47%, the amplitude alongY direction was reduced by 70.60%, and the amplitude alongZ direction was reduced by 70.21%. Field experiments showed that 4SY-2.9 typed rape windrower had a good operation performance with a good throughput capacity and a high work efficiency, and achieved an orderly intermediate strip paving. The paving width met the requirement of the working width of the collecting sheller. After cut down and dried, the average paving width of rapeseed stalks was 1674 mm, the average stubble height of rapeseed stalks was 330 mm, and the average stack height of rapeseed stalks was 603 mm. The optimized rape windrower frame had a good dynamic performance, and the field operation effect could meet the requirement of the actual production. This research may provide references for the design and improvement of the similar broad frames.关键词
有限元方法/振动/优化/试验/油菜割晒机/机架/模态分析Key words
finite element method/vibrations/optimization/testing/rape windrower/frame/modal analysis分类
农业科技引用本文复制引用
蒋亚军,廖宜涛,秦川,关卓怀,廖庆喜..4SY-2.9型油菜割晒机机架振动分析及改进[J].农业工程学报,2017,33(9):53-60,8.基金项目
农业部科研杰出人才及创新团队(145)湖北省技术创新专项重大项目(2016ABA094) （145）
