Research On Structure Optimal Design Of Vibration Snow Shovel

As we all know, the winter in the northern area always lasts for a long time with lowtemperature and heavy snow. If the accumulated snow can not be cleared away in time, itwould become compacted mixture snow and ice after being rolled by vehiclesand pedestrians.What is worse, highways and urban roads with snow and ice bring a lotadverse effects to people’s daily life and road traffic. Clearing the compacted mixture ofsnow and ice on the road quickly and efficiently or not, had been a subject of science andtechnology to solve. Therefore, a kind of snow-removal machine that could clear bothfloating snow and compressed snow would be adapt to the demands of modern society.Thispaper focused on the structural performance of vibration snow shovel to start an in-depthstudy, with vibration snow shovel and shovel blade vibration system for the study.Combining with its working conditions, the classical theory calculation method, thedynamic simulation analysis, the coupled analysis method, fatigue simulation analysismethod and other methods were used to do analysis to draw relevant characteristics ofvibration snow shovels.The main contents were as follows:1.The first part described three snow removal methods of different mechanisms.Based on the three mechanisms, technology development and characteristics of snowremoval structure at home and abroad were introduced. The significance of the researchwas analyzed and the methods of analysis were given in this paper.2.Related properties and fracture mechanism of the operation object on compactedsnow were analyzed, in particular the ice shear strength and compressive strength, and theice shear strength was chosen as the analysis basis through comparative analysis in theactual ambient temperature. Because the principle of vibration snow shovel in this paperwas vibration shock to clear the compacted snow, the principle of forced vibration wasdescribed and analyzed. A physical model of the mechanism was established to providetheoretical basis for later design of the returning spring. According to the actual force ofthe snow shovel, the theoretical force analysis was carried out, and the force of a singleshovel blade to break the ice was5562N. The calculated force would provide the basis forthe next simulation and design.3.In view of the relevant literature and vibration snow shovel structural arrangement,the beginning amplitude was approximately4mm for its intended benefits. Based on theamplitude of4mm below the first analysis, the frequency matching was selected.Dynamicsimulation analysis of vibration snow shovel was carried out, and the simulation condition was the constant vibration amplitude4mm with vibration frequency in the range of5Hz～16Hz.Then ice-breaking force obtained by simulation was compared with the previouslycalculated theoretical force. The other simulation condition was the constant vibrationfrequency of10Hz with vibration amplitude in the range of1mm~6mm.The most validmatch amplitude4mm and frequency10Hz were obtained by those force comparision.4.Based on the effective matching of frequency and amplitude from the abovesimulation of the system, and according to the actual working conditions of snow shovels,the returning spring of snow shovels was designed and verified by simulation in AMESim.The spring stiffness in actual theory design was45.8N/mm, while the spring stiffness inhydraulic simulation was43N/mm. And both were consistent to be able to meet therequirements. At the same time, the original hydraulic pump was optimized. When thesnow shovel worked under vibration frequency of10Hz combined with the amplitude of4mm, the motor displacement of hydraulic system must be choosed28ml/r.5.Due to the snow shovel was in a reciprocating motion under a certain frequency andthe blade contacting with the ice back and forth, the maximum stress of the shovel bodywas at the connecting bolts through the analysis of the connecting bolts. Based on thelinear fatigue cumulative damage theory and according to the revised as law estimatetheory of blade connection bolt life, it was concluded that the theory of fatigue life was7.3months. And based on the fatigue simulation software using the dynamic load file fromrigid-flexible coupled simulation, nSoft was used to calculate the fatigue life of6.8months.The two values were basically similar.