Design And Development Of A Scraping-Rotating-Brushing Type Of Dehilling Machine

Dehilling machine is a grape field management machine matching with hilling machine,used to clear the cold-proof soil buried by hilling machine.Based on the effective work width and rigid structure of the scraper in the traditional single scraper type of dehilling machine,leading to low soil removal rate and easy to damage grape vine,for according to the agronomic paramaters of clearing soil on grape vine in Ningxia,developed a scraping-rotating-brushing type of dehilling machine.This machine adopted the way of clearing soil in sequece by scraper,rotary blade and brush,increased soil removal rate without increasing the damage,and had certain promoting effect of improving the mechanization level of clearing soil on grape vine.Specific research contents include:(1)The agronomic paramaters of clearing soil on grape vine in Ningxia were determined.Through field investigation,the soil conditions of major grape producing areas in Ningxia were analyzed,the wine grape planting base of Yuquanying farm was selected as the research site to carry out field performance test of physical prototype,and the soil of this producing area was determined as sandy load(wind-sand soil type).By field measurement and statistical analysis,the structural parameters of single hedge frame and ridge parameters of soil buried on grape vine in Yuquanying farm were obtained,which provided the basis for the structural design of prototype and establishment of discrete element model.(2)The overall structure of the scraping-rotating-brushing type of dehilling machine was designed and its key parameters were analyzed and determined.According to the agronomic paramaters of clearing soil on grape vine in Ningxia,a scraping-rotating-brushing type of dehilling machine with scraper,rotary blade and brush was designed.Combination of movement and force analysis,the main factors influencing the power consumption of the prototype and the soil removal rate were bulldozing angle,cutting angle and turning angle of scraper,rotation speed,radius and blade number of rotary balde,rotation speed,radius and brush number of brush,which provided the basis for detemining the factors and indexes of simulation experiment of optimizing prototype parameters.(3)Based on discrete element method and EDEM,the simulation experiment of prototype parameters optimization was carried out.EDEM 2021.2 software was used to establish the discrete element model of ridge and prototype.Taking horizontal forward resistance,torque and soil removal rate as test indexes,combined with single factor test,orthogonal test and quadratic center combination test methods,the optimal combination parameters of scraper were obtained.In the scraper,bulldozing angle was 44°,cutting angle was 40° and turning angle was 75°,which generated that the horizontal forward resistance was 1415.58N and the soil removal rate was 44.75%.In the rotary balde,rotation speed was 500r/min,radius was 300mm and blade number was 6,which generated that the torque was 172.69Nm and the soil removal rate was 69.68%.In the brush,rotation speed was 550r/min,radius was 250mm and brush number was 7,which generated that the torque was 113.6Nm and the soil removal rate was 88.7%.(4)Field performance tests of the prototype were carried out.Reference on the national standard of agricultural machinery field trials and local and group standards of the contact type dehilling machine,selection of the number of broken vines,the damage points in unit length,the soil removal rate and the stability coefficient of clearing soil as the performance evaluation indexes of prototype,carried out the field performance tests of the traditional single scraper type of dehilling machine,the sraping-rotating type of dehilling machine and scraping-rotating-brushing type of dehilling machine.According to measurement and calculation,the number of broken vines and the damage points in unit length were 0.In the traditional single scraper type of dehilling machine,the soil removal rate was 44.21%and the stability coefficient of clearing soil was 91.27%.In the sraping-rotating type of dehilling machine,the soil removal rate was 71.4%and the stability coefficient of clearing soil was 98.87%.In the scrapingrotating-brushing type of dehilling machine,the soil removal rate was 88.66%and the stability coefficient of clearing soil was 99.23%.The experimental results showed that the performance indexes of the srapingrotating type of dehilling machine and the scraping-rotating-brushing type of dehilling machine were adequate.Compared with the traditional single scraper type of dehilling machine,its soil removal rate was increased by 61.5%and 1.01 times.And the difference between the actual value and simulated value of soil removal rate was 2.47%and 0.05%,which verified that the development of the prototype was effective and the simulation model was reliable.