| Conservation tillage is a new type of sustainable agricultural technology in mechanized agricultural production,which is a farming technology system to protect soil ecological environment and improve ecological,economic and social benefits.As one of the four basic techniques of conservation tillage,subsoiling technology is an effective means to break the bottom layer of soil plough and improve the ability of crop nutrient absorption and soil water storage and moisture conservation.Under the condition of conservation tillage,when the subsoiling machine is used to subsoiling in the corn stubble field,the subsoiling shovel jam and drag pile phenomenon exist,which leads to the decline of subsoiling operation quality,and has certain influence on the development of subsoiling technology and subsoiling machine.Through consulting the research status of subsoiler at home and abroad,using the combination of theoretical analysis and experiment,based on the lateral straw cleaning and anti blocking technology,this paper designed a subsoiler suitable for the soil conditions of conservation tillage,realized the inter row subsoiling operation of corn original stubble field,and improved the subsoiling shovel through performance.The optimum operation parameters and structure parameters of the device and subsoiler are analyzed and optimized.The main research contents are as follows:（1）design of anti-blocking device and selection of subsoiling shovel:The causes of blocking in subsoiling machine operation project are analyzed,the overall design scheme of anti-blocking device is put forward,and its working principle is expounded,the design scheme of the driving system of the anti-blocking device for cleaning Straw is put forward,and the structure design scheme of the cleaning mechanism assembly is put forward by analyzing the influence of various factors on the stubble pitch and uniformity,the general layout of the assembly of the cleaning mechanism is determined,and the conditions that the anti-blocking device of the cleaning device should not be blocked are obtained by analyzing the amount of Straw input and the amount of Straw removed,and the movement track of the discharged material is analyzed,through the analysis of the mechanism of subsoiling soil and the working characteristics of several main subsoiling shovels,the subsoiling shovel used in this research was selected and the overall design scheme of the subsoiling device was put forward.（2）parameter optimization test of anti-blocking device for clearing Straw:the operation process of the anti-blocking device for clearing straw was simulated by using discrete element simulation analysis software,and the anti-blocking device for clearing Straw was determined through single factor simulation test,the optimum parameters of the anti-blocking device are determined by Orthogonal test,which are:600 r·min-1 of the cutter shaft,3.6 km·h-1of the working speed and 1 cm of the cutter teeth off the ground,there was no blockage of subsoiling shovel.The primary and secondary relations of the influence of various factors on the trafficability of subsoiler are as follows:the clearance of Cutter Teeth from the Ground>the Working Speed>the rotation speed of cutter shaft.（3）field performance test:based on the parameter combination obtained from the parameter optimization test of the anti-blocking device,the operation parameter optimization test of the lateral anti-blocking device was carried out,the working performance of subsoiling under the condition of the anti-blocking device with and without the anti-blocking device was compared,and the working performance and working effect of the whole machine were tested,the results are as follows:In the orthogonal test,the primary and secondary effects of each factor on the stability of subsoiling are:subsoiling shovel Type>Working Speed>subsoiling depth;Working Speed>depth of subsoiling;the influence of various factors on soil porosity is as follows:subsoiling shovel Type>subsoiling Depth>working speed.According to the principle of optimization,three parameters were combined and tested.The measured values of the test indexes were in good agreement with the predicted values.At this time,the stability of subsoiling was 94.15%～94.67%,the soil disturbance coefficient was 59.35%～64.07%,and the soil bulkiness was 24.23%～29.92%,all of them are better than the reference index and can meet the operation performance requirements.The results showed that the three indexes of subsoiling stability,Soil Disturbance Coefficient and soil bulkiness under the condition of clear Straw device were better than those under the condition without clear Straw device,and the difference was significant（P<0.05）. |
