Research Of Ridge Decompression System Of Potato Combine Harvester

With the continuous improvement of domestic potato harvesting mechanization level,on the basis of drawing lessons from advanced technology at home and abroad,combined with the actual situation of potato harvesting terrain difference in China,we designed and manufactured a copying excavation structure-rocking structure which can adapt to various harvesting terrain.According to the problem that the digging device of potato combine harvester can not adjust the pressure on the ridge at present,the design scheme of the ridge decompression system is put forward.The physical and mechanical characteristics of potato whole stem,the distribution of potato tuber growth and soil physical and mechanical characteristics were studied to provide theoretical basis for system design.The main research contents and conclusions are as follows:(1)Define the range of pressure regulation on potato ridge,carry out the whole stem compression test on Potato in laboratory,and analyze its biomechanical characteristics,obtain the minimum pressure value of 3689.4N which can damage potato in soil under positive pressure;secondly,analyze the breaking process of potato ridge,carry out field measurement and static pressure test,respectively,to obtain the actual harvest time.The soil hardness and the area of action when the ridge of potato was broken were calculated,and the critical pressure value was 3453 N.Comparing the two pressure values,the minimum value is used as the upper limit of the ridge pressure.(2)Considering the influence of various factors on the pressure on the ridge,the stress analysis of the excavating shovel and the profile crushing roller is carried out,and the mechanical model of the excavating shovel is established through mechanical analysis and formula deduction.Formula calculator is compiled by using LabVIEW program development software,and the pressure on ridge can be calculated rapidly under given parameters.Through the analysis of the calculated data,the following conclusions are drawn: with the increase of excavation depth,the pressure on the ridge will increase linearly and positively;with the increase of the inclination angle of the shovel,the pressure on the ridge will decrease in a non-linear negative correlation trend;with the increase of harvesting speed,the pressure on the ridge will increase in a non-linear positive correlation trend.According to the parameters obtained from harvesting experience,the additional stress of excavation shovel on the ridge is calculated to be 744 N,which provides theoretical basis and data support for the optimization and upgrading of the pressure relief system on the ridge.(3)According to the test data obtained from the preliminary test,the system is designed,and the designed ridge decompression system is installed on the swing excavation device to verify the experiment.The results are as follows: the ridge decompression system can achieve the purpose of decompression,maintain the stability of the oil pressure in the system to a certain extent,and change the spirit of the decompression system by setting different pressure thresholds.Sensitivity,the smaller the pressure range,the higher the sensitivity of the system,the more frequent the operation of controlling the hydraulic oil in and out of the system.The set pressure range is between 1000 N and 12000 N.(4)The validated ridge decompression system was installed on 4ULZ-170 potato combine harvester and field test was carried out.The pressure range of the system was set between 4MPa and 5.5MPa,and the harvest condition was good.The rationality of the system design was verified.The system was optimized and improved by analyzing the test data.The designed ridge decompression system improves the flexibility and accuracy of potato combine harvester digging device,improves the potato harvesting efficiency,solves the problem of decompression existing in potato harvesting digging device at the present stage,and is of great significance for reducing power consumption,reducing the damage rate of potatoes and enhancing the effect of potato soil separation in the later stage.