Design And Tests Of Winter Protection Soil Cleaning Machine With Auto-adjustable Double-scraper For Wine Grape

The geographical environment of Ningxia and Northern Xinjiang is the main production areas of wine grape in China.It is a typical cold and dry area with high wind and low temperature in winter.In order to prevent the drying and frostbite of grape vines,measures for safe wintering protection of burying vines with soil in winter and putting them on fresh soil in spring are widely adopted.At present,the operation of spring clear soil and vine is still mainly manual with low degree of mechanization,which makes the production of wine grape in Northwest China more difficult and the production cost increased.At present,some of the single-scraper type clear-soil ratchets on trial are designed and improved based on the practical experience of farmers or tractor operators,lacking of systematic theoretical calculation process and research on interaction mechanism between particle groups of cold-resistant soil and scraper components,which leads to the scraper backed up seriously,the low soil cleaning rate,low efficiency and poor adaptability.In order to solve these problems,the interaction mechanism between particle groups and scrapers in cold soil is studied in this paper,and the key parameters required for the research are calibrated,including recovery coefficient,static friction coefficient and rolling friction coefficient of soil-soil and soil-machine.The auto-adjustable double-scraper soil cleaning machine with high working efficiency and high soil cleaning rate is developed,which can meet the current agricultural requirements of clean soil.The main contents of this paper are as follows:Firstly,calibration of simulation parameters of wine grape cold soil by discrete element method.The ridge size,row spacing and grape vine buried area in cold-resistant soil of vineyard in planting area are measured;intrinsic parameters of soil particles in different ridge layers are determined,including particle size,water content,density,internal friction angle,cohesion,accumulation angle,Poisson ratio and shear modulus.Gradually determine the value of the significant influence factors by Plackett-Burman test method,steepest climbing test method and Box-Behnken response surface analysis method,combining stacking angle test and direct shear test.The general regression equation of the three-layer ridge model was obtained through the combined simulation test of two-factor universal rotating center,and the elastic recovery coefficient,static friction coefficient and rolling friction coefficient between soil particles and scraper are obtained.Based on the obtained simulation parameters,a three-layer ridge model was established in EDEM.Secondary,overall design of automatic adjustable double scraper soil cleaner for grape brewing.According to the existing research experience of wine grape scavenging ratchet,the design requirements and technical requirements of automatic adjustable double scraper scavenging ratchet are put forward.The designed automatic adjustable double scraper scavenging ratchet for wine grape is mainly composed of frame,double scraper parts,large scraper lateral expansion device,small scraper intelligent expansion device,side disturbance device and contact alarm device.The control system mainly includes small scraper intelligent telescopic system,injury prevention rattan alarm system and real-time monitoring system.Then,design of automation auxiliary function.The requirements of each system of the whole machine are put forward.The smart scraper expansion system,contact alarm system and video monitoring system are carried out.Next,EDEM simulation analysis of mechanical-soil interaction of clean-soil rattan machine.Based on the EDEM discrete element simulation,the soil-mechanical interaction between the designed scrapers with different surface forms,cutting angles and inclination angles is simulated and analyzed.The best working parameters of the scraper are obtained by the orthogonal test method.It is determined that the backlog of the scraper is the minimum when the scraper surface is parabolic,the cutting angle is 55° and the inclination angle is 60°.EDEM-ANSYS Workbench coupling method is used to check and analyze the strength and rigidity of the whole machine structure.Finally,test on influence factors of backfill of scraper and cleaning rate of prototype.Bench tests are carried out on scrapers with different surface forms,cutting angles and inclination angles to verify the correctness of simulation results.Orthogonal tests and single factor tests are carried out to observe the influence of different scraper parameters on backup volume by combining the records of actual tests with high-speed camera.The results show that the backup volume of scrapers is small when parabolic shape,55° cutting angle and 60° inclination angle.A grape brewing automatic adjustable double-scraper soil cleaner prototype is trial-manufactured and compared with the traditional single-scraper soil cleaner.The test results show that the soil cleaning rate of the automatic adjustable double-scraper soil cleaner is 75.03%,which is 27.2%higher than that of the traditional single-scraper soil cleaner.