Design And Experiment On Key Components Of The Intermediate Conveying Device Of Oil Sunflower Combine Harvester

Oil sunflower is one of the four major oil crops in China,second only to soybean,rape and peanut.Oil sunflower is an excellent economic crop,widely used in food,chemical industry,agriculture,animal husbandry and other fields.Therefore,the market potential of oil sunflower is extremely broad,and its long industrial chain and subsequent processing can effectively promote economic development.However,since 2016,the planting area and output of sunflower in China have been decreasing year by year,mainly due to the low level of sunflower mechanization in China and the fact that sunflower harvest is mainly artificial,which leads to high labor intensity,more labor and high production cost.Therefore,it is very important for the rapid development of sunflower industry to accelerate the research and development of sunflower combine harvester and improve the mechanized production level of sunflower.It is quite different from other crops such as rice and wheat that the oil sunflower plant is cut off with a stout stalk and a large sunflower dish during the harvest of the oil sunflower.Therefore,the structure form and parameters of the existing auger and chain rake conveying device of the rice and wheat combine harvester are not able to complete the material conveying of oil sunflower well,and there are problems such as reentry and blockage.On the basis of summarizing and analyzing the current research situation of augers and chain rake conveyors at home and abroad,this subject used a combination of theoretical analysis,simulation analysis and bench test to analyze and improve the key structures,and the structural parameters and motion parameters of the key components of the conveyor were determined.At the same time,the study provided a reference for the design of the auger and chain rake conveyor of the oil sunflower combine harvester.And the main research content of this paper is:(1)In order to improve the adaptability of the auger and chain rake conveying device to the oil sunflower,the main geometric and physical parameters of the oil sunflower were measured,including the thickness of the sunflower dish,the diameter of the sunflower dish,the diameter of the stem,the length of the cut stem,the water content of the stem and the water content of the seeds.(2)A test was carried out to measure the angle of friction between the oil sunflower plant and the spiral blade of the dragon.The friction angle between the oil sunflower plant and the dragon blade was 26.5 °.Two schemes to solve the problem of unsmooth conveying were put forward and the scheme of adopting a smooth transition method between the auger and chain rake conveyor was determined by comprehensive analysis.The minimum feeding capacity of auger and chain rake conveyor was determined to be 15 plants/second.(3)Improvement of key components of auger and chain rake conveyor.The auger dial,transition area between auger and chain rake conveyor and chain rake conveyor scraper were improved,and the structure parameter range was determined by analysis.The fixed vertical auger dial was improved to the fixed auger dial with dip angle,and the tilting angle of the auger dial was determined to be less than 19.22° through the pull out analysis of the oil sunflower.The installation position of driven shaft of chain rake conveyor was determined as(294.8,191.5)by the stress analysis of oil sunflower in the transition area.The trajectory analysis of the oil sunflower in the transition area determines that the smooth transition between the header auger and the chain rake conveyor is beneficial to the oil sunflower transportation.The tooth shape of the scraper was cancelled and the height range of the scraper was determined to be 25-50 mm by analyzing the thickness of the sunflower plate.(4)Analysis of structural parameters and motion parameters of key components of auger and chain rake conveyor.The spiral angle of the auger blade was determined to be 32.48 ° through the analysis of the movement of oil sunflower;the distance between the scrapers of the chain rake conveyor was determined to be 228.6mm through the analysis of the diameter of the sunflower disk;and it is determined that the ratio of driving shaft speed and auger speed of chain rake conveyor should be greater than 1.52 by analyzing the throughput of auger and chain rake conveyor.(5)Simulation analysis.The 3D model of the experimental bench of the oil sunflower combined harvester cutter and chain rake conveyor was created by Creo Parametric software.ANSYS Workbench was used for static analysis of auger dials,and the stress distribution,strain distribution and total deformation of auger dials were obtained.The stress and deformation of the auger dial during operation indicated that the auger dial made of Q235 material and with inclined angle structure can withstand greater dialing resistance without permanent deformation.(6)The single-factor test research and analysis of the auger and chain harrow conveyor.A single factor test was carried out on five factors,namely,auger speed,auger dial dip angle,auger bottom dip angle,scraper height and conveying clearance,with the oil sunflower conveying rate and grain shedding rate as the experimental indexes.And obtained the change rule of the conveying rate and the grain shedding rate affected by different factors.According to the analysis,the closer the angle of the auger bottom plate is to the angle of the chain rake conveyor,the higher the oil sunflower conveying rate and the lower the seed dropping rate is.And the optimal level of scraper height is 50 mm,the optimal level of conveying gap is 25 mm.According to the analysis,the rotation speed range of the auger is 150?190r/min,the inclination angle of the auger dial is 8?16°,and the conveyor trough dip angle is 20?30°in the follow-up orthogonal test.(7)Orthogonal test of auger and chain rake conveyor.The three factors and three levels orthogonal test were carried out by selecting the auger speed,auger dial dip angle,and the conveyor trough dip angle.The results of variance analysis showed that the conveyor trough dip angle had a very significant effect on the conveying rate and significant effect on the grain shedding rate and the auger speed had a significant effect on the conveying rate.The range analysis showed that the primary and secondary order of factors affecting the conveying rate were the conveyor trough dip angle,auger speed and auger dial dip angle,and the primary and secondary order of factors affecting the grain shedding rate were the conveyor trough dip angle,auger dial dip angle and auger speed.Through comprehensive analysis,the better parameter combination was that the conveyor trough dip angle was 25 °,the auger speed was 170 r/min and the angle dial dip angle was 12 °.And at this time,we had the best effect that the transmission rate was up to 100% and the grain shedding rate was less than 0.6%.The conveying process is stable and reliable,without clogging problems,and fully meets the requirements of the oil sunflower combine harvester.