| Rape is an important oil crop,China is the largest consumer of rapeseed oil and the largest producer,Rapeseed oil is widely used in the fields of food,chemical industry,new energy and so on.In recent years,the planting area of rapeseed has declined in China,In order to improve the production efficiency,the study of mechanized harvest of rape is of great significance.At present,the harvest of rape mainly includes three kinds of methods:combined harvest,segmented harvest and artificial harvest,of which combined harvest is the development direction of rapeseed mechanized harvest.The rape stem has strong stem,high moisture content,many branches and intertwined.The height of pods is different.When the grain is impacted,it will easily fall off and cause losses.The special biological characteristics of rapeseed increase the difficulty of combined harvest.The loss rate of the harvester was high,and stalks easily blocked the threshing cylinder,the impurity content after cleaning was high while harvester harvesting rapeseed.The characteristics of stripping harvest of rapeseed is the use of strpping rotor to strip pods,compared with the traditional full feeding harvest,the stem does not enter the threshing cylinder and cleaning system,thereby reducing the harvester threshing and sorting system of material containing irmpurity rate,and improving efficiency of harvesting machine.A kind of experimental device for stripping rape pods is designed in this paper.The device is mainly composed of stripping rotor,reel and feeding device.The paper focuses on the analysis of the working mechanism of the device,the structure designing and the experiment.The main contents of the paper include:(1)In order to improve the adaptability of the stripping device to rape,the geometric parameters of rape plant were measured,including plant height,branch number of main stem,average branching radius,branching height,diameter of main stem stalk and planting density.Then the working process of combined stripping harvester and the working principle of stripping rotor cooperating with other components in the harvester were introduced.The paper has analyzed the relationship between the strcture parameters of stripping device and the speed of main stalks and stripping conditions.(2)About the structural designing of the stripping rotor,on the basis of the mechanism of inverted cam pendulum mechanism,the overall structure of the cam slide track stripping rotor is proposed and designed,which is mainly composed of the stripping fingers and the cam slide track mechanism.According to the geometric parameters of rape plant,such as the average height,the diameter of the stem and the average extension radius,the length of the stripping finger is designed as 175mm,and the height of the rotor is designed as 590mm.The arrangement of the stripping fingers is the uniform arrangement of the single stripping finger holder and the interlaced arrangement of the adjacent finger holder to increase the cover area of the cole with the stripping finger.The structural parameters of the stripping rotor are determined.(3)The mathematical model of the roller motion path of the cam slide track is set up,and the curve equation of the cam slide track with the swing angle of the dial as the dependent variable is obtained.Combined with the acceleration and swing posture needed for different positions in the stripping rotor,the movement of finger removal is divided into three working segments:stripping section,suction section and buffer swing section.'By setting the swing angle of the fingers in the critical position of each working section,the corresponding cam slide track curve equation is determined,and the graph of cam slide track curve is obtained by using the Solidworks equation driven curve tool.At the same time,the method of drawing the cam profile by setting the swinging gesture of the finger to set off the finger is summed up.(4)The design of the reel for the stripping device.Considering the problem of rape tilting towards the cutting head under the action of the stripping rotor,the structural parameters of the reel,the relative position and the motion parameters of the stripping rotor are analyzed and designed.The relationship between the speed ratio of the reel and the conveying capacity of the plants is introduced.The condition that the transfer time of the dialing pulley is greater than that of the stripping rotor is analyzed.The design of the radius of the reel is 350 mm and the speed is 30 r/min.The influence of the position of the reel and the rotor on the rapeseed stripping was analyzed.The axis height of the dial wheel was 1250mm,the axis of the stripping rotor is 750mm,the supporting end of the stem was 350mm high,and the horizontal wheelbase of the stripping rotor and the reel wheel was 400mm.A rapeseed carrying device was designed for the stripping device bedstand.(5)The simulation analysis of the cam slide track stripping rotor stripping process is carried out,and the mechanism simulation model is established.The angular velocity curve of the stripping finger in each working section is obtained.The finite element analysis is carried out on the finger of the rotor,as well as the distribution diagram of the stress,displacement and strain of the dial finger is obtained.(6)An experiment on the stripping performance of the cam slide track stripping device was carried out,which is a contrastive between cam an round slide track.The experimental results show that when the feeding speed is 0.6m/s and the drum speed is 260r/min,the weighted average of stripping performance of cam slide track rotor reaches the peak value of 44.0%,which is 10.7%higer than round track rotor.The experiment proved the improvement of cam slide track rotor.(7)The single factor and orthogonal test of the loss rate of the cam slide track stripping device are carried out.The relation curves of the rotational speed of the stripping rotor is abtained,that is influenced by the feeding speed,the stripping rotor and the horizontal wheelbase of the reel and the loss rate of the cutting platform are obtained.The best working parameters of the stripping device are 260 r/min of the stripping rotor speed,0.6 m/s of feed speed and 400 mm of the horizontal wheelbase of the stripping rotor and the reel.The field test of rapeseed harvester was carried out,and the collection rate of the pods and the distribution of dropping point distribution were tested. |
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