| Pickup combine is an important machine for peanut harvesting,which has good adaptability to different soil and different planting patterns.Based on the characteristics of vertical type peanut in China,designed large width pickup header for picking combine,and in view of the problem of missed picking,fruit drop in pickup harvesting technology,carried out experiment study and mechanism optimization for combine’s header.The main research contents are as follows:(1)According to the main parameters of China’s vertical type peanut varieties,Tianfu No.9 and TaihuaNo.3 two varieties of peanut were analyzed in the periodof harvesting.Meanwhile,access to relevant information,the statistics of the 149 kinds of peanut pods formwas provided for the design of key components ofcombine header.Water content and tensile force of the peanut harvest experiment showed the optimal harvest time in the interval which is 4~6 days,moisturecontent about 20%.(2)The basic structure of pickup header is determined,which includes pickup device,conveying auger,supporting and transferring device,header rack and transmission system.Pickup device is mainly composed ofpickupspring-finger,rotating shaft,shaft head,according to the characteristics of peanut shape,determine the basic parameters of the pickup device,and through the kinematics simulation analysis,obtained the conclusion:the six row of spring-finger.The design of the conveying auger is symmetrically arranged,which mainly includes the auger head,the cylinder body and the spiral blade.Through the kinematic analysis,the formula was obtained:α<π/2-θ_f,for the spiral angle.Support transfer device includes pressing device,grass sliding board,auger plate;pressing device and grass sliding board were designed according tothe pickup device parameter;auger plate is formed by two parts,the two plates are provided with oblique long hole for soil leakage;pickup rack is mainly composed of right frame,the left frame and,middle connecting rod,connecting structure.Transmission system is composed of a chain drive system independently,power by the system was first arrived at the auger,thenpower to the gearbox driving pickup device.(3)To pickup rate and drop rate as test indexes,a single factor experiment was carried out:the results show that the height of pickup spring-finger tip from ground,pickup spring-finger tip length,peanut seedling laying form has no obvious influence on the rate of picking up;pickupspring-finger tip height and pickup spring-finger tip length,tip angle of spring-fingerof pickup tooth tip of drop rate has no significant influence.On the selected level,index values are ideal.Meanwhile,the forward speed of the machine and a pickup device rotary speed was significant,using SPSS obtained curve regression.(4)Based on the single factor experiment,the forward speed of the machine,rotary speed,tip angle of spring-finger as the influence factors,to pickup rate and drop rate as the study index,using the theory of Box-Benhnken,carriedout experimental research.The mathematical model of the response surface is established,so the influence of each influencing factor on the quality of the operation is analyzed,and the relevant parameters are optimized.The results showed that trial factors had great effects on the working quality.The significant effects of rotary speed of spring-finger,forward speed of machine and tip angle of spring-finger on increasing pickup rate were in a decreasing order.The significant effects of forward machine speed,rotary speed of spring-finger and tip angle of spring-finger on reduce the rate of peanut pods drop were in a decreasing order.The optimal parameter combination was obtained,which was 0.8m/s as the forward speed of machine,5.0rad/s as rotary speed of spring-finger,165~oas tip angle of spring-finger,with this optimal parameter combination,the pickup rate was 99.36%,the rate of peanut pods drop the rate of peanut pods drop was 0.58%... |
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