Study On The Optimization For Header Parameters Of Rape Combine Harvester

Rape is one of the major oil crops in China.It has a wide area for planting and the yield is highest in the world.Rapeseed,as the main vegetable oil raw material,is rich in oleic acid and has high nutritional value.With the increase of per ca pita intake of vegetable fats,rapeseed production has become more important.But it is difficult to mechanize harvesting because the growth status and characteristics of oilseed rape.The rapeseed plants are tall,the stalks are thick and tough,and the b ranches are densely cross-connected which makes it difficult to divide each other.The most important is its fruit can easily burst and shatter.The machine used for harvesting is also modified on the basis of a rice-wheat combine harvester.There is no real and detailed research on the characteristics of rapeseed harvest,so the performance is not perfect,and the harvesting loss rate is high.In order to solve this problem,this study analysis to determine main structure parameters and motion parameters of the header,combining the biological traits of rape and physical mechanical properties,around the cause of the high loss.The optimization of structure and motion parameters is mainly verified by field tests.And a hydraulic adjustment system of the reel was designed and simulated to reduce the loss of the header during the harvesting of rapeseed.The main research contents and results of this study are as follows:(1)Refer to relevant literature and introduces the status.On the basis of fully researching and reviewing the literature related to the header of combine harvester,a brief introduction to the current situation at home and abroad was made.Understand the problems existing in the current rapeseed harvesting and propose a new optimization for the high loss rate.And corresponding research methods and technical routes are given.(2)Analysis of structural features of combine harvester.Theoretical analysis and parameter calculation of the main components of combine harvester are given such as r eel,cutter,and auger.Based on it,it analyzes the characteristics of rapeseed harvester header.Mainly to install the vertical knife to reduce the rape branch pull loss;increase the length of the header to ensure the fluency of the transfer;increase t he baffle to reduce the loss of grain caused by splashing;change reel’s parameters,etc.(3)Experimental study on mechanical properties of rape stalks.It mainly includes the biological characteristics measurement and cutting test of rape stalks.The mea surement of rape stalk includes its height,culm diameter,bottom bract height,mass,moisture content,etc.Cutting test analyze the change of cutting force from several aspects including different varieties,different heights of the same plant,different diameters,and different loading speeds.The cutting forces are different under the same loading speed for the same part of different varieties.The cutting force of the upper part of the same variety of different height at the same cutting speed is small er than the cutting force at the bottom.The cutting force showed an increasing trend with the increase of stem diameter.The cutting force as a decreases as the cutter loading speed increases.(4)Rapeseed combine harvester field test.Choose the reel’s h orizontal position,reel’s vertical position and reel’s rotation speed as the main parameters,and take the header loss rate as the main objective.At the same time,use the total feeding amount as an auxiliary target considering the harvester’s operating efficiency.Firstly,single-factor tests were performed on the three main parameters,and the effects of various factors on the loss rate and feed amount were analyzed.On the basis of single factor,a response surface test was conducted on three main parameters according to the Box-Benhnken Center combinatorial test design theory.It establishes a regression model to determine the factors affecting significance.In the test results,only the reel rotation speed has a significant influence on the feed amount,and the test results are consistent with the results of the single-factor test.And the significant order of influence is Reel’s vertical position> Reel’s rotation speed> Reel’s horizontal position through the analysis of impact effects.Then find the b est combination of parameters with high efficiency and low loss as constraints.Determining the optimum working parameter combination of the rapeseed harvester’s header is that the horizontal position of the reel is 50 mm,the vertical position of the reel is 1056 mm,and the rotation speed of the reel is 30r/min.Under the optimized conditions,the head loss rate is 0.97%,the feed amount is 8.35 kg/s,and the experimental value is 1.01% for the head loss rate,8.48 kg/s for the feed amount,so the fitting d egree was high.(5)Design of reel hydraulic control system.In order to reduce the vibration of the header,reduce the loss of the falling grain and optimize the drive structure of the header,designing the hydraulic control system of the reel based on the field experiment.The scheme design and simulation analysis were mainly based on the working conditions of reel.Reel hydraulic control system can control its hydraulic cylinder and hydraulic motor to complete the corresponding fu nctions,maintain high synchronization accuracy and meet the requirements of economy and practicality.Different solutions were designed on the premise of satisfying design requirements.Through the comparative analysis of each scheme,we can see that the scheme 1 has a simple structure and it is economical and convenient.Then calculate and select the main parameters of hydraulic motor and hydraulic pump.Choose hydraulic motor model BMR50 while choose hydraulic pump model CBN-E320.In order to verify its performance and determine whether the program meets the design requirements,the hydraulic simulation software AMESim was used to simulate and analyze the hydraulic system,and the results meet the requirements.