Study On The Cabbage Key Harvesting Technology And Harvester

After decades of development, the level of Agricultural Mechanization in China has greatlyimproved, but, the overall level is still relatively low compared with the developed countries. Atpresent especially each link of vegetables production of agricultural production in China stillmainly rely on manual work.Vegetable production harvest has been strongly seasonal and largeaverage labor intensity, a lot of labor are required to complete harvest. And as our country townstep speeding up, the transfer of rural population to the second and the three industry is faster andfaster, the rural labor force reduced year by year, young labor occur shortage.Due to the characteristics of high yield, good quality, cold-resistant, resistant storage and easytransportation, cabbage has been one of the main vegetables in china. So far, cabbage harvester hasbeen not developed in China except for Taiwan, so the research of cabbage harvester is greatsignificance. This study aimed at the problem such as high production cost, high labor intensity,low production efficiency, higher loss rate caused by harvesting the cabbage by hand. Thedevelopment of a cabbage harvester is the urgent need. A cabbage harvester has been developedafter full investigation, with rural reality of our country and the optimization analysis.The mainresearch contents include the following.（1） Study on the physical and mechanical properties of cabbages. The overall height,head sizeand weight, root length and geometric parameters were explored;pulling force, moisture content ofthe root in different parts and were explored; and cut force were explored by the self-madeexperimental device,through the field and lab determination of the ridge precocious cabbages inharvest time. The statistical recognition method is applied and the data was analyzed by means ofsoftware the Design-Expert Version6.0.10.The result of experiments showed that the pulling forcein the condition of natural growth in soil was in the range of [103.0,279.0]N. The moisture contentof roots from top to bottom gradually decreased, those were in the range of [87.85,90.89]%,[84.45,91.45]%,[75.83,83.31]%,[79.79,87.11]%. The shear strength of roots from top to bottomgradually increased, those were in the range of [5.37x10^-2,2.85x10^-2] MPa,[2.58x10^-2,1.10x10^-2]MPa,[1.06,1.78] MPa,[1.25,1.97] MPa.（2） Design of cabbage harvester. Through the investigation of northern cabbage planted inChina that Its main mode, as a single ridge, seedling after transplanting, according to China’sexisting rural power machine type spectrum, the cabbage harvester design the scheme. Traction mode, auxiliary power, harvest rows and determined the main technical parameters. This machineis mainly composed of double disc into the device, select the device profiling mechanism, thedouble helix, belt type support device, cutting device, chain lifting and conveying device, leaivesremoval device, collecting device, land wheels, frame and transmission system.（3） Study on the experiment of cabbage harvester conveyer. the analysis model of force wasestablished; the conditions and the influence factors of cabbage normal delivery were obtained byanalysis of the force on the cabbage pulling mechanism, which laid the theoretical foundation forthe experiment. Test method of second orthogonal rotational combination design with four factorsand five levels was applied. Screw speed, distance between the screw rod, the span of rod and angleof screw and ground were selected four factors, the delivery rate and cut the root failure rate wereselected as the objective function,based on the analysis results of the force model. The optimalstructure parameters and the influence of factors on the target of cabbage harvester transportationmechanism were explored.The experiment results showed that the influencing the contribution rate of four factors werescrew pitch, screw rod, screw speed and angle of screw and ground successively. Optimizedparameters were rotating speed of627r/min, the screw rod of28mm, the rod span of38mm, angleof screw and ground of14°.（4） Study on the experiment of peeling of cabbage harvester conveyer. A peeling mechanismof friction extrusion was developed. The principle of the peeling mechanism composed of a rollerand belt was analyzed. Analysis model of friction force of cabbage peeling was established. Themain factors of effect on the cabbage peeling were obtained. Test method of second orthogonalrotational combination design of four factors and five levels was applied, based on analysis of thestrength, the belt speed, wheel speed, distance of wheel and tire and angle of wheel and tire wereselected as four factors, the peeling rate and delivery rate were selected as the objective function,Optimum parameters the effect of each factor on the target.of peeling and conveying mechanismcabbage harvester were explored.The experiment results showed that the influencing the contribution rate of four factors werethe wheel speed, belt speed, distance of wheel and tire and angle of wheel and tire. Optimizedparameters were the belt speed of2.0m/s, wheel speed of192r/min, distance of wheel and tire ofangle of wheel and tire of43°.（5） Study on key institutions design. The cabbage by artificial transplanting, the ridge line isnot straight situation, developed double disc unit, established the motion model, the transmissionmode was determined, the functions of the device is will deviate from the ridge center line of thecabbage into the midline and fed to the pulling mechanism. Study on the belt support mechanism,support mechanism, plow profiling mechanism, chain type lifting mechanism, collecting device andtransmission system.（6） Study on cabbage harvester based on virtual prototype technology. The modeling of the parts on the structure was established by the application of3D CAD software. Assembly of virtualprototype of cabbage harvester was completed through the interference check, basis of easymanipulation and optimizing the structure. The force model of key institutions was established byApplication of dynamic simulation software ADAMS. Kinematic pairs of the mechanism weredefined, the simulation of the main organs were analyzed by loading force and loading;applicationof finite element analysis software, the finite element stress analysis of the framework of the mostconcentrated stress in harvester was analyzed. Optimize the structure by discovering the key pointis, reduce material consumption.（7） Study on the design, manufacture and field performance test of cabbage harvester. Wedesigned and manufactured a prototype of the first cabbage harvester, the machine can harvestChinese cabbage based on the harvest of cabbage, the machine achieved a multi-purpose in onemachine. Through the field test of cabbage harvester, the performances were obtained: pulling rateof93%, the root qualified rate of92%, the working efficiency of0.08⁰.1hm2/h, cabbageharvest rate of0.93balls per second, technical indexes met the requirements of design. Theeconomic evaluation was analyzed, through the analysis of single depreciation cost, labor cost, fuelconsumption and other indicators, the operation cost was￥902.4/hm2, only manual operationcosts occupied30.1%, the purchase cost can be recovered in that year, so the market prospect isvery broad.