Design and Experiment of 4YQZ-3A Combine Harvester for CornZhang Xirui Dong Youfu Zhang Daolin(School of Mechanics and Electrics Engineering Hainan University Danzhou, China )资料个人收集整理，勿做商业用途AbstractDue to the problem of the low retrieving rate of straw while harvesting, fodder went sort in stock raising and to overcome the practical problem of corn harvester reaping both corn stalk and spike while in operation, 4YQZ-3A combine harvester was designed, analyzed and the parameters of key components were pointed out for better gripping delivery mechanism, vertical picking and chopping cutter, helicinae and throwing apparatus.During the corn harvesting season, numerous performance testing and the production assessment were carried out in the field. Results achieved from the experiment indicate that the whole machine has better performance and can accomplish reaping both corn stalk and spike well.资料个人收集整理，勿做商业用途Keywords- corn harvester; picking and threshing harvester; design;Experiment资料个人收集整理，勿做商业用途1.introductionCorn is Chinas second-largest food crop, occupies an important position in food production1. Maize straw contains a lot of crude protein, crude fat and fiber nutrient component, etc. Thus it is one of the most perfect forage of high quality in animal husbandry.The national annual production of corn straw is about 60,000 tons, which is a huge potential forage source 4.Corn harvester reaping both corn stalk and spike can complete the harvest of corn ear and stalks within one time, so it has significant economic, social and eco- system efficiency 5-6. At present, corn harvester reaping both corn stalk and spike still develops very slow, and the domestic model mainly are hanging type. Because of underpowered, low production efficiency and straw cleanness, it has not been rapidly promoted 7-8.Foreign models are mainly Ukrainian KCKY-6 Corn harvest machine and Corn Star series united harvest machine developed by Kempe Co. in German, due to untidy stubble height and higher price, this type of air-craft is not suitable for Chinas national conditions 9-11.资料个人收集整理，勿做商业用途Foundation item: Public beneficial(agriculture)Science research fund issue(9-04)资料个人收集整理，勿做商业用途On the basis of the tenth-five national research tackle key problems in science and technologyresearch, in this article 4YQZ-3A combine harvester was designed, which combines existing corn harvest and corn silage mechanization technique and improves the design and optimizes the combination for each working device. During the of harvest cornear, the 4YQZ-3A combine harvester can also complete cutting, conveying, chopping collection and root crop broken tasks and so on; With the popularization and appli-cation of this technique , we can solve the problem of corn straw recovery and reduce the waste of straw resources and improve the environment and soil pollution caused by straw burning. Thereinto, the straw recovery can provide high quality feed for livestock and reduce the excessive dependence on pasture, so this technique has important practical significance to our countrys increasingly developing animal husbandry and related industries.资料个人收集整理，勿做商业用途2. Overall Institutions and Main TechnicalIndicators资料个人收集整理，勿做商业用途2.1. Whole Structure and Work PrincipleAs shown in figure 1, 4YQZ-3A combine harvester for corn is mainly made up of gripping delivery mechanism, spike picking device, stem shredding mechanism, cast cylinder, spike collecting box, stem crushing box, counters-field device and helicinae and delivery apparatus of stalks, etc. This machine can once completed the picking, rising and transportation, setting into the box, stalks cutting, conveying, chopping, throwing and collection and root crop crushing of corn grain. While the machinesk is operating, nearsidedivider subdivided maize plants, reciprocating cutter cut the plants, clamping chain clamps maize plants of which root is sundered and then convey them to vertical spike-picking roller to pick off the ear, the corn ear are conveyed to the spike collecting box by the delivery mechanism; Stalks are chopped by vertical hob behind the stem pulling roller , and then are casted by casting device to stem crushing box; and corn root are broken by counters-field device.资料个人收集整理，勿做商业用途2.2. Technology Index of the MachineAccording to the requirements of the chopping and ensiling craft of the corn stalks and the function characteristics of the prototype requirements, The main technical parameters are determined as is shown in Table 1.资料个人收集整理，勿做商业用途Table 1. The main technical parameters of 4YQZ-3A combine harvester资料个人收集整理，勿做商业用途ParametersNumerical valueParametersNumerical valueBoundary dimension (lengthwidthheight)/mm710025003600Minimum groundclearance/mm210Entire machine weight/kg5090Revolving speed of spike Picking roller/rmin-11080Mating Power/kW88.2Revolving speed of Stalkschopping machine/rmin-12100Number of H