1、 Design principle and analyses of the motion characteristics of4H-2type peanut harvester Shang Shuqi,Wang Jiangang,Wang Fangyan,Liu Shuguang,Jiang Yuanzhi (EngineeringSchool,LaiyangAgricultural University,Laiyang,Shandong265200,China) Abstract: The structure, working principle and design of main par
2、ts of the 4H-2 type peanut harvester were described andanalyzed, and the kinematics model of the main work parts was founded. On the basis of the optimized structure, therepresentative tracks of the work parts were described by means of Visual Basic and SPSS software and the machinefunction characte
3、ristics. The theoretical foundation has been provided for further study of this kind of machines. Key words: Peanut harvester； design principle； motion characteristics CLC number: S225.73 Document Code: A Article ID:1002-6819(2005)01-0087-05 1 Introduction The peanut is one of the main oil plants in
4、 the world, which is only inferior to soybean but ranks the second for oil production and international trade.For a long time, the planting, harvesting and processing of peanut were mostly completed by manual work. It is a piece of labored work with low efficiency, which affects the peanut productio
5、n seriously. Especially in the last few years, as the transferring surplus rural labors to urban areas, the contradiction of each link of peanut production is more intensifying, the mechanization of the peanut production becomes particularly important. It has been a long time for researching and dev
6、eloping the peanut harvesters in developed countries, it is a typical representative that the LP-2 type peanut harvester and peanut combine harvester of Courtesy lf Lilli ston Mfg. Co. in the United States and PH-2 type peanut harvester of Michigan in Netherlands. The development of peanut harvester
7、 in China is later than that in developed countries, perhaps the beginning of the 1960s. Since the 1970s, many representative mimic peanut harvesters were introduced into China such as the Dongfeng 69 type, 4HW-800 type and 4H-150 type peanut harvester etc.These products bring convenience for harves
8、ting peanut, but the structure of all current harvesters adopted the two steps of harvest principle scoop and separating chain combine together. These machines have to match with the medium-big power tractors. It is not only complex in structure, higher manufacturing costs, more power consumption, p
9、oor reliability, but also higher harvesting loss rate, peanut vines spread disorderly, and inconvenient for manual collection. It is not suitable for the current requirement of peanut harvesting and results in that the harvesting of peanut is almost completed by manual work at present. The mechaniza
10、tion level of peanut harvesting affected the development of the peanut production seriously. 2 Structure design of the peanut harvester Analysis of the whole machine structure 4H-2 type peanut harvester combines with the advanced method of planting and agricultural requirement, which can harvest two
11、 rows at one working stroke. It matches with the 8.813.0 kW small four-wheel tractors. 4H-2 type peanut harvester is composed of gaging wheel, transmission shaft, eccentric wheel, pitman, long rocker-arm, erect axis, harvesting parts, long pitman, rocker-arm, mounting device and frame etc. The figur
12、e 2 shows its structure. 1.gaging wheel 2.joint coupling 3.transmission shaft 4.erectaxis 5.long rocker-arm 6.long pitman 7.mounting device 8.rocker-arm 9.erect axis 10.harvester part 11.eccentricwheel 12.pitman 13.harvest part 14.frame Fig.2 Diagram of peanut harvester The driving power needed of t
13、he work parts of 4H-2 type peanut harvester comes from the PTO of tractor. When the machine with tractor goes forward, the PTO drives eccentric wheel 11 pass through joint coupling 2 and transmission shaft 3. Then eccentric wheel 11 drives long rocker-arm 5 to move pass through pitman 12. As erect a
14、xis 4 and harvest parts 13 are made together, rocker 8 with long pitman 6 and long rocker-arm 5 constitute an inverse parallelogram mechanism, therefore harvest parts 10 and 13 swing with erect axis 4 and 9 with the same frequency and angle but contrary direction. The working process is: the scoops
15、10 and 13 digging the peanut out and moving the peanut backward, while the lengthways grids continuously make the fanlike swing, and then break the admixture of soil and peanuts. By this movement the heavy soil sinks down via the grids, and the lighter peanut moves up, so that peanut is separated fr
16、om soil well. The peanut is moving rearward continuously, finally even laying on the excavated ground, so it is convenient for manual collection. 3： Function characteristics of the harvester The swing-digging principle and the inverse parallelogram mechanism have been successfully created and applied to 4H-2 type peanut harvester. It had broken the traditional way which is scoop and separate chain to combine together for harvesting.
