【機(jī)械類畢業(yè)論文中英文對照文獻(xiàn)翻譯】4H-2型花生收獲機(jī)的設(shè)計(jì)原理及運(yùn)動特性分析【word英文2451字10頁word中文翻譯3850字9頁】
【機(jī)械類畢業(yè)論文中英文對照文獻(xiàn)翻譯】4H-2型花生收獲機(jī)的設(shè)計(jì)原理及運(yùn)動特性分析【word英文2451字10頁word中文翻譯3850字9頁】,機(jī)械類畢業(yè)論文中英文對照文獻(xiàn)翻譯,word英文2451字10頁,word中文翻譯3850字9頁,機(jī)械類,畢業(yè)論文,中英文,對照,對比,比照,文獻(xiàn),翻譯,花生,收獲,收成,設(shè)計(jì),原理,運(yùn)動,特性,分析,word
Design principle and analyses of the motion characteristics of 4H-2 type peanut harvester
Collection of Extent Abstracts of 2004 CIGR International Conference(Volume.2) 2004.
Shuqi Shang;?Professor;Head of Engineering School;?Laiyang Agricultural College;?Shandong 265200;?China Fangyan WangEngineering School of Laiyang Agricultural College (Shandong 265200;China) Shuguang LiuEngineering School of Laiyang Agricultural College (Shandong 265200;China)
Abstract
The structure, working principle and design of main parts of the 4H-2 type peanut harvester were described and analyzed, and the kinematics model of the main work parts was founded. On the basis of the optimized structure, the representative tracks of the work parts were described by means of Visual Basic and SPSS software and the machine function characteristics. The theoretical foundation has been provided for further study of this kind of machines.
Key words: Peanut harvester; design principle; motion characteristics
1 Introduction
The peanut is one of the main oil plants in the world, which is only inferior to soybean but ranks the second for oil production and international trade[1,2]. 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 production 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 developing 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[3]. The development of peanut harvester 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.[4]. These products bring convenience for harvesting 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, poor 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 mechanization level of peanut harvesting affected the development of the peanut production seriously.
With the environment deterioration, at sowing-season in spring or autumn, the phenomenon of dry and little rainfall appears. The peanut production suffered from the weather. It had led to
adopting technique of plastic film covering(Figure 1 shows its section structure). This new technique will play an important role in keeping the moisture of soil, increasing ground temperature, and reducing management in seedling period, and then increasing the output of peanut. The peanut seeding-machine with many functions has already applied in large-scale areas, but the quantity of the film remains is increased, which influences the following work[5-9].
Fig.1 Profile of peanut covering plastic film and seeding beds[8]
For solving the problems mentioned above, a new type of peanut harvester with new working principle and structure was invented, which has already come to the market. The harvester has already acquired the petty patent now (patent number: ZL 01221476.0), and patent for invention ( patent number: 99124518.0) has been investigating in substance.
2 Structure design of the peanut harvester
2.1 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 rows at one working stroke. It matches with the 8.8～13.0 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 figure 2 shows its structure.
1.gaging wheel 2.joint coupling 3.transmission shaft 4.erect axis 5.long rocker-arm 6.long pitman 7.mounting device 8.rocker-arm 9.erect axis 10.harvester part 11.eccentric wheel 12.pitman 13.harvest part 14.frame
Fig.2 Diagram of peanut harvester
The driving power needed of the 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 axis 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 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 from soil well. The peanut is moving rearward continuously, finally even laying on the excavated ground, so it is convenient for manual collection.
2.2 Main technique parameters
The table 1 shows the main technique parameters of 4H-2 type peanut harvester.
Table 1 Main technique parameters
Power requirement
8.8～13.0 kW small four-wheeled tractor
Productivity/hm2·h-1
0.10～0.13
Losing rate of nuts
≤2%
Containing rate of soil in peanut
(by quantity calculation)
<5%
Broken rate of nuts
<1%
Picked rate of nuts by mechanisms
<3.5%
Overall size (L×W×H mm)/mm3
1280×l180×780
Net weight/kg
158
3 Design of main working parts
3.1 Design of the transmission parts
For overcoming the weakness of the traditional peanut harvesters mentioned in this paper, the 4H-2 type peanut harvester has been invented with a new structure and principle. Its scoops and separating parts have been combined together that can reduce the power consumption, the size of the machine and harvesting loss. The transmission and control devices are designed for transmitting power efficiently and adjust conveniently. In order to match the tractor of 8.8 kW, the power input shaft 1 of 4H-2 type peanut harvester is located in flank of left. The inverse parallelogram mechanism is the remarkable characteristics of this machine. It swings both scoops with the same angle but opposite direction. The side forces acted on two scoop frames are balanced each other. The stability of the machine is ensured and the investment of manufacturing is reduced greatly, which is benefited to large-scale production and popularization of the harvesters.
3.2 Design of scoop frames
When the harvester working in field with dense peanut stalks, the flowing channel of the peanut is easily jammed, resulting in that the working resistance is increasing, and peanut separating is ineffective, even the harvester cannot continue to work. For resolving this problem, the structure of half open arm " " has been created for the scoop frame (show in the figure 3) and the bottom is the scoop. As there are tow scoops, the form respectively is " " and " ", tow of them forming the " " channel, which makes the peanut stalks easily to pass it.
Fig.3 Diagram of scoop frames
3.3 Design of the transmission with V-belt
According to the different circumstances of the fields, the swing frequency of harvesting parts should be adjusted and changed. For this reason, the one step V-belt transmission has been adopted for changing the swing frequency by replacing the V-belt pulleys. After optimizing the four-bar linkage and the size of the belt pulleys, the frequencies and the range of swing are more reasonable.
3.4 Design of the grid shape
If the sectional shape of grid is round, the connection point of grids with scoop will be broken easily after working. In order to increase its anti-bent intensity, the " flat" rectangle sectional grids have been selected out and application after making theoretical design and experimental analysis (the figure 4 shows its structure).
Fig.4 Diagram of grid shape
4 Equation of kinematics
4.1 Theoretical analysis of the main parts
Figure 5 shows the structure of transmission parts of 4H-2 type peanut harvesters. In this figure, No.3 is transmission shaft and No.11 is eccentric wheel, the AE and BD respectively indicate the rocker-arm 5 and 8, the CD and EF indicate pitman 6 and 12 respectively, the A and B is respectively erect axes 4 and 9 (reference Figure 2).
Fig.5 Diagram of transmission parts structure
Fig.6 Simplification diagram of movement[9,10]
When 4H-2 type peanut harvester working, transmission shaft 3 drives eccentric wheel 11 running. As the track of point E is a space arc, but its length is far shorter than AE rocker' s in XOY coordinate plane (<10%), so that E point track may approximately be the straight line movement which is in the XOY coordinate plane. The figure 6 shows the movement form. O′F stands for eccentricity and EF stands for pitman 12. As O′F=R,EF=L, then the track of E point may approximate be considered a straight line OE. So the rectangular system of axis can be established to find the kinematics equation. Turn O to be the origin of coordinates, the direction of OO′ is the positive direction of X axes. According to the known condition, at beginning t= 0,F is in the place for F′,E is in the place for O. Obviously OF′+O′F′=L+R. At any time E point coordinates is:
According to the crank rocker structure, K is usually among 1/6～1/4. By the binomial equation, then
As the other numbers are much small from the third number, so all of them are ignored.
Videlicet: , then E point kinematics equation approximately is:
The motion characteristics of inverse parallelogram mechanism ABCD depends on the track of point E. The figure 7 shows the structure. A and B stand for erect axes 4 and 9 respectively, AE and BD are respectively rocker 5 and 8,CD is pitman 6. If A is at zero (0, 0). The direction of AX is the positive direction of polar axes.AE=L1. Then A (erect axis) angular velocity equation approximate is:
Fig.7 Schematic of inverse parallelogram mechanism
4.2 Kinematics equation of the harvest parts
As the figure 8 shows, when 4H-2 type peanut harvester is static to the ground relatively, any point of swing grid AH motion as horizontal and fan-shape reciprocating movement, around its erect axis. When working, the movement of any point of swing grid AH is composed of the swing motion of erect axis and moving of tractor. Because of the swing velocity of erect axis is different, the motion track is not the same, but there is certain regulation. Take the farthest point H of swing grid, its relatively static equation is:
Its relatively kinematics equation is:
On the basis of optimum parameter, the track of the farthest point H of swing grid has been gotten by making use of the Visual Basic and SPSS software (Shows in the figure 9).
Fig.8 Diagram of velocity synthesis
Fig.9 Relatively kinematics track of H point
5 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.
(1) 4H-2 type peanut harvester should be matched with the small four-wheel tractors which are very universal. Its design is reasonable, with reliable working, steady function, convenient adjustment, higher adaptability, and this machine can work in various fields and harvest all kinds of peanut.
(2) The swing-digging principle had been created for merging scoop and separator together. That has successfully realized the work of digging and separating peanut by one set of part, and simplified the working procedure. The two harvest parts were used through inverse parallelogram mechanism to transfer power, turning them by the same angle for swing but opposite direction, making the two sides force acted on scoop frames balanced each other, the operation stability of it is ensured, the resistance and the power consumption have been reduced.
(3) In harvesting process, plastic film was not broken and easy collected with the peanut stalks.
There is none leavings of them on the ground.
(4) As created the swing-digging principle, the whole resistance and the power consumption of the harvester have been reduced. By means of the swing function, the soil with heavy specific gravity sinking passes through the grids, and the peanut with lighter specific gravity moves up, so that the loss rate of peanut was reduced remarkably.
(5) The various working and performance indexes of the machine are superior to the similar type of peanut harvesters, and productivity of it was higher, loss rate lower, the economic benefit remarkable.
4H-2 type peanut harvester is the new typical agricultural implement for the small scale farms of China and more suitable for Chinese peanut production. This harvester has the simpler structure and lower price. Its various performance indexes are superior to the Standard of technique indexes for peanut harvesting in China. It can bring more economic benefit to the customers. After application and extension to peanut production, the 4H-2 type peanut harvesters have won broad praise from the society. This patent achievement indicates fully that the design and principle of 4H-2 type peanut harvesters has reached a new high level.
References
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