Journal of Agricultural Science; Vol. 9, No. 6; 2017 ISSN 1916-9752 E-ISSN 1916-9760 Published by Canadian Center of Science and Education
Optimization Design and Simulation for Pricking Mechanism of Off-Centre Embedded Seed Metering Device Mutong Li1, Fujun Zhou1, Tianyu Li1 & Yuan Wei1 1
College of Engineering, Northeast Agricultural University, Harbin, China
Correspondence: Fujun Zhou, College of Engineering, Northeast Agricultural University, No. 59 Mucai Street, Xiangfang District, Harbin, Heilongjiang Province, China. Tel: 86-451-5519-1280 E-mail:
[email protected] Received: March 22, 2017 doi:10.5539/jas.v9n6p221
Accepted: April 13, 2017
Online Published: May 15, 2017
URL: https://doi.org/10.5539/jas.v9n6p221
The research is financed by National Science and Technology Support Program 12th Five-Year 810056. Abstract In order to improve the quality of pricking hole and reduce throwing soil as merering the field, this paper presents a method of off-centre embedded pricking mechanism operation. Established a mathematical model of pricking hole mechanism, preparation of computer aided analysis platform by using VB software, and the simulation effects are buried and the effects of the eccentricity, rocker arm length, pricking hole connected with the handle, the swing rod length, length the pricking hole angle and swing arm and the connecting rod handle parameters related to the initial position. One group of optimization parameters: radial eccentricity 50mm, pricking hole arm length 220 mm, connecting handle length 135 mm, pendulum length 120 mm, pricking hole arm and the connecting handle 55 degree angle, pendulum hinge rotation center end and rocker wire length 130 mm, connecting with the horizontal angle of 5 degrees. Through the verification, pricking hole mechanism after optimization has been a significant improvement in reducing throwed soil problems and improve the pricking quality. Keywords: seeder, pricking mechanism, parameter optimization, computer-aided analyzing, design 1. Introduction At present, no-tillage planter was parted into mechanical and pneumatic according to the operation mode. Because ditching devices are assembled in the front of metering device in traditional tools. High resistance operation that sources from the interaction between ditching devices and soil will increase the traction energy consumption and equipment vibration (Yuexia, 2003), moreover, the metering pipeline of seed-outlet often clogs up with soil. These problems always affect the seeding quality, thus impediment the development of seed metering mechanism and the improvement of operation mode. This paper aimed at above problems and based on the principle of crank-rocker mechanism, put forward a type of pricking mechanism with off-centre embedded seed metering device operation mode (Fei et al., 2016; Hongxin, 2017; Jinwu et al., 2015). Optimize the pricking motion trace by using VB programming software. Furthermore, improve structure parameters and installation angle of pricking mechanism, and verify its applicability to overcome the main disadvantages of the traditional seed metering device, that within high resistance and large power, and solve the phenomenon of soil plugging. 2. Mechanism Composition and Principle 2.1 Mechanism Composition Its working principle is: when it works, the power output connecting hole on the off-centre concave hole wheel is a power input, and the off-centre concave hole wheel driven by rotating principal axis eccentricity. Inside the off-centre concave hole wheel, embed a non-circular concave slideway. The return spring loaded in the piston chamber of pricking arm shell. Slideway and spring both drives the piston whose end loads in bearing to take linear recipro-cating motion in the piston chamber, which is in the pricking arm shell. At the same time, the off-centre concave hole wheel drives the pricking arm shell to take reciprocating rotation; when the pricking arm shell is rotated close to the ground, the piston out from the piston chamber into the soil and prick a hole under the function of the non-circular concave slideway. When the piston moves upward under the function of return spring which is compressed, seeds are thrown out from the seed metering chamber of the pricking arm to the 221
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piston chaamber, and thenn they are throown out from tthe connectingg port at the low wer end of thee piston chamb ber to the hole. T This is a continnuous and inteegrated operatiion by prinkinng hole and seeed metering. (C Chinese Patent No. 2017100077400.9, 201710007398)
Figure 1. 3D model off the off-centree embeded priccking hole mettering mechaniism Note. 1. P Pricking arm shell; s 2. Off-ccentre concavee hole wheel; 3. Piston; 4. Return springg; 5. Swing ro od; 6. Principal aaxis; 7. Mountiing shaft; 8. Piiston chamber; 9. Bearing. m shell, it only exist relative motion with ppricking arm shell. s Because thhe piston intallled inside thee pricking arm This papeer focuses on optimization design for ccomposition pparameters andd penetrating trace of pric cking mechanism m. The motionn principle skeeleton of the m mechanism is shown in Figgure 2. It mainnly consists of o the rocker, thee pricking arm m, the connectinng handle and the swing rodd. The point O is the rocker rrotation centerr, and equipped w with coaxial on o mounting raack. The pointt C is the hingge point betweeen the end off the swing rod d and mounting rack. The disttance of Line O OC is L4, andd the angle bettween horizonttal plane and O OC is γ. The angle a between thhe rocker and the t connectingg handle is δ. T The rocker andd the connectinng handle are hhinged on the point p A. The coonnecting handdle and the sw wing rod are hhinged on the point B. The point D is thee prickly endp point. When the pricking mecchanism operaates, the rockeer takes circullar motion aroound the pointt O and drives the pricking aarm to swing periodically, thus cause thhe change of the trace of ppricking cusp.. By adjusting g the parameterss, we get the absolute a motioon trace that m meets the workking requiremeent of the prickking mechanissm to achieve thhat the angle between b the returned line off the pricking cusp and the eentered line off the pricking cusp limited in 0°-10°, accorddingly, reduce the phenomennon of soil diggging.
Figurre 2. The princciple skeleton oof mechanism m; 5. Prickingg arm. Note. 1. Roocker; 2. Connnecting handlee; 3. Swing rodd; 4. Fixed beam 222
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3. Establish Mathematical Mode Pricking mechanism kinematics analysis as shown in Figure 2, as known constant L1, L2, L3, L10, L2A, L3C, xC, yC, . α1, as known variables α1. Establish vector equation of mechanism OA + OB = OC + CB Transform as analytic form: xA = L1 cosα1 y = L sinα 1 1 A
(1)
xB = xC + L3 cosα3 = xA + L2 cosα2 y = y + L sinα = y + L sinα 3 3 2 2 B C A
(2)
Simplify Equations (2): (xC – xA)2 + (yC – yA)2 – L22 + L33 + 2L3 [(xC – xA)cosα3 + (yC – yA)sinα3] = 0 For formula: L1: The length of Rocker OA, mm; L2: The length of connecting handle AB, mm; L3: The length of oscillationg bar BC, mm; α1: The rotation angle of Rocker OA, (o); α2: The intersection angle of connecting handle AB and x . axis, (o); α3: The intersection angle of oscillationg bar BC and level, (o); α1: The palstance of Rocker AB, rad/s. Set the intersection angle between the AC line and the x axis as β, then. tanβ = (yA – yC)/(xA – xC)
(3)
Simplify the two formulas above: 2
cos α3 – β =
2
L33 + xA – xC + yA – yC – L22 2L3
2
xA – xC + yA – yC
2
(4)
As α3 – β is an inner angle of ΔABC, α3 – β belongs to 0~π (Yun, 2005). Thus α3 can be figure out. OA rod centroid coordinate: x1 = L10 cosα1 y1 = L10 sinα1
(5)
x2 = xA + L2A cosα2 y = y + L sinα 2A 2 2 A
(6)
The coordinate of AB rod centroid:
From the formula above: tanα2 = (yB – yA)/(xB – xA)
(7)
The coordinate of BC rod centroid: x3 = xC + L3C cosα3 y = y + L sinα 3C 3 3 C
(8)
For formula: L10: The distance from OA centroid to O, mm; L2A: The distance from AB centroid to A, mm; L3C: The distance from BC centroid to C, mm. 3.1 The Displacement Equation of Pricking Cusp Relative motion displacement of pricking cusp D: xD = xA + LAD cos (α2 + αAD ) yD = yA + LAD sin(α2 + αAD )
(9)
For formula: LAD: The length of pricking limb AD, mm; α2: The angle between connecting handle AB and x axis, (o); αAD: The angle between pricking limb AD and x axis, (o).
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Absolute m motion displaccement of prickking cusp D:
= xD – α1 H/3600 xD' = yD' = yD
(10)
For formula: H: Corn spacing in rows,, mm 3.2 The Veelocity Equatioon of Pricking Cusp If the priccking hole mecchanism posseess horizontal forward speedd v1 = 0, the relative velocity equation of o the pricking cuusp D would be: b
xD = xA – (α2 + αAD ) LAD sinn (α2 + αAD ) yD = yA + (α2 + αAD ) LAD coos(α2 + αAD )
(11)
If the priccking hole mecchanism posseess horizontal forward speedd v1 = 0, the aabsolute veloccity equation of o the pricking cuusp D would be: b 4. Parameeter Optimizaation
xDD' = xD – v1 yD' = yD
α1 α1
(12)
In this papper, by using VB V software, w writing a proggram optimizess the structuree parameters oof the pricking hole mechanism m. Depend onn the scale m method, the cooordinate is trransformed innto cartesian ccoordinates th hat is conveniennt to actualize the t programmiing (Xiaohuann et al., 2011; C Chunxiang et aal., 2016). Thee program is mainly m uesd to opptimize the sttructure param meters of prickking hole mechanism. The settings interrface of param meter directly pllaced on the riight side can bbe convenientlly debugging eeach parameteer value. Meannwhile, in the main interface, aall kind of tracces which is reelated with priccking arm cuspp can be obserrved and the reeliability of va arious data also ccan be analysissed.
Figure 3. Absolute motiion trace of priicking mechannism p hole iinto soil smooothly, and witthout holding and lifting upp soil, the trac ce of In order too impel the pricking pricking cuusp should fullfil: (1) Prickinng hole into sooil with zero sppeed, the anglee between the rreturned line of o the pricking ccusp and the enntered line off the pricking ccusp is less thhan 10o. (2) Thhe trace of hoole is limited to the range of 112~20 mm (Jinnfeng et al., 20010). (3) The depth of hole is limited to tthe range of 330~50 mm. (4)) The hole distannce is limitedd to the range of 200~300 mm. In orderr to enhance tthe quality of pricking hole e and improve thhe dynamic chharacteristics oof pricking holle mechanism, set the targett of optimizatiion parameterss: L1, L2, L3, L4, L5, γ, δ and so on. By adjusting the parameter vaalues, the tracce of prickingg arm cusp ca an be dynamicallly adjusted. Using U real-timee coordinate ppositioning meethods selectedd the optimal trace to satisfy fy the conditionss above as show wn in Figure 33. For the valuee of the param meters: L1 = 50 mm, L2 = 135 mm, L3 = 120 0 mm, L4 = 130 m mm, L5 = 220 mm, γ = 5o, δ = 55o. With the optimal reesults, the anglle between priicking cusp and the
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horizontal plane is limiited to 65o~775o when pricking into solii, the depth off pricking holle is 44.6 mm m, the lengthwisee length of hole is 13.8mm, tthe hole distannce is 245 mm, satisfy the design requiremeents. 5. Velocityy Analysis On the baasis of the opttimal parameteers of the VB B program, draaw the 3D moodel perfectlyy. According to o the simulationn of Adams which w is a kindd of dynamic analysis softw ware, the relative velocity simulation curv ve of pricking arrm cusp D cann be obtained, aas shown in Fiigures 4 and 5..
F Figure 4. The axial a velocity ccurve of the D point at the cuusp of prickingg arm for relative motion
F Figure 5. The tootal velocity cuurve of the D ppoint at the cuusp of pricking arm for relativve motion As shown in Figure 3, analysis a the D ppoint speed cuurve from X diirection, whenn the rocker arm m angle is rolled to the range of 70o~190o, the t pricking hole mechanism m is in the retuurn process. A Analysis the D point speed curve c from Y dirrection, when the pricking ccusp is divorceed from soil, thhe pricking arm m owns biggissh speed so tha at the lifting actiion can be rapiidly completedd; when the rocker arm anglee is greater thaan 190°, the m mechanism getss into the process of pricking hole; h when thee rocker arm aangle is about 2250o, the prickking hole mechhanism is closed to the groundd. According too Figure 5, thee maximum sppeed of the pricking arm cussp D is up to 00.52 m/s, which h can ensure a perfect effect too prick into soiil. As shown inn Figure 4, whhen the rocker arm angle is llimited in the range r of [280o, 3360o] and [0o, 35o], the motioon of prickingg arm cusp is inn soil, which iis metering proocess. As show wn in Figure 5, the motional velocity v of priicking cusp iss gentle and ddecreasing, whhich is conducive to improve the stability off metering in thhe hole and to reduce the soiil disturbance. It satisfies thee design requirrements. 6. Conclussions Put forwarrd a kind of offf-centre embeddded type crannk rocker motiion principle of pricking holee seeding operration mode. throough the establlishment of maathematical moodel and usingg VB software platform for ddynamic simulation (Chuanyu et al., 2008; Ge G et al., 20000), determine the pricking hhole mechanissm parameterss: rocke is 50 mm, connectingg handle is 1355 mm, swing rrod is 120 mm m, fixed beam iis 140 mm, prricking arm is 220 mm, the angle a between hhorizontal planne and fixed beeam is 5o, the angle betweenn the rocker aand the conneccting handle iss 55o. We get thee speed variattion of D poiint by relative motion simullation of 3D m model based onn Adams softw ware, and analyzzes the adaptabbility of prickiing capability and metering performance. Verify the opttimized param meters of prickingg arm cusp thaat the return traace and uneartthed penetratinng trace is lesss than 10o. Meeet the requirem ments that reducing the phenoomenon of soiil disturbance. Furthermore, lay the theorretical foundattion for the fu urther design of m metering mechhanism.
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Acknowledgements First of all, thank you for the guidance of Professor Fujun Zhou and the funds of National Science and technology support program 12th Five-Year. Secondly, thanks to the help from Li Tianyu and Wei Yuan during the design translation process. Third, thanks to editors and experts of the journal with valuable views and suggestions. Therefore, with the basis above the manuscript could be further improved. References Anantachar, M., Prasanna, G., Kumar, V., & Guruswamy, T. (2010). Neural network prediction of performance parameters of an inclined plate seed metering device and its reverse mapping for the determination of optimum design and operational parameters. Computers and Electronics in Agriculture, 72, 87-98. Barut, Z. B., & Ozmerzi, A. (2004). Effect of Different Operating Parameters on Seed Holding in the Single SeedMetering Unit of a Pneumatic Planter. Turkish Journal of Agriculture & Forestry, 6, 435-441. Chuanyu, W., Yun, Z., & Jianneng, C. (2008). Rice transplanter transplantingmechanism visual optimization design of human-computer interaction. Transactions of the Chinese Society for Agricultural Machinery, 39(1), 46-49. Chunxiang, L., Jinwu, W., Han, T., Wenqi, Z., Qi, W., & Wenpan, Y. (2016). Dynamics Analysis and Test on Picking Hole Mechanism of Liquid Fertilizer Based on Bezier Curve. Transactions of the Chinese Society for Agricultural Machinery, 47(5), 115-122. https://doi.org/10.6041/j.issn.1000-1298.2016.05.016 Fei, D., Wuyun, Z., Linrong, S., Xuepeng, T., Jiuxin, W., & Xiaolong, L. (2016). Design and Experiment of Hill-seeder with Whole Plastic-film Mulching on Double Ridges for Corn Based on Mechanism with Approximate Constant Speed. Transactions of the Chinese Society for Agricultural Machinery, 47(11), 74-81. https://doi.org/10.6041/j.issn.1000-1298.2016.11.010 Ge, L., Yun, Z., & Gaohong, Y. (2000). Theoretical Analysis and Parameters Optimizing of Separating Planting Mechanism with Planetary Elliptic Gears. Transactions of the Chinese Society of Agricultural Engineering, 16(4), 78-81. Hongxin, L. (2007). Experimental study on optimizing structural parameters of 2B-JP-FL01 seed-metering device. Transactions of the Chinese Society of Agricultural Engineering, 23(9), 106-110. Jinfeng, W., Jinwu, W., Yiyuan, G., Yahua, L., & Jinyan, J. (2010). Design on Pricking Hole Mechanism of Deep-fertilization Liquid Fertilizer Applicator. Transactions of the Chinese Society for Agricultural Machinery, 41(4), 52-55. https://doi.org/10.3969/j.issn.1000-1298.2010.04.011 Jinwu, W., Han, T., Wenqi, Z., Wenpan, Y., & Qi, W. (2015). Improved Design and Experiment on Pickup Finger Precision Seed Metering Device. Transactions of the Chinese Society for Agricultural Machinery, 46(9), 68-76. https://doi.org/10.6041/j.issn.1000-1298.2015.09.010 Mutong, L., Xiangyu, W., & Fujun, Z. (2016). Working Parameters Optimization and Experiment of Precision Hole Fertilization Control Mechanism for Intertilled Crop. Transactions of the Chinese Society for Agricultural Machinery, 47(9), 37-43. https://doi.org/10.6041/j.issn.1000-1298.2016.09.006 Raji, A. O., & Favier, J. F. (2004). Model for the deformation in agricultural and food particulate materials under bulk compressive loading using discrete element method. II. Compression of oilseeds. Journal of Food Engineering, 64(3), 373-380. Singh, D. C., Singh, G., & Saraswat, D. C. (2004). Optimisation of Design and Operational Parameters of a Pneumatic Seed Metering Device for planting Cottonseeds. Biosystems Engnineering, 92(4), 429-438. Xiaohuan, X., Jinwu, W., Chunling, L., & Chengliang, Z. (2011). Optimal Design and Simulation on Pricking Hole Mechanism of Liquid Fertilizer Applicator. Transactions of the Chinese Society for Agricultural Machinery, 42(2), 80-83. https://doi.org/10.3969/j.issn.1000-1298 Yuexia, Z. (2003). The key technology of mechanical precision seed-metering device. Nanjing Agricultural University. Yun, Z. (2005). Numerical analysis and synthesis of mechanism. Mechanical Industry Press.
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Appendixx Appendix A. The parameeter optimizatiion platform based on Visuall Basic (Chineese button)
Appendix B. Dynamic siimulation and its trajectory bby ADAMS
Appendix C. Velocity annalysis gragh oof by ADAMS
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Copyrights Copyright for this article is retained by the author(s), with first publication rights granted to the journal. This is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
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