機(jī)械專(zhuān)業(yè)中英文翻譯免耕播種機(jī)鋸切防堵裝置設(shè)計(jì)及其切割機(jī)理的研究

1、<p>　　Design of sawing anti-blocking mechanism for</p><p>　　no-tillage planter and its cutting mechanism</p><p>　　Liao Qingxi1,Gao Huanwen2,Shu Caixia1</p><p>　　(1.Engineering

2、and Technology College,Huazhong Agricultural University,Wuhan430070,China;</p><p>　　2.Engineering College,China Agricultural University,Beijing100083,China)</p><p>　　Abstract: Based on blocking

3、issues of no-tillage planter for dry-land farming in two-crop-a-year region in North of China and shortcomings of anti-blocking mechanism developed, such as higher rotation speed (above 1500 r/min) and bigger power consu

4、mption (width power consumption per unit up to 16～41.74 kW/m, including traction power), a new sawing anti-blocking mechanism was developed and its cutting mechanism was investigated in this paper. Meanwhile stress distr

5、ibution of the saw-tooth blade c</p><p>　　Key words: no-tillage planter; sawing anti-blocking mechanism; cutting mechanism; cutting rate</p><p>　　CLC number: S223.2　　　　Document code: A　　　　Articl

6、e ID:1002-6819(2003)05-0064-07</p><p>　　Received date:2003-06-15</p><p>　　1　Introduction</p><p>　　Anti-blocking issue of no-tillage planter had become one of the key factors affecti

7、ng production efficiency and seeding quality of two-crop-a-year region in North of China. It was because there was a great deal of crop stubbles and crop seeding was started shortly after crop had been harvested, leaving

8、 no time for crop stubbles to decay. At present, there are two methods to solve anti-blocking issue of no-tillage: 1) Straws were chopped by the straw chopper before seeding, it would lead to addin</p><p>　　

9、It was reported that the blade base linear velocity of several main straw chopping mechanisms was between 37～56 m/s[2], mostly chopping mechanism combined with cutting and striking had higher striking velocity and higher

10、 power consumption[3], e.g. the blade base linear velocity up to 34 m/s could obtain fine cutting effect for corn straws[4], and 24 m/s on rice and wheat straws by supporting pole, respectively[5]. Even if corn straws we

11、re cut by sliding cut with vertical blade, its velocity of c</p><p>　　Based on practical problems, the objective in this paper is to find a way to solve the shortcoming that it 64 is difficult for common smo

12、oth blade to seize straws and it must run at higher rotation speed, decrease power consumption and improve cutting effect as well as anti-blocking performance of no-tillage planter. Additionally some experiments were don

13、e by selecting saw-tooth as cutting blade of no-tillage planter and cutting mechanism of the sawing anti-blocking mechanism was investigated.</p><p>　　2　Structure and cutting rule of the sawing anti-blocking

14、 mechanism</p><p>　　2.1　Structure and characteristics</p><p>　　The sawing anti-blocking mechanism was made up of saw-tooth blade, throwing ban device, principal shaft, moved and fixed blade comb

15、ination, covering shell, opener and working frame as well as transmission system. Sketch of the sawing anti-blocking mechanism is shown in Fig. 1. The main parts included saw-tooth blade, throwing ban device as well as f

16、ixed blade combinations. Diameter of saw-tooth with 60 teeth was 350 mm; throwing ban device with max 270 mm turning diameter was fixed on between ad</p><p>　　2.2　Cutting principle</p><p>　　The

17、sawing anti-blocking mechanism was driven to reverse rotation by power. First, straws were cut in no-sustaining mode by saw-tooth blades while saw-tooth blades touched straws, then after straws were completely cut down,

18、they would be free and be thrown to the rear of opener by throwing ban device and inertial force. Second, straws not being completely cut down would be thrown to former upward and be cut in sustaining mode by fixed blade

19、 combinations until any of straws would be cut down, st</p><p>　　Working procedures of the sawing anti-blocking mechanism were as follows: 1) no-sustaining cut phase: static straws relative to ground were c

20、ut firstly atNpoint by saw-tooth blades, then, straws would be cut down completely or embedded in saw-tooth. Straws being cut down completely would be free and 65　Liao Qingxi et al: Design of anti-blocking mechanism for

21、 no-tillage planter dropped into adjacent saw-tooth; 2) dragging and delivering phase: after straws dropped into adjacent saw-tooth, they w</p><p>　　4)throwing phase: straws being cut down were thrown direct

22、ly to the rear of opener by tooth former slanting angle of the saw-tooth and throwing ban device, time and again, straws would be carried out continuously to cut and throw. The working principle of the sawing anti-blocki

23、ng mechanism is shown in Fig.2.</p><p>　　2.3　Analysis of mechanics characteristics of saw-tooth blade </p><p>　　Cutting properties of saw-tooth to cut straws belong to wriggly cut of no-metal ma

24、terials, its ultimate objective is not only to improve surface cutting quality, but also to raise cutting efficiency, so it can decrease sawing force and power consumption[9]. Because the ratio of its diameter 350 mm to

25、its thickness 1.8 mm is over 150, the saw-tooth blade belongs to exceed thin disc. It is as plane stress and no-axis symmetry problem according to elasticity theory. And because the saw-tooth blade </p><p>　

26、　The stress distribution of the saw-tooth blade was calculated by the ANASYS finity element software. Number of the tooth participating in cutting straws was determined to 2～3 teeth while diameter of straws was in 20～45

27、mm[11]. The saw-tooth made in 65Mn ofEequal to 210 GPa[12]andμto 0.28 was separated into 1200 cells and 1260 nodes by trapezia gridding. Thus the stress distributions ofX,YandXYplane had been obtained by the ANASYS softw

28、are according to the most average wring value 26.8 Nm[13]of t</p><p>　　3　Materials and method</p><p>　　3.1　Experimental equipment</p><p>　　The experiment was conducted in the soil b

29、in device, of 20m-long, 0.89m-wide, 0.6m-high, the available working journey of vehicle was 16 m, and the working velocity of vehicle was from 0.12 m/s to 1.2 m/s. And other equipment included: AKC-205 type wring sensor,

30、 the sawing anti-blocking mechani-sm, control tank, computer operation platform, etc.</p><p>　　3.2　Experimental materials</p><p>　　The average height and diameter of corn straw is 2.25 m, 25. 6

31、mm, respectively. It is made up of leaves and skin and marrow. The weight of leaves and marrow occupy above 55% of whole straw and their mechanical intension are much lower; and the weight of skin made up of scarfskin an

32、d bunchy organization occupy 35% or so, the mechanical intension of skin is much higher up to 90 MPa of portrait resistant pulling intension and 3 MPa of landscape orientation resistant pulling intension by measuremen<

33、;/p><p>　　3.3　Experimental methods</p><p>　　The sawing anti-blocking mechanism was hung up in the soil bin device, and its ascending was controlled by hydraulic pressure system, and the wringM meas

34、ured by wring sensor was automatically noted in computer, repeat three times, and then the power consumption could be calculated by expressionP=M×n/9549, the cutting rateηcould be calculated by expressionη= (G-G0)/G

35、×100%, where,G——the total mass of effective width/kg,G0——total mass of the straws cut down between adjacent openers.</p><p>　　4　Results and discussion</p><p>　　4.1　Experiments and analysis

36、of rotation direction of the saw-tooth blade for cutting quality</p><p>　　Some experiments were done by clockwise and counter-clockwise rotation of the saw-tooth blade in the soil bin device. The results are

37、 listed in Table 1. </p><p>　　Table 1　Experimental results of rotation direction of the saw-tooth blade</p><p>　　Table 1 showed that the way of cutting straws at counter-clockwise rotation would

38、 be of benefit to improve cutting quality and throwing effect, and boost up adaptability of weight of different stubble mulch. Therefore, counter-clockwise rotation direction of the saw-tooth blade had been determined.&l

39、t;/p><p>　　4.2　Effect of the rotation speed on cutting quality</p><p>　　The experiments were done by selecting velocity 0.3 m/s of vehicle and interval 5 mm of the moved and fixed blade, and spacin

40、g 20 mm between the saw-tooth and ground as well as weight 11250 kg/hm2of the straws mulch, experimental results are shown in Fig.4. The results indicated that the power consump-tion and cutting rate would increase with

41、rising of rotation speed of the saw-tooth blade. Because the wring values of cutting straws were equal basically on the same working condition, the cutting</p><p>　　Fig.4　Relationships among rotation speed,

42、cutting rate and power consumption</p><p>　　4.3　Effect of the straw moisture on cutting quality</p><p>　　The straw moisture of the same crops is different for different autumn and reaping time.

43、The moisture were 20%, 40.5%, 64.4% and 80.16% respectively, after corn straws had been placed in field for different periods. Experiments were done by selecting velocity 0.3 m/s of vehicle and interval 5 mm between the

44、moved and fixed blade and spacing 20 mm between sawtooth and ground, and rotation speed 650 r/min as well as mass 11250 kg/hm2of straws mulch, the results were shown in Fig.5. Fig.5　Results o</p><p>　　Experi

45、mental results show that power consumption decreased with increasing of straw moisture and cutting rate of straws increased with increasing of straws moisture on the same working condition, which had connected importantl

46、y with different moisture of straws. Straws would take on bigger hardness and best firmness and fine brittleness when straws moisture was in higher, which demonstrated that it had been easy to finish to cut straws. But s

47、traws would take on tired and soft status for fine fle</p><p>　　tearing while straw moisture was up to 20%(Fig.7). </p><p>　　4.4Effect of interval between the fixed and moved blade and velocity

48、 of vehicle on cutting quality</p><p>　　Experiments were done by selecting velocity 0.3 m/s of the vehicle and spacing 20 mm between saw-tooth and ground, and rotation speed 650 r/min as well as weight 11250

49、 kg/hm2of the straws mulch, experimental results are shown in Fig.8. The results proved that power consumption increased with increasing of velocity of vehicle on the same working condition. The power consumption increas

50、ed with increasing interval between the fixed and moved blade and no fixed blade, at the same time, power consump</p><p>　　in that straws would be cut down completely while the small interval between the fix

51、ed and moved blade, the bigger interval between the fixed and moved blade or near diameter of corn straws, corn straws could be embedded into saw-tooth and participated in cutting again, so feeding quantities of straws w

52、ere increased. And straws could not be cut down completely which brought to rearing phenomenon. The cutting rate of 68 Vol.19, No.5 Transactions of the CSAE Sept.2003　 straws decreased with increa</p><p>　　5

53、　Conclusions</p><p>　　1) A new type of sawing anti-blocking mechanism, which could get rid of some shortcoming that common smooth blade is difficult to seize straws as well as high rotation speed, was design

54、ed according to the anti-blocking requirements of no-tillage planter and need in practice. The sawing anti-blocking mechanism had strong capability to seize straws and lower rotation (650 r/min) speed and lower consumpti

55、on (power consumption per unit width up to 2.95 kW/m) and higher cutting rate of straws, a new </p><p>　　2) The stress distribution of the saw-tooth blade was calculated by the ANASYS finity element software

56、. The results showed that its intension would be difficult to be destroyed and the sawtooth blade was feasible to cut corn straws.</p><p>　　3) The sawing anti-blocking mechanism realized an integrated functi

57、on of directly throwing and cutting straws by counter-clockwise. The straws could be cut down completely by two cutting modes of sustaining and no-sustaining cut. Meanwhile, the straws being cut down completely could be

58、directly thrown to the rear of opener by the former tooth horn of sawtooth blade and throwing ban device.</p><p>　　4) Experimental results showed in the soil bin device that: (1) Cutting rate of straws incre

59、ased with increasing of rotation speed of saw-tooth blade and moisture of straws, and higher moisture of straws would be of benefit to improve cutting quality; (2) Power consumption increases along with increasing of rot

60、ation speed, and that decreased with increasing of moisture of straws; ( 3 ) Cutting rate of straws decreased with increasing of velocity of the vehicle while interval between the fixed an</p><p>　　Compared

61、with the other driving anti-blocking mechanism, the theoretical analysis and experimental results showed that the sawing anti-blocking mechanism had better capability to cut and lower rotate speed and power consumption a

62、s well as stronger suitability for different stubbles mulch. </p><p>　　[References]</p><p>　　[1]　Zhang Jinguo, Gao Huanwen. Study on the strip chopping anti-blocking mechanism[J]. Transactions o

63、f the Chinese Society of Agricultural Machinery, 2000,31(4):33～35(in Chinese).</p><p>　　[2]　Luan Yuzhen, Tian Hongwei. Research on performance and matched pattern of chopper for cornstalk and root[J]. Transa

64、ctions of Jilin Agriculture University,1991,13(3): 65～68(in Chinese).</p><p>　　[3]　Mao Hanping, Chen Cuiying. Research status of the straw chopper[J]. Transactions of the Chinese Society of</p><p&

65、gt;　　Agricultural Machinery, 1996, 12 ( 2 ): 152～154 (in Chinese).</p><p>　　[4]　Mao Hanping, Chen Cuiying. Analysis of working mechanism and parameters of the straw chopper [J]. Transactions of the CSAE, 199

66、5, 11 (4): 62～66 (in Chinese).</p><p>　　[5]　Wu Fengsheng, Jin Mei. Design of 4Q—31 chopper mechanism for rice and wheat stalk[J]. Transactions of</p><p>　　the CSAE,1998,14(3):248～250(in Chinese)

67、.</p><p>　　[6]　Wu Ziyue, Gao Huanwen, Zhang Jinguo. Study on 69　Liao Qingxi et al: Design of anti-blocking mechanism for no-tillage planter cutting velocity and power requirement in a maize stalk chopping pr

68、ocess[J]. Transactions of the Chinese Society of Agricultural Machinery, 2001, 32 (2): 38～41 (in Chinese).</p><p>　　[7]　Li Jinyi, Wang Xiangfa. Cutting mechanism of forage harvester [ J ]. Agriculture Machin

69、ery and Food</p><p>　　Machinery,1995(4):19～20(in Chinese).</p><p>　　[8]　Woodworker Machinery Compiled Group. Woodworkermachinery [ M ]. Beijing: China Forest Publishing Company,1998(in Chinese).

70、</p><p>　　[9]　Zhou Canfeng, Chen Qingshou, Li Zuguang. Randomness of sawing forces and wear blade [J]. Explore Mine</p><p>　　Engineering,2000,(2):52～55(in Chinese).</p><p>　　[10]　Wa

71、ng Longbu. Elasticity theory[M]. Beijing: Science Publishing Company, 1979(in Chinese).</p><p>　　[11]　Liao Qingxi, Gao Huanwen. Experimental study on anti-blocking mechanism of the sawing anti-blocking</p

72、><p>　　mechanism for no-tillage planter [J]. Transactions of China Agricultural University, 2003, (4): 45～48 (in</p><p><b>　　Chinese).</b></p><p>　　[12]　Zhou Kaiqin. Handbo

73、ok of mechanical parts [ M ]. Beijing:Advanced Education Publishing Company, 1994.</p><p>　　[13]　Liao Qingxi, Gao Huanwen. Experimental study on the sawing anti-blocking mechanism for no-tillage planter [J].

74、 Transactions of the Chinese Society of Agricultural</p><p>　　Machinery,2003(6):to be published(in Chinese).</p><p>　　[14]　Yang Zhongpin, Yang Linqing, Guo Kangquan. A preliminary study on the t

75、echnology of making cornstalk cuticles particleboard[J]. Transactions of Northwestern Agricultural University, 1995, 10 ( 3 ): 67～72 ( in Chinese).</p><p>　　免耕播種機(jī)鋸切防堵裝置設(shè)計(jì)及其切割機(jī)理的研究</p><p>　　廖慶喜‘，

76、高煥文2，舒彩霞</p><p>　?。?.華中農(nóng)業(yè)人學(xué)工程技術(shù)學(xué)院，武漢430070; 2. （中國(guó)農(nóng)業(yè)大學(xué)工學(xué)院，北京 100083）</p><p>　　摘要:針對(duì)我國(guó)北方旱地一年兩熟地區(qū)免耕播種機(jī)堵塞現(xiàn)象和已有卞動(dòng)式防堵裝置轉(zhuǎn)速高( 1500 r/ min以上)、功耗人 (單位幅寬達(dá)16- 41.74 kW/m，含牽引功率)的現(xiàn)實(shí)問(wèn)題，設(shè)計(jì)了一種新型免耕播種機(jī)鋸切防堵裝置

77、，分析了該裝置的切割機(jī)理，應(yīng)用有限元ANSYS軟件計(jì)算了鋸齒圓盤(pán)切刀的應(yīng)力分布，得出了鋸齒圓盤(pán)切刀川于玉米秸稈切割的可行性。上槽試驗(yàn)表明:1)該裝置采用逆轉(zhuǎn)式作業(yè)，兼有無(wú)支撐和有支撐兩種切割方式，切割徹底，并能借助刀齒前角和拋撒板將已切斷秸稈定向拋送到開(kāi)溝器后方，實(shí)現(xiàn)了切割、定向拋撒一體化功能;2)秸稈切碎率隨轉(zhuǎn)速和秸稈含水率的增人而增人，秸稈含水率高時(shí)有利于提高切割質(zhì)量;3)秸稈切碎率在動(dòng)定刀間隙一定時(shí)，隨前進(jìn)速度增人而降低，小間隙時(shí)

78、無(wú)漏切和撕皮現(xiàn)象，切害日質(zhì)量高，功耗小。理論和試驗(yàn)結(jié)果表明:與其他卞動(dòng)式防堵裝置相比，鋸切防堵裝置具有良好的切害少h'}能，其轉(zhuǎn)速低 (650 r/min)、功耗小(單位幅寬為2.95 kW/m)、秸稈覆蓋量適應(yīng)性強(qiáng)，為改善免耕播種機(jī)防堵性能提供了一條新途徑。</p><p>　　關(guān)鍵詞:免耕播種機(jī);鋸切防堵裝置;切割機(jī)理;切碎率</p><p>　　免耕播種機(jī)鋸切防堵裝置設(shè)計(jì)及其

79、切割機(jī)理的研究</p><p>　　廖慶喜1，高煥文2，舒彩霞</p><p>　　（1.華中農(nóng)業(yè)人學(xué)工程技術(shù)學(xué)院，武漢430070; 2. （中國(guó)農(nóng)業(yè)大學(xué)工學(xué)院，北京 100083）</p><p>　　摘要:針對(duì)我國(guó)北方旱地一年兩熟地區(qū)免耕播種機(jī)堵塞現(xiàn)象和已有卞動(dòng)式防堵裝置轉(zhuǎn)速高( 1500 r/ min以上)、功耗大 (單位幅寬達(dá)16- 41.74 k

80、W/m，含牽引功率)的現(xiàn)實(shí)問(wèn)題，設(shè)計(jì)了一種新型免耕播種機(jī)鋸切防堵裝置，分析了該裝置的切割機(jī)理，應(yīng)用有限元ANSYS軟件計(jì)算了鋸齒圓盤(pán)切刀的應(yīng)力分布，得出了鋸齒圓盤(pán)切刀川于玉米秸稈切割的可行性。上述試驗(yàn)表明:1)該裝置采用逆轉(zhuǎn)式作業(yè)，兼有無(wú)支撐和有支撐兩種切割方式，切割徹底，并能借助刀齒前角和拋撒板將已切斷秸稈定向拋送到開(kāi)溝器后方，實(shí)現(xiàn)了切割、定向拋撒一體化功能;2)秸稈切碎率隨轉(zhuǎn)速和秸稈含水率的增大而增大，秸稈含水率高時(shí)有利于提高切割質(zhì)

81、量;3)秸稈切碎率在動(dòng)定刀間隙一定時(shí)，隨前進(jìn)速度增大而降低，小間隙時(shí)無(wú)漏切和撕皮現(xiàn)象，切割質(zhì)量高，功耗小。理論和試驗(yàn)結(jié)果表明:與其他卞動(dòng)式防堵裝置相比，鋸切防堵裝置具有良好的切割性能，其轉(zhuǎn)速低 (650 r/min)、功耗小(單位幅寬為2.95 kW/m)、秸稈覆蓋量適應(yīng)性強(qiáng)，為改善免耕播種機(jī)防堵性能提供了一條新途徑。</p><p>　　關(guān)鍵詞:免耕播種機(jī);鋸切防堵裝置;切割機(jī)理;切碎率</p>

82、<p>　　中圖分類(lèi)號(hào)：S223 文獻(xiàn)標(biāo)識(shí)碼：A </p><p>　　文章編號(hào)：1002-6819(2003)05-0064-07 收稿日期：2003-06-15</p><p><b>　　1、 說(shuō)明</b></p><p>　　免耕播種機(jī)堵塞問(wèn)題是影響

83、我國(guó)一年兩熟的北方旱地地區(qū)的生產(chǎn)效率和播種質(zhì)量關(guān)鍵因素之一。這是因?yàn)橛写罅康淖魑锔缍以谧魑锸崭畈痪镁鸵M(jìn)行播種，不留時(shí)間使作物根茬腐爛。目前，有兩種方法來(lái)解決免耕播種機(jī)的堵塞問(wèn)題：1）在播種前用秸稈刀切碎秸稈，這將導(dǎo)致增加的工作程序，并增加生產(chǎn)成本，以及推遲播期; 2）茬被安裝在免耕播種機(jī)上的切除機(jī)構(gòu)清除，如在河北農(nóng)哈哈機(jī)械有限公司的紡紗地帶和溝小麥播種機(jī)和中國(guó)產(chǎn)農(nóng)業(yè)大學(xué)[ 1 ]的2BMDF玉米地帶等等。在實(shí)踐中，駕駛砍機(jī)制在防堵

84、問(wèn)題上有巨大作用，但是因?yàn)榻斩捛兴闀r(shí)的高轉(zhuǎn)速，會(huì)產(chǎn)生更大的振動(dòng)和噪聲以及降低安全。</p><p>　　據(jù)報(bào)道，幾個(gè)主要秸稈切碎機(jī)制的刀片基礎(chǔ)線速度是37 ? 56米/秒[ 2 ] ，其中大部分是砧板機(jī)制結(jié)合切割突出了更高的驚人速度和更高的功率消耗[ 3 ] ，例如：刀片基礎(chǔ)線速度高達(dá)34米/秒能取得削減玉米秸稈的良好效果[ 4 ] ，而大米和小麥秸稈高達(dá)24米/秒 [ 5 ] 。即使玉米秸稈被與與垂直的滑動(dòng)切口

85、相切，其切割一個(gè)和兩三個(gè)秸稈的速度必須上升到10.3米/秒， 13.6米/秒， 15.8米/秒[ 6 ] ，并且有較高的功率消耗。簡(jiǎn)言之,因?yàn)轳{駛砍機(jī)制目前開(kāi)發(fā)有高旋轉(zhuǎn)速度(上面 1500轉(zhuǎn)/分 )并且更高的力量消費(fèi)(寬度單位能耗高達(dá)16 ? 41.74千瓦/米，包括牽引動(dòng)力),在實(shí)踐中以減少旋轉(zhuǎn)速度和力量消費(fèi)將是迫切的.</p><p>　　根據(jù)實(shí)際問(wèn)題，本文件中的目標(biāo)是要找到一種辦法來(lái)解決64個(gè)缺陷，制造出對(duì)

86、抓住稻草并且它必須在更高的旋轉(zhuǎn)速度下，減少能耗和提高切割效果以及防堵性能免耕播種機(jī)。另外一些實(shí)驗(yàn)，對(duì)選擇了齒形切削刀片的免耕播種機(jī)和切削機(jī)理的鋸切防堵機(jī)制進(jìn)行了研究。</p><p>　　2結(jié)構(gòu)和規(guī)則的鋸切防堵裝置的切割原理</p><p><b>　　2.1結(jié)構(gòu)和特性</b></p><p>　　鋸切防堵裝置由鋸齒圓盤(pán)切刀、定刀組合、拋撒板、

87、主軸、罩殼、機(jī)架、以及傳動(dòng)系統(tǒng)組成。鋸切防堵裝置的零件圖如圖1.其中鋸齒圓盤(pán)切刀、拋撒板、和定刀組合是該裝置的主要組成部分。設(shè)計(jì)的鋸齒圓盤(pán)直徑為350 mm,60齒;拋撒板安裝在相鄰兩鋸齒圓盤(pán)間,其最大回轉(zhuǎn)直徑為270 mm;定刀組合由鋸齒形定刀和直刀形定刀組合而成,鋸齒形定刀與鋸齒圓盤(pán)切刀配合對(duì)秸稈進(jìn)行剪切,而直刀形定刀主要起阻擋未切斷秸稈落入拋撒區(qū)的作用,同時(shí)也參與剪切。該裝置安裝在土槽試驗(yàn)臺(tái)上,工作幅寬為600 mm，相鄰間隔為2

88、00毫米。其工作特點(diǎn)是秸稈既可由鋸齒切刀直接切碎,也可由鋸齒切刀和定刀組合作用而切碎,兼有無(wú)支撐與有支撐2種切割方式,鋸齒刀端線速度低于甩刀式切割器線速度,即具有將高速砍切變?yōu)榈退黉徢械奶攸c(diǎn)。</p><p>　　開(kāi)溝鏟組合; 2.鋸齒圓盤(pán)切刀; 3.秸稈導(dǎo)向板; 4.定刀組合; 5.主軸; 6.拋散弧板；</p><p>　　7.罩殼; 8.機(jī)架; 9.軸承

89、座; 10.傳感器; 11.電纜; 12.調(diào)速電機(jī); 13.臺(tái)車(chē)懸掛臂</p><p>　　圖1　鋸齒防堵裝置結(jié)構(gòu)示意圖</p><p><b>　　2.2切割原理</b></p><p>　　鋸齒圓盤(pán)切刀由動(dòng)力驅(qū)動(dòng)作逆時(shí)針旋轉(zhuǎn)。首先，當(dāng)鋸齒底部與秸稈接觸時(shí),鋸齒嵌住秸稈進(jìn)行無(wú)支撐切割,已切斷的秸稈,依靠鋸齒圓盤(pán)切刀的刀齒和拋撒

90、板的旋轉(zhuǎn)作用向后拋送。其次，未完全切斷的秸桿在刀齒作用下,向前上方運(yùn)動(dòng)與定刀組合發(fā)生剪切作用,秸稈進(jìn)行有支撐切割,從而完成秸稈的全部切斷,由鋸齒切刀和拋散板將斷稈拋送到開(kāi)溝器后方。如此反復(fù),實(shí)現(xiàn)秸桿的連續(xù)切割和拋送。工作時(shí)圓盤(pán)鋸齒不入土,其旋轉(zhuǎn)最低點(diǎn)離地15~30 mm。就田間垂直存在的秸稈的散布情況或某個(gè)角度的前進(jìn)方向而言，鋸切防堵裝置的橫向的鋸齒是為了減少重復(fù)切割、漏割和撕裂稻谷。</p><p>　　鋸切防

91、堵裝置的工作程序制如下：1）無(wú)支撐切割階段：相對(duì)地面靜止的稻草首先被鋸齒片切割，然后秸稈被完全切除或牢牢嵌入鋸齒中。已切斷的秸稈做自由運(yùn)動(dòng)并落到鄰近的鋸齒上; 2 )拖拽交付階段:在稻草落下了相鄰近的鋸牙齒以后，他們將被拋灑裝置向上扔到前者,而且，被嵌入鋸牙齒的稻草將被更高的速度旋轉(zhuǎn)的鋸牙齒向前拋出; 3 )支撐切階段:在無(wú)支撐階段未被切割的稻草被定刀組合切割直到被完全切割。4 )拋撒階段:正在被切割的稻草直接被鋸齒圓盤(pán)切刀和拋散弧板扔

92、到開(kāi)溝器的后面,再一次,稻草將被連續(xù)地切割和拋撒。鋸切防堵裝置的工作的原理如圖2所示</p><p>　　1.待切秸稈; 2.定刀組合; 3.罩殼; 4.鋸齒圓盤(pán)切刀; 5.拋撒板;</p><p>　　6.開(kāi)溝器; 7.斷稈; 8.地表; 9.放大定刀組合; 10.鋸齒型定刀;</p><p>　　N為無(wú)支撐切割點(diǎn);K為支撐切割點(diǎn);

93、M為研究對(duì)象</p><p>　　圖2　鋸齒防堵裝置防堵原理示意圖</p><p>　　2.3鋸齒圓盤(pán)切刀的力學(xué)性能</p><p>　　切割秸稈的鋸齒圓盤(pán)切刀的切割特性屬于無(wú)金屬材料蠕動(dòng)切割,它的最終的目的是不僅提供切割表面的質(zhì)量,而且提高切碎效率，因此它能減少切削力和能量的消耗[ 9 ].因?yàn)樗?50毫米的直徑與它1.8毫米的厚度的比值超過(guò)了150 ,鋸齒圓盤(pán)切

94、刀屬于超過(guò)薄圓盤(pán)。它是根據(jù)彈性理論的水平壓力和無(wú)軸對(duì)稱問(wèn)題。并且因?yàn)殇忼X圓盤(pán)切刀是，由凸緣托盤(pán)緊縮,它的中心洞的6個(gè)自由被限制,因此它的中心部件被認(rèn)作完全約束而沒(méi)有任何旋轉(zhuǎn)和移動(dòng)。.鋸齒圓盤(pán)切刀屬于過(guò)度的切刀工具,在秸稈切割中它使其達(dá)到非傳統(tǒng)的切割力，主要原因如下：1 )內(nèi)空并且外硬的稻草結(jié)構(gòu)決定了微硬部分的差異分布,因此單個(gè)鋸齒的力在切稻草時(shí)是不明確的; 2 ) 因?yàn)殇忼X圓盤(pán)切刀的鋸齒不連續(xù)所以鋸齒圓盤(pán)切刀的全部的切削力在水平方向?qū)⒉?/p>

95、確定。這些選擇特征將使鋸齒圓盤(pán)切刀變得更理想，而且這些理想特性大小要與外部承受載荷上的承載特性和鋸齒圓盤(pán)切刀尺寸相比較。因此為保證切割的平穩(wěn)需弄清鋸齒圓盤(pán)切刀所受的力。</p><p>　　圖3 鋸齒圓盤(pán)切刀的壓力分布</p><p>　　鋸齒圓盤(pán)切刀的壓力分布由有限元ANSYS軟件計(jì)算評(píng)估。當(dāng)秸稈直徑在20~45毫米時(shí)參與切割秸稈的齒數(shù)一般為2~3個(gè)[11].由E等于210Gpa[12

96、] 、μ為0.28的25Mn制成的鋸齒圓盤(pán)切刀被分成1200隔間和1260個(gè)小節(jié)。這樣ANASYS 軟件根據(jù)鋸齒圓盤(pán)切刀切割秸稈26.8牛米的最平均扭矩 [ 13 ]的擰傳感器就獲得了X,Y和XY平面的力的分布，計(jì)算結(jié)果如下：1）看到鋸齒圓盤(pán)切刀曾擔(dān)任替代從整體應(yīng)力分布的鋸齒波，牙齒和周?chē)行目椎匿忼X波已分發(fā)給主應(yīng)力，最大壓應(yīng)力達(dá)70776帕，此外，最大的拉應(yīng)力高達(dá)19945帕。與鋸齒圓盤(pán)切刀735兆帕產(chǎn)量疲勞內(nèi)涵[ 12 ]相比，該鋸

97、齒圓盤(pán)切刀很難被摧毀，因此削減玉米秸稈是可行的; 2 ）圖3顯示，鋸齒圓盤(pán)切刀的應(yīng)力是對(duì)稱分布的，相對(duì)更壓力的區(qū)域只占整體的3.33 ％，其他占96.67 ％；3 ）在前齒首先接觸秸稈時(shí)，鋸齒圓盤(pán)切刀的前牙的承受最大的力，其應(yīng)力值在切削秸稈前最小，可是當(dāng)開(kāi)始切斷秸稈時(shí)，應(yīng)力值將大幅增加，其值將比剛切割時(shí)大倍。在完成切割秸稈時(shí)壓力將降到最低點(diǎn)。因此，鋸齒圓盤(pán)切刀將承擔(dān)交變應(yīng)力。</p><p><b>　

98、　3材料和方法 </b></p><p><b>　　3.1實(shí)驗(yàn)設(shè)備</b></p><p>　　中國(guó)農(nóng)業(yè)大學(xué)自制的土槽試驗(yàn)臺(tái)。土槽結(jié)構(gòu)尺寸20 m×0·89 m×0·6 m;臺(tái)車(chē)有效行程為16 m,前進(jìn)速度為0·12~1·2 m·s-1AKC-205型扭矩傳感器,量程300 Nm,精度

99、0·3%;自制的鋸齒式防堵裝置;控制柜;計(jì)算機(jī)操作平臺(tái)。</p><p><b>　　3.2試驗(yàn)材料</b></p><p>　　玉米秸稈,平均自然高度2·25m,平均直徑25·6 mm。它是由葉片和葉皮和骨髓組成。葉片的重量和骨髓占有全秸稈的55 ％以上而且機(jī)械強(qiáng)度低得多;皮膚的重量由表皮和束組織占據(jù)35 ％左右，皮膚機(jī)械強(qiáng)度高達(dá)90兆

100、帕的抗拉力強(qiáng)度和3兆帕的橫向抗拉力強(qiáng)度的測(cè)量，這是鋸齒圓盤(pán)切刀選擇橫向的原則以減少電力消耗至關(guān)重要的理論基礎(chǔ)。</p><p><b>　　3.3試驗(yàn)方法</b></p><p>　　鋸齒式防堵裝置懸掛在土槽臺(tái)車(chē)上,由液壓系統(tǒng)控制防堵裝置的離地間隔。功耗P的測(cè)定方法是,由扭矩傳感器測(cè)得扭矩M,數(shù)據(jù)自動(dòng)記錄在計(jì)算機(jī)上,按照扭矩傳感器的標(biāo)定及P=M×n/9 54