離心式切片機的設計
離心式切片機的設計,離心,切片機,設計
畢業(yè)設計(論文)任務書
學 院：
題 目： 離心式切片機設計
起 止 時 間： 2011.12.28～2012.5.30
學 生 姓 名：
班 級：
指 導 老 師：
系 室 主 任：
院 長：
2011 年 12 月 27 日
論文 (設計) 內(nèi)容及要求：
一、 畢業(yè)設計（論文）原始依據(jù)
隨著人們的生活水平越來越高，對一些莖塊作物的食用要求也越來越高。例如在食用土豆或一些薯類的時候要將其切成絲或片，因而離心式切片機應運而生。此設計的切片機主要針對中小型場合，例如加工作坊、食堂、家庭等；針對一些莖塊的形狀而設計的。本文分別對帶、軸、刀片、刀盤等進行設計計算，對軸承、鍵等元件進行了選擇。切片機有較高的效率，能分別對土豆、紅薯、洋蔥等進行工作?！痢痢痢痢痢痢痢?
二、 畢業(yè)設計（論文）主要內(nèi)容
主要技術參數(shù)：
切割裝置由回轉葉輪和定刀片組成；配套動力：1～1.5 kW
切片厚度：2～5 mm ；葉輪轉速：200～550轉/分；生產(chǎn)率：500～1000 kg/h
三、 畢業(yè)設計（論文）基本要求
1）所設計的切片機應具有以下特點：
①適應于各類水果和塊莖類物料；
②進行優(yōu)化設計，達到主要技術參數(shù)的要求。
2）需要提交的（電子）文稿：
（1）完成3張A0圖（折合），并要求利用計算機繪圖軟件繪出裝配原理圖及各零部件圖，正稿電子文檔各一份；
（2）設計說明書20000字以上，并有3000字的外文文獻翻譯和300字左右中英文摘要；提交正稿、正稿電子文檔各一份。要求計算合理、數(shù)據(jù)可靠，格式按南華大學畢業(yè)設計的相關規(guī)定；
（3）設計說明書的內(nèi)容包括：①設計離心式切片機的目的和意義；②設計原理和研究的主要內(nèi)容；③整體方案的確定；④主要零、部件的選擇和設計；⑤切片過程分析與計算：⑥重要零、部件的計算與校核；⑦參考文獻；⑧鳴謝。
四、 畢業(yè)設計（論文）進度安排
2011.12.27～2012.1.13 查閱文獻資料，翻譯外文資料，完成開題報告；
2012.2.8～2012.3.8 根據(jù)相關資料進行設計數(shù)據(jù)的計算與校核；
2012.3.9～2012.4.8 根據(jù)數(shù)據(jù)和相關資料完成設計說明書初稿；
2012.4.9～2012.5.8 進行CAD圖紙的繪制；
2012.5.9～2012.5.30 完成設計說明書的撰寫與裝訂，CAD出圖，檢查說明書和圖紙，準
備答辯。
五、 主要參考文獻
[1] 任顯云,侯明亮.多功能塊根狀蔬菜加工機的研制[N].青島農(nóng)業(yè)大學學報（自然科學版）,2008（01）:61~63
[2] 馬海樂.食品機械與設備[M].北京:中國農(nóng)業(yè)出版社,2004
[3] 陳云芬.綠色能源開發(fā)新亮點[N].云南科技報,2006（12）:17~18
[4] 沈再春.農(nóng)產(chǎn)品加工機械與設備[M].北京:中國輕工業(yè)出版社,1993
[5] 農(nóng)業(yè)知識.薯類食品加工發(fā)展前景[J].致富與農(nóng)資,2010（09）:37
[6] 劉秉忠.我市土豆產(chǎn)業(yè)發(fā)展前景展望——訪市農(nóng)科院院長溫埃清[N].巴彥淖爾日報,2008（05）:25~27
[7] 郭春華.云南薯類作物生產(chǎn)現(xiàn)狀與產(chǎn)業(yè)化前景分析[N].西南農(nóng)業(yè)學報, 2004（17）:384~387
[8] 陸國權.第12屆熱帶薯類作物學會國際研討會[J].世界農(nóng)業(yè),2001（01）:52~53
[9] 借力小土豆發(fā)展大經(jīng)濟[N].中國信息報,2011（04）:23~24
[10] 李良藻,湯楚宙.農(nóng)產(chǎn)品加工機械[M].長沙:湖南教育出版社，1989
[11] 謝中生.國外切片機發(fā)展評述[J].電子工業(yè)專業(yè)設備,1996（03）:36~42
[12] 厲建國,趙 濤.食品與加工機械[M].成都:四川科學技術出版社出版,1984
[13] 蔡 軍,李靜霞.6P-400型切片機[J].農(nóng)業(yè)機械化與電氣化,1998（01）:31~32
[14] 李昌滿.6PSL-550型離心式人參切片機[J].農(nóng)村機械化,1997（01）:16~16
[15] 李昌滿,劉福文.離心式人參切片機設計研究[J].糧油加工與食品機械,1996（06）:22~23
[16] 濮良貴,紀明剛.機械設計（第八版）[M]. 北京:高等教育出版社,2006.05
[17] 成大先.機械設計手冊（第五版）1~ 5卷[M].北京:化學工業(yè)出版社,2007
[18] 寇尊權,王 多.機械設計課程設計[M]. 北京:高等教育出版社,2006.10
[19] Deyong Yang,Jianping Hu.Study and Improvement for Slice Smoothness in Slicing Machine of Lotus Root[J].Ministry of Education Jiangsu Province Jiangsu University.2009(03)
[20] Laichun Suo, Pingping Liu. Numerical Simulation of Cutting Process of The Slice Components Cutting Machine[J].Journal of Harbin Institute of Technology (New Series).Vol 17.no.1.2010。
[21] Yuan Liu, Haitao Wu. Design According to the Pastry Slice Machine of SolidWorks Terrace[J].Faculty of Mechanical and Electrical Engineering , Kunming Univer sity of Science and Technolog y, Kunming , China.2011(03)
指導教師：
年 月 日
南華大學機械工程學院畢業(yè)設計（論文）
Study and Improvement for Slice Smoothness in Slicing Machine of Lotus Root
De-yong YANG ,Jian-ping HU , En-zhu WEI , Heng-qun LEI ,and Xiang-ci KONG
Key Laboratory of Modern Agricultural Equipment and Technology
Ministry of Education Jiangsu Province Jiangsu University . Zhenjiang .
Jiangsu Province .P.R.China212013
Tel.: +86-511-8;Fax:+86-511-8
yangdy@163.com
Jinhu Agricultural Mechanization Technology Extension Station . Jinhu county
Jiangsu Province .P.R.China 211600
Abstract: Concerning the problem of the low cutting quality and the bevel edge in the piece of lotus root, the reason was analyzed and the method of improvement was to reduce the force in the vertical direction of link to knife. 3D parts and assemblies of cutting mechanism in slicing machine of lotus were created under PRO/E circumstance. Based on virtual prototype technology, the kinematics and dynamics analysis of cutting mechanism was simulated with ADAMS software, the best slice of time that is 0.2s~0.3s was obtained，and the curve of the force in the vertical direction of link to knife was obtained. The vertical force of knife was changed according with the change of the offset distance of crank. Optimization results of the offest distance of crank showed the vertical force in slice time almost is zero when the offset distance of crank is -80mm. Tests show that relative error of thickness of slicing is less than 10% after improved design, which is able to fully meet the technical requirements.
Keywords: lotus root; cutting mechanism; smoothness; optimization
1 Introduction
China is a country of producing lotus toot, lotus root system of semi-finished products of domestic consumption and external demand for exports is relatively large. In order to improve efficiency, reduce labor intensity, the group work, drawing on the principle of the artificial slice based on the design and development of a new type of lotus root slice (Bi Wei and Hu Jianping, 2006). This new type of slice solved easily broken cutting, stick knives, hard to clean up and other issues, but the process appears less smooth cutting, and some have a problem of hypotenuse piece of root. In this paper, analyzing cutting through the course of slice knife, the reasons causing hypotenuse was found, and the corresponding improvement of methods was proposed and was verified by the experiments.
2 Structure of Cutting Mechanism of Slicing Machine
Cutting mechanism of the quality of slice lotus root is the core of the machine, the performance of its direct impact on the quality of slice. Virtual prototyping of cutting mechanism of slice lotus root (Fig.1) was built by using PRO/E, and mechanism diagram of the body is shown in Fig.2. Cutting principle of lotus slicer adopted in the cardiac type of slider-crank mechanism was to add materials inside, which can be stacked several lotus root, lotus root to rely on the upper part of the self and the lower part of the lotus press down, so that it arrives in the material under the surface of the baffle. While slider-crank mechanism was driven by motor, the knife installed on the slider cut lotus root. In the slice-cutting process it was found that parallelism of the surface at both ends of part of piece lotus was not enough, which can not meet the technical requirements for processing.
Fig.1 Virtual prototyping of cutting mechanism
Fig.2 Diagram of cutting mechanism
Study and improvement for slice smoothness in slicing machine of lotus root.
3 The Cause of the Bevel Edge
Uneven thickness and bevel edge of cutting were related with forces on the slice knife in the process of cutting. In accordance with cutting mechanism (Fig.2), without taking into account the friction and weight, the direction of force F of point C was along the link. Force F may be decomposed with a horizontal direction force component and a vertical direction force component. The horizontal force component pushed the knife moving for cutting, but the vertical force component caused the knife moving along the vertical direction. Because of the gap between the slider and the rail, the vertical force component made the blade deforming during the movement, and knife could not move along the horizontal direction to cut lotus root, which caused the emergence of bevel edge. Thus, to reduce or eliminate the vertical force component in the cutting-chip was key to solve the problem of bevel edge and improve the quality of cutting.
When crank speed was 69~90r/min, the horizontal and vertical direction of the force curve of point C connecting link and the blade hinge are shown in Fig.3 and Fig.4 respectively. As can be seen from the chart, with the crank speed improvement the horizontal and vertical direction of the force in point C also increased. The horizontal force changed relatively stable during 0s~0.2s, which was conducive to cutting lotus, but the vertical force increased gradually. The more the vertical force was, the more detrimental to the quality cutting.
Fig.3 Horizontal force of C
Fig.4 Vertical force of C
4 Simulation and Optimization
If improving flatness of the slicer, the structure was optimized to reduce the vertical force component, so as far as possible the level of cutting blade.
When crank speed was 60~90r/min the velocity curve and acceleration curve of the knife center of mass are shown in Fig.5 and Fig.6 respectively. According to the speed curve, the speed of the knife center of mass was relatively large in a period of 0.2s~0.3s. In accordance with the requirements that the knife should have a higher speed during cutting lotus, so this period time was more advantageous to cutting than other terms. According to acceleration curve. When calculates by one cycle, the acceleration value was relatively quite small in the period of time, 0.15s~0.3s compared with other time section. Which indicated that the change of velocity was relatively small, simultaneously the force of inertia was small, and the influence of vibration caused by the force was small to the slicer. Therefore,this period of time, 0.2s~0.3s, to cut root piece was advantageous in enhances the cutting quality of lotus root piece.
Fig.5 Velocity curve of center of mass of knife
Fig.6 Acceleration curve of center of mass of knife
Based on the above analysis, the vertical force component between link and the knife was the main reason for bevel edge. According to the characteristics of slider-crank mechanism, reducing the vertical force on the knife in the period of cutting time by altering crank offest was tried to enhance the quality of the cutting. When crank speed was 60r/min, the crank eccentricity was optimized. When the offest of the crank was 40mm, 20mm, 0mm, -20mm, -40mm, -80mm, -120mm respectively, the mechanism was simulated and the vertical force curves under different crank eccentricity were obtained, as shown in Fig.7.
Fig.7 vertical force curves in different offest
Fig.7 indicates that: When the eccentricity was positive, the vertical force on point C increased gradually in 0.2s~0.3s with the increase of crank oddest: When the eccentricity was negative, the force decreased gradually first and then begun to increase along with -80mm. So when the offest was -80mm, the numerical of the force in 0.2s~0.3s achieved the minimum and the quality of cutting was the best.
When the crank rotated in the other speed, there were the same optimization results. Fig.8 show the curve of vertical force in the offest of 0mm and -80mm when the speed of crank was 80r/min. From the Fig.8 it is obvious that vertical direction of the force of point C in 0.2s~0.3s reduced a lot when the eccentricity is -80mm. Therefore, the vertical force could be reduced by optimizing the slider-crank mechanism of eccentricity.
Fig.8 Vertical force of C
5 Experimental Analysis
The relative error of thickness of lotus root piece reflects the quality of cutting. Which is generally controlled of 10%. There always existed bevel edge phenomenon and the relative error of thickness was about 15% before structural optimization and improvement, which was difficult to meet the technical requirements. The offset in the slider-crank mechanism was optimized, and its structure was improved according to the results of optimization. After improvement cutting test were done in the conditions of crank speed for 80~110r/min and statistical data about the relative error of thickness was shown in Table.1. Four levels were separated in the experiment, three times for each level.
Table 1 Relative error of thickness of slicing
NO
Crank speed (r/min)
80
90
100
110
1
6.6%
6.4%
8.2%
9.5%
2
5.3%
6.1%
8.5%
9.2%
2
6.4%
7.9%
7.9%
9.4%
Average
6.1%
6.8%
8.2%
9.4%
It is derived from Table.1 that the relative error of the thickness of slices could meet the technical indicators when the crank speed was 80~110r/min, especially in the crank rotation speed 80r/min, 90r/min the relative error of thickness was less than 7%,and high quality was achieved.
6 Conclusion
The vertical force component acted on the knife in the process of cutting was the main reason for surface formation and bevel edge, so the key of improving the quality was to reduce the vertical force. Through slice knife and velocity acceleration simulation analysis the best time for slicing, 0.2s~0.3s, was obtained. By optimizing the offset of the crank the vertical force during cutting time was greatly reduced when the offset was -80mm. Experiments were made after improving the design of lotus root slicer, which results showed that by changing the offset of the crank, the relative error of the thickness could fully meet the requirements of less than 10%. So the problem was basically solved that the flatness was not ideal and was the issue of bevel edge.1
References
[1] Wei,B . jianping,H.: Study of lotus root slicing techniques and design of new model,Journal of agricultural mechanization research (12),112-114(2006)(in Chinese)
[2] Enzhu, w.:the simulation and optimization on the new slicing machine of lotus root based on virtual prototype technology .jiangsu university [2008)[in Chinese)
[3] Ce ,Z .:mechanical dynamics .higher education press[1999)
[4]Xiuning ,C.:optimal design of machinery .zhejiang university press[1999)
[5]Liping,C.,yunqing,Z.,weiqun,R.: dynamic analysis of mechanical systems and application Guide ADAMS . Tsinghua university press ,Beijing(2005)
Page 8 of 8
南華大學機械工程學院畢業(yè)設計（論文）
蓮藕切片機切片平滑度的研究和改進
楊德勇 胡建平 韋恩鑄 雷恒群 孔祥次
農(nóng)業(yè)設備和現(xiàn)代技術的國家重點實驗室
江蘇省教育部 江蘇大學.江蘇.鎮(zhèn)江
中國 江蘇省 212013
電話 +86-511-8:傳真+86-511-8
yangdy@163.com
金湖農(nóng)業(yè)機械化技術推廣站
中國 江蘇省 211600
摘要：針對蓮藕切削質(zhì)量不高和蓮藕片的斜邊問題，通過分析原因，改進的方法就是減少刀在垂直方向的力。在Pro/E的環(huán)境下創(chuàng)建了蓮藕切片機的3D零件和裝配體。基于虛擬樣機技術，切片機的運動學和動力學分析是在ADAMS軟件模擬實驗下實現(xiàn)的，獲得最佳的切削時間為0.2s~0.3s，并且得到了刀在垂直方向上的力的曲線。刀在垂直方向上的力隨著曲柄偏移量的變化而改變。曲柄的偏移量優(yōu)化結果表明，當曲柄的偏移量為-80mm時，在切削時間里的垂直方向上的力幾乎為零。測試結果表明，經(jīng)過改進設計后，切片厚度的相對誤差小于10％，這是能夠完全滿足技術要求的。
關鍵詞：蓮藕；切削機制；平滑度；優(yōu)化
1前言
中國是一個生產(chǎn)蓮藕的大國，蓮藕半成品系列食品的國內(nèi)消費和外部的出口需求量比較大，為了提高工作效率，減輕勞動強度，設計工作組，在借鑒人工切蓮藕片原理的基礎上設計和開發(fā)一個新型的切片機（畢偉，胡建平，2006年）。這種新型的切片機容易解決切片易斷，粘刀，難清理等問題，但過程中還是出現(xiàn)不平滑切削和一些斜邊的現(xiàn)象。本文通過對切削時刀片的分析，發(fā)現(xiàn)了一些造成斜邊現(xiàn)象的原因，并提出了相應的改進方法，并通過實驗得到了驗證。
2 切片機切削結構原理
蓮藕切片的切削原理是機器的核心，性能直接影響切片的質(zhì)量。在使用PRO / E平臺下建立了蓮藕切削原理的虛擬樣機（圖1），結構本身的原理圖如圖2所示。蓮藕切片機的切削原理是通過核心的曲柄滑塊機構往里面添加材料，它可以堆疊許多蓮藕，蓮藕依靠自己本身上部和下部的蓮藕，以便它能夠到達擋板的表面。曲柄滑塊機構是由電機驅(qū)動，在滑塊上安裝刀片切蓮藕。但在切削過程中，發(fā)現(xiàn)在一塊蓮藕兩端面的平行度是不足夠的，這不能滿足加工的技術要求。
圖1 蓮藕切削原理的虛擬樣機
圖2 切片原理結構圖
切片機的蓮藕片平滑度的研究和提高。
3 斜邊的原因
厚薄不均勻和斜邊問題與刀片在切削過程中的力量有關。按照結構原理（圖2），不考慮相互間摩擦和重量的因素，C點的力F的方向是沿鏈接方向。力F可以分解為一個水平方向的分力和一個垂直方向的分力。水平分力造成的刀沿垂直方向移動切削，但垂直方向上的力造成的刀沿垂直方向移動。由于滑塊和導軌之間的差距，垂直分力會使葉片在運動時變形，刀不能沿水平方向切蓮藕，導致出現(xiàn)斜邊。因此，解決斜邊的問題和提高切削質(zhì)量的關鍵是減少或消除切片時的垂直分力。
當曲軸轉速為60~90轉/分鐘，C點和刀片連接部位的水平和垂直方向的力曲線如圖3和圖4所示。從圖上可以看出，當曲柄的速度提高后，C點水平和垂直方向的力也增加了，相對穩(wěn)定的水平力有利于切削蓮藕期間，但垂直方向上的力也逐漸增加。越多的垂直方向上的力，越不利于切削的質(zhì)量。
圖3 C點的水平力
圖4 C點的垂直方向上的力
4 仿真和優(yōu)化
如果提高切片的平整度，結構優(yōu)化可以減少垂直分力，所以盡可能的要刀片保持水平。
當曲柄速度60~90轉/分鐘時，刀質(zhì)量中心的速度曲線和加速度曲線分別如圖5和圖6所示。根據(jù)速度曲線，在0.2s~0.3s時間里，刀質(zhì)量中心的速度是比較大的。按照刀應該有更高的速度來切削蓮藕的要求，這期間的時間切削比其他時間更有利。根據(jù)加速度曲線，一個周期計算，在0.15s~0.3s的時間里，相比其他的時間段加速度值是相對比較小。這表明速度的變化相對較小，同時慣性產(chǎn)生的力小，切片機受力引起的振動影響小。因此，在0.2s~0.3s里來切蓮藕有利于提高蓮藕片的切削質(zhì)量。
圖5 刀片的質(zhì)量中心速度曲線
圖6 刀片的質(zhì)量中心加速度曲線
基于上述分析，刀片和鏈接之間的垂直分力是造成斜邊的主要原因。根據(jù)曲柄滑塊機構的特點，在切削時間段通過改變曲柄偏移來減少對刀垂直方向上的力，從而提高切削質(zhì)量。當曲軸轉速為60轉/分鐘，曲軸偏心率得到了優(yōu)化。當曲柄偏移量分別為40mm，20mm，0mm，-20mm, -40mm, -80mm, -120mm時，在不同的偏移量下模擬其原理，獲得了垂直方向上的力曲線，如圖7所示。
圖7 不同偏移下的垂直方向上的力曲線
圖7表明：偏心率為正值時，在0.2s~0.3s隨著曲柄偏移量增加，C點的垂直方向上的力逐漸增加；當偏心率為負值時，隨著曲柄偏移量的增加，力開始下降，然后在-80mm處開始逐步增加。所以，當偏移量為-80mm，力在0.2s~0.3s的數(shù)值降到最低，這時切削質(zhì)量是最佳的。
當曲柄在其他的速度旋轉，有相同的優(yōu)化結果。圖8顯示的是曲軸轉速為80轉/分鐘、曲軸偏移量為0mm到-80mm時，垂直方向上的力。從圖8可以看出，當偏移量為-80mm時，C點垂直方向的里在0.2s~0.3s大大減少。因此通過優(yōu)化曲柄偏移量可以減少垂直方向上的力。
圖8 C點的垂直方向上的力
5 實驗分析
蓮藕片的厚度相對誤差反映了切削質(zhì)量，一般控制在10％。在結構的優(yōu)化和改進前，總是存在斜邊現(xiàn)象，厚度相對誤差約為15%左右，這是難以滿足的技術要求。對曲柄滑塊機構的偏移量進行優(yōu)化，并根據(jù)優(yōu)化的結果，它的結構有了一些改進。改進后的曲柄，在速度的條件為80?110轉/分鐘時，切削試驗出來的厚度相對誤差的統(tǒng)計數(shù)據(jù)如表?1所示。從四個速度層次進行分析實驗，每個速度層次進行三次實驗。
表 1 切片厚度相對誤差
序號
曲柄速度(轉/分鐘)
80
90
100
110
1
6.6%
6.4%
8.2%
9.5%
2
5.3%
6.1%
8.5%
9.2%
2
6.4%
7.9%
7.9%
9.4%
平均
6.1%
6.8%
8.2%
9.4%
來自表1的數(shù)據(jù)顯示，當曲柄速度為80?110轉/分鐘時，切片厚度相對誤差能滿足各項技術指標，尤其是當曲軸旋轉速度為80轉/分鐘和90轉/分鐘時，厚度相對誤差低于7％，達到了較高的切削質(zhì)量。
6 總結
切削的過程中，表面不平整和斜邊的主要原因是作用在刀組件上的垂直分力，因此提高質(zhì)量的關鍵是減小垂直方向上的力。通過刀片質(zhì)量中心速度和加速度模擬分析曲線得到，0.2s?0.3s是切片的最佳時間。通過優(yōu)化曲柄的偏移量，當偏移量為-80mm時，垂直方向上的力在切削時間大大減小。經(jīng)過實驗改進蓮藕切片機后，實驗結果表明，通過改變曲柄偏移量，厚度相對誤差不到10％，完全能夠滿足要求。因此，平整度不理想和斜邊問題基本解決。
參考文獻
[1] 胡建平.蓮藕切片技術的學習和新的模型設計. 中國農(nóng)業(yè)機械化研究（12）,112~114.2006
[2] 韋恩鑄.基于虛擬樣機技術的新型蓮藕切片機仿真優(yōu)化.江蘇大學,2008
[3] 張 策.機械動力學.高等教育出版社,1999
[4] 陳秀林.機械優(yōu)化設計.浙江大學出版社,1999.
[5] 陳麗萍,鄭云群,容微群.機械系統(tǒng)的動態(tài)分析和應用指南ADAMS.北京:清華大學出版
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