生產(chǎn)線皮帶運(yùn)輸機(jī)控制系統(tǒng)設(shè)計(jì)
生產(chǎn)線皮帶運(yùn)輸機(jī)控制系統(tǒng)設(shè)計(jì),生產(chǎn)線皮帶運(yùn)輸機(jī)控制系統(tǒng)設(shè)計(jì),生產(chǎn)線,皮帶,運(yùn)輸機(jī),控制系統(tǒng),設(shè)計(jì)
封面樣式
湖 南 科 技 大 學(xué)
英文文獻(xiàn)翻譯
學(xué) 生 姓 名:
學(xué) 院: 機(jī)電工程學(xué)院
專業(yè)及班級(jí): 機(jī)械設(shè)計(jì)制造及其自動(dòng)化四班
學(xué) 號(hào):
指導(dǎo)教師:
2015 年 6 月 6 日
國(guó)內(nèi)外帶式輸送機(jī)動(dòng)力學(xué)與控制
宋偉剛
摘要:分析國(guó)內(nèi)外帶式輸送機(jī)動(dòng)力學(xué)的研究進(jìn)展與方法,進(jìn)而給出動(dòng)力學(xué)分析的基本方法與過(guò)程。
關(guān)鍵詞:帶式輸送機(jī);動(dòng)力學(xué)模型;動(dòng)態(tài)分析
1 .帶式輸送機(jī)的設(shè)計(jì)計(jì)算方法與動(dòng)力學(xué)問(wèn)題
帶式輸送機(jī)是當(dāng)代最重要的散狀物料輸送設(shè)備,廣泛地應(yīng)用于煤炭、鋼鐵、電力、建材等工業(yè)領(lǐng)域,也是港口、料場(chǎng)等物流系統(tǒng)中散料存儲(chǔ)、輸送的重要裝備。
帶式輸送機(jī)的設(shè)計(jì)計(jì)算方法的發(fā)展經(jīng)歷了漫長(zhǎng)的歷史,作為機(jī)械設(shè)備的帶式輸送機(jī)其設(shè)計(jì)計(jì)算方法和其他機(jī)械系統(tǒng)類似地,計(jì)算式可以從基本的力學(xué)定理、物理學(xué)法則所得出。其進(jìn)展隨著理論研究的深入,計(jì)算手段的進(jìn)步越來(lái)越細(xì)致與精確。最早可以見到的計(jì)算方法是德國(guó)HETZL方法,另外,一些公司也提出了較有影響的計(jì)算方法,如美國(guó)的GOODYEAR公司、GOODRICH公司和日本的阪東橡膠公司等計(jì)算方法,這些計(jì)算方法的主要阻力計(jì)算都屬于概算法。20世紀(jì)的50年代,德國(guó)的LACHMANN和VIERLING教授提出了精確計(jì)算主要阻力中各個(gè)分項(xiàng)的計(jì)算方法、80年代以后荷蘭的SPAANS教授、美國(guó)的CDI公司進(jìn)一步發(fā)展了精確計(jì)算主要阻力中各個(gè)分項(xiàng)的計(jì)算方法,他們都是從帶式輸送機(jī)主要阻力的構(gòu)成角度得出相應(yīng)的各個(gè)分項(xiàng)。然而精確計(jì)算方法當(dāng)前仍然極少采用,即使在德國(guó)標(biāo)準(zhǔn)中。
從功率和張力計(jì)算過(guò)程看,出現(xiàn)過(guò)兩種不同的方法:一種方法是根據(jù)輸送帶垂度條件確定傳動(dòng)滾筒奔離點(diǎn)張力,再采用逐點(diǎn)張力計(jì)算方法計(jì)算出傳動(dòng)滾筒相遇點(diǎn)張力,滾筒上的張力差就是所要求的驅(qū)動(dòng)功率。早期的蘇聯(lián)計(jì)算方法和TD75、DX帶式輸送機(jī)設(shè)計(jì)手冊(cè)[7-9]主要是采用此類方法;另一種是直接將各種阻力疊加在一起得出輸送機(jī)總的功率需求,進(jìn)而通過(guò)輸送帶和滾筒不打滑條件和垂度限制條件按逐點(diǎn)計(jì)算方法計(jì)算輸送帶各特征點(diǎn)張力。在當(dāng)前帶式輸送機(jī)設(shè)計(jì)計(jì)算的主導(dǎo)方法德國(guó)標(biāo)準(zhǔn)DIN22101-2002和CEMA(第5版)帶式輸送機(jī)功率和張力計(jì)算方法。DIN22101計(jì)算方法屬于上述的第2類、而CEMA計(jì)算方法介乎第1和第2類之間,這是由于該方法考慮到運(yùn)行阻力和張力相關(guān)。從上述方法的分析可以看出,計(jì)算結(jié)果的是否準(zhǔn)確的關(guān)鍵問(wèn)題并不取決于計(jì)算次序,而在于輸送機(jī)運(yùn)行過(guò)程中的阻力計(jì)算是否準(zhǔn)確。
帶式輸送機(jī)的運(yùn)行過(guò)程由啟動(dòng)-穩(wěn)定運(yùn)行-停機(jī)構(gòu)成,盡管一條輸送機(jī)在絕大部分時(shí)間處于穩(wěn)定運(yùn)行或停機(jī)狀態(tài),但是由于在啟動(dòng)和停機(jī)過(guò)程會(huì)有加速或減速產(chǎn)生慣性載荷,因而在輸送機(jī)的設(shè)計(jì)中需要考慮動(dòng)載荷的影響。傳統(tǒng)的設(shè)計(jì)計(jì)算方法(如DIN22101)是將輸送機(jī)上所有運(yùn)動(dòng)部件看成剛性聯(lián)結(jié)在一起,同時(shí)加速或減速(可以看作“準(zhǔn)靜態(tài)”),不考慮輸送帶的粘彈性性質(zhì)以及在啟動(dòng)、停機(jī)過(guò)程中驅(qū)動(dòng)的輸入力(矩)隨時(shí)間變化的作用,從而不能給出輸送機(jī)在啟動(dòng)、停機(jī)過(guò)程的瞬態(tài)過(guò)程。從帶式輸送機(jī)的瞬態(tài)過(guò)程角度來(lái)看,在下列幾個(gè)方面存在動(dòng)力學(xué)問(wèn)題:
(1)輸送機(jī)的啟動(dòng)、停機(jī)過(guò)程的輸送機(jī)縱向的速度和應(yīng)力(張力)的傳播
帶式輸送機(jī)(特別是大型帶式輸送機(jī))的結(jié)構(gòu)特點(diǎn)體現(xiàn)在:輸送帶、托輥和物料是散布在輸送線上,輸送帶本質(zhì)上是粘彈性體,因而驅(qū)動(dòng)裝置的啟動(dòng)過(guò)程是逐漸地將驅(qū)動(dòng)力和速度傳播到整個(gè)輸送帶上,輸送機(jī)的啟動(dòng)是一個(gè)漸進(jìn)的過(guò)程,輸送帶的張力由靜止?fàn)顟B(tài)下的張力變化到穩(wěn)定運(yùn)行下的張力,張力的變化導(dǎo)致輸送帶的變形量的變化,由拉緊裝置的伸長(zhǎng)或縮短和輸送帶的撓度變化所吸收。另一個(gè)特點(diǎn)是多驅(qū)動(dòng)單元與多點(diǎn)驅(qū)動(dòng)。當(dāng)沒有考慮到縱向動(dòng)力學(xué)瞬態(tài)過(guò)程的影響可能出現(xiàn)的問(wèn)題包括:
1)選擇過(guò)大的驅(qū)動(dòng)設(shè)備的投資費(fèi)用過(guò)高,造成啟動(dòng)和停機(jī)過(guò)程中的輸送帶的張力過(guò)大;
2)變坡線路的帶式輸送機(jī)停機(jī)過(guò)程中造成輸送帶的局部張力過(guò)?。?
3)拉緊裝置的位移設(shè)計(jì)的不準(zhǔn)確,出現(xiàn)拉緊行程不夠或拉緊反應(yīng)滯后,不能滿足系統(tǒng)的傳動(dòng)要求;
4)驅(qū)動(dòng)裝置、制動(dòng)裝置和拉緊裝置的配置與位置布置不合理;
5)在多驅(qū)動(dòng)單元系統(tǒng)中啟動(dòng)或制動(dòng)過(guò)程中由于加載次序與時(shí)間控制上的問(wèn)題產(chǎn)生振蕩,造成各驅(qū)動(dòng)單元的輸出無(wú)法實(shí)現(xiàn)同步與功率平衡。
(2)輸送帶在橫截面上的垂直于輸送帶面的振動(dòng)
輸送帶在張力、載荷和輸送帶固有特性下,當(dāng)托輥的激振頻率與固有頻率接近或一致時(shí),在輸送帶的橫截面的鉛垂面方向存在振動(dòng)問(wèn)題,此振動(dòng)將會(huì)使輸送機(jī)機(jī)架甚至建筑物發(fā)生破壞[12-14]。
(3)輸送帶在輸送機(jī)橫向的跑偏
輸送帶跑偏是廣泛存在的問(wèn)題,跑偏是引起輸送機(jī)停機(jī)、撒料、機(jī)架堵塞、輸送帶使用期限縮短等后果的主要原因,跑偏的調(diào)整是非常麻煩的事情,從理論上對(duì)跑偏分析方法是建立輸送帶橫用運(yùn)動(dòng)動(dòng)力學(xué)方程,進(jìn)而應(yīng)用穩(wěn)定性理論進(jìn)行分析。
(4)輸送物料量的變化引起的運(yùn)行狀態(tài)的變化
輸送物料量的變化會(huì)引起運(yùn)行狀態(tài)的變化,然而這種變化相對(duì)于輸送帶的波動(dòng)周期要長(zhǎng)得多,因而一般不會(huì)單獨(dú)對(duì)此問(wèn)題進(jìn)行研究,研究的關(guān)注點(diǎn)是不同物料載荷分布下的縱向波動(dòng)問(wèn)題。
(5)受料過(guò)程物料對(duì)托輥和輸送帶的沖擊
輸送帶受料處物料沖擊(特別是大塊物料)的沖擊直接危害帶式輸送機(jī)的正常使用,是輸送帶損壞的重要原因,導(dǎo)致輸送帶發(fā)生磨損、上覆蓋層、帶芯、甚至是整個(gè)輸送帶的擊穿,致使輸送帶的損壞和撕裂,增加托輥的沖擊載荷。
(6)輸送帶經(jīng)過(guò)托輥的輸送帶覆蓋層的擠壓變形與恢復(fù)輸送帶下覆蓋層在輸送帶的擠壓變形是產(chǎn)生輸送機(jī)主要阻力中的壓陷阻力的原因。
從帶式輸送機(jī)的控制角度來(lái)說(shuō),除滿足帶式輸送機(jī)滿足工藝要求的順序控制與不同輸送量下的速度改變以及對(duì)帶式輸送機(jī)的保護(hù)控制外,主要的控制要求僅體現(xiàn)在對(duì)輸送機(jī)瞬態(tài)過(guò)程的控制。
從上述的分析可見,帶式輸送機(jī)動(dòng)力學(xué)問(wèn)題涉及帶式輸送機(jī)系統(tǒng)的各個(gè)方面,本文將重點(diǎn)討論上面所列問(wèn)題的第(1)方面,而對(duì)其他5個(gè)方面的問(wèn)題僅做簡(jiǎn)要探討。首先分析國(guó)內(nèi)外的研究進(jìn)展與方法;進(jìn)而給出動(dòng)力學(xué)分析的基本方法與過(guò)程,包括:數(shù)學(xué)模型、求解技術(shù)、軟件的發(fā)展;典型帶式輸送機(jī)系統(tǒng)的動(dòng)力學(xué)分析、動(dòng)態(tài)分析的作用及其應(yīng)用范圍等。
動(dòng)力學(xué)研究的主要內(nèi)容與方法:
帶式輸送機(jī)的動(dòng)力學(xué)分析與動(dòng)態(tài)設(shè)計(jì)方法的研究與應(yīng)用之所以受到廣泛的關(guān)注,是由于隨著帶式輸送機(jī)系統(tǒng)的大型化,傳統(tǒng)的半靜態(tài)設(shè)計(jì)計(jì)算方法已經(jīng)不能滿足工程實(shí)際應(yīng)用的需求。另一方面,動(dòng)態(tài)設(shè)計(jì)方法的采用有助于提高設(shè)計(jì)水平,達(dá)到提高企業(yè)競(jìng)爭(zhēng)力。動(dòng)態(tài)設(shè)計(jì)與動(dòng)態(tài)優(yōu)化設(shè)計(jì)也是面向產(chǎn)品廣義質(zhì)量的綜合設(shè)計(jì)方法[96]的重要組成部分。因而,帶式輸送機(jī)的動(dòng)力學(xué)與動(dòng)態(tài)設(shè)計(jì)方法涉及到帶式輸送機(jī)的所有方面,即:
1)帶式輸送機(jī)各個(gè)運(yùn)動(dòng)部件的力學(xué)性能,特別是輸送帶;
2)輸送機(jī)運(yùn)行阻力的計(jì)算方法及其規(guī)律性問(wèn)題;
3)驅(qū)動(dòng)、制動(dòng)、拉緊、傳動(dòng)裝置的結(jié)構(gòu)與特性以及控制方法;
4)帶式輸送機(jī)各運(yùn)動(dòng)部件的數(shù)學(xué)模型以及由各個(gè)部件的數(shù)學(xué)模型所構(gòu)成的整機(jī)模型;
5)所建立的動(dòng)力學(xué)模型的求解方法與軟件開發(fā);
6)各種驅(qū)動(dòng)裝置、制動(dòng)裝置和拉緊裝置動(dòng)態(tài)響應(yīng)對(duì)啟制動(dòng)特性的影響;
7)復(fù)雜帶式輸送機(jī)系統(tǒng)各種運(yùn)行工況下動(dòng)態(tài)行為研究,包括啟動(dòng)、制動(dòng)、上運(yùn)、下運(yùn)等;
8)各種工況下的現(xiàn)場(chǎng)測(cè)試分析,控制系統(tǒng)的動(dòng)態(tài)調(diào)整。
Dynamics and Control of Belt Conveyor at Home and Abroad
SONG Wei-gang
Abstract: analysis of the belt conveyor dynamics both at home and abroad research progress and the method, and dynamics analysis of the basic method and the process is given.
Key words: belt conveyor; Dynamic model; A dynamic analysis
1. The belt conveyor and the design method of dynamic problems
Belt conveyor is the most important contemporary material conveying equipment, widely used in industrial area, such as coal, steel, power, building material, port, yard logistics system such as releasing the importance of materials storage, transportation and equipment.
The development of the design and calculation method of belt conveyor has experienced a long history, as the belt conveyor design calculation methods of mechanical equipment and other mechanical systems similarly, calculation formula can be from basic mechanics theorem, obtained from the laws of physics. Its progress with the deepening of theoretical research, the calculation method of progress more and more detailed and accurate. Is the earliest can meet the calculation method of German HETZL method, in addition, some companies are put forward and the calculation method of influential companies, such as America's GOODYEAR GOODRICH and Japan e. calculation methods, such as east rubber company, the main resistance calculation of these calculation methods are approximate method. The 50 s of the 20th century, the German professor LACHMANN and VIERLING presented the calculation method of precise calculation of the main resistance of each component, SPAANS professor after the Netherlands in the 80 s, the United States of CDI company in the further development of the precise calculation of the main resistance and the calculation method of each item they are from the Angle of the composition of the main belt conveyor resistance of the various disciplines. Accurate method to calculate the current still rarely used, however, even in the German standa
From the power and tension calculation process, there have been two different methods: a method is based on a conveyor belt sag condition determine the transmission drum ran away from the point of tension, then use point by point tension calculation method to calculate the transmission drum meet some tension, tension difference of the roller is the driving power required. The calculation method of the Soviet union and early TD75, DX belt conveyor design manual [7-9] is mainly adopted such methods; Another kind is the superposition of all kinds of resistance directly together conveyor total power demand, and then through the conveyor belt and roller not skid and sag restriction conditions according to the point by point calculation method to calculate the conveyor belt tension of the feature points. In the current belt conveyor design and calculation the dominant method of Germany and CEMA standard DIN22101-2002 (fifth edition) power belt conveyor, and tension calculation method. DIN22101 calculation method belongs to the second class, and CEMA calculation method between 1 and 2 class, this is due to the method considering the running resistance and tension. Can be seen from the analysis of the above methods, the calculated results are accurate sequence does not depend on the key problems in the calculation, but in the conveyor running resistance in the process of calculation is accurate.
The operation process of belt conveyor consists of start-up - stable operation - stop, although in most of the time in the stable operation of a conveyor or stop state, but the process at the start and stop will have inertia load produced by the acceleration or deceleration, and therefore need to be considered in the design of the conveyor dynamic load. Traditional design and calculation methods (such as DIN22101) are all moving parts on the conveyor as rigid connection together, at the same time accelerate or decelerate (which can be seen as a "quasi static"), regardless of the viscoelastic properties of conveyor belt and drive in the process of start-up, stop input force (torque) change over time, and so cannot be given conveyor in transient process in the process of start-up, stop. From the Angle of the transient process of belt conveyor, the dynamic problems in the following aspects:
(1) the start of the conveyor, stop the conveyor in the process of the longitudinal stress (strain) and the speed of transmission
especially large belt conveyor belt conveyor structure characteristics embodied in: conveyor belt, roller, and material is spread on the transmission line, conveyor belt is essentially a viscoelastic body, thus drive the boot process is gradually will spread to the whole conveyor belt, driving force and speed of the conveyor start is a gradual process, conveyor belt tension by static state changes to stable operation under tension, change of the amount of deformation of the conveyor belt tension, the tension device of elongation or shortening and absorbed by the deflection of conveyer belt change. Another characteristic is more drive unit and multi-points driving. When there is no considering the influence of the longitudinal dynamic transient process possible problems include:
1) choose too driven equipment investment cost is too high, cause in the process of start and stop the conveyer belt tension is too large;
2) changing slope line of the belt conveyor downtime caused the conveyor belt in the process of local tension is too small;
3) displacement of the tension device design is not accurate, appear taut enough or pull tight schedule response lag, cannot satisfy the requirement of the system transmission;
4) drive, brake and tension device configuration and location layout is unreasonable;
5) in a multiple drive unit in the system to start or braking process due to the loading sequence and time control on the oscillation problem, caused by the drive unit of output cannot realize synchronization and power balance.
(2) the conveyor belt on cross section perpendicular to the conveyor belt surface vibration
Intrinsic properties in tension, the load and conveyor belt conveyor belt, when the vibration frequency and inherent frequency of roller close to, or agreement, conveyor belt of the cross section in the direction of the vertical surface vibration problems, the vibration will make the conveyor frame buildings destroyed even [12-14].
(3) the conveyor belt running deviation in horizontal conveyor
Conveyor belt running deviation is widespread problem, running deviation is conveyor downtime, and materials, frame jam, conveyor belt use shortened the main reason for the consequences, such as running wide adjustment is very troublesome, theoretically analyzing the running deviation method is to establish a dynamics equation of movement of the conveyor belt cross use, and application of the theory of stability was analyzed.
(4) conveying material quantity changes caused by changes in the running state
Conveying material quantity change will cause the change of running state, but the change relative to the conveyor belt is much longer, and the volatility of the cycle and generally will not separate study on this question, the research focus is on different materials under the load distribution of longitudinal wave problem.
(5) materials by the process of material on the roller and the impact of the conveyor belt
Conveyor belt is impacted by the material in the material (especially the big materials) impact directly endanger the normal use of belt conveyor, is the important reason for the damage of conveyor belt, conveyor belt leads to wear, covering layer, core, and even the breakdown of the whole conveyor belt, cause the damage of the conveyor belt and tear, increase the impact load of roller.
(6) after a roller conveyor belt conveyor belt cover extrusion deformation and recovery
Conveyor belt under extrusion deformation of cover on the conveyor belt is conveyor main drag in the sag resistance.
From the point of view, the control of belt conveyor in addition to meet the meet the technological requirements of belt conveyor under different throughput sequence control and the speed of change and the protection of a belt conveyor control, the control requirements of main lies only in the conveyor of the transient process control.
Visible from the above analysis, the belt conveyor dynamic problems involved in all aspects of the belt conveyor system, this article focuses on the first (1) aspects of listed above, and the other five aspects of the problem only briefly discussed in this paper. First analysis of the domestic and foreign research progress and the method; , in turn, dynamics analysis is given of the basic method and process, including: the development of mathematical models, solving technology, software; Dynamics analysis of a typical belt conveyor system, function and application scope of dynamic analysis, etc.
The main content and method of dynamics research
Belt conveyor's dynamic analysis and dynamic design method of research and application are widely attention, is because with the large-scale of belt conveyor system, traditional half static design calculation methods have been can't meet the needs of engineering application. On the other hand, the adoption of the dynamic design method is helpful to improve the design level, to improve enterprise competitiveness. Dynamic design and dynamic optimization design is a comprehensive design method of generalized quality oriented products is an important part of the [. Therefore, the dynamics of belt conveyor and dynamic design method involves all aspects of belt conveyor, namely:
1) all the moving parts of belt conveyor mechanical properties, especially the conveyor belt;
2) the calculation method of conveyor running resistance and its regularity problem;
3) driving, braking, taut, the structure and characteristic of transmission device and control method;
4) the mathematical model of the moving parts and belt conveyor consists of mathematical model of the parts of the whole machine model;
5) the established dynamic model of solving method and software development;
6) all kinds of drive, brake and tension device to rev braking characteristics of dynamic response;
7) complex belt conveyor system dynamic behavior under various operating conditions, including starting, braking, on delivery and shipment, etc.;
8) all kinds of conditions of the site test and analysis, dynamic adjustment of the control system.
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