梳棉機(jī)箱體加工工藝及組合機(jī)床設(shè)計
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編號
無錫太湖學(xué)院
畢業(yè)設(shè)計(論文)
相關(guān)資料
題目: 梳棉機(jī)箱體加工工藝
及組合機(jī)床設(shè)計
信機(jī) 系 機(jī)械工程及自動化專業(yè)
學(xué) 號: 0923034
學(xué)生姓名: 管星宇
指導(dǎo)教師: 尤麗華(職稱:副教授)
(職稱: )
2012年5月25日
目 錄
一、畢業(yè)設(shè)計(論文)開題報告
二、畢業(yè)設(shè)計(論文)外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文(論文)計劃、進(jìn)度、檢查及落實表”
四、實習(xí)鑒定表
無錫太湖學(xué)院
畢業(yè)設(shè)計(論文)
開題報告
題目: 梳棉機(jī)箱體加工工藝
及組合機(jī)床設(shè)計
信機(jī) 系 機(jī)械工程及自動化 專業(yè)
學(xué) 號: 0923034
學(xué)生姓名: 管星宇
指導(dǎo)教師: 尤麗華 (職稱:副教授 )
(職稱: )
2012年11月25日
課題來源
在工藝制定過程中,通過生產(chǎn)批量的分析確定梳棉機(jī)箱體結(jié)合件的加工方案,并尋求最佳的工藝方案,借此說明了工藝在生產(chǎn)過程中的重要性;在組合鉆孔工序的工裝設(shè)計過程中,結(jié)合實例,介紹了夾具設(shè)計方法,特別是對孔的加工精度進(jìn)行了探討;在液壓控制系統(tǒng)設(shè)計過程中,以雙面鉆孔組合機(jī)床為對象,依據(jù)液壓系統(tǒng)設(shè)計的基本原理,擬出合理的液壓系統(tǒng)圖。通過系統(tǒng)主要參數(shù)的計算確定了液壓元件的規(guī)格;在組合機(jī)床設(shè)計過程中,結(jié)合具體實例和設(shè)計經(jīng)驗, 闡述了通用件(如液壓滑臺,動力箱等)的選取及專用部件(如主軸箱)的設(shè)計計算。
科學(xué)依據(jù)(包括課題的科學(xué)意義;國內(nèi)外研究概況、水平和發(fā)展趨勢;應(yīng)用前景等)
梳棉機(jī)是棉紡工藝流程中的關(guān)鍵性機(jī)臺,一直被稱為紡紗工藝的“心臟”設(shè)備,可見梳棉機(jī)在紡紗過程中占有極為重要的位置,而我國的梳棉機(jī)研制已有五十余年的歷史,并且于五十年代后期就曾經(jīng)達(dá)到過世界先進(jìn)水平。建國后,我國自行研制了1181型彈性針布梳棉機(jī)(英制),性能良好、質(zhì)量穩(wěn)定、臺時產(chǎn)量達(dá)5-7kg,改公制后定型為A181型梳棉機(jī)。隨著生產(chǎn)技術(shù)的發(fā)展,制成以金屬針布替代彈性針布的A181E型梳棉機(jī),臺時產(chǎn)量為15-20kg。在此基礎(chǔ)上,采取提高刺轆與錫林速度、加大卷裝籌措施,使臺時產(chǎn)量又提高到15-25kg,并定型為A186到梳棉機(jī)。之后在對傳動機(jī)構(gòu)、鋸條和針布規(guī)格以及部分零件的改進(jìn)基礎(chǔ)上,生產(chǎn)了A186G型梳錦機(jī)。隨后又在對吸塵裝置以及主要部件和精板加固的基礎(chǔ)上,生產(chǎn)了A186D梳棉機(jī),該機(jī)可加工棉、棉型化纖和中長纖維。為了提高國產(chǎn)梳棉機(jī)水平,在A186D型梳棉饑基礎(chǔ)上,吸取了部分引進(jìn)設(shè)備的特點,又試制TAl86E型梳棉機(jī)。近年來,又先后研制了FA203型梳棉機(jī)、FA231型等多種型號的梳錦機(jī)。采用抬高錫林中心位置、增加工作蓋板根數(shù)、錫林前后加裝固定蓋板、刺轆下安裝分梳板取代小漏底以及使用新疆針布等項技術(shù)措施,使臺時產(chǎn)量達(dá)到2O-35kg。
國產(chǎn)梳棉機(jī)的發(fā)展主要體現(xiàn)在以下幾個方面:
(一)速度與產(chǎn)量不斷提高 產(chǎn)量由最初的4~6kg/h到現(xiàn)在的45~85kg/h,國外有的機(jī)型可達(dá)成100~140kg/h。
(二)適紡范圍不斷擴(kuò)大,新型梳棉機(jī)的適紡范圍在22~76mm,既能加工棉,棉型化纖,還可以加工中長化纖。
(三)主要機(jī)件、支撐件的剛度和加工精度不斷提高,從而改善了梳棉機(jī)的穩(wěn)定性。
(四)擴(kuò)大分梳區(qū)域,改進(jìn)附加分梳元件和采用新型針布,使分梳質(zhì)量和除雜效果大大提高。
(五)采用吸塵機(jī)構(gòu)及密封機(jī)殼,以降低工人勞動強(qiáng)度,改善生產(chǎn)環(huán)境。
(六)采用自調(diào)勻整機(jī)構(gòu),進(jìn)一步提高生條質(zhì)量。
國外新型梳棉機(jī)有騎士立達(dá)公司的CIO型、C51型,德國特呂茨勒公司的DK760型、DK803型,英國克洛斯洛爾公司的MA型以及意大利馬佐利公司的CX400型等。各機(jī)均 具特點,且自動化程度很高。國外各公司先后推出了具有國際先進(jìn)水平的梳棉機(jī)C50C51 DK760 DK788 DK803 DK903 CX400 MK5等超高產(chǎn)梳棉機(jī),產(chǎn)量為50-120kgtho2004年國外又推出了TC03 C60 MK6等超高產(chǎn)梳棉機(jī)
本文針對組合機(jī)床在梳棉機(jī)制造過程中的應(yīng)用現(xiàn)狀,以梳棉機(jī)箱體結(jié)合件的加工為例,闡述了工藝、工裝、組合機(jī)床的設(shè)計過程及其與經(jīng)濟(jì)效益之間的關(guān)系。并以梳棉機(jī)箱體結(jié)合件為例進(jìn)行了工藝技術(shù)及加工設(shè)備、裝夾設(shè)備的簡單設(shè)計。
研究內(nèi)容
應(yīng)用組合機(jī)床加工大批量零件,快捷高效,生產(chǎn)效率高是機(jī)械加工的發(fā)展方向。本次設(shè)計任務(wù)是制定梳棉機(jī)箱體結(jié)合件的加工工藝、組合鉆孔工序的工裝設(shè)計、組合機(jī)床設(shè)計。在工藝制定過程中,通過生產(chǎn)批量的分析確定梳棉機(jī)箱體結(jié)合件的加工方案,并尋求最佳的工藝方案;結(jié)合組合鉆孔工序,進(jìn)行工裝夾具設(shè)計;最后設(shè)計出鉆孔的組合機(jī)床。簡單闡述了工藝、工裝、組合機(jī)床的設(shè)計過程及其與經(jīng)濟(jì)效益之間的關(guān)系。簡要說明了現(xiàn)代制造工藝和制造設(shè)備與梳棉機(jī)的關(guān)系
擬采取的研究方法、技術(shù)路線、實驗方案及可行性分析
(1) 通過生產(chǎn)批量的分析確定梳棉機(jī)箱體結(jié)合件的加工方案,并尋求最佳的工藝方案;
(2) 結(jié)合組合鉆孔工序,進(jìn)行工裝夾具設(shè)計;
(3) 以雙面鉆孔組合機(jī)床為對象,組合機(jī)床設(shè)計,并繪制相應(yīng)的二維圖紙;
(4)繪制相應(yīng)的二維裝配圖
研究計劃及預(yù)期成果
由本文的論述,我們了解到,通過對梳棉機(jī)箱體結(jié)合件加工設(shè)備及工藝的研究與應(yīng)用,在機(jī)床、夾具、刀具、工藝流程等方面進(jìn)行合理設(shè)計和選擇,有效提高了加工效率和產(chǎn)品質(zhì)量,擴(kuò)大了加工適應(yīng)范圍,提高了可靠性,具備一定的先進(jìn)性,取得了良好的經(jīng)濟(jì)效益和社會效益,為解決此類多孔同時加工問題舉了一件實例。
本成果設(shè)計制造的機(jī)床為六軸鉆孔雙面臥式組合機(jī)床。我們將鉆削主軸設(shè)為機(jī)械傳動,而進(jìn)給系統(tǒng)為液壓控制,使在滿足使用要求的前提下降低了成本。作為關(guān)鍵部件的液壓滑臺采用國產(chǎn)通用部件。以比較簡單的方式完成旋轉(zhuǎn)運(yùn)動和直線運(yùn)動的同步進(jìn)行,非常實用。
本機(jī)床所用夾具的通用性強(qiáng),工件采用液壓定位夾緊,快速方便。定位采用兩面一銷的定位方式,夾緊采用液壓加緊,采用這種方式完全能夠滿足精度要求。而且簡易方便,制造成本低,通用性好。
在刀具方面,由于所加工孔的尺寸精度和表面粗糙度要求都不算高,采用麻花鉆。這種鉆頭采購比較方便,而且價格比深孔鉆頭也要便宜。在刀具的幾何角度方面,麻花鉆頭的螺旋角即是其軸向前角。當(dāng)加工工件時,切削力和切削熱隨鉆頭螺旋角的增大而減小(減 少),切削輕快,刀具耐用度高。為此,我們選取鉆頭螺旋角為32,在保證強(qiáng)度的前提下,有效降低了切削力和切削溫度,提高了刀具使用壽命和生產(chǎn)效率。
通過本成果的實施,進(jìn)排氣搖臂的深孔加工質(zhì)量和生產(chǎn)效率得到較大幅度提高,經(jīng)濟(jì)和社會效益顯著。而且加工精度也完全能夠滿足設(shè)計要求。則在直接經(jīng)濟(jì)效益方面,節(jié)省了大量加工工時。
特色或創(chuàng)新之處
任何一個較為復(fù)雜的機(jī)械零件,都有不同的加工工藝方案,特別是一個新產(chǎn)品,從開發(fā)設(shè)計,試制,小批量投產(chǎn)到產(chǎn)品發(fā)展和成熟時期的大批量生產(chǎn),都要經(jīng)歷不同的生產(chǎn)批量過程。作為組成這一產(chǎn)品的機(jī)械零件必須根據(jù)生產(chǎn)批量來確定其工藝方案,現(xiàn)以梳棉機(jī)箱體結(jié)合件為例,說明在不同生產(chǎn)批量情況下,如何合理選擇定位基準(zhǔn),采用適宜的生產(chǎn)設(shè)備和工藝手段,以保證加工質(zhì)量可靠,滿足市場的需求。達(dá)到生產(chǎn)批量的能力,同時投資小,見效快,成本低,從而獲得企業(yè)的最大經(jīng)濟(jì)效益。
已具備的條件和尚需解決的問題
已具備的條件:
1.計算機(jī)以及繪圖軟件;
2.各種技術(shù)參考以及課題背景資料
尚需解決的問題:對一些結(jié)構(gòu)設(shè)計部分的具體設(shè)計,以及三維軟件的高級運(yùn)用技巧。
指導(dǎo)教師意見
指導(dǎo)教師(簽名): 年 月 日
系主任(簽名): 年 月 日
Structural analysis in control systems design of hydraulic drives
Benno Stein, Elmar Vier
Abstract:The design of hydraulic control systems is a complex and time-consuming task that, at the moment, cannot be automated completely. Nevertheless, important design subtasks like simulation or control concept selection can be efficiently supported by a computer. Prerequisite for a successful support is a well-founded analysis of a hydraulic system's structure. This paper provides a systematics for analyzing a hydraulic system at different structural levels and illustrates how structural information can be used within the design process. Another important point of this paper is the automatic extraction of structural information from a circuit diagram by means of graph-theoretical investigations.
Keywords: Algorithms and knowledge-based methods for CACSD; Structural analysis of hydraulic systems; Graph theory
1. Introduction
Hydrostatic drives provide advantageous dynamic properties and therefore represent a major driving concept for industrial applications. Large-scale hydraulic systems such as plants in marine technology as well as drives for machine tools possess a large number of actuators. Consequently, sophisticated inter-dependences between single components or entire subsystems may occur, which leads to a variety of challenging and demanding design and control tasks. As a representative example with respect to complexity and dimension, Fig. 1 shows the circuit diagram of a cold-rolling plant (Wessling, 1995; Ebertshaè user, 1994). Here,more than 20 actuators work on the coiled steel strips.Designing such large hydraulic control systems implies a systematic procedure. In practice, this is done rather implicitly } based on the intuition and the experience of the human designer. This paper introduces a systematics of hydrostatic drives which reveal their underlying structures, as well as relations and depen-dencies among substructures. This approach allows a thorough structural analysis from which fundamenta conclusions for the automation of the design process can be drawn.The concepts of this paper have been realized and integrated within deco, a knowledge-based system for hydraulic design support (Stein, 1995). Currently, deco combines basic CAD facilities tailored to uidics,checking and structure analysis algorithms, simulation methods, and basic design rule processing. The operationalization of hydraulic design knowledge requires a formal definition and automatic extraction of structural information from a circuit diagram. The paper contributes within these respects; it is organized as follows. Section 2 describes both conceptually and exemplarily the structural levels at which a hydraulic system can be investigated. Section 3 briefly discusses the benefits that go along with a structural analysis. Section 4 precisely defines
different types of couplings between the functional units of a hydraulic system, hence establishing a basis for a computer-based analysis. Moreover, it is outlined how a structural analysis is automated. Section 5 outlines the exploitation of structural information within deco.
2. Structural analysis of hydraulic systems
The majority of hydraulic systems is designed by exploiting the experience and intuition of a single engineer. Due to the lack of a structural methodology, a thorough analysis of the system structure is not carried out. Instead, a limited repertory of possible solutions is used, making the result highly dependent on the capabilities of the individual. Such an approach is suitable only for recurring design tasks with little variation.In the following, a systematics of the structural set-up of hydraulic plants is introduced which leads to a problem-oriented system analysis. Its application to a hydrostatic drive given as a preliminary design facilitates a consequent and purposive derivation of structural information, which is necessary to make the system's behavior meet the customer's demands.
2.1. Structural levels of hydraulic systems
The systematics developed here is based on three levels of abstraction. The differentiation between functional structure, component structure, and system-theoretical structure corresponds to system descriptions of different characteristics (Fig. 2). From this distinction results an overall view of how to influence the system's behavior. To illustrate the concept of structural levels, we will concentrate on a sample subsystem of the cold-rolling plant, the four-roll stand is sketched in Fig. 3.The functional structure shows the fundamental modes of action of a hydraulic circuit by analyzing the different tasks (functions) the plant has to fulfill. It represents some kind of qualitative system description. A key element within the functional structure is the so-called ``hydraulic axis'', which is defined as follows. A hydraulic axis A represents and fulfills a subfunction f of an entire hydraulic plant. A defines the connections and the interplay among those working, control, and supply elements that realize f. The hydraulic actuators of the four-roll stand perform two tasks each of which defined by a directional load and motional quantities. A representation of the roll stand at the functional level is given in Fig. 4. The detection of hydraulic axes and their interdependences admits far-reaching conclusions, which are stated in Section 3.On the level of the component structure the chosen realization of a function is investigated. The arrangement structure comprises information on the hydraulic elements (pumps, valves, cylinders, etc.) as well as their geometric and physical arrangement. By the switching-state structure the entirety of the possible combinations of switching positions is characterized: A valve, for instance, can be open or closed. Fig. 6 depicts the representation of the roll stand at the component level. The system-theoretical structure contains information on the dynamic behavior of both the hydraulic drive as a whole and its single components. Common ways of describing dynamics are differential and difference equations or the state-space form (Schwarz, 1991). The system-theoretical view comprises information on the controlled quantities, as well as the dynamic behavior of the controlled system. The block diagram in Fig. 7 reveals the system-theoretical structure of the roll stand. By comparing analysis and simulation results with the performance demands at the drive, a decision can be made for each hydraulic axis whether open- or closed-loop control concepts are adequate. In a further step, an appropriate control strategy (linear, nonlinear, etc.) can be assigned.
Remarks. While the functional structure yields a qualitative representation, the system description becomes more quantitative at the component and system-theoretical level, respectively. Moreover, the analysis of the structural set-up shows in which way the behavior of a hydraulic plant can be influenced (cf. Fig. 2): (1) at first, the functional structure must be considered as invariant, because it results from the customer's demands. Only if the given structure proves to be unsatisfactory, a modification } resulting from a heuristic analysis approach } is advisable; (2) note that at the component level, a combination of heuristic and analytic methods is required for the variation or exchange of hydraulic elements, which form the controlled system; (3) the system-theoretical level facilitates the investigation of the dynamic behavior: control theory provides an analytic approach for the selection of a suitable control strategy, parameterization, etc.
2.2. Hydraulic axes and their couplings
Focusing on the investigation of the functional structure of hydraulic systems, the detection and evaluation of hydraulic axes is of central interest. Their analysis contributes to a deeper understanding of the inner correlations of the plant and provides an overview of the energy flows with respect to the functions to be fulfilled. The definition of the hydraulic axis given in Section
2.1 is based on the criterion of elements working together in order to fulfill a single function. Note that several actuators (hydraulic motors/cylinders) may
contribute to the same function, thus forming a single hydraulic axis (Fig. 8). This situation is given for (a) identical sub-circuits that are controlled by one
single control element, (b) synchronized movements that are carried out by open or closed loop control, or (c,d) mechanical couplings such as guides and gear units that enforce a unique behavior. Beyond the consideration of isolated hydraulic axes, it is necessary to investigate their interdependences. The following coupling types have been worked out Level 0 (No coupling.) Hydraulic axes possess no coupling, if there is neither a power nor an informational connection between them. Level 1 (Informational coupling.) Hydraulic axes which are connected only by control connections are
called informationally coupled. Level 2 (Parallel coupling.) Hydraulic axes which possess their own access to a common power supply are coupled in parallel. Level 3 (Series coupling.) A series coupling connects the hydraulic axes whose power supply (or disposal) is realized via the preceding or the following axis. Level 4 (Sequential coupling.) A sequential coupling is given, if the performance of a following axis depends on the state variables, e.g. the pressure or the position of the preceding one in order to work in a sequence.
Applying the concept of functional structure to the cold-rolling plant of Fig. 1, 15 hydraulic axes along with their couplings can be found. The left-hand side of Fig. 9 envisions the membership of the components in the diagram to the axes, the right-hand side shows the entire coupling scheme in the form of a tree.
3. Benefits of a structural analysis
A structural analysis of hydraulic systems reveals basic design decisions. Especially the functional analysis, which is based on the detection of a system's hydraulic axes, will simplify the modification, the extension, and the adaptation of the system (Stein,1996). The separate treatment of hydraulic axes remarkably reduces the design effort within the following respects: Smart simulation. Smart simulation is a human strategy when analyzing a complex system: subsystems are identified, cut free, and simulated on their own. This strategy reduces the simulation complexity and simplifies the interpretation of its results. Hydraulic axes establish suited subsystems to be cut free, since they perform an indivisible but complete subtask. Static design. Information on the hydraulic axes driving concept (open/closed center, load sensing, regenerative circuit, etc.) allows the selection of computation procedures relating the static design. Moreover, the
application of modification knowledge has to consider the axes' coupling levels.Control concept selection. The consideration of couplings between input and output variables supplies a necessary decision basis for the selection of control concepts. Analyzing the decouplability matrix D (Schwarz, 1991) yields a common approach here. Note that the system order that can be tackled is limited. The functional structure analysis provides a separation into (1) SISO systems, to which standard methods of controller design can be applied, and (2) coupled subsystems of a reduced order, for which decouplability can be investigated more efficiently or even becomes possible at all. Diagnosis. Having a hydraulic circuit decomposed into its hydraulic axes, the diagnosis process can focus onto a single axis according to the following working hypothesis: if symptoms are observed merely at a single hydraulic axis, then the defect component(s) must be amongst the components of this axis. If symptoms are observed at several axes, the axes
coupling type will give further answers with respect to defect components. Hesse and Stein (1998) describe a system where this idea has been set into operation. Note that a smart classification of the couplings between hydraulic axes forms the rationale of whether a decomposition of a hydraulic design problem is permissible. While subsystems with level 0 or level 1 couplings can always be cut free, additional information is required for parallel, series, and sequential couplings.
在液壓傳動控制系統(tǒng)設(shè)計的結(jié)構(gòu)分析
本諾·斯坦,艾瑪四
摘要:液壓控制系統(tǒng)的設(shè)計是一項復(fù)雜的任務(wù),而且費(fèi)時,此刻,不能完全自動化。然而,重要的設(shè)計任務(wù)是仿真或控制概念選擇計算機(jī)能有效地支持。一個成功的先決條件是一個很好的支持建立一個液壓系統(tǒng)的結(jié)構(gòu)分析。本文提供了一個系統(tǒng)的分析在不同的結(jié)構(gòu)層次,液壓系統(tǒng),說明了結(jié)構(gòu)信息,可以在設(shè)計過程中的應(yīng)用。本文的另一個重要的一點是自動提取結(jié)構(gòu)信息從一個電路圖用圖論的理論研究方法。
關(guān)鍵詞:CACSD算法和基于知識的方法;液壓系統(tǒng)的結(jié)構(gòu)分析;圖論
1。簡介
靜液壓驅(qū)動提供了有利的動態(tài)特性,因此代表了工業(yè)應(yīng)用的一個主要的驅(qū)動概念。大型液壓系統(tǒng)如海洋科技廠以及機(jī)床的驅(qū)動器具有大量的致動器。因此,復(fù)雜的國際單部件或整個子系統(tǒng)之間的依賴關(guān)系可能會發(fā)生,導(dǎo)致各種各樣的挑戰(zhàn)和要求,設(shè)計和控制任務(wù)。方面的復(fù)雜性和尺寸作為一個代表性的例子,圖1顯示了一個冷軋廠的電路圖(韋斯林,1995;ebertshaè用戶,1994)。在這里,20多個執(zhí)行器工作在連續(xù)帶鋼。這樣的大型液壓控制系統(tǒng)的設(shè)計意味著一個系統(tǒng)的方法。在實踐中,這是做得相當(dāng)含蓄}基于直覺和設(shè)計者的經(jīng)驗。本文介紹了一種系統(tǒng)的靜液驅(qū)動,揭示其基本結(jié)構(gòu),以及結(jié)構(gòu)之間的關(guān)系和依賴dencies。這種方法允許一個徹底的結(jié)構(gòu)分析,為設(shè)計過程的自動化基本可以得出的結(jié)論。本文的概念已經(jīng)實現(xiàn),集成在德科,知識型液壓設(shè)計支持系統(tǒng)(斯坦,1995)。目前,裝飾結(jié)合基本CAD設(shè)施為uidics,檢查和結(jié)構(gòu)分析的算法,仿真方法,和基本的設(shè)計規(guī)則處理。液壓設(shè)計知識的運(yùn)作需要一個正式的定義和結(jié)構(gòu)信息的自動提取從一個電路圖。本文在這些方面;它的組織結(jié)構(gòu)如下。第2節(jié)描述的概念和模范結(jié)構(gòu)水平在液壓系統(tǒng)可以進(jìn)行調(diào)查。第3節(jié)簡要的闡述了隨結(jié)構(gòu)分析的好處。4節(jié)精確地定義
一個液壓系統(tǒng)的功能單元之間的耦合不同的類型,因此,建立一個基于計算機(jī)的分析基礎(chǔ)。此外,它概述了如何結(jié)構(gòu)分析的自動化。5節(jié)概述了結(jié)構(gòu)信息利用的裝飾。
2。液壓系統(tǒng)的結(jié)構(gòu)分析
液壓系統(tǒng)多數(shù)是利用經(jīng)驗和一個工程師的直覺設(shè)計。由于一個構(gòu)造方法的不足,對系統(tǒng)結(jié)構(gòu)的深入分析,不進(jìn)行。相反,可能的解決方案是使用有限的劇目,使結(jié)果高度依賴于個人的能力。這種方法只適合重復(fù)出現(xiàn)的設(shè)計任務(wù),幾乎沒有什么變化。在下面,一個系統(tǒng)的液壓設(shè)備的結(jié)構(gòu)設(shè)置的引入,導(dǎo)致一個面向問題的系統(tǒng)分析。一種靜液壓傳動給出一個初步的設(shè)計有利于隨之而來的、有目的的結(jié)構(gòu)信息的推導(dǎo)及其應(yīng)用,它是必要的,使系統(tǒng)的性能滿足客戶的需求。
2.1。液壓系統(tǒng)的層次結(jié)構(gòu)
這里開發(fā)的系統(tǒng)是基于三個層次的抽象。之間的功能結(jié)構(gòu),分化的組成結(jié)構(gòu),以及系統(tǒng)的理論結(jié)構(gòu)對應(yīng)于不同的特點,系統(tǒng)的描述(圖2)。從這種區(qū)別,結(jié)果總的看法如何影響系統(tǒng)的行為。說明結(jié)構(gòu)層次的概念,我們將集中在冷軋廠一個樣品子系統(tǒng),四輥架被描繪在圖3。功能結(jié)構(gòu)表明液壓回路中的動作的基本模式,通過分析不同的任務(wù)(功能)的工廠已經(jīng)完成。它代表了一種定性的系統(tǒng)描述。一個關(guān)鍵的元素在功能結(jié)構(gòu)是所謂的` `液壓軸”,它的定義如下。液壓軸代表和實現(xiàn)整個液壓廠隸屬函數(shù)f。一個定義在這些工作,控制的相互連接,并供應(yīng)元件,實現(xiàn)F四輥液壓致動器站執(zhí)行兩個任務(wù)分別由定向負(fù)荷和運(yùn)動量。在功能層面的表示在圖4中給出了輥站。液壓軸及其相互關(guān)系承認(rèn)深遠(yuǎn)的結(jié)論檢測,在3節(jié)規(guī)定的水平。在組成結(jié)構(gòu)的功能實現(xiàn)所選擇的研究。裝置的結(jié)構(gòu)包括在液壓元件(泵,閥門,氣瓶信息,等)以及它們的幾何和物理布局。通過開關(guān)結(jié)構(gòu)的開關(guān)位置的可能的組合的整體特征是:一個閥門,例如,可打開或關(guān)閉。圖6描述了軋機(jī)機(jī)架的表示在組件級別。該系統(tǒng)的理論結(jié)構(gòu)包含兩個液壓驅(qū)動作為一個整體,其單一成分的動態(tài)行為的信息。描述動力學(xué)的常用方法是微分方程和差分方程或狀態(tài)空間形式(施瓦茨,1991)。系統(tǒng)理論觀點,包括對控制量的信息,以及控制系統(tǒng)的動態(tài)行為。圖7塊圖揭示了軋機(jī)系統(tǒng)的理論結(jié)構(gòu)。通過分析和仿真結(jié)果在驅(qū)動器的性能要求相比,可以決定每個液壓軸是否開放或閉環(huán)控制的概念是足夠的。在進(jìn)一步的步驟,一個合適的控制策略(線性,非線性,等等)可以被分配。
備注。而功能結(jié)構(gòu)產(chǎn)生的定性描述,系統(tǒng)描述在組件和系統(tǒng)的理論水平更定量,分別。此外,該結(jié)構(gòu)設(shè)置的分析表明,一個水電廠的行為的影響(參見圖2):(1)首先,功能結(jié)構(gòu)必須被視為不變的,因為它來自于客戶的需求。如果給定的結(jié)構(gòu)被證明是不能令人滿意的,修改}而產(chǎn)生的一種啟發(fā)式分析方法}是可取的;(2)注意到,在組件級,啟發(fā)式和分析相結(jié)合的方法是對液壓元件的變化或交換的需要,構(gòu)成控制系統(tǒng);(3)系統(tǒng)的理論水平方便的動態(tài)行為的調(diào)查:控制理論提供了一個合適的控制策略,選擇一種解析方法的參數(shù),等等。
2.2。液壓軸和聯(lián)軸器
針對液壓系統(tǒng)的功能結(jié)構(gòu)的調(diào)查,和液壓軸檢測評價是中央的興趣。他們的分析有助于植物內(nèi)部的關(guān)系有了更深的了解,提供的能量流的一個概述相對于功能得以實現(xiàn)。給出部分液壓軸的定義
2.1是根據(jù)元素在一起,致力于實現(xiàn)一個功能的標(biāo)準(zhǔn)。請注意,多執(zhí)行機(jī)構(gòu)(液壓馬達(dá)/氣缸)可能
有助于相同的功能,從而形成一個單一的液壓軸(圖8)。這種情況給出了(一)相同的子電路是由一個
控制單元,(B)的同步運(yùn)動,通過開環(huán)或閉環(huán)控制下進(jìn)行的,或(C,D)機(jī)械接頭,如導(dǎo)軌和齒輪單元,執(zhí)行一個獨特的行為。除了考慮孤立的液壓軸,它是必要的調(diào)查,他們的相互關(guān)系。下面的耦合類型已制定了0級(無耦合。)液壓軸沒有耦合,既沒有實力也沒有它們之間的信息聯(lián)系。1級(信息耦合。)液壓軸,只有通過控制連接連接
所謂信息耦合。2級(平行耦合。)液壓軸具有自己進(jìn)入一個共同的電源并聯(lián)耦合。3級(串聯(lián)耦合。)一系列耦合連接液壓軸的電源(或處理)是經(jīng)前或以下軸實現(xiàn)。4級(順序耦合。)一個順序耦合是給定的,如果一個跟隨軸的性能依賴于狀態(tài)變量,如壓力或前一個為了在一個序列中的工作位置。
運(yùn)用泛函結(jié)構(gòu)的概念圖1的冷軋廠,15個液壓軸連同他們的聯(lián)軸器可以發(fā)現(xiàn)。圖9的左邊設(shè)想圖中的組件的軸的會員,右邊顯示在樹的形式,整個耦合方案。
3。結(jié)構(gòu)分析的好處
液壓系統(tǒng)的結(jié)構(gòu)分析揭示了決策的基本設(shè)計。尤其是功能分析,它是基于一個系統(tǒng)的液壓軸檢測,將簡化修改,擴(kuò)展,和系統(tǒng)的適應(yīng)性(斯坦,1996)。液壓軸單獨處理顯著降低了設(shè)計的努力在以下幾個方面:智能仿真。智能仿真是人類的一種策略在分析一個復(fù)雜的系統(tǒng):系統(tǒng)識別,減少自由,并在他們自己的模擬。這種策略減少了計算的復(fù)雜性和簡化對結(jié)果的解釋。液壓軸建立適合子系統(tǒng)可以減少自由,因為他們執(zhí)行一個不可分割的同時完成任務(wù)。靜態(tài)設(shè)計。在驅(qū)動概念的液壓軸信息(打開/關(guān)閉中心,負(fù)荷傳感,再生電路,等)允許計算程序有關(guān)的靜態(tài)設(shè)計的選擇。此外,本
改性知識的應(yīng)用,考慮了軸的耦合水平控制概念的選擇??紤]耦合之間的輸入和輸出變量為控制概念的選擇的一個必要的決策依據(jù)。分析decouplability矩陣D(施瓦茨,1991)產(chǎn)生的一種常見的方法。注意,系統(tǒng)可以解決是有限的。功能結(jié)構(gòu)分析提供了一種分離成(1)的SISO系統(tǒng),其控制器的設(shè)計標(biāo)準(zhǔn)的方法可以應(yīng)用,和(2)的降階耦合的子系統(tǒng),它可以更有效地decouplability影響甚至可能在所有。診斷。具有液壓電路分解成液壓軸,診斷過程可以集中到一個單一的軸根據(jù)以下假設(shè):如果癥狀僅僅觀察到一個單一的液壓軸,然后缺陷部件(S)必須在該軸組件。如果癥狀在多軸的軸線觀察,
耦合式將與缺陷部件進(jìn)一步回答。黑塞和Stein(1998)描述了一個系統(tǒng),這種想法已經(jīng)被設(shè)置成操作。注意液壓軸之間的耦合智能分類形式是否水力設(shè)計問題的一種分解是允許的理由。在0級或1級耦合總是可以減少自由子系統(tǒng),額外的信息是平行的,要求和順序聯(lián)軸器系列。
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