載重汽車懸架減震器設計【含7張cad圖紙+文檔全套資料】
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載重汽車懸架減震器設計及其三維建模
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隨著社會的不斷發(fā)展,人們對汽車的要求也越來越高。包括有汽車的動力性、經(jīng)濟性、制動性、操縱穩(wěn)定性、平順性、通過性等性能的要求。減震器是安裝在車體與負重輪之間的一個阻尼元件,其作用是衰減車體的振動并阻止共振情況下車體振幅的無限增大,能減小車體振動的振幅和振動次數(shù),因而能延長彈性元件的疲勞壽命和提高人乘車的舒適性[1]。長期以來,人們對汽車的平順性一直都在研究,在技術上也有重大的改駛員操縱輕便,乘員更加舒服。
因外部條件的不同,對減振器的使用要求也會相應的不同。在不同的國家或不同的地區(qū),他們各自的天氣環(huán)境、道路建筑等都有著很大的區(qū)別。單一的減振器是可能都滿足他們的性能要求。隨著社會的發(fā)展,汽車市場出現(xiàn)了細分化。純黑色的“福特”時代,早已經(jīng)過去,針對各國道路交通情況,各國汽車生產(chǎn)商們開始生產(chǎn)有屬于自己特色的汽車了。本文就是針對我國大多數(shù)城市道路情況,而進行研究設計的。
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為加速車身振動的衰減,改善汽車行使平順性,大多數(shù)轎車的懸架內(nèi)都裝有減震器。減震器和彈性元件是并聯(lián)安裝的。其中采用最廣泛的是液力減震器,又稱筒式液力減振器,現(xiàn)簡稱為筒式減振器。根據(jù)結(jié)構形式不同,減振器分為搖臂式和筒式兩種。而筒式減震器工作壓力僅在2.5~5MPa,但是它的工作性能穩(wěn)定而在現(xiàn)代的汽車上得道廣泛的應用。又可以分為單筒式、雙筒式和充氣筒式三種[3]。減震器的阻尼力越大,振動消除得越快,但卻使并聯(lián)的彈性元件的作用不能充分發(fā)揮;還可能導致連接件及車架損壞。通常為了保證伸張過程內(nèi)產(chǎn)生的阻尼力比壓縮行程內(nèi)產(chǎn)生的阻尼力大得多,所以伸張閥彈簧剛度和預緊力比壓縮閥大;在同樣油壓力作用下,伸張閥及相應的通??p隙的同道截面積總和小于壓縮閥及相應的通常縫隙的通常截面積總和。這樣也保證了懸架在壓縮行程內(nèi),減震器的阻尼力較小,以便充分利用彈性元件的彈性來緩和沖擊;在伸張行程內(nèi),減震器的阻尼力應較大,以求迅速減振[2]。由于汽車行駛的路面狀況不同,所用的減震器要求也會有所不同。
參考文獻:
[1]中國知識網(wǎng) “充氣式汽車減震器的研制” 哈爾濱工業(yè)大學 高起波 曾祥榮
[2]《汽車構造 第2版》 吉林大學 陳家瑞 主編 機械工業(yè)出版社
[3]《汽車設計 第4版》 吉林大學 王望予 主編 機械工業(yè)出版社
[4]《機械設計與研究》的“新型減震器的研究”華中理工大學 李輝 何程
[5]《橡膠減震器設計與計算》 第二研究室 王光
[6]《可調(diào)阻尼減振器優(yōu)化設計的研究》 吉林大學碩士學問論文 孫雪梅
[7]《汽車工程手冊 設計篇》《汽車手冊》編輯委員會編 人民交通出版社
[8]《液壓系統(tǒng)設計簡明手冊》 楊培元 朱福元主編 機械工業(yè)出版社
[9]《減振器設計專家系統(tǒng)的研究與開發(fā)》 重慶大學 李若剛
[10]《機械設計手冊》 機械設計手冊編委會 機械工業(yè)出版社
[11]《液壓氣動技術速查手冊》 張利平 等編著 化學工業(yè)出版社
[12]《國內(nèi)外通用標準件手冊》 鳳凰出版?zhèn)髅郊瘓F 江蘇科學技術出版社
[13]《汽車高級減振器油的開發(fā)和應用》 蔣振森 王家乃
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本文的設計是要滿足一般性能要求,具體是:一是要具有一般的舒適性;二是可以滿足中國現(xiàn)代一般城市道路的使用要求;三能保證有足夠的使用壽命;四是在使用期間保證汽車行駛平順性的性能穩(wěn)定。在減振器中,流通閥和補償閥是一般的單向閥,其彈簧很弱。當閥上的油壓作用力同向時,只要很小的油壓,閥便能開啟;壓縮閥和伸張閥是卸載閥,其彈簧較強,預緊力較大,只有當油壓到一定程度時,閥才能開啟;而當油壓降低到一定程度時,閥即自行關閉。根據(jù)它們不同的工作要求,各閥系設計計算和裝配都有所不同。
根據(jù)以上要求,本文設計的基本步驟有:
1)確定減振器的阻尼系數(shù)和相對阻尼系數(shù);
2)計算出各機械結(jié)構的主要參數(shù),其中包括缸筒、儲油缸筒、活塞桿導向座和活塞的尺寸設計計算;
3)在總體參數(shù)出來以后,就對減振器連接結(jié)構、密封結(jié)構的設計,彈簧片以及減振器油的選擇等;
4)總體參數(shù)確定后,建立各閥系的力學模型、各閥系模型以及阻尼閥閥片的撓曲變形模型,完成各閥系的設計計算。
5)完成設計計算后,對主要受力部件進行校核驗證。
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(1)通過查閱相關資料,掌握汽車減震器的主要參數(shù)。
(2)充分考慮已有汽車減震器的優(yōu)缺點來確定電動滾筒的總體設計方案,對現(xiàn)有裝置的不足進行分析。
(3)對設計的汽車減震器進行修改和優(yōu)化,最終設計出能滿足要求的汽車減震器。
研究技術路線
(1)根據(jù)題目和原始數(shù)據(jù)查看相關資料,了解當今國內(nèi)外汽車減震器的發(fā)展現(xiàn)狀及發(fā)展前景,撰寫文獻綜述和開題報告。
(2)根據(jù)產(chǎn)品功能和技術要求提出多種設計方案,對各種方案進行綜合評價,從中選擇較好的方案,再對所選擇的方案做進一步的修改或優(yōu)化,最終確定總體設計方案。
(3)具體設計汽車減震器的驅(qū)動裝置、工作裝置等。
(4)對所設計的機械結(jié)構中的重要零件進行校核計算,如齒輪、軸、軸承等,保證設計的合理性和可行性。;
(5)繪制零件圖、裝配圖,完成要求的圖紙量;
(6)整理各項設計資料,撰寫論文。
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世界最新機械設計理念
來源:中國科技期刊
摘要:根據(jù)目前國內(nèi)外設計學者進行機械產(chǎn)品設計時的主要思維特點,將產(chǎn)品方案的設計方法概括為系統(tǒng)化、結(jié)構模塊化、基于產(chǎn)品特征知識和智能。這幾種方法的特點及其相互間的有機聯(lián)系,提出產(chǎn)品方案設計計算機實現(xiàn)的努力方向。
關鍵詞:機械產(chǎn)品方案設計方法發(fā)展趨勢
設計文件是將語義設計網(wǎng)作為設計工具,在其開發(fā)的活性語義設計網(wǎng)ASK中,采用結(jié)點和線條組成的網(wǎng)絡描述設計,結(jié)點表示元件化的單元(如設計任務、功能、構件或加工設備等),線條用以調(diào)整和定義結(jié)點間不同的語義關系,由此為設計過程中的所有活動和結(jié)果預先建立模型,使早期設計要求的定義到每一個結(jié)構的具體描述均可由關系間的定義表達,實現(xiàn)了計算機輔助設計過程由抽象到具體的飛躍。
系統(tǒng)化設計方法
系統(tǒng)化設計方法的主要特點是:將設計看成由若干個設計要素組成的一個系統(tǒng),每個設計要素具有獨立性,各個要素間存在著有機的聯(lián)系,并具有層次性,所有的設計要素結(jié)合后,即可實現(xiàn)設計系統(tǒng)所需完成的任務。
系統(tǒng)化設計思想于70年代由德國學者Pahl和Beitz教授提出,他們以系統(tǒng)理論為基礎,制訂了設計的一般模式,倡導設計工作應具備條理性。德國工程師協(xié)會在這一設計思想的基礎上,制訂出標準VDI2221技術系統(tǒng)和產(chǎn)品的開發(fā)設計方法。
1. 將用戶需求作為產(chǎn)品功能特征構思、結(jié)構設計和零件設計、工藝規(guī)劃、作業(yè)控制等的基礎,從產(chǎn)品開發(fā)的宏觀過程出發(fā),利用質(zhì)量功能布置方法,系統(tǒng)地將用戶需求信息合理而有效地轉(zhuǎn)換為產(chǎn)品開發(fā)各階段的技術目標和作業(yè)控制規(guī)程的方法。
2. 將產(chǎn)品看作有機體層次上的生命系統(tǒng),并借助于生命系統(tǒng)理論,把產(chǎn)品的設計過程劃分成功能需求層次、實現(xiàn)功能要求的概念層次和產(chǎn)品的具體設計層次。同時采用了生命系統(tǒng)圖符抽象地表達產(chǎn)品的功能要求,形成產(chǎn)品功能系統(tǒng)結(jié)構。
3. 將機械設計中系統(tǒng)科學的應用歸納為兩個基本問題:一是把要設計的產(chǎn)品作為一個系統(tǒng)處理,最佳地確定其組成部分(單元)及其相互關系;二是將產(chǎn)品設計過程看成一個系統(tǒng),根據(jù)設計目標,正確、合理地確定設計中各個方面的工作和各個不同的設計階段。
由于每個設計者研究問題的角度以及考慮問題的側(cè)重點不同,進行方案設計時采用的具體研究方法亦存在差異。下面介紹一些具有代表性的系統(tǒng)化設計方法。
4. 設計元素法
用五個設計元素(功能、效應、效應載體、形狀元素和表面參數(shù))描述“產(chǎn)品解”,認為一個產(chǎn)品的五個設計元素值確定之后,產(chǎn)品的所有特征和特征值即已確定。我國亦有設計學者采用了類似方法描述產(chǎn)品的原理解。
5. 圖形建模法
研制的“設計分析和引導系統(tǒng)”KALEIT,用層次清楚的圖形描述出產(chǎn)品的功能結(jié)構及其相關的抽象信息,實現(xiàn)了系統(tǒng)結(jié)構、功能關系的圖形化建模,以及功能層之間的聯(lián)接。
將設計劃分成輔助方法和信息交換兩個方面,利用Nijssen信息分析方法可以采用圖形符號、具有內(nèi)容豐富的語義模型結(jié)構、可以描述集成條件、可以劃分約束類型、可以實現(xiàn)關系間的任意結(jié)合等特點,將設計方法解與信息技術進行集成,實現(xiàn)了設計過程中不同抽象層間信息關系的圖形化建模。
6. “構思”—“設計”法
將產(chǎn)品的方案設計分成“構思”和“設計”兩個階段?!皹嬎肌彪A段的任務是尋求、選擇和組合滿足設計任務要求的原理解?!霸O計”階段的工作則是具體實現(xiàn)構思階段的原理解。
將方案的“構思”具體描述為:根據(jù)合適的功能結(jié)構,尋求滿足設計任務要求的原理解。即功能結(jié)構中的分功能由“結(jié)構元素”實現(xiàn),并將“結(jié)構元素”間的物理聯(lián)接定義為“功能載體”,“功能載體”和“結(jié)構元素”間的相互作用又形成了功能示意圖(機械運動簡圖)。方案的“設計”是根據(jù)功能示意圖,先定性地描述所有的“功能載體”和“結(jié)構元素”,再定量地描述所有“結(jié)構元素”和聯(lián)接件(“功能載體”)的形狀及位置,得到結(jié)構示意圖。Roper,H.利用圖論理論,借助于由他定義的“總設計單元(GE)”、“結(jié)構元素(KE)”、“功能結(jié)構元素(FKE)”、“聯(lián)接結(jié)構元素(VKE)”、“結(jié)構零件(KT)”、“結(jié)構元素零件(KET)”等概念,以及描述結(jié)構元素尺寸、位置和傳動參數(shù)間相互關系的若干種簡圖,把設計專家憑直覺設計的方法做了形式化的描述,形成了有效地應用現(xiàn)有知識的方法,并將其應用于“構思”和“設計”階段。
7. 鍵合圖法
將組成系統(tǒng)元件的功能分成產(chǎn)生能量、消耗能量、轉(zhuǎn)變能量形式、傳遞能量等各種類型,并借用鍵合圖表達元件的功能解,希望將基于功能的模型與鍵合圖結(jié)合,實現(xiàn)功能結(jié)構的自動生成和功能結(jié)構與鍵合圖之間的自動轉(zhuǎn)換,尋求由鍵合圖產(chǎn)生多個設計方案的方法。
提倡在產(chǎn)品功能分析的基礎上,將產(chǎn)品分解成具有某種功能的一個或幾個模塊化的基本結(jié)構,通過選擇和組合這些模塊化基本結(jié)構組建成不同的產(chǎn)品。這些基本結(jié)構可以是零件、部件,甚至是一個系統(tǒng)。
本結(jié)構應該具有標準化的接口(聯(lián)接和配合部),并且是系列化、通用化、集成化、層次化、靈便化、經(jīng)濟化,具有互換性、相容性和相關性。我國結(jié)合軟件構件技術和CAD技術,將變形設計與組合設計相結(jié)合,根據(jù)分級模塊化原理,將加工中心機床由大到小分為產(chǎn)品級、部件級、組件級和元件級,并利用專家知識和CAD技術將它們組合成不同品種、不同規(guī)格的功能模塊,再由這些功能模塊組合成不同的加工中心總體方案。
以設計為目錄作為選擇變異機械結(jié)構的工具,提出將設計的解元素進行完整的、結(jié)構化的編排,形成解集設計目錄。并在解集設計目錄中列出評論每一個解的附加信息,非常有利于設計工程師選擇解元素。
網(wǎng)絡技術的蓬勃發(fā)展,異地協(xié)同設計與制造,以及從用戶對產(chǎn)品的功能需求→設計→加工→裝配→成品這一并行工程的實現(xiàn)成為可能。但是,達到這些目標的重要前提條件之一,就是實現(xiàn)產(chǎn)品方案設計效果的三維可視化。為此,不僅三維圖形軟件、智能化設計軟件愈來愈多地應用于產(chǎn)品的方案設計中,虛擬現(xiàn)實技術以及多媒體、超媒體工具也在產(chǎn)品的方案設計中初露鋒芒。目前,德國等發(fā)達國家正著力于研究超媒體技術、產(chǎn)品數(shù)據(jù)交換標準STEP,以及標準虛擬現(xiàn)實造型語言上基于虛擬環(huán)境的標準交換格式)在產(chǎn)品設計中的應用。
機械產(chǎn)品的方案設計正朝著計算機輔助實現(xiàn)、智能化設計和滿足異地協(xié)同設計制造需求的方向邁進,由于產(chǎn)品方案設計計算機實現(xiàn)方法的研究起步較晚,目前還沒有成熟的、能夠達到上述目標的方案設計工具軟件。作者認為,綜合運用文中四種類型設計方法是達到這一目標有效途徑。雖然這些方法的綜合運用涉及的領域較多,不僅與機械設計的領域知識有關,而且還涉及到系統(tǒng)工程理論、人工智能理論、計算機軟硬件工程、網(wǎng)絡技術等各方面的領域知識,但仍然是產(chǎn)品方案設計必須努力的方向。國外在這方面的研究已初見成效,我國設計學者也已意識到CAD技術與國際交流合作的重要性,及其應當采取的措施。
基于產(chǎn)品特征知識設計方法的主要特點是:用計算機能夠識別的語言描述產(chǎn)品的特征及其設計領域?qū)<业闹R和經(jīng)驗,建立相應的知識庫及推理機,再利用已存儲的領域知識和建立的推理機制實現(xiàn)計算機輔助產(chǎn)品的方案設計。
機械系統(tǒng)的方案設計主要是依據(jù)產(chǎn)品所具有的特征,以及設計領域?qū)<业闹R和經(jīng)驗進行推量和決策,完成機構的型、數(shù)綜合。欲實現(xiàn)這一階段的計算機輔助設計,必須研究知識的自動獲取、表達、集成、協(xié)調(diào)、管理和使用。為此,國內(nèi)外設計學者針對機械系統(tǒng)方案設計知識的自動化處理做了大量的研究工作,采用的方法可歸納為下述幾種。
The worlds Latest Mechanical Design Conceptssource:China Science and Technology JournalAbstract:According to scholars at home and abroad to carry out mechanicaldesign product design features of the main ideas, product design method of theprogramsummarizedassystematic,modularstructure,basedonproductcharacteristics of knowledge and wisdom. The characteristics of these methods andtheir organic connection between them and put forward to achieve the computerproduct design direction.Key words: Mechanical Product Design MethodDevelopment Trends Design documents will be Semantic Web as a design tool inthe design of its Semantic Web activity of the development of ASK, using nodes andlines to describe the design a network, nodes that components of the cell (such asdesign tasks, functions, components or processing equipment, etc. ), used to adjust thelines and definitions between nodes of different semantic relations, thus the designprocess all the activities and results of pre-built models so that the definition of theearly design requirements to the specific description of each structure can be definedby the relationship between the expression, achieved a computer-aided design process,the leap from the abstract to the concrete.Asystematic design methodThe main features of a systematic design method are: the design as designed by anumber of elements of a system, the independence of each design elements, eachelement of an organic link between the existence of, and is layered, with all the designelements , you can design systems to achieve the required task.Systematic design idea in the 70s by the German scholar Professor Pahl andBeitz, the system based on the theory they developed a general pattern of the design,advocacy design work should have organized. German Engineers Association, on thebasis of this design concept to develop a standard VDI2221 technology systems andproduct development design methods.1.The user needs functional characteristics as a product concept, structuredesign and part design, process planning, job control, etc. based on the macro fromthe product development process of starting the use of quality function deploymentmethod and system to user demand information reasonably and efficiently convertedto the various stages of product development, technical goals and operational controlprocedures method.2.The level of the product life of the organism as a system, and means ofliving systems theory, the product design process can be divided into successfulhierarchy of needs to achieve the functional requirements of the conceptual level andproduct level of the specific design. At the same time life-support systems used toexpress the abstract icons of the product functional requirements, system structureformation of product features.3.The mechanical design of the application of systems science into two basicquestions: First, to be designed as a system dealing with the products, the best way todetermine its component parts (modules) and their mutual relations1; is the productdesign process as a system, according to design objectives, a correct and reasonablydetermine the various aspects of the design work and various design stage.Because each designers point of research questions and to consider the questionof emphasis, to design a specific research methods used is also different. Here aresome representative of the systematic design methods.4.Design Element MethodWith the five design elements (functions, effects, effects vector, shape, elements,and surface parameters) describe the product solutions that a product to determinethe value of the five design elements, the product of all the features and characteristicsof the value of i.e. determined. Scholars in China have adopted similar methodsdesigned to describe the products original understanding.5.Graphic modeling methodAnd developed a design analysis and guidance systems KALEIT, with thelevel of clear graphic description of a products functional structure and its associatedabstract information, to the system structure and function relationship of graphicalmodeling, and functional connection between the layers 2.Assistance will be designed to be divided into two aspects of methodology andexchange of information using the Nijssen Information Analysis Method can be usedgraphic symbols, with a rich semantic model structure, can be described as integrationconditions, can be divided into types of constraints can be achieved in relationsbetween any combination of characteristics , the design method to solve integrationand information technology to realize the design process of information betweendifferent abstraction layers between the graphical modeling.6.Concept - Design methodProducts design is divided into concept and design in two stages. Conceptphase of the task is to find, choose and mix to meet the requirements of the originalunderstanding of design tasks. Design stage of work is a concrete realization of theoriginal understanding of the conceptual stage.Of the programs idea of specific described as: In accordance with theappropriate functional structure, seeking to meet the design requirements of theoriginal understanding of the task. The functional structure of the sub-function isperformed by the structural elements to achieve, and structural elements of thephysical connection between the definition of a feature vector, feature vector andstructural elements further the interaction between the formation of the functionaldiagram ( mechanical diagram). The program design is based on functional diagram,the first qualitative description of all of the feature vector and structural elements,and then quantitatively describe all the structural elements and the connection parts( feature vectors), the shape and location to be structure diagram3. Roper, H. usinggraph theory, by means of which he defines as the total design unit (GE), structuralelements (KE), functional structural elements (FKE), connect structural elements(VKE), Structural Parts (KT), structure element part (KET) concepts, as well asdescribe the structure element size, location, and transmission parameters of theinteractions between a number of kinds of schematics, the intuitive designprofessionals have done a formal design method a description of the formation of aneffective application of existing knowledge, methods, and applied to ideas anddesign stage.7.Bond Graph MethodFunction of the composition of system components will be divided into produceenergy, consumed energy, changing energy forms, such as various types of energytransfer, and to use bond graphs to express the function component solution, hoping tofunction-based model and bond graph combine to achieve functional structure theautomatic generation and functional structure with the bond graph automaticconversion between the search for bond graph generated by a number of designmethods.To promote the product on the basis of functional analysis, the product has somefeatures broken down into one or several modular basic structure, by selection andcombination of the basic structure of these modular form into different products.These basic structures can be parts, components, or even a system.The structure should have a standardized interface (connection and co-operationdepartment),andisserialized,universal,integrated,hierarchical,agile,economic-oriented, with interchangeability, compatibility and relevance. Chinascombination of software component technology and CAD technology, variant designcombined with the modular design, according to modular principle of classification,will be divided into descending Machining Center Machine Tool product level,component level, component level and component level, and use expert knowledgeand CAD technology to combine them into different species, different specificationsof functional blocks, and then by the combination of these functions into differentmodules of the overall program processing center.To design a directory as an alternative variation of the mechanical structure ofthe tool, the solution proposed by the design elements of a complete, structured layout,the formation of the solution set design catalogs. And in the solution set designed tocomment on each one listed in the directory solution additional information, is verybeneficial to design engineers select solution elements.The vigorous development of network technology, collaborative design andmanufacturing, as well as the product from the users functional requirements design processing assembly finished product of this realization of concurrentengineering possible. However, an important prerequisite to achieve these goals oneof the conditions is to realize the effect of product design three-dimensionalvisualization. To this end, three-dimensional graphics software, more and moreintelligent design software programs used in the product design, virtual realitytechnology and multimedia, hypermedia tools for product design is also its first debut.At present, Germany and other developed countries are focused on researchhypermedia technology, product data exchange standard STEP, as well as standardvirtual reality modeling language based on a standard exchange format for virtualenvironments) in the product design applications.Mechanical product design is moving in computer-aided realization of intelligentdesign and to meet the needs of distributed collaborative design and manufacture ofdirection, due to the computer product design Study on the implementation startedlate, not yet mature, to achieve the above objectives program design tools4. Authorbelieves that the integrated use of paper, four types of design method is an effectiveway to achieve this goal. Although the integrated use of these methods are moreinvolved in the field, not only with the mechanical design of the field-relatedknowledge, but also to the systems engineering theory, artificial intelligence theory,computer hardware and software engineering, network technology areas such asdomain knowledge, it is still product design must be working for. Abroad in researchin this area has achieved initial success, our scholars have been aware of CAD designtechnology and the importance of international exchange and cooperation, and itsmeasures to be taken.Feature-based design methodology of knowledge The main features are: using acomputer can identify the language to describe the characteristics of the product andits design experts in the field of knowledge and experience to establish the appropriateknowledge base and inference engine, re-use of stored domain knowledge and theestablishment of the inference mechanism to bring computer-aided product design.The mechanical system design is mainly based on the characteristics of a product,and design experts in the field of knowledge and experience to push volume anddecision-making, the completion of body type, the number of synthesis. To achievethis stage of computer-aided design, must study the automatic acquisition ofknowledge, expression, integration, coordination, management and use. To this end,the design and scholars at home and abroad program for the mechanical systemdesign knowledge of the automated processing done a lot of research work, theapproach can be summarized into the following several.
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