基于UG 鼓式制動器設計的參數(shù)化研究【中文4600字】【PDF+中文WORD】
基于UG?鼓式制動器設計的參數(shù)化研究【中文4600字】【PDF+中文WORD】,中文4600字,PDF+中文WORD,基于,UG,制動器,設計,參數(shù),研究,中文,4600,PDF,WORD
【中文4600字】
基于UG?鼓式制動器設計的參數(shù)化研究
Liu Hongpu,Peng Erbao
機械工程,河南理工大學,Henan473009,中國
摘要
本文運用UG軟件的設計和研究上的制動器的類型參數(shù)。論基礎離散化的原則,離散對制動鼓的結構圖案。選取的典型特征制動器總成的三維參數(shù)化建模工作的各個部分,以構建一個模型來參數(shù)庫調用。
?2011下的[南的責任由發(fā)布Elsevier公司的選擇和/或同行審查
關鍵詞:剎車; UG,參數(shù)化,離散化;研究
制動器是汽車行業(yè)的關鍵部件。隨著社會的快速發(fā)展和人民生活水平的提高對制動器的設計汽車提出了更為嚴格的要求。不僅要滿足制動的基本性能要求,還要滿足環(huán)境保護的嚴格要求。本文主要研究在制動鼓上的參數(shù)化設計。
1,制動離散
隨著參數(shù)的變化,在模板特點下可能出現(xiàn)的變化情況: 一)特征維護不變,只有通過受電弓的大小重現(xiàn);二)結構特征性改變。
上述兩種變化情況,在實際操作中,因為選擇使用模擬目標不同大小,所以模板必須設計的不是很大,因此,主要有第一類的情況下,在特性保修范圍的大小變化。當參數(shù)變化是相當
大時,是第二種情況,申請建立模板必須全面描述模型。當然,如果一個模板更接近模型,它必須手動增加的特點就會減少,但這種模板所具有的代表性和典型性相對差一些;模板與待建模型之間有一定的差距,需要手動增加的特性是多方面的,但其代表性和典型性都好一些。這是一對相互矛盾的,在該構建體中應該找一個比較好的平衡點,這樣既可以建立代表
模板,并加快零部件的設計速度。 然后根據(jù)一定的分離規(guī)則,分離各型號相應的剎車零部件,從這些部件中撤銷典型的特征,形成模板參數(shù)化設計要求。
需要遵守的規(guī)則有:
1.1 近似元提取相同的特征。
1.2 單獨特有的部分進行特征提取。
1.3 進行特征提取時,應盡可能撤銷相似的特征。
1.4 特征提取,考慮其實現(xiàn)的可能性。
鼓式制動器離散化之后,組件如下:
* 摩擦盤(大約兩片);
* 剎車蹄片(型);
* Sells on consignment?
* 制動輪缸主體(類型);
* 活塞(類型);
* 皮碗(類型);
* 制動鼓(型);
* 制動底板(型);
* 變動的支承桿(類型);
* 彈簧(類型);
* 附件(襯套防塵套,活塞防塵套,泄氣螺栓螺母,進油口防護罩,密封圈,螺栓防松橡皮筋保護,分離主缸離開油密密封環(huán)及各種彈簧等)
上述名單后僅是離散的組件統(tǒng)一名稱,具體的就下命名,有許多種特性不同的組件,這個請求分別建立模板,以滿足下缸體名需求攻方設計,例如,具有至少5個各種不同類型的氣缸體,因此,必須單獨建立的模板。雖然提取合理的制動帶模板的一定的周期,而且還建立了許多特殊的特性組件模板,所以說從本質上來說,它是基于每個組件離散。選擇模板離散元件后,并按照要求的尺寸制作新組件模型,再組裝制動系統(tǒng)。
當每個組件為參數(shù)化,參數(shù)的整數(shù)必須嚴格控制,必須盡可能的使用盡可能少的參數(shù)來描述整個組件。當然,這里參數(shù)是指可以改變大小的,部件大多數(shù)尺寸需要使用這些成為可能,以改變驅動的大?。醋兓癁樽宰兞浚瑢懙氖浅叽珧寗雍瘮?shù)形式),也就是引起了眾多大小來進行連接,使整體聯(lián)動,完成參數(shù)化建模工作。
2. 制動參數(shù)
本設計采用基于特征的參數(shù)化建模方法,實現(xiàn)了汽車制動零部件快速設計和自動設計。因此,需要明確以下一些具有特征的相關概念。
2.1.特征定義
特征是高層次的抽象描述,設計師描述設計對象的功能,形狀,結構,制造,裝配,檢測,管理和使用信息,并具有準確的項目的含義等的關系。特征模型用邏輯的相互依存,相互進行描述和表達的影響語義網絡的特性實例和關系。與低層次的幾何形狀比較元件表面,側面,所表達的幾何實體的方法所不同的是:該特性模型表達了高水平的具有功能意義的實體,如孔,槽等,其操作對象不是原始的幾何元素,但為該產品的功能要素,在產品技術信息和管理信息,體現(xiàn)了設計者的意圖。
2.2.特征分類
特點是產品描述信息集。不同的應用領域和不同的對象,特征抽象和分類方法是不同的。通過分析機械產品的大量零部件藍圖信息和加工工藝信息,可構成成分特征劃分為五個大類:
經營特色:隨著組件管理相關通信集合,包括標題欄信息(例如組件名稱,圖表或插圖編號,設計者,設計日期等),各組分的材料,并沒有傾倒的信息,如粗糙度等。
技術特點:描述組件的性能和規(guī)格通信集合。
材料熱處理特點:與元件材料及熱處理通信集合,像材料的性能,熱處理方式,硬度值的程度等有關。
精密特性:描述元件的形狀,大小許可量變化通信集合,包括公差(尺寸公差和形狀位置公差)和表面粗糙度。
形態(tài)特征:通信集合這都與描述元件的形狀,大小,包括函數(shù)的形狀,加工工藝造型,裝配輔助形狀有關。
組裝特性:組件相關的方向,相互活性表面和協(xié)調關系。
在上述特征中,形狀特征是描述元件或產品最重要的特征。其可分離主要特征和輔助特征,前者是用來描述結構對象的基本幾何形狀,后者是其中進行表達的對象部分的形狀特征。
2.3.特征關系
為了描述中的特征之間的關系,可應用于特征類,特征實例的概念。特征類是關于類型特征的描述,是所有相同的信息特征的總結。該典型例子是具體特征后,特征屬性的評價,特征是類的成員。其中特性類和典型例子有如下關系:
繼承涉及的特征之一。構成層次關系,這是位于水平更高權限被稱為超類特性,位于水平較低的水平上被稱為亞組的特性。該子組特征可以繼承的超類特征的屬性和方法的,這種繼承關系被稱為關系。另一種繼承關系的特征是類和這種特性的例子,這種關系被稱為關系之間的關系。例如,一些具體的圓柱是一個例子,圓柱特征類,它們之間反映的關系。
相鄰關系。反映了形狀特征之間的相互位置關系,與CONT表示。間的構成鄰接關系形狀特征鄰接條件可以共享。有關例如,階梯軸,每相鄰的兩個軸部的之間的關系是毗連關系,其中每個相鄰表面條件可以共享。
從屬關系是關于形狀特征符合,或者連接的關系的描述,表明與 輔助。下屬形狀特征依賴于形狀特征是服從是存在的,就像是附著在圓柱斜邊。
引用關系:特征描述類作為連接屬性,它的相互引用,表示與重組。引用關系主要存在于引用的形狀特征的精確特性,該材料特性。
2.4.特征建模
基于特征的描述產品的特性所作為建模的基本元素稱為建模技術的方法。特征建??赡苷T發(fā)大約分為三個種類的互動特性定義,識別和設計基于特征的圖案。
互動特性的定義。使用現(xiàn)有的幾何造型系統(tǒng)建立產品的幾何模型,用戶在圖形交互計劃流程定義特征的幾何要素,并添加信息,例如特性參數(shù)或精度,規(guī)格,材料熱處理等,以幾何模型為屬性。這種建模方法的自動化程度低,產品數(shù)據(jù)共享也是難實現(xiàn)的,在信息處理過程中很容易出現(xiàn)人為錯誤。
特征識別。它定義預先特性進行了比較幾何模型,確定特征的具體類型和其他信息。通常它是由通過以下步驟:(1)在搜索產品的幾何形狀的數(shù)據(jù)庫相匹配地形特征的幾何模型;(2)從其自己區(qū)分數(shù)據(jù)庫撤回特征信息為:(3)定特性參數(shù)為:(4)完成對特征幾何模型為:(5)結合了簡單的特點,以成為新的特點。
基于特征的設計。用戶直接定義了組件的幾何實體的特性,不久之后在特征庫預先定義特征實例化,例如取特征為基本單元建立特征模型,從而完成產品的定義和設計。
2.5.參數(shù)化設計
參數(shù)化設計是定義了幾何圖形的大小值并且贊同組參數(shù)的大小關系,提供給設計者進行幾何造型使用。該參數(shù)的辦法很簡單,在參數(shù)和設計對象的尺寸控制有明確的對應關系,設計結果修改接收驅動的大小。在生產中常用的monlding在設計對象的結構形狀,序列化的標準字母屬于這種類型的產品。如圖1參數(shù)化設計系統(tǒng)的原理。
幾何形狀 方程
幾何約束 案例匹配 應用示例
幾何尺寸
參數(shù)化設計系統(tǒng)原理圖1
2.6.參數(shù)設計
在參數(shù)設計的過程中,搜索從CAD圖形文件的約束關系,然后打開圖形大小固定到參數(shù)化圖形自動,新開發(fā)的參數(shù)繪圖軟件算法將被認為是有利的舊圖表參數(shù)化改造。目前,這是最方法的參數(shù)化設計應用。關于系列化,通用化和標準化的定型產品(如模具,夾具,液壓缸,組合機床,閥門等)的設計的數(shù)學模型和產品結構,運用一切都是相對固定不變的,只有產品混合尺寸有差異,結構尺寸的差異是造成年由相同數(shù)目和類型數(shù)據(jù)取離散值的不同規(guī)格的產品設計。這類產品可以取代它的變化以及產品規(guī)格與相應的變量的基本參數(shù),然后根據(jù)這些數(shù)據(jù)和基本參數(shù),使用電腦自動查詢圖形數(shù)據(jù)庫,通過在專用繪圖軟件自動設計圖屏幕。如圖2的參數(shù)化設計過程。
3d模型 讀設計參數(shù) 參數(shù)化設計方法 修改設計參數(shù) 推導出新的三維模型
圖23-D模型的參數(shù)化設計過程
3. 三維實體參數(shù)化設計
參數(shù)化建模的主要思想是,以顯示產品模型的形狀特征與幾何約束,數(shù)學方程和關系,從而設計具有類似的形狀和功能。參數(shù)化實體建模的關鍵是幾何約束關系的提取和表達,解決方案以及參數(shù)化幾何模型結構。多種幾何約束關系,可以寫一種特定格式的文件,包括聯(lián)立方程組(即用戶編程)中,輸入電腦,驅動幾何設計組。例如,確定一個立方體的約束條件L, W,H可形成使用多維數(shù)據(jù)集中的建筑面積和底面周長,面對人工智能知識的表達方式,這種方式將描述幾何結構的體魄,幾何和拓撲結構與步邏輯謂語形式的約束關系,將讀取的知識庫。一方面是知識的表達方式是改變到表單的標記來表示每一種類型的數(shù)據(jù),求標記解決方案,而另一方面則增加了幾何推理基礎上的克制,求數(shù)值解,從而實現(xiàn)在更大程度機械產品智能化設計。的三維參數(shù)化模型是兩個主要的部分是由幾何模型和約束信息組成。根據(jù)什么尺寸約束和拓撲信息模型結構的順序,也就是它們之間的相互依存關系,參數(shù)化建??煞譃閮深愊群蟆R环N是幾何約束作用于固定拓撲體質幾何組織,幾何約束值不會改變幾何模型的拓撲結構,但改變了幾何模型的標稱尺寸。
這種參數(shù)化建模系統(tǒng)的引用B邊界表示作為其內部表達主要模式。另一種是解釋了參數(shù)化模型的幾何構成要素第一和它們之間的約束關系,但模型的拓撲結構是由約束關系決定。這種參數(shù)化建模系統(tǒng)采取南玻表達式作為內部的主要模式,可能會改變滿量程實體模型的拓撲結構,并有利于結構記錄整個過程的程序形式。
4. 制動鼓模型的建立范例
通過對制動鼓分離的部件的結構分析中,組件建模可以使用三種建模方法。
4.1.使用部件的鈑金建模
鈑金建模和參數(shù)化的過程是類似的實體建模,通過二維原理圖計劃組件相關特性,加入了克制,并標記相關的大小。使用弧形側板的工作模塊,坑的操作,沖壓消除等制作的三維實體模型。通過表達把主要參數(shù)與次要參數(shù)關聯(lián)。像圖3是制動蹄片的金屬模型。
圖3金屬片的3-D模型參數(shù)化設計
4.2.羅塔范圍怎么定,例如彈簧使用的規(guī)則的曲線函數(shù)建模版
取彈簧作為一個例子,首先分析每個點的彈簧的結構,并表示例如假設彈簧外環(huán)直徑的基本功能,內孔直徑,轉彎等等的主要參數(shù),然后編輯記錄的規(guī)則功能在X,Y,例如主參數(shù)的基礎上,Z軸方向的規(guī)則曲線彈簧
X1=半徑-r1-cos(dir*180*t)*rl
Y1=r1*sin(dir*180*t)+高+wire-dia/2+r+l
移動這些規(guī)則曲線函數(shù),可能會產生彈簧的中心路徑曲線,再通過掃掠產生彈簧全實體模型,如圖4。
圖5機箱的3-D模型參數(shù)化設計
參考文獻
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作者
劉轟蒲(1964 - ),男,籍貫:南陽市,河南省。河南省數(shù)控技術教學團隊的成員。本科:河南工業(yè)職業(yè)技術學院機械工程系,副教授,學歷的老師。研究方向:機械制造,CAD / CAM。
地址:河南工業(yè)職業(yè)技術學院機械工程系473009
1876-6102?2012由海南大學負責發(fā)布 由Elsevier公司選取和/或同行審查。
DOI:10.1016/j.egypro.2012.02.095
Energy Procedia 17 (2012)279 285 1876-6102 2012 Published by Elsevier Ltd.Selection and/or peer-review under responsibility of Hainan University.doi:10.1016/j.egypro.2012.02.095 2012 International Conference on Future Electrical Power and Energy Systems The Study of the Parameterization of the Drum Brake Design Based on UG Liu Hongpu,Peng Erbao Mechanical Engineering,Henan Polytechnic Institute,Henan473009,China Abstract This text apply UG software to the design and study on the type parameter of the brakes.On the basis of the principles of discretization,discretize the structural pattern of the brake drum.select the typical characteristic of the brake assemblies and the individual parts of the 3d parameterization modeling work,to build a model for parameterization library calls.2011 Published by Elsevier Ltd.Selection and/or peer-review under responsibility of name organizer Keywords:the brakes;ug;parameterization;discretization;research The brake is the key components of the car industry.with the rapid development and people living standards improve in the design of the brake the car raised a more stringent requirements.not only to satisfy the brake the basic properties are required,to satisfy the stringent requirements of the environmental protection.this article mainly study on the brake drum the parameterization design.1.The Brake Discretization With the parameter change,the change situation which in the template characteristic possibly appears:a)the characteristic maintenance is invariable,is only the size reproduce by pantograph;b)the structure characteristic changes.Above two kind of change situation,in actual operation,because selects the template with the simulated target size difference which must design is not very big,therefore mainly has the first kind of situation,the size changes in the characteristic maintenance scope.when the parameter change quite is fierce,is the second kind of situation,this request establishment template must describe the model comprehensively.Certainly,if a template closer model,the characteristic which must increase manually are less,but this template has representative and typical nature bad somewhat;The template with awaits construction the model to have certain disparity,needs to increase manually the characteristic are many,but its representation and typical nature are good somewhat.This is a pair of contradictory,in the construct Available online at 2012 Published by Elsevier Ltd.Selection and/or peer-review under responsibility of Hainan University.280 Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 of the template should find a quite good balance point,like this can both establish the representative template,and speeds up the spare part the design speed.Then according to certain separate rule,is separated each model brake the corresponding spare part,withdraws the typical characteristic from these spare parts,forms the template that the parameterization design request.The deference separate rule is:1.1.Approximate components extraction same characteristic.1.2.Peculiar part alone carries on the characteristic extraction.1.3.Carries on the characteristic extraction,should withdraw the similar characteristic as far as possible.1.4.Characteristic extraction,considers its realization the possibility.After the drum brake discretization,components is as follows:?Friction disk(about two pieces);?Bbrake shoe(type);?Sells on consignment?The cylinder body(type)?Piston(type);?Leather cup(type);?Brake drum(type);?Brake shield plate(type);?Fluctuates the supporting pole(type);?Spring(type);?The appendix(bushing dirt-proof boot,piston dirt-proof boot,deflates bolt nut,oil inlet safety mask,seal packing collar,bolt guards against loose rubber band,separates master cylinder to leave oil tight sealing ring and each kind of spring and so on)After above lists only is the discretization the components unification name,regarding under a specific name,there are many kind of characteristic different components,this request separately establishes the template,to satisfy the demand about the design,for instance under the cylinder body name,has at least 5 kind of different type cylinder bodies,therefore must establish the template separately.Although extracted certain cycle of songss brake to take the template,but has also established many special characteristic components template,therefore said from essentially,its based on each components discretization.After the choice discretization template components,and defer to the request the size to produce the new components model,again assembles the brake system.When each components is parameterized,the parameter integer must control strictly,must use as far as possible few parameters to describe the entire components.Size which certainly here parameter refers to the size which is may change,the components majority of sizes needs to use which these to be possible to change the size actuation(i.e.changes is independent variable,writes is actuated size function form),also is causes the multitudinous sizes to be connected,causes the overall linkage,completes the parameterization modeling work.Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 2812.Brake Parameterization This design uses the method based on the characteristic parameterization modeling,realizes the automobile brake spare part fast design and the automatic design.Therefore needs to make clear following several with the characteristic correlation concept.2.1.Characteristic definition Characteristic is high level abstract description that the designer describe the design object the function,the shape,the structure,the manufacture,the assembly,the examination,the management and the use information and the relations which has the accurate project meaning and so on.The characteristic model use logic in the interdependence,mutually carries on the description and the expression for the influence semantic network to the characteristic instance and the pare with the low level geometry element surface,side,expressed the geometry entity method the difference is:The characteristic model expresses the high level to have the function significance entity,like the hole,the trough and so on,its operation object is not the primitive geometry element,but is the product function essential factor,the product technical information and the management information,manifests designers intention.2.2.Characteristic classification Characteristic is the product description information set.The different application domain and the different object,the characteristic abstract and the classified method is different.Through analyzing mechanical product massive components blueprint information and the processing craft information,may constitute the components characteristic to divide into five big kinds:?Management characteristic:With the components management related communications ensemble,including the title block information(for example components name,chart or illustration number,designer,design date and so on),the components material,has not poured information such as roughness and so on.?Technical characteristic:Description components performance and specification communications ensemble.?Material heat treatment characteristic:associated with components material and heat treatment communications ensemble,like material performance,heat treatment way,degree of hardness value and so on.?Precision characteristic:Description components shape,size permission amount of variation communications ensemble,including common difference(size common difference and shape position common difference)and surface roughness.?Shape characteristic:The communications ensemble which are related to description components shape,size,including function shape,processing craft shape,assembly auxiliary shape.?Assembles characteristic:Components correlation direction,mutual active surface and coordinate relations.In the characteristic above,the shape characteristic is most important characteristic that describes the components or the product.Its separable primarily characteristic and the auxiliary characteristic,the former is used to describe the structure object basic geometry shape,the latter is the characteristic which carries on the expression to the object partial shape 2.3.Characteristic relation In order to describe the relation among characteristic,may apply the concept of characteristic class,the characteristic example.The characteristic class is the description about the characteristic type,is summary of all same information characteristic.The characteristic example is specific characteristic after the 282 Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 characteristic attribute evaluation,is the member of characteristic class.Among the characteristic class,the characteristic example,the characteristic class and the characteristic example has relation as follows:?Inherits relates.Constituted level relation among the characteristic,which is located the level higher authority to be called the ultra kind of characteristic,is located the level lower level to be called the subgroup characteristic.The subgroup characteristic may inherit the ultra kind of characteristic the attribute and the method,this kind of inheritance relation is called the relation.Another kind of inheritance relation is the relation between characteristic class and this kind of characteristic example,this kind of relation is called the relation.For example,some concrete circular cylinder is a example that circular cylinder characteristic class,among themselves has reflected the relation.?Adjacent relation.Reflected the mutual position relations among the shape characteristic,indicated with CONT.Among the constitution adjacency relation shape characteristic adjacency condition may share.For example,a steps and ladders axis,between each neighboring two axis sections relations are the syntopy,in which each adjacency surface condition may share.?Hypotaxis.the description about shape characteristic compliance or the attached relations,indicated with IST.The subordinate shape characteristic relies on in the shape characteristic which is subordinated is existed,like bevel edge attached in circular cylinder.?Quote relation.describing characteristic class as the connection attribute which the quotes mutually,indicated with RE.The quotation relation mainly exists in the quotation that the shape characteristic to the precision characteristic,the material characteristic.2.4.Characteristic modeling The method that describing product by characteristic as the modeling fundamental element is called modeling technology based on the characteristic.The characteristic modeling may induce approximately into three kind of patterns that the interactive characteristic definition,the trick recognition and the design based on the characteristic.?Interactive characteristic definition.Using the existing geometry modeling system establishment product geometry model,the user,definition characteristic geometry essential factor in the graph interactive plan process,and add the information for example characteristic parameter or precision,specification,material heat treatment and so on to geometry model as the attribute.This kind of modeling methods automaticity is low,product data sharing is also difficulty realized,in the information processing process it is easy to arise the artificial mistake.”.?Characteristic recognition.the characteristic which defines in advance is carried on the comparison geometry model,definite characteristic concrete type and additional information.Usually it is composed by the following steps:?Searching product geometry database,match characteristic topo geometry model;?Withdraws the characteristic information from the database which oneself distinguishes;?Definite characteristic parameter;?Completes characteristic geometry model;?Combines the simple characteristic to become the new characteristic.?The design based on characteristic.The user directly defines components geometry entity with the characteristic,after soon in characteristic storehouse pre-definition characteristic instantiation,take example characteristic as basic unit establishment characteristic model,thus completes the product the definition or the design.2.5.Parameterization design Parameterization design is defines the geometric figure size value and agrees the size relations with group of parameters,provides to the designer to carry on the geometry modeling use.The parameters solution is simple,the parameter and the design object control size has the explicit corresponding relations,the design result revision receives the size actuation.In the production commonly used the product which Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 283monlding in the design object structure shape,the serialized standard letter belongs to this type.Parameterization design system principle as shown in Figure 1.2.6.Parameter design In the process of the parameter design,search the restraint relations from the CAD graphic file,then turn the graph fixed size into the parameterization graph automatic,the new development parameter cartography software algorithm will be supposed to be advantageous to the old chart parameterization reconstruction.At present,this is the most methods in the parameterization design applies.Regarding serialized,universalized and the standardized stereotypia product(for example mold,jig,hydraulic cylinder,aggregate machine-tool,valve and so on)s design the mathematical model and the product structure which uses all are relatively fixed invariable,only the product mix size have a difference,the difference of the structure size is caused by the same number and the type datum takes the discrete value in the different specification product design.This kind of product may replace the basic parameter which changes along with the product specification with the corresponding variable,then according to these data and the basic parameter,use the computer automatic inquiry graph database,designs the graph automatically by the special cartography software on the screen.As shown in Figure 2 for the parameterization design process.3.The Three Dimensional Entity Parameterization Design Parameterization modeling s main thought is to show the product model the shape characteristic with the geometry restraint,mathematics equation and the relations,thus the designs has the similar in the shape and the function.The parameterization entity modeling s key is the geometry restraint relations extraction and expression,the solution as well as the parameterization geometry model structure.Many kinds of geometry restraint relations,may write one kind of specific form document including the simultaneous equation group(i.e.user programming),inputs the computer,actuates geometry design in groups.For Fig.1 Principle of parameterized design system Fig.2 The course of 3-Dmodel Parameterized design hlauhsfo284 Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 example,determined a cube s constraint condition L,W,H may form using the cube the floor space and the bottom surface perimeter,face the expression way of artificial intelligence knowledge,this way will describe the restraint relations of the geometry physique,the geometry and topology with a step logic predicate form,and will read in the knowledge library.On the one hand the knowledge expression way is changes into the form by the mark to express each kind of type the data,seeking mark solution;On the other hand is adds on geometry inference based on restraint,seeking numerical solution,thus realizes the mechanical product intelligent design in a greater degree.The 3D parameterization model is two major part is composed by the geometry model and the restraint information.According to on what size restraint and the order of the topo information model structure,that is the interdependence relations between them,the parameterization modeling may divide into two kinds successively.One kind is the geometry restraint acting on the fixed topology physique geometry tissue,geometry restraint value does not change the geometry model topology,but changes the nominal size of the geometry model.This kind of parameterization modeling system take B-rep as its internal expression principal-mode.Another kind is explains the parameterization model the geometry integrant part first and the restraint relations between them,but model topology is decided by the restraint relations.This kind of parameter modeling system take CSG expression as internal principal-mode,may change the full-scale mockup topology,and is advantageous recording structure entire process by the procedural form.4.The Drum Brake Model Establishment Example Through to structure analysis of the drum brake separate components,the components modeling may use three modeling methods.4.1.Uses the plate work modeling of parts Plate work modeling and the parameterization process is similar to the entity modeling,through the two-dimensional schematic diagram plan components correlation characteristic,joins the restraint,and labels the related size.Using the operation of plate work module in curved side,the pit,the ramming eliminates and so on producing three-dimensional entity model.And associate main parameter with secondary parameter through expression.Like Figure 3 is the brake shoe sheet metal model.4.2.What about rotascope for example the spring use the rule curve function edition modeling Take the spring as an example,first analyzes the spring structure in each spot,and express the main parameter for example hypothesis spring outer annulus diameter with the fundamental function,the internal bore diameter,the turn and so on,then edits rule function of the spring in the rule curve in X,Y,the Z axis direction on the basis of the main parameter for example?rltdirrradiusX*180*cos11?rY?1?lrdiawireheighttdirrZ?2_*180*sin*11 Moves Fig.3 The3-D model Parameterized design of sheet metal Liu Hongpu and Peng Erbao /Energy Procedia 17 (2012)279 285 285these rule curve function,may produce the springs central path curve,again through sweeps plunders produce the spring full-scale mockup,as shown in Figure 4.4.3.May use the compound method modelling regarding the structure complex components Regarding the complex shape components often not to be able to realize using several modelling method any kind above,by now we might use the method above,use several methods to establish the geometry model we need.As shown in Figure 5 the brake chassis is uses compound method which the entity modeling and the sheet metal modeling unifies to complete.References 1Guan xin,Shen Junfeng,Guan renmei,Zhan jun.Drum brake multi-flexible body ADAMS modeling and simulation.Automobile technology,2007,(10).2Meng Jie.Drum brake design system development research based on parametrization technology.Hebei industrial university,2009,(6):17-24.3Guan xin,Shen Junfeng,Guan renmei,Zhan jun.Drum brake correlation parameter to its brake potency influence.Science technology and project,2009,(4)4Zhang Ping.Automobile drum type brake.P2007,(6).5Xu Yongkang.Automobile brake.Automobile practical technology 2004,(1).Author Liu Hongpu(1964-),male,native place:Nanyang city,Henan Province.The member of Henan Province numerical control technology teaching team.The teacher of Henan industry professional technology institute mechanical engineering department,associate professor,school record:Undergraduate course.Research direction:Machine manufacture,CAD/CAM.Address:Henan industry professional technology institute mechanical engineering department 473009 Fig.5 The3-D model Parameterized design of chassis
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