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技術(shù)學(xué)院
畢業(yè)設(shè)計論文
設(shè)計課題: 密封墊圈—模具設(shè)計
班 級:
姓 名:
學(xué) 號:
專 業(yè): 模具設(shè)計與制造
教 研 室: 模具教研室
指導(dǎo)老師:
聯(lián)系電話:
E-mail:
目 錄
目錄··············································································1
摘要···············································································3
前言···············································································4
1.沖裁模設(shè)計課題·································································6
2.零件的工藝分析·················································6
2.1畫出零件圖······················································6
2.2結(jié)構(gòu)尺寸·····················································6
2.3精度························································6
2.4材料······································································· 6 3.確定沖裁工藝方案·················································6
3.1沖裁工序的組合方式確定·············································6
3.2級進(jìn)模工藝方案順序的確定·············································6
4.沖壓模具結(jié)構(gòu)總體結(jié)構(gòu)設(shè)計·············································7
4.1模具類型······················································7
4.2操作與定位方式················································8
4.3卸料方式······················································8
4.4模具類型及精度················································8
5.工藝設(shè)計與計算·····················································8
5.1排樣圖設(shè)計與計算················································8
5.2計算沖壓力和壓力中心,初選壓力機(jī)······························9
6. 壓力機(jī)的校核····················································10
6.1公稱壓力·····················································10
6.2滑塊行程···················································· 10
6.3行程次數(shù)··················································· 10
6.4工作臺面的尺寸·············································· 10
6.5滑塊模柄尺寸·····················································10
6.6閉合高度·····················································10
7.模具材料及主要零件設(shè)計··············································10
7.1模具材料的選定·····················································11
7.2凸凹模的結(jié)構(gòu)型式與固定方法·········································12
7.3 模具刃口尺寸計算···························································12
7.3.1計算凸模、凹模、凸凹模刃口的結(jié)構(gòu)尺寸及公差·····························14
7.3.2落料凹模尺寸計算·····························································14
7.3.3沖孔凸模與凸凹模機(jī)構(gòu)尺寸計算·················································14
7.4凸模固定板設(shè)計·························································14
7.5定位零件·························································14
7.6卸料裝置的設(shè)計及類型···············································15
7.6.1卸料板的外形尺··········································15
7. 6. 2卸料板與凸模之間的間隙確定···········································15
7.6.3卸料螺釘·················································15
7. 6 .4卸料彈簧的選用·························································15
7.6.5橡膠墊的設(shè)計·····························································15
8.模架及其他零件的選用··········································15
8. 8 .1 模柄···································································15
8 .8 .2 模座···································································16
8.8.3 模架選用后側(cè)導(dǎo)柱標(biāo)準(zhǔn)模架·············································16
8.8.4 導(dǎo)柱導(dǎo)套····························································16
8.8.5 沖壓設(shè)備的選用···················································16
8.8.6 緊固件的選用···················································16
9.模具主要零件加工藝規(guī)程的編制······································17
9.1沖壓模具的制造技術(shù)及加工要求··································17
9.3主要零、部件的加工工藝····································17
9.3.1墊板的加工工藝············································17
9.3.2凸模固定板的加工工藝····································18
9.3.3 沖孔凸模的加工工藝····································18
9.3.4 卸料板的加工工藝·······································18
9.3.5落料凹模的加工工藝····································18
9.3.6凸凹模的加工工藝·······································19
9.3.7 凸凹模固定板的加工工藝·································19
總 結(jié)····························································20
致 謝····························································20
參考文獻(xiàn)···························································22
目 錄
摘要··············································································2
1.緒論··············································································4
2.零件的工藝分析·················································6
2 1 畫出零件圖····························································6
2 2結(jié)構(gòu)尺寸···························································6
2 3 精度要求···························································6
2 4 材料選定····························································· 6
3.確定沖裁工藝方案·················································6
3.1 沖裁工序的組合方式確定·············································6
3.2 級進(jìn)模工藝方案順序的確定············································6
4.沖壓模具總體結(jié)構(gòu)設(shè)計·············································7
4.1 模具類型及精度······················································7
4.2 操作與定位方式···················································8
4.3 卸料與出件方式······················································8
5.工藝設(shè)計與計算·····················································8
5 1排樣圖設(shè)計與計算················································8
5 1 1 搭邊值計算···················································8
5 1 2 條料寬度計算···················································8
5 1 3 導(dǎo)料板間距計算················································8
5 1 4 排樣確定······················································8
5 1 5 材料利用率計算················································8
5 2計算沖壓力和壓力中心,初選壓力機(jī)············································9
6.壓力機(jī)的校核····················································10
6 1 公稱壓力························································10
6 2 滑塊行程······················································· 10
6 3 行程次數(shù)··················································· 10
6 4 工作臺面的尺寸················································· 10
6 5 滑塊模柄尺寸·····················································10
6 6 閉合高度·····················································10
7.模具材料及主要零件設(shè)計························································10
7 1 模具材料的選定··························································11
7 2 凸凹模的結(jié)構(gòu)型式與固定方法······································12
7 3 模具刃口尺寸計算·······························································14
7 3 1 凸模、凹模、凸凹模刃口尺寸計算·················································14
7 3 2 落料凹模尺寸計算································································14
7 3 3 沖孔凸模與凸凹模結(jié)構(gòu)尺寸計算·················································14
7 4凸模固定板設(shè)計·····································································14
7 5定位零件的設(shè)計·······································································15
7 6卸料與推件零件設(shè)計·················································15
7 6 1 卸料板的外形尺寸設(shè)計··················································15
7 6 2 卸料板與凸模之間的間隙確定···········································15
7 6 3 卸料彈簧的設(shè)計·························································15
7 6 4 橡膠墊的設(shè)計···························································15
8.模架及其它零件選用··········································15
8 1 模柄··················································15
8 2 模座·················································16
8 3 模架選用············································16
8 4 導(dǎo)柱導(dǎo)套············································16
8 5 沖壓設(shè)備選用······································16
8 6 緊固件的選用······································16
9.模具主要零件加工藝規(guī)程的編制················································17
9.1沖壓模具的制造技術(shù)及加工要求····································17
9.2主要零、部件的加工工藝····································17
9 2 1 導(dǎo)料板的加工工藝····································17
9 2 2 凸模固定板的加工····································18
9 2 3 沖孔凸模的加工工藝····································18
9 2 4 卸料板的加工工藝·······································18
9 2 5 落料凹模的加工工藝·······································18
9 2 6 上模板的加工工藝·······································19
9 2 7 下模板的加工工藝·······································19
總 結(jié)····························································20
致 謝····························································20
參考文獻(xiàn)···························································22
摘 要
本設(shè)計為一密封墊圈的冷沖壓模具設(shè)計,在分析沖裁模沖壓工藝的基礎(chǔ)上,通過查閱相關(guān)文獻(xiàn)資料,對該零件進(jìn)行了工藝分析,選擇并確定了符合于給定條件的最優(yōu)方案,并進(jìn)行了工藝與設(shè)計的有關(guān)計算如:選擇基本工序,確定順序,工序數(shù)目及工序組合形式,介紹了主要零部件的設(shè)計理念,詳細(xì)剖析了設(shè)計中的一些思路,以及某些非標(biāo)準(zhǔn)零件的使用和特點(diǎn)通過計算模具中的尺寸、沖壓過程中的各工藝力等主要工藝參數(shù)和落料刃口、沖孔刃口等主要工作部分尺寸,設(shè)計出主要零件結(jié)構(gòu)和實(shí)體模型,繪制了模具的裝配圖及部分主要凹凸模的零件圖,分析了模具的動作過程及加工制造方案。如今,模具在航空、汽車、機(jī)械等各行業(yè)得到越來越廣泛的應(yīng)用
關(guān)鍵詞:模具; 沖裁件;凸模;凹模;凸凹模;
Abstract
This design is a gasket cold stamping die design, stamping die stamping process in the analysis, based on a review of the relevant literature, the parts of the process analysis, select and determine the compliance with the conditions of a given optimal solution and carried out on the calculation process and design such as: select the basic steps to determine the order of the number of processes and process combinations, introduces the main components of the design concept, a detailed analysis of the design of some of the ideas, as well as some non-standard parts the use and characteristics of the working portion size calculated by the major dimensions of the mold, stamping process various process parameters and force other major edge blanking, punching edge, etc., to design the structure and main parts of the solid model, drawing die the assembly drawings and some of the major bump mold parts diagram, analyze the mold of action process and manufacturing solutions. Today, mold in the aerospace, automotive, machinery and other industries to be more widely applied
Keywords: mold; stamping parts; punch; die; punch;
緒論
1.1沖壓的概念、特點(diǎn)及應(yīng)用
沖壓是利用安裝在沖壓設(shè)備(主要是壓力機(jī))上的模具對材料施加壓力,使其產(chǎn)生分離或塑性變形,從而獲得所需零件(俗稱沖壓或沖壓件)的一種壓力加工方法。沖壓通常是在常溫下對材料進(jìn)行冷變形加工,且主要采用板料來加工成所需零件,所以也叫冷沖壓或板料沖壓。沖壓是材料壓力加工或塑性加工的主要方法之一,隸屬于材料成型工程術(shù)。
沖壓所使用的模具稱為沖壓模具,簡稱沖模。沖模是將材料(金屬或非金屬)批量加工成所需沖件的專用工具。沖模在沖壓中至關(guān)重要,沒有符合要求的沖模,批量沖壓生產(chǎn)就難以進(jìn)行;沒有先進(jìn)的沖模,先進(jìn)的沖壓工藝就無法實(shí)現(xiàn)。沖壓工藝與模具、沖壓設(shè)備和沖壓材料構(gòu)成沖壓加工的三要素,只有它們相互結(jié)合才能得出沖壓件。
與機(jī)械加工及塑性加工的其它方法相比,沖壓加工無論在技術(shù)方面還是經(jīng)濟(jì)方面都具有許多獨(dú)特的優(yōu)點(diǎn)。主要表現(xiàn)如下。
(1) 沖壓加工的生產(chǎn)效率高,且操作方便,易于實(shí)現(xiàn)機(jī)械化與自動化。這是因?yàn)闆_壓是依靠沖模和沖壓設(shè)備來完成加工,普通壓力機(jī)的行程次數(shù)為每分鐘可達(dá)幾十次,高速壓力要每分鐘可達(dá)數(shù)百次甚至千次以上,而且每次沖壓行程就可能得到一個沖件。
(2)沖壓時由于模具保證了沖壓件的尺寸與形狀精度,且一般不破壞沖壓件的表面質(zhì)量,而模具的壽命一般較長,所以沖壓的質(zhì)量穩(wěn)定,互換性好,具有“一模一樣”的特征。
(3)沖壓可加工出尺寸范圍較大、形狀較復(fù)雜的零件,如小到鐘表的秒表,大到汽車縱梁、覆蓋件等,加上沖壓時材料的冷變形硬化效應(yīng),沖壓的強(qiáng)度和剛度均較高。
(4)沖壓一般沒有切屑碎料生成,材料的消耗較少,且不需其它加熱設(shè)備,因而是一種省料,節(jié)能的加工方法,沖壓件的成本較低。但是,沖壓加工所使用的模具一般具有專用性,有時一個復(fù)雜零件需要數(shù)套模具才能加工成形,且模具制造的精度高,技術(shù)要求高,是技術(shù)密集形產(chǎn)品。所以,只有在沖壓件生產(chǎn)批量較大的情況下,沖壓加工的優(yōu)點(diǎn)才能充分體現(xiàn),從而獲得較好的經(jīng)濟(jì)效益。
沖壓技術(shù)在現(xiàn)代工業(yè)生產(chǎn)中,尤其是大批量生產(chǎn)中應(yīng)用十分廣泛。相當(dāng)多的工業(yè)部門越來越多地采用沖壓法加工產(chǎn)品零部件,如汽車、農(nóng)機(jī)、儀器、儀表、電子、航空、航天、家電及輕工等行業(yè)。在這些工業(yè)部門中,沖壓件所占的比重都相當(dāng)?shù)拇螅賱t60%以上,多則90%以上。不少過去用鍛造=鑄造和切削加工方法制造的零件,現(xiàn)在大多數(shù)也被質(zhì)量輕、剛度好的沖壓件所代替。因此可以說,如果生產(chǎn)中不諒采用沖壓工藝,許多工業(yè)部門要提高生產(chǎn)效率和產(chǎn)品質(zhì)量、降低生產(chǎn)成本、快速進(jìn)行產(chǎn)品更新?lián)Q代等都是難以實(shí)現(xiàn)的。
1.2 沖壓的基本工序及模具
由于沖壓加工的零件種類繁多,各類零件的形狀、尺寸和精度要求又各不相同,因而生產(chǎn)中采用的沖壓工藝方法也是多種多樣的。概括起來,可分為分離工序和成形工序兩大類:
分工序:指使坯料沿一定的輪廓線分離而獲得一定形狀、尺寸和斷面質(zhì)量的沖壓(俗稱沖裁件)的工序。
成形工序:指使坯料在不破裂的條件下產(chǎn)生塑性變形而獲得一定形狀和尺寸的沖壓件的工序。
上述兩類工序,按基本變形方式不同又可分為沖裁、彎曲、拉深和成形四種基本工序,每種基本工序還包含有多種單一工序。
在實(shí)際生產(chǎn)中,當(dāng)沖壓件的生產(chǎn)批量較大、尺寸較少而公差要求較小時,若用分散的單一工序來沖壓是不經(jīng)濟(jì)甚至難于達(dá)到要求。這時在工藝上多采用集中的方案,即把兩種或兩種以上的單一工序集中在一副模具內(nèi)完成,稱為組合的方法不同,又可將其分為復(fù)合、級進(jìn)復(fù)合-級進(jìn)三種組合方式。
復(fù)合沖壓——在壓力機(jī)的一次工作行程中,在模具的同一工位上同時完成兩種或兩種以上不同單一工序的一種組合方法式。
級進(jìn)沖壓——在壓力機(jī)上的一次工作行程中,按照一定的順序在同一模具的不同工位上完面兩種或兩種以上不同單一工序的一種組合方式。
復(fù)合-級進(jìn)——在一副沖模上包含復(fù)合和級進(jìn)兩種方式的組合工序。
沖模的結(jié)構(gòu)類型也很多。通常按工序性質(zhì)可分為沖裁模、彎曲模、拉深模和成形模等;按工序的組合方式可分為單工序模、復(fù)合模和級進(jìn)模等。但不論何種類型的沖模,都可看成是由上模和下模兩部分組成。
上模被固定在壓力機(jī)工作臺或墊板上,是沖模的固定部分。工作時,坯料在下模面上通過定位零件定位,壓力機(jī)滑塊帶動上模下壓,在模具工作零件(即凸模、凹模)的作用下坯料便產(chǎn)生分離或塑性變形,從而獲得所需形狀與尺寸的沖件。上?;厣龝r,模具的卸料與出件裝置將沖件或廢料從凸、凹模上卸下或推、頂出來,以便進(jìn)行下一次沖壓循環(huán)。
1.3 沖壓技術(shù)的現(xiàn)狀及發(fā)展方向
隨著科學(xué)技術(shù)的不斷進(jìn)步和工業(yè)生產(chǎn)的迅速發(fā)展,許多新技術(shù)、新工藝、新設(shè)備、新材料不斷涌現(xiàn),因而促進(jìn)了沖壓技術(shù)的不斷革新和發(fā)展。其主要表現(xiàn)和發(fā)展方向如下。
(1).沖壓成形理論及沖壓工藝方面
沖壓成形理論的研究是提高沖壓技術(shù)的基礎(chǔ)。目前,國內(nèi)外對沖壓成形理論的研究非常重視,在材料沖壓性能研究、沖壓成形過程應(yīng)力應(yīng)變分析、板料變形規(guī)律研究及坯料與模具之間的相互作用研究等方面均取得了較大的進(jìn)展。特別是隨著計算機(jī)技術(shù)的飛躍發(fā)展和塑性變形理論的進(jìn)一步完善,近年來國內(nèi)外已開始應(yīng)用塑性成形過程的計算機(jī)模擬技術(shù),即利用有限元(FEM)等有值分析方法模擬金屬的塑性成形過程,根據(jù)分析結(jié)果,設(shè)計人員可預(yù)測某一工藝方案成形的可行性及可能出現(xiàn)的質(zhì)量問題,并通過在計算機(jī)上選擇修改相關(guān)參數(shù),可實(shí)現(xiàn)工藝及模具的優(yōu)化設(shè)計。這樣既節(jié)省了昂貴的試模費(fèi)用,也縮短了制模具周期。
研究推廣能提高生產(chǎn)率及產(chǎn)品質(zhì)量、降低成本和擴(kuò)大沖壓工藝應(yīng)用范圍的各種壓新工藝,也是沖壓技術(shù)的發(fā)展方向之一。目前,國內(nèi)外相繼涌現(xiàn)出精密沖壓工藝、軟模成形工藝、高能高速成形工藝及無模多點(diǎn)成形工藝等精密、高效、經(jīng)濟(jì)的沖壓新工藝。其中,精密沖裁是提高沖裁件質(zhì)量的有效方法,它擴(kuò)大了沖壓加工范圍,目前精密沖裁加工零件的厚度可達(dá)25mm,精度可達(dá)IT16~17級;用液體、橡膠、聚氨酯等作柔性凸模或凹模的軟模成形工藝,能加工出用普通加工方法難以加工的材料和復(fù)雜形狀的零件,在特定生產(chǎn)條件下具有明顯的經(jīng)濟(jì)效果;采用爆炸等高能效成形方法對于加工各種尺寸在、形狀復(fù)雜、批量小、強(qiáng)度高和精度要求較高的板料零件,具有很重要的實(shí)用意義;利用金屬材料的超塑性進(jìn)行超塑成形,可以用一次成形代替多道普通的沖壓成形工序,這對于加工形狀復(fù)雜和大型板料零件具有突出的優(yōu)越性;無模多點(diǎn)成形工序是用高度可調(diào)的凸模群體代替?zhèn)鹘y(tǒng)模具進(jìn)行板料曲面成形的一種先進(jìn)技術(shù),我國已自主設(shè)計制造了具有國際領(lǐng)先水平的無模多點(diǎn)成形設(shè)備,解決了多點(diǎn)壓機(jī)成形法,從而可隨意改變變形路徑與受力狀態(tài),提高了材料的成形極限,同時利用反復(fù)成形技術(shù)可消除材料內(nèi)殘余應(yīng)力,實(shí)現(xiàn)無回彈成形。無模多點(diǎn)成形系統(tǒng)以CAD/CAM/CAE技術(shù)為主要手段,能快速經(jīng)濟(jì)地實(shí)現(xiàn)三維曲面的自動化成形。
(2.)沖模是實(shí)現(xiàn)沖壓生產(chǎn)的基本條件.在沖模的設(shè)計制造上,目前正朝著以下兩方面發(fā)展:一方面,為了適應(yīng)高速、自動、精密、安全等大批量現(xiàn)代生產(chǎn)的需要,沖模正向高效率、高精度、高壽命及多工位、多功能方向發(fā)展,與此相比適應(yīng)的新型模具材料及其熱處理技術(shù),各種高效、精密、數(shù)控自動化的模具加工機(jī)床和檢測設(shè)備以及模具CAD/CAM技術(shù)也在迅速發(fā)展;另一方面,為了適應(yīng)產(chǎn)品更新?lián)Q代和試制或小批量生產(chǎn)的需要,鋅基合金沖模、聚氨酯橡膠沖模、薄板沖模、鋼帶沖模、組合沖模等各種簡易沖模及其制造技術(shù)也得到了迅速發(fā)展。
精密、高效的多工位及多功能級進(jìn)模和大型復(fù)雜的汽車覆蓋件沖模代表了現(xiàn)代沖模的技術(shù)水平。目前,50個工位以上的級進(jìn)模進(jìn)距精度可達(dá)到2微米,多功能級進(jìn)模不僅可以完成沖壓全過程,還可完成焊接、裝配等工序。我國已能自行設(shè)計制造出達(dá)到國際水平的精度達(dá)2~5微米,進(jìn)距精度2~3微米,總壽命達(dá)1億次。我國主要汽車模具企業(yè),已能生產(chǎn)成套轎車覆蓋件模具,在設(shè)計制造方法、手段方面已基本達(dá)到了國際水平,但在制造方法手段方面已基本達(dá)到了國際水平,模具結(jié)構(gòu)、功能方面也接近國際水平,但在制造質(zhì)量、精度、制造周期和成本方面與國外相比還存在一定差距。
模具制造技術(shù)現(xiàn)代化是模具工業(yè)發(fā)展的基礎(chǔ)。計算機(jī)技術(shù)、信息技術(shù)、自動化技術(shù)等先進(jìn)技術(shù)正在不斷向傳統(tǒng)制造技術(shù)滲透、交叉、融合形成了現(xiàn)代模具制造技術(shù)。其中高速銑削加工、電火花銑削加工、慢走絲切割加工、精密磨削及拋光技術(shù)、數(shù)控測量等代表了現(xiàn)代沖模制造的技術(shù)水平。高速銑削加工不但具有加工速度高以及良好的加工精度和表面質(zhì)量(主軸轉(zhuǎn)速一般為15000~40000r/min),加工精度一般可達(dá)10微米,最好的表面粗糙度Ra≤1微米),而且與傳統(tǒng)切削加工相比具有溫升低(工件只升高3攝氏度)、切削力小,因而可加工熱敏材料和剛性差的零件,合理選擇刀具和切削用量還可實(shí)現(xiàn)硬材料(60HRC)加工;電火花銑削加工(又稱電火花創(chuàng)成加工)是以高速旋轉(zhuǎn)的簡單管狀電極作三維或二維輪廓加工(像數(shù)控銑一樣),因此不再需要制造昂貴的成形電極,如日本三菱公司生產(chǎn)的EDSCAN8E電火花銑削加工機(jī)床,配置有電極損耗自動補(bǔ)償系統(tǒng)、CAD/CAM集成系統(tǒng)、在線自動測量系統(tǒng)和動態(tài)仿真系統(tǒng),體現(xiàn)了當(dāng)今電火花加工機(jī)床的技術(shù)水平;慢走絲線切割技術(shù)的發(fā)展水平已相當(dāng)高,功能也相當(dāng)完善,自動化程度已達(dá)到無人看管運(yùn)行的程度,目前切割速度已達(dá)到300mm/min,加工精度可達(dá)±1.5微米,表面粗糙度達(dá)Ra=01~0.2微米;精度磨削及拋光已開始使用數(shù)控成形磨床、數(shù)控光學(xué)曲線磨床、數(shù)控連續(xù)軌跡坐標(biāo)磨床及自動拋光等先進(jìn)設(shè)備和技術(shù);模具加工過程中的檢測技術(shù)也取得了很大的發(fā)展,現(xiàn)在三坐標(biāo)測量機(jī)除了能高精度地測量復(fù)雜曲面的數(shù)據(jù)外,其良好的溫度補(bǔ)償裝置、可靠的抗振保護(hù)能力、嚴(yán)密的除塵措施及簡單操作步驟,使得現(xiàn)場自動化檢測成為可能。此外,激光快速成形技術(shù)(RPM)與樹脂澆注技術(shù)在快速經(jīng)濟(jì)制模技術(shù)中得到了成功的應(yīng)用。利用RPM技術(shù)快速成形三維原型后,通過陶瓷精鑄、電弧涂噴、消失模、熔模等技術(shù)可快速制造各種成形模。如清華大學(xué)開發(fā)研制的“M-RPMS-Ⅱ型多功能快速原型制造系統(tǒng)”是我國自主知識產(chǎn)權(quán)的世界惟一擁有兩種快速成形工藝(分層實(shí)體制造SSM和熔融擠壓成形MEM)的系統(tǒng),它基于“模塊化技術(shù)集成”之概念而設(shè)計和制造,具有較好的價格性能比。一汽模具制造公司在以CAD/CAM加工的主模型為基礎(chǔ),采用瑞士汽巴精化的高強(qiáng)度樹脂澆注成形的樹脂沖模應(yīng)用在國產(chǎn)轎車試制和小批量生產(chǎn)開辟了新的途徑。
(3) 沖壓設(shè)備和沖壓生產(chǎn)自動化方面
性能良好的沖壓設(shè)備是提高沖壓生產(chǎn)技術(shù)水平的基本條件,高精度、高壽命、高效率的沖模需要高精度、高自動化的沖壓設(shè)備相匹配。為了滿足大批量高速生產(chǎn)的需要,目前沖壓設(shè)備也由單工位、單功能、低速壓力機(jī)朝著多工位、多功能、高速和數(shù)控方向發(fā)展,加之機(jī)械乃至機(jī)器人的大量使用,使沖壓生產(chǎn)效率得到大幅度提高,各式各樣的沖壓自動線和高速自動壓力機(jī)紛紛投入使用。如在數(shù)控四邊折彎機(jī)中送入板料毛坯后,在計算機(jī)程序控制下便可依次完成四邊彎曲,從而大幅度提高精度和生產(chǎn)率;在高速自動壓力機(jī)上沖壓電機(jī)定轉(zhuǎn)子沖片時,一分鐘可沖幾百片,并能自動疊成定、轉(zhuǎn)子鐵芯,生產(chǎn)效率比普通壓力機(jī)提高幾十倍,材料利用率高達(dá)97%;公稱壓力為250KN的高速壓力機(jī)的滑塊行程次數(shù)已達(dá)2000次/min以上。在多功能壓力機(jī)方面,日本田公司生產(chǎn)的2000KN“沖壓中心”采用CNC控制,只需5min時間就可完成自動換模、換料和調(diào)整工藝參數(shù)等工作;美國惠特尼公司生產(chǎn)的CNC金屬板材加工中心,在相同的時間內(nèi),加工沖壓件的數(shù)量為普通壓力機(jī)的4~10倍,并能進(jìn)行沖孔、分段沖裁、彎曲和拉深等多種作業(yè)。
近年來,為了適應(yīng)市場的激烈競爭,對產(chǎn)品質(zhì)量的要求越來越高,且其更新?lián)Q代的周期大為縮短。沖壓生產(chǎn)為適應(yīng)這一新的要求,開發(fā)了多種適合不同批量生產(chǎn)的工藝、設(shè)備和模具。其中,無需設(shè)計專用模具、性能先進(jìn)的轉(zhuǎn)塔數(shù)控多工位壓力機(jī)、激光切割和成形機(jī)、CNC萬能折彎機(jī)等新設(shè)備已投入使用。特別是近幾年來在國外已經(jīng)發(fā)展起來、國內(nèi)亦開始使用的沖壓柔性制造單元(FMC)和沖壓柔性制造系統(tǒng)(FMS)代表了沖壓生產(chǎn)新的發(fā)展趨勢。FMS系統(tǒng)以數(shù)控沖壓設(shè)備為主體,包括板料、模具、沖壓件分類存放系統(tǒng)、自動上料與下料系統(tǒng),生產(chǎn)過程完全由計算機(jī)控制,車間實(shí)現(xiàn)24小時無人控制生產(chǎn)。同時,根據(jù)不同使用要求,可以完成各種沖壓工序,甚至焊接、裝配等工序,更換新產(chǎn)品方便迅速,沖壓件精度也高。
(4)沖壓標(biāo)準(zhǔn)化及專業(yè)化生產(chǎn)方面
模具的標(biāo)準(zhǔn)化及專業(yè)化生產(chǎn),已得到模具行業(yè)和廣泛重視。因?yàn)闆_模屬單件小批量生產(chǎn),沖模零件既具的一定的復(fù)雜性和精密性,又具有一定的結(jié)構(gòu)典型性。因此,只有實(shí)現(xiàn)了沖模的標(biāo)準(zhǔn)化,才能使沖模和沖模零件的生產(chǎn)實(shí)現(xiàn)專業(yè)化、商品化,從而降低模具的成本,提高模具的質(zhì)量和縮短制造周期。目前,國外先進(jìn)工業(yè)國家模具標(biāo)準(zhǔn)化生產(chǎn)程度已達(dá)70%~80%,模具廠只需設(shè)計制造工作零件,大部分模具零件均從標(biāo)準(zhǔn)件廠購買,使生產(chǎn)率大幅度提高。模具制造廠專業(yè)化程度越不定期越高,分工越來越細(xì),如目前有模架廠、頂桿廠、熱處理廠等,甚至某些模具廠僅專業(yè)化制造某類產(chǎn)品的沖裁?;驈澢?,這樣更有利于制造水平的提高和制造周期的縮短。我國沖模標(biāo)準(zhǔn)化與專業(yè)化生產(chǎn)近年來也有較大發(fā)展,除反映在標(biāo)準(zhǔn)件專業(yè)化生產(chǎn)廠家有較多增加外,標(biāo)準(zhǔn)件品種也有擴(kuò)展,精度亦有提高。但總體情況還滿足不了模具工業(yè)發(fā)展的要求,主要體現(xiàn)在標(biāo)準(zhǔn)化程度還不高(一般在40%以下),標(biāo)準(zhǔn)件的品種和規(guī)格較少,大多數(shù)標(biāo)準(zhǔn)件廠家未形成規(guī)?;a(chǎn),標(biāo)準(zhǔn)件質(zhì)量也還存在較多問題。另外,標(biāo)準(zhǔn)件生產(chǎn)的銷售、供貨、服務(wù)等都還有待于進(jìn)一步提高。
2、沖壓件工藝分析
2 1如下圖所示零件:密封墊圈
圖2–1 零件圖
工作任務(wù):制定沖壓加工工藝并設(shè)計模具
技術(shù)要求:生產(chǎn)批量:大批量
材料:Q235
厚度:1.2mm
未注尺寸公差I(lǐng)T14
未注圓角R1
2.2結(jié)構(gòu)與尺寸
由(圖2–1)可知,該孔的內(nèi)徑為φ30 中徑為φ45 外徑為φ60 定位孔為4xφ8。
該產(chǎn)品為圓片落料、圓片沖孔。產(chǎn)品形狀結(jié)構(gòu)簡單對稱,孔與孔之間、孔與零件之間的最小距離滿足C≥(1~1.5)t要求。(t為材料厚度)
( 1.5t=1.8)根據(jù)課本 P86頁知沖孔時,因受凸模強(qiáng)度的限制,孔的尺寸不應(yīng)太小.沖孔的最小尺寸取決于材料性能,凸模的強(qiáng)度和模具結(jié)構(gòu)等.根據(jù)表3-3可查得圓形孔最小值得
d=0.9t=0.9X2=1.8mm<φ8所以滿足工藝性要求.
2.3精度分析
零件內(nèi)、外尺寸均未注公差,屬于自由公差,可按IT14級確定工件尺寸的公差,經(jīng)查表得各尺寸偏差分別為:
φ30,φ8,φ60
2.4材料
該零件材料為Q235,是普通碳素結(jié)構(gòu)鋼,拉力強(qiáng)度為375–500MPa;屈服235MPa 伸長率26%, 綜合性能較好,強(qiáng)度、塑性,沖裁加工性能好。
根據(jù)以上分析,該零件的工藝性較好,可以進(jìn)行沖裁加工。
3、 確定沖裁工藝方案
由圖2–1可知,該零件包括落料、沖孔兩個基本工序,可以采用以下幾種工藝方案:
方案一:先沖孔,后落料,采用單工序模生產(chǎn)。
方案二:采用落料—— 沖孔復(fù)合沖壓,采用復(fù)合模生產(chǎn)。
方案三:用沖孔——落料級進(jìn)沖壓,采用級進(jìn)模生產(chǎn)。
方案一的優(yōu)點(diǎn):結(jié)構(gòu)簡單,制造成本低周期短,易于加工和模具的維修,適用于小批量或試制件。缺點(diǎn):單工序模在壓力機(jī)一次行程內(nèi)只能完成一個沖壓工序而此零件需要兩道工序,兩套模具才能完成零件的加工,生產(chǎn)效率低,難以滿足零件大批量生產(chǎn)的要求。
方案二是一種多工序的沖模,是在壓力機(jī)的一次工作行程中,在模具同一部位置時完成數(shù)道分離工序它在結(jié)構(gòu)上主要特征是有一個既是落料凹模有沖孔凸模的凸凹模復(fù)合模的特點(diǎn)是生產(chǎn)率高,沖裁件的內(nèi)孔與外緣的相對位置精度高,板料的定位精度要求比級進(jìn)模低。缺點(diǎn):復(fù)合模結(jié)構(gòu)復(fù)雜,制造精度要求高,成本高,并且凸凹模容易受到最小壁厚的限制,而使得一內(nèi)孔間距、內(nèi)孔與邊緣間距較小的下件不宜采用,但工件精度較高,同軸度,對稱度及位置度誤差較小,生產(chǎn)效率較高,對材料要求不嚴(yán),可用邊角料.。
方案三是一種工位多、效率高的沖模。整個沖件的成形是連續(xù)過程中完成的連續(xù)成形是工序集中的工藝方法,可使切邊、切口、切槽、沖孔、塑性成形等多種工序在一副模具上完成。級進(jìn)模操作安全,在設(shè)計時,工序可以分散。不必集中在一個工位,不存在復(fù)合模中的最小壁厚問題,因而模具強(qiáng)度相對較高,壽命較長??梢圆捎酶咚賶毫C(jī)生產(chǎn),因?yàn)楣ぜ蛷U料可以直接往下漏,易于自動化,即容易實(shí)現(xiàn)自動送料,自動出件,自動疊片,缺點(diǎn):結(jié)構(gòu)復(fù)雜,制造精度高,周期長成本高。材料利用率低,產(chǎn)品精度低。
由于零件結(jié)構(gòu)簡單,為了提高生產(chǎn)效率,主要采用復(fù)合沖裁或級進(jìn)沖裁方式。采用復(fù)合沖裁時,沖出的零件精度和平直度好,生產(chǎn)效率高,操作方便,通過設(shè)計合理的模具結(jié)構(gòu)和排樣方案可以達(dá)到較好的零件質(zhì)量。
根據(jù)以上分析,該零件采用方案二為最佳。
4、確定模具總體結(jié)構(gòu)方案
4.1、模具類型
根據(jù)零件的沖裁工藝方案,采用復(fù)合沖裁模 。復(fù)合模分為正裝試復(fù)合模和倒裝試復(fù)合模,在確定采用復(fù)合模后,便要考慮采用正裝式還是倒裝式復(fù)合模。大多數(shù)情況優(yōu)先采用倒裝式復(fù)合模,這是因?yàn)榈寡b式復(fù)合模的沖孔廢料可以通過凸凹模從壓力機(jī)工作臺孔中漏出。工件由上面的凹模帶上后,由推薦裝置推出,再由壓力機(jī)附上的接件裝置接走。條料由下模的卸料裝置脫出。這樣操作方便而且安全,能保證較高的生產(chǎn)率。而正裝式復(fù)合模不適于板料太?。ㄒ话銥閠<0.3mm)、孔徑小于1.5mm或較軟的材料,導(dǎo)正時孔邊可能會變形,因而不宜采用,沖孔廢料由上模帶上,再由推料裝置推出,工件則由下模的推件裝置向上推出,條料由上模卸料裝置脫出,三者混雜在一起,如果萬一來不及排出廢料或工件而進(jìn)行下一次沖壓,就容易崩裂模具刃口。且正裝復(fù)合模,沖孔廢料由下模漏出,工件落在下模表面,需要及時清理。安全性相對較低。
故本零件采用倒裝式復(fù)合模結(jié)構(gòu)。采用倒裝式復(fù)合模省去了頂出裝置,結(jié)構(gòu)簡單,便操作,因此采用倒裝式復(fù)合沖裁模 。
4.2、操作與定位方式
雖然零件的生產(chǎn)批量較大,但合理安排生產(chǎn),可用手工送料方式能 夠達(dá)到批量要求,且能降低模具成本,因此采手工送料方式 ??紤]到零件尺寸大小,材料厚度,為了便于操作和保證零件的精度,宜采用導(dǎo)料板導(dǎo)向,固定擋料銷擋料,并與導(dǎo)正銷配合使用以保證送料位置的準(zhǔn)確性,進(jìn)而保證零件精度。為了保證首件沖裁的正確定距,采用始用擋料銷 ,采用使用擋料銷的目的是為了提高材料利用率 。
4.3、 卸料與出件方式
卸料方式分剛性卸料和彈性卸料兩種:
剛性卸料裝置主要是利用固定的卸料板來完成卸料其主要的特點(diǎn)就是能提供較大的卸料力,但是卸料板和板料之間不存在壓力作用,所以當(dāng)材料比較軟時,可能導(dǎo)致沖出的制件平整度比較差。因此,該結(jié)構(gòu)只適用于材料比較硬、板料較厚(大于0.5mm)、,并且平整度要求不高的制件。
彈性卸料裝置是依靠彈簧的彈力來卸料,沖壓時可用,具有卸料和壓料的雙重作用,主要用于沖材料厚在1.5mm以下的板料,由于有壓料作用,可以保證沖裁件表面的平面度。為了方便操作,提高零件生產(chǎn)率,沖件和廢料采用由凸模直接從凹模洞口推下的下出件方式 。
根據(jù)以上分析該模具設(shè)計采用彈性卸料裝置進(jìn)行卸料。沖件和廢料采用由凸模直接從凹模洞口推下的下出件方式 。
4.4、模架類型及精度
考慮到送料與操作的方便性,模架采用后側(cè)式導(dǎo)柱的模架,用導(dǎo)柱導(dǎo)套導(dǎo)向。由于零件精度要求不是很高,但沖裁間隙較小,因此采用I級模架精度。
4.4.1模架參數(shù)
5、工藝設(shè)計計算
5.1、 排樣設(shè)計
零件外形為圓形,輪廓尺寸為φ60??紤]操作方便并為了保證零件精度 ,采用直排有廢料排樣 。如下圖所示:
查《冷沖壓工藝及模具設(shè)計》表2-9,當(dāng)t=1.2時,工件的沿邊搭邊值a = 1.8 工件間搭邊值 b = 1.5復(fù)合模送料步距為S=60+1.5=61.5mm
5.2條料寬度按表2-9中公式計算:
計算條料寬度有三種情況需要考慮;
有側(cè)壓裝置時條料的寬度。
無側(cè)壓裝置時條料的寬度。
有定距側(cè)刃時條料的寬度。有定距側(cè)刃時條料的寬度。
有側(cè)壓裝置的模具,能使條料始終沿著導(dǎo)料板送進(jìn)。
條料寬度公式:
B-0△=(Dmax+2a)-△0 查表2-9得:△=0.6
B=(60+2×1.8)=63.6 (㎜)
5.3導(dǎo)料板間距公式
A=B+Z
表5—4得Z=5mm
根Z——導(dǎo)料板與條料之間的最小間隙(mm);
因此 A= B+Z
=63.6+5
=68.6(mm)
表5—4 導(dǎo)料板與條料之間的最小間隙Zmin(mm)
材料厚度t/mm
有 側(cè) 壓 裝 置
條 料 寬 度B/mm
100以下
100以上
~0.5
0.5~1
1~2
2~3
3~4
4~5
5
5
5
5
5
5
8
8
8
8
8
8
5.4材料利用率η
式中 —一個歩距內(nèi)沖裁件數(shù)目; A——沖裁件面積(包括內(nèi)形結(jié)構(gòu)廢料);
S——?dú)i距長度; B——板料寬度;
?。簄=1; A=π*302=2826;S=61.5;B=63.6
η=2826/61.5*63.6=72.4%
5.5、計算壓力與壓力中心,初選壓力機(jī)
5.5.1沖裁力
總沖裁力公式為
式中 f—沖裁力;
—沖孔沖裁力;
—落料沖裁力。
5.5.2沖孔沖裁力
式中 K—系數(shù)(取K=1.3);
—孔的個數(shù),n=5。
—沖孔周長,94.2mm
mm
—材料厚度, t=1.2mm
—材料抗剪強(qiáng)度,查參考文獻(xiàn)[2]知LY12,375~500MPa,取MPa。
=111030.4=111KN
查《冷沖壓工藝及模具設(shè)計》附表1可知可知て=260MPa
查《冷沖壓工藝及模具設(shè)計》附表3可知 Kx=0.05 K T = 0.055 .
5.5.3落料力:
L落=πd=π×80=188.4mm
F落= K L1 t T
=1.3×188.4×1.2×400
=118KN
5.5.4沖孔力:
F孔1 = K L1 t T
= 1.3 ×30π×1.2×400
=59KN
F孔2= K L2 t T
= 1.3 ×4×8π×1.2×400
=63KN
卸料力: