0137-中葉板零件沖壓工藝與沖模設(shè)計(jì)【全套13張CAD圖】
0137-中葉板零件沖壓工藝與沖模設(shè)計(jì)【全套13張CAD圖】,全套13張CAD圖,中葉,零件,沖壓,工藝,沖模,設(shè)計(jì),全套,13,cad
.
畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
題目 中頁板零件沖壓工藝及模具設(shè)計(jì)
.
一、選題的依據(jù)及意義：
設(shè)計(jì)的主要目的是：通過對產(chǎn)品的分析設(shè)計(jì)適合的模具，利用安裝在壓力機(jī)上的沖模對金屬板材進(jìn)行塑性變形加工以得到符合設(shè)計(jì)要求和使用要求的產(chǎn)品零件；檢驗(yàn)對所學(xué)相關(guān)課程理論、技能的理解程度；培養(yǎng)理論聯(lián)系實(shí)際的良好作風(fēng)。
設(shè)計(jì)的主要意義是：通過此次設(shè)計(jì)了解設(shè)計(jì)沖壓模的一般程序，了解相關(guān)的理論知識(shí)并加以應(yīng)用和鞏固；熟練的運(yùn)用有關(guān)技術(shù)資料，如《冷沖模國家標(biāo)準(zhǔn)》、《模具設(shè)計(jì)與制造簡明手冊》、《冷沖壓模具結(jié)構(gòu)圖冊》及其他有關(guān)規(guī)范等；初步的掌握設(shè)計(jì)冷沖壓模具的能力，為將來的工作打下初步的基礎(chǔ)。
二、國內(nèi)外研究概況及發(fā)展趨勢（含文獻(xiàn)綜述）：
隨著制造行業(yè)的發(fā)展，材料加工方法也隨著發(fā)展，其中冷沖壓加工方法在制造行業(yè)得到了廣泛的發(fā)展，特別在汽車制造行業(yè)。隨著冷沖壓加工方法的應(yīng)用，許多汽車零件的外形和精度得到了改善。側(cè)減震片的加工方法也得到了發(fā)展，最后由冷沖壓加工而成。最近的幾年里，冷沖壓加工方法得到了廣泛的發(fā)展。
冷沖壓（cold pressing）是建立在金屬塑性變形的基礎(chǔ)上，在常溫下利用安裝在壓力機(jī)上的模具對材料施加壓力，使其產(chǎn)生分離或塑性變形，從而獲得一定形狀、尺寸和性能的零件的一種加工方法。
在冷加工中，將材料（金屬或非金屬）加工成零件（或半成品）的一種特殊工藝裝備，稱為冷沖壓模具（俗稱冷沖模）。冷沖模在實(shí)現(xiàn)冷沖壓加工中是必不可少的工藝裝備，沒有先進(jìn)的模具技術(shù)，先進(jìn)的沖壓工藝就無法實(shí)現(xiàn)。隨著國民經(jīng)濟(jì)的高速發(fā)展、沖壓技術(shù)的發(fā)展和新型模具材料的不斷研究開發(fā)，市場對模具的需求量不斷增長，模具的結(jié)構(gòu)也發(fā)生了一定的變化，對模具的制造，裝配等都有了很大的影響。近年來，模具工業(yè)一直以15%左右的增長速度快速發(fā)展。模具是機(jī)械制造業(yè)中技術(shù)先進(jìn)、影響深遠(yuǎn)的重要工藝裝備,具有生產(chǎn)效率高、材料利用率高、制件質(zhì)量優(yōu)良、工藝適應(yīng)性好等特點(diǎn),被廣泛應(yīng)用于汽車、機(jī)械、航天、航空、輕工、電子、電器、儀表等行業(yè)。中國模具的“珠江三角洲、長江三角洲和以成都/重慶為代表的西部模具”三足鼎立局面已經(jīng)基本形成，然而與國際先進(jìn)水平相比,中國的模具行業(yè)的差距不僅表現(xiàn)在精度差距大、交貨周期長等方面,模具壽命也只有國際先進(jìn)水平的50%左右,大型、精密、技術(shù)含量高的轎車覆蓋件沖壓模具和精密沖裁模具,每年都需要花費(fèi)大量資金進(jìn)口。
一、經(jīng)過幾十年的發(fā)展,我國的沖壓模具行業(yè)獲得了飛速發(fā)展,具體體現(xiàn)在：
(1)輔助設(shè)計(jì)/加工/工程技術(shù)得到廣泛使用,模具總量名列世界第三位。
(2)大型模具企業(yè)擁有高速數(shù)控加工/加工中心/數(shù)控機(jī)床等先進(jìn)的加工工藝與裝備,可以開展RP/RT或模具逆向工程工作,硬件裝備已經(jīng)站在了與世界基本同步的水平線上。
(3)在沖模的表面精整加工技術(shù)方面,開展了積極探索、積累了一些經(jīng)驗(yàn)。
（4）以汽車覆蓋件為代表的大型、復(fù)雜、精密沖壓模具,采用CAD /CAM /CAE軟件進(jìn)行三維設(shè)計(jì)和模擬,減少試模時(shí)間和縮短周期。借助高速、精密的加工設(shè)備加工生產(chǎn),獲得良好的尺寸精度和表面粗糙度,用新型的研磨或拋光方法代替?zhèn)鹘y(tǒng)的手工研磨拋光,提高模具質(zhì)量[1]。這些都代表了沖壓模具發(fā)展的趨勢。例如，吉林大學(xué)汽車覆蓋件成型技術(shù)所獨(dú)立研制的汽車覆蓋件沖壓成型分析KMAS軟件，華中理工大學(xué)模具技術(shù)國家重點(diǎn)實(shí)驗(yàn)室開發(fā)的注塑模、汽車覆蓋件模具和級(jí)進(jìn)模CAD/CAE/CAM軟件，上海交通大學(xué)模具CAD國家工程研究中心開發(fā)的冷沖模和精沖研究中心開發(fā)的冷沖模和精沖模CAD軟件等在國內(nèi)模具行業(yè)擁有不少的用戶。
二、國際模具制造業(yè)的技術(shù)特點(diǎn)如下：
（1）產(chǎn)品專業(yè)化車身模具企業(yè)向?qū)I(yè)化發(fā)展，如德國大眾公司模具廠、奧迪公司模具廠、SCHULLER公司，意大利COMAU公司，美國AUTODIE、SECKLY，日本豐田公司模具廠、荻原公司、富士公司，韓國現(xiàn)代汽車模具中心等。有的專業(yè)制造整體側(cè)圍模具，有的專業(yè)生產(chǎn)四門模具，有的專門生產(chǎn)地板及結(jié)構(gòu)件模具。模具向多工位自動(dòng)化以及級(jí)進(jìn)模方向發(fā)展。
（2）制造數(shù)字化三維實(shí)體設(shè)計(jì)廣泛應(yīng)用于模具制造中，二維DL圖轉(zhuǎn)為三維DL圖后可直接用于有限元分析和數(shù)控編程，百分之百采用CAE分析。模具設(shè)計(jì)采用3D參數(shù)化設(shè)計(jì)。實(shí)現(xiàn)了不等厚板成形模具設(shè)計(jì)，將同模模具推向生產(chǎn)。模具數(shù)控加工技術(shù)包括實(shí)型鑄造技術(shù)、精細(xì)化編程、高速加工技術(shù)、型面數(shù)控強(qiáng)化和修補(bǔ)技術(shù)[2]。
三、沖壓模具制造技術(shù)發(fā)展趨勢：
（1）制造沖壓件用的傳統(tǒng)金屬材料，正逐步被高強(qiáng)鋼板、涂敷鍍層鋼板、塑料夾層鋼板和其他復(fù)合材料或高分子材料替代。隨著材料科學(xué)的發(fā)展，加強(qiáng)研究各種新材料的沖壓成形性能，不斷發(fā)展和改善沖壓成形技術(shù)。
? （2）精沖與半精沖、液壓成形、旋壓成形、爆炸成形、電水成形、電磁成形、超塑成形等技術(shù)得到不斷發(fā)展和應(yīng)用，某些傳統(tǒng)的沖壓加工方法將被它們所取代，產(chǎn)品的沖壓加工趨于更合理、更經(jīng)濟(jì)。其中精密沖裁技術(shù)得到了較快發(fā)展，精密沖裁是一種先進(jìn)制造技術(shù)，可取代某些零件的切削加工，具有優(yōu)質(zhì)、高效、低耗、應(yīng)用廣的特點(diǎn)。以齒圈壓板精沖而論，在普通液壓機(jī)上進(jìn)行精沖，工藝裝備簡單而工件精密[3]。它以金屬板材為原料，采用少無切削的塑性加工方法，一次成形即可得到尺寸精度高、剪切面粗糙度低的零件，采用精沖技術(shù)生產(chǎn)的零件稱為精沖、件[4]。
(3) 隨著計(jì)算機(jī)圖形技術(shù)的發(fā)展成熟，近年來在沖壓成形領(lǐng)域興起了計(jì)算機(jī)輔助設(shè)計(jì)(CAD)、計(jì)算機(jī)輔助工程(CAE)和計(jì)算機(jī)輔助制造(CAM)技術(shù)。該技術(shù)的出現(xiàn)對傳統(tǒng)沖壓技術(shù)的變革產(chǎn)生了重要的影響。尤其是板料成形數(shù)值模擬技術(shù)的出現(xiàn)，使板料沖壓成形技術(shù)徹底擺脫了“經(jīng)驗(yàn)”和“定性”的水平，進(jìn)入了“科學(xué)”和“定量”的發(fā)展階段。采用這一技術(shù)進(jìn)行板材沖壓成形工藝過程的模擬，可以預(yù)知沖壓成形過程中金屬的流動(dòng)、應(yīng)力應(yīng)變及厚度場的分布、模具受力及皺曲、破裂、沖擊線等可能的缺陷及失效形式。這為優(yōu)化工藝參數(shù)和模具結(jié)構(gòu)提供了極為有效的工具，在減少甚至取消試模過程，縮短產(chǎn)品開發(fā)周期，降低產(chǎn)品開發(fā)成本方面發(fā)揮著越來越重要的作用，已逐漸成為指導(dǎo)模具設(shè)計(jì)和優(yōu)化的重要手段[5]。
(4)高速銑削加工，國外近年來發(fā)展的高速銑削加工，大幅度提高了加工效率，并可獲得極高的表面光潔度。另外，還可加工高硬度模塊，還具有溫升低、熱變形小等優(yōu)點(diǎn)。高速銑削加工技術(shù)的發(fā)展，對汽車、家電行業(yè)中大型型腔模具制造注入了新的活力。目前它已向更高的敏捷化、智能化、集成化方向發(fā)展。
(5)模具掃描及數(shù)字化系統(tǒng)，高速掃描機(jī)和模具掃描系統(tǒng)提供了從模型或?qū)嵨飹呙璧郊庸こ銎谕哪Ｐ退璧闹T多功能，大大縮短了模具的在研制制造周期。有些快速掃描系統(tǒng)，可快速安裝在已有的數(shù)控銑床及加工中心上，實(shí)現(xiàn)快速數(shù)據(jù)采集、自動(dòng)生成各種不同數(shù)控系統(tǒng)的加工程序、不同格式的CAD數(shù)據(jù)，用于模具制造業(yè)的“逆向工程”。模具掃描系統(tǒng)已在汽車、摩托車、家電等行業(yè)得到成功應(yīng)用，相信在“十五”期間將發(fā)揮更大的作用。
(6)優(yōu)質(zhì)材料及先進(jìn)表面處理技術(shù)，選用優(yōu)質(zhì)鋼材和應(yīng)用相應(yīng)的表面處理技術(shù)來提高模具的壽命就顯得十分必要。模具熱處理和表面處理是否能充分發(fā)揮模具鋼材料性能的關(guān)鍵環(huán)節(jié)。模具熱處理的發(fā)展方向是采用真空熱處理。模具表面處理除完善應(yīng)發(fā)展工藝先進(jìn)的氣相沉積、等離子噴涂等技術(shù)。
四、沖壓在機(jī)械制造中的地位及特點(diǎn)：
沖壓既能夠制造尺寸很小的儀表零件，又能夠制造諸如汽車大梁、壓力容器封頭一類的大型零件；既能夠制造一般尺寸公差等級(jí)和形狀的零件，又能夠制造精密（公差在微米級(jí)）和復(fù)雜形狀的零件。占全世界鋼產(chǎn)60%～70%以上的板材、管材及其他型材，其中大部分經(jīng)過沖壓制成成品。沖壓在汽車、機(jī)械、家用電器、電機(jī)、儀表、航空航天、兵器等制造中，具有十分重要的地位。
??? 沖壓件的重量輕、厚度薄、剛度好。它的尺寸公差是由模具保證的，所以質(zhì)量穩(wěn)定，一般不需再經(jīng)機(jī)械切削即可使用。冷沖壓件的金屬組織與力學(xué)性能優(yōu)于原始坯料，表面光滑美觀。冷沖壓件的公差等級(jí)和表面狀態(tài)優(yōu)于熱沖壓件[6]。
??? 沖壓生產(chǎn)的工藝和設(shè)備正在不斷發(fā)展，除傳統(tǒng)的使用壓力機(jī)和鋼制模具制造沖壓件外，液壓成形以及旋壓成形、超塑成形、爆炸成形、電水成形、電磁成形等各種特種沖壓成形工藝亦迅速發(fā)展，把沖壓的技術(shù)水平提高到了一個(gè)新的高度。特種沖壓成形工藝尤其適合多品種的中小批量（甚至是數(shù)十件）零件的生產(chǎn)。對于普通沖壓工藝，可采用簡易模具、低熔點(diǎn)合金模具、成組模具和沖壓柔性制造系統(tǒng)等，組織多品種的中小批量零件的沖壓加工。
??? 總之，沖壓模具具有生產(chǎn)率高、加工成本低、材料利用率高、操作簡單、便于實(shí)現(xiàn)機(jī)械化與自動(dòng)化等一系列優(yōu)點(diǎn)。采用沖壓與焊接、膠接等復(fù)合工藝，使零件結(jié)構(gòu)更趨合理，加工更為方便，可以用較簡單的工藝制造出更復(fù)雜的結(jié)構(gòu)件。
三、研究內(nèi)容及實(shí)驗(yàn)方案：
研究內(nèi)容：
1了解模具的工作過程；
2懂得利用工具手冊查找模具的標(biāo)準(zhǔn)；
3自主設(shè)計(jì)中頁板卷圓成型模具；
4擬寫設(shè)計(jì)說明明書；
采用的設(shè)計(jì)方案及技術(shù)路線有：
1、根據(jù)圖紙對“中頁板”進(jìn)行工藝分析；
2、對零件材料進(jìn)行彎曲性能分析并確定毛坯形狀，尺寸和下料方式；
3、審查制件是否符合沖壓結(jié)構(gòu)工藝性以及沖壓的經(jīng)濟(jì)性；
4、擬定工藝方案，在分析工藝性的基礎(chǔ)上，確定沖壓件的總體工藝方案，然后確定沖壓加工工藝方案；
5、根據(jù)零件在生產(chǎn)中的具體要求合理地確定沖裁間隙；
6、沖壓工藝計(jì)算及設(shè)計(jì)：（1）排樣及材料利用率的計(jì)算，選擇合理的排樣方式，決定出搭邊值，并確定出條料的寬度，并力求取得最佳的材料利用率；（2）沖壓力，沖壓中心計(jì)算及沖壓設(shè)備初步選擇；
7、分析沖壓工序所的沖壓件的沖壓成形的工藝性能并在此基礎(chǔ)上制定沖壓成形工藝方案；
8、進(jìn)行主要參數(shù)計(jì)算：（1）毛坯尺寸計(jì)算；（2）壓力中心計(jì)算；（3）彎曲力計(jì)算；
9、彎曲模結(jié)構(gòu)設(shè)計(jì)：（1）確定模具類型；（2）工作零件設(shè)計(jì)；（3）定位零件設(shè)計(jì)；（4）卸料，出件及壓料零，部件設(shè)計(jì)；（5）彈簧和橡膠零件設(shè)計(jì)；（6）導(dǎo)向及支承固定零件設(shè)計(jì)；（7）確定模具的閉合高度；（8）對以上設(shè)計(jì)零件進(jìn)行組裝并檢驗(yàn)和修改零，部件結(jié)構(gòu)；（9）最后確定模具的整體結(jié)構(gòu)；
13、繪制彎曲模裝配圖；
14、繪制彎曲模零件圖
15、編寫技術(shù)文件及說明書。
四、目標(biāo)、主要特色及工作進(jìn)度
工作內(nèi)容及完成時(shí)間：
1. 查閱相關(guān)資料，外文資料翻譯（6000字符以上），撰寫開題報(bào)告。
第1周—第2周
2. 繪制中葉板沖件圖，分析沖件成形工藝及坯料展開 第3周—第6周
3. 編制中葉板沖壓成形工藝規(guī)程； 第7周—第8周
4. 繪制吊中葉板卷圓成形模總裝圖及零件圖； 第9周—第13周
5. 撰寫畢業(yè)設(shè)計(jì)說明書（論文） 第14周—第16周
6. 畢業(yè)設(shè)計(jì)審查，畢業(yè)答辯。 第17周
模具的設(shè)計(jì)中可能存在的問題：
1、沖壓模的間隙選擇不當(dāng)，進(jìn)而影響沖裁件斷面質(zhì)量，沖裁件尺寸精度，沖裁力，卸料力，推料力，頂料力，模具的壽命；
2、模具壓力中心確定不當(dāng)，模具在工作中產(chǎn)生偏彎距，使沖模發(fā)生歪斜，從而會(huì)加速模具磨損，影響模具的壽命；
3、沖裁件的質(zhì)量及影響因素；
4、排樣方式選擇不當(dāng)，影響材料利用率；
5、沖裁尺寸的計(jì)算和確定的誤差分析；
6、模邊值確定不當(dāng)，進(jìn)而影響制件的合格性；
7、彎曲力不適當(dāng)，進(jìn)而造成彎曲變形的回彈或出彎曲缺陷；
8、沖裁件與彎曲件之間計(jì)算不當(dāng)造成尺寸精度低。
五、參考文獻(xiàn)
[1]、劉勝國，《我國沖壓模具技術(shù)的現(xiàn)狀與發(fā)展》，黃石理工學(xué)院機(jī)電工程學(xué)院，黃石理工學(xué)院學(xué)報(bào)，2007年1期；
[2]、朱偉成，《沖壓技術(shù)發(fā)展趨勢》，中國第一汽車集團(tuán)公司，汽車工藝與材料，2007年1期；
[3]、《沖模設(shè)計(jì)手冊》編寫組.沖模設(shè)計(jì)手冊.北京：沖模設(shè)計(jì)手冊，1995
[4]、陳為國. 鉸鏈卷圓成形工藝及模具設(shè)計(jì).模具工業(yè)，1998.7
[5]、王新華，袁聯(lián)富編.沖模結(jié)構(gòu)圖冊.北京：機(jī)械工業(yè)出版社，2003
[6]、羅益旋.沖壓新工藝新技術(shù)及模具設(shè)計(jì)實(shí)用手冊. 銀聲音像出版社，2004
[7]、GB2851～2875《冷沖?！穱覙?biāo)準(zhǔn)
中葉板零件沖壓工藝與沖模設(shè)計(jì)
摘要：模具是工業(yè)產(chǎn)品生產(chǎn)用的重要工藝設(shè)備，模具工業(yè)已是工業(yè)發(fā)展的基礎(chǔ)，許多新產(chǎn)品的開發(fā)和研制在很大程度上都依賴與模具的生產(chǎn)?？梢灶A(yù)言，隨著工業(yè)生產(chǎn)的不斷發(fā)展，模具工業(yè)在國民經(jīng)濟(jì)中的地位將日益提高，并在國民經(jīng)濟(jì)發(fā)展過程中發(fā)揮越來越重要的作用。在沖壓零件的生產(chǎn)中，合理的沖壓成形工藝、先進(jìn)的模具、高效的沖壓設(shè)備是必不可少的三要素 。
本文介紹了止動(dòng)件沖壓模具的設(shè)計(jì)，先介紹了對工件進(jìn)行工藝分析和模具設(shè)計(jì)的要點(diǎn)，然后介紹了模具設(shè)計(jì)的思路，模具的主要結(jié)構(gòu)和主要零件的設(shè)計(jì)。最后確定了選用沖孔落料復(fù)合模。
本次設(shè)計(jì)繪圖采用AotuCAD，以AotuCAD為計(jì)算機(jī)輔助制圖工具，使用簡單，方便快捷，而且有極強(qiáng)的圖形處理功能，可以大大縮短繪圖的周期，在國內(nèi)使用的較廣泛。
關(guān)鍵詞:沖壓模具 落料 沖裁預(yù)彎 剪裁 卷圓
stamping process and die design of hinge Vol yen
ABSTRACT ：The mold was the important process unit which the manufactured products production used, the mold industry already is the industrial development foundation, many new product's developments and the development relied on to a great extent with mold's production. May predict that along with industrial production's unceasing development, the mold industry will enhance day by day in national economy's status, and plays more and more vital role in the national economy developing process. In the ramming components' production, the reasonable ramming forming craft, the advanced mold, the highly effective ramming equipment are the essential three essential factors. Ramming processing characteristic: Because the cold stamping processing has the above prominent merit, therefore obtained the widespread application in the volume production, holds the very important status in the modern industry production, is the defense industry and in the consumer industry production the essential processing method. this article introduced the lock ramming mold's design, introduced first carries on the process study and the mold design main point to the work piece, then introduced the mold design mentality, mold's primary structure and the major parts design. Finally had determined selects the punch holes to fall the material superposable die. the this design cartography uses AotuCAD, take AotuCAD as the computer auxiliary charting tool, the use is simple, facilitates quickly, and has the greatly strengthened graphic processing function, may reduce cartography greatly the cycle, in domestic use widespread.
key word: Stamping die falls the material Blanking of Preflex Clipping
Vol yen
Signature of Supervisor:
外文翻譯
General all-steel punching die’s punching accuracy
Accuracy of panel punching part is display the press accuracy of the die exactly. But the accuracy of any punching parts’ linear dimension and positional accuracy almost depend on the blanking and blanking accuracy,. So that the compound mould of compound punching’s accuracy, is typicalness and representation in the majority.
Analyse of the die’s accuracy
For the analyse of pracyicable inaccuracy during production of dies to inactivation, we could get the tendency when it is augmentation in most time. From this we could analyse the elements. When the new punch dies pt into production to the first cutter grinding, the inaccuracy produced called initial error; if the die grinding more than twenty times, until it’s discard, the inaccuracy called conventional error; and before the dies discard, the largest error of the last batch permit, called limiting error. at job site, the evidence to confirm life of sharpening is the higher of the blanking, punched hole or punched parts. Because all finished parts had been blanked ,so it is especially for the compound dies. Therefore, the analyse of burr and measurement is especially important when do them as enterprise standardization or checked with <>.
The initial error usually is the minimal through the whole life of die. Its magnitude depend on the accuracy of manufacture, quality, measure of the punching part, thickness of panel, magnitude of gap and degree of homogeneity. The accuracy of manufacture depend on the manufacture process. For the 1 mm thicked compound punching part made in medium steel, the experimental result and productive practice all prove that the burr of dies which produced by spark cutting are higher 25%~~30% than produced by grinder ,NC or CNC. The reason is that not only the latter have more exact machining accuracy but also the value of roughness Ra is less one order than the formmer, it can be reached 0.025μm. Therefore, the die’s initial blanked accuracy depends on the accuracy of manufacture, quality and so on.
The normal error of the punch die is the practicable error when the fist cutter grinding and the last cutter grinding before the die produce the last qualified product. As the increase of cutter grinding, caused the measure the nature wear of the dies are gradual increasing, the error of punching part increase also, so the parts are blew proof. And the die will be unused. The hole on the part and inner because the measure of wear will be small and small gradually, and its outside form will be lager in the same reason. Therefore, the hole and inner form in the part will be made mould according to one-way positive deviation or nearly equal to the limit max measure. In like manner, the punching part’s appearance will be made mould according to one-way negative deviation or nearly equal to limit mini measure. For this will be broaden the normal error, and the cutter grinding times will be increased, the life will be long.
The limit error in punching parts are the max dimension error which practicable allowed in the parts with limit error. This kind of parts usually are the last qualified products before the die discard.
For the all classes of dies, if we analyse the fluctuate, tendency of increase and decrease and law which appeared in the die’s whole life, we will find that the master of the error are changeless; the error that because the abrade of the cutter and impression will be as the cutter grinding times increased at the same time. And that will cause the error oversize gradually; and also have another part error are unconventional , unforeseen. Therefore, every die’ s error are composed of fixed error, system error, accident error and so on.
1. fixed error
At the whole process when the New punching die between just input production to discard, the changeless master error that in qualified part are called fixed error. It’s magnitude is the deviation when the die production qualified products before the first cutter grinding. Also is the initial error, but the die have initial punching accuracy at this time. Because of the abrade of parts, the die after grinding will be change the dimension error. And the increment of deviation will oversize as the times of cutter grinding. So the punching accuracy after cutter grinding also called “grinding accuracy” and lower tan initial accuracy. The fixed error depend on the elements factor as followed :
(1) the material , sorts, structure, (form) dimension, and thick of panel
the magnitude of punching gap and degree of homogeneity are have a important effect for the dimension accuracy. Different punching process, material, thick of panel, have completely different gap and punching accuracy. A gear H62 which made in yellow brass with the same mode number m=0.34, 2mm thick and had a center hole, when the gap get C=0.5%t (single edge) , and punched with compound punching die, and the dimension accuracy reached IT7, the part have a flat surface ,the verticality of tangent plane reached 89.5°, its roughness Ra magnitude are 12.5μm, height of burr are 0.10mm; and the punching part are punched with progressive die, the gap C=7%t (single edge) , initial accuracy are IT11, and have an more rough surface, even can see the gap with eyes. In the usual situation, flushes a material and its thickness t is theselection punching gap main basis. Once the designation gap haddetermined flushes the plane size the fixed error main body; Flushesthe structure rigidity and the three-dimensional shape affects itsshape position precision.
(2) punching craft and molder structure type
Uses the different ramming craft, flushes a precision and the fixederror difference is really big. Except that the above piece gearexample showed, the essence flushes the craft and ordinary punching flushes a precision and the fixed error differs outside a magnitude,even if in ordinary punching center, uses the different gap punching, thefixed error difference very is also big. For example material thickt=1.5mm H62 brass punching, selects C <= the 40%t unilateral I kind ofsmall gap punching compared to select C <= 8%t (unilaterally) III kindof big gap punching, will flush a fixed error to enlarge 40% ~ 60%, theprecision at least will fall a level. Side in addition, whether thereis picks builds a row of type side, flushes a error to have far to bebigger than has builds a row of type to flush. Side not builds a rowof type to flush. Side not builds a row of type to flush a precisionto be lower than the IT12 level side, but most has builds a row oftype to flush a precision in IT11 between ~ IT9 level, material thickt > 4mm flushes, the size precision can lower some. Different die’s structure type, because is suitable the rammingmaterial to be thick and the manufacture precision difference, causesto flush a fixed error to have leaves. Compound die center, multi-locations continuous type compound die because flushes continuously toduplicate the localization to add on the pattern making error to bebigger, therefore it flushes a fixed error compound punching die to wantcompared to the single location Big 1 ~ 2 levels
(3) the craft of punching die’s manufacture
the main work of punching die namely are raised, the concave moldprocessing procedure, to operates on the specification not to behigh, can time form a more complex cavity. But its processing surfaceapproximately is thick > 0.03 ~ 0.05mm is the high temperatureablation remaining furcated austenite organization, degree ofhardness may reach as high as HRC67 ~ 70, has the micro crack, easilywhen punching appears broke the cutter or flaking. The Italian CorradaCorporation''s related memoir called "the line cut the processing contruction to have the disadvantageous influence to the superficialgold, in fact already changed the gold contruction. We must use theJin''gang stone powder to grind or the numerical control continual pathcoordinates rub truncate (cut to line) to make the precision work ". In recent years country and so on Switzerland and Japan, has conductedthe thorough research to the electrical finishing equipment and abigger improvement, makes function complete high accuracy NC and theCNC line cutter, the processing precision may reach ±0.005 ~ 0.001mm,even is smaller. The processing surface roughness Ra value can achieve0.4 mu m. According to the recent years to the domestic 12 productionlines cutter factory investigation and study, the domesticallyproduced line cutter processing precision different factory differentmodel line cutter might reach ±0.008 ~ ±0.005mm, generally all in±0.01mm or bigger somewhat, was individual also can achieve±0.005mm, the processing surface roughness Ra value was bigger than1.6μm. However, the electrical finishing ablation metal surface thus the change and the damage machined surface mental structure character can not change, only if with rubs truncates or other ways removes this harmful level. Therefore, merely uses electricity machining, including the spark cutting and the electricity perforation, achieves with difficulty punching, especially high accuracy, high life punching die to size precision and work components surface roughness Ra value request.
With precisely rubs truncates the law manufacture punching die, specially makes the high accuracy, the high life punching die, such as: Thin material small gap compound punching die, multi- locations continuous type compound die and so on, has the size precision high, the work component smachined surface roughness Ra value is small, the mold life higher characteristic. Its processing craft at present changed the electrical fire by the past ordinary engine bed rough machining spark cutting or the electricity puncher rough machining, finally precisely rubs truncates, also from takes shape rubs, optics curve rubs, the manual grid reference rubs gradually filters the continual path grid reference to rub and NC and the CNC continual path grid reference rubs, Processing coarseness may reach ±0.001 ~ 0.0005mm, the processing surface roughness Ra value may reach 0.1 ~ 0.025 mu m. Therefore, with this craft manufacture the die , regardless of the size precision, the work components surface roughness, all can satisfy die, each kind of compound request, the die is especially higher than the electrical finishing craft manufacture scale.
(4) gap size and degree of homogeneity
the flange and other sheet forming sgene rally all must first punching (fall material) the plate to launch the semi finished materials, after also has the forming to fall the material, the incision obtains the single end product to flush. Therefore punching the work, including is commonly used punching hole, the margin, cut side and so on, regarding each kind of sheet pressing partall is necessary. Therefore punching the gap to flushes a out form in chprecision to have the decisive influence. punching the gap small and is even, may cause punching the size gain high accuracy. Regarding drawability, is curving and so on mould, the gap greatly will decide increases flushes the oral area size error and the snapping back. The gapnon-uniformity can cause to flush a burr enlarges and incurs cutting edge the non-uniform attrition.
(5) ramming equipment elastic deformation In the ramming process
After the punch press load bearing can have the certain elastic deformation. Although this kind of distortion quantity according to flushes the pressure the size to change also to have the obvious directivity, but on the pressing part, mainly is to has the volume ramming archery target stamping, embosses, the equalization, the pressure is raised, the wave, flushes crowds, the shape, the flange, hits flatly, thinly changes draw ability and so on the craft work punching forming flushes, has the significant influence to its ramming aspect size precision
普通全鋼沖模的沖壓精度分析
板料沖壓件的精度準(zhǔn)確顯示出其沖模的沖壓精度。而任何沖件的線性尺寸精度與形位精度主要取決于沖模沖裁和立體成形沖壓件展開平毛坯的落料精度。因此，多工步復(fù)合沖壓的單工位復(fù)合模、多工位連續(xù)模的沖壓精度，在普通沖壓的眾多種類與不同結(jié)構(gòu)的沖模中，最具典型性和代表性。
沖模的沖壓精度分析
對沖模投產(chǎn)至失效報(bào)廢各個(gè)時(shí)期沖件的實(shí)際誤差分析，可以看出其增大的時(shí)期及趨向，從而分析其增大的因素。新沖模投產(chǎn)至第一次刃磨前沖制沖件的誤差即所謂的初始誤差；沖模經(jīng)過20次左右刃磨至失效報(bào)廢前沖制的沖件誤差稱之為常規(guī)誤差；而沖模失效報(bào)廢前沖制的最后一批合格沖件的允許最大誤差稱之為極限誤差。在現(xiàn)場，確定沖模刃磨壽命的依據(jù)是沖件沖孔與落料的毛刺高度。由于任何成形件都具有沖裁作業(yè)（毛坯落料或沖孔），對于復(fù)合模尤為如此。所以，沖件毛刺高度的觸模檢查和測量并按企業(yè)標(biāo)準(zhǔn)或JB4129-85《沖壓件毛刺高度》對照檢測就顯得十分重要。
沖模的初始誤差通常是沖模整個(gè)壽命中沖件誤差最小的。其大小主要取決于沖模的制造精度與質(zhì)量及沖件尺寸、料厚以及間隙值大小與均勻度。沖模的制造精度及質(zhì)量又取決于制模工藝。對于料厚t≤1mm的中碳鋼復(fù)合沖裁模沖件，實(shí)驗(yàn)結(jié)果與生產(chǎn)實(shí)踐都證明，電火花線切割制造的沖模沖件毛刺高度比用成型磨或NC與CNC連續(xù)軌跡座標(biāo)磨即精密磨削工藝制造的沖模沖件要高25%～30%。這是因?yàn)楹笳卟粌H加工精度高，而且加工面粗糙度Ra值要比前者小一個(gè)數(shù)量級(jí)，可達(dá)到0.025μm。因此，沖模的制造精度與質(zhì)量等因素決定了沖模的初始沖壓精度，也造就了沖件的初始誤差。
沖件的常規(guī)誤差是沖模經(jīng)第一次刃磨到最后一次刃磨后沖出最后一個(gè)合格沖件為止，沖件實(shí)際具有的誤差。隨著刃磨次數(shù)的增加，刃口的自然磨損而造成的尺寸增量逐漸加大，沖件的誤差也隨之加大。當(dāng)其誤差超過極限偏差時(shí)，沖件就不合格，沖模也就失效報(bào)廢。///////沖件上孔與內(nèi)形因凸模磨損尺寸會(huì)逐漸變??；其外形落料尺寸會(huì)因凹模磨損而逐漸增大。所以，沖件上孔與內(nèi)形按單向正偏差標(biāo)允差并依接近或幾乎等于極限最大尺寸制模。同理，沖件外形落料按單向負(fù)偏差標(biāo)注允差并依接近或幾乎等于極限最小尺寸制模。這樣就使沖件的常規(guī)誤差范圍擴(kuò)大，沖模可刃磨次數(shù)增加，模具壽命提高。
沖件的極限誤差是具有極限偏差的沖件所具有的實(shí)際允許的最大尺寸誤差。這類沖件通常是在沖模失效報(bào)廢前沖制的最后一批合格沖件。
對各類沖模沖件誤差在沖模整個(gè)壽命中出現(xiàn)的波動(dòng)、增減趨向及規(guī)律等進(jìn)行全面分析便可發(fā)現(xiàn)：沖件誤差的主導(dǎo)部分是不變的；因刃口或型腔的自然磨損而出現(xiàn)的誤差增量隨沖模刃磨沖數(shù)增加而使這部分誤差逐漸加大；還有部分誤差的增量是非常規(guī)的、不可預(yù)見的。所以，各類沖模沖件誤差是由因定誤差、漸增誤差、系統(tǒng)誤差及偶發(fā)誤差等幾部分綜合構(gòu)成。
1、固定誤差
新沖模在指定的沖壓設(shè)備上投入使用至失效報(bào)廢的整個(gè)（總）壽命過程中，其合格沖件誤差的主導(dǎo)部分固定不變即所謂固定誤差。其大小就是新沖模第一次刃磨前沖制的合格沖件的偏差，也即沖模的初始誤差，而此時(shí)的沖模具有初始沖壓精度。刃磨后的沖模，因其工作零件（凸、凹模）磨損而改變尺寸誤差，使沖件識(shí)差增量隨刃磨次數(shù)增加而逐漸加大，故沖模刃磨后的沖壓精度亦稱“刃磨精度”比其初始精度要低。沖模沖件的固定誤差取決于以下各要素：
（1）沖件的材料種類、結(jié)構(gòu)（形狀）尺寸及料厚
沖裁間隙的大小及其均勻度對沖裁件的尺寸精度有決定性的影響。不同沖裁工藝、不同材料種類與不等料厚，間隙相差懸殊，沖壓精度差異很大。同一種模數(shù)m=0.34的2mm的料厚、中心有孔的H62黃銅材料片齒輪復(fù)合模沖件，當(dāng)取間隙C=0.5%t（單邊），用復(fù)合精沖模沖制，沖件尺寸精度達(dá)到IT7級(jí)，沖件平直無拱彎，沖切面垂直度可達(dá)89.5°，其表面粗糙Ra值為0.2μm；而用普通復(fù)合模沖制，間隙C=5%t（單邊），沖件初始誤差亦即沖模的初始沖壓精度為1T9級(jí)，沖切面粗糙度Ra值為12.5μm，毛刺高度為0.10mm；還是這個(gè)沖件用連續(xù)模沖制，間隙C=7%t（單邊），初始沖件精度為IT11級(jí)，沖切面更粗糙，甚至有肉眼可見的臺(tái)階。通常情況下，沖件材料及其厚度t是選取沖裁間隙的主要依據(jù)。一旦選定間隙就確定了沖件的平面尺寸的固定誤差的主體；沖件結(jié)構(gòu)剛度及立體形狀則影響其形位精度。
（2）沖壓工藝及沖模結(jié)構(gòu)類型
采用不同的沖壓工藝，沖件的精度及固定誤差相差甚大。除上述片齒輪實(shí)例說明，精沖工藝與普通沖裁的沖件精度與固定誤差相差一個(gè)數(shù)量級(jí)之外，即便在普通沖裁中，采用不同間隙沖裁，固定誤差相差也很大。例如料厚t=1.5mm的H62黃銅沖裁件，選用C≤40%t單邊Ⅰ類小間隙沖裁比選用C≤8%t（單邊）Ⅲ類大間隙沖裁，沖件固定誤差將加大40%～60%，精度至少降一級(jí)。此外，采有無搭邊排樣，沖件的誤差要遠(yuǎn)大于有搭邊排樣沖件。無搭邊排樣沖件。無搭邊排樣沖件的精度低于IT12級(jí)，而多數(shù)有搭邊排樣的沖件精度在IT11～I(xiàn)T9級(jí)之間，料厚t＞4mm的沖件，尺寸精度會(huì)更低一些。
不同沖模結(jié)構(gòu)類型，由于適用沖壓料厚及制造精度的差異，導(dǎo)致沖件的固定誤差有別。復(fù)合模中，多工位連續(xù)式復(fù)合模由于沖件連續(xù)重復(fù)定位加上制模誤差較大，故其沖件的固定誤差比單工位復(fù)合沖裁模要
大1～2級(jí)。
（3）沖模制造工藝
沖模主要工作零件即凸、凹模的加工程序，對操作上的技術(shù)要求不高，能夠一次成形較復(fù)雜的模腔。但其加工表面約厚＞0.03～0.05mm為高溫?zé)g的殘余樹枝狀?yuàn)W氏體組織，硬度可高達(dá)HRC67～70，有顯微裂紋，容易在沖裁時(shí)出現(xiàn)崩刃或剝落。意大利Corrada公司的有關(guān)研究報(bào)告稱“線切割加工對表面金相結(jié)構(gòu)產(chǎn)生不利的影響，實(shí)際上已經(jīng)改變了金相結(jié)構(gòu)。我們必須用金剛石粉研磨或數(shù)控連續(xù)軌跡坐標(biāo)磨削（對線切割件）作精加工”。近年來瑞士和日本等國，對電加工設(shè)備進(jìn)行了深入的研究和較大的改進(jìn)，制造出功能齊全的高精度NC和CNC線切割機(jī)，加工精度可達(dá)±0.005～0.001mm，甚至更小。加工表面粗糙度Ra值能達(dá)到0.4μm。根據(jù)近年對國內(nèi)12家生產(chǎn)線切割機(jī)工廠的調(diào)研，國產(chǎn)線切割機(jī)加工精度各別廠家的各別型號(hào)線切割機(jī)可達(dá)±0.008～±0.005mm，一般都在±0.01mm或更大一些，個(gè)別也能達(dá)到±0.005mm，加工表面粗糙度Ra值均大于1.6μm。然而，電加工燒蝕金屬表面從而改變和損壞加工面金相結(jié)構(gòu)的特性不會(huì)改變，除非用磨削或其他加工法去除這一有害層。所以，僅僅用電加工法，包括電火花線切割與電穿孔，難以達(dá)到?jīng)_模，尤其高精度、高壽命沖模對尺寸精度與工作零件表面粗糙度Ra值要求。
用精密磨削法制造沖模，特別是制造高精度、高壽命沖模，諸如：薄料小間隙復(fù)合沖裁模、多工位連續(xù)式復(fù)合模等，具有尺寸精度高、工作零件加工面粗糙度Ra值小、模具壽命高等特點(diǎn)。其加工工藝目前已由過去的普通機(jī)床粗加工改為電火花線切割或電穿孔機(jī)粗加工，最后精密磨削，也由成型磨、光學(xué)曲線磨、手動(dòng)座標(biāo)磨逐步過濾到連續(xù)軌跡座標(biāo)磨及NC與CNC連續(xù)軌跡座標(biāo)磨，加工粗度可達(dá)±0.001～0.0005mm，加工表面粗糙度Ra值可達(dá)0.1～0.025μm。所以，用該工藝制造的沖模，無論尺寸精度、工作零件表面粗糙度，都能滿足沖模，尤其各種復(fù)合模的要求，比電加工工藝制造的沖模高一個(gè)檔次。
（4）間隙的大小與均勻度
拉深、彎曲、翻邊及其他板料成形件一般都要先沖裁（落料）出平板展開毛坯，也有成形后落料、切開得到單個(gè)成品沖件。故沖裁作業(yè)，包括常用的沖孔、切口、切邊等，對于每種板料沖壓件都是必要的。所以沖裁間隙對沖件的外廓尺寸精度有決定性的影響。沖裁間隙小而均勻，可使沖裁尺寸獲取更高精度。對于拉深、彎曲等成形模，間隙大定將增大沖件口部尺寸誤差及回彈。間隙不均勻會(huì)使沖件毛刺加大并招致刃口的不均勻磨損。
（5）沖壓設(shè)備的彈性變形
在沖壓過程中，沖床承載后會(huì)產(chǎn)生一定的彈性變形。雖然這種變形量依沖壓力的大小變化且具有明顯的方向性，但就沖壓件，主要是對具有體積沖壓性質(zhì)的壓印、壓花、校平、壓凸、起波、沖擠、鐓形、翻邊、鐓粗、打扁、變薄拉深等工藝作業(yè)沖制成形的沖件，對其沖壓方面的尺寸精度有重大影響。
收藏