變速器箱體機(jī)械加工工藝及夾具設(shè)計(jì)
變速器箱體機(jī)械加工工藝及夾具設(shè)計(jì),變速器,箱體,機(jī)械,加工,工藝,夾具,設(shè)計(jì)
理工科類
本科生畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
論文(設(shè)計(jì))題目
變速器箱體機(jī)械加工工藝及
夾具設(shè)計(jì)
作者所在系別
機(jī)械電子工程
作者所在專業(yè)
作者所在班級
作 者 姓 名
作 者 學(xué) 號
指導(dǎo)教師姓名
指導(dǎo)教師職稱
完 成 時(shí) 間
2017
年
2
月
說 明
1.根據(jù)學(xué)?!懂厴I(yè)設(shè)計(jì)(論文)工作暫行規(guī)定》,學(xué)生必須撰寫《畢業(yè)設(shè)計(jì)(論文)開題報(bào)告》。開題報(bào)告作為畢業(yè)設(shè)計(jì)(論文)答辯委員會對學(xué)生答辯資格審查的依據(jù)材料之一。
2.開題報(bào)告應(yīng)在指導(dǎo)教師指導(dǎo)下,由學(xué)生在畢業(yè)設(shè)計(jì)(論文)工作前期內(nèi)完成,經(jīng)指導(dǎo)教師簽署意見及所在專業(yè)教研室論證審查后生效。開題報(bào)告不合格者需重做。
3.畢業(yè)設(shè)計(jì)開題報(bào)告各項(xiàng)內(nèi)容要實(shí)事求是,逐條認(rèn)真填寫。其中的文字表達(dá)要明確、嚴(yán)謹(jǐn),語言通順,外來語要同時(shí)用原文和中文表達(dá)。第一次出現(xiàn)縮寫詞,須注出全稱。
4.開題報(bào)告中除最后一頁外均由學(xué)生填寫,填寫各欄目時(shí)可根據(jù)內(nèi)容另加附頁。
5.閱讀的主要參考文獻(xiàn)應(yīng)在10篇以上(土建類專業(yè)文獻(xiàn)篇數(shù)可酌減),其中外文資料應(yīng)占一定比例。本學(xué)科的基礎(chǔ)和專業(yè)課教材一般不應(yīng)列為參考資料。
6.參考文獻(xiàn)的書寫應(yīng)遵循畢業(yè)設(shè)計(jì)(論文)撰寫規(guī)范要求。
7.開題報(bào)告應(yīng)與文獻(xiàn)綜述、一篇外文譯文和外文原文復(fù)印件同時(shí)提交,文獻(xiàn)綜述的撰寫格式按畢業(yè)設(shè)計(jì)(論文)撰寫規(guī)范的要求,字?jǐn)?shù)在2000字左右。
畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
學(xué)生姓名
專 業(yè)
車輛工程
班 級
指導(dǎo)教師姓名
職 稱
副教授
工作單位
課題來源
教師自擬題目
課題性質(zhì)
課題名稱
變速器箱體機(jī)械加工工藝及夾具設(shè)計(jì)
本設(shè)計(jì)的科學(xué)依據(jù)(科學(xué)意義和應(yīng)用前景,國內(nèi)外研究概況,目前技術(shù)現(xiàn)狀、水平和發(fā)展趨勢等)
科學(xué)意義和應(yīng)用前景: 減速器箱體是減速器的基礎(chǔ)零件,能使減速器的軸、齒輪等有關(guān)零件連接成一個(gè)整體的情況下使其保證正確的相互位置,使他們能傳遞扭矩或改變轉(zhuǎn)速用以完成規(guī)定動(dòng)作的運(yùn)動(dòng)。所以說減速器箱體的整理加工質(zhì)量將直接影響到整個(gè)機(jī)器的各種性能。
用來使各種原材料、半成品成為成品的方法和過程稱作工藝,它在生產(chǎn)不但是構(gòu)思和想法,而且也是實(shí)在的方法與手段,同時(shí)直接落實(shí)在通過工件、刀具、機(jī)床、夾具所構(gòu)成的工藝系統(tǒng)中,因此工藝所包含和涉及的范圍很廣,所以說工藝是生產(chǎn)中最為活躍的因素。
對于工藝裝備來說夾具是其主要的組成部分,因此夾具設(shè)計(jì)在制造系統(tǒng)中占據(jù)著不可或缺尤為重要的地位。由于它可以直接影響到零件的整體加工質(zhì)量,生產(chǎn)效率和制造成本,因而夾具也被認(rèn)為是在工藝過程中的最為活躍的因素的一份子,相應(yīng)的對與夾具的研究在制造業(yè)中也極為重視。
現(xiàn)狀分析:機(jī)加工是我們國民基礎(chǔ)產(chǎn)業(yè),也是國民經(jīng)濟(jì)增長和國防能力的重要保證。而今機(jī)械制造技術(shù)也正向著高度自動(dòng)化、精密化、智能化、高效化、集成化的方向發(fā)展,并且開始應(yīng)用了計(jì)算機(jī)輔助設(shè)計(jì)與制造(CAD/CAM),但總體來說我們國家與發(fā)達(dá)國家相比還有很大的距離,例如我們機(jī)床用的都是日本法蘭克系統(tǒng)、德國西門子系統(tǒng)。所以還需要我們不斷地努力,去改變發(fā)展我們國家的機(jī)械制造業(yè)。
技術(shù)現(xiàn)狀和發(fā)展趨勢:在科學(xué)技術(shù)飛速發(fā)展的今天,先進(jìn)加工工藝技術(shù)亦日新月異,主要發(fā)展如下:
1. 采用模擬技術(shù),優(yōu)化工藝設(shè)計(jì)
2. 成形精度向近無余量方向發(fā)展
3. 成形質(zhì)量向近無“缺陷”方向發(fā)展
4. 機(jī)械加工向超精密、超高速方向發(fā)展
5. 采用新型能源及復(fù)合加工。解決新型材料的加工和表面改性難題
6. 采用自動(dòng)化技術(shù),實(shí)現(xiàn)工藝過程的優(yōu)化控制
7. 采用清潔能源及原材料、實(shí)現(xiàn)清潔生產(chǎn)
8. 加工與設(shè)計(jì)之間的界限逐漸淡化,并趨向集成及一體化。
9. 工藝技術(shù)信息技術(shù)管理技術(shù)緊密結(jié)合,先進(jìn)制造生產(chǎn)模式獲得不斷發(fā)展。
設(shè)計(jì)內(nèi)容和預(yù)期成果(具體設(shè)計(jì)內(nèi)容和重點(diǎn)解決的技術(shù)問題、預(yù)期成果和提供的形式)
1. 課題調(diào)研,完成開題報(bào)告、外文資料翻譯、文獻(xiàn)綜述;
2. 編制給定零件機(jī)械加工工藝文件,完成機(jī)械加工工序卡片一套:設(shè)備和工裝清單一份;機(jī)械加工工藝流程卡片一份;繼續(xù)加工工序卡片一份(填寫卡片內(nèi)所有內(nèi)容);
3. 根據(jù)給定工序內(nèi)容設(shè)計(jì)兩套專用夾具,完成總裝圖2張;
4. 設(shè)計(jì)并繪制一張總裝圖中的所有非標(biāo)準(zhǔn)零件;
5. 編寫設(shè)計(jì)說明書一份。
擬采取設(shè)計(jì)方法和技術(shù)支持(設(shè)計(jì)方案、技術(shù)要求、實(shí)驗(yàn)方法和步驟、可能遇到的問題和解決辦法等)
首先,認(rèn)真研究汽車變速箱箱體圖紙,明確零件幾何形體的各個(gè)細(xì)節(jié)形狀及加工工藝要求;
查閱資料,學(xué)習(xí)研究汽車減速箱箱體材料選取,加工工藝的一般方法;
結(jié)合課本學(xué)習(xí)的知識和工程訓(xùn)練的實(shí)踐,查閱相關(guān)手冊,根據(jù)箱體零件的幾何形體,以及工藝要求,制定出箱體加工的工藝路線;
明確所涉及的加工工藝中,對鏜床夾具的具體需求;
查閱夾具設(shè)計(jì)課本,構(gòu)思夾具的結(jié)構(gòu),功能實(shí)現(xiàn)方法,繪制結(jié)構(gòu)草圖;
查閱手冊,完成鏜床專用夾具定位誤差分析及夾緊力計(jì)算夾具;
總圖技術(shù)條件的確定及尺寸鏈的分析;
繪制所設(shè)計(jì)的鏜床夾具圖紙,出圖;
繪制其中以個(gè)非標(biāo)零件的零件圖;
完成箱體工藝制定和夾具設(shè)計(jì),完成畢業(yè)設(shè)計(jì)。
實(shí)現(xiàn)本項(xiàng)目預(yù)期目標(biāo)和已具備的條件(包括過去學(xué)習(xí)、研究工作基礎(chǔ),現(xiàn)有主要儀器設(shè)備、設(shè)計(jì)環(huán)境及協(xié)作條件等)
工作環(huán)境及技術(shù)條件:
1. 掌握箱體零件的加工工藝;
2. 繪制變速器箱體零件圖
3. 給定零件生產(chǎn)類型:中批生產(chǎn)。
學(xué)習(xí)、研究工作基礎(chǔ):
1. 熱加工工藝基礎(chǔ)的學(xué)習(xí)
2. 生產(chǎn)實(shí)習(xí)
3. 機(jī)械制造基礎(chǔ)課程的學(xué)習(xí)
4. 計(jì)算機(jī)輔助作圖軟件CAD/CAM的學(xué)習(xí)
5. 變速器拆裝實(shí)習(xí)
各環(huán)節(jié)擬定階段性工作進(jìn)度
(以周為單位)
1. 查閱資料,撰寫文獻(xiàn)綜述,并翻譯外文資料、開題報(bào)告,完成開題(4周);
2. 準(zhǔn)備相關(guān)的設(shè)計(jì)資料,熟悉零件圖,并繪制零件圖(1周);
3. 繪制零件的毛坯圖(1周);
4. 完成機(jī)械加工工藝卡片的編制(3周);
5. 根據(jù)給定工序,設(shè)計(jì)專用夾具(3周);
6. 設(shè)計(jì)并繪制整套零件圖(2周);
7. 完成設(shè)計(jì)說明書一份(1周);
8. 準(zhǔn)備答辯(1周)。
開 題 報(bào) 告 審 定 紀(jì) 要
時(shí) 間
地點(diǎn)
主持人
參
會
教
師
姓 名
職 務(wù)(職 稱)
姓 名
職 務(wù)(職 稱)
論
證
情
況
摘
要
記錄人:
指
導(dǎo)
教
師
意
見
指導(dǎo)教師簽名: 年 月 日
教
研
室
意
見
教研室主任簽名: 年 月 日
本科生畢業(yè)設(shè)計(jì)(論文)文獻(xiàn)綜述
設(shè)計(jì) (論文)題目
變速箱箱體機(jī)械加工工藝
及夾具設(shè)計(jì)
作者所在系別
機(jī)電工程學(xué)院
作者所在專業(yè)
作者所在班級
作 者 姓 名
作 者 學(xué) 號
指導(dǎo)教師姓名
指導(dǎo)教師職稱
完 成 時(shí) 間
2017
年
3
月
畢 業(yè) 設(shè) 計(jì)(論 文)文 獻(xiàn) 綜 述
變速箱箱體機(jī)械加工工藝文獻(xiàn)綜述題目
摘要:制造業(yè)一直以來是國民經(jīng)濟(jì)生產(chǎn)的基礎(chǔ)產(chǎn)業(yè),也是支柱性產(chǎn)業(yè),是實(shí)現(xiàn)經(jīng)濟(jì)目標(biāo),國防發(fā)展的重要保證。本文主要介紹了變速器箱體的結(jié)構(gòu)特點(diǎn)以及箱體類零件的發(fā)展及機(jī)械加工業(yè)發(fā)展趨勢。變速器箱體零件加工是典型零件的加工,而變速器箱體零件的結(jié)構(gòu)相對復(fù)雜,加工工藝方案也相對復(fù)雜。因?yàn)樵谛W(xué)習(xí)和實(shí)習(xí)以及對相關(guān)資料的查閱,對變速器箱體加工及夾具有一定的理論和實(shí)際基礎(chǔ),同時(shí)本次設(shè)計(jì)又和所學(xué)知識聯(lián)系十分緊密,能對在校四年的知識內(nèi)容進(jìn)行一次理論匯總和實(shí)際運(yùn)用,更能促進(jìn)我們更規(guī)范、全面的了解零件的工藝加工過程,更是我們畢業(yè)后邁入工作的不大不小的一次挑戰(zhàn)。
關(guān)鍵詞:變速器箱體;機(jī)械加工;夾具設(shè)計(jì)
Abstract: Manufacturing has been the basic industry of national economy, It is also a pillar industry. It is an important guarantee to achieve economic goals and national defense development. This paper mainly introduces the structural characteristics of the gearbox and the development of the box parts and the development trend of the machinery industry. Gearbox parts processing is a typical part of the processing, while the transmission box parts of the structure is relatively complex, the processing technology is relatively complex. Because the school learning and practice as well as access to relevant information, has certain theoretical and practical basis for the transmission and processing clamp, the design and knowledge closely, to knowledge of the contents of the school four years of a theoretical summary and practical application, we can promote more standardized a comprehensive understanding of the process, the process, it is a challenge we enter the job after graduation job.
Keyword: Gearbox, machining, fixture design
前言:隨著科學(xué)技術(shù)的發(fā)展,我國的工業(yè)技術(shù)水平也在不斷上升,尤其在汽車市場的興起,使得我國工程技術(shù)人員在變速器箱體加工方面積累了相當(dāng)豐富的經(jīng)驗(yàn),并與國外部分先進(jìn)技術(shù)結(jié)合及時(shí)采用新的技術(shù)和先進(jìn)工藝裝備,如以前車床的手動(dòng)操作而現(xiàn)如今用的是日本法蘭克系統(tǒng),更先進(jìn)的已經(jīng)用上了德國西門子系統(tǒng),大大提高了生產(chǎn)效率,使得我國工業(yè)發(fā)展出現(xiàn)了很顯著的進(jìn)步。
變速器箱體是主要用于支撐和包容著各種傳動(dòng)零件,保證其運(yùn)動(dòng)和動(dòng)力進(jìn)給驅(qū)動(dòng)和分配,彼此按照一定的傳動(dòng)關(guān)系進(jìn)行協(xié)調(diào)的運(yùn)動(dòng)。因此,必須使眾多的軸套及齒輪等零件保持正確的相互位置關(guān)系,所以箱體零件加工質(zhì)量的好壞,對整臺機(jī)器的精度﹑性能和壽命都有直接的影響。箱體多為鑄造件,結(jié)構(gòu)復(fù)雜,壁薄且不均勻,其內(nèi)部呈腔形,零件的整體剛性較差,難以裝夾。一般都需要進(jìn)行多工位孔系及平面加工,形位公差及空間位置度要求較嚴(yán),要保證其位置精度要求,必須在一次裝夾中完成銑面、鏜孔、鉆、鉸孔等多工序。精度要求較高,一般箱體類零件都有很高的軸承孔和表面的形位公差要求及軸承孔尺寸公差要求。加工內(nèi)容多,通常要經(jīng)過銑面、銷孔鉆鏜加工、鏜削軸承孔、深孔鏜削、深槽銑削、攻螺紋等加工,需頻繁更換刀具,所以對夾具的設(shè)計(jì)要求比較高,考慮到的方面比較多,同時(shí)變速器箱體體積比較大,設(shè)計(jì)時(shí)也需要注意到。
我國減速器產(chǎn)品的技術(shù)多源于美國、德國、日本幾個(gè)國家,引進(jìn)技術(shù)多為國外上世紀(jì)80—90年代的產(chǎn)品。作為高級技術(shù)領(lǐng)域的變速器在國內(nèi)漫長的引進(jìn)消化過程中,如今已有長足的進(jìn)步,能夠在原有技術(shù)引進(jìn)的基礎(chǔ)上,通過改型自行開發(fā)出符合配套要求的新產(chǎn)品,每年變速器行業(yè)都能有十幾個(gè)新產(chǎn)品推向市場。但從當(dāng)今變速器的發(fā)展情況來看,在新產(chǎn)品開發(fā)上國內(nèi)變速器仍然走的是一般性的開發(fā)過程,沒有真正的核心技術(shù)產(chǎn)品;從國內(nèi)變速器市場容量來看,有三分之一的產(chǎn)品來自進(jìn)口,而另外三分之二的產(chǎn)品中有80%以上源自國外技術(shù),國內(nèi)自主開發(fā)的變速器產(chǎn)品銷量很小,從而說明國內(nèi)變速器廠家的自主開發(fā)能力仍然很薄弱,應(yīng)對新型配套產(chǎn)品的能力遠(yuǎn)遠(yuǎn)不夠,就足以說明國內(nèi)的變速器企業(yè)仍然很渺小,在技術(shù)方面仍然有很長的路要走。 國內(nèi)的減速器多以齒輪傳動(dòng)、蝸桿傳動(dòng)為主,但普遍存在著功率與重量比小,或者傳動(dòng)比大而機(jī)械效率過低的問題。另外,材料品質(zhì)和工藝水平上還有許多弱點(diǎn),特別是大型的減速器問題更突出,使用壽命不長。國內(nèi)使用的大型減速器(500kw以上),多從國外(如丹麥、德國等)進(jìn)口,花去不少的外匯。國外減速器箱體的發(fā)展現(xiàn)狀 目前,德國FLENDER、比利時(shí)HANSEN、日本住友等公司在減速器制造業(yè)處于技術(shù)領(lǐng)先地位,國內(nèi)企業(yè)通過改進(jìn)設(shè)計(jì)方法、制造工藝使減速器的品質(zhì)不斷提高,部分中、低端產(chǎn)品已經(jīng)可以和國外的部分產(chǎn)品相媲美,但與FLENDER等公司相比,在產(chǎn)品性能、外觀造型等方面仍存在一定差距。其根本原因是在設(shè)計(jì)理念、設(shè)計(jì)方法上存在一定差異。例如,在設(shè)計(jì)理念上,國外公司重視減速器外觀造型的設(shè)計(jì),由此樹立品牌特征,而國內(nèi)企業(yè)往往只注重產(chǎn)品的性能而忽略了外觀設(shè)計(jì);在設(shè)計(jì)方法上,國外公司在20世紀(jì)80年代將模塊化設(shè)計(jì)應(yīng)用于減速器,而國內(nèi)直到20世紀(jì)末才引進(jìn)模塊化的概念。實(shí)踐證明,設(shè)計(jì)方法的改進(jìn)與創(chuàng)新對縮小國內(nèi)外減速器的差距至關(guān)重要。 渦輪箱體在各行各業(yè)應(yīng)用廣泛,國外的減速器,以德國、丹麥和日本處于領(lǐng)先地位,特別在材料和制造工藝方面占據(jù)優(yōu)勢,減速器工作可靠性好,使用壽命長。但其傳動(dòng)形式仍以定軸齒輪傳動(dòng)為主,體積和重量問題,也未解決好。 當(dāng)今的減速器是向著大功率、大傳動(dòng)比、小體積、高機(jī)械效率以及使用壽命長的方向發(fā)展。因此,除了不斷改進(jìn)材料品質(zhì)、提高工藝水平外,還在傳動(dòng)原理和傳動(dòng)結(jié)構(gòu)上深入探討和創(chuàng)作??偨Y(jié) 變速器箱體加工屬于典型零件加工,且零件結(jié)構(gòu)復(fù)雜,加工工藝復(fù)雜。夾具的設(shè)計(jì)關(guān)系到零件在加工過程中的位置是否準(zhǔn)確、可靠、裝夾方便和安全,也關(guān)系到機(jī)加工的精度。機(jī)械加工工藝制定的正確與否,直接關(guān)系到產(chǎn)品是否能夠順利進(jìn)行機(jī)械加工,是產(chǎn)品加工能否達(dá)到所需的尺寸精度和表面粗糙度要求的關(guān)鍵,也關(guān)系到零件加工的經(jīng)濟(jì)性。設(shè)計(jì)出合理方便廉價(jià)夾具,能有效提升生產(chǎn)效率。
參考文獻(xiàn)
[1] 濮良貴,紀(jì)名剛等著.機(jī)械設(shè)計(jì)(第八版).北京:高等教育出版社,2006 [2] 孫恒,陳作模,葛文杰.機(jī)械原理(第七版).高等教育出版社,2006
[3] 于駿一.機(jī)械制造技術(shù)基礎(chǔ).機(jī)械工業(yè)出版社,2009
[4] 馬蘭.機(jī)械制圖.機(jī)械工業(yè)出版社,2006
[5] 王先逵.機(jī)械加工工藝手冊.北京:機(jī)械工業(yè)出版社,2008
[6] 蔡建國.機(jī)床夾具設(shè)計(jì)原理.西安:陜西科技出版社,1981
[7] Yoram Koren. The Global Manufacturing Revolution. Published by John Wiley & Sons, Inc., Hoboken, New Jersey, 2010.
[8] Robert A. Daiber, Thomas L. Erekson.Manufacturing technology : today and tomorrow.Mission Hills, Calif. : Glencoe/McGraw-Hill, c1991.
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Precision Machining Technology
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精密機(jī)械加工工藝
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精密機(jī)械加工工藝
原文標(biāo)題
Precision Machining Technology
作 者
Peter J. Hoffman
譯 名
彼得·J·霍夫 曼
國 籍
美國
原文出處
Cengage Learning
譯文:
精密機(jī)械加工工藝
在機(jī)械加工過程中,工件受到切削力、離心力、慣性力等作用,為了保證在這些外力作用下,工件仍能在夾具中保持已由定位元件確定的加工位置,而不致發(fā)生振動(dòng)或位移、夾具結(jié)構(gòu)中應(yīng)設(shè)置夾緊裝置將工件可靠夾牢。
一、夾緊裝置的組成
夾緊裝置的種類很多,但其結(jié)構(gòu)均由兩部分組成。
1. 動(dòng)力裝置
夾緊力的來源,一是人力;二是某種裝置所產(chǎn)生的力。能產(chǎn)生力的裝置稱為夾具的動(dòng)力裝置。常用的動(dòng)力裝置有:氣動(dòng)裝置、液壓裝置、電動(dòng)裝置、電磁裝置、氣—液聯(lián)動(dòng)裝置和真空裝置等。由于手動(dòng)夾具的夾緊力來自人力,所以它沒有動(dòng)力裝置。
2. 夾緊部分
接受和傳遞原始作用力使之變?yōu)閵A緊力并執(zhí)行夾緊任務(wù)的部分,一般由下列機(jī)構(gòu)組成:
1)接受原始作用力的機(jī)構(gòu)。如手柄、螺母及用來連接氣缸活塞桿的機(jī)構(gòu)等。
2)中間遞力機(jī)構(gòu)。如鉸鏈、杠桿等。
3)夾緊元件。如各種螺釘壓板等。
其中中間遞力機(jī)構(gòu)在傳遞原始作用力至夾緊元件的過程中可以起到諸如改變作用力的方向、改變作用力的大小以及自鎖等作用。
二、夾緊裝置的基本要求
在不破壞工件定位精度,并保證加工質(zhì)量的前提下,應(yīng)盡量使夾緊裝置做到:
1. 夾緊力的大小適當(dāng)。既要保證工件在整個(gè)加工過程中其位置穩(wěn)定不變、振動(dòng)小,又要使工件不產(chǎn)生過大的夾緊變形。
2. 工藝性好。夾緊裝置的復(fù)雜程度應(yīng)與生產(chǎn)綱領(lǐng)相適應(yīng),在保證生產(chǎn)效率的前提下,其結(jié)構(gòu)應(yīng)力求簡單,便于制造和維修。
3. 使用性好。夾緊裝置的操作應(yīng)當(dāng)方便、安全、省力。
三、基本夾緊機(jī)構(gòu)
原始作用力轉(zhuǎn)化為夾緊力是通過夾緊機(jī)構(gòu)來實(shí)現(xiàn)的。在眾多的夾緊機(jī)構(gòu)中以斜楔、螺旋、偏心以及由它們組合而成的夾緊機(jī)構(gòu)應(yīng)用最為普遍。
1. 斜楔夾緊機(jī)構(gòu)
采用斜楔作為傳力元件或夾緊元件的夾緊機(jī)構(gòu)稱為斜楔夾緊機(jī)構(gòu)。 直接采用斜楔夾緊時(shí),斜楔的自鎖條件是:斜楔的升角小于斜楔與工件、斜 楔與夾具體之間的摩擦角之和.即:
α≤Φ1+Φ2
為保證自鎖可靠,手動(dòng)夾緊機(jī)構(gòu)一般取α=6°~8°。用氣壓或液壓裝置驅(qū)動(dòng)的斜楔不需要自鎖,可取
a =15 ° ~35 °。
斜楔夾緊具有結(jié)構(gòu)簡單,增力比大,自鎖性能好等特點(diǎn),因此獲得廣泛應(yīng)用。
(二)螺旋夾緊機(jī)構(gòu)
采用螺桿作中間傳力元件的夾緊機(jī)構(gòu)統(tǒng)稱為螺旋夾緊機(jī)構(gòu)。由于它結(jié)構(gòu)簡單、夾緊可靠、通用性好,而且由于螺旋升角小,螺旋夾緊機(jī)構(gòu)的自鎖性能好,夾緊力和夾緊行程都較大,是手動(dòng)夾具上用得最多的一種夾緊機(jī)構(gòu)。
1. 簡單螺旋夾緊機(jī)構(gòu)
最簡單的螺旋夾緊機(jī)構(gòu)由于直接用螺釘頭部壓緊工件,易使工件受壓表面損傷,或帶動(dòng)工件旋轉(zhuǎn)。因此常在頭部裝有擺動(dòng)的壓塊。由于壓塊與工件間的摩擦力矩大于壓塊與螺釘間的摩擦力矩,壓塊不會隨螺釘一起轉(zhuǎn)動(dòng)。夾緊動(dòng)作慢、工件裝卸費(fèi)時(shí)是單個(gè)螺旋夾緊機(jī)構(gòu)的另一個(gè)缺點(diǎn)。為克服這一缺點(diǎn),可采用快速夾緊機(jī)構(gòu)。
2. 螺旋壓板夾緊機(jī)構(gòu)
在夾緊機(jī)構(gòu)中,螺旋壓板的使用非常普遍,常見的螺旋壓板典型結(jié)構(gòu)其結(jié)構(gòu)尺寸均已標(biāo)準(zhǔn)化,設(shè)計(jì)者可參考有關(guān)國家標(biāo)準(zhǔn)和夾具設(shè)計(jì)手冊進(jìn)行設(shè)計(jì)。
2. 偏心夾緊機(jī)構(gòu)
用偏心件直接或間接夾緊工件的機(jī)構(gòu),稱為偏心夾緊機(jī)構(gòu)。偏心件有兩種形式,即圓偏心和曲線偏心,其中,圓偏心機(jī)構(gòu)因結(jié)構(gòu)簡單、制造容易而得到廣泛應(yīng)用。
偏心夾緊加工操作方便、夾緊迅速,缺點(diǎn)是夾緊力和夾緊行程都小。一般用于切削力不大、振動(dòng)小、沒有離心力影響的加工中。
1.圓偏心輪的工作原理
2.圓偏心輪的夾緊行程及工作段
3.偏心輪的自鎖條件
αmax≤Φ1+Φ2
推導(dǎo)得: f1≥ 2e/D
當(dāng) f= 0.1 時(shí),e/D ≥20 當(dāng) f= 0.15 時(shí),e/D ≥14
四、定心夾緊機(jī)構(gòu)
當(dāng)工件被加工面以中心要素(軸線、中心平面等)為工序基準(zhǔn)時(shí),為使基準(zhǔn)重合以減少定位誤差,需采用定心夾緊機(jī)構(gòu)。
定心夾緊機(jī)構(gòu)具有定心和夾緊兩種功能,如臥式車床的三爪自定心卡盤即為最常用的典型實(shí)例。
定心夾緊機(jī)構(gòu)按其定心作用原理有兩種類型,一種是依靠傳動(dòng)機(jī)構(gòu)使定心夾緊元件等速移動(dòng),從而實(shí)現(xiàn)定心夾緊,如螺旋式、杠桿式、楔式機(jī)構(gòu)等;另一種是利用薄壁彈性元件受力后產(chǎn)生均勻的彈性變形(收縮或擴(kuò)張) ,來實(shí)現(xiàn)定心夾緊,如彈簧筒夾、膜片卡盤、波紋套、液性塑料等。
1. 螺旋式定心夾緊機(jī)構(gòu)
螺桿兩端的螺紋旋向相反,螺距相同。當(dāng)其旋轉(zhuǎn)時(shí),使兩個(gè) V 形鉗口作對向等速移動(dòng),從而實(shí)現(xiàn)對工件的定心夾緊或松開。V 形鉗口可按工件不同形狀進(jìn)行更換。
這種定心夾緊機(jī)構(gòu)的特點(diǎn)是:結(jié)構(gòu)簡單、工作行程大、通用性好,但定心精度不高,主要適用于粗加工或半精加工中需要行程大而定心精度要求不高的場合。
2. 杠桿式定心夾緊機(jī)構(gòu)
杠桿式三爪自定心卡盤中,滑套作軸向移動(dòng)時(shí),圓周均布的三個(gè)鉤形杠桿便繞軸轉(zhuǎn)動(dòng), 撥動(dòng)三個(gè)滑塊沿徑向移動(dòng),從而帶動(dòng)其上卡爪將工件定心并夾緊或松開。
這種定心夾緊機(jī)構(gòu)具有剛性大、動(dòng)作快、增力倍數(shù)大、工作行程也比較大等特點(diǎn),但其定心精度較低。一般為 0.1mm 左右,它主要用于工件的粗加工。由于杠桿機(jī)構(gòu)不能自鎖,所以這種機(jī)構(gòu)自鎖要靠氣壓或其它機(jī)構(gòu)。
3. 楔式定心夾緊機(jī)構(gòu)
機(jī)動(dòng)的楔式夾爪自動(dòng)定心機(jī)構(gòu)中,當(dāng)工件以內(nèi)孔及左端面在夾具上定位后,汽缸通過拉桿使六個(gè)夾爪左移, 由于本體上斜面的作用,夾爪左移的同時(shí)向外脹開,將工件定心夾緊;反之,夾爪右移時(shí),在彈簧卡圈的作用下使夾爪收攏,將工件松開。
這種定心夾緊機(jī)構(gòu)的結(jié)構(gòu)緊湊,定心精度一般可達(dá) 0.02mm0.07mm,比較適用于工件內(nèi)孔作定位基面的半精加工工序。
4. 彈簧筒夾式定心夾緊機(jī)構(gòu)
這種定心夾緊機(jī)構(gòu)常用于安裝軸套類工件。
彈性定心夾緊機(jī)構(gòu)的結(jié)構(gòu)簡單、體積小、操作方便迅速,因而應(yīng)用十分廣泛。其定心精度可穩(wěn)定在 0.04mm0.010mm 之間。除上述介紹的定心夾緊機(jī)構(gòu)外,常用的還有膜片卡盤機(jī)構(gòu)、波紋套定心夾緊機(jī)構(gòu)以及液性塑料夾緊機(jī)構(gòu)等。
夾具是機(jī)械加工中不可缺少的部件,在機(jī)床技術(shù)向高速、高效、精密、復(fù)合、智能、環(huán)保方向發(fā)展的帶動(dòng)下,夾具技術(shù)正朝著高精、高效、模塊、組合、通用、經(jīng)濟(jì)方向發(fā)展。
一、 高精
隨著機(jī)床加工精度的提高,為了降低定位誤差,提高加工精度對夾具的制造精度要求更高高精度夾具的定位孔距精度高達(dá)±0.5mm,夾具支撐面的垂直度達(dá)0.01mm/300mm,平行度高達(dá) 0.01mm/500mm。瑞士EROWA柔性夾具的重復(fù)定位精度高達(dá)2~5微米。機(jī)床夾具的精度已提高到微米級,世界知名的夾具制造公司都是精密機(jī)械制造企業(yè)。為了適應(yīng)不同行業(yè)的需求和經(jīng)濟(jì)性,夾具有不同的型號以及不同檔次的精度標(biāo)準(zhǔn)供選擇。
二、 高效
為了提高機(jī)床的生產(chǎn)效率,雙面、四面和多件裝夾的夾具產(chǎn)品越來越多。為了減少工件的安裝時(shí)間,各種自動(dòng)定心夾緊、精密平口鉗、杠桿夾緊、凸輪夾緊、氣動(dòng)和液壓夾緊等,快速夾緊功能部件不斷的推陳出新。新型的電控永磁夾具,夾緊和松開工件只用1、2秒,夾具結(jié)構(gòu)簡化,為機(jī)床進(jìn)行多工位、多面和多件加工創(chuàng)造了條件。采用美國杰金斯公司的球鎖裝夾系統(tǒng),1分鐘內(nèi)就能將夾具定位和鎖緊在機(jī)床工作臺上,球鎖裝夾系統(tǒng)用于柔性生產(chǎn)線上更換夾具,起到縮短停機(jī)時(shí)間,提高生產(chǎn)效率的作用。
三、 模塊
組合夾具元件模塊化是實(shí)現(xiàn)組合化的基礎(chǔ)。利用模塊化設(shè)計(jì)的系列化、標(biāo)準(zhǔn)化夾具元件,快速組裝成各種夾具,已成為夾具技術(shù)開發(fā)的基點(diǎn)。省工、省時(shí)、節(jié)材、節(jié)能,體現(xiàn)在各種先進(jìn)夾具系統(tǒng)的創(chuàng)新之中。模塊化設(shè)計(jì)為夾具的計(jì)算機(jī)輔助設(shè)計(jì)與組裝打下了基礎(chǔ)。應(yīng)用CAD技術(shù),可建立元件庫、典型夾具庫、標(biāo)準(zhǔn)和用戶使用檔案庫,進(jìn)行夾具優(yōu)化設(shè)計(jì),為用戶三維實(shí)體組裝夾具。模擬仿真刀具的切削過程,既能為用戶提供正確、合理的夾具與元件配套方案,又能積累使用經(jīng)驗(yàn),了解市場需求,不斷的改進(jìn)和完善夾具系統(tǒng)。
四、 通用
經(jīng)濟(jì)夾具的通用性直接影響其經(jīng)濟(jì)性。采用模塊、組合式的夾具系統(tǒng),一次性投資比較大,只有夾具系統(tǒng)的可重組性、可重構(gòu)性及可擴(kuò)展性功能強(qiáng),應(yīng)用范圍廣,通用性好,夾具利用率高,收回投資快,才能體現(xiàn)出經(jīng)濟(jì)性好。
附錄:
Cengage Learning
In the machining process the work piece by the cutting force, centrifugal force, inertia force, such as the role of, in order to ensure that these external force, the workpiece can remain in the fixture by the positioning of the processing to determine the location of components, and should be no vibration or displacement, fixture structure should be set up reliable work piece clamping device folder will be in prison. First, the composition of clamping devices.
Many different types of clamping devices, but their structures are composed of two parts.
1. Power plant The source of clamping force, one human; second is generated by a power device.The device can generate power as the power unit fixture. Commonly used in power plant are: pneumatic devices hydraulic devices electrical devices electromagnetic devices gas - liquid interaction devices and vacuum devices. Fixture as a result of manual clamping force from the human so it does not power plants.
2. Clamping part
Receive and impart into the original clamping force to clamp the task force and part of the implementation of the general composition of the following agencies:
1) to accept the original force of bodies. Such as handles nuts and used to connect the institutions such as cylinder piston rod.
2) Force the middle of delivery. Such as hinges levers and so on.
3) Clamping components. Such as plate such as screws.
Force delivery of them in the middle of the original transmission of force to the process of clamping devices can play such as changes in the direction of force to change the size of forces as well as the role of self-locking and so on.
Second the basic requirements for clamping device
Without damaging the work piece positioning accuracy and quality assurance process under the premise of clamping devices should be enabled to:
1. The size of the appropriate clamping force. It is necessary to ensure that the work piece in the whole process of its stable position vibration small but also so that the work piece does not produce excessive clamping deformation.
2. Technology is good. The complexity of the clamping device should be suited to the production of the Program to ensure production efficiency its structure should be kept simple easy to manufacture and maintenance.
3. Good use. The operation of clamping device should be convenient safe and labor-saving.
Third the basic Clamp
iginal force into a clamping force through the clamping body to achieve.Among the many institutions in the clamping wedge oblique spiral and by their eccentric combination of the most common application of clamping.
(A) Wedge Clamp
used as components or transmission of the clamping device clamping body known as the Wedge Clamp.
Wedge clamping directly the oblique wedge of the self-locking conditions are:Wedge angle smaller than the work piece Wedge Wedge and folders between the concrete and the friction angle.
Namely: α≤Φ1+Φ2
In order to ensure a reliable self-locking manual clamping generally take a =6 °~ 8 °. Using pneumatic or hydraulic device drivers do not need the self-locking oblique wedge it is desirable to a =15 ° ~35 °.
Wedge clamp is simple in structure than by large self-locking features such as performance it is widely available.
(B) Helical Clamp
Used as intermediate screw transmission components are collectively referred to as the clamping screw clamping body organs. Because of its simple structure reliable clamping common good and as a result of the small helix angle spiral of self-locking clamping body good clamping force and the clamping itinerary are larger fixture on manual with the most a clamping body.
1. Simple screw clamp body
The simplest spiral as a result of the direct use of clamping bodies pressed workpiece screw head so easy to damage the surface of the work piece under pressure or driven rotating work piece. So often in the head with swinging Press. Press with the work piece as a result of friction between the Press and the torque is greater than the friction between the screw torque screw together with the Press will not rotate.
Clamping action slow time-consuming loading and unloading the work piece is a single spiral Another drawback of the Clamp. To overcome this shortcoming the rapid clamping bodies can be.
2. Clamp screw plate
Institutions in the clamping the use of spiral plate is very common common structure of the spiral structure of a typical plate size has been standardized the designer can refer to the relevant national standards and fixture design manual design.
(C) Eccentric Clamp
With eccentric pieces, directly or indirectly, the work piece clamping body, known as the eccentric clamping body. There are two types of eccentric pieces, that is, and the curveof eccentricity eccentric circle, which, due to a round eccentric structure is simple and easy to manufacture and is widely used.
Eccentric clamping processing is easy to operate, rapid clamp, the disadvantage of clamping force and clamping trip are small. Not generally used in cutting force, vibration small there is no centrifugal force of the impact of the processing.
1. Round the working principle of eccentric
2. Eccentric clamping round trip and paragraph
3. Eccentric self-locking condition of αmax≤Φ1+Φ2 Was derived: f1 ≥2e / D
When f =0.1 hours, e / D≥ 20, when f =0.15 pm, e / D ≥14
Fourth institutions centering clamping
When the work piece is processed by the central element of surface (axis, the center plane, etc.) for the base process in order to enable the base to reduce the positioning error of coincidence to be used centering clamping body.
Centering centering clamping body and clamping the two functions such as horizontal self-centering three-jaw lathe chuck is a classic example of the most commonly used.
Centering centering clamping the role of institutions according to their principle, there are two types, one is relying on the transmission mechanism so that mobile speed centering clamping device in order to achieve centering clamping, such as spiral leveraged institutions such as wedge; the other is the use of thin-walled elastic element force even after the elastic deformation (contraction or expansion), to achieve centering clamping, such as a spring clip drum, diaphragm chuck, bellows units, such as liquid plastic.
1. Centering clamping body spiral
Rotary screw thread at both ends to the contrary, the same pitch. When it spins, the two V-shaped gag against the constant movement in order to achieve the centering of the work piece clamping or release. V-shaped work pieces of different shapes can shut up the replacement.
Centering clamping bodies such features are: simple structure the work trip and general good but the centering accuracy is not high mainly suitable for rough or semi-finished tour of the needs of large and less demanding precision centering occasions.
2. Leveraged institutions centering clamping
Three-jaw self-centering leveraged trading cards, sleeve for axial movement the circle are three fabric hook lever will rotate around the axis, the three struck the slider along the radial movement of the cards in order to promote its claws the work piece centering and clamping or release.
This centering clamping rigid body, and move fast, by force multiplier, and the worktrip is also characterized by relatively large, but its relatively low precision centering. Generally about 0.1mm it is mainly used for rough work. Since the body can not self-locking lever, so that organizations rely on self-locking air pressure or other agencies.
3. Centering clamping wedge bodies
Wedge mobile folder automatically centering body claw when the work piece surface within the hole and left the position in the fixture after the six-cylinder through the rod so that the left claw clip due to the role of ontology on the slope while the left claw folder to the opened outside the bulge will be centering the workpiece clamping the other hand claw shifted to right folder in the role of spring circle card folder under claw to release the work piece.
Centering clamping bodies such compact structure usually ranging from precision centering 0.02mm~ 0.07mm compared with the hole for the workpiece surface for positioning the base of the semi-finishing processes.
4. Clip-on spring-centering clamping cylinder body
This centering clamping sleeve body type commonly used in the installation of the work piece.
Elastic centering clamping simple structure, small size, easy to operate quickly, so a wide range of applications. Centering accuracy of its stability in between0.04mm~ 0.010mm. In addition to the above described centering clamping bodies, are commonly used diaphragm chuck body, corrugated centering clamping sets of institutions, as well as fluid bodies such as plastic clamping.
Machining fixture is an indispensable component in the machine tool technology to high-speed, high efficiency, precision, complex, intelligent, environmentally-friendly direction, driven by technology is moving fixture high-precision, high-performance, modular, mix, general economic direction.
First, high-precision Machining with improved accuracy, in order to reduce the positioning error and improve machining accuracy of the fixture manufacturing precision demanding high-precision positioning jig Distance accuracy up to ± 5μm the bearing surface of the vertical fixture achieve 0.01mm / 300mm up to parallelism0.01mm/500mm. Switzerland duplication EROWA Flexible fixture positioning accuracy of up to 2 ~5μm. Precision machine tool fixture to the micron level has been raised the worlds leading manufacturer of fixture is precision machinery manufacturing enterprises. It is true that, in order to meet the needs of different industries and economy, folders with different models, as well as the different grades for the accuracy of the standard options.
Second, efficient tool To improve production efficiency, double-sided, four and more than clamping fixture of more and more products. Work piece in order to reduce the installation time, all kinds of auto-centering clamping, precision flat clamp, clamping levers, cam clamp, such as pneumatic and hydraulic clamping, rapid clamping new features constantly. New type of electronically controlled permanent magnet fixture, step up and release the work piece only 1~2 seconds, simplifying the fixture structure for the machine to carry out stage, faceted and processing to create the condition. American JERGENS the company's ball lock clamping system,1 minutes, will be able to locate and lock fixture in the machine tool table, the ball lock clamping system of flexible production line for the replacement of fixtures, played reduce downtime and increase the role of productivity.
Third, modules Modular components of modular fixture is the basis of the realization of portfolio. Take advantage of the modular design of serialization, standardization fixture elements, quickly assembled into a variety of fixtures, has become a fixture technology development basis points.Save labor, time, materials, energy-saving, being reflected in a variety of advanced fixture system innovation. The modular design laid the foundation for the the fixture computer-aided design and assembly. Application of CAD technology to create a component library the typical fixture library, standard and user archive fixture optimization design, assembly fixtures for users dimensional solid. Cutting process simulation tool, both to provide users with the correct fixtures and components supporting the program, but also the accumulation of experience, understand the market demand, and continue to improve and perfect the fixture system.
Fourth, GM Economic fixture versatility direct impact on the economy. Modules, modular fixture system, a one-time investment is relatively large, the only fixture system reconfigurable and scalability features a wide range of applications, common good, fixture utilization, faster recovery of investment to reflect the economic good.
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