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XK714數(shù)控銑床總體設(shè)計(jì)及主傳動系統(tǒng)的設(shè)計(jì)
專業(yè):機(jī)械設(shè)計(jì)制造及其自動化 學(xué)號: 姓名: 指導(dǎo)老師: 職稱:
摘要
本文介紹了立式數(shù)控銑床XK714的一些基本概況,簡述了機(jī)床主傳動系統(tǒng)方面的原理和類型,分析了各種傳動方案的機(jī)理,立式數(shù)控銑床主傳動系統(tǒng)包括了主軸電動機(jī)、主軸傳動系統(tǒng)和主軸組件三部分組成。其次詳細(xì)介紹了XK714的設(shè)計(jì)過程,該立式數(shù)控銑床主軸變速箱是靠齒輪進(jìn)行傳動的,主軸變速采用雙聯(lián)滑移齒輪。齒輪傳動具有傳動效率高,結(jié)構(gòu)緊湊,工作可靠,壽命長,傳動比準(zhǔn)確等優(yōu)點(diǎn)。文中介紹了數(shù)控銑床主傳動系統(tǒng)各種優(yōu)缺點(diǎn)的比較,主傳動方案的選擇和確定、主傳動變速系統(tǒng)的設(shè)計(jì)計(jì)算、主軸組件的設(shè)計(jì)、軸承的選用及其潤滑、關(guān)鍵零件的校核等。
關(guān)鍵詞:立式數(shù)控銑床、主傳動系統(tǒng)、主軸組件
一. 緒論
(一)概述
1.數(shù)控銑床概述
數(shù)控銑床是一種功能很強(qiáng)大的數(shù)控機(jī)床,目前迅速發(fā)展起來的加工中心柔性加工單元都是在數(shù)控銑床、數(shù)控鏜床的基礎(chǔ)上生產(chǎn)的,兩者都離不開銑削方式,由于數(shù)控銑削方比較復(fù)雜,需要解決的技術(shù)問題也就很多,因此,人們在研究和開發(fā)數(shù)控系統(tǒng)級自動化編程語言軟件時(shí),一直把銑削加工作為重點(diǎn),數(shù)控銑床機(jī)械部分與普通銑床基本相同,工作臺可以做橫向、縱向和垂直三個(gè)方向的運(yùn)動,因此普通銑床能加工的工藝內(nèi)容,數(shù)控銑床都能做到。
2.數(shù)控機(jī)床的發(fā)展
隨著機(jī)械性能不斷的提高,其價(jià)格成倍地下降;隨著網(wǎng)絡(luò)通訊的普及化、信息處理的智能化、多媒體技術(shù)的實(shí)用化;數(shù)控技術(shù)的普及應(yīng)用越來越廣泛,越來越深入,數(shù)控技術(shù)正在向著開放、集成、智能和標(biāo)準(zhǔn)化的方向發(fā)展。90年代以來,從事科研和應(yīng)用開發(fā)數(shù)控的技術(shù)人員認(rèn)識到,要讓數(shù)控技術(shù)成為第一生產(chǎn)力,關(guān)鍵是讓設(shè)計(jì)人員都用上、會用數(shù)控系統(tǒng)。今天,許多地方、企業(yè)己經(jīng)推廣了數(shù)控技術(shù),取得了較好的效果,但也還存在一些問題值得探討。?
二.?dāng)?shù)控銑床的結(jié)構(gòu)設(shè)計(jì)
(一) 控銑床結(jié)構(gòu)組成
1.數(shù)控銑床組成
數(shù)控銑床的機(jī)械結(jié)構(gòu)主要由:主傳動系統(tǒng);進(jìn)給傳動系統(tǒng);支撐件;輔助裝。本次設(shè)計(jì)的銑床采用工作臺移動,主軸升降轉(zhuǎn)動的布局形式。
2.XK714主傳動系統(tǒng)方案的確定
為了適應(yīng)不同的加工要求,目前主傳動系統(tǒng)分為三種變速方式:(1)、二級以上齒輪變速系統(tǒng);(2)、一級帶傳動方式;(3)、調(diào)速電動機(jī)直接驅(qū)動方式。
由于二級以上齒輪變速系統(tǒng)變速裝置多采用齒輪變速結(jié)構(gòu)。通常使用滑移齒輪實(shí)現(xiàn)二級變速的主傳動系統(tǒng)?;讫X輪的移位大都采用液壓驅(qū)動。因?yàn)閿?shù)控銑床使用可調(diào)無機(jī)變速交流、直流電動機(jī),所以經(jīng)齒輪變速后,實(shí)現(xiàn)分段無級變速,調(diào)速范圍增加。其優(yōu)點(diǎn)是能夠滿足各種切削運(yùn)動的轉(zhuǎn)矩輸出,且具有大范圍調(diào)速的能力。故本次設(shè)計(jì)采用二級以上齒輪變速系統(tǒng)。
三.主傳動變速系統(tǒng)主要參數(shù)計(jì)算
(一)計(jì)算切削功率
1.切削功率的計(jì)算
銑削時(shí)切削公式:
2.切削功率的計(jì)算
切削功率計(jì)算公式:
3.主傳動功率的計(jì)算及電動機(jī)的初選
用一下公式初選電動機(jī)的功率;
其中為銑床傳動總的機(jī)械效率,
則主軸電動機(jī)選用5.5KW,額定轉(zhuǎn)速為:1500Rr/min;最高轉(zhuǎn)速為:6000r/min。
(二)分級變速箱的傳動系統(tǒng)的設(shè)計(jì)
1.變速范圍
計(jì)算轉(zhuǎn)速的確定:=380;
主軸要求恒功率調(diào)速范圍:
電動機(jī)恒功率的調(diào)速范圍:
變速級數(shù):=1.99; 可以取Z=2
(三)傳動系統(tǒng)圖
圖1 傳動系統(tǒng)圖
四.齒輪傳動設(shè)計(jì)
(一)齒輪的概述
1.齒輪簡單概述齒輪
齒輪傳動式機(jī)械傳動種應(yīng)用最廣泛的一種傳動形式。齒輪的直徑可以從不足1mm到100m,甚至超過100m,傳遞的功率可以不足1W到數(shù)萬KW,圓周速度可以從很小到200m/s以上。常見的齒輪傳動場合包括家用電器的機(jī)械定時(shí),機(jī)床主軸箱以及用于各種加速器等
(二)齒輪設(shè)計(jì)
1.齒輪設(shè)計(jì)方法
(1).材料選擇熱處理方式及進(jìn)度等級
考慮到該銑床功率較大,且有中等的沖擊載荷,故大小齒輪采用40Cr鋼表面淬火,平均硬度52HRC,選用6級精度。
(2).按齒輪接觸疲勞強(qiáng)度設(shè)計(jì):;可取d=70mm
則m=2
(3).采用齒根彎曲疲勞強(qiáng)度進(jìn)行校核:
2.齒輪基本參數(shù)
齒輪參數(shù)
=35
=77
=35
=41
=73
d
70mm
154mm
158mm
70mm
82mm
146mm
m
2mm
2mm
2mm
2mm
2mm
2mm
b
14mm
15mm
16mm
15mm
15mm
16mm
a
112mm
114mm
114mm
表1 齒輪基本參數(shù)表
五.主軸組件的設(shè)計(jì)
(一)主軸的結(jié)構(gòu)設(shè)計(jì)
1.概述
主軸部件設(shè)計(jì)是機(jī)床設(shè)計(jì)重要的部件之一,它是機(jī)床的執(zhí)行件。它的功用是支持并帶動工件或刀具旋轉(zhuǎn)進(jìn)行切削,承受切削力和驅(qū)動力等載荷,完成表面成型運(yùn)動。
2.結(jié)構(gòu)設(shè)計(jì)
主軸的結(jié)構(gòu)如圖
(二)主軸的校核
1.主軸剛度校核
階梯軸的剛度條件:; =0.168°/m;
查手冊
六.軸承的選用
(一)概述
滾動軸承是現(xiàn)代化機(jī)器中廣泛應(yīng)用的部件之一,它是依靠主要元件間的滾動接觸來支撐主動零件的。與滑動軸承相比,滾動軸承具有摩擦阻力小,啟動靈活,效率高,潤滑方便和互換性好等優(yōu)點(diǎn),其缺點(diǎn)是抗干擾能力差,工作時(shí)有噪聲,工作壽命不及液體摩擦的滑動軸承。
1.壽命計(jì)算
壽命計(jì)算公式:
滿足機(jī)床的設(shè)計(jì)要求
2.軸承的潤滑
本設(shè)計(jì)采用脂潤滑,其優(yōu)點(diǎn)是潤滑膜強(qiáng)度高,能夠承受較大的載荷,不易流失,容易密封,一次加脂可以維持相當(dāng)長的一段時(shí)間,方便簡潔。
3.軸承的密封
本次采用非接觸式密封中的迷宮密封,其優(yōu)點(diǎn)是在于工作中幾乎不產(chǎn)生摩擦熱沒有磨損,特別適用于高速和高溫場合。前段軸承受力較大,且要求較高故采取迷宮密封方式。
七.結(jié)論
本次設(shè)計(jì)任務(wù)是XK714的總傳動系統(tǒng)及主傳動系統(tǒng)的設(shè)計(jì),主要是數(shù)控銑床主傳動系統(tǒng)的設(shè)計(jì),該立式數(shù)控銑床主軸采用齒輪傳動的,傳動形式采用集中式傳動,主軸變速采用多聯(lián)滑移齒輪變速。齒輪傳動具有傳動效率高,結(jié)構(gòu)緊湊,工作可靠,壽命長,傳動比準(zhǔn)確等優(yōu)點(diǎn)。還對立式數(shù)控銑床各種傳動系統(tǒng)做了對比,主傳動方案的選擇與確定,主傳動變速系統(tǒng)的計(jì)算,主軸組件設(shè)計(jì),軸承的選用密封及潤滑等,關(guān)鍵零件的設(shè)計(jì)校核。
本次畢業(yè)設(shè)計(jì)中所有零件的設(shè)計(jì)與繪制均是在三維繪圖軟件solidworks中進(jìn)行的,然后完成所繪零件的裝配,完成主軸箱的三維繪制。最終與同組成員所繪制的部分進(jìn)行總體的裝配完成XK714的總體設(shè)計(jì)。最后按照要求對相應(yīng)的零部件進(jìn)行工程圖的生成并修改完成任務(wù)的要求。
經(jīng)過三個(gè)月的努力,我們的畢業(yè)設(shè)計(jì)完成了,大學(xué)生活也即將結(jié)束,畢業(yè)設(shè)計(jì)是我們對大學(xué)四年的機(jī)械知識的總結(jié)與整理,也是理論與實(shí)踐的結(jié)合。在這次畢業(yè)設(shè)計(jì)過程中我們學(xué)習(xí)到了很多東西,不光是理論知識,還有互相幫助的重要,團(tuán)隊(duì)合作的重要性等,這些收獲會將在今后的道路上幫助我指導(dǎo)我前行的更遠(yuǎn)。
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XK714數(shù)控銑床總體設(shè)計(jì)及床身設(shè)計(jì)
專業(yè):機(jī)械設(shè)計(jì)制造及其自動化 學(xué)號: 姓名: 指導(dǎo)老師: 職稱:
摘要
本文介紹了立式數(shù)控銑床XK714的一些基本概況,簡述了機(jī)床主傳動系統(tǒng)方面的原理和類型,分析了各種傳動方案的機(jī)理,立式數(shù)控銑床主傳動系統(tǒng)包括了主軸電動機(jī)、主軸傳動系統(tǒng)和主軸組件三部分組成。其次詳細(xì)介紹了XK714的設(shè)計(jì)過程,機(jī)床床身的整體設(shè)計(jì),軸變速采用雙聯(lián)滑移齒輪。齒輪傳動具有傳動效率高,結(jié)構(gòu)緊湊,工作可靠,壽命長,傳動比準(zhǔn)確等優(yōu)點(diǎn)。文中介紹了數(shù)控銑床主傳動系統(tǒng)各種優(yōu)缺點(diǎn)的比較,主傳動方案的選擇和確定、床身是不是的設(shè)計(jì)計(jì)算、床身組件的設(shè)計(jì)、軸承的選用及其潤滑、關(guān)鍵零件的校核等。
關(guān)鍵詞: 立式數(shù)控銑床 床身設(shè)計(jì) 鑲裝導(dǎo)軌 軸承 絲杠
一、緒論
(一)概述
1.數(shù)控銑床概述
數(shù)控機(jī)床是數(shù)字控制機(jī)床(Computer numerical control machine tools)的簡稱,是一種裝有程序控制系統(tǒng)的自動化機(jī)床。該控制系統(tǒng)能夠邏輯地處理具有控制編碼或其他符號指令規(guī)定的程序,并將其譯碼,從而使機(jī)床動作。過去的數(shù)控機(jī)床經(jīng)歷了一個(gè)由單一向多元轉(zhuǎn)換的一個(gè)過程,數(shù)控機(jī)床的快速發(fā)展是整個(gè)世界經(jīng)濟(jì)、科技發(fā)展的重要體現(xiàn)。數(shù)控機(jī)床在現(xiàn)代工業(yè)中占據(jù)著不可替代的位置,與我們生活的各個(gè)方面都有直接或間接的關(guān)系。未來數(shù)控機(jī)床將會有一個(gè)前所未有的發(fā)展,世界上主要工業(yè)發(fā)達(dá)國家都十分重視數(shù)控加工技術(shù)的研究和發(fā)展.
二、數(shù)控銑床的結(jié)構(gòu)設(shè)計(jì)
(一) 數(shù)控銑床結(jié)構(gòu)組成
1.數(shù)控銑床組成
(1)主機(jī),他是數(shù)控銑床的主題,包括機(jī)床身、立柱、主軸、進(jìn)給機(jī)構(gòu)等機(jī)械部件。他是用于完成各種切削加工的機(jī)械部件。
?。?)數(shù)控裝置,是數(shù)控銑床的核心,包括硬件以及相應(yīng)的軟件,用于輸入數(shù)字化的零件程序,并完成輸入信息的存儲、數(shù)據(jù)的變換、插補(bǔ)運(yùn)算以及實(shí)現(xiàn)各種控制功能。
?。?)輔助裝置,指數(shù)控銑床的一些必要的配套部件,用以保證數(shù)控銑床的運(yùn)行,如冷卻、排屑、潤滑、照明、監(jiān)測等。它包括液壓和氣動裝置、排屑裝置、交換工作臺、數(shù)控轉(zhuǎn)臺和數(shù)控分度頭,還包括刀具及監(jiān)控檢測裝置等。
?。?)編程及其他附屬設(shè)備,可用來在機(jī)外進(jìn)行零件的程序編制、存儲等。
(5)驅(qū)動裝置,他是數(shù)控銑床執(zhí)行機(jī)構(gòu)的驅(qū)動部件,包括主軸驅(qū)動單元、進(jìn)給單元、主軸電機(jī)及進(jìn)給電機(jī)等。他在數(shù)控裝置的控制下通過電氣或電液伺服系統(tǒng)實(shí)現(xiàn)主軸和進(jìn)給驅(qū)動。當(dāng)幾個(gè)進(jìn)給聯(lián)動時(shí),可以完成定位、直線、平面曲線和空間曲線的加工。
數(shù)控銑床在制造工業(yè),特別是在汽車、航空航天、以及軍事工業(yè)中被廣泛地應(yīng)用,數(shù)控技術(shù)無論在硬件和軟件方面,都有飛速發(fā)展
2.XK714主傳動系統(tǒng)方案的確定
為了適應(yīng)不同的加工要求,目前主傳動系統(tǒng)分為三種變速方式:
(1)二級以上齒輪變速系統(tǒng);
(2)一級帶傳動方式;
(3)調(diào)速電動機(jī)直接驅(qū)動方式。
由于二級以上齒輪變速系統(tǒng)變速裝置多采用齒輪變速結(jié)構(gòu)。通常使用滑移齒輪實(shí)現(xiàn)二級變速的主傳動系統(tǒng)?;讫X輪的移位大都采用液壓驅(qū)動。因?yàn)閿?shù)控銑床使用可調(diào)無機(jī)變速交流、直流電動機(jī),所以經(jīng)齒輪變速后,實(shí)現(xiàn)分段無級變速,調(diào)速范圍增加。其優(yōu)點(diǎn)是能夠滿足各種切削運(yùn)動的轉(zhuǎn)矩輸出,且具有大范圍調(diào)速的能力。故本次設(shè)計(jì)采用二級以上齒輪變速系統(tǒng)。
三、數(shù)控銑床XK714床身設(shè)計(jì)
(一)床身設(shè)計(jì)
1.材料的選擇
灰鑄鐵材料
2.切削力的計(jì)算:Fc=CF?apxf?fzyf?aeμF?zd°qF?nwf=37.68N
3.導(dǎo)軌的選擇
由精度的選擇和型號的選擇最后得出選用的是鑲裝導(dǎo)軌
計(jì)算導(dǎo)軌的壽命L=fnfifcfgGafwp?u?k
(二)滾珠絲杠螺母副的確定
1.滾珠絲杠螺母副的循環(huán)方式
采用內(nèi)循環(huán)方式
2.滾珠絲杠間隙與調(diào)整預(yù)緊
3.滾珠絲杠的選定原則和選型
Pn=VmaxNmax
(三)軸承的選用
1.概述
滾動軸承是現(xiàn)代化機(jī)器中廣泛應(yīng)用的部件之一,它是依靠主要元件間的滾動接觸來支撐主動零件的。與滑動軸承相比,滾動軸承具有摩擦阻力小,啟動靈活,效率高,潤滑方便和互換性好等優(yōu)點(diǎn),其缺點(diǎn)是抗干擾能力差,工作時(shí)有噪聲,工作壽命不及液體摩擦的滑動軸承。
2.壽命計(jì)算
壽命計(jì)算公式:Lh=166671500×ft?Cfp?P?=18886.4h
滿足機(jī)床的設(shè)計(jì)要求
3.軸承的潤滑
本設(shè)計(jì)采用脂潤滑,其優(yōu)點(diǎn)是潤滑膜強(qiáng)度高,能夠承受較大的載荷,不易流失,容易密封,一次加脂可以維持相當(dāng)長的一段時(shí)間,方便簡潔。
4.軸承的密封
本次采用非接觸式密封中的迷宮密封,其優(yōu)點(diǎn)是在于工作中幾乎不產(chǎn)生摩擦熱沒有磨損,特別適用于高速和高溫場合。前段軸承受力較大,且要求較高故采取迷宮密封方式。
四、結(jié)論
本次設(shè)計(jì)任務(wù)是XK714的總傳動系統(tǒng)及主傳動系統(tǒng)的設(shè)計(jì),主要是數(shù)控銑床主傳動系統(tǒng)的設(shè)計(jì),該立式數(shù)控銑床主軸采用齒輪傳動的,傳動形式采用集中式傳動,主軸變速采用多聯(lián)滑移齒輪變速。齒輪傳動具有傳動效率高,結(jié)構(gòu)緊湊,工作可靠,壽命長,傳動比準(zhǔn)確等優(yōu)點(diǎn)。還對立式數(shù)控銑床各種傳動系統(tǒng)做了對比,主傳動方案的選擇與確定,主傳動變速系統(tǒng)的計(jì)算,主軸組件設(shè)計(jì),軸承的選用密封及潤滑等,關(guān)鍵零件的設(shè)計(jì)校核。
本次畢業(yè)設(shè)計(jì)中所有零件的設(shè)計(jì)與繪制均是在三維繪圖軟件solidworks中進(jìn)行的,然后完成所繪零件的裝配,完成主軸箱的三維繪制。最終與同組成員所繪制的部分進(jìn)行總體的裝配完成XK714的總體設(shè)計(jì)。最后按照要求對相應(yīng)的零部件進(jìn)行工程圖的生成并修改完成任務(wù)的要求。
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XK714數(shù)控銑床總體設(shè)計(jì)及立柱的設(shè)計(jì)
專業(yè):機(jī)械設(shè)計(jì)制造及其自動化 學(xué)號: 姓名: 指導(dǎo)老師: 職稱:
摘要
本文是以XK714型立式數(shù)控銑床立柱的設(shè)計(jì)為研究對象,主要進(jìn)行立柱傳動系統(tǒng)的設(shè)計(jì)。根據(jù)給定的參數(shù)的要求,對進(jìn)給傳動結(jié)構(gòu)和各部件:導(dǎo)軌、絲杠、支撐軸承、驅(qū)動電機(jī)進(jìn)行具體計(jì)算、并選型,再逐一對選定的部件進(jìn)行強(qiáng)度、壽命校核確定各設(shè)計(jì)部件的可靠性和可行性。導(dǎo)軌采用直線滾動導(dǎo)軌,摩擦系數(shù)小,反應(yīng)速度快,動態(tài)響應(yīng)好。進(jìn)給傳動采用雙螺母滾珠絲杠,確保高定位精度;同時(shí)滾珠絲杠采用預(yù)拉伸裝置,補(bǔ)償熱膨脹。最后通過對機(jī)械傳動的誤差計(jì)算與分析從理論上確定所設(shè)計(jì)的各部件符合設(shè)計(jì)要求。利用solidworks繪制出立柱部分總裝配圖和關(guān)鍵零件圖。
關(guān)鍵詞:立式數(shù)控銑床; 導(dǎo)軌; 絲杠; 校核
一.緒論
(一).概述
1.我國數(shù)控機(jī)床的發(fā)展現(xiàn)狀
國內(nèi)一些專家在對我國數(shù)控機(jī)床產(chǎn)業(yè)的發(fā)展進(jìn)行了分析,得出了如下的結(jié)論:
一是我國數(shù)控機(jī)床產(chǎn)業(yè)化低,與國外發(fā)達(dá)國家數(shù)控機(jī)床產(chǎn)業(yè)相比仍有很大差距。
二是高速、柔性、精密機(jī)床配套技術(shù)的自主研發(fā)能力低。數(shù)控機(jī)床的機(jī)械結(jié)構(gòu)設(shè)計(jì)、制造的配套環(huán)節(jié)、集成技術(shù)和制造工藝等方面比較落后。
三是適應(yīng)市場經(jīng)濟(jì)需求的以企業(yè)為主體、產(chǎn)學(xué)研相結(jié)合的技術(shù)創(chuàng)新體系尚未形成,無法有效整合相關(guān)技術(shù)、產(chǎn)業(yè)和資源優(yōu)勢,形成合力開展聯(lián)合攻關(guān),共同打造技術(shù)創(chuàng)新平臺。
四是缺乏吸引高層次、高素質(zhì)人才創(chuàng)新創(chuàng)業(yè)的環(huán)境,造成數(shù)控機(jī)床領(lǐng)域共性關(guān)鍵技術(shù)的持續(xù)創(chuàng)新能力不足。
五是對國外技術(shù)重引進(jìn)、輕消化吸收的問題仍很突出。
2.我國數(shù)控機(jī)床的發(fā)展趨勢
目前,世界先進(jìn)制造技術(shù)不斷興起,超高速切削、精密加工等技術(shù)的應(yīng)用,柔性制造系統(tǒng)的迅速發(fā)展和計(jì)算機(jī)集成系統(tǒng)的不斷成熟,對數(shù)控加工技術(shù)提出了更高的要求。當(dāng)今數(shù)控機(jī)床正在朝著以下幾個(gè)方面發(fā)展。
(1) 高速度、高精度化。速度和精度是數(shù)控機(jī)床的兩個(gè)重要指標(biāo),它直接關(guān)系到加工效率和產(chǎn)品質(zhì)量。
(2) 多功能化配有自動換刀機(jī)構(gòu)的各類數(shù)控銑床,能在同一臺機(jī)床上同時(shí)實(shí)現(xiàn)銑削、鏜削、鉆削、車削、鉸孔、擴(kuò)孔、攻螺紋等多種工序加工,現(xiàn)代數(shù)控機(jī)床還采用多主軸,多面體切削,即同時(shí)對一個(gè)零件的不同部位進(jìn)行不同方式的切削加工。
(3) 智能化現(xiàn)代數(shù)控機(jī)床將引進(jìn)自適應(yīng)控制技術(shù),根據(jù)切削條件的變化,自動調(diào)節(jié)工作參數(shù),使加工過程中能保持最佳工作狀態(tài),從而得到較高的加工境地和較小的表面粗糙度,同時(shí)也能提高刀具的使用壽命和設(shè)備的生產(chǎn)效率。
二. 數(shù)控銑床的結(jié)構(gòu)設(shè)計(jì)
(一)數(shù)控銑床結(jié)構(gòu)組成
1.數(shù)控銑床組成
數(shù)控銑床的機(jī)械結(jié)構(gòu)主要由:(1)主傳動系統(tǒng);(2)進(jìn)給傳動系統(tǒng);(3)支撐件;(4)輔助裝。本次設(shè)計(jì)的銑床采用工作臺移動,主軸升降轉(zhuǎn)動的布局形式。
2.XK714主傳動系統(tǒng)方案的確定
為了適應(yīng)不同的加工要求,目前主傳動系統(tǒng)分為三種變速方式:(1)、二級以上齒輪變速系統(tǒng);(2)、一級帶傳動方式;(3)、調(diào)速電動機(jī)直接驅(qū)動方式。
由于二級以上齒輪變速系統(tǒng)變速裝置多采用齒輪變速結(jié)構(gòu)。通常使用滑移齒輪實(shí)現(xiàn)二級變速的主傳動系統(tǒng)。滑移齒輪的移位大都采用液壓驅(qū)動。因?yàn)閿?shù)控銑床使用可調(diào)無機(jī)變速交流、直流電動機(jī),所以經(jīng)齒輪變速后,實(shí)現(xiàn)分段無級變速,調(diào)速范圍增加。其優(yōu)點(diǎn)是能夠滿足各種切削運(yùn)動的轉(zhuǎn)矩輸出,且具有大范圍調(diào)速的能力。故本次設(shè)計(jì)采用二級以上齒輪變速系統(tǒng)。
三.?dāng)?shù)控銑床立柱部分總體方案設(shè)計(jì)思路
(一)計(jì)算切削功率
1.切削功率的計(jì)算
銑削時(shí)切削公式: FZ=μPV×103
FZ--主切削力;
μ—機(jī)械效率,取μ=0.8;
v---主軸的計(jì)算轉(zhuǎn)速;
2.電動機(jī)的計(jì)算和初選
用一下公式初選電動機(jī)的功率pL=Pcηc=3.1kw;
其中ηc為銑床傳動總的機(jī)械效率,ηc=0.90
則主軸電動機(jī)選用3.1KW,額定轉(zhuǎn)速為:2500r/min;最高轉(zhuǎn)速為:6000r/min。
(一) .滾珠絲杠覺得設(shè)計(jì)計(jì)算
1.計(jì)算滾珠絲杠螺母副的軸向負(fù)載力
最大軸向負(fù)載力:Famax=Fμ+FV=282.65N
最小軸向負(fù)載力:Famin=Fμ0=15.45N
2.滾珠絲杠的動負(fù)荷計(jì)算與直徑估算
確定滾珠絲杠的導(dǎo)程L0 L0=Vmaxinmm
3.計(jì)算滾珠絲杠螺母副的平均轉(zhuǎn)速
絲杠螺母副的平均轉(zhuǎn)速:nm=q1100n1+q2100n2+…qn100nn=560r/min
4.確定滾珠絲杠預(yù)期的額定動載荷
按預(yù)定工作時(shí)間估算:Cm=360nmLhFmfw100ffca=4529.6N
5.數(shù)控銑床滾珠絲杠的計(jì)算
切削方式
軸向載荷/N
進(jìn)給速度/(m/min)
時(shí)間比例/(%)
備注
強(qiáng)力切除
282.65
v1=0.6
10
F1=Famax
粗加工
71.98
v2=0.8
30
F2=Famin+20%Famax
精加工
29.58
v3=1
50
F3=Famin+5%Famax
快移和鉆鏜定位
15.45
v4=8
10
F4=Famin
四.總結(jié)
本次課程設(shè)計(jì)主要是立式數(shù)控銑床總體方案設(shè)計(jì)及立柱部分的設(shè)計(jì)。立柱是承載主軸箱實(shí)現(xiàn)機(jī)床Z向進(jìn)給運(yùn)動的重要部件。在其上擬設(shè)計(jì)Z向的導(dǎo)軌,在兩導(dǎo)軌間擬設(shè)計(jì)安裝Z方向的滾珠絲杠裝置。因此,立柱的設(shè)計(jì)同樣要解決好提高剛性的問題。
總體方案設(shè)計(jì)的思路主要是對立柱上Z向進(jìn)給傳動的重要部件:滾珠絲杠螺母副的類型、絲杠支撐方式、以及軸承、聯(lián)軸器、電機(jī)、導(dǎo)軌的選擇,以及銑床Z向傳動主要精度的提高措施。
1、 選用內(nèi)循環(huán)雙螺母滾珠絲杠螺母副作為Z軸向傳動機(jī)構(gòu)。
2、 為了使設(shè)計(jì)的數(shù)控機(jī)床達(dá)到預(yù)定的精度、剛度的要求,滾珠絲杠采用兩端固定式(F-F)的支撐方式。
3、 為了保證其高速、高精度可靠性,及經(jīng)濟(jì)因素。選用600接觸角推力角接觸球軸承。兩端選用DF型安裝。
4、 選用利用夾緊螺絲固定的單節(jié)夾緊螺絲固定式聯(lián)軸器,使電機(jī)與滾珠絲杠直接,實(shí)現(xiàn)無鍵傳動,無反向間隙,還可以調(diào)節(jié)安裝時(shí)間軸度。
5、 交流伺服電動機(jī)具有響應(yīng)迅速、精度和效率高、負(fù)載能力大、控制性能優(yōu)越等優(yōu)點(diǎn),被廣泛使用在閉環(huán)或半閉環(huán)控制的伺服系統(tǒng)中,故本設(shè)計(jì)選用交流伺服電機(jī)。
6、 在立柱兩側(cè)設(shè)置有支撐主軸箱的導(dǎo)軌,導(dǎo)軌采用直線滾動導(dǎo)軌,導(dǎo)軌滑塊為四個(gè),導(dǎo)軌采用楔塊進(jìn)行固定安裝。
7、 在Z向?qū)к?,設(shè)計(jì)了伸縮式不銹鋼防護(hù)罩,以防Z向?qū)к壓蜐L珠絲杠;
8、 提高立柱的剛度是設(shè)計(jì)立柱部分的關(guān)鍵。立柱采用長方體開式結(jié)構(gòu),在其內(nèi)腔合理布筋,以加強(qiáng)立柱部件的彎曲剛度和扭轉(zhuǎn)剛度。
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外文資料翻譯
The Numerical Control Engine Bed Transforms
Harvey B.M ackey
First numerical control system development summary brief history and tendency
In 1946 the first electronic accounting machine was born in the world, this indicated the humanity created has been possible to strengthen and partially to replace the mental labor the tool. It with the humanity these which in the agriculture, the industry society created only is strengthens the physical labor the tool to compare, got up the quantitive leap, entered the information society for the humanity to lay the foundation.
After 6 years, in 1952, computer technology applied to the engine bed , the first numerical control engine bed were born in US. From this time on, the traditional engine bed has had the archery target change. Since nearly half century, the numerical control system has experienced two stages and six generation of development.
1.1 Numerical control (NC) stage (1952 ~ 1970)
The early computer operating speed is low, was not big to then science computation and the data processing influence, but could not adapt the engine bed real-time control request. The people can not but use numeral logic circuit "to build" to become an engine bed special purpose computer to take the numerical control system, is called the hardware connection numerical control (HARD-WIRED NC), Jian Chengwei numerical control (NC). Along with the primary device development, this stage has had been through repeatedly three generations, namely 1952 first generation of -- electron tube; 1959 second generation of -- transistor; 1965 third generation -- small scale integration electric circuit.
1.2 Computer numerical control (CNC) stage (in 1970 ~ present)
In 1970, the general minicomputer already appeared and the mass production. Thereupon transplants it takes the numerical control system the core part, from this time on entered the computer numerical control (CNC) the stage ("which should have computer in front of the general" two characters to abbreviate). In 1971, American INTEL Corporation in the world first time the computer two most cores part -- logic units and the controller, used the large scale integrated circuit technology integration on together the chip, called it the microprocessor (MICROPROCESSOR), also might be called the central processing element (to be called CPU).
The microprocessor is applied to 1974 in the numerical control system. This is because minicomputer function too strong, controlled an engine bed ability to have wealthily (therefore once uses in controlling the multi- Taiwan engine bed at that time, called it group control), was inferior to used the microprocessor economy to be reasonable. Moreover then small machine reliability was not ideal. The early microprocessor speed and the function although insufficiently are also high, but may solve through the multi-processor structure. Because the microprocessor is the general-purpose calculator core part, therefore still was called the computer numerical control.
In 1990, PC machine (personal computer, domestic custom had called microcomputer) the performance has developed to the very high stage, may satisfiedly take the numerical control system core part the request. The numerical control system henceforth entered based on the PC stage.
In brief, the computer numerical control stage has also experienced three generations. Namely 1970 fourth generation of -- minicomputer; 1974 five dynasties -- microprocessor and 1990 sixth generation -- (overseas was called PC-BASED) based on PC.
Also must point out, although overseas already renamed as the computer numerical control (namely CNC).
Also must point out, although overseas already renamed as the computer numerical control (namely CNC), but our country still the custom called the numerical control (NC). Therefore we daily say "numerical control", the materially already was refers to "computer numerical control".
1.3 the numerical control future will develop tendency
1.3.1 open style continues to, to develop based on the PC sixth generation of direction
The software and hardware resources has which based on PC are rich and so on the characteristic, the more numerical controls serial production factory can step onto this path. Uses PC machine to take at least its front end machine, processes the man-machine contact surface, the programming, the association
Question and so on net correspondence, undertakes the numerical control duty by the original system. PC machine has the friendly man-machine contact surface, will popularize to all numerical controls system. The long-distance communication, the long-distance diagnosis and the service will be more common.
1.3.2 approaches and the high accuracy development
This is adapts the engine bed to be high speed and the high accuracy direction need to develop.
1.3.3 develops to the intellectualized direction
Along with the artificial intelligence in the computer domain unceasing seepage and the development, the numerical control system intellectualized degree unceasingly will enhance.
(1) applies the adaptive control technology
The numerical control system can examine in the process some important information, and the automatic control system related parameter, achieves the improvement system running status the goal.
(2) introduces the expert system instruction processing
The skilled worker and expert's experience, the processing general rule and the special rule store in the system, take the craft parameter database as the strut, the establishment has the artificial intelligence the expert system.
(3) introduces the breakdown to diagnose the expert system
(4) intellectualized numeral servo drive
May through the automatic diagnosis load, but the automatic control parameter, causes the actuation system to obtain the best movement.
Second, engine bed numerical control transformation necessity
2.1 microscopic looks at the transformation the necessity
From on microscopic looked below that, the numerical control engine bed has the prominent superiority compared to the traditional engine bed, moreover these superiority come from the computer might which the numerical control system contains.
2.1.1 may process the traditional engine bed cannot process the curve, the curved surface and so on the complex components.
Because the computer has the excellent operation ability, may the instant accurately calculate each coordinate axis instant to be supposed the movement physiological load of exercise, therefore may turn round the synthesis complex curve or the curved surface.
2.1.2 may realize the processing automation, moreover is the flexible automation, thus the efficiency may enhance 3 ~ 7 times compared to the traditional engine bed.
Because the computer has the memory and the memory property, may the procedure which inputs remember and save, then the order which stipulated according to the procedure automatic carries out, thus realization automation. The numerical control engine bed so long as replaces a procedure, may realize another work piece processing automation, thus causes the single unit and the small batch of production can automate, therefore is called has realized "flexible automation".
2.1.3 processings components precision high, size dispersion degree small, makes the assembly to be easy, no longer needs "to make repairs".
2.1.4 may realize the multi- working procedures centralism, reduces the components in engine bed between frequent transporting.
2.1.5 has auto-alarm, the automatic monitoring, automatic compensation and so on the many kinds of autonomy function, thus may realize long time nobody to safeguard the processing.
2.1.6 advantage which derives by above five.
For example: Reduced worker's labor intensity, saved the labor force (a person to be possible to safeguard the multi- Taiwan engine bed), reduced the work clothes, reduced the new product trial manufacturing cycle and the production cycle, might to the market demand make rapid reaction and so on.
Above these superiority are the predecessor cannot imagine, is an extremely significant breakthrough. In addition, the engine bed numerical control carries out FMC (flexible manufacture unit), FMS (flexible manufacture system) as well as CIMS (computer integration manufacture system) and so on the enterprise becoming an information based society transformation foundation. The numerical control technology already became the manufacturing industry automation the core technology and the foundation technology.
2.2 great watches the transformation the necessity
From on macroscopic looked that, the industry developed country armed forces, the airplane weapon industry, in the end of the 70's, at the beginning of the 80's started the large-scale application numerical control engine bed. Its essence is, uses the information technology to the traditional industry (including the armed forces, airplane weapon industry) carries on the technological transformations. Except that uses outside the numerical control engine bed, FMC, FMS in the manufacture process, but also includes in the product development carries out CAD, CAE, CAM, the hypothesized manufacture as well as carries out MIS in the production management (management information system), CIMS and so on. As well as increases the information technology in its production product, including artificial intelligence and so on content. Because uses the information technology to the country foreign troops, the airplane weapon industry carries on the thorough transformation (to call it becoming an information based society), finally causes them the product in the international military goods and in the goods for civilian use market the competitive power greatly is the enhancement. But we in the information technology transformation tradition industry aspect compared to the developed country to fall behind approximately for 20 years. Like in our country engine bed capacity, numerical control engine bed proportion (numerical control rate) to 1995 only then 1.9%, but Japan has reached 20.8% in 1994, therefore every year has the massive mechanical and electrical products import. This also on from on macroscopic explained the engine bed numerical control transformation necessity.
Thord, the numerical control transformation content and superiorly lacks
3.1 Transformation industry starting
In US, Japan and Germany and so on the developed country, their engine bed transforms took the new economical growth profession, thrives abundantly, is occupying the golden age. As a result of the engine bed as well as the technical unceasing progress, the engine bed transformation is "the eternal" topic. Our country's engine bed transformation industry, also enters from the old profession to by the numerical control technology primarily new profession. In US, Japan, Germany, have the broad market with the numerical control technological transformations engine bed and the production line, has formed the engine bed and the production line numerical control transformation new profession. In US, the engine bed transformation industry is called the engine bed regeneration (Remanufacturing) industry. Is engaged in the regeneration industry famous company to include: The Bertsche engineering firm, the ayton engine bed company, Devlieg-Bullavd (are valuable) serves the group, the US equipment company and so on. The American valuable company has set up the company in China. In Japan, the engine bed transformation industry is called the engine bed to reequip (Retrofitting) industry. Is engaged in the reequipment industry famous company to include: Big indentation project group, hillock three mechanical companies, thousand substitute fields labor machine company, wild engineering firm, shore field engineering firm, mountain this engineering firm and so on.
3.2 Numerical control transformation content
The engine bed and the production line numerical control transformation main content has following several points:
First is extensively recovers the function, to the engine bed, the production line has the breakdown partially to carry on the diagnosis and the restoration;
Second is NC, the addend reveals the installment on the ordinary engine bed, or adds the numerical control system, transforms the NC engine bed, the CNC engine bed;
Third is renovates, for increases the precision, the efficiency and the automaticity, to the machinery, the electricity partially carries on renovates, reassembles the processing to the machine part, extensively recovers the precision; Does not satisfy the production request to it the CNC system to carry on the renewal by newest CNC;
Fourth is the technology renews or the technical innovation, for enhances the performance or the scale, or in order to use the new craft, the new technology, carries on the big scale in the original foundation the technology to renew or the technical innovation, the great scope raises the level and the scale renewal transformation. The new electrical system transforms after, how carries on the debugging as well as the determination reasonable approval standard, also is the technology preparatory work important link. The debugging work involves the machinery, the hydraulic pressure, the electricity, the control, and so on, therefore must carry on by the project person in charge, other personnel coordinate. The debugging step may conform to simplicity to numerous, from infancy to maturity, carries on from outside to in, after also may the partial overall situation, after first the subsystem the
3.3 The numerical control transformation superiorly lacks
3.3.1 reduced investment costs, the date of delivery are short
With purchases the new engine bed to compare, may save 60% ~ 80% expense generally, the transformation expense is low. Large-scale, the special engine bed especially is specially obvious. The common large-scale engine bed transforms, only spends the new engine bed purchase expense 1/3, the date of delivery is short. But some peculiar circumstances, like the high speed main axle, the tray automatic switching unit manufacture and the installment too requires a lot of work, costs a great deal of money, often transforms the cost to enhance 2 ~ 3 times, with purchases the new engine bed to compare, only can economical invest about 50%.
3.3.2 machine capability stable are reliable, the structure is limited
Uses foundation and so on lathe bed, column all is heavy but the firm casting component, but is not that kind of welding component, after the transformation engine bed performance high, the quality is good, may take the new equipment continues to use many years. But receives the original mechanism the limit, not suitably makes the unprecedented transformation.
3.3.3 familiar understood the equipment, is advantageous for the operation service
When purchases the new equipment, did not understand whether the new equipment can satisfy its processing request. The transformation then otherwise, may precisely calculate the engine bed the processing ability; Moreover, because many years use, the operator already understood to the engine bed characteristic, uses and services the aspect to train the time in the operation short, effective is quick. The transformation engine bed as soon as installs, may realize the capacity load revolution.
3.3.4 may fully use the existing condition
May fully use the existing ground, does not need to like buys when the new equipment such to have reto construct the ground.
3.3.5 may use the newest control technology
enhances the production equipment the automated level and the efficiency, improves the equipment quality and the scale, alters to the old engine bed now the horizontal engine bed.
數(shù)控機(jī)床
1 數(shù)控系統(tǒng)發(fā)展簡史及趨勢
1946年誕生了世界上第一臺電子計(jì)算機(jī),這表明人類創(chuàng)造了可增強(qiáng)和部分代替腦力勞動的工具。它與人類在農(nóng)業(yè)、工業(yè)社會中創(chuàng)造的那些只是增強(qiáng)體力勞動的工具相比,起了質(zhì)的飛躍,為人類進(jìn)入信息社會奠定了基礎(chǔ)。
6年后,即在1952年,計(jì)算機(jī)技術(shù)應(yīng)用到了機(jī)床上,在美國誕生了第一臺數(shù)控機(jī)床。從此,傳統(tǒng)機(jī)床產(chǎn)生了質(zhì)的變化。近半個(gè)世紀(jì)以來,數(shù)控系統(tǒng)經(jīng)歷了兩個(gè)階段和六代的發(fā)展。
1.1 數(shù)控(NC)階段(1952~1970年)
早期計(jì)算機(jī)的運(yùn)算速度低,對當(dāng)時(shí)的科學(xué)計(jì)算和數(shù)據(jù)處理影響還不大,但不能適應(yīng)機(jī)床實(shí)時(shí)控制的要求。人們不得不采用數(shù)字邏輯電路"搭"成一臺機(jī)床專用計(jì)算機(jī)作為數(shù)控系統(tǒng),被稱為硬件連接數(shù)控(HARD-WIRED NC),簡稱為數(shù)控(NC)。隨著元器件的發(fā)展,這個(gè)階段歷經(jīng)了三代,即1952年的第一代--電子管;1959年的第二代--晶體管;1965年的第三代--小規(guī)模集成電路。
1.2 計(jì)算機(jī)數(shù)控(CNC)階段(1970年~現(xiàn)在)
到1970年,通用小型計(jì)算機(jī)業(yè)已出現(xiàn)并成批生產(chǎn)。于是將它移植過來作為數(shù)控系統(tǒng)的核心部件,從此進(jìn)入了計(jì)算機(jī)數(shù)控(CNC)階段(把計(jì)算機(jī)前面應(yīng)有的"通用"兩個(gè)字省略了)。到1971年,美國INTEL公司在世界上第一次將計(jì)算機(jī)的兩個(gè)最核心的部件--運(yùn)算器和控制器,采用大規(guī)模集成電路技術(shù)集成在一塊芯片上,稱之為微處理器(MICROPROCESSOR),又可稱為中央處理單元(簡稱CPU)。
到1974年微處理器被應(yīng)用于數(shù)控系統(tǒng)。這是因?yàn)樾⌒陀?jì)算機(jī)功能太強(qiáng),控制一臺機(jī)床能力有富裕(故當(dāng)時(shí)曾用于控制多臺機(jī)床,稱之為群控),不如采用微處理器經(jīng)濟(jì)合理。而且當(dāng)時(shí)的小型機(jī)可靠性也不理想。早期的微處理器速度和功能雖還不夠高,但可以通過多處理器結(jié)構(gòu)來解決。由于微處理器是通用計(jì)算機(jī)的核心部件,故仍稱為計(jì)算機(jī)數(shù)控。
到了1990年,PC機(jī)的性能已發(fā)展到很高的階段,可以滿足作為數(shù)控系統(tǒng)核心部件的要求。數(shù)控系統(tǒng)從此進(jìn)入了基于PC的階段。
總之,計(jì)算機(jī)數(shù)控階段也經(jīng)歷了三代。即1970年的第四代--小型計(jì)算機(jī);1974年的第五代--微處理器和1990年的第六代--基于PC(也就是為PC-BASED)。
1.3 數(shù)控未來發(fā)展的趨勢
1.3.1 繼續(xù)向開放式、基于PC的第六代方向發(fā)展
基于PC所具有的開放性、低成本、高可靠性、軟硬件資源豐富等特點(diǎn),更多的數(shù)控系統(tǒng)生產(chǎn)廠家會走上這條道路。至少采用PC機(jī)作為它的前端機(jī),來處理人機(jī)界面、編程、聯(lián)網(wǎng)通信等問題,由原有的系統(tǒng)承擔(dān)數(shù)控的任務(wù)。PC機(jī)所具有的友好的人機(jī)界面,將普及到所有的數(shù)控系統(tǒng)。遠(yuǎn)程通訊,遠(yuǎn)程診斷和維修將更加普遍。
1.3.2 向高速化和高精度化發(fā)展
這是適應(yīng)機(jī)床向高速和高精度方向發(fā)展的需要。
1.3.3 向智能化方向發(fā)展
隨著人工智能在計(jì)算機(jī)領(lǐng)域的不斷滲透和發(fā)展,數(shù)控系統(tǒng)的智能化程度將不斷提高。
(1)應(yīng)用自適應(yīng)控制技術(shù)
數(shù)控系統(tǒng)能檢測過程中一些重要信息,并自動調(diào)整系統(tǒng)的有關(guān)參數(shù),達(dá)到改進(jìn)系統(tǒng)運(yùn)行狀態(tài)的目的。
?。?)引入專家系統(tǒng)指導(dǎo)加工
將熟練工人和專家的經(jīng)驗(yàn),加工的一般規(guī)律和特殊規(guī)律存入系統(tǒng)中,以工藝參數(shù)數(shù)據(jù)庫為支撐,建立具有人工智能的專家系統(tǒng)。
(3)引入故障診斷專家系統(tǒng)
?。?)智能化數(shù)字伺服驅(qū)動裝置
可以通過自動識別負(fù)載,而自動調(diào)整參數(shù),使驅(qū)動系統(tǒng)獲得最佳的運(yùn)行。
2 機(jī)床數(shù)控化改造的必要性
2.1 微觀看改造的必要性
從微觀上看,數(shù)控機(jī)床比傳統(tǒng)機(jī)床有以下突出的優(yōu)越性,而且這些優(yōu)越性均來自數(shù)控系統(tǒng)所包含的計(jì)算機(jī)的威力。
2.1.1 可以加工出傳統(tǒng)機(jī)床加工不出來的曲線、曲面等復(fù)雜的零件。
由于計(jì)算機(jī)有高超的運(yùn)算能力,可以瞬時(shí)準(zhǔn)確地計(jì)算出每個(gè)坐標(biāo)軸瞬時(shí)應(yīng)該運(yùn)動的運(yùn)動量,因此可以復(fù)合成復(fù)雜的曲線或曲面。
2.1.2 可以實(shí)現(xiàn)加工的自動化,而且是柔性自動化,從而效率可比傳統(tǒng)機(jī)床提高3~7倍。
由于計(jì)算機(jī)有記憶和存儲能力,可以將輸入的程序記住和存儲下來,然后按程序規(guī)定的順序自動去執(zhí)行,從而實(shí)現(xiàn)自動化。數(shù)控機(jī)床只要更換一個(gè)程序,就可實(shí)現(xiàn)另一工件加工的自動化,從而使單件和小批生產(chǎn)得以自動化,故被稱為實(shí)現(xiàn)了"柔性自動化"。
2.1.3 加工零件的精度高,尺寸分散度小,使裝配容易,不再需要"修配"。
2.1.4 可實(shí)現(xiàn)多工序的集中,減少零件 在機(jī)床間的頻繁搬運(yùn)。
2.1.5 擁有自動報(bào)警、自動監(jiān)控、自動補(bǔ)償?shù)榷喾N自律功能,因而可實(shí)現(xiàn)長時(shí)間無人看管加工。
2.1.6 由以上五條派生的好處。
如:降低了工人的勞動強(qiáng)度,節(jié)省了勞動力(一個(gè)人可以看管多臺機(jī)床),減少了工裝,縮短了新產(chǎn)品試制周期和生產(chǎn)周期,可對市場需求作出快速反應(yīng)等等。
以上這些優(yōu)越性是前人想象不到的,是一個(gè)極為重大的突破。此外,機(jī)床數(shù)控化還是推行FMC(柔性制造單元)、FMS(柔性制造系統(tǒng))以及CIMS(計(jì)算機(jī)集成制造系統(tǒng))等企業(yè)信息化改造的基礎(chǔ)。數(shù)控技術(shù)已經(jīng)成為制造業(yè)自動化的核心技術(shù)和基礎(chǔ)技術(shù)。
2.2 宏觀看改造的必要性
從宏觀上看,工業(yè)發(fā)達(dá)國家的軍、民機(jī)械工業(yè),在70年代末、80年代初已開始大規(guī)模應(yīng)用數(shù)控機(jī)床。其本質(zhì)是,采用信息技術(shù)對傳統(tǒng)產(chǎn)業(yè)(包括軍、民機(jī)械工業(yè))進(jìn)行技術(shù)改造。除在制造過程中采用數(shù)控機(jī)床、FMC、FMS外,還包括在產(chǎn)品開發(fā)中推行CAD、CAE、CAM、虛擬制造以及在生產(chǎn)管理中推行MIS(管理信息系統(tǒng))、CIMS等等。以及在其生產(chǎn)的產(chǎn)品中增加信息技術(shù),包括人工智能等的含量。由于采用信息技術(shù)對國外軍、民機(jī)械工業(yè)進(jìn)行深入改造(稱之為信息化),最終使得他們的產(chǎn)品在國際軍品和民品的市場上競爭力大為增強(qiáng)。
3 數(shù)控化改造的內(nèi)容及優(yōu)缺
3.1 數(shù)控改造業(yè)的興起
在美國、日本和德國等國家,機(jī)床改造作為新的經(jīng)濟(jì)增長行業(yè),生意盎然,正處在黃金時(shí)代。由于機(jī)床以及技術(shù)的不斷進(jìn)步,機(jī)床改造是個(gè)"永恒"的課題。在美國、日本、德國,用數(shù)控技術(shù)改造機(jī)床和生產(chǎn)線具有廣闊的市場,已形成了機(jī)床和生產(chǎn)線數(shù)控改造的新的行業(yè)。在美國,機(jī)床改造業(yè)稱為機(jī)床再生(Remanufacturing)業(yè)。從事再生業(yè)的著名公司有:Bertsche工程公司、ayton機(jī)床公司、Devlieg-Bullavd(得寶)服務(wù)集團(tuán)、US設(shè)備公司等。。在日本,機(jī)床改造業(yè)稱為機(jī)床改裝(Retrofitting)業(yè)。從事改裝業(yè)的著名公司有:大隈工程集團(tuán)、崗三機(jī)械公司、千代田工機(jī)公司、野崎工程公司、濱田工程公司、山本工程公司等。
3.2、數(shù)控化改造的內(nèi)容
機(jī)床與生產(chǎn)線的數(shù)控化改造主要內(nèi)容有以下幾點(diǎn):
其一是恢復(fù)原功能,對機(jī)床、生產(chǎn)線存在的故障部分進(jìn)行診斷并恢復(fù);
其二是NC化,在普通機(jī)床上加數(shù)顯裝置,或加數(shù)控系統(tǒng),改造成NC機(jī)床、CNC機(jī)床;
其三是翻新,為提高精度、效率和自動化程度,對機(jī)械、電氣部分進(jìn)行翻新,對機(jī)械部分重新裝配加工,恢復(fù)原精度;對其不滿足生產(chǎn)要求的CNC系統(tǒng)以最新CNC進(jìn)行更新;
其四是技術(shù)更新或技術(shù)創(chuàng)新,為提高性能或檔次,或?yàn)榱耸褂眯鹿に?、新技術(shù),在原有基礎(chǔ)上進(jìn)行較大規(guī)模的技術(shù)更新或技術(shù)創(chuàng)新,較大幅度地提高水平和檔次的更新改造。
3.3、數(shù)控化改造的優(yōu)缺
3.3.1 減少投資額、交貨期短
同購置新機(jī)床相比,一般可以節(jié)省60%~80%的費(fèi)用,改造費(fèi)用低。特別是大型、特殊機(jī)床尤其明顯。一般大型機(jī)床改造,只花新機(jī)床購置費(fèi)用的1/3,交貨期短。但有些特殊情況,如高速主軸、托盤自動交換裝置的制作與安裝過于費(fèi)工、費(fèi)錢,往往改造成本提高2~3倍,與購置新機(jī)床相比,只能節(jié)省投資50%左右。
3.3.2 機(jī)械性能穩(wěn)定可靠,結(jié)構(gòu)受限
所利用的床身、立柱等基礎(chǔ)件都是重而堅(jiān)固的鑄造構(gòu)件,而不是那種焊接構(gòu)件,改造后的機(jī)床性能高、質(zhì)量好,可以作為新設(shè)備繼續(xù)使用多年。但是受到原來機(jī)械結(jié)構(gòu)的限制,不宜做突破性的改造。
3.3.3 熟悉了解設(shè)備、便于操作維修
購買新設(shè)備時(shí),不了解新設(shè)備是否能滿足其加工要求。改造則不然,可以精確地計(jì)算出機(jī)床的加工能力;另外,由于多年使用,操作者對機(jī)床的特性早已了解,在操作使用和維修方面培訓(xùn)時(shí)間短,見效快。改造的機(jī)床一安裝好,就可以實(shí)現(xiàn)全負(fù)荷運(yùn)轉(zhuǎn)。
3.3.4 可充分利用現(xiàn)有的條件
可以充分利用現(xiàn)有地基,不必像購入新設(shè)備時(shí)那樣需重新構(gòu)筑地基。
3.3.5 可以采用最新的控制技術(shù)
可根據(jù)技術(shù)革新的發(fā)展速度,及時(shí)地提高生產(chǎn)設(shè)備的自動化水平和效率,提高設(shè)備質(zhì)量和檔次,將舊機(jī)床改成當(dāng)今水平的機(jī)床。
精度主要決定于步進(jìn)電機(jī)的角位移精度,齒輪絲杠等傳動元件的節(jié)距精度,所以系統(tǒng)的位移精度較低。
該系統(tǒng)結(jié)構(gòu)簡單,調(diào)試維修方便,工作可靠,成本低,易改裝成功。
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