汽車發(fā)動(dòng)機(jī)飛輪殼支架鉆削多軸頭與夾具設(shè)計(jì)（全套CAD圖+翻譯）,汽車發(fā)動(dòng)機(jī),飛輪,支架,鉆削多軸頭,夾具,設(shè)計(jì),全套,cad,翻譯 畢業(yè)設(shè)計(jì)(論文)參考文獻(xiàn)譯文 系 別： 機(jī) 械 工 程 系 專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 可調(diào)式多軸頭加工工具 摘要：在多軸頭匹配類型機(jī)床上，加工單元包括一個(gè)基于處理進(jìn)退運(yùn)動(dòng)的原始的職位和一個(gè)加工的位置,第一個(gè)環(huán)形導(dǎo)軌包括一個(gè)可移動(dòng)的軌道包圍的加工單元,它坐落在原來(lái)的位置，第二個(gè)環(huán)形鋼導(dǎo)軌和處理在一個(gè)地方上的軸向位移的從前導(dǎo)軌,分別為多軸頭進(jìn)行的第一和第二支導(dǎo)軌。第一和第二索引機(jī)制的交換連接頭分別為多軸第一和第二導(dǎo)軌等同為駕車前往角位移,處理和電梯機(jī)制從第一次和第二次側(cè)導(dǎo)軌的垂距在一個(gè)地方移動(dòng)為鐵路提供更換多軸頭之間的第一個(gè)和第二個(gè)導(dǎo)軌,靜止軌道交通發(fā)展的一個(gè)重要組成部分的第一導(dǎo)軌和部分第二導(dǎo)軌的分歧是生活在一個(gè)圓弧鋼軌在一個(gè)地方上相應(yīng)的舉升機(jī)構(gòu),例如,電梯機(jī)制相互連接組成的電梯扶手電梯的第一和第二,升降導(dǎo)軌是指連接到電梯,都還有待提高,并降低了之間的第一個(gè)和第二個(gè)導(dǎo)軌。 關(guān)鍵詞：多軸頭、導(dǎo)軌、電梯機(jī)制、角位移  1.領(lǐng)域的發(fā)明 本發(fā)明涉及一種多抽頭類型機(jī)床上，加工單元包括一個(gè)基地處理進(jìn)退運(yùn)動(dòng)之間的一個(gè)原始的職位和加工的位置,第一個(gè)環(huán)形導(dǎo)軌包括一個(gè)可移動(dòng)的軌道積分與加工單元和一個(gè)固定的軌道包圍了加工單元,它坐落在原來(lái)的位置,第二環(huán)形鋼導(dǎo)軌和處理在一個(gè)地方上的軸向位移的從前導(dǎo)軌,復(fù)數(shù)個(gè)多軸的連接頭每頭進(jìn)行了第一和第二支導(dǎo)軌,第一和第二索引機(jī)制的替代連接頭分別多軸的與第一和第二導(dǎo)軌多軸頭連接為駕車前往角位移等處理,電梯機(jī)制從第一次和第二次側(cè)導(dǎo)軌在一個(gè)地方移動(dòng)鋼軌的垂距提供更換多軸頭之間的第一和第二支導(dǎo)軌。 2.原有的類型描述 這樣的多軸頭代替型機(jī)工具，是由通常為人所知的No.13923/86日本出版。與上述常規(guī)機(jī)床不同,搭車機(jī)制和轉(zhuǎn)移機(jī)制的要求，是多軸頭之間傳遞的第一和第二道軌和電梯機(jī)制,導(dǎo)致了一個(gè)復(fù)雜的施工。此外,一個(gè)空間必須被遺棄在第二個(gè)導(dǎo)軌更換多軸相應(yīng)減少,導(dǎo)致儲(chǔ)存一定數(shù)量的多軸頭。 3.總結(jié)已經(jīng)發(fā)明的 本發(fā)明已經(jīng)完成這樣的情況下,它是針對(duì)本發(fā)明的對(duì)象類型提供一個(gè)多軸頭機(jī)床,所述頭替換轉(zhuǎn)移的機(jī)制多軸頭之間的第一個(gè)和第二個(gè)道軌和電梯結(jié)構(gòu)簡(jiǎn)化,同時(shí)也增加了一定數(shù)量的多軸頭儲(chǔ)存。根據(jù)本發(fā)明的一個(gè)組成部分,靜止軌道的第一導(dǎo)軌和部分第二軌道的分歧是搭車軌道在在一個(gè)地方一個(gè)圓弧相應(yīng)的舉升機(jī)構(gòu),分別為舉升機(jī)構(gòu)組成一個(gè)電梯設(shè)備相互連接的電梯扶手第一和第二,電梯驅(qū)動(dòng)導(dǎo)軌是指連接到電梯,都還有待提高,并降低了之間的第一個(gè)和第二個(gè)導(dǎo)軌。采用上述的建設(shè),多軸頭可以移動(dòng)之間的第一個(gè)和第二個(gè)道軌和另外,當(dāng)電梯軌道的第一導(dǎo)軌移到第二導(dǎo)軌,一個(gè)多軸頭儲(chǔ)存在第二個(gè)導(dǎo)軌是撤退出來(lái)。因此,同樣數(shù)量的多軸主管能夠儲(chǔ)存在第一和第二支導(dǎo)軌。這就使得它能夠增加適當(dāng)?shù)亩噍S頭儲(chǔ)存為比上年更佳和簡(jiǎn)化的安排替換運(yùn)動(dòng)。這是本發(fā)明的另一個(gè)對(duì)象類型提供一個(gè)多軸頭替換機(jī)床所取代多軸取決于頭是順利的變化對(duì)該類型的作品,并提高了加工效率。這是本發(fā)明的進(jìn)一步的對(duì)象類型提供一個(gè)多軸頭替換機(jī)床其中所述的上升和降低多軸頭運(yùn)動(dòng)的穩(wěn)定性。 上述和其他物體、主要特點(diǎn)和優(yōu)點(diǎn),從閱讀以下的描述了優(yōu)先化身會(huì)同繪圖形，這項(xiàng)發(fā)明將變得明顯。 圖紙同類體現(xiàn)本發(fā)明將簡(jiǎn)要描述如下 圖一：是一個(gè)可調(diào)式多軸頭加工工具的全圖；圖二：是一個(gè)切面機(jī)床的角度,顯示在1被簡(jiǎn)化部分；圖三：是截取的圖一中III的半切面圖片；圖四：是對(duì)圖三一比一放大的截面圖；圖五：是截取的圖三中箭頭V所示的圖片；圖六：是對(duì)圖四一比一放大的截面圖；圖七：是截取的圖三中箭頭VII所示的圖片；圖八：是截取的圖七中箭頭VIII所示的圖片；圖九：是截取的圖三中箭頭IX所示的圖片；圖十：對(duì)圖三側(cè)面的截圖圖片；圖十一：對(duì)圖三中XI的一比一放大的圖片；圖十二：是圖三中的XII的一比一放大的圖片；圖十三：可調(diào)多軸頭加工工具的外部圖片；圖十四：不同種類的可調(diào)多軸頭圖片。 圖2 切面機(jī)床的角度,顯示在1被簡(jiǎn)化部分 圖1 可調(diào)式多軸頭加工工具的全圖 圖3 截取的圖一中III的半切面圖片 圖4 對(duì)圖三一比一放大的截面圖 圖3 截取的圖一中III的半切面圖片 。 。 圖5 截取的圖三中箭頭V所示的圖片 圖6 對(duì)圖四一比一放大的截面圖 圖8 截取的圖七中箭頭VIII所示的圖片 圖7 截取的圖三中箭頭VII所示的圖片 圖9 截取的圖三中箭頭IX所示的圖片 圖10 圖三側(cè)面的截圖圖片 圖12 圖三中的XII的一比一放大的圖片 圖11 圖三中XI的一比一放大的圖片 圖13 可調(diào)多軸頭加工工具的外部圖片 圖14 不同種類的可調(diào)多軸頭圖片 多軸頭運(yùn)作圖形的分析 電梯機(jī)制在降低60圖14所示（五）向下移動(dòng)的多主軸頭，相應(yīng)的第二導(dǎo)軌6，也向下移動(dòng)的多主軸頭C1到其立場(chǎng)相應(yīng)的第一個(gè)導(dǎo)軌5。在這種情況下，一間多主軸頭D3和指數(shù)臂第二個(gè)索引機(jī)制的關(guān)系是26 31順序控制存儲(chǔ)在99個(gè)同樣，雖然多主軸頭C1的相應(yīng)機(jī)制的第二個(gè)索引的數(shù)據(jù)26 99的順序控制存儲(chǔ)在索引手臂協(xié)會(huì)與索引機(jī)制的第一個(gè)25 28。 在一個(gè)由多主軸B2的加工，多軸頭C2是從第二個(gè)引導(dǎo)降低到第一軌導(dǎo)軌5 6，以及由多主軸頭B3的加工，多軸頭C3是下調(diào)第二導(dǎo)軌6入第一個(gè)導(dǎo)軌5。此外白衣更換多軸箱C2和C3，多主軸頭A2和A3為指導(dǎo)，從第一軌移動(dòng)到第二個(gè)5導(dǎo)軌6。 當(dāng)一個(gè)工作復(fù)本的是經(jīng)過(guò)加工的工作工務(wù)局運(yùn)輸，多軸箱的C1，C2和C3可以依次帶入到加工位置MP的效果由個(gè)人多軸箱的C1，C2和順序補(bǔ)體C3。 在由多軸箱的C1，C2和C3等加工，多軸頭D1和D2和D3是從第二個(gè)引導(dǎo)降低到第一軌指南6軌5提供一個(gè)工作將隨后運(yùn)送。 例如，在由多主軸頭C2的加工，多軸D2是降低到5首導(dǎo)軌，如圖14所示。在這種情況下，多主軸D3是上面的第二個(gè)指導(dǎo)多軸頭位于D2的軌道6。于是，當(dāng)25索引機(jī)制，使經(jīng)營(yíng)加工完成后，由多主軸頭C2的進(jìn)入加工位置MP多主軸頭體C3，第二個(gè)索引機(jī)制也運(yùn)作方式，26到60方位取代，如圖所示在圖14。 如果多主軸頭C3是要以先進(jìn)的加工位置國(guó)會(huì)議員到機(jī)器的工作廁所，然后電梯機(jī)制60解除運(yùn)動(dòng)，以提高多主軸頭B3到第二軌操作指南6，而在同一撤退時(shí)從第二引導(dǎo)多軸頭向上軌6格A1，如圖14所示。 此后，第二個(gè)索引機(jī)制運(yùn)作方式，轉(zhuǎn)26在圖14所示的為60在一個(gè)方向相反的描述，參考圖14所示，從而將多主軸頭D3上電梯導(dǎo)軌10。 10在這種條件下，降低電梯的機(jī)制使60多主軸頭D3的第一要到5導(dǎo)軌在圖14所示，降低。 在這種方式的多軸箱A1到每一個(gè)地方，B1到B3中，C1到C3和D1至D3可以加工成所需的地位，影響到加工到國(guó)會(huì)議員提出。此外，由于多主軸頭可放置，為后續(xù)加工。此外，由于多主軸頭可放置，為后續(xù)加工，加工效率可提高。此外，由于多軸箱相同數(shù)量可以在第一和第二指導(dǎo)存儲(chǔ)軌5,6，對(duì)多主軸頭數(shù)，可以存儲(chǔ)比以前更多的藝術(shù)。自導(dǎo)柱61 10成員是通過(guò)連接在電梯66和60 69大幅機(jī)制與基一整體的，也有可能支持一個(gè)穩(wěn)定的方式垂直導(dǎo)柱61。此外，在電梯上升和下降60機(jī)制，支持13個(gè)鐵路連接兩個(gè)18歲以下的電梯導(dǎo)軌為指導(dǎo)的梳84和85，和連鎖塊的多軸箱A1至A3，B1的36到B3，C1到C3和D1to維生素D3是在頭部引導(dǎo)會(huì)員86 87.的指導(dǎo)下，多軸箱A1至A3，B1至B3，C1到C3和D3的D1to被提出，并在穩(wěn)定地降低。在上下電梯62對(duì)是相互關(guān)聯(lián)的成員74通過(guò)連接，并連接到上電梯62鏈77一雙繞在鏈輪上可旋轉(zhuǎn)的導(dǎo)柱的上端支持61輪76個(gè)，權(quán)重的平衡鏈被連接到77。因此，電梯運(yùn)行了62個(gè)可以在一個(gè)上升和降低其水平與穩(wěn)定的方式維護(hù)和另外的態(tài)度，可以通過(guò)單動(dòng)式驅(qū)動(dòng)器驅(qū)動(dòng)的動(dòng)作方式63， 在第一和第二個(gè)索引機(jī)制，25日和26日，大幅U形從事成員在38個(gè)被出售的武器28and指數(shù)每31領(lǐng)先結(jié)束，具有彈性偏置項(xiàng)目的形式領(lǐng)先結(jié)束，加上44和指導(dǎo)突起在45所提供的中央上部和下部的38個(gè)成員參與的部分，以及領(lǐng)先結(jié)束鎖定36座，形成符合響應(yīng)的導(dǎo)突起44和45，因此，輪廓的上升和下降運(yùn)動(dòng)對(duì)多軸箱A1至A3，B1至B3，C1到C3和D1至D3，訂婚和鎖塊之間的36和28,31脫離接觸指數(shù)手臂很容易實(shí)現(xiàn)，而且每時(shí)，國(guó)家可以從事堅(jiān)決維護(hù)。 可調(diào)多軸頭型機(jī)床的的原理和作用 1.可調(diào)多軸頭型機(jī)床上加工單元組成的一對(duì)進(jìn)退之間的原始位置和加工位置，第一個(gè)環(huán)形導(dǎo)軌包括一個(gè)可移動(dòng)的軌道積分的動(dòng)作說(shuō)加工基地出售單位和一個(gè)靜止軌道圍繞加工單元說(shuō)這是在說(shuō)，原來(lái)的位置，第二個(gè)同心環(huán)形導(dǎo)軌與軸向偏移，在處理從一個(gè)地方說(shuō)，第一導(dǎo)軌，一個(gè)多主軸頭多元化的每個(gè)進(jìn)行說(shuō)第一和第二導(dǎo)軌，第一和第二個(gè)索引機(jī)制釋放地分別連接到多軸箱??上說(shuō)，第一和第二駕駛導(dǎo)軌說(shuō)多軸箱的角位移，和電梯處置機(jī)制，從側(cè)面說(shuō)，第一和第二指導(dǎo)偏移量表示，從一個(gè)地方移動(dòng)軌鐵路提供的多軸箱更換第一和第二之間說(shuō)導(dǎo)軌，其中一個(gè)說(shuō)：靜止軌道的一部分被劃分為一圓弧如電梯導(dǎo)軌在一個(gè)地方，相應(yīng)地說(shuō)道電梯機(jī)制，分別表示電梯機(jī)制包括連接到電梯的每一個(gè)電梯導(dǎo)軌的說(shuō)，第一和第二導(dǎo)軌，解除驅(qū)動(dòng)方式連接到電梯將被提高，降低了第一和第二之間說(shuō)導(dǎo)軌。 2.可調(diào)多軸頭型機(jī)床的作用，還包括為提供一個(gè)信號(hào)后，多主軸頭類型的不同信號(hào)發(fā)生器連接到的多軸箱，每年至少一個(gè)探測(cè)器在固定的位置相應(yīng)的接收信號(hào)表示信號(hào)發(fā)生器的第一和第二導(dǎo)軌每處理，表示探測(cè)器被連接，用于控制所述第一和第二次指數(shù)序列的機(jī)制操作控制，說(shuō)電梯機(jī)制??來(lái)存儲(chǔ)各個(gè)位置的多軸箱上說(shuō)，第一和第二導(dǎo)軌在說(shuō)順序控制，以及用于檢測(cè)的工作是要工作的新加工型探測(cè)器，探測(cè)器的工作表示被連接到一個(gè)控制面板，提供了一個(gè)預(yù)備動(dòng)作到順序控制信號(hào)，為新的移動(dòng)工作多主軸頭一首導(dǎo)軌既定立場(chǎng)。 3. 可調(diào)多軸頭型機(jī)床的作用，第一次和第二次是在導(dǎo)軌垂直間隔一定距離排列的互相之間的距離，除了表示對(duì)首先是導(dǎo)軌之間的配對(duì)相同，先說(shuō)是導(dǎo)軌之間的第二導(dǎo)軌副，每上下電梯導(dǎo)軌副，同樣是集成，通過(guò)相互支持的鐵路。 4. 可調(diào)多軸頭型機(jī)床根據(jù)權(quán)利要求為指導(dǎo)不斷上升和下降的升降機(jī)1或2，其中指導(dǎo)會(huì)員是固定地傾向于垂直擴(kuò)展。 5.一個(gè)可調(diào)多軸頭型機(jī)床的作用，鎖定對(duì)多軸頭安裝在每一個(gè)項(xiàng)目對(duì)各自的第一和第二導(dǎo)軌內(nèi)，頭部指導(dǎo)會(huì)員棄置在一個(gè)地方是對(duì)應(yīng)于每個(gè)電梯導(dǎo)軌的說(shuō)，是適應(yīng)擴(kuò)大垂直從事于上升和下降的升降機(jī)上升和指導(dǎo)等，后者降低時(shí)間鎖定塊。 1. Field of the Invention The present invention relates to a multi-spindle head-replacing type machine tool comprising a machining unit disposed on a base for advancing and retreating movements between an original position and a machining position, a first annular guide rail including a movable rail integral with the machining unit and a stationary rail to surround the machining unit which is located in the original position, a second annular guide rail disposed concentrically with and at a place axially offset from the first guide rail, a plurality of multi-spindle heads travellably carried on each of the first and second guide rails, first and second index mechanism releasably connected respectively to the multi-spindle heads on the first and second guide rails for driving such multi-spindle heads for angular displacement, and an elevator mechanism disposed sideways from the first and second guide rails at a place offset from the movable rails for providing replacement of the multi-spindle heads between the first and second guide rails. 2 .Description of the Prior Art Such multi-spindle head-replacing type machine tool is conventionally known from Japanese Parent Publication No.13923/86. With the above conventional machine tool, however, a lift mechanism and a shift mechanism are required for transferring of a multi-spindle head between the first and second guide rails and the elevator mechanism, resulting in a complicated construction. In addition, a space must be left in the second guide rail for replacement of the multi-spindle, resulting in a correspondingly decreased amount of the multi-spindle heads stored. SUMMARY OF THE INVENTION The present invention has been accomplished with the such circumstances in view, and it is an object of the present invention to provide a multi-spindle head-replacing type machine tool, wherein a mechanism for transferring of a multi-spindle head between the first and the second guide rails and the elevator mechanism is simplified, while increasing the amount of the multi-spindle head stored. According to the present invention, a part of the stationary rail of the first guide rail and a part of the second rail are divided as a lift rail in a circular arc at a place corresponding to the elevator mechanism, respectively, and the elevator mechanism comprises an elevator connected to each of the lift rails of the first and second guide rails, and lift-drive means connected to the elevator which is to be raised and lowered between the first and second guide rails. With the above construction, the multi-spindle head can be moved between the first and second guide rails and moreover, when the lift rail of the first guide rail is moved to the second guide rail, one multi-spindle head stored on the second guide rail is retreated outwardly. Therefore, the same number of multi-spindle heads can de stored on the first and second guide rails. This makes it possible to increase the amount of multi-spindle heads stored as compared with the prior art and to simplify the arrangement for replacing movement. It is another object of the present invention to provide a multi-spindle head-replacing type machine tool wherein the multi-spindle heads are smoothly replaced depending upon a variation in the type of works, and a machining efficiency is improved. It is further object of the present invention to provide a multi-spindle head-replacing type machine tool wherein the rising and lowering motions of the multi-spindle head are stabilized. The above and the other objects, features and advantages of the invention will become apparent from reading of the following description of the preferred embodiments taken in conjunction with the accompanying drawings. Extend vertically between the second guide rails 6 and are fixed to support plates 19. this stabilizes the rising and lowering motions of the elevators 62.between the index arms 28 and 31 which are in their position corresponding to the lift rails 10 and 18,a head guide member 86 is fixed to the support plate 19 to extend vertically and adapted to be fitted to the leading end of the locking block 36 for guiding of rising and lowering movements of each of the multi-spindle heads A1 to A3,B1 to B3,C1 to C3 and D1to D3 and further, a head guide member 87 is fixed to the connecting member 69 to extend vertically above the index arm 31.The head guide members 86 and 87 stabilize the rising and lowering motions of the locking block 36 and thus each of the multi-spindle heads A1 to A3,B1 to B3,C1 to C3 and D1 to D3 Referring back to fig.4,detectors 88 and 89 are mounted on the support plates 14 integrals with the sationary rails 8 and 9 in the first upper guide rail 5 for detecting the type of the multi-spindle heads A1 to A3,B1to B3,C1 to C3 and D1 to D3 locate in positions corresponding to the movable rail 7 and the lift rail 10,and a singal generator 91 is mounted on each of the multi-spindle heads A1 to A3,B1 to B3,C1 to C3 and D1 to D3 for generating a singal depending upon the type when it is located in opposition to the detectors 88 and 89. Referring to fig.5, a detector 90 is mounted on the support plate 19 integral with the sationary rail 17 of the second upper guide rail 6 for receiving a signal in opposition to the signal generator 91 of one of the multi-spindle heads A1 to A3,B1to B3,C1 to C3 and D1 to D3 locate in positions corresponding to the movable rail 18. Referring to fig.13,multi-spindle head-replacing type machine tools M are constructed in the above manner ,Each pair of the machine tools M is disposed at a plurality of ,e.g, five maching stations s1,s2,s3,s4 and s5 so as to machine from the opposite sides a plurality of ,e.g, four types of works WA,WB，WC and WD intermittently transported .More specifically ,a conveyor 95 is disposed in an endless manner to pass the machining stations s1 to s5 successtively at opposite sides of the conveyor 95 at a place corresponding to each of the machining stations s1 to s5 A plurality of pallets 96 are placed on the conveyor 95 ,so that one of the plural types of works WA,WB，WC and WD which is placed onto the pallet 96 in a loading station Si which is set at a stationary location before entering each of the machining stations s1 to s5.also ,an unloading station so is set at a stationary location after passing each of the machining stations s1 to s5,so that each of the works WA,WB，WC and WD which has been machined at each of the machining atations s1 to s5 is unloaded from the pallet 96 at the unloading station so ,moreover ,the unloading pallet 96 circulates to the loading station si , A work detector 97 is disposed at the loading station si for detecting which work WA,WB，WC and WD is supplied to the loading station si ,so that a signal resulting from the detection in the work detector 97 is delived into a total control pannel 98. on the other hand ,a sequence control 99 and a CNC system are added to each of the machine tools M,so that a signal indicative of the type of the work which has been supplied to the loading station si is transmitted from the total control planel 98 to each of the sequence controls 99 In each of the machine tools M, it has been detected which multi-spindle head A1 to A3,B1 to B3,C1 to C3 and D1 to D3 is engaged with either of the index arms 28 or 31 ,through reading-out of a signal from the generator 91 by the detector 89,90, and date therefor have been stored in the sequence control 99.signals indicative of command to read-out the multi-spindle head and of machining command are delivered from the CNC system 100 into the sequence control 99 ,whereby comparison of these signals with the data stored in the sequence control 99 causes a desired multi-spindle head to move toward the machining position MP ,in this case ,when a desired multi-spindle head is located on the first guide rails 5 ,the operation of only the first index mechanism 25 causes such head to move toward the machining position MP ,but when a desired multi-spindle head is located on the second guide rails 6, the operation of the elevator mechanism 60 and the second index mechanism 26 cause such desired multi-spindle head to be brought down onto the first guide rails 5 and then , the first index mehanism 25 causes such head to move toward the machining position MP. Signals indicative of the type work and indicative of the numbers of the stations and steps from the loading station Si to a selected station are delivered as reference commands from the total control panel 98 into the sequence control 99 ,whereby multi-spindle heads to be prepared are searched by comparison of the reference command signals with the data stored in the sequence control 99 and are caused to sequentially move toward the first guide rails 5 by command from the sequence control 99 . The operation of this embodiment will be described below in conjunction with FIGS ,14(a)to14(j).suppose that the multi-spindle head A1 to A3 and B1 to B3 have been placed successively on the first guide rails 5 ,while the multi-spindle heads C1 to C3 and D1 to D3 have been placed successively on the second guide rails 6,as shown in FIGS ,14(a),for example ,when works WA,WB,WC and WD are intended to be delivered in this order and subjected successively to three steps of srilling ,tapping and reaming in a certain machine tool M In this case ,the multi-spindle head A1 is brought into the machining position MP to effect drilling of a work WA and then ,the multi-spindle heads A2 and A3 are sequentially brought into the machining position MP to effect tapping and reaming of the work WA in sequence Thereafter with the transporting of a work WB ,the multi-spindle head B1 is brought into the machining position MP as shown in FIG.14(b) to effect drilling of the work WB ,Because the multi-spindle heads C1,C2and C3 for a work which will be subsequently transported are located on the second guide rails 6 at this time the multi-spindle head C1 is moved from the second guide rails 6 to the first guide rails 5 during machining by the multi-spindle head B1. That is ,the multi-spindle heads A1 and D3 which are in their positions corresponding to the lift rails 10 and 18 are raised to the upper limit positions by the elevator mechanism 60 ,as shown in FIG.14(c).this causes the the multi-spindle heads A1 to move up to a position corresponding to the second rails 6 and also causes the multi-spindle heads D3 to retreat upwardly from the second guide rails 6 ,in this case ,the data for the retreated multi-spindle head D3 is erased from the sequence control 99 ,and data for the multi-spindle head A1 from the Signal generator 91 is read out in the detector 90,whereby a relationship between the index arm 31 in the second index mechanism 26 and the multi-spindle head A1 is newly stored in the sequence control 99. Then,the multi-spindle heads C1 to C3,D1,D2 and A1 are driven by the second index mechanism 26 to be angularly displaced through 60 in a clockwise direction along the second guide rails 6,as shown in FIG.14(d). Consequently, the multi-spindle head C1 is brought into a position corresponding to the lift rails 18. Thereupon, the elevator mechanism 60 is lowered as shown in FIG.14(e) to move down the multi-spindle head D3 to its position corresponding to the second guide rails 6 and also to move down the multi-spindle head C1 to its position corresponding to the first guide rails 5. In this case , a relationship between the multi-spindle head D3 and the index arm 31 of the second index mechanism 26 is stored again in the sequence control 99,while the data for multi-spindle head C1 corresponding to the second index mechanism 26 in the sequence control 99 is stored in association with the index arm 28 of the first index mechanism 25. Such motion is done in the same manner even at machining by the multi-spindle heads B2 and B3. At machining by the multi-spindle B2, the multi-spindle head C2 is lowered from the second guide rails 6 onto the first guide rails 5, and at machining by the multi-spindle head B3 , the multi-spindle head C3 is lowered from the second guide rails 6 onto the first guide rails 5. Moreover for replacement whit the multi-spindle heads C2 and C3,the multi-spindle head A2 and A3 are moved from the first guide rails 5 to the second guide rails 6. Thus , when a work WC has been transported after machining of the work WB , the multi-spindle heads C1 , C2 and C3 can be sequentially brought into the machining position MP to effect sequential machinings by the individual multi-spindle heads C1 , C2 and C3. During such machining by the multi-spindle heads C1, C2 and C3, the multi-spindle heads D1,D2andD3 are lowered from the second guide rails 6 onto the first guide rails 5 to provide for a work WD which will be subsequently transported. For example ,during machining by the multi-spindle head C2, the multi-spindle D2 is lowered onto the first guide rails 5,as shown in FIG.14(f). In this case , the multi-spindle D3 is located above the multi-spindle head D2 on the second guide rails 6. Thereupon, when the index mechanism 25 is operated to bring the multi-spindle head C3 into the machining position MP after completion of machining by the multi-spindle head C2, the second index mechanism 26 is also operated to angularly displace through 60, as shown in FIG.14(g). If the multi-spindle head C3 is to be advanced to the machining position MP to machine the work WC, then the elevator mechanism 60 is operated for lifting movement to raise the multi-spindle head B3 to the second guide rails 6, while at same time retreating the multi-spindle head A1 upwardly from the second guide rails 6,as shown in FIG.14(h). Thereafter, the second index mechanism 26 is operated to turn by 60 as shown in FIG.14(i) in a direction opposite to that described with reference to and shown in FIG.14(g), thereby placing the multi-spindle head D3 onto the lift rails 10. 10 In such condition, the lowering of the elevator mechanism 60 enables the multi-spindle head D3 to be lowered onto the first guide rails 5, as shown in FIG.14(j). In this manner, each of the multi-spindle heads A1 to A#, B1to B3,C1 to C3 and D1 to D3 can be brought into the machining position MP as desired to effect into the machining . Moreover, since the multi-spindle heads can be preparatorily placed to provide for the subsequent machining. Moreover ,since the multi-spindle heads can be preparatorily placed to provide for the subsequent machining , the machining efficiency can be improved. Additionally, since the same number of multi-spindle heads can be stored on the first and second guide rails 5,6,the number of the multi-spindle heads which can be stores is more than that in the prior art. Since the guide pillars 61 are substantially integral with the base 1 through the connecting members 66 and 69 in the elevator mechanism 60, it is possible to support the guide pillars 61 vertically in a stabilized manner . In addition, during rising and lowering of the elevator mechanism 60,the rail support 13 which connects both the lift rails 18 are guided on the guide bars 84 and 85,and the locking blocks 36 of the multi-spindle heads A1 to A3,B1 to B3, C1 to C3 and D1to D