注塑-玩具汽車上蓋模具設(shè)計(jì)及型腔加工仿真-說明書

1、摘要：普通車床作為最早的金屬切削機(jī)車的一種，目前仍然有許多有用的和為人們所需要的特性?，F(xiàn)在，這些機(jī)床主要用在規(guī)模較小的工廠中，進(jìn)行小批量的生產(chǎn)，而不是進(jìn)行大規(guī)模的生產(chǎn)。普通車床的加工偏差主要依賴與操作者的技術(shù)熟練程度。設(shè)計(jì)工程師應(yīng)該認(rèn)真地確定由熟練工人在普通車床上加工的試驗(yàn)零件的公差。在把試驗(yàn)零件重新設(shè)計(jì)為生產(chǎn)零件時(shí)，應(yīng)該選用經(jīng)濟(jì)的公差。關(guān)鍵詞:機(jī)械；車床目錄摘要：1前言2總體方案論證3具體設(shè)計(jì)說明3.1塑件三維造型3.1.1塑件的測(cè)繪3.1.2塑件三維造型3.2模具設(shè)計(jì)計(jì)算3.2.1塑件材料性能分析3.2.2型腔數(shù)的確定3.2.3 型腔壁厚計(jì)算3.3 澆注系統(tǒng)設(shè)計(jì)3.3.1 澆口位置選擇3.

2、3.2 澆注系統(tǒng)的平衡3.3.3 澆注系統(tǒng)設(shè)計(jì)計(jì)算3.4分型面的設(shè)計(jì)3.5冷卻系統(tǒng)設(shè)計(jì)3.5.1設(shè)計(jì)計(jì)算3.5.2冷卻流道結(jié)構(gòu)設(shè)計(jì)3.6頂出系統(tǒng)設(shè)計(jì)3.7模架設(shè)計(jì)3.8模流分析3.9 型腔加工仿真3.9.1加工零件工藝審查3.9.2 毛坯的選擇3.9.3 基準(zhǔn)選擇3.9.4 Master CAM 9.0仿真加工4 結(jié)論參 考 資 料致 謝用于車外圓，端面和鏜孔等加工的機(jī)床稱作車床。車削很少在其他種類的機(jī)床上進(jìn)行，因?yàn)槠渌麢C(jī)床都不能像車床那樣方便地進(jìn)行車削加工。由于車床除了用于車外圓還能用于鏜孔，車端面，鉆孔和鉸孔，車床的多功能性可以使工件在一次定位安裝中完成多種加工。這就是在生產(chǎn)中普遍使用各種

3、車床比其他種類車床都要多的原因。兩千多年前就已經(jīng)有了機(jī)床?，F(xiàn)代車床可以追溯到大約1797年，那時(shí)亨利莫德斯利發(fā)明了一種具有絲杠的車床。這種車床可以控制工具的機(jī)械進(jìn)給。這位聰明的英國(guó)人還發(fā)明了一種把主軸和絲杠相連接的變速裝置，這樣就可以切削螺紋。車床的主要部件：床身，主軸箱組件，尾架組件，拖板組件，變速齒輪箱，絲杠和光杠。床身是車床的基礎(chǔ)件。它通常是由經(jīng)過充分正火或時(shí)效處理的灰鑄鐵或者球墨鑄鐵制成，它是一個(gè)堅(jiān)固的剛性框架，所有其他主要部件都安裝在床身上。通常在床身上面有內(nèi)外兩組平行導(dǎo)軌。一些制造廠生產(chǎn)的四個(gè)導(dǎo)軌都采用倒“V”型，而另一些制造廠則將倒“V”型導(dǎo)軌和平面導(dǎo)軌相結(jié)合。由于其他的部件要安

4、裝在導(dǎo)軌上并在導(dǎo)軌上移動(dòng)，導(dǎo)軌要經(jīng)過精密加工，以保證其裝配精度。同樣地，在操作中應(yīng)該小心以避免損傷導(dǎo)軌。導(dǎo)軌上的任何誤差，常常會(huì)使整個(gè)機(jī)床的精度遭到破壞。大多數(shù)現(xiàn)代機(jī)床的導(dǎo)軌都要進(jìn)行表面淬火處理，以減少磨損和擦傷，更大的耐磨性。主軸箱安裝在床身一端內(nèi)導(dǎo)軌的固定位置上。它提供動(dòng)力，使工件在各種速度下旋轉(zhuǎn)。它基本上由一個(gè)安裝在精密軸承中的空心主軸和一系列變速齒輪-類似于卡車變速箱所組成，通過變速齒輪，主軸可以在許多種轉(zhuǎn)速下旋轉(zhuǎn)。大多數(shù)車床有818種轉(zhuǎn)速，一般按等級(jí)數(shù)排列。在現(xiàn)代車床上只需扳動(dòng)24個(gè)手柄，就能得到全部擋位的轉(zhuǎn)速。目前發(fā)展的趨勢(shì)是通過電氣的或者機(jī)械的裝置進(jìn)行無級(jí)變速。由于車床的精度在很

5、大程度上取決于主軸，因此主軸的結(jié)構(gòu)尺寸較大，通常安裝在緊密配合的重型圓錐滾子軸承或球軸承中。主軸中有一個(gè)貫穿全長(zhǎng)的通孔，長(zhǎng)棒料可以通過該孔送料。主軸孔的大小是車床的一個(gè)重要尺寸，因?yàn)楫?dāng)工件必須通過主軸孔供料時(shí)，它確定了能夠加工棒料毛坯的最大外徑尺寸。主軸的內(nèi)端從主軸箱中凸出，其上可以安裝多種卡盤、花盤和擋塊。而小型的車床常帶有螺紋截面供安裝卡盤之用。很多大車床使用偏心夾或鍵動(dòng)圓錐軸頭。這些附件組成了一個(gè)大直徑的的圓錐體，以保證對(duì)卡盤進(jìn)行精確的裝配，并且不用旋轉(zhuǎn)這些笨重的附件就可以鎖定或者松開卡盤或者花盤。主軸由電動(dòng)機(jī)經(jīng)V帶或者無聲鏈裝置提供動(dòng)力。大多數(shù)現(xiàn)代車床都裝有515馬力的電動(dòng)機(jī)，為硬質(zhì)合

6、金和金屬陶瓷合金刀具提供足夠的動(dòng)力，進(jìn)行高速切削。尾座組件主要由三部分組成。底座和床身的內(nèi)側(cè)導(dǎo)軌配合，并可以在導(dǎo)軌上做縱向移動(dòng)，底座上有一個(gè)可以使整個(gè)尾架組件夾緊在任意位置上的裝置。尾座安裝在底座上，可以沿鍵槽在底座上橫向移動(dòng)，使尾架和主軸箱中的主軸對(duì)中并為切削圓錐體提供方便。尾座組件的第三部分是尾架套筒，它是一個(gè)直徑通常在23英寸之間的鋼制空心圓柱軸。通過手輪和螺桿，尾座套筒可以在尾座體中縱向移入和移出幾英寸?；顒?dòng)套筒的開口一端具有莫氏錐度，可以用于安裝頂尖或諸如鉆頭之類的各種刀具。通常在活動(dòng)套筒的外表面刻有幾英寸長(zhǎng)的刻度，以控制尾座的前后移動(dòng)。鎖定裝置可以使套筒在所需要的位置夾緊。拖板組件

7、用于安裝和移動(dòng)切削工具。拖板是一個(gè)相對(duì)平滑的H形鑄件，安裝在床身外側(cè)導(dǎo)軌上并可以在上面移動(dòng)。大拖板上有橫向?qū)к?，使橫向拖板可以安裝在上面，并通過絲杠使其運(yùn)動(dòng)，絲杠由一個(gè)小手柄和刻度盤控制。橫拖板可以帶動(dòng)刀具垂直于工件的旋轉(zhuǎn)軸線切削。大多數(shù)車床的刀架安裝在復(fù)式刀座上，刀座上有底座，底座安裝在橫拖板上，可繞垂直軸和上刀架轉(zhuǎn)動(dòng)。上刀架安裝在底座上，可用受輪和刻度盤控制一個(gè)短絲杠使其前后移動(dòng)。溜板箱裝在大拖板前面，通過溜板箱內(nèi)的機(jī)械裝置可以手動(dòng)和動(dòng)力驅(qū)動(dòng)大拖板以及動(dòng)力驅(qū)動(dòng)橫拖板。通過轉(zhuǎn)動(dòng)溜板箱前的手輪，可以手動(dòng)操作拖板沿床身移動(dòng)。手輪的另一端與溜板箱背面的小齒輪連接，小齒輪與齒條嚙合，齒條倒裝在床身前

8、上邊緣的下面。利用光杠可以將動(dòng)力傳遞給大拖板和橫拖板。光杠上有一個(gè)幾乎貫穿整個(gè)光杠的鍵槽，光杠通過兩個(gè)轉(zhuǎn)向相反并用鍵相連接的錐齒輪傳遞動(dòng)力。通過溜板箱前的換向手柄可以使嚙合齒輪與其中的一個(gè)錐齒輪嚙合，為大拖板提供“向前”或“向后”的動(dòng)力。合適的離合器或者與小齒輪連接或者與和橫拖板的螺桿連接，使拖板縱向移動(dòng)或使橫拖板橫向移動(dòng)。對(duì)于螺紋加工，絲杠提供第二種縱向移動(dòng)的方法。光杠通過摩擦離合器驅(qū)動(dòng)拖板移動(dòng)，離合器可能會(huì)產(chǎn)生打滑現(xiàn)象。而絲杠產(chǎn)生的運(yùn)動(dòng)是通過溜板箱與絲杠之間的直接機(jī)械連接來實(shí)現(xiàn)的，對(duì)開螺母可以實(shí)現(xiàn)這種連接。通過溜板箱前面的夾緊手柄可以使對(duì)開螺母緊緊包含絲杠。當(dāng)對(duì)開螺母閉合時(shí)，可以沿絲杠直接

9、驅(qū)動(dòng)拖板，而不會(huì)出現(xiàn)打滑的可能性?，F(xiàn)代車床有一個(gè)變速齒輪箱，齒輪箱的輸入端由車床主軸通過合適的齒輪傳動(dòng)來驅(qū)動(dòng)。齒輪箱的輸出端與光杠和絲杠連接。主軸就是這樣通過齒輪傳動(dòng)鏈來驅(qū)動(dòng)變速齒輪箱，再帶動(dòng)絲杠和光杠，然后帶動(dòng)拖板，刀具就可以按主軸的轉(zhuǎn)數(shù)縱向的或橫向地精確移動(dòng)。一臺(tái)典型的車床的主軸沒旋轉(zhuǎn)一圈，通過光杠可以獲得從0.002到0.118英寸尺寸范圍內(nèi)的48種進(jìn)給量；而使用絲杠可以車削從1.5到92牙/英寸范圍內(nèi)的48種不同螺紋。一些老式的或廉價(jià)的車床為了能夠得到所有的進(jìn)給量和加工出所有的螺紋，必須更換主軸和變速齒輪箱之間的齒輪系中的一個(gè)或兩個(gè)齒輪。車床的規(guī)格用兩個(gè)尺寸表示。第一個(gè)稱為車床床面上最

10、大加工直徑。這是在車床上能夠旋轉(zhuǎn)的工件的最大尺寸。它大約是兩頂尖連線與導(dǎo)軌上最近點(diǎn)之間距離的兩倍。第二個(gè)規(guī)格尺寸是兩頂尖之間的最大距離。車床床面上最大加工直徑表示在車床上能夠車削在最大工件直徑，而兩頂尖之間的最大距離則表示在兩個(gè)頂尖之間能夠安裝工件的最大長(zhǎng)度。普通車床是生產(chǎn)中最經(jīng)常使用的車床種類。它們是具有前面所敘述的所有那些部件的重載機(jī)床，并且除了小刀架之外，全部刀具的運(yùn)動(dòng)都有機(jī)動(dòng)進(jìn)給。它們的規(guī)格通常是：車床床面上最大加工直徑為305610mm（1224英寸）；兩頂尖之間的距離為6101219mm（2448英寸）。但是床面上最大加工直徑達(dá)到1270mm（50英寸）和兩頂尖之間距離達(dá)到3658

11、（12英尺）的車床也并不少見。這些車床大部分都有切削盤和一個(gè)安裝在內(nèi)部的冷卻液循環(huán)系統(tǒng)。小型的普通車床車床床面最大加工直徑一般不超過330 mm（13英寸）被設(shè)計(jì)成臺(tái)式車床，其床身安裝在工作臺(tái)或柜子上。雖然普通車床有很多用途， 是很有用的機(jī)床，但是更換和調(diào)整刀具以及測(cè)量工件花費(fèi)很多時(shí)間，所以它們不適合在大量生產(chǎn)中應(yīng)用。 通常，它們的實(shí)際加工時(shí)間少于其加工時(shí)間的30%。 此外， 需要技術(shù)熟練的工人來操作普通車床，這種工人的工資高而且很難雇到。然而，操作工人的大部分時(shí)間卻花費(fèi)在簡(jiǎn)單的重復(fù)調(diào)整和觀察切屑產(chǎn)生的過程上。因此，為了減少或者完全不雇用這類熟練工人，六角車床、螺紋加工車床和其他類型的半自動(dòng)和

12、自動(dòng)車床已經(jīng)很好的研究出來，并已經(jīng)在生產(chǎn)中得到廣泛應(yīng)用。普通車床作為最早的金屬切削機(jī)車的一種，目前仍然有許多有用的和為人們所需要的特性。現(xiàn)在，這些機(jī)床主要用在規(guī)模較小的工廠中，進(jìn)行小批量的生產(chǎn)，而不是進(jìn)行大規(guī)模的生產(chǎn)。在現(xiàn)代的生產(chǎn)車間中，普通車床已經(jīng)被種類繁多的自動(dòng)車床所取代。現(xiàn)在，設(shè)計(jì)人員已經(jīng)熟知先利用單刃刀具去除大量的金屬余量，然后利用成型刀具獲得表面光潔度和精度。這種加工方法的生產(chǎn)速度與現(xiàn)在工廠中使用的最快加工設(shè)備的速度相等。普通車床的加工偏差主要依賴與操作者的技術(shù)熟練程度。設(shè)計(jì)工程師應(yīng)該認(rèn)真地確定由熟練工人在普通車床上加工的試驗(yàn)零件的公差。在把試驗(yàn)零件重新設(shè)計(jì)為生產(chǎn)零件時(shí)，應(yīng)該選用經(jīng)濟(jì)

13、的公差。 LathesAbstract: The engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered. Tolerances for the engine lathe de

14、pend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been product on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used.Key works: machine; l

15、atheThe basic machines that are designed primarily to do turning, facing and boring are called lathes. Very litter turning is done on other types of machine tools, and none can do it with equal facility. Because lathe can do boring, facing, drilling, and reaming in addition to turning, their versati

16、lity permits several operations to be performed with a single setup of the workpiece. This accounts for the fact that lathes of various types are more widely used in manufacturing than any other machine tool.Lathes in various forms have existed for more than two thousand years. Modern lathes date fr

17、om about 1797, when Henry Maudsley developed one with a leadscrew. It provided controlled, mechanical feed of the tool. This ingenious Englishman also developed a change-gear system that could connect the motions of the spindle and leadscrew and thus enable threads to be cut.Lathe construction. Thes

18、e are the bed , headstock assembly, tailstock assembly, carriage assembly, quick-change gear box, and the leadscrew and feed rod.The bed is the backbone of a lathe. It usually is made of well-normalized or aged gray or nodular cast iron and provides a heavy, rigid frame on which all the other basic

19、components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets. Because several other components a

20、re mounted and/or move on the ways they must be made with precision to assure accuracy of alignment. Similarly, proper precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed. The

21、 ways on most modern lathes are surface hardened to offer greater resistance to wear and abrasion.The headstock is mounted in a fixed position on the inner ways at one end of the lathe bed. It provides a powered means of rotating the work at various speeds. It consists, essentially, of a hollow spin

22、dle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission-through which the spindle can be rotated at a number of speeds. Most lathes provide from eight to eighteen speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained mere

23、ly by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapere

24、d roller or ball types. A longitudinal hole extends through the spindle so that long bar stock can be fed through it. The size of this hole is an important size dimension of a lathe because it determines the maximum size of bar stock that can be machined when the material must be fed through the spi

25、ndle.The inner end of the spindle protrudes from the gear box and contains a means for mounting various types of chucks, face plates, and dog plates on it. Whereas small lathes often employ a threaded section to which the chucks are screwed, most large lathes utilize either cam-lock or key-drive tap

26、er noses. These provide a large-diameter taper that assures the accurate alignment of the chuck, and a mechanism that permits the chuck or face plate to be locked or unlocked in position without the necessity of having to rotate these heavy attachments.Power is supplied to the spindle by means of an

27、 electric motor through a V-belt or silent-chain drive. Most modern lathes have motors of from 5 to 15 horsepower to provide adequate power for carbide and ceramic tools at their high cutting speeds.The tailstock assembly consists, of there parts. A lower casting fits on the bed and can slide longit

28、udinally thereon, with a means for clamping the entire assembly in any desired location. An upper casting fits on the lower one and can be moved transversely upon it on some type of keyed ways. This transverse motion permits aligning the tailstock and headstock spindles and provides a method of turn

29、ing tapers. The third major component of the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 2 to 3 inches in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw. The open end of the quill hole t

30、erminates in a Morse toper in which a lathe center, or various tools such as drills, can be held. A graduated scale, several inches in length, usually is engraved on the outside of the quill to aid in controlling its motion in and out of the upper casting. A locking device permits clamping the quill

31、 in any desired position.The carriage assembly provides the means for mounting and moving cutting tools. The carriage is a relatively flat H-shaped casting that rests and moves on the outer set of ways on the bed. The transverse bar of the carriage contains ways on which the cross slide is mounted a

32、nd cab be moved by means of a feed screw that is controlled by a small hand wheel and a graduated dial. Through the cross slide a means is provided for moving the lathe tool in the direction normal to the axis of rotation of the work.On most lathes the tool post actually is mounted on a compound res

33、t. This consists of a base, which is mounted on the cross slide so that it can be pivoted about a vertical axis, and an upper casting. The upper casting is mounted on ways on this base so that it can be moved back and forth and controlled by means a short lead screw operated by a hand wheel and a ca

34、librated dial.Manual and powered motion for the carriage, and powered motion for the cross slide, is provided by mechanisms within the apron, attached to the front of the carriage. Manual movement of the carriage along the bed is effected by turning a hand wheel on the front of the apron, which is g

35、eared to a pinion on the back side. This pinion engages a rack that is attached beneath the upper front edge of the bed in an inverted position.To impart powered movement to the carriage and cross slide, a rotating feed rod is provided. The feed rod, which contains a keyway throughout most of its le

36、ngth, passes through the two reversing bevel pinions and is keyed to them. Either pinion can be brought into mesh with a mating bevel gear by means of the reversing lever on the front of the apron and thus provide “forward” or “reverse” power to the carriage. Suitable clutches connect either the rac

37、k pinion or the cross-slide screw to provide longitudinal motion of the carriage or transverse motion of cross slide.For cutting threads, a second means of longitudinal drive is provided by a lead screw. Whereas motion of the carriage when driven by the feed-rod mechanism takes place through a frict

38、ion clutch in which slippage is possible, motion through the lead screw is by a direct, mechanical connection between the apron and lead screw. This is achieved by a split nut. By mean of a clamping lever on the front of the apron, the split nut can be closed around the lead screw. With the split nu

39、t closed, the carriage is moved along the bed screw by direct drive without possibility of slippage.Modern lathes have a quick-change gear box. The input end of this gear box ix driven from the lathe spindle by means of suitable gearing. The output end of the gear box is connected to the feed rod an

40、d lead screw. Thus, through this gear train, leading from the spindle to the quick-change gear box, thence to the lead screw and feed rod, and then to the carriage, the cutting tooling tool can be made to move a specific distance, either longitudinally or transversely, for each revolution of the spi

41、ndle. A typical lathe provides, through the feed rod, forty-eight feeds ranging from 0.002 inch to 0.118 inch per revolution of the spindle, and, through the lead screw, leads for cutting forty eight different threads from 1.5 to 92 per inch. On some older and some cheaper lathes, one or two gears i

42、n the gear train between the spindle and the change gear box must be changed in order to obtain a full range of threads and feeds.The size of a lathe is designated by two dimensions. The first is known as the swing. This is maximum diameter of work that can be rotated on a lathe. It is approximately

43、 twice the distance between the line connecting the lathe centers and the nearest point on the ways. The second size dimension is the maximum distance between centers. The swing thus indicates the maximum workpiece diameter that can be turned in the lathe, while the distance between centers indicate

44、s the maximum length of workpiece that can be mounted between centers.Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all movement except on the compound rest. They commonly rang

45、e in size from 305 to 610 mm ( 12 to 24 inch ) swing and from 610 to 1219 mm( 24 to 48 inch ) center distances, but swing up to 1270 mm ( 50 inch ) and center distances up to 3658 mm ( 12 feet ) are not uncommon. Most have chip pans and a built-in coolant circulating system. Smaller engine lathes-wi

46、th swings usually not over 330 mm (13 inches ) -also are available in bench type, designed for the to be mounted on a bench or cabinet.Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the workpiece, they

47、are not suitable for quantity production. Often the actual chip-production time is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operators time is consumed by sim

48、ply, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing.The e

49、ngine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered.The engine lathe has been replaced in todays production shops by a wide variety of lathes. All the advantages of single-point tooling for maximum metal removal, and the use of form tools for finish and accuracy, are now at the designers fingertips with production speeds on a par with the fastest processing equipment