2.3 注射成型 2.31 注射成型 注塑主要用于生產熱塑性塑料零件，也是最原始的方法之一。目前注塑占所有塑料樹脂消費量的 30%。典型的注塑成型產品“塑料杯、容器、外殼、工具手柄、旋鈕、電氣和通信組件 (如電話接收器 )、玩具、和水暖配件。 聚合物熔體由于其分子量具有很高的粘度；它們不能像金屬液在重力的條件下倒進模 ,必須在高壓力下注入模具。因此 ,金屬鑄造的力學性能是由模具壁傳熱的速度決定，同時也決定了在最終鑄件的晶粒尺寸和晶粒取向 , 高壓注射成型過程中熔體的注射剪切力產生的主要原因是材料最后的分子取向。力學性能影 響成品都是因為在模具里的注塑條件很冷卻條件。 注塑已應用于熱塑性塑料和熱固性材料 ,發泡部分 ,也已被修改過用于展現注射成型（ RIM）反應過程，其中有兩個部分組成，一種是熱固性樹脂體系，另一種是聚合物快速注射模具。然而大多數注射成型是熱塑性塑料 ,后面的討論集中于這樣的模型。 一個典型的注塑周期或序列由五個階段組成 (見圖 2 - 1): 注射或模具填充 ； (2) 包裝或壓縮 ； (3) 保持 ； (4) 冷卻 ； (5)部分排除物 圖 2 - 1 注射成型過程 塑料顆粒（或粉末）被裝入進料斗并通過注塑缸上的 開口在那里它們被旋轉螺桿結轉。螺桿的旋轉使顆粒處于高壓下加上受熱缸壁使它們融化。加熱溫度范圍從 265 到 500 F。隨著壓力的增大 ,旋轉螺絲被迫向后 ,直到積累了足夠的塑料可以進行注射。注射活塞 (或螺釘 )迫使熔融塑料從料桶通過噴嘴、澆口和流道系統 ,最后進入模腔。在注射過程中 ,熔融塑料充滿模具型腔。當塑料接觸冷模具表面 ,它迅速凝固 (凍結 )產生皮膚層。由于核心仍在熔融狀態 ,塑料流經核心來完成填充。一般的，該空腔被注入期間填充到 95 ?98。 然后成型工藝轉向了填充的階段。型腔填充后，熔融塑料開始冷卻。由于冷卻塑料 會收縮產生缺陷，如縮孔、氣泡，而且空間存在不穩定性。所以被迫實行空穴用來補償收縮、添加塑料。一旦模腔被填充，壓力應用熔體防止腔內熔融塑料會流進澆口。壓力必持續到澆口部分就凝固了。該過程可以分成兩個步驟（填充和保持）或者可能在一個步驟中（保持或第二級）所涵蓋。在填充過程中，熔體被用于收縮的填充壓力補償壓入型腔中。保持過程中，壓力只是防止聚合物熔體的倒流。 保持階段結束后冷卻階段開始。在冷卻過程中，部分在模具持有指定期間。冷卻階段的持續時間主要取決于材料的性質和厚度。通常，該部分的溫度必須冷卻到低于材料的脫模溫 度。 在冷卻部件，這臺機器塑性熔化在下一個周期。聚合物受剪切作用以及電熱絲的能量。一旦開槍，塑化停止。這應該是在冷卻階段結束之前。然后將模具開啟，一部分被排出。 2.3.2注塑模具 注塑模具的多種多樣的設計、復雜程度和大小作為它們的生產部分。功能熱塑性塑料模具，基本上是傳授理想的形狀，然后進行聚合物注射件的冷卻。 一種模具是由兩組部件組成：（ 1）型腔和型芯（ 2）空腔和型芯的安裝。模塑部件的尺寸和重量限制了模腔的數量并且還決定了所要求的設備的能力。考慮成型工藝，模具必須設計的安全地吸收由于夾緊。注塑。脫模帶來 的力。同時，澆口和流道的設計必須允許有效流動和統一的模具型腔填充。 圖 2-2 示出了一個典型的注塑模具。模具主要由兩部分組成：一個部分精止不動的（模腔板），在那邊熔融聚合物被注入，另一部分可以移動（型心板）在截止面上或噴射器的注塑設備上。兩個半模之間的分離線被稱為分型線。注射的材料是通過中央進料通道，稱為澆口。物料位于錐形流道，便于套管在打開的模具中釋放模具材料。在多數模具、物料聚合物熔體助長了流道系統，通過一個澆口流向每個模具型腔。 核心板的主要核心。主要的核心的目的是建立內部部分的配置。核心目的是建立內部 結構。核心板具有備份或支撐板，支撐板是由支柱所支撐的，這個支柱是作為噴射器殼體的 u 型結構為人所知，它由后部夾持板和隔塊組成。此 U 形結構是用螺栓固定在核心板，它為起模行程也就是脫模行程提供了空間。在凝固過程中該部分圍繞主芯收縮，使模具打開時，第二部分和澆道一起被移動的半模進行。隨后，中央噴射器被激活時，使頂出板向前移動，導致頂出桿可以推動這部分遠離核心。兩個半模設置有冷卻通道，通過該冷卻通道，水被循環以吸收由熱塑性聚合物熔體輸送到模具的熱量。模腔還采用精細的通風口（ 0.02?0.08 毫米 5毫米）的，以確保填 充過程中沒有空氣殘留。 注塑模具現在在使用中有六種基本類型。它們是：（ 1）雙板模具，（ 2）三板模，（ 3）熱澆道模，（ 4）絕緣熱澆道模，（ 5）熱歧管模具，以及層疊模具。圖。 2-3 和圖 2-4 說明了這六種基本類型的注塑模具。 圖 2 - 2 注塑模具 1 - 頂桿 2 - 推板 3 - 導套 4 - 導柱 5 - 頂桿底板 6 鉤料桿銷 7 推回針 8 針限制 9 導柱 10 - 導柱 11 腔板 12 - 澆口套 13 塑料工件 14 芯 圖 2-3 這說明三者的六種基本類型的注塑模具 (1) 兩板注射模具（ 2）三板注塑模（ 3）熱流道模具 見圖 . 2-4 其他三種型。 圖 2-4 這說明三者的六種基本類型的注塑模具 （ 1）絕緣熱流道注塑模具（ 2）熱歧管注塑模具（ 3）堆疊式注塑模具 見圖 .2-3 對于其他三種類型。 1兩板模 一種雙板模具由兩個板與腔和型芯安裝在任一模版上 .板被固定到壓板上。移動一半的模具通常含有推出結構和澆道系統。所有注塑模具的基本設計有這樣的設計理念。兩板模具是最合乎邏輯的類型對于一些需要使用那些需要很大澆口零件的工具來說。 2三板模具 這種類型的模具是由三塊板組成：（ 1）固定或流道板是連接到靜止的滾筒，通 常包含澆道和半流道，（ 2）中間板或模腔板，包含一半道和澆口，允許在開模時浮動，（ 3）移動板或受力板塑造和推出系統部分切除塑造的部分。當通道開始打開，中間板和可動板一起移動，從而釋放澆道和流道系統和去澆口的成型部件。這種類型的模具的設計能夠分隔流道系統和部件當模具打開時。這種模具的設計可以使用點澆口澆注系統。 3 .熱流道模具 在注射成型的過程中，流道保持熱量以保證熔融塑料是流體狀態，在任何時候。實際上這是一個 無澆道 成型工藝而且有時被稱為是相同的。在無流道模具中，流道包含在一個獨立的板上。熱流道模具類似三 板注塑模具，除了模具流道的部分在成型周期打不開。加熱流道板與其余的冷模隔熱。除了加熱板是為了流道設計，模具剩余部分是一個標準兩板模。 無流道成型較傳統澆道式成型有很多優點。沒有成型的副產物（澆口，流道，或主流道）被處理掉或循環再使用，沒有從主流到分離。周期時間是成型部分被冷卻，從模具中頂出。在這個系統中，一個均勻的熔體溫度可以從注射模具型腔的汽缸達到的。 4絕緣熱流道模具 這是一個變化的保溫模具。在這種類型的模具中，流道的外表面材料是絕緣體的優質材料。在絕熱模具中，成型材料鑄造成型仍然通過保持熱量。有時 一個分料梭和熱探測器需要更多的靈活性。這種類型的模具多腔中心澆口部分是理想的。、 5.熱流道模具 這是一個變化的保溫流道模具。在熱流道模具中，流道是加熱的而不是流道板。這是通過使用一個電子嵌入探針完成的。 6.堆疊模具 堆疊注塑模具，顧名思義就是多個兩板模具放置一起。這種結構也可以用于三板模具和保溫流道模具。堆疊兩模板的構造重點提出一個單一通道要求比同樣數量的模具減少一般夾緊壓力。這個方法有時候被稱為“二級成型”。 2.3.3 成型機 1.傳統注塑機 在這個過程中 ,塑料顆粒或顆粒注入機料斗并注入加熱缸腔內 。然后柱塞壓縮材料 ,迫使它逐步通過加熱缸的溫度區域 ,在那里它被分料梭分散的很薄。分料梭安裝在缸的中心，目的是為了加快塑料中心的加熱質量。分料梭也可從內部加熱處理使塑料內外都加熱。 材料從加熱缸流動通過一個管口進入模具。這個管口是缸和和模具的分割點 ,它是用來防止產生壓力導致物質泄漏。模具是關閉了有夾鉗一端的機器。對于聚苯乙烯 ,夾鉗上兩到三噸的壓力要用于材料和系統的每一寸空間。傳統的柱塞機是唯一可以產生雜色部件的注塑機 ,其他類型的完全將塑料材料融合在一起 ,只會產生一種顏色。 2.柱塞式預塑機 這臺機器使用一個分 料梭加熱器來預塑塑料顆粒。融化階段后 ,液體塑料是被排入一個存放腔內，直到可以進入模具。這種類型的機器生產速度比傳統的機器快 ,由于成型室是在冷卻時不斷釋放能量。由于注射柱塞作用于流體材料 ,在顆粒壓縮時沒有壓力損失。這允許更大的部件有更大的投影面積。它其余的特性與傳統單活塞注射機相同。圖 2 - 5 演示了一個柱塞式預塑機。 3.螺桿式預塑機 這種注射機用擠出機塑化塑料材料。車削螺桿向擠壓機內表面供料。將擠出機熔融、塑化的材料移動到另一個存放腔 ,然后從那里被注射柱塞擠入模具。使用螺旋有以下優點 :(1)塑性材料 能更好的融合和受力 ；(2)流動材料更硬，熱敏感材料能流動 ；(3)顏色變化可以在更短的時間內處理 (4)模制品受更小的壓力。 4.往復式螺桿注塑機 這種類型的注塑機在加熱室處采用臥式擠壓機。塑料材料由于螺桿的旋轉被推進擠壓機管道。隨著材料通過加熱筒與螺桿時 ,它正在從顆粒變成塑料熔融狀態。在往復式螺桿注塑機中 ,熱量傳遞到模塑料的熱量是由螺桿之間的摩擦傳導和擠壓機管道壁。材料移動時 ,螺桿又回到極限狀態 ,這種狀態是決定材料在壓力機管道前的體積的。這時 ,與典型壓力機的相似之處結束了。在材料注入模具時 ,螺桿向前移動，重新 塑造管道中的材料。在這臺機器中，螺桿的角色既是一個柱塞又是一個螺桿。在模型澆口部分已經凝固不能回流時，螺桿開始旋轉回程，走下一圈。圖 2-5 是一個往復式螺桿注塑機。 這種注塑方法有幾個優點。它能使熱敏材料更有效地塑化，使顏色融合更快 ,材料的溫度通常更低，整個循環時間也更短。 2.3 Injection Molds 2.3.1 Injection Molding Injection molding is principally used for the production of thermoplastic parts, and it is also one of the oldest. Currently injection-molding accounts for 30% of all plastics resin consumption.Typical injection-molded products are cups, containers, housings, tool handles, knobs, electrical and communication components (such as telephone receivers), toys, and plumbing fittings. Polymer melts have very high viscosities due to their high molecular weights； they cannot be poured directly into a mold under gravity flow as metals can, but must be forced into the moldunder high pressure. Therefore while the mechanical properties of a metal casting are predominantly determined by the rate of heat transfer from the mold walls, which determines the grain size and grain orientation in the final casting, in injection molding the high pressure during the injection of the melt produces shear forces that are the primary cause of the final molecularorientation in the material. The mechanical properties of the finished product are therefore affected by both the injection conditions and the cooling conditions within the mold. Injection molding has been applied to thermoplastics and thermosets, foamed parts, and has been modified to yield the reaction injection molding (RIM) process, in which the twocomponents of a thermosetting resin system are simultaneously injected and polymerize rapidly within the mold. Most injection molding is however performed on thermoplastics, and the discussion that follows concentrates on such moldings.Chapter 2 Plastics Molds A typical injection molding cycle or sequence consists of five phases (see Fig. 2-1): （ 1） Injection or mold filling； (2) Packing or compression； (3) Holding； (4) Cooling； (5) Part ejection. Plastic pellets (or powder) are loaded into the feed hopper and through an opening in the injection cylinder where they are carried forward by the rotating screw. The rotation of the screw forces the pellets under high pressure against the heated walls of the cylinder causing them to melt. Heating temperatures range from 265 to 500 F. As the pressure builds up, the rotating screw is forced backward until enough plastic has accumulated to make the shot. The injection ram (or screw) forces molten plastic from the barrel, through the nozzle, sprue and runner system,and finally into the mold cavities. During injection, the mold cavity is filled volumetrically.When the plastic contacts the cold mold surfaces, it solidifies (freezes) rapidly to produce the skin layer. Since the core remains in the molten state, plastic flows through the core to complete mold filling. Typically, the cavity is filled to 95%98% during injection. Then the molding process is switched over to the packing phase. Even as the cavity is filled,the molten plastic begins to cool. Since the cooling plastic contracts or shrinks, it gives rise to defects such as sink marks, voids, and dimensional instabilities. To compensate for shrinkage,addition plastic is forced into the cavity. Once the cavity is packed, pressure applied to the melt prevents molten plastic inside the cavity from back flowing out through the gate. The pressure must be applied until the gate solidifies. The process can be divided into two steps (packing and holding) or may be encompassed in one step (holding or second stage). During packing, melt forced into the cavity by the packing pressure compensates for shrinkage. With holding, the pressure merely prevents back flow of the polymer melt. After the holding stage is completed, the cooling phase starts. During cooling, the part is held in the mold for specified period. The duration of the cooling phase depends primarily on the material properties and the part thickness. Typically, the part temperature must cool below the materials ejection temperature. While cooling the part, the machine plasticates melt for the next cycle. The polymer is subjected to shearing action as well as the condition of the energy from the heater bands. Once the shot is made, plastication ceases. This should occur immediately before the end of the cooling phase. Then the mold opens and the part is ejected. 2.3.2 Injection Molds Molds for injection molding are as varied in design, degree of complexity, and size as are the parts produced from them. The functions of a mold for thermoplastics are basically to impart the desired shape to the plasticized polymer and then to cool the molded part. A mold is made up of two sets of components: (1) the cavities and cores, and (2) the base in which the cavities and cores are mounted. The size and weight of the molded parts limit the number of cavities in the mold and also determine the equipment capacity required. From consideration of the molding process, a mold has to be designed to safely absorb the forces of clamping, injection, and ejection. Also, the design of the gates and runners must allow for efficient flow and uniform filling of the mold cavities. Fig.2-2 illustrates the parts in a typical injection mold. The mold basically consists of two parts: a stationary half (cavity plate), on the side where molten polymer is injected, and a moving half (core plate) on the closing or ejector side of the injection molding equipment. The separating line between the two mold halves is called the parting line. The injected material is transferred through a central feed channel, called the sprue. The sprue is located on the sprue bushing and is tapered to facilitate release of the sprue material from the mold during mold opening. In multicavity molds, the sprue feeds the polymer melt to a runner system, which leads into each mold cavity through a gate. The core plate holds the main core. The purpose of the main core is to establish the inside configuration of the part. The core plate has a backup or support plate. The support plate in turn is supported by pillars against the U-shaped structure known as the ejector housing, which consists of the rear clamping plate and spacer blocks. This U-shaped structure, which is bolted to the core plate, provides the space for the ejection stroke also known as the stripper stroke. During solidification the part shrinks around the main core so that when the mold opens, part and sprue are carried along with the moving mold half. Subsequently, the central ejector is activated,the ejector plates to move forward so that the ejector pins can push the part off the core.Both mold halves are provided with cooling channels through which cooled water is circulated to absorb the heat delivered to the mold by the hot thermoplastic polymer melt. The mold cavities also incorporate fine vents (0.02 to 0.08 mm by 5 mm) to ensure that no air is trapped during filling. There are six basic types of injection molds in use today. They are: (1) two-plate mold； (2)three-plate mold, (3) hot-runner mold； (4) insulated hot-runner mold； (5) hot-manifold mold； and（ 6） stacked mold. Fig. 2-3 and Fig. 2-4 illustrate these six basic types of injection molds. 1. Two-Plate Mold A two-plate mold consists of two plates with the cavity and cores mounted in either plate.The plates are fastened to the press platens. The moving half of the mold usually contains the ejector mechanism and the runner system. All basic designs for injection molds have this design concept. A two-plate mold is the most logical type of tool to use for parts that require large gates. 2. Three-Plate Mold This type of mold is made up of three plates: (1) the stationary or runner plate is attached to the stationary platen, and usually contains the sprue and half of the runner； (2) the middle plate or cavity plate, which contains half of the runner and gate, is allowed to float when the mold is open； and (3) the movable plate or force plate contains the molded part and the ejector system for the removal of the molded part. When the press starts to open, the middle plate and the movable plate move together, thus releasing the sprue and runner system and degating the molded part.This type of mold design makes it possible to segregate the runner system and the part when the mold opens. The die design makes it possible to use center-pin-point gating. 3. Hot-Runner Mold In this process of injection molding, the runners are kept hot in order to keep the molten plastic in a fluid state at all times. In effect this is a runnerless molding process and is sometimes called the same. In runnerless molds, the runner is contained in a plate of its own. Hot runner molds are similar to three-plate injection molds, except that the runner section of the mold is not opened during the molding cycle. The heated runner plate is insulated from the rest of the cooled mold. Other than the heated plate for the runner, the remainder of the mold is a standard two-plate die. Runnerless molding has several advantages over conventional sprue runner-type molding.There are no molded side products (gates, runners, or sprues) to be disposed of or reused, and there is no separating of the gate from the part. The cycle time is only as long as is required for the molded part to be cooled and ejected from the mold. In this system, a uniform melt temperature can be attained from the injection cylinder to the mold cavities. 4. Insulated Hot-Runner Mold This is a variation of the hot-runner mold. In this type of molding, the outer surface of the material in the runner acts like an insulator for the melten material to pass through. In the insulated mold, the molding material remains molten by retaining its own heat. Sometimes a torpedo and a hot probe are added for more flexibility. This type of mold is ideal for multicavity center-gated parts. 5. Hot-Manifold This is a variation of the hot-runner mold. In the hot-manifold die, the runner and not the runner plate is heated. This is done by using an electric-cartridge-insert probe. 6. Stacked Mold The stacked injection mold is just what the name implies. A multiple two-plate mold is placed one on top of the other. This construction can also be used with three-plate molds and hot-runner molds. A stacked two-mold construction doubles the output from a single press and reduces the clamping pressure required to one half, as compared to a mold of the same number of cavities in a two-plate mold. This method is sometimes called “two-level molding”. 2.3.3 Mold Machine 1. Conventional Injection-Molding Machine In this process, the plastic granules or pellets are poured into a machine hopper and fed into the chamber of the heating cylinder. A plunger then compresses the material, forcing it through progressively hotter zones of the heating cylinder, where it is spread thin by a torpedo. The torpedo is installed in the center of the cylinder in order to accelerate the heating of the center of the plastic mass. The torpedo may also be heated so that the plastic is heated from the inside as well as from the outside. The material flows from the heating cylinder through a nozzle into the mold. The nozzle is the seal between the cylinder and the mold； it is used to prevent leaking of material caused by the pressure used. The mold is held shut by the clamp end of the machine. For polystyrene, two to three tons of pressure on the clamp end of the machine is generally used for each inch of projected area of the part and runner system. The conventional plunger machine is the only type of machine that can produce a mottle-colored part. The other types of injection machines mix the plastic material so thoroughly that only one color will be produced. 2. Piston-Type Preplastifying Machine This machine employs a torpedo ram heater to preplastify the plastic granules. After the melt stage, the fluid plastic is pushed into a holding chamber until it is ready to be forced into the die. This type of machine produces pieces faster than a conventional machine, because the molding chamber is filled to shot capacity during the cooling time of the part. Due to the fact that the injection plunger is acting on fluid material, no pressure loss is encountered in compacting the granules. This allows for larger parts with more projected area. The remaining features of a piston-type preplastifying machine are identical to the conventional single-plunger injection machine. Fig. 2-5 illustrates a piston or plunger preplastifying injection molding machine. 3. Screw-Type Preplastifying Machine In this injection-molding machine, an extruder is used to plasticize the plastic material. The Chapter 2 Plastics Molds 41turning screw feeds the pellets forward to the heated interior surface of the extruder barrel. The molten, plasticized material moves from the extruder into a holding chamber, and from there is forced into the die by the injection plunger. The use of a screw gives the following advantages:(1) better mixing and shear action of the plastic melt； (2) a broader range of stiffer flow and heatsensitive materials can be run； (3) color changes can be handled in a shorter time, and (4)fewer stresses are obtained in the molded part. 4. Reciprocating-Screw Injection Machine This type of injection molding machine employs a horizontal extruder in place of the heating chamber. The plastic material is moved forward through the extruder barrel by the rotation of a screw. As the material progresses through the heated barrel with the screw, it is changing from the granular condition to the plastic molten state. In the reciprocating screw, the heat delivered to the molding compound is caused by both friction and conduction between the screw and the walls of the barrel of the extruder. As the material moves forward, the screw backs up to a limit switch that determines the volume of material in the front of the extruder barrel. It is at this point that the re- semblance to a typical extruder ends. On the injection of the material into the die, the screw moves forward to displace the material in the barrel. In this machine, the screw performs as a ram as well as a screw. After the gate sections in the mold have frozen to prevent backflow, the screw begins to rotate and moves backward for the next cycle. Fig.2-5 shows a reciprocating-screw injection machine. There are several advantages to this method of injection molding. It more efficiently plasticizes the heat-sensitive materials and blends colors more rapidly, due to the mixing action of the screw. The material heat is usually lower and the overall cycle time is shorter. 2.1 計算機輔助設計和計算機輔助 CAD/CAM 縱觀人類工業社會的歷史 ,許多發明獲得了專利，整個新技術也逐漸形成。惠特尼的通用零件的思路 ,瓦特的蒸汽機和福特的流水線不僅是幾個少數的發展階段而且是人類工業的幾個重要的發展階段。正如我們所知的任何一個這樣的發展都影響了制造業并且在歷史的掛鉤中贏得了這些個體應得的承認。或許單個的發展影響制造業更快，而影響比先前技術更大的是數字電腦。 自從電腦技術 出現以來 ,制造業人員一直希望自動化設計過程和使用數據庫開發自動制造過程。計算機輔助設計 /計算機輔助制造 (CAD/CAM),當成功執行 ,應該消除存在于設計和生產部件之間的傳統屏障。 CAD/CAM 意味著用電腦進行設計和制造過程。因為 CAD/CAM 的出現其他方面也 發展起來： 計算機圖形 CG 電腦輔助工程 CAE 電腦輔助設計和繪圖設計 CADD 計算機輔助工藝規劃 CAPP 這些附帶條件是指包括解答 11 項具體方面的 CAD / CAM 的概念而 CAD / CAM 本身就是一個更廣泛平臺 ,它是在生產的自動化和集成的核心。 CAD/CAM 成功的一個關鍵目標是創建可以用來產品的數據當成功實施的產品設計的發展數據庫。 CAD/CAM 致力于一個在設計和生產部件分享通用的數據庫的公司。 交 互 式 計 算 機 圖 形 學 (ICG) 在 CAD/CAM 扮演一個重要角色，雖然 ICG 用途上 ,設計師沖洗被設計的產品的一個圖表圖象 ,當存放電子上組成圖表圖象的數據。圖表圖象在二維可以被提出二維 (2-D)三維 (3-D)或者固體格式化。 ICG 圖象被修建使用這樣基本的幾何字符象點、線、圈子和曲線。一旦生成 ,這些圖象可以容易地 被編輯和被操作用各種各樣的方式包括擴大、減少、自轉和運動。 lCG 系統有三個主要成份 ,1)硬件 ,包括計算機和各種各樣的外圍設備 ； 2)軟件 ,包括系統的計算機程序和技術指南 ； 3)設計師 ,最重要三個組分。 ICG 系統的典型的硬件構造包括一個電腦 ,一個顯示終端、磁盤的一個驅動器單位，一個硬盤或者兩個 ； 并且輸入 -輸出設備例如鍵盤，繪圖器和打印機。這些設備 ,與軟件一起，是現代工具設計師用以開發和提供他們的設計的。 ICG 系統能通過允許人的設計師集中提高設計過程于設計過程的智力方面，例如概 念化 和做出基于評斷的決定。計算機執行它更好地適合，例如數據的各種各樣的反復操 作數學演算、存貯與檢索，和各種各樣的反復操作比如交叉涂畫。 2.11CAD/CAM 的基本原理 CAD/CAM 的基本原理類似于制造業以前證明技術為基礎的提高。它來源于一個需要不斷提高生產率，質量和反過來的競爭力。還有其他原因，可能使公司從手工流程轉換為 CAD / CAM 的。 提高生產力 質量更好 更好的溝通 共同的數據庫與制造 降低建造成本原型 更快的響應客戶 2.12 CAD/CAM 的歷史發展 CAD/CAM 的歷史發展在計算機科技的發展之后緊密跟隨了和對應了 ICG 技術的發展。使得 CAD/CAM 的重大發展在 20 世紀 50 年代和 60 年代初期末期開始了。最先發展的是在麻省理工學院 (MIT)進行的刀具控制程序自動編制系統 (APT)計算機程式語言。 APT 的目的是將數字控制器部分方案的開發進行簡化。它是為此計劃被使用的第一 種計算機語言。 APT 語言代表了主要步往制造過程的自動化。 在 CAD/CAM 的歷史中的另一重大發展在 APT 之后 緊密跟隨了，也被開發在 MIT，一個項目被稱之為草圖項目。這個項目， Ivan Sutherland 誕生了 ICG 的概念。草圖項目是第一個計算機在實時中被用于生成和操作在 CRT 中顯示的圖表圖象。 在 20 世紀 60 年代和 70 年代的剩下的人中， CAD 繼續被開發，多家廠商提出了自己的名字生產和銷售生產全套 CAD 系統。這是一個完整的系統方案包括硬，軟件，銷售和維修培訓。這些早期的系統被大型機和小型機左右。因此 ,它們太昂貴一直不能實現大規模被中小型制造業接受。 在 20 世紀 70 年代末之前 微型計算機在 CAD/CAM 的更加一步的發展中最終將扮演一個重要角色變得日益清晰。然而早期的微型計算機沒有配置為 ICG 需要的處理能 力、記憶能力或者圖表能力。結果 ,早期嘗試在微型計算機附近配置 CAD/CAM 系統的嘗試失敗了。 在 1983 IBM 介紹了 IBM PC 第一個有處理能力、記憶能力和圖表能力可被用于 CAD/CAM 的微型計算機。這使得了 CAD/CAM 供營商的數量的迅速增量。截止到 l989 安裝 CAD/CAM 設施的數量的微型計算機等于安裝在大型機和小型機上的數量 。 2.13 CAD 到 CAM 接口 使用 CAD/CAM，設計和制造之間的真正的接，是他們分享的共同的數據庫。這是 CAD/CAM 精華。 手工設計和制造，工程師審閱在設計，起草生產圖紙和其他文件傳達設計的每步，生產人員使用圖畫開發處理計劃，車間人員負責實際上的生產。 與舊方法相比 ,直到設計和起草人員完成他們的工作，生產人員都沒有看到它。設計和起草部門做他們的工作，把計劃再扔過墻再讓制造部門做他們的工作。這種做法導致溝通的不暢通以及制造部分與設計部分的脆弱關系。其結果是生產力 的損失。 使用 CAD/CAM,生產人員可以盡快進入創建的數據的設計階段。在任何一點在設計過程中，他們可以調用數據庫中的信息并使用它。因為數據分享從開始到結束，所以當設計成到準備生產時沒有一點吃驚。 當設計師創造時數據庫和起草者提供的設計，使生產人員也成為項目的一部分。生產人員生產產品的任何需要都被包含在一個共同的數據庫里。數學模型，圖形圖像，用料清單，零件清單，尺寸，從區位尺寸到公差規格和原材料明細表都包含數據庫 。 2.1 Computer-aided Design and Computer-aided Manufacturing(CAD/CAM) Throughout the history of our industrial society ,many invention have been patented and whole new technologies have evolved .Whitney is concept of interchangeable parts ,Watts steam engine,and Ford is assembly line are but a few developments that are most noteworthy during our industrial period . Each of these developments has impacted manufacturing as we know it,and has earned these individuals deserved recognition in 0ur history hooks. Perhaps the single development that has impacted manufacturing more quickly and significantly than any previous technology is the digital computer. Since the advent 0f computer technology, manufacturing professionals have wanted to automate the design process and use the database developed therein for automating manufacturing processes. Computeraided design,computer-aided manufacturing (CAD/CAM),when successfully implemented, should remove the “wall” that has traditionally existed between the design and manufacturing components . CAD/CAM means using computers in the design and manufacturing processes. Since the advent of CAD/CAM other terms have developed: Computer graphics(CG) Computeraided engineering(CAE) Computer-aided design and drafting(CADD) Computer aided process planning(CAPP) These spin-off terms a11 refer to specific aspects of the CAD/CAM concept CAD/CAM itself is a broader,more inclusive term. It is at the heart of automated and integrated manufacturing. A key goal of CAD/CAM is to produce data that can be used in manufacturing a product while developing the database for the design of that product When successfully implemented, CAD/CAM involves the sharing of a common database between the design and manufacturing components of a company, Interactive computer graphics (ICG) plays an important role in CAD/CAM, Though the use of ICG, designers develop a graphic image of the product being designed while storing the data that electronically make up the graphic image. The graphic image can be presented in a two-dimensional (2-D) , three-dimensional(3-D),or solids format. ICG image are constructed using such basic geometric characters as points, lines, circles, and curves. Once created, these images can be easily edited and manipulated in a variety of ways including enlargements,reductions, rotations, and movements. An lCG system has three main components :1 ) hardware, which consists of the computer and various peripheral devices； 2) software, which consists of the computer programs and technical manuals for the system ； and 3) the human designer, the most important of the three components. A typical hardware configuration for an ICG System include a computer,a display terminal, a disk drive unit for floppy diskettes, a hard disk, or both； and input/output devices such as a keyboard,plotter, and printer. These devices, along with the software, are the tools modern designers use to develop and document their designs. The ICG systems could enhance the design process by allowing the human designer to focus on the intellectual aspects of the design process, such as conceptualization and making judgment-based decisions. The computer performs tasks for which it is better suited, such as mathematical calculations, storage and retrieval of data and various repetitive operations such as crosshatching. 2.1.1 Rationale for CAD/CAM The rationale CAD/CAM is similar to that used to justify any technology-based improvement in manufacturing . It grows out of a need to continually improve productivity,Quality and in turn competitiveness. There are also other reasons why a company might make a conversion from manual processes to CAD/CAM: increased productivity better quality better communication common database with manufacturing reduced prototype construction costs faster response to customers 2.12 Historical Development of CAD/CAM The historical development of CAD/CAM has followed close behind the development of computer technology and has paralleled the development of ICG technology. The significant developments leading to CAD/CAM began in the late 1950s and early 1960s. The first of these was the development, at Massachusetts Institute of Technology (MIT),of the Automatically Programmed Tools (APT) computer programming language. The purpose of APT was to simplify the development of parts programs for numerical control machines. It was the first computer language to be used for this purpose. The APT language represented a major step toward automation of manufacturing processes. Another significant development in the history of CAD/CAM followed close behind APT, also developed at MIT, was called the Sketchpad project. With this project, Ivan Sutherland gave birth to the concept of ICG.