門把手注塑模具設(shè)計

門把手注塑模具設(shè)計,門把手,注塑,模具設(shè)計 2 Injection molding machine From Plastics Wiki, free encyclopedia Injection molding machines consist of two basic parts, an injection unit and a clamping unit. Injection molding machines differ in both injection unit and clamping unit. The name of the injection molding machine is generally based on the type of injection unit used. 2.1 Types of injection molding machines Machines are classified primarily by the type of driving systems they use: hydraulic, electric, or hybrid. 2.1.1 Hydraulic Hydraulic presses have historically been the only option available to molders until Nissei Plastic Industrial Co., LTD introduced the first all-electric injection molding machine in 1983. The electric press, also known as Electric Machine Technology (EMT), reduces operation costs by cutting energy consumption and also addresses some of the environmental concerns surrounding the hydraulic press. 2.1.2 Electric Electric presses have been shown to be quieter, faster, and have a higher accuracy, however the machines are more expensive. 2.1.3 Hybrid Hybrid injection molding machines take advantage of the best features of both hydraulic and electric systems. Hydraulic machines are the predominant type in most of the world, with the exception of Japan. 2.2 Injection unit The injection unit melts the polymer resin and injects the polymer melt into the mold. The unit may be: ram fed or screw fed. The ram fed injection molding machine uses a hydraulically operated plunger to push the plastic through a heated region. The high viscosity melt is then spread into a thin layer by a "torpedo" to allow for better contact with the heated surfaces. The melt converges at a nozzle and is injected into the mold. Reciprocating screw A combination melting, softening, and injection unit in an injection molding machine. Another term for the injection screw. Reciprocating screws are capable of turning as they move back and forth. The reciprocating screw is used to compress, melt, and convey the material. The reciprocating screw consists of three zones (illustrated below): · feeding zone · compressing zone · metering zone While the outside diameter of the screw remains constant, the depth of the flights on the reciprocating screw decreases from the feed zone to the beginning of the metering zone. These flights compress the material against the inside diameter of the barrel, which creates viscous (shear) heat. This shear heat is mainly responsible for melting the material. The heater bands outside the barrel help maintain the material in the molten state. Typically, a molding machine can have three or more heater bands or zones with different temperature settings. Injection molding reciprocating screw An extruder-type screw rotates within a cylinder, which is typically driven by a hydraulic drive mechanism. Plastic material is moved through the heated cylinder via the screw flights and the material becomes fluid. The injection nozzle is blocked by the previous shot, and this action causes the screw to pump itself backward through the cylinder. (During this step, material is plasticated and accumulated for the next shot.) When the mold clamp has locked, the injection phase takes place. At this time, the screw advances, acting as a ram. Simultaneously, the non-return valve closes off the escape passages in the screw and the screw serves as a solid plunger, moving the plastic ahead into the mold. When the injection stroke and holding cycle is completed, the screw is energized to return and the non-return valve opens, allowing plastic to flow forward from the cylinder again, thus repeating the cycle. 2.2.1 Feed hopper The container holding a supply molding material to be fed to the screw. The hopper located over the barrel and the feed throat connects them. 2.2.2 Injection ram The ram or screw that applies pressure on the molten plastic material to force it into the mold cavities. 2.2.3 Injection screw The reciprocating-screw machine is the most common. This design uses the same barrel for melting and injection of plastic. The alternative unit involves the use of separate barrels for plasticizing and injecting the polymer. This type is called a screw-preplasticizer machine or two-stage machine. Plastic pellets are fed from a hopper into the first stage, which uses a screw to drive the polymer forward and melt it. This barrel feeds a second barrel, which uses a plunger to inject the melt into the mold. Older machines used one plunger-driven barrel to melt and inject the plastic. These machines are referred to as plunger-type injection molding machines. 2.2.4 Barrel Barrel is a major part that melts resins transmitted from hopper through screws and structured in a way that can heat up resins to the proper temperature. A band heater, which can control temper atures in five sections, is attached outside the barrel. Melted resins are supplied to the mold passing through barrel head, shot-off nozzle, and one-touch nozzle. 2.2.5 Injection cylinder Hydraulic motor located inside bearing box, which is connected to injection cylinder load, rotates screw, and the melted resins are measures at the nose of screw. There are many types of injection cylinders that supply necessary power to inject resins according to the characteristics of resins and product types at appropriate speed and pressure. This model employs the double cylinder type. Injection cylinder is composed of cylinder body, piston, and piston load. 2.3 Clamping unit The clamping unit holds the mold together, opens and closes it automatically, and ejects the finished part. The mechanism may be of several designs, either mechanical, hydraulic or hydromechanical. Toggle clamps - a type clamping unit include various designs. An actuator moves the crosshead forward, extending the toggle links to push the moving platen toward a closed position. At the beginning of the movement, mechanical advantage is low and speed is high; but near the end of the stroke, the reverse is true. Thus, toggle clamps provide both high speed and high force at different points in the cycle when they are desirable. They are actuated either by hydraulic cylinders or ball screws driven by electric motors. Toggle-clamp units seem most suited to relatively low-tonnage machines. Two clamping designs: (a) one possible toggle clamp design (1) open and (2) closed; and (b) hydraulic clamping (1) open and (2) closed. Tie rods used to guide movuing platens not shown. Hydraulic clamps are used on higher-tonnage injection molding machines, typically in the range 1300 to 8900 kN (150 to 1000 tons). These units are also more flexible than toggle clamps in terms of setting the tonnage at given positions during the stroke. Hydraulic Clamping System is using the direct hydraulic clamp of which the tolerance is still and below 1 %, of course, better than the toggle system. In addition, the Low Pressure Protection Device is higher than the toggle system for 10 times so that the protection for the precision and expensive mold is very good. The clamping force is focus on the central for evenly distribution that can make the adjustment of the mold flatness in automatically. Hydromechanical clamps - clamping units are designed for large tonnages, usually above 8900 kN (1000 tons); they operate by (1) using hydraulic cylinders to rapidly move the mold toward closing position, (2) locking the position by mechanical means, and (3) using high pressure hydraulic cylinders to finally close the mold and build tonnage. 2.3.1 Injection mold There are two main types of injection molds: cold runner (two plate and three plate designs) and hot runner – the more common of the runnerless molds. 2.3.2 Injection platens Steel plates on a molding machine to which the mold is attached. Generally, two platens are used; one being stationary and the other moveable, actuated hydraulically to open and close the mold. It actually provide place to mount the mould. It contains threaded holes on which mould can be mounted using clamps. 2.3.3 Clamping cylinder A device that actuates the chuck through the aid of pneumatic or hydraulic energy. 2.3.4 Tie Bar Tie bars support clamping power, and 4 tie bars are located between the fixing platen and the support platen. 3 Injection mould From Wikipedia, the free encyclopedia Mold A hollow form or cavity into which molten plastic is forced to give the shape of the required component. The term generally refers to the whole assembly of parts that make up the section of the molding equipment in which the parts are formed. Also called a tool or die. Moulds separate into at least two halves (called the core and the cavity) to permit the part to be extracted; in general the shape of a part must be such that it will not be locked into the mould. For example, sides of objects typically cannot be parallel with the direction of draw (the direction in which the core and cavity separate from each other). They are angled slightly; examination of most household objects made from plastic will show this aspect of design, known as draft. Parts that are "bucket-like" tend to shrink onto the core while cooling and, after the cavity is pulled away, are typically ejected using pins. Parts can be easily welded together after moulding to allow for a hollow part (like a water jug or doll's head) that couldn't physically be designed as one mould. More complex parts are formed using more complex moulds, which may require moveable sections, called slides, which are inserted into the mould to form particular features that cannot be formed using only a core and a cavity, but are then withdrawn to allow the part to be released. Some moulds even allow previously moulded parts to be re-inserted to allow a new plastic layer to form around the first part. This system can allow for production of fully tyred wheels. Traditionally, moulds have been very expensive to manufacture; therefore, they were usually only used in mass production where thousands of parts are being produced. Molds require: Engineering and design, special materials, machinery and highly skilled personnel to manufacture, assemble and test them. Cold-runner mold Cold-runner mold Developed to provide for injection of thermoset material either directly into the cavity or through a small sub-runner and gate into the cavity. It may be compared to the hot-runner molds with the exception that the manifold section is cooled rather than heated to maintain softened but uncured material. The cavity and core plates are electrically heated to normal molding temperature and insulated from the cooler manifold section. 3.1.1 Types of Cold Runner Molds There are two major types of cold runner molds: two plate and three plate. 3.1.2 Two plate mold A two plate cold runner mold is the simplest type of mold. It is called a two plate mold because there is one parting plane, and the mold splits into two halves. The runner system must be located on this parting plane; thus the part can only be gated on its perimeter. 3.1.3 Three plate mold A three plate mold differs from a two plate in that it has two parting planes, and the mold splits into three sections every time the part is ejected. Since the mold has two parting planes, the runner system can be located on one, and the part on the other. Three plate molds are used because of their flexibility in gating location. A part can be gated virtually anywhere along its surface. 3.1.4 Advantages The mold design is very simple, and much cheaper than a hot runner system. The mold requires less maintenance and less skill to set up and operate. Color changes are also very easy, since all of the plastic in the mold is ejected with each cycle. 3.1.5 Disadvantages The obvious disadvantage of this system is the waste plastic generated. The runners are either disposed of, or reground and reprocessed with the original material. This adds a step in the manufacturing process. Also, regrind will increase variation in the injection molding process, and could decrease the plastic's mechanical properties. 3.1.6 Hot runner mold Hot-runner mold - injection mold in which the runners are kept hot and insulated from the chilled cavities. Plastic freezeoff occurs at gate of cavity; runners are in a separate plate so they are not, as is the case usually, ejected with the piece. Hot runner molds are two plate molds with a heated runner system inside one half of the mold. A hot runner system is divided into two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point above the cavity. The drops, situated perpendicular to the manifold, convey the plastic from the manifold to the part. 3.1.7 Types of Hot Runner Molds There are many variations of hot runner systems. Generally, hot runner systems are designated by how the plastic is heated. There are internally and externally heated drops and manifolds. 3.1.8 Externally heated hot runners Externally heated hot runner channels have the lowest pressure drop of any runner system (because there is no heater obstructing flow and all the plastic is molten), and they are better for color changes none of the plastic in the runner system freezes. There are no places for material to hang up and degrade, so externally heated systems are good for thermally sensitive materials. 3.1.9 Internally heated hot runners Internally heated runner systems require higher molding pressures, and color changes are very difficult. There are many places for material to hang up and degrade, so thermally sensitive materials should not be used. Internally heated drops offer better gate tip control. Internally heated systems also better separate runner heat from the mold because an insulating frozen layer is formed against the steel wall on the inside of the flow channels. 3.1.10 insulated hot runners A special type of hot runner system is an insulated runner. An insulated runner is not heated; the runner channels are extremely thick and stay molten during constant cycling. This system is very inexpensive, and offers the flexible gating advantages of other hot runners and the elimination of gates without the added cost of the manifold and drops of a heated hot runner system. Color changes are very easy. Unfortunately, these runner systems offer no control, and only commodity plastics like PP and PE can be used. If the mold stops cycling for some reason, the runner system will freeze and the mold has to be split to remove it. Insulated runners are usually used to make low tolerance parts like cups and frisbees. 3.1.11 Disadvantages Hot-runner mold is much more expensive than a cold runner, it requires costly maintenance, and requires more skill to operate. Color changes with hot runner molds can be difficult, since it is virtually impossible to remove all of the plastic from an internal runner system. 3.1.12 Advantages They can completely eliminate runner scrap, so there are no runners to sort from the parts, and no runners to throw away or regrind and remix into the original material. Hot runners are popular in high production parts, especially with a lot of cavities. Advantages Hot Runner System Over a Cold Runner System include: · no runners to disconnect from the molded parts · no runners to remove or regrind, thus no need for process/ robotics to remove them · having no runners reduces the possibility of contamination · lower injection pressures · lower clamping pressure · consistent heat at processing temperature within the cavity · cooling time is actually shorter (as there is no need for thicker, longer-cycle runners) · shot size is reduced by runner weight · cleaner molding process (no regrinding necessary) · nozzle freeze and sprue sticking issues eliminated 中文翻譯 注塑模具設(shè)計與制造 2 注射機(jī) 選自《維基百科》 注射機(jī)由兩個基本部分組成，注射裝置和夾緊裝置。注射機(jī)在注射裝置和夾緊裝置上各不相同。注射機(jī)的名稱一般是根據(jù)所用注塑單位的類型來定的。 2.1 注射機(jī)的種類 注射機(jī)主要是由他們使用的驅(qū)動系統(tǒng)類型分類的：分為液壓，電動，或混合動力。 2.1.1 液壓動力機(jī) 一直以來注射機(jī)都是用液壓動力的，直到日精塑料工業(yè)有限公司在1983推出了第一款全電動注射機(jī)。電動壓力機(jī)，也被稱為電機(jī)技術(shù)（EMT），降低了運(yùn)行成本，降低能源消耗，也解決了一些圍繞液壓機(jī)的環(huán)境問題。 2.1.2 電動機(jī) 事實(shí)證明電動壓力機(jī)更安靜，速度更快，并具有更高的精度，但機(jī)器更昂貴。 2.1.3 混合動力 混合動力注射機(jī)擁有液壓和電氣系統(tǒng)，性能比較好?，F(xiàn)在除了日本，液壓動力注射機(jī)是世界上最主要的類型。 2.2 注射裝置 注射裝置熔化聚合物樹脂并將聚合物熔體注入模具中。該裝置可能是：沖壓式或者螺旋式的。 柱塞式注射機(jī)使用液壓操作柱塞將塑料通過加熱區(qū)域推動高粘度的熔體，然后形成薄薄的一層“魚雷”，以便更好地與受熱面接觸。熔體在噴嘴處受壓并注入模具中。 往復(fù)式螺桿組合融化、軟化，注射裝置注射成型。往復(fù)式螺桿是注射螺桿的另一個術(shù)語。往復(fù)式螺桿能夠使他們來回移動。 往復(fù)式螺桿用于壓縮、熔化和輸送物料。往復(fù)螺桿由三個區(qū)域組成（如下所示）： · 進(jìn)料區(qū) · 壓縮區(qū) · 測量區(qū) 當(dāng)螺桿的外徑保持恒定時，往復(fù)式螺桿上的螺紋的深度從進(jìn)料區(qū)到計量區(qū)的開始減小。這些螺紋和筒的內(nèi)徑材料相互壓縮，從而產(chǎn)生粘性（剪切）熱。這種剪切熱主要是熔化材料。桶外的加熱帶幫助保持熔融狀態(tài)下的物料。通常情況下，注射機(jī)可以有三個或更多的加熱器帶或帶不同的溫度裝置。 注塑往復(fù)式螺桿擠出機(jī)螺桿在滾筒內(nèi)旋轉(zhuǎn)，通常由液壓驅(qū)動機(jī)構(gòu)驅(qū)動。塑料材料是通過加熱氣缸通過螺桿旋轉(zhuǎn)熔化材料成為流體。噴油嘴被上一個步驟堵塞，這個動作使螺桿通過泵反向泵入。（在這一步中，物料的塑化，為下一個步驟。積累）當(dāng)模具夾具已鎖定，注射過程發(fā)生。此時，螺桿前進(jìn)，完成一個沖程。同時，止回閥關(guān)閉螺桿中的溢流通道，螺桿作為固體柱塞，將塑料向前移動到模具中。當(dāng)注射行程和保持循環(huán)完成后，螺桿被通電返回，止回閥打開，使塑料再次從氣缸向前流動，從而重復(fù)循環(huán)。 2.2.1 進(jìn)料槽 容器保持供給到螺桿的熔融原料。 位于機(jī)筒上方的料斗和進(jìn)料口連接它們。 2.2.2 注射機(jī) 將熔化塑料材料上施加壓力注入模具型腔的機(jī)器。 2.2.3 注射螺桿 往復(fù)式螺桿機(jī)是最常見的。 該設(shè)計使用相同的進(jìn)料筒來熔化和注入塑料。 替代單元涉及使用單獨(dú)的桶來塑化和注入聚合物。這種類型稱為螺桿預(yù)增塑機(jī)或雙級機(jī)。 塑料顆粒第一階段從料斗進(jìn)料，其使用螺桿將聚合物向前驅(qū)動并熔化。 該桶供給第二個料斗，其使用柱塞將熔體注入模具中。 較舊的機(jī)器使用一個柱塞驅(qū)動的桶來熔化和注入塑料。 這些機(jī)器被稱為柱塞型注射機(jī)。 2.2.4 進(jìn)料斗 桶是一個主要部分,可以加熱樹脂到適當(dāng)?shù)臏囟龋瑥牧隙吠ㄟ^螺絲和結(jié)構(gòu)熔化。一個帶熱水器，可五段溫度控制，連接外筒。熔融樹脂提供給模具通過料斗，射出噴嘴，和一個觸摸噴嘴。 2.2.5 注射缸 液壓馬達(dá)位于軸承箱內(nèi)，連接噴油缸負(fù)荷，旋轉(zhuǎn)螺桿，熔融樹脂在螺桿的前端進(jìn)行測量。有許多類型的注射筒提供必要的力量注入樹脂根據(jù)樹脂和產(chǎn)品類型的特點(diǎn)，在適當(dāng)?shù)乃俣群蛪毫?。該模型采用雙缸式。噴油缸由缸體、活塞和活塞載荷組成。 2.3 夾緊裝置 夾緊裝置是將模具固定在一起，自動打開和關(guān)閉，并推出成品塑件。 該機(jī)構(gòu)可以是機(jī)械，液壓或液壓機(jī)械的幾種設(shè)計。 切換夾具-一個類型夾緊裝置包括各種設(shè)計。執(zhí)行器向前移動十字頭，延伸撥動桿，使移動壓板朝關(guān)閉位置移動。在運(yùn)動開始時，機(jī)械的優(yōu)勢低，速度快，但接近結(jié)束的行程，機(jī)械的優(yōu)勢很明顯。因此，當(dāng)需要時，開關(guān)夾具在循環(huán)中的不同點(diǎn)處提供高速度和高壓。他們是由液壓缸或滾珠絲杠驅(qū)動電機(jī)驅(qū)動。 切換夾具比較適合于相對較低噸位的機(jī)器。 兩個夾緊裝置：（a）一個是切換夾具裝置（1）打開和（2）關(guān)閉；（b）另外一個是液壓夾緊（1）打開，（2）關(guān)閉。 用于引導(dǎo)未示出的移動壓板的拉桿。 液壓夾具用于高噸位注射機(jī)，通常在1300至8900 kN（150至1000噸）范圍內(nèi)。 這些裝置也比切換夾具在設(shè)定位置時的噸位更靈活。 液壓夾緊系統(tǒng)正在使用公差仍然低于1％的直接液壓夾，當(dāng)然比切換裝置系統(tǒng)更好。 此外，低壓保護(hù)裝置比切換裝置系統(tǒng)高10倍，使保護(hù)精度高，當(dāng)然價格會更高。 夾緊力集中在中心，均勻分布，可以自動調(diào)整模具平面度。 液壓夾具的夾緊裝置設(shè)計的大噸位，通常超過8900千牛（1000噸）；;他們通過( 1 )使用液壓缸快速移動模具走向關(guān)閉位置, ( 2 )通過機(jī)械手段鎖定位置, ( 3)使用高壓液壓缸來最終關(guān)閉模具來制造噸位。 2.3.1 注塑模具 注塑模具主要有兩種類型：冷流道（兩板和三板的設(shè)計）和熱流道–比較常見的無流道模具。 2.3.2 注射擋板 連接模具的成型機(jī)的鋼板。一般來說，使用兩個擋板；一是固定的，另一個是可移動的，液壓地驅(qū)動以打開和關(guān)閉模具。它實(shí)際上提供了安裝模具的地方。模具可以使用夾具安裝在模具上。 2.3.3 夾緊缸 一種裝置，驅(qū)動卡盤通過氣動或液壓能源援助。 2.3.4 連接桿 連接桿支撐夾緊力，4個拉桿位于固定壓板和支承壓板之間。 3 注射模具 選自《維基百科》 模具一種中空形狀或空腔，熔融塑料被迫向其中形成所需部件的形狀。這個術(shù)語一般是指組成零件的成型設(shè)備的零件的整個裝配, 也稱為工具或模具。 模具分為至少兩半(稱為型芯和型腔) ,以允許提取零件，通常,零件的形狀一定不能被鎖定在模具中。例如，物體的側(cè)面通常不能與拉伸方向平行（型芯和型腔相互分離的方向）。他們略有角度; 對塑料制成的大多數(shù)家居用品的檢查將顯示設(shè)計的這一方面，稱為草案?！巴盃睢钡牟考A向于在冷卻時收縮到芯上，并且在空腔被拉開之后，通常使用銷來推出。以便可以將物理上不能設(shè)計成一個模具的中空部分（如水壺或玩偶的頭部）的零件可以在模制后很容易地焊接在一起。 更復(fù)雜的部分是使用更復(fù)雜的模具，這可能需要可移動的部分，稱為滑塊，這是插入到模具，形成不能僅使用芯部和空腔形成的特定特征，但然后撤回允許部分被釋放。有些模具甚至允許先前模制的部件重新插入，以允許在第一部分周圍形成新的塑性層。該系統(tǒng)可以允許生產(chǎn)的全輪胎車輪。 通常，模具制造成本非常昂貴，因此，它們通常只用于大規(guī)模大批量的生產(chǎn)。 模具要求：工程設(shè)計，特殊材料，機(jī)械和高技能的人員來制造，組裝和測試它們。 冷流道模具 冷流道模具用于將熱固性材料直接注入型腔或通過小流道和澆口進(jìn)入腔?？梢詫⑵渑c熱流道模具進(jìn)行比較，它是多段冷卻而不是加熱以保持軟化但未固化的材料。 空腔和芯板電加熱到正常模制溫度并與冷卻器管部分絕緣。 3.1.1 冷流道模具的類型 冷流道模具主要有兩種：兩板模和三板模。 3.1.2 兩板模 兩板冷流道模具是最簡單的模具。 它被稱為雙板模具，因?yàn)橛幸粋€分型平面，模具分成兩半。 流道系統(tǒng)必須位于該分型面上，因此該部件只能在其周邊處被選通。 3.1.3 三板模 三板模具與兩塊板的不同之處在于它具有兩個分離平面，并且當(dāng)塑件被彈出時，模具分成三個部分。 由于模具具有兩個分型面，所以澆注系統(tǒng)可以分別在兩個分型面上， 由于其靈活的澆口位置，使用三個平板模具可以使塑件在其表面幾乎沒有澆口疤。 3.1.4 優(yōu)勢 模具設(shè)計非常簡單，而且比熱流道系統(tǒng)便宜得多。模具需要較少的維護(hù)和較少的技能設(shè)置和操作。顏色變化也很容易，因?yàn)槟＞咧械乃兴芰隙伎梢栽诿總€循環(huán)中加染料。 3.1.5 劣勢 該系統(tǒng)的明顯缺點(diǎn)是廢塑料產(chǎn)生。 塑料是用原始材料處理或重新處理和再處理。 這增加了制造過程的一個步驟。 此外，再研磨會增加注射成型過程的變化，并且可能降低塑料的力學(xué)性能。 3.1.6 熱流道模具 熱流道模具注塑模具，其中的熱流道保持熱和絕緣的冷卻腔。 塑性自由度發(fā)生在型腔，塑料是在一個單獨(dú)的擋板，所以他們不像通常一樣,用這塊板彈出。 熱流道模具是兩板模具，在模具的一半內(nèi)部具有加熱流道系統(tǒng)。 熱流道系統(tǒng)分為兩部分：熱流道板和熱噴嘴。 熱流道板具有將平行于分型線的單個平面上的塑料輸送到空腔上方的通道。 垂直于熱流道板定位的熱噴嘴將塑料從熱流道板傳送到塑件。 3.1.7 熱流道模具類型 熱流道系統(tǒng)有許多變化。一般來說，熱流道系統(tǒng)由塑料的加熱方式來指定。有內(nèi)部和外部加熱熱噴嘴和熱流道板。 3.1.8 外部加熱熱流道 外部加熱的熱流道通道的壓力下降最小的任何流道系統(tǒng)(因?yàn)闆]有加熱器阻塞流動和所有的塑料都是熔融狀態(tài)),他們的顏色變換