【正文】 following expressions [23] 9 In E q. 9, is the mechanical advantage of the hydraulic cylinder for power transmission during molding, and the resulting electric power cost of CE = HK$, the sum of the required injection pressures Pin in the feeding system and cavity during molding need to be found. Required injection pressures. Based on the mold layout design, the volume flow rate Q in the sprue is equal to the overall flow rate, and the volume flow rate in each primary and secondary runner will be divided by the separation number, Ni, according to: The volume flow rate in a gate and cavity equals to that of the runner connecting to them. Tan [24] derived simplified models For filling circular and rectangul a r channels that can be employed for the feeding system design in this study 1. Sprue and runner (circular channel) The pressure drop of sprue and runner is express e d a s: 10 2. Cavity and gate (rectangular channel) The pressure drop of cavity and gate is expressed as: Further, the temperaturedependent power law viscosity model can be defined as: Based on the values of the volume flow rate and consistency index m (T) for each simple unit, the pressure drop P can be found by using E q s. 12to15. Thus, the required filling pressure is the sum of pressure drops P in the sprue, primary runner, secondary runner, gate, and cavity: Required power consumption. Given the shape and dimensions of the part and feeding channel, the pressure drops of the sprue , runner, gate , and cavity are obtained through the calculation froE q s. 12 to 15, and are substituted into E q. 16. The required injection pressure Pin is calculated and substituted into the E q. E q s. 10 and 11, the power consumption cost CPC is calculated and depends on the variation of injection pressure, which is indirectly affected by the thickness of product as shown in the following E q .17. After substitution, this bees: 11 Then the molding cost After calculation, C molding = $+$,when HP =, n =3. on the current practical approach Based on Esq. 8 to 18 it can be shown that as the part thickness,Hp, increases, the necessary injection pressure . Molding process cost versus thickness consumption cost) decreases but the cycle time (and thus labor cost) increases and so there is a minimum total molding process cost, as shown in for the example in this study. As can be seen the minimum molding process cost is Hp =. If the test example part thickness, Hp, were increased from to , the plastic material cost is increased by %。 Department of Manufacturing Engineering amp。 1 Minimizing manufacturing costs for thin injection molded plastic ponents Abstract： Minimizing the cost of manufacturing a plastic ponent is very important in the highly petitive plastic injection molding industry. The current approach of Ramp。 After substitution which is rounded To n =3,since the mold cannot 8 contain cavities. The machine operation capacity and the leadtime of production in the example are given as , respectively. Moreover, as mentioned in the previous section, the cycle time is directly proportional to the part thickness HP. A curve of batch size against thickness is plotted in Fig. 5. As shown, at HP =, the production capability (batch size) is the production capability of n =3 is larger than the required lot size (202000units). For simplicity, the time taken for machining the depth of a thin ponent is treated as a given constant and added to the required time t CC for making a cavity insert. The C mm can then be calculated by n as expressed [1] process In the molding process, the cycle cost and power consumption cost are used to establish the molding operations cost as described in the following sections. . Mold making cost versus part thickness Cycle cost The cycle cost C is defined as the labor cost for molding machine operations. The calculation of cycle cost, given by E q. 8, mainly depends on the cycle time and number of mold cavities For the example, the value of labor cost per hour, L, is given as $, Cp can be calculated, as t cycle = n = 3 when HP = , as found earlier. And so Cp =$ Power consumption cost Typically， within the operating cycle of a molding machine， maximum power is required during injection. Hence, longer injection times and higher injection pressures increase the power consumption cost. For the purposes of this example, an injection time of tin = applied for the molding process。這種方法 就是在 產(chǎn)品設(shè)計階段 進行 分層考慮，并采用優(yōu)化技術(shù)，以降低模具設(shè)計和制造成本。 用一個 例子 來說明 這個 問題 以比較目前 常用 的做法和 文中的 新方法的不同。 假設(shè) 設(shè)計模具及成型過程的最小厚度要求 是直接 導(dǎo)致制造 的 最低成本。 因此，處理 超薄 塑料零件，需要一種新的方法， 以適應(yīng) 現(xiàn)有的模具設(shè)計原則和成型工藝。因 此，成型條件可以預(yù)測和驗證，以使早期設(shè)計的修 改是可以實現(xiàn)的。這些嘗試 在 基礎(chǔ)上最大限度地 限制了 熔融材料 在 成型過程中使用的經(jīng)驗與船舶之間的產(chǎn)品和模具的設(shè)計參數(shù)。然而，他們只是解決了設(shè)計參數(shù)的塑料零件和模具單獨在設(shè)計階段。 [ 3 ]介紹了模糊神經(jīng)自動復(fù)位的方法成型工藝參數(shù)。莫乃光等人 [ 20 ] 20 提出了一種混合神經(jīng)網(wǎng)絡(luò)和遺傳算法的辦法納入基于案例推理（ CBR的）得到初步設(shè)定成型參數(shù)的部分有類似的設(shè)計特點迅速，準(zhǔn)確。 一般來說，目前的切合實際的辦法 是 盡量減少生產(chǎn)成本的塑料部件在產(chǎn)品設(shè)計階段盡量減少厚度和尺寸的部分，然后計算出的費用，模具設(shè)計與成型過程的一部分，如圖 1中顯示。 圖 1 。一個主要目標(biāo)的產(chǎn)品設(shè)計是建立在物理尺寸的一部分，如它的厚度，寬度和長度。模具制造成本是 下列參 數(shù)費用 的總 和： – 切削深度（厚度） – 模具腔 數(shù)量 – 轉(zhuǎn)輪直徑 – G澆注系統(tǒng) 厚度 模具 生產(chǎn) * 確定射出壓力引腳， 和 能耗成本 ? 確定共同的冷卻時間 t ， 和 機器的成本運作。設(shè)計最小厚度 HP 的塑料組件，以滿足蠕變載入中撓度約束坐標(biāo)“ （ ） ，并盡量減少使用塑料材料成本 。圖 4顯示了冷卻通道布局下列標(biāo)準(zhǔn)行業(yè)慣例。 一般來說一些模具腔，模具制造費用的數(shù)額取決于加工的工作，形成所需數(shù)目的核心 /腔，橫澆道，和澆注系統(tǒng)。因此，在機器工作的切削加工澆道和澆口所 涉及的工作，形成了核心 /腔，不必加以考慮。曲線的批量大小對厚度在圖 5 中 繪制 。 24 圖 5 。因此，較長時間和較高的注射液注射壓力增加 了 能耗成本?；谀＞叩牟季衷O(shè)計，體積流量Q 在澆道等于總流量和流速的數(shù)量在每個 初級和中級階段 將 被 離職 數(shù)量所分割 ， 通過 體積流量 澆注系統(tǒng) 和腔等于該轉(zhuǎn)輪將它們連接在一起。所需注射壓力 Pin和代入計算的 E q. E q s. 10 到 11，電力消費的成本 CPC 計算 取決與變化的注射壓力 ，這是 間接受到影響的產(chǎn)品的厚度所示以下 在替代，這已成為： 26 然后 是 成型費用 After calculation, C molding = $+$,when HP =, n =3. 經(jīng) 。 如果測試的一部分厚度例如，Hp，增加了從 到 ，塑 性 原料成本增加 ％ 。目前切實可行的辦法主要側(cè)重于盡量減少