機(jī)械專業(yè)文獻(xiàn)翻譯--微型模具成型的熱量和擠壓控制-資料下載頁
2025-05-12 00:20本頁面
【導(dǎo)讀】小核心傳感器組合起來，構(gòu)建一個注射模具的擠壓系統(tǒng)。它作為原動力，驅(qū)動中心模具工作。舉例說吧，在注射以后，模腔中的壓力會從二十兆帕上升。那些小小的感應(yīng)器形成感受到壓力，那些周圍的裝置和熱敏傳感器，排列在洞。為了評估該注射系統(tǒng)，我們做了一個厚度為1lm角度為140℃三角凹朝槽來進(jìn)行工作。這個部件配備有特殊裝置來控制模腔。是圓柱形的，直徑為25mm，高度為54mm，它的溫度約在20℃和120℃之間。就會測出其位移，并作出下一步的控制動作。該位移傳感器是非接觸式傳感器，其最大是量程。注射壓力的測量由位于注射壓力機(jī)后面的壓。力計來測量，并以數(shù)字表格形式在輸出裝置上顯示。在注射壓力保持不變的那一階段，模腔內(nèi)的應(yīng)力迅速下降到零。歷了與模腔內(nèi)壓力變化規(guī)律相似的變化。源不斷地流經(jīng)流道，最終達(dá)到成型模腔。原因就是因與注射時的速度與模具微小結(jié)構(gòu)的質(zhì)量有關(guān)，另外三角形凹槽的深度。和排列密度也是其原因之一。
【正文】 oad cell placed behind the injection molding machine screw derived the injection pressure in the figure. Fig. 3. Measurements Fig. 4. Measurements of sensors (without) of sensors (with) Upper figures of Fig. 3 show the molding cycle. First at s, the injection starts and the injection pressure suddenly rises. At s, the injection pressure is held at 34 MPa for 2 s. The cavity 機(jī)械專業(yè)中英文文獻(xiàn)翻譯 pressure, measured by the 1 axis force sensor, increase with a s delay, to reach only 20 MPa, which is 59% of the injection pressure. The cavity pressure quickly went down to about zero during the injection pressure holding period. This shows that despite the pushing force at the source of the injection molding machine, friction reduces pressure which is dropped at cavity. Also, when the resin solidified in the cavity, it parted from the mold to drop the pressure to zero. The core displacement shows a transition similar to the cavity pressure indicating that it was pressed back by the resin. After further cooling to 14 s, the mold was opened. Lower figures of Fig. 3 show the surface temperature and heat flux transitions. The horizontal axes are magnified in the lower figures around the pressure holding figure shows the sequential surface temperature rise at the lock pin, gate, and cavity as resin passed over them. The heat flux maximized immediately after injection and gradually decreased. Especially at the gate, the heat flux went down to about zero during pressure holding. In Fig. 4, a voltage of 1000 V was applied to the piezo element for 2 s starting at s. The voltage raised the cavity pressure to 34 MPa. The core gradually advanced with drop in cavity pressure from the position pressed in by the resin to eventually reach 9 lm ahead of its original position. Cutting the voltage retracted the core to its original position. But, we were not able to observe change in surface temperature and heat flux due to change in heat transfer from applying voltage. Next we pare form features on the product with and without the moldcore extrusion. Figures 5 and 6 show the SEM photographs and the AFM measurement results. The photographs reveal that the triangular grooves had a uniform pitch with smooth surface regardless of moldcore extrusion, and good form transfer to the products. The reasons are smooth flow of polystyrene and the small aspect ratio of the groove depth and pitch.
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