靜水壓擠製成'形之製程控制

Abstract

靜水壓擠製係利用高壓液體做為媒介將工件擠壓過模具成形，此一製程有高擠製比及成品低缺陷之優點，然而高靜水壓擠製設備之設計製造的困難度與費用均高，致使現今國內相關的研究仍嫌不足。目前，本實驗室已有超高靜水壓擠製筒、高壓擠桿、高壓油封及背壓系統等擠製設備，並也完成擠製測試。 為求可以將此一設備達到工業界實用的目標，所以本研究將現有設備加以改進並增加回饋設計，以求取精確的控制。另外，為求減少人為造成的誤差，所以擠製程序之控制也在研究中完成了設計製造與測試。最後，利用改進得到的靜水壓設備及控制系統，進行了系統化的擠製實驗，以觀察並探索製程中包含主壓擠製，給壓方式及背壓等參數對擠製製程的影響。

Hydrostatic extrusion is a process under which a high hydrostatic pressure is directly used to push the material through extrusion die. High extrusion ratio and high quality for products are two main advantages for this process. Traditionally, the hydrostatic extrusion apparatus is expensive and difficult to manufacture, therefore there are almost no researches of hydrostatic extrusion in Taiwan. Recently, our laboratory established an apparatus of hydrostatic extrusion , which included ultrahigh hydrostatic extruder, high-pressure plunger, high-pressure seal and backpressure system. Preliminary extrusion tests had also been conducted successfully. This research focused on improving this apparatus by adding feedback control system for accurate control of extrusion process. In addition, PC-based process control interface had been designed, set up, and tested in order to reduce the human error during operations. Finally, a series of extrusion experiment had been conducted using this improved apparatus. The effects upon extrusion products resulted by process parameters, such as the input modes of main pressure, the backpressure and the controlled extrusion speed, were observed.