Research On IPC-based Multi-way High-speed Vacuum Control Technology For High Vacuum Die Casting

During the filling process of the die casting process, high vacuum die casting process is a novel technology, which means the vacuum degree of the die cavity can reach about90kPa. Therefore the high-vacuum die casting can reduce the casting’s inner gas porosity to improve its mechanical properties. It is suitable for the production of complex and thin-walled parts with high intensity and toughness. Especially for the manufacturing of auto safety parts, this process owned many merits from the technology way and production efficiency.It is aimed to the applications of high vacuum die-casting in the important aluminum-alloy parts of auto. The novel multi-way high speed vacuum die casting technology was researched in the paper. The key technology is to vent gas of the die cavity from multiple ways, which means to exhaust the air out of the injection chamber, mold cavity, and the mold body. Compared to the traditional venting way, the novel method is of high venting speed and can increase the vacuum degree in the cavity.Because of the common blockage of the vacuum gate during vacuum pumping of the injection chamber, flow patterns of the aluminum fluid in the injection chamber was analyzed in this paper under the condition of different slow injection velocities and filling percentages in the chamber. And the research tries to find out the optimum parameters of the position of the plunger to guarantee the metal not to be involved into the vacuum-pumping gate and the optimum degree of the vacuum in the chamber.The new vacuum valve of the vacuum die-casting control system is the key point to guarantee the system’s reliable running. An active vacuum valve driven by hydraulic pressure was designed, whose function is to open and close the exhausting gates. In contrast to the former vacuum valve driven by liquid metal pressure, this kind of valve structure is simple and convenient to maintain. Furthermore, the more reliability and durability can be increased by large driving force of the hydraulic pressure.This high vacuum control system based on IPC-PLC method was developed. The IPC, as the master computer, was used to monitor the technology process. Meanwhile the PLC, as the slave computer, was taken charge of driving the system’s actions. The vacuum degree and humidity during the exhausting were detected by the Data Acquisition Modules (DAM). The communication between IPC and PLC was fulfilled by the RS485BUS. The system has owned such advantages as quick exhausting rate, convenience for extending, visual menu and powerful data-processing capacity etc.