Patent ID: 6186219
Filing Date: 2001-02-13
Classification: B22D

Abstract:
A method for controlling a low pressure die casting machine during a mass production casting operation comprising a plurality of consecutive casting cycles, said casting machine including a crucible that receives a volume of molten metal, a pair of dies that are operable to cast a part, and means for communicating molten metal from the crucible to the dies, said method comprising the steps of:closing said dies;determining whether said casting machine is ready to begin the casting cycle;introducing pressurized air into a space in said crucible relatively above said molten metal, a pressure developed in said space gradually increasing during a first period of time and remaining generally constant during a second, subsequent period of time;forcing said molten metal through said communication means and into said dies during said first period of time;maintaining said generally constant pressure within said space during said second period of time during which said molten metal hardens into the cast part;sensing pressuring within said space during said first period of time and, if said pressure deviates from a predetermined desired pressure by a first predetermined amount, terminating the casting operation before the end of the casting cycle;exhausting pressure from said space during a third period of time, said third period of time being subsequent to said second period of time;opening said dies and removing said cast part to terminate said casting cycle;repeating the foregoing steps for subsequent casting cycles in the mass production casting operation.