Patent Number: 7,784,525

Title: Economical methods and injection apparatus for high pressure die casting process

Abstract: A method of and an apparatus for high pressure die casting are disclosed. The method uses a die casting apparatus which comprises a group of three plungers for casting metal. The two of which, injection plunger 1 and assistant plunger 3, are used to reduce metal loading time and reduce entrapped gases in die casting during a fast injection stage. By moving into injection sleeve 2, the assistant plunger separates the mold cavity 11 from the space defined by assistant plunger 3, injection sleeve 2, and injection plunger 1. The flow power device for moving said assistant plunger 3 is mounded on a back plate 8. A third plunger, the intensification plunger 12, is used to squeeze casting as soon as the injection plunger advances to a position in which the runner is separated from the closed space. This separated injection and intensification systems eliminates slow shot speed and fast shot deceleration stages and can use a position-limiting switch to start intensification which eliminates the need for a complex hydraulic valve system.

Inventors: Dai; Zhongnan (Palatine, IL)


International Classification: B22D 17/08 (20060101); B22D 18/02 (20060101); B22D 27/11 (20060101)

Expiration Date: 8/31/12018