This application relates to a shot sleeve for use in a die cast mold, wherein an insert is selectively placed at a shot end of a shot sleeve body.
Die cast molds are known and, typically, include a moving mold portion and a fixed mold portion. A die cavity is formed between the two portions. A shot sleeve is an elongated member that receives a molten metal. A plunger drives the molten metal through the shot sleeve and into the die cavity.
Shot sleeves may be formed of steel for a number of reasons. As the plunger moves the molten metal through the shot sleeve, there are compressive forces applied to a shot, or forward, end of the shot sleeve. In addition, there may be prolonged temperature exposure at the shot end.
These challenges are particularly true at a portion of the shot end which is aligned with a larger portion of the die cavity and, thus faces more molten metal than a more remote portion of the shot end.
In the prior art, the shot end of the shot sleeve has sometimes developed cracks. When this occurs, the molten metal may be driven into those cracks and as a part hardens within the die cavity, the molten metal may solidify within the cracks in the shot sleeve.
In the prior art, as the moveable die portion moves away from the fixed die portion, the cast part may remain stuck within the cracks in the shot sleeve. This is, of course, undesirable.
USPTO Backgrounds
USPTO Backgrounds