Mounting expendable core in die cast die
AssigneeGeneral Motors Corporation
InventorsStuart W. Anderson, Bradley C. Menaugh, Donnie D. Rhum
Life of this patent
Estimating the term…
Abstract
An expendable core is positioned in the molding cavity of a die casting die including hollow mounting pins affixed to the die which mate with recesses formed in the expendable core. Vacuum applied to the recesses through the hollow mounting pins anchors the core in the die cavity.
Claims17
A method for positioning an expendable core in a molding cavity defined by a plurality of die segments forming a permanent molding die comprising the steps of:
- a. forming an internal passageway in at least one of said segments;
- b. anchoring at least one mounting pin on a face of said segment such that said pin projects into said cavity, said pin having a bore extending therethrough in alignment with said passageway;
- c. forming a recess in said core conforming substantially to the external shape of said pin and adapted to mate with said pin;
- d. positioning said core on said segment such that said pin nests in said recess;
- and
- e. drawing a vacuum in said passageway, bore and recess sufficient to anchor said core securely in place on said pin.
In a die casting die comprising a plurality of die segments cooperating in a die-closed position to define a molding cavity for shaping molten metal into a casting having a desired configuration conforming to the shape of said cavity, and an expendable core positioned in said cavity for forming a chamber within said casting following removal of said core from said casting, the improvement comprising:
- a. a passageway in one of said die segments for connecting to a source of vacuum;
- b. at least one mounting pin projecting from a face of said die segment into said cavity;
- c. a recess in said core conforming substantially to the external shape of said pin, said recess receiving said pin in close fitting relation;
- and
- d. a bore extending through said pill and in alignment with said passageway for applying vacuum to the interior surface of said recess to anchor said core to said segment.
A method of making a block for a liquid-cooled internal combustion engine, said block defining at least one cylindrical combustion chamber and a cooling jacket surrounding said combustion chamber and separated from said combustion chamber by a cylinder wall, comprising the steps of:
- a. providing an expendable core conforming to the shape of the cooling jacket, said core having a mounting end, a distal end remote from said mounting end, and an internal annular wall extending between said ends and defining a cylindrical opening in said core;
- b. providing a plurality of die segments which together, in a die-closed position, form a permanent molding die defining a molding cavity for shaping said block, at least one of said die segments having a face from which a cylindrical mandrel projects for forming said combustion chamber, said mandrel having an external surface;
- c. forming an internal passageway in said one die segment;
- d. anchoring at least one mounting pin on a face of said one die segment such that said pin projects into said cavity adjacent said mandrel, said pin having a bore extending therethrough in alignment with said passageway;
- e. forming a recess in said mounting end of said core adapted to mate with said pin;
- f. positioning said core around said mandrel such that said internal annular wall is substantially uniformly spaced from the external surface of said mandrel, and said recess mates with said pin;
- g. drawing a vacuum in said passageway, bore and recess sufficient to anchor said mounting end of said core securely in place on said pin;
- h. closing said molding die;
- i. casting molten metal into said cavity about said core;
- j. removing said block from said molding die following solidification of said metal;
- and
- k. removing said expendable core from the block so as to provide said cooling jacket about said combustion chamber.
Dependencies are inferred from the claim text.