Molten metal molding machine

Abstract

A molten metal molding machine is provided with a heating cylinder, a linear motion member for successively feeding preheated metal rods into the heating cylinder from its rear end to successively push the metal rods toward a forward end of the heating cylinder, and a heater arranged on the heating cylinder such that the metal rods are gradually molten as they move through the heating cylinder from its rear end toward its forward end. The heating cylinder, the metal rods and a cylindrical forward end portion of the linear motion member are dimensioned such that a predetermined clearance is provided between an inner circumference of the heating cylinder and an outer circumference of each of the metal rods, the cylindrical forward end portion can enter the heating cylinder, and an outer circumference of the cylindrical forward end portion is slidable relative to the inner circumference of the heating cylinder. A preheated new metal rod of a same kind as the metal rods can, therefore, be fully pushed into the heating cylinder irrespective of a fill volume into a mold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified cross-sectional view of a molten metal molding machine according to one embodiment of the present invention at a stage that a linear motion member is at a most retracted position and a preheated metal rod is about to be newly fed to a position opposite to an opening formed at a rear end of a heating cylinder.

FIG. 2 is a similar simplified cross-sectional view as in FIG. 1, but the molten metal molding machine is at a stage that a forward end portion of the metal rod has been pushed by the linear motion member into the heating cylinder through the opening formed at the rear end of the heating cylinder.

FIG. 3 is a similar simplified fragmentary cross-sectional view as in FIGS. 1 and 2, but the linear motion member has advanced further until its pushing portion (cylindrical forward end portion) enters the heating cylinder through the opening formed at the rear end of the heating cylinder, and molten metal has been downwardly fed from a nozzle section, which is arranged on a forward end of the heating cylinder, into an injection sleeve.

FIG. 4 is a similar simplified cross-sectional view as in FIGS. 1 to 3, but injection and filling of the molten metal from the injection sleeve into a cavity of a mold has been completed.

FIG. 5 is a simplified fragmentary cross-sectional view of the molten metal molding machine of FIGS. 1 through 4 at a stage that the newly fed metal rod has been fully pushed within the heating cylinder by the pushing portion of the linear motion member.

FIG. 6 is a similar simplified cross-sectional view as in FIGS. 1 to 4, and illustrates a relationship between a push stroke of the linear motion member for a single-shot pouring of the molten metal and an overall length of one of the metal rods.

FIGS. 7A through 7F are simplified fragmentary cross-sectional views of a conventional molten metal molding machine at different stages of a molten metal molding operation, respectively.

Claims

1. A molten metal molding machine provided with a heating cylinder, a linear motion member for successively feeding preheated metal rods into said heating cylinder from a rear end thereof to successively push said metal rods toward a forward end of said heating cylinder, and a heater arranged on said heating cylinder such that said metal rods are gradually molten as said metal rods move through said heating cylinder from said rear end thereof toward said forward end thereof, wherein: said heating cylinder, said metal rods and a cylindrical forward end portion of said linear motion member are dimensioned such that a predetermined clearance is provided between an inner circumference of said heating cylinder and an outer circumference of each of said metal rods, said cylindrical forward end portion can enter said heating cylinder, and an outer circumference of said cylindrical forward end portion is slidable relative to said inner circumference of said heating cylinder,whereby a preheated new metal rod of a same kind as said metal rods can be fully pushed into said heating cylinder irrespective of a fill volume into a mold.

2. A molten metal molding machine according to claim 1, wherein said cylindrical forward end portion of said linear motion member remains in said heating cylinder except when feeding of said preheated new metal rod into said heating cylinder is performed.

3. A molten metal molding machine according to claim 1, wherein a rear-end bore section of said heating cylinder is maintained under an inert gas atmosphere.

4. A molten metal molding machine according to claim 1, further comprising: a nozzle section arranged on a side of a front end of said heating cylinder,an injection sleeve into which molten metal is downwardly fed and poured from said nozzle section, andan injection plunger for injecting and filling said molten metal, which has been fed into said injection sleeve, into said mold.

5. A molten metal molding machine according to claim 4, wherein a push stroke of said linear motion member for said pouring is set longer than an overall length of one of said metal rods.