# US 2018/0021847 A1 · Sprue Structure for Low-Pressure Casting Device and Low-Pressure Casting Device Having Said Sprue

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- Number: US 2018/0021847 A1
- Document ID: US20180021847A1
- Status: Published application
- Kind: A1
- Application number: 15/549,470
- Filed: 2015-02-19
- Published: 2018-01-25
- Earliest claimed: 2015-02-19
- Assignees: Nissan Motor Co., Ltd.
- Applicants: Nissan Motor Co., Ltd.
- Inventors: Yuta Sugiyama; Carl Schubeler; Giichirou Okamura
- Web page: https://patentgrep.com/patent/US20180021847A1

## CPC

- B22C 9/082: {Sprues, pouring cups}
- B22C 9/08: Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22D 18/04: Low pressure casting, i.e. making use of pressures up to a few bars to fill the mould
- B22D 18/08: Controlling, supervising, e.g. for safety reasons (controlling or regulating in general G05)
- B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B)
- B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22)

## Abstract

A sprue for a low-pressure casting device includes a stalk connection part to be connected to a stalk, a molten metal reservoir and a cavity connection part to be connected to the cavity. The shape of the molten metal reservoir is such that the perimeter of the cross section perpendicular to the flow direction of molten metal gradually increases toward the cavity connection part while the area of the cross section remains constant.

## Claims

### Claim 1

A sprue structure that is used for a low-pressure casting device to communicate a stalk with a cavity of a mold, comprising:
a stalk connection part configured to be connected to the stalk; a molten metal reservoir; and a cavity connection part configured to be connected to the cavity,
wherein the shape of the molten metal reservoir is such that a perimeter of a cross section perpendicular to a flow direction of the molten metal increases toward the cavity connection part while an area of the cross section remains constant.

### Claim 2 (depends on 1)

The sprue structure for a low-pressure casting device according to claim 1, wherein the stalk connection part has a circular cross section.

### Claim 3 (depends on 1)

The sprue structure for a low-pressure casting device according to claim 1, wherein the molten metal reservoir has a ratio of a cross-sectional perimeter at an upper end/a cross-sectional perimeter at a lower end of 1.05 or more.

### Claim 4 (depends on 1)

The sprue structure for a low-pressure casting device according to claim 1, further comprising a heater configured to heat the molten metal reservoir.

### Claim 5

A low-pressure casting device, comprising: a holding furnace configured to hold molten metal; a stalk with a lower end configured to be dipped in the molten metal in the holding furnace; a sprue communicating the stalk to a cavity of a mold; and a pressure controller configured to control a pressure in the holding furnace,
wherein the sprue comprises:
a stalk connection part configured to be connected to the stalk;
a molten metal reservoir; and
a cavity connection part configured to be connected to the cavity, and
the shape of the molten metal reservoir is such that a perimeter of a cross section perpendicular to a flow direction of the molten metal increases toward the cavity connection part while an area of the cross section remains constant.

### Claim 6 (depends on 5)

The low-pressure casting device according to claim 5, wherein the sprue comprises a plurality of sprues, and the plurality of sprues have different lengths of cavity connection parts and/or different perimeters of the cavity connection parts.

### Claim 7 (depends on 6)

The low-pressure casting device according to claim 6, wherein the stalk comprises an expanding part with a diameter increasing toward the sprue, and
the expanding part is disposed inside the holding furnace.

### Claim 8 (depends on 5)

The low-pressure casting device according to claim 5, further comprising a suctioning device configured to vacuum the cavity.

### Claim 9 (depends on 5)

The low-pressure casting device according to claim 5, wherein the stalk connection part has a circular cross section.

### Claim 10 (depends on 5)

The low-pressure casting device according to claim 5, wherein the molten metal reservoir has a ratio of a cross-sectional perimeter at an upper end/across-section a perimeter at a lower end of 1.05 or more.

### Claim 11 (depends on 5)

The low-pressure casting device according to claim 5, further comprising a heater configured to heat the molten metal reservoir.