Low-pressure casting device and low-pressure casting method

• US 10,272,488 B2
• Filed: 12/24/2014
• Issued: 04/30/2019
• Est. Priority Date: 12/24/2014
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Masuta, Tatsuya, Hayashi, Kenji, Tsuchiya, Shinichi
• Primary Examiner(s): Kerns, Kevin P
• Application Number:
  US15/538,968
• Publication Number:
  US 20170348767A1
• Time in Patent Office: 1,588 Days
• Field of Search: 164457, 164254, 164255, 164256, 164257, 164258, 164 61, 164 63, 164 65
• CPC Class Codes: B22C 9/067 Venting means for moulds
• CPC Class Codes: B22D 18/04 Low pressure casting, i.e. making use of pressures up to a few bars to fill the mould
• CPC Class Codes: B22D 18/08 Controlling, supervising, e.g. for safety reasons controlling or regulating in general G05
• CPC Class Codes: B22D 29/00 Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots B22D13/10, B22D11/124, B22D17/00 take precedence
• CPC Class Codes: G01F 23/00 Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm

Abstract

A low-pressure casting device is provided with a holding furnace, a stoke, a pressure control device and a molten-metal level sensor. The holding furnace holds molten metal. The stoke supplies molten metal into a casting mold via a sprue. The pressure control device moves the molten metal in the stoke and fills the molten metal in the casting mold. The molten-metal level sensor detects a surface level of the molten-metal in the stoke. The stoke has a lower end immersed in the molten metal in the holding furnace. The low-pressure casting device is configured to correct filling of the molten metal in the casting mold in a next casting based on the height of the molten metal surface detected by the molten-metal level sensor.

Claims

1. A low-pressure casting device comprising:

a holding furnace for holding molten metal;

a stoke having a lower end immersed in the molten metal in the holding furnace for supplying molten metal into a casting mold via a sprue,

a pressure control device configured to move the molten metal in the stoke and fill the casting mold with the molten metal, the pressure control device including a controller programmed to control the pressure control device during a casting cycle in which molten metal is supplied to the casting mold and a solidified article is taken out of the casting mold;

an extraction device configured to take out the molded article;

a molten-metal level sensor configured to detect a height of a molten metal surface of the molten metal in the stoke, the molten-metal level sensor being provided on the extraction device, and

the controller being programmed to correct a filling of the casting mold with the molten metal in a subsequent casting cycle based on the height of the molten metal surface detected by the molten-metal level sensor in a current casting cycle.

2. The low-pressure casting device according to claim 1, wherein

the controller of the pressure control device is further programmed to maintain the molten-metal surface in the stoke at a position higher than a molten-metal surface in the holding furnace while transitioning from the current casting cycle to the subsequent casting cycle.

3. The low-pressure casting device according to claim 1, wherein

the casting mold comprises a suction port to suction an inside of the casting mold before molten metal flows into the casting mold.

4. The low-pressure casting device according to claim 1, wherein

the controller executes a pressurization pattern to fill the casting mold with the molten metal, and the controller corrects the filling of the casting mold in the subsequent casting cycle by correcting the pressurization pattern.

5. The low-pressure casting device according to claim 4, wherein

the pressure control device further includes a pressure sensor that detects a pressure inside the holding furnace and a valve arranged to regulate a supply of air to the holding furnace,

the controller executes the pressurization pattern by controlling the valve.

6. The low-pressure casting device according to claim 1, wherein

the molten-metal level sensor is a non-contact type molten-metal level sensor.

7. A low-pressure casting method comprising:

filling a casting mold with molten metal in a holding furnace including raising the molten metal in a stoke having a lower end immersed in the molten metal in the holding furnace for supplying the molten metal into a casting mold via a sprue;

stopping the filling of the casting mold and lowering the molten metal in the stoke; and

opening the casting mold and taking a molded article out of the casting mold using an extraction device configured to take out the molded article,

detecting a height of a molten metal surface of the molten metal in the stoke using a molten-metal level sensor provided on the extraction device,

correcting the filling of the casting mold with the molten metal in a subsequent casting based on the detected height of the molten-metal surface.

8. The low-pressure casting method according to claim 7, further comprising

a suctioning step for suctioning inside the casting mold, wherein the suctioning step starts suctioning inside the casting mold before the molten metal flows into the casting mold.