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US 6,745,817 B2Granted
Casting method and casting apparatus
AssigneeNissin Kogyo Co., Ltd.
InventorsKeisuke Ban, Akira Sunohara, Yasuhiro Sasaki, Koichi Ogiwara
Life of this patent
Estimating the term…
Abstract
A casting apparatus for performing a casting while an oxide film formed on a surface of a molten metal is reduced by allowing the molten metal and a reducing compound to be contacted with each other, includes: a molding die having a cavity for receiving the molten metal, a sprue from which the molten metal is poured and a feeder head portion arranged between the sprue and the cavity. A difference of heat insulation is partially provided between the feeder head portion and the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion.
Claims25
A gravity die casting method for casting a cast product having a desired shape, comprising the steps of:
- using a molding die having a cavity, a sprue from which a molten metal is poured and a feeder head portion arranged between the sprue and the cavity for casting a cast product, the molding die being formed from a material having a higher heat insulating property than a material forming the cavity such that the molding die being formed has a difference of heat insulation between the feeder head portion and the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion;
- pouring the molten metal into the cavity of the molding die;
- reducing an oxide film formed on a surface of the molten metal by allowing the molten metal and a reducing compound to be contacted with each other in the cavity of the molding die;
- setting a cooling rate of the molten metal filled in an uncoated area of the cavity at about 500° C./min. or more and a cooling rate of the molten metal poured into the feeder head portion at about 500° C./min. or less;
- and
- solidifying the molten metal filled in the cavity,
- whereby at least a part of the molten metal filled in the feeder head portion is replenished in the cavity, when a void is formed by shrinkage at the time of the solidifying step.
4 more elements
A gravity die casting method for casting a cast product having a desired shape, comprising the steps of:
- using a molding die having a cavity, a sprue from which a molten metal is poured and a feeder head portion arranged between the sprue and the cavity for casting a cast product, the cavity having a first portion, a second portion and an intermediate narrow portion disposed between the first portion and the second portion, the feeder head portion and the narrow portion being formed from a same material having a higher heat insulating property than a material forming the first portion and the second portion of the cavity such that the feeder head portion and narrow portion has a difference of heat insulation provided than the first and second portion of the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion;
- pouring the molten metal into the cavity of the molding die;
- reducing an oxide film formed on a surface of the molten metal by allowing the molten metal and a reducing compound to be contacted with each other in the cavity of the molding die;
- setting a cooling rate of the molten metal filled in an uncoated area of the cavity at about 500° C./min. or more and a cooling rate of the molten metal poured into the feeder head portion at about 500° C./min. or less;
- and
- solidifying the molten metal filled in the cavity,
- whereby at least a part of the molten metal filled in the feeder head portion is replenished in the cavity, when a void is formed by shrinkage at the time of the solidifying step.
4 more elements
A gravity die casting method for casting a cast product having a desired shape, comprising the steps of:
- using a molding die having a cavity, a sprue from which a molten metal is poured and a feeder head portion arranged between the sprue and the cavity for casting a cast product, the cavity having a first portion, a second portion and an intermediate narrow portion disposed between the first portion and the second portion, the feeder head portion being formed from a material having a higher heat insulating property than a material forming the first portion and the second portion of the cavity and the narrow portion being coated with a non-oxide insulating coating having a higher heat insulating property than the material forming the first portion and the second portion of the cavity such that the feeder head portion and narrow portion has a difference of heat insulation than the first and second portion of the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion;
- pouring the molten metal into the cavity of the molding die;
- reducing an oxide film formed on a surface of the molten metal by allowing the molten metal and a reducing compound to be contacted with each other in the cavity of the molding die;
- setting a cooling rate of the molten metal filled in an uncoated area of the cavity at about 500° C./min. or more and a cooling rate of the molten metal poured into the feeder head portion at about 500° C./min. or less;
- and
- solidifying the molten metal filled in the cavity,
- whereby at least a part of the molten metal filled in the feeder head portion is replenished in the cavity, when a void is formed by shrinkage at the time of the solidifying step.
4 more elements
A casting method for casting a cast product having a desired shape, comprising the steps of:
- using a molding die having a cavity, a sprue from which a molten metal is poured and a feeder head portion arranged between the sprue and the cavity for casting a cast product, the feeder head portion being formed from a material having a higher heat insulating property than a material forming portions of the cavity such that the molding die being formed has a difference of heat insulation between the feeder head portion and the portions of the cavity such that the molten metal filled in the cavity and the feeder head portion is sequentially solidified in a direction of from a terminal portion of the cavity to the feeder head portion;
- pouring the molten metal into the cavity of the molding die;
- reducing an oxide film formed on a surface of the molten metal by providing a carrier gas into a receptacle which holds a reducing compound to transfer the reducing compound from the receptacle to the cavity, the carrier gas does not react with the reducing compound during the transfer to the cavity;
- allowing the molten metal and the reducing compound to be contacted with each other in the cavity of the molding die;
- and
- solidifying the molten metal filled in the cavity,
- whereby at least a part of the molten metal filled in the feeder head portion is replenished in the cavity, when a void is formed by shrinkage at the time of the solidifying step.
4 more elements
Dependencies are inferred from the claim text.