Nissei Plastic Industrial Co., Ltd.

Koji Takei

Kazuo Anzai

Ko Yamazaki

Toshiyasu Koda

Kiyoto Takizawa

Mamoru Miyagawa

Ikuo Uwadaira

To insert a cylindrical metallic raw material into a melting cylinder provided in a heating holding cylinder of a metal molding apparatus and to efficiently semi-melt or completely melt the cylindrical metallic raw material, a clearance between an inner circumferential surface of the melting cylinder and an outer circumferential surface of the cylindrical metallic raw material is limited to a range in which the clearance does not exceed 1.0 mm with respect to the inner diameter of the melting cylinder and the diameter of the metallic raw material during thermal expansion and the insertion of the metallic raw material in a non-thermal expansion state into the thermally expanding melting cylinder is possible, from a linear expansion coefficient of a metallic raw material and a linear expansion coefficient of a material of the melting cylinder.

Method for melting metallic raw material in metal molding apparatus

In a metal molding machine provided having a tilt to a clamping device with an injection unit which is constituted by a liquid metallic material reservoir in which a cylinder having a nozzle portion at the tip portion equipped with a heating device at the outer periphery and an injection plunger having advance or retreat freely in the inside, and the injection cylinder at the rear portion, the metallic material feeding to the above liquid metallic material reservoir is performed in liquid by melt to the temperature of above the liquidus temperature in a melting cylinder standing the liquid metallic material reservoir to liquid metallic material surface from a feeding pipe having a smaller diameter than the inner diameter of the cylinder. The melting and feeding of metallic material is performed at an atmosphere of an inert gas such as argon.

Melting and feeding method and apparatus of metallic material in metal molding machine

The present invention relates to a method of molding a low-melting-point metal alloy which exhibits thixotropy properties in a solid-phase and liquid-phase coexisting temperature region. In this method, a temperature of a heating holding cylinder is increased to a liquidus temperature or higher at the start of a molding operation. Then a remaining material in the preceding molding remaining in the heating holding cylinder in a solid state is wholly melted. After that a temperature of the heating holding cylinder is lowered to a temperature in the solid-phase and a liquid-phase coexisting temperature region. At the same time a molding material is supplied and a provisional molding is carried out. After the temperature has reached the solid-phase and liquid-phase coexisting temperature region, a regular molding is started. By the present invention a problem of a remaining material in the heating holding cylinder, which becomes a trouble at the start of molding by injection, is solved.

Method of molding low melting point metal alloy

A method of molding a low melting point metal alloy which exhibits thixotropy properties at a solid-liquid coexisting temperature, said method comprising the steps of heating said metal alloy at a temperature in the solid-liquid coexisting temperature region to form a semisolid, supplying said semisolid to a heating/holding cylinder to be accumulated, and injecting said semisolid into a mold. At the end of the molding process, a remaining semisolid material is heated to a wholly molten state, then discharged by injection, and heating is stopped so that the molding operation is finished; or, at a temporary suspension of molding, an accumulated material is heated to a wholly molten state and, at the resumption of molding, the temperature of the heating holding cylinder is lowered to the original solid-liquid coexisting temperature region while discharging said wholly molten material by injection and resupplying with new semisolid molding material.

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Nagano-ken, Japan

Koji Takei