JPS6321915Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention is an induction furnace in which a pouring spout is provided at the bottom of a crucible-shaped furnace body, which has been improved to prevent solidification of molten metal at the pouring spout. related to things.

[Prior art and its problems]

In induction furnaces that have a pouring spout at the bottom of the crucible-shaped furnace body, the pouring nozzle with the pouring spout is generally made of a heat-resistant material such as alumina, but alumina is non-magnetic and the magnetic flux caused by the excitation of the induction heating coil is Since the molten metal does not flow through the pouring nozzle, the temperature of the pouring nozzle may drop, and the molten metal may solidify at the pouring port during pouring.

[Purpose of invention]

The object of this invention is to provide a crucible-type induction furnace that can prevent the solidification of molten metal at the pouring hole at the bottom of the furnace body, in order to eliminate the above-mentioned drawbacks.

[Key points of the idea]

In order to achieve the above-mentioned object, this invention forms a cylindrical pouring nozzle from a magnetic material, and also bends the lower end of the vertical yoke so that the tip surface is aligned with the lower end of the pouring nozzle. By bringing them closer together, the magnetic flux generated by the excitation of the induction heating coil is passed through the pouring nozzle to heat the pouring nozzle.

[Example of idea]

Figures 1 and 2 show an embodiment of this invention, in which an induction heating coil 2 is wound around the outer periphery of a crucible-shaped furnace body 1 made of a refractory material. It is supported by yoke 3. A cylindrical pouring nozzle 4 having a pouring port 4a is provided at the center of the bottom of the furnace body 1, and this pouring nozzle 4 is made of a magnetic material such as iron. Directly above the pouring spout 4a is a vertical rod-shaped stopper (opening/closing valve) 5 whose lower end opens and closes the pouring spout 4a.
is provided to be movable up and down, and when the stopper 5 is raised, the pouring port 4a opens and the molten metal 6 in the furnace body 1 is poured out. The lower end of the yoke 3 is bent so that the tip surface is close to the lower end of the pouring nozzle 4, and the magnetic flux 7 accompanying the excitation of the coil 2 is directed to the lower end bent portion of the yoke 3 as shown by the dotted line. The molten metal is made to flow through the pouring nozzle 4. In addition, in order to prevent the magnetic flux 7 from short-circuiting and flowing from the lower end of the yoke 3 through the refractory material to the molten metal 6, the inner surface of the lower part of the furnace body 1 is formed obliquely into a funnel shape to increase the thickness of the refractory material. It's like this. The furnace body 1 is housed in a bottomed cylindrical frame 8 with its upper outer edge sealed with a refractory material 9.

According to the embodiment, the magnetic flux 7 accompanying the excitation of the coil 2 circulates through the yoke 3, the pouring nozzle 4, and the molten metal 6, and the eddy current heat generated by the induction action of this magnetic flux 7 causes the pouring nozzle 4 to flow. Since it is heated and maintained at a high temperature, it is possible to prevent the molten metal 6 from solidifying and clogging the pouring port 4a during pouring.

In FIG. 3 showing another embodiment, the pouring nozzle 34 is a cylindrical body 34 made of a heat-resistant material such as alumina.
It is formed by surrounding the outer periphery except the upper part of a with a cylindrical body 34b made of a magnetic material such as iron, and the magnetic flux 7 flows through the cylindrical body 34b on the outer periphery and heats the entire pouring nozzle 34. ing. According to this embodiment, since a heat-resistant material such as alumina is used for the contact portion with the molten metal 6, it is possible to suppress the wear and tear of the pouring nozzle 34 due to the molten metal 6.

[Effect of idea]

According to this invention, in a crucible-type induction furnace, a cylindrical pouring nozzle at the bottom of the furnace body is made of a magnetic material, and the lower end of the vertical yoke is bent to form a tip end surface at the lower end of the pouring nozzle. The magnetic flux generated by the excitation of the induction heating coil is caused to flow through the pouring nozzle by placing the coil close to the pouring nozzle, so the pouring nozzle can be inductively heated to a high temperature and the molten metal can be prevented from solidifying at the pouring spout. This effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of this invention, FIG. 2 is a transverse sectional view taken along the - line of FIG. 1, and FIG. 3 is a longitudinal sectional view of another embodiment of this invention. 1...furnace body, 2...coil, 3...yoke, 4,
34...Pouring nozzle, 4a...Pouring port, 5...Opening/closing valve.

Claims (1)

[Scope of utility model registration request] A crucible-shaped furnace body made of a refractory material, an induction heating coil wrapped around the outer periphery of the furnace body, a plurality of vertical yokes that support the coil from the outside, and a pouring port provided at the bottom of the furnace body. In the induction furnace, the cylindrical pouring nozzle having the pouring spout is made of a magnetic material, and the induction furnace is equipped with an on-off valve that is movable up and down directly above the pouring spout and opens and closes the pouring spout. A crucible-shaped induction furnace characterized in that the lower end of the yoke is bent so that the tip surface approaches the lower end of the pouring nozzle.