JPS6038878Y2 - Induction furnace heating coil fixing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a coil fixing device for preventing movement of a heating coil.

First, a conventional induction furnace will be explained with reference to Fig. 1. The figure shows a so-called crucible in which the material to be melted is melted by passing an electric current through the material in the crucible by electromagnetic induction. In the figure, 1 is a lining material forming a crucible, 2 is a molten metal, 3 is a heating coil wound around the lining material 1, and 4 is a combination of the lining material 1 and the heating coil 3. The coil cement 5 is applied to the outer side of the lining material 1, and a plurality of iron cores are arranged at equal intervals around it. forming a passage.

6 is a lower refractory, 7 is a bottom plate, 8 is a side furnace frame, and 9 is an upper furnace frame, which is connected to the side furnace body frame 8 with bolts 10, and a refractory 11 is packed inside. The object supports the upper part of the lining material 1 from the side and at the same time presses the upper end of the heating coil 3 downward.

Reference numeral 12 denotes an electrical insulator interposed between the upper end surface of the heating coil 3 and the refractory 11.

Generally, a conventional crucible induction furnace is configured as described above.
By supplying AC power to the heating coil 3, heat is generated to the material to be melted in the crucible, which serves as a secondary conductor, and the material to be melted is melted by this heat. An attempt is made to move the heating coil 3 upward by electromagnetic force due to energization, repeated thermal contraction movement of the coil cement 4 and lining material 1, or repeated mechanical stress when tilting the furnace body for pouring. When this stress acts and exceeds the strength of the refractory 11 holding down the heating coil 3, this refractory breaks and cracks occur, and the holding effect on the heating coil 3 is lost. As a result, the heating coil moves upward, creating a gap between the lower part of the heating coil 3 and the lower part of the lining 1, and there is a risk that hot water may leak.

The present invention was developed in order to eliminate such drawbacks of the conventional induction furnace, and a holding plate is provided to press and fix the heating coil 3 from above.

Next, an embodiment of the present invention will be described with reference to FIGS. 2 and 3.

In the figure, 1 is a lining material, 3 is a heating coil, 4 is coil cement, 5 is an iron core, 8 is a side furnace body frame, 9 is an upper furnace body frame, 11 is a refractory, 12 is an electrical insulator, The configuration of each of the above parts is similar to that of the conventional induction furnace shown in FIG. The inner portions of the lower end surfaces of these presser plates are brought into contact with the upper surface of the electrical insulator 12 to press the heating coil downward.

In this case, the holding plate 13 is provided in such a way that the heating coil 3 is directly held down, so that the force holding down the heating coil is strengthened, and as described above, the holding plate 13 is provided and the heating coil 3 is held down directly. Electromagnetic force or lining material 1
Even if stress is generated in the direction of lifting the heating coil due to repeated thermal contraction of the coil cement 4, the heating coil will not move upward, and therefore there will be no gap at the bottom of the coil or lining material as in the conventional case. There is no risk of molten metal leaking from this part, and since the presser plate is made of a non-magnetic material, there is no fear of leakage magnetic flux caused by the presser plate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional induction furnace, and FIGS. 2 and 3 show an embodiment of the present invention. FIG. 2 is a plan view of a half part, and FIG. 3 is an enlarged sectional view of a part. 3... Heating coil, 9... Upper furnace body frame, 13... Pressing plate.

Claims (1)

[Scope of utility model registration request] A heating coil fixing device for an induction furnace, characterized in that a non-magnetic holding plate that presses the heating coil downward is attached to the upper furnace frame.