JP5464699B2 - Inductor manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an inductor that is provided on a side portion of a molten metal plating tank and heats the molten metal in an induction heating coil section to heat the molten metal in the molten metal plating tank.

  A molten metal plating tank for performing molten metal plating on a steel sheet is provided with a molten metal runner communicating with the molten metal plating tank to heat the molten metal in the tank, and the molten metal flowing into the molten metal runner is induction heating coil An inductor for heating at the part is provided.

  Conventionally, when an inductor is manufactured, the casing of the inductor is an outer frame, the bush that protects the induction heating coil portion is an inner frame, and a core having a shape of a molten metal runner is arranged at a predetermined position to constitute a mold, A castable in a fluidized state in which water is added and kneaded is poured into a mold and filled, and after naturally drying and forced drying, the core is removed by cooling (for example, Patent Document 1).

  Here, the bush that houses and protects a part of the induction heating coil part is configured by adhering a non-conductive material such as an ebonite material or a miker sheet to a part of the stainless steel cylindrical part for the purpose of cutting off the current. . As described above, the inductor is forcedly dried after castable casting and natural drying, but when heated above 200 ° C., the above-mentioned adhesion is removed and the non-conductive material is lost, and in this state, induction heating is performed. Then, the molten metal is not heated, the bush is heated, and the function as an inductor is not exhibited. From this, in the conventional manufacturing method, the upper limit of the temperature of forced drying was 200 ° C. (Even in Patent Document 1, 200 ° C. is the upper limit).

  However, the castable state by forced drying at 200 ° C. is a so-called half-life dry state in which moisture remains inside. The inductor is attached to the plating tank in this state, and when the inductor is suddenly heated to a high temperature of about 450 ° C. by operation, the castable may expand due to the presence of moisture inside, and cracks may occur. is there.

  Further, the inductor is usually stored for a long period of time as a replacement / spare part for damage to the inductor during operation. In this case, the semi-dry inductor as described above absorbs moisture and deteriorates due to long-term storage and becomes unusable for actual operation.

JP 2009-13457 A

  The problem to be solved by the present invention is to provide an inductor manufacturing method capable of completely drying a castable.

  The present invention relates to a molten metal runner that is provided at a side portion of a molten metal plating tank, communicates with the inside of the molten metal plating tank, and has a castable periphery, and an induction heating coil section that heats the molten metal in the molten metal runner A gap securing member is attached to the outer surface of a dummy bush having the shape of a bush that is disposed inside the casing of the inductor and accommodates a part of the induction heating coil portion, and the inner surface of the casing. A mold is formed by placing the dummy bush and the core having the shape of the molten metal runner at a predetermined position in the casing; a castable castable is cast into the mold; and the castable is naturally dried. And removing the dummy bush and the core from the castable and extracting the castable from the casing. Forcibly drying the extracted castable at 300 to 500 ° C., attaching a heat-resistant buffer material to the outer surface of the bush and the inner surface of the casing, and shrinking the layer thickness of the heat-resistant buffer material, Mounting the castable and mounting the castable in a casing.

  As described above, in the present invention, the castable extracted from the casing after natural drying has no bush and no casing, so that the drying temperature can be increased to 300 to 500 ° C. in the subsequent forced drying. By this high-temperature forced drying, the castable is brought into a completely dry state in which no moisture is contained in the castable from the conventional half-life dry state. For this reason, even if the castable becomes a high temperature of about 450 ° C. due to the operation, it does not contain moisture inside, so that the expansion is small and the castable does not crack. In addition, even when stored for a long period of time as a replacement or spare part for damage to the inductor, it does not absorb moisture or deteriorate.

  If the temperature of forced drying of the castable is less than 300 ° C., some moisture remains inside the castable after drying. On the other hand, if the temperature exceeds 500 ° C., the heating effect is saturated, resulting in energy loss. Therefore, the appropriate temperature for forced drying is 300 to 500 ° C.

  After forced drying, the castable is fitted with a bush and is used for operation. In this operation, the bush is not cooled by a water-cooled pipe and heated to 200 ° C. or higher, so there is no problem in operation.

  In the present invention, the gap securing material is used to secure a gap between the two to facilitate removal of the dummy bush from the castable and extraction of the castable from the casing after natural drying. Therefore, the clearance ensuring material should just be a contractibility of the grade which can ensure the said clearance gap. Specifically, foamable plastics such as polystyrene foam and polyurethane are preferred. The dummy bush is generally made of metal, and the bush is strongly compressed by the shrinkage of the castable by natural drying, but the foamable plastic is burned and burned by heating to about 80 ° C, and a gap is formed so that it can be easily removed. It becomes possible.

  The gap securing material is removed or burned out when the dummy bushing is removed from the castable and the castable is removed from the casing, or thereafter, but the gap secured by the gap securing material is replaced with a heat-resistant cushioning material in the subsequent process. Used as a space for placement.

  During operation, the castable is constantly subjected to slight vibration from the induction heating coil. At this time, if there is a gap between the casing and the castable, the castable moves within the casing, and if a gap is formed between the molten metal plating tank, the molten metal leaks. Similarly, when the bush moves in the inductor, the non-conductive effect of the bush is lost, and energization, red heat, erosion, and the inability to heat the molten metal by induction heating occur.

  Therefore, in the present invention, the heat-resistant cushioning material is disposed between the outer surface of the bush and the inner surface of the casing and the castable so that the layer thickness is contracted. As a result, a buffering effect (spring effect) by the heat-resistant buffer material is obtained, and the occurrence of the above-described problems can be prevented.

  Any heat-resistant cushioning material may be used as long as it can exhibit a cushioning effect (spring effect) at room temperature to high temperature (operation), and specifically, a crystalline ceramic fiber is preferable.

  In the present invention, the core can be formed of a foamable plastic such as expanded polystyrene or polyurethane. Since the foamable plastic is burned and burned by heating to about 80 ° C., it can be burned by heating instead of removing the core from the castable.

  According to the present invention, the castable which is the main body of the inductor can be completely dried during the manufacturing process of the inductor. Therefore, it is possible to solve the problems of cracking during operation and moisture absorption / deterioration during storage, which were caused by the conventional semi-dry dry castable.

It is explanatory drawing of the inductor manufactured with the manufacturing method of this invention. It is explanatory drawing of the inductor manufactured with the manufacturing method of this invention. In the manufacturing method of this invention, it is explanatory drawing which shows the process of arrange | positioning a dummy bush and a core in a casing, and casting a castable. It is a perspective view which shows the shape of the core used in FIG. In the manufacturing method of this invention, after natural drying of a castable, it is explanatory drawing which shows the process of taking out a dummy bush and a core from the castable, and extracting a castable casing. It is explanatory drawing which shows the process of forcedly drying a castable in the manufacturing method of this invention. In the manufacturing method of this invention, while attaching a bush to the castable after forced drying, it is explanatory drawing which shows the process of mounting the castable to a casing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 are explanatory views of an inductor manufactured by the manufacturing method of the present invention. As shown in FIG. 1 and FIG. 2, the inductor 10 is provided at a side portion of a molten metal plating tank 40 that forms a molten metal plating layer on the surface of the steel plate 30, and communicates with the inside of the molten metal plating tank 40. A molten metal runner 12 constituted by the castable 11 and an induction heating coil portion 13 for heating the molten metal in the molten metal runner 12 are provided. A part of the induction heating coil portion 13 is accommodated in a bush 15 (see FIG. 2) disposed inside the casing 14. In FIG. 2, the induction heating coil portion 13 is omitted.

  Hereinafter, a method for manufacturing the inductor 10 will be described. First, as shown in FIG. 3, a gap securing material 21 made of foamed plastic is attached to the outer surface of the dummy bush 20 having the shape of the bush 15 and the inner surface of the casing 14, and then the dummy bush 20 and the molten metal are combined. A mold 22 is formed by placing the core 22 having the shape of the runner 12 at a predetermined position in the casing 14. At this time, a lid 14a is attached to the surface of the casing 14 to be mounted on the side of the molten metal plating tank 40 (see FIG. 1) to form a mold. In the embodiment, the dummy bush 20 is made of steel, and the core 22 is made of foamed plastic. Moreover, the code | symbol 23 in FIG. 3 is a bush fixed metal fitting.

  FIG. 4 shows the shape of the core 22. The core 22 is provided with two through holes 22a, and the dummy bush 20 is inserted into the through holes 22a and arranged in the casing 14 to form a mold.

  The castable 11 in a fluidized state in which water is added and kneaded is poured into the mold thus formed, and cast into the mold while being vibrated by, for example, a rod-shaped vibrator 50 as shown in FIG.

  After the castable 11 is naturally dried, the dummy bush 20 and the core 22 are removed from the castable 11. In the embodiment, as shown in FIG. 5, the lid 14a (see FIG. 3) of the casing 14 is removed, the dummy bush 20 is pulled upward in FIG. 5, and then the core 22 is moved horizontally from the side from which the lid 14a is removed. Pull out.

  Thereafter, the castable 11 is extracted from the casing 14. In the embodiment, the exclusive suspension 60 is mounted using the gap from which the dummy bush 20 is removed, and the castable 11 is extracted from the casing 14 by connecting the dedicated suspension 60 and lifting the wire 61. Further, a balance adjusting metal fitting 62 that holds the outer surface of the castable 11 may be used together so that the posture of the castable 11 is stabilized after the castable 11 is removed from the casing 14.

  In the steps of taking out the dummy bush 20 and the core 22 from the castable 11 and removing the castable from the casing 14 as described above, as described above, the gap securing member 21 (see FIG. 3) is provided on the outer surface of the dummy bush 20. Therefore, the dummy bush 20 can be easily taken out from the castable 11 due to its contractibility. Similarly, since the gap ensuring member 21 is attached to the inner surface of the casing 14, the castable 11 can be easily pulled out of the casing 14 due to its contractibility. Further, when the lid 14a of the casing 14 is removed and the gap between the casing 14 and the castable is widened as in the embodiment, the castable 11 can be pulled out of the casing 14 more easily.

  In the embodiment, the dummy bush 20 and the core 22 are extracted from the castable 11 and then the castable 11 is extracted from the casing 14. However, after the castable 11 is extracted from the casing 14, the dummy bush is extracted from the castable 11. 20 and the core 22 may be taken out. Further, when the core 22 is formed of foamed plastic, the core 22 can be burned off by heating at about 80 ° C. instead of being removed from the castable 11. The heating for burning out the core 22 can be performed after the natural drying of the castable until the forced drying described later. However, the core 22 may be burned out by heating for forced drying described later. it can.

  In addition, when the gap ensuring material 21 is formed of foamed plastic, after the castable 11 is naturally dried, the gap securing material 21 may be burned off by heating to facilitate the removal of the dummy bush 20 and the extraction of the castable 11. it can.

  The castable 11 extracted from the casing 14 is forcibly dried at 300 to 500 ° C. For this forced drying, a drying furnace 70 as shown in FIG. 6 can be used. That is, the castable 11 is placed in the drying furnace 70 and heated to 300 to 500 ° C. to be completely dried. The castable 11 at the time of forced drying is not provided with a bush as in the prior art and has no casing. Therefore, the temperature of forced drying can be increased to 300 to 500 ° C. As a result of the drying, the castable 11 becomes a completely dry state in which no water is contained in the castable from the conventional semi-dry state.

  After the castable 11 is forcibly dried, the castable 11 is mounted in the casing 14 as shown in FIG. At this time, the heat-resistant buffer material 24 is attached to the inner surface of the casing 14, and the castable 11 is mounted in the casing 14 so that the layer thickness of the heat-resistant buffer material 24 is contracted.

  In the embodiment, a crystalline ceramic fiber is used as the heat-resistant buffer material 24, and the crystalline ceramic fiber is compressed by the slide iron plate 80. For example, when a crystalline ceramic fiber having a thickness of 5 mm is compressed to 4 mm, a buffering effect (spring effect) can be significantly obtained. An example of the crystalline ceramic fiber is MLS-2 manufactured by Mitsubishi Plastics.

  A bush 15 is attached to the castable 11 after forced drying at the position where the dummy bush is disposed. At this time, the heat-resistant buffer material 24 is attached to the outer surface of the bush 15, and the bush 15 is attached to the castable 11 so that the layer thickness of the heat-resistant buffer material 24 is contracted. The mounting of the bush 15 may be performed before or after the castable 11 is mounted on the casing 14. In the castable 11 after forced drying, as shown in FIG. 7, a molten metal runner 12 is formed at a position where the core is disposed.

  After that, as shown in FIGS. 1 and 2, the inductor is completed when the induction heating coil portion 13 is attached to the bush 15 and installed on the side of the molten metal plating tank 40.

DESCRIPTION OF SYMBOLS 10 Inductor 11 Castable 12 Molten metal runner 13 Induction heating coil part 14 Casing 15 Bush 20 Dummy bush 21 Clearance securing material 22 Core 22a Through-hole 23 Bush fixed metal 24 Heat-resistant buffer 30 Steel plate 40 Molten metal plating tank 50 Rod vibrator 60 Dedicated lifting tool 61 Wire 62 Bracket for balance adjustment 70 Drying furnace 80 Slide iron plate

Claims (4)

An inductor provided on a side of a molten metal plating tank, including a molten metal runner that communicates with the inside of the molten metal plating tank and has a castable periphery, and an induction heating coil portion that heats the molten metal in the molten metal runner A manufacturing method of
A clearance securing material is attached to the outer surface of the dummy bush having the shape of a bush that is disposed inside the casing of the inductor and accommodates a part of the induction heating coil portion, and the inner surface of the casing, and the dummy bush and the molten metal runway Arranging a core having a shape at a predetermined position in the casing to form a mold;
Casting a fluid castable into the mold, and after the castable is naturally dried, removing the dummy bush and the core from the castable and extracting the castable from the casing;
Forcibly drying the extracted castable at 300 to 500 ° C .;
Attaching a heat-resistant cushioning material to the outer surface of the bush and the inner surface of the casing, and shrinking the layer thickness of the heat-resistant cushioning material to attach the bush to the castable and attach the castable to the casing; An inductor manufacturing method including:   The method for manufacturing an inductor according to claim 1, wherein the gap ensuring material is made of a foamable plastic.   The method for manufacturing an inductor according to claim 1, wherein the heat-resistant buffer material is made of a crystalline ceramic fiber.   The method for manufacturing an inductor according to claim 1, wherein the core is made of a foamable plastic, and the core is burned away by heating instead of being removed from the castable.

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