JP2009218017A - Movable iron core induction heating furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating furnace can minimize heat generation of a magnetic circuit. <P>SOLUTION: The induction heating furnace includes a superconductive fixed body connected with a DC power source, a movable iron core arranged on a space formed by dividing a DC current path of the fixed body, and a rotary drive source for rotating the movable iron core. A mounting section of an object to be heated is formed between one movable iron core arranged in the space and the fixed body, between a pair of movable iron cores arranged in the space in the series direction, or between the other dividing sections of the fixed body. Magnetic resistance generated between the movable iron core and a fixed iron core becomes small when the movable iron core is directed in the consecutive direction with the fixed iron core by rotating the movable iron core, magnetic resistance generated between the movable iron core and the fixed iron core becomes large when the movable iron core is directed in the non-consecutive direction wherein a gap is generated between the movable iron core and the fixed iron core, and the object to be heated is heated in this structure by generating a variable magnetic field in the vicinity of the object to be heated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a movable iron core induction heating furnace, in which an object to be heated is not directly heated using a burner, a heater or the like, but is induction heated.

When a metal material is heated in hot forging or the like, the metal material is often directly heated using a burner or a heater.
Instead of the direct heating method of the metal material using this burner or the like, a metal rod is inserted in a coil connected to an alternating current in a non-contact manner, and an eddy current having a density near the surface of the metal rod is caused by the alternating current flowing in the coil. There is provided a high-frequency induction heating method in which the surface of a metal rod is heated in a non-contact manner by this eddy current.
However, the high-frequency induction heating method has a problem in that the coil itself generates heat because a large alternating current flows through the coil to generate eddy current. For this reason, a copper tube in which cooling water is circulated is used as a coil conductor, so that there is a problem that heating efficiency is deteriorated and heating cannot be performed with high efficiency.

In addition, in the induction heating of a moving metal product provided in Japanese Patent Application Laid-Open No. 60-10581 (Patent Document 1), a conveyance roller that moves the product to be heated in a horizontal direction and a conveyance path are continuously provided. It is described that the laminated magnetic circuit and the induction coil housed in the groove of the magnetic circuit, the induction coil generates a heating magnetic flux to heat the product to be heated, and the heating magnetic flux changes with time. ing.
In this Patent Document 1, the induction coil is composed of a normal conducting wire, and a considerably large magnetomotive force (current) is necessary to obtain an effective heating force. When the current value is increased, heat generation becomes intense, and cooling is performed as in Patent Document 1. Water is needed. Therefore, since the conveyance roller needs to be cooled, a water channel for circulating a cooling fluid such as water is provided. That is, even in Patent Document 1, there is a problem that a cooling water channel is required in order not to lower the magnetic permeability of the magnetic material, heating efficiency is deteriorated, and heating cannot be performed with high efficiency.

JP-A-60-10581

  The present invention eliminates the heat generation of the coils constituting the magnetic circuit when energizing a large current, which is a problem in the induction heating method, while adopting the induction heating method. The problem is to be able to heat with the.

In order to solve the above problems, the present invention provides:
A superconducting fixed body connected to a DC power source;
A movable iron core disposed in a space formed by dividing the DC current path of the stationary body;
A rotation drive source for rotating the movable iron core;
Between one movable iron core and a fixed body arranged in the space, between a pair of movable iron cores arranged in series in the space, or between other divided parts of the fixed body as an arrangement part of the object to be heated,
When the movable iron core rotates and becomes a continuous direction with the fixed iron core, the magnetic resistance generated between the movable iron core and the fixed iron core is reduced, and when the movable iron core becomes a non-continuous direction in which a gap is formed between the fixed iron core and the movable iron core. A movable core induction heating furnace characterized in that a variable magnetic field is generated with a large magnetic resistance generated between an iron core and a fixed iron core, an alternating magnetic field is generated around the object to be heated, and the object to be heated is heated. Is provided.

The fixed body is formed by winding a superconducting coil connected to a DC power source around a fixed iron core.
Note that the opposing N pole and S pole of a permanent magnet made of a bulk superconducting material may be coupled to a fixed iron core, or the fixed iron core may be made of a permanent magnet made of the bulk superconducting material.
The fixed iron core is preferably a laminated body of silicon steel in order to suppress generation of eddy current due to iron loss.
Further, the movable iron core is formed of a magnetic material such as a silicon steel plate having a rod shape or a rectangular flat plate shape, and the center in the length direction is fixed to a rotating shaft rotated by the rotation driving source including a motor. preferable.

In the present invention, as described above, a superconducting coil is connected to a DC power source, a large DC current is passed, and the magnetic resistance is increased or decreased in combination with a movable iron core that is driven to rotate, thereby using a superconducting material for heating. It is characterized by being. That is, since the superconducting coil is used while being held at a superconducting temperature of extremely low temperature, it has not been used as a heating conductor. However, in the present invention, a superconducting coil (or superconducting magnet) capable of flowing a large current is used. Heat generation occurs when an AC large current is applied to the superconducting coil when used for heating, but when a large DC current is applied, the heat generation does not occur. Heat generation is suppressed, heating efficiency is increased, and an object to be heated can be heated with high efficiency.
In addition, when an alternating current is used, an alternating magnetic field can be generated in the vicinity of the object to be heated, but the present invention uses a direct current. Therefore, as described above, the fixed core around which the superconducting coil is wound is divided. A space is formed, and a movable iron core that is rotated by rotation driving means is disposed in the space, and the gap between the movable iron core and the fixed iron core is periodically increased or decreased to increase or decrease the magnetic resistance periodically, and a direct current is passed. However, a fluctuating magnetic field is formed. As a result, similarly to the case where an alternating current is used, a varying magnetic field is generated around the object to be heated, and the object to be heated can be heated.
In addition, when a motor is used as the rotation driving means for the movable iron core, the rotation speed of the movable iron core can be arbitrarily controlled, and the magnetic field amplitude and frequency can be adjusted accordingly, and the heating temperature can be easily adjusted.

In a specific first form, the fixed iron core is C-shaped to form the space between both ends,
One said movable iron core is arrange | positioned in the said space at the one end side of a fixed iron core, and it is the arrangement | positioning part of the said to-be-heated object between this movable iron core and the other end side of the said fixed iron core.
When the movable core is rotated, one end of the movable core is continuous with the tip of the fixed core with a minute gap, and the other end is continuous with the object to be heated with a minute gap. The reluctance is reduced. When rotated 90 degrees from this state, the gap between one end of the movable core and the fixed core, the gap between the other end and the object to be heated is maximized, and the magnetic resistance generated in the gap is increased. According to the rotation, the magnetic resistance can be periodically changed from small to large to small to large.

In a specific second form, the fixed iron core is C-shaped to form the space between both ends,
In the space, a pair of the movable iron cores are arranged on both ends of the fixed iron core, and the space between the movable iron cores serves as an arrangement portion for the object to be heated, and the pair of movable iron cores are synchronously rotated.
In the second form, if the space formed by dividing the fixed core is the same length as the first form, the length of the pair of movable cores can be shortened, and the pair of movable cores can be rotated at high speed. In addition, the switching time for increasing / decreasing the magnetic resistance can be shortened, and the frequency can be made higher than in the first embodiment.

In a specific third form, the fixed core is a pair of left and right rod-shaped fixed cores arranged in parallel,
In the central portion sandwiched between the pair of fixed iron cores, a pair of upper and lower rod-shaped fixed iron cores of a permanent magnet made of a bulk superconductor is disposed on both upper and lower sides by placing an arrangement portion of an object to be heated,
A pair of upper and lower left movable iron cores are disposed in a space formed between upper and lower ends of the left fixed iron core and the central upper and lower fixed iron core, and between the upper and lower ends of the right upper iron core and the central upper and lower fixed iron core. A pair of upper and lower right movable iron cores are arranged in the space formed in
The rotation drive source rotates the right movable iron core and the left movable iron core 90 degrees in phase.
In the above configuration, four movable iron cores are required on the left, right, top, and bottom, and a motor that rotates each of these movable iron cores is required. However, high-frequency and high-power output according to the rotation of the left and right movable iron cores that rotate 90 degrees in phase. A variable magnetic field can be generated.

In a specific fourth embodiment, the fixed iron core is two fixed iron cores of L type and inverted L type,
One movable iron core is arranged in a space between one ends of the two fixed iron cores, and a space between the other ends of the two fixed iron cores is used as an arrangement portion for the object to be heated.

  In a specific fifth form, the fixed iron core is formed of a cylindrical frame, and a pair of projecting pieces project from the upper and lower inner surfaces at both left and right ends, and each is rotated by a motor in a central space between the upper and lower projecting pieces. A magnetic rotating shaft to be driven is arranged, the center of the movable iron core is fixed to the magnetic rotating shaft, and the arrangement portion of the object to be heated is disposed in a cylindrical frame surrounded by the fixed iron core on the left and right magnetic rotating shafts. Open and project in opposition.

The object to be heated to be heated in the induction heating furnace of the present invention may be a metal material. When the material to be heated is an insulating material, the object to be heated is disposed in the arrangement portion of the object to be heated while being accommodated in a magnetic container. can do.
Furthermore, the arrangement part of the object to be heated may be either an arrangement part that can detachably mount the whole or a part of the object to be heated, or an arrangement part that moves the object to be heated.

In the present invention, since a DC superconducting coil is used, the heat generation of the coil can be minimized even when a large current flows, and the magnetic resistance is increased / decreased in combination with the movable iron core to be rotationally driven. By generating a variable magnetic field at the periphery, the object to be heated can be efficiently heated.
In particular, since the movable iron core is rotated by a motor, high-speed rotation is possible and a high-frequency, high-output variable magnetic field can be generated. The input energy becomes the rotational force of the motor, and the motor efficiency becomes the heating efficiency. It can be heated with efficiency. And the rotational speed of a movable iron core can be arbitrarily controlled with a motor, and according to it, the amplitude and frequency of a magnetic field can also be adjusted and heating temperature can be adjusted easily.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a movable core induction heating furnace 10-1 of the first embodiment.
The movable core induction heating furnace 10-1 has a fixed body formed by winding a superconducting coil 12 around a vertical wall 11a of a substantially C-shaped fixed core 11 in a housing 20 indicated by a one-dot chain line in FIG. Yes. Superconducting coil 12 is connected to DC power supply 13. The fixed iron core 11 is formed from a laminate of steel plates.
A cooling jacket 14 that seals the superconducting coil 12 is attached to the vertical wall 11a of the fixed iron core 11 around which the superconducting coil 12 is wound, and the superconducting coil 12 is held in the cooling jacket 14 at a superconducting temperature such as liquid nitrogen. Filled with coolant.

  The fixed iron core 11 has upper and lower horizontal walls 11b and 11c projecting from upper and lower ends of the vertical wall 11a, and projecting downward projecting portions 11d and upward projecting portions 11e from the tips of the upper and lower horizontal walls 11b and 11c. The space S1 is divided.

  In the space S1, one movable iron core 15 is arranged on the tip surface side of the downward projecting portion 11d, and the space between the movable iron core 15 and the upward projecting portion 11e serves as an arrangement portion of the object to be heated 16, and the projecting portion 11d The space S <b> 1 between 11 e is made continuous with the movable iron core 15 and the object to be heated 16 arranged in series. The object to be heated 16 is a bar in this embodiment. The iron bar is placed on an arrangement frame portion 17 provided on the upper surface of the upward projecting portion 11e.

  The movable iron core 15 is made of a substantially rectangular plate made of silicon steel plate, and both lengthwise ends 15a and 15b are arcuate. A shaft hole 15c is provided at the center of the movable iron core 15, and a rotary shaft 19 that is rotationally driven by a motor 18 is passed through and fixed to the shaft hole 15c. When the rotary shaft 19 that supports the movable core 15 is supported by a bearing (not shown) of the housing 20, and the movable core 15 is positioned in the vertical direction shown in FIG. The tip end surface is set to be a substantially continuous position with a minute gap, and the other end 15b is set to be a substantially continuous position with the heated object 16 and a minute space. Therefore, as shown in FIG. 1 (B), when the movable iron core 15 rotates 90 degrees and is in a direction perpendicular to the line connecting the protruding portions 11d and 11e, the one end 15a is larger than the front end surface of the protruding portion 11d. The discontinuous position with C1 is opened, and the other end 15b is also a discontinuous position with the object 16 to be heated and a large gap C2.

In the movable core induction heating furnace 10-1 having the above-described configuration, a direct current is passed through the superconducting coil 12, and the dielectric 15 is rotated by the motor 18 in the counterclockwise direction indicated by the arrow.
As shown in FIG. 1 (A), when the upper end 15a of the movable iron core 15 is located at the front end surface of the protruding portion 11d of the fixed iron core 11 and the lower end 15b is substantially continuous with the upper end surface of the article to be heated 16, these continuous positions are obtained. The generated resistance magnetic field is minimized. When the movable iron core 15 rotates, both ends 15a and 15b move away from the tip surface of the projecting portion 11d and the object to be heated 16, and the gap between them gradually increases and the magnetic resistance increases. When the position shown in FIG. 1B is reached, the gaps C1 and C2 are maximized and the magnetic resistance is maximized. Further, when rotating in the direction shown in FIG. 1 (A), the magnetic resistance gradually decreases.

That is, as shown in FIG. 3, the magnetic field repeatedly increases and decreases periodically to generate a fluctuating magnetic field around the object to be heated 16, and an eddy current can be generated to heat the object to be heated 16.
In particular, since the superconducting coil 12 capable of flowing a large current is used and a direct current is passed through the superconducting coil 12, no heat is generated or the heat generation can be minimized. The energy input for heating the object to be heated 16 becomes rotational driving energy of the motor that rotates the movable iron core 15, the efficiency of the motor becomes the heating efficiency, and the object to be heated 16 can be heated with high efficiency.

4 to 6 show a second embodiment.
In the movable core induction heating furnace 10-2 of the second embodiment, the two movable iron cores 15-1 and 15-2 are arranged in the space S1 between the protruding portions 11d and 11e of the C-type fixed iron core 11, A portion between the two movable iron cores 15-1 and 15-2 is an arrangement portion of the object to be heated 16.
Since the distance of the space S1 is the same as that of the first embodiment, the two movable iron cores 15-1 and 15-2 are shorter than the movable iron core 15 of the first embodiment.
These two movable iron cores 15-1 and 15-2 are rotated synchronously as indicated by the arrows in FIG. 4 on the rotating shafts 19-1 and 19-2 which are driven to rotate by a motor (not shown). is doing.
Moreover, the to-be-heated object 16 arrange | positioned between the movable iron cores 15-1 and 15-2 is supported by the support part 21 provided in the right-and-left both sides wall of the housing 20 shown in FIG.
Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the second embodiment, since two short movable cores 15-1 and 15-2 are used, the movable core 15 can be rotated at a higher speed than the movable core 15 of the first embodiment. As a result, as shown in FIG. 6, the increase / decrease interval of the magnetic field can be shortened, the frequency can be increased, and the frequency can be made higher than that of the first embodiment.

7 and 8 show a third embodiment.
In the movable core induction heating furnace 10-3 of the third embodiment, the fixed iron core is a pair of left and right rod-like fixed iron cores 11-1 and 11-2 arranged in parallel, and the fixed iron cores 11-1 and 11-2 respectively. Superconducting coils 12-1 and 12-2 connected to a DC power source (not shown) are wound.
A pair of upper and lower fixed iron cores 22-1 and 22-2 made of rod-shaped superconducting permanent magnets are arranged at a central position between the left and right fixed iron cores 11-1 and 11-2. A space is provided between the pair of upper and lower fixed iron cores 22-1 and 22-2 as an arrangement part of the object to be heated 16.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.

In the upper space between the upper end of the left fixed iron core 11-1 and the central upper fixed iron core 22-1, the first movable iron core 15-3, the fixed iron core 11-1, and the lower fixed iron core 22-2 in the center, The second movable iron core 15-4 is arranged in the lower space between the two. Further, in the upper space between the upper end of the right fixed iron core 11-2 and the central upper fixed iron core 22-1, the third movable iron core 15-5, the fixed iron core 11-2 and the central lower fixed iron core 22-2. The fourth movable iron core 15-6 is arranged in the lower space between the two.
The first to fourth movable iron cores 15-3 to 15-6 are fixed to rotational drive shafts 19-3 to 19-6 of motors (not shown), respectively. The first and second movable iron cores 15-3 and 15-4 on the left side are rotated counterclockwise in synchronization, and the third and fourth movable iron cores 15-5 and 15-6 on the right side are also synchronized counterclockwise. And the left first and second movable iron cores 15-3 and 15-4 and the right third and fourth movable iron cores 15-5 and 15-6 are rotated by 90 degrees and shifted. is doing.

  In the said 3rd Embodiment, it operate | moves as shown to FIG. 7 (A) (B) (C), In FIG. 7 (A), the 1st, 2nd movable iron cores 15-3 and 15-4 on the left are both sides. The fixed iron cores 11-1 and 22-1, and 11-1 and 22-2 are in continuous positions, and the magnetic resistance is minimized. At this time, the third and fourth movable cores 15-5 and 15-6 on the right side are in the discontinuous positions where the fixed cores 11-2 and 22-1 and 11-2 and 22-2 on the both sides are the most spaced. The magnetoresistance is maximized.

When the first to fourth movable iron cores 15-3 to 15-6 rotate 45 degrees to the position shown in FIG. 7B, the upper ends and the center of the first movable iron core 15-3 and the left fixed iron core 11-1 are arranged. An air gap increases between the upper fixed iron core and the upper end of 22-1 and the air gap between the second movable iron core 15-4 and the lower end of the fixed iron core 11-1 and the lower end of 22-2 increases.
Similarly, the space | gap between the fixed iron cores 11-2 and 22-1 and 22-2 also increases on both sides of the third and fourth movable iron cores 15-4 and 15-5 on the right side.
Thus, the magnetic resistance becomes large at four locations due to the large gaps on both sides of the four movable iron cores 15-3 to 15-6.

  When the first to fourth movable iron cores 15-3 to 15-6 are further rotated 45 degrees to the position shown in FIG. 7C, the first and second movable iron cores on the right side are reversed. The gap on both sides of 15-3 and 15-4 is maximized and the magnetic resistance is maximized. On the other hand, the third and fourth movable iron cores 15-5 and 15-6 on the right side are continuous with the fixed iron cores 11-2, 22-1, and 22-2 on both sides, and the magnetic resistance is minimized.

As shown in FIGS. 7A, 7B and 7C, when the first to fourth movable iron cores 15-3 to 15-6 rotate, a magnetic field is generated as shown in FIG. In FIG. 8, point A shows the magnetic field generated at the position shown in FIG. 7A, point B shows the position shown in FIG. 7B, and point C shows the magnetic field generated at the position shown in FIG. Thus, by increasing the amplitude of the magnetic field, the variable magnetic field generated at the periphery of the object to be heated 16 can be increased, and the object to be heated 16 can be heated with high output. And since the four 1st-4th movable iron cores 15-3 to 15-6 are small, they can be rotated at high speed, and can be heated at a high frequency as in the second embodiment.
That is, when the heating furnace of the first embodiment is low-frequency induction heating and the heating furnace of the second embodiment is high-frequency induction heating, the heating furnace of the third embodiment can be induction-heated with high frequency and high output.

FIG. 9 shows a fourth embodiment.
In the movable core induction heating furnace 10-4 of the fourth embodiment, two fixed iron cores, that is, a fixed iron core 11-3 as an L shape and a fixed iron core 11-4 as an inverted L shape are used. These fixed iron cores 11-3 and 11-4 are arranged so as to form a rectangular frame with a space between both ends, one movable iron core 15 is arranged in one space, and the other space is heated. The arrangement part of the object 16 is used.
The two fixed iron cores 11-3 and 11-4 are respectively wound with superconducting coils 12-1 and 12-2 connected to a DC power source (not shown), and the movable iron core 15 is a motor (not shown). It is fixed to the rotation axis.

  Also in the fourth embodiment, the movable iron core 15 rotates, and at the position shown in FIG. 9A, the fixed iron cores 11-3 and 11-4 and the movable iron core 15 become continuous positions, and the magnetic resistance decreases. Further, the position rotated 90 degrees in FIG. 9B becomes a discontinuous position, and the magnetic resistance increases. Thus, by increasing or decreasing the magnetic resistance, a variable magnetic field can be generated around the object to be heated 16 and heated.

10 to 12 show a fifth embodiment.
In the movable core dielectric heating furnace 10-5 of the fifth embodiment, the fixed core 11-5 is formed of a cylindrical frame, and the superconducting coil 12 is wound around the inner peripheral surface thereof. The fixed iron core 11-5 has a pair of protruding pieces 11-5a and 11-5b, 11-5c and 11-5d protruding from the upper and lower inner surfaces at both left and right ends. Iron rotating shafts 19-7, 19 that are rotationally driven by a motor (not shown) in central spaces sandwiched between left and right upper and lower protruding pieces 11-5a and 11-5b, 11-5c and 11-5d, respectively. The first movable iron core 15-7 and the second movable iron core 15-8, whose centers are fixed to -8, are arranged, and the first and second movable iron cores 15-7 and 15-8 are rotated in the same direction in synchronization. Yes. Further, the left and right rotating shafts 19-7 and 19-8 are protruded into a cylindrical frame 11-5 serving as a fixed iron core, and the space between them serves as an arrangement portion for the object 16 to be heated.

  In the fifth embodiment, the rotating shafts 19-7 and 19-8 of the first and second movable iron cores 15-7 and 15-8 are used as a magnetic circuit. In accordance with the rotation of the first and second movable iron cores 15-7 and 15-8, the magnetic resistance increases and decreases as shown in FIGS. 11A and 11B, and a variable magnetic field is generated and rotated as shown in FIG. An alternating magnetic field can be generated and heated around the object to be heated 16 disposed in the space between the shafts 19-7 and 19-8.

FIG. 13 shows a sixth embodiment.
In the movable iron core induction heating furnace 10-6 of the sixth embodiment, a permanent magnet made of a U-shaped bulk superconductor is used as the fixed iron core 11-6 without using a superconducting coil, and both ends of the fixed iron core 11-6 are used. Protruding portions 11-6a and 11-6b that are vertically opposed to each other are provided. In the space between the protrusions 11-6a and 11-6b, there is provided an arrangement portion for the movable iron core 15 and the object to be heated 16 that are rotationally driven by a motor.
The sixth embodiment is similar to the first embodiment only in that a permanent magnet made of a bulk superconductor is used, and the heating action is the same.

In any of the above-described embodiments, the object to be heated 16 is mounted on the arrangement part and the entire object to be heated 16 is heated. However, a part of the object to be heated 16 is mounted on the arrangement part. It is also possible to use a configuration in which heating is partially performed.
Moreover, it is good also as a structure which arrange | positions a continuous conveyance material in the arrangement | positioning part of the to-be-heated material 16, and heats the to-be-heated material 16 moving continuously.
Further, when the object to be heated 16 is an insulating material, the insulating material is accommodated in the magnetic container and heated.

  The movable core induction heating furnace of the present invention can be used for various industrial heating applications such as hot forging and extrusion molding of aluminum molds.

(A) (B) is the schematic which shows the magnetic circuit of 1st Embodiment. (A) is a schematic perspective view of the heating furnace of 1st Embodiment, (B) is principal part sectional drawing. It is a diagram which shows the magnetic field which generate | occur | produces at the low frequency of 1st Embodiment. (A) (B) is the schematic which shows the magnetic circuit of 2nd Embodiment. It is the schematic which shows the arrangement | positioning part of the to-be-heated material in 2nd Embodiment. It is a diagram which shows the magnetic field which generate | occur | produces at the high frequency of 2nd Embodiment. (A), (B), and (C) are schematic views showing a magnetic circuit of a third embodiment. It is a diagram which shows the magnetic field generate | occur | produced with the high frequency and high output of 2nd Embodiment. (A) (B) is the schematic which shows the magnetic circuit of 4th Embodiment. A 5th embodiment is shown, (A) is a schematic sectional view and (B) is a side view. (A) (B) is the schematic which shows the magnetic circuit of 5th Embodiment. It is drawing which shows the magnetic field of 5th Embodiment. It is the schematic which shows 6th Embodiment.

Explanation of symbols

10-1 to 10-6 Movable iron core induction heating furnace 11 (11-1 to 11-6) Fixed iron core 12 Superconducting coil 13 DC power source 15 (15-1 to 15-8) Movable iron core 16 Heated object 18 Motor 19 ( 19-1 to 19-8) Rotating shaft

Claims (8)

A superconducting fixed body connected to a DC power source;
A movable iron core disposed in a space formed by dividing the DC current path of the stationary body;
A rotation drive source for rotating the movable iron core;
Between one movable iron core and a fixed body arranged in the space, between a pair of movable iron cores arranged in series in the space, or between other divided parts of the fixed body as an arrangement part of the object to be heated,
When the movable iron core rotates and becomes a continuous direction with the fixed iron core, the magnetic resistance generated between the movable iron core and the fixed iron core is reduced, and when the movable iron core becomes a non-continuous direction in which a gap is formed between the fixed iron core and the movable iron core. A movable core induction heating furnace having a configuration in which a magnetic resistance generated between an iron core and a fixed iron core is increased, and a variable magnetic field is generated around the object to be heated to heat the object to be heated. The fixed body is formed by winding a superconducting coil connected to a DC power source around a fixed iron core,
Alternatively, a permanent magnet made of a bulk superconductor is formed in a fixed iron core, and
The movable iron core according to claim 1, wherein the movable iron core is formed of a silicon steel plate having a rod shape or a rectangular flat plate shape, and a center in a length direction is fixed to a rotating shaft that is rotated by the rotation driving source including a motor. Induction furnace. The fixed iron core is C-shaped to form the space between both ends,
One or more said movable iron cores are arrange | positioned in the said space at the one end side of a fixed iron core, The space | interval between this movable iron core and the other end side of the said fixed iron core is used as the arrangement | positioning part of the said to-be-heated material. 2. A movable iron core induction heating furnace according to 2. The fixed iron core is C-shaped to form the space between both ends,
A pair of said movable iron cores are arrange | positioned in the said space at the both ends of a fixed iron core, Between these movable iron cores is an arrangement | positioning part of the said to-be-heated material, The said pair of movable iron cores rotate synchronously. The movable core induction heating furnace according to claim 2. The fixed core is a pair of left and right rod-shaped fixed cores arranged in parallel,
In the central part sandwiched between the pair of fixed iron cores, a pair of upper and lower rod-shaped fixed iron cores made of permanent magnets made of bulk superconducting material are arranged on both upper and lower sides by placing an arrangement part of the object to be heated,
A pair of upper and lower left movable iron cores are disposed in a space formed between upper and lower ends of the left fixed iron core and the central upper and lower fixed iron core, and between the upper and lower ends of the right upper iron core and the central upper and lower fixed iron core. A pair of upper and lower right movable iron cores are arranged in the space formed in
3. The movable core induction heating furnace according to claim 1, wherein rotation of the right movable core and the left movable core is rotated 90 degrees out of phase by the rotation drive source. The fixed iron core is made up of two fixed iron cores, an L type and an inverted L type,
One or more said movable iron cores are arrange | positioned in the space between the one ends of the said two fixed iron cores, The space between the other ends of these two fixed iron cores is used as the arrangement | positioning part of the said to-be-heated material. 2. A movable iron core induction heating furnace according to 2.   The fixed iron core is formed of a cylindrical frame, with a pair of projecting pieces projecting from the upper and lower inner surfaces at both left and right ends, and a magnetic rotating shaft that is driven to rotate by a motor in each central space between the upper and lower projecting pieces. The center of the movable iron core is fixed to the magnetic rotating shaft, and the left and right magnetic rotating shafts are provided in a cylindrical frame surrounded by the fixed iron core so as to be opposed to each other with an arrangement portion of the object to be heated. The movable iron core induction heating furnace according to claim 1 or 2.   The object to be heated is made of a conductive material or an insulating material accommodated in a conductive container, and the arrangement part of the object to be heated is an arrangement part in which the whole or a part of the object to be heated can be detachably mounted, or The movable iron core induction heating furnace according to any one of claims 1 to 7, wherein the moving object is an arrangement portion for moving the object to be heated.

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