JP3027082B2 - Metal induction heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal induction heating apparatus, which can be used, for example, in a step of plating a metal surface, for heating a metal to which a molten metal adheres and for alloying it. Further, for example, it can be used for applying a coating on a metal surface and drying it by heating.

[0002]

2. Description of the Related Art For example, equipment for producing a welded galvanized steel strip mainly used for automobiles is provided with an induction heating device. This induction heating device is used to heat the metal to which the molten zinc adheres and alloy it.

As shown in FIG. 5, this type of induction heating device includes a single electric coil (ie, induction coil) formed by winding several turns around a steel strip passage. ,
A power supply device is connected to both ends of the electric coil and supplies high-frequency power thereto. By passing a high-frequency current through the induction coil, an eddy current is generated inside the steel strip passing therethrough, and the eddy current heats the steel strip.

The prior art relating to the induction heating apparatus is disclosed in, for example, JP-A-64-68455 and JP-A-2-10.
No. 685.

[0005]

By the way, it is ideal that the eddy current flowing in the steel strip by the induction heating device flows only in the width direction of the steel strip (direction perpendicular to the conveying direction).
When an eddy current flows in the steel strip conveying direction (longitudinal direction), a potential difference is generated between one end and the other end in the steel strip conveying direction. For example, a cutter for cutting a steel sheet downstream of the induction heating device. This is because, when the cutter is installed, when the cutter is operated, a short circuit of the current passing through the steel plate occurs, which causes a problem such as breakage of the teeth of the cutter.

However, the electric coil of an actual induction heating device is formed by winding a very thick electric wire in order to flow a large current, and a sufficient gap is provided between the wires for insulation. Since it is inevitable, the electric coil is formed to spiral around the steel strip, and the current flowing through the electric coil flows in a direction slightly inclined with respect to the width direction of the steel strip. Since the eddy current flows in the same axial direction as the direction in which the current flows in the electric coil, the eddy current also flows in a spiral direction. That is, since the eddy current includes a component directed in the transport direction of the steel strip, it is inevitable that a potential difference occurs in the transport direction of the steel strip.

Accordingly, it is a first object of the present invention to provide an induction heating device capable of preventing a potential difference from occurring in the conveying direction of a steel strip.

By the way, unless special control is performed on the steel strip passing through the induction heating device, a striped pattern called noise stripes is generated. That is, a compressive force is generated in the steel strip by the eddy current flowing through the steel strip by the induction heating device, and the compressive force changes periodically, so that the steel strip generates vibration in the width direction of the steel strip. , A stripe pattern is formed on the surface of the steel strip. Since this type of stripe is a serious defect in quality, the occurrence of this phenomenon must be prevented.

Therefore, in the technique disclosed in Japanese Patent Application Laid-Open No. 64-68455, a power supply frequency of an induction heating device is modulated by using a variable capacitor or a variable inductor to prevent the occurrence of resonance, thereby forming a striped pattern. The occurrence is suppressed.

In the technique disclosed in Japanese Patent Application Laid-Open No. 2-10685, a resonance circuit is formed by an induction coil and a capacitor, and a power source (inverter) for supplying power to the circuit.
It has been proposed to selectively use two kinds of signals having different phases from each other as a gate signal for controlling the switching of.

A second object of the present invention is to prevent the occurrence of a stripe pattern in a steel strip passing through an induction heating device.

By the way, in the induction heating apparatus used to heat the steel strip, it is necessary to supply a large amount of electric power to the induction coil, and it is very difficult to manufacture a high-frequency inverter for generating the electric power. In other words, a single switching element alone cannot switch the large power required for the inverter, so a switching unit having a large number of switching elements connected in parallel or in series must be used. However, since it is necessary to switch a plurality of switching elements at the same time, it is necessary to trim the variations in characteristics existing for each element in detail, which makes manufacturing difficult and increases the apparatus cost.

[0013] Accordingly, the present invention is to facilitate the manufacture of a high frequency inverter for supplying power to an induction heating device.
Subject.

[0014]

According to a first aspect of the present invention, there is provided an electric coil arranged to surround a metal passage and a power supply device for supplying high-frequency electric power to the electric coil. In a metal induction heating device provided with: a plurality of electric coils (2A, 2B, 2) each having a coil surface arranged in a direction orthogonal to the traveling direction of the metal (1);
C, 2D, 2E, 2F); and a plurality of independent power supplies (3A, 3B, 3C, 3D, 3E, 3) connected to and supplying power to each of the plurality of electric coils.
F); is provided.

According to a second aspect of the present invention, there is provided a metal induction heating device including an electric coil disposed so as to surround a metal passage and a power supply device for supplying high-frequency power to the electric coil. A plurality of electric coils (2A, 2B, 2C, 2D, 2E) having coil surfaces arranged in a direction orthogonal to the traveling direction (AR1) of the , 2F); and a plurality of independent power supplies (3A, 3A) connected to and supplying power to each of the plurality of electric coils.
B, 3C, 3D, 3E, 3F).

According to a third aspect of the present invention, the plurality of power supply devices are configured to supply power having at least one of frequency, phase, and power different from each other to each of the plurality of electric coils.

According to a fourth aspect of the present invention, there is provided a power supply control means for changing at least one of a frequency and a phase of the plurality of power supply devices in accordance with a change in characteristics of a metal passing through the induction heating device. ;

In the invention according to claim 5, each of the plurality of electric coils is constituted by setting the number of turns to one.

The symbols shown in the parentheses indicate the reference numerals of the corresponding elements and the like in the embodiments described later for reference. However, each component of the present invention is embodied in the embodiments. It is not limited to only specific elements.

[0020]

According to the first and second aspects of the present invention, since there are a plurality of electric coils, for example, the
Can be one. Since the electric coil having one turn is not helical, by arranging its coil surface in a direction perpendicular to the traveling direction of the metal, the eddy current flowing through the metal has a component in the traveling direction of the metal. Can be avoided. When the number of turns is two or more, the eddy current flowing in the metal has a component in the direction of travel of the metal. For example, two adjacent electric coils are symmetrically wound (opposite to each other). By doing so, the eddy current component in the traveling direction of the metal can be canceled. Therefore, the first problem is solved. The plurality of electric coils are generally arranged at positions different from each other with respect to the traveling direction of the metal, but for example, a plurality of electric coils having different sizes can be arranged at the same position on the same axis. is there.

Further, the electric coil is divided into a plurality of parts,
Since power is supplied to each of the divided electric coils from a plurality of power supplies independent of each other, the power that must be supplied by each of the power supplies is smaller than in the conventional case. As a result, the manufacture of the power supply device is facilitated, and the third problem is solved.

According to the third aspect of the present invention, the frequency of the high-frequency power supplied to each of the plurality of electric coils,
Since at least one state of the phase and the power is different from each other, the metal passing through these electric coils hardly resonates at a specific frequency, so that it is possible to suppress the occurrence of poor quality such as noise stripes. Thereby, the second problem is solved.

According to the fourth aspect of the present invention, the power supply control means changes at least one of the frequency, phase, and power of the power supply according to a change in the characteristics of the metal passing through the induction heating device. The resonance frequency and vibration mode of the mechanical vibration generated on the metal passing through the induction heating device depend on the characteristics of the metal,
For example, it varies depending on the shape of the metal, the material of the metal, the passing speed, the tension, and the like. Therefore, depending on the state of the metal at that time, there are states of frequency, phase difference, and power where resonance is least likely to occur. Therefore, under the control of the power supply control means, the occurrence of resonance can be prevented, and the occurrence of quality defects such as noise stripes can be suppressed. Thereby, the second problem is solved.

In the first to fourth aspects of the present invention, since the number of turns of each electric coil is one, it is only necessary to arrange its coil surface in a direction perpendicular to the traveling direction of the metal. Since the generation of eddy current in the traveling direction of can be prevented, electric coils of the same configuration may be arranged at equal intervals,
The structure becomes simple. In the invention of claim 5, each of
Since the number of turns of the electric coil is 2 or more,
The eddy current has a component in the direction of travel of the metal.
The windings of two adjacent electric coils are symmetrical (anti-
Eddy current component in the direction of metal movement
Can be negated.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of one type of induction heating apparatus for carrying out the present invention is shown in FIGS. 1 is a front view, FIG. 2 is a transverse sectional view, and FIG. 3 is a sectional view taken along the line III-III in FIG.
This induction heating device is a thin plate (metal) that is continuously passed
It is installed in a part of one passage so as to surround it.
In this embodiment, when the thin plate 1 passes through a hot-dip galvanizing bath (not shown) (not shown) in the preceding step, hot zinc adheres to the surface thereof. On the way from the hot-dip galvanizing bath in the vertical direction (AR1 direction), the gas flow blown from the nozzle controls the amount of hot-dip zinc adhered to the thin plate 1, after which the thin plate 1 passes through the induction heating device. Is heated.

As shown in the figures, in this embodiment, the induction coil of the induction heating device is composed of six electric coils 2A, 2B, 2C, 2D, 2E and 2F each having a one-turn configuration. These electric coils 2A, 2B, 2C, 2D, 2
E and 2F are arranged at regular intervals in the traveling direction of the thin plate 1. Further, the electric coils 2A, 2B, 2C, 2
Each of D, 2E and 2F is arranged such that its coil surface (the plane through which the orbital axis passes) exactly coincides with a plane orthogonal to the traveling direction (AR1 direction) of the thin plate 1. This is to prevent the eddy current generated in the thin plate 1 from having a component in the AR1 direction.

In this embodiment, specific dimensions of the electric coil and the like are as follows.

Dimensions of the thin plate 1: Width: 1800 [mm] (z-axis direction) Thickness: 0.5 [mm] (y-axis direction) Wire dimensions of each coil: Height: 54 [mm] (x-axis direction) = AR1) Thickness: 20 [mm] (y-axis direction) Gap between adjacent coils: 43 [mm] (x-axis direction) Gap between coil and thin plate: 640 [mm] (y-axis direction) See FIG. Then, the electric coils 2A, 2B, 2C, 2
D, 2E and 2F are independent inverters 3 respectively.
A, 3B, 3C, 3D, 3E and 3F are connected to output terminals. These inverters 3A, 3B, 3C, 3
D, 3E, and 3F are controlled by independent signals S1, S2, S3, S4, S5, and S6 output from the signal generator 5, respectively. Therefore, the electric coils 2A, 2B, 2
C, 2D, 2E and 2F are each independently energized. The signal generator 5 generates signals S1, S2, S3, S4, S5 and S6 according to the information set by the control device 4. Various information is input to the control device 4 from the process computer 6 that manages the entire manufacturing process.

That is, when the characteristics of the thin plate 1 itself or its passing state change, the resonance frequency and the vibration mode of the thin plate 1 in the induction heating device change, and the information on the characteristics of the thin plate 1 itself and its passing state is obtained. Knowing that the electric coils 2A, 2A, 2A,
The energization (frequency difference or phase difference) of 2B, 2C, 2D, 2E and 2F can be controlled. For this purpose, the control unit 4 inputs information such as the shape (dimensions) of the thin sheet currently passing through, the material of the thin sheet, the passing speed, and the tension from the process computer 6, and outputs a signal in accordance with predetermined conditions. Generate setting information to be output to the generator.

FIG. 4 shows a specific configuration of the signal generator 5 and the inverter 3A. The configurations of the other inverters 3B to 3F are the same as those of the inverter 3A. This will be described with reference to FIG. The six sets of setting information output by the control device 4 are stored in six registers 52 via a communication port (interface) 51, and these setting information is input with new setting information next. Until it is held in each register. The values held in the six registers 52 are preset in six counters 54, respectively. A pulse signal having a constant frequency output from the oscillator 53 is applied to the clock signal input terminals of the six counters 54, and each counter outputs a signal obtained by dividing the signal from the oscillator 53. The ratio is determined according to the preset value set for each. That is, by presetting different values to the six counters 54, six types of signals having different frequencies can be output from the six counters 54. The signals output from the six counters 54 pass through the flip-flops 55, respectively, and the signals S
1, S2, S3, S4, S5 and S6. Signal S
1, S2, S3, S4, S5 and S6 are inverters 3A, 3B, 3C, 3D and 3 respectively, as shown in FIG.
Input to E and 3F.

The inverter 3A has four switching transistors 31, 32, 33 and 34 and a diode 3.
5, 36, 37 and 38, a gate driver 39 and a DC power supply PW. Four signals generated by the gate driver based on the signal S1 output from the signal generator 5 are applied to the transistors 31, 32, 33 and 34. The electric coil 2 is connected to the connection between the transistors 31 and 33 and the connection between the transistors 32 and 34.
A terminals 2a and 2b are connected. In this example, the resonance capacitor circuit CC is connected in parallel with the electric coil 2A.
Is connected. The resonance capacitor circuit CC is composed of three capacitors and a switch.
By turning off, the capacitance of the capacitor connected to the electric coil 2A can be switched to change the resonance frequency of the circuit.

As shown in FIG. 7, the signal S1 repeats on / off at a predetermined short repetition cycle, so that a high-frequency current flows through the electric coil 2A. That is, when the signal S1 is on, the transistors 31 and 34 are turned on and the other transistors 32 and 33 are turned off.
Current flows clockwise, and when the signal S1 is off, the transistors 31 and 34 are turned off and the other transistor 3
Since the switches 2 and 33 are turned on, a current flows counterclockwise through the electric coil 2A, and this operation is repeated in a short cycle.

The frequency of the current flowing through the electric coils 2A to 2F is basically determined as follows.

T: thickness of thin plate [m] δ: penetration depth of eddy current [m] r = t / δ (for example, 3.0) f: frequency of induction heating μ: magnetic permeability σ: conductivity (= 1) / Ρ) [1 / Ωm] P: electric power [W] Ha: magnetic field strength [A / m] Aw: cross-sectional area of thin plate [m ² ] Lc: coil length [m] Q: coefficient (for example, 0. 4) Bm: Defined as saturation magnetic flux density [Wb / m ² ], the following equations (1), (2), (3), and (4)
The equation holds. Then, when the expression (4) is substituted into the expression (2), the following expression (5) is obtained. When the equation (5) is solved for Ha, the following equation (6) is obtained. By substituting the power P and other numerical values into the equation (6), Ha is obtained. Substituting this Ha into equation (3) gives μ. Therefore,
By substituting a numerical value into the equation (5), the frequency f is obtained.

[0035]

(Equation 1)

However, the six electric coils 2A to 2
When current is applied to all F under the same conditions, resonance vibration is likely to occur in the thin plate 1, thereby causing a striped defect on the surface of the thin plate 1. In particular, if resonance vibration continues for a long time in the same portion on the thin plate 1, a stripe pattern is likely to occur. In this embodiment, the induction coil is divided into six sets of electric coils 2A to 2A.
Since it is constituted by F, it is possible to prevent resonance from continuing for a long time by shifting these biasing states from each other. That is, a certain portion on the thin plate 1 is
Assuming that the time required to pass through the entirety of A to 2F is T, the time required to pass through each of the electric coils 2A to 2F is about T / 6. Even if resonance occurs, the time during which the resonance continues is T / 6, which is short, so that a stripe pattern is unlikely to occur.

Therefore, in this embodiment, in order to suppress the occurrence of a stripe pattern, the frequencies of the high-frequency currents applied to the six sets of electric coils 2A to 2F are controlled so as to be slightly shifted from each other. A specific setting example of the frequency is shown below.

Setting conditions: relative permeability of air: 1 conductivity of air: 0 relative permeability of thin plate: 30.0 conductivity of thin plate: 1.0 e + 7 relative permeability of coil space: 1 conductivity in coil space Ratio: 0 Thin plate thickness: 0.5 [mm] Energizing frequency of each coil: Coil 2A: 6.0 [KHz] Coil 2B: 6.1 [KHz] Coil 2C: 6.2 [KHz] Coil 2D: 6 .3 [KHz] Coil 2E: 6.4 [KHz] Coil 2F: 6.5 [KHz] Actually, the control device 4 controls the energizing frequency of each coil based on information input from the process computer 6. And outputs six sets of numerical values according to the energizing frequency to the signal generator 5. The signal generator 5 outputs 6 from the control device 4.
The set of numerical values is held in each of the six registers 52. Thereby, each of the six counters 54 has
The frequency division ratio according to the numerical value held in the register 52 is set. The signals S1 and S output by the signal generator 5
The frequencies of 2, S3, S4, S5 and S6 are, for example, 6.0, 6.1, 6.2, 6.3, 6.4 and 6.5, respectively.
[KHz]. The waveforms of the signals S1 to S6 are, for example, as shown in FIG.

In this manner, six sets of coils 2A to 2A
In one part of F, the frequency of the mechanical vibration caused by the eddy current matches the natural resonance frequency existing in the thin plate, and relatively large vibration may occur, but when passing through other coil parts, Since the frequency of the eddy current deviates from the resonance frequency, the resonance of the thin plate stops.
That is, the thin plate does not continuously vibrate over the entire area of the coils 2A to 2F, and the vibration time is short.
Stripes are less likely to occur.

FIGS. 9, 10 and 11 show the results obtained by computer simulation of the Maxwell stress distribution when the energizing frequencies of the six sets of coils 2A to 2F are all the same (the arrows indicate the stresses). Vector). The conditions of the simulation are as follows.

Applied voltage to each coil: 400 [Vrms] Electric resistance of coil: 1.5926e-7 Energizing frequency: 6.1 [KHz] (Other conditions are the same as those described above.) FIG. Referring to FIGS. 10 and 11, at any position in the thickness direction (t = 1/9 to 9/9), the stress distribution forms one wave, and the waves at each position are similar to each other. Therefore, it can be seen that resonance occurs over the entire thin plate. When such resonance continues for a long time, a striped pattern is formed on the thin plate. However, in this embodiment, six coils 2
Since the energizing frequencies of A to 2F are slightly shifted from each other, the occurrence of such resonance is limited to a short period of time, and therefore, a stripe pattern is unlikely to occur.

Next, another embodiment will be described.
In this embodiment, of the elements shown in FIG.
And the configuration and operation of the signal generator 5 are changed. The configuration of the signal generator 5B used in this embodiment is shown in FIG. In this embodiment, control is performed so that currents flowing through the six sets of electric coils 2A to 2F have a phase difference with each other. The control device 4 outputs frequency information and five sets of phase difference information to the signal generator 5B. The signal generator 5B sets the frequency information output from the control device 4 in the frequency register 52, and sets the phase difference information in the five phase registers 56.

As in the previous embodiment, the frequency register 52
The frequency division ratio of the counter 54 is determined according to the value held in the counter 53, and the frequency of the signal output from the oscillator 53 and the counter 54
, The frequency of the signal S1 is determined. In this embodiment, the signal S1 is also input to each of the five delay circuits 57. Signals S1 delayed by five sets of delay circuits 57 are signals S2, S3, S4, respectively.
S5 and S6. In this example, the delay circuit 57 is composed of a multi-stage shift register and a data selector. The delay time of each of the five sets of delay circuits 57 is determined by the value held in each of the five sets of phase registers 56. It is determined. Since an appropriate value is set in advance in each of the phase registers 56 according to the information output by the control device 4, the signals S1, S2, and S output from the signal generator 5B are set.
At S3, S4, S5 and S6, for example, as shown in FIG. In this way, the high-frequency currents flowing through the electric coils 2A to 2F also have a phase difference with each other, thereby suppressing the resonance of the thin plate.

In the case where such a phase difference was provided, the distribution of Maxwell stress on the thin plate was determined by computer simulation. 12, 13, and 14 show the results obtained for Condition 1 shown below, and FIGS. 15, 16, and 17 show the results obtained for Condition 2.

Condition 1: energizing frequency: 6.1 [KHz] in all Phase difference: coil 2A: 0 [degree] coil 2B: 60 [degree] coil 2C: 120 [degree] coil 2D: 180 [degree] coil 2E : 240 [degree] Coil 2F: 300 [degree] (The conditions other than the above are the same as those described above) Condition 2: Energizing frequency: 6.1 [KHz] Phase difference: coil 2A: 0 [degree] Coil 2B: 180 [degree] Coil 2C: 60 [degree] Coil 2D: 240 [degree] Coil 2E: 120 [degree] Coil 2F: 300 [degree] (Other conditions are the same as those described above.) Referring to FIGS. 12 to 17, the waveform of the stress distribution changes according to the difference in the position in the thickness direction, and the region where the large wave exists is relatively in the traveling direction (x-axis direction) of the thin plate. Narrow range It is limited. That is, FIGS.
It can be understood that the resonance vibration of the thin plate is suppressed as compared with the example of FIG. Therefore, when a current is applied to the electric coils 2A to 2F, a phase difference is provided between the electric coils 2A to 2F, whereby a striped pattern can be prevented from being formed on the thin plate.

In the above embodiment, the electric coil 2
Regarding the energization of A to 2F, the resonance of the thin plate is prevented by shifting the frequency or the phase from each other, but when the resonance does not occur, the power of the same frequency and the same phase may be supplied. In the above embodiment, the electric coil 2A
2 to 2F have a single turn, but a plurality of electric coils of several turns may be provided. However, in that case,
For example, it is desirable to dispose two electric coils having the same number of turns in directions symmetrical to each other to cancel a potential difference in the traveling direction of the thin plate.

[0047]

As described above, according to the first and second aspects of the present invention, since there are a plurality of electric coils, for example, the number of turns of each electric coil can be one. Since the electric coil having one turn is not helical, by arranging the coil surface in a direction perpendicular to the traveling direction of the thin plate, the eddy current flowing through the metal has a component in the traveling direction of the metal. Can be avoided.

Also, the electric coil is divided into a plurality of parts,
Since power is supplied to each of the divided electric coils from a plurality of power supplies independent of each other, the power that must be supplied by each of the power supplies is smaller than in the conventional case. As a result, the manufacture of the power supply device becomes easy.

According to the third aspect of the present invention, the frequency of the high-frequency power supplied to each of the plurality of electric coils,
Since the phases or the powers are different from each other, the metal passing through these electric coils hardly causes resonance at a specific frequency, and thus can suppress the occurrence of poor quality such as noise stripes.

According to the fourth aspect of the present invention, the power supply control means changes at least one of the frequency, phase, and power of the power supply in accordance with a change in the characteristics of the metal passing through the induction heating device. Depending on the condition of the metal
By setting the frequency, phase difference, or power at which resonance is least likely to occur, it is possible to prevent the occurrence of resonance and suppress the occurrence of poor quality such as noise stripes.

[0051] In the invention of claim 5, each of the electrical coil motor - Since the number of emissions is 2 or more, although ingredients in the traveling direction of the metal to the eddy current flowing through the metal occurs to adjacent
Symmetrical winding of two electric coils (opposite each other)
Eddy current component in the direction of metal movement
Can be turned off.

[Brief description of the drawings]

FIG. 1 is a front view showing an induction coil of an embodiment and a thin plate passing therethrough.

FIG. 2 is a sectional view of the plane of FIG. 1;

3 is a block diagram showing a configuration of an induction coil and a circuit for supplying power to the induction coil, as viewed from a cross section taken along line III-III of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a signal generator 5 and an inverter 3A of FIG.

FIG. 5 is a perspective view showing a conventional example of an induction heating device.

FIG. 6 is a block diagram showing a configuration of a signal generator 5B according to a modification.

FIG. 7 is a time chart showing an example of signals S1 to S6 in FIG. 4;

8 is a time chart showing an example of signals S1 to S6 in FIG.

FIG. 9 is a map showing a stress distribution on a thin plate when all coils have the same frequency and phase.

FIG. 10 is a map showing a stress distribution on a thin plate when all coils have the same frequency and phase.

FIG. 11 is a map showing a stress distribution on a thin plate when all coils have the same frequency and phase.

FIG. 12 is a map showing a stress distribution on a thin plate when the coils 2A to 2F have a phase difference of Condition 1.

FIG. 13 is a map showing a stress distribution on a thin plate when the coils 2A to 2F have a phase difference of Condition 1.

FIG. 14 is a map showing a stress distribution on a thin plate when the coils 2A to 2F have a phase difference of Condition 1.

FIG. 15 is a map showing a stress distribution on a thin plate when coils 2A to 2F are provided with a phase difference of condition 2.

FIG. 16 is a map showing a stress distribution on a thin plate when coils 2A to 2F are provided with a phase difference of condition 2.

FIG. 17 is a map showing a stress distribution on a thin plate when the coils 2A to 2F have a phase difference of Condition 2.

[Explanation of symbols]

1: Thin plate 2A-2F: Electric coil 3A-3F: Inverter 4: Controller 5, 5B: Signal generator 6: Process computer 31-34: Transistor 35-38: Diode 39: Gate Driver 51: Communication port 52: Register 53: Oscillator 54: Counter 55: Flip-flop PW: DC power supply

Claims (5)

(57) [Claims] 1. A metal induction heating device comprising an electric coil arranged so as to surround a metal passage and a power supply device for supplying high-frequency power to the electric coil: a direction orthogonal to a traveling direction of the metal. A plurality of single-turn electric coils having a coil surface disposed at a plurality of independent power supplies connected to and supplying power to each of the single-turn electric coils; A metal induction heating device characterized by having; 2. A metal induction heating device comprising an electric coil arranged to surround a metal passage and a power supply for supplying high-frequency power to the electric coil: a direction orthogonal to the direction in which the metal travels. have arranged the coil surface, which is arranged at different positions with respect to the traveling direction of the metal, electrical coils of the plurality of the number of turns is 1; and the plurality of the number of turns is in each of the first electrical coil A metal induction heating device, comprising: a plurality of power supply devices connected to and supplying power to each other; 3. The power supply device according to claim 1, wherein the plurality of power supply units supply electric power having at least one of frequency, phase, and power different from each other to each of the plurality of electric coils having one turn. Alternatively, the metal induction heating apparatus according to claim 2 . 4. Power supply control means for changing at least one of a frequency, a phase, and a power state of the plurality of power supply devices according to a change in characteristics of a metal passing through the induction heating device;
The metal induction heating apparatus according to claim 1 or 2, further comprising : 5. An electric core disposed so as to surround a metal passage.
And a power supply for supplying high frequency power to the electric coil.
In a metal induction heating device comprising: each arranged in a direction perpendicular to the direction of travel of the metal
It has a coil surface and positions different from each other in the
Electrical switches with a number of turns of 2 or more
And a plurality of said plurality of turns connected to and supplying power to each of the two or more electric coils.
A plurality of standing power supplies; two adjacent power supplies
Characterized in that the windings of the electric coils are opposite to each other
That the metal of the induction heating device.