JP3900752B2 - Induction heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating apparatus in which a matching adjustment unit is improved.
[0002]
[Prior art]
As is well known, an induction heating device supplies an output (for example, an output frequency of 3 kHz) obtained by an inverter device to a heating coil via a load matching circuit to heat a member to be heated. 7 and 8 are schematic configuration diagrams of the induction heating device. In FIG. 7, reference numeral 11 denotes an inverter device. A heating coil 13 is connected to the output terminal of the inverter device 11 via a load matching circuit 12. The load matching circuit 12 includes a matching transformer 14 with a tap, a switch 15 of the tap, and a capacitor 16. In FIG. 8, a heating coil 13a is connected to the output terminal of the inverter device 11a via a load matching circuit 12a. The load matching circuit 12a includes a capacitor 17, an air-core coil (hereinafter referred to as a dummy coil) 18, and a short circuit 19 including a switch.
[0003]
The operation range of the inverter devices 11 and 11a in the induction heating apparatus configured as shown in FIGS. 7 and 8 is a region generally shown in the range surrounded by the solid line in FIG. 9 from the inverter output voltage and output current. .
[0004]
Further, since the relationship between the inverter output voltage and the output current shown in FIG. 9 is determined by the load R · L, when the heating coils 13 and 13a and the material in the coil change, the relationship between the inverter output voltage and the output current also changes. It will change. As a result, in the case of the load B shown in FIG. 9, power can be supplied up to the inverter rated output, but in the case of the loads A and C, power can be supplied up to the rated output by the overcurrent limit and overvoltage limit, respectively. Can not. In order to solve this problem, means for providing matching is provided by providing the load matching circuits 12 and 12a described above between the inverter devices 11 and 11a and the heating coils 13 and 13a.
[0005]
In FIG. 7 described above, a matching transformer 14 with a tap is provided as a matching adjustment unit of the load matching circuit 12, and the tap is switched by the switch 15 to adjust the relationship between the inverter output voltage and the output current. is there. In FIG. 8, a dummy coil 18 and a circuit 19 for short-circuiting the coil 18 are provided as a matching adjustment unit, and the relationship between the inverter output voltage and the output current is adjusted by opening and closing the short-circuit 19. .
[0006]
[Problems to be solved by the invention]
As described above, in the induction heating device, between the inverter device and the heating coil, in order to improve load efficiency, as shown in FIGS. 7 and 8, a tapped matching transformer, a dummy coil, and a short circuit are provided. A matching adjustment unit is provided. Among these matching adjustment units, the matching transformer shown in FIG. 7 is very expensive, and thus has a problem of incurring an economic burden on the facility. In addition, in the dummy coil and the short circuit shown in FIG. 8, since there are only two types of matching switching, “when the short circuit is open” and “when the short circuit is connected”, it is not possible to cope with an increase in the types of loads. There is also a problem.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an induction heating apparatus in which good matching can be obtained by widening the load and the matching adjustment range.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, when the induction heating is performed while supplying the output of the inverter device to the heating coil and moving the load in the heating coil, the inverter device and the heating coil In the induction heating apparatus in which a load matching circuit is provided in the electric circuit for electrically connecting the inverter apparatus and the maximum output can be supplied from the inverter apparatus to the heating coil
The heating coil is fixed;
The load matching circuit is provided with a dummy coil and a matching adjustment unit including a circuit for short-circuiting the coil, and the matching adjustment unit is configured to be movable in a direction orthogonal to the axial direction of the heating coil.
Whether the load in the heating coil is supplied to the dummy coil of the matching adjustment unit to perform load matching or load matching without supply is selected by moving the matching adjustment unit. It is a feature.
[0009]
The second invention provides a load matching circuit in an electric circuit that electrically connects the inverter device and the heating coil when the output of the inverter device is supplied to the heating coil and induction heating is performed while moving the load in the heating coil. In the induction heating device that is provided and can supply the maximum output from the inverter device to the heating coil,
The load matching circuit is provided with a dummy coil and a matching adjustment unit including a circuit for short-circuiting the coil,
The heating coil and the dummy coil having the matching adjustment unit are arranged at a constant interval on the same coil mounting table, the dummy coil is arranged in the axial direction of the heating coil, and the load in the heating coil is or take load matching by supplied into the dummy coil of the matching adjusting unit, the take the load matching is not supplied, it is characterized in that it has to be selected by Rukoto move the load.
[0010]
In a third aspect of the invention, the inner diameter of the dummy coil and the inner diameter of the heating coil are the same.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. B is a schematic plan view and a front view showing the first embodiment of the present invention. The same parts as those in FIG. 1A and 1B, the heating coil 13a is fixed to the first coil mounting table 21. A second coil mounting table 22 that is movable in a direction orthogonal to the axial direction of the heating coil 13a is disposed at a right end in the figure in the axial direction of the heating coil 13a with a certain distance from the first coil mounting table 21. . On the second coil mounting table 22, a dummy coil 23 constituting a matching adjustment unit is mounted in the same direction as the heating coil 13a.
[0012]
The dummy coil 23 is formed to have the same inner diameter as the heating coil 13 a and is electrically connected to the heating coil 13 a by a flexible cable 24. The second coil mounting table 22 is provided with a moving mechanism 25 composed of wheels or the like, and the second coil mounting table 22 is formed so as to be movable as necessary.
[0013]
In the first embodiment configured as described above, the load 26 of the non-flexible member to be heated is passed through the heating coil 13a from the direction of the arrow at the left end of the figure, and the inside of the dummy coil 23 is heated. By matching, the matching with the inverter device 11 is taken. At this time, the short circuit 19 is opened as shown in the equivalent circuit of FIG.
[0014]
FIGS. 3A and 3B are operation examples of the first embodiment showing the matching means in the case shown in FIG. 8. The second coil mounting table 22 is moved by the moving mechanism 25 so that the load 26 does not pass through the dummy coil 23. It is a thing when letting it. At this time, the short circuit 19 is left open. Note that, depending on the load, the short circuit 19 is connected if matching can be achieved without the need for the dummy coil 23. FIG. 4 is an equivalent circuit of FIGS. 3A and 3B.
[0015]
As described above, in the first embodiment, since the number of matching means between the inverter device 11 and the heating coil 13a is increased by one according to the type of load, the matching selection range is widened, and matching is further improved. You can be sure.
[0016]
FIG. 5A is a schematic front view showing a second embodiment in the case where a flexible load 27 such as a wire is heated, and FIG. 5A is an example in which matching is performed through the dummy coil 23 through the load 27. In the figure, reference numeral 28 denotes a roll, 29 is a load avoidance mechanism comprising a roll and the like. The heating coil 13a and the dummy coil 23 are arranged on the same coil mounting table 30 with a certain interval. The inner diameter of the dummy coil 23 is the same as that of the heating coil 13a as in the first embodiment. In addition, in the same way as in the first embodiment, the selection range for matching is widened.
[0017]
FIG. 6A shows an operation example of the second embodiment in which matching is performed without passing the load 27 through the dummy coil 23. In this case, the load 27 is guided to the avoidance mechanism 29 before the dummy coil 23 as shown in the figure. It is a thing. 5B is an equivalent circuit of FIG. 5A, and FIG. 6B is an equivalent circuit of FIG. 6A.
[0018]
【The invention's effect】
As described above, according to the present invention, the matching selection range is wider than the matching adjustment circuit based on the dummy coil connection method, and there is an advantage that the matching adjustment can be made better. In addition, since the matching transformer is not used, the configuration can be simplified and it is economically advantageous.
[Brief description of the drawings]
1A and 1B are a schematic plan view and a front view showing a first embodiment of the present invention.
FIG. 2 is an equivalent circuit diagram of the first embodiment.
FIGS. 3A and 3B are a schematic plan view and a front view showing an operation example of the first embodiment; FIGS.
FIG. 4 is an equivalent circuit diagram of an operation example of the first embodiment.
FIGS. 5A and 5B are a schematic front view and an equivalent circuit diagram showing a second embodiment of the present invention. FIGS.
6A and 6B are a schematic front view and an equivalent circuit diagram of an operation example of the second embodiment.
FIG. 7 is a schematic configuration diagram of an induction heating device.
FIG. 8 is a schematic configuration diagram of an induction heating device.
FIG. 9 is a characteristic diagram of an inverter operation range with respect to a load.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11, 11a ... Inverter apparatus 12, 12a ... Load matching circuit 13, 13a ... Heating coil 21 ... 1st coil mounting base 22 ... 2nd coil mounting base 23 ... Dummy coil 24 ... Cable 25 ... Moving mechanism 29 ... Avoidance mechanism 30 ... Coil mounting table

Claims (3)

When induction heating is performed while moving the load in the heating coil by supplying the output of the inverter device to the heating coil, a load matching circuit is provided on the electric circuit that electrically connects the inverter device and the heating coil. In the induction heating device that can supply the maximum output to the heating coil,
The heating coil is fixed;
The load matching circuit is provided with a dummy coil and a matching adjustment unit including a circuit for short-circuiting the coil, and the matching adjustment unit is configured to be movable in a direction orthogonal to the axial direction of the heating coil.
Whether the load in the heating coil is supplied to the dummy coil of the matching adjustment unit for load matching or load matching without supply is selected by moving the matching adjustment unit. A feature of the induction heating device. When induction heating is performed while moving the load in the heating coil by supplying the output of the inverter device to the heating coil, a load matching circuit is provided on the electric circuit that electrically connects the inverter device and the heating coil. In the induction heating device that can supply the maximum output to the heating coil,
The load matching circuit is provided with a dummy coil and a matching adjustment unit including a circuit for short-circuiting the coil,
The heating coil and the dummy coil having the matching adjustment unit are arranged at a constant interval on the same coil mounting table, the dummy coil is arranged in the axial direction of the heating coil, and the load in the heating coil is or take load matching by supplied into the dummy coil of the matching adjusting unit, the induction heating device to take the load matching is not supplied, characterized in that so as to select by Rukoto move the load.   The induction heating apparatus according to claim 1 or 2, wherein the inner diameter of the dummy coil and the inner diameter of the heating coil are the same size.

Images