JP2009266916A - High-frequency induction heating type resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency induction heating type resistor that efficiently converts unnecessary regenerative electric power into heat while preventing a peripheral device from being excessively heated, has compact and simple constitution, and is highly reliable. <P>SOLUTION: The high-frequency induction heating type resistor includes a body to be heated, a heat insulator substantially enclosing the whole body to be heated, a heating coil wound around a periphery of the heat insulator to induction-heat the body to be heated, and a power supply means for supplying high-frequency electric power to the heating coil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrothermal converter that converts electrical energy into heat energy, and in particular, a high-frequency power generated during regeneration of a drive device such as a motor is reliably converted into heat by an induction heating coil, and includes an induction heating coil. The present invention relates to a high-frequency induction heating type resistor capable of safely radiating heat without overheating the device.

Many devices that convert high-frequency power into heat using an induction heating coil have been proposed. For example, Patent Document 1 discloses induction for continuously heating (quenching) a steel sheet by passing the steel sheet through an induction heating furnace having a solenoid induction heating coil wound around a hollow heat insulating material. A heating device is disclosed. This induction heating coil heats a steel sheet by receiving a high-frequency current from a normal high-frequency power source, but supplies high-frequency power generated during motor regeneration as described above to an induction heating furnace to produce electrical energy. Can be converted into thermal energy.
JP-A-4-59931

However, since the induction heating device of Patent Document 1 requires a mechanism for continuously passing a steel plate through an induction heating furnace, there is a problem that the overall size of the device becomes large for use as a resistor.
Moreover, when the induction heating apparatus of patent document 1 is used as a resistor, the mechanism which cools the steel plate heated in the induction heating furnace is also required, and there exists a problem that the structure of the whole apparatus becomes complicated.

  Accordingly, an object of the present invention is to provide a highly reliable high-frequency induction heating resistor with a small and simple configuration, while efficiently converting electric energy into heat energy and without overheating peripheral devices. .

  According to one aspect of the present invention, there is provided a high-frequency induction heating resistor comprising: a heated object; a heat insulating body that substantially surrounds the heated object; and the heated object wound around the heat insulating body. A heating coil for induction heating the heating body, and power supply means for supplying high frequency power to the heating coil are provided.

  According to one aspect of the present invention, it is highly reliable to have a small and simple configuration that can efficiently convert unnecessary regenerative power into heat while preventing the peripheral device from being excessively heated. A high frequency induction heating type resistor can be provided.

Before describing the embodiments of the present invention, as an example, an entire apparatus that drives an elevator and converts high-frequency power generated during regeneration of an electric motor (motor) of the elevator car into heat energy will be described.
In general, when the motor is driven, electric power is supplied from the power source to the motor via a power converter such as an inverter, and when the motor is braked, an electromotive force is generated in the motor. Such operation of the motor during braking of the motor is referred to as power regeneration operation, and the power during the power regeneration operation is referred to as regenerative power.

  FIG. 11 is a block diagram showing a schematic configuration of a general AC elevator control apparatus 100. The control device 100 includes a converter (for example, a diode bridge) 102 that converts the three-phase AC power sources R, S, and T into a DC current, a power source smoothing capacitor 104 connected to the output terminal of the converter 102, And an inverter 106 connected in parallel. The inverter 106 converts the direct current from the converter 102 into an alternating current and supplies it to the electric motor 108. Further, control device 100 includes switch 110 and resistor 1 for processing regenerative power, which are connected in parallel to power supply smoothing capacitor 104.

  When the alternating current from the inverter 106 is supplied to the electric motor 108, the electric motor 108 rotates, and the rotational motion of the electric motor 108 is transmitted to the driving sheave 114 via the reduction gear 112 and is connected to the driving sheave 114. The weight 116 and the passenger car 118 are moved up and down.

  Generally, in an elevator driven by an electric motor, a car 118 and a counterweight 116 are coupled in a slidable manner. The weight of the counterweight 116 is set to a weight that balances about half of the capacity, and the electric motor 108 has a difference between the weight of the car 118 including the passenger and the weight of the counterweight 116, and the lifting direction of the elevator car 118. A driving force corresponding to (up or down) is applied to the car 118 or the counterweight 116.

  That is, when the car 118 is lighter than the counterweight 116, the motor 108 needs to pull up the counterweight 116 when the car 118 is lowered, and when the car 118 is heavier than the counterweight 116, it is necessary to pull up the car 118 when the car 118 is raised. .

  On the other hand, when the car 118 is lighter than the counterweight 116 and when the car 118 is raised, and when the car 118 is heavier than the counterweight 116 and when the car 118 is lowered, the motor 108 is countered. It is not necessary to drive the weight 116 and the passenger car 118. Rather, the motor 108 is rotated by raising and lowering the counterweight 116 and the passenger car 118, and regenerative power (regenerative energy) is generated.

  As described above, an operation in which the electric motor 108 consumes electric energy and drives the counterweight 116 and the passenger car 118 is called a power running operation, and the counterweight 116 and the passenger car 118 drives the electric motor 108 to generate regenerative power. Operation that causes this is called regenerative operation.

  The regenerative power is normally charged to the smoothing capacitor 104 via the inverter 106, and the voltage across the both ends rises. At this time, if the voltage across the smoothing capacitor 104 exceeds the rated voltage, the smoothing capacitor 104 may be destroyed, or the voltage across the smoothing capacitor 104 is also applied to the converter 102 and the inverter 106. For this reason, similarly, there is a possibility that electric elements such as diodes and IGBTs constituting these elements are destroyed. Therefore, as shown in FIG. 11, using the switch 110 and the resistor 1 connected in parallel to the smoothing capacitor 104, the regenerative power is appropriately converted (consumed) into thermal energy, and the voltage of the smoothing capacitor 104 increases. It is necessary to suppress.

Embodiment 1

  A first embodiment of a high frequency induction heating resistor 1 (hereinafter simply referred to as “resistor”) according to the present invention will be described below with reference to FIGS. In the following description of the embodiment, for easy understanding, terms representing directions (for example, “X direction”, “Y direction”, “Z direction”, etc.) are used as appropriate. These terms are not intended to limit the invention.

  As shown in FIG. 1, the resistor 1 according to the first embodiment of the present invention is roughly a body to be heated 10, a heat insulator 20 that surrounds the body to be heated 10, and a solenoid around the heat insulator 20. A wound heating coil 30 and a high-frequency power source 40 that supplies high-frequency power to the heating coil 30 are provided.

  Any material can be selected as the material constituting the object to be heated 10 as long as it is induction-heated by the heating coil 30, and may be a magnetic or nonmagnetic metal material. A magnetic metal material is a metal material attracted by a magnet, and a non-magnetic metal material is a metal material that is not attracted by a magnet. The fact that induction heating can be performed even with a non-magnetic metal material, for example, is understood from the fact that copper pans and aluminum pans can be heated with an IH cooking heater, for example, driving conditions for the high-frequency current supplied to the heating coil 30 of the resistor 1 Even if it is a nonmagnetic metal material, it can heat by adjusting. However, in order to perform induction heating more efficiently, the object to be heated 10 preferably has a high magnetic permeability, such as a steel plate to which nickel, iron, or silicon is added, and in order to increase the amount of heat storage as described later. What has iron as a main component with a large heat capacity is more preferable. Furthermore, JIS standard SS400 etc. are the most preferable from a viewpoint that it can obtain cheaply and a composition does not change easily (less carbon ratio).

The heat insulator 20 is usually made of a heat insulating material such as a cement board. The heat insulator 20 is for gradually dissipating the heat generated in the heated body 10 to the outside and preventing the heating coil 30 and peripheral devices (not shown) from overheating. Therefore, as shown in FIG. 2, the heat insulator 20 covers at least a part of the heated body 10, and does not necessarily surround the entire surface of the heated body 10, but in the longitudinal direction (X direction). When it is necessary to cut off the heat from the body to be heated 10 also at the end portion, a lid portion 21a and a bottom portion 21b made of the same constituent materials as those of the heat insulator 20 are provided so that the entire body to be heated 10 is surrounded. Is done.
Further, in order to suppress the heat radiation action to the outside and increase the heat storage action in the heat insulator 20, as shown in FIG. 3, a heat insulating layer 12 made of a material having a higher heat insulation effect is attached to the object to be heated 10. You may arrange | position between the heat insulators 20. The heat insulating layer 12 can be made of, for example, ceramic fibers. The ceramic fiber may be hard to adhere, such as glass wool or a gel-like heat insulating material.

  The heating coil 30 may be made of any conductive material, and may be, for example, a commercially available electric wire with an insulating coating. The heating coil 30 may be an alternating current of several kHz to several hundred kHz from the high-frequency power source 40 that is regenerative power from the motor 108. As a result, an alternating magnetic field is generated, and as a result, an eddy current is formed in the heated body 10, and the heated body 10 is induction-heated by the eddy current.

  As described above, when the resistor 1 of the present invention is used for consuming the regenerative power generated in the elevator motor 108, the regenerative power is generated intermittently. The energy-converted heat can be temporarily stored and gradually dissipated during a period in which regenerative power is not generated. Therefore, it is preferable that the resistor 1 according to the present invention gradually dissipates the heat generated in the heated body 10 to the outside so that the heating coil 30 and the peripheral device do not overheat as described above.

  On the other hand, the conventional cement resistance is composed of a wired resistor, and problems such as disconnection tend to occur when the allowable heat-resistant temperature is exceeded. On the other hand, the resistor 1 according to the present invention induction-heats the object to be heated 10, and the temperature of the heating coil 30 itself can be kept relatively low, so that the object to be heated 10 has a Curie point ( For example, in the case of an iron material, the object to be heated 10 can be heated to a higher temperature unless the temperature reaches about 700 ° C. That is, the resistor 1 according to the present invention can convert the regenerative electric power having a larger capacity than the conventional cement resistance with high reliability (without causing problems such as disconnection). In other words, when regenerative power having the same capacity is converted into heat, the resistor 1 of the present invention can be made smaller than a conventional cement resistor, and a longer life can be achieved. Furthermore, since the to-be-heated body 10, the heat insulating body 20, and the heating coil 30 can be decomposed | disassembled easily, the resistor 1 which concerns on this invention can reuse or recycle these decomposed | disassembled things.

In addition, when the resistor 1 according to the present invention is designed, the heating coil 30 and peripheral devices exceed their allowable heat-resistant temperature in addition to the configuration in which the heated body 10 does not exceed the Curie point. Similarly, it should be noted that there is no configuration. At this time, the temperature of the heating coil 30 rises due to Joule heat generated by energization and radiant heat from the heated object 10.
In addition, the regenerative power supplied to the heating coil 30 is converted into Joule heat consumed by the heating coil 30 and heat generated by the heating coil 30 by induction heating. It is preferable that the resistor 1 is configured such that the amount of heat generated from the heated body 10 is larger than that of the heating coil 30 by configuring the material with a high magnetic permeability.
Furthermore, in order to sufficiently store the heat generated in the heated body 10 and dissipate it more slowly (at a slower rate), it is necessary to reduce the surface area relative to the volume of the heated body 10 as much as possible. Specifically, it is preferable that the resistor 1 has a cylindrical shape as shown in FIG. 3 or a cubic shape or a spherical shape (not shown) rather than a rectangular parallelepiped shape (square prism) as shown in FIG. .

Embodiment 2

The resistor 2 according to the second embodiment will be described below with reference to FIGS.
The resistor 2 according to the second embodiment has the same configuration as that of the resistor 1 according to the first embodiment except that the heated body 10 is formed in a toroidal shape (donut shape) instead of being formed in a rectangular parallelepiped shape. Therefore, description of overlapping points is omitted.

  As described above, the object to be heated 10 according to the second embodiment is configured to have a toroidal shape as shown in FIGS. 5 and 6, and the first region 14 in which the heating coil 30 is wound, The heating coil 30 has a second region 16 that is not wound. That is, the resistor 2 according to the second embodiment not only stores the heat generated by converting the regenerative power into the heated body 10 but also radiates the heat generated in the heated body 10 to the outside more quickly. It is configured. Also in the second embodiment, as in the first embodiment, the heating coil 30 is not heated in the first region 14 so that the heating coil 30 does not exceed the allowable heat-resistant temperature due to the heat transmitted from the object 10 to be heated. A heat insulator 20 is provided between 30 and the heated object 10.

Similarly, the cross-sectional area of the cross section parallel to the YZ plane of the object to be heated 10 is configured to be larger in the second region 16 than in the first region 14 as illustrated. That is, the amount of heat (so-called iron loss) generated in the heated object 10 by the high-frequency magnetic field of the heating coil 30 increases depending on the magnetic flux density, but by configuring as described above, the first region 14 having a large cross-sectional area. The amount of heat generated in the second region 16 having a smaller cross-sectional area can be further increased. Thus, the object to be heated 10 in the second region 16 exposed from the heat insulator 20 is exposed to the surrounding air to increase the heat dissipation effect, and is allowed until the object to be heated 10 in the first region 14 reaches the Curie point. The amount of regenerative power that is generated, that is, the processing (consumption) capability of regenerative power can be significantly improved.
Further, the resistor 2 according to the second embodiment does not use the conventional wired cement resistance as in the first embodiment, and therefore can be converted to heat with high reliability without causing a problem due to disconnection.

  Furthermore, the resistor 2 according to the second embodiment is provided with a mechanism (not shown) for allowing a fluid such as air or water to pass through the opening 17 disposed in the toroidal-shaped body 10 to be heated. The to-be-heated body 10 in 16 can be cooled more efficiently. In this way, the processing capability of the regenerative power of the resistor 2 can be further improved, or the resistor 2 can be further downsized.

  In addition or alternatively, in order to dissipate the heat generated in the heated body 10 more efficiently, the heated body 10 may have a plurality of cooling fins 18 as shown in FIG. Good. Moreover, the to-be-heated body 10 may be comprised with a different material in the 1st and 2nd area | regions 14 and 16, and it uses the material (for example, silicon steel plate) which does not generate | occur | produce more heat in the 1st area | region 14, and it 16, the material to be heated 10 may be configured using a material that easily generates heat (for example, SS400).

Embodiment 3

The resistor 3 according to the third embodiment will be described below with reference to FIGS.
The resistor 3 according to the third embodiment generally has the same configuration as that of the resistor 1 according to the first embodiment except that the heated object 10 has at least one, preferably a pair of flanges 50. Description of overlapping points is omitted.

As described above, the heated object 10 shown in FIG. 8 has a pair of flanges 50, and each flange 50 is covered with the heating coil 30 in the first region 14 in a cross section parallel to the YZ plane. Having a cross-sectional area larger than that of In FIG. 8, the to-be-heated body 10 and the heat insulating body 20 have a cylindrical shape, and the flange 50 is illustrated as having a disk shape. The flange 50 includes a plurality of heat radiation fins 52 protruding in the longitudinal direction (X direction). The radiating fins 52 may be arranged at equal intervals in the circumferential direction in the vicinity of the peripheral end portion of the flange 50, and are preferably formed of a metal material having high thermal conductivity. Further, the flange 50 and the heat radiation fin 52 may be configured using the same metal material as that of the body to be heated 10.
Therefore, the resistor 3 according to the third embodiment dissipates the heat generated in the heated object 10 more efficiently and has a higher regenerative power processing capability or a smaller size (the processing capability is the same). Case) The resistor 3 can be realized.

  Alternatively, the resistor 3 according to the third embodiment has a plurality of heated bars 54 that extend between a pair of flanges 50 and connect the two, as shown in FIG. You may do it. The heated bar 54 is formed of a metal material having high thermal conductivity, like the radiating fins 52, but is preferably configured using the same metal material as the flange 50 and the heated object 10. It is possible to obtain an effect of more efficiently dissipating the heat generated in Furthermore, since the heated bar 54 forms a magnetic flux closed loop together with the heated object 10 and the flange 50, the heated bar 54 also generates heat (is heated). Moreover, since the heated bar 54 has a substantially smaller cross-sectional area than the heated body 10, the magnetic flux density in the heated bar 54 is increased, the amount of generated heat is increased, and the entire heated bars 54 are Since the surface area also increases, the cooling effect can be dramatically improved.

Modified example

  Here, some modified sequences applicable to the resistor according to the above-described embodiment will be described.

(Modification 1)
According to the modified example 1 shown in FIG. 10, the pleated structure 60 is attached to the heat insulator 20 or is integrally formed. Since the heat insulator 20 is usually for protecting the heating coil 30 from radiant heat from the object to be heated 10, it is preferable that the surface temperature of the heat insulator 20 is as low as possible. Therefore, the heat insulator 20 according to the modified example 1 is intended to improve the heat dissipation effect by disposing the pleated structure 60 and increasing the surface area of the heat insulator 20. Therefore, a structure having an arbitrary shape may be disposed on the heat insulator 20 as long as the surface area of the heat insulator 20 is increased. For example, the structure may be a protrusion or an uneven structure. May be.

(Modification 2)
The high frequency magnetic field generated in the heating coil 30 and the object to be heated 10 may adversely affect the peripheral device as EMI (electromagnetic interference) noise. Therefore, in order to eliminate such EMI noise, the resistors 1 to 3 as a whole according to the above embodiment are surrounded by an electromagnetic shielding member such as a metal foil or a metal case (not shown), and such EMI noise is transmitted to the outside. It is preferable to shut off so as not to leak.

It is a schematic perspective view of the resistor of Embodiment 1 which concerns on this invention. It is sectional drawing when the resistor shown in FIG. 1 is cut | disconnected by the YZ plane. FIG. 3 is a cross-sectional view when a heat insulating layer is added to the resistor shown in FIG. 2. It is a perspective view similar to FIG. 1 of the resistor which has a cylindrical shape. It is a schematic perspective view of the resistor of Embodiment 2 which concerns on this invention. It is the top view (a) of the resistor shown in FIG. 5, a front view (b), and a side view (c). It is a top view (a), a front view (b), and a side view when a cooling fin is added to the resistor shown in FIG. 5 (c). It is a top view of the resistor of Embodiment 3 which concerns on this invention. It is a top view of another resistor of Embodiment 3 concerning the present invention. It is a schematic perspective view of the resistor of the modification 1 of Embodiment 3 which concerns on this invention. It is a block diagram which shows the schematic structure of the control apparatus of an AC elevator.

Explanation of symbols

1-3: High frequency induction heating type resistor, 10: Heated object, 12: Thermal barrier layer, 14: First region, 16: Second region, 18: Cooling fin, 20: Thermal insulator, 21a: Lid 21b: bottom part, 30: heating coil, 40: high frequency power supply, 50: flange, 52: radiating fin, 54: heated bar, 60: pleated structure, 100: AC elevator control device,
102: Converter, 104: Power source smoothing capacitor, 106: Inverter, 108: Electric motor, 110: Switch, 112: Reduction gear, 114: Drive sheave, 116: Counterweight, 118: Elevator car for passengers

Claims (9)

An object to be heated;
A heat insulator surrounding substantially the whole of the heated body;
A heating coil wound around the heat insulator for induction heating the object to be heated;
A high-frequency induction heating resistor comprising power supply means for supplying high-frequency power to the heating coil.   The high-frequency induction heating resistor according to claim 1, wherein the object to be heated and the heat insulator have a rectangular parallelepiped shape, a cylindrical shape, a cubic shape, or a spherical shape. A heated body having a toroidal shape;
A heat insulator surrounding at least a part of the heated object;
A heating coil wound around the heat insulator for induction heating the object to be heated;
A high-frequency induction heating resistor comprising power supply means for supplying high-frequency power to the heating coil.   The heated body has a first region in which the heating coil is wound and a second region in which the heating coil is not wound, and the cross-sectional area of the heated body in the first region is The high-frequency induction heating resistor according to claim 3, wherein the high-frequency induction heating resistor is larger than a cross-sectional area in the second region. An object to be heated having at least one flange portion protruding from the heat insulator, and a heat dissipating fin extending from the flange portion;
A heat insulator surrounding at least a part of the heated object;
A heating coil wound around the heat insulator for induction heating the object to be heated;
A high-frequency induction heating resistor comprising power supply means for supplying high-frequency power to the heating coil. A heated body having a pair of flange portions protruding from the heat insulator and a plurality of heated bars extending between the pair of flange portions;
A heat insulator surrounding at least a part of the heated object;
A heating coil wound around the heat insulator for induction heating the object to be heated;
A high-frequency induction heating resistor comprising power supply means for supplying high-frequency power to the heating coil.   The high-frequency induction heating resistor according to any one of claims 1 to 6, wherein the object to be heated has cooling fins.   The high-frequency induction heating resistor according to any one of claims 1 to 7, wherein the heat insulator has a pleated structure.   The high-frequency induction heating resistor according to claim 1, further comprising an electromagnetic wave shielding member surrounding the heating coil and the object to be heated.

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