JP2008004774A - Transformer and high-frequency induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer that achieves high output and miniaturization and is excellent in cooling efficiency. <P>SOLUTION: The transformer 1 has a primary-side winding 2, as a primary-side conductor, and a secondary-side conductor 3. A cooling jacket 4 includes a cooling path 4a for flowing a cooling medium. The cooling jacket is connected to the end of the secondary-side conductor 3, so that the secondary-side conductor 3 connected to the cooling jacket 4 is directly cooled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transformer, and more particularly to a transformer used in a high-frequency circuit device such as a high-frequency induction heating device. The present invention relates to a heating device.

  Conventionally, various transformers have been proposed as transformers. For example, in the high frequency induction heating apparatus described in Patent Document 1 below, a circuit configuration in which a high frequency transformer is connected between a power supply circuit and a resonance circuit including a high frequency induction heating coil is shown. Here, the power supply circuit includes a rectifier circuit that rectifies an alternating current supplied from a high power supply into a direct current, and a voltage-type inverter circuit that converts the direct current supplied from the rectifier circuit into a high frequency. This voltage type inverter circuit is connected to a primary side conductor of the high frequency transformer, and a high frequency induction heating apparatus in which an LC resonance circuit including a high frequency induction heating coil and a capacitor is connected to a secondary side conductor of the high frequency transformer Therefore, miniaturization and high output are strongly demanded.

  However, in order to achieve high output in a high-frequency transformer, it is necessary to make the transformer itself large. A structure is also used in which the transformer is housed in a container filled with insulating oil and the transformer is directly cooled by insulating oil. However, since the transformer is housed in a container filled with insulating oil, it must be large.

  Therefore, Patent Document 2 below discloses a water-cooled transformer in which at least a secondary conductor is formed of a pipe made of a conductive material, and cooling water can be passed through the pipe.

  In the water-cooled transformer described in Patent Document 2, the secondary conductor of the transformer is formed of a pipe made of a conductive material, and cooling water is directly passed through the pipe to perform cooling. Therefore, since the secondary side conductor of the transformer can be directly cooled, the cooling efficiency is improved. Therefore, it is said that high output and miniaturization of the transformer can be achieved.

  However, in the water-cooled transformer described in Patent Document 2, since the secondary conductor is formed of a pipe made of a conductive material as described above, the dimensions of the secondary conductor itself, particularly the cross-sectional shape, must be large. There wasn't. Therefore, it has been difficult to make the transformer itself sufficiently small.

In addition, if the temperature of the transformer itself is too low, the loss in the iron core as the core material of the coil is increased, and as a result, the efficiency of the transformer may be reduced.
Japanese Patent Laid-Open No. 3-216989 JP 2000-12340 A

  An object of the present invention is to provide a transformer that can be suitably used for high-frequency applications such as a high-frequency induction heating device in view of the current state of the prior art described above, and that can be reduced in size and increased in power, and the transformer. The object is to provide a high-frequency induction heating device used.

  The transformer according to the present invention is a transformer having a primary side conductor and a secondary side conductor, and a cooling jacket provided with a flow path for flowing a cooling medium at an end of the secondary side conductor. It is connected, The secondary side conductor connected with this cooling jacket is cooled directly, It is characterized by the above-mentioned.

  In the transformer of the present invention, preferably, a plurality of the secondary side conductors are provided, a portion connected to the cooling jacket of the plurality of secondary side conductors has a plate-like shape, A secondary-side conductor holding portion that sandwiches the plate-like portion of the secondary-side conductor is provided, and the plate-like portion of the secondary-side conductor is connected in surface contact with the secondary-side conductor holding portion. In this case, the plate-like portion of the secondary conductor is sandwiched so as to be in surface contact with the secondary conductor sandwiching portion of the cooling jacket. Therefore, the secondary side conductor is efficiently cooled by the cooling jacket.

  In the transformer according to the present invention, preferably, the primary-side conductor or the primary-side winding, and the primary-side winding and the plurality of sheets so that the primary-side winding is inserted between the plurality of secondary-side conductors. A secondary side conductor is disposed, and the primary side winding is indirectly cooled through the secondary side conductor cooled by the cooling jacket. In this case, when the secondary conductor is cooled, the primary winding is effectively cooled because the primary winding is disposed between the plurality of secondary conductors.

  In the transformer according to the present invention, it is preferable that the end of the secondary conductor connected to the cooling jacket also serves as a terminal. In this case, the cooling jacket is not only excellent in thermal conductivity like metal, but also composed of a material having excellent conductivity, so that the cooling jacket has an electrical connection function of the secondary conductor. Can also be given. Therefore, for example, when a plurality of secondary conductors are connected to the cooling jacket, the terminals of the plurality of secondary conductors can be electrically connected to the outside simply by electrically connecting the cooling jacket to the outside. Can do.

  But in this invention, the edge part connected with the cooling jacket of the secondary side conductor does not necessarily need to serve as a terminal.

  In the transformer according to the present invention, preferably, as the cooling jacket, a first cooling jacket coupled to one end of the secondary conductor and a second coupled to the other end of the secondary conductor. The cooling flow paths of the first and second cooling jackets are connected by a cooling medium connection tube. In this case, since the first and second cooling jackets are connected by the cooling medium connecting tube, it is only necessary to supply the cooling medium from one cooling jacket side, so that one end and the other end of the secondary conductor are provided. The cooling medium can be quickly supplied by the first and second cooling jackets connected to the section. In addition, since the first and second cooling jackets are connected by the cooling medium connecting tube, compared to a case where a large cooling jacket that cools both one end and the other end of the secondary conductor is used. Therefore, the size can be reduced.

  In the present invention, preferably, a temperature sensor for detecting the temperature of the transformer is provided. In this case, the temperature of the transformer is detected by the temperature sensor, and the flow rate of the cooling medium is determined according to the temperature of the transformer. Can be adjusted. Therefore, the transformer can be operated at a more ideal temperature.

  In the present invention, as the cooling medium, various liquids that can perform a cooling action can be used, but cooling water is preferably used. In the case of cooling water, the transformer is inexpensive and can effectively cool the transformer.

  Further, the cooling medium may be a material other than the cooling water, and in the present invention, insulating oil may be used. When insulating oil is used, the transformer can be effectively cooled while preventing an electrical short circuit.

  A high-frequency induction heating apparatus according to the present invention includes a power source, an inverter connected to the power source, a high-frequency induction heating coil, and a high-frequency transformer connected between the inverter and the high-frequency induction heating coil. The transformer is composed of a transformer configured according to the present invention, and a primary side conductor of the transformer is connected to the inverter, and the secondary side conductor is connected to the high-frequency induction heating coil.

  In the transformer according to the present invention, the cooling jacket provided with the flow path for flowing the cooling medium is connected to the end of the secondary side conductor. The side conductor can be directly cooled. Therefore, the cooling efficiency can be increased.

  Moreover, since it is not necessary to flow a cooling medium through the secondary conductor itself, it is not necessary to increase the cross-sectional shape of the secondary conductor. That is, in the transformer described in Patent Document 2, since the secondary conductor has a tubular shape through which cooling water is passed, miniaturization is prevented, whereas in the transformer of the present invention, The cross-sectional shape of the secondary side conductor can be reduced, thereby making it possible to reduce the size of the transformer. Therefore, it is possible to provide a transformer that is excellent in cooling efficiency and can therefore easily cope with high output and can be miniaturized.

  Since the high frequency induction heating according to the present invention includes the transformer of the present invention as a high frequency transformer, the high frequency induction heating apparatus can be reduced in size and output.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  FIGS. 1A and 1B are a front view and a plan view of a transformer according to an embodiment of the present invention, and FIGS. 2A and 2B are a left side view and a right side view of the transformer. It is.

  The transformer 1 of this embodiment includes a primary winding 2 as a primary conductor and a plurality of secondary conductors 3. FIGS. 3A and 3B are a plan view and a front view showing the primary winding 2. As shown in FIGS. 3A and 3B, the primary winding 2 as the primary conductor is wound so that a plate-like member made of a plurality of metals has a winding portion 2a having a plurality of turn portions. It is configured by turning. In addition, in the winding part 2a, the plate-shaped metal plate is wound so that the main surfaces of the plate-shaped metal plate face each other.

  On the other hand, FIGS. 4A and 4B are a plan view and a front view showing one secondary conductor 3. The secondary conductor 3 is made of metal and has a substantially U-shape. The one end 3a and the other end 3b of the secondary conductor 3 also have a plate shape. In the present embodiment, the end portions 3a and 3b are formed in a plate shape, and the remaining portions are also formed in a plate shape, but the portions other than the one end portion 3a and the other end portion 3b are It does not necessarily have to be a plate shape. However, preferably, in the present embodiment, it is desirable that the portions other than the one end portion 3a and the other end portion 3b also have a plate-like shape, and thereby downsizing can be promoted.

  In addition, the one end 3a and the other end 3b also serve as a secondary conductor terminal in the present embodiment. Through holes 3c and 3d are formed in the one end portions 3a and 3b, respectively.

  Further, as shown in FIGS. 1A and 1B, the plurality of secondary conductors 3 are laminated so that their main surfaces face each other. Each secondary conductor 3 is connected to the first and second cooling jackets 4 and 5. FIGS. 5A to 5C are a plan view, a front view, and a right side view of the first cooling jacket 4.

  The 1st cooling jacket 4 consists of a metal excellent in heat conductivity, and has a substantially rectangular parallelepiped shape. And in the cooling jacket 4, the cooling path 4a extended in an up-down direction is formed. A cooling medium, which will be described later, passes through the cooling path 4a.

  On the other hand, the cooling jacket 4 has a secondary-side conductor clamping portion 4b that clamps the secondary-side conductor 3. The secondary side conductor clamping portion 4b extends in the horizontal direction and is provided at a plurality of height positions as shown in FIG. 5 (b). Each secondary side conductor clamping part 4b is open toward the right side surface of the cooling jacket 4, and a plate-like part in the vicinity of one end 3a of the secondary side conductor 3 is clamped by the secondary side clamping part 4b. Thereby, the secondary conductor 3 is connected to the cooling jacket 4 in surface contact.

  As shown in FIG. 1B, a second cooling jacket 5 is provided in addition to the first cooling jacket 4. The second cooling jacket 5 is connected to the other end 3 b of the secondary conductor 3. The second cooling jacket 5 has the same structure as the first cooling jacket 4.

  In the present embodiment, the one end 3 a and the other end 3 b of the secondary conductor 3 also serve as terminals for electrically connecting the secondary conductor 3. Therefore, since the cooling jackets 4 and 5 are made of metal, the terminals of the secondary side conductors 3 are electrically connected to each other by the cooling jackets 4 and 5. Therefore, when electrically connecting to the outside, the electrical connection can be easily achieved using the cooling jacket 4 or the cooling jacket 5.

  However, the plate-like portion of the secondary conductor 3 may be a portion different from the terminal that achieves electrical connection as long as the secondary conductor 3 can be sandwiched in surface contact and efficiently cooled. In that case, the cooling jackets 4 and 5 may be made of a material having no conductivity.

  Further, as shown in FIGS. 5A and 5B, a through hole 4c is formed so as to extend in the vertical direction in the portion where the secondary side conductor clamping portion 4b is provided.

  As shown in FIG. 5B, the cooling path 4a extends in the up-down direction, and the cooling path 4a opens at the upper side and the lower side.

  On the other hand, as shown in FIGS. 1A and 1B, the first and second cooling jackets 4 and 5 are connected by a cooling medium connection tube 6. That is, the end of the cooling medium connection tube 6 is liquid-tightly connected to the upper opening of the cooling path of the first and second cooling jackets 4 and 5.

  Further, a cooling medium such as cooling water is passed through the lower opening of the cooling path 4 a of the first cooling jacket 4, and the cooling medium also enters the cooling path of the second cooling jacket 5 via the connection tube 6. Finally, it is taken out from the lower opening of the cooling path of the second cooling jacket 5.

  FIG. 6 is a schematic exploded view showing the components of the transformer 1 of the present embodiment in an exploded manner. In the transformer 1, the primary conductor 2 is interposed between the secondary conductors 3 so that the winding portion 2a of the primary conductor 2 is inserted between the secondary conductors 3, that is, as shown by the arrows in FIG. It is assembled so that the turn part of the winding part 2a is located. Therefore, in the transformer 1, the turn portion of the winding portion 2 a of the primary side winding 2 is sandwiched between the adjacent secondary side conductors 3.

  In the transformer 1, cores 8a and 8b constituting a core material made of iron or the like are disposed above and below the portion where the primary side conductor 2 and the secondary side conductor 3 are interleaved, and the base member 9 and the top plate 10 are stacked one above the other, and these are integrated by bolts 11 and nuts 12.

  Reference numerals 13a and 13b are washers.

The secondary conductor 3 is connected to the cooling jacket 4 by a bolt 14 and a nut 15 shown in FIG. That is, as described above, the through-hole 4c is provided so as to penetrate the portion of the cooling jacket 4 where the secondary conductor holding portion 4b is provided in the vertical direction. The bolt 14 is inserted into the through hole 4 c and the through holes 3 c of the end portions 3 a and 14 of the secondary conductor 3. Then, by fastening with the bolt 14, the nut and the nut 15, the vicinity of the one end 3 a of the secondary conductor 3 is firmly clamped and fixed to the cooling jacket 4 in the secondary conductor clamp 4 b. . Also on the cooling jacket 5 side, the end 3b of the secondary conductor 3 is firmly clamped and connected to the secondary conductor clamp 4b by a bolt (not shown).

  In FIG. 5, a part of the cooling medium connection tube 6 is schematically shown. Further, the connector 16 provided below the cooling jacket 4 is connected to the cooling path 4 a in order to supply the cooling medium below the cooling path 4 a of the cooling jacket 4. The connector 16 is connected to a cooling medium supply source (not shown).

  In the transformer 1 of the present embodiment, a cooling medium is supplied to the cooling jacket 4, and the cooling medium passes through the cooling medium connection tube 6 from the cooling path 4 a of the cooling jacket 4 and the cooling path of the second cooling jacket 5. To be discharged from the second cooling path. Accordingly, the first and second cooling jackets 4 and 5 are cooled by the cooling medium. In the plurality of secondary conductors 3, one end 3 a and the other end 3 b are at least plate-like portions, and these plate-like portions sandwich the secondary conductors of the cooling jackets 4, 5. It is firmly connected so as to come into surface contact with the portion 4b. Therefore, since the area of the contact portion between the cooling jacket 4 and the secondary conductor 3 is sufficiently large, when the cooling jackets 4 and 5 are cooled, the secondary conductor 3 is also quickly cooled by the heat transfer action. It will be.

  In addition, since the winding portion of the primary side winding 2 is inserted between the secondary side conductors 3 at the portion opposite to the end portions 3a, 3b of the secondary side conductor 3, the primary side winding The wire 2 is also indirectly cooled when the secondary conductor 3 is cooled. That is, as shown in FIG. 7, in the transformer 1, cooling water as a cooling medium is supplied to the plurality of secondary conductors 3 side, the secondary conductors are cooled, and the secondary conductors 3 as described above. The primary winding 2 in which the winding portion is inserted between the tips of the wires is also cooled. Therefore, the transformer 1 is effectively cooled by the cooling medium. Moreover, the transformer 1 does not require a large container for immersing the transformer 1 in insulating oil. Further, it is not necessary to form a large secondary conductor so that the cooling medium passes through the secondary conductor itself. Therefore, the transformer 1 can be reduced in size and can easily cope with higher output.

  In the above embodiment, the first and second cooling jackets 4 and 5 are connected by the cooling medium connecting tube 6. However, the first and second cooling jackets 4 and 5 are electrically insulated from each other. As long as it is obtained, the first and second cooling jackets may be integrated. However, as in this embodiment, the first and second cooling jackets 4 and 5 are individually provided on the one end 3a and the other end 3b side of the secondary conductor 3, thereby reducing the dimensions of the cooling jacket itself. It can be reduced, and further miniaturization can be achieved, which is desirable.

  Further, each turn portion of the winding portion 2 a of the primary side winding 2 is not necessarily arranged so as to be positioned between the plurality of secondary side conductors 3. However, as in the above-described embodiment, the primary side winding 2 and the secondary side conductor 3 are arranged such that the turn part of the winding part 2 a of the primary side winding 2 is inserted between the plurality of secondary side conductors 3. So that the primary winding 2 can also be effectively cooled as described above.

  Preferably, a temperature sensor for detecting the temperature of the transformer may be provided. An appropriate temperature sensor can be used as such a temperature sensor, and more preferably a temperature sensor other than a thermocouple is used. Examples of the temperature sensor other than the thermocouple include a bimetal, a thermostat, or a non-contact thermometer.

  When detecting the temperature of the transformer, it is preferable to measure the temperature of the core material because the temperature of the core material of the transformer greatly affects the conversion efficiency of the transformer among the parts constituting the transformer.

  More preferably, the temperature sensor, the control device, and a flow rate adjusting device for adjusting the flow path of the cooling medium are connected, and the temperature range of the core material having good conversion efficiency is stored in advance in the control device. When the temperature of the core material detected by the temperature sensor is outside the above temperature range, the flow rate adjusting device is controlled by the control device to adjust the flow rate of the cooling medium so that the temperature of the core material is within the above temperature range. It is desirable to control so that there is. As such a flow rate adjusting device, an appropriate device such as a device using an electromagnetic valve or a device for changing the flow rate can be used. With such control, the transformer can be operated at an ideal temperature.

  As the cooling medium, cooling water that is inexpensive and easy to handle is preferably used, but liquids other than cooling water may be used, and examples of such liquids include insulating oil and antifreeze liquid. Can do.

  When the insulating oil is used, since it has electrical insulation, an undesired short circuit or the like can be prevented even if the insulating oil leaks.

  The transformer of the present invention is used for voltage transformation in various applications, and the application is not particularly limited, but is preferably used as a transformer for high frequency applications such as a high frequency induction heating apparatus.

  FIG. 8 is a circuit diagram showing an example of a high-frequency induction heating apparatus to which the present invention is applied.

  The high-frequency induction heating device 21 includes a rectifier circuit 23 connected to a commercial power supply 22 and an inverter 24 connected to a subsequent stage of the rectifier circuit 23. The output side of the inverter 24 is electrically connected to the primary winding 2 of the transformer 1. On the other hand, a resonance circuit including a high-frequency induction heating coil 25 and a capacitor 26 connected in series to the high-frequency induction heating coil 25 is connected to the secondary-side conductor including the plurality of secondary-side conductors 3a. Here, the alternating current supplied from the commercial power source 22 is rectified by the rectifier circuit 23, and a high frequency voltage is applied to the transformer 1 from the voltage type inverter circuit 24. Then, the LC resonance circuit including the high frequency induction heating circuit 25 and the capacitor 26 is driven by the voltage transformed by the transformer 1, thereby heating other members and devices using the high frequency induction heating coil 25. be able to.

  In such a high-frequency transformer, high output and miniaturization are strongly demanded, but the transformer 1 of the above embodiment can be suitably used for such a use.

(A) And (b) is the front view and top view of a trans | transformer which concern on one Embodiment of this invention. (A) And (b) is the left view and right view of the trans | transformer which concern on one Embodiment of this invention. (A) And (b) is the top view and front view of a primary side winding which are used for the transformer of one embodiment of the present invention. (A) And (b) is the top view and front view of one secondary side conductor which are used with the transformer of one Embodiment of this invention. (A) is a top view of the 1st cooling jacket used with the transformer of one embodiment of the present invention, (b) is a front view of the 1st cooling jacket, and (c) is the 1st cooling jacket. Right side view. The typical exploded front view of the transformer concerning one embodiment of the present invention. 1 is a circuit diagram schematically showing a circuit configuration of a transformer according to an embodiment of the present invention. The circuit diagram of the high frequency induction heating apparatus of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transformer 2 ... Primary side winding 3 ... Secondary side conductor 3a ... One end 3b ... Other end 3c, 3d ... Through-hole 4 ... 1st cooling jacket 4a ... Cooling path 4b ... Secondary side conductor clamping part 4c ... Through Hole 5 ... second cooling jacket 6 ... cooling medium connection tube 8a, 8b ... core 9 ... base member 10 ... top plate 11 ... bolt 12 ... nut 13a, 13b ... washer 14 ... bolt 15 ... nut 16 ... connector 21 ... high frequency Induction heating device 22 ... Power source 23 ... Rectification 24 ... Inverter circuit 25 ... High frequency induction heating coil 26 ... Condenser

Claims (9)

  A transformer having a primary side conductor and a secondary side conductor, wherein a cooling jacket provided with a flow path for flowing a cooling medium is connected to an end of the secondary side conductor, and the cooling A transformer characterized in that the secondary conductor connected to the jacket is directly cooled.   A plurality of the secondary side conductors are provided, a portion of the plurality of secondary side conductors connected to the cooling jacket has a plate shape, and the cooling jacket includes the plate shaped portion of the secondary side conductor. 2. The transformer according to claim 1, further comprising a secondary-side conductor sandwiching portion to be sandwiched, wherein the plate-like portion of the secondary-side conductor is connected to the secondary-side conductor sandwiching portion in surface contact.   The primary side conductor or the primary side winding, and the primary side winding and the plurality of secondary side conductors are arranged so that the primary side winding is inserted between the plurality of secondary side conductors, The transformer according to claim 2, wherein the primary winding is indirectly cooled through the secondary conductor cooled by the cooling jacket.   The transformer according to claim 1, wherein the end portion of the secondary conductor connected to the cooling jacket also serves as a terminal of the secondary conductor.   The cooling jacket includes a first cooling jacket connected to one end of the secondary conductor, and a second cooling jacket connected to the other end of the secondary conductor, The transformer according to any one of claims 1 to 4, wherein the cooling flow path of the second cooling jacket is connected by a cooling medium connection tube.   The transformer according to any one of claims 1 to 5, further comprising a temperature sensor for detecting a temperature of the transformer.   The transformer according to any one of claims 1 to 6, wherein the cooling medium is cooling water.   The transformer according to claim 1, wherein the cooling medium is an insulating oil. A power source, an inverter connected to the power source, a high frequency induction heating coil, and a high frequency transformer connected between the inverter and the high frequency induction heating coil,
The high-frequency transformer comprises the transformer according to any one of claims 1 to 8, wherein a primary side conductor of the transformer is connected to the inverter and the secondary side conductor is connected to the high-frequency induction heating coil. A high-frequency induction heating device that is characterized.

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