JP2007141981A - Matching transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a matching transformer for high-frequency heating while increasing cooling efficiency by improving the cooling arrangement of the matching transformer to simplify its structure. <P>SOLUTION: A conductive bottom plate closes a part between an inner tube and an outer tube of one end of a dual tube consisting of the conductive inner and outer tubes to form a secondary winding, a load side terminal is provided on the other end of the dual tube, a primary winding is wound between the inner and outer peripheries of the dual tube, a circular iron core made of a magnetic material is incorporated into an inner space between the inner and outer tubes of the dual tube, and a cooling water is flown into the inner space, thereby performing cooling. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a matching transformer for matching a power source and a load, and more particularly to a matching transformer inserted between a heating device for induction heating an object to be heated and a high frequency power source.

In order to efficiently supply power from the high-frequency power source to the high-frequency heating device, it is necessary to perform load matching (impedance matching). For that purpose, as shown in FIG. High frequency power is supplied to the high frequency induction heating coil 61 through the capacitor 66, the high frequency cable 67 and the matching transformer (matching transformer) 68. The use of such a matching transformer 68 is described in Patent Document 1, for example.
Japanese Patent Laid-Open No. 11-167980

  By the way, as the matching transformer used in the high-frequency heating device, a transformer having a winding formed of a water-cooled copper pipe is generally used, and the iron core is cooled by the same water-cooled copper pipe. However, since the conventional matching transformer is one in which the primary winding and the secondary winding are individually wound around the annular iron core, cooling pipes are required for cooling the iron core, and the cooling system becomes complicated and the outer shape is also reduced. There was a problem of becoming large.

  Accordingly, an object of the present invention is to improve the cooling system of the matching transformer, simplify the structure, and reduce the size while increasing the cooling efficiency.

In order to solve the above problems, the invention of claim 1 is characterized in that the inner tube and the outer tube are electrically connected by connecting a conductive bottom plate to one end of a double tube comprising a conductive inner tube and an outer tube. And the secondary coil is formed by closing the opening between the two tubes, and the load connection terminals are drawn out from the inner tube and the outer tube at the other end of the double tube, The primary winding is wound around the circumference.
According to the first aspect of the present invention, an annular body having a U-shaped cross section formed by closing one end of a double tube with a bottom plate is used as a secondary winding, and this secondary winding has one turn (U-shaped). The coil is configured to be continuous in an annular shape. Accordingly, a large cross-sectional area of the current path can be obtained even with a thin double tube.

  According to a second aspect of the present invention, in the first aspect of the present invention, an annular iron core made of a magnetic material is incorporated into the internal space between the outer tube and the inner tube of the double tube. A third aspect of the present invention is that in the first or second aspect, the cooling water is passed through the internal space between the outer pipe and the inner pipe of the double pipe.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the conductive first pipe is joined to the inner peripheral surface of the inner pipe along the axial direction, and the end of the first pipe on the bottom plate side is joined. The portion is folded in a U-shape to communicate with the internal space between the outer tube and the inner tube of the double tube, and one of the load connection terminals is formed at the opposite end, and the outer surface of the outer tube A conductive second pipe is joined along the axial direction, the end of the second pipe on the bottom plate side is used as one connection end of the cooling water pipe, and the other end is connected to the other end. A load connection terminal is formed, and a connection end of another cooling water pipe leading to the internal space is attached to the double pipe, and the cooling water supplied from the connection end of any one of the cooling water pipes is supplied to the two pipes. The internal space of the heavy pipe and the first and second pipes are discharged from the connection end of the other cooling water pipe. And it is characterized in and.

  The invention according to claim 5 is the invention according to claim 4, wherein a water-cooling type heating coil is connected to the load connection terminal, and the cooling water is simultaneously passed through the heating coil. It is.

  Furthermore, the invention of claim 6 is characterized in that in the invention of any one of claims 1 to 5, the entire transformer is accommodated in an insulating case, and a carrying handle is attached to the insulating case. Is.

According to the present invention, an annular body having a U-shaped cross section formed by closing one end of a double tube with a bottom plate is used as a secondary winding, and the secondary winding is a coil of one turn (U-shape). Is configured to be continuous in an annular shape. Therefore, since a large current path cross-sectional area can be obtained even with a thin double tube, there is an effect that a large current matching transformer can be reduced in size.
Further, by passing cooling water through the internal space between the outer pipe and the inner pipe of the double pipe constituting the secondary winding, the secondary winding and the iron core accommodated therein can be effectively cooled. In addition, by selecting the combination, not only the secondary winding but also the induction heating coil that is the load and the cooling water circuit of the primary winding can be made common, so the configuration of the cooling water piping becomes simple, The matching transformer can be reduced in size and weight.

  Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.

1 and 2 are configuration diagrams showing Embodiment 1 of the present invention.
In FIG. 1 and FIG. 2, 1 and 2 are the primary winding and the secondary winding which comprise the matching transformer MT.

  First, the structure of the secondary winding 2 shown in detail in FIG. 1 will be described. FIG. 1 shows the configuration of the secondary winding 2, in which (a) is a longitudinal sectional view thereof and (b) is a side view thereof. In FIG. 1, reference numerals 21 and 22 denote an outer tube and an inner tube constituting a conductive double tube. The outer tube 21 and the inner tube 22 are joined at one end (left end) by a conductive ring-shaped bottom plate 23 so that the outer tube 21 and the inner tube 22 are electrically connected and mechanically closed. As a result, the secondary winding 2 having an annular body having a U-shaped cross section is formed. Then, the conductive plates 28 and 29 are joined to the outer peripheral surface of the outer tube 21 and the inner peripheral surface of the inner tube 22, respectively, and are drawn out to the outside of the double tube on one end (right end) side thereof to the secondary side (load side). Connection terminals 28a and 29a are provided. Since the secondary winding 2 has a structure in which one-turn (U-shaped) coils are continuously connected in an annular shape, even a thin double tube can have a large current path cross-sectional area.

  In addition, since the space between the outer tube 21 and the inner tube 22 on the other end (right end) side of the double tube is closed with a ring-shaped insulating cap 25, the thickness of the end portion of the outer tube 21 is supplemented. Therefore, the ring-shaped collar 24 is joined by brazing or the like, and an insulating cap 25 is inserted between the collar 24 and the inner tube 22. By mounting an O-ring 26 in an annular groove provided on the outer peripheral surface of the insulating cap 24, the gap between the cap and the double pipe is sealed. Then, the insulating cap 25 is locked to the outer tube 21 by mounting the C ring 27 in the groove provided on the inner periphery of the collar 24 so that the insulating cap 25 does not come out of the double tube. As a result, an internal space 30 is formed between the outer tube 21 and the inner tube 22 of the double tube.

  In order to use the formed internal space 30 as a cooling water passage, in the first embodiment, water pipes 31 and 32 made of copper pipes are joined to the outer periphery of the outer pipe 21, and one water pipe 31 is connected. Is connected to the inner space 30 of the double pipe through the outer pipe 21 on the right end side of the double pipe, and the other water pipe 32 is connected to the inner space 30 through the outer pipe 21 on the left end side. Yes. The other end of each of the water pipes 31 and 32 is a connection end connected to the cooling water pipe.

  For example, when cooling water is supplied from the water pipe 31 side, the cooling water enters the internal space 30 from the right end side of the double pipe, flows to the left end side, and flows out from the water pipe 32. Thus, the outer tube 21 and the inner tube 22 constituting the secondary winding are directly cooled by the cooling water flowing through the inner space 30, and the secondary winding 2 can be efficiently cooled.

  In order to configure the matching transformer MT, it is necessary to electromagnetically couple the primary winding to the secondary winding 2.

  FIG. 2 shows a configuration in which the primary winding 1 is wound around the primary winding 2. (A) is a longitudinal cross-sectional view, (b) is a side view.

  The conductor constituting the primary winding 1 is formed of a copper pipe so that cooling water can be passed inside, and is formed in advance so that it can be wound from the outer circumference to the inner circumference of the double pipe constituting the secondary winding 2. The divided conductors 11 to 16 are connected to each other by the copper pipe connector 17 and, for example, as shown in FIG. In order to insulate each of the conductors from the secondary winding 2, a predetermined insulation is provided by covering an insulating tube. Primary side (power supply) connection terminals 18 and 19 are provided from the ends of the winding start conductor 11 and the winding end conductor 16 and are connected to a power supply line from a high frequency power supply (not shown).

  If comprised in this way, the primary winding 1 and the secondary winding 2 will be electromagnetically couple | bonded, and electric power transformation will be performed by the turn ratio of both windings. When the high frequency power supplied to the primary winding 1 is supplied, the secondary side connection terminals 28a and 29a drawn from the outer tube 21 and the inner tube 22 constituting the secondary winding 2 are connected to this. High frequency power transformed according to the turn ratio of both windings, for example, 6: 1, can be supplied to the heating coil of the high frequency heating device.

  3 and 4 show Embodiment 2 of the present invention. The configuration of the second embodiment is basically the same as that of the first embodiment. A different point of the second embodiment is that an annular space made of a magnetic material is formed in the internal space 30 of the double pipe constituting the secondary winding so that the leakage of magnetic flux in the matching transformer MT can be suppressed and high efficiency transformation can be performed. The required number of iron cores 4 is incorporated. These iron cores 4 are fitted into the inner tube 22 via an insulating sheet 42, and both ends in the axial direction are fixed by an insulating collar 43 and an insulating cap 25 and insulated from the secondary winding 2. An insulating ring 44 is interposed between the iron cores 4. The outer diameter of the insulating ring 44 is smaller than the outer diameter of the iron core 4 as shown in the figure. Although the insulating ring 44 can be omitted, by providing the insulating ring 44 as in the embodiment, a gap is formed between the iron cores 4, and the contact area between the iron core 4 and the cooling water increases. Therefore, the cooling efficiency is improved as compared with the case where the insulating ring 44 is not provided.

The insulating structure of the iron core is not limited to the above-described structure. For example, when the entire annular iron core is covered with an insulating resin or the like in advance, the insulating sheet 42 and the insulating ring 44 can be omitted, and the structure Can be easy.
According to the second embodiment, by providing the iron core, the electromagnetic coupling between the primary winding 1 and the secondary winding 2 is strengthened and the leakage of magnetic flux is suppressed, so that the transformation efficiency is increased. Similarly to the first embodiment, the cooling water is supplied to the internal space 30 of the double pipe in which the iron core is stored from the water pipes 31 and 32 and is cooled by water. At the same time, it can be performed efficiently.

  FIG. 5 shows a third embodiment of the present invention. The configuration of this embodiment is basically the same as that of the two embodiments. The difference between the third embodiment and the second embodiment is that the cooling water when the water-cooled heating coil 5 is connected as a load to the secondary side connection terminals 28a and 29a of the secondary winding 2 of the matching transformer MT. The circuit configuration.

The conductor which comprises the heating coil 5 is also comprised with the copper pipe so that cooling water can be let through. The conductors 28 and 29 constituting the secondary side (load) connection terminals 28a and 29a provided on the outer tube 21 and the inner tube 22 constituting the secondary winding 2 are also constituted by copper tubes. The conductor 28 joined to the outer peripheral surface of the outer tube 21 along the axial direction is drawn to the outside of both ends of the double tube. A conductor 29 joined in the axial direction to the inner peripheral surface of the inner tube 22 is folded in a U shape at one end outside the double tube, passes through the bottom plate 23, and forms a cooling water flow path. It communicates with the internal space 30. The other end is pulled out to the outside of the double tube and becomes one connection terminal 29a for the heating coil 5. The water pipe 31 communicates with the internal space 30 of the double pipe as in the previous two embodiments. One end of the conductor 28 forms the heating coil 5 and the other connection terminal 28a, and the other end serves as a connection end of the cooling water pipe.
As shown in the drawing, both ends of the heating coil 5 are coupled to the connection terminals 28a and 29a of the lead conductors 28 and 29 by couplers 51 and 52 that can circulate cooling water and can also be electrically connected.

  Thereby, the cooling water circuit of the secondary winding 2 and the cooling water circuit of the heating coil 5 are connected in series to form a common circuit. For this reason, when cooling water is supplied to one end of the water pipe 31 from a cooling water supply device (not shown), the cooling water enters the internal space 30 of the double pipe from the other end of the water pipe 31 as indicated by an arrow, From the bottom plate 23 side of the internal space 30, the U-shaped portion of the lead conductor 29 enters the inside, and flows from the other end of the conductor 29 to one end of the lead conductor 28 joined to the outer tube 21 via the heating coil 5. It flows in the path | route which returns to the cooling water supply apparatus from the other end of 28.

  Thus, since the cooling water circuit of the secondary winding of the matching transformer MT and the heating device such as the water-cooling type heating coil connected to the secondary winding can be made common, the configuration of the cooling water piping is simplified.

FIG. 6 is an example in which the third embodiment of FIG. 5 is developed, and is a common circuit up to the cooling water circuit of the primary winding 1 of the transformer.
FIG. 6 shows a schematic perspective view of the matching transformer MT with a part cut away for easy understanding of the structure.

  The primary winding 1 is wound around the outer periphery and the inner periphery of the secondary winding 2 composed of a double pipe by the required number of turns. Primary side (power supply) connection terminals 11e, 16e and water distribution connection ends 11w, 16w are provided in the lead portions 11a, 16a at both ends of the primary winding. As in the case of the third embodiment, the heating coil 5 is connected to the secondary side (load) connection terminals 28a and 29a formed on the secondary side lead conductors 28 and 29 having a configuration capable of passing cooling water. It couple | bonds with the couplers 51 and 52 which connect both of a cooling water circuit.

  The water distribution connection end 16w of the primary winding 1 and the water pipe 31 joined to the secondary winding 2 are connected by an insulating tube 35, and the other water distribution connection end 11w is connected to a cooling water supply device (not shown). Connect to the cooling water supply pipe. The water distribution connection end 28 w of the secondary lead conductor 28 is connected to the cooling water return insulating tube of the cooling water supply device.

Thereby, the cooling water supplied from the cooling water supply device is, as indicated by an arrow, the water distribution connection end 11 w of the primary winding 1, the primary winding 1, the water distribution connection terminal 16 w, the insulating tube 35, and the water pipe 31. -The inner space 30 of the double pipe constituting the secondary winding 30-the secondary side lead conductor 29-the heating coil-the secondary side lead conductor 28 flows through the path, the primary winding 1, the secondary winding 2 and the heating The cooling water circuit of the coil is connected in series and becomes common.
Therefore, according to the fourth embodiment, the cooling water circuit of the primary winding, the secondary winding of the matching transformer MT, and the heating coil of the iron core arrangement heating device can be configured as one common circuit. Therefore, the apparatus can be miniaturized.

  The matching transformer MT described as each of the embodiments may be entirely housed in a case made of an insulating material, and a portable handle can be attached to the case so as to be portable.

It is a block diagram of the secondary winding of the matching transformer by Example 1 of this invention, (a) is a longitudinal cross-sectional view, (b) is a side view. It is a block diagram of the matching transformer by Example 1 of this invention, (a) is a longitudinal cross-sectional view, (b) is a side view. It is a block diagram of the secondary winding of the matching transformer by Example 2 of this invention, (a) is a longitudinal cross-sectional view, (b) is a side view. It is a block diagram of the matching transformer by Example 2 of this invention, (a) is a longitudinal cross-sectional view, (b) is a side view. It is a longitudinal cross-sectional view which shows the structure of the matching transformer by Example 3 of this invention. It is a perspective view including the partial cross section which shows the structure of the matching transformer by Example 4 of this invention. It is a block circuit diagram which shows the general structure of a high frequency induction heating apparatus.

Explanation of symbols

MT Matching Transformer 1 Primary Winding 2 Secondary Winding 21 Outer Tube 22 Inner Tube 23 Bottom Plate 25 Insulation Cap 28, 29 Secondary Leader Conductor 30 Internal Space 31, 32 Water Pipe 4 Iron Core 5 Heating Coil

Claims (6)

  A secondary winding is formed by closing a space between the inner tube and the outer tube at one end of a double tube comprising a conductive inner tube and an outer tube with a conductive bottom plate, and at the other end of the double tube. A matching transformer, wherein a load side terminal is provided and a primary winding is wound between the inner and outer peripheries of the double pipe.   2. The matching transformer according to claim 1, wherein an annular iron core made of a magnetic material is incorporated in an internal space between the outer tube and the inner tube of the double tube.   3. The matching transformer according to claim 1, wherein cooling water is passed through an internal space between the outer pipe and the inner pipe of the double pipe.   A conductive first pipe is joined to the inner peripheral surface of the inner pipe along the axial direction, and the end of the first pipe on the bottom plate side is folded back into a U shape to One end of the load side terminal is formed at the opposite end of the inner space between the pipe and the inner pipe, and a conductive second pipe is provided along the outer peripheral surface of the outer pipe along the axial direction. The end of the second pipe on the bottom plate side is used as one connection end of the cooling water pipe, and the other load side terminal is formed on the opposite end, and the double pipe is further formed. A connecting end of the other cooling water pipe leading to the internal space is attached, and the cooling water supplied from the connecting end of any one of the cooling water pipes is supplied to the internal space of the double pipe and the first and second 4. The matching transformer according to claim 3, wherein the matching transformer is discharged from a connection end of the other cooling water pipe through a pipe.   5. The matching transformer according to claim 4, wherein a water-cooled heating coil is connected to the load-side terminal, and the cooling water is simultaneously passed through the heating coil.   6. The matching transformer according to claim 1, wherein the entire transformer is accommodated in an insulating case, and a carrying handle is attached to the insulating case.

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