JP3644238B2 - High frequency heating device output transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an output transformer suitable for use in a high-frequency heating device such as a high-frequency induction heating device or a high-frequency quenching device.
[0002]
[Prior art]
Conventionally, as an output transformer used in a high-frequency heating device, for example, one disclosed in JP-A-6-151212 is known. The output transformer includes a core portion formed by combining a plurality of E-type ferrite cores, a coil portion arranged to wind the core portion a plurality of times by bending a copper pipe, A first conductive member connected to each of a start end portion and a rear end portion of the coil portion and a pair of second conductive members connected between the first conductive members of the coil portion are provided.
[0003]
[Problems to be solved by the invention]
However, in this output transformer, since the coil portion is wound around the middle leg portion of the E-type core, a large-shaped E-type core must be used when the number of turns of the coil portion is large. However, it is difficult to reduce the size of the output transformer itself. For example, the output transformer cannot be easily moved, and its use range is limited. In addition, since it is necessary to use a relatively expensive E-type core as the core, the output transformer itself tends to be expensive.
[0004]
The present invention has been made in view of such circumstances, and the object of the invention according to claim 1 or 2 is that the output transformer can be reduced in size and weight, and can be configured at low cost, and the external noise can be reduced. An object of the present invention is to provide an output transformer for a high-frequency heating device that can prevent generation and the like. In addition to the object of the invention described in claim 1 or 2, the object of the invention described in claim 3 is that the output transformation of the high-frequency heating apparatus that can easily set the characteristics of the output transformer and improve the design freedom. Is to provide a vessel. The object of the invention described in claim 4 is to provide an output transformer for a high-frequency heating apparatus that can facilitate the movement of the output transformer and improve its usability in addition to the objects of the inventions of claims 1 to 3. It is to provide.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 is a plate-like secondary conductor having a substantially U-shaped recess, and a substantially rectangular parallelepiped first conductor disposed in the U-shaped recess of the secondary conductor. 1 core, a ring-shaped second core disposed outside the first core, and a protrusion projecting from the upper and lower surfaces of the secondary conductor of the first core and the second core. And a heating coil connected to the opening side end of the U-shaped recess of the secondary conductor.
[0006]
With this configuration, a predetermined current supplied from the primary conductor is induced as a large current in the plate-like secondary conductor, and this large current is supplied to the heating coil and disposed in the vicinity of the heating coil. The workpiece is induction-heated, for example. The primary conductor is between the substantially rectangular parallelepiped first core protrusion disposed in the U-shaped recess of the secondary conductor and the ring-shaped second core disposed outside the first core. Since it is wound, for example, the number of turns can be increased with respect to the size of the first core, and the output transformer itself can be reduced in size and weight.
[0007]
Further, the first core may be a substantially rectangular parallelepiped core and the second core may be a ring-shaped core, both of which can be used at low cost, and the output transformer itself can be configured at low cost. Furthermore, since the second core is disposed outside the first core, the magnetic flux induced in the first core can flow through the second core, and leakage of the magnetic flux to the outside is prevented. The coupling coefficient of the output transformer itself is improved, so that the size can be further reduced and the generation of external noise can be suppressed.
[0008]
The invention described in claim 2 is characterized in that the thickness of the first core is set to approximately twice the plate thickness of the second core. By configuring in this way, the magnetic flux induced by the first core is distributed and passed through the ring-shaped second core that is disposed outside the first core and whose plate thickness is set to approximately one half. The thickness of the first core and the second core can be reduced, and the output transformer can be further reduced in size and weight.
[0009]
The invention described in claim 3 is characterized in that a plurality of second cores are stacked in the width direction. With this configuration, the output characteristics of the output transformer can be easily set by increasing or decreasing the number of stacked second cores, and the design flexibility of the output transformer can be improved.
[0010]
The invention described in claim 4 is characterized in that a flexible connection cable is connected to the primary conductor. By comprising in this way, an output transformer can be easily moved to a predetermined place, and the usability can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 4 show an embodiment of an output transformer of a high-frequency heating device according to the present invention, FIG. 1 is a cross-sectional view thereof, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 is a cross-sectional view taken along line B-B in FIG. 1, and FIG. 4 is a cross-sectional view taken along line CC in FIG.
[0012]
The output transformer 1 includes a flat secondary coil 2, a rectangular parallelepiped rectangular core 3, a ring core 4, a primary coil 5, and a heating coil 6. The secondary coil 2 is formed into a flat plate shape by brazing a pair of L-shaped copper square pipes 8 on the outside of the U-shaped copper plate 7, and a U-shaped recess 9 is formed at the center thereof. Is formed.
[0013]
The square pipe 8 of the secondary coil 2 has a hole 8a therein, one end side 8b (opening 9a side of the U-shaped recess 9) is opened, and the other end side 8c is hose connector 10 respectively. It is fixed. A disk-shaped copper plate 11 is brazed and fixed to the opening 9a of the U-shaped recess 9 of the secondary coil 2, and holes 11a communicating with the holes 8a of the square pipe 8 are formed in the copper plate 11, respectively. In addition, four screw holes 11b (see FIG. 4) are formed.
[0014]
The heating coil 6 has a fixed portion 12 made of a copper square pipe, a straight portion 14 made of a copper square pipe, and a substantially ring-shaped coil portion 15 formed at the tip of the straight portion 14, for example. . The fixing portion 12 is fixed by brazing to a fixing plate 13 made of a flat copper plate. The fixing plate 13 is provided with a hole 13a communicating with the hole 11a of the copper plate 11, and four mounting holes 13b (see FIG. 4) is formed. The fixing plate 13, that is, the heating coil 6 is attached to the copper plate 11 by screwing the bolt 16 into the screw hole 11 b of the copper plate 11 from the attachment hole 13 b.
[0015]
Thereby, the heating coil 6 and the copper plate 11, that is, the secondary coil 2 are electrically connected, and the hole 8a of the square pipe 8, the hole 14a of the straight portion 14 of the heating coil 6, and the hole 15a of the coil portion 15 are The holes 11a of the copper plate 11, the holes 13a of the fixing plate 13, and the holes 12a of the fixing portion 12 communicate with each other. An O-ring 17 for preventing leakage of cooling water is fitted on the surface of the hole 13a of the fixing plate 13 facing the copper plate 11, and an insulating plate 18 is interposed between the pair of straight portions 14. It is disguised.
[0016]
The rectangular core 3 is formed by a ferrite core having a rectangular parallelepiped shape and a thickness t1 and a width w1. The rectangular core 3 protrudes from the upper surface 2a and the lower surface 2b of the secondary coil 2 by a predetermined length into the U-shaped recess 9 of the secondary coil 2. It is arranged in this way. The ring core 4 disposed outside the rectangular core 3 is formed by a ferrite core having a thickness t2 and a width w2, and a predetermined number of layers are laminated in the width w2 direction. The corners of the rectangular core 3 are substantially in contact with the ring core 4 at substantially diagonal positions, or are arranged with a slight gap.
[0017]
And the thin insulation arrange | positioned on the outer surface side of protrusion part 3a, 3b between the outer surface of protrusion part 3a, 3b protruded from the upper and lower surfaces 2a, 2b of the secondary coil 2 of the square core 3 and the inner surface of the ring core 4 The primary coil 5 is wound a predetermined number of times through the plate 19. The primary coil 5 is formed of a copper round pipe, and in a state where an insulating tube (not shown) is fitted on the outer peripheral surface thereof, in series with the outer periphery of the protruding portions 3a and 3b of the rectangular core 3, respectively. The coil is wound a predetermined number of times so as to be substantially parallel to the secondary coil 2.
[0018]
Further, a hose connector 20 (see FIG. 4) and a terminal plate 21 are fixed to both ends of the primary coil 5, respectively, and one end of a flexible connection cable 22 (see FIG. 1) is connected to the terminal plate 21. Has been. The other end of the connection cable 22 is connected to, for example, an output terminal of a high-frequency heating device (transistor inverter) (not shown). The output transformer 1 and the high-frequency heating device are electrically connected by the connection cable 22. A cooling water circulation passage which will be described later is formed.
[0019]
In addition, the insulating tape 23 is wound around the outer peripheral surface of the ring core 4 laminated in a predetermined number, or the ring core 4 is inserted into an insulating resin case, thereby preventing the ring core 4 from being separated or moved. Has been. Further, the opening provided on the counter heating coil 6 side in the stacking direction of the ring core 4 is closed by a circular insulating plate 24.
[0020]
As a result, the output transformer 1 exposes the hose connectors 10 and 20 and the terminal plate 21 on the primary side where the insulating plate 24 is disposed, and one end side of the connection cable 22 is connected to the exposed portion. With the heating coil 6 protruding on the secondary side, the entire outer shape is formed in a substantially cylindrical shape. The turns ratio of the primary coil 5 and the secondary coil 2 is preset to n: 1 according to the output characteristics of the output transformer 1, and the outer diameter, thickness t2, and width w2 of the ring core 4. The shape and the number of stacked layers are also set in advance according to the output characteristics.
[0021]
According to this output transformer 1, when a predetermined high-frequency current is supplied from a high-frequency heating device (not shown) to the primary coil 5 via the connection cable 22 and the terminal plate 21, the turn ratio is applied to the secondary coil 2 by inductive coupling. A large current according to the current flows. This large current is supplied to the heating coil 6, and a work (not shown) disposed in the vicinity of the heating coil 6 is induction-heated.
[0022]
Simultaneously with the supply of the high-frequency current, a cooling water supply device provided in a high-frequency heating device (not shown) is operated, and the square pipe 8 of the secondary coil 2 and the heating coil 6 are connected from the inside of the connection cable 22 and the hose connector 10. The cooling water circulates through the hose connector 20 and the connection cable 22, and the cooling water is also circulated and supplied into the primary coil 5, so that the primary coil 5, the secondary coil 2, the heating coil 6 and the like generate heat due to a large current. It can be suppressed.
[0023]
As described above, according to the output transformer 1 of the above embodiment, the rectangular core 3 is disposed in the U-shaped recess 9 of the plate-like secondary coil 2 and the ring core 4 is laminated outside the rectangular core 3. Since the primary coil 5 is wound around the outer periphery of the protrusions 3a and 3b from the upper and lower surfaces 2a and 2b of the secondary coil 2 of the square core 3 and the inner surface side of the ring core 4, the primary coil 5 is The secondary coil 2 can be wound many times in a substantially parallel state, and the winding ratio of the primary coil 5 to the rectangular core 3 can be increased.
[0024]
In addition, since the ring core 4 having a thickness t2 that is substantially half the thickness t1 is disposed outside the rectangular core 3 having the thickness t1, the magnetic flux induced in the rectangular core 3 is changed to the direction of arrows a and b in FIG. Thus, the magnetic flux is confined in the ring core 4, that is, the leakage of the magnetic flux to the outside is eliminated, and the inductive coupling coefficient between the primary coil 5 and the secondary coil 2 is increased. From these facts, it is possible to reduce the size of the rectangular core 3, the primary coil 4, and the like, that is, the size and weight of the output transformer 1 itself.
[0025]
In addition, since the ring core 4 is disposed on the outer periphery of the output transformer 1, it is possible to suppress the generation of external noise due to leakage of magnetic flux to the outside, and external noise at a location where the output transformer 1 is used. Can prevent adverse effects on other devices. Further, since the output transformer 1 is connected to the high-frequency heating device by the flexible connection cable 22, the output transformer 1 can be easily moved in combination with the reduction in size and weight. Can be easily used for high-frequency heating and brazing work, brazing and soldering work of large workpieces that are difficult to move, and the range of use of the heating coil 6 can be greatly expanded. The usability of the output transformer 1 can be greatly improved.
[0026]
In addition, since the outer shape of the output transformer 1 is formed in a substantially cylindrical shape by the ring core 4 (insulating tape 23 or the like), the outer shape can be further reduced in size and the usability can be further improved. In addition, since the rectangular core 3 and the ring core 4 which are simple and inexpensive in shape made of a ferrite core are used, the cost of the cores 3 and 4 can be reduced, and the output transformer 1 itself can be configured at low cost. become.
[0027]
Furthermore, the ring core 4 can be used by appropriately selecting the ring core 4 of various sizes (diameter and thickness t2 and width w2) that are commercially available, and by increasing or decreasing the number of layers, Characteristics such as the turn ratio and coupling coefficient of the output transformer 1 can be set as appropriate, and the design flexibility of the output transformer 1 can be greatly improved. Further, since the primary coil 4 can be tightly wound between the rectangular core 3 and the ring core 4, the output transformer 1 having a good coupling coefficient substantially equal to or higher than the conventional one can be easily obtained.
[0028]
In the above embodiment, the secondary coil 2 is formed of a single conductor (number of turns 1). However, the present invention is not limited to this, and, for example, a plurality of conductors are stacked at intervals. The primary coil 5 may be wound in series between the conductors and the upper and lower surfaces thereof. In the above embodiment, the secondary coil 2 is formed so as to have the U-shaped recess 9, but the substantially U-shaped recess in the present invention includes U-shaped and C-shaped recesses. Further, the shape of the rectangular core 3 and the ring core 4, the shape of the secondary coil 2 and the heating coil 6, the fixing position of the terminal plate 21 to the primary coil 5, the shape of the terminal plate 21, etc. are examples. Needless to say, various modifications can be made without departing from the scope of the present invention.
[0029]
【The invention's effect】
As described above in detail, according to the first aspect of the present invention, the square-shaped first core is disposed in the substantially U-shaped concave portion of the secondary conductor, and the ring-shaped second core is disposed outside thereof. Since the primary conductor is wound between the upper and lower protrusions of the first core and the second core, for example, the number of turns of the primary conductor can be increased with respect to the size of the first core, and the output transformer itself Can be reduced in size and weight, the shapes of the first and second cores are simplified, the output transformer itself can be constructed at low cost, and the second core prevents leakage of magnetic flux to the outside. The generation of external noise can be suppressed.
[0030]
According to the second aspect of the present invention, the magnetic flux induced by the first core is distributed to the ring-shaped second core which is disposed outside the first core and whose plate thickness is set to approximately one half. The thickness of the first core and the second core can be reduced, and the output transformer can be further reduced in size and weight.
[0031]
According to the third aspect of the present invention, the characteristics of the output transformer can be easily changed by increasing or decreasing the number of stacked second cores, and the degree of freedom in designing the output transformer can be improved.
[0032]
Further, according to the invention described in claim 4, the output transformer can be easily moved to a predetermined place by the flexible connection cable connected to the primary conductor, and the usability can be improved. There are effects such as being able to.
[Brief description of the drawings]
1 is a cross-sectional view of an output transformer of a high-frequency heating device according to the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is a cross-sectional view taken along the line CC in FIG. 1 [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Output transformer 2 Secondary coil 2a Upper surface 2b Lower surface 3 Rectangular core 3a, 3b Protrusion part 4 Ring core 5 Primary coil 6 Heating coil 7 Copper plate 8 Square pipe 9 U-shaped recessed part 11 Copper plate 12 Fixing part 13 Fixing board 14 Straight part 15 Coil part 22 Connection cable

Claims (4)

A plate-like secondary conductor having a substantially U-shaped recess, a substantially rectangular parallelepiped first core disposed in the U-shaped recess of the secondary conductor, and disposed outside the first core A ring-shaped second core, a primary conductor wound between the second core and a protruding portion protruding from the upper and lower surfaces of the secondary conductor of the first core, and a U-shaped concave portion of the secondary conductor. An output transformer for a high-frequency heating device, comprising: a heating coil connected to an opening side end. 2. The output transformer of the high frequency heating device according to claim 1, wherein the thickness of the first core is set to approximately twice the plate thickness of the second core. The output transformer of the high-frequency heating device according to claim 1 or 2, wherein a plurality of the second cores are stacked in the width direction. 4. The output transformer of the high frequency heating device according to claim 1, wherein a flexible connection cable is connected to the primary conductor.

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