JP4707131B2 - Output transformer for high frequency heating equipment - 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. It is difficult to reduce the size of the output transformer itself. For example, the output transformer cannot be easily moved, and the use range thereof is limited. Further, since it is necessary to use a relatively expensive E-type core as a core, the output transformer itself is liable to be expensive.
[0004]
Accordingly, the present applicant has filed an application for an output transformer disclosed in Japanese Patent Application Laid-Open No. 11-243020 in order to eliminate such inconvenience. The output transformer includes a plate-like secondary coil having a substantially U-shaped recess, a substantially rectangular parallelepiped first core disposed in the U-shaped recess of the secondary coil, and the first core A ring-shaped second core disposed on the outside; a primary coil wound between a second core and a protruding portion protruding from the upper and lower surfaces of the secondary coil of the first core; and the secondary coil And a heating coil connected to the end of the opening of the U-shaped recess.
[0005]
According to this output transformer, it is possible to reduce the size and weight of the output transformer and to make it inexpensive, and to generate external noise, by appropriately setting the shape and positional relationship between the first core and the second core. However, the following problems were clarified by subsequent experiments. That is, since the output transformer is simply connected to the high-frequency heating device with a flexible connection cable, when the output transformer is mounted on a welding robot or the like, for example, a primary coil or a secondary coil is used. The cooling coil is not sufficiently cooled, the impedance of the heating coil is not stable, it is difficult to stably secure sufficient heating efficiency, and the mounting state to the movable arm of the welding robot is not stable, making it easy to use It tends to be insufficient in terms of surface.
[0006]
The present invention has been made in view of such circumstances, and its object is to co obtains achieving size and weight reduction and the stabilization of the heating efficiency at the same time, greater heating efficiency by stabilizing the impedance An object of the present invention is to provide an output transformer for a high-frequency heating device that can be stabilized and improved in usability.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 is characterized in that a primary coil made of a copper pipe wound around an I-type core a predetermined number of times and a heating coil connected to one end of the primary coil are connected to the outside of the primary coil. A secondary coil composed of a copper pipe connected to the heating coil connection plate, a ring core disposed so as to surround the secondary coil and the primary coil, a cylindrical cover disposed outside the ring core, A flexible cooling cable connected to each end of the primary coil and the secondary coil, and the cooling cable is a primary coil side flow path in which a conducting wire is accommodated in a flexible tube. The forward and return paths and the secondary coil side flow path have the forward and return paths, and the primary coil side tubes and secondary coil side tubes or the primary coil side and secondary coil side forward paths and return paths are integrated. Together are characterized in that the inside diameter of each forward path of the tube the is set as larger than the inner diameter of the return tube.
[0008]
According to a second aspect of the present invention, a connecting plate having four holes is disposed in the opening on the counter heating coil side of the cylindrical cover, and the primary coil side is disposed in the cylindrical cover inside the connecting plate. And the hose connector fixed to the end of the copper pipe of the secondary coil are located, and the tubes of the cooling cable are respectively fitted and arranged in the holes provided in the connection plate and connected to the hose connector. It is characterized by that. The invention according to claim 3 is characterized in that the cylindrical cover has a mounting plate on an outer surface thereof.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIGS. 1-7 has shown one Example of the output transformer for high frequency heating apparatuses concerning this invention. In the figure, an output transformer 1 includes a secondary coil 3, an I-type core 4, a ring core 5 and a primary coil 6 disposed in a cylindrical cover 2, and connection plates disposed at both ends of the cylindrical cover 2. 7 and a heating coil connecting plate 8, a heating coil 9 and a pair of cooling cables 10 and 11.
[0010]
The secondary coil 3 has, for example, a pair of square pipes of substantially U-shaped copper and is formed in a single winding shape, and a hose connector 12 is fixed to one end of each square pipe via the pipe. At the same time, the heating coil connecting plate 8 is fixed to the other end. The heating coil 9 is connected to the heating coil connecting plate 8.
[0011]
The heating coil 9 has a fixed portion 9a made of a copper square pipe, a straight portion 9b made of a copper square pipe, and a coil portion 9c formed at the tip of the straight portion 9b. The fixing portion 9a is fixed by brazing to a fixing plate 13 made of a flat copper plate, and the fixing plate 13 is fixed to the heating coil connecting plate 8 so as to be detachable. The heating coil 9 is electrically connected to the secondary coil 3 via the fixed plate 13 and the heating coil connection plate 8 and is connected to the flow path by a connecting hole provided in the fixed plate 13 and the heating coil connection plate 8. Are connected in a state of forming.
[0012]
The I-type core 3 is formed in a rectangular parallelepiped shape by connecting a plurality of ferrite cores, for example, and protrudes a predetermined length from the upper and lower surfaces of the secondary coil 3 in the U-shaped recess of the secondary coil 3. It is arranged in this way. The ring core 4 disposed outside the I-type core 3 is formed by laminating a plurality of ferrite cores in the width direction.
[0013]
Then, between the inner surface of the outer surface and the ring core 4 of the I-shaped core 3, the primary coil 6 outer peripheral surface thereof is made of copper pipe that is coated with an insulating material is wound a predetermined number of times around, both ends of the primary coil 6 is cylindrical It is pulled out to one opening side of the cover 2 and a hose connector 14 is fixed to the tip thereof. The connection plate 7 made of a circular plate is disposed in one opening of the cylindrical cover 2 , and four holes 7 a are formed in the connection plate 7, and the cooling cable 10 is formed in the four holes 7 a. , 11 are arranged so as to be fitted and arranged with two flow paths 10a, 11a and two return paths 10b, 11b.
[0014]
The cooling cables 10 and 11 are configured such that a conducting wire made of a net or the like is accommodated in a flexible tube, and a pair of flexible outward paths 10a and 11a and a pair of tubes 10b and 11b are integrated. Thus, the interval between the conductive wires in the tube is set to be substantially constant in the longitudinal direction of the cooling cables 10 and 11. In addition, as a method of integrating a pair of tubes, it is performed by integral molding, bonding with an adhesive, fastening with an appropriate band, or the like. As a tube to be integrated, the tubes on the primary coil 6 side and the secondary coil are used. Although the tubes on the 3 side are preferable, it is of course possible to integrate the outgoing paths and the returning paths on the primary coil 6 side and the secondary coil 3 side.
[0015]
Although not shown, the cooling cables 10 and 11 are set such that the inner diameters of the tubes on the forward paths 10a and 11a are larger than the inner diameters of the tubes on the return paths 10b and 11b. The reason for this is that if the flow rates on the outward paths 10a and 11a are small, the cooling water is not sufficiently circulated in the heating coil 9 and the like, and the cooling cable 10 This is because there is a possibility that the service life of 11 or the service life of the internal conductor may be reduced or the cooling effect may be further reduced. Of course, if the inner diameter is set larger, the inner diameters of the tubes on the forward paths 10a and 11a and the return paths 10b and 11b can be set to the same inner diameter. Thereby, the circulation efficiency of cooling water can also be improved.
[0016]
The other ends of the cooling cables 10 and 11 are connected to an output terminal of a high-frequency heating device (transistor inverter) (not shown), for example. The output transformer 1 and the high-frequency heating device are electrically connected by the cooling cables 10 and 11. And a circulation path for cooling water is formed. An attachment plate 15 is fixed to the outer surface of the cylindrical case 2, and the output deformer 1 is attached to, for example, a movable arm of a welding robot via the attachment plate 15.
[0017]
According to the output transformer 1, when a predetermined high-frequency current is supplied from a high-frequency heating device (not shown) to the primary coil 6 via the cooling cables 10 and 11, the secondary coil 3 is inducted according to the turn ratio by inductive coupling. A large current flows. This large current is supplied to the heating coil 9, and a work (not shown) disposed close to the heating coil 9 is induction-heated.
[0018]
Simultaneously with the supply of the high-frequency current, a cooling water supply device provided in a high-frequency heating device (not shown) is activated, and the square pipe of the secondary coil 3 and the heating coil are connected from the forward path 11a of the cooling cable 10 and the hose connector 12. 9, the cooling water circulates through the hose connector 12 and the return path 10b of the cooling cable 10, and the cooling water is also circulated and supplied into the primary coil 6 through the cooling cable 11, the hose connector 14 and the like. Heat generation of the primary coil 6, the secondary coil 3, the heating coil 9, and the like is suppressed.
[0019]
At this time, by integrating the tubes of the cooling cables 10 and 11, the distance between the conductors can be maintained substantially constant, the inductance between the conductors (that is, the impedance of the heating coil 9) is stabilized, and the heating efficiency is improved. In addition, by appropriately setting the inner diameters of the tubes of the forward paths 10a and 11a and the return paths 10b and 11b, a good circulation state of the cooling water can be obtained, and the heating coil 9, the primary coil 6, and the secondary coil 3 The cooling efficiency is improved, and as a result, the heating efficiency of the workpiece by the heating coil 9 can be further improved.
[0020]
Thus, according to the output transformer 1 of the above embodiment, the I-type core 4 is disposed in the U-shaped recess of the secondary coil 3, and the ring core 5 is laminated outside the I-type core 4 in a laminated state. Since the primary coil 6 is wound between the outer periphery of the I-type core 4 and the inner surface of the ring core 5, the primary coil 6 can be wound many times in a substantially parallel state with the secondary coil 3. The turn ratio of the primary coil 6 to the mold core 4 can be increased.
[0021]
Further, since the ring core 5 having a half thickness is disposed outside the I-type core 4, the magnetic flux induced by the I-type core 4 can be dispersed to the left and right, and the magnetic flux is contained in the ring core 5. That is, the leakage of the magnetic flux to the outside is eliminated, and the inductive coupling coefficient between the primary coil 6 and the secondary coil 3 is increased. From these facts, it is possible to reduce the size of the I-type core 4 and the primary coil 6, that is, the size and weight of the output transformer 1 itself.
[0022]
In addition, since the ring core 5 is disposed on the outer peripheral portion 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. Furthermore, since the output transformer 1 is connected to the high-frequency heating device by the flexible cooling cables 10 and 11, the output transformer 1 can be easily moved in combination with the reduction in size and weight, In particular, by using the mounting plate 15 provided on the cylindrical cover 2 , the output transformer 1 can be easily and firmly fixed to a movable arm of a welding robot, for example, and the usage range of the heating coil 9 can be greatly expanded. It becomes possible to greatly improve the usability of.
[0023]
Further, since the outer shape of the output transformer 1 is formed in a substantially cylindrical shape by the cylindrical cover 2 corresponding to the ring core 5, the outer shape can be further reduced in size and the usability can be further improved. In addition, since the I-type core 4 and the ring core 5 which are simple and inexpensive in shape made of a ferrite core are used, the costs of the cores 4 and 5 can be reduced, and the output transformer 1 itself can be configured at a low cost. Is possible.
[0024]
Furthermore, the ring core 5 can be used by appropriately selecting a commercially available ring core 5 of various sizes, and by increasing or decreasing the number of layers, the turn ratio or coupling coefficient of the output transformer 1 is increased. Thus, the design flexibility of the output transformer 1 can be greatly improved. Further, since the primary coil 6 can be tightly wound between the I-type core 4 and the ring core 5, the output transformer 1 having a good coupling coefficient substantially equal to or higher than the conventional one can be easily obtained.
[0025]
In the above embodiment, the secondary coil 3 is formed of a single conductor (number of turns 1). However, the present invention is not limited to this. For example, a plurality of conductors are stacked with an interval. The primary coil 6 may be wound in series between the conductors or the upper and lower surfaces thereof. In the above embodiment, the secondary coil 3 is formed to have a U-shaped recess, but the substantially U-shaped recess in the present invention includes U-shaped and C-shaped recesses. Furthermore, the shape of the I-type core 4 and the ring core 5, the shape of the secondary coil 3 and the heating coil 9, the shape of the primary coil 6 and the like in the above embodiment are examples, and in a range not departing from the gist of the present invention, It can be changed as appropriate.
[0026]
【The invention's effect】
As described above in detail, according to the first or second aspect of the invention, the primary coil is wound around the I-type core a predetermined number of times, and the secondary coil is disposed outside the primary coil. Since the ring core is arranged so as to surround the secondary coil and the primary coil, and flexible cooling cables are connected to the ends of the primary coil and the secondary coil, respectively, the output transformer is reduced in size and weight. In addition, it is possible to simultaneously stabilize the heating efficiency by effectively using the ring core and the cooling cable.
[0027]
In addition, since the forward path and the return path of the primary coil side flow path and secondary coil side flow path of the cooling cable are integrated, the inductance associated with the cooling cable is made uniform, the impedance of the heating coil is stabilized, and the heating coil is heated. The efficiency can be further improved. Furthermore, since the flow path diameters of the primary coil side flow path and secondary coil side flow path of the cooling cable are set to be different, the cooling water can be circulated well inside the heating coil and the like. Thus, the cooling performance is improved, and the heating efficiency can be further improved.
[0029]
According to the invention described in claim 3 , in addition to the effect of the invention described in claim 1 or 2 , the cylindrical cover has a mounting plate on its outer surface. It is possible to attach an output transformer to the movable arm and improve the usability.
[Brief description of the drawings]
FIG. 1 is a plan view of an output transformer for a high-frequency heating device according to the present invention. FIG. 2 is a front view thereof. FIG. 3 is a right side view thereof. Fig. 5 Right side view of the same Fig. 6 Cross sectional view of the same Fig. 7 Vertical cross sectional view of the same
DESCRIPTION OF SYMBOLS 1 Output transformer 2 Cylindrical cover 3 Secondary coil 4 I-type core 5 Ring core 6 Primary coil 7 Connection board 8 Heating coil connection board 9 Heating coil 9a Fixing part 9b Straight part 9c Coil parts 10 and 11 Cooling cables 10a and 11a Outward path 10b, 11b Return path 12, 14 Hose connector 15 Mounting plate

Claims (3)

A primary coil having a predetermined number of times wound copper pipe around the I-shaped core, the two made of copper pipe having one end disposed outside is connected to the heating coil connection plate where the heating coil is connected to the primary coil primary A coil, a ring core disposed so as to surround the secondary coil and the primary coil, a cylindrical cover disposed outside the ring core, and an end connected to the ends of the primary coil and the secondary coil. A flexible cooling cable ,
The cooling cable has a forward path and a return path of a primary coil side flow path, and a forward path and a return path of a secondary coil side flow path in which a conducting wire is accommodated in a flexible tube. The tubes on the secondary coil side, or the outgoing paths on the primary coil side and the secondary coil side, and the return paths are integrated, and the inner diameter of the tube on each forward path is set to be larger than the inner diameter of the tube on each return path. high-frequency heating apparatus output transformer, characterized in that there. A connecting plate having four holes is disposed in the opening on the side of the cylindrical cover opposite to the heating coil, and in the cylindrical cover inside the connecting plate, at the end of the copper pipe of the primary coil and the secondary coil. The fixed hose connector is located, and each tube of the cooling cable is inserted and arranged in the hole provided in the connection plate, respectively, and connected to the hose connector . Output transformer for high frequency heating equipment. The output transformer for a high-frequency heating device according to claim 1 or 2 , wherein the cylindrical cover has a mounting plate on an outer surface thereof.

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