JP5473127B2 - Induction heating coil - Google Patents

Description

  The present invention relates to an induction heating coil used when induction heating various workpieces.

  In general, for example, when the entire surface of a workpiece made of a steel plate having a rectangular shape in plan view and a plate thickness of about 0.5 mm to several mm is quenched or annealed, it is performed by high frequency induction heating using an induction heating coil. This high frequency induction heating is performed by supplying a high frequency current of a predetermined frequency from a transistor inverter to the induction heating coil with a work inserted horizontally in the induction heating coil and inducing an eddy current on the surface of the work. ing.

  Conventionally, as an induction heating coil used for such high frequency induction heating, a copper pipe as a conductor is spirally wound in a predetermined number of turns so that a predetermined inductance is obtained at both ends thereof. The high frequency current is supplied from the transistor inverter to both ends of the induction heating coil. In addition, this kind of induction heating coil is disclosed by patent document 1 and patent document 2, for example.

JP 2008-63627 A Japanese Utility Model Publication 4-27114

  However, in such an induction heating coil, a copper pipe is wound around a spiral lock a predetermined number of times so as to obtain a predetermined inductance at both ends in order to obtain a predetermined quenching quality and the like on the workpiece. Inductance is uniquely determined according to the number of turns of the induction heating coil itself, and it is difficult to finely adjust the inductance of the induction heating coil itself. For example, to obtain uniform quenching quality on the entire surface of a plate-like workpiece that easily warps during induction heating. In this case, it is necessary to adjust the heating conditions one by one, for example, by reducing the high-frequency current supplied to the induction heating coil, and the induction heating work itself tends to be troublesome.

  In addition, since the induction heating coil itself is formed by winding a single copper pipe a predetermined number of times, the value of current and voltage flowing through the induction heating coil itself having a predetermined inductance is increased. In view of safety, there is a risk of electric shock when touching the induction heating coil by mistake.

  The present invention has been made in view of such circumstances, and the object thereof is to reduce the inductance of a plurality of coil portions connected in parallel to easily obtain a uniform heating state on the workpiece. An object of the present invention is to provide an induction heating coil capable of safely performing induction heating work.

In order to achieve such an object, the invention described in claim 1 of the present invention is an induction heating coil used when induction heating a workpiece having a predetermined shape, and is each wound a plurality of times in the axial direction . A plurality of coil portions, and a pair of linear conductors in which both ends of each coil portion are electrically and mechanically connected, and the plurality of coil portions each have the same copper round pipe multiple times. By winding in a shape and continuously connecting in the axial direction, the overall shape is cylindrical and arranged coaxially, and the pair of linear conductors have the same length and are closed at both ends. Are arranged in parallel with a predetermined interval, and a plurality of circular communication holes are formed on one side surface of each linear conductor at predetermined intervals and in the longitudinal direction of each linear conductor. A pair of corresponding communication in the longitudinal direction of the conductor Both end portions of the plurality of coil portions by each coil portion is brazed in a continuously provided conditions are respectively connected in parallel, with the inductance between the linear conductor is set to a predetermined, said linear conductors The communication holes are shifted in the longitudinal direction of the linear conductors in the same direction as the pair of communication holes to which both ends of the coil portions are connected at the middle position in the longitudinal direction of the side surface opposite to the one side surface, respectively. The pipe, the linear conductor, and each coil part are formed from the hose connector by brazing each pipe with a hose connector brazed to the tip of the communication hole and electrically connected to a high frequency power source. in the cooling water flow path communicating are formed respectively, to said high-frequency current from the high frequency power is supplied to each coil section through the pipe and linear conductors .

The invention according to claim 2 is characterized in that the pipe is electrically and mechanically connected to a holder having a pair of copper plates press-contacted via an insulating plate . According to a third aspect of the present invention, the pair of linear conductors are configured such that the length thereof can be adjusted via the connecting portion, so that the number of the coil portions can be increased or decreased. and said that you are.

  According to the first aspect of the present invention, the plurality of coil portions wound a predetermined number of times are arranged coaxially, and are electrically and in parallel with a pair of linear conductors arranged in parallel. Because it is mechanically connected, a predetermined inductance can be obtained in the entire induction heating coil by a plurality of coil parts that are connected in parallel and have low inductance, and the current flowing through each coil part can be distributed in a well-balanced manner so that it is even on the workpiece. Thus, it is possible to easily obtain a simple heating state, and to reduce the value of the current flowing through each coil portion having a low inductance, thereby improving the safety of the induction heating operation.

In addition, a cooling water flow path is formed inside the plurality of coil parts and the pair of linear conductors, and is connected to a high frequency power source and connected to a cooling water supply device. As a result, the heating efficiency can be improved and the safety can be further enhanced. Further, since the number of turns of the plurality of coil portions is set to be the same, for example, the entire surface of a flat workpiece can be uniformly induction-heated .

Furthermore, according to the invention described in claim 2 , in addition to the effect of the invention described in claim 1 , the pair of linear conductors are electrically and mechanically connected to a holder made of an insulating plate and a pair of copper plates. Therefore, the induction heating coil can be unitized, and the induction heating coil can be reliably and easily installed at a predetermined position by connecting and fixing the holder to the output terminal of the high frequency power source, and the usability can be improved.

According to the invention described in claim 3 , in addition to the effect of the invention described in claim 1 or 2 , the pair of linear conductors are formed such that the length thereof can be adjusted via the connecting portion, and the coil Since the number of parts can be increased or decreased, the number of coil parts can be easily increased according to the length of the workpiece, and the versatility and usability of the induction heating coil can be further improved.

The perspective view which shows one Embodiment of the induction heating coil concerning this invention The front view Plan view Side view Equivalent circuit diagram The top view which shows other embodiment of the induction heating coil concerning this invention AA arrow view of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
1 to 5 show an embodiment of an induction heating coil according to the present invention. As shown in FIGS. 1 to 4, the induction heating coil 1 includes a pair of linear conductors 2a and 2b arranged in parallel with a predetermined interval, and both ends fixed to the linear conductors 2a and 2b, respectively. A plurality of (in the figure, four) coil portions 3a to 3d are provided. The pair of linear conductors 2a and 2b are formed by copper rectangular pipes having the same length, and are arranged in parallel at a predetermined interval on the same plane.

  The coil portions 3a to 3d are formed by winding a round copper pipe into a rectangular shape in plan view a predetermined number of times (three turns in the figure), so that the overall shape of each of the coil portions 3a to 3d is a substantially rectangular tube. It is formed in a shape, and the outer peripheral surface of each pipe is covered with an insulating tube or coated with an insulating paint as necessary for insulation treatment. Then, both end portions of each of the coil portions 3a to 3d are drawn out in the direction of the linear conductors 2a and 2b, and the end portions thereof are brazed perpendicularly to one side surface of each of the conductors 2a and 2b to be mechanically supported. Thus, the coil portions 3a to 3d are set to be coaxial.

  Further, as shown in FIG. 2, the linear conductors 2a and 2b are formed with a cooling water flow path 4 therein and closed at both ends thereof, and the coil portions 3a to 3d are As shown in FIG. 3, the cooling water flow path 5 is formed in the inside, and the edge part is open | released. This one linear conductor 2a and one end of each of the coil portions 3a to 3d and the other linear conductor 2b and the other end of each of the coil portions 3a to 3d are one side of each of the linear conductors 2a and 2b. The internal cooling water flow paths 4 and 5 are in communication with each other through a circular communication hole 6 (see FIG. 2) provided in.

  Further, a circular communication hole (on the side surface of the linear conductors 2a, 2b opposite to the side where the coil portions 3a to 3d are brazed is located at a substantially intermediate position in the longitudinal direction and does not overlap in the longitudinal direction. (Not shown) are formed, and copper round pipes 8a and 8b each having a conductive hose connector 7a and 7b brazed to the tip are brazed to the communication hole. As a result, cooling water circulation passages are formed from the hose connectors 7a, 7b to the pipes 8a, 8b and the cooling water passages 4, 5.

  And as shown in FIG. 2, the both ends of each said coil part 3a-3d are induction heating apparatuses 9 as a high frequency power supply via the linear conductors 2a and 2b, the pipes 6a and 6b, and the hose connectors 7a and 7b. The transistor inverter 10 is electrically connected, for example, via a flexible cable 11, and the hose connectors 7 a, 7 b are connected to the cooling water supply device 12 of the induction heating device 9 via the tube 13. At this time, the flexible cable 11 and the tube 13 are integrated, and the cooling water supply device 12 and the transistor inverter 10 are also integrated so that the induction heating coil 1 is mounted. 9 is downsized.

  As shown in FIG. 5A, the induction heating coil 1 is mechanically and electrically connected to the pair of linear conductors 2a and 2b at both ends of the four coil portions 3a to 3d. In addition, when the coil portions 3a to 3d are connected in parallel and the inductance of the induction heating coil 1 is L, the inductance L1 of the coil portions 3a to 3d becomes 1 / 4L, and the inductance L1 of the coil portions 3a to 3d. Is set smaller.

  Next, the operation of the induction heating coil 1 will be described. First, the inductance L of the induction heating coil 1 for obtaining a desired quenching or annealing quality is set on the workpiece, for example, according to the form of the plate-like workpiece, and the coil portions 3a to 3d are set according to the inductance L. Inductance L1 is set to 1 / 4L. Then, the induction heating coil 1 is mounted on the induction heating device 9, a plate-like workpiece is disposed in a horizontal state in each of the coil portions 3 a to 3 d, and the transistor inverter 10 of the induction heating device 9 is operated to perform induction heating. A high-frequency current with a predetermined output is supplied to each of the coil portions 3a to 3d of the coil 1 at a predetermined frequency.

  The high-frequency current supplied to the induction heating coil 1 is distributed in a well-balanced manner because the coil portions 3a to 3d having the same inductance L1 are connected in parallel. As a result, the voltage value (current value) itself becomes low, and the risk of electric shock or the like can be avoided. And by the high frequency current supplied to each coil part 3a-3d, an eddy current is induced in a workpiece | work and a workpiece | work is induction-heated, At this time, the same high frequency current is supplied to each coil part 3a-3d with sufficient balance. For this reason, the entire surface of the workpiece is uniformly induction-heated, and for example, good quenching quality can be obtained on the entire surface of the workpiece without warping the plate-shaped workpiece.

  In addition, when the high frequency current is supplied to the induction heating coil 1, the cooling water supply device 12 is operated, and the cooling water is circulated and supplied into the coil portions 3a to 3d, so that the heat of the coil portions 3a to 3d is generated. It is suppressed, and the fall of heating efficiency is suppressed. That is, in the case of the induction heating coil 1, by connecting the four coil portions 3a to 3d in parallel to the pair of linear conductors 2a and 2b, the inductance L1 of each of the coil portions 3a to 3d is lowered and each coil is reduced. A high-frequency current having a reduced current value is allowed to flow through the portions 3a to 3d in a well-balanced manner so that a uniform heating state is obtained on the workpiece.

  Thus, according to the induction heating coil 1, the four coil portions 3a to 3d wound a predetermined number of times are arranged coaxially and in parallel to the pair of linear conductors 2a and 2b arranged substantially in parallel. Since the coils are electrically and mechanically connected in a state, a predetermined inductance L is obtained in the induction heating coil 1 by the coil portions 3a to 3d connected in parallel, and the inductance L1 of each of the coil portions 3a to 3d is lowered. be able to. As a result, the high-frequency current can be distributed in a balanced manner to each of the coil portions 3a to 3d, and a uniform heating state can be easily obtained on the workpiece. In particular, since the number of turns of the plurality of coil portions 3a to 3d is set to be the same, the entire surface of a flat work, for example, can be induction-heated more uniformly.

  In addition, by reducing the inductance of each of the coil portions 3a to 3d, the current value flowing through each of the coil portions 3a to 3d can be reduced to reduce the voltage value, thereby preventing an electric shock accident. Can be increased. Further, cooling water passages 4 and 5 are formed inside the four coil portions 3a to 3d and the pair of linear conductors 2a and 2b, and are connected to the transistor inverter 10 and to the cooling water supply device 12. Therefore, it is possible to suppress the heat generation of each of the coil portions 3a to 3d during induction heating and prevent a decrease in heating efficiency due to the heat generation, and to reduce the surface temperature of the coil portions 3a to 3d themselves during induction heating. Therefore, the safety of induction heating work can be further improved.

  6 and 7 show another embodiment of the induction heating coil according to the present invention. Hereinafter, the same parts as those in the above embodiment will be described with the same reference numerals. The feature of the induction heating coil 1 of this embodiment is that the induction heating coil 1 is unitized by connecting a pair of linear conductors 2 a and 2 b to the holder 14. That is, one end of a predetermined length of copper pipes 8a and 8b at a substantially intermediate position in the longitudinal direction of the side surface opposite to the side surface to which the coil portions 3a to 3d of the pair of linear conductors 2a and 2b are brazed. The other ends of the pipes 8a and 8b are electrically and mechanically connected (supported) to the holder 14.

  At this time, the holder 14 has a pair of copper plates 15a and 15b with the pipes 8a and 8b brazed on the outer surface thereof, and an insulating plate 16 interposed between the copper plates 15a and 15b. 15b and the insulating plate 16 are fixed by a nut 17 in a pressure contact state. The tip portions of the pipes 8a and 8b are bent 90 degrees outward, and the hose connectors 7a and 7b are brazed to the end portions. The holder 14 is sandwiched between a pair of copper plates of the output terminal of the transistor inverter 10, whereby the induction heating coil 1 is mounted on the induction heating device 9, and the holder 14 is removed from the output terminal of the induction heating device 9. Thus, the induction heating coil 1 can be replaced or repaired.

  In this embodiment, in addition to obtaining the same operational effects as in the previous embodiment, the holder 14 is integrated with the induction heating coil 1, so the holder 14 is connected and fixed to the output terminal of the induction heating device 9. By doing so, the induction heating coil 1 can be reliably and easily installed at a predetermined position, the induction heating coil 1 can be exchanged according to the form of the workpiece, and the usability can be improved.

  In each of the above-described embodiments, the case where a predetermined number of the coil portions 3a to 3d are fixed in advance to the linear conductors 2a and 2b has been described. However, as shown by a two-dot chain line in FIG. The extension coil 20 having the linear conductors 21a and 21b and the coil part 22 may be connected to the ends of the conductors 2a and 2b so that the coil part of the induction heating coil 1 can be increased. In this case, the ends of the linear conductors 2a and 2b are opened, and the linear conductors 2a and 2b of the induction heating coil 1 and the straight lines of the extension coil 20 are connected by a rectangular tube-shaped connecting member 23 as a connecting portion. The conductors 21a and 21b may be connected by, for example, brazing.

  If comprised in this way, since the length of a pair of linear conductor 2a, 2b is adjusted via the connection member 23, increase / decrease in the number of coil parts is attained, and it responds to the length etc. of a workpiece | work. Therefore, the versatility of the induction heating coil 1 can be improved and the usability can be further improved. Further, since the length of the induction heating coil 1 itself in the axial direction can be increased by adding the coil portion, even a long workpiece can be heated simultaneously and uniformly by induction heating, for example, induction There is no need to perform induction heating while moving the heating coil 1 one by one, and induction heating work can be performed efficiently.

  Moreover, in each said embodiment, although the number of each coil part of the induction heating coil 1 was demonstrated and the case where all the turns were the same, this invention is not limited to this, For example, FIG. As shown in b), the number of turns of the coil portions 3a and 3d on both sides may be increased, or conversely, the number of turns of the coil portions 3b and 3c at the center portion may be increased, or from one coil portion 3a to the other. For example, the number of turns of each of the coil parts 3a to 3d can be made different from each other by increasing or decreasing the number of turns toward the coil part 3d. With this configuration, it is possible to set (adjust) the number of turns according to the shape of the workpiece, and even a workpiece having an uneven portion in the axial direction can be uniformly induction-heated over the entire area. . Further, the number of coil portions is not limited to four, but may be plural.

  Furthermore, the shape of each coil part 3a-3d in each said embodiment is not restricted to a rectangular shape, For example, a substantially circular shape, a substantially triangular shape, etc. may be sufficient, and the pull-out directions of the said pipes 8a and 8b are also the direction of a workpiece | work. Depending on the form and the heating position, the linear conductors 2a and 2b can be drawn out from the appropriate side surfaces. In addition, the shape of the linear conductors 2a, 2b and the holder 14 in each of the above embodiments is also an example. For example, the linear conductors 2a, 2b may be linear (bar-shaped) as a whole, and some of them are curved portions. An appropriate configuration can be employed without departing from the gist of the present invention, such as a shape having the above or using a square as the pipes 8a and 8b.

  The present invention relates to all inductions used when induction heating of a workpiece, such as an induction heating coil in which a cooling jacket used as a cooling means when quenching a workpiece is integrated in all or a part of each coil portion. Can be used for heating coils.

  DESCRIPTION OF SYMBOLS 1 ... Induction heating coil, 2a, 2b ... Linear conductor, 3a-3d ... Coil part, 4, 5 ... Cooling water flow path, 6 ... Communication hole, 7a, 7b ... Hose connector, 8a, 8b ... pipe, 9 ... induction heating device, 10 ... transistor inverter, 11 ... flexible cable, 12 ... cooling water supply device, 13 ... tube, 14 ... Holder, 15a, 15b ... Copper plate, 16 ... Insulating plate, 17 ... Nut, 20 ... Additional heating coil, 21a, 21b ... Linear conductor, 22 ... Coil part, 23 ... connecting member.

Claims (3)

An induction heating coil used for induction heating of a workpiece having a predetermined shape, each of which has a plurality of coil portions wound in the axial direction, and both ends of each coil portion are electrically and mechanically respectively. A pair of linear conductors connected to each other,
The plurality of coil portions are arranged coaxially with the overall shape presenting a cylindrical shape by winding a copper round pipe a plurality of times in the same shape and connecting them in the axial direction,
The pair of linear conductors are formed by copper square pipes having the same length and closed at both ends, arranged in parallel with a predetermined interval, and arranged on one side surface of each linear conductor at a predetermined interval. In addition, a plurality of circular communication holes are formed by shifting in the longitudinal direction of each linear conductor, and both end portions of the plurality of coil portions are continuously provided in a pair of corresponding communication holes in the longitudinal direction of each linear conductor. And the coil portions are connected in parallel, whereby the inductance between the linear conductors is set to a predetermined value,
The linear conductor is shifted in the longitudinal direction of each linear conductor in the same direction as the pair of communication holes to which both end portions of each coil part are connected at an intermediate position in the longitudinal direction of the side surface opposite to the one side surface of the linear conductor. The communication holes are respectively formed, and pipes that are electrically connected to the high-frequency power source are brazed to the communication holes by hose a hose connector at the tip, respectively. An induction heating coil, characterized in that a cooling water flow path communicating with the conductor and each coil part is formed, and a high-frequency current from the high-frequency power source is supplied to each coil part via the pipe and the linear conductor. .   2. The induction heating coil according to claim 1, wherein the pipe is electrically and mechanically connected to a holder having a pair of copper plates press-contacted via an insulating plate.   The pair of linear conductors are configured such that the number of the coil portions can be increased or decreased by forming the length of the pair of linear conductors via a connecting portion. The induction heating coil described in 1.

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