JP2003064414A - Induction heating coil device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating coil device capable of unifying heating temperature along the axial direction of a substantially columnar work and easily obtaining the work of high quality by effectively setting a winding direction. SOLUTION: In the induction heating coil device which heats the work having the entirely substantially columnar shape through the induction heating, a coil device 1 comprises a first coil part 4 with a conductor coiled toward a predetermined direction by a large number of turns, and a second coil part 5 with a conductor coiled in the direction opposite to the predetermined direction at a predetermined position along the axial direction of the first coil part. The second coil part 5 has less turns than the first coil part, and located inside the first coil part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency induction heating coil device used for high frequency induction heating of a work having a substantially columnar shape.

[0002]

2. Description of the Related Art Conventionally, for example, in the manufacture of a motor core, a large number of silicon steel plates having a predetermined shape are used, with a stainless plate interposed between an intermediate portion and both ends, and a shaft provided through a shaft,
This is performed by forming a laminated iron core by integrating the silicon steel plates by, for example, adhesive fixing. High-frequency induction heating is used as a heating method for forming the laminated iron core, and the coil device is formed, for example, by winding a copper pipe whose outer peripheral surface is insulated in the same direction a plurality of times. Has been done.

[0003]

However, since this coil device is formed by winding the copper pipe in the same direction a predetermined number of times, the direction of the magnetic flux induced in the laminated iron core is The iron core has a fixed direction from one end side to the other end side, and the heating temperature of the stainless steel plate portions provided for reinforcing at both end portions and the intermediate portion is likely to be higher than other portions.

As a result, the heating temperature of each silicon steel sheet in the axial direction of the laminated iron core becomes non-uniform, and the adhesion strength of the silicon steel sheet and the like vary, so that highly accurate rotation characteristics can be obtained for the iron core. It has a problem that it is difficult. This tendency tends to become more prominent as the length of the laminated iron core increases and the number of intermediate stainless steel plates (reinforcing plates) increases, and the actual situation is that improvement is desired.

The present invention has been made in view of the above circumstances, and an object thereof is to make the heating temperature uniform along the axial direction of a substantially columnar work by effectively setting the winding direction. It is to provide a coil device for high-frequency induction heating that can easily obtain a high-quality work.

[0006]

In order to achieve the above object, the invention according to claim 1 of the present invention is a coil device for high frequency induction heating for heating a work having a substantially columnar shape as a whole by high frequency induction heating. The coil device includes a first coil portion in which a conductor is wound a plurality of times in a predetermined direction, and a winding direction opposite to the predetermined direction at a predetermined position along the axial direction of the first coil portion. And a second coil portion wound in the direction. And claim 2
The invention described is characterized in that the second coil portion is set to have a smaller number of turns than the first coil portion and is located inside the first coil portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 4 show an embodiment of a coil device for high frequency induction heating according to the present invention. In the figure, a coil device 1 includes a coil portion 2 formed by winding a copper pipe whose outer peripheral surface is insulated, and the coil portion 2 that is detachably fixed to an output terminal of a transistor inverter (not shown). And a fixing portion 3 for

The coil portion 2 has a circular first coil portion 4 wound a predetermined number of times n1 (for example, n1 = 34 times) in a predetermined direction (for example, a clockwise direction), and is serially connected to the first coil portion 4. A second circular coil wound around the first coil portion 4 at a substantially intermediate position in the axial direction and wound a predetermined number of times n2 (for example, n2 = 1 time) in the direction opposite to the coil portion 4 (for example, the left winding direction). It is composed of a part 5 and the like. The number of turns n2 of the second coil portion 5 is set to, for example, 1/10 or less of the number of turns n1 of the first coil portion 4, and the second coil portion 5 is inserted and arranged inside the first coil portion 4. There is.

Both ends of the coil portion 2, that is, one end side of the first coil portion 4 and the other end side of the second coil portion 5 are corners of the surface of the pair of copper plates 6 pressed against each other via the insulating plate 9. Each of the square pipes 7 is connected to a pipe 7, and a hose connector 8 is fixed to the tip of each square pipe 7. Further, the copper plate 6 is formed in a U shape in a plan view, and the square pipe 7 is fixed to the bent curved surface 6a on the front end side and the flat surface portion 6b, and the bent curved surface 6c on the rear end side serves as a fixing surface to the transistor inverter. Is forming. The hose connector 8 fixed to the square pipe 7 is connected to a cooling device that is integrated with the transistor inverter, for example, and the cooling water is supplied to the square pipe 7.
And is circulated and supplied to the coil unit 2.

According to this coil device 1, the bent curved surfaces 6c of the copper plate 6 are fixed to the output terminals of the transistor inverter by bolts or the like, and the cooling device and the hose connector 8 are connected by a flexible hose. Then, when a laminated iron core as a work is inserted and supported by a supporting device (not shown) in the circle of the coil portion 2 and the transistor inverter is operated, a high frequency current is passed through the copper plate 6 and the copper pipe 7 to cause the high frequency current of the coil portion 2 It is supplied to the first coil portion 4 and the second coil portion 5. Further, cooling water is circulated and supplied into the copper pipe of the coil portion 2 through the hose at substantially the same time as the supply of the high-frequency current, and heat generation of the coil portion 2 is suppressed.

When a high frequency current is supplied to the coil section 2,
Magnetic fluxes in predetermined directions are respectively generated from the first coil portion 4 and the second coil portion 5, and the magnetic fluxes are set so that the winding directions of the first coil portion 4 and the second coil portion 5 are opposite to each other. Magnetic fluxes in opposite directions intersect each other at a substantially intermediate portion in the axial direction, and the magnetic flux generated by the first coil portion 4 in the portion is partially canceled by the magnetic flux of the second coil portion 5.

As a result, the eddy currents induced in the reinforcing plate portion arranged at the substantially intermediate position in the longitudinal direction of the work are smaller than those in the other portions, and the induction heating state in the entire longitudinal direction of the work, that is, the heating temperature. Are made uniform. By uniformizing the heating temperature, a large number of silicon steel plates having a laminated iron core are uniformly adhered and fixed. By using the laminated iron core as a rotor of a motor, for example, stable rotation can be obtained. According to the experiment, it is confirmed that the temperature difference in the longitudinal direction of the laminated iron core can be set within several degrees (for example, 3 ° C.) by using the coil device 1.

That is, by partially canceling the magnetic flux in the stainless plate portion provided for reinforcing the laminated iron core and dividing the poles, the eddy current induced in the portion is reduced,
By averaging the eddy currents with other portions, the heating temperature of the entire area of the laminated iron core in the longitudinal direction can be made uniform, and the fixing state between the laminated iron cores can be stabilized. Further, since the second coil portion 5 having a small number of turns is located inside the first coil portion 4, the second coil portion 5 can be protected by the first coil portion 4, and the shape and stability of the coil device 1 can be improved. Can be improved.

In the above description, the coil portion 2
Although it is formed in a circular shape, it may be formed in a rectangular shape depending on the shape of the work, or may be formed in a horseshoe shape as the shape of the coil portion 2. The first embodiment of the above embodiment
The number of turns n1 and n2 of the coil portion 4 and the second coil portion 5 is also an example, and can be appropriately increased or decreased. The present invention is not limited to the laminated iron core as the work, and can be applied to other work having a substantially columnar shape. Can be applied.

[0015]

As described above in detail, according to the first aspect of the invention, the first coil portion wound in the predetermined direction and the second coil portion in which the winding direction of the first coil portion are opposite to each other. Since the second coil portion can weaken the magnetic flux of the first coil portion, for example, the heating temperature of the reinforcing plate portion provided in the middle portion of the work can be lowered to make the temperature uniform throughout the axial direction of the work. It is possible to obtain a high quality work.

In addition to the effect of the invention according to claim 1, the invention according to claim 2 is characterized in that the second coil having a small number of turns is the first coil.
Since it is located inside the coil portion, the second coil portion can be protected by the first coil portion, the durability of the coil device can be improved, and the usability can be improved.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a coil device for high frequency induction heating according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a right side view of FIG.

FIG. 4 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

1 coil device 2 coil part 3 Fixed part 4 First coil part 5 Second coil section 6 Copper plate 7 square pipe

Claims (2)

[Claims] 1. A high-frequency induction heating coil device for heating a work having a generally columnar shape by high-frequency induction heating, the coil device comprising a conductor wound a plurality of times in a predetermined direction. For high frequency induction heating, comprising: a coil part; and a second coil part wound at a predetermined position along the axial direction of the first coil part in a winding direction opposite to the predetermined direction. Coil device. 2. The coil device for high frequency induction heating according to claim 1, wherein the second coil portion is set to have a smaller number of turns than the first coil portion and is located inside the first coil portion.