JPH07220863A - High-frequency induction heating device - Google Patents

Abstract

PURPOSE:To provide a high-frequency induction heating device capable of uniformly and efficiently heating a ring-shaped work. CONSTITUTION:A ring-shaped work W horizontally directed with its axis is guided into the inner space of a coil 3, rotated around the axis by a pair of rotary rollers 21, 22, and induction-heated. The coil 3 forms the magnetic flux in the vertical direction, and the whole periphery of the work W can pass through the portion having a high magnetic flux density as the work W is rotated.

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 device for heating a ring-shaped work.

[0002]

2. Description of the Related Art Conventionally, when a ring-shaped work, which is a material for a gear, is subjected to plastic working such as rolling in a hot or warm region, the work is heated by a high frequency induction heating device. Is commonly done. This high-frequency induction heating device is equipped with a heating coil wound around a vertical axis, and the work is introduced into the internal space of the coil with its axis oriented vertically, and eddy current is applied to the work by electromagnetic induction. Is generated and heated by Joule heat.

[0003]

The high-frequency induction heating device having the above-mentioned structure allows the magnetic flux to pass along the axis of the work, and the current flowing through the work is larger as it is closer to the surface.
It will decrease toward the center. Therefore, although it depends on the resistivity of the work and the frequency of the applied current, in general, induction heating can be performed only to a depth of about several mm from the outer peripheral surface of the work, and a deeper portion can be heated by the outer surface. It needs to be heated by conduction. Therefore, there has been a problem that it takes time to heat the center side of a particularly large workpiece to a desired temperature, resulting in poor production efficiency and high cost.

Further, since the work cannot be heated uniformly and temperature unevenness occurs, it is necessary to set the heating temperature to be long, and there is a problem that the heating time is further prolonged. In order to suppress the occurrence of this temperature unevenness, the work is also heated while being rotated concentrically with the coil, but since the gap between the work and the coil is constant, the magnetic flux density does not change. However, temperature unevenness cannot be effectively suppressed.

Further, in order to raise the temperature on the center side of the work to some extent, it is necessary to raise the heating temperature on the outer circumference side of the work considerably, so that scale is generated on the outer peripheral surface of the work, resulting in deterioration of quality. There was also a problem. Therefore, it is also possible to suppress the generation of scale by blowing nitrogen gas or the like on the work, but since the temperature is lowered by blowing air, it takes more time to heat to the desired temperature, and the gas There is also a problem that the cost is high because the cost is required.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-frequency induction heating device capable of uniformly and efficiently heating a work at low cost.

[0007]

A high-frequency induction heating apparatus of the present invention for achieving the above object is a high-frequency induction heating apparatus for heating a ring-shaped work by high-frequency induction heating. Work rotation support means for rotating around the axis of the, and a heating coil having an internal space for introducing and heating the work, and passing magnetic flux in a direction orthogonal to the axis of the work, the work support and the coil. And moving means for moving the workpiece supported by the workpiece rotation supporting means into and out of the internal space of the coil.

However, in the above high-frequency induction heating device, the work rotation supporting means is provided with a pair of rotating rollers for receiving the outer peripheral lower portion of the erected work, and the internal space of the coil is arranged immediately above the rotating rollers. In this case, it is preferable to include a work discharging unit that rolls and discharges the work supported by the pair of rotating rollers by lowering one of the pair of rotating rollers.

[0009]

According to the high-frequency induction heating apparatus having the above-mentioned structure, the work supporting means and the coil are moved relatively by the moving means while the ring-shaped work is supported by the work rotating and supporting means. It can be introduced into the internal space of the coil, and in this state, the work can be heated by passing a high-frequency current through the heating coil. At this time, the work can be heated while being rotated about its axis by the work rotation supporting means, and the coil allows the magnetic flux to pass in the direction orthogonal to the axis of the work, so that the work comes closest to the coil. It is possible to pass the entire circumference of the work to the portion having a high magnetic flux density. Therefore, the work can be heated uniformly and efficiently.

Particularly, when the work rotating means is provided with a pair of rotating rollers for receiving the outer peripheral lower portion of the erected work, and the internal space of the coil is arranged immediately above the rotating rollers, the pair of rotating rollers is provided. Most of the work can be introduced into the internal space by moving the rotating roller and the coil relatively to bring them close to each other. Therefore, the work can be heated more uniformly and efficiently.

Further, in the case of including a work discharging means for rolling and discharging the work supported by the pair of rotating rollers by lowering one of the pair of rotating rollers, the work is supported by the pair of rotating rollers. The scraped work can be easily discharged to the outside of the device.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a partially cutaway front view showing an embodiment of the high frequency induction heating apparatus of the present invention.
Is a side view. This high-frequency induction heating device is for heating a ring-shaped work W, which is a material for gears, in a hot or warm region.
And a work rotation supporting means 2 for supporting the shaft center with its axis oriented in the horizontal direction and rotating the shaft center around the axis.
A coil 3 for heating the work W, a moving means 4 for moving the work rotation support means 2 up and down to insert and remove the work W into the coil 3, and a work W for supplying the work rotation support means 2 with the work W. The supply means 5 and the work discharge means 6 for discharging the heated work W to the outside of the apparatus are provided.

The work rotation support means 2 is provided with a pair of rotation rollers 21 and 22 for receiving the lower outer peripheral portion of the work W supplied in the upright state, and a rotation drive mechanism 23 for rotationally driving one rotation roller 21. There is. The one rotating roller 21 is fixed to an upper part of a column 25a standing upright on the lifting table 24, and the other rotating roller 22 can be raised and lowered along the column 25b standing upright on the lifting table 24. It is provided. Further, the rotary drive mechanism 23 transmits the driving force of the motor 23a as a drive source to one of the rotary rollers 21 via a chain, a sprocket, etc., and can be moved up and down together with the pair of rotary rollers 21 and 22. It is mounted on the lifting table 24. Work W above
The number of rotations depends on the size and material, but is generally 50
It is set to about 70 rpm.

Further, the work rotation supporting means 2 is provided with a guide member 26 for sandwiching both sides of the work W supported by the pair of rotation rollers 21 and 22 to prevent the work W from falling. . This guide member 26 is
It is composed of a pipe bent in an annular shape, and is prevented from overheating by passing cooling water inside thereof. The elevating table 24 is driven up and down by a predetermined stroke by a cylinder 41 which constitutes the moving means 4, and a pair of rotating rollers 21 and 22 are located at its ascending position.
But approaches the bottom of the coil 3.

The coil 3 is supported above the work rotation supporting means 2 by an upper pedestal 11 provided on the pedestal 1. The coil 3 has an internal space 31 for introducing and heating the work W, and a coil material 32 made of a conductor is wound around the vertical axis around the internal space 31. The internal space 31 is formed in such a size that almost the entire work W and the guide member 26 can be introduced therein, and the periphery thereof is covered with a refractory cement 33. Further, the ceiling portion of the internal space 31 is formed in an arch shape so as to substantially follow the outer circumference of the work W, and the winding diameter of the coil material 32 is gradually reduced along the ceiling portion. A high frequency current is applied to the coil 3 from a power source 34.

The work supply means 5 includes an inclined chute 51 that rolls and supplies the work W in an upright state, a receiving member 52 that receives the work W supplied to the lower end of the chute 51, and the receiving member. A rotating mechanism 5 for rotating the receiving member 52 so as to supply the work W received by the 52 between the pair of rotating rollers 21, 22.
In order to prevent the work W on the chute 51 from rolling down while the work W is being supplied between the pair of rotating rollers 21 and 22, the lower part of the receiving member 52 is provided. An arc-shaped stopper 54 is provided.

The work discharging means 6 is provided with a cylinder 61 for moving the rotating roller 22 up and down. This cylinder 6
1 is erected on the upper part of the lifting table 24, and in the raised position, the rotating roller 21 is
The workpiece W supported by the pair of rotating rollers 21 and 22 can be rolled and guided to the discharge chute 62 at the lowered position while maintaining the same height as the above.

With the above construction, the work supply means 5 supplies the work W between the pair of rotating rollers 21 and 22 while the work rotation supporting means 2 is lowered, and then the moving means 4 operates. By raising the work rotation support means 2, the work W can be introduced into the internal space 31 of the coil 3. At this time, the rotating roller 2
Since the parts 1 and 22 receive the lower part of the outer periphery of the work W and approach the bottom part of the coil 3, the most part of the work W can be introduced into the internal space 31. In this state, the rotary drive mechanism 23 rotates one of the rotary rollers 21 and applies a high-frequency current to the coil 3 to rotate the work W around the horizontal axis (axial center).

Since the coil 3 is wound around the vertical axis, the magnetic flux B passes in the vertical direction, that is, in the direction orthogonal to the axis of the work W (see FIG. 3). The density of the magnetic flux B is highest at both side portions where the work W and the coil 3 are closest to each other, and the entire circumference of the work W passes through the portion having the highest magnetic flux density, so that the work W is uniformly and efficiently. It can be heated. Therefore,
Even a large work W can be heated in a short time while suppressing temperature unevenness. As a result, the center side can be raised to a desired temperature without raising the temperature on the outer peripheral side of the work W so much that it is possible to suppress the generation of scale on the outer peripheral surface of the work W.

Particularly, in the above embodiment, most of the work W is introduced into the internal space 31 of the coil 3, so that the work W can be heated more uniformly and efficiently. For the workpiece W that has been heated, the workpiece rotation supporting means 2 is lowered and the workpiece discharging means 6 is used.
By lowering the rotating roller 22 by means of, it is possible to easily discharge to the outside of the apparatus via the discharge chute 62.

The work rotation support means 2 is a work W.
May be sandwiched between the pair of rotating rollers 21 and 22 and the auxiliary roller 26 (see FIG. 4). In this case, the work W is only vertically moved with respect to the internal space 31 of the coil 3. Instead, it can be introduced from the left and right.
Further, the work W can be heated while rotating with the axis of the work W oriented in the vertical direction or any other direction.

The high-frequency induction heating apparatus of the present invention is not limited to the above-mentioned embodiment, and for example, instead of moving the work supporting means 2, the coil 3 is moved to move the work W into the internal space 31 of the coil 3. Various design changes can be made, such as a configuration in which it is inserted into and removed from.

[0023]

As described above, according to the high frequency induction heating apparatus of the present invention, the ring-shaped work is rotated around its axis and the magnetic flux is passed in the direction orthogonal to the axis. Since induction heating is performed, the work can be uniformly and efficiently heated as a result of being able to pass the entire circumference of the work in a portion having a high magnetic flux density. For this reason,
The center side of the work can be heated to a desired temperature without heating the outer peripheral side of the work to a high temperature, and it is possible to suppress the generation of scale on the surface of the work. Therefore, it is possible to obtain a heating work of good quality at low cost.

Further, according to the high frequency induction heating device of the second aspect, since the pair of rotating rollers receives the lower part of the outer periphery of the erected work, by bringing the rotating rollers close to the inner space of the coil, Most of the work can be introduced into the internal space. Therefore, there is a unique effect that the work can be heated uniformly and efficiently.

Further, according to the high frequency induction heating apparatus of the third aspect, the work which has been heated can be rolled and discharged to the outside of the apparatus only by lowering one of the pair of rotating rollers. The unique effect that the work can be easily discharged with a simple mechanism is exhibited.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a high frequency induction heating apparatus of the present invention.

FIG. 2 is a side view of the high frequency induction heating device shown in FIG.

FIG. 3 is a schematic diagram showing a heating state of a work.

FIG. 4 is a partially cutaway front view showing another embodiment.

[Explanation of symbols]

 2 Work rotation supporting means 21 Rotating roller 22 Rotating roller 3 Coil 31 Internal space 4 Moving means 6 Work discharging means W Work B Magnetic flux

Claims (3)

[Claims] 1. A high-frequency induction heating apparatus for heating a ring-shaped work by high-frequency induction heating, and a work rotation support means for supporting the work and rotating it about an axis of the work, the work being introduced and heated. The heating coil, which has an internal space and passes magnetic flux in a direction orthogonal to the axis of the work, and the work supporting means and the coil are relatively moved to move the work supported by the work rotation supporting means to the coil. A high-frequency induction heating device, comprising: a moving unit that is inserted into and removed from an internal space. 2. The work rotation support means comprises a pair of rotation rollers for receiving a lower portion of the outer periphery of the upright work,
The high frequency induction heating device according to claim 1, wherein an internal space of the coil is arranged immediately above the rotating roller. 3. A work discharging means for rolling and discharging the work supported by the pair of rotating rollers by lowering one of the pair of rotating rollers.
The described high-frequency induction heating device.