JPH0715834B2 - High frequency induction heating coil - Google Patents

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 used for quenching the surface of a stepped shaft-shaped work.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings. Conventionally, for example, when quenching the surface of a stepped shaft-shaped workpiece 300 shown in FIG. 4, a semi-open type high frequency induction heating coil 200 shown in FIG. 3 is used. The stepped shaft-shaped workpiece 300, which is a rotationally symmetrical body, includes a small shaft diameter portion 301, a large shaft diameter portion 303, a shoulder portion 302 between the small shaft diameter portion 301 and the large shaft diameter portion 303, and the shoulder portion 302 and the small shaft. It has a corner 304 at the boundary with the diameter 301.

The high frequency induction heating coil 200 has a small shaft diameter portion 30.
Connect a pair of straight and parallel conductors 201 that heat 1 and a pair of straight and parallel conductors 203 that heat the large-axis diameter portion 303, and connect the conductors 201 and 203 to the shoulder of the work 300. A pair of linear conductors 202 for heating the portion 302, a substantially semi-circular conductor 204 connecting end portions of the pair of conductors 203, and 1
The pair of conductors 201 is provided with a pair of conductors 205 having an approximately ¼ arc shape for connecting the ends of the pair of conductors 201 to the high frequency power supply 101.

When quenching the work 300, the conductors 201 and 203 of the high frequency induction heating coil 200 are arranged close to the small shaft diameter portion 301 and the large shaft diameter portion 303, respectively, and
202 is placed close to the shoulder 302 and the workpiece 300 is placed on its axis 310
While rotating around the center, when a high-frequency current is supplied from the high-frequency power supply 101 to the high-frequency induction heating coil 200 and then rapidly cooled, the small shaft diameter portion 301, the shoulder portion 302, the large shaft diameter portion 303 and the corner portion 3
Hardened layers 301a, 302a, 303a, and 304a are formed on 04, respectively.

[0005]

However, the hardened layers 301a, 302a, 303a and 304a thus obtained are obtained.
Of these, the depth of the hardened layers 301a, 302a and 303a is within the allowable limit, but the depth of the hardened layer 304a at the corner 304 is often at the margin of the allowable lower limit, and the hardened layers 301a, 302a, 303a and
It was difficult to form a hardened layer with a uniform depth through 304a.

The present invention was devised in view of the above circumstances, and has a uniform depth on the surface of a stepped shaft-like work having a small shaft diameter portion, a shoulder portion, a large shaft diameter portion and a corner portion 304. It is an object of the present invention to provide a high frequency induction heating coil capable of forming a hardened layer.

[0007]

In order to solve the above-mentioned problems, the invention of claim 1 provides a small shaft diameter portion, a large shaft diameter portion, a shoulder portion between these shaft portions, and this shoulder portion. In a high-frequency induction heating coil that induction-heats a shaft-shaped work having a corner portion of a boundary with the small shaft diameter portion, first heating the small shaft diameter portion and the corner portion.
A second coil that is connected in series to the first coil and that heats the small shaft diameter portion, the shoulder portion, and the large shaft diameter portion.
The conductor that heats the small axis diameter part of the coil is arranged on the side opposite to the work side of the conductor that heats the small axis diameter part of the first coil.

In order to solve the above-mentioned problems, the invention of claim 2 provides a small shaft diameter portion, a large shaft diameter portion, a shoulder portion between these two shaft portions, and the shoulder portion and the small shaft diameter. A high-frequency induction heating coil for inductively heating a shaft-shaped work having a corner of a boundary with a portion, the first coil including a first coil and a second coil connected in series to the first coil, and the first coil , A pair of linear first conductors that are arranged parallel to the axial direction of the axial work and heat the small shaft diameter portion, and one end of the first conductors are connected to each other, and the corner portions are arranged in the circumferential direction of the corner portion. A pair of substantially semi-arcuate second conductors to be heated, and one end each connected to the other end of the first conductor and arranged in the circumferential direction of the small shaft diameter portion to heat the small shaft diameter portion. And a second coil having a linear shape parallel to the first conductor and having a substantially equal length and arranged on the side opposite to the work side of the first conductor. And a pair of linear fifth conductors, one end of which is connected to one end of the fourth conductor, is orthogonal to the fourth conductor, and is arranged away from the fourth conductor, and heats the shoulder portion, A pair of linear sixth conductors which are connected to the other end of the fifth conductor and are parallel to the fourth conductor and are spaced apart from the fourth conductor and heat the large-diameter portion, and the other ends of the sixth conductors. And a substantially semi-circular arc-shaped seventh conductor which is arranged in the circumferential direction of the large shaft diameter part and heats the large shaft diameter part, and one end of each of the other ends of the fourth conductors is connected to the opposite work side of the third conductor. Almost 1 placed
/ 4 arc-shaped eighth conductor, the other end of the one third conductor and the other end of the one eighth conductor are connected to one end and the other end of the high frequency power source, respectively, and the other end of the other third conductor. Is connected to the other end of the other eighth conductor.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are drawings for explaining one embodiment of the present invention, FIG. 1 is a perspective view, and FIG. 2 is A- of FIG.
It is an A line arrow cross section explanatory view.

The high frequency induction heating coil 100 of this embodiment is
The workpiece 300 described in FIG. 4, namely, the small shaft diameter portion 301, the large shaft diameter portion 303, the shoulder portion 302 and the small shaft diameter portion between these two shaft portions.
Workpiece 300 with corner 304 at the boundary of 301 and shoulder 302
A coil for induction heating a saddle-shaped coil 100A (first
Saddle type coil) and 100B (second saddle type coil). The saddle type coils 100A and 100B are connected in series, and each of them is made of a good conductive metal tube.

The saddle coil 100A is a conductor connected in series.
3a (3rd conductor), 1a (1st conductor), 2 (2nd conductor),
The saddle-type coil 100B is provided with 1b (first conductor) and 3b (third conductor), and conductors 8a (8th conductor), 4a (4th conductor), 5a (5th conductor) connected in series. , 6a (sixth conductor)
, 7 (7th conductor), 6b (6th conductor), 5b (5th conductor)
, 4b (fourth conductor) and 8b (eighth conductor). The conductor 8a is connected to the conductor 3b in series.

The conductors 1a, 1b, 4a, 4b, 6a and 6b are linear and are arranged in the axial direction of the work 300, and the conductors 5a and 5b are linear and are arranged substantially in the radial direction of the work 300. To be done. The conductors 2 and 7 have a substantially semi-circular shape and are arranged in the circumferential direction of the corner portion 304 and the large-axis diameter portion 303, respectively. Further, the conductors 3a, 3b, 8a and 8b have a substantially quarter arc shape and are arranged in the circumferential direction of the small shaft diameter portion 301.

The conductors 1a and 4a are parallel and the adjacent conductor 4a is outside the conductor 1a (opposite work side), the conductors 1b and 4b are parallel, the adjacent conductor 4b is outside the conductor 1b, and the conductors 3a and 8a are parallel. Moreover, the adjacent conductor 8a is arranged outside the conductor 3a, and the conductors 3b and 8b are arranged such that the adjacent conductor 8b is outside the conductor 3b.

The conductors 1a, 1b, 3a and 3b have a small shaft diameter portion 301.
, Conductor 2 at corner 304, conductors 5a and 5b at shoulder 302
The conductors 6a, 6b and 7 are used for heating the large shaft diameter portion 303, respectively. 21 and 22 are conductors 3a and
A high frequency power supply 101 is connected between the power supply conductors 21 and 22 which are power supply conductors connected to the end of 8b.

As a result of providing the conductor 2 for exclusively heating the corner portion 304, extra conductors 8a and 8b unnecessary for heating the small shaft diameter portion 301 are formed. Department
In order to minimize the heating of 301, the conductors 8a and 8b are arranged on the non-work side of the conductors 1a and 1b as described above.

Next, the operation of this embodiment will be described. The conductors 1a, 1b, 3a and 3b of the high frequency induction heating coil 100 are placed on the small shaft diameter portion 301, the conductor 2 on the corner portion 304, and the conductors 5a and 5b on the shoulder portion.
302, the conductors 6a, 6b and 7 are arranged close to the large shaft diameter portion 303 so as to face each other, and then the work 300 is rotated about its axis 310 while the high frequency power supply 101
High-frequency induction heating coil 100 is energized with high-frequency current.

The high frequency current is applied to the conductors 21, 3a, 1a, 2, 1b,
The small shaft diameter portion 301 of the work 100 flows by flowing in the direction of the arrow in FIG. 1 through the paths of 3b, 8a, 4a, 5a, 6a, 7 6b, 5b, 4b, 8b and 22 or in the opposite direction. , Large shaft diameter part 303, shoulder part
302 and corner 304 are heated.

At this time, the small shaft diameter portion 301 is made up of the conductors 1a and 1b.
Is heated by the induction current generated by the high-frequency current flowing in the conductors 8a and 8b and the high-frequency current flowing in the conductors 8a and 8b.
Since 8b is arranged on the opposite side of the work from conductors 1a and 1b, heating of small shaft diameter portion 301 by conductors 8a and 8b is extremely small. In addition, the small shaft diameter portion 30 formed by the conductors 1a, 1b, 8a and 8b
Adjust the heating degree of 1 by adjusting the conductors 1a and 1b and the small shaft diameter part.
This can be done by adjusting the distance d (see Fig. 2) from 301.

The corner 304 is sufficiently heated by the high frequency current flowing through the conductor 2. In addition, the shoulder 302 is caused by the high-frequency current flowing through the conductors 5a and 5b, and the large-axis diameter portion 303 is further affected by the conductor 6.
It is heated by the high frequency current flowing in a, 6b and 7. Then, after a high-frequency current is passed through the high-frequency induction heating coil 100 for a predetermined time, a quenching liquid is jetted onto the work 300 from a jacket (not shown), or the work 300 is immersed in the cooling liquid to complete the quenching of the work 300. A hardened layer having a uniform depth is formed on the small shaft diameter portion 301, the large shaft diameter portion 303, the shoulder portion 302, and the corner portion 304 of the work 100 thus quenched.

[0020]

As described above, according to the first and second aspects.
The high-frequency induction heating coil of the invention comprises a small shaft diameter portion, a large shaft diameter portion, a shoulder portion between these shaft portions, and a corner portion of a boundary between the shoulder portion and the small shaft diameter portion. In a high-frequency induction heating coil for induction heating a shaft-shaped work, a first coil for heating a small shaft diameter portion and a corner portion, and a small shaft diameter portion, a shoulder portion, and a large shaft diameter portion connected in series to the first coil. And a second coil for heating the second coil, and the conductor for heating the small-axis diameter portion of the second coil is arranged on the opposite work side of the conductor for heating the small-axis diameter portion of the first coil.

That is, in the high frequency induction heating coil of the present invention, a conductor for heating the corner, which is not present in the conventional high frequency induction heating coil, is arranged along the circumferential direction of the corner so as to face the corner. In addition, the extra heating conductor of the small shaft diameter portion derived by providing this conductor is arranged on the side opposite to the work side of the conductor that originally heats the small shaft diameter portion, and is transferred to the small shaft diameter portion of the extra heating conductor. Since overheating is prevented, it is possible to form a hardened layer having a uniform depth on the surface of the stepped shaft-like work having a small shaft diameter portion, a shoulder portion, a large shaft diameter portion and a corner portion.

[Brief description of drawings]

FIG. 1 is a perspective view of a high frequency induction heating coil according to an embodiment of the present invention.

FIG. 2 is a cross sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a conventional high frequency induction heating coil.

FIG. 4 is a cross-sectional view of a stepped shaft-shaped work.

[Explanation of symbols]

 1a Conductor 1b Conductor 2 Conductor 3a Conductor 3b Conductor 4a Conductor 4b Conductor 5a Conductor 5b Conductor 6a Conductor 6b Conductor 7 Conductor 8a Conductor 8b Conductor 100A 1st coil 100B 2nd coil 100 High frequency induction heating coil 300 Stepped axial work 301 Small axis Diameter 302 Shoulder 303 Large shaft Diameter 304 Corner

Claims (2)

[Claims] 1. A shaft-shaped work piece having a small shaft diameter portion, a large shaft diameter portion, a shoulder portion between these shaft portions, and a corner portion of a boundary between the shoulder portion and the small shaft diameter portion. In a high-frequency induction heating coil for induction heating, a first coil that heats a small shaft diameter portion and a corner portion, and a small shaft diameter portion, a shoulder portion, and a large shaft diameter portion that are connected in series to the first coil are heated. A high-frequency induction heating coil, comprising: a second coil, wherein a conductor for heating a small axis diameter portion of the second coil is arranged on a side opposite to a work of a conductor for heating a small axis diameter portion of the first coil. 2. A shaft-shaped work piece having a small shaft diameter portion, a large shaft diameter portion, a shoulder portion between these shaft portions, and a corner portion of a boundary between the shoulder portion and the small shaft diameter portion. An induction current wave heating coil for induction heating, comprising a first coil and a second coil connected in series to the first coil, the first coil being arranged parallel to the axial direction of the axial work and having a small axis. A pair of linear first conductors that heat the diameter portion, and a second semi-circular arc that connects one ends of the first conductors and is arranged in the circumferential direction of the corner portion to heat the corner portion.
One end of each of the conductor and the other end of the first conductor is connected to each other and arranged in the circumferential direction of the small shaft diameter portion to heat the small shaft diameter portion approximately 1/4.
A pair of third conductors in an arc shape, and the second coil has a pair of linear fourth conductors parallel to and substantially equal in length to the first conductor and arranged on the side opposite to the work of the first conductor; One pair of linear fifth conductors, one end of which is connected to one end of the fourth conductor, is orthogonal to the fourth conductor, and is arranged away from the fourth conductor to heat the shoulder portion; and one end of the fifth conductor is the other end of the fifth conductor. Is connected to the fourth conductor in parallel with the fourth conductor and is arranged away from the fourth conductor, and a pair of linear sixth conductors for heating the large-diameter portion and the other end of the sixth conductor are connected to each other to form the large-axis diameter. A substantially semi-circular arc-shaped seventh conductor that is arranged in the circumferential direction of the portion and that heats the large-diameter portion, and one end that is connected to the other end of the fourth conductor and that is arranged on the opposite work side of the third conductor
/ 4 arc-shaped eighth conductor, the other end of the one third conductor and the other end of the one eighth conductor are connected to one end and the other end of the high frequency power source, respectively, and the other end of the other third conductor. Is connected to the other end of the other eighth conductor, which is a high-frequency induction heating coil.