JP2000087135A - Induction heating and hardening apparatus for shaft member with foot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating and hardening apparatus for shaft member with foot particularly having the large foot part, such as flange. SOLUTION: This apparatus is provided with a heating coil 10 for induction- heating a hardening part in the shaft member W, a cooling means 20 for jetting a cooling liquid onto the hardening part in the shaft member W moved to a cooling position, and moving means 25, 26 for moving and holding the shaft member W between the heating coil position and the cooling position. The cooling means 20 is disposed separately from the heating coil 10. The heating coil 10 for the shaft member W with the foot having two or more steps of step parts 2, 3 is provided with two or more of arc-state conductors 11, 13, 16 surrounding the shaft outer peripheries 2, 3 in the hardening parts and the arc-state conductors with the adjacent steps are connected to each other so that the current flow in mutually reverse direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a shaft body with a foot, such as a knuckle, provided with a foot such as an arm or a flange at a shaft end, a neck portion where the shaft portion is connected to the foot portion, or a shaft portion having a stepped portion. In the case of a shaft with a shaft, it is desirable to harden not only the outer periphery of the shaft but also the root of the shaft in order to increase the fatigue strength of the neck portion where the small diameter shaft is connected to the large diameter shaft. Hereinafter, this neck portion is referred to as a shaft root portion or a step corner portion. The present invention relates to a quenching device for a shaft member with a foot, which is mainly such a shaft body and particularly has a foot portion such as a large flange.

[0002]

2. Description of the Related Art In the conventional quenching of a shaft member with a foot, particularly in the quenching of a shaft member with a large foot portion such as a knuckle, the prior art has a problem in that the exact position of an induction-heated member is quickly determined. Because of the difficulty in the movement, a cooling means was used in which a cooling box 7 was fixed to a plate 9 to which heating coils 5 and 6 were attached as shown in FIG. That is,
After the shaft member to be quenched is induction-heated by the heating coils 5 and 6, etc., the cooling liquid is jetted from the injection hole 8 of the cooling box 7 toward the shaft member from the gap between the heating coils at the heating position without being moved, and rapidly cooled and quenched. Was done.

[0003] Further, when simultaneously hardening the outer periphery of two or more steps of a shaft member with feet having two or more steps,
For example, as shown in FIG.
6, an induction heating coil connected so that current flows in the same direction was used.

[0004]

However, in the conventional cooling device, the cooling liquid to be injected is limited to the heating coil, and the cooling liquid hardly reaches the quenched portion of the shaft member with foot.
In the case of a shaft root portion of a foot portion and a shaft portion or a step shaft, there is a problem that quenching hardness of a step corner of a shaft step is insufficient. Furthermore, since the heating coil and the cooling box are integrated, the cooling box must be integrally removed every time maintenance such as repair or adjustment of the coil is performed, and there is a problem that it is complicated and costly. . On the other hand, arranging the cooling box below the coil makes it difficult to secure the space from the viewpoint of the device configuration.

In the conventional coil shown in FIG. 3, when the outer periphery of the stepped shaft portion of two or more shafts of the shaft member with foot is simultaneously heated, the two coils 5 and 6 are simultaneously heated as shown in FIG. To generate a magnetic field in the direction, the root of each axis (step corner) 1
While the temperatures of a and 3a are unlikely to rise, the temperature of the protruding corner 2a is likely to rise. Therefore, for example, in the case of induction heating a footed shaft member having two or more steps as shown in FIGS. 1 and 2 and having a short shaft length of the stepped part 2, the corners 1a and 3a are set to the quenching temperature. When heated, there is a problem that the corners 2a are overheated to a temperature higher than the quenching temperature and coarsened.

Accordingly, an object of the present invention is to provide an induction heating and quenching apparatus for a shaft member with a foot which eliminates the above-mentioned problems and has no such defects.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, an induction heating and quenching apparatus for a shaft member with a foot according to the present invention has a heating coil for induction heating a quenched portion of the shaft member, and has been moved to a cooling position. Cooling means for injecting a cooling liquid into a quenched portion of the shaft member, and moving means for moving and holding the shaft member between the heating coil position and a cooling position of the cooling means, wherein the cooling means is It is characterized by being disposed separately from the heating coil.

That is, instead of cooling the footed shaft member heated to the quenching temperature at the heating position as in the prior art, the footed shaft member heated at the position of the heating coil is cooled by the moving means by the cooling means. Then, the quenched part is cooled by spraying a coolant at this cooling position. Therefore, the injection of the cooling liquid is not interrupted by the heating coil, the injection angle and the like can be arbitrarily set, and the injection liquid can be made to strike the cooling surface at right angles. As a result, the cooling efficiency can be increased up to the step corners, so that appropriate hardening hardness can be obtained up to the step corners and the protruding corners that are concave. Further, by providing the cooling means separately from the heating coil, the manufacturing cost is reduced and the maintenance of the heating coil is facilitated.

In the case of quenching a shaft member with a foot for simultaneously heating and quenching the outer periphery of two or more step shaft portions, the shaft outer periphery of the step portion to be quenched is formed into a circular arc with a predetermined gap formed.
It is desirable to provide the above-described arc-shaped conductor, and to provide an induction heating coil in which the arc-shaped conductors of adjacent stages are connected so that currents flow in opposite directions.

That is, in the induction heating coil of the quenching device of the present invention, unlike the conventional coil, the currents of the coils corresponding to the respective stages of the shaft member with feet flow in mutually opposite directions. When the step shaft length is short, even when the step corner of the root of the shaft is heated to the quenching temperature, the protruding shaft corner does not overheat to the quenching temperature.

Therefore, even when the step shaft length of the shaft member with foot is short, an appropriate hardened layer can be obtained at the corners and corners of the step shaft. The number of shaft stages of the shaft member with foot may be not only two stages but also three or more stages. In the case of three or more stages, the conductors of the adjacent stages of the coil corresponding to each stage are connected in opposite directions. What is necessary is just to connect so that an electric current may flow.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. FIG. 1 is a sectional view showing a configuration of an induction heating and quenching device for a shaft member with a foot according to the present invention, and FIG. 2 is a perspective view showing one example of a heating coil used in the induction heating and quenching device of the present invention. The configuration of the induction heating and quenching device for the shaft member with foot of the present invention will be described with reference to these drawings.

The quenched footed shaft member W of this embodiment has a shaft portion having a large-diameter shaft portion 2 and a small-diameter shaft portion 3 and a large-diameter shaft portion 2 as shown by a chain line in FIGS. It comprises a foot 1 such as an arm or a flange provided at one end. Then, in order to increase the fatigue strength, a quenched layer as shown in FIG. 1 is to be formed at the root of the foot 1, the large diameter shaft 2 and the small diameter shaft 3.

As shown in FIG. 2, the induction heating coil 10 comprises a notched large-diameter arc-shaped conductor 11 and two small-diameter arc-shaped conductors 13 and 16. Large-diameter arc-shaped conductor 11
Is a notched arc having a predetermined gap with the outer periphery of the large-diameter shaft portion 2, and the small-diameter arc-shaped conductors 13 and 16 form a partial arc having a predetermined gap with the outer periphery of the small-diameter shaft portion 2. Both ends of the notch of the large-diameter arc-shaped conductor 11 are
And 15 are connected to one ends of small-diameter arc-shaped conductors 13 and 16. Leads 14 and 17 are connected to the other ends of the arc-shaped conductors 13 and 16, respectively. As a result, when electric power is supplied from the lead portions 14 and 17, the large-diameter arc-shaped conductor 1 as shown by the arrow in FIG.
1 and the currents flowing in the small-diameter arc-shaped conductors 13 and 16 flow in opposite directions, thereby preventing the corner 2a from being overheated as described above with reference to FIG. .

Although these arc-shaped conductors form a 1/4 circumference in the figure, the length of the circumference may be arbitrarily set and may be substantially the entire circumference or a 1/2 circumference. . Further, in order to heat the surface of the arm 1, it is desirable that the coil cross section of the large-diameter arc-shaped conductor 11 be wedge-shaped as shown in FIG.

In this embodiment, a two-stage footed shaft member is shown. However, for three or more footed shaft members, current flows in opposite directions through adjacent arc-shaped conductors corresponding to each stage. The same effect can be obtained by connecting in such a manner.

Next, a quenching apparatus according to the present invention will be described with reference to FIG. In the figure, an induction heating coil 10 is fixed to a frame (not shown), and power is supplied from a high-frequency power source (not shown). A cylindrical or hollow arcuate cooling box 21 having a hollow cross section surrounding the outer periphery of the heating coil 10 is arranged on the circumference and fixed to a frame (not shown). A plurality of injection holes 22 are provided on the lower surface of the cooling box 21 so that a cooling liquid supplied to a hollow portion of the cooling box 21 from a supply pipe (not shown) is injected. The injection holes 22 are directed so that the injected cooling liquid strikes the heating portion of the shaft member with quenched feet moved to a cooling position to be described later at right angles from obliquely above.

A mounting table 2 on which a shaft member W to be hardened is mounted.
Numeral 5 is driven up and down by the moving means 26 to rapidly move the loaded hardened shaft member W between the position of the heating coil 10 and the lower cooling position to accurately hold the shaft member W at each position. It is supposed to. The quenched footed shaft member W is mounted on the mounting table 25 by a method according to the shape such as being supported between the centers, and a known means such as a servo lifter is used as a moving means.

Hereinafter, the operation of the induction heating and quenching apparatus of the present invention having the above configuration will be described. First, the quenched footed shaft member W is mounted on the mounting table 25 at the lower cooling position in FIG. 1, and the quenched footed shaft member W is moved upward by the moving means 26 to the position of the heating coil 10. When the heating coil 10 is energized and induction-heated at this position, the outer diameter of the large-diameter shaft portion 2 and the base of the foot 1 are heated by the large-diameter arc-shaped inductor 11, and the small-diameter arc-shaped inductor 12 is heated. The outer diameter of the small diameter shaft portion 3 is heated.

The quenched footed shaft member W heated to the quenching temperature at the position of the heating coil is quickly moved by the moving means 26 to the lower cooling position in FIG. Then, the heating part is rapidly cooled and quenched by the cooling liquid injected from the injection hole 22 of the cooling means 20 immediately.

At the time of the above-mentioned heating, in the heating coil of the present invention, unlike the conventional coil, the corner 2a of the large-diameter shaft portion 2 is not overheated to the quenching temperature or higher, and the step corner 1
The a, 3a and the corner 2a can be heated to an appropriate quenching temperature, and an appropriate quenching hardness can be obtained. In addition, during the cooling, the injection liquid in the injection holes 22 hits the entire surface of the heating section, so that the corners are uniformly cooled, and there is no decrease in quenching hardness at the step corners as in the conventional case. Further, since the cooling box 21 is disposed on the circumference, the cooling box 21 is also cooled uniformly in the circumferential direction, and uniform hardening hardness can be obtained.

As described above, the induction heating and quenching apparatus for a shaft member with a foot according to the embodiment of the present invention includes a number of arc-shaped conductors corresponding to the outer diameter of the shaft of the stepped portion. Are provided with heating coils connected so that currents flow in opposite directions, so that the corners are not overheated even during induction heating of a short shaft, and the corners and corners of the shaft In both cases, uniform hardening depth and hardness can be obtained.

Also, a cooling means separate from the heating coil is provided, and the shaft member with the quenched foot, which has been induction-heated at the heating coil position, is moved to the cooling position by the moving means, and the cooling liquid is injected over the entire circumference of the heating section at the cooling position. Since the cooling coil does not hinder the injection as in the past, the coolant shines evenly and is completely quenched to the corners of the step shaft. can get. Further, by separating the heating coil and the cooling means, maintenance of the heating coil is facilitated, and the manufacturing cost can be reduced.

[0024]

As described above, according to the induction heating and quenching apparatus for a shaft member with a foot of the present invention, even when the shaft length of the step portion of the shaft member is short, the corner portion of the step shaft does not overheat. It can be heated to the quenching temperature up to the corner. In addition, the heated part of the quenched footed shaft member is spray-cooled at a position away from the heating position, so it is cooled rapidly enough to the corners, and especially a footed shaft with a large flange such as a knuckle or arm foot An appropriate quenched layer is obtained in the member, and the fatigue strength of the stepped portion is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a configuration of an induction heating and quenching device for a shaft member with a foot according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a configuration of a heating coil used in the induction heating and quenching apparatus according to the embodiment of the present invention.

FIG. 3 shows a configuration of a conventional induction heating coil of a shaft member with a foot.
It is a perspective view showing an example.

FIG. 4 is a cross-sectional view showing an example of a conventional induction heating and quenching device for a shaft member with a foot.

FIG. 5 is a diagram illustrating a heating state of a shaft step portion by a conventional induction heating coil.

[Explanation of symbols]

 W Shaft member with quenched foot 1 Arm 1a Corner 2 Large diameter shaft 2a Corner 3 Small diameter shaft 3a Step corner (root of shaft) 4 Foot 5 Large diameter coil 6 Small diameter coil 7 Cooling box 8 Injection hole 9 Plate 10 Induction heating coil 11 Large-diameter arc-shaped conductor 12 Connector 13 Small-diameter arc-shaped conductor 14 Lead 15 Connection 16 Small-diameter arc-shaped conductor 17 Lead 20 Cooling means 21 Cooling box 22 Injection hole 25 Mounting table 26 Moving means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/38 H05B 6/38 6/44 6/44 F term (Reference) 3K059 AA09 AB20 AB24 AC07 AC33 AC72 AD05 AD15 AD26 AD34 AD35 CD48 CD52 CD73 CD79 4K042 AA15 BA04 BA13 DA01 DB01 DD04 DE02 DF01 EA01

Claims (2)

[Claims] 1. A heating coil for inductively heating a quenched portion of a shaft member, cooling means for spraying a cooling liquid to a quenched portion of the shaft member moved to a cooling position, and a cooling position of the heating coil position and the cooling means. Moving means for moving and holding the shaft member between the heating coil and the cooling means, and the cooling means is disposed separately from the heating coil. 2. A quenching of a shaft member with a foot for simultaneously heating and quenching the outer periphery of two or more stepped shaft portions. 2. An induction heating coil for a shaft member with a foot according to claim 1, further comprising: an induction heating coil connected so that currents flow in opposite directions to each other. Input device.