JP2009287074A - Induction heat treatment apparatus, induction heat treatment method and rolling bearing with annular component having undergone induction heat treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heat treatment apparatus and an induction heat treatment method which perform induction heat treatment on the whole of an annular component by one treatment, and to provide a rolling bearing with the annular component having undergone the induction heat treatment method. <P>SOLUTION: The induction heat treatment apparatus 1 is provided with: an annular component supporting part 2 for supporting the annular component W being a heat treatment object rotatably around a center axis P from beneath; a heating coil 4 which is disposed at a prescribed interval between the heating coil and a part of a circumferential-direction portion of the annular component W supported by the annular component supporting part 2; and a high-frequency current power supplying means 6 for supplying power of high-frequency current to the heating coil 4. In the induction heat treatment apparatus 1, the annular component supporting part 2 is provided with a plurality of supporting rollers 12 which are made of ceramic material, formed cylindrical, disposed radially beneath the annular component W and are brought into contact with the lower end face Wa of the annular component W, wherein a lower-end face heating coil 20 provided in the heating coil 4 and opposite to the lower end face Wa of the annular component W is disposed between the adjoined supporting rollers 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention performs, for example, a high-frequency heat treatment apparatus, a high-frequency heat treatment method, and a high-frequency heat treatment method for performing heat treatment such as quenching and tempering on an annular part such as an outer ring and an inner ring included in a rolling bearing by high-frequency induction heating. The present invention relates to a rolling bearing having an annular part.

For example, large bearings and ultra-large bearings used in windmill speed reducers and steel rolling mills require a longer life than small bearings. For this reason, in order to obtain good toughness, durability and the like, annular parts such as outer rings and inner rings provided in such a bearing use carburized steel instead of bearing steel as a material, and perform long-term carburizing or carbonitriding. Often formed by going.
Since the carburized bearing formed in this manner has a lower core hardness than the surface layer, the toughness can be improved. Further, since the austenite phase remains only on the surface, the dimensional stability of the product can be improved.

However, in order to obtain a hardened layer having a depth required in the carburizing process or the carbonitriding process, a very long heat treatment is required, and thus a very large heat treatment strain may occur.
On the other hand, as a heat treatment method capable of improving productivity and reducing manufacturing costs, a heating coil is disposed in the vicinity of the annular component, and a high-frequency current is supplied to the heating coil to heat the annular component, that is, There is a method by high frequency induction heating. The high-frequency heat treatment method using high-frequency induction heating is a heat treatment method that enables low-cost, low-heat-treatment deformation, and clean heat treatment in a short time, so it can be applied to heat treatment of various structural members and machine parts such as gears and shafts. There are many.

The high-frequency heat treatment of steel materials by high-frequency induction heating mainly includes surface quenching in which only the surface layer of the steel material is quenched in a short time, and the whole to obtain a constant quenching hardness up to the core of the steel material. There is quenching. Surface quenching is a method that is often used for gears, axle support bearings, and the like, and overall quenching is a method that is often used for steel materials such as rods and plates.
As a method for performing such high-frequency induction heating on a large-sized annular component provided in the large-sized or super-large-sized bearing as described above, for example, a heat treatment method described in Patent Documents 1 to 3 is used. is there.

The heat treatment method described in Patent Document 1 is a method in which surface quenching is performed on an annular part formed to have a large diameter and a thin wall while suppressing heat treatment deformation.
In addition, the heat treatment method described in Patent Document 2 is a method of heat-treating an annular part using a horseshoe-shaped heating coil fed with a high-frequency current. Furthermore, the heat treatment method described in Patent Document 3 is a method of heat-treating an annular part using a U-shaped heating coil fed with a high-frequency current. In the heat treatment methods described in Patent Documents 2 and 3, the entire annular part is uniformly heated, and the entire part is quenched.

As a method for improving the quality of the overall quenching for the annular part, for example, there are heat treatment methods as described in Patent Documents 4 and 5.
The heat treatment method described in Patent Document 4 is a method in which the temperature is measured at a plurality of measurement points set on the annular part, and the entire quenching is performed when the temperature difference between the measurement points becomes small.
Further, the heat treatment method described in Patent Document 5 calculates the diffusion length of carbon in the annular part based on the temperature at a position away from the heating coil among the annular parts, and the carbon is contained in the matrix of the annular part. This is a method of cooling the annular part when it is sufficiently melted.
JP-A-11-140543 JP 2005-325409 A JP 2006-179359 A JP 2005-310645 A JP 2006-152429 A

By the way, as described above, it is possible to improve toughness by hardening only the surface layer of a large-sized annular component such as an outer ring or an inner ring included in a large-sized bearing or a super-large-sized bearing. As a method of curing only the surface layer of the annular part, there are a method of performing surface quenching on the entire annular part at once and a method of performing surface quenching in two or more steps.
As a method of performing surface quenching on the entire annular component in two or more times, for example, after performing surface quenching on the outer diameter surface and the inner diameter surface in a state in which both end surfaces of the annular component are constrained, There is a method in which surface quenching is performed on both end surfaces in a state in which the diameter surface and the inner surface are constrained.

  However, in the method of performing surface quenching on the entire annular part in two or more times, there is a problem that a crack such as a crack occurs in the annular part during the second and subsequent surface quenching, that is, re-quenching. May occur. The cracking of the annular part occurs when the region where the first surface quenching is performed overlaps with the region where the second and subsequent surface quenching is performed. For this reason, in order to suppress the occurrence of cracking in the annular part, a portion having a low hardness, that is, surface quenching, is performed between the first surface quenching region and the second and subsequent surface quenching regions. There is a way to leave a part that is less affected by the entry. However, in this method, a low hardness portion is formed on the surface layer of the annular part.

In addition, in the method of performing surface quenching in two or more times for the entire annular part, the portion subjected to the first surface quenching is tempered by the second and subsequent surface quenching, so that sufficient There is a possibility that a problem that the hardness and retained austenite cannot be obtained may occur. This problem also occurs when the region where the first surface quenching is performed overlaps with the region where the second and subsequent surface quenching is performed, as in the case of the quench cracking of the annular part.
These problems can be solved by using a method of performing surface quenching once for the entire annular part. However, in order to perform surface quenching for the entire annular part at one time. Requires that the whole annular part be subjected to high-frequency heat treatment in a uniform state.

On the other hand, in the heat treatment methods described in Patent Documents 1 to 5 described above, it is difficult to perform uniform high-frequency heat treatment along the circumferential direction of the annular component on the lower end surface of the annular component. For this reason, it is difficult to sufficiently harden the lower end surface of the annular part as compared with other surfaces. Therefore, a desired quenching hardness can be obtained with a single high-frequency heat treatment for the entire annular part. Is difficult to get. This is because, in the heat treatment methods described in Patent Documents 1 to 5, the arrangement state of the heating coil with respect to the lower end surface of the annular component is different from the arrangement state of the heating coil with respect to the other surface. This is because it is difficult to perform uniform high-frequency heat treatment.
The present invention has been made paying attention to the above problems, and a high-frequency heat treatment apparatus and a high-frequency heat treatment apparatus capable of performing uniform high-frequency heat treatment along the circumferential direction of the annular component on the entire annular component. It is an object to provide a heat treatment method.

  In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is such that the annular part to be heat-treated is downwardly rotatable around the central axis of the annular part with the axis directed in the vertical direction. An annular component supporting portion that is supported by the annular component, a heating coil that is arranged at a predetermined distance from a portion in the circumferential direction with respect to the annular component supported by the annular component supporting portion, and a high-frequency current is supplied to the heating coil A high-frequency heat supply apparatus comprising:

The annular part support portion includes a plurality of cylindrical or conical support rollers that are formed using a metal material or a ceramic material and that are arranged radially below the annular part to contact the lower end surface of the annular part. ,
The heating coil includes an outer diameter surface heating coil facing the outer diameter surface of the annular component, an inner diameter surface heating coil facing the inner diameter surface of the annular component, and an upper end surface heating coil facing the upper end surface of the annular component. And a lower end surface heating coil facing the lower end surface of the annular part,
The lower end surface heating coil is arranged between the adjacent support rollers.

According to the present invention, the plurality of support rollers arranged radially below the annular component supports the annular component so as to be rotatable around the central axis, and the lower end surface heating coils facing the lower end surface of the annular component are adjacent to each other. Place between support rollers.
For this reason, it becomes possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular component with respect to the entire lower end surface of the annular component, and uniform along the circumferential direction of the annular component with respect to the entire annular component. High frequency heat treatment can be performed.

Next, the invention described in claim 2 is the invention described in claim 1, wherein three or more positioning rollers are arranged on the outer diameter surface side or inner diameter surface side of the annular component, and the three or more positioning rollers are arranged. Positioning roller pressing means for pressing the positioning roller against the annular component,
The roller pressing means causes the annular component to be pressed against the annular component so that the interval between the annular component, the outer diameter surface heating coil, and the inner diameter surface heating coil is maintained at the predetermined interval.
At least one of the three or more positioning rollers includes positioning roller rotating means for rotating the positioning roller,
The positioning roller is rotated so that the annular part rotates around the central axis.

According to the present invention, three or more positioning rollers arranged on the outer diameter surface side or inner diameter surface side of the annular member are maintained at a predetermined interval between the annular component, the outer diameter surface heating coil, and the inner diameter surface heating coil. In this way, the annular part is pressed. Further, at least one positioning roller is rotated so that the annular member rotates around the central axis.
For this reason, it becomes possible to hold | maintain the space | interval of an annular member, an outer diameter surface heating coil, and an inner diameter surface heating coil at a fixed distance, and it is in the circumferential direction of an annular component with respect to the outer diameter surface and inner diameter surface of an annular component. Along with this, uniform high-frequency heat treatment can be performed.

Next, the invention described in claim 3 is the invention described in claim 1 or 2, wherein at least one of the outer surface heating coil and the inner surface heating coil is disposed in the axial direction of the annular component. It is characterized by dividing along.
According to the present invention, since at least one of the outer diameter surface heating coil and the inner diameter surface heating coil is divided along the axial direction of the annular component, the state of the high frequency heat treatment on the surface of the annular component facing the divided heating portion is set. It becomes possible to control each part divided along the axial direction of the annular part.

Next, an invention described in claim 4 is the invention described in any one of claims 1 to 3, wherein the outer diameter surface heating coil, the inner diameter surface heating coil, the upper end surface heating coil, and A plurality of at least one of the lower end surface heating coils is arranged along the circumferential direction of the annular component.
According to the present invention, since at least one of the outer diameter surface heating coil, the inner diameter surface heating coil, the upper end surface heating coil, and the lower end surface heating coil is disposed along the circumferential direction of the annular component, a plurality of heating portions are disposed. It is possible to raise the temperature of the surface of the annular component facing the surface in a short time.

Next, the invention described in claim 5 is the invention described in any one of claims 1 to 4, wherein a surface of the support roller facing the annular part is defined as an inner diameter surface of the annular part. Inclined downward from the side toward the outer diameter surface.
According to the present invention, the surface of the support roller facing the annular part is inclined downward from the inner diameter surface side to the outer diameter surface side of the annular part, so that the contact area between the support roller and the annular part can be reduced. It becomes possible.
For this reason, it becomes possible to make the state of expansion and contraction generated in the annular part whose temperature has changed uniform in the entire annular part.

Next, according to the sixth aspect of the present invention, while supporting the annular part to be heat-treated from below and rotating it around the central axis of the annular part, a part of the annular part is spaced apart from the circumferential part by a predetermined distance. A high-frequency heat treatment method for performing high-frequency heat treatment on the annular component by feeding a high-frequency current to a heating coil arranged with a gap between
The annular part is formed by using a metal material or a ceramic material, and is supported by a plurality of cylindrical or conical support rollers that are radially arranged below the annular part and contact the lower end surface of the annular part,
The heating coil includes an outer diameter surface heating coil facing the outer diameter surface of the annular component, an inner diameter surface heating coil facing the inner diameter surface of the annular component, and an upper end surface heating coil facing the upper end surface of the annular component. And a lower end surface heating coil facing the lower end surface of the annular part,
Performing high-frequency heat treatment on the lower end surface of the annular component by feeding the high-frequency current to the lower end surface heating coil disposed between the adjacent support rollers while rotating the annular component around the central axis. It is characterized by.

According to the present invention, the plurality of support rollers arranged radially below the annular part feeds a high-frequency current to the lower end surface heating coil arranged between adjacent support rollers while rotating the annular part around the central axis. Then, high-frequency heat treatment is performed on the lower end surface of the annular part.
For this reason, it becomes possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular component with respect to the entire lower end surface of the annular component, and uniform along the circumferential direction of the annular component with respect to the entire annular component. High frequency heat treatment can be performed.

Next, the invention described in claim 7 is the invention described in claim 6, wherein the annular component, the outer surface heating coil, and the inner surface are rotated while the annular component is rotated around the central axis. Three or more pressing positions set on the outer diameter surface or the inner diameter surface of the annular part are pressed so that the distance from the heating coil is maintained at the predetermined distance.
According to the present invention, the outer diameter surface or inner diameter of the annular member is maintained such that the intervals between the annular component, the outer diameter surface heating coil, and the inner diameter surface heating coil are maintained at predetermined intervals while rotating the annular member around the central axis. Press the surface.
For this reason, it becomes possible to hold | maintain the space | interval of an annular member, an outer diameter surface heating coil, and an inner diameter surface heating coil at a fixed distance, and it is in the circumferential direction of an annular component with respect to the outer diameter surface and inner diameter surface of an annular component. Along with this, uniform high-frequency heat treatment can be performed.

Next, the invention described in claim 8 is the invention described in claim 6 or 7, wherein the axial direction of the annular component is at least one of the outer diameter surface and the inner diameter surface of the annular component. The high-frequency heat treatment is performed at a plurality of locations divided along the line.
According to the present invention, high-frequency heat treatment is performed at a plurality of locations divided along the axial direction of the annular component on at least one of the outer diameter surface and the inner diameter surface of the annular component.
For this reason, it is possible to control the state of the high-frequency heat treatment for the surface of the annular component divided into a plurality of locations along the axial direction of the annular component for each part corresponding to the plurality of locations divided along the axial direction of the annular component. It becomes.

Next, the invention described in claim 9 is the invention described in any one of claims 6 to 8, wherein the outer diameter surface of the annular component, the inner diameter surface of the annular component, and the annular component At least one of the upper end surface and the lower end surface is subjected to high-frequency heat treatment at a plurality of locations set along the circumferential direction of the annular component.
According to the present invention, at least one of the outer diameter surface, inner diameter surface, upper end surface, and lower end surface of the annular component is subjected to high-frequency heat treatment at a plurality of locations set along the circumferential direction of the annular component.
For this reason, it becomes possible to heat up the surface of the annular component in a plurality of locations set along the circumferential direction of the annular component in a short time.

Next, an invention described in claim 10 is the invention described in any one of claims 6 to 9, wherein the surface of the support roller facing the annular part is defined as an inner diameter surface of the annular part. It is made to contact with the lower end surface of a cyclic | annular component in the state inclined below as it goes to the outer-diameter surface side from the side.
According to the present invention, the surface of the support roller facing the annular component is brought into contact with the lower end surface of the annular component while being inclined downwardly from the inner diameter surface side to the outer diameter surface side of the annular component.
For this reason, it becomes possible to make the state of expansion and contraction generated in the annular part whose temperature has changed uniform in the entire annular part.

Next, the invention described in claim 11 is a rolling bearing including an outer ring and an inner ring facing each other with a plurality of rolling elements interposed therebetween,
At least one of the outer ring and the inner ring is an annular part subjected to the high frequency heat treatment method according to any one of claims 6 to 10.
According to the present invention, the high-frequency heat treatment method according to any one of claims 6 to 10 is performed on at least one of an outer ring and an inner ring included in the rolling bearing.
For this reason, the rolling bearing provided with the annular component subjected to the high-frequency heat treatment method can obtain good toughness and durability, and the life of the rolling bearing can be extended.

  According to the present invention, since it is possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular component on the entire annular component, it is possible to perform high-frequency heat treatment on the entire annular component at a time. It becomes possible.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
First, a first embodiment of the present invention will be described with reference to the drawings.
(Configuration of induction heat treatment equipment)
First, the configuration of the present embodiment will be described with reference to FIGS.
FIG. 1 is a diagram showing a configuration of a high-frequency heat treatment apparatus 1 of the present embodiment. FIG. 2 is a top view of the high-frequency heat treatment apparatus 1 and a cross-sectional view taken along line AA.

As shown in FIG. 1, the high-frequency heat treatment apparatus 1 includes an annular component support portion 2, a heating coil 4, a high-frequency current power supply unit 6, three positioning rollers 8 a to 8 c, and a positioning roller pressing unit 10. This is an apparatus for performing high-frequency heat treatment on the annular part W to be heat-treated.
The annular part W is a member that is provided in a rolling bearing used in a steel rolling mill or the like, and is formed in an annular shape from a steel material such as carburized steel, such as an outer ring or an inner ring that faces each other with a plurality of rolling elements interposed therebetween. In the present embodiment, the case where the annular component W is a rolling bearing, specifically, an outer ring provided in a cylindrical roller bearing using cylindrical rollers as rolling elements will be described.

The annular component support part 2 is arranged radially with respect to the annular component W with the axis directed in the vertical direction, and is arranged radially below the annular component W so as to contact the lower end surface Wa of the annular component W. It has.
Each support roller 12 is formed in a cylindrical shape using a ceramic material. In addition, the material which forms the support roller 12 is not limited to this, For example, you may form using a metal material. Similarly, the shape of the support roller 12 is not limited to this, and may be formed in a conical shape, for example.

  The rotation axis RA of each support roller 12 is arranged radially about the central axis P of the annular part W when viewed from the axial direction of the annular part W. The intervals between the support rollers 12 are equal. That is, the rotation direction of each support roller 12 is a tangential direction with respect to the circumferential direction of the annular component W. Thereby, the annular component support part 2 supports the annular component W in a state where the axis is directed in the vertical direction from below so as to be rotatable around the central axis P of the annular component W. In FIG. 2, the rotation direction of the annular part W is indicated by an arrow CD.

Further, each support roller 12 has a surface 12a facing the annular component W of each support roller 12, that is, a contact surface with the annular component W, as viewed from the circumferential direction of the annular component W, and an inner diameter surface Wb of the annular component W. It arrange | positions so that it may incline below as it goes to the outer diameter surface Wc side.
The heating coil 4 includes an outer surface heating coil 14, an inner surface heating coil 16, an upper surface heating coil 18, and a lower surface heating coil 20 that are independent of each other. The outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20 are all formed in a plate shape. 2, illustration of the outer surface heating coil 14, the inner surface heating coil 16, and the upper surface heating coil 18 is omitted for the sake of explanation.

  Further, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18 and the lower end surface heating coil 20 are respectively supported by heating unit supporting means (not shown). The heating unit support means detachably supports the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20, and the distance and angle with respect to the annular component W. Supports adjustable.

  Further, the outer surface heating coil 14, the inner surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20 are arranged in the circumferential direction of the annular component W with respect to the annular component W supported by the annular component support portion 2. A part and a predetermined interval are arranged. The predetermined interval is determined in order to perform high-frequency heat treatment on the annular component W in a desired state in accordance with the shape and material of the annular component W, a high-frequency current supplied from the high-frequency power source to the outer surface heating coil 14, and the like. Adjust to an appropriate interval.

  Specifically, the outer diameter surface heating coil 14 is opposed to the outer diameter surface Wc of the annular component W, and the inner diameter surface heating coil 16 is opposed to the inner diameter surface of the annular component W. Further, the upper end surface heating coil 18 is opposed to the upper end surface Wd of the annular component W. The outer surface heating coil 14 and the inner surface heating coil 16, and the upper surface heating coil 18 and the lower surface heating coil 20 are arranged at positions displaced from each other along the circumferential direction of the annular component W.

The lower end surface heating coil 20 is opposed to the lower end surface Wa of the annular component W and is disposed between the adjacent support rollers 12. Further, the lower end surface heating coil 20 is disposed at a position overlapping the support roller 12 when viewed from the circumferential direction of the annular component W.
The high-frequency current feeding means 6 is connected to the outer surface heating coil 14, the inner surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20.

  The high-frequency current feeding means 6 includes a high-frequency power source (not shown), and a high-frequency current adjusted to an arbitrary frequency is supplied to the outer surface heating coil 14, the inner surface heating coil 16, the upper surface heating coil 18, and the like. Power is supplied to the lower end surface heating coils 20 respectively. The high frequency power source includes, for example, a thyristor inverter, a transistor inverter, and the like, and obtains a current from an AC commercial power source or the like via a power receiving panel. The high-frequency current feeding means 6 adjusts the frequency of the high-frequency current to an appropriate frequency in order to perform high-frequency heat treatment on the annular component W in a desired state according to the shape and material of the annular component W, a predetermined gap, and the like. To do.

Here, with reference to FIGS. 1 and 2, the reason why the configuration of the annular component support portion 2 includes a plurality of support rollers 12 as described above will be described with reference to FIGS. 3 and 4. FIG. .
FIG. 3 is a view showing the high-frequency heat treatment apparatus 1 of Comparative Example 1 with respect to the high-frequency heat treatment apparatus 1 of the present embodiment, and is a top view of the high-frequency heat treatment apparatus 1 and a cross-sectional view taken along line AA. Moreover, FIG. 4 is a figure which shows the high frequency heat processing apparatus 1 of the comparative example 2 with respect to the high frequency heat processing apparatus 1 of this embodiment, and is the top view of the high frequency heat processing apparatus 1, and an AA sectional view. In FIG. 3 and FIG. 4 and the following description, the same reference numerals are given to the same components as those of the high-frequency heat treatment apparatus 1 of the present embodiment.

  As shown in FIG. 3, in the high frequency heat treatment apparatus 1 of Comparative Example 1, the annular component W is installed on the annular support base 22, and the lower end surface heating coil 20 is disposed below the support base 22. is doing. That is, the support base 22 is interposed between the annular component W and the lower end surface heating coil 20. The support base 22 is formed using a nonmagnetic material such as stainless steel, and includes an actuator (not shown) and has a function of rotating the annular component W in the circumferential direction. In FIG. 3, the rotation direction of the annular component W and the support base 22 is indicated by an arrow CD.

  In the induction heat treatment apparatus 1 of the comparative example 1, since the support base 22 is interposed between the annular component W and the lower end surface heating coil 20, the lower end surface heating coil is compared with the induction heat treatment apparatus 1 of the present embodiment. As the heat loss of 20 increases, the transmission of power decreases. As a result, it becomes difficult to sufficiently quench the lower end surface Wa of the annular part W as compared with other surfaces, and thus it is difficult to obtain a desired quenching hardness for the entire annular part W. It is.

  On the other hand, as shown in FIG. 4, the high frequency heat treatment apparatus 1 of Comparative Example 2 has the annular component W installed on a support base 22 in which a plurality of gaps are formed, and supports the lower end surface heating coil 20. It is arranged below the table 22. That is, a gap is formed between the annular component W and the lower end surface heating coil 20 so as to interpose the support base 22, and the annular component W and the lower end surface heating are formed at positions where a plurality of gaps are formed. A support base 22 is not interposed between the coil 20 and the coil 20. The support base 22 is formed using a nonmagnetic material such as stainless steel, like the high-frequency heat treatment apparatus 1 of Comparative Example 1, and includes an actuator (not shown) and has a function of rotating the annular component W in the circumferential direction. . Further, in FIG. 4, the rotation direction of the annular part W and the support base 22 is indicated by an arrow CD.

  In the induction heat treatment apparatus 1 of the comparative example 2, the portion corresponding to the position where the gap is formed in the lower end surface Wa of the annular component W can be sufficiently quenched, so that the desired quenching hardness is achieved. It is possible to obtain However, in the lower end surface Wa of the annular part W, the portion installed on the support base 22 is difficult to sufficiently quench, so that a soft tissue remains, and the desired quenching is performed. It is difficult to obtain hardness. Thereby, it is difficult to form a homogeneous structure on the entire annular part W.

Hereinafter, the description returns to FIGS. 1 and 2.
All of the three positioning rollers 8a to 8c are arranged on the outer diameter surface Wc side of the annular component W. 2, illustration of each positioning roller 8a-8c is abbreviate | omitted for description.
The three positioning rollers 8 a to 8 c are arranged at equal intervals along the circumferential direction of the annular component W. That is, the three positioning rollers 8a to 8c are arranged so as to press the three pressing positions 24a to 24c set on the outer diameter surface Wc of the annular part W as shown in FIG. Accordingly, the three positioning rollers 8a to 8c are arranged so as to form an equilateral triangle centered on the central axis P of the annular part W when viewed from the axial direction of the annular part W, as shown in FIG. It is. FIG. 5 is a top view of the high-frequency heat treatment apparatus 1. In the drawing, illustrations other than the annular part W and the three positioning rollers 8a to 8c are omitted for the sake of explanation.

The positioning roller pressing means 10 includes an actuator (not shown) having a cylinder or the like and movable in the radial direction of the annular part W, and a pressing control unit (not shown) for controlling the driving state of the actuator. Yes.
The pressing controller is configured to position each positioning roller 8a with respect to the outer diameter surface Wc of the annular component W so that the intervals between the annular component W and the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at predetermined intervals. ˜8c is pressed in a line contact state. Specifically, the interval between the outer diameter surface Wc of the annular component W and the outer diameter surface heating coil 14 and the interval between the inner diameter surface Wb of the annular component W and the inner diameter surface heating coil 16 are maintained at a predetermined interval. Next, the positioning rollers 8a to 8c are pressed against the outer diameter surface Wc of the annular component W. In FIG. 5, the pressing directions in which the three positioning rollers 8 a to 8 c press the outer diameter surface Wc of the annular component W are indicated by arrows FD, respectively.

  Further, the press control unit keeps the intervals between the annular component W and the outer surface heating coil 14 and the inner surface heating coil 16 at a predetermined interval in accordance with the thermal expansion generated in the heated annular component W. Next, the positioning rollers 8a to 8c are pressed against the outer diameter surface Wc of the annular component W. The amount of movement of each positioning roller 8a-8c used for this may be calculated according to the material, shape, processing time, etc. of the annular part W, or may be calculated based on data stored in advance in a database.

Here, the reason why the intervals between the annular component W and the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at a predetermined distance will be described.
When the annular component W is placed on the plurality of support rollers 12 and the annular component W is rotated around the central axis P, the annular component W may be rotated in an eccentric state from the central axis P. In general, induction heating by high frequency heat treatment becomes stronger as the distance between the annular component W and the heating coil becomes shorter. Therefore, when the high frequency heat treatment is performed on the annular component W rotating eccentrically from the central axis P, the annular component W is performed. The inner diameter surface Wb and the outer diameter surface Wc may be non-uniform high-frequency heat treatment. Specifically, the inner diameter surface Wb and the outer diameter surface Wc of the annular part W may be in a state in which an overheated tissue, an underheated tissue, and a normally heated tissue are mixed.
Therefore, as described above, the intervals between the annular component W and the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at predetermined intervals, so that the inner diameter surface Wb and the outer diameter surface Wc of the annular component W are maintained. On the other hand, uniform high-frequency heat treatment can be performed.

Hereinafter, the description returns to FIGS. 1 and 2.
Of the three positioning rollers 8 a to 8 c, the positioning roller 8 a, that is, one positioning roller 8 includes a positioning roller rotating means 26.
The positioning roller rotating means 26 includes an actuator (not shown) such as a motor that can be driven to rotate, and rotates the positioning roller 8a while pressing the outer diameter surface Wc of the annular component W. Thereby, the positioning roller 8a rotates while pressing the outer diameter surface Wc of the annular part W, and rotates the annular part W around the central axis P.

(High-frequency heat treatment method)
Next, a high-frequency heat treatment method (hereinafter referred to as “high-frequency heat treatment method”) using the high-frequency heat treatment apparatus 1 having the above configuration will be described with reference to FIGS. 1, 2, and 5.
In the high frequency heat treatment method of the present embodiment, first, the annular component support portion 2 supports the annular component W with its axis directed in the vertical direction from below. Specifically, after the upper end surface heating coil 18 is removed from above the support roller 12 by the heating unit support means, the inside of the three positioning rollers 8a to 8c and the outer surface heating coil 14 and the inner surface heating coil. The annular component W is disposed between the support roller 12 and the annular component W. Thereby, the annular component W with the shaft directed in the vertical direction is supported by the annular component support portion 2 from below so as to be rotatable around the central axis P of the annular component W.

  At this time, each support roller 12 is inclined so that the contact surface with the annular component W is inclined downward from the inner diameter surface Wb side to the outer diameter surface Wc side of the annular component W when viewed from the circumferential direction of the annular component W. It is arranged in. For this reason, the surface of the support roller 12 facing the annular part W is in contact with the lower end surface Wa of the annular part W while being inclined downwardly from the inner diameter face Wb side to the outer diameter face Wc side of the annular part W. Will be allowed to.

  After the annular part W is supported from below by the annular part support part 2 so as to be rotatable around the central axis P of the annular part W, the upper end surface heating coil 18 is arranged above the annular part W by the heating part support means. Then, the upper end surface Wd of the annular component W is opposed to the annular component W. Thereby, the upper end surface heating coil 18 and the lower end surface heating coil 20 are arranged with respect to the annular component W at a predetermined interval from a part of the circumferential direction of the annular component W, and the annular component W and the upper end surface heating are arranged. The distance between the coil 18 and the lower end surface heating coil 20 is kept constant.

  Next, the actuator that can move in the radial direction of the annular part W is controlled by the pressing control unit, and the three positioning rollers 8a to 8c are moved toward the outer diameter surface Wc of the annular part W, and the positioning rollers 8a to 8c are moved. The outer diameter surface Wc of the annular component W is pressed by 8c. Thereby, the positioning rollers 8a to 8c press the three pressing positions 24a to 24c set on the outer diameter surface Wc of the annular part W.

  At this time, the pressing control unit determines that the distance between the outer diameter surface Wc of the annular component W and the outer diameter surface heating coil 14 and the interval between the inner diameter surface Wb of the annular component W and the inner diameter surface heating coil 16 are predetermined intervals. The positioning rollers 8a to 8c are pressed against the outer diameter surface Wc of the annular component W so as to be held. Thereby, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are arranged with respect to the annular component W at a predetermined distance from a part of the circumferential direction of the annular component W, and the annular component W and the outer diameter are arranged. The distance between the surface heating coil 14 and the inner surface heating coil 16 is kept at a constant distance.

In a state where the outer diameter surface Wc of the annular component W is pressed by the positioning rollers 8a to 8c, the actuator provided in the positioning roller rotating means 26 is rotationally driven to rotate the positioning roller 8a. Thereby, the positioning roller 8a is rotated while pressing the outer diameter surface Wc of the annular part W, and the annular part W is rotated around the central axis P.
Here, in this embodiment, the rotational speed at which the annular part W is rotated about the central axis P is the rotational speed at which the rotational speed of the annular part W is within the range of 5 to 100 min ⁻¹ , and the rotational speed of the positioning roller 8a. Is a speed corresponding to the rotational speed of the annular part W.

  Further, the high-frequency current adjusted by the high-frequency current power supply means 6 to an arbitrary frequency in a state where the outer diameter surface Wc of the annular component W is pressed by the positioning rollers 8a to 8c, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16 is used. The upper end surface heating coil 18 and the lower end surface heating coil 20 are supplied with power. Thereby, while the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, the lower end surface heating coil 20, and the annular component W are relatively moved along the circumferential direction of the annular component W, the annular component The whole W is heated. Specifically, when a high frequency current is supplied to the outer surface heating coil 14, the inner surface heating coil 16, the upper surface heating coil 18 and the lower surface heating coil 20, an alternating magnetic flux is generated and the annular component W is induction-heated. The That is, due to hysteresis loss, eddy current loss, and the like due to changes in magnetic flux passing through the annular component W, a heat generation phenomenon occurs in the annular component W, and the annular component W is heated according to the frequency of the high-frequency current and the input power.

Here, in the present embodiment, the frequency of the high-frequency current adjusted by the high-frequency current power supply means 6 is set in the range of 1 to 50 kHz. Accordingly, in the present embodiment, when the frequency of the high-frequency current is in the range of 1 to 50 kHz, the temperature for heating the annular part W is in the range of 800 to 1100 ° in the present embodiment. Set to distance. In addition, the temperature of the annular component W is measured using, for example, temperature measuring means formed by a radiation thermometer.
The annular component W is rotated about the central axis P, and a high frequency current is supplied to the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20, so Heat treatment is performed.

Here, in this embodiment, the processing time for performing the high-frequency heat treatment on the annular component W is set within a range of 10 seconds to 15 minutes. Specifically, the induction heat treatment is continued within a range of 10 seconds to 15 minutes from the time when the temperature for heating the annular component W is within a range of 800 to 1100 °. The processing time is adjusted according to the shape and material of the annular part W, the predetermined gap, the frequency of the high-frequency current, etc., in order to perform the high-frequency heat treatment on the annular part W in a desired state.
In the present embodiment, after the induction heat treatment is performed on the annular part W under the above-described conditions, the annular part W is quenched by using an oil, an aqueous solution, or the like to quench the annular part W. This quenching is performed not only on the surface of the annular part W but also on the entire core.

  And in this embodiment, after performing hardening with respect to the annular component W, while rotating the annular component W to the surroundings of the central axis P similarly to the high frequency heat processing mentioned above, the outer surface heating coil 14 and the inner surface heating coil 16 are rotated. The high-frequency current is supplied to the upper end surface heating coil 18 and the lower end surface heating coil 20. As a result, the annular part W is tempered. At this time, the frequency of the high-frequency current is set to a height at which the temperature for heating the annular part W is in the range of 120 to 350 °, and the processing time for tempering the annular part W is in the range of 1 minute to 3 hours. Within. However, tempering in a tempering furnace may be performed.

(Effects of the first embodiment)
Therefore, in the induction heat treatment apparatus 1 of the present embodiment, the annular component W is rotatably supported around the central axis P by the plurality of support rollers 12 arranged radially below the annular component W, and the lower end surface heating coil 20 is supported. Between the adjacent support rollers 12.
For this reason, it becomes possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular component W on the entire lower end surface Wa of the annular component W, and in the circumferential direction of the annular component W with respect to the entire annular component W. Along with this, uniform high-frequency heat treatment can be performed.
As a result, the entire annular part W can be subjected to high-frequency heat treatment at a time, and it is possible to suppress the occurrence of cracks in the annular part W, a decrease in hardness, and a decrease in retained austenite.

Moreover, in the high frequency heat processing apparatus 1 of this embodiment, since the cyclic | annular component W is supported by the some support roller 12 from the downward direction, compared with the case where the cyclic | annular component W is supported by a plate-shaped member, each cyclic | annular component W and each The contact area with the support roller 12 can be reduced.
As a result, it becomes possible to suppress heat loss of the annular part W, and it becomes possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular part W on the entire lower end surface Wa of the annular part W. It becomes possible to shorten the time for raising the temperature of the annular part W.

Furthermore, in the high frequency heat treatment apparatus 1 of the present embodiment, the plurality of support rollers 12 are formed using a ceramic material.
As a result, even when the annular component W is subjected to high-frequency heat treatment and the temperature of the annular component W is increased, the deformation of the support roller 12 due to this heat can be suppressed.
In addition, in the high frequency heat treatment apparatus 1 of the present embodiment, the three positioning rollers 8a to 8c arranged on the outer diameter surface Wc side of the annular component W are connected to the annular component W, the outer diameter surface heating coil 14, and the inner diameter surface heating coil 16. The annular part W is pressed so that the distance between the two holds a predetermined distance. Further, the positioning roller 8a is rotated so that the annular component W rotates around the central axis P.

For this reason, it becomes possible to hold | maintain the space | interval of the annular component W, the outer diameter surface heating coil 14, and the inner diameter surface heating coil 16 at a fixed distance, and with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W, A uniform high-frequency heat treatment can be performed along the circumferential direction of the annular component W.
As a result, a uniform heat treatment structure can be obtained along the circumferential direction of the annular component W with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W. It is possible to perform high-frequency heat treatment at a time.

Moreover, in the high frequency heat processing apparatus 1 of this embodiment, the opposing surface with the annular component W of the support roller 12 is made to incline below as it goes to the outer diameter surface Wc side from the inner diameter surface Wb side of the annular component W.
For this reason, the support roller 12 and the lower end surface Wa of the annular component W are in point contact, and the support roller 12 and the annular component are compared with the case where the support roller 12 and the lower end surface Wa of the annular component W are in line contact. It is possible to reduce the contact area with W.
As a result, the state of expansion and contraction occurring in the annular part W whose temperature has changed can be made uniform throughout the annular part W, and heat loss of the annular part W can be suppressed.

In the high-frequency heat treatment method of the present embodiment, a high-frequency current is applied to the lower end surface heating coil 20 disposed between the adjacent support rollers 12 while rotating the annular part W around the central axis P by the plurality of support rollers 12. Power is supplied and high-frequency heat treatment is performed on the lower end surface Wa of the annular part W.
For this reason, it becomes possible to perform uniform high-frequency heat treatment along the circumferential direction of the annular component W on the entire lower end surface Wa of the annular component W, and in the circumferential direction of the annular component W with respect to the entire annular component W. Along with this, uniform high-frequency heat treatment can be performed.
As a result, it is possible to perform high-frequency heat treatment on the entire annular part W at a time.

Further, in the high frequency heat treatment method of the present embodiment, while the annular component W is rotated around the central axis P, the intervals between the annular component W, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at a predetermined interval. In this way, the outer diameter surface Wc of the annular component W is pressed.
For this reason, it becomes possible to hold | maintain the space | interval of the annular component W, the outer diameter surface heating coil 14, and the inner diameter surface heating coil 16 at a fixed distance, and with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W, A uniform high-frequency heat treatment can be performed along the circumferential direction of the annular component W.
As a result, a uniform heat treatment structure can be obtained along the circumferential direction of the annular component W with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W.

Further, in the high frequency heat treatment method of the present embodiment, the surface of the support roller 12 facing the annular component W is inclined downwardly from the inner diameter surface Wb side of the annular component W toward the outer diameter surface Wc side. The lower end surface Wa of the component W is brought into contact.
For this reason, the support roller 12 and the lower end surface Wa of the annular component W are in point contact, and the support roller 12 and the annular component are compared with the case where the support roller 12 and the lower end surface Wa of the annular component W are in line contact. It is possible to reduce the contact area with W.
As a result, the state of expansion and contraction occurring in the annular part W whose temperature has changed can be made uniform throughout the annular part W, and heat loss of the annular part W can be suppressed.

Further, in the rolling bearing including the annular component W subjected to the high frequency heat treatment method of the present embodiment, uniform high frequency heat treatment can be performed on the entire lower end surface Wa of the annular component W along the circumferential direction of the annular component W. It becomes possible.
For this reason, since it becomes possible to perform uniform induction heat treatment along the circumferential direction of the annular part W on the entire annular part W, the induction heat treatment is performed once on the entire annular part W. Is possible.
As a result, it becomes possible to add good toughness, durability, etc. to the annular part W, so that the life of the rolling bearing can be extended. Accordingly, it is possible to improve the durability of a machine tool or the like using a rolling bearing, and it is possible to extend the life of the machine tool, thereby reducing the maintenance cost.

(Application example)
In the high-frequency heat treatment apparatus 1 of the present embodiment, all the three positioning rollers 8a to 8c are arranged on the outer diameter surface Wc side of the annular component W, but the present invention is not limited to this. That is, as shown in FIG. 6, all of the three positioning rollers 8 a to 8 c may be arranged on the inner diameter surface Wb side of the annular component W. In this case, the pressing control unit positions each position relative to the inner diameter surface Wb of the annular component W so that the intervals between the annular component W and the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at predetermined intervals. The rollers 8a to 8c are pressed in a line contact state. FIG. 6 is a view showing a modification of the high frequency heat treatment apparatus 1. In FIG. 6, as in FIG. 5, the pressing directions in which the three positioning rollers 8 a to 8 c press the inner diameter surface Wb of the annular component W are indicated by arrows FD, respectively.

Moreover, in the high frequency heat processing apparatus 1 of this embodiment, although it was set as the structure provided with the three positioning rollers 8a-8c, it is not limited to this, It is good also as a structure provided with four or more positioning rollers 8a-8c. In short, what is necessary is just a structure provided with the three or more positioning rollers 8a-8c.
Furthermore, in the high frequency heat treatment apparatus 1 of the present embodiment, only one positioning roller 8a out of the three positioning rollers 8a to 8c is configured to include the positioning roller rotating means 26. However, the present invention is not limited to this. That is, for example, all of the three positioning rollers 8 a to 8 c may be configured to include the positioning roller rotating means 26. The point is that one or more positioning rollers 8 among the three or more positioning rollers 8 a to 8 c may be configured to include the positioning roller rotating means 26.

  Moreover, in the high frequency heat processing apparatus 1 of this embodiment, although the positioning roller 8a was set as the structure provided with the positioning roller rotating means 26, it is not limited to this, It is good also as a structure which is not provided with the positioning roller rotating means 26. . In this case, for example, an actuator that can be driven to rotate is connected to at least one of the support rollers 12, and the support roller 12 is rotated by the actuator to rotate the annular component W around the central axis P. .

  Moreover, in the high frequency heat processing apparatus 1 of this embodiment, although it was set as the structure provided with the positioning roller 8, it is not limited to this, It is good also as a structure which is not provided with the positioning roller 8. FIG. However, like the high-frequency heat treatment apparatus 1 of this embodiment, the configuration including the positioning roller 8 makes the intervals between the annular component W, the outer surface heating coil 14 and the inner surface heating coil 16 constant. Since it becomes easy to hold | maintain, it is suitable.

  In addition, in the induction heat treatment apparatus 1 of the present embodiment, when each support roller 12 is viewed from the circumferential direction of the annular component W, the facing surface 12a facing the annular component W is an outer diameter surface from the inner diameter surface Wb side of the annular component W. Although it arrange | positions so that it may incline below as it goes to the Wc side, it is not limited to this. That is, for example, when each support roller 12 is viewed from the circumferential direction of the annular component W, the facing surface 12a of the annular component W is parallel to the lower end surface Wa of the annular component W, that is, each support roller 12 and the annular component W. You may arrange | position so that lower end surface Wa of may be in line contact. However, the arrangement of the respective support rollers 12 as in the high-frequency heat treatment apparatus 1 of the present embodiment makes it possible to make the entire annular part W uniform and to suppress heat loss of the annular part W. Therefore, it is preferable.

  Further, in the high frequency heat treatment apparatus 1 of the present embodiment, the annular part W is an outer ring provided in the cylindrical roller bearing. However, the present invention is not limited to this, and the annular part W may be an inner ring provided in the cylindrical roller bearing. In short, the annular component W may be at least one of an outer ring and an inner ring included in the cylindrical roller bearing. In this case, the position where the positioning roller 8 is arranged is not limited to the outer diameter surface Wc side of the annular component W as shown in FIG. 7A, but is shown by a broken line in FIG. 7B. Alternatively, the position at which the positioning roller 8 is disposed may be on the inner diameter surface Wb side of the annular component W. In the case where the annular part W is an inner ring provided in the cylindrical roller bearing, as shown in FIG. 7B, the outer diameter surface Wc is formed in a more complicated shape than the inner diameter surface Wb. Due to that.

Further, even when the annular part W is an outer ring and an inner ring included in the tapered roller bearing, as shown in FIGS. 7 (c) and 7 (d), the positioning roller 8 has an outer diameter for the outer ring. The positioning roller 8 is disposed on the inner diameter surface Wb side with respect to the inner ring.
Further, as shown by broken lines in FIGS. 7E and 7F, when the annular component W is an outer ring and an inner ring included in the deep groove ball bearing, the positioning roller 8 is located with respect to the outer ring and the inner ring. Is arranged on the inner diameter surface Wb side.

Further, as shown in FIGS. 7 (g) and 7 (h), when the annular component W is an outer ring and an inner ring included in a self-aligning roller bearing, The positioning roller 8 is arranged on the outer diameter surface Wc side, and the positioning roller 8 is arranged on the inner diameter surface Wb side for the inner ring.
However, as indicated by solid lines in FIGS. 7B, 7E, and 7F, the outer surface Wc and the inner surface Wb of the inner ring of the cylindrical roller bearing, the outer ring and the inner ring of the deep groove ball bearing, etc. In both cases, the positioning roller 8 may be arranged on the outer diameter surface Wc side. This is because the arrangement of the positioning roller 8 on the outer diameter surface Wc side can simplify the configuration of the high-frequency heat treatment apparatus 1 compared to the case where the positioning roller 8 is arranged on the inner diameter surface Wb side. In addition, it is easy to apply to the small-diameter annular part W. FIG. 7 is a view showing a variation of the bearing including the annular component W.

  Moreover, in the high frequency heat processing apparatus 1 of this embodiment, although the annular component W was made into the outer ring | wheel with which a cylindrical roller bearing is provided, it is not limited to this. That is, the annular component W may be a coupling used for a driving force transmission system of a vehicle, for example, in addition to the outer ring and the inner ring included in the cylindrical roller bearing. In short, the annular component W may be a component formed in an annular shape or a cylindrical shape using a metal material.

  In addition, in the high frequency heat treatment apparatus 1 of the present embodiment, the heating coil 4 includes the outer surface heating coil 14, the inner surface heating coil 16, the upper surface heating coil 18, and the lower surface heating coil 20 that are independent of each other. However, the present invention is not limited to this. That is, for example, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, and the upper end surface heating coil 18 may be configured as a U-shaped integrated coil, and the lower end surface heating coil 20 may be independent from the integrated coil. Good.

  Further, in the high frequency heat treatment apparatus 1 of the present embodiment, the outer surface heating coil 14 and the inner surface heating coil 16 are arranged at positions displaced from each other along the circumferential direction of the annular component W, but the present invention is limited to this. It is not a thing. That is, as shown in FIG. 8, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 may be disposed at positions facing each other with the annular component W interposed therebetween. FIG. 8 is a view showing a modification of the high-frequency heat treatment apparatus 1, and is a top view of the high-frequency heat treatment apparatus 1 and a cross-sectional view taken along line AA. Further, in FIG. 8, illustrations other than the annular component W, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20 are omitted for explanation.

  In the high frequency heat treatment method of the present embodiment, the three pressing positions 24a to 24c set on the outer diameter surface Wc of the annular part W are pressed by the three positioning rollers 8a to 8c. However, the present invention is not limited to this. Absent. That is, for example, when four or more positioning rollers 8 are provided, the four pressing positions 24 may be pressed. In short, it is only necessary to press three or more pressing positions 24 so that the intervals between the annular component W, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are maintained at predetermined intervals.

  Further, in the high frequency heat treatment method of the present embodiment, the surface of each support roller 12 facing the annular part W is inclined downward from the inner diameter surface Wb side to the outer diameter surface Wc side of the annular part W. Although it contacts with the lower end surface Wa of the annular component W, it is not limited to this. That is, for example, the support rollers 12 and the lower end surface Wa of the annular component W may be arranged to be in line contact. However, the contact between each support roller 12 and the annular part W as in the high-frequency heat treatment method of the present embodiment makes it possible to make the entire annular part W uniform and suppress heat loss of the annular part W. This is preferable.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings.
(Configuration of induction heat treatment equipment)
First, the configuration of the present embodiment will be described with reference to FIG. Detailed description of the same configuration as that of the first embodiment described above will be omitted.

FIG. 9 is a diagram showing a configuration of the high-frequency heat treatment apparatus 1 of the present embodiment, and is a top view, a cross-sectional view taken along the line AA, and a cross-sectional view taken along the line BB.
As shown in FIG. 9, the high-frequency heat treatment apparatus 1 of the present embodiment has the same configuration as that of the first embodiment described above, except for the configuration of the outer surface heating coil 14 and the inner surface heating coil 16. 9, illustrations other than the annular component W, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20 are omitted for the sake of explanation.

  The outer surface heating coil 14 is divided into two along the axial direction of the annular component W. In the drawings and the following description, out of the outer surface heating coil 14 divided into two, the outer surface heating coil 14 disposed on the upper end surface Wd side of the annular component W is referred to as the outer surface heating coil 14a. The outer diameter surface heating coil 14 described and disposed on the lower end surface Wa side of the annular component W is referred to as an outer diameter surface heating coil 14b.

The outer diameter surface heating coil 14a and the outer diameter surface heating coil 14b are formed in the same shape.
The outer diameter surface heating coil 14 a faces the upper half portion of the outer diameter surface Wc of the annular component W. The outer diameter surface heating coil 14 b faces the lower half portion of the outer diameter surface Wc of the annular component W. Thereby, the outer diameter surface heating coil 14a and the outer diameter surface heating coil 14b, that is, the outer diameter surface heating coil 14 are opposed to all the portions with respect to the outer diameter surface Wc of the annular component W.

  The inner surface heating coil 16 is divided into two along the axial direction of the annular component W, like the outer surface heating coil 14. In the drawings and the following description, the inner surface heating coil 16 disposed on the upper end surface Wd side of the annular component W among the inner surface heating coils 16 divided into two is described as an inner surface heating coil 16a. The inner diameter surface heating coil 16 disposed on the lower end surface Wa side of the annular component W is referred to as an inner diameter surface heating coil 16b.

The inner surface heating coil 16a and the inner surface heating coil 16b are formed in the same shape.
The inner surface heating coil 16 a faces the upper half of the inner surface Wb of the annular component W. The inner surface heating coil 16 b faces the lower half portion of the inner surface Wb of the annular component W. Thereby, the inner diameter surface heating coil 16a and the inner diameter surface heating coil 16b, that is, the inner diameter surface heating coil 16 are opposed to all the portions with respect to the inner diameter surface Wb of the annular component W.
Other configurations are the same as those of the first embodiment described above.

(High-frequency heat treatment method)
Next, a high-frequency heat treatment method using the high-frequency heat treatment apparatus 1 having the above-described configuration will be described with reference to FIG. In the following description, differences from the above-described first embodiment will be mainly described.
In the high frequency heat treatment method of the present embodiment, a high frequency current adjusted to an arbitrary frequency while rotating the annular component W supported from below by the annular component support portion 2 around the central axis P is applied to the outer surface heating coil 14a. , 14b and the inner surface heating coils 16a, 16b. Accordingly, the outer diameter surface Wc and the inner diameter surface Wb of the annular component W are heated at a plurality of locations divided along the axial direction of the annular component W with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W. Then, high frequency heat treatment is performed.
Other processes are the same as those in the first embodiment described above.

(Effect of the second embodiment)
Therefore, in the high frequency heat treatment apparatus 1 of the present embodiment, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are divided along the axial direction of the annular component W.
For this reason, the surface of the annular component W facing the divided outer diameter surface heating coil 14 and inner diameter surface heating coil 16, specifically, the state of the high frequency heat treatment for the outer diameter surface Wc and the inner diameter surface Wb of the annular component W, It becomes possible to control each part divided along the axial direction of the annular part W.
As a result, the state of the high frequency heat treatment for the outer diameter surface Wc and the inner diameter surface Wb of the annular component W can be controlled with high accuracy, and the accuracy of the high frequency heat treatment for the annular component W can be improved.

Further, in the high frequency heat treatment method of the present embodiment, the high frequency heat treatment is performed on the outer diameter surface Wc and the inner diameter surface Wb of the annular component W at a plurality of locations divided along the axial direction of the annular component W.
For this reason, the surface of the annular component W divided into a plurality of locations along the axial direction of the annular component W, specifically, the state of the high-frequency heat treatment on the outer diameter surface Wc and the inner diameter surface Wb of the annular component W is defined as the annular component W. It becomes possible to control every part corresponding to a plurality of parts divided along the axial direction.
As a result, the state of the high frequency heat treatment for the outer diameter surface Wc and the inner diameter surface Wb of the annular component W can be controlled with high accuracy, and the accuracy of the high frequency heat treatment for the annular component W can be improved.

(Application example)
In the high-frequency heat treatment apparatus 1 of the present embodiment, the outer diameter surface heating coil 14 and the inner diameter surface heating coil 16 are divided along the axial direction of the annular component W. However, the present invention is not limited to this. That is, at least one of the outer surface heating coil 14 and the inner surface heating coil 16 may be divided along the axial direction of the annular component W.
Further, in the high frequency heat treatment method of the present embodiment, the high frequency heat treatment is performed on the outer diameter surface Wc and the inner diameter surface Wb of the annular component W at a plurality of locations divided along the axial direction of the annular component W. Not what you want. That is, high-frequency heat treatment may be performed at a plurality of locations divided along the axial direction of the annular component W on at least one of the outer diameter surface Wc and the inner diameter surface Wb of the annular component W.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings.
(Configuration of induction heat treatment equipment)
First, the configuration of the present embodiment will be described with reference to FIG. Detailed description of the same configuration as that of the first embodiment described above will be omitted.

FIG. 10 is a diagram showing the configuration of the high-frequency heat treatment apparatus 1 of the present embodiment, and is a top view, a cross-sectional view taken along the line AA, a cross-sectional view taken along the line BB, and a cross-section taken along the line CC FIG.
As shown in FIG. 10, the high frequency heat treatment apparatus 1 of the present embodiment has the same configuration as that of the first embodiment described above, except for the configuration of the heating coil 4. In FIG. 10, illustrations other than the annular component W, the outer diameter surface heating coil 14, the inner diameter surface heating coil 16, the upper end surface heating coil 18, and the lower end surface heating coil 20 are omitted for explanation.

  The outer surface heating coil 14 is divided into three along the axial direction of the annular component W. In the drawings and the following description, out of the three outer diameter surface heating coils 14, the outer diameter surface heating coil 14 disposed on the upper end surface Wd side of the annular component W is referred to as the outer diameter surface heating coil 14a. The outer diameter surface heating coil 14 described and disposed on the lower end surface Wa side of the annular component W is referred to as an outer diameter surface heating coil 14b. Of the outer surface heating coil 14 divided into three, the outer surface heating coil 14 disposed at a height between the outer surface heating coil 14a and the outer surface heating coil 14b is used as the outer surface heating. It is described as a coil 14c.

The outer surface heating coil 14a, the outer surface heating coil 14b, and the outer surface heating coil 14c are all formed in the same shape. Further, the outer diameter surface heating coil 14 a, the outer diameter surface heating coil 14 b, and the outer diameter surface heating coil 14 c are arranged at equal intervals along the circumferential direction of the annular component W.
The outer diameter surface heating coil 14a is opposed to an upper part of the outer diameter surface Wc of the annular component W, which is obtained by dividing the outer diameter surface Wc of the annular component W into three equal parts. Out of the outer diameter surface Wc of the component W, it faces the lower part of the outer diameter surface Wc of the annular component W divided into three equal parts. Further, the outer diameter surface heating coil 14c is opposed to a central portion of the outer diameter surface Wc of the annular component W that is obtained by dividing the outer diameter surface Wc of the annular component W into three equal parts. Thereby, the outer diameter surface heating coil 14a, the outer diameter surface heating coil 14b, and the outer diameter surface heating coil 14c, that is, the outer diameter surface heating coil 14 is opposed to all the parts with respect to the outer diameter surface Wc of the annular component W. is doing.

  The inner surface heating coil 16 is divided into three along the axial direction of the annular part W. In the drawings and the following description, the inner surface heating coil 16 arranged on the upper end surface Wd side of the annular component W among the inner surface heating coils 16 divided into three is described as the inner surface heating coil 16a. The inner diameter surface heating coil 16 disposed on the lower end surface Wa side of the annular component W is referred to as an inner diameter surface heating coil 16b. Of the inner surface heating coil 16 divided into three, the inner surface heating coil 16 disposed at a height between the inner surface heating coil 16a and the inner surface heating coil 16b is referred to as an inner surface heating coil 16c. .

The inner surface heating coil 16a, the inner surface heating coil 16b, and the inner surface heating coil 16c are all formed in the same shape. The inner surface heating coil 16a, the inner surface heating coil 16b, and the inner surface heating coil 16c are arranged at equal intervals along the circumferential direction of the annular component W.
The inner surface heating coil 16a is opposed to an upper part of the inner surface Wb of the annular component W, which is obtained by dividing the inner surface Wb of the annular component W into three equal parts. Out of the surface Wb, it opposes the lower portion obtained by dividing the inner diameter surface Wb of the annular part W into three equal parts. The inner surface heating coil 16c is opposed to a central portion of the inner surface Wb of the annular component W, which is obtained by dividing the inner surface Wb of the annular component W into three equal parts. Thereby, the inner surface heating coil 16a, the inner surface heating coil 16b, and the inner surface heating coil 16c, that is, the inner surface heating coil 16 are opposed to all the portions with respect to the inner surface Wb of the annular component W.

  The upper end surface heating coil 18 and the lower end surface heating coil 20 are arranged three by three along the circumferential direction of the annular component W. In the drawings and the following description, of the three upper end surface heating coils 18, the upper end surface heating coil 18 disposed between the outer diameter surface heating coil 14a and the outer diameter surface heating coil 14b is replaced with the upper end surface heating coil. This is described as 18a. Further, the upper end surface heating coil 18 disposed between the outer diameter surface heating coil 14b and the outer diameter surface heating coil 14c is referred to as an upper end surface heating coil 18b, and the outer diameter surface heating coil 14a and the outer diameter surface heating coil 14c. The upper end surface heating coil 18 disposed between the upper end surface heating coil 18 and the upper end surface heating coil 18 is described as an upper end surface heating coil 18c. The same applies to the lower end surface heating coil 20.

The upper end surface heating coil 18a, the upper end surface heating coil 18b, and the upper end surface heating coil 18c are all formed in the same shape. Further, the upper end surface heating coil 18 a, the upper end surface heating coil 18 b, and the upper end surface heating coil 18 c are arranged at equal intervals along the circumferential direction of the annular component W.
The lower end surface heating coil 20a, the lower end surface heating coil 20b, and the lower end surface heating coil 20c are all formed in the same shape. Further, the lower end surface heating coil 20a, the lower end surface heating coil 20b, and the lower end surface heating coil 20c are arranged at equal intervals along the circumferential direction of the annular component W.
Other configurations are the same as those of the first embodiment described above.

(High-frequency heat treatment method)
Next, a high-frequency heat treatment method using the high-frequency heat treatment apparatus 1 having the above configuration will be described with reference to FIG. In the following description, differences from the above-described first embodiment will be mainly described.
In the high frequency heat treatment method of the present embodiment, a high frequency current adjusted to an arbitrary frequency while rotating the annular component W supported from below by the annular component support portion 2 around the central axis P is applied to the outer surface heating coil 14a. To 14c and the inner surface heating coils 16a to 16c. Accordingly, the outer diameter surface Wc and the inner diameter surface Wb of the annular component W are heated at a plurality of locations divided along the axial direction of the annular component W with respect to the outer diameter surface Wc and the inner diameter surface Wb of the annular component W. Then, high frequency heat treatment is performed.

Further, a high-frequency current adjusted to an arbitrary frequency is supplied to the upper end surface heating coils 18a to 18c and the lower end surface heating coils 20a to 20c while rotating the annular part W around the central axis P. As a result, the upper end surface Wd and the lower end surface Wa of the annular part W are heated at three locations set along the circumferential direction of the annular part W with respect to the upper end face Wd and the lower end face Wa of the annular part W. Heat treatment is performed.
Other processes are the same as those in the first embodiment described above.

(Effect of the third embodiment)
Therefore, in the high frequency heat treatment apparatus 1 of this embodiment, the outer diameter surface heating coils 14a to 14c, the inner diameter surface heating coils 16a to 16c, the upper end surface heating coils 18a to 18c, and the lower end surface heating coils 20a to 20c are respectively formed into annular parts. Arranged along the circumferential direction of W.
For this reason, compared with the case where the one heating coil 4 is arrange | positioned, the surface of the annular component W which opposes the three heating coils 4a-4c, specifically, the upper end surface Wd and the lower end surface Wa of the annular component W are shown. It is possible to raise the temperature in a short time.
As a result, since it is possible to perform the high-frequency heat treatment on the annular part W in a short time, it is possible to improve the work efficiency of the high-frequency heat treatment.

Further, in the high frequency heat treatment method of the present embodiment, high frequency heat treatment is performed on the upper end surface Wd and the lower end surface Wa of the annular component W at three locations set along the circumferential direction of the annular component W.
For this reason, it is possible to raise the temperature of the surface of the annular component W, specifically, the upper end surface Wd and the lower end surface Wa of the annular component W in three locations set along the circumferential direction of the annular component W in a short time. It becomes possible.
As a result, since it is possible to perform the high-frequency heat treatment on the annular part W in a short time, it is possible to improve the work efficiency of the high-frequency heat treatment.

(Application example)
In the high-frequency heat treatment apparatus 1 of the present embodiment, the three upper end surface heating coils 18a to 18c and the lower end surface heating coils 20a to 20c are arranged along the circumferential direction of the annular component W. However, the present invention is not limited to this. Absent. That is, two upper end surface heating coils 18 and lower end surface heating coils 20 may be arranged along the circumferential direction of the annular component W, and four or more upper end surface heating coils 18 and lower end surface heating coils 20 are annular. You may arrange | position along the circumferential direction of the components W. FIG. In addition, two or more outer surface heating coils 14 and inner surface heating coils 16 may be arranged along the circumferential direction of the annular component W. In short, at least one of the outer surface heating coil 14, the inner surface heating coil 16, the upper surface heating coil 18, and the lower surface heating coil 20 may be arranged along the circumferential direction of the annular component W.

  Moreover, in the high frequency heat processing apparatus 1 of this embodiment, although the outer surface heating coil 14 and the inner surface heating coil 16 were divided into three along the axial direction of the annular component W, it is not limited to this. That is, the outer surface heating coil 14 and the inner surface heating coil 16 are integrated, and a plurality of the outer surface heating coil 14 and the inner surface heating coil 16 are arranged along the circumferential direction of the annular component W. May be.

  Furthermore, in the high frequency heat treatment method of the present embodiment, the high frequency heat treatment is performed on the upper end surface Wd and the lower end surface Wa of the annular component W at three locations set along the circumferential direction of the annular component W, but the present invention is limited to this. It is not a thing. That is, the high-frequency heat treatment may be performed at two locations set along the circumferential direction of the annular component W with respect to the upper end surface Wd and the lower end surface Wa of the annular component W, or may be performed at four or more locations. In addition, high-frequency heat treatment may be performed on the outer diameter surface Wc and the inner diameter surface Wb of the annular component W at two or more locations set along the circumferential direction of the annular component W. In short, at least one of the outer diameter surface Wc, inner diameter surface Wb, upper end surface Wd, and lower end surface Wa of the annular component W is subjected to high-frequency heat treatment at a plurality of locations set along the circumferential direction of the annular component W. Just do it.

It is a figure which shows the structure of the high frequency heat processing apparatus of 1st embodiment of this invention. It is the top view of a high frequency heat processing apparatus, and an AA sectional view. It is the top view which shows the high frequency heat processing apparatus of the comparative example 1, and an AA sectional view. It is the top view which shows the high frequency heat processing apparatus of the comparative example 2, and an AA sectional view. It is a top view of a high frequency heat treatment apparatus. It is a figure which shows the modification of a high frequency heat processing apparatus. It is a figure which shows the variation of a bearing provided with an annular component. They are the top view which shows the modification of a high frequency heat processing apparatus, and an AA sectional view. It is the top view which shows the structure of the high frequency heat processing apparatus of 2nd embodiment of this invention, AA sectional view, and BB sectional drawing. It is the top view which shows the structure of the high frequency heat processing apparatus of 3rd embodiment of this invention, AA sectional view, BB sectional drawing, and CC sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High frequency heat processing apparatus 2 Ring component support part 4 Heating coil 6 High frequency electric current feeding means 8 Positioning roller 10 Positioning roller pressing means 12 Support roller 14 Outer diameter surface heating coil 16 Inner diameter surface heating coil 18 Upper end surface heating coil 20 Lower end surface heating coil 22 Support base 24 Pressing position 26 Positioning roller rotating means W Annular part Wa Lower end surface of annular part Wb Inner surface of annular part Wc Outer diameter surface of annular part Wd Upper end surface of annular part RA Rotation axis of support roller P Center axis of annular part

Claims (11)

With respect to the annular component supported by the annular component support portion, the annular component support portion that supports the annular component to be heat-treated from below so as to be rotatable around the central axis of the annular component with the shaft directed vertically A high-frequency heat treatment apparatus comprising: a heating coil disposed at a predetermined interval from a part in a circumferential direction; and a high-frequency current power supply unit configured to supply a high-frequency current to the heating coil,
The annular part support portion includes a plurality of cylindrical or conical support rollers that are formed using a metal material or a ceramic material and that are arranged radially below the annular part to contact the lower end surface of the annular part. ,
The heating coil includes an outer diameter surface heating coil facing the outer diameter surface of the annular component, an inner diameter surface heating coil facing the inner diameter surface of the annular component, and an upper end surface heating coil facing the upper end surface of the annular component. And a lower end surface heating coil facing the lower end surface of the annular part,
The high-frequency heat treatment apparatus, wherein the lower end surface heating coil is disposed between the adjacent support rollers. Three or more positioning rollers disposed on the outer diameter surface side or inner diameter surface side of the annular component, and positioning roller pressing means for pressing the three or more positioning rollers against the annular component,
The roller pressing means causes the annular component to be pressed against the annular component so that the interval between the annular component, the outer diameter surface heating coil, and the inner diameter surface heating coil is maintained at the predetermined interval.
At least one of the three or more positioning rollers includes positioning roller rotating means for rotating the positioning roller,
The high frequency heat treatment apparatus according to claim 1, wherein the positioning roller is rotated so that the annular part rotates about the central axis.   3. The high frequency heat treatment apparatus according to claim 1, wherein at least one of the outer diameter surface heating coil and the inner diameter surface heating coil is divided along an axial direction of the annular component.   A plurality of at least one of the outer diameter surface heating coil, the inner diameter surface heating coil, the upper end surface heating coil, and the lower end surface heating coil are arranged along a circumferential direction of the annular component. The high frequency heat treatment apparatus according to any one of 1 to 3.   5. The apparatus according to claim 1, wherein a surface of the support roller facing the annular part is inclined downward from an inner diameter surface side to an outer diameter surface side of the annular part. High frequency heat treatment equipment. While supporting the annular part to be heat-treated from below and rotating it around the central axis of the annular part, a high-frequency current is fed to a heating coil that is arranged at a predetermined distance from a part of the annular part in the circumferential direction. A high-frequency heat treatment method for performing high-frequency heat treatment on the annular component,
The annular part is formed by using a metal material or a ceramic material, and is supported by a plurality of cylindrical or conical support rollers that are radially arranged below the annular part and contact the lower end surface of the annular part,
The heating coil includes an outer diameter surface heating coil facing the outer diameter surface of the annular component, an inner diameter surface heating coil facing the inner diameter surface of the annular component, and an upper end surface heating coil facing the upper end surface of the annular component. And a lower end surface heating coil facing the lower end surface of the annular part,
Performing high-frequency heat treatment on the lower end surface of the annular component by feeding the high-frequency current to the lower end surface heating coil disposed between the adjacent support rollers while rotating the annular component around the central axis. A high-frequency heat treatment method characterized by the above.   While rotating the annular part around the central axis, the outer diameter surface of the annular part is maintained such that the gap between the annular part, the outer diameter surface heating coil, and the inner diameter surface heating coil is maintained at the predetermined distance. Alternatively, the high-frequency heat treatment method according to claim 6, wherein three or more pressing positions set on the inner diameter surface are pressed.   The high frequency heat treatment is performed at a plurality of locations divided along the axial direction of the annular component on at least one of the outer diameter surface and the inner diameter surface of the annular component. Induction heat treatment method.   With respect to at least one of the outer diameter surface of the annular component, the inner diameter surface of the annular component, the upper end surface and the lower end surface of the annular component, high-frequency heat treatment is performed at a plurality of locations set along the circumferential direction of the annular component. The high-frequency heat treatment method according to any one of claims 6 to 8, wherein the method is performed.   The surface facing the annular part of the support roller is brought into contact with the lower end surface of the annular part in a state of being inclined downward as it goes from the inner diameter side to the outer diameter side of the annular part. The high frequency heat treatment method according to any one of 6 to 9. A rolling bearing comprising an outer ring and an inner ring facing each other with a plurality of rolling elements interposed therebetween,
A rolling bearing characterized in that at least one of the outer ring and the inner ring is an annular part subjected to the high-frequency heat treatment method according to any one of claims 6 to 10.

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