WO2017221789A1

WO2017221789A1 - Induction heating apparatus and induction heating method

Info

Publication number: WO2017221789A1
Application number: PCT/JP2017/021990
Authority: WO
Inventors: 慎太郎鈴木; 義也真野; 勇輝田渕
Original assignee: Ntn株式会社
Priority date: 2016-06-24
Filing date: 2017-06-14
Publication date: 2017-12-28

Abstract

This induction heating apparatus 1 is provided with: a transfer device 10 for transferring a rotatable workpiece W along a linear guide transfer path P; and a heating coil 2 for inductively heating the workpiece W being transferred along the guide transfer path P. The transfer device 10 is provided with: a first shaft member 11 and a second shaft member 12 spaced apart from and parallel to each other; and a rotation mechanism 6 for driving and rotating at least one (the second shaft member 12) of the shaft members 11, 12 about the axis thereof. The second shaft member 12 comprises a screw shaft having a helical protrusion 13 provided along the outer circumference thereof. The helical protrusion 13 defines a helical groove 14 on the second shaft member 12 and the groove bottom 15 of the helical groove 14 forms the guide transfer path P.

Description

Induction heating apparatus and induction heating method

The present invention relates to an induction heating device and an induction heating method used when induction heating a work.

For example, in the manufacturing process of a workpiece that requires high mechanical strength and hardness, such as a rolling element such as a roller constituting a rolling bearing, a heat treatment for imparting the mechanical strength required for the workpiece ( A quench hardening process is performed. This heat treatment includes a heating step for heating the workpiece to be heat-treated to a target temperature, a cooling step for cooling the heated workpiece, and the like. The heating process can be performed using, for example, an atmosphere heating furnace such as a mesh belt type continuous furnace. However, since the atmosphere heating furnace needs to be heated together with the atmosphere, the energy efficiency is low. There is a problem of becoming.

Therefore, for example, as described in Patent Document 1 below, the above heating process may be performed using a high frequency induction heating apparatus. Inductive heating has the advantage that a compact heat treatment facility can be realized in addition to achieving high energy efficiency because only the workpiece can be directly heated.

The induction heating device of Patent Document 1 is a guide tube as a guide member that guides and moves a work, a heating coil that is arranged on the outer periphery of the guide tube and induction-heats the work that moves in the guide tube, and an inlet side of the guide tube. And pushing means for sequentially pushing the workpiece into the guide tube. In this case, a feeding force is applied to the workpiece in the guide tube as the subsequent workpiece is pushed into the guide tube.

JP 2005-331005 A JP 2009-84664 A

In the induction heating device of Patent Document 1, since the work is induction-heated while moving in the guide tube in a fixed posture, the heating temperature difference between the contact area of the work with the guide pipe and the other areas is different. Is likely to occur. For this reason, temperature unevenness is likely to occur in the workpiece after completion of heating, and as a result, there is a possibility that desired mechanical strength cannot be imparted to the workpiece.

It is considered that the above problem can be solved as much as possible by applying vibration to the guide member that guides and moves the workpiece, as described in Patent Document 2, for example. However, even if the guide member is vibrated, the work cannot always be induction-heated while appropriately changing the posture of the work.

In view of the above circumstances, an object of the present invention is to provide a technical means capable of uniformly inductively heating a workpiece (particularly a rotatable workpiece) without temperature unevenness, and thereby appropriately and efficiently bringing the workpiece to a target temperature. It is to enable heating.

The present invention devised to achieve the above-described object includes a conveyance device that conveys a rotatable workpiece along a linear guide conveyance path, and induction heating of the workpiece conveyed along the guide conveyance path. An induction heating device comprising a heating coil, wherein the conveying device is arranged in parallel and spaced apart from each other, and a first shaft member and a second shaft member that form a guided conveying path in cooperation with the other side A screw shaft having a helical convex portion provided along the outer periphery of at least one of the shaft members. The guide conveyance path is formed by a groove bottom surface of the spiral groove defined on the one shaft member by the convex portion and a surface facing the groove bottom surface of the other shaft member.

Note that examples of the “rotatable workpiece” in the present invention include a rolling element of a rolling bearing. The rolling bearing here is a concept including a ball bearing, a cylindrical roller bearing, a tapered roller bearing, a needle roller bearing and the like. Therefore, the rolling element is a concept including a ball, a cylindrical roller, a tapered roller, a needle roller, and the like.

When using the induction heating apparatus having the above-described configuration, the workpiece to be heated is introduced into the guide conveyance path provided in the conveyance apparatus, and then conveyed along the guide conveyance path. The guide conveyance path includes a groove bottom surface of a spiral groove defined on at least one shaft member (screw shaft) of the first shaft member and the second shaft member arranged in parallel and spaced apart from each other; Since the shaft member is formed by the surface facing the groove bottom surface, the workpiece to be heated is disposed in the spiral groove, and a part thereof contacts the groove bottom surface of the spiral groove. Since the spiral groove is partitioned and formed by the spiral convex portion, when the screw shaft is driven to rotate around its axis while the workpiece is placed in the spiral groove (on the guide conveyance path), the workpiece is Can be applied simultaneously and continuously with a feed force for conveying the roller along the guide conveyance path and a rotational force for rotating the same (specifically, a rotational force in the direction opposite to the rotational direction of the screw shaft). it can. Therefore, induction heating can be performed while rotating the workpiece conveyed along the guide conveyance path. As a result, the workpiece can be induction-heated efficiently and uniformly without temperature unevenness.

Moreover, if it is a conveying apparatus which has said structure, since a workpiece | work can be conveyed along a guide conveyance path like the patent document 1, even if there is no pushing by a subsequent workpiece | work, one workpiece | work to be heated Or it can apply preferably also when it is a small lot of about several pieces. Thereby, the application object of an induction heating apparatus can be expanded and versatility can also be improved.

In addition, as in Patent Document 1, when induction heating is performed in a state where each workpiece is in contact with an adjacent workpiece in the conveyance direction, the workpieces are welded together, and the workpiece after heating may not be used as a product. There is sex. Further, even if the workpieces are not welded to each other, the workpieces are affected by the thermal effects of adjacent workpieces, and therefore, the workpieces may not be heated in a predetermined manner. For this reason, when conveying a some workpiece | work along a guide conveyance path, it is preferable to convey two adjacent workpiece | work in the state mutually spaced apart. In this respect, in the induction heating device according to the present invention, the guide conveyance path is formed by the groove bottom surface of the spiral groove, and therefore the pitch of the convex portion (the dimension in the direction along the guide conveyance path of the groove bottom surface of the spiral groove) is appropriately set. If it is set to, two adjacent workpieces can be reliably conveyed in a state of being separated from each other. Therefore, also from this point, the workpiece can be heated with high accuracy.

Of the first shaft member and the second shaft member, the other shaft member can be configured by a screw shaft similar to the one shaft member, or can be configured by a cylindrical shaft having a constant diameter. If the other shaft member is constituted by a cylindrical shaft, the shape of the other shaft member can be simplified and the production cost thereof can be suppressed, so that the induction heating device capable of achieving the above-described effects can be realized at low cost. Can do. In this case, the guide conveyance path is formed by the groove bottom surface of the spiral groove and the outer diameter surface of the cylindrical shaft.

If the axis of the first shaft member and the axis of the second shaft member are positioned at the same height (on the same plane), it is possible to effectively reduce the possibility of the workpiece falling off from the guide conveyance path.

The rotation mechanism can be configured to rotate the first shaft member and the second shaft member in the same direction at the same speed. If it does in this way, the work conveyed along a guidance conveyance way can be rotated smoothly.

Among the first shaft member and the second shaft member, one shaft member (screw shaft) may be disposed relatively upward and the other shaft member may be disposed relatively below. In this case, the guide conveyance path can be formed by the groove bottom surface of the spiral groove and the work support surface provided on the other shaft member.

In the above configuration, the first shaft member and the second shaft member are preferably formed of a nonmagnetic material. If both shaft members are made of a magnetic material such as metal, not only the workpiece but also the shaft member is induction-heated. Therefore, the shaft member softens and melts, and the shape accuracy of the shaft member and thus the workpiece support and transport accuracy are improved. This is because it has an adverse effect.

If the heat treatment equipment includes the induction heating device according to the present invention having the above-described configuration and a cooling device that cools the workpiece discharged from the induction heating device (the workpiece after heating is completed), the workpiece is appropriately quenched and hardened. It is possible to easily and surely obtain a workpiece having a desired mechanical strength after being subjected to the treatment.

In addition, the above object is achieved by the induction heating method according to the present invention, that is, by energizing the heating coil arranged outside the guide conveyance path while conveying the rotatable workpiece along the linear guide conveyance path. In addition, when the work is induction-heated to a target temperature, the work can be also achieved by an induction heating method characterized in that each work introduced sequentially to the guide conveyance path is conveyed while being rotated.

In the above configuration, it is preferable that each of the workpieces sequentially introduced into the guide conveyance path is conveyed while being rotated in a non-contact state with an adjacent workpiece.

As described above, according to the present invention, the workpiece to be heated can be uniformly induction-heated without temperature unevenness. Thereby, it becomes possible to induction-heat each of a some workpiece | work to the target temperature appropriately and efficiently.

It is a schematic diagram which shows the whole structure of the heat processing equipment provided with the induction heating apparatus which concerns on embodiment of this invention. It is a schematic side view of the induction heating apparatus which concerns on embodiment of this invention. It is a schematic front view of an induction heating apparatus. It is a partial enlarged plan view of an induction heating device. It is the elements on larger scale of the conveying apparatus which comprises an induction heating apparatus. FIG. 5B is a schematic sectional view taken along line BB in FIG. 5A. FIG. 10 is a partially enlarged plan view of the transfer device, showing a case where the posture of the workpiece to be transferred is changed. FIG. 6B is a schematic sectional view taken along line BB in FIG. 6A. It is the schematic which shows an example of the support aspect of the 1st shaft member and 2nd shaft member which comprise a conveying apparatus. It is a principal part cross-sectional view of the conveying apparatus which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing the overall structure of a heat treatment facility A provided with an induction heating apparatus 1 according to an embodiment of the present invention, FIG. 2 is a schematic side view of the induction heating apparatus 1, and FIG. FIG. 2 is a schematic front view of FIG. The heat treatment equipment A shown in FIG. 1 is used for subjecting a conductive metal workpiece W to a quench hardening treatment, and aims at conveying the workpiece W along a linear guide conveyance path P. It is configured to inductively heat to a temperature and then cool the workpiece W. In the following, an embodiment of the present invention will be described by taking as a representative example a case where a rolling element (conical roller) of a tapered roller bearing which is a kind of rolling bearing is subjected to quench hardening. In short, the workpiece W of the present embodiment is a tapered roller (a base material for a tapered roller) as shown in FIGS. 4, 5A, 5B and the like.

As shown in FIG. 1, the heat treatment facility A includes an induction heating device 1 that performs induction heating to a target temperature while conveying the workpiece W along a linear guide conveyance path P, and the workpiece W discharged from the induction heating device 1. And a cooling unit 23 as a cooling device for cooling the. The cooling unit 23 is configured by a cooling liquid tank in which a cooling liquid such as quenching oil is stored, for example.

As shown in FIGS. 1 and 2, the induction heating device 1 includes a transport device 10 that transports a workpiece W along a linear guide transport path P, and a work W that is transported along the guide transport path P. Control the heating coil 2 for induction heating, the frame 3 that supports the heating coil 2 and a part of the conveying device 10, the high-frequency power source 20 that supplies a high-frequency current to the heating coil 2, and the output of the high-frequency power source 20. And a control device 21. The frame body 3 of the present embodiment includes first to third base frames 3a to 3c that are erected at three positions spaced apart in the axial direction, and extend in the axial direction, with one end and the other end being the second base frame 3b. And a horizontal bar 3d fixed to the third base frame 3c. Although the detailed illustration is omitted, the cross rails 3d are equally arranged at three locations spaced apart in the circumferential direction of the heating coil 2.

The heating coil 2 is a spiral coil (multi-winding coil) in which a tubular body (for example, a copper tube) made of a conductive metal is spirally wound, and is supported by a horizontal beam 3d of the frame 3 via a bolt member 4. Has been. As the heating coil 2, a coil whose full length is sufficiently longer than the full length of the workpiece W is used so that a plurality of workpieces W can be induction-heated simultaneously. For example, when induction heating a workpiece W having a total length Y (see FIG. 5A) of about 15 mm, a heating coil 2 having a total length of 600 mm or more can be used. One end and the other end of the heating coil 2 are electrically connected to the high-frequency power source 20 shown in FIG. The high frequency power supply 20 is electrically connected to the control device 21 shown in FIG. 1, and supplies a high frequency current to the heating coil 2 with a predetermined size and timing based on a signal output from the control device 21. To do.

Although detailed illustration is omitted, the induction heating device 1 can be provided with a cooling circuit for cooling the heating coil 2. If such a cooling circuit is provided, the temperature of the heating coil 2 can be controlled appropriately and efficiently, so that the workpiece W can be induction-heated to the target temperature with high accuracy and efficiency. Since the heating coil 2 is formed of a tubular body, the cooling circuit, for example, connects the heating coil 2 (hollow part thereof) and a cooling liquid tank storing the cooling liquid via a pipe, and on the pipe. It can be constructed by providing a pump.

As shown in FIGS. 2 and 4, the conveying device 10 includes a first shaft member 11 and a second shaft member 12 which are arranged in parallel to each other on the inner periphery of the heating coil 2, and both shaft members 11, And a rotation mechanism 6 that rotates at least one of the two (both in the present embodiment; details will be described later) around its axis. As shown in FIG. 5B, the

shaft members

11 and 12 are rotatably supported with respect to the frame body 3 with their axis lines (rotation centers) positioned at the same height (on the same plane). Both

shaft members

11, 12 are longer than the heating coil 2, and one end and the other end protrude outside the heating coil 2.

As shown in FIGS. 4 and 5B, the first shaft member 11 is formed of a cylindrical shaft having an outer diameter surface 11a formed on a cylindrical surface having a constant diameter, and the second shaft member 12 is formed in a spiral shape along the outer periphery thereof. It consists of a screw shaft provided with a convex portion 13. The first and

second shaft members

11 and 12 are both made of a nonmagnetic material. As the nonmagnetic material, for example, ceramics (for example, alumina, zirconia, silicon carbide, etc.) having high hardness and excellent heat resistance are preferably used.

As shown in FIGS. 4, 5A and 5B, the groove bottom surface 15 of the spiral groove 14 defined on the outer periphery of the second shaft member 12 by the spiral convex portion 13 is the first shaft member 11 facing this. In cooperation with the outer diameter surface 11a, a guide conveyance path P for guiding and conveying the workpiece W and the workpiece support 16 are formed. In the present embodiment, the outer peripheral surface of the workpiece W is contact-supported by the workpiece support unit 16. The pitch and width dimension of the convex portion 13 are set so that the relational expression of Y <X1 is established between the groove width X1 of the spiral groove 14 and the overall length Y of the workpiece W. From the above, in the transport device 10, the linear guide transport path P is formed by the cooperation of the first shaft member 11 and the second shaft member 12, and each of them can support and support the work W. 16 are formed at a plurality of locations separated in the extending direction of the guide conveyance path P.

2 to 4, the rotation mechanism 6 includes an electric motor (for example, a servo motor) 22 and a power transmission mechanism 7 that transmits the rotational power of the electric motor 22 to both

shaft members

11 and 12. The power transmission mechanism 7 has a small gear 7 a, a gear shaft 18 A connected to one end of the first shaft member 11 via a connection pin 17, and a small gear 7 b, and a second through the connection pin 17. A gear shaft 18B connected to one end of the shaft member 12, a large gear 7c rotatably supported by the frame 3 and meshed with the

small gears

7a and 7b, and a drive pulley connected to the output shaft of the electric motor 22 7d, a driven pulley 7e connected to the large gear 7c, and an endless belt member (which may be a chain) 7f spanned on the outer peripheral surfaces of the

pulleys

7d and 7e. The pitches of the tooth surfaces of the

small gears

7a and 7b are the same, and among the large gear 7c, the pitch of the tooth surfaces meshing with the small gear 7a and the pitch of the tooth surfaces meshing with the small gear 7b are the same. When the electric motor 22 is driven by the power transmission mechanism 7 (rotation mechanism 6) having the above configuration, the first shaft member 11 and the second shaft member 12 are rotationally driven in the same direction at the same speed. The electric motor 22 is electrically connected to a power supply (not shown) and the control device 21 shown in FIG. 1, and is driven to rotate at a predetermined speed based on a signal output from the control device 21.

When the heat treatment equipment A having the above configuration is used, the quench hardening treatment for the workpiece W is performed in the following manner.

First, by driving the electric motor 22, the first shaft member 11 and the second shaft member 12 are driven to rotate around the axis (see the white arrow in FIG. 4), and the heating coil 2 is energized together. . Then, the workpiece W is loaded into the transport apparatus 10 from the workpiece loading position shown in FIG. As described above, the work support portion 16 (and the guide conveyance path P) is formed by the groove bottom surface 15 of the spiral groove 14 defined in the second shaft member 12 formed of a screw shaft. While the motor 22) is driven and the

shaft members

11 and 12 are rotating around the axis, the workpiece W supported by the workpiece support 16 is conveyed along the guide conveyance path P. The feed force is continuously applied. Thereby, the workpiece W is induction-heated to a target temperature by the energized heating coil 2 while being conveyed along the guide conveyance path P (guide movement along the outer diameter surface 11a of the first shaft member 11). As shown in FIG. 1, the workpiece W discharged from the heating coil 2 is charged into the coolant stored in the cooling unit 23 by free fall, and cooled to a predetermined temperature range and hardened by hardening.

When the workpiece W is transported in the above-described manner, the

shaft members

11 and 12 that contact and support the outer peripheral surface of the workpiece W are rotationally driven in the same direction. Therefore, the workpiece W is painted black in FIGS. 5A and 5B. As indicated by the arrows, a rotational force that rotates the workpiece W about its axis is continuously applied.

As described above, in order to rotate the workpiece W around its axis in addition to the feed force along the extending direction of the guide conveyance path P, the workpiece W supported by the workpiece support unit 16 while the conveyance device 10 is driven. Is continuously applied. For this reason, the rod-shaped workpiece W conveyed along the guide conveyance path P is induction-heated while rotating around its axis. Thereby, each part of the workpiece | work W can be induction-heated uniformly, and it can prevent effectively that temperature nonuniformity generate | occur | produces in the workpiece | work W after completion of a heating. Therefore, when the work W after completion of heating is cooled, a high-quality work W having no difference in mechanical strength in each part in the circumferential direction and the cross-sectional direction can be obtained.

In particular, the rotation mechanism 6 according to the present embodiment is configured to rotationally drive the first and

second shaft members

11 and 12 in the same direction at the same speed, so that the work supported by the work support unit 16 is supported. W can be rotated smoothly and continuously around its axis. In addition, since both

shaft members

11 and 12 are formed of ceramics, which is a kind of nonmagnetic material, both

shaft members

11 and 12 themselves are prevented from being heated by induction and softened, melted, etc. It can be supported and transported with high accuracy. Accordingly, it is possible to further effectively prevent the temperature W from being uneven in the workpiece W after the heating is completed, and to further increase the heating accuracy of the workpiece W.

In the present embodiment, a plurality of workpieces W are transported in a state of being separated from each other by feeding the workpieces W one by one with a predetermined interval from the workpiece loading position shown in FIG. However, a plurality of workpieces W are simultaneously induction-heated. In this case, it is possible to prevent as much as possible problems such as the workpieces W being transported (during induction heating) contacting each other and welding the workpieces W, and each workpiece W being affected by the heat of adjacent workpieces W. Thus, the workpiece W can be heated with higher accuracy. For example, if a relational expression of X1 <2Y is established between the groove width X1 of the spiral groove 14 and the axial dimension Y of the workpiece W, each workpiece support section 16 has a single workpiece W. Only the contact will be supported. In this case, since the plurality of workpieces W can be reliably transported and heated in a state of being separated from each other, the possibility that each workpiece W is affected by the heat of the adjacent workpieces W can be further effectively reduced. .

Further, with the transport device 10 described above, the workpiece W can be transported without being pushed by a subsequent workpiece as in Patent Document 1. Therefore, the induction heating device 2 provided with the transfer device 10 has excellent versatility that can be preferably applied even when the workpiece W to be heated is one or several small lots. Each workpiece W can be heated with high accuracy.

In the embodiment described above, as shown in FIG. 5A and FIG. 5B, the work support portion 16 contacts and supports the outer peripheral surface of the work W, and the work W is conveyed along its axial direction. The support mode of the workpiece W by the support portion 16 (the posture of the workpiece W during conveyance) is not limited to this.

That is, for example, as shown in FIGS. 6A and 6B, the workpiece W is in contact with and supported on one end surface by the groove bottom surface 15 of the spiral groove 14 of the second shaft member 12, and the outer peripheral surface of the workpiece W of the first shaft member 11. The outer diameter surface 11a may be contact-supported. In this case, the workpiece W is transported along the guide transport path P in a state where the axis of the work W intersects (orthogonally) the extending direction of the guide transport path P.

As shown in FIGS. 5A and 5B, when the outer peripheral surface of the work W is contact-supported by the work support portion 16, the outer peripheral surface of the work W is the outer diameter surface 11 a of the first shaft member 11 and the second shaft member 12. It is conveyed by rolling contact while sliding with respect to the groove bottom surface 15. On the other hand, when supporting and transporting the workpiece W in the mode shown in FIGS. 6A and 6B, the outer periphery of the workpiece W is the outer diameter surface 11a of the first shaft member 11 and the spiral of the second shaft member 12. The convex portion 13 is conveyed while being in rolling contact with no slip. Therefore, it is advantageous for preventing the occurrence of temperature unevenness on the outer peripheral surface of the work W after completion of heating, and for preventing the occurrence of minute defects such as scratches on the outer peripheral surface of the work W. In particular, when the workpiece W is a tapered roller (base material) or a cylindrical roller (base material) as in this embodiment, the workpiece W is formed in the manner shown in FIGS. 6A and 6B. It is preferable to support and convey. This is because the outer peripheral surface of the tapered roller or cylindrical roller is a surface that rolls along the raceway surfaces of the inner ring and outer ring that constitute the rolling bearing, and is a surface that requires high shape accuracy and mechanical strength.

As mentioned above, although the induction heating apparatus 1 which concerns on one Embodiment of this invention was demonstrated, it is possible to give a various change to the induction heating apparatus 1 in the range which does not deviate from the summary of this invention.

For example, in particular, when long ones are used as the first shaft member 11 and the second shaft member 12 constituting the transport device 10, as shown in FIG. Further, a support member (support roller) 19 that contacts and supports a region other than the region where the workpiece support 16 is formed may be provided. If such a support roller 19 is provided, it is possible to prevent the

shaft members

11 and 12 from being bent as much as possible, so that the workpiece W can be supported and transported with high accuracy. W can be heated with high accuracy. In addition, although detailed illustration is abbreviate | omitted, in the induction heating apparatus 1 shown in FIG. 2, the support roller 19 can be provided in the 2nd and 3rd base frames 3b and 3c.

Further, when the

shaft members

11 and 12 are driven to rotate as in the embodiment described above, the rotational speeds around the axis of the

shaft members

11 and 12 are not necessarily the same, and may be different from each other. I do not care. In order to make the rotational speeds of the

shaft members

11 and 12 different from each other, for example, the pitch of the tooth surfaces of the small gear 7a provided on the first shaft member 11 and the large gear 7c meshing with the small gear 7a, and the second shaft member 12 What is necessary is just to make the pitch of the tooth surface of the small gear 7b and the large gear 7c which meshes with this mutually differ. Even when both the

shaft members

11 and 12 are driven to rotate, a rotating mechanism 6 having a configuration different from that of the rotating mechanism 6 described above may be employed. For example, it is possible to provide two electric motors, connect the first shaft member 11 to the output shaft of one electric motor, and connect the second shaft member 12 to the output shaft of the other electric motor.

In the embodiment described above, the workpiece W conveyed along the guide conveyance path P by driving the first shaft member 11 and the second shaft member 12 to rotate in the same direction at the same speed (synchronous rotation). However, such a rotational force is also applied to the workpiece W by rotating only the shaft member (the second shaft member 12 in the embodiment described above). can do. Therefore, the rotation mechanism 6 may be configured to rotate only the shaft member including the screw shaft. In this case, since it is not necessary to provide the rotation mechanism 6 with a complicated mechanism (power transmission mechanism 8) for synchronously rotating the

shaft members

11 and 12, the transport device 10 can be simplified and reduced in cost. Can do.

Moreover, in embodiment described above, although only one shaft member (2nd shaft member 12) was comprised with the screw shaft among both

shaft members

11 and 12, the other shaft member (1st shaft member 11). It is also possible to constitute a screw shaft similar to the one shaft member (not shown). In this case, the guide conveyance path P and the work support portion 16 are formed on the groove bottom surface 15 of the spiral groove 14 formed in each of the

shaft members

11 and 12.

Further, not only one heating coil 2 but also a plurality of heating coils 2 can be arranged along the extending direction of the guide conveyance path P.

Further, in the embodiment described above, the first shaft member 11 and the second shaft member 12 are arranged so that the centers thereof are located at the same height. As shown in FIG. 4, they may be different from each other. In FIG. 8, the second shaft member 12 formed of a screw shaft is disposed relatively upward, and the first shaft member 11 ′ having a substantially L-shaped cross section is disposed relatively downward. In this case, a guide conveyance path P is formed by the groove bottom surface 15 of the spiral groove 14 provided in the second shaft member 12 and the work support surface 11a ′ of the first shaft member 11 ′, and the work support portion 16 is formed by the first shaft. It is comprised by the workpiece | work support surface 11a 'of member 11'. According to such a configuration, the workpiece support surface 11a ′ of the first shaft member 11 ′ constituting the workpiece support portion 16 (more specifically, the workpiece support surface 11a ′ faces the groove bottom surface 15 of the spiral groove 14). When the second shaft member 12 is rotationally driven around its axis in this state, the feed force in the direction along the guide conveyance path P and the black in the figure are A rotational force in the direction indicated by the paint arrow is applied. In this case, from the viewpoint of reducing the contact area of the work W with respect to the work support surface 11a ′ of the first shaft member 11 ′ as much as possible, the work support surface 11a ′ has an uneven shape as shown in the illustrated example, and a plurality of locations on the work W are formed. A point contact support is preferred.

Although the tapered roller which comprises a tapered roller bearing was illustrated as the workpiece | work W of the heating object by the induction heating apparatus 1 which concerns on embodiment of this invention above, the induction heating apparatus 1 is a ball (ball) which comprises a ball bearing. Also, it can be preferably used when induction rolling is performed on rolling elements of other rolling bearings such as a cylindrical roller constituting a cylindrical roller bearing or a needle roller constituting a needle roller bearing. The induction heating apparatus 1 according to the embodiment of the present invention can be preferably used not only for the solid workpiece W such as the various rolling elements described above but also for the induction heating of the hollow workpiece W. In short, the induction heating device 1 according to the present invention induces a work W that can rotate as one or both of the

shaft members

11 and 12 constituting the transport device 10 are rotationally driven around the axis. Any type of workpiece can be used as long as it is heated.

The present invention is not limited to the embodiment described above, and can be implemented in various forms without departing from the gist of the present invention. That is, the scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings recited in the claims and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Induction heating apparatus 2 Heating coil 3 Frame 6 Rotating mechanism 7 Power transmission mechanism 10 Conveying apparatus 11 1st shaft member 12 2nd shaft member 13 Spiral convex part 14 Spiral groove 15 Groove bottom face 16 Work support part 20 High frequency power supply 23 Cooling unit (cooling device)
A Heat treatment equipment P Guide conveyance path W Workpiece

Claims

An induction heating apparatus comprising: a conveyance device that conveys a rotatable workpiece along a linear guide conveyance path; and a heating coil that induction-heats the workpiece conveyed along the guide conveyance path,
The conveying device is arranged in parallel with being spaced apart from each other, and cooperates with the other side to form the guide conveying path, and at least one of the two shaft members. And a rotation mechanism that rotates the shaft around its axis,
At least one of the shaft members includes a screw shaft having a spiral convex portion provided along an outer periphery thereof, and the groove bottom surface of the spiral groove defined on the one shaft member by the convex portion and the other The induction heating apparatus, wherein the guide conveyance path is formed by a surface of the shaft member facing the groove bottom surface.
The induction heating apparatus according to claim 1, wherein the other shaft member is formed of a cylindrical shaft having a constant diameter, and the guide conveyance path is formed by a groove bottom surface of the spiral groove and an outer diameter surface of the cylindrical shaft.
The induction heating apparatus according to claim 1 or 2, wherein an axis of the first shaft member and an axis of the second shaft member are located at the same height.
The induction heating device according to any one of claims 1 to 3, wherein the rotation mechanism is configured to rotationally drive the first shaft member and the second shaft member in the same direction at the same speed.
The one shaft member is disposed relatively above and the other shaft member is disposed relatively below;
The induction heating apparatus according to claim 1, wherein the guide conveyance path is formed by a groove bottom surface of the spiral groove and a work support surface provided on the other shaft member.
The induction heating device according to any one of claims 1 to 5, wherein the first shaft member and the second shaft member are formed of a nonmagnetic material.
The induction heating apparatus according to any one of claims 1 to 6, wherein the workpiece is a rolling element constituting a rolling bearing.
A heat treatment facility comprising the induction heating device according to any one of claims 1 to 7 and a cooling device for cooling the work discharged from the induction heating device.
While conducting a rotatable workpiece along a linear guide conveyance path, by energizing a heating coil disposed outside the guide conveyance path, when induction heating the workpiece to a target temperature,
An induction heating method, wherein each of the workpieces sequentially introduced into the guide conveyance path is conveyed while being rotated.
The induction heating method according to claim 9, wherein each of the workpieces sequentially introduced into the guide conveyance path is conveyed while being rotated in a non-contact state with the adjacent workpiece.