JP2008202102A - Induction hardening apparatus and induction hardening method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction hardening apparatus and an induction hardening method for uniformly hardening a plurality of shaft-shaped workpieces at one time. <P>SOLUTION: The induction hardening apparatus 1 includes: a workpiece holding plate 10 which is arranged so as to be rotated around the main axis 11 extending vertically and has a plurality of workpiece holding means 12 disposed on a concentric circle around the main axis 11; and a first rotating means 20 for rotating the workpiece holding plate 10, and is further equipped with: a high-frequency induction heating coil 3 which is arranged in an annular manner on the concentric circle around the main axis 11 outside the workpiece holding plate 10; a cooling means 4 arranged below the high-frequency induction heating coil 3; a moving means 21 for vertically moving the workpiece holding plate 10; and a second rotating means 30 for rotating a shaft-shaped workpiece B held by each workpiece holding means 20 around the axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an induction hardening apparatus and an induction hardening method for quenching a shaft-shaped workpiece such as a steel bolt, and in particular, it is possible to uniformly quench a plurality of shaft-shaped workpieces at a time. The present invention relates to an induction hardening apparatus and an induction hardening method.

Conventionally, as an invention of an induction hardening apparatus for a shaft-like workpiece, for example, the one shown in FIG. 5 is known (see Patent Document 1).
FIG. 5 is a plan view of a non-oxidation induction hardening apparatus for a three-dimensional workpiece according to Patent Document 1. FIG.
A non-oxidation induction hardening apparatus 100 shown in FIG. 5 rotates a plurality of work receivers 101 on which gears (workpieces) W are placed, a turntable 102 through which the work receivers 101 are inserted, and the turntable 102 in a step shape. Rotating means (not shown) and lifting / lowering means (not shown) for raising and lowering the workpiece receiver 101 are provided. Further, the non-oxidation induction hardening apparatus 100 includes a tunnel-shaped heat treatment chamber 104 disposed in the path of the gear W, and an automatic opening / closing door 105 that blocks the entire entrance of the heat treatment chamber 104. The heat treatment chamber 104 has a preliminary zone 106, a preheating zone 107, and a main heating and quenching zone 108. The preheating zone 107 is provided with a pair of preheating coils 109 arranged in parallel. Further, the main heating and quenching zone 108 is provided with an annular heating coil 110 that can surround the gear W mounted on each workpiece receiver 101. Further, a cooling liquid tank (not shown) in which a cooling liquid is accommodated is disposed below the heat treatment chamber 104.

  In the non-oxidation induction hardening apparatus 100, first, after the turn table 102 starts to rotate stepwise in the direction of arrow T shown in FIG. It is placed on the receiver 101. Then, the gear W is conveyed into the heat treatment chamber 104 through the automatic opening / closing door 105 as the turntable 102 rotates. The gear W transported into the heat treatment chamber 104 is first preheated by the preheating coil 109 in the preheating zone 107. When the gear W is conveyed to the main heating and quenching zone 108, the heating coil 110 is lowered to surround the gear W. The gear W is then heated by the heating coil 110. Further, the gear W that has been completely heated is cooled by being immersed in the coolant when the work receiver 101 is lowered by the lifting means. Then, the gear W that has been cooled is raised on the liquid level of the coolant by raising the workpiece receiver 101 by the lifting means. Further, the gear W raised to the liquid level of the coolant is removed from the workpiece receiver 101. Further, the second gear W is placed on the work receiver 101 in front of the automatic opening / closing door 105 when the first gear W is conveyed to the spare zone 107, and thereafter, similarly to the first gear W. Quenching is performed. The same applies to the third and subsequent gears W.

Moreover, as another invention of the induction hardening apparatus of a shaft-shaped workpiece, for example, the one shown in FIG. 6 is known (see Patent Document 2).
FIG. 6 is a side view of the induction hardening apparatus according to Patent Document 2. As shown in FIG.
An induction hardening apparatus 200 shown in FIG. 6 includes a plurality of workpiece receivers 201 on which gears (workpieces) W are placed, a turntable 202 provided with the workpiece receivers 201, a workpiece revolving means 203 that rotates the turntable 202, A workpiece lifting / lowering means 204 for lifting and lowering the workpiece receiver 201 and a workpiece rotation means 205 for rotating the workpiece receiver 201 are provided. In addition, the induction hardening apparatus 200 includes a preheating unit 206, a main heating unit 207, and a cooling unit 208 disposed in the path of the gear W.

The turntable 202 is disposed in a tank 209 in which the quenching liquid L is stored. Then, the turntable 202 is intermittently rotated by the work revolving means 203 via the shaft 220.
A plurality of vertical rods 210 are inserted at equal intervals in the peripheral portion of the turntable 202. Each workpiece receiver 201 is disposed at the upper end of each vertical rod 210. Each workpiece receiver 201 is rotated by a workpiece rotation means 205 via a vertical rod 210. Each workpiece receiver 201 is lifted and lowered by the workpiece lifting / lowering means 204 via the vertical rod 210.

The preheating means 206 includes a preheating coil 211 and a transformer 212 that supplies high-frequency power to the preheating coil 211.
The heating means 207 includes an annular high-frequency heating coil 213 horizontally disposed so as to surround the gear W placed on the workpiece receiver 201, a transformer 214 that supplies high-frequency power to the high-frequency heating coil 213, a heating A coil elevating device 215.

In the induction hardening apparatus 200, first, the gear W is placed on the work receiver 201 in the carry-in station (not shown), and the work revolving means 203 is activated. Then, the gear W is conveyed to the preheating station B as the turntable 202 is rotated, and is heated by the preheating coil 211 while being rotated by the work rotation means 205. Next, when the gear W is conveyed to the main heating station C, the high-frequency heating coil 213 is lowered by the heating coil lifting device 215 and installed so as to surround the gear W. The gear W is heated by the high-frequency coil 213 while being rotated by the work rotation means 205. The gear W that has been heated is cooled by being immersed in the quenching liquid L when the workpiece receiver 201 is lowered by the workpiece lifting means 204. The gear W that has been cooled is raised onto the liquid surface of the quenching liquid L when the work receiver 201 is raised by the work lifting means 204. Further, the gear W raised to the liquid surface of the quenching liquid L is taken out from the workpiece receiver 201 and the quenching is completed. When the first gear W arrives at the preheating station B, the second gear W is placed on the work receiver 201 that has arrived at the carry-in station, and quenching is performed in the same manner as the first gear W. The same applies to the third and subsequent gears W.
Utility Model Registration No. 2541495 JP-A-6-1000094

  However, in the non-oxidation induction hardening apparatus 100 shown in FIG. 5 and the induction hardening apparatus 200 shown in FIG. 6, in order to prevent variations in quality such as hardness of the quenched product, workpieces are one by one. It is configured to process. Therefore, the non-oxidation induction hardening apparatus 100 shown in FIG. 5 and the induction hardening apparatus 200 shown in FIG. 6 have a problem that processing efficiency is poor.

The present invention has been made to solve the above-described problems of the prior art, and its purpose is to simultaneously quench a plurality of shaft-like workpieces at a time, thereby improving the processing efficiency. It is to provide an induction hardening apparatus and an induction hardening method.
Another object of the present invention is to provide an induction hardening apparatus and an induction hardening apparatus capable of uniformly hardening all of the shaft-shaped workpieces when simultaneously quenching a plurality of shaft-shaped workpieces at the same time. It is to provide an entry method.

The induction hardening apparatus for a shaft-like workpiece according to claim 1 of the present application is disposed so as to be rotatable about a main shaft extending in a vertical direction, and a plurality of work holding means are provided on concentric circles centering on the main shaft. A workpiece holding plate,
First rotating means for rotating the work holding plate,
Each of the work holding means is an induction hardening apparatus that holds the shaft-like work as a vertical direction in which the axis extends,
A high-frequency heating coil disposed outside the workpiece holding plate in an annular shape on a concentric circle centered on the main shaft;
Cooling means disposed below the high-frequency heating coil;
Moving means for moving the workpiece holding plate in the vertical direction;
And a second rotating means for rotating the shaft-like work held by the work holding means about the axis.

Further, the induction hardening method for a shaft-like workpiece according to claim 2 of the present application is on a concentric circle centered on the main axis of the work holding plate disposed so as to be rotatable about a main axis extending in the vertical direction. A step of heating a plurality of shaft-like workpieces held with the direction in which the shaft extends as a vertical direction by a high-frequency heating coil;
A step of cooling the respective shaft-shaped workpieces held on the workpiece holding plate after the heating step by a cooling means, and induction hardening,
The heating of each of the shaft-like workpieces held on the workpiece holding plate by the high-frequency heating coil causes the workpiece holding plate to rotate about the main axis and causes each of the shaft-like workpieces to rotate about the axis. The method is characterized in that it is performed simultaneously on all the shaft-like workpieces held on the workpiece holding plate.

  Furthermore, the induction hardening method for a shaft-like workpiece according to claim 3 of the present application is the induction hardening method for a shaft-like workpiece according to claim 2, wherein each of the shaft-like workpieces held on the workpiece holding plate by the cooling means. Cooling the workpiece holding plate about the main shaft and rotating each of the shaft-like workpieces about the axis to all the shaft-like workpieces held on the workpiece holding plate. It is characterized by being performed simultaneously.

According to the induction hardening apparatus according to claim 1 of the present application or the induction hardening method according to claim 2 or 3, when quenching is performed on the shaft-shaped workpiece, the shaft-shaped workpiece is heated while revolving and rotating. In addition, it is possible to simultaneously quench a plurality of shaft-like workpieces at a time, thereby improving the processing efficiency.
In addition, according to the induction hardening apparatus according to claim 1 or the induction hardening method according to claim 2 or 3, when quenching the shaft-like workpiece, heating and cooling are performed while the shaft-like workpiece is revolving and rotating. With this configuration, when simultaneously quenching a plurality of axial workpieces at a time, it is possible to uniformly quench all the axial workpieces.

Hereinafter, an induction hardening apparatus according to an embodiment of the present invention will be described with reference to the drawings.
The induction hardening apparatus according to the present invention is for quenching shaft-like workpieces such as steel bolts and steel gears. In this embodiment, the case where the induction hardening apparatus according to the present invention is configured as an induction hardening apparatus for hardening steel bolts will be described as an example.

FIG. 1 is a schematic perspective view of an induction hardening apparatus according to an embodiment of the present invention. 2 is a side cross-sectional view of the induction hardening apparatus shown in FIG. 3 is a side sectional view of a bolt holding hole provided in the induction hardening apparatus shown in FIG.
An induction hardening apparatus 1 shown in FIGS. 1 and 2 includes a workpiece moving unit 2, a high frequency heating coil 3 disposed outside the workpiece moving unit 2, and a vertical direction of the high frequency heating coil 3 (FIGS. 1 and 2). And a cooling means 4 disposed below.

As shown in FIGS. 1 and 2, the workpiece moving unit 2 includes a workpiece holding plate 10 that holds a plurality of bolts (works) B, a first rotating means 20 that rotates the workpiece holding plate 10, and a workpiece holding plate. A moving means 21 for moving 10 in the vertical direction and a plurality of second rotating means 30 for rotating each bolt B held on the work holding plate 10 are provided. In addition, illustration of the 2nd rotation means 30 is abbreviate | omitted in FIG.
As shown in FIG. 1, the work holding plate 10 is formed in a disk shape, and a main shaft 11 that extends upward in the vertical direction is disposed at the center. The work holding plate 10 is formed of an insulator. A plurality (eight in this embodiment) of work holding means 12 are provided at equal intervals on a concentric circle α centered on the main shaft 11 of the work holding plate 10.

As shown in FIG. 3, each work holding means 12 is configured as a through hole into which the threaded portion of the bolt B can be inserted from above. The diameter of each work holding means 12 is set to be equal to or larger than the diameter of the threaded portion of the bolt B and smaller than the diameter of the head of the bolt B. That is, the work holding means 12 can hold the bolt B in a state where the direction in which the shaft extends is the vertical direction.
The first rotating means 20 is configured to be able to rotate the workpiece holding plate 10 in the circumferential direction (direction of arrow A in FIG. 1) via the main shaft 11.
The moving means 21 is configured to be able to move the workpiece holding plate 10 in the vertical direction via the main shaft 11.

  As shown in FIG. 2, each second rotating means 30 includes a pair of sandwiching shafts 31 that extend in the vertical direction and can be opened and closed with each other, and a rotating unit 32 that rotates the pair of sandwiching shafts 31. ing. The pair of clamping shafts 31 clamp the bolts B held by the workpiece holding means 12 of the workpiece holding plate 10 from the vertical direction. And the 2nd rotation means 30 rotates the volt | bolt B clamped by both the clamping shafts 31 in the circumferential direction (arrow C direction shown in FIG. 3), when the rotation part 32 rotates both the clamping shafts 31. FIG. Is possible. Here, each second rotating means 30 is synchronized with each work holding means 12 when each work holding means 12 moves on a concentric circle α centered on the main shaft 11 as the work holding plate 10 rotates. Are configured to move on a concentric circle α. Each of the second rotating means 30 is configured to descend in synchronization with each work holding means 12 when each work holding means 12 is lowered by lowering the work holding plate 10.

As shown in FIGS. 1 and 2, the high-frequency heating coil 3 is arranged in an annular shape on a concentric circle with the main shaft 11 as the center, outside the work holding plate 10. The high-frequency heating coil 3 can heat the bolts B held by the workpiece holding means 12 of the workpiece holding plate 10.
As shown in FIG. 2, the cooling unit 4 is disposed below the high-frequency heating coil 3 in the vertical direction. In this embodiment, the cooling means 4 is configured as a cooling nozzle capable of injecting cooling water. The cooling means 4 is arranged in an annular shape on a concentric circle with the main shaft 11 as the center, and the cooling water L can be injected to the bolts B held by the work holding means 12 of the work holding plate 10. It is possible.

Next, the effect | action at the time of quenching of the volt | bolt B with the induction hardening apparatus 1 is demonstrated.
In the initial state of the induction hardening apparatus 1, the work holding plate 10 is lifted by the moving means 21 and is disposed in the vertical direction above the induction heating coil 3. Moreover, both the clamping shafts 31 of the second rotating means 30 are in an open state.
When quenching the bolt B by the induction hardening apparatus 1, first, the bolt B is inserted into each workpiece holding means 12 of the workpiece holding plate 10 of the induction hardening apparatus 1 in the initial state.

Then, when both clamping shafts 31 of the second rotating means 30 are closed to each other, the bolt B held by each work holding means 12 of the work holding plate 10 is held by the second rotating means 30.
Next, the rotation of the work holding plate 10 by the first rotating means 20 is started, and the rotation of the bolt B held by each work holding means 12 by the second rotating means 30 is started. In this case, each bolt B moves on a concentric circle α about the main shaft 11 (hereinafter referred to as revolution) as the work holding plate 10 is rotated, and each bolt B itself rotates about the axis (hereinafter referred to as “revolution”). , Called autorotation).

  Then, the work holding plate 10 is lowered by the moving means 21 and disposed inside the high-frequency heating coil 3. Thereby, the bolt B held by each work holding means 12 of the work holding plate 10 is heated by the high-frequency heating coil 3. In this case, the heating of the bolts B held by the work holding means 12 by the high-frequency coil 3 is simultaneously performed on all the shaft-like works B held by the work holding plate 10. Further, the bolt B held by each work holding means 12 of the work holding plate 10 is heated by the high frequency heating coil 3 while revolving and rotating. Therefore, according to the induction hardening apparatus 1, it becomes possible to heat-process several bolts B at once, and to heat all the bolts B uniformly.

  After the heating of the bolt B is completed, the work holding plate 10 is lowered by the moving means 21 and disposed inside the cooling means 4. As a result, the bolts B held by the workpiece holding means 12 of the workpiece holding plate 10 are cooled by the cooling means 4. In this case, the cooling of the bolts B held by the work holding means 12 by the cooling means 4 is simultaneously performed for all the shaft-like works B held by the work holding plate 10. Also in this case, the bolts B held by the workpiece holding means 12 of the workpiece holding plate 10 are cooled by the cooling means 4 while revolving and rotating, so that a plurality of bolts B are cooled at a time. Can be performed, and all the bolts B can be uniformly cooled.

After the cooling of the bolt B is completed, the work holding plate 10 is raised by the moving means 21 and is disposed above the high-frequency heating coil 3.
Then, the rotation of the work holding plate 10 by the first rotating means 20 is stopped, and the rotation of the bolts B held by the respective work holding means 12 by the second rotating means 30 is stopped.
Further, the clamping of the bolts B held by the work holding means 12 of the work holding plate 10 by the second rotating means 30 is released, and the bolts B are taken out from the holding means 12.
Thus, quenching of the bolt B by the induction hardening apparatus 1 is completed.

Thus, according to the induction hardening apparatus 1, when performing quenching on the bolt B, by performing the heating and cooling while revolving and rotating the bolt B, quenching a plurality of bolts B at the same time. It is possible to improve the processing efficiency. Further, according to the induction hardening apparatus 1, when quenching the bolt B, by performing heating and cooling while revolving and rotating the bolt B, simultaneously quenching a plurality of bolts B at the same time. It becomes possible to uniformly quench all the bolts B.
Although the embodiments of the present invention have been described above, various modifications can be made in the embodiments of the present invention.
For example, the cooling means 4 is configured as a cooling nozzle in the present embodiment, but may be configured as a cooling tank filled with cooling water.

Next, the effect is compared between the case where the bolt is quenched using the induction hardening apparatus according to the embodiment of the present invention and the case where the bolt is quenched using the induction hardening apparatus according to the comparative example. Will be explained.
FIG. 4 is a diagram comparing the hardness of a bolt quenched by the induction hardening apparatus according to the present invention and the hardness of the bolt quenched by the induction hardening apparatus according to the comparative example.

In the present example, the case where the bolts are quenched by the induction hardening apparatus 1 shown in the above embodiment, the case where the bolts are quenched without rotating each bolt in the induction hardening apparatus 1 is shown. It was set as a comparative example.
In addition, 8 bolts were quenched at a time, and the maximum quenching temperature was 900 ° C. Each bolt to be quenched was M10 size.

And the evaluation of each hardened bolt cut | disconnected the axial part of each bolt, and measured the hardness of the center part with the Vickers hardness meter. Moreover, the measurement was performed 3 times for each bolt.
As shown in FIG. 4, the bolts quenched by the induction hardening apparatus according to the comparative example have a large variation in hardness, whereas they are quenched by the induction hardening apparatus 1 according to the present invention example. The bolts have almost uniform hardness.

It is a schematic perspective view of the induction hardening apparatus which concerns on embodiment of this invention. It is side surface sectional drawing of the induction hardening apparatus shown in FIG. It is side surface sectional drawing of the bolt holding hole provided in the induction hardening apparatus shown in FIG. It is a figure which compares the hardness of the volt | bolt quenched by the induction hardening apparatus which concerns on the example of this invention, and the hardness of the volt | bolt quenched by the induction hardening apparatus which concerns on a comparative example. It is a top view of the non-oxidation induction hardening apparatus of the three-dimensional workpiece | work which concerns on patent document 1. It is a side view of the induction hardening apparatus which concerns on patent document 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction hardening apparatus 2 Work moving part 3 High frequency heating coil 4 Cooling means B Bolt (shaft workpiece)
DESCRIPTION OF SYMBOLS 10 Work holding plate 11 Main shaft 12 Work holding means 20 First rotating means 21 Moving means 30 Second rotating means 31 Holding shaft 32 Rotating part

Claims (3)

A work holding plate disposed so as to be rotatable about a main shaft extending in the vertical direction and provided with a plurality of work holding means on concentric circles centered on the main shaft;
First rotating means for rotating the work holding plate,
Each of the work holding means is an induction hardening apparatus that holds the shaft-like work as a vertical direction in which the axis extends,
A high-frequency heating coil disposed outside the workpiece holding plate in an annular shape on a concentric circle centered on the main shaft;
Cooling means disposed below the high-frequency heating coil;
Moving means for moving the workpiece holding plate in the vertical direction;
An induction hardening apparatus, comprising: a second rotating means for rotating the shaft-like work held by each work holding means about the axis. A plurality of shaft-like workpieces held with the extending direction of the shaft as a vertical direction on a concentric circle around the main shaft of a work holding plate arranged so as to be able to rotate around a main shaft extending in the vertical direction. Heating with a heating coil;
A step of cooling the respective shaft-shaped workpieces held on the workpiece holding plate after the heating step by a cooling means, and induction hardening,
The heating of each of the shaft-like workpieces held on the workpiece holding plate by the high-frequency heating coil causes the workpiece holding plate to rotate about the main axis and causes each of the shaft-like workpieces to rotate about the axis. The induction hardening method is performed simultaneously on all the shaft-like workpieces held on the workpiece holding plate.   Cooling of each of the shaft-like workpieces held on the workpiece holding plate by the cooling means rotates the workpiece holding plate around the main shaft, and rotates each of the shaft-like workpieces around the axis, 3. The induction hardening method according to claim 2, wherein the induction hardening is performed simultaneously on all the shaft-like workpieces held on the workpiece holding plate.

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