JP2010027483A - Induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating device capable of evenly induction-heating the peripheral surface of a sprocket, in which the width of the top and the width of the bottom of a gear tooth are different from each other. <P>SOLUTION: The induction heating device 1 induction-heats the peripheral surface 11 of a sprocket 2, in which the top width d1 and the bottom width d2 of a gear tooth are different from each other, and includes an annular heating coil 3. The heating coil 3 includes a part 5 formed narrow in width and a part 4 formed wide in width. In the heating coil 3, the circumferential length of the part 5 formed narrow in width and the circumferential length of the part 4 formed wide in width are formed nearly equal to each other, and the part 5 formed narrow in depth and the part 4 formed wide in width are arranged each other, and width dimension D2 of the part 5 formed narrow in the width of the heating coil 3 is formed nearly equal to the width dimension d2 of the bottom 7 of the gear tooth the sprocket 2, and width dimension D1 of the part 4 formed wide in the width of the heating coil 3 is formed nearly equal to the width dimension d1 of the top 6 of the gear tooth of the sprocket 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating apparatus for induction heating an outer peripheral surface of a gear or a sprocket.

  When induction heating of the teeth on the outer peripheral surface of the sprocket (or gear), if the tooth tip and bottom of the tooth are induction heated separately, a continuous hardened layer cannot be formed on the entire circumference, improving the rigidity of the entire sprocket. I can't let you.

  Therefore, as disclosed in Patent Document 1 and Patent Document 2, when the sprocket is induction-heated with an annular heating coil, the induced current flows from the tooth tip to the tooth bottom along the outer peripheral surface of the sprocket, and from the tooth bottom to the tooth tip. It becomes possible to form a continuous hardened layer over the entire circumference of the outer peripheral surface.

  As disclosed in Patent Document 1, an annular heating coil of an induction heating device that induction-heats the outer peripheral surface of a sprocket is well known. In the sprocket manufacturing method of Patent Document 1, a process is disclosed in which an annular heating coil is arranged around the sprocket and the tooth surface is induction-heated.

  In the sprocket manufacturing method of Patent Document 1, a general sprocket manufacturing method is disclosed in which the diameter is relatively small, and the width of the tooth tip and the width of the tooth bottom is uniform. As shown, an annular heating coil is arranged around the sprocket, and the tooth surface (outer peripheral surface) of the sprocket is induction-heated.

  FIG. 6 of Patent Document 2 also depicts a state in which an annular high frequency induction heating coil is disposed on the outer periphery of the sprocket. In the example of FIG. 6 of Patent Document 2, the high-frequency induction heating coil undulates in accordance with the shape of the teeth, and performs a quenching operation without moving the sprocket.

As disclosed in Patent Document 1 and Patent Document 2, when the outer peripheral surface of the sprocket is induction-heated, an annular current is flown so that an induced current flows from the tooth tip to the tooth bottom and from the tooth bottom to the tooth tip. A heating coil is often employed. Thus, by using the annular heating coil, a continuous hardened layer can be formed on the outer peripheral surface of the sprocket.
JP-A-8-143967 JP-A-5-156345

  By the way, there are various shapes and sizes of sprockets (or gears). For example, sprockets used for power transmission on endless tracks used in construction machines and the like have a tooth tip width of the root. Some are larger than the width. Conventionally, regardless of the shape of the sprocket (or gear), it is an annular shape as depicted in FIG. 4 of Patent Document 1 or FIG. It was induction heated with a coil. That is, an annular heating coil having a uniform width is disposed opposite to the outer peripheral surface of the sprocket (or gear) whose tooth tip width is larger than the tooth bottom width, and induction heating is performed. As a result, a difference in the quenching depth is likely to occur, and in particular, the end surface portion and the center portion of the tooth bottom are difficult to be hardened uniformly.

  Further, the heating coil depicted in FIG. 6 of Patent Document 2 is bent along the shape of the sprocket teeth, and the heating coil does not rotate with respect to the sprocket during induction heating. Therefore, the entire circumference of the sprocket is not heated evenly, especially because the heating coil sandwiches the tooth tip, the quenching of the tooth tip part becomes deeper than other parts, and furthermore, the shape of the heating coil is complicated, Production cost increases.

  Then, an object of this invention is to provide the induction heating apparatus which can equalize the induction heating of the outer peripheral surface of the gearwheel and sprocket from which the width | variety of a tooth tip differs from the width | variety of a tooth root.

  The invention of claim 1 for solving the above-mentioned problem is an induction heating device for induction heating the outer peripheral surface of a gear or sprocket having a different tooth tip width and tooth bottom width, and includes an annular heating coil, The heating coil and the gear or the sprocket are relatively rotatable, and the heating coil has a portion configured to be narrow and a portion configured to be wide. Device.

  In the invention of claim 1, since the heating coil and the gear or the sprocket are relatively rotatable, the outer peripheral surface of the gear or the sprocket is heated evenly. Furthermore, since the heating coil has a portion having a narrow width and a portion having a wide width, a portion having a narrow width and a wide portion that can be heated can be formed. Thereby, when the outer peripheral surface of a gear or sprocket having a different tip width and bottom width is induction-heated, it is possible to equalize the quenching depth of the outer peripheral surface of the gear or sprocket.

  The invention according to claim 2 is characterized in that the heating coil is ring-shaped, and has a portion configured to be narrow and a portion configured to be wide in one turn. This is an induction heating device.

  In the invention of claim 2, since the heating coil has a ring shape and has a portion configured to be narrow and a portion configured to be wide in one turn, the configuration can be simplified. .

  According to a third aspect of the present invention, in the heating coil, the length in the circumferential direction of the portion configured to be narrow and the portion configured to be wide are approximately the same. It is an induction heating apparatus of description.

  In the invention of claim 3, since the circumferential length of the portion of the heating coil that is configured to be narrow and the portion of the configuration that is configured to be wide are approximately the same, the outer peripheral surface of the sprocket is heated with a narrow width. The opportunity to be heated and the opportunity to be heated widely are even. Thereby, excessive heating of the wide tooth tip is prevented, and heating of the tooth root far from the heating coil can be sufficiently performed. Here, having the same length means that the difference between the two is less than 10 to 20%.

  In the invention of claim 4, the width dimension of the portion where the width of the heating coil is configured is approximately the same as the width dimension of the tooth bottom of the gear or sprocket, and the width dimension of the portion where the width of the heating coil is configured wide The induction heating device according to any one of claims 1 to 3, characterized in that is approximately equal to a width dimension of a tooth tip of a gear or a sprocket.

  In the invention of claim 4, the width dimension of the portion where the width of the heating coil is configured is the same as the width dimension of the tooth bottom of the gear or the sprocket, and the width dimension of the portion where the width of the heating coil is configured wide. Is approximately the same as the width of the tooth tip of the gear or sprocket, so that the gear or sprocket is heated appropriately. Here, that the width dimension is comparable means that the difference between the two is less than 10 to 20%.

  When the present invention is implemented, when the outer peripheral surface of a gear or sprocket having a different tip width and bottom width is induction-heated, the quenching depth of the outer peripheral surface of the gear or sprocket can be equalized.

  FIG. 1 is a front view of the induction heating device of the present invention, where (a) shows a state immediately before the sprocket is placed in the heating coil, and (b) shows a state in which the sprocket is placed in the heating coil. Show. As shown in FIG. 1 (a), an induction heating apparatus 1 of the present invention is a pedestal on which a high-frequency power source, a transformer, a water tank 14 for storing a coolant 21 and a sprocket 2 (or gears) similar to a known induction heating apparatus are placed. 12, a heating coil 3, and a driving device 13 for rotating and raising and lowering the pedestal 12 are provided. A partition 27 is provided inside the water tank 14, and a coolant 21 is stored in a chamber above the partition 27.

  The driving device 13 is disposed in a room below the water tank 14, and a rotating shaft 28 that supports and rotates the pedestal 12 penetrates the partition 27 while keeping the watertight. The rotary shaft 28 can be moved up and down by an elevating mechanism (not shown) provided in the drive device 13, and the rotary shaft 28, the pedestal 12, and the sprocket 12 move up and down integrally. Thereby, at the time of induction heating, the sprocket 2 can be disposed inside a heating coil 3 described later on the liquid surface, or the sprocket 2 after induction heating can be submerged in the cooling liquid 21 of the water tank 14 and cooled. Furthermore, the drive device 13 can rotate the sprocket 2 together with the base 12 by the rotating shaft 28 during induction heating.

  Below, the shape of the sprocket 2 which is the object of induction heating will be described first, and then the structure of the heating coil 3 which is a characteristic part of the induction heating device 1 of the present invention will be described. FIG. 2 is a perspective view of a sprocket that is induction-heated by the induction heating apparatus of the present invention. FIG. 3 is a partially enlarged view of the sprocket, (a) is a partially broken front view, (b) is a view taken along the line bb of (a), and (c) and (d) are (a). FIG. FIG. 3C shows a quenching state when induction heating is performed by the induction heating device of the present invention, and FIG. 3D is a quenching state when induction heating is performed by a conventional induction heating device. It is shown.

  The sprocket 2 that performs quenching with the induction heating device 1 of the present invention is used for a construction machine having a diameter of 400 mm or more. As shown in FIG. 2, the sprocket 2 includes a flat plate portion 9. A hole 10 through which the drive shaft passes is provided in the central portion of the flat plate portion 9. An annular outer peripheral portion 11 is formed on the outer peripheral edge of the flat plate portion 9, and teeth 8 are formed on the annular outer peripheral portion 11 (outer peripheral surface).

  The width of the tooth 8 of the sprocket 2 is not constant, and the width d1 of the tooth tip 6 is larger than the width d2 of the center portion 7a of the tooth bottom 7. That is, the bottom 7 is constricted, and the width of the bottom 7 becomes wider as it goes away from the tooth tip 6 (that is, it becomes narrower as it approaches the center portion 7a). Therefore, in the annular outer peripheral portion 11, the central portion 7a portion of the tooth bottom 7 is most easily induction-heated.

  The induction heating apparatus 1 of the present invention for induction heating the sprocket 2 which is a workpiece having a non-uniform thickness and width dimension of the annular outer peripheral portion 11 as described above includes a heating coil 3 having the following configuration. . FIG. 4 is a perspective view of a heating coil provided in the induction heating apparatus of the present invention.

  As shown in FIG. 4, the heating coil 3 of the induction heating device 1 has a one-turn shape. As shown in FIG. 1, a wide portion 4 having a wide width is formed on one end side, and on the other end side. A narrow portion 5 having a narrow width is formed. The difference between the width dimension D1 of the wide portion 4 and the width dimension d1 of the tooth tip 6 of the sprocket 2 is less than 10 to 20%. The difference between the width dimension D2 of the narrow portion 5 and the width dimension d2 of the central portion 7a of the tooth bottom 7 of the sprocket 2 is also less than 10 to 20%. Furthermore, the difference of the length of the circumferential direction of the wide part 4 and the narrow part 5 is also less than 10-20%, and both are connected on the way.

  The heating coil 3 is supplied with power from a high frequency power source after being amplified by a transformer. A cooling water passage (not shown) for allowing the cooling water to pass therethrough is provided inside the heating coil 3 so that the heating coil 3 does not burn out during induction heating. The width of the cooling water passage is set to be wide in the wide portion 4 and narrow in the narrow portion 5. That is, the thickness of the heating coil 3 is made uniform. Therefore, when the cooling water is supplied to the cooling water passage, the heating coil 3 is cooled substantially uniformly.

  The heating coil 3 is disposed above the water tank 14 (FIG. 1) so that the annular center line C faces the vertical direction. And at the time of induction overheating, the sprocket 2 is driven up by the drive device 13 and disposed in the heating coil 3 so that the center of the sprocket 2 is on the center line C of the heating coil 3.

  Moreover, although the sprocket 2 is rotationally driven by the drive device 13, the distance from the heating coil 3 to the sprocket 2 is constant at any rotational position. That is, the distance from the heating coil 3 to the sprocket 2 is different between the tooth tip 6 portion and the tooth bottom 7 portion, but the distance to the heating coil 3 in each part is unchanged. For example, the distance from the tooth tip 6 to the heating coil 3 and the distance from the tooth bottom 7 to the heating coil 3 are unchanged.

  As described above, the thickness of the annular outer peripheral portion 11 of the sprocket 2 is non-uniform, the thickness of the tooth bottom 7 is relatively thin, and the width of the central portion 7a is larger than the width of other portions. It is narrower. For this reason, in the tooth bottom 7 (particularly the central portion 7a), the quenching depth is likely to be deeper than other portions. However, the heating coil 3 of the induction heating apparatus 1 embodying the present invention includes the wide portion 4 and the narrow portion 5, and the tooth tip 6 is deeply quenched, but the tooth bottom 7 (central portion 7a). Is not deeply quenched.

  That is, when the sprocket 2 is rotated by the driving device 13, the respective tooth tips 6 and the respective tooth bottoms 7 alternately face the wide portion 4 and the narrow portion 5. Accordingly, the wide tooth tip 6 is heated extensively and deeply, and the narrow tooth bottom 7 (center portion 7a) is separated from the heating coil 3 and is heated by the narrow portion 5. Since the range becomes narrow, it is heated almost evenly.

  As a result, as shown in FIG. 3A, the quenching depth of the annular outer peripheral portion 11 (outer peripheral surface) is substantially uniform from the tooth tip 6 to the tooth bottom 7. That is, in FIG. 3A, the region indicated by hatching that rises to the left is the quenching portion 23 that has been induction-heated. The quenching portion 23 is continuously formed from the tooth tip 6 to the tooth bottom 7 in the annular outer peripheral portion 11 of the sprocket 2.

  In FIG. 3A, only a part of the quenching portion 23 (that is, the hardened layer) is depicted, but actually, it is continuously formed over the entire circumference of the sprocket 2. Therefore, the sprocket 2 induction-heated by the induction heating device 1 is provided with wear resistance and rigidity over the entire periphery.

  Moreover, as shown in FIG.3 (c), the quenching depth of the tooth root 7 of the sprocket 2 becomes substantially the same (linear shape) in both ends and the center part. In FIG. 3 (c), the part indicated by hatching that rises to the left is the quenched part 23. This quenching part 23 is embossed by etching the cross section of the sprocket 2 after induction heating (quenching).

  Incidentally, FIG. 3D shows a quenching portion 24 when the sprocket 2 of the same type is induction-heated with a conventional heating coil that does not have the wide portion 4 and the narrow portion 5. When the sprocket 2 is induction-heated with an annular heating coil having a uniform width around the entire circumference, as shown in FIG. 3 (d), there is a difference in the quenching depth between the both ends and the center of the bottom 7 of the sprocket 2. End up. That is, both end portions are quenched deeper than the central portion.

  Although the heating coil 3 includes the wide portion 4 and the narrow portion 5, a heating coil 15 as shown in FIG. 5 may be employed instead. FIG. 5 is a perspective view of a heating coil that can be employed in the induction heating apparatus of the present invention, different from the heating coil of FIG.

  As shown in FIG. 5, in the heating coil 15, the copper pipe 25 is branched into the hollow pipes 16 and 17 having the same thickness at the branch part 19, and the pipes 16 and 17 are joined at the joining part 20. To the conduit 26. Cooling water is supplied into the hollow pipe lines 16 and 17. The current supplied to the heating coil 15 is an alternating current. However, for the sake of explanation, it is assumed that the current is a direct current. The current and the cooling water branch from the pipe 25 to the pipes 16 and 17 at the branch portion 19. And then merges at the merging portion 20 and reaches the pipe 26. That is, in the pipes 16 and 17, the current flows in the same direction, and the induced current generated in the workpiece (sprocket) is not canceled out.

  Moreover, the pipe lines 16 and 17 are bent in the middle, and step portions 28 and 18 are formed. Therefore, the intervals between the pipes 16 and 17 are different on both sides of the step portions 28 and 18. That is, the distance between the two on the branching portion 19 side (width disposed opposite to the workpiece) is D1, and the distance between the two on the junction 20 side (width disposed opposite to the workpiece) is D2. Thereby, the heating coil 15 can have the same effect as the heating coil 3 described above.

  Although the example in which the wide part 4 and the narrow part 5 of the heating coil 3 (, 15) are each divided into two regions has been described above, the wide part and the narrow part are alternately arranged. A heating coil may be configured as described above.

In addition, it is preferable to adjust suitably the electric power supplied to the heating coil 3 or the heating coil 15, and the heating time according to the magnitude | size and shape of the sprocket 2 to be induction-heated.
Moreover, although the example which rotates the sprocket side was shown in the above-mentioned embodiment, even if it rotates the heating coil side, the same effect is acquired.

  Next, a modification of the heating coil shown in FIGS. 4 and 5 is shown in FIG. FIG. 6 is a perspective view of a heating coil that can be employed in the induction heating device of the present invention, different from the heating coil of FIGS. 4 and 5.

  The heating coil 30 shown in FIG. 6 has a structure in which the pipe line 25 branches into the pipe line 16 and the pipe line 17 at the branching portion 19, similarly to the heating coil 15 in FIG. 5. The interval between the pipe line 16 and the pipe line 17 (the width facing the workpiece) is D1 as in the heating coil 15.

  The other ends of the pipes 16 and 17 branched at the branching portion 19 are bent and connected to the pipe 31. The width of the pipe line 31 is D2 similarly to the heating coil 3 of FIG. Therefore, the pipe line 31 of the heating coil 30 has the same configuration as the narrow portion 5 of the heating coil 3. Step portions 28 and 18 are formed at portions where the pipeline 16 and the pipeline 17 are connected to the pipeline 31.

  A pipe 26 is connected to the other end side of the pipe 31. Therefore, the power supplied from the pipe 25 side (actually an alternating current but assumed to be a direct current) and cooling water branch into the pipe 16 side and the pipe 17 side at the branching section 19. And then merge again in the pipe 31 to reach the pipe 26. The direction in which power or cooling water flows may be reversed. That is, electric power or cooling water may be supplied from the pipeline 26 side and recovered from the pipeline 25 side. The heating coil 30 configured in this way can achieve the same effects as the heating coils 3 and 15 described above.

  Furthermore, the modification of the heating coil shown in FIGS. 4-6 is shown in FIG. FIG. 7 is a perspective view of a heating coil that can be employed in the induction heating apparatus of the present invention, which is different from the heating coil of FIGS. 4 to 6.

  The heating coil 40 shown in FIG. 7 has a structure in which the branch portion 19 is not provided and the pipe line 25 makes two rounds like the heating coil 15 in FIG. As shown in FIG. 7, the pipeline 25 does not branch on the way, and includes bent portions 41a, 41b, 42a, 42b, 43a, 43b, and 44a, 44b. By these bent portions, a wide portion 45 having a width D1 and a narrow portion 46 having a width D2 are formed between the pipeline 25 in the first round and the pipeline 25 in the second round. That is, the heating coil 40 is configured by bending the pipe 25. Moreover, the length of the circumferential direction of the wide part 45 and the narrow part 46 is comparable (the difference of both is less than 10 to 20%).

  In such a heating coil 40, since the current flowing on the pipe line 25 does not branch in the middle, induction heating equivalent to that of the heating coil 15 is performed with less current (about half the current) than the heating coil 15 shown in FIG. be able to.

  The sprocket according to the present embodiment is used for power transmission of an endless track (caterpillar) employed in construction machines or the like, but has teeth with different tooth tip widths and tooth bottom widths. If it is a sprocket (or gear), it can harden equally by induction heating with the induction heating apparatus of this invention irrespective of a use.

It is a front view of the induction heating apparatus of this invention, (a) has shown the state just before arrange | positioning a sprocket in a heating coil, (b) has shown the state which has arrange | positioned the sprocket in a heating coil. It is a perspective view of the sprocket which carries out induction heating with the induction heating apparatus of this invention. It is the elements on larger scale of a sprocket, (a) is a partially broken front view, (b) is a bb arrow line view of (a), (c) and (d) are cc section arrows of (a). FIG. It is a perspective view of the heating coil provided in the induction heating apparatus of this invention. It is a perspective view of the heating coil which can be employ | adopted for the induction heating apparatus of this invention different from the heating coil of FIG. It is a perspective view of the heating coil which can be employ | adopted for the induction heating apparatus of this invention different from the heating coil of FIG. 4, FIG. It is a perspective view of the heating coil which can be employ | adopted for the induction heating apparatus of this invention different from the heating coil of FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction heating apparatus 2 Sprocket 3 Heating coil 4 Wide part of heating coil 5 Narrow part of heating coil 6 Sprocket tooth tip 7 Sprocket tooth bottom 8 Sprocket tooth 11 Annular outer periphery (outer peripheral surface)
15 Heating coil 23 Quenching part 30 Heating coil d1 Sprocket tooth tip width d2 Sprocket tooth bottom width D1 Heating coil wide part width D2 Heating coil narrow part width

Claims (4)

  An induction heating device that induction-heats the outer peripheral surface of a gear or sprocket having a different tip width and bottom width, and is provided with an annular heating coil, and the heating coil and the gear or sprocket are relatively rotatable. The induction heating apparatus is characterized in that the heating coil has a portion having a narrow width and a portion having a wide width.   The induction heating apparatus according to claim 1, wherein the heating coil has a ring shape and has a portion configured to be narrow and a portion configured to be wide in one turn.   The induction heating apparatus according to claim 1 or 2, wherein the length of the heating coil in the circumferential direction is substantially the same as that of the portion configured to be narrow and the portion configured to be wide.   The width dimension of the part where the width of the heating coil is configured is the same as the width dimension of the tooth bottom of the gear or sprocket, and the width dimension of the part where the width of the heating coil is configured is The induction heating device according to any one of claims 1 to 3, wherein the induction heating device is approximately equal to a width dimension.

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