JP2014232615A - Heating device for multi-stage shaft member, heating method and heating coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device and method for a multi-stage shaft member capable of simultaneously heating a large-diameter shaft part and a small-diameter shaft part to an equal extent and further simplifying the shape of a heating coil.SOLUTION: When simultaneously heating a large-diameter shaft part W1 of a workpiece W and a small-diameter shaft part W2 which is provided coaxially with the large-diameter shaft part W1, by serially electrifying a first coil 21 and a second coil 31 while making the first coil 21 opposite to an outer peripheral surface of the large-diameter shaft part W1, making the second coil 31 opposite to an outer peripheral surface of the small-diameter shaft part W2 and rotating the workpiece W, while using the second coil 31 including a pair of extension conductor parts 32 extending in one direction and a connection conductor part 33 connecting the pair of extension conductor parts 32 at a distal end side, the small-diameter shaft part W2 is disposed between the pair of extension conductor parts 32, a separation distance between the small-diameter shaft part W2 and the connection conductor part 33 is adjusted in such a manner that the small-diameter shaft part W2 can be heated at an equal extent to the large-diameter shaft part W1, and the first coil 21 and the second coil 31 are electrified.

Description

  The present invention relates to a heating device, a heating method, and a heating coil for a multistage shaft member that induction-heats the outer peripheral surface of a large-diameter shaft portion and the outer peripheral surface of a small-diameter shaft portion that are provided coaxially.

  When manufacturing a multi-stage shaft member having a large-diameter portion and a small-diameter portion on the same axis, heat treatment such as quenching is performed by induction heating the outer peripheral surface of the large-diameter portion and the outer peripheral surface of the small-diameter portion with a heating coil. Has been done.

  For example, in Patent Document 1 below, a stepped shaft that heats each outer peripheral surface portion provided on a stepped shaft-shaped workpiece using a heating coil having a plurality of arc portions having an inner diameter slightly larger than each outer peripheral surface portion. A high-frequency heating device for a workpiece has been proposed. In this heating apparatus, the heating coil and the workpiece are relatively moved, and the respective arc portions are sequentially brought close to each outer peripheral surface portion to be heated. In this heating apparatus, since the plurality of outer peripheral surface portions are sequentially heated by moving the heating coil, the cycle time is long and the production efficiency is poor.

  Patent Document 2 below proposes an induction heating coil of a multi-stage shaft member in which a plurality of annular conductors are connected in series and the axial lengths of the annular conductors are different so that the areas of the heated parts are substantially equal. Has been. In this heating coil, each current diameter portion is uniformly heated by reducing the current density of the annular conductor facing the large diameter portion of the workpiece and increasing the current density of the annular conductor facing the small diameter portion of the workpiece. Therefore, a plurality of diameter portions from the small diameter portion to the large diameter portion can be heated at a time, and the production efficiency can be improved.

JP2003-119519A WO2005 / 107324

  However, in the induction heating coil as in Patent Document 2, in order to adjust the current density of each annular conductor, the shape of each annular conductor tends to be complicated, and it takes time to manufacture the heating coil. In addition, when the shafts have the same diameter but have different axial lengths, separate heating coils are required, and a plurality of heating coils are used for one type of workpiece. In order to do so, a variety of heating coils had to be prepared.

  Therefore, in the present invention, it is an object to provide a heating device and a heating method for a multi-stage shaft member that can simultaneously heat the large-diameter shaft portion and the small-diameter shaft portion to the same extent and that can simplify the shape of the heating coil, It is another object of the present invention to provide a heating coil that can be suitably used for the heating device and the heating method.

  The heating device for a multi-stage shaft member of the present invention that achieves the above object includes a first coil opposed to an outer peripheral surface of a large-diameter shaft portion of a workpiece, and an outer peripheral surface of a small-diameter shaft portion provided coaxially with the large-diameter shaft portion. A multi-stage shaft member that inductively heats the large-diameter shaft portion and the small-diameter shaft portion simultaneously by energizing the first coil and the second coil in series while rotating the workpiece. In the heating device, the second coil includes a pair of extended conductor portions that extend in one direction and are oppositely disposed on both radial sides of the small-diameter shaft portion, and a connecting conductor portion that connects the pair of extended conductor portions on the distal end side. The distance between the small-diameter shaft portion and the connecting conductor portion arranged between the pair of extended conductor portions can be adjusted by relatively moving the small-diameter shaft portion and the second coil along one direction. It has become.

  The heating method for a multi-stage shaft member according to the present invention that achieves the above object is such that the first coil is opposed to the outer peripheral surface of the large-diameter shaft portion of the workpiece, and the outer peripheral surface of the small-diameter shaft portion provided coaxially with the large-diameter shaft portion. A heating method for a multi-stage shaft member in which a large diameter shaft portion and a small diameter shaft portion are simultaneously induction-heated by energizing the first coil and the second coil in series while rotating the workpiece while facing the second heating coil. A second coil comprising a pair of extended conductor portions extending in one direction and a connecting conductor portion connecting the pair of extended conductor portions on the distal end side is prepared, and a small diameter shaft portion is provided between the pair of extended conductor portions. The pair of extended conductor portions are opposed to both sides of the small-diameter shaft portion, and the distance between the small-diameter shaft portion and the connecting conductor portion is such that the small-diameter shaft portion is heated to the same extent as the large-diameter shaft portion. This is a method in which the first coil and the second coil are energized.

  The heating coil that achieves the other object is a heating coil that performs induction heating while rotating the shaft portion of the workpiece, and connects a pair of extension conductor portions extending in one direction and a pair of extension conductor portions on the tip side. A space for disposing the shaft portion between the pair of extended conductor portions, and the separation distance between the shaft portion disposed in the space and the connecting conductor portion can be adjusted. Yes.

  According to the present invention, the relative movement of the workpiece and the second coil along one direction intersecting the axis of the workpiece allows the small-diameter shaft portion disposed between the pair of extended conductor portions and the connection conductor portion. Can be adjusted. Therefore, it is possible to adjust the amount of heat generated in the small-diameter shaft portion by induction heating by adjusting the area where the second coil and the small-diameter shaft portion are closely opposed to each other. As a result, when the first and second coils are energized in series to simultaneously heat the large-diameter shaft portion and the small-diameter shaft portion, the heating amount of the small-diameter shaft portion is adjusted so that the small-diameter shaft portion becomes the large-diameter shaft portion. It is possible to heat to the same degree.

In addition, the second coil has a complicated shape as long as a space having a size capable of adjusting the separation distance between the small-diameter shaft portion and the connecting conductor portion is formed between the pair of extended conductor portions extending in one direction. There is no need.
Therefore, the large-diameter shaft portion and the small-diameter shaft portion can be simultaneously heated to the same extent, and the shape of the heating coil can be simplified.

It is a perspective view which shows the principal part of the heating apparatus in embodiment of this invention. It is a fragmentary sectional view showing arrangement of the 1st coil of the heating device in the embodiment of the present invention, and the 2nd coil. It is a principal part top view which shows arrangement | positioning of the 2nd coil of the heating apparatus in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the workpiece W to be heated of the present embodiment is a multistage shaft member in which a large diameter shaft portion W1 and a small diameter shaft portion W2 are provided coaxially. The outer peripheral surface of the large-diameter shaft portion W1 and the outer peripheral surface of the small-diameter shaft portion W2 have a circular cross section around the axis C. Heated regions are respectively provided on a part of the outer peripheral surface in the axial direction of the large-diameter shaft part W1 and a part of the outer peripheral surface in the axial direction of the small-diameter shaft part W2. Note that the inside of the large-diameter shaft portion W1 is hollow.

The heating apparatus according to the present embodiment can heat and rapidly cool the heated regions of the large-diameter shaft portion W1 and the small-diameter shaft portion W2 of the workpiece W so that each heated region is uniformly quenched over the entire circumference.
As shown in FIG. 1, the heating device includes a workpiece support portion 11 that supports a workpiece W and rotates around a shaft C, a first coil 21 that heats a large-diameter shaft portion W1, and a first coil 21. A second coil 31 that is connected in series to heat the small-diameter shaft portion W2 and a coil base 13 that supports the first coil 21 and the second coil 31 are provided.

The coil base 13 includes a fixed support portion 14 that fixes and supports the first coil 21 at a predetermined position, a movable support portion 15 that can be adjusted in position by moving the second coil 31 in a direction intersecting the axis C, and a workpiece. And a power feeding unit 16 for feeding the first coil 21 and the second coil 31 with high-frequency power adjusted according to W and each coil.
The heating device is provided with a cooling unit such as a jacket for bringing the coolant into contact with the heated workpiece W, but the detailed illustration is omitted.

  As shown in FIGS. 1 and 2, the first coil 21 of the heating device includes a pair of one-turn annular conductor portions 22 surrounding the outer periphery of the large-diameter shaft portion W <b> 1 and a pair of ends connected to both ends of the annular conductor portion 22. 1st connection conductor part 23 is provided. The annular conductor portion 22 has an inner side surface formed in a constant circular cross section, and can be disposed with high precision and a predetermined gap with a heated region on the outer peripheral surface of the large-diameter shaft portion W1. One of the pair of first connection conductor portions 23 is connected to the power feeding portion 16 and the other is connected to the second coil. The annular conductor portion 22 and the first connecting conductor portion 23 are capable of passing a cooling liquid therein.

  The fixed support portion 14 that supports the first coil 21 can fix the pair of first connection conductor portions 23 to accurately align the center of the annular conductor portion 22 with the axis C of the workpiece W. The fixed support part 14 fixes the 1st coil 21 so that attachment or detachment is possible, and the 1st coil 21 according to the workpiece | work W can be fixed.

  As shown in FIGS. 1 to 3, the second coil of the heating device includes a pair of extended conductor portions 32 that extend in a direction intersecting with the axis C and are opposed to both radial sides of the outer peripheral surface of the small-diameter shaft portion W2. The connection conductor portion 33 that connects the pair of extension conductor portions 32 on the distal end side, the end conductor portions 34 provided on the other end side of the pair of extension conductor portions 32, and the end conductor portions 34, respectively. A pair of second connecting conductor portions 35, and a space S is formed between the pair of extended conductor portions 32. One of the pair of second connection conductor portions 35 is connected to the power feeding portion 16, and the other is connected to the first connection conductor portion 23 of the first coil. Note that each conductor portion is capable of passing a cooling liquid therein.

  The pair of extended conductor portions 32 are respectively provided in a straight line and arranged in parallel to each other, and the inner side surfaces are flat surfaces parallel to each other. The connecting conductor portion 33 has an arc shape projecting outward, specifically a semicircular shape, and the inner side surface has a constant semicircular cross section. These are the left and right objects with respect to the center line intersecting the axis C of the workpiece W.

  Inner side surfaces on the workpiece W side of the pair of extended conductor portions 32 and connecting conductor portions 33 are formed so as to accurately follow the heated region on the outer peripheral surface of the small-diameter shaft portion W2. The separation distance between the inner side surfaces of the pair of extended conductor portions 32 is longer than the diameter of the small-diameter shaft portion W2. The pair of extended conductor portions 32 can be disposed to oppose each other with high accuracy by providing a predetermined gap between the portion of the small diameter shaft portion W2 and the heated region on the outer peripheral surface of the small diameter shaft portion W2 at a position closest to the small diameter shaft portion W2. Yes.

As shown in FIG. 3, the length in the direction intersecting the axis C of the workpiece W in the space S is such that the magnetic field and end portions generated in the connecting conductor portion 33 when energized when the workpiece W is arranged at the center in the longitudinal direction of the space S. It is preferable that the work W is not induction-heated by the magnetic field generated in the conductor portion 34, or has a length that can be reduced to such an extent that the heating amount can be ignored.
Here, the separation distance between the inner side surface of the connecting conductor portion 33 and the inner side surface of the end conductor portion 34 is at least three times the diameter of the workpiece W. That is, when the workpiece W is arranged in the center in the longitudinal direction of the space S, the workpiece W and the connecting conductor portion 33 can be separated by a length corresponding to the diameter of the workpiece W. A length separation corresponding to the diameter of the workpiece W can be made between the conductor portion 34.
Thereby, when the small-diameter shaft portion W2 is arranged at the center in the longitudinal direction of the space S, it can be heated by a magnetic field generated mainly at a portion where the pair of extended conductor portions 32 face each other during energization.

The movable support portion 15 that supports the second coil 31 may support the second coil 31 so as to be movable along one direction intersecting the axis C of the workpiece W. For this purpose, a pair of second connection conductor portions 35 of the second coil 31 is fixed, and a slide member 17 is provided that is mounted on a support (not shown) so as to be able to advance and retract. For example, even if the slide member 17 has a structure in which the operator adjusts the advance / retreat amount and fixes the slide member 17 to the support body, the slide member 17 is configured to adjust the advance / retreat amount by being driven forward / backward by a driving device attached to the support body. Also good.
Since the second coil 31 is configured to be movable back and forth by the movable support portion 15, the pair of second connection conductor portions 35 is a connection line having flexibility between the power supply portion 16 and the first coil 21. Connected by.

Next, a method for heat-treating a large number of workpieces W having the same shape using a heating apparatus having such a configuration will be described.
In order to heat the workpiece W, first, the first coil 21 and the second coil 31 having shapes corresponding to the heating regions of the large-diameter shaft portion W1 and the small-diameter shaft portion W2 are prepared. The first coil 21 is fixed to the fixed support portion 14 of the coil base 13, the second coil 31 is fixed to the movable support portion 15 of the coil base 13, and the first coil 21 and the second coil 31 are connected in series. At the same time, the power supply unit 16 is connected. Then, after the position of the second coil 31 is adjusted, heat treatment is performed by heating and cooling a number of workpieces W.
The position adjustment of the second coil 31 can be completed by fixing the second coil 31 to the movable support portion 15 of the coil base 13 when an appropriate position is known in advance according to the workpiece W. .

  In order to fix the first coil 21 to the fixed support part 14, the first coil 21 is arranged so that the axis C of the work W supported by the work support part 11 and the axis of the annular conductor part 22 coincide with each other, and a pair of first connections The conductor part 23 is fixed to the fixed support part 14. At that time, the annular conductor portion 22 of the first coil 21 has a gap set in advance around the entire circumference except for the vicinity of the first connection conductor portion 23 with respect to the heated region on the outer peripheral surface of the large-diameter shaft portion W1. , Make the opposing arrangement with high accuracy.

  In order to fix the second coil 31 to the movable support portion 15, the small-diameter shaft portion W <b> 2 of the workpiece W supported by the workpiece support portion 11 is disposed in the space S between the pair of extended conductor portions 32, and the pair of second coils 31. The connecting conductor portion 35 is fixed to the slide member 17 of the movable support portion 15. The pair of extended conductor portions 32 are arranged to face the heated region on the outer peripheral surface of the small-diameter shaft portion W2 with high accuracy so as to form a preset gap on both sides in the diameter direction.

In the position adjustment of the second coil 31, the distance between the small diameter shaft portion W2 and the connecting conductor portion 33 is adjusted by moving the slide member 17 along one direction intersecting the axis C.
As shown in FIG. 3, the space S between the pair of extended conductor portions 32 has a size that allows the small-diameter shaft portion W <b> 2 to be relatively movable in the direction intersecting the axis C of the workpiece W, and thus is disposed in the space S. By moving the small-diameter shaft portion W2 and the second coil 31 relative to each other, the separation distance between the small-diameter shaft portion W2 and the connecting conductor portion 33 is appropriately changed.

In the position adjustment, when the large-diameter shaft portion W1 is heated by the first coil 21, the first coil 21 is connected in series with the first coil 21 under conditions set so that the heated region of the large-diameter shaft portion W1 can be heated to a desired degree. The heated region of the small diameter shaft portion W2 is heated by the second coil 31 connected to the same extent as the large diameter shaft portion W1.
The conditions set so that the heated region of the large-diameter shaft portion W1 can be heated to a desired level include, for example, the rotational speed of the workpiece W by the workpiece support portion 11, the energization time, the frequency of the high-frequency power, and the like. Good.
Further, heating to the same extent means that the depth and temperature of the heated region, and the depth and hardness of the quenching region obtained by rapid cooling thereafter can be regarded as equivalent.

When the separation distance between the small-diameter shaft portion W2 and the connecting conductor portion 33 is reduced, the heating amount of the heated region can be increased by the magnetic field generated in the connecting conductor portion 33, and the small-diameter shaft portion W2 and the connecting conductor portion 33 can be increased. The heating amount can be reduced by increasing the separation distance. When the region to be heated of the small-diameter shaft portion W2 is most strongly heated by the second coil 31, the small-diameter shaft portion W2 becomes a predetermined gap with respect to the connecting conductor portion 33 as shown by an imaginary line in FIG. It only has to be close.
Then, the slide member 17 is fixed at that position while the distance between the small-diameter shaft portion W2 and the connecting conductor portion 33 is optimally adjusted, and the second coil 31 position adjustment is completed.

After the position adjustment, a number of workpieces W are sequentially supported by the workpiece support unit 11, high-frequency power is fed from the feeding unit 16 while rotating the workpiece W, and the first coil 21 and the second coil 31 are energized in series. The large-diameter shaft portion W1 and the small-diameter shaft portion W2 are simultaneously induction-heated.
Further, after the heating, the quenching process for each heated region is completed by bringing the cooling liquid into contact and quenching.

According to the heating method using the above heating device, the small-diameter shaft portion W2 is disposed between the pair of extended conductor portions 32 of the second coil 31, and the workpiece W and the second portion are arranged along one direction intersecting the axis C. By moving the coil 31 relatively, the separation distance between the small-diameter shaft portion W2 and the connecting conductor portion 33 can be adjusted. Therefore, it is possible to adjust the amount of heat generated in the small-diameter shaft portion W2 by induction heating by adjusting the area where the second coil 31 and the small-diameter shaft portion W2 are close to each other and face each other. Accordingly, when the first coil 21 and the second coil 31 are energized in series to simultaneously heat the large-diameter shaft portion W1 and the small-diameter shaft portion W2, the heating amount of the small-diameter shaft portion W2 is adjusted and the small-diameter shaft portion is adjusted. It is possible to heat W2 to the same extent as the large diameter shaft portion W1.
Moreover, the first coil 21 may be formed in a simple shape corresponding to the large-diameter shaft portion W1, and the second coil 31 has a small-diameter shaft portion W2 and a connecting conductor between a pair of extended conductor portions 32 extending in one direction. It is only necessary to form a space S having a size capable of adjusting the separation distance from the portion 33, and it is not necessary to form a complicated shape.
Therefore, the large-diameter shaft portion W1 and the small-diameter shaft portion W2 can be simultaneously heated to the same extent, and the shape of the heating coil can be simplified.

In addition, the said embodiment can be suitably changed in the scope of the present invention.
For example, in the above description, the example of the workpiece W having two shaft portions of the large-diameter shaft portion W1 and the small-diameter shaft portion W2 has been described as the multistage shaft member, but the number of shaft portions may be three or more. Well, the number is not limited. In that case, the shaft portion having the maximum diameter may be heated by the first coil 21 and the other shaft portions may be heated by the second coil 31 corresponding to the respective shaft portions. It is possible to heat it.
In the above description, the second heating coil has the pair of extended conductor portions 32 formed in parallel to each other, but is not particularly limited. For example, a pair of extension conductor portions 32 are arranged at different positions in the rotation axis C direction, and the pair of extension conductor portions 32 are connected by a connecting conductor portion 33 inclined obliquely, or a pair of extension conductor portions 32. It is possible to appropriately change the shape such that the gap is close on the connecting conductor portion 33 side and separated on the end conductor portion 34 side.
Further, in the above description, the heated regions of the large-diameter shaft portion W1 and the small-diameter shaft portion W2 each have a columnar shape having a constant circular cross section. However, as long as the first coil 21 and the second coil 31 can be arranged facing each other and heated. There is no particular limitation. For example, a heated region may be provided over the entire length of the large-diameter shaft portion W1 and the entire small-diameter shaft portion W2, and each heated region is formed on an uneven surface such as a tapered surface or a spline inclined along the axial direction. It may be. In that case, you may use the 1st coil 21 and the 2nd coil 31 which respond | corresponded to the virtual surface used as a reference | standard accurately.

S Space W Work W1 Large diameter shaft portion W2 Small diameter shaft portion 11 Work support portion 13 Coil base 14 Fixed support portion 15 Movable support portion 16 Power feeding portion 17 Slide member 21 First coil 22 Annular conductor portion 23 First connection conductor portion 31 2 coil 32 extension conductor part 33 connection conductor part 34 end conductor part 35 2nd connection conductor part

Claims (3)

A first coil opposed to the outer peripheral surface of the large-diameter shaft portion of the workpiece, and a second heating coil opposed to the outer peripheral surface of the small-diameter shaft portion provided coaxially with the large-diameter shaft portion, and rotating the workpiece A heating device for a multi-stage shaft member that inductively heats the large-diameter shaft portion and the small-diameter shaft portion simultaneously by energizing the first coil and the second coil in series,
The second coil includes a pair of extended conductor portions that extend in one direction and are disposed opposite to both sides in the radial direction of the small-diameter shaft portion, and a connecting conductor portion that connects the pair of extended conductor portions on the distal end side. ,
By relatively moving the small diameter shaft portion and the second coil along the one direction, a separation distance between the small diameter shaft portion disposed between the pair of extension conductor portions and the connection conductor portion is increased. A heating device for a multi-stage shaft member that can be adjusted. The first coil is opposed to the outer circumferential surface of the large-diameter shaft portion of the workpiece, the second heating coil is opposed to the outer circumferential surface of the small-diameter shaft portion provided coaxially with the large-diameter shaft portion, and the workpiece is rotated while rotating the workpiece. A heating method for a multi-stage shaft member, wherein the first coil and the second coil are energized in series to simultaneously inductively heat the large-diameter shaft portion and the small-diameter shaft portion,
Preparing the second coil including a pair of extended conductor portions extending in one direction and a connecting conductor portion for connecting the pair of extended conductor portions on the distal end side;
The small-diameter shaft portion is disposed between the pair of extended conductor portions so that the pair of extended conductor portions are opposed to both sides of the small-diameter shaft portion, and the small-diameter shaft portion is heated to the same extent as the large-diameter shaft portion. Adjusting the separation distance between the small-diameter shaft portion and the connecting conductor portion,
A method for heating a multi-stage shaft member, wherein the first coil and the second coil are energized. It is a heating coil that performs induction heating while rotating the shaft part of the workpiece,
A pair of extended conductor portions extending in one direction, and a connecting conductor portion for connecting the pair of extended conductor portions on the tip side,
A heating coil in which a space for arranging the shaft portion is provided between the pair of extended conductor portions, and a separation distance between the shaft portion arranged in the space and the connecting conductor portion can be adjusted.

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