JP2023150355A - Induction heating coil and high-frequency hardening device - Google Patents

Abstract

To provide an induction heating coil that can uniformly heat the entire inner wall of a metal member having a hemispherical depression and to provide a high-frequency hardening device including the same.SOLUTION: The induction heating coil is inserted into a hemispherical depression provided on a metal member to be heated. The induction heating coil has a configuration in which a plurality of arc-shaped first conductors 1, second conductors 3a, third conductors 3b, and fourth conductors 5 extending from the bottom to the top portion of an inner wall along the inner wall of the hemispherical depression is provided radially from the bottom to the top portion of the inner wall, and top ends of the plurality of conductors are connected by a fifth conductor 2 and a sixth conductor 4. The high-frequency hardening device uses the induction heating coil.SELECTED DRAWING: Figure 1

Description

The present invention relates to an induction heating coil, particularly an induction heating coil suitable for hardening the inner wall of a hemispherical recess provided in a metal member to be heated, and an induction hardening apparatus using the induction heating coil.

Metal members, such as bearing balls, that have a hemispherical depression on the inner periphery have a rolling surface that is heat-treated by quenching and tempering to ensure the hardness of the rolling surface. For quenching, an induction heating coil is inserted into a hemispherical depression (bowl-shaped hollow part, bottomed bowl-shaped body) formed in the metal member to be heated (Patent Document 1). and 2).

Patent Document 1 states, ``In a multi-turn induction heating coil that is inserted into a bowl-shaped hollow part formed in an object to be heated and rotates relative to the object to be heated around a predetermined rotation axis, The first winding is wound along the side wall of the bowl-shaped hollow portion while the boundary line of two adjacent windings of the plurality of windings is inclined at a predetermined angle within a range of less than 90° with respect to the predetermined rotation axis. An induction heating coil comprising: a conductor portion; and a second conductor portion extending continuously from the first conductor portion along the bottom wall of the bowl-shaped hollow portion.” (Claim 1) ``In the first conductor section 30, as described above, the boundary line 36 between the first turn 32 and the second turn 34 is at an angle within the range of 75 degrees or more and 82 degrees or less with respect to the rotation axis 42. Therefore, when the metal member 10 and the induction heating coil 20 are rotated relative to each other, the position of the portion of the side wall 14 of the metal member 10 facing the boundary line 36 moves moment by moment, and the side wall 14 is almost never heated. As a result, all parts of the side wall 14 are heated evenly. Also, since the second conductor part 40 extends along the bottom wall 16, the metal member 10 and the induction heating coil 20 relative to each other, the position of the part of the bottom wall 16 facing the second conductor part 40 moves moment by moment, and all parts of the bottom wall 16 are heated evenly. Therefore, even if the wire diameter of the induction heating coil 20 is large and the hollow part 12 is small, the side wall 14 of the hollow part 12 can be heated by the first conductor part 30, and the bottom wall 16 can be heated by the second conductor part 40. It is possible to heat the side wall 14 and the bottom wall 16 uniformly.'' (Paragraph [0019]).

Patent Document 2 states, ``The induction hardening apparatus 12 of this example shown in FIG. A high-frequency induction heating coil 14 is arranged corresponding to the curved inner circumferential surface 3b of the mouth portion 3 and heats the inner circumferential surface 3b by high-frequency induction, and an inert gas, a reducing gas, or A gas introduction pipe (gas injection pipe) 15 for introducing a mixed gas of an inert gas and a reducing gas and an opening of the socket part 3 held in the workpiece holding jig 13 are arranged at the upper part thereof. a gas discharge pipe 17 for discharging the gas filled in the housing 16 to the outside of the housing 16; a coolant injection pipe 18 for injecting coolant to the heating part of the socket 3; and a coolant discharge pipe 19 for discharging the coolant accumulated in the housing 16 to the outside of the housing 16.'' (Paragraph [0011]), ``Then, the outer ring 4 is moved to the workpiece holding jig by a workpiece rotation mechanism (not shown). "The high-frequency induction heating coil 14 is made of a copper pipe that can be water-cooled inside, and is rotated together with the receptacle 3. In order to induction heat the groove 8 in a non-contact state, it is wound in a plurality of ways along the shape of the workpiece with a required gap from the surface to be heated.The high frequency induction heating coil 14 has a coil lead. "The high-frequency current is appropriately supplied from the high-frequency power supply 20 via the high-frequency power supply 14a" (paragraph [0013]).

Further, induction heating coils having a shape different from the wound induction heating coils described in Patent Documents 1 and 2 are known (see Patent Documents 3 and 4).

Patent Document 3 states that ``Three conductors shaped to form a predetermined gap with the surface of the irregularly shaped cylindrical member to be treated are disposed in the axial direction along the outer circumferential shape of the irregularly shaped cylindrical member; One ends of the conductors are connected to each other, the other ends of the two conductors on both sides are connected to each other, and a power source is connected to the lead part at the other end of the central conductor and the lead part to which the other ends of the two conductors on both sides are connected. An induction heating coil made of an irregularly shaped cylindrical member, characterized in that a three-legged coil is formed by forming a three-legged coil.''(Claim 1) 12 and 13 are conductors bent into a curve to form a predetermined gap with the surface of the workpiece W, and are arranged to extend in the axial direction along the outer circumferential shape of the workpiece W. One end thereof. 11a, 12a, and 13a are connected by a semicircular conductor 14.'' (Paragraph [0015]), ``On the other hand, the other ends 11b and 13b of the two conductors 11 and 13 on both sides are connected by a semicircular conductor 15. The lead portion 16 is connected from the approximate center of the conductor 15.The lead portion 17 is connected to the other end 12b of the central conductor 12, and an insulating layer is provided between the lead portion 17 and the lead portion 16. Both lead parts are pulled out in parallel with the object 18 in between.The lead part 17 and the lead part 16 are connected to a power source (not shown) to form the three-legged coil 10.'' (Paragraph [0016]) Are listed.

Patent Document 4 states, "In a high-frequency induction heating coil body that performs high-frequency induction heating of the outer circumferential surface of a shaft-like member having a plurality of outer circumferential portions of different diameters or the inner circumferential surface of a cylindrical member having inner circumferential portions of different diameters,
(a) A linear portion disposed parallel to the axial direction of the shaft-like member or the cylindrical member and facing the outer peripheral surface of the shaft-like member or the inner peripheral surface of the cylindrical member. four first, second, third, and fourth heating conductors having
(b) an annular first connecting conductor to which one end portions of the four first, second, third, and fourth heating conductors are respectively connected;
(c) One of the power feeding lead portions of the pair of power feeding lead portions connected to the high frequency power supply, and two of the four first, second, third, and fourth heating conductors. an annular second connection conductor for connecting the other ends of the first and second heating conductors, respectively;
(d) the other of the pair of power feeding lead portions and the third and fourth heating conductors of two of the four first, second, third, and fourth heating conductors; a third connecting conductor having an arc shape for connecting the heating conductor to the heating conductor;
A high-frequency induction heating coil body characterized by comprising the following. '' (Claim 1), and ``As shown in FIG. The first to fourth heating conductors 22, 23, 24 each have a linear portion arranged parallel to the axial direction of the inner shaft 21 and facing the outer circumferential surface 21a of the inner shaft 21. , 25 (Hereinafter, these heating conductors 22 to 25 will be referred to as linear first to fourth heating conductors 22, 23, 24, and 25, since their linear portions constitute the main part) , an annular first connection conductor 26 to which all of one end portions (lower end portions in FIG. 1) of these heating conductors 22 to 25 are connected, and a first connection conductor 26 opposite to the one end portion of the heating conductors 22 to 25 described above. An annular second connection conductor 27 and an arcuate third connection conductor 28 to which two of the other ends (top ends in FIG. 1) of the sides are connected, respectively, and the second connection conductor 27 and the high frequency It is composed of a first power supply lead part 30 connected between the power supply 29 and a second power supply lead part 31 connected between the second connection conductor 28 and the high frequency power supply 29. ” (paragraph [0011]).

Japanese Patent Application Publication No. 11-26150 Japanese Patent Application Publication No. 2007-297718 Japanese Patent Application Publication No. 2002-167618 Patent No. 3733089

When quenching a non-heated metal member without moving it using a wound induction heating coil as described in Patent Documents 1 and 2, the inner wall of the hemispherical depression of the metal member to be heated is In order to heat the metal member uniformly, the metal member to be heated and the induction heating coil were rotated relative to each other, but uniform heating was not sufficient.

In addition, as an induction heating coil, an induction heating coil in which multiple conductors are connected instead of a wound type is also known (see Patent Documents 3 and 4), but the induction heating coil described in Patent Document 3 is The three conductors are arranged along the outer circumferential shape of the irregularly shaped cylindrical member, and are not shown to be inserted into the hemispherical recess. The induction heating coil described in Patent Document 4 has four heating conductors, but the main part is a linear part, and the heating conductor is arranged along the inner wall of a hemispherical depression. It has not been shown to form in this way.

Therefore, an object of the present invention is to provide an induction heating coil that can uniformly heat the entire inner wall of a hemispherical depression provided in a metal member to be heated, and an induction hardening device using the induction heating coil. do.

In order to solve the above problems, the present invention employs the following means.
(1) An induction heating coil inserted into a hemispherical depression provided in a metal member to be heated, the coil being inserted from the bottom to the top of the inner wall along the inner wall of the hemispherical depression. An induction heating coil in which a plurality of extending arcuate conductors are provided radially from the bottom to the top, and the plurality of conductors are connected.
(2) An induction hardening device for induction hardening the inner wall of a hemispherical recess provided in a metal member to be heated, comprising the induction heating coil described in (1) above, An induction hardening device that hardens an inner wall of the hemispherical recess while rotating the induction heating coil relative to the induction heating coil.

In the present invention, the induction heating coil inserted into the hemispherical recess provided in the metal member to be heated has a plurality of conductors provided along the inner wall of the hemispherical recess. This has the effect that the entire inner wall of the hemispherical depression can be uniformly heated and uniformly quenched.

FIG. 1 is a conceptual perspective view of an induction heating coil according to an embodiment of the present invention. FIG. 2 is a conceptual perspective view of a metal member according to an embodiment of the present invention. FIG. 3 is a conceptual front view of an induction hardening apparatus according to an embodiment of the present invention.

(induction heating coil)
The induction heating coil for quenching in the embodiment of the present invention is an induction heating coil inserted into a hemispherical recess provided in a metal member to be heated, and the coil is inserted along the inner wall of the hemispherical recess. , a plurality of arc-shaped conductors extending from the bottom to the top of the inner wall are provided radially from the bottom to the top, and the plurality of conductors are connected.
In this way, the plurality of arc-shaped conductors extending from the bottom to the top of the inner wall of the hemispherical depression are provided radially from the bottom to the top, so that the conductors are provided on the metal member to be heated. The entire inner wall of the hemispherical recess can be uniformly heated and uniformly hardened.

It is preferable that the plurality of arc-shaped conductors be four or more.
By providing four or more arcuate conductors extending from the bottom to the top, the entire inner wall of the hemispherical recess can be heated and hardened more uniformly.

An induction heating coil according to an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described using FIG. 1.

(Heating coil part)
The heating coil portion of the induction heating coil 9 of this embodiment has a circular arc shape extending from the bottom to the top of the inner wall of the recess along the inner wall of the hemispherical recess provided in the metal member to be heated. 1 conductor 1, a second conductor 3a and a third conductor 3b which extend in an arc shape from the bottom to the top apart from the first conductor 1 (the second conductor 3a and the third conductor 3b are connected to each other at the bottom of the inner wall of the recess) A fourth conductor 5 is provided which extends in an arc shape from the bottom toward the top apart from the first conductor 1, the second conductor 3a, and the third conductor 3b.

The four conductors, the first conductor 1, the second conductor 3a, the third conductor 3b and the fourth conductor 5, extending in an arc shape from the bottom to the top, are aligned along the inner wall of the hemispherical depression. They are provided radially from the bottom to the top of the inner wall.
The upper ends of the first conductor 1 and the second conductor 3a adjacent to each other among the conductors are connected by the horizontal fifth conductor 2, and the upper ends of another adjacent third conductor 3b and the fourth conductor 5 among the conductors are connected by the horizontal fifth conductor 2. They are connected by a horizontal sixth conductor 4. That is, the plurality of conductors 1, 2, 3a, 3b, 4, and 5 are connected in this order in a single stroke to form a heating coil section.
Note that the horizontal fifth conductor 2 and sixth conductor 4 are connected to each other at the lower end of the bottom side of the inner wall of the recess, starting from the connection position of the second conductor 3a and third conductor 3b, which are connected to each other at the lower end of the bottom side of the inner wall of the recess. It is preferable to provide an arc shape as shown in FIG. 1 with an imaginary straight line extending linearly from the bottom toward the top as the center point.
It is preferable that the lead portion is provided in such a circular arc shape because it makes it easier to arrange the lead portion, which will be described later.

(Lead part)
In this embodiment, the lower end of the first conductor 1 is connected to a first lead part 6 (6a, 6b) that extends linearly from the bottom to the upper part of the inner wall of the recess, and the lower end of the fourth conductor 5 is connected to A second lead part 7 (7a, 7b) extending linearly from the bottom to the top of the inner wall of the recess is connected, and an insulator 8 is sandwiched between the first lead part 6b and the second lead part 7b. The lead parts 6 and 7 are drawn out in parallel to form an induction heating coil 9 of four conductors 1, 3a, 3b, and 5. 6a and 6b of the first lead part 6 are connected, and 7a and 7b of the second lead part 7 are also connected. The first lead portion 6b and the second lead portion 7b are each connected to a power source (not shown).
That is, the first lead part 6, the plurality of conductors 1, 2, 3a, 3b, 4, 5, and the second lead part 7 are connected in this order in a single stroke to form the induction heating coil 9. In this way, since the induction heating coil 9 is configured in a single stroke, connection to a power source and installation of the coil are facilitated.

(Current flow to induction heating coil)
In this embodiment, when high-frequency power is supplied to the induction heating coil 9, a high-frequency current flows through the induction heating coil 9 at a certain instant along a path in the direction indicated by the arrow R in FIG. High frequency currents alternately flow along paths in the opposite direction to the direction of the arrow R. Specifically, the high-frequency current is transmitted from the first power feeding lead part 6 to an arc-shaped first conductor 1, a horizontal fifth conductor 2, an arc-shaped second conductor 3a, an arc-shaped third conductor 3b, It sequentially flows to the horizontal sixth conductor 4, the arc-shaped fourth conductor 5, and the second power feeding lead portion 7, and vice versa.

(Other configurations of induction heating coil)
The material of the induction heating coil 9 is, for example, copper. The induction heating coil 9 has a flow path through which a cooling liquid flows to cool the induction heating coil 9 itself. In order to cool the induction heating coil 9 itself, when a cooling liquid is injected into the inlet at the upper end of the first lead part 6a by a cooling liquid supply means (not shown), the cooling liquid flows through the arc-shaped first conductor 1, the horizontal 5 conductor 2, an arc-shaped second conductor 3a, an arc-shaped third conductor 3b, a horizontal sixth conductor 4, an arc-shaped fourth conductor 5, and is discharged from the outlet at the upper end of the second lead part 7a. , will be recovered.

(Metal member to be heated having a hemispherical depression)
The induction heating coil of this embodiment is used for hardening the inner wall of a metal member to be heated having a hemispherical depression as shown in FIG.
The hemispherical depression formed in the metal member to be heated does not have to be a half-spherical shape, and includes a half-spherical depression that is shallower than a half-spherical shape. Conversely, it may be a spherical surface deeper than half.
The metal member is preferably a steel member, and carbon steel, for example, can be used as the steel member.

(Induction hardening equipment)
An induction hardening apparatus for induction hardening the inner wall of a heated metal member 10 (hereinafter referred to as the metal member 10) having a hemispherical recess is equipped with the above-mentioned induction heating coil 9, and the metal member 10 The inner wall of the hemispherical recess is hardened by the induction heating coil 9 while rotating the induction heating coil 9 relatively.

FIG. 3 shows the configuration of the induction hardening apparatus 15 according to this embodiment.
A metal member 10 having a hemispherical recess is placed and fixed by a fixing means (not shown) on a rod-shaped member 11a of a rotary table 11 for rotating the metal member 10, and the rotary table 11 is a base. 12 so that it can move vertically and rotatably.
Further, the induction heating coil 9 is arranged above the metal member 10.
The metal member 10 is placed on the rod-shaped member 11a of the rotary table 11 so that the hemispherical depression faces upward, and the induction heating coil 9 is placed on the rod-shaped member 11a of the rotary table 11 so that the hemispherical recess faces upward. It is arranged along the inner wall of the planar depression with a required gap from the heated surface, which is the inner wall.
Contrary to the above, instead of moving the rotary table 11 up and down, the induction heating coil 9 may be moved up and down.

In the induction heating coil 9, between the inside of the heating coil part and the lead parts 6 and 7, the induction heating coil 9 is cooled from the outside, and the inside of the hemispherical depression of the metal member 10 is also cooled (quick cooling). ) is provided with a cooling jacket 13 for cooling. The cooling jacket 13 may be placed outside the induction heating coil 9.
Cooling fluid is supplied to the cooling jacket 13 from a pipe 13a, and the cooling fluid is discharged from a cooling fluid supply hole (not shown) provided at the lower end of the cooling jacket 13 located above the heating coil portion of the induction heating coil 9. , the heating coil portion and the inner wall of the hemispherical recess of the high-frequency heated metal member 10 are rapidly cooled.

In hardening the inner wall of the hemispherical recess of the metal member 10 using the induction hardening device 15, the following method is used.
The metal member 10 is placed on the rotary table 11 so that the hemispherical recess faces upward, and the induction heating coil 9 is inserted into the hemispherical recess so that the bottom of the hemispherical recess is placed. While the metal member 10 is rotated around the rotation axis passing through the center of the wall, the inner wall (bottom wall and side walls) is heated to a predetermined temperature and subjected to high-frequency induction heating, and then the cooling liquid is supplied from the cooling jacket 13 to the metal member 10. It is hardened by supplying it to the inner wall of the hemispherical depression of the member 10 and rapidly cooling it. As a result, the inner wall of the hemispherical depression is uniformly heated to a uniform depth at any position, and a hardened layer with a uniform depth is obtained on the inner wall of the hemispherical depression.

The induction hardening device 15 according to the present embodiment injects a cooling liquid from the upper part of the rotary table 11 (below the metal member 10) to heat the hemispherical recess during high-frequency induction heating or during quenching during rapid cooling. Preferably, a cooling device 14 is provided for cooling the opposite side of the metal member 10.
That is, it is preferable that the rotary table 11 is provided with a coolant injection hole 14a, a hose or the like (not shown) is connected to the rotary table 11 to supply the coolant, and the coolant is injected from the above-mentioned injection hole 14a.
In this way, by providing the cooling device 14 that cools the opposite side of the inner wall of the hemispherical recess of the metal member 10 during induction heating, the quenching depth of the inner wall and the amount of heat of the metal member 10 can be controlled. can do.

In the induction hardening device 15 described above, the metal member 10 is placed at the bottom and the induction heating coil 9 is placed at the top. However, as shown in Patent Document 1, the metal member is placed upside down. It is also possible to place the induction heating coil at the bottom.
When the metal member is placed on the top and the induction heating coil is placed on the bottom, in this embodiment, the bottom of the induction heating coil 9 becomes the top, the top becomes the bottom, the top becomes the bottom, and the bottom becomes the top.
Further, in the above case, a cooling device for rapidly cooling the metal member is also provided at the top.

Further, the induction hardening apparatus according to the present invention includes an induction heating coil, and can harden the inner wall of the hemispherical depression while relatively rotating the metal member to be heated and the induction heating coil. If possible, the structure is not limited to the structure shown in FIG. 3, and a wide variety of structures can be used.

By induction hardening using the induction heating coil of the present invention, it is possible to uniformly heat the inner wall of a metal member (particularly a steel member) having a hemispherical recess, resulting in uniform hardening. Therefore, it can be effectively used for induction hardening of metal members (particularly steel members) where the inner wall of the recess needs to be hardened.

1: Arc-shaped conductor (first conductor) extending from one location on the bottom toward the top
2: Horizontal conductor (fifth conductor) connecting the upper end of the first conductor 1 and the upper end of the second conductor 3a
3a: An arcuate conductor portion (second conductor) that is part of the conductor 3 and extends from a location on the bottom away from the conductor 1 toward the top.
3b: An arc-shaped conductor portion (third conductor) extending from a location on the bottom away from the first conductor 1 toward the top in the opposite direction to the second conductor 3a.
4: Horizontal conductor (sixth conductor) connecting the upper end of the third conductor 3b and the upper end of the fourth conductor 5
5: Arc-shaped conductor extending from one place on the bottom toward the top (fourth conductor)
6 (6a, 6b): Lead part connected to the lower end of conductor 1 and extending in the axial direction (first lead part)
7 (7a, 7b): Lead part connected to the lower end of the conductor 5 and extending in the axial direction (second lead part)
8: Insulator 9: Induction heating coil 10: Metal member to be heated 11: Turntable 11a: Rod-shaped member 12: Base 13: Cooling jacket 13a: Cooling liquid supply pipe 14: Cooling device 14a: Cooling water injection hole 15: Induction hardening equipment

Claims (2)

An induction heating coil inserted into a hemispherical recess provided in a metal member to be heated, the induction heating coil having an arcuate shape extending from the bottom of the inner wall toward the top along the inner wall of the hemispherical recess. A plurality of conductors are provided radially from the bottom toward the top, and the plurality of conductors are connected. An induction hardening apparatus for induction hardening an inner wall of a hemispherical recess provided in a metal member to be heated, comprising the induction heating coil according to claim 1, wherein the metal member to be heated and the induction heating coil are An induction hardening device that hardens the inner wall of the hemispherical depression while relatively rotating the two.

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