JPH0730671Y2 - High frequency heating coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a high frequency coil (hereinafter simply referred to as a heating coil), and particularly, for example, as an inner surface of a hub unit used in an automobile or the like, or a raceway of a bearing. The present invention relates to a heating coil used when high-frequency heating is performed on recesses on both sides of the to-be-quenched product (workpiece) having the protrusions and recesses on the inner wall of the apertures in the depth direction of the hole.

<Prior Art> A conventional technology will be described below with reference to the drawings.

FIG. 6 is a cross-sectional explanatory view of a hub unit used in an automobile or the like. A hole is formed in the inner wall 18 of the substantially cylindrical hole 17 formed in the hub unit, which is the workpiece 10 placed on the table 19.
The annular recesses 11 and 12 each having a substantially arcuate cross section are formed in the depth direction of the groove 17, and the annular projection 13 is provided between the recesses 11 and 12.
Are formed. In some cases, it is required to form the hardened layer in the concave portions 11 and 12 but not to form the hardened layer in the convex portion 13.

In such a case, the 2-turn same-direction winding coil 20 shown in FIG. 7A or the 2-turn different-direction winding coil 30 shown in FIG. 7B is usually used.

The same-direction winding coil 20 has a first arc portion 21 and a second arc portion 22 connected to the tips of the two power supply conductors 24 and 25, respectively, and currents flowing through these arc portions are in the same direction. Both arcs are connected so that they are in series. Further, between the two arc portions, three arc-shaped conductor segments 23 made of copper and supported by the power supply conductor 25 are provided.

"The different direction winding coil 30 is also provided with the power supply conductors 24 and 25, the first arc portion 21 and the second arc portion 22 like the same direction winding coil 20. Both arcs are connected so that the direction of the flowing current is opposite, and no arc-shaped conductor segment is provided.

In order to quench the recesses 11 and 12 of the hub unit 10 using the same-direction winding coil 20 or the different-direction winding coil 30, the first and second arcuate portions 21 and 22 are arranged corresponding to the recesses 11 and 12, respectively. After the high-frequency current is applied to the same-direction winding coil 20 or the different-direction winding coil 30 for a predetermined time, the cooling liquid is sprayed from the jacket (not shown) to the recesses 11 and 12.

<Problems to be Solved by the Invention> However, when a two-turn coil of the same-direction winding is used, the arc-shaped conductor segment is easily heated and deteriorated by induction, and a two-turn coil of the different-direction winding is used. At times, the magnetic field generated by the coil of one turn is reduced by the magnetic field generated by the coil of the other turn, so there is a problem that the power efficiency for heating the work is poor.

The present invention has been made in view of the above circumstances, and overcomes the disadvantages of the same-direction winding coil and the different-direction winding coil described above, and has two annular recesses on the inner surface and is located between these recesses. It is an object of the present invention to provide a heating coil capable of forming a hardened layer on a concave portion of a work having an annular convex portion and heating the work without forming the hardened layer on the convex portion.

<Means for Solving the Problems> In order to solve the above problems, the heating coil of the present invention is
The surface of the first and second annular concave portions formed in the depth direction of the hole on the inner wall of the hole formed in the work is heated, and the surface of one annular convex portion formed between these concave portions is not heated. In the high-frequency heating coil, first and second conductors, which are arranged so as to face each other substantially parallel to each other in the central portion of the hole, and one ends of the first and second conductors are connected to one another, and are separated from each other. Third and fourth arranged as
The conductor, the fifth and sixth conductors, one end of each of which is connected to the other ends of the first and second conductors and are arranged so as to be distant from each other, and the other ends of the third and fourth conductors are connected to each other.
And an arc-shaped seventh conductor that is disposed so as to project substantially at a right angle to the second conductor and is arranged so as to face the first recess, and the other ends of the fifth and sixth conductors are connected to each other. An arc-shaped eighth conductor that is disposed so as to project in a direction substantially perpendicular to the second conductor and in a direction opposite to the seventh conductor and that is arranged so as to face the second recess, and the first and second conductors face each other. The magnetic bodies attached to the first and second conductors so as to cover the surfaces other than the surfaces that are formed, and the surfaces other than the surfaces of the seventh and eighth conductors that face the first and second recesses, respectively. A magnetic body attached to the seventh and eighth conductors,
1st, 2nd, 3rd, 4th, 5th, 6th, 7th or 8th
And a pair of power supplies connected to the cut surface of any one of the conductors.

<Operation> The first and second conductors do not generate magnetic flux in these conductors in the direction of the inner wall of the work due to the magnetic substance. 3rd, 4th, 5th
Since the sixth conductor and the sixth conductor are arranged in a direction away from the inner wall of the work, few magnetic fluxes generated by these conductors cross the inner wall of the work. The magnetic flux generated by the seventh and eighth conductors crosses the first and second recesses on the inner wall of the work by the magnetic material provided in these conductors to heat the surfaces of these recesses, and Since it does not intersect, the surface of the convex portion is not heated.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 5 to FIG. 5 are drawings for explaining an embodiment of the present invention, FIG. 1 is a schematic perspective view showing the basic structure of a heating coil, and FIG. 2 and FIG. The typical perspective view of the heating coil of 2nd Example, FIG. 4 (a),
(B) and (c) are lines A-A and B- in FIG. 1, respectively.
Sectional views taken along the lines B and C--C, and FIG. 5 is A-- in FIG.
It is an A line arrow cross section explanatory view.

The heating coil 40 of this embodiment is the work 10 described in FIG.
A heating coil that heats the surfaces of the recesses 11 (first recesses) and 12 (second recesses) of the inner wall 18 of the above, but does not heat the surface of the protrusions 13. As shown in FIG. Ignoring the connection between the first and second conductors 41, 42, which are linear and have equal lengths, which are arranged so as to face each other substantially in parallel at the center of the hole 17 of the work 10. First and second conductors 41, 42, one end of each of which is connected to one end of each of the first and second conductors 41, 42, and linear third and fourth linear conductors 43, 44 which are arranged so as to be distant from each other;
Linear and equal lengths of fifth and sixth conductors 4 which are connected to the other end of the second conductor and are arranged apart from each other.
5, 46 and the other ends of the third and fourth conductors 43, 44 are connected to each other so as to protrude substantially at right angles to the first and second conductors 41, 42 and to be opposed to the recess 11 of the work 10. The arc-shaped seventh conductor 47 and the other ends of the fifth and sixth conductors 45 and 46 are connected to each other in a direction substantially perpendicular to the first and second conductors 41 and 42 and the seventh conductor 47.
And an arc-shaped eighth conductor 48 arranged so as to project in the opposite direction and to face the recess 12 of the work 10.

The heating coil 40 is made of ferrite or the like attached to the first and second conductors 41 and 42 so as to cover the surfaces of the first and second conductors 41 and 42 excluding the surfaces 41a and 41b facing each other. The seventh and eighth conductors 47 and 48 are formed so as to cover the surfaces of the magnetic cores 51 and 52 and the seventh and eighth conductors 47 and 48 except the surfaces 47a and 48a facing the recesses 11 and 12 of the work 10, respectively. And magnetic cores 53 and 54 made of ferrite or the like.

Practically, as the first embodiment, a heating coil 40a as shown in FIG. 2 is used. The heating coil 40a cuts a connection portion between the second conductor 42 and the fourth conductor 44, and power supply conductors 49, 50 connected to a high frequency power source (not shown) on the cut surface.
Is connected. When the heating coil 40a is manufactured, the power supply conductor 49 and the second conductor 42 are integrally formed.

As a second embodiment, a heating coil 40 as shown in FIG.
b is also used. The heating coil 40b is formed by connecting power supply conductors 49 and 50, which are connected to a high frequency power source (not shown), to the cut surface of the central portion of the arc-shaped seventh conductor. In this case, the range of the distance d between the power supply conductors 49 and 50 does not contribute to the heating of the recess 11. Therefore, in order to make the heating amount of the concave portion 11 by the seventh conductor 47 and the heating amount of the concave portion 12 by the eighth conductor 48 the same, the length 2a of the seventh conductor 47 and the length b of the eighth conductor 48 are set. It is necessary to form the seventh conductor 47 and the eighth conductor 48 so that they are equal to each other.

Generally, the connection method of the high frequency power source as shown in FIG. 2 is common.

Next, the operation of this embodiment will be described.

As shown in FIG. 6, while rotating the work 10 placed on the table 19 in the direction of arrow D by a rotating device (not shown), the heating coil 40a or the heating coil 40b is inserted into the hole 17 of the work 10, After the seventh conductor 47 and the eighth conductor 48 are installed close to each other so as to face the recesses 11 and 12, respectively, both ends of the power supply conductors 49 and 50 are connected to a high frequency power source (not shown), and the heating coil 40a or A high frequency current is applied to the heating coil 40b.

In this case, the magnetic fluxes generated by the seventh conductor 47 and the eighth conductor 48 are concentrated on the surfaces of the recesses 11 and 12 and in the vicinity thereof due to the presence of the cores 53 and 54, and do not intersect with the recess 13. Further, since the magnetic fluxes generated by the first and second conductors 41, 42 are mainly generated by the cores 51, 52 in the center direction of the hole 17 of the work 10, that is, in the direction away from the inner wall 18 of the hole 17, the recess 11, These magnetic fluxes do not cross the 12 and the convex portion 13. Furthermore, the third
The currents flowing through the conductor 43, the fourth conductor 44, the fifth conductor 45 and the sixth conductor 46 are in the direction perpendicular to the inner wall 18, and since these conductors are arranged in the direction away from the inner wall 18 of the hole 17, Few magnetic fluxes generated by these conductors cross the inner wall 18.

Further, since the seventh conductor 47 and the eighth conductor 48 project in the opposite directions, the facing portions of the recesses 11 and 12 are not heated at the same time. The heating of the convex portion 13 is less than in the case of using the conventional same-direction winding coil or different-direction winding coil.

Therefore, after energizing the heating coil 40a or the heating coil 40b,
Recessed quench liquid from the quenching liquid injection jacket (not shown) 1
When sprayed onto 1 and 12, the hardened layer 15 is formed on the concave portions 11 and 12, but not on the convex portion 13.

The power supply conductors 49 and 50 are not limited to being connected as in the above-described embodiment, but can be connected to the cut surface of any of the first to eighth conductors. However, when the heating coil is inserted into the hole 17 of the work 10, the power supply conductors 49 and 50 are arranged so as not to contact the inner wall 18 of the hole 17, and the power supply conductors 49 and 50 are generated. It is necessary to dispose the magnetic field to the inner wall 18 of the hole 17 so as not to cross as much as possible.

In addition, the above-mentioned first to eighth conductors and power supply conductors 49, 50
Is usually made of a hollow pipe made of a good conductive metal.
Then, the heating coil can be cooled by circulating the cooling liquid in the hollow portions of these conductors.

<Effects of the Invention> As described above, the heating coil of the present invention includes the first to eighth conductors, and the inner arc-shaped seventh and eighth conductors of these conductors are the first and the first inner wall of the work, respectively. The magnetic body is attached so as to face the concave portion of the second conductor and to cover the surfaces of the seventh and eighth conductors other than the surface facing the concave portion, and the magnetic field generated by the first and second conductors is applied to the work. The magnetic body is attached to the first and second conductors so as not to face the inner wall of the
There are few magnetic fields generated by other conductors that cross the inner wall of the work, and the arc-shaped seventh and eighth conductors that heat the recess are made to project in opposite directions from the first and second conductors. As a result, the opposing portions of the first and second recesses are prevented from being heated at the same time.
It is possible to heat the surfaces of the concave portions and not to heat the surfaces of the convex portions between these concave portions.

That is, since the high-frequency heating coil of the present invention does not require the arc-shaped conductor segment provided in the two-turn coil of the same direction, there is no problem of deterioration of this segment.
Further, since the magnetic flux generated by the seventh conductor and the magnetic flux generated by the eighth conductor do not cancel each other out, it is possible to overcome the drawback of the one-turn different direction winding coil that the power loss is large.

[Brief description of drawings]

1 to 5 are drawings for explaining one embodiment of the present invention. FIG. 1 is a schematic perspective view showing the basic structure of a heating coil, and FIGS. 2 and 3 are respectively Schematic perspective views of the heating coils of the first and second embodiments, FIGS. 4 (a), (b) and (c) are respectively AA of FIG.
Line, BB line and CC line arrow sectional view, FIG.
It is an AA line arrow cross section explanatory drawing of a figure. 6 and 7 are drawings for explaining a conventional technique, and FIG. 6 is a sectional explanatory view of a work, FIG. 7 (a).
Is a perspective view of a two-turn same-direction winding coil, and FIG. 7 (b) is a perspective view of a two-turn different-direction winding coil. 10 …… Workpiece, 11 …… First recess, 12 …… Second recess,
13: convex part, 17: hole, 18: inner wall, 41: first conductor,
42 ... second conductor, 43 ... third conductor, 44 ... fourth conductor, 45
...... Fifth conductor, 46 ...... Sixth conductor, 47 ...... Seventh conductor, 48 ...
… Eighth conductor, 49, 50 …… Power supply conductor, 51 ～ 54 …… Core.

Claims (1)

[Scope of utility model registration request] 1. A single annular convex portion formed between these concave portions by heating the surfaces of first and second annular concave portions formed in the inner wall of the hole formed in the work in the depth direction of the hole. In a high-frequency heating coil that does not heat the surface of the first and second conductors, which are disposed so as to face each other in substantially parallel to each other in the central portion of the hole, and one ends of the first and second conductors are connected to each other. Third arranged so as to be separated from each other
And a fourth conductor, and fifth and sixth conductors, one end of each of which is connected to the other ends of the first and second conductors and which are arranged apart from each other, and the other ends of the third and fourth conductors are connected to each other. And connecting the other ends of the fifth and sixth conductors with the arc-shaped seventh conductor which is disposed so as to project substantially at right angles to the first and second conductors and which is arranged so as to face the first recess. An arc-shaped eighth conductor, which is disposed so as to project in a direction substantially perpendicular to the first and second conductors and in a direction opposite to the seventh conductor, and is arranged so as to face the second recess, and first and second conductors Magnetic bodies attached to the first and second conductors so as to cover surfaces of the first and second conductors other than the surfaces facing each other;
Magnetic bodies attached to the seventh and eighth conductors so as to cover the surfaces of the conductors except the surfaces facing the first and second recesses, respectively, and the first, second, third, fourth, fifth, 6th and 7th
Or a pair of power supply bodies connected to a cut surface of one of the eighth conductors.