JP3304297B2 - High-frequency three-sided heating coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency three-sided heating coil for simultaneously heating three surfaces of an inner peripheral surface, an outer peripheral surface, and an end surface between both surfaces of a cylindrical workpiece.

[0002]

2. Description of the Prior Art The three surfaces W1, W2, W3 of a cylindrical work W having an inner peripheral surface W1 and an outer peripheral surface W2 concentrically and having an end surface W3 between both peripheral surfaces W1, W2 are simultaneously heated. As the high-frequency three-sided heating coil, there was one as shown in FIG.

The high-frequency three-sided heating coil includes a heating conductor 500 for simultaneously heating three surfaces of an inner peripheral surface W1 and an outer peripheral surface W2 of a cylindrical workpiece W and an end surface W3 between the two peripheral surfaces; A high-frequency three-sided heating coil having a power supply conductor section 600 for supplying a high-frequency current to the coil 500;
A pair of arc-shaped outer peripheral surface heating conductors 510A, 510B
A substantially semicircular inner peripheral surface heating conductor portion 520 along the inner peripheral surface W1, a pair of end surface heating conductor portions 530A and 530B along the end surface W3, and an end surface heating conductor portion 530.
A, 530B and the outer peripheral surface heating conductor portions 510A, 510
B and a pair of outer connecting conductors 540A, 540
B, and a pair of inner connecting conductors 550A and 550B for connecting the end surface heating conductor portions 530A and 530B and the inner peripheral surface heating conductor portion 520. The end surface heating conductor portions 530A and 530B are It is formed straight in a substantially I-shape when viewed.

[0004] That is, the end surface heating conductor 530A has an outer connection conductor 540A and an inner connection conductor 550A connected to both ends, and has a substantially inverted concave shape as a whole. In addition, the end face heating conductor portion 530B has outer connection conductors 5 at both ends.
40B and the inner connecting conductor 550B are connected to each other to form a substantially inverted concave shape as a whole.

When high-frequency heating is performed on a cylindrical workpiece W using the high-frequency three-sided heating coil, the cylindrical workpiece W
While rotating about its own central axis. Thereby, the entire outer peripheral surface W2, the inner peripheral surface W1, and the end surface W3 can be heated. Thereafter, if the heated portion is rapidly cooled by spraying a cooling liquid or the like, a hardened layer associated with induction hardening can be formed.

[0006]

However, the above-mentioned conventional high-frequency three-sided heating coil has the following problems. In other words, when induction hardening is performed using this high-frequency three-sided heating coil, the center is not constant, and the center of the end face tends to be shallower or the inner peripheral surface side tends to be deeper.

This is due to the fact that the end surface heating conductor is formed straight in a substantially I-shape in plan view. That is, since the outer portion of the end face heating conductor is heated per unit time, the inner portion of the end face heating conductor is larger than the area heated per unit time, so that an optimal hardened layer is formed on the inner peripheral surface. To prioritize the heating of the inner peripheral surface,
Of the end faces heated by the end face heating conductor, the outer part is less heated than the inner part. For this reason,
The hardened layer formed especially on the outer portion of the end face becomes shallower.

Conversely, if the heating of the end face is prioritized in order to form an optimal hardened layer on the end face, a portion heated inside the end face heating conductor portion is excessively heated, and as a result, it is formed on the inner peripheral surface. The hardened layer becomes too deep.

The present invention has been made in view of the above circumstances, and can simultaneously heat the three inner surfaces, the outer peripheral surface, and the end surface at the same time. It is an object of the present invention to provide a high-frequency three-sided heating coil capable of obtaining a cured layer of

[0010]

A high-frequency three-sided heating coil according to the present invention comprises: a heating conductor portion for simultaneously heating three surfaces of an inner peripheral surface, an outer peripheral surface, and an end surface between both peripheral surfaces of a cylindrical work; A high-frequency three-sided heating coil having a power supply conductor for supplying a high-frequency current to the heating conductor, wherein the heating conductor comprises a pair of substantially 1/4 arc-shaped outer peripheral surface heating conductors along the outer peripheral surface; A substantially semi-circular inner surface heating conductor along the inner surface, a pair of end surface heating conductors along the end surface, and connecting the end surface heating conductor to the outer surface heating conductor. to a pair of outer connection conductors, and a pair of inner coupling conductor portion connecting the inner peripheral surface heating conductor portion and the end surface heating conductor portion, said end face heating conductor portion, the outer
An outer edge heating section inward from the upper end of the side connection conductor section;
Central heating section that connects to the outer edge heating section at an obtuse angle outward
And the inner edge heating section connected at right angles to this central heating section.
Surface that the central heating unit heats per unit time
Product and the area that the inner edge heating unit heats per unit time
They are set equal .

[0011]

[0012]

FIG. 1 is a schematic plan view of a high-frequency three-sided heating coil according to an embodiment of the present invention. FIG. 2 is a schematic side view of a high-frequency three-sided heating coil according to an embodiment of the present invention. 3 is a sectional view taken along line AA of the high-frequency three-sided heating coil according to the embodiment of the present invention, and FIG. 4 is a schematic plan view of a high-frequency three-sided heating coil according to another embodiment of the present invention.

The high-frequency three-sided heating coil according to the embodiment of the present invention is a high-frequency hardened three-sided surface of the cylindrical workpiece W, namely, the inner peripheral surface W1, the outer peripheral surface W2, and the end surface W3 between the two peripheral surfaces W1, W2. The heating conductor 100 is a part of a high-frequency quenching coil body for applying the heat treatment, and has a heating conductor 100 for heating the three surfaces simultaneously, and a feeding conductor 200 for supplying a high-frequency current to the heating conductor 100.

First, as shown in FIG. 3, the inner peripheral surface W1 of the cylindrical work W heated by the high-frequency three-surface heating coil has an inner large-diameter portion W11 and an inner small-diameter portion following the inner large-diameter portion W11. W12 and an inner tapered portion W13 that expands in diameter following the inner small diameter portion W12, and induction hardening is performed only on the inner large diameter portion W11. The outer peripheral surface W2 of the cylindrical work W is formed by the inner large-diameter portion W1.
Induction hardening is performed only on the large-diameter portion W21 on the outer surface opposed to the first portion. Further, the end face W3 of the cylindrical work W is subjected to induction hardening over the entire surface. The inner peripheral surface W1 and the outer peripheral surface W2 are concentric.

Heating conductor 1 of the high-frequency three-sided heating coil
00 is a pair of substantially 1/4 arc-shaped outer surface heating conductors 110A along the outer surface large diameter portion W21 of the outer surface W2;
110B, a substantially semicircular inner peripheral surface heating conductor portion 120 along the inner surface large diameter portion W11 of the inner peripheral surface W1, and a pair of end surface heating conductor portions 130A, 130 along the end surface W3.
B, a pair of outer connecting conductors 140A, 140B connecting the end surface heating conductors 130A, 130B and the outer peripheral surface heating conductors 110A, 110B, the end surface heating conductors 130A, 130B, and the inner peripheral surface heating. Conductor 120
And a pair of inner connecting conductors 150A, 150B
And

The outer peripheral surface heating conductors 110A and 110B
Is located below the outer-surface large-diameter portion W21 to be heated. Therefore, the outer peripheral surface heating conductors 110A, 110B
Does not heat the entire outer large-diameter portion W21 to be heated, but heats the outer large-diameter portion W21 together with the outer connecting conductors 140A and 140B.

That is, the outer connecting conductor portion 140A is connected to one end of the outer peripheral surface heating conductor portion 110A in an upward orthogonal direction, and is responsible for heating the outer outer large diameter portion W21 above the outer peripheral surface heating conductor portion 110A. is there.

Further, like the outer connecting conductor 140A, the outer connecting conductor 140B has an outer peripheral surface heating conductor 110B.
Is connected to one end of the upper surface in the orthogonal direction, and is responsible for heating the outer large-diameter portion W21 above the outer-peripheral-surface heating conductor 110B.

As shown in FIG. 2, the outer peripheral surface heating conductor 110A is set slightly above the outer peripheral surface heating conductor 110B. This is because if the two outer peripheral surface heating conductors 110A and 110B are at the same height position, heating of that portion will be greater than that of the other portions, and this is to prevent this.

Further, the end surface heating conductors 130A, 130B
Is formed in a substantially rectangular shape in plan view, as shown in FIG. That is, the end surface heating conductor portion 130A is formed by the outer edge heating portion 13 inward from the upper end of the outer connection conductor portion 140A.
1A, a central heating section 132A connected to the outer edge heating section 131A outward at an obtuse angle, and a central heating section 132A.
The inner heating section 133A is connected to the inner heating section 133A and the center heating section 132A is connected to the inner heating section 133A at a right angle.

Similarly, the end surface heating conductor portion 130B includes an outer edge heating portion 131B directed inward from the upper end of the outer connecting conductor portion 140B, a central heating portion 132B connected to the outer edge heating portion 131B inward at an obtuse angle, and Central heating unit 13
The inner edge heating part 133B which goes inward from 2B is respectively connected, and the center heating part 132B and the inner edge heating part 133B are connected at right angles.

The inner edge heating section 133A and the inner edge heating section 133B are located on a straight line as shown in FIG.

The inner-peripheral-surface heating conductor 120 is located at the lowermost position of the inner-surface large-diameter portion W11 to be heated. Therefore, the inner peripheral surface heating conductor 120 does not heat the entire inner large diameter portion W11 to be heated, but heats the inner large diameter portion W11 together with the inner connecting conductors 150A and 150B.

That is, the inner connecting conductor 150A is connected to one end of the inner peripheral surface heating conductor 120 and the end surface heating conductor 1
30A is connected to one end of the inner edge heating portion 133A, and is connected in an upward orthogonal direction when viewed from the inner heating conductor portion 120, and is connected to the inner peripheral surface heating conductor portion 150A.
It is in charge of heating the inner large diameter portion W11 on the upper side.

The inner connecting conductor 150B is connected to the other end of the inner peripheral surface heating conductor 120 and the end surface heating conductor 130.
B is connected to one end of the inner edge heating portion 133B, and is connected in an upward orthogonal direction when viewed from the inner heating conductor portion 120, and has a larger inner surface diameter above the inner peripheral surface heating conductor portion 150B. It is responsible for heating the section W11.

On the other hand, the power supply conductor 200 for connecting the heating conductor 100 and a high-frequency power source (not shown) is connected to the power supply conductor 2 connected to the outer peripheral surface heating conductor 110A.
10A, the other power supply conductor 210B connected to the outer peripheral surface heating conductor 110B, and both power supply conductors 210A, 210B.
It has a plate-shaped insulating member 220 interposed therebetween, and a pair of electrode plates 230A and 230B attached to the both power supply conductors 210A and 210B, respectively.

One end of each of the power supply conductors 210A and 210B is connected to the outer peripheral surface heating conductors 110A and 110B at a portion where the outer peripheral surface heating conductors 110A and 110B are close to each other. Therefore, the two power supply conductors 210A, 210A,
10B prevents the short circuit by interposing the insulating member 220 therebetween.

Further, both power supply conductors 210A, 210B
Has the other end bent outward in the orthogonal direction,
Connecting parts 240A, 240 for circulation of a cooling liquid described later
B.

Further, the two power supply conductors 210A, 210B
The electrode plates 230A and 230B are respectively attached to the inner side surfaces. And this electrode plate 230A,
The insulating member 220 is interposed between 230B.

By the way, the high-frequency three-sided heating coil configured as described above circulates a coolant through each conductor in order to prevent overheating of itself. That is, FIG.
As shown in, except that the inner circumferential surface heating conductor portion 120 of the heating conductor portion 100 is formed of a pipe having a substantially home base shape in cross section, the other portion is formed of a square pipe, and is internally provided. Coolant can be circulated.

Further, as shown in FIG. 3, the wall 1 is located at the boundary between the end surface heating conductor 130A and the inner connecting conductor 150B.
Because of the provision of 70, the coolant circulates in two systems. And the wall 17
0, on both sides of the connection part 160A for circulation of the coolant,
160B are provided.

That is, on the one hand, the connecting part 160A → the inner connecting conductor 150B → the inner peripheral heating conductor 120 → the inner connecting conductor 150A → the end heating conductor 130A → the outer connecting conductor 140A → the outer peripheral heating conductor 110A → a power supply conductor 210A → a path through which the coolant circulates in the order of the connecting part 240, and the other is a connecting part 160B → the end face heating conductor part 130.
B → outer connecting conductor 140B → outer surface heating / heating conductor 1
This is a path through which the coolant circulates in the order of 10B → the power supply conductor 210B → the connecting portion 240B.

As described above, since the cooling path for cooling the high-frequency three-sided heating coil itself is provided in two systems, it is possible to efficiently cool the high-frequency three-sided heating coil.

The high-frequency three-sided heating coil is provided with a cooling jacket (not shown) so that the cooling liquid is sprayed onto the cylindrical work W heated by the high-frequency three-sided heating coil so as to perform the induction hardening. Has become.

Next, the induction hardening of the cylindrical work W using the high-frequency three-sided heating coil as described above will be described. First, the cylindrical work W is placed on a rotary table (not shown), and a high-frequency three-sided heating coil is set on the cylindrical work W. That is, the outer peripheral surface heating conductor portions 110A and 110B and the outer connecting conductor portions 140A and 140B face the outer peripheral large diameter portion W21 of the outer peripheral surface W2, and the inner peripheral surface heating conductor portion 120 and the inner coupling conductor portions 150A and 150B have the inner peripheral surface. The inner surface large-diameter portion W11 of the surface W1 is opposed to the end surface heating conductor portions 130A and 130A.
0B faces the end face W3.

In this state, a high-frequency current is supplied to the high-frequency three-sided heating coil while rotating the cylindrical work W about its own central axis. Then, the inner surface large-diameter portion W11 of the inner peripheral surface W1, the screen large-diameter portion W21 of the outer peripheral surface W2, and the end surface W3
Are heated by the induced current. At this time, it is a matter of course that the coolant is circulated through each conductor.

When the predetermined heating is completed, the supply of the high-frequency current is stopped, and a cooling liquid is injected from a cooling jacket (not shown) to perform the high-frequency quenching. That is, a hardened layer is formed as indicated by WA in FIG.

Here, differences from the conventional high-frequency three-sided heating coil shown in FIG. 5 will be described. In the conventional high-frequency three-sided heating coil, since the end surface heating conductor portions 530A and 530B are formed straight in a plan view, the end surface heating conductor portions 530A and 530B are larger in area than the area heated outside per unit time. Since the inner portion of the portions 530A and 530B is larger than the area to be heated per unit time, if the heating of the inner peripheral surface W1 is prioritized to form an optimal hardened layer on the inner peripheral surface W1, the end surface heating conductor portion 530A,
The outer part of the end face W3 heated by 530B is not heated by the inner part. For this reason,
The hardened layer formed especially on the outer portion of the end face W3 becomes shallower.

On the other hand, in the high-frequency three-sided heating coil according to the embodiment of the present invention, the end surface heating conductor 130A,
Since 130B is formed in a substantially rectangular shape in plan view, the center heating portion 132 of the end surface heating conductor portions 130A and 130B is formed.
Since the area heated by the unit A and 132B per unit time and the area heated by the inner edge heating units 133A and 133B per unit time are almost equal, the depth of the hardened layer formed in each part is constant. .

As another form of the high-frequency three-sided heating coil according to the embodiment of the present invention, as shown in FIG. 4, the inner edge heating portion 133A and the inner edge heating portion 133B are not in a straight line. In this case, the central heating unit 132A,
132B is longer.

[0041]

The high-frequency three-sided heating coil according to the present invention comprises:
A high-frequency three-sided heating device having a heating conductor portion for simultaneously heating three surfaces of an inner peripheral surface, an outer peripheral surface, and an end surface between both peripheral surfaces of a cylindrical workpiece, and a power supply conductor portion for supplying a high-frequency current to the heating conductor portion. A coil, wherein the heating conductor portion comprises a pair of substantially quarter-arc outer peripheral surface heating conductor portions along the outer peripheral surface, and a substantially semicircular inner peripheral surface heating conductor along the inner peripheral surface. Part, a pair of end face heating conductors along the end face, a pair of outer connection conductors connecting the end face heating conductor and the outer circumference heating conductor, the end face heating conductor and the inner circumference And a pair of inner connecting conductors for connecting the heating conductor with the heating conductor .
The outer edge heating section that goes inward from the upper end and the outer edge heating section
A central heating section connected outward at an obtuse angle and this central heating section
With an inner edge heating section connected at right angles to the
The area heated by the heating unit per unit time and the inner edge heating unit
Is set equal to the area to be heated per unit time
I have .

For this reason, the end surface heating conductor portion is substantially I
With the conventional high-frequency three-sided heating coil formed in a U-shape, uniform heating can be performed on three surfaces of the inner peripheral surface, the outer peripheral surface, and the end surface of the cylindrical work, and as a result, a more uniform hardened layer can be formed.

[0043]

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a high-frequency three-sided heating coil according to an embodiment of the present invention.

FIG. 2 is a schematic side view of the high-frequency three-sided heating coil according to the embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of the high-frequency three-sided heating coil according to the embodiment of the present invention.

FIG. 4 is a schematic plan view of a high-frequency three-sided heating coil according to another embodiment of the present invention.

FIG. 5 is a schematic plan view of a conventional high-frequency three-sided heating coil of this type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 Heating conductor part 110A, 110B Outer peripheral surface heating conductor part 120 Inner peripheral surface heating conductor part 130A, 130B End surface heating conductor part 200 Power supply conductor part W Cylindrical work W1 Inner peripheral surface W2 Outer peripheral surface W3 End surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C21D 1/10 C21D 1/42 C21D 9/40 H05B 6/36

Claims (1)

(57) [Claims] 1. A heating conductor for simultaneously heating three surfaces of an inner peripheral surface, an outer peripheral surface, and an end surface between both peripheral surfaces of a cylindrical work, and a feeding conductor for supplying a high-frequency current to the heating conductor. In the high-frequency three-sided heating coil having the above, the heating conductor portion includes a pair of substantially 1/4 arc-shaped outer peripheral surface heating conductor portions along the outer peripheral surface, and a substantially semi-circular inner periphery along the inner peripheral surface. A surface heating conductor portion, a pair of end surface heating conductor portions along the end surface, a pair of outer connection conductor portions connecting the end surface heating conductor portion and the outer peripheral surface heating conductor portion, the end surface heating conductor portion, and comprises a pair of inner connection conductors for connecting the inner peripheral surface heating conductor portion, said end face heating conductor portion, said
An outer edge heating portion that goes inward from the upper end of the outer connection conductor portion,
Central heating section connected to this outer edge heating section at an obtuse angle outward
And the inner edge heating section connected at right angles to this central heating section.
Surface that the central heating unit heats per unit time
Product and the area that the inner edge heating unit heats per unit time
A high-frequency three-sided heating coil, which is set to be equal .