JPH10324910A - Induction hardening coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply uniform heating regardless of the thickness in a triport housing member without complicating the whole constitution. SOLUTION: In an induction hardening coil for heating the inner surface of the triport housing with plural grooves formed on the inner surface, a heating conductive part 100 faced to the inner surface, one pair of electric supplying conductive parts 200A, 200B connected with this heating conductive part 100 and a core 300 composed of a magnetic body fitted to a part faced to the thick part positioned between the grooves in the heating conductive part 100 are provided, and the core 300 is closed at the side faced to the thick part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction hardening coil for heating the inner surface of a bottomed cylindrical work having an uneven thickness.

[0002]

2. Description of the Related Art As a bottomed cylindrical work having a plurality of grooves formed on an inner surface, there is a tripod housing member W used for a constant velocity joint. An induction hardening coil for induction hardening the inner surface of the tripod housing member W shown in FIG. 5 is shown in FIG.

First, the induction hardening coils shown in FIG. 6 are arranged facing each other at substantially constant intervals along the inner surfaces of the tripod housing member W. However, in this induction hardened coil, although the thickened portion W3 is subjected to induction hardening to form a hardened layer (shown by oblique lines in FIG. 6), the left and right side surfaces W11 of the groove W1 and the thin wall are formed. There is a problem that induction hardening is not performed on the portion W12 and a hardened layer is not formed. The cause of this is a characteristic in high frequency heating in which the convex portion is easily heated but the concave portion is hard to be heated. In addition, the groove W
In order to form a hardened layer by performing induction hardening on both side surfaces W11 and the thin portion W12 of FIG. 1, a larger current may be applied.
The corner portion, which is a boundary between the thick portion W3 and the thick portion W3, may be overheated, and the inner surface of the tripport housing member may be deformed due to thermal imbalance.

Therefore, the induction hardening coil shown in FIG. 7 can be considered. In such an induction hardening coil, a heating conductor corresponding to the thick portion W3 is provided separately from the thick portion W3. In this state, when a current capable of performing a predetermined induction hardening on the thick portion W3 is applied to the induction hardening coil, both side surfaces W11 of the groove W1 and the thin portion W12 are overheated, and particularly, the thin portion W12 has a bump. It may be hardened. As described above, even if the heating conductor of the induction hardened coil is separated from the corner, overheating of the corner is inevitable due to circumferential magnetic lines of force.

To solve such a problem, Japanese Patent Publication No. Sho 63
An induction hardening coil as described in U.S. Pat. No. 4,428,39 has been devised. Such induction hardening coil,
As set forth in the claims, "Induction hardening coil for moving and quenching a cylindrical inner surface having an unequal thickness portion, in a heating conductor corresponding to the thick portion of the cylindrical inner surface. , A pair of rising portions extending along the axial direction of the tubular body and extending parallel to the thickest portion are provided, and these rising portions are arranged in parallel and close to each other, The arrangement is such that currents in opposite directions flow through the arranged rising portions.

As a result, since the electromagnetic action is canceled at the rising portion facing the (most) thick portion, the heating of the thick portion by the rising portion is suppressed, and overheating of the thick portion is prevented. .

[0007]

However, in the induction hardening coil as described in Japanese Patent Publication No. 63-42839, there is a problem that the rising portion is formed and the entire structure becomes complicated. .

The present invention has been made in view of the above circumstances, and has as its object to provide an induction hardening coil capable of performing uniform heating regardless of thickness without complicating the entire structure. The purpose is.

[0009]

The induction hardening coil according to the present invention is an induction hardening coil for heating the inner surface of a bottomed cylindrical work having a non-uniform thickness, and a heating conductor portion facing the inner surface. And a pair of power supply conductors connected to the heating conductor, and a core made of a magnetic material attached to a portion of the heating conductor facing the thick portion of the bottomed cylindrical work. The side of the core facing the inner surface of the bottomed cylindrical work is closed.

[0010]

FIG. 1 is a schematic perspective view showing a state in which a core is removed from an induction hardened coil according to an embodiment of the present invention. FIG. 2 is a perspective view of the induction hardened coil according to the embodiment of the present invention. FIG. 3 is a schematic bottom view showing the relationship between the induction hardened coil according to the embodiment of the present invention and a tripod housing member as a bottomed cylindrical work, and FIG. 4 is an embodiment of the present invention. It is a schematic sectional drawing which shows the relationship between the heating conductor and core of the induction hardening coil which concerns on a form.

An induction hardening coil for heating the inner surface of a tripod housing member W as a bottomed cylindrical work having a non-uniform thickness, a heating conductor portion 100 facing the inner surface;
A pair of power supply conductors 2 connected to the heating conductor 100
00A and 200B, and a core 300 made of a magnetic material and attached to a portion of the heating conductor portion 100 that faces the thick portion W3 of the tripport housing member W.

In the triport housing member W, as shown in FIG. 5, three grooves W1 are formed at 120 ° intervals. Therefore, the groove W1 is formed on both the left and right side surfaces W11 of the groove W1.
And a thin portion W12 between the side surfaces W11. Further, between the grooves W1, the thickest portion W3 having the largest thickness is provided.
It has become.

Each of the conductors constituting the induction hardened coil has a conductive property capable of circulating a cooling liquid therein in order to prevent itself from being overheated when the tripod housing member W is heated. It is composed of a pipe having.

The heating conductor 100 includes three groove heating conductors 110A, 110B, 110C, two intermediate heating conductors 120A, 120B, and a pair of end heating conductors 130.
It is formed by connecting A and 130B.

First, the three groove heating conductors 110A, 11
Reference numerals 0B and 110C are for heating the three grooves W1, and are formed in a substantially C-shape in a plan view along the shape of the grooves W1. That is, each groove heating conductor portion 110A, 110
B and 110C are arranged to face the left and right side surfaces W11 of the groove W1 and the thin portion W12 between them with a predetermined interval. These three groove heating conductors 11
0A, 110B, and 110C are set to be lined up on the same plane.

The three groove heating conductors 110A, 11
0B and 110C are arranged at an angle of 120 ° to each other because the groove W1 is formed every 120 °. In addition, the three groove heating conductor portions 110A and 110
In B and 110C, an open portion, that is, a C-shaped unconnected portion faces inward.

Groove heating conductor portion 110A and groove heating conductor portion 11
0B, that is, the groove heating conductor portion 110A
Heating conductor part 100 for connecting the groove heating conductor part 110B
The intermediate heating conductor portion 120A as a part of the groove heating conductor portion 100A is a portion opposed to the thick portion W3 of the tripod housing member W.
Is set wider than the distance between the groove and the groove W1.

Further, the groove heating conductor 1 is located between the groove heating conductor 110B and the groove heating conductor 110C.
The intermediate heating conductor portion 120B as a part of the heating conductor portion 100 connecting the groove heating conductor portion 110C to the thick heating portion W3 is a portion facing the thick portion W3 of the tripod housing member W. Is set wider than the distance between the groove heating conductor 100A and the groove W1, similarly to the intermediate heating conductor 120A.

The end heating conductors 130A and 130B
Is formed between the groove heating conductor portions 110A and 110C and the pair of power feeding conductor portions 200A and 200B.
The pair of end heating conductors 130A and 130B are portions that heat the thick portion W3, like the intermediate heating conductors 120A and 120B. This end heating conductor portion 130
An insulator (not shown) for preventing a short circuit is provided between A and 130B.

On the other hand, the intermediate heating conductors 120A, 12
A core 300 made of a magnetic material such as ferrite is attached to the 0B and the end heating conductors 130A and 130B. The core 300 includes the intermediate heating conductors 120A,
It is formed in a substantially U-shape to close the surfaces 121A and 121B (the surfaces of the end heating conductor portions 130A and 130B are not visible) facing the thick portion W3 of the end heating conductor portions 130A and 130B. I have. That is, since the core 300 is attached to the induction hardened coil as shown in FIG. 4, the magnetic field lines pass through the core 300 (FIG. 4).
(Refer to arrow), thick portion W3 of triport housing member W
Does not pass through the magnetic field lines. For this reason, the thick portion W
3, the core 300 has the intermediate heating conductors 120A and 120B.
It is less heated than if it were not attached to such.

The core 300 is formed by cutting ferrite or the like into a substantially U-shape. Some of the cores 300 are formed in a generally U-shaped thin plate and can be attached according to the dimensions of the intermediate heating conductor 120A and the like.

Here, the degree of concentration of the lines of magnetic force changes depending on the shape of the core 300, the distance between the core 300 and the thick portion W3, the high-frequency current supplied to the high-frequency hardening coil, and the like. It is important to adopt an appropriate one based on this.

On the other hand, a pair of power supply conductors 200A and 200B connected to a high-frequency power source (not shown)
It is suspended from 30A and 130B. An insulator (not shown) for preventing a short circuit is also provided between the power supply conductors 200A and 200B.

Further, below the heating conductor 100 of the induction hardening coil, an inner cooling jacket (injecting a cooling liquid to a portion heated by the heating conductor 100, that is, an inner peripheral surface of the tripod housing member W). (Not shown). Since this inner cooling jacket is attached to the induction hardening coil, it moves inside the tripod housing member W together with the induction hardening coil.

Further, in order to prevent overheating of the tripod housing member W, an outer cooling jacket for spraying a cooling liquid to the outer peripheral surface of the tripod housing member W is provided.

Next, the induction hardening of the inner peripheral surface of the tripod housing member W by the induction hardening coil configured as described above will be described. The tripod housing member W is placed on an unillustrated outlet ring with the open side facing downward. As shown in FIG. 3, the fixed induction hardened coil is inserted into the tripod housing member W,
The tripod housing member W is moved downward. At this time, it goes without saying that the groove heating conductor portions 110A, 110B and 110C are inserted into the three grooves W1.

Since a high frequency current is supplied to the induction hardening coil, the left and right side surfaces W11 which are the inner surfaces of the groove W1.
And the thin portion W12 and the thick portion W3 between them are sequentially heated from the lower side. The high frequency current is applied to the power feeding conductor portion 200.
A → end heating conductor 130A → groove heating conductor 110A →
The intermediate heating conductor 120A → the groove heating conductor 110B → the intermediate heating conductor 120B → the groove heating conductor 110C → the end heating conductor 130B → the power supply conductor 200B or the reverse direction.

Groove heating conductors 110A, 110B, 110
C heats both side surfaces W11 and the thin portion W12 of the groove W1 from the inner surface side. In addition, the intermediate heating conductors 120A, 12
0B and the end heating conductors 130A and 130B heat the thick portion W3 from the inner surface side. Here, the intermediate heating conductor portion 1
20A, 120B and end heating conductors 130A, 130B
Since the core 300 is attached, the lines of magnetic force do not pass through the thick portion W3 but pass through the core 300, so that heating of the thick portion W3, that is, overheating of the corner portion is prevented.

The portion heated by the induction hardening coil is induction hardened by being cooled by the inner cooling jacket. Further, since the triport housing member W is also cooled by the outer cooling jacket, the hardened layer due to the induction hardening does not reach the outer peripheral surface of the quench hardening state.

[0030]

The induction hardening coil according to the present invention is an induction hardening coil for heating the inner surface of a bottomed cylindrical work having a non-uniform thickness, the heating conductor portion facing the inner surface, and this heating. A pair of power supply conductors connected to the conductor, and a core made of a magnetic material attached to a portion of the heating conductor facing the thick portion of the bottomed cylindrical work, wherein the core is The side facing the inner surface of the bottomed cylindrical work is closed.

According to this structure, the magnetic lines of force do not pass through the thick wall portion but through the core, so that heating of the corner portion, which is the boundary between the groove and the thick wall portion, is prevented. Therefore, by using this induction hardening coil, it is possible to perform appropriate induction hardening on both the groove and the thick portion while preventing overheating of the corner portion, which was difficult with the conventional induction hardening coil.

Further, the bottomed cylindrical work has a plurality of grooves formed on an inner surface, and a heating conductor facing a thick portion located between the grooves has a core made of a magnetic material. Is attached.

Therefore, in the case of a bottomed cylindrical work such as a tripod housing member having a plurality of grooves formed on the inner surface and having a thick portion between the grooves, the configuration of the induction hardening coil is provided. Prevents overheating not only on both sides and the thin part of the groove, but also on the corner part, which was difficult with the conventional induction hardening coil, and appropriately heats both the thin part and the thick part without complicating Has the effect that it becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a state where a core is removed from an induction hardening coil according to an embodiment of the present invention.

FIG. 2 is a schematic bottom view of the induction hardening coil according to the embodiment of the present invention.

FIG. 3 is a schematic bottom view showing a relationship between the induction hardened coil according to the embodiment of the present invention and a tripod housing member as a bottomed cylindrical work.

FIG. 4 is a schematic cross-sectional view showing a relationship between a heating conductor and a core of the induction hardening coil according to the embodiment of the present invention.

FIG. 5 is a schematic bottom view of a triport housing member as a bottomed cylindrical work.

FIG. 6 is a schematic bottom view showing a relationship between a tripod housing member as a bottomed cylindrical work and a conventional induction hardening coil.

FIG. 7 is a schematic bottom view showing the relationship between a tripod housing member as a bottomed cylindrical work and another conventional induction hardened coil.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 heating conductor portion 110A, 110B, 110C groove heating conductor portion 120A, 120B intermediate heating conductor portion 130A, 130B end heating conductor portion 200A 200B power supply conductor portion 300 core W tripod housing member (bottomed cylindrical work)

Claims (2)

[Claims] 1. An induction hardening coil for heating an inner surface of a bottomed cylindrical work having a non-uniform thickness, a heating conductor facing the inner surface, and a pair of power supply conductors connected to the heating conductor. A core made of a magnetic material attached to a portion of the heating conductor portion facing the thick portion of the bottomed cylindrical work, the core being closed on a side facing the inner surface of the bottomed cylindrical work. Induction hardening coil characterized by being 2. The bottomed cylindrical workpiece has a plurality of grooves formed on an inner surface, and a heating conductor facing a thick portion located between the grooves has a core made of a magnetic material. The induction hardened coil according to claim 1, wherein the coil is attached.