JPH0715833B2 - High frequency 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 heating coil used for heating an end portion of a cylindrical work such as a spindle used for holding a chuck of a lathe.

[0002]

2. Description of the Related Art For example, the end surface of a spindle used for holding a chuck of a lathe and the inner and outer peripheral surfaces of the end portion are reinforced by induction hardening. FIG. 3 shows the end shape of the spindle and the induction hardening conventionally performed on the end.
Will be described. The inner peripheral surface 32 of the end portion of the spindle 30 has a trumpet shape, that is, a taper shape whose inner diameter gradually increases as it approaches the end surface 31. The end surface 31 is orthogonal to the axis of the spindle 30. Outer peripheral surface 33 in the vicinity of the end surface 31
Has a straight surface with the same outer diameter in the axial direction. Its outer diameter is significantly increased compared to the outer diameter of the outer peripheral surface 35 other than the ends to form a flange. Outer peripheral surface
An outer peripheral surface 34 having a slightly larger diameter is formed between 33 and 35.

Three types of induction heating coils have been used for induction hardening of the end of the spindle 30. One is a spiral winding coil 41 inserted into the inner surface of the end of the spindle 30. This winding coil 41 is
It is wound along the inner peripheral surface 32 while gradually expanding in diameter in a direction approaching the end surface 31, and is used for high frequency heating of the inner peripheral surface 32. The other is a circular coil 42 used for high-frequency heating of the end surface 31, which is wound in the circumferential direction of the end surface 31.
The other one is a circular coil 43 which is used for high frequency heating of the outer peripheral surface 33 and is wound along the circumferential direction of the outer peripheral surface 33.

Conventionally, while rotating the spindle 30 about its axis, the three types of high-frequency heating coils are used in order to perform induction hardening stepwise on the end of the spindle 30.

[0005]

However, in such induction hardening, only the range shown by the fine hatching in FIG. 3 is quenched, and the boundary portion 36 between the end surface 31 and the inner peripheral surface 32 and the end surface 31 are formed. The boundary portion 37 with the outer peripheral surface 33 was not quenched. Because the winding coil 41, the circular coils 42 and 43
It is possible to heat the entire surfaces of the end face 31, the inner peripheral surface 32, and the outer peripheral surface 33 by high-frequency heating by adjusting the dimensions of the above. In such a case, however, as shown in FIG. The high frequency heating overlaps at the boundary portion 36 and the boundary portion 37 between the end surface 31 and the outer peripheral surface 33, and a quench crack occurs in these portions. Alternatively, the previously-quenched portion may be heated afterwards to cause tempering, resulting in an unquenched region in these portions. Further, since three types of high-frequency heating coils are required, the apparatus becomes complicated, and since the quenching work is repeated three times, the number of work steps is large.

The present invention was devised in view of such circumstances, and it is possible to simultaneously heat the inner surface, the end surface, and the outer peripheral surface of a cylindrical work without causing quenching cracks or tempering, and high-frequency heating having a simple structure. The purpose is to provide a coil.

[0007]

In order to solve the above problems, a high frequency heating coil according to the invention of claim 1 is a high frequency heating coil for simultaneously heating an end surface, an inner peripheral surface and an outer peripheral surface of an end portion of a cylindrical work. A coil portion wound along the inner peripheral surface in a spiral shape corresponding to the shape of the inner peripheral surface so as to heat the inner peripheral surface, and a half for heating the end surface and the outer peripheral surface. An open coil unit is provided, and the winding coil unit and the semi-open coil unit are connected in series.

In order to solve the above-mentioned problems, a high frequency heating coil according to a second aspect of the present invention is the high frequency heating coil according to the first aspect, wherein the semi-open type coil portion is connected in series and has a substantially linear shape. A first linear coil portion, an arc-shaped coil portion, and a substantially linear second linear coil portion, and the first linear coil portion extends radially outward of the workpiece along the end face. The arc-shaped coil portion is arranged along the outer peripheral surface, and the second linear coil portion extends radially inward of the work along the end surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the high frequency heating coil of this embodiment, and FIG. 2 is a front view thereof. The induction heating coil 10 shown here is used for induction hardening the end of a spindle 30 as a cylindrical work. The heating surface for the end of the spindle 30 is as described in the prior art,
The end surface 31, the inner peripheral surface 32, and the outer peripheral surface 33 shown in FIG.

The high frequency heating coil 10 has a spiral winding coil portion 11 and a semi-open coil portion 12 which is integrally and serially connected to the spiral winding coil portion 11. The winding coil portion 11 has an inner peripheral surface 32.
Is concentrically inserted into the inside of the contactless body, and is spirally wound along the inner peripheral surface 32 while gradually increasing in diameter as it approaches the end surface 31.

The semi-open type coil portion 12 includes a first linear coil portion 12a, an arc-shaped coil portion 12b and a second linear coil portion 12c which are connected in series. The first linear coil portion 12a has an end surface facing the end surface 31 of the spindle 30.
A linear shape is formed along the radial direction 31 of the spindle 30 along one end, one end of which is bent to the tip of the maximum diameter portion 11a of the winding coil portion 11, and the other end is bent from the vicinity of the other end along the end face 31. The arcuate coil portions 12b are connected to each other.

The arc-shaped coil portion 12b is formed in a substantially semi-circular shape along the outer peripheral surface 33, and the second linear coil portion 12c is connected to the end portion of the arc-shaped coil portion 12b. The second linear coil portion 12c is an end surface of the spindle 30.
It is formed linearly in the radial inner direction of the spindle 30 along the end face 31 so as to face 31.

Winding coil section 11 and semi-open coil section 12
Is made of a good conductive metal in the shape of a rectangular tube whose inside is a cooling water channel. The lead portion 13 extends from the tip of the smallest diameter portion 11b of the winding coil portion 11 through the axial center position. The lead portion 14 also extends from the tip of the second linear coil portion 12c. The lead portions 13 and 14 are connected to a high frequency power source (not shown).

In order to induction quench the end of the spindle 30, the induction heating coil 10 is used as follows. First, the spindle 30 is set on a work table (not shown). Next, the winding coil portion 11 of the high-frequency heating coil 10 is concentrically inserted inside the inner peripheral surface 32 of the spindle 30, and the end surface 31 is provided with the first linear coil portion 12a and the second linear coil portion 12c. , The arc-shaped coil portion 12b on the outer peripheral surface 33
The high frequency heating coil 10 is set so as to face each other. Then, while rotating the spindle 30 around the axis on the work table, the high frequency heating coil 10 is driven by the high frequency power source.
Pass a high frequency current.

As a result, the inner peripheral surface 32 of the spindle 30 is heated by the winding coil portion 11 of the high frequency heating coil 10 at high frequency. At the same time, the end surface 31 and the outer peripheral surface 33 are respectively subjected to high-frequency heating by the first linear coil portion 12a, the second linear coil portion 12c and the arc-shaped coil portion 12b of the semi-open coil portion 12. In addition, the boundary between the end surface 31 and the inner peripheral surface 32
36 is subjected to high-frequency heating in the vicinity of the connection between the winding coil portion 11 and the first linear coil portion 12a, and the boundary portion 37 between the end surface 31 and the outer peripheral surface 33 is bent at the first linear coil portion 12a. High frequency heating is performed near the ends.

In this way, the boundary portions 36, 37 are heated with high frequency without interruption to the other portions, the escape of heating is prevented, and the situation where the high frequency heating overlaps with the boundary portions 36, 37 is avoided. It also prevents cracking and tempering. When the end surface 31, the inner peripheral surface 32 and the outer peripheral surface 33 are heated to a predetermined temperature by high frequency, these surfaces are rapidly cooled and quenched. Thus,
Quenching is completed with one induction heating.

[0017]

As described above, in the case of the high-frequency heating coil according to the present invention, since the winding coil portion and the semi-open type coil portion are integrated, the boundary portion between the end surface and the inner peripheral surface of the end portion. Also, the boundary portion between the end surface and the outer peripheral surface of the end portion can be heated by one high-frequency heating, like other portions,
The entire surface is quenched without causing cracking and tempering in these parts. Therefore, unlike the conventional case, when quenching the end surface and the inner and outer peripheral surfaces of the end portion of the cylindrical work, it is not necessary to repeat the heating work of sequentially heating the end surface, the inner peripheral surface and the outer peripheral surface, and the work efficiency is improved. To do. Furthermore, the structure of the heating device is also significantly simplified.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a front view of an embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a conventional technique.

FIG. 4 is an explanatory diagram of a problem of the conventional technique.

[Explanation of symbols]

 10 High-frequency heating coil 11 Winding coil 12 Semi-open coil 12a First straight coil 12b Arc coil 12c Second straight coil 30 Spindle 31 End face 32 Inner surface 33 Outer surface

Claims (2)

[Claims] 1. A high-frequency heating coil for simultaneously heating an end surface, an inner peripheral surface of an end portion, and an outer peripheral surface of a cylindrical work, wherein the inner peripheral surface of the inner peripheral surface is heated along the inner peripheral surface so as to heat the inner peripheral surface. A spirally wound coil portion corresponding to the shape; and a semi-open coil portion for heating the end surface and the outer peripheral surface, and the spiral coil portion and the semi-open coil portion. A high-frequency heating coil, which is connected in series. 2. The semi-open type coil portion has a substantially linear first linear coil portion, an arc-shaped coil portion and a substantially linear second linear coil portion which are connected in series. The linear coil portion extends outward in the radial direction of the work along the end surface, the arc-shaped coil portion is disposed along the outer peripheral surface, and the second linear coil portion extends on the end surface. The high-frequency heating coil according to claim 1, wherein the high-frequency heating coil extends inward in the radial direction of the work.