JPH0719658B2 - Method for manufacturing semi-open saddle type high frequency heating coil for crankshaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a half open saddle type high frequency heating coil for a crankshaft for heating a journal or a pin which is a hardened portion of a crankshaft (hereinafter referred to as a heating coil, a half for a crankshaft). Open saddle type high frequency heating coil).

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings. When heating the journal or pin that is the hardened part of the crankshaft, the hardened part has a columnar shape, and after the heating coil is placed close to the hardened part,
A high frequency current is applied to this heating coil. First, the structure of this heating coil will be described.

FIG. 9 is a perspective view of a semi-open saddle type high frequency heating coil for a crankshaft manufactured by a conventional manufacturing method. As shown in FIG. 9, the heating coil 300 has a first coil piece 300A, a first coil piece 300A, a first coil piece 300A, and a first coil piece 300A.
A second coil piece arranged so as to face the coil piece 300A.
300B, a third coil piece which is an arc-shaped heating conductor 35 connecting the first coil piece 300A and the second coil piece 300B, and a pair of power supply conductors not shown.

The first coil piece 300A is wound in a rectangular shape by heating conductors 30 to 34 connected in series, and the heating conductors 31 and 33 are perpendicular to the axial direction of the crankshaft (direction of arrow P). Is formed in a substantially circular arc shape (normally 1/5 to 1/7 circular arc shape) in a different direction (circumferential direction of the hardened part). One ends of the conductors 31 and 33 are connected to each other by a linear heating conductor 32 parallel to the axial direction of the crankshaft. One end of the heating conductor 30 parallel to the heating conductor 32 is connected to the other end of the heating conductor 31, and a heating conductor parallel to the heating conductor 32 is provided between the other end of the heating conductor 33 and one end of the heating conductor 35. Connected by 34.

The second coil piece 300B is provided with heating conductors 36-40 corresponding to the heating conductors 30-34 of the first coil piece 300A. The pair of power supply conductors (not shown) are the other end 30m of the heating conductor 30 and the end 4 of the heating conductor 40 corresponding to the other end 30m.
It is connected to 0m. The space 300D between the heating conductors 30 and 36 and the space between the heating conductors 34 and 40
300E is a space for arranging a spacer (not shown) for keeping the space between the heating coil 300 and the hardened part constant. The heating conductors 31, 33, 3 formed in an arc shape
The diameters of 5, 37 and 39 are all the same.

In order to manufacture the heating coil 300, first, a hollow conductive tube made of copper or the like having a square or rectangular cross section is cut and bent to form the heating conductors 30 to 30.
40 and the power supply conductor. Next, these conductors are connected by brazing to complete the heating coil 300.

[0007]

However, the above heating coil 300 thus manufactured has the following problems. That is, the heating conductors 30 and 31, 31 and 32, 32
33, 33 and 34, 34 and 35, 35 and 36, 36 and 37 are connected by brazing parts 311 to 317, respectively. Also,
The heating conductors 37 and 38 are also connected by a brazing part (not shown). Furthermore, the heating conductors 38 and 39, 39 and 40 are connected by brazing parts 318 and 319, respectively.
The power supply conductor (not shown) and the heating conductors 30 and 40 are also connected by a brazing portion (not shown).

When a high-frequency current is passed through the heating coil 300, the high-frequency current flows mainly in the portion of the heating coil 300 facing the hardened portion and the portion close to the hardened portion. Since a portion facing the hardened portion and a portion close to the hardened portion are formed in this manner, a high-frequency current flows in such a brazed portion.

Therefore, when the heating coil 300 is used for a long period of time, such a brazed portion is deteriorated, the heating coil 300 is damaged, the cooling liquid of the heating coil 300 leaks, and the heating coil 300 is exposed to the hardened part. Contact them.

The present invention was devised in view of the above circumstances, and there is no brazing portion in the portion facing the hardened portion or in the portion close to the hardened portion, and therefore does not deteriorate even after long-term use. It is an object to provide a method of manufacturing a heating coil.

[0011]

In order to solve the above problems, a method for manufacturing a half-open saddle type high frequency heating coil for a crankshaft according to the present invention is provided on a peripheral surface of a pin or a journal which is a hardened portion of a crankshaft. A high-frequency heating coil that is placed close to and straddles and heats a hardened part,
The first and second coil pieces of the same shape which are wound in a substantially rectangular shape are connected to one ends of the open ends provided on the opposite sides of the coil pieces and on the substantially axial side of the crankshaft. A third coil piece provided in a direction substantially perpendicular to the direction, the first and second coil pieces are connected in series by the third coil piece, and the first to third coil pieces have grooves. A method of manufacturing a semi-open saddle type high frequency heating coil for a crankshaft, comprising: a substantially gutter-shaped main body formed by drilling; and a flat plate-shaped lid soldered to the main body so as to close the groove. Then, the first step of forming the groove on the peripheral surface of the cylindrical first metal material and the first metal material after the first step are soldered to the inner surface with an inner diameter equal to the diameter of the first metal material. After inserting into the cylindrical second metal material coated with paste, The second step of heating the first and second metal materials to bond the first and second metal materials, and the peripheral surfaces of the first and second metal materials after the second step are cut to remove the main body. It includes a third step of forming and a fourth step of forming a cylindrical through hole around the axis of the first metal material in the first metal material after the third step.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 8 are drawings for explaining the present embodiment, FIG. 1 is a perspective view of a completed heating coil (excluding a power supply conductor), and FIG. 2 is a diagram of a first metal material before the first step. 4 is a perspective view, FIG. 3 is a perspective view of the first metal material after the first step, and FIG.
Is a perspective view of the first and second metal materials after the second step, FIG. 5 is a perspective view of the first metal material after the third step, and FIG. 6 is a perspective view of the first and second metal materials after the fourth step. FIG. 7, FIG. 7 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 8 is an explanatory view of a state in which the heating coil manufactured according to this embodiment is placed on the hardened portion.

The heating coil 100 (excluding the power supply conductor) shown in FIG. 1 manufactured by the method of this embodiment is
In the outer diameter shape, the conventional heating coil described in FIG.
Same as 300. As shown in FIG. 8, the heating coil 100 is a part to be hardened 50 which is a peripheral surface of a crankshaft journal 500 (which may be a pin) which rotates about a shaft 502.
Used to heat 1.

As shown in FIG. 1, the heating coil 100 is equivalent to or corresponds to the first coil piece 300A, the second coil piece 300B and the heating conductors 30 to 40 of the heating coil 300 described in the prior art. The first coil piece 100A, the second coil piece 100B, and the heating conductors 10 to 20 are provided. However, the heating conductor 15 is a third coil piece 100C that is equivalent to or corresponds to the third coil piece that is the heating conductor 35 of the heating coil 300. As with the heating coil 300, a pair of power supply conductors (not shown) are connected to the one end 10m of the heating conductor 10 and the end 20m of the heating conductor 20 by brazing.

The heating coil 100 comprises a heating coil between the heating conductors 10 and 16,
And between the heating conductors 14 and 20, there are spaces 100D and 100E for disposing spacers. In addition, 100F
And 100G are voids formed by the first coil piece 100A and the second coil piece 100B, respectively.

Next, the sectional structure of the heating conductors 10 to 20 will be described. Since the heating conductors 10 to 20 all have the same sectional structure, they will be described with reference to FIG. 7 showing the sectional structure of the heating conductor 11. The heating conductor 11 is a conductor formed in a gutter shape by forming a groove 11f, and has a substantially U-shaped cross section,
A main body 11a having a pair of parallel side plates 11c and a flat bottom plate 11d that connects the lower ends of the side plates 11c to each other and is integrally formed with both side plates 11c, and the main body 11a so as to close the opening 11g of the groove 11f.
And a flat plate-shaped lid 21 attached by soldering 111 to the upper end surface 11e thereof. Therefore, the main body 11a and the lid 21 form a hollow portion 11h. The lid 21 is integrally formed with other heating conductor lids described below.

Like the heating conductor 11, the heating conductors 10, 12-20
Also has main bodies 10a, 12a to 20a, respectively, and the openings of the main bodies are closed by a lid 21 common to all the main bodies. The heating conductors 11, 13, 15, 17, 19 formed in an arc shape have the same diameter.

The method of manufacturing the heating coil 100 will be described below. As shown in FIG. 2, first, as a material for each heating conductor of the heating coil 100, a first metal material 1 (hereinafter simply referred to as metal material 1) made of a good conductive metal (for example, copper) is prepared. This metal material 1 has a cylindrical portion 1f and one side surface 1a of the cylindrical portion 1f.
It is provided with a cylindrical portion 1f and a cylindrical portion 1g that is integrally provided with the cylindrical portion 1f. Select equally. The diameter of the cylindrical portion 1g is smaller than the diameter of the alternate long and short dash line 1b. However, the diameter of the circle indicated by the one-dot chain line 1b is equal to the dimension of the diameter of the lower surface of the bottom plate 11d of the main body 11a of the heating conductor 11, for example, the arc-shaped heating conductor.

Then, the center of the other side surface 1a of the metal material 1 is supported by a center (not shown), the peripheral surface of the cylindrical portion 1g is held by a chuck (not shown), and the metal material 1 is rotated using an NC processing device or the like. However, by milling, as shown in FIG. 3, on the peripheral surface of the metal material 1, the grooves 10 of the heating conductors 10 to 20 are formed.
Form f to 20f by cutting (first step).

Next, a cylindrical second metal material 2 (hereinafter simply referred to as metal material 2) whose inner diameter is equal to the diameter of the metal material 1 and whose thickness is equal to the thickness of the lid 21 is the same material as the metal material 1. ) After applying solder paste etc. on the inner surface, insert the metal material 1 into the metal material 2 and put the integrated metal materials 1 and 2 into an electric furnace, for example, and heat them as shown in FIG. By doing so, the solder is melted to bond the metal materials 1 and 2 (second step).

After this, as in the first step, metal materials 1 and 2
While rotating, the peripheral surface of the metal material 2 is milled from the peripheral surface side of the metal material 2 as shown in FIG.
0D, 100E, void 100F, 100G and 2 heating coils 100
By forming the spaces 100J and 100K between them, the lid 21 is formed on the metal material 2, and the main bodies 10a to 20a of the heating conductors 10 to 20 are formed on the peripheral surface of the metal material 1.

However, the alternate long and short dash line 1b on the side surface 1a of the metal material 1
The diameter of the arc is a circular arc having the same diameter as the diameter of the bottom surface of the bottom plate 11d of the main body 11a of the heating conductor 11, for example, the spaces 100D, 100E and the cavities 100F, 100G.
Is cut deeper than the one-dot chain line 1b, and space 100J and
For 100K, cut a little shallower than the one-dot chain line 1b (3rd process).

Next, when a cylindrical through hole having the one-dot chain line 1b as an inner surface is formed in the metal material 1 by a lathe or the like, as shown in FIG. 6, two pieces are connected by a thin plate-shaped connecting portion 1c. It is possible to obtain the integrally formed heating coil 100 of (4th step). Then, by cutting the end portion 1d of the connecting portion 1c of the two heating coils 100,
Two heating coils 100 are available. Finally, one end 10m of the heating conductor 10 and one end 20m of the heating conductor 20 are brazed with a pair of power supply conductors (not shown) to complete the production of the heating coil 100.

[0024]

As described above, the method of manufacturing the semi-open saddle type high frequency heating coil for crankshaft according to the present invention,
A high-frequency heating coil that is closely arranged so as to straddle the peripheral surface of a pin or a journal that is a hardened portion of a crankshaft and that heats the hardened portion. The first coil has the same shape and is wound in a substantially rectangular shape. A second coil piece and a third coil piece that is provided in a direction substantially perpendicular to the direction in which the opposite ends of the coil pieces are connected to each other and one ends of the open ends provided on the substantially axial side of the crankshaft are connected to each other. And the first and second coil pieces are connected in series by the third coil piece, and the first to third coil pieces are substantially gutter-shaped bodies formed by forming grooves. A method for manufacturing a semi-open saddle type high frequency heating coil for a crankshaft, comprising: a flat lid soldered to the main body so as to close the groove; A first step of cutting and forming the groove; The first metal material after the first step, an inner diameter equal to the diameter of the first metallic material, after inserted into the cylindrical second metallic material coated with the solder paste on the inner surface,
The second step of heating the first and second metal materials to bond the first and second metal materials, and the peripheral surfaces of the first and second metal materials after the second step are cut to remove the main body. Third step of forming and third
After the step, a fourth step of forming a cylindrical through hole centered on the axis of the first metal material is included in the first metal material.

Therefore, according to the manufacturing method of the present invention, since the lid and the main body of the heating conductor forming the heating coil can be simultaneously processed, the manufacturing process of the heating coil can be simplified and the heating Since there is no brazing part in the part of the coil facing the hardened part or the part close to the hardened part, the heating coil manufactured by the manufacturing method of the present invention does not deteriorate even after long-term use.

[Brief description of drawings]

FIG. 1 is a perspective view of a heating coil (excluding a power supply conductor) manufactured according to an embodiment of the present invention.

FIG. 2 is a perspective view of the first metal material before the first step of the embodiment of the present invention.

FIG. 3 is a perspective view of the first metal material after the first step of the embodiment of the present invention.

FIG. 4 is a perspective view of the first and second metal materials after the second step of the embodiment of the present invention.

FIG. 5 is a perspective view of the first metal material after the third step of the embodiment of the present invention.

FIG. 6 is a perspective view of the first and second metal materials after the fourth step of the embodiment of the present invention.

7 is a cross-sectional view taken along the line AA of FIG.

FIG. 8 is an explanatory diagram showing a state where the heating coil manufactured according to this example is placed on a journal.

FIG. 9 is a perspective view of a heating coil manufactured by a conventional manufacturing method.

[Explanation of symbols]

 1 First metal material 2 Second metal material 10a to 20a Main body 10f to 20f Groove 21 Lid 100 Heating coil 100A 1st coil piece 100B 2nd coil piece 100C 3rd coil piece 500 Journal 501 Hardened part

Claims (1)

[Claims] 1. A high-frequency heating coil, which is disposed close to a hardened portion of a crankshaft so as to straddle a peripheral surface of a pin or a journal and heats the hardened portion, and has the same shape and is wound in a substantially rectangular shape. The first and second coil pieces are connected to each other, and one ends of the open ends provided on the opposite sides of the coil pieces in the substantially axial direction of the crankshaft are connected to each other and provided in a direction substantially perpendicular to the direction. And a third coil piece, the first and second coil pieces are connected in series by the third coil piece, and the first to third coil pieces are formed by forming a groove. A method for manufacturing a semi-open saddle type high frequency heating coil for a crankshaft, comprising: a substantially gutter-shaped main body; and a flat plate-shaped lid soldered to the main body so as to close the groove, which is a cylindrical first metal. Form the groove on the peripheral surface of the material Insert the first step and the first metal material after the first step into a cylindrical second metal material having an inner diameter equal to the diameter of the first metal material and an inner surface coated with solder paste, By heating the first and second metal materials, the first and second
The second step of adhering the metal material and the peripheral surfaces of the first and second metal materials after the second step are cut to form the main body on the first metal material and the lid on the second metal material. Third step and third
After the step, a fourth step of forming, in the first metal material, a cylindrical through hole centering on the axis of the first metal material, a semi-open saddle type high frequency heating coil for crankshafts, characterized in that Method.