JPH05239541A - High-frequency induction heating method and high-frequency induction heating coil - Google Patents

Abstract

PURPOSE:To shorten heating process to the whole surface of a work providing a spherical top part and a columnar foot part by using a high-frequency induction heating coil having parallel heating conductors and circular arc heating conductor. CONSTITUTION:A work 30 is laid on a work laying table 51 so that a rotating axis 39 becomes perpendicular, and while rotating the work 30, the work laying table 51 is shifted as circular arc. The heating surface of the work 50 is approached to a heating coil 10 and the surface of a top part 31 and the peripheral surface of a foot part 32 in the work 30 are heated by facing the heating surface to the second heating conductor 12. Successively, the top part 31 in the work 50 is passed through between one pair of the first heating conductors 11a, 11b to heat the whole surface of the top part 31. Further, the peripheral surface of the foot part 32 is heated by the first heating conductor 11a. Successively, the surface of the top part 31 and the peripheral surface of the foot part 32 are heated by facing the heating surface of the work 30 to a third heating conductor 13. Intensity of the high-frequency current conducted to the heating coil 10 and shifting velocity of the work 30 are selected so as to heat the heating surface of the work 30 to the desired temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head portion of a work having a substantially spherical head portion and a columnar leg portion having a diameter smaller than that of the head portion and projecting from the head portion. The present invention relates to a high-frequency heating method for heating the surface of the above and the peripheral surface of the leg portion that is close to the head and a high-frequency heating coil capable of realizing this method (hereinafter, the high-frequency heating coil is simply referred to as a heating coil).

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings. A work 30 whose cross section is shown in FIG. 4 is a type of ball stud used in a traveling system of an automobile, and has a spherical head 31, a columnar leg 32 projecting from the head 31, It has a columnar protrusion 33 protruding from the leg portion 32. The heated surface 36 of the work 30 is the surface 34 of the head 31,
It consists of a peripheral surface 35 of a portion of the leg portion 32 which is close to the head portion 31. Then, in order to form the hardened layer 38 shown in the drawing by heating the heated surface 36 and then cooling it, the high frequency heating coil 40 shown in FIG. 5 is conventionally used.

The heating coil 40 has a circular arc-shaped heating conductor 41 formed to correspond to the shape of the head 31 of the work 30 and a circumferential shape of the peripheral surface 35 of the leg 32. An arc-shaped heating conductor 42 formed and connected to both ends of the heating conductor 41, a heating coil power supply transformer 44 connected to a split point of the heating conductor 42, and a pair of transformers 44 on the input side of the transformer 44. The high frequency power supply 50 is connected via the flexible cables 43, 43. The work 30 is a rotationally symmetric body, 39 is the axis of the leg portion 32, and the shaft 39 also passes through the center of the head 31 and is therefore also the rotation axis of the work 30.

Next, a method for heating the heated surface 36 of the work 30 will be described. First, the work 30 is placed on the work placement table 51 so that the rotation axis 39 is vertical. Next, the work table 51 is rotated in the direction of arrow D, for example, to rotate the work 30 about the rotation shaft 39. Then, the heating coil 40 is advanced in the direction of arrow P to move the head of the work 30.
The surface 34 of 31 is surrounded by a heating conductor 41, and the heating coil 42 is arranged so that the heating conductor 42 closely faces and faces the peripheral surface 35 of the leg 32 near the head 31.
40 is provided.

Thereafter, a high frequency current is passed from the high frequency power source 50 to the heating coil 40 for a predetermined time to heat the surface 36 to be heated of the work 30. When the heating is completed, the heating coil 40 moves in the direction opposite to the arrow P and returns to the original standby position. At the same time, the work table 51 is moved, for example, in the direction perpendicular to the arrow P, that is, in the direction of the arrow Q to move the work 30 to the cooling position, and then the work 30 is heated with a cooling liquid from a jacket not shown. The heated surface 36 is sprayed onto the heated surface 36 to cool the heated surface 36 and a hardened layer 38 is formed on the heated surface 36.

[0006]

However, the above-mentioned conventional high-frequency heating method has the following problems. That is, when starting heating, the heating coil 40,
The heating coil 40 is moved forward from the standby position in the direction of the arrow P so as to closely face the surface to be heated of the work 30, and after heating is completed, the heating coil 40 is placed so as not to interfere with the movement of the work 30 to the cooling position. You have to move it back to its original standby position.

Therefore, since it takes time to advance and retract the heating coil 40 as described above, when heating a large number of works 30, the entire heating process becomes long.

The present invention was devised in view of the above circumstances, and has a substantially spherical head portion and a cylindrical leg portion having a diameter smaller than the diameter of the head portion and projecting from the head portion. To provide a high-frequency heating method capable of shortening the entire heating process when high-frequency heating the surface of the head of a workpiece provided with and the peripheral surface of the leg portion that is close to the head. Has a purpose.

[0009]

In order to solve the above-mentioned problems, a high-frequency heating method according to claim 1 has a substantially spherical head and a diameter smaller than the diameter of the head, which protrudes to the lower part of the head. In a high-frequency heating method for heating a heated surface consisting of the surface of the head and the peripheral surface of the leg in the vicinity of the head, the pair of parallel first parts is provided. High frequency heating provided with one heating conductor and second and third heating conductors each having one end and the other end of each of the first heating conductors and which are formed in a substantially arc shape so as to correspond to the shape of the head. A high-frequency current is applied to the coil, and the workpiece is continuously rotated about the axis of the leg and moved in a direction perpendicular to the axis while the surface to be heated is heated by the second heating. Place it close to the conductor and face it before passing it between the first heating conductors. Then, after facing the third heating conductor, it is moved away from the third heating conductor, and when the heated surface passes between the first heating conductors, one of the first heating conductors approaches the lower part of the head. And the first of the other
The heating conductor is approached by a head near the top of the head on the opposite side of the bottom from the top of the head.

A high frequency heating coil according to a second aspect of the present invention includes a substantially spherical head portion and a substantially columnar leg portion having a diameter smaller than the diameter of the head portion and protruding from the lower portion of the head portion. In a high-frequency heating coil that heats a surface to be heated consisting of the surface of the head of the work and the peripheral surface of the legs near the head,
A pair of parallel first heating conductors, and second and third heating conductors of substantially arc shape connecting one end and the other end of these first heating conductors, respectively, and the second and third
The heating conductor is formed so as to correspond to the shape of the head, and the first heating conductor is formed such that the surface to be heated is inserted between the first heating conductors. At the same time, when the heated surface is inserted, one of the first
The lower part of the head is close to the heating conductor, and the other first heating conductor is close to the head near the top of the head on the opposite side of the lower part from the top of the head. It is arranged.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are drawings for explaining one embodiment of a heating coil capable of realizing the method of the present invention,
1 is a schematic perspective view, FIG. 2 is a cross-sectional view taken along the line EE of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line FF of FIG. The same components as those described in the related art are designated by the same reference numerals. As the work, a case will be described in which the same heated surface of the same work as described in the related art is heated.

As shown in FIG. 1, the heating coil of this embodiment
Reference numeral 10 denotes a pair of parallel first heating conductors 11a and 11b, and second and third heating conductors 1 having a substantially arc shape connecting one end and the other end of the first heating conductors 11a and 11b, respectively.
It has 2 and 13. A high-frequency power source 50 is connected to the first heating conductor 11b at two points. High frequency power 50
The connection is not limited to the dividing point of the first heating conductor 11b, but may be the dividing point of the first heating conductor 11a, the second heating conductor 12, or the third heating conductor 13.

The second and third heating conductors 12, 13 are work pieces.
In order to heat the surface 34 of the head 31 of the 30 and the peripheral surface 35 of the portion of the leg 32 which is close to the head 31, the one end part of the work 30 is circumferentially shaped so as to correspond to the shape of the head 31. It is formed so as to face the surface 35.

The first heating conductors 11a and 11b are formed such that the heated surface 36 is inserted between the first heating conductors 11a and 11b, and when the heated surface 36 is inserted. , The lower portion of the head portion 31 is close to one of the first heating conductors 11a, and the other surface of the first heating conductor 11b from the top portion 37 of the head portion 31 on the opposite side of the lower portion to the surface 34 near the top portion 34. Are arranged so that they are close to each other. The first heating conductor 11a
, 11b are both formed in an arc shape.

The method of heating the heated surface 36 of the work 30 will be described below. First, the work 30 is placed on the work placement table 51 so that the rotation shaft 39 is vertical, and then the work placement table 51 is rotated in the direction of arrow B, for example, so that the work 30 is continuously rotated about the rotation axis 39. To rotate. While the work 30 is continuously rotated about the rotation shaft 39, the work mounting table 51 is continuously moved in an arc shape in the direction of arrow A. The work placing table 51 is a position near the periphery of a turntable (not shown), which is moved between the arcs formed by the first heating conductors 11a and 11b, and is rotatably attached to the turntable. Since it is attached, by rotating this turntable, the first heating conductor 11a
, 11b, the work 30 moves.

Then, the surface 36 to be heated of the work 30 is gradually brought closer to the heating coil 10 and, as shown in FIG. 2, the surface 36 to be heated is first brought close to the second heating conductor 12 and opposed thereto. At this time, the second heating conductor 12 causes the surface 34 of the head 31 and the legs 32 to
The peripheral surface 35 of the is heated.

Next, as shown in FIG. 3, the head 31 of the work 30 is passed between the first heating conductors 11a and 11b. At this time, the work 30 is rotating around the rotating shaft 39, and the one first heating conductor 11a is on the lower part of the head 31, and the other first heating conductor 11b is on the top of the head 31. The first heating conductors 11a are arranged so as to be close to the surface 34 near the top portion 37 on the opposite side of the lower portion from 37.
, 11b heats the entire surface 34 of the head 31, and the first heating conductor 11a heats the peripheral surface 35 of the leg 32.

Thereafter, the surface 36 to be heated of the work 30 is brought close to the third heating conductor 13 so as to be opposed thereto. At this time, the third heating conductor
The surface 34 of the head 31 and the peripheral surface 35 of the leg 32 are heated by 13.

The magnitude of the high-frequency current flowing through the heating coil 10 and the moving speed of the work 30 in the direction of arrow A are selected so that the surface 36 to be heated of the work 30 is heated to a desired temperature.

The work 30 separated from the third heating conductor 13 reaches the cooling position, and the cooling liquid is sprayed from the jacket (not shown) onto the heated surface 36 of the work 30 to complete the quenching of the heated surface 36.

Although the above description has been made for the heating of one work 30, the heating of the surfaces 36 to be heated of the plurality of works 30 is performed in the same manner. That is, a plurality of work placement tables are arranged in the direction of arrow A, and the works 30 are placed on these work placement tables,
After moving all the work mounts in the direction of the arrow A at the same speed to gradually pass through the heating coil 10 to heat the surface 36 to be heated, the work 30 is sequentially cooled at the cooling position as described above.

As described above, since the heated surfaces 36 of the continuously moving works 30 can be heated by the fixed heating coil 10, the step of heating the works 30 can be shortened. ..

In the above-mentioned embodiment, the work 30 is moved along the arc, but it is possible to obtain the same effect as that of the above-mentioned embodiment even if the work 30 is moved linearly without being particular about this.

[0024]

As described above, according to the high frequency heating method of the present invention, a pair of parallel first heating conductors and one end and the other end of these first heating conductors are connected to each other to form a head shape. A high-frequency current is passed through a high-frequency heating coil having substantially arcuate second and third heating conductors formed in a corresponding manner, and the work is rotated about the axis of the leg and is perpendicular to the axis. Direction of movement, the heated surface is made to face the second heating conductor so as to face the first heating conductor, and then the first heating conductor is passed between the first heating conductor and then the third heating conductor. , When moving away from the third heating conductor and the heated surface passes between the first heating conductors, the lower part of the head is brought close to one of the first heating conductors, and the other first heating conductor is From the top of the head, on the other side of the lower part, near the top It is made to close.

Further, the high-frequency heating coil of the present invention includes a pair of parallel first heating conductors and a substantially arc-shaped second heating conductor that connects one end and the other end of each of the first heating conductors.
And a third heating conductor, the second and third heating conductors are formed so as to correspond to the shape of the head of the work, and the first heating conductor is provided between these first heating conductors. The heated surface of the work is formed to be inserted, and when the heated surface is inserted, the lower part of the head approaches one of the first heating conductors and the other of the first heating The conductor is disposed such that the head near the top is close to the top of the head, opposite the bottom.

Therefore, according to the high-frequency heating method of the present invention, or when the high-frequency heating coil of the present invention is used to heat the surface to be heated of such a work, heating is performed as in the conventional high-frequency heating method. It is not necessary to move the heating coil forward and backward toward the work before and after, and since the work moves continuously, shorten the entire heating process to heat the heated surfaces of multiple works. You can

[Brief description of drawings]

FIG. 1 is a schematic perspective explanatory view of an embodiment of a high-frequency heating coil capable of realizing the method of the present invention.

FIG. 2 is a cross sectional view taken along the line EE of FIG. is there.

FIG. 3 is a cross sectional view taken along the line FF of FIG.

FIG. 4 is a vertical sectional view of a work.

FIG. 5 is an explanatory diagram of a conventional heating method.

[Explanation of symbols]

 10 Heating coil 11a, 11b 1st heating conductor 12 2nd heating conductor 13 3rd heating conductor 30 Work piece 31 Head 32 Leg 34 Surface 35 Circumferential surface 36 Heated surface 37 Top 39 Axis

Claims (2)

[Claims] 1. A surface of the work head and a head having a substantially spherical head and a leg having a diameter smaller than that of the head and protruding from a lower portion of the head. In a high-frequency heating method for heating a surface to be heated composed of a peripheral surface of a leg portion in the vicinity of the section, a pair of parallel first heating conductors and one end and the other end of these first heating conductors are connected to each other A high-frequency current is supplied to a high-frequency heating coil having second and third heating conductors formed in a substantially arc shape corresponding to the shape of the portion, and the work is centered on the shaft of the leg portion. While continuously rotating and moving in a direction perpendicular to the axis, the surface to be heated is brought close to and facing the second heating conductor, then is passed between the first heating conductors, and then the third heating conductor is passed. After facing the heating conductor, move it away from the third heating conductor and When the heating surface passes between the first heating conductors, the lower part of the head is brought closer to one of the first heating conductors, and the other first heating conductor is connected from the top of the head to the lower part of the head. A high-frequency heating method, characterized in that the head near the top is approached on the opposite side. 2. A surface of the work head and a head having a substantially spherical head and a substantially columnar leg portion having a diameter smaller than that of the head portion and projecting from a lower portion of the head portion. In a high-frequency heating coil that heats a surface to be heated that is composed of the peripheral surface of a leg near the section, a pair of parallel first heating conductors and one end and the other end of these first heating conductors are connected to each other. Arc-shaped second and third heating conductors, the second
And the third heating conductor is formed so as to correspond to the shape of the head, and the first heating conductor has the first heating conductor.
Between the heating conductor, the heated surface is formed to be inserted, and when the heated surface is inserted,
The lower part of the head is close to one of the first heating conductors, and the other head of the head is close to the first heating conductor on the opposite side of the lower part from the top of the head. The high-frequency heating coil is characterized in that it is arranged as described above.