JPH0141192Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an induction heating coil for an irregularly shaped member, such as a ball stud, etc., which has a narrow constriction in its longitudinally intermediate portion.

(Prior Art) A conventional induction heating coil used for forming a quenched layer of a predetermined depth along the longitudinal outer periphery of a deformed member having unevenness on its longitudinal circumferential surface has been developed by the present applicant. Utility model registration number provided by
No. 1243430 (Utility Model Application Publication No. 1982-49162).

The coil is shown in Figure 2 a and b as C' or
As shown as C″, in a predetermined portion of the plate conductor 1,
A cutout portion 2 of a predetermined shape is provided on the opposing surface along the outer circumferential shape of the irregularly shaped member so as to face it with a certain gap therebetween, and the conductor portion extending on the outer circumference at an axially symmetrical position of the heated member W is connected to the heating portion. In order to generate a magnetic flux substantially perpendicular to the axial direction of the member W, the gap is changed according to the degree of unevenness of the member W, such as P1 in a, and P2 and P3 in b. This structure enables uniform heating to a predetermined depth along the outer circumference of the member in the longitudinal direction.

(Problems with conventional technology) Conventional induction heating coils C', C'', etc. for irregularly shaped parts, etc.
If the difference in the unevenness of the circumferential surface in the longitudinal direction of the member W is up to a certain extent, the heating effect in the longitudinal direction can be made uniform, but the difference in the unevenness as shown in FIG. 2c is extremely large. For example, when trying to uniformly heat the outer periphery of W such as a ball stud along the longitudinal direction, the heating effect on the narrow constriction N is slightly inferior.
The quenched hardened layer indicated by the double diagonal line h' tends to be shallow in depth at the corresponding portion.

Recently, there has been a demand for functional enhancement of irregularly shaped parts, and for this purpose, it has become necessary to form a deep quenched hardened layer in the narrow constriction part N to improve the mechanical properties of the narrow constriction part N. There was a need for uniform heating measures as a prerequisite for forming a quenched hardened layer of uniform depth.

(Purpose of the invention) The present invention was made to eliminate the above-mentioned drawbacks of conventional induction heating coils for irregularly shaped members. An object of the present invention is to provide an induction heating coil for an irregularly shaped member that can be heated uniformly along the direction.

(Structure of the invention) The structure of the invention is as follows: (1) One end face of one plate-shaped conductor and the other end face of the other plate-shaped conductor are symmetrical about the axis of the irregularly shaped member having a thin constriction. (3) One of the plate-shaped conductors has one end in the longitudinal direction,
The other plate-shaped conductor has its other end in the longitudinal direction connected to a power source, and (4) is connected by a connecting conductor that detours away from the member at the opposing portion of the constriction, and (5) the member. An induction heating coil for an irregularly shaped member is capable of heating the circumference of a rotating member using magnetic flux perpendicular to the axis of the member.

(Example) The present invention will be described in detail below according to an example shown in FIG. 1a.

In FIG. 1a, C is an induction heating coil for a deformed member of the present invention, and Ca and Cb are one plate-shaped conductor and the other plate-shaped conductor, respectively. One side end surface sa of one plate-shaped conductor Ca and one side end surface sb of the other plate-shaped conductor Cb are provided with a predetermined shape so that they can face each other at a predetermined gap along the shape of the longitudinal outer periphery of the member to be heated. It is formed in the shape of , and is arranged so that the axis of the heated member becomes the axis of symmetry.
Leads Ra and Rb are fixed to one longitudinal end of one plate-shaped conductor Ca (for example, at the top in the figure) and the other end of the other plate-shaped conductor Cb (at the bottom in the figure), and their tips are connected to a power source E. ing. One side end surface sa of one plate-shaped conductor Ca and one side end surface sb of the other plate-shaped conductor Cb are opposite to the narrow constriction N of the member to be heated, that is, the opposite side of the protruding parts shown as Na and Nb. The end face is
They are connected by a connecting conductor designated as J. A bus bar, a braided conductor, or the like is used as the connecting conductor J, and it has a horseshoe shape or a U-shape detoured so as to be sufficiently spaced from the heated member.

The electric path of the induction heating coil of the present invention having the above configuration is power supply E - broken line arrow E - solid line arrow L - broken line arrow H - solid line arrow K - broken line arrow H - power supply E, but the electric path that directly contributes to heating is The solid lines B and D are solid lines. Therefore, for example, the heated material is carried between one plate-shaped conductor Ca and the other plate-shaped conductor Cb by relative movement as shown by arrow A, is placed on a rotary table S with the axis in the vertical direction in the figure, and is rotated about the axis. The member is generated from a high-frequency current that flows through the electric path indicated by the solid line arrow B on one plate-shaped conductor Ca above the constriction N, and through the electric path indicated by the solid line arrow D on the other plate-shaped conductor Cb below the constriction N. . Induction heating occurs due to magnetic flux in a direction substantially perpendicular to the axis.

In this state, the electric circuit indicated by solid arrow B and the electric circuit indicated by solid arrow D are connected to the protrusions Na and Nb, respectively.
Since the narrow constricted part N of the heated member where the protrusions Na and Nb are opposed to each other is sufficiently penetrated by the magnetic flux, uniform heating in the longitudinal direction of the outer circumference is achieved, as shown in Fig. 1. As shown in b, a quenched hardened layer h having the same depth as the other parts is obtained also in the constricted part N.

By the way, below the protrusion Na of one plate-shaped conductor Ca and above the protrusion Nb of the other plate-shaped conductor Cb, due to the nature of the current, which tends to take the shortest path,
It is disconnected from the electrical circuit. However, each of the conductors in the part separated from the electric circuit generates repulsive energy against the magnetic flux generated from the electric circuit indicated by solid arrow d and the electric circuit indicated by solid arrow b on the opposite side of the axis of symmetry, and heats the heated member. Bring about improved efficiency.

The above is a kind of magnetic flux control, and the effect is that the inventor cut the portions below the protruding portion Na of one plate-shaped conductor Ca and above the protruding portion Nb of the other plate-shaped conductor Cb, which do not form an electric path. As a result of heating comparison experiments between the prototype induction heating coil and the induction heating coil of the present invention, it was found that in the same amount of time as the induction heating coil of the present invention required to raise the temperature of the specimen to the specified quenching temperature, the prototype induction heating coil This effect was confirmed because the specimen was only heated to a temperature approximately 50°C lower than the prescribed quenching temperature.

(Other Embodiments) In the above embodiments, an example of a member in which the narrow constriction part N is one place is explained. For example, the narrow constriction part N
In the case of an iron bell-shaped member with two places, the conductor Ca
If a connection conductor similar to the connection conductor J of the above embodiment is used to connect each of the protrusions sa and sb facing the two constrictions N of Cb and Cb, exactly the same effect can be obtained. . Of course, the same applies even if there are three or more constrictions N.

(Function of the invention) In conventional induction heating coils for irregularly shaped members, the main flow path of the current that exerts the heating effect did not fully reach the tip of the protrusion N as shown by the solid line in Figure 2a.
The present invention not only guides the main current path to the conductor portion facing the thin constriction, but also generates repulsive energy against the magnetic flux generated from the plate-shaped conductor on the axially opposite side of the member in the conductor portion that does not become an electric path. Demonstrate.

(Effects of the invention) By implementing the invention, it is possible to uniformly heat an irregularly shaped member having a narrow constriction part along the outer circumferential longitudinal direction with high heating efficiency, and to form a hardened layer with a uniform depth. The purpose is to improve the mechanical properties of the thin constriction, thereby enhancing the function of the irregularly shaped member, so it is highly prized.

[Brief explanation of the drawing]

Fig. 1a is a perspective view showing an embodiment of the induction heating coil for irregular shaped parts of the present invention, Fig. 1b is a cross-sectional front view of a ball stud surface hardened using the induction heating coil of the invention, and Fig. 2 a and b are respectively a perspective view of one embodiment of a conventional induction heating coil for irregularly shaped parts and a cross-sectional front view of another embodiment, and FIG. FIG. 3 is a cross-sectional front view of the ball stud. C...Induction heating coil for irregularly shaped parts, Ca...One plate conductor, Cb...The other plate conductor, sa...
One side end face, sb...Other side end face, N...Slim constriction of odd-shaped member, Na, Nb...Constriction opposing part, J
...Connection conductor, E...Power supply.

Claims (1)

[Scope of utility model registration request] One side end face of one plate-shaped conductor and the other side end face of the other plate-shaped conductor can be arranged facing each other at a predetermined interval from the longitudinal outer periphery with the axis of the irregularly shaped member having a thin constriction as the axis of symmetry. One of the plate-shaped conductors is connected to a power source at one longitudinal end, and the other plate-shaped conductor is connected to a power source at the other longitudinal end, and both conductors are separated from the member at the opposing portions of the constriction. An induction heating coil for an irregularly shaped member, which is connected by a connecting conductor that detours around the member, and is capable of heating the periphery of a rotating member using magnetic flux in a direction perpendicular to the axis of the member.