JP4292118B2 - High frequency induction heating coil body - Google Patents

Description

  The present invention relates to a high frequency induction heating coil body that performs high frequency induction heating of circumferential surfaces for rolling steel balls that are arranged in parallel symmetrically on an inner surface of a cylindrical member such as a hub unit of an automobile, for example.

  For example, a cylindrical member 1 such as a hub unit used in an automobile has an axial cross-sectional shape as shown in FIG. That is, at least two circumferential surfaces 2 and 3 for rolling steel balls having a substantially ¼ arc-shaped cross-section are formed on the inner surface of the cylindrical member 1. The upper steel ball rolling circumferential surface 2 and the lower steel ball rolling circumferential surface 3 are symmetrical to each other, and each has a circumferential surface (ring with an arc-shaped cross section) along the horizontal direction. Surface). Therefore, due to the shape as described above, the upper steel ball rolling circumferential surface 2 and the lower steel ball rolling circumferential surface 3 and the minimum inner diameter portion 4 of the tubular member 1 are the corner portion 5. , 6 cross each other. In addition, when the space | interval W of the axial direction of the circumferential surface 2 for rolling the upper steel ball and the circumferential surface 3 for rolling the lower steel ball is narrow, the corner portions 5 and 6 are positioned close to each other. Will be formed.

  As a high-frequency induction heating coil body that performs high-frequency induction heating on the upper and lower steel ball rolling circumferential surfaces 2 and 3 of the cylindrical member 1 having the above-described structure for quenching or the like, for example, FIG. A high-frequency induction heating coil body 7 as shown is conventionally used. As shown in FIG. 4, the conventional high-frequency induction heating coil body 7 includes an upper high-frequency induction heating coil body 7a and a lower high-frequency induction heating coil body 7b that are juxtaposed in parallel with each other at an appropriate interval L. In the high frequency induction heating, the high frequency induction heating coil bodies 7a and 7b are arranged on the inner surface of the cylindrical member 1 in parallel with each other in a symmetrical shape, and the upper steel ball rolling circumferential surface 2 and The steel balls are arranged horizontally in a state of facing the lower circumferential steel ball rolling surface 3 at substantially the same height position.

  That is, the high-frequency induction heating coil bodies 7a and 7b on the upper side and the lower side have substantially the same shape (substantially the same dimensions) as a whole, and are provided with ring-shaped high-frequency induction heating coils 8, respectively. A coil head 9 having a curved cross section (for example, a semicircular cross section) provided on the outer peripheral side of the high frequency induction heating coil 8 is arranged along the horizontal direction as shown in FIG. More specifically, the ring-shaped high-frequency induction heating coil 8 constituting the high-frequency induction heating coil bodies 7a and 7b includes a top portion (most projecting portion) P of the coil head portion 9 having a curved cross section and the coil head portion 9. Under the state where the center of curvature C is arranged on the same horizontal plane, these coil heads 9 are arranged to face the circumferential surfaces 2 and 3 for rolling the steel balls with a predetermined interval. Yes.

  The ring-shaped high-frequency induction heating coil 8 is provided with a magnetic body 11 for concentrating magnetic flux on a coil portion 10 having a U-shaped cross section excluding the coil head 9. Encapsulated. Thus, the ring-shaped high-frequency induction heating coil 8 and the magnetic body 11 constitute high-frequency induction heating coil bodies 7a and 7b. And at the time of high frequency induction heating, the said coil part 10 and the magnetic body 11 are also arrange | positioned horizontally similarly to the said coil head 9. As shown in FIG.

  Further, as indicated by arrows in FIG. 4, the direction of the high-frequency current I flowing in the upper high-frequency induction heating coil body 7a and the direction of the high-frequency current I flowing in the lower high-frequency induction heating coil body 7b are opposite to each other. It is set to be. The reason for this setting is as follows. In other words, since the upper steel ball rolling circumferential surface 2 and the lower steel ball rolling inner circumferential surface 3 are formed with protruding corner portions 5 and 6, these corner portions 5 and 6 (protruding) Part) is likely to be overheated during high frequency induction heating. In order to prevent this, the directions of the high-frequency currents I flowing in the upper-side high-frequency induction heating coil body 7a and the lower-side high-frequency induction heating coil body 7b are reversed, thereby causing mutual interference (cancellation effect) between the currents. At the same time, the corner portions 5 and 6 are prevented from overheating.

In addition, as a high frequency induction heating coil body for quenching a spherical surface such as a circumferential surface for rolling steel balls, for example, those disclosed in Japanese Patent Application Laid-Open No. 2002-161311 (patent document) can be cited. Examples of the high frequency induction heating of the outer surface and the inner surface of the shaft body include those disclosed in Japanese Patent Application Laid-Open No. 11-217627 (Patent Document 2), and the high frequency induction heating as shown in FIG. There is no published technique that approximates the coil body 7.
Japanese Patent Laid-Open No. 2002-161311 JP 11-217627 A

  As described above, the high frequency on the upper side is to prevent the corner portions 5 and 6 formed on the circumferential surface 2 for rolling the upper steel ball and the inner circumferential surface 3 for rolling the lower steel ball from being overheated. The direction of the high frequency current I flowing through the induction heating coil body 7a and the lower side high frequency induction heating coil body 7b is reversed, but the distance between the circumferential surfaces 2 and 3 for rolling the steel balls is narrow. Correspondingly, when the interval L between the high frequency induction heating coil bodies 7a and 7b is narrowed, there are the following problems. That is, as the distance L becomes narrower, the mutual interference of the high-frequency current I flowing in the opposite direction increases and the heating efficiency decreases. Therefore, the upper and lower steel ball rolling circumferential surfaces 2 3, there is a problem that the formation of the hardened and hardened layer S becomes insufficient at the portion where the hardened and hardened layer S is most required to be formed (the central portions of the arcs indicated by the symbols α and β in FIG. 4). . In other words, the magnetic fluxes of the high-frequency induction heating coil bodies 7a and 7b cannot be concentrated on these portions α and β, so that sufficient high-frequency induction heating cannot be performed on these portions α and β. It causes a defect.

  The present invention has been made to solve such problems, and the object thereof is to sufficiently efficiently use a portion requiring the most magnetic flux concentration (a portion requiring the most hardened and hardened layer). High-frequency induction heating coil bodies that are juxtaposed even when the distance between the circumferential surfaces of the steel balls or roller rolling is reduced and the interval between the high-frequency induction heating coil bodies is reduced It is an object of the present invention to provide a high-frequency induction heating coil body in which there is little mutual interference between high-frequency currents flowing in opposite directions, and overheating of a corner portion of a steel ball or a roller rolling circumferential surface hardly occurs.

In order to achieve the above-described object, in the present invention, a pair of curved steel balls or roller rolling circumferential surfaces arranged symmetrically in parallel with each other at an appropriate interval on the inner surface of the cylindrical member, respectively. In the high frequency induction heating coil body for high frequency induction heating, a pair of rings each having a coil head with a curved cross section disposed corresponding to each of the pair of curved steel balls or roller rolling circumferential surfaces. A line connecting the apex of the coil head and the center of curvature of the coil head is inclined with respect to the axis of the cylindrical member , and the inclination angle is the pair The angle of intersection between the normal line passing through the portion of the hardened and hardened layer to be formed on the circumferentially curved steel ball or the rolling rolling circumferential surface of the cylindrical member and the axis of the cylindrical member. wherein the plurality of ring-shaped to match the Configure frequency induction heating coil, along with this, when the pair of ring-shaped high-frequency induction heating coil, juxtaposed to one another coil head of the pair of ring-shaped high-frequency induction heating coil without providing the tilt angle The pair of ring-shaped high-frequency induction heating coils are spaced apart from each other so that a high-frequency current flows through the pair of ring-shaped high-frequency induction heating coils in opposite directions.
In the present invention, the inclination angle formed by the line connecting the apex of the coil head and the center of curvature of the coil head and the axis of the cylindrical member is 25 ° to 85 °.
In the present invention, a magnetic material for concentrating magnetic flux is attached to the ring-shaped high-frequency induction heating coil, and the magnetic material is also arranged with an inclination angle similar to that of the ring-shaped high-frequency induction heating coil.

The present invention according to claim 1 is a pair of ring-shaped high-frequency induction heating each having a pair of curved coil heads disposed corresponding to a pair of curved steel balls or roller rolling circumferential surfaces, respectively. A coil comprising a coil head, and a line connecting the apex of the coil head and the center of curvature of the coil head is inclined with respect to the axis of the cylindrical member , the inclination angle of which is a pair of cross-section steel balls or A pair of ring shapes so as to coincide with the angle of intersection between the normal line passing through the portion of the hardened and hardened layer to be formed on the circumferential surface of the roller rolling that is most required to form the hardened and hardened layer and the axis of the cylindrical member. A high-frequency induction heating coil is configured , and accordingly, a pair of ring-shaped high-frequency induction heating coils is paired with a pair of ring-shaped high-frequency induction heating coils that are parallel to each other without providing an inclination angle. Between ring-shaped high frequency induction heating coils Than the spacing, widely spaced and each other, because the pair of ring-shaped high-frequency induction heating coil is obtained by the flow a high frequency current in the opposite directions, the coil heads of the ring-shaped high-frequency induction heating coil According to the inclined arrangement, the steel ball is arranged toward the portion of the circumferential surface for rolling the steel ball that requires the most hardened hardened layer, so that the portion is sufficiently efficient. In addition, high-frequency induction heating can be performed, and a good hardened and hardened layer can be formed in this portion. On the other hand, the circumferential surface for rolling steel balls arranged in parallel with the inner surface of the cylindrical member is formed symmetrically, and the upper side and the lower side are formed as the coil head of the high-frequency induction heating coil body is inclined. Since the interval between the ring-shaped high-frequency induction heating coil parts of the high-frequency induction heating coil body is wider than in the conventional case, mutual interference of high-frequency currents (currents flowing in opposite directions) between the two is reduced, and as a whole A good quench hardened layer can be formed.

  Further, in the present invention according to claim 2, the inclination angle formed between the line connecting the apex of the coil head and the center of curvature of the coil head and the axis of the cylindrical member is 25 ° to 85 °. Therefore, by setting such an inclination angle, the coil head is disposed opposite to the portion where it is most necessary to form a hardened and hardened layer, and a good hardened and hardened layer is most effective. Can be formed.

  According to a third aspect of the present invention, a magnetic body for concentrating magnetic flux is attached to a ring-shaped high-frequency induction heating coil, and the magnetic body is arranged with an inclination angle similar to that of the ring-shaped high-frequency induction heating coil. Therefore, the magnetic force can be further strengthened with the inclination of the magnetic body enclosing the coil head of the ring-shaped high-frequency induction heating coil.

  Hereinafter, a high frequency induction heating coil body according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3, the same parts as those in FIG. 4 are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 shows a high-frequency induction heating coil body 20 according to an embodiment. The high-frequency induction heating coil body 20 quenches the circumferential surfaces 2 and 3 for rolling steel balls of the tubular member 1. For high frequency induction heating. As shown in FIG. 1, the high frequency induction heating coil body 20 is composed of a pair of high frequency induction heating coil bodies, that is, an upper side high frequency induction heating coil body 20a and a lower side high frequency induction heating coil body 20b. These coil bodies 20a and 20b have the same shape as each other and are arranged vertically symmetrically across a horizontal plane.

  As shown in FIGS. 1 and 2, the upper and lower high-frequency induction heating coil bodies 20a and 20b are respectively provided with ring-shaped high-frequency induction heating coils 21 arranged along the horizontal direction, and their coil heads. The portion 22 is inclined by an angle θ (see FIG. 2). That is, as clearly shown in FIG. 2, a straight line A connecting the apex P of the coil head 22 and the center of curvature C of the coil head is inclined with respect to the axis M of the cylindrical member 1 at an angle θ. Are arranged as follows. In the present embodiment, the above-described line A coincides with the cross-sectional central axis X (see FIG. 2) of the high-frequency induction heating coil bodies 20a and 20b. Thus, the entire ring-shaped high-frequency induction heating coil 21 is inclined at an angle θ, and the coil head 22 is most required to form a hardened hardened layer among the circumferential surfaces 2 and 3 for rolling the steel balls. It is comprised so that it may be in the position which opposes the parts (alpha) and (beta) to be performed.

  On the other hand, a magnetic body 23 for concentrating magnetic flux is attached to the ring-shaped high-frequency induction heating coil 21, and the coil head portion 22 is encapsulated by the magnetic body 23. Thus, the ring-shaped high-frequency induction heating coil 21 and the magnetic body 23 constitute upper and lower high-frequency induction heating coil bodies 20a and 20b, respectively. In addition, in the ring-shaped high frequency induction heating coils 21a and 21b of the high frequency induction heating coil bodies 20a and 20b, in order to prevent overheating in the corner portions 5 and 6 of the cylindrical member 1, as in the conventional case, FIG. As indicated by the arrows, high-frequency currents I flow in opposite directions.

Here, the above-described inclination angle θ will be described. As shown in FIG. 2, in the present embodiment, a portion α that is most required to form a hardened hardened layer in the hardened hardened layer S to be formed on the upper circumferential surface 2 for rolling steel balls. , Β normal line (normal line at the center of the circumferential surface 2, 3 for rolling steel balls) N
And the angle of intersection with the axis B of the cylindrical member 1 substantially coincides with the inclination angle θ. It has been confirmed by experiments that the value of the angle θ is preferably 25 ° to 85 ° in the cylindrical member 1 such as a normal hub unit. Therefore, in this embodiment, the inclination angle θ is set in the range of 25 ° to 85 ° similar to the above.

By setting the inclination angle θ to the value of the upper and lower two ring-shaped high-frequency induction heating coil 21 constituting the upper side and the lower side of the high-frequency induction heating coil body 20a, and 20b as shown in FIG. 1, a pair A pair of ring-shaped high-frequency induction heating coils 21 when the coil heads 22 and 22 of the pair of ring-shaped high-frequency induction heating coils 21 and 21 are arranged side by side without providing an inclination angle θ. than the distance between 21, it is arranged to widely spaced apart from each other. For this reason, even if the high-frequency current I flowing in the both directions is in the opposite direction, the degree of mutual interference of the high-frequency current is greatly reduced as compared with the conventional case.

  According to the high frequency induction heating coil body 20 of the present embodiment, the portions α and β that are most required to form a hardened hardened layer can be efficiently subjected to high frequency induction heating, and thus rapid cooling treatment after high frequency induction heating. In addition to forming a desired hardened and hardened layer, the overheating of the corner portions 5 and 6 of the cylindrical member 1 can be reduced, and a high quality hardened and hardened layer S can be formed as a whole. it can. In addition, since efficient high-frequency induction heating is possible, it is possible to reduce the input power compared to the conventional case. Conversely, if the input power is constant, the heating time can be shortened and workability can be improved. Can be achieved. Furthermore, since the load applied to the ring-shaped high-frequency induction heating coil 21 is reduced, it is possible to improve the life, that is, improve the durability.

  FIG. 3 schematically shows the effect of the magnetic material encapsulating the coil head. This FIG. 3 is a diagram of 1998 Flextrol Manufacturing Inc. Is referenced from This is one in which the outer periphery of the shaft body 30 is subjected to high frequency induction heating by a high frequency induction heating coil 31, the left side of FIG. 3 is a bare high frequency induction heating coil body 31 without a magnetic body, and the right side of FIG. A power enhancement type high frequency induction heating coil 31 encapsulated by a body 32 is shown. As shown in FIG. 3, it can be seen that the concentration of the magnetic flux Φ varies greatly depending on the presence or absence of the magnetic body 32, and the encapsulating effect of the magnetic body 32 is extremely large. In addition, the high frequency induction heating coil body 20 of this embodiment uses the magnetic body 23 which encloses the coil head 22, and it is supported that the magnetic flux concentration efficiency is large.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, in the above-described embodiment, the tubular member to be heated is a member such as a hub unit of an automobile. However, the tubular member is not limited to the hub unit as a matter of course. It is possible to apply as a high-frequency induction heating coil body for heating a member having a symmetrical steel ball rolling circumferential surface. Further, the present invention can be applied not only to the circumferential surface for rolling steel balls but also to the circumferential surface for roller rolling.

It is sectional drawing which shows the state which has arrange | positioned the high frequency induction heating coil body of this invention corresponding to the circumferential surface for steel ball rolling of a hub unit. It is a typical enlarged view for demonstrating the position of the part most necessary for formation of a hardening hardening layer in the circumferential surface for steel ball rolling. It is typical explanatory drawing for demonstrating the effect of the magnetic body which encapsulates a high frequency induction heating coil body. It is sectional drawing which shows the state which has arrange | positioned the high frequency induction heating coil body of this invention corresponding to the circumferential surface for steel ball rolling of a hub unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical member 2,3 Circumferential surface for rolling steel balls 5,6 Corner part 20 High frequency induction heating coil body 21 Ring-shaped high frequency induction heating coil 22 Coil head 23 Magnetic body A Straight line B Axis C Center of curvature P Top part θ Inclination Angle N Normal

Claims (3)

In a high-frequency induction heating coil body for high-frequency induction heating each of a pair of cross-section curved steel balls or roller rolling circumferential surfaces arranged in parallel symmetrically at positions appropriately spaced on the inner surface of the cylindrical member,
A pair of ring-shaped high-frequency induction heating coils each having a section-curved coil head disposed corresponding to each of the pair of section-curved steel balls or roller rolling circumferential surfaces,
The line connecting the apex of the coil head and the center of curvature of the coil head is inclined with respect to the axis of the cylindrical member , and the inclination angle is the pair of cross-section steel balls or The pair of pairs so as to coincide with an intersection angle between a normal line passing through a portion most required to form the quench-hardened layer and an axis of the cylindrical member in the hardened-hardened layer to be formed on the circumferential surface for roller rolling. Construct a ring-shaped high frequency induction heating coil ,
Accordingly, the pair of ring-shaped high-frequency induction heating coils is a pair of ring-shaped high-frequency induction heating coils when the coil heads of the pair of ring-shaped high-frequency induction heating coils are arranged side by side without providing the inclination angle. Placed farther apart than the spacing between the heating coils,
The pair of ring-shaped high-frequency induction heating coils is configured to cause a high-frequency current to flow in directions opposite to each other,
A high frequency induction heating coil body characterized by.   The inclination angle formed by a line connecting the apex of the coil head and the center of curvature of the coil head and the axis of the cylindrical member is set to 25 ° to 85 °. High frequency induction heating coil body.   3. A magnetic material for concentrating magnetic flux is attached to the ring-shaped high-frequency induction heating coil, and the magnetic material is also arranged with an inclination angle similar to that of the ring-shaped high-frequency induction heating coil. The high frequency induction heating coil body according to 1.

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