JP2008101664A - Induction heating apparatus for outer ring of constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably perform tempering treatment by effectively induction-heating only a hardened layer formed on a cup part inside diameter surface of an outer ring of a constant velocity joint. <P>SOLUTION: A coil 2a for induction-heating a stem part 11a is disposed in such a manner of winding in the circumferential direction on an outside diameter side of the stem part 11a, a coil 2b for induction-heating a cup part 11b is divided into three in the circumferential direction of the cup part 11b in such a manner of going around in the axial direction on an outside diameter side of the cup part 11b, and the divided coils 2b are arranged on an outside diameter side of a recessed groove 14 spaced apart in the circumferential direction of the cup part 11b, and thereby, only the hardened layer formed on a roller guide inner surface 12a formed on an inside diameter side of the recessed groove 14 is effectively induction-heated, and tempering treatment can be suitably performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an induction heating device for a constant velocity joint outer ring that temperes the outer ring of the constant velocity joint by induction heating.

  The outer ring of the constant velocity joint has a cup portion in which a plurality of track grooves on which rolling elements roll are provided at intervals in the circumferential direction of the inner diameter surface, and an outer diameter surface extending in the axial direction from the bottom of the cup portion. Some of them have a stem portion in which a tooth mold portion such as serration is formed. The rolling element is a ball or trunnion roller, and the outer ring of a tripod type constant velocity joint that expands and contracts in the axial direction has an inner diameter of a cylindrical cup portion 11b as shown in FIG. 2 (b) explaining the embodiment of the present invention. Three horizontally elongated track grooves 12 extending in the axial direction with a phase of 120 ° are formed on the surface, and roller guide surfaces 12a on which the rollers roll are provided on both side surfaces. The roller guide surfaces 12a facing each other are connected by a large inner diameter portion 13a, and each track groove 12 is connected by a small inner diameter portion 13b.

  The outer ring of such a constant velocity joint was subjected to a quenching process to form a hardened layer on the roller guide surface of the track groove on the outer diameter surface of the stem part and the inner diameter surface of the cup part, and then formed by the quenching process. A tempering process is performed to release stress in the vicinity of the hardened layer, but the tempering process may be performed by induction heating (see, for example, Patent Document 1).

  In such a tempering process of the constant velocity joint outer ring by induction heating, a round solenoid coil 21 as shown in FIGS. 3 (a) and 3 (b) or a hairpin as shown in FIGS. 4 (a) and 4 (b). The coil 22 is used, and the outer ring 24 of the constant velocity joint mounted on the cradle 23 is moved into the solenoid coil 21 and the hairpin coil 22, and high frequency current is passed through these coils 21, 22 to induce the outer ring 24. Heating. When the solenoid coil 21 that covers the outer peripheral side of the outer ring 24 spirally is used, the entire outer periphery of the outer ring 24 can be heated evenly, but when the hairpin coil 22 that extends in the axial direction on the outer peripheral side of the outer ring 24 is used, The cradle 23 on which 24 is mounted is rotated so that the entire circumference of the outer ring 24 is heated evenly. The magnitude and frequency of the coil current flowing through the coils 21 and 22 are appropriately set depending on the type and shape of the outer ring 24.

Japanese Patent Laid-Open No. 5-9584

  In the conventional induction heating apparatus that heats the entire circumference of the constant velocity joint outer ring described above from the outer periphery side and temperes the stem portion where the hardened layer formed by the quenching process is on the entire circumference of the outer diameter surface, it extends over the circumferential direction. Although the tempering process can be performed uniformly, the cup portion in which the hardened layer of the roller guide surface of the track groove is partly in the circumferential direction of the inner diameter surface is also heated excessively in the circumferential portion where the hardened layer is not formed. As shown in (b), the outer ring 11 of the tripod type constant velocity joint in which the roller guide surfaces 12a facing each other are connected by the large inner diameter portion 13a, the large inner diameter portion 13a is overheated, and the outer ring 11 is outside the large inner diameter portion 13a. There is a problem that an oxide film is generated on the diameter surface, which adversely affects the adhesion of the paint after tempering. Further, if the tempering temperature is lowered in order to prevent the generation of such an oxide film, the tempering treatment of the hardened layer becomes insufficient.

  Accordingly, an object of the present invention is to efficiently induction-heat only the portion of the hardened layer formed on the inner diameter surface of the cup portion of the constant velocity joint outer ring so that it can be sufficiently tempered.

  In order to solve the above-mentioned problems, the present invention provides a cup portion in which a plurality of track grooves on which rolling elements roll are provided at intervals in the circumferential direction of the inner diameter surface, and an axial direction from the bottom of the cup portion. In a constant velocity joint outer ring induction heating apparatus for tempering an outer ring of a constant velocity joint having an extending stem portion by induction heating, the coil for induction heating the stem portion is arranged circumferentially on the outer diameter side of the stem portion. The coil for induction heating is arranged so as to circulate, and the coil for induction heating is arranged so as to circulate in the axial direction on the outer diameter side of the cup part. The structure provided with the means to provide was employ | adopted.

  That is, the coil for induction heating of the stem portion is arranged to circulate in the circumferential direction on the outer diameter side of the stem portion, and the coil for induction heating of the cup portion is circulated in the axial direction on the outer diameter side of the cup portion. By providing a means for providing a difference in the degree of induction heating in the circumferential portion of the cup portion, it is possible to efficiently remove only the portion of the hardened layer formed on the inner diameter surface of the cup portion of the constant velocity joint outer ring. Induction heating was used to ensure sufficient tempering treatment.

  As means for giving a difference in the degree of induction heating in the circumferential part of the cup part, the coil that circulates in the axial direction is divided into a plurality of parts in the circumferential direction of the cup part, and the divided coils are A means for arranging the cup portions at intervals in the circumferential direction can be employed.

  By connecting the coil for induction heating the stem portion and the coil for induction heating the cup portion in parallel or in series to the same power source, induction heating can be performed with a single high frequency power source. The price can be kept at the same level.

  In the induction heating device for constant velocity joint outer ring of the present invention, the coil for induction heating the stem portion is arranged to circulate in the circumferential direction on the outer diameter side of the stem portion, and the coil for induction heating of the cup portion is connected to the cup. Since it is arranged so as to circulate in the axial direction on the outer diameter side of the part, and a means for giving a difference to the induction heating degree in the circumferential part of the cup part is provided, the cup part inner diameter surface of the constant velocity joint outer ring is provided. Only the portion of the formed hardened layer can be efficiently induction-heated and sufficiently tempered, and generation of an oxide film on the outer diameter surface of the cup portion due to excessive heating can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This induction heating device for the constant velocity joint outer ring is for tempering, and as shown in FIGS. 1 and 2A and 2B, the constant velocity joint is positioned and fixed by the upper and lower fixing jigs 1a and 1b. The coil 2a is arranged to circulate in the circumferential direction on the outer diameter side of the stem portion 11a of the outer ring 11, and the coil 2a circulates in the axial direction on the outer diameter side of the cup portion 11b, and is divided into three parts in the circumferential direction. A coil 2b arranged at a phase of 120 °, and these coils 2a and 2b are connected in parallel or in series to the same high-frequency power source (not shown) to inductively heat the stem portion 11a and the cup portion 11b, respectively. It is like that.

  The constant velocity joint outer ring 11 is a tripod type whose rolling element is a trunnion roller, the cup portion 11b is cylindrical, and three laterally elongated axially extending phases of 120 ° on the inner diameter surface thereof. A track groove 12 having a cross section is formed, and a hardened layer is formed by a prior quenching process on the roller guide surface 12a on which the rollers on both side surfaces roll. The roller guide surfaces 12a facing each other are connected by a large inner diameter portion 13a, each track groove 12 is connected by a small inner diameter portion 13b, and a circle corresponding to the space between each track groove 12 is formed on the outer diameter surface of the cup portion 11b. A concave groove 14 extending in the axial direction is formed at the circumferential portion. Further, a serrated tooth mold portion 15 is formed in a part of the stem portion 11a, and a hardened layer is formed over the entire circumference thereof.

  The coil 2a that circulates in the circumferential direction on the outer diameter side of the stem portion 11a uniformly induction-heats the hardened layer of the stem portion 11a over the entire circumference. Further, the coil 2b divided into three that circulates in the axial direction is disposed in a portion where the concave groove 14 is formed on the outer diameter side of the cup portion 11b, and each track groove located on the inner diameter side of each concave groove 14 Only the portion of the 12 roller guide surfaces 12a is induction-heated uniformly in the axial direction. Therefore, the outer diameter surface of the stem portion 11a on which the hardened layer is formed by the quenching process and the portions of the roller guide surfaces 12a of the cup portion 11b are tempered efficiently and uniformly.

  In the embodiment described above, the coil that circulates in the axial direction in which the cup portion is induction-heated is divided in the circumferential direction and arranged at intervals in the circumferential direction on the outer diameter side of the cup portion. Instead of dividing in the circumferential direction, the circulation density can be changed in the circumferential direction to give a difference in the degree of induction heating in the circumferential portion of the cup portion.

Front view showing an embodiment of an induction heating device for constant velocity joint outer ring a is a sectional view taken along line IIa-IIa in FIG. 1, and b is a sectional view taken along line IIb-IIb in FIG. a is a front sectional view showing a conventional induction heating apparatus, and b is a plan view of a. a is a front view showing another conventional induction heating apparatus, and b is a plan view of a.

Explanation of symbols

1a, 1b Fixing jig 2a, 2b Coil 11 Constant velocity joint outer ring 11a Stem portion 11b Cup portion 12 Track groove 12a Roller guide surface 13a Large inner diameter portion 13b Small inner diameter portion 14 Concave groove 15 Tooth shape portion

Claims (3)

  An outer ring of a constant velocity joint having a cup portion in which a plurality of track grooves on which the rolling elements roll are spaced apart in the circumferential direction of the inner diameter surface, and a stem portion extending in the axial direction from the bottom of the cup portion, In the induction heating device for a constant velocity joint outer ring tempered by induction heating, a coil for induction heating the stem portion is arranged so as to circulate in the circumferential direction on the outer diameter side of the stem portion, and the cup portion is induction heated. The coil is arranged so as to circulate in the axial direction on the outer diameter side of the cup portion, and provided with means for giving a difference in the degree of induction heating at the circumferential portion of the cup portion. Induction heating device for joint outer ring.   The means for providing a difference in the degree of induction heating in the circumferential portion of the cup portion divides the coil that circulates in the axial direction into a plurality of portions in the circumferential direction of the cup portion, and the plurality of divided coils are cupped. The induction heating device for a constant velocity joint outer ring according to claim 1, wherein the constant velocity joint outer ring is arranged at intervals in a circumferential direction of the portion.   The induction heating device for a constant velocity joint outer ring according to claim 1 or 2, wherein a coil for induction heating the stem portion and a coil for induction heating the cup portion are connected in parallel or in series to the same power source.

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