JP4352231B2 - Manufacturing method of outer race - Google Patents

Description

  The present invention relates to a method for manufacturing an outer race that accommodates an inner race of a constant velocity joint.

The outer race of the constant velocity joint is generally heat-cured in order to improve the hardness. As a conventional outer lace manufacturing method, a method is known in which an external force is applied to the outer race after the thermosetting treatment to bring it close to the final target shape (for example, see Patent Document 1).
Japanese translation of PCT publication No. 2002-542435 (Claims 3-6, FIG. 4)

  However, in the above-described conventional manufacturing method, the shape of the outer race is corrected after the thermosetting process, so that a crack may occur in the cured layer due to the thermosetting process. Further, when the correction die is pressed against the hardened layer and is worn, and the outer race is mass-produced, the die replacement frequency becomes high and the production efficiency is poor.

  This invention is made | formed in view of the said situation, and aims at provision of the manufacturing method of the outer race which can improve the production efficiency of an outer race.

In order to achieve the above object, the outer lace manufacturing method according to the invention of claim 1 comprises three bosses at positions where the outer circumferential surface of the inner race is equally distributed, and three rollers on the three bosses. And three guide grooves extending from the back to the open end are formed in the inner surface of the bottomed cylindrical portion provided in the outer race, and three rollers are accommodated in the three guide grooves. An outer race manufacturing method for a constant velocity joint in which an inner race and an outer race are connected to each other so that the inner race and the outer race can be rotated and linearly moved . leave distorted shape, in the manufacturing method of the outer race closer to the shape of the final target distorts the outer race by a thermal curing treatment to remove its strain, the material, After squeezing and cutting to form an outer lace with a shape close to the final shape, an external force is applied to distort a portion of the outer lace cylinder into a shape that is curved in the axial direction before thermosetting. A feature is that the outer race is brought close to the final target shape by changing a part of the cylindrical portion into a flat shape along the axial direction by a thermosetting process so as to remove the distortion .

The invention of claim 2 is the manufacturing method of the outer race according to claim 1, while allowing the inner surface of the guide groove B over La with the inner race of the cylindrical portion abuts curved outwardly prior to thermal curing treatment , It is characterized in that the wall portion between the adjacent guide grooves is curved inward.

  In the outer lace manufacturing method according to claim 1, the shape of the outer race before the thermosetting treatment is made distorted with respect to the final target shape, and the outer race is formed by thermosetting treatment so as to remove the distortion. Since it is distorted and close to the final target shape, the work of correcting the shape after the thermosetting process is reduced or reduced, and the production efficiency is improved.

Further, in the outer lace manufacturing method of the present invention, a part of the cylindrical portion that accommodates the inner race of the outer race is curved in the axial direction of the cylindrical portion before the thermosetting treatment, and is distorted by the thermosetting treatment. Since it is made into the flat shape along an axial direction, an inner race can be smoothly linearly moved within the cylinder part after a thermosetting process. Specifically, the curved inner surface of the guide groove B over La with the inner race of the cylindrical portion abuts while curving outward prior to thermal curing treatment, the wall between the adjacent guide grooves on the inside By doing so, the cylindrical part after the thermosetting treatment can be brought close to the final target shape (invention of claim 2 ).

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a constant velocity joint 10 in which an inner race 11 is accommodated in an outer race 20 so as to be linearly movable. The inner race 11 has a ring shape as a whole, and three bosses 12 project from the outer peripheral surface at three equal positions. The outer surface of the inner race 11 is provided with a roller 14 that is rotatably inserted into the boss 12.

  The outer race 20 includes a cylindrical portion 21 having one end and a shaft portion 23 protruding from the outer surface of the bottom wall 22 of the cylindrical portion 21. As shown in FIG. 2, three guide grooves 24 are formed in the cylindrical portion 21 at intervals of 120 degrees. The guide groove 24 extends from the axial depth of the cylindrical portion 21 to the open end. Further, as shown in FIG. 2, the bottom surface 25 </ b> A and the side surfaces 25 </ b> B and 25 </ b> B constituting the inner surface 25 of the guide groove 24 are curved so as to swell outward when viewed from the axial direction of the cylindrical portion 21. And the roller 14 with which the inner race 11 was equipped is accommodated in each guide groove 24, and contact | abuts to the side surfaces 25B and 25B in each guide groove 24. FIG. As a result, the inner race 11 and the outer race 20 rotate together, and the inner race 11 can be directly moved in the axial direction of the tube portion 21.

  When the inner race 11 is linearly moved in the outer race 20, the roller 14 rolls while abutting against the side surfaces 25B and 25B of the guide groove 24. At this time, the final target of the outer race 20 is set so that the roller 14 rolls smoothly and the gap between the roller 14 and both side surfaces 25B and 25B does not change according to the linear movement position of the inner race 11. In the shape, the side surfaces 25 </ b> B and 25 </ b> B of the guide groove 24 are flat in the axial direction of the cylindrical portion 21 and parallel to the axial direction of the cylindrical portion 21. Here, the “final target shape” is a target shape when all the steps for manufacturing the outer race 20 are completed, and refers to a design reference shape for the outer race 20 to become an acceptable product. .

Next, a method for manufacturing the outer race 20 will be described.
For example, a high carbon steel round material as a material is cut into a predetermined size. Then, a warm forging process is performed to perform a cold ironing process. Next, cutting is performed on necessary portions such as the inner surface of the shaft portion 23 and the cylindrical portion 21 to form the outer race 20 close to the final target shape as shown in FIG.

  By the way, if the cylindrical portion 21 of the outer race 20 has such a hardness that it can be cut, it will be deformed and worn when the roller 14 comes into contact therewith. Therefore, it is necessary to perform a thermosetting treatment by quenching on the inner surface of the cylindrical portion 21, particularly the inner surface 25 of the guide groove 24.

  However, as shown in FIG. 3A, when the outer race 20 that has been brought close to the final target shape in the cutting process is subjected to thermosetting treatment, the entire outer race 20 as shown in FIG. The shape of is distorted with the thermosetting treatment.

  At this time, the guide groove 24 in the outer race 20 has a shape close to the final target in the cutting process as shown in FIG. In addition, the cylindrical portion 21 is distorted inward, resulting in a shape different from the final target shape.

  Therefore, in the present embodiment, the strain when the outer race 20 is subjected to the thermosetting process is estimated before the thermosetting process. Then, as shown in FIG. 4A, an external force is applied to the shape of the outer race 20 before the thermosetting treatment so as to be distorted on the opposite side to the estimated strain. Specifically, as shown in FIG. 7A at the AA section of FIG. 2, the mold 30 is pressed against the inner surface 31 of the cylindrical portion 21 and the outer surface of the cylindrical portion 21. And an external mold 32. Both the internal mold 31 and the external mold 32 are arranged at positions close to the open end in the axial direction of the cylindrical portion 21. Further, as shown in FIG. 5, the internal mold 31 includes opposed molds 33 and 33 that are accommodated in pairs inside the guide grooves 24 of the cylindrical portion 21. The opposed molds 33 and 33 are guides. The groove 24 is pressed against the side surfaces 25B and 25B. As a result, the space between the opposing inner surfaces 25B and 25B is expanded, and the side surfaces 25B and 25B are curved outward.

  Further, the external die 32 is pressed against the outer surface of the wall portion 35 that joins between the adjacent guide grooves 24 and 24 in the cylindrical portion 21. Thereby, the wall part 35 between the adjacent guide grooves 24 and 24 becomes a shape curved inside. As shown in FIG. 4B, the overall shape of the outer race 20 before the thermosetting treatment after the cutting process is shown in FIG. The shape of the guide groove 24 is distorted with respect to the final target shape (see FIGS. 4C and 7C) as shown in FIG. 7B.

  Next, the outer race 20 is subjected to a thermosetting process. Here, the thermosetting treatment may be any method such as induction hardening or laser hardening. When the thermosetting process is performed, the cylindrical portion 21 is distorted due to a difference in the cooling rate of each part in the outer race 20, and the overall shape of the outer race 20 after the thermosetting process is shown in FIG. The shape of the guide groove 24 approaches the final target shape shown in FIG. Specifically, the side surface 25B of the guide groove 24 curved before the thermosetting treatment is parallel to the axial center of the cylindrical portion 21, and the distance between the opposed side surfaces 25B and 25B is constant.

  Next, after the outer race 20 reaches a normal temperature, the accuracy of a required portion in the outer race 20 is measured, and a product that falls within a predetermined reference accuracy with respect to the final target shape is defined as a finished product. In addition, what did not fall within the reference accuracy may be subjected to correction processing to be put within the reference accuracy to be a finished product.

  As described above, in the outer lace manufacturing method of the present embodiment, the shape of the outer race 10 before the thermosetting process is made distorted with respect to the final target shape, and the thermosetting process is performed so as to remove the distortion. As a result, the outer race 10 is distorted and brought close to the final target shape, so that the work of correcting the shape after the thermosetting process is reduced or reduced, and the production efficiency is improved. In addition, a part of the guide groove 24 of the outer race 20 is curved in the direction of the guide groove 24 before the thermosetting process and is distorted by the thermosetting process so as to have a flat shape along the axial direction. It becomes possible to move the inner race 11 smoothly in the rear guide groove 24 smoothly. In addition, since the mold 30 for applying external force is pressed against the outer race 20 before curing, wear of the mold 30 can be suppressed as compared with the conventional manufacturing method in which the mold is pressed against the outer race after curing. That is, the replacement frequency of the mold 30 is reduced, the production efficiency is improved, and the manufacturing cost can be suppressed.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and can be implemented with various modifications other than those described above without departing from the scope of the invention.

Sectional drawing of the constant velocity joint which concerns on one Embodiment of this invention. Front view of outer race Side cross section of outer race Side cross section of outer race Front sectional view of the outer race with the mold pressed Sectional drawing of the outer race in the AA cut surface of FIG. Sectional drawing of the outer race in the AA cut surface of FIG.

DESCRIPTION OF SYMBOLS 10 Constant velocity joint 11 Inner race 14 Roller 20 Outer race 21 Cylindrical part 30 Type 35 Wall part

Claims (2)

Three bosses are provided at positions where the outer circumferential surface of the inner race is equally distributed, and three rollers are rotatably supported by the three bosses. Forming three guide grooves extending from the portion to the open end, accommodating the three rollers in the three guide grooves, and connecting the inner race and the outer race so as to be capable of interlocking rotation and linear movement, etc. A method of manufacturing the outer race in a speed joint,
The shape of the outer race before the thermosetting treatment is made distorted with respect to the shape of the final target, and the shape of the final target is distorted by the thermosetting treatment so as to remove the distortion. In the manufacturing method of the outer race that comes close to
The material is cut after cold ironing to form the outer race having a shape close to the final shape, and an external force is applied so that a part of the cylindrical portion of the outer race is subjected to the thermosetting treatment in the axial direction. The outer race is made to be the final target by distorting it into a previously curved shape and changing a part of the cylindrical portion into a flat shape along the axial direction by the thermosetting process so as to remove the distortion. The manufacturing method of the outer race characterized by approaching the shape of this . The inner surface of the guide groove with which the roller provided in the inner race contacts the cylindrical portion is curved outward before the thermosetting treatment, while the wall portion between the adjacent guide grooves is curved inward. The manufacturing method of the outer race of Claim 1 characterized by the above-mentioned.

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