JP2008024977A - Method for manufacturing annular member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for accurately manufacturing an annular member which has a thin wall, a large diameter and a machined inner circumferential surface. <P>SOLUTION: This manufacturing method includes quenching the outer circumferential surface 74 of a ring gear (R) before machining the inner circumferential surface 75 of the ring gear (R) to improve the rigidity of the outer circumferential surface 74 and to reduce the deformation of the outer circumferential surface 74 of the ring gear (R) due to machining even when the outer circumferential surface 74 is machined. Thereby manufactured ring member acquires less thermal deformation originating in quenching, and improves the accuracy in the circularity of the ring gear (R) and in the straightness of a direction of the central axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an annular member whose inner peripheral surface is machined, such as a ring gear of a planetary gear device provided in an automatic transmission for a vehicle, and more particularly, the roundness and shaft of the annular member. This relates to improving the accuracy of straightness in the direction of the heart.

  There is an annular member in which inner peripheral teeth and the like are formed by machining the inner peripheral surface, such as a ring gear of a planetary gear device provided in an automatic transmission for a vehicle. Such an annular member is required to have relatively high accuracy because a power transmission portion such as an inner peripheral tooth is provided on the inner peripheral surface. To deal with this problem, Patent Document 1 discloses a technique in which a tooth portion (inner circumference) and a main body (outer circumference) of an internal gear (corresponding to an annular member in the present specification) are manufactured separately and integrated. ing. According to this technique, it is possible to manufacture an internal gear with high accuracy while quenching after processing. Patent Document 2 discloses a technique in which a tooth part (inner circumference) and a main body (outer circumference) of an internal gear are made of different materials. According to this technology, the outer gear (outer circumference) is made of a light material, the tooth portion (inner circumference) is made of a material excellent in pressure resistance and wear resistance, and the internal gear is manufactured. An internal gear with excellent accuracy can be manufactured.

JP 2000-154850 A JP 2006-15452 A

  By the way, the conventional annular member manufacturing methods including Patent Document 1 and Patent Document 2 described above all quench the processed portion after machining the inner peripheral surface. For this reason, when the wall thickness of the annular member is reduced and the diameter is increased, machining strain is likely to occur due to the low rigidity of the outer circumferential surface of the annular member during machining of the inner circumferential surface. Since the inner peripheral surface is quenched with the occurrence of heat, thermal deformation also increases, and the roundness of the annular member and the straightness in the axial direction may be significantly impaired.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to accurately manufacture an annular member having a thin wall and a machined inner peripheral surface having a large diameter. It is to provide a way to do.

  In order to achieve the above object, the gist of the invention according to claim 1 is (a) a method of manufacturing an annular member in which an inner peripheral surface is machined, and (b) quenching the outer peripheral surface of the annular member. A first quenching step for performing the machining, (c) a machining step for machining the inner circumferential surface of the annular member that has been quenched to the outer circumferential surface, and (d) an annular member for which the machining has been performed. And a second quenching step of quenching the inner peripheral surface of the steel sheet.

  According to a second aspect of the present invention, in the method for manufacturing an annular member according to claim 1, the machining is gear cutting for forming inner peripheral teeth on an inner peripheral surface of the annular member. It is characterized by being.

  According to a third aspect of the present invention, in the method for manufacturing an annular member according to claim 1 or 2, the annular member is a ring gear constituting a planetary gear device.

  According to the manufacturing method of the annular member of the invention according to claim 1, the rigidity of the outer peripheral surface is improved by quenching the outer peripheral surface of the annular member before machining the inner peripheral surface of the annular member. Even if machining is performed, the processing strain on the outer peripheral surface of the annular member can be suppressed. Thereby, the thermal deformation by quenching is also reduced, and the accuracy of the circularity of the annular member and the straightness in the axial direction can be improved.

  Moreover, according to the manufacturing method of the annular member of the invention concerning Claim 2, since gear cutting of the inner peripheral surface of the annular member is performed before the second quenching step to the inner peripheral surface, it is performed by quenching. The influence can be avoided, and an accurate inner peripheral tooth can be formed.

  According to the annular member manufacturing method of the invention of claim 3, since the annular member is a ring gear constituting a planetary gear device, the accuracy of the roundness of the ring gear and the straightness in the axial direction is improved. In addition, the meshing transmission error of the planetary gear device can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a part of an automatic transmission 8 for a vehicle to which the present invention is applied. A first input shaft 10 and a second input shaft 12 are arranged in series on a coaxial core C at the axial center portion of the vehicle automatic transmission 8. The first input shaft 10 and the second input shaft 12 are the spline teeth 14 provided on the inner peripheral surface of the first input shaft 10 on the second input shaft 12 side, and the first input shaft 10 of the second input shaft 12. The spline teeth 16 provided on the outer peripheral surface of the side mesh with each other to rotate integrally around the axis. The first and second input shafts 12 and 14 are turbine shafts of a torque converter (not shown) that are rotationally driven by a traveling drive source such as an engine.

  A flange portion 18 is formed at the end of the first input shaft 10 on the second input shaft 12 side. Spline teeth 20 are formed on the outer peripheral surface of the flange portion 18, and a protruding portion 22 that protrudes radially outward from one side in the axial direction is formed. The sun gear S is made non-rotatable relative to the first input shaft 10 because the spline teeth 24 formed on a part of the inner peripheral surface mesh with the spline teeth 20 of the flange portion 18. Further, the sun gear S is prohibited from moving toward the protruding portion 22 in the axial direction because the side surface thereof is brought into contact with the side surface of the protruding portion 22.

  A pinion gear P is meshed with the sun gear S, and the pinion gear P is also meshed with the ring gear R. A pinion shaft 26 is inserted through the shaft center of the pinion gear P, and the pinion shaft 26 is supported by the carrier CA. The planetary gear unit 28 is constituted by the sun gear S, the carrier CA, the pinion gear P, the ring gear R, and the like.

  The carrier CA is connected to the hub portion 30, the connecting portion 32 that is connected to one end of the hub portion 30 toward the radially outer side, and the outer peripheral end of the connecting portion 32. It extends to the opposite side and comprises a cylindrical support portion 34 that supports the pinion shaft 26. The hub portion 30 is provided on the outer peripheral side of the second input shaft 12 and is spline-fitted to a first intermediate shaft 36 that is coaxial with the second input shaft 12 and is rotatable relative to the second input shaft 12. Has been. The pinion shaft 26 is inserted into an axial hole 38 penetrating the support portion 34 in the axial direction, and both ends thereof are supported by the support portion 34. Therefore, the pinion gear P is rotated integrally with the carrier CA. .

  At the end of the support portion 34 of the carrier CA opposite to the hub portion 30, a first radial hole 40 that communicates the outer peripheral surface of the support portion 34 and the axial hole 38, and its first radial direction A second radial hole 42 communicating with the inner peripheral surface of the support portion 34 and the axial center hole 38 is formed coaxially with the hole 40.

  Further, the pinion shaft 26 penetrates the pinion shaft 26 in the radial direction, and the through-hole 44 communicates with the first radial hole 40 and the second radial hole 42 in a state where the pinion shaft 26 is supported by the carrier CA. Is formed. The tip of the pinion shaft fixing pin 46 inserted into the first radial hole 40 is fitted into the through hole 44, whereby the pinion shaft 26 is fixed to the carrier CA. Further, the pinion shaft 26 is provided with an axial hole 48 that passes through the axial center of the pinion shaft 26 and has one end communicating with the through hole 44.

  A bush 50 (slide bearing) is fitted by press-fitting to the inner peripheral surface of the end portion of the support portion 34 of the carrier CA where the first radial hole 40 and the second radial hole 42 are formed. Yes. A brake hub 52, which is a constituent member of the friction engagement device, is spline-fitted to the outer peripheral surface of the end portion of the support portion 34 on the side where the bush 50 is press-fitted.

  A sleeve 54 is further fitted on the inner periphery of the bush 50, and the carrier CA is supported by the case 56, which is a non-rotating member, via the sleeve 54 and the bush 50 so as to be relatively rotatable.

  Further, a thrust bearing 60 is interposed between the side surface of the sun gear S opposite to the hub portion 30 and the stepped wall 58 of the case 56, and the sun gear S is inserted into the case 56 via the thrust bearing 60. It is supported so that relative rotation is possible.

  Spline teeth 62 are formed at one end of the outer peripheral surface of the ring gear R, and are fitted to the spline teeth 66 formed on the inner peripheral surface of the cylindrical portion of the bottomed cylindrical brake hub 64 so that they cannot rotate relative to each other. It has become. An annular groove 68 is formed at the center of the spline teeth 62 of the ring gear R, and an annular groove 70 having the same groove width as the annular groove 68 is also formed on the spline teeth 66 of the brake hub 64. The snap ring 72 is fitted in each of the annular grooves 68 and 70 to prevent movement in the axial direction.

  FIG. 2 is an enlarged sectional view of the ring gear R of FIG. The ring gear R is an annular member that is relatively thin and has a large diameter. Spline teeth 62 are formed at one end of the outer peripheral surface 74, and the snap ring 72 of FIG. An annular groove 68 for fitting is formed. Inner peripheral teeth 76 for meshing with the pinion gear P are formed on the inner peripheral surface 75 of the ring gear R. Since the ring gear R is symmetric with respect to the axis C, the lower half of the axis C is omitted in FIG. Further, the ring gear R constituting the planetary gear device 28 of the present embodiment corresponds to the annular member of the present invention.

  FIG. 3 is a flowchart showing a series of steps for manufacturing the ring gear R. First, in the outer peripheral surface quenching step S1, the outer peripheral surface 74 of the ring gear R is quenched. The quenching is performed by, for example, induction quenching, and the rigidity of the outer peripheral portion of the ring gear R indicated by the oblique lines in FIG. 2 is improved by thermosetting by quenching. In addition, the outer peripheral surface quenching process S1 of a present Example respond | corresponds to the 1st quenching process of this invention.

  Next, in the gear cutting step S <b> 2, gear cutting is performed on the inner peripheral surface 75 of the ring gear R to form inner peripheral teeth 76. The inner peripheral teeth 76 are cut by a gear machining machine such as a gear shaving machine or broaching machine. In this gear cutting, since the rigidity of the outer peripheral portion of the ring gear R is improved by the outer peripheral surface quenching step S1, processing distortion to the outer peripheral portion that occurs during gear cutting is suppressed. Further, since the inner peripheral surface 75 of the ring gear R is not thermally cured by the outer peripheral surface quenching step S1, the load applied to the blade portion of the gear machining machine during gear cutting is increased, and the life of the blade portion is shortened. Detrimental effects such as lowering are avoided. In the inner peripheral tooth quenching step S3, the surface layer of the inner peripheral teeth 76 is hardened by quenching the chopped inner peripheral teeth 76. In addition, the quenching of the inner peripheral teeth 76 is also performed by induction quenching as described above. Further, the gear cutting step S2 of this embodiment corresponds to the machining step of the present invention, and the inner peripheral tooth quenching step S3 corresponds to the second quenching step of the present invention.

  Here, in the outer peripheral surface quenching step S1, the rigidity of the outer peripheral portion of the ring gear R is improved, so in the gear cutting process of the gear cutting step S2, processing distortion due to the gear cutting of the ring gear R is suppressed, and the inner peripheral tooth Also in the quenching step of the quenching step S3, thermal deformation is reduced, and the accuracy of the roundness of the ring gear R and the straightness in the axial direction can be improved.

  As described above, according to the present embodiment, the outer peripheral surface 74 of the ring gear R is quenched before the inner peripheral surface 75 of the ring gear R is machined, so that the rigidity of the outer peripheral surface 74 is improved. Even if it processes, the process distortion to the outer peripheral surface 74 of the ring gear R can be suppressed. As a result, thermal deformation due to quenching is reduced, and the accuracy of the roundness of the ring gear R and the straightness in the axial direction can be improved.

  Further, according to the above-described embodiment, the gear cutting of the inner peripheral surface 75 of the ring gear R is performed before the quenching process to the inner peripheral surface 75, so that the influence of quenching is avoided and the inner periphery is highly accurate. Teeth 76 can be molded.

  Further, according to the above-described embodiment, the ring gear R is the ring gear R constituting the planetary gear device 28. Therefore, the accuracy of the roundness of the ring gear R and the straightness in the axial direction is improved, and the planetary gear device 28 is improved. The meshing transmission error can be suppressed.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the present embodiment, the annular member of the present invention is the ring gear R. However, the present invention is not limited to the planetary gear ring gear, and the present invention is not limited to the inner peripheral surface such as a member having spline teeth formed on the inner peripheral surface. It can also be applied to other annular members that are machined.

  In the above-described embodiment, the quenching of the ring gear R is performed by induction quenching. However, the quenching is not particularly limited to induction quenching, and other quenching methods such as flame quenching and laser quenching may be used. I do not care.

  In the above-described embodiment, the inner peripheral teeth 76 of the ring gear R are formed by a gear shaving machine or broaching machine, but are not particularly limited to this, and other gear machining machines such as a hobbing machine. Alternatively, the inner peripheral teeth 76 may be molded.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

It is sectional drawing which shows a part of automatic transmission for vehicles with which this invention was applied. It is sectional drawing which expanded and showed the ring gear of FIG. It is the flowchart which showed a series of processes which manufacture a ring gear.

Explanation of symbols

28: Planetary gear device 74: Outer peripheral surface 75: Inner peripheral surface R: Ring gear (annular member)

Claims (3)

A method of manufacturing an annular member that performs machining on an inner peripheral surface,
A first quenching step for quenching the outer peripheral surface of the annular member;
A machining step of machining the inner circumferential surface of the annular member that has been quenched to the outer circumferential surface;
A second quenching step of quenching the inner peripheral surface of the annular member subjected to the machining,
A method for manufacturing an annular member, comprising:   The method of manufacturing an annular member according to claim 1, wherein the machining is gear cutting for forming inner peripheral teeth on an inner peripheral surface of the annular member. The said annular member is a ring gear which comprises a planetary gear apparatus, The manufacturing method of the annular member of Claim 1 or 2 characterized by the above-mentioned.

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