JP4211213B2 - Input shaft of toroidal type continuously variable transmission and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an input shaft of a toroidal-type continuously variable transmission used for a transmission mechanism of, for example, an automobile and a method for manufacturing the same.
[0002]
[Prior art]
As a transmission used for a vehicle or the like, a continuously variable transmission called a so-called CVT has been put into practical use. A toroidal continuously variable transmission has been developed as an example of a continuously variable transmission. The toroidal continuously variable transmission includes an input disk that rotates integrally with an input shaft, an output disk that faces the input disk, a power roller that is provided between the two disks, and presses the input disk toward the output disk. For example, a pressing mechanism is provided.
[0003]
FIG. 7 shows a part of a conventional toroidal continuously variable transmission. As shown in this figure, a flange portion 101 is formed on one end side of the input shaft 100, and a thrust bearing 103 is provided between the flange portion 101 and the cam disk 102. The cam disk 102 constitutes a part of the pressing mechanism. A loading nut 106 is screwed into a screw portion 105 formed on the other end side of the input shaft 100. When the loading nut 106 is fastened to the threaded portion 105, the collar portion 101 is held by a jig such as a socket, thereby preventing the input shaft 100 from rotating. Accordingly, the collar portion 101 has a hexagonal shape similar to the head of a bolt.
[0004]
[Problems to be solved by the invention]
In the toroidal continuously variable transmission, as shown in FIGS. 8 and 9, a hexagonal non-circular portion 110 is provided on the flange portion 101 ′ of the input shaft 100, and a circular disc portion 111 is adjacent to the non-circular portion 110. It was necessary to provide them as a single unit. In this case, conventionally, a part of the large-diameter portion at the end of the material is machined into a hexagonal shape to form the non-circular portion 110 and the portion that is not processed remains as the disc portion 111. However, when such machining is performed, the outer peripheral edge 112 of the disk portion 111 becomes a so-called edge corner due to machining of the non-circular portion 110, which causes a problem that flash is likely to occur.
[0005]
Accordingly, an object of the present invention is to provide an input shaft of a toroidal continuously variable transmission and a method for manufacturing the same so that no flash is generated between a disk portion and a non-circular portion constituting the collar portion.
[0006]
[Means for Solving the Problems]
An input shaft of a toroidal type continuously variable transmission according to the present invention for achieving the above object is an input shaft having a cylindrical shaft body, and is formed at an end portion of the shaft body and has an outer diameter larger than that of the shaft body. A large disk part, and a non-circular part formed at a position including the end face of the input shaft adjacent to the disk part and having two or more flat surfaces parallel to each other when viewed from the end face side , and The flat surface side of the annular groove is machined at the edge of the flat surface side of the outer periphery of the disk portion, with an intermediate position in the groove width direction of the annular groove along the circumferential direction formed before the processing of the flat surface as a boundary. have a cross section arcuate working surface of the boundary by Ri said intermediate position Rukoto comprising leaving the disc portion side portion of the annular groove, and the said annular groove between the flat surfaces adjacent to each other It has a part in the circumferential direction. In the input shaft of the present invention, since the processed surface is formed at the edge on the flat surface side of the outer periphery of the disk portion, the occurrence of edge corners can be avoided, and the occurrence of flash is suppressed.
[0007]
The manufacturing method of the present invention for manufacturing the input shaft includes a first step of forming an annular groove continuous in a circumferential direction of the large diameter portion by processing an outer peripheral surface of the large diameter portion of the material end portion. The flat surface is formed by processing the outer peripheral portion on the end surface side of the material end portion with the intermediate position in the groove width direction of the annular groove as a boundary, and the flat surface side of the outer periphery of the disk portion that remains without being processed A second step of leaving a part of the annular groove on the edge of the flat groove, and in the second step, by machining the flat surface side at the intermediate position in the groove width direction of the annular groove. A processed surface having an arc-shaped cross section composed of a part of the annular groove is formed, and a part of the annular groove in the circumferential direction is left between the flat surfaces adjacent to each other . In the manufacturing method of the present invention, after forming the annular groove in advance in the first step, each flat surface of the non-circular portion is formed in the second step, and a part of the annular groove is formed in the disk portion during the processing. By leaving it at the outer peripheral edge, the occurrence of edge corners can be avoided and the occurrence of flash is avoided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows a variator (Variator) that constitutes a main part of a double cavity half-toroidal continuously variable transmission 10. The transmission 10 includes an input disk 12a and an output disk 13a that form a first cavity 11, and an input disk 12b and an output disk 13b that form a second cavity 14.
[0009]
A pair of power rollers 15 is provided between the first input / output disks 12a and 13a. The outer peripheral surface of the power roller 15 is in contact with the traction surfaces of the disks 12a and 13a. A pair of power rollers 15 is also provided between the second input / output disks 12b and 13b. These power rollers 15 are rotatably attached to the trunnion 17 by power roller bearings 16. Each trunnion 17 is swingable about a trunnion shaft 18.
[0010]
The first input disk 12a is attached to the input shaft (CVT shaft) 20 so as to be relatively movable in the direction of the axis P while being prevented from rotating by the first ball spline 21. The second input disk 12b is attached to the input shaft 20 so as to be relatively movable in the direction of the axis P while being prevented from rotating by the second ball spline 22. Therefore, the input disks 12a and 12b rotate integrally with the input shaft 20. The input shaft 20 is connected to a drive shaft 25 that is rotated by a drive source such as an engine via a bearing 26 so as to be relatively rotatable.
[0011]
The output disks 13a and 13b are provided between the input disks 12a and 12b. The first output disk 13a faces the first input disk 12a, and the second output disk 13b faces the second input disk 12b. The output disks 13a and 13b are supported on the input shaft 20 through bearings 30 and 31 so as to be relatively rotatable. The output disks 13a and 13b are connected by a connecting member 32 and rotate in synchronization with each other. The connecting member 32 is provided with an output gear 33. The output gear 33 rotates in conjunction with an output shaft (not shown).
[0012]
A loading cam mechanism 40 that functions as a pressing mechanism is provided on the back side of the first input disk 12a. The loading cam mechanism 40 includes a cam disk 41 and a roller 42. The cam disk 41 is rotatably supported with respect to the input shaft 20 via a ball bearing 43. Cam surfaces 44 and 45 are formed on the mutually facing portions of the cam disk 41 and the input disk 12a, respectively, and a roller 42 is sandwiched between the cam surfaces 44 and 45.
[0013]
When the drive shaft 25 rotates while the rollers 42 are sandwiched between the cam surfaces 44 and 45, the cam disk 41 rotates, so that the first input disk 12a is pressed toward the first output disk 13a. At the same time, the first input disk 12 a rotates together with the cam disk 41. Further, since the reaction force received by the cam disk 41 is applied to the input shaft 20 via the ball bearing 43, the second input disk 12b is pressed toward the second output disk 13b. Thus, the rotational force of the engine transmitted from the drive shaft 25 to the cam disk 41 rotates the input disks 12a and 12b, and the rotation of the input disks 12a and 12b is transmitted to the output disks 13a and 13b via the power roller 15, The output gear 33 rotates.
[0014]
As shown in FIG. 2, the input shaft 20 has a cylindrical shaft body 20a extending in the axis P direction. On the outer peripheral portion on one end side of the shaft main body 20a, a flange portion 50 that spreads in a flange shape is provided. A first spline groove 51 is formed in the vicinity of the flange portion 50. As shown in FIG. 1, a spline groove 52 is formed at a position corresponding to the spline groove 51 on the first input disk 12a. In these spline grooves 51 and 52, balls 53 functioning as members for fixing the input disk 12a and the input shaft 20 to each other in the rotational direction are accommodated. Therefore, the input disk 12a is fixed in the rotational direction with respect to the input shaft 20, and can move in the axis P direction.
[0015]
A threaded portion 60 is formed on the other end side of the input shaft 20. A loading nut 61 (shown in FIG. 1) is screwed onto the screw portion 60. A second spline groove 62 is formed in the vicinity of the screw portion 60. A spline groove 63 is formed in the second input disk 12 b at a position corresponding to the second spline groove 62. By accommodating the balls 64 in these spline grooves 62 and 63, the input disk 12b and the input shaft 20 are fixed in the rotation direction, and the input disk 12b can move in the direction of the axis P of the input shaft 20. . The input disk 12b is urged toward the cam disk 41 by an elastic member 65 such as a disc spring. The elastic member 65 is fixed by a loading nut 61.
[0016]
The collar portion 50 has a disc portion 70 formed at the end portion of the cylindrical shaft main body 20a and a non-circular portion 71 formed integrally with the disc portion 70 at the end portion of the shaft main body 20a. The disc part 70 is concentric with the shaft main body 20a, and its outer diameter D (shown in FIG. 3) is larger than the outer diameter of the shaft main body 20a. A raceway surface 72 with which the bearing 43 is in contact is formed in the disk portion 70. Since the bearing 43 has a spherical shape, the cross section of the raceway surface 72 has an arc shape. That is, the disk part 70 also serves as a bearing disk for the bearing 43. A hole 73 along the axis P direction is formed in the shaft main body 20a.
[0017]
The non-circular portion 71 has a substantially regular hexagonal shape when viewed from the end face 82 side (the direction along the axis P) of the input shaft 20. That is, as shown in FIG. 3, the non-circular portion 71 has a flat surface 75 of two or more sides parallel to each other (in the illustrated example, a total of six surfaces because it is a hexagon). The distance W between the flat surfaces 75 parallel to each other is smaller than the outer diameter D of the disk portion 70. The non-circular portion 71 having such a flat surface 75 prevents the input shaft 20 from rotating by a jig such as a socket that is fitted to the non-circular portion 71 when the loading nut 61 is fastened to the screw portion 60. be able to.
[0018]
A groove-like processed surface 80 is formed over the entire circumference of the disk portion 70 on the edge 70b on the flat surface 75 side of the outer periphery 70a of the disk portion 70. As shown in an enlarged view in FIG. 5, the processed surface 80 has a shape in which the cross section is recessed in an arc shape, and a first step (step of forming the annular groove 80 a) and a second step described below. (Step of forming the flat surface 75).
[0019]
First, in the first step, by processing the outer peripheral surface of the large-diameter portion 81 of the material end portion 20b of the input shaft 20, an annular groove 80a having a semicircular cross section continuous in the circumferential direction of the large-diameter portion 81 (see FIG. 6). Is formed). After that, as shown in FIG. 5, by machining the outer peripheral portion 83 on the end face 82 side of the material end portion 20b with the center of the groove bottom of the annular groove 80a, that is, the intermediate position H in the groove width direction X as a boundary. The flat surface 75 is formed. During the processing, a part of the annular groove 80a is left on the edge 70b on the flat surface 75 side of the outer periphery 70a of the disk portion 70 that remains without being processed, so that the processing surface 80 continuous in the circumferential direction of the disk portion 70 is left. Is obtained.
[0020]
Since the processed surface 80 is formed on the edge 70b on the flat surface 75 side of the outer periphery 70a of the disk part 70, the edge 70b of the disk part 70 is prevented from becoming an edge corner, and the occurrence of flash is avoided. . In particular, it is desirable to cut to a position H ′ closer to the disk portion 70 than the center of the groove bottom of the annular groove 80a. By doing so, since the angle θ of the edge of the processed surface 80 can be made as large as possible than 90 degrees, the chamfering effect is enhanced. However, the cross section of the annular groove 80a is not limited to the semicircular shape as in this embodiment. In short, when the flat surface 75 is machined while leaving a part of the annular groove 80a, a processed surface having a desired cross sectional shape is obtained. An annular groove 80a having such a shape that 80 can be obtained.
[0021]
Further, the number of flat surfaces 75 of the non-circular portion 71 is not limited to six. In short, the non-circular portion 71 may have one or more flat surfaces, preferably two or more flat surfaces parallel to each other (so-called parallel two-surface width). In implementing this invention, the elements constituting this invention, such as the shaft body of the input shaft, the disk part, the non-circular part, the number of flat surfaces, the annular groove, and the shape and dimensions of the machined surface, are appropriately modified. Needless to say, it can be implemented. In the above embodiment, the double-cavity half-toroidal continuously variable transmission is described. However, the present invention can be similarly applied to a single-cavity half-toroidal continuously variable transmission.
[0022]
【The invention's effect】
According to the present invention, it is possible to prevent a flash from being generated between a disk portion and a non-circular portion formed at the end flange portion of the input shaft of the toroidal-type continuously variable transmission. For this reason, the deburring process can be omitted, and the cost can be reduced. In addition, since sharp edges do not occur in the collar portion, handling safety is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a toroidal continuously variable transmission showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the axial direction of an input shaft used in the toroidal continuously variable transmission shown in FIG.
FIG. 3 is a front view of the input shaft shown in FIG. 2 as viewed from the end face side.
4 is a cross-sectional view of a part of the input shaft along line F4-F4 in FIG.
FIG. 5 is an enlarged cross-sectional view of a part of the input shaft shown in FIG.
6 is a cross-sectional view of a part of the input shaft taken along line F6-F6 in FIG.
FIG. 7 is a cross-sectional view of a part of a toroidal-type continuously variable transmission having a conventional input shaft.
FIG. 8 is a front view of an input shaft showing another conventional example as viewed from the end surface side.
9 is a cross-sectional view of a part of the input shaft along the line F9-F9 in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 20 ... Input shaft 20a ... Shaft body 50 ... Collar part 70 ... Disc part 71 ... Non-circular part 75 ... Flat surface 80 ... Processing surface 80a ... Annular groove

Claims (2)

An input shaft having a cylindrical shaft body ,
A disk portion formed at an end of the shaft body and having an outer diameter larger than that of the shaft body;
A non-circular portion formed at a position including the end surface of the input shaft next to the disk portion and having two or more flat surfaces parallel to each other when viewed from the end surface side ; and
The flat surface side of the annular groove is machined at the edge of the flat surface side of the outer periphery of the disk portion, with an intermediate position in the groove width direction of the annular groove along the circumferential direction formed before the processing of the flat surface as a boundary. have a cross section arcuate working surface of the boundary by Ri said intermediate position Rukoto comprising leaving the disc portion side portion of the annular groove, and the said annular groove between the flat surfaces adjacent to each other An input shaft for a toroidal-type continuously variable transmission, characterized by having a part in the circumferential direction. Input of a toroidal continuously variable transmission having a large-diameter disk portion formed at the end of the shaft body and a non-circular portion having two or more parallel flat surfaces formed next to the disk portion. In the manufacturing method of the shaft,
A first step of forming an annular groove continuous in the circumferential direction of the large diameter portion by processing the outer peripheral surface of the large diameter portion of the material end;
The flat surface is formed by processing the outer peripheral portion on the end surface side of the material end portion at the intermediate position in the groove width direction of the annular groove, and the flat surface side of the outer periphery of the disk portion remaining without being processed is formed. A second step of leaving a part of the annular groove at the edge,
In the second step, the flat surface side is machined at the intermediate position in the groove width direction of the annular groove to form a cross-section arc-shaped machining surface formed of a part of the annular groove, and A method for manufacturing an input shaft of a toroidal-type continuously variable transmission, wherein a part of the annular groove in the circumferential direction is left between the adjacent flat surfaces.

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