JP2000061702A - End face machining method of disc for troidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissolve high cost of end surface machining by machining both end faces in the axial direction of an input side disc or an output side disc to be a flat face by hard turning of a lathe. SOLUTION: When finish working is executed on both end faces in the axial direction of an input disc 2, the input side disc 2 is supported and fixed with the extreme end of the main spindle 16 of a lathe through a chuck 17 provided on the extreme end part. In this case, by running the outer end face of the input side disc extending over the whole circumference or partially in the circumferential direction against the extreme end part of the main spindle 16, the center axes of the input side disc 2 and the main spindle 16 are conformed to each other. Under this condition, while rotating the main spindle 16 and while abutting the cutting edge of a machining tool 18 such as a cutting tool against the inner end face 13 of the input side disc 2, this inner end face 13 is copyingly worked. As a result of this, the inner end face 13 can be flatly finished by hard turning.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing an end face of a disk for a toroidal type continuously variable transmission, for example, a toroidal type continuously variable transmission used as an automobile transmission. It is used for processing the end surface of the input disk or the output disk into a flat surface. 2. Description of the Related Art The use of a toroidal type continuously variable transmission as schematically shown in FIG. 5 has been studied, for example, as an automobile transmission. This toroidal-type continuously variable transmission is a half-toroidal type.
As described in Japanese Patent Application Laid-Open Publication No. H10-260, the input side disk 2 is provided at the end of the input shaft 1, the output side disk 4 is provided at the end of the output shaft 3,
We support each. And these two disks 2,
The trunnions 20, 20 that do not intersect with the center axis of the axis 4 but exist in the direction perpendicular to the direction of the center axis and swing about a pivot (not shown),
The inclination angle can be freely adjusted. The power rollers 6, 6 rotatably supported by the displacement shafts 5, 5 are sandwiched between the input side and output side disks 2, 4. The inner surfaces 2a and 4a of the input and output disks 2 and 4 facing each other are concave surfaces having an arc-shaped cross section, and the peripheral surfaces 6a and 6a of the power rollers 6 and 6 are
As a spherical convex surface, the peripheral surfaces 6a, 6a of these power rollers 6, 6 are in contact with the inner side surfaces 2a, 4a. A loading cam device 7 is provided between the input shaft 1 and the input side disk 2 to rotate the input side disk 2 while pressing the input side disk 2 toward the output side disk 4 in the axial direction.
Is provided. The loading cam device 7 includes a cam plate 8 which engages with the input shaft 1 and rotates together with the input shaft 1. On one surface (the right surface in FIG. 5) of the cam plate 8, a first cam surface 9 is formed as irregularities extending in the circumferential direction.
Further, a second cam surface 10 is formed on the outer side surface (the left side surface in FIG. 5) of the input side disk 2 as irregularities extending in the circumferential direction. A plurality of rollers 12, 12 are held between the second cam surface 10 and the first cam surface 9 in such a manner that the rollers 12, 12 are rotatably held by a ring-shaped retainer 11. I have. During operation of the toroidal type continuously variable transmission configured as described above, when the cam plate 8 is rotated by the input shaft 1, the plurality of rollers 12,
12 is pressed against the second cam surface 10. As a result, the input side disk 2 is pressed toward the output side disk 4, and the inner side surfaces 2a, 4a
And the peripheral surfaces 6a, 6a of the power rollers 6, 6 come into strong contact. Further, the input side disk 2 rotates based on the pressing between the rollers 12 and 12 and the convex portion of the second cam surface 10. Then, the rotation of the input-side disk 2 is transmitted to the output-side disk 4 via the power rollers 6, 6, and the output shaft 3 to which the output-side disk 4 is fixed rotates in the opposite direction to the input shaft 1. . In the case where the rotational motion is transmitted from the input shaft 1 to the output shaft 3 in this manner, as shown in FIG. 5, the peripheral surfaces 6a of the power rollers 6, 6
The inner side surface 2a of the output side disk 4 and the center side of the inner side surface 4a of the output side disk 4 are respectively brought into contact with each other.
When the displacement shafts 5 and 5 are tilted, the speed increase between the input shaft 1 and the output shaft 3 is performed. Conversely, each power roller 6,
6, the inner surface 2a of the input side disk 2
Of the input shaft 1 and the output shaft 3 by inclining the displacement shafts 5 and 5 so as to abut against the portion near the center of the output disk 4 and the portion near the outer periphery of the inner surface 4a of the output side disk 4 respectively. Deceleration is performed. By setting the inclination angles of the displacement shafts 5 and 5 at an intermediate value, an intermediate speed ratio can be obtained between the input shaft 1 and the output shaft 3. The input side disk 2 and the output side disk 4 of the toroidal type continuously variable transmission as described above are forged and cut in sequence from a metal material such as chromium molybdenum steel having sufficient strength and surface hardness. After the application, heat treatment is performed to increase the surface hardness. Next, the inner side surfaces 2a, 4a and both end surfaces in the axial direction are subjected to grinding processing to
a, 4a and the shape and dimensions of both end faces in the axial direction are properly finished. Conventionally, the grinding process on both end faces in the axial direction has been performed by surface grinding using a surface grinding machine or a cylindrical grinding machine, or end grinding using a jig grinding machine. FIG. 6 shows a processed portion of the end face of the input side disk 2 (or the output side disk 4) performed as described above. That is, the inner side surface 2a of the input side disk 2
The inner end face 13 located on the inner diameter side of the
An outer end surface central portion 14 existing in a portion of the outer surface near the inner diameter,
Similarly, the outer end surface outer peripheral portion 15 is finished to a flat surface by the above-described grinding. In the conventional method for processing the end face of a disk for a toroidal-type continuously variable transmission performed as described above, the following problems to be solved are to be solved. was there. The difference between the diameters of the inner end face 13 and the outer end face is so large that it cannot be firmly supported and fixed to the table of the grinding machine as it is. For this reason, a dedicated mounting jig is required, and the cost is increased. There is a step δ between the outer end surface center portion 14 and the outer end surface outer peripheral portion 15 provided concentrically on the outer end surface. For this reason, it is difficult to process the outer end surface central portion 14 on the concave side by ordinary surface grinding, and a special tool or the like is required, which also increases the cost. Since the amount of deformation accompanying the heat treatment performed after the cutting is large and the grinding allowance is increased, the processing time is long in the grinding, which also increases the cost. The end face machining method for a disk for a toroidal type continuously variable transmission according to the present invention has been invented in order to eliminate such disadvantages. An end face machining method for a disk for a toroidal type continuously variable transmission according to the present invention is directed to an input side disk and an output side disk supported concentrically and independently rotatably. And a plurality of pivots present at a twisted position which does not intersect with the central axes of the two disks at a portion between the two disks, but which is perpendicular to the direction of the central axis. A plurality of trunnions swinging about a pivot, a displacement shaft protruding from the inner surface of each of the trunnions, and both the input side and the output side discs rotatably supported around these displacement axes. The input side disk or the output side disk constitutes a toroidal-type continuously variable transmission having a plurality of power rollers sandwiched between inner side surfaces of the input side disk or the output side disk. A flat surface is formed by turning. According to the method for processing the end face of a disk for a toroidal type continuously variable transmission of the present invention having the structure described above, finishing both the axial end faces of both the input side and output side disks is particularly costly. It is possible to reduce the cost of the toroidal-type continuously variable transmission including both the input side and the output side disks by performing the operation efficiently without using such a jig or the like. That is, by supporting both the input-side and output-side discs at the ends of the main spindle of the lathe by means of chucks, it is possible to machine both end faces in the axial direction of these discs. There is no. Processing of a part of the end face that is recessed in the axial direction as compared with the other part can be easily performed without using a special tool. Hard turning with a lathe can achieve a cutting depth of about 1 mm at the maximum, so that the machining time can be shortened even when the grinding allowance is large. 1 and 2 show a first embodiment of the present invention. For example, when finishing both ends in the axial direction of the input-side disk 2 (the same applies to the output-side disk 4), first, as shown in FIG. Is supported and fixed to the portion by a chuck 17 provided at the distal end. At this time, the center axes of the input side disk 2 and the main shaft 16 are connected to each other by, for example, abutting the outer end surface of the input side disk 2 over the entire circumference or partially in the circumferential direction with the tip of the main shaft 16. To match. In this state, while rotating the main shaft 16, the cutting edge of the cutting tool 18 such as a cutting tool is abutted against the inner end surface 13 of the input side disk 2, and the inner end surface is copied. As a result, the inner end surface 13 is finished to a flat surface by hard turning. After the inner end surface 13 of the input side disk 2 is finished to a flat surface as described above, the input side disk 2 is then turned over as shown in FIG.
6 is supported and fixed. At this time, the inner end surface 13 which has already been finished is abutted against the front end surface of the main shaft 16 and is used as a reference surface when the outer end surface of the input side disk 2 is subjected to finish processing. Then, while rotating the main shaft 16 in this state, the cutting edge of the cutting tool 18 such as a cutting tool is moved to the center 1 of the outer end surface of the input side disk 2.
These parts 14 and 15 are copied while abutting against the outer end face outer peripheral part 15 and the outer end face 4. As a result, these outer end surface central portions 1
4 and the outer end surface outer peripheral portion 15 are finished to a flat surface by hard turning. Even when there is a step between the outer end face center portion 14 and the outer end face outer peripheral portion 15, only the feed amount of the cutting tool 18 in the axial direction of the input side disk 2 is changed, without any trouble. The finish processing of the outer end surface center portion 14 and the outer end surface outer peripheral portion 15 can be performed. FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of this example, a drawbar-type collet chuck 19 is used to support and fix the input-side disk 2 whose end face is to be machined to the tip of the spindle 16 of the lathe. That is, the collet chuck 19 is supported and fixed to the tip of the main shaft 16 concentrically with the main shaft 16, and the collet chuck 19 holds down the input side disk 2 from the inner diameter side. By using such a drawbar type collet chuck 19, the elastic deformation of the input side disk 2 at the time of processing is suppressed, so that more accurate finishing can be performed. That is, in the case of the first example described above, the spindle 1
In order to support and fix the input side disk 2 at the tip of the input disk 6, the input side disk 2 is pressed down from the outer diameter side by a chuck 17 (FIGS. 1 and 2). When the input side disk 2 is supported and fixed to the main shaft 16 in this manner, the amount of elastic deformation of the input side disk 2 becomes relatively large. On the other hand, as in this example, the draw bar type collet chuck 1 is used.
If the input side disk 2 is pressed down from the inner diameter side by the step 9, elastic deformation of the input side disk 2 at the time of processing can be suppressed, and more accurate finishing can be performed. Further, as shown in FIG. 3, in the state where the outer end face of the input side disk 2 is subjected to the finish processing, the inner end face 13 which has already been subjected to the finish processing is provided.
And the degree of adhesion with the collet chuck 19 is increased,
The degree of parallelism between the inner end surface 13 and the outer end surface central portion 14 and the outer end surface outer peripheral portion 15 can be increased. When the method for processing the end face of a disk for a toroidal type continuously variable transmission according to the present invention is performed, the cutting tool 18 is used.
The shape of the cutting edge is not particularly limited, but if the radius of curvature of the cutting edge is increased, the roughness of the end face to be finished and the processing speed can be improved. That is, as shown in FIG. 4A, when using a cutting tool 18a having a sharp tip (the radius of curvature of the tip which is a processing portion is small), unless the feed speed of the cutting tool 18a is reduced, As shown in the figure, the roughness of the processed surface is deteriorated. On the other hand, as shown in FIG.
When using a cutting tool 18b with a rounded tip (the radius of curvature of the tip that is a processing portion is large), make the feed speed of the cutting tool 18b particularly slow (within a range allowed from the viewpoint of cutting resistance). Even if it is not provided, as shown in the figure, the roughness of the processed surface is improved (the surface becomes smoother). The method for machining an end face of a disk for a toroidal type continuously variable transmission according to the present invention is constructed and operates as described above. Therefore, the toroidal type continuously variable transmission including both the input side and the output side disks. The cost of the transmission can be reduced, and the toroidal type continuously variable transmission can be contributed to practical use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cut-away plan view showing a first example of an embodiment of the present invention and showing a state in which finishing processing is performed on an inner end surface of a disk. FIG. 2 is a partially cut plan view showing a state in which the outer end face is subjected to finish processing. FIG. 3 is a partially cutaway plan view showing a state in which finishing processing is performed on the outer end surface of the disk, showing a second example of the embodiment of the present invention. FIG. 4 is a partial plan view showing two examples of the relationship between the shape of the cutting edge of a cutting tool and the properties of a surface to be processed. FIG. 5 is a side view showing the basic configuration of a toroidal-type continuously variable transmission incorporating a disk at the time of maximum speed increase. FIG. 6 is a cross-sectional view showing only a disk to be subjected to finish processing on an end face. [Description of Signs] 1 Input shaft 2 Input side disk 2a Inner surface 3 Output shaft 4 Output side disk 4a Inner surface 5 Displacement shaft 6 Power roller 6a Peripheral surface 7 Loading cam device 8 Cam plate 9 First cam surface 10 Second Cam surface 11 cage 12 roller 13 inner end surface 14 outer end surface central portion 15 outer end surface outer peripheral portion 16 main shaft 17 chucks 18, 18a, 18b cutting tool 19 collet chuck 20 trunnion

Claims (1)

Claims 1. An input-side and an output-side disk supported concentrically and independently rotatably, and intersects a central axis of the two disks at a portion between the two disks. Although there is no need to do so, a plurality of pivots present at a twist position perpendicular to the direction of the central axis, a plurality of trunnions swinging about these respective pivots, and Displacement shafts protruding from the side surfaces, and a plurality of power rollers sandwiched between inner surfaces of the input side and output side disks while being rotatably supported around the respective displacement shafts. A disk for a toroidal type continuously variable transmission, wherein both end faces in the axial direction of the input side disk or the output side disk constituting the toroidal type continuously variable transmission are flattened by hard turning using a lathe. The end face processing method.