JP2000061790A - Machining method of cam surface of loading cam device and machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and stably carry out work to form a cam surface of a second cam surface, etc., on a machining member of an input side disc 2, etc. SOLUTION: A shape and a phase of an outside surface of an input side disc 2 are found by a sensor 21 after the input side disc 2 is supported and fixed on a clamper 18 of a head end part of a main spindle 17. Thereafter, a grinding program is computed in accordance with the shape and the phase found in this way. Thereafter, the outside surface of this input side disc 2 is ground by rotating the input side disc 2 in the A direction while displacing a ceramic grinding stone 19 while rotating the ceramic grinding stone 19 in accordance with this program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for machining a cam surface of a loading cam device, which includes a cam surface of a loading cam device incorporated in a toroidal type continuously variable transmission, which is used as a transmission for an automobile, for example. Used for processing.

[0002]

2. Description of the Related Art For example, as a transmission for an automobile, use of a toroidal type continuously variable transmission as schematically shown in FIG. 4 has been studied. This toroidal type continuously variable transmission is disclosed in, for example, Japanese Utility Model Laid-Open No. 62-71465.
The input side disk 2 is supported at the end of the input shaft 1 and the output side disk 4 is supported at the end of the output shaft 3, and is rotatably supported by the displacement shafts 5 and 5 which are provided with adjustable tilt angles. The power rollers 6 and 6 are sandwiched between the input side and output side disks 2 and 4.

Inner side surfaces 2a and 4a of the input side and output side disks 2 and 4 facing each other are concave surfaces having arcuate cross sections, and the peripheral surfaces 6a and 6a of the power rollers 6 and 6 are
As the spherical convex surface, the peripheral surface 6 of each power roller 6, 6 is formed.
a and 6a are in contact with the inner side surfaces 2a and 4a. Further, between the input shaft 1 and the input side disk 2,
A loading cam device 7 is provided for rotating the input side disk 2 toward the output side disk 4 while pressing it in the axial direction.

The loading cam device 7 includes a cam plate 8 that engages with the input shaft 1 and rotates together with the input shaft 1. A first cam surface 9 is formed on one surface (right surface in FIG. 4) of the cam plate 8 as unevenness extending in the circumferential direction.
A second cam surface 10 is formed on the outer side surface (left side surface in FIG. 4) of the input side disk 2 as unevenness in the circumferential direction as shown in FIGS. 5 to 7, for example. In the illustrated example, curved portions 13 and 13 that are recessed in an arcuate cross-section are formed on the bottom of the concave portion, and flat portions 14 and 14 are formed on the top of the convex portion, and the curved portions 13 and 13 that are adjacent to each other in the circumferential direction are formed. The flat portions 14 and 14 are connected to each other by the inclined portions 15 and 15. Then, such a second cam surface 10 and the first cam surface 9
And a plurality of rollers 12, 12 between them and a ring-shaped cage 1
It is clamped in a state in which it is rotatably held at 1.

The shapes of the first and second cam surfaces 9 and 10 are basically the same. In other words, the shape of the first cam surface 9 is the same as that in FIGS. Further, the input side disk 2 shown in FIGS. 5 to 6 represents a shape to be actually incorporated in the toroidal type continuously variable transmission, and therefore the through hole 1 is formed at the center thereof.
6 is formed. Regarding the state in which the input side disk 2 having such a through hole 16 is incorporated in a toroidal type continuously variable transmission, there are disclosed in Japanese Patent Laid-Open No. 4-29659 and 6-229.
As described in Japanese Patent Publication No. 452, etc., it has been widely known from the past and is not directly related to the gist of the present invention.

[0006] The loading cam device 7 configured as described above
In the case of a toroidal type continuously variable transmission incorporating the above, when the cam plate 8 is rotated by the input shaft 1, the first cam surface 9 causes the plurality of rollers 12, 12 to move to the second cam surface 10.
Pressed against. As a result, the input side disk 2
Are pressed toward the output side disk 4, and the inner side surfaces 2a, 4a of both disks 2, 4 and the power rollers 6,
The peripheral surfaces 6a and 6a of 6 strongly contact. Also, each time 1
The input side disk 2 rotates on the basis of the pressure between the projections 2 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 of transmitting the rotary motion from the input shaft 1 to the output shaft 3 in this way, as shown in FIG. 4, the peripheral surfaces 6a, 6a of the respective power rollers 6, 6 are connected to the input side disk 2 as shown in FIG.
So as to come into contact with the outer peripheral portion of the inner side surface 2a and the central portion of the inner side surface 4a of the output side disk 4, respectively.
When the displacement shafts 5 and 5 are tilted, the speed is increased between the input shaft 1 and the output shaft 3. On the contrary, each power roller 6,
6, the peripheral surfaces 6a, 6a are the inner surface 2a of the input side disk 2.
Of the displacement shafts 5, so as to come into contact with the portion near the center of the
When 5 is tilted, deceleration is performed between the input shaft 1 and the output shaft 3. By setting the inclination angles of the displacement shafts 5 and 5 to be intermediate, it is possible to obtain an intermediate gear ratio between the input shaft 1 and the output shaft 3.

The first and second cam surfaces 9 and 10 of the loading cam device 7 of the toroidal type continuously variable transmission as described above are
Formed by subjecting the cam plate 8 or the input side disk 2 to a heat treatment for surface hardening, and then grinding the surfaces to be the first and second cam surfaces 9 and 10 with a rotating grindstone. To do. When such a grinding process is performed, conventionally, a general grindstone or a diamond electrodeposition grindstone in which the radius of curvature of the outer peripheral surface is matched with the radius of curvature of each of the curved portions 13, 13 is used. The grindstone and the cam plate 8 or the input side disk 2 which is the member to be processed are relatively displaced.

[0009]

When the first and second cam surfaces 9 and 10 are formed by using a general grindstone or a diamond electrodeposition grindstone having a radius of curvature that matches the curved portions 13 and 13, respectively. The setup of the cam surfaces 9 and 10 is troublesome, the processing time becomes long as a whole, and the manufacturing cost of the cam plate 8 and the input side disk 2 increases. That is, the cam plate 8 and the input side disk 2 are made into a material having a shape close to a finished product by subjecting a metal material such as carbon steel to forging and cutting, and the material is subjected to grinding to complete. It is considered as an item. However, since the material is deformed by the heat treatment applied to the material before performing the grinding processing, it is unavoidable that the portion to be removed from the material (grinding allowance) is increased by the grinding processing. On the other hand, when a rotating grindstone having a radius of curvature that matches the curved portions 13 and 13, in other words, a large radius of curvature of the outer peripheral surface is used, the curved portions 13 and 1 described above are used.
When forming No. 3, the processing load on the rotary grindstone becomes large and the processing speed cannot be increased, so that the processing time becomes long as described above. Further, as the processing load increases, the rotary grindstone is consumed so much that the rotary grindstone needs to be frequently replaced, which inevitably increases the processing cost.

Further, when setting a workpiece to be ground in a grinding machine, there are formed a concavo-convex shape formed on the surface on which the cam is to be machined by the forging process and a concavo-convex shape on the completed cam surface. It is necessary to match the phases. This work is troublesome and requires setup time, which causes the cost of the input side disk 2 and the cam plate 8 having the cam surface to be high. The processing method and processing device for the cam surface of the loading cam device of the present invention have been invented in view of such circumstances.

[0011]

SUMMARY OF THE INVENTION A method and apparatus for processing a cam surface of a loading cam device according to the present invention includes a first cam surface formed as an unevenness in the circumferential direction and an uneven surface formed in the circumferential direction. A second cam surface that is formed and axially faces the first cam surface, and rolls to a ring-shaped cage that is mounted between the first cam surface and the second cam surface. Processing the first and second cam surfaces, which constitutes a loading cam device composed of a plurality of rollers abutting the first cam surface and the second cam surface in a freely held state. Is.

Particularly, in the method for machining the cam surface of the loading cam device according to the first aspect, the workpiece having the cam surface to be machined is rotatable about the central axis of the cam surface to be machined. The ceramic grindstone having a cylindrical outer peripheral surface with a radius of curvature smaller than the radius of curvature of the curved portion which is supported at the bottom of the concave portion of the cam surface to be machined and which has a concave cross section. It is arranged in a state in which the direction of the central axis of the grindstone and the diameter direction of the cam surface to be machined are made to coincide with each other and can be displaced relative to the cam surface in the axial direction of the cam surface to be machined. Then, the phase and shape of the surface of the portion of the workpiece to be processed on the cam surface is detected by a sensor, and based on the difference between this detected value and the finished shape of the cam surface to be processed, A program for relatively displacing the workpiece and the ceramic grindstone is calculated. Thereafter, based on this program, while rotating the ceramic grindstone, the ceramic workpiece is rotated relative to the cam surface in the direction of the central axis of the cam surface to be machined, and at the same time, the workpiece is rotated to produce the workpiece. The cam surface to be machined is formed by synchronously controlling the rotation angle of the machined member and the axial displacement of the ceramic grindstone.

Further, according to a second aspect of the present invention, there is provided a device for machining a cam surface of a loading cam device, wherein a holder for supporting a workpiece having a cam surface to be machined, the holder, and a central axis of the workpiece. A rotation drive device that rotates as a center, a ceramic grindstone that can freely rotate the diameter direction of the cam surface to be machined and the direction of its center axis, and the direction of the central axis of the cam surface to be machined. A feed device for relative displacement with respect to the cam surface, a sensor for detecting the surface shape and phase of a portion of the workpiece to be processed on the cam surface, and a controller. Prepare Then, this controller has an arithmetic processing circuit for calculating a program for relatively displacing the workpiece and the ceramic grindstone based on the difference between the detected value of the sensor and the finished shape of the cam surface to be machined. Have. Then, based on the program calculated by the arithmetic processing circuit, the rotation angle of the workpiece to be processed by the rotary drive device and the relative displacement amount of the ceramic grindstone and the cam surface by the feed device are controlled while being synchronized.

[0014]

According to the cam surface machining method and machining device of the loading cam device of the present invention configured as described above, the cam surface can be efficiently machined in a short time. That is, the cam surface is machined while synchronously controlling the rotational angle of the workpiece and the axial displacement of the ceramic grindstone, so that a ceramic grindstone whose outer surface has a radius of curvature smaller than that of the curved portion can be used. You can As a result, it is possible to reduce the processing load applied to the ceramic grindstone when processing the curved portion. Further, using a ceramic grindstone, creep grinding (“creep grinding” or “creep-feed grinding”) in which the displacement of the ceramic grindstone and the rotation of the workpiece are performed at low speed.
Therefore, since the cam surface is formed, the cutting amount, which is the amount by which the ceramic grindstone scrapes off the surface to be processed at once,
Can be made bigger. As a result, the machining speed can be increased and the cam surface machining time can be shortened.

Further, a program for detecting the shape and phase of a portion of the surface of the member to be machined where the cam surface is to be machined by a sensor and performing the displacement of the ceramic grindstone and the rotation of the member to be machined. Therefore, even if the phase of the workpiece is not particularly taken into consideration when mounting the workpiece on the holder, and even if the deformation of the workpiece due to heat treatment is large, the ceramic grindstone Can be reliably and efficiently contacted with the portion where the cam surface is to be formed. Therefore, the time required for mounting the member to be processed in the holder can be shortened, and the time for the ceramic grindstone to idle without contacting the surface to be processed can be eliminated, so that the processing time for the cam surface can also be shortened. .

[0016]

1 to 3 show an example of an embodiment of the present invention. This example shows a case where the present invention is implemented with respect to forming the second cam surface 10 on the outer surface of the input side disk 2. The input side disk 2, which is a member to be machined having a cam surface to be machined, is supported and fixed to the tip of the main shaft 17 by a clamper 18 concentrically with the main shaft 17. The main shaft 17 and the clamper 18 correspond to the holder described in claim 2. Further, the main shaft 17 is driven by a precision rotary drive device (not shown) to
It can be slowly rotated in the direction of arrow A in FIG.

In the vicinity of the tip of the main shaft 17 as described above, C
A cylindrical ceramic grindstone 19 made of BN (cubic boron nitride) is arranged. The ceramic grindstone 19 rotates while being fixed to the tip of the rotary shaft of the drive device such as the electric motor 20. The center axis of the rotary shaft and the center axis of the ceramic grindstone 19 are aligned with each other, and the direction of the center axis is perpendicular to the direction of the center axis of the main shaft 17. The electric motor 20 is supported and fixed to the head of a feeding device such as a three-dimensional precision moving device (not shown). Therefore, the ceramic grindstone 19 moves in the X, Y, and Z directions of FIG.
Precision movement is possible (in the X direction, which is the direction coinciding with the central axis direction).

When the second cam surface 10 is formed on the outer side surface of the input side disk 2, the input side disk 2 is slowly rotated in the direction of arrow A in FIG. The ceramic grindstone 19 is gradually displaced in the direction of arrow X in the figure. That is, the outer surface of the input side disk 2 is creep-ground while the rotation of the input side disk 2 and the displacement of the ceramic grindstone 19 are synchronized. During this creep grinding, the rotation of the spindle 17 and the displacement of the ceramic grindstone 19 are calculated in advance by an NC controller (not shown), which is a controller having an arithmetic processing circuit, and recorded in the memory of this NC controller. It is controlled synchronously by the stored program. Further, this program is calculated in advance based on a signal from the sensor 21 described below before the grinding of the second cam surface 10 is started.

That is, in order to obtain data for calculating the above-mentioned program, a contact type or non-contact type sensor 21 is supported on a head (not shown) which supports and fixes the driving means such as the electric motor 20. . The sensor 21 detects the shape of the outer side surface of the input side disk 2, which should form the second cam surface 10, and outputs the detection signal to the NC.
Send to controller. However, in practice, in order to keep the distance between the detection portion of the sensor 21 and the outer side surface constant (when a non-contact type sensor is used), the head is displaced in the axial direction of the main shaft 17 while The input side disk 2 is rotated by the main shaft 17, and the shape and phase of the outer surface in the circumferential direction are calculated from the rotation angle of the main shaft 17 and the displacement amount of the head in the axial direction. That is, prior to grinding the outer surface of the input side disk 2 with the ceramic grindstone 19, as shown in FIGS. 3 (A) and 3 (B),
The coordinates of a plurality of points on this outer surface are obtained. It should be noted that this coordinate is composed of an A coordinate (angle) in the rotation direction of the input side disk 2 and an X coordinate (axial position) in the axial direction of the main shaft 17, and is represented by (A _n , X _n ). Represent. Such coordinates are set at a plurality of points on the outer surface, and (A ₁ , X ₁ )
(A ₂ , X ₂ ) --- (A _n , X _n )

Then, the coordinates (A ₁ , X ₁ ) (A ₂ , X ₂ )-A--
From (A _n , X _n ) the outer surface of the input side disk 2 (in the state before the second cam surface 10 is ground)
Find the shape and phase across the direction of rotation. Then, based on the difference between the shape thus obtained and the shape of the second cam surface 10 to be finished by performing grinding, the input side disk 2 and the ceramic grindstone 19 which are the members to be processed, A program (including phase indexing, grinding allowance, cutting amount, and number of times of machining) for relative displacement of is calculated.

Thereafter, as described above, as shown in FIG.
While rotating the ceramic grindstone 19 by the driving means such as the electric motor 20, the ceramic grindstone 19 is rotated.
2 is displaced at a low speed in the axial direction of the main shaft 17, as indicated by the arrow X in FIG. At the same time, the main shaft 17 is rotated at a low speed as shown by an arrow A in FIG. At this time, the displacement amount of the ceramic grindstone 19 in the arrow X direction and the rotation angle of the spindle 17 in the arrow A direction are automatically performed according to the program. Then, the main spindle 17
Is rotated once or several times, the second cam surface 10 having a desired shape is formed on the outer surface of the input side disk 2.
Are formed by grinding.

According to the cam surface machining method and machining apparatus of the loading cam device of the present invention configured as described above, the machining of the second cam surface 10 can be efficiently formed in a short time. That is, while synchronously controlling the rotation angle of the main shaft 17 that supports the input side disk 2 that is the member to be processed and the axial displacement amount of the head (not shown) that supports the electric motor 20 for rotationally driving the ceramic grindstone 19. Since the second cam surface 10 is machined, the radius of curvature of the outer peripheral surface is such that the curved portion 13 exists at the bottom of the concave portion which constitutes the second cam surface 10.
A ceramic grindstone 19 having a radius of curvature smaller than 13 can be used. As a result, it is possible to reduce the processing load applied to the ceramic grindstone 19 when processing the curved portions 13, 13. Further, by using a ceramic grindstone 19 such as a CBN grindstone that is harder than a general grindstone, the displacement of the ceramic grindstone 19 and the rotation of the input side disk 2 are performed at a low speed, and the second grinding is performed by creep grinding. Since the surface 10 is formed, it is possible to increase the cut amount, which is the amount by which the ceramic grindstone 19 scrapes off the surface to be processed at one time. As a result, the processing speed can be increased and the processing time for the second cam surface 10 can be shortened.

Further, the shape and position of the outer side surface of the input side disk 2 on which the second cam surface 10 is to be formed is detected by the sensor 21, and the ceramic grindstone 1 is detected.
In order to calculate the program for performing the displacement of 9 and the rotation of the input side disk 2, when the input side disk 2 is mounted on the clamper 18 provided at the tip of the main shaft 17, the input side disk 2 is Even if the amount of deformation of the input side disk 2 due to heat treatment is large, the ceramic grindstone 19 contacts the outer side surface of the input side disk 2 reliably and efficiently. I can do things. Therefore, the input side disk 2 is connected to the clamper 1
8 and the time required for the ceramic grindstone 19 to idle without contacting the outer surface of the input side disk 2 is eliminated, and the machining time of the second cam surface 10 is also reduced. Can be shortened. Further, since the processing state can be made constant, the properties of the obtained second cam surface can be stabilized. The operation of forming the first cam surface 9 (see FIG. 4) on one surface of the cam plate 8 is similar to the above-described case of forming the second cam surface 10 on the outer surface of the input side disk 2. To do.

[0024]

Since the method and apparatus for machining the cam surface of the loading cam device according to the present invention are constructed and operate as described above, the machining of the cam surface constituting the loading cam device can be performed in a short time and stably. You can do it.
As a result, it is possible to reduce the cost and improve the performance of a mechanical device incorporating a loading cam device such as a toroidal type continuously variable transmission.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of an embodiment of the present invention and schematically showing the overall configuration of a processing apparatus.

FIG. 2 is a view schematically showing the relationship between a cam surface and a ceramic grindstone, as viewed from below in FIG.

FIG. 3 is a diagram schematically showing two examples of the relationship between the cam surface and the sensor, as viewed from above in FIG.

FIG. 4 is a side view showing a basic configuration of a toroidal type continuously variable transmission incorporating a loading cam device in a state of maximum acceleration.

FIG. 5 shows the cam surface formed on the outer surface of the input side disc,
The figure shown in the state seen from the left side of FIG.

6 is a sectional view taken along the line EE of FIG.

FIG. 7 is a partially developed view showing the shape of a cam surface.

[Explanation of symbols]

1 input axis 2 Input side disk 2a Inside surface 3 output axes 4 Output side disc 4a inner surface 5 Displacement axis 6 power rollers 6a peripheral surface 7 Loading cam device 8 cam plate 9 First cam surface 10 Second cam surface 11 cage Around twelve 13 curved part 14 Flat part 15 Inclined part 16 through holes 17 spindle 18 clamper 19 Ceramic grindstone 20 electric motor 21 sensor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masami Tanaka             Gunma Prefecture Maebashi City 1-8-1 Sojamachi Japan             Within Seiko Co., Ltd. F-term (reference) 3C049 AA03 AA13 AB04 BA04 BA07                       BB02 BB06 BB09 BC01 BC02                       CA01 CA03 CB03 CB05                 3J051 AA03 BA03 BB02 BE09 CA05                       EC02 EC06 FA02

Claims (2)

[Claims] 1. A first cam surface formed as an unevenness in the circumferential direction, and a second cam surface formed as an unevenness in the circumferential direction and facing the first cam surface in the axial direction. And a state in which the first cam surface and the second cam surface are rotatably held by a ring-shaped retainer mounted between the first cam surface and the second cam surface. Forming a loading cam device composed of a plurality of rollers contacting the first,
A machining method for machining a second cam surface, in which a workpiece having a cam surface to be machined is rotatably supported about a central axis of the cam surface to be machined and A ceramic grindstone having a cylindrical outer peripheral surface with a radius of curvature smaller than the radius of curvature of a curved portion concave in an arcuate cross section, which is present at the bottom of the concave portion of the power cam surface, and the direction of the central axis of the ceramic grindstone Among the above-mentioned members to be machined, the cam surface is arranged so as to be displaceable relative to the cam surface to be machined and in the axial direction of the cam surface to be machined in a state where the diameter direction of the cam surface to be machined coincides. The phase and shape of the surface of the portion to be machined is detected by a sensor, and based on the difference between the detected value and the finished shape of the cam surface to be machined, the workpiece and the ceramic grindstone are relatively displaced. I should let you After calculating the gram, based on this program, while rotating the ceramic grindstone, it is displaced relative to the cam surface in the direction of the central axis of the cam surface to be machined and at the same time the workpiece is rotated. Then, the cam surface of the loading cam device is formed by synchronously controlling the rotational angle of the workpiece and the axial displacement of the ceramic grindstone to form the cam surface to be processed. 2. A machining device for a cam surface of a loading cam device for carrying out the machining method according to claim 1, wherein the holder supports a workpiece having a cam surface to be machined, and the holder. A rotary drive device that rotates about the central axis of the member to be processed, a ceramic grindstone that can freely rotate the diameter direction of the cam surface to be machined and the direction of the central axis, and the ceramic grindstone described above. A feed device for displacing the cam surface in the direction of the central axis of the cam surface to be machined, and detecting the shape and phase of the surface of the part of the workpiece to be machined where the cam surface is machined. Sensor and a program for calculating relative displacement between the workpiece and the ceramic grindstone based on the difference between the detected value of this sensor and the finished shape of the cam surface to be machined. And a rotation amount of the workpiece to be processed by the rotary drive device and the relative displacement amount of the ceramic grindstone and the cam surface by the feed device are synchronized with each other based on a program calculated by the calculation processing circuit. A device for processing the cam surface of the loading cam device, which is provided with a controller for controlling the same.