JP2003260650A - Super finishing method of groove, and grinding wheel for super finishing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a super finishing method capable of super finishing, by a single process, right and left surfaces of a groove in which curvature centers of the right and left surfaces in the width direction lie at different positions similarly to a track surface of a four-point contact ball bearing, and to provide a grinding wheel used for the super finishing method. <P>SOLUTION: This super finishing method is used for super finishing, by a single process, the right and left surfaces 1a and 1b of the groove in which curvature center positions c1 and c2 of the right and left surfaces 1a and 1b are different with the grinding wheel oscillating about an oscillating shaft core S. A grinding wheel part 7 for the left surface disposed on the left surface 1a side for super finishing the left surface 1a of the groove and a grinding wheel part 8 for the right surface disposed on the right surface 1b side for super finishing the right surface 1b of the groove are arranged shifted in the direction of the oscillating shaft core S. The grinding wheel part 7 for the left surface and the grinding wheel part 8 for the right surface oscillate about the oscillating shaft core S in a state in which the oscillating shaft core S passes through both the curvature center c1 of the left surface 1a of the groove and the curvature center c2 of the right surface 1b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for superfinishing a groove having different curvature centers on the left and right, such as a grooved raceway surface of a four-point contact ball bearing, and a superfinishing grindstone suitable for the method. It is a thing.

[0002]

8 and 9 show a state in which a normal deep groove ball bearing 100 is superfinished by a superfinishing device. This superfinishing device is provided with a raceway surface 100 of an inner ring 100 that rotates about a rotation axis X by a main shaft 101.
A grindstone shaft device including a grindstone 102 for superfinishing a, a grindstone head 103 to which the grindstone 102 is mounted, and a grindstone shaft 104 that rocks the grindstone 102 around a grindstone rocking axis S ing.

In the grindstone shaft device, the wobbling axis S of the grindstone is the raceway surface 1.
00a is arranged orthogonal to the rotational axis X of the main shaft 101 so as to be parallel to the longitudinal direction of the spindle 00a, and the grindstone 102 is swung left and right at high speed in a state of being pressed against the raceway surface 100a. The super finishing process is performed.
In the case of the normal deep groove ball bearing 100 as described above, the raceway surface 1
Since the cross-sectional shape of 00a is a circular arc having a single curvature, if the grindstone shaft device is arranged so that the center of curvature of the raceway surface 100a and the whetstone rocking axis S coincide with each other, superfinishing can be performed without problems.

On the other hand, in the four-point contact ball bearing, the balls make contact with the groove-shaped raceway surfaces of the inner ring and the outer ring at four points, and the cross section of the raceway surface has the curvature of the left and right circular arcs of the raceway surface. The centers are formed so as to be at different positions. That is, as shown in FIGS. 10 and 11, the raceway surface of the four-point contact ball bearing has different curvature center positions between the left side 110a and the right side 110b, and the curvature center c1 of the left side raceway 110a is
It is offset by a1 on the right side, which is the opposite side to the center Y in the lateral direction of the raceway surface, and the center of curvature C2 of the right raceway surface 100b is offset by a2 on the left side, which is the opposite side to the center Y of the raceway surface. Has been done.

In the superfinishing process, it is necessary to swing the grindstone to the left and right with the center of curvature of the raceway surface as the swing center.
Left and right raceways 110, like the races of a four-point contact ball bearing
When the centers of curvature C1 and C2 of a and 110b are different from each other, conventionally, the left and right raceway surfaces 110a and 110b cannot be simultaneously superfinished.

Therefore, in order to superfinish a bearing ring of a four-point contact ball bearing, as shown in FIGS. 10 (a) and 11 (a), the left side raceway surface 110a is superfinished with a grindstone 111 for the left side. Orbital surface machining process and Fig. 10 (b) and Fig. 1
As shown in FIG. 1 (b), it was necessary to perform the right raceway surface machining step of superfinishing the right raceway surface 110b with the grindstone 112 for the right side in a separate step (in FIG. 11, arrow B1).
Indicates the swing direction of the left-side grindstone 111 with the center of curvature c1 as the swing center, and arrow B2 indicates the swing direction of the right-side grindstone 112 with the center of curvature c2 as the swing center. ).

[0007]

Therefore, in the conventional super-finishing process for a four-point contact ball bearing, equipment for left side raceway surface processing and equipment for right side raceway surface processing are required, respectively. Equipment cost was higher than that of ball bearing processing.

The present invention has been made in view of the above problems, and the left and right surfaces of the groove at the positions where the centers of curvature of the left and right surfaces in the width direction are different, such as the raceway surface of a four-point contact ball bearing, are formed. An object of the present invention is to provide a superfinishing method capable of superfinishing in one step and a grindstone used in the superfinishing method.

[0009]

According to the present invention relating to a superfinishing method, a grindstone which swings around both sides of a groove formed so that the center of curvature of the left and right sides are different from each other around a swing axis. According to the method for superfinishing in a single step, the left side grindstone portion arranged on the left side for superfinishing the left side of the groove, and the superposition for the right side of the groove In a state where the right surface grindstone portion arranged on the right surface side is displaced in the swing axis direction, and the swing axis passes through both the center of curvature of the left surface and the center of curvature of the right surface of the groove. The left-side grindstone portion and the right-side grindstone portion swing about the swing axis. According to this method, of the left and right surfaces of the groove having different centers of curvature, the left surface can be processed by the left surface grindstone portion and the right surface can be processed by the right surface grindstone portion.

The left-side grindstone portion arranged on the left side and the right-side grindstone portion arranged on the right side are displaced in the swing axis direction, and the swing axis is aligned with the center of curvature of the left surface. By inclining with respect to the groove longitudinal direction so as to pass through the center of curvature of the right surface together, the center of swing of the grindstone portion for the left surface and the center of swing of the grindstone portion for the right surface are viewed in the groove width direction, It will be in a different position. That is, the center of swing of the grindstone for the left surface coincides with the center of curvature of the left surface, while the center of swing of the grindstone for the right surface coincides with the center of curvature of the right surface. Therefore, even if the centers of curvature of the left and right surfaces are different, superfinishing can be performed in a single step.

The center position of the grindstone portion for the left surface in the swing axis direction substantially coincides with the curvature center position of the left surface, and the center position of the grindstone portion for the right surface in the swing axis direction is the right surface. If it is substantially coincident with the curvature center position of, the more appropriate superfinishing can be performed.

Further, according to the present invention relating to the superfinishing grindstone, in the superfinishing grindstone in which the left and right sides of the groove are superfinished by swinging left and right about the swing axis, the left side of the groove is used. The left side grindstone portion for superfinishing, and a right side grindstone portion for superfinishing the right surface of the groove, and the left side grindstone portion and the right surface grindstone portion, the swing axis direction It is characterized in that they are arranged side by side in the state of being shifted to. By using this grindstone for superfinishing, even if the centers of curvature of the left and right surfaces of the groove are different, superfinishing can be performed in a single step by the above-mentioned superfinishing method.

Further, the superfinishing grindstone has a first dummy grindstone part which is consumed on the right side of the grindstone part for the left surface and which does not substantially contribute to the superfinishing process, and is provided on the left side of the grindstone part for the right surface. Is preferably provided with a second dummy grindstone portion that is consumed without substantially contributing to superfinishing. It is preferable that there are whetstones on the right side of the left side grindstone and on the left side of the right side grindstone as well because the overall shape of the superfinishing whetstone is simple, but on the right side of the left side grindstone and on the left side of the right side grindstone. If there is a grindstone, the grindstone may break the curvature of the groove. Therefore, on the right side of the grindstone for the left side and the left side of the grindstone for the right side, a dummy grindstone part that is consumed without substantially contributing to the superfinishing process is provided to simplify the overall shape of the superfinishing grindstone. At the same time, it is possible to prevent the curvature from collapsing.

Further, if the grindstone for the left side and the grindstone for the right side are integrated, it is preferable that the structure of the device for holding and swinging the superfinishing grindstone can be simplified.
If the left-side grindstone portion and the right-side grindstone portion are integrally coupled by the first and second dummy grindstone portions,
It is possible to obtain a simple connecting structure between the grindstone for the left surface and the grindstone for the right surface.

The center position of the grindstone portion for the left surface in the swing axis direction substantially coincides with the center of curvature of the left surface, and the center position of the grindstone portion for the right surface in the swing axis direction is the right surface. If it is formed so as to substantially coincide with the curvature center position of, the more appropriate superfinishing can be performed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as the groove to be superfinished, the groove-shaped raceway surface 1a of the inner ring 1 of the ball bearing,
1b will be described as an example. FIG. 1 shows a ball bearing raceway superfinishing machine, which includes a main shaft 2 to which an inner ring 1 (raceway) of a ball bearing is mounted, and a superfinishing grindstone 3 for superfinishing the raceway surface of the inner ring 1. , A grindstone shaft device 4 for holding and swinging the superfinishing grindstone 3.

The main shaft 2 rotates about a rotation axis X, and the inner ring 1 is attached to the main shaft 1 such that the axis of the inner ring 1 is coaxial with the rotation axis X. The grindstone shaft device 4 includes a grindstone mounting head 5 on which the superfinishing grindstone 3 is mounted, and a grindstone shaft 6 that is swung at a high speed to swing the grindstone about a grindstone swing axis S. ing. This grindstone shaft device 4 is different from that of FIG.
Are not parallel to the longitudinal direction of the raceway surface 1a, but are inclined with respect to the longitudinal direction Y of the raceway surface by an angle α.

The raceway surface 1a of the inner ring 1 shown in FIGS. 1 and 2,
1b is formed such that the left surface 1a and the right surface 1b have the same curvature, but the curvature center positions c1 and c2 are different between the left surface 1a and the right surface 1b. That is, left side 1
The center of curvature c1 of a is offset to the right side on the opposite side to the center position in the width direction of the track surfaces 1a and 1b (corresponding to the position indicated by Y in FIG. 2), and the center of curvature c2 of the right surface 1b is
The track surfaces 1a, 1b are offset to the left side opposite to the center position Y in the width direction. The left side 1a and the right side 1
Since the curvature of b is the same, the offset amount a1 of the curvature center c1 of the left surface 1a and the offset amount a2 of the curvature center c2 of the right surface 1b are the same.

The superfinishing grindstone 3 is formed in a rectangular shape in a plan view by integrally combining a left-side grindstone portion 7, a right-side grindstone portion 8, a first dummy grindstone portion 9 and a second dummy grindstone portion 10. ing. In the drawing, the left-side grindstone portion 7 and the right-side grindstone portion 8 are shown as shaded portions. The surface 3a where the grindstone 3 contacts the raceway surfaces 1a and 1b is curved along an arc in the circumferential direction of the raceway surfaces 1a and 1b (see FIG. 3).

As the left-side grindstone portion 7 and the right-side grindstone portion 8, general grindstones used for superfinishing the raceway surface are used. On the other hand, the first dummy whetstone portion 9 and the second dummy whetstone portion 1
0 is formed of a brittle and fragile material, and the first dummy whetstone portion 9 and the second dummy whetstone portion 10 are
At the time of superfinishing, it is consumed by peeling due to contact with the rotating raceway surfaces 1a and 1b and does not substantially contribute to superfinishing.

The grindstone portion 7 for the left surface has a rectangular shape in plan view, and the swing axis S is positioned so as to be located on the left side 1a of the raceway surface.
It is located on the left side of. Further, the right surface grindstone portion 8 has a rectangular shape in a plan view and is arranged on the right side of the swing axis S so as to be located on the right side 1b of the raceway surface. The grindstone portion 7 for the left surface and the grindstone portion 8 for the right surface are arranged so as to be offset from each other in the swing axis S direction, and one side of the center position 3b of the grindstone 3 in the axial center S direction (upper side in FIGS. 1 and 3). The grindstone portion 7 for the left surface is located on the other side, and the grindstone portion 8 for the right surface is located on the other side (lower side in FIGS. 1 and 3) of the central position 3b of the grindstone 3 in the axial center S direction. That is, when the intersection of the swing axis S and the center position 3b of the grindstone 3 in the axis S direction is the grindstone center 3c, the left surface grindstone portion 7 and the right surface grindstone portion 8 are point-symmetric with respect to the grindstone center 3c. It is located in.

As for the swing axis S, the swing axis S in the range of the grindstone portion 7 for the left surface passes through the center position c1 of the curvature of the left surface, and the swing axis S in the range of the grindstone portion 8 for the right surface has the right surface curvature. It is inclined so as to pass through the center position c2. Here, the grindstone center 3c passes through the center position Y in the width direction of the raceway surfaces 1a and 1b, and the center position 7a of the grindstone portion 7 for the left surface on the swing axis S in the S direction passes through the center c1 of the left surface curvature. The center position 8a of the grindstone 8 for the right surface on the moving shaft center S in the shaft center S direction is set to pass through the center of curvature of the right surface c2.

By arranging the grindstone 3 as described above, the rocking axis S is such that the center of curvature c1 of the left and right surfaces 1a and 1b of the raceway surface is c1.
Since it passes through c2, it is possible to perform superfinishing on both the left and right sides 1a and 1b by a single step with one grindstone shaft device 4. That is, as shown in FIG. 4A, the left surface 1a of the raceway surface is the center of the left surface curvature c1 offset to the right.
It is superfinished by the grindstone 7 for the left side that swings around the center. In addition, as shown in FIG. 4B, the right side of the raceway surface 1
b is superfinished by the right-side grindstone 8 that swings about the right-side curvature center c2 that is offset to the left.
As a result, it is not necessary to prepare each of the grindstone shaft device 4 for the left side and for the right side, so that the equipment for superfinishing can be inexpensive.

As described above, since the first dummy grindstone portion 9 and the second dummy grindstone portion 10 do not substantially contribute to the superfinishing process, the function of the grindstone 3 shown in FIGS.
It is substantially equivalent to the grindstone having only the left-side grindstone portion 7 and the right-side grindstone portion 8 shown in FIG. However, in the case of FIG. 5, if the grindstone 3 as a whole has a complicated shape and the left-side grindstone portion 7 and the right-side grindstone 8 are independent, the grindstone mounting head 5 for mounting the grindstone 3
Becomes complicated and it becomes difficult to mount the grindstone 3.

On the other hand, in the grindstones shown in FIGS. 1 to 4, the first dummy grindstone portion 9 provided on the right side of the grindstone portion 7 for the left surface.
And a second dummy grindstone portion 10 provided on the left side of the right-side grindstone portion 8 are formed in a block shape and have a simple shape. Since the left surface grindstone portion 7 and the right surface grindstone portion 8 are connected by the dummy grindstone portions 9 and 10, the grindstone mounting head 5 can be simplified. Furthermore, since the entire shape of the grindstone 3 is the same as that of the conventional grindstone 102 shown in FIG. 9, it can be mounted on the conventional grindstone mounting head 5 as it is.

The first dummy grindstone portion 9 is formed in a rectangular shape in a plan view, and one side thereof coinciding with the swing axis S is adjacent to the left surface grindstone portion 7. In addition, it is also adjacent to the right side grindstone portion 8 on the other side. Second dummy grindstone part 1
0 is also formed in a rectangular shape in a plan view, one side coinciding with the swing axis S is adjacent to the right surface grindstone portion 8, and the other side is also adjacent to the left surface grindstone portion 7.

Incidentally, the first and second dummy grindstones 9 and 10
May be adhered to the left-side grindstone portion 7 and the right-side grindstone portion 8 with an adhesive, or may be joined by integrally sintering with the left-side grindstone portion 7 and the right-side grindstone portion 8. Good.

Here, since the range in which the first dummy grindstone 9 is provided is on the right side of the swing axis S, if the first dummy grindstone 9 is a normal grindstone, at the time of superfinishing, the right surface 1b of If the second dummy grindstone 10 is a normal grindstone, the curvature of the left surface 1a is also broken. On the other hand, in the present embodiment, since the dummy grindstones 9 and 10 are consumed without substantially contributing to the superfinishing process, it is possible to prevent the curvature of the raceway surfaces 1a and 1b from being unnecessarily collapsed. In this way, even if the members 9 and 10 are provided between the left-side grindstone portion 7 and the right-side grindstone portion 8 to join the both grindstone portions 7 and 8, the joining members 9 and 10 do not contribute to superfinishing. Since it is a dummy grindstone that consumes a lot, it is possible to prevent the curvature of the raceways 1a and 1b from being adversely affected.

FIGS. 6 and 7 show a superfinishing grindstone 23 according to a second embodiment of the present invention. The inner ring raceway surfaces 21a, 21b superfinished by the grindstone 23 have different curvatures of the left surface 21a and the right surface 21b of the raceway surface, and the offset amount a1 of the left surface curvature center c1 and the offset amount a2 of the right surface curvature center c2. And are different. As shown in FIG. 7, the diameter of the pitch circle drawn by the center of curvature of the left surface c1 in the circumferential direction of the inner ring 21 (= left PCD) and the diameter of the pitch circle drawn by the center of curvature of the right surface c2 in the circumferential direction of the inner ring 21. (= Right PCD) is also different.

Also in the second embodiment, the swing axis S is set so as to pass through the respective curvature centers c1 and c2.
Regarding the inclination of the swing axis S, the center position 27a of the grindstone portion 27 for the left surface on the swing axis S in the direction of the axis S is the center of the left surface curvature c1.
And the center side corner portion 27b of the grindstone portion 27 for the left side is set to coincide with the center position Y in the width direction of the raceway surfaces 21a, 21b. Further, the right surface grindstone portion 28 is arranged with reference to the position 28a where the swing axis S intersects the right surface curvature center c2 in the tilt of the swing axis S set in this way. That is, the central position of the right surface grindstone portion 28 on the swing axis S in the axis S direction is the position 28.
The right surface grindstone portion 28 is arranged so as to be a.

In the second embodiment, the first dummy grindstone portion 29 and the second dummy grindstone portion 30 correspond to the large deviation in the axial center S direction between the left surface grindstone portion 27 and the right surface grindstone portion 28. , The left side grindstone 27 and the right side grindstone 2 respectively
8 are formed so as to be adjacent to both sides of the first dummy grindstone portion 29 and the second dummy grindstone portion 3 respectively.
0 is also integrally formed, and the integrity of the entire grindstone 3 is secured.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the matters described in the claims. For example, the present invention can be applied to the machining of grooves formed such that the outer ring raceway surface of a four-point contact ball bearing or other left and right surfaces have different curvature center positions.

[0033]

According to the present invention relating to the superfinishing method, even if the centers of curvature of the left and right surfaces of the groove are different, the left surface is the left surface grindstone portion and the right surface is the right surface grindstone portion. Can be superfinished. Further, the center position in the swing axis direction of the grindstone portion for the left surface substantially coincides with the center position of the curvature of the left surface, and the center position of the grindstone portion for the right surface in the swing axis direction is the center of curvature of the right surface. If the position is substantially the same, more appropriate superfinishing can be performed.

Further, according to the present invention relating to the superfinishing grindstone, even if the centers of curvature of the left and right surfaces of the groove are different, the left surface is the left surface grindstone portion and the right surface is the right surface grindstone portion. Super finishing can be done with. Further, the superfinishing whetstone has a first grindstone on the right side of the left grindstone part.
Since the dummy grindstone portion is provided and the second dummy grindstone portion is provided on the left side of the right surface grindstone portion, it is possible to prevent the curvature of the groove from collapsing while simplifying the overall shape of the superfinishing grindstone.

Furthermore, if the grindstone for the left side and the grindstone for the right side are integrated, the structure of the device for holding and swinging the superfinishing grindstone can be simplified. In particular,
If the left-side grindstone portion and the right-side grindstone portion are integrally coupled by the first and second dummy grindstone portions,
It is possible to obtain a simple connecting structure between the grindstone for the left surface and the grindstone for the right surface.

The center position of the grindstone portion for the left surface in the swing axis direction substantially coincides with the center of curvature of the left surface, and the center position of the grindstone portion for the right surface in the swing axis direction is the right surface. If it is formed so as to substantially match the center of curvature of,
More suitable superfinishing can be performed.

[Brief description of drawings]

FIG. 1 is a plan view of a superfinishing device according to a first embodiment.

FIG. 2 is an enlarged plan view of a grindstone for superfinishing.

FIG. 3 is a side view of a superfinishing whetstone (view III in FIG. 2).

FIG. 4 (a) is a diagram showing a state of superfinishing by the grindstone portion for the left surface and the first dummy grindstone portion, and (b) is a state of superfinishing by the grindstone portion for the right surface and the second dummy grindstone portion. FIG.

FIG. 5 is a plan view of a grindstone including a grindstone for the left surface and a grindstone for the right surface.

FIG. 6 is an enlarged plan view of a superfinishing grindstone according to a second embodiment.

FIG. 7A is a diagram showing a state of superfinishing by the left-side grindstone portion and the first dummy whetstone portion, and FIG. 7B is a state of superfinishing by the right-side grindstone portion and the second dummy whetstone portion. It is a conceptual diagram which shows.

FIG. 8 is a plan view of a conventional superfinishing device.

FIG. 9 is a diagram showing a state of superfinishing with a conventional grindstone.

10A is a plan view showing how the left side grindstone superfinishes the left side, and FIG. 10B is a plan view showing how the right side grindstone superfinishes the right side.

11A is a front view showing how the left side grindstone superfinishes the left side, and FIG. 11B is a front view showing how the right side grindstone superfinishes the right side.

[Explanation of symbols]

1a Left side of raceway (left side of groove) 1b Right side of raceway (right side of groove) 3 Super finishing whetstone 7 Grindstone for left side 7a Center position in the swing axis direction of the grindstone for the left side 8 Grindstone for right side 8a The center position of the grindstone for the right side in the swing axis direction 9 First dummy whetstone part 10 Second dummy whetstone part S swing axis c1 Center of curvature on the left side c2 center of curvature of right side

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Claims (7)

[Claims] 1. A method for superfinishing a left and right surfaces of a groove formed so that the centers of curvature of the left and right surfaces are different from each other in a single step with a grindstone that rocks around a rocking axis. In the above, the left surface grindstone portion arranged on the left surface side for superfinishing the left surface of the groove and the right surface grindstone portion arranged on the right surface side for superfinishing the right surface of the groove are rocked. Displaced in the axial direction, and in a state in which the swing axis passes through both the center of curvature of the left surface and the center of curvature of the right surface of the groove, the grindstone portion for the left surface and the grindstone portion for the right surface are A method of superfinishing a groove, which comprises swinging about the swing axis. 2. A center position in the swing axis direction of the grindstone portion for the left surface substantially coincides with a curvature center position of the left surface, and a center position in the swing shaft center direction of the grindstone portion for the right surface is the right surface. The method for superfinishing a groove according to claim 1, wherein the position of the center of curvature substantially coincides with the position of the center of curvature. 3. By swinging left and right about the swing axis,
In a superfinishing whetstone for superfinishing both left and right sides of the groove, a left side whetstone for superfinishing the left side of the groove, and a right side whetstone for superfinishing the right side of the groove, The grindstone for the left side and the grindstone for the right side are arranged side by side in the state of being displaced in the swing axis direction, side by side. 4. A first dummy grindstone portion which is consumed without substantially contributing to superfinishing is provided on the right side of the left side grindstone, and a left side of the right side grindstone is substantially used for superfinishing. The superfinishing whetstone according to claim 3, further comprising a second dummy whetstone part that is consumed without contributing to the above. 5. The grindstone part for the left side and the grindstone part for the right side are integrated with each other.
The superfinishing whetstone described. 6. The grindstone for superfinishing according to claim 4, wherein the grindstone section for the left side and the grindstone section for the right side are integrally coupled by the first and second dummy grindstone sections. 7. The center position of the grindstone portion for the left surface in the swing axis direction substantially coincides with the center position of the curvature of the left surface, and the center position of the grindstone portion for the right surface in the swing axis direction is the right surface. The groove super-finishing method according to any one of claims 3 to 6, wherein the groove is formed so as to substantially coincide with the center position of the curvature.