JPH11123652A - Polishing tool with spherical concave surface, its manufacture, and polishing method using such tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a lap rod easily, by using a lathe processing mainly. SOLUTION: A raw material is turned in the form of a support part 33 having globular part 22 by an NC lathe or the like, and several lines of parallel grooves 34 are cut surrounding the globular part 22. A hole 35 passing the center of the globular part is opened square to the axial line of the holding part 33, the globular part is cut off, and a handle 23 separately prepared is pressed in or adhered to the hole of the globular part, so as to obtain a lap rod 21 having the handle to the globular part. Since the direction of the globular part is different 90 deg. from the turning time in this lap rod 21, an outline 31 with a good roundness which is important in the lap processing can be utilized. The parallel grooves 34 surrounding the globular part are made in a reservoir of lapping agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polishing tool and a polishing method for polishing a spherical concave surface in the manufacture of various tools and machines.

[0002]

2. Description of the Related Art As an example of a mechanical element using a spherical concave surface,
There is a spherical bearing as shown in FIG. This is achieved by connecting the spherical portion 2 at one end of the shaft 1 to the housing A (3) and the housing B
It is housed in the spherical space created by (4) and is supported via a number of balls 8 as rolling elements. The other end of the shaft 1 is a screw portion 1a for coupling to a structure (not shown), and parallel planes 1b are provided on both sides of an intermediate flange portion of the shaft 1 for engaging a screw tightening tool. The housing A (3) and the housing B (4) have spherical concave surfaces 5 and 6, respectively, and are joined together by a mating surface with a set screw 7 to form a spherical space.
The balls 8 are individually housed in pockets of shell-shaped retainers 9, 9 and are spaced from one another. The cages 9, 9 are divided into two by a plane passing through the center. With such a structure, the shaft 1 can be tilted in any direction up to a certain angle, can rotate around its axis, and the spherical portion 2 is rolled and supported by a large number of balls 8 in the housings A, B (3, 4). Therefore, the resistance received by the shaft 1 during operation can be reduced. The mounting screws are passed through the concentric through holes 10 and 11 provided in the housing A (3) and the housing B (4),
Secure the spherical bearing to the structure. An example of such a spherical bearing is found in JP-A-8-338422.

[0003] In the spherical bearing of FIG.
The spherical concave surfaces 5 and 6 of B (3, 4) are subjected to precision polishing such as lapping or superfinishing to increase dimensional accuracy and smooth the surface. The method is as shown in FIG. 3 and uses a wrapping bar 21. The wrapping bar 21 has a spherical portion 22 with a handle 23.
The spherical concave surface 25 is wrapped by pressing the wrapping rod as shown by the arrow 26 while rotating the workpiece 24 as shown by the arrow 27.
Depending on the structure of the lapping machine, the lap bar 21 is rotated around the axis of the handle 23 to swing the workpiece 24. In short, the lap bar 21 and the workpiece 24 are moved relative to each other as shown in FIG. Is performed.

[0004]

In order to improve the finishing accuracy in the above-mentioned polishing method, the shape of the lap bar 21 must be accurate. The lap bar 21 is formed by, for example, turning with a numerical control (NC) lathe. FIG. 4 shows this state, in which the left side is a front view of the lap bar 21 being cut by the cutting tool 28, and the right side is a side view of the spindle of the NC lathe as viewed in the axial direction. Wrap rod 21 from material
In order to cut out the spherical portion 22, the cutting tool 28 is fed in the X and Y directions in the figure to create a spherical outline.

[0005] However, after the hemisphere on the right side of the center line 29 of the spherical portion 22 is cut out by the cutting tool 28 in the figure, the left hemisphere cannot be cut by the same cutting tool. It is. Therefore, in order to cut the left side of the center line 29, a cutting tool having a shape symmetrical to the cutting tool 28 must be used. As described above, since the cutting of the spherical portion 22 is performed by switching between two types of cutting tools, the accuracy of the shape is difficult to be obtained. In particular, the shape of the cutting portion of the cutting by the both cutting tools near the center line 29 is easily deformed. It is difficult to increase the roundness of the contour 30.

Alternatively, instead of using a cutting tool as shown in FIG. 4, the cutting edge may be formed in a semicircular shape, a lateral clearance angle may be provided on both sides, and the cutting tool may be symmetrical. It is not impossible. But even then,
For example, consider a cutting in which a cutting tool is sent from the position in FIG. 4 downward and left to cut out the right hemisphere, and then moves to the left beyond the center line 29, and then a cutting tool is sent upward and to the left to cut the left hemisphere. On the right side, the cutting tool moves toward the near side in the Y direction, but moves beyond the center line 29 to the left side, and moves toward the far side in the Y direction. Even with a precision machine tool, there is a small amount of play in the guide section of the tool table and the feed screw. Is generated. Even if soft measures are taken to compensate for such errors,
It is difficult to completely eliminate the effects of play.

On the other hand, the spherical contour 31 appearing in the right-hand view of FIG. 4 is created by the rotation of the spindle, and therefore has much better roundness than the contour 30.
However, as can be seen with reference to FIG. 3, it is not the contour 31 with good roundness but the contour 30 with poor roundness that affects the finishing of the lapping.

[0008] The spherical portion 22 of the wrap rod 21 is
It is preferable to provide a groove or a depression on the surface as a lapping agent reservoir, rather than a spherical surface as described above. The lapping agent is a mixture of water or oil mixed with abrasive grains such as diamond powder. If a lapping agent reservoir is provided on the surface of the spherical portion 22 so that the lapping agent accumulates, the lapping can be performed on the polished surface during lapping. Good polishing can be performed over the agent. FIG.
In the lapping operation as described above, it is natural to provide a plurality of meridian grooves 32 when the spherical portion 22 of the lapping rod 21 is regarded as the earth as shown in FIG. Although it is effective to provide the concave portion, it is not preferable because the spherical portion 22 can be processed in such a way, but it takes time and makes the wrap bar expensive.
The present invention provides a wrap rod improved with respect to the above-mentioned matters,
It enables easy manufacture mainly by lathing.

[0009]

According to the present invention, first, NC
Using a lathe or the like, the material is turned into a shape with a spherical portion at the tip of the support portion, and several grooves are cut in parallel around the spherical portion. A hole is then drilled through the center of the bulb at right angles to the axis of the support. Then, the spherical portion is cut off from the support portion, and a separately prepared handle is press-fitted or adhered into the hole of the spherical portion to form a wrap stick having a handle on the spherical portion.

[0010] In the wrapping bar made in this manner, since the direction of the spherical portion with respect to the axis of the handle is rotated by 90 ° compared to the time of turning, the profile of the spherical portion is good in the direction important in lapping. Will have a perfect roundness. Further, the groove cut so as to surround the spherical portion becomes an effective lapping agent reservoir during wrapping.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are used for the same kind of parts and portions as in the above description. FIG. 1 shows a procedure for manufacturing a wrap bar according to the present invention. As shown in the front view on the left side of FIG. 3A, the shape in which the spherical portion 22 is attached to the support portion 33 is cut out from the material by an NC lathe. The figure on the right is a side view of the spindle of the lathe viewed in the axial direction. Then, a plurality of grooves 34 surrounding the spherical portion 22 are cut.

As described above with reference to FIG. 4, whether the cutting of the spherical portion 22 is performed by switching the cutting tool or by using only one cutting tool, the contour 30 of the spherical portion 22 in the front view has a very good roundness. Absent. However, the contour 31 in the right side view is obtained by rotating the spindle, and the roundness is sufficiently good.

Next, as shown in FIG.
A hole 35 passing through the center and perpendicular to the axis of the support portion 33 is formed in 2. According to the multi-function NC lathe, the rotation can be stopped while the workpiece is chucked to the spindle, and such drilling can be accurately performed. Then, the spherical portion 22 is cut off from the support portion 33 at a position 36.

Next, as shown in FIG. 1C, the handle 23 separately manufactured is fixed to the hole 35 of the separated spherical portion 22 by press-fitting or bonding. Thus, the wrap bar 21 having the handle 23 on the spherical portion 22 is completed.

As can be seen from the above description, FIG.
In the completed lap bar 21, the spherical portion 22 is rotated by 90 ° as compared with FIGS. 7A and 7B showing the turning state, and the contour 31 formed with good roundness by the rotation of the spindle. Is facing the front. 1A, each surface of the spherical portion 22 including each groove 34 is perpendicular to the axis of the support portion 33. However, in the completed lap rod 21 of FIG. Is parallel to the axis of the handle 23. This is different from the meridian arrangement as shown in FIG. 5, but conforms to this, and is effective as a lapping agent reservoir in the lapping operation of FIG.

In order to leave the maximum diameter of the spherical portion obtained by turning, it is desirable not to cut the groove 34 at the position of the maximum diameter of the spherical portion 22 in FIG. In the figure, the groove 3
Although the cross-section of V is V-shaped, the cross-sectional shape is not limited to this, and an arbitrary shape such as a semicircle or a square can be used.

[0017]

As described above, the spherical portion obtained by turning has a non-uniform roundness depending on the direction. However, the wrapping rod of the present invention provides a spherical portion having good circularity in a direction useful for lapping. And cannot be obtained by simply turning a wrapped bar with a handle on the spherical part. Also, the grooves provided on the surface of the spherical part are shaped and arranged effectively as a lapping agent reservoir, and if the spherical concave surface is polished using a lapping rod with such characteristics, a highly accurate finish can be obtained. It contributes to improving the performance and extending the life of machines and equipment.

[Brief description of the drawings]

FIG. 1 is a view showing a polishing tool according to the present invention and a manufacturing procedure thereof.

FIG. 2 is a sectional view of a spherical bearing.

FIG. 3 is a view showing a method of polishing a spherical concave surface of a workpiece by a polishing tool.

FIG. 4 is a view showing a production state of the polishing tool of FIG. 3;

FIG. 5 is a view showing an example in which a groove is provided in the polishing tool of FIG. 3;

[Explanation of symbols]

 2, 22 Spherical part 3 Housing A 4 Housing B 5, 6, 25 Spherical concave surface 8 Ball 21 Lapping rod 23 Pattern 24 Workpiece 28 Byte 32, 34 Groove 33 Supporting part

Claims (3)

[Claims] 1. A shape having a handle on a spherical portion, a plurality of grooves surrounding the spherical portion, and cross sections of the spherical portion along each groove are parallel to each other and to the axis of the handle. A polishing tool with a spherical concave surface characterized by the following. 2. The method for producing a spherical concave polishing tool according to claim 1, wherein a supporting portion is provided and a spherical portion and a plurality of parallel grooves surrounding the spherical portion are cut out by turning. Making a hole perpendicular to the axis of the support portion through the center, separating the spherical portion from the support portion, and fixing a separate handle to the hole of the spherical portion, a method for manufacturing a polishing tool having a spherical concave surface, . 3. A spherical concave surface characterized in that a lapping agent is applied to the spherical concave polishing tool according to claim 1 so as to abut against the spherical concave surface of the workpiece, and the polishing tool and the workpiece are relatively moved. Polishing method.