JPS59169761A - Super-finishing method for ball bearing track surface and device thereof - Google Patents

Abstract

PURPOSE:To improve processing precision, by a method wherein a grindstone pressurizing cylinder is located coaxially with a grinding swing shaft, a piston is operated in the direction of the swing axis of a grindstone and the working force is converted in a right-angled direction through the working of a link mechanism. CONSTITUTION:A grindstone 10, pressed against a track surface R of a rotating workpiece W, carries out a super-finishing work as it swings around the center of curvature of the track surface R. In which case, a grindstone pressurizing cylinder 11 is mounted coaxially with the axis center part of a grindstone swing shaft 13 provided at its forward end with a grindstone holder 12, the working force of a piston 14 is converted in a right-angled direction through the working of a link mechanism 16, and the grindstone 10 is pressurized through the medium of a pressurizing lever 15. This permits increasing of the swing speed of the grindstone, reduces production of vibration caused by swing, and enables manufacture of a ball bearing with high precision. Further, this allows a device to be miniaturized and to be produced compactly.

Description

[Detailed Description of the Invention] The invention provides a method and apparatus for superfinishing a ball bearing raceway surface,
In particular, it relates to improvements in the pressure means for superfinishing grindstones.

BACKGROUND ART Conventionally, a ball bearing raceway surface superfinishing device described in Japanese Utility Model Publication No. 46-1496 or a superfinishing device as shown in FIGS. 1 and 2 have been known. In both of these, a cylinder 2 of a pressurizing device that presses the grindstone 1 against the raceway surface of the workpiece W is arranged perpendicular to the axis of the grindstone swing shaft 3, and the grindstone 1 is pressed via a lever 4. It is.

The workpiece W is rotated by a rotating device (not shown),
The grinding wheel 1 has a center of curvature 0 of the raceway surface of the workpiece W and a center of curvature of the workpiece W.
On a plane passing through the rotational axis OW, the oscillating motion is performed within an angle β around the center of curvature 0, that is, the axis of the grindstone oscillating shaft 3.

On the other hand, in recent years, precision requirements for ball bearings have become increasingly severe, and the conventional superfinishing methods described above are no longer able to meet these requirements satisfactorily.

In other words, according to the conventional method described above, since the grinding wheel pressure cylinder is arranged upright on the grinding wheel swing axis, the centrifugal force and inertia caused by changes in the angular velocity of the grinding wheel swing axis have a large influence. The force applied to the grinding wheel on the workpiece raceway surface fluctuates.

Due to changes in the length of the grinding wheel due to wear of the grinding wheel,
The position of the piston of the pressure cylinder that pressurizes the grindstone changes with respect to the center of the swing axis, and as the centrifugal force and inertia change, the grindstone pressing force also changes.

Therefore, there is a certain limit to the swinging speed, and there is a drawback that highly accurate machining cannot be performed.

This invention eliminates the above-mentioned conventional drawbacks, enables the rocking motion at a much higher speed than the conventional one, eliminates fluctuations in the grinding wheel pressure, and dramatically improves the machining accuracy in the superfinishing process. The purpose of this invention is to achieve improvements in performance and miniaturization of superfinishing equipment.

In this invention, a grindstone pressure cylinder is arranged coaxially with a grindstone swinging wheel so that their axes substantially coincide with each other, a piston of the grindstone pressure cylinder is operated in the axial direction of the grindstone swinging shaft, and this acting force is applied. The shaft is characterized in that the shaft is transformed into a direction perpendicular to the axis through a link mechanism or the like.

The present invention will be described in detail below with reference to the illustrated embodiments.

In FIGS. 3 and 4, the raceway surface R of the workpiece W is rotated around the rotation axis Ow by a rotating device (not shown).
In a device in which superfinishing is performed while the grinding wheel 10 pressed against the grinding wheel is oscillated with a rotary wheel with the center of curvature 0 on a plane passing through the center of curvature ○ of the raceway surface R and the rotational axis OW of the workpiece W, A whetstone pressure cylinder 11 is coaxially provided at the center of a whetstone swing shaft 13 having a whetstone holder 12 at its tip, and its piston 14
is configured to operate in the axial direction of the grindstone swing shaft 13.

The grindstone holder 12 is provided with a pressurizing lever 15 that slides in a direction perpendicular to the axis of the grindstone swing shaft 13, and a link 16 is pivotally attached to the grindstone holder 12, and one end of the link 16 is connected to the piston rod 1.
7, and the other end is connected to the pressure lever 15.
is connected to convert the operating force of the grindstone pressurizing cylinder 11 into the right angle direction and pressurize the grindstone 10.

In the figure, 20 is a return spring of the piston 14, 21 is a holder that swingably supports the whetstone swing shaft 13f via a bearing 22, 23 is a pressure lever guide provided on the whetstone holder 12, and 24 is a pressure oil or air It is a supply pipe.

Note that the axes of the whetstone pressurizing cylinder 11 and the whetstone swing shaft 13 do not necessarily have to coincide, and may be arranged so that their axes substantially coincide.

Since this invention has the above-described configuration, the effect of centrifugal force due to the arrangement of the grindstone pressurizing cylinder during the swing of the grindstone swing axis about the center of curvature of the raceway surface is zero or can be ignored. At the same time, the magnitude of inertia and its fluctuations due to changes in the angular velocity of the whetstone rocking axis have been significantly reduced, and the fluctuations in the grinding wheel pressure force due to conventional centrifugal force and inertia have almost disappeared. The pressure becomes zero or close to zero, making the pressurizing force much more stable than in the past.

Furthermore, even if the position of the piston of the grindstone pressurizing cylinder changes due to wear of the grindstone, the change occurs in the axial direction of the grindstone rocking shaft, so there is no effect on the centrifugal force and inertia.

Therefore, according to this invention, it is possible to significantly increase the rocking speed of the grinding wheel compared to the conventional method, and there is less vibration caused by the rocking, which is sufficient to meet the demands for higher precision of ball bearings. Furthermore, by providing the grindstone pressure cylinder coaxially with the grindstone swing axis, the device can be made smaller and more compact.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a cross-sectional side view of the conventional device taken along the line I-I in Fig. 2, Fig. 2 is a longitudinal sectional front view taken along the [-II line] of Fig. 1, and Fig. 3 is the present invention. FIG. 4 is a cross-sectional side view taken along the line ■--■ of the embodiment, and FIG. 4 is a vertical cross-sectional front view taken along the line ■--■ in FIG. W...workpiece, R...raceway surface, 0...center of curvature,
Ow...Rotation axis of workpiece, 10...Wheelstone, 11.
... Grinding wheel pressure cylinder, 13... Grinding wheel swing axis, 15.
...Pressure lever, 16...Link applicant Koyo Seiko Co., Ltd. 9-

Claims (1)

[Claims] (1) Superfinishing of the ball bearing raceway surface by swinging a grindstone pressed against the raceway surface of a rotating workpiece around the center of curvature on a plane passing through the center of curvature of the raceway surface and the rotational axis of the workpiece. The grindstone pressurizing cylinder is actuated in the axial direction at the center of the grindstone swing axis, and the operating force is converted into a direction perpendicular to the grindstone swing axis to pressurize the grindstone toward the raceway surface. (2) A pressure cylinder for pressing a grindstone against the raceway surface of a rotating workpiece, and the center of curvature on a plane passing through the center of curvature of the raceway surface and the axis of rotation of the workpiece. In a ball bearing raceway superfinishing device equipped with a whetstone rocking shaft for rocking the whetstone, the pressurizing cylinder is arranged such that its operating axis is located at the center of the whetstone rocking shaft. A pressurizing lever and a pressurizing cylinder, which are provided on the whetstone swing shaft and are slidably provided on the whetstone swing shaft in a direction orthogonal to the axis, are connected via a link pivoted at an appropriate position on the whetstone swing shaft. A superfinishing device for a ball bearing raceway surface, characterized in that the grinding wheel is connected to enable transmission of operating force and pressurizes the grindstone toward the raceway surface.