JPH0241867A - Sphere polishing device - Google Patents

Abstract

PURPOSE:To polish a sphere with good efficiency and to increase the sphericity thereof by rotating the driving lap with holding the sphere to be polished in a lap liquid among the driving lap, a pressurizing lap and guide ring. CONSTITUTION:A pressurizing lap 3 is pressed via a buffer member 7 by a pressurizing means 4 and the sphere 2 to be polished is pressed to a driving lap 1 thereby. The sphere 2 is rolled in a lap liquid by the rotation of the driving lap 1, the movement direction of this sphere 2 is constrained in a circular shape by a guide ring 5 as well and the sphere 2 is subjected to polishing with high sphericity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ball polishing device that polishes balls with high polishing efficiency and precision. This invention relates to a sphere polishing device that can polish with high polishing efficiency and sphericity, and is particularly suitable for polishing spheres used in ball bearings and the like.

[Conventional technology] Ball polishing has conventionally been used to polish spheres such as ball hair rings, especially spheres that require high precision such as ceramic ball bearings essential for jet engines and vacuum equipment bearings, with high polishing efficiency. As an example, a device using a magnetic fluid is known, as shown in FIG. 4, for example.

As shown in the figure, this ball polishing device rotates a driving lap 1 while holding a ball 2 to be polished between a guide ring 5, a float 19, and a driving lap 1 in a magnetic fluid 18 containing abrasive grains. It is used for polishing. During polishing, the float 19 receives a levitation force together with the magnetic fluid 18 by the magnet 20 provided at the lower part of the guide ring 5. Therefore, due to the rotation of the drive wrap 1, the float 1
The ball 2 to be polished, which is orbiting on the surface of the drive lap 1, is moved by the float 19 to the contact surface 10 of the lower end of the drive lap 1 with an appropriate processing pressure.
be forced to. Further, the float 19 also rotates due to the rolling of the ball 2 to be polished.

[Problems to be Solved by the Invention] However, although such conventional techniques are excellent in terms of polishing efficiency and polishing precision, they have the disadvantage that the magnetic fluid used is expensive. Another aspect of magnetic fluids is that they are difficult to handle.

In view of the problems of the prior art, an object of the present invention is to
The object of the present invention is to provide a ball polishing device that can achieve the above-mentioned high precision and efficiency without using magnetic fluid.

[Means for Solving the Problems] FIG. 1 is a sectional view showing an example of a ball polishing apparatus of the present invention.

In order to achieve the above object, the present invention includes, as shown in the figure, a rotatable driving lap 1, a pressurizing lap 3 that contacts the ball to be polished 2 and presses it against the driving lap 1,
a pressing means 4 applying force to the pressing lap 3 so that the pressing lap 3 presses the ball 2 to be polished against the driving lap 1;
The drive lap 1, the pressurized lap 3, and the guide ring 5 are provided with a guide ring 5 that circularly restrains the movement direction of the ball 2 to be polished which rolls due to the rotation of the drive lap 1. Polishing is carried out by rotating the driving lap 1 while holding it by the holder.

Preferably, the pressure means 4 comprises a buffer member 7 via which force is transmitted to the pressure wrap 3.

Furthermore, FIGS. 2 and 3 are cross-sectional views showing other examples of the pressurizing means 4. As shown in FIG. 2, the pressurizing means 4 is
In some cases, a thrust bearing 8 is provided, through which a force is applied to the pressure wrap 3 so that the pressure wrap 3 can rotate. Further, as shown in FIG. 3, a pressure wrap rotation means 9 for rotating the pressure wrap 3 may be provided so that the pressure wrap 3 can be forcibly rotated.

The drive wrap 1 of FIG. 1 is capable of horizontal rotation about a vertical axis and has a tapered contact surface 10 at its lower end. During polishing, the ball 2 to be polished is placed on this contact surface 10.
contact and roll it. Further, since the driving lap t is worn out by polishing the ball 2 to be polished, it can also be moved up and down so that it can be lowered accordingly.

The contact surface 10 plays an important role in holding the ball 2 to be polished on a circular orbit between the pressure lap 3 and the inner wall surface of the guide ring 5, and for stable and smooth rotational polishing.
Contributes to improving the sphericity of the sphere. The inclination angle E of the contact surface 10 with respect to the vertical direction is preferably 20 to 80 degrees. If the angle exceeds 80 degrees, the force pressing the ball 2 to be polished against the inner wall surface of the guide ring 5 will be weakened, and if the angle is less than 20 degrees, the processing pressure will not be effectively applied to the ball 2 to be polished from the contact surface 10. In each case, the motion of the polished ball 2 becomes unstable and the sphericity does not improve.

The material of the yiAfflIII wrap 1 is not particularly limited in the case of rough polishing, and for example, 5LJ3304.
Examples include metals such as stainless steel, brass, and aluminum, and in the case of finishing, brittle materials such as cast iron, ceramics, and resin are preferred.

The inner wall surface of the guide ring 5 is preferably lined with rubber, resin, or the like to suppress vibration of the guide ring.

As the material of the pressure wrap 3, various materials such as metal, plastic, ceramics, rubber, etc. can be appropriately selected and used.

The lap liquid 6 usually contains abrasive grains, such as AIL20s (corundum), 5i
Known polishing abrasive grains such as C (silicon carbide: carborundum) and diamond can be appropriately selected and used. Further, instead of including such abrasive grains in the lapping liquid 6, they may be used by being fixed to the contact surface 1o at the lower end of the drive lap 1.

The guide ring 5 is normally attached to the pressure wrap 3 via an 0 (O) ring 11, and the guide ring 5
A lap liquid 6 containing abrasive grains is stored by the pressurized lap 3 and the pressurized lap 3. When the abrasive grains are crushed during polishing and the polishing efficiency is reduced, the lapping liquid is discharged through the drain port 12 provided in the guide ring 5 and replaced.

Also, a magnetic fluid seal can be used instead of the O-ring. In this case, for example, a permanent magnet, an electromagnet, etc. is provided on the inner wall of the guide ring 5 facing the side surface of the pressure wrap 3, and the generated magnetic field causes the pressure wrap to
A magnetic fluid seal is formed between the guide ring 5 and the guide ring 5. According to this method, the lower end of the guide ring 5 is wrapped around the pressure wrap 3.
By raising the lap liquid 6 above the upper surface level, the lap liquid 6 can be quickly drained and replaced. ! When a magnet is used, the lap liquid 6 can be discharged from between the pressure wrap 3 and the guide ring 5 by stopping the current and releasing the magnetic fluid seal. Note that this magnetic fluid seal can also be applied to a ball polishing device in which the contact surface 10 is provided horizontally, substantially facing the upper surface of the pressure lap, as shown in FIG. Customer equipment 15
A magnet 16 is provided on the inner wall of the container, thereby forming a l111 fluid seal 17 between the inner wall and the pressure wrap 3, which serves the same function as described above as the outer container 15 moves up and down.

The pressurizing means 4 may include a cylinder-piston mechanism using a fluid such as oil, water, or air as a pressure transmission medium, a mechanism utilizing the buoyancy of water, a mechanism using an elastic body such as a spring, or a mechanism using other dead weight systems. etc. can be used. In particular, an air cylinder is preferable because it also acts as a buffer means. An example of a device that utilizes the buoyancy of water is a structure in which a float is connected to the bottom of the pressure wrap 3 via vertical guidance and is positioned underwater. The dead weight method is one in which the pressure wrap 3 is pressed against the drive wrap 1 with a constant load, for example, a mechanism using rollers and lobes, or a weight applied by applying the lever principle. Mechanisms such as this can be used.

Although a rubber plate or the like can be used as the buffer member 7, it is preferably provided directly below the pressure wrap 3 in order to improve the response when absorbing the impact caused by the convex portion of the ball 2 to be polished.

As the thrust bearing 8, for example, a ball bearing type is preferable because of its low frictional resistance.

The pressurized wrap rotation means 9 is, for example, as shown in FIG.
It includes a drive shaft 13 that transmits rotational driving force to the pressure wrap 3, and a drive means (not shown) that rotates the drive shaft 13. In this case, as the driving portion of the pressurizing means 4, for example, two or three wooden air cylinders 14 can be used, as shown in the figure.

[Function] In the ball polishing apparatus of the present invention, the pressure lap 3 is raised by the pressure means 4 in the lap liquid 6, and the ball 2 to be polished is raised.
The upper surface of the pressure wrap 3, the contact surface 1 of the lower end of the drive wrap 1
0 and the inner wall surface of the guide ring 5. and,
IfJ, by driving the dynamic lap 1 and rotating it in the horizontal direction, the rotational motion is transmitted to the ball 2 to be polished. As a result, the ball 2 to be polished rolls on a circular orbit in the lapping liquid 6. In this manner, relative movement occurs between the ball to be polished 2 and the lapping liquid 6, so that polishing occurs on the surface where the ball to be polished 2 is held, particularly on the tapered contact surface 10 at the lower end of the driving lap 1. It is done efficiently.

During this polishing, especially when the sphere to be polished 2 is a rough sphere in the initial stage of polishing, stress concentration on the convex portion is significant.
Severe surface damage is likely to occur due to impact, but such impact is particularly effectively absorbed by the loose member 7. Therefore, there is no need to reduce the pressure applied by the pressurizing means 4 or the rotational speed of the drive lap 1, and as a result, polishing is performed with high efficiency.

Furthermore, when the thrust bearing 8 is provided, the pressure lap 3 rotates due to the frictional force received from the moving ball 2 to be polished, thereby improving polishing accuracy. - Even when the pressurized lap driving means 9 is provided, polishing can be performed with high accuracy and similar effects.

[Example code] The present invention will be explained in detail below.

Example 1 A test was conducted using a polishing device having the cross-sectional shape shown in FIG. Drive wrap is stainless steel (SUS304)
The diameter is 30mm and the height is 30mm.

The wrap angle (#oblique angle) E is 45°. The inner diameter of the guide ring was 37 mm, and the inner wall of the guide ring was lined with urethane rubber at the portion that came into contact with the spherical object to be polished. GC#400 is used as the polishing abrasive grain. In addition, the upper surface of the pressure wrap is made of acrylic and has a diameter of 35 mm, and instead of providing a buffer member, an air cylinder that also has a buffer effect is used as the pressure means, and the pressure load is 500 g.
Adjust so that

Using this device, the diameter was 7.7 mm and the sphericity was 20 μm.
Eleven silicon nitride (S 13NJ ) bare balls were polished by rotating a driving lap at 9000 r, p, m for 40 minutes.

The sphericity of the resulting sphere was 2.0 μm, and the polishing rate was 2.5 μm/min.

The same ball to be polished was polished using the same equipment and conditions as in Example 1, except that a thrust ball hair ring was further provided to enable the pressurized wrap to rotate.

As a result, a sphere with a sphericity of 1.5 μm was obtained, and the polishing rate was 2
．． It was 2 μm/mi.

Comparative Example 1 Pressurizing wrap, pressurizing means, and fourth wrap liquid
As shown in the figure, a flat float, a magnet, and a magnetic fluid (W
A ball to be polished was polished in the same manner as in Example 1 using the same apparatus and conditions, except that the ball was used.

As a result, the sphericity of the obtained sphere was 17 μm, and the polishing rate was 1.9 μm/min.

As mentioned above, the results of Examples 1 and 2 show almost the same results as those of Comparative Example 1, and the use of the air cylinder and Ni street material has the same sphericity and sphericity as when using magnetic fluid. It can be seen that this is effective in obtaining polishing efficiency. In particular, it can be seen that the use of thrust bearings contributes to high sphericity.

[Effects of the Invention] As explained above, according to the present invention, polishing efficiency and sphericity can be improved by using a buffer member, an air cylinder, and a thrust bearing. Therefore, even with a pressurizing means such as an air cylinder that does not use magnetic fluid, it is possible to achieve polishing efficiency and sphericity equivalent to those using magnetic fluid, which is expensive and inconvenient to handle.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a ball polishing device according to an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views showing other examples of pressurizing means of the device in FIG. 1, and FIG. 1 is a cross-sectional view illustrating a ball polishing device to which a tn fluid seal is applied, and FIG. 5 is a cross-sectional view of a conventional ball polishing device. 1: 2: 3: 4: 5; 6; 7: 8: Drive lap, ball to be polished, pressure lap, pressure means, guide ring, lapping liquid containing abrasive grains, buffer material, thrust bearing, pressure Wrap rotation means, : contact surface, : sealing material, : drain opening, : drive shaft. Figure

Claims (1)

[Claims] 1. A rotatable driving lap, a pressure lap that contacts the ball to be polished and presses it against the driving lap, and the pressure lap presses the ball to be polished against the driving lap. It is equipped with a pressure means that applies force to the pressurized lap in a pressing manner, and a guide ring that restrains the movement direction of the ball to be polished, which rolls due to the rotation of the driving lap, in a circular manner, and the ball to be polished is placed in the lapping liquid. A ball polishing device characterized in that polishing is carried out by rotating the driving lap while holding it between the driving lap, the pressure lap, and the guide ring. 2. A rotatable drive wrap, a pressure wrap that contacts the ball to be polished and presses it against the drive wrap, and a pressure wrap that presses the ball to be polished against the drive wrap. It includes a pressurizing means that applies force to the lap, and a guide ring that circularly restrains the movement direction of the ball to be polished that rolls due to the rotation of the driving lap, and the ball to be polished is moved into the driving lap in the lapping liquid. , a ball polishing device that polishes by rotating the driving lap while being held between a pressure lap and a guide ring, the pressurizing means includes a buffer member,
A ball polishing device characterized in that a force is applied to the pressure lap through this. 3. A rotatable drive wrap, a pressure wrap that contacts the ball to be polished and presses it against the drive wrap, and a pressure wrap that presses the ball to be polished against the drive wrap. It is equipped with a pressurizing means that applies force to the lap, and a guide ring that restrains the movement direction of the ball to be polished, which rolls in a circular manner due to the rotation of the driving lap, and the ball to be polished is moved in the lapping liquid by the driving lap and the guide ring. In a ball polishing device that polishes by rotating the drive lap while being held between a pressure lap and a guide ring, the pressure means includes a thrust bearing and applies force to the pressure lap through the thrust bearing. Features of ball polishing equipment.