JP2001260009A - Polishing device for spherical body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device for spherical bodies, having a machining pressure adjusting mechanism stable in a case where an elastic polishing pad is used as a tool and having high precision and small surface roughness. SOLUTION: The polishing device is provided with a position control means 12 for position-controlling a distance of a tool unit 2 for pinching and machining spherical bodies 10 as work pieces. In a case where elastic polishing pads 7 having low rigidity are used as polishing tools for the spherical bodies 10, elastic restoring force of the tools is effectively used to make high-precise machining for the spherical bodies possible without the effect of a change of the number of the spherical bodies 10 between the tools on machining pressure to be applied to individual spherical bodies 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball polishing apparatus used as a rolling element such as a ball bearing.

[0002]

2. Description of the Related Art Conventionally, for example, as a device for polishing the surface of a sphere used as a rolling element in a ball bearing or the like, a ball polishing device 40 (shown in FIG. 3) disclosed in Japanese Utility Model Laid-Open No. 54-164189 has been disclosed. ) Or a polishing apparatus disclosed in JP-A-47-8599.

[0003] The polishing apparatuses exemplified in these figures are both shown in FIG.
Are provided. This work unit
62 is a turntable 63 rotatably provided around the axis Pa1.
And a fixed platen 64 arranged opposite to the rotary plate 63,
Driving means 65 for rotating the rotating disk 63;
There is provided a pressing means 66 for pressing the rotary member 63 toward the rotary disk 63 along the axis Pa2, and a working fluid supply means 68.

The pressing means 66 conventionally uses a hydraulic or pneumatic cylinder and presses at a constant pressure. Turntable 63
The axes Pa1 and Pa2 of the fixed plate 64 and the fixed plate 64 are provided at positions coaxial with each other, and at least one of the surfaces 63a and 64a facing each other has a recess having a cross section formed in an arc shape or a V shape. A groove 71 is formed. The groove 71 has an axis P
It is formed in an annular shape around a1 and Pa2.

The work unit 62 holds the sphere 70 in the groove 71, that is, with the sphere 70 sandwiched between the rotating disk 63 and the fixed disk 64, and presses the fixed disk 64 by the pressing means 66.
The surface of the sphere 70 is polished while being pressed at a constant pressure and rotating the turntable 63 using the driving means 65.

[0006] Recently, the polishing accuracy and dimensional accuracy of the spherical body 70,
In the case where the surface roughness is improved more than before or the material of the sphere 70 is a brittle material such as a silicon sphere used for forming a semiconductor circuit or a nonmetallic ceramic, the rotating disk 63 and the fixed disk 64 include In addition to a highly rigid grindstone such as a resin bond, a vitrified bond, and a metal bond, a polishing pad using an elastic body such as a resin such as polyurethane or a rubber-like polishing plate is used. Rubber-like polishing plates and polishing pads are suitable for polishing brittle materials because the elastic body absorbs impact.

[0007]

However, in the conventional polishing apparatus, since a hydraulic or pneumatic cylinder is used as a driving source as the pressing means 66, it is a so-called pressure control processing.
The processing conditions were determined by changing the pressure. This pressure control process is suitable when a highly rigid grindstone is used, but is not suitable for an elastic polishing pad or a rubber-like polishing plate.

For example, conventional pressure control processing (constant pressure)
When a low-rigidity elastic polishing pad, rubber-like polishing plate, or the like is used as a tool, when the pressing force starts to be applied, the tool interval is narrowed, and the sphere 70 to be sandwiched enters the tool surface. The amount of sinking (holding of the tool by the sphere) is determined by the number of spheres 70 as the workpiece between the rotary plate 63 and the fixed plate 64 as well as the pressing force. FIG. 5 is a schematic diagram showing this. P is a pressing force, that is, a processing pressure (constant pressure), and q is a processing pressure, and a reaction force (= one sphere) generated by a distortion representing a tool holding margin generated on a tool side of a portion where the sphere 70 contacts the tool side. (Processing pressure applied). That is, in FIG. 5B, q schematically represents a reaction force distribution applied to one sphere, and the sum (integral value) thereof is q. When there are n spheres 70 between the rotating plate 63 and the fixed plate 64 which are tools, there is a relation of P = n · q.

That is, the tool holding of the sphere 70 increases in proportion to the pressing force, and decreases in inverse proportion to the number of spheres existing between the tools. Therefore, depending on the balance between the pressing force and the number of spheres, the tool interval is reduced, and eventually the rotating disk 63 and the fixed disk 64 come into close contact with each other, making it impossible to perform machining. The processing pressure applied to one piece also changes. In other words, when an elastic body having low rigidity is used as a tool, when processing is performed with a constant pressing force P,
Since the influence of the change in the number of spheres existing between the sphere 70 and the fixed platen 64 cannot be ignored as a cause of the above-described problem, it is very difficult to provide the sphere 70 with stable processing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is an object of the present invention to effectively utilize the elastic restoring force of a polishing pad when polishing a sphere with an elastic polishing pad. Another object of the present invention is to provide a polishing apparatus for a sphere that can be easily processed and that can be uniformly processed without being affected by a change in the number of spheres to be processed.

[0011]

In order to achieve the above object, the present invention comprises a rotating disk rotating about an axis and a fixed disk disposed opposite to the rotating disk. In a polishing apparatus for polishing the surface of the sphere by interposing a sphere between the fixed plate and rotating the rotating plate around the axis, at least one of the surfaces of the rotating plate and the fixed plate facing each other, A polishing pad provided with elasticity for polishing the surface of the sphere, and a position for controlling the distance between the rotary plate and the fixed platen and adjusting the amount of elastic deformation of the polishing pad when the sphere is sandwiched between the two. And control means.

According to the above configuration, the position control means
The fixed plate is fixed at a position where the fixed plate is advanced in the direction of the turntable by the amount of elastic deformation of the polishing pad that applies an appropriate processing pressure to the sphere. In such a state, the sphere rolls under a constant processing pressure determined by the positioning control between the polishing pad attached to the rotating disk and the polishing pad attached to the fixed disk, and the polishing liquid The polishing pad stably mirror-finishes the surface.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment, and a polishing apparatus 1
Has a work unit 2. The work unit 2 includes a rotary plate 3, a fixed plate 4, a drive unit 5, a position control unit 12, an elastic polishing pad 7, and a working liquid supply unit 8, and is used for a semiconductor circuit of a brittle material, for example. This is an apparatus for polishing the surface of a spherical body 10 made of silicon spheres, ceramics, or the like. The polishing pad 7, for example, is formed by compressing a resin such as polyurethane into a fibrous form, and forming it into a felt form, a fibrous form, or a similar resin molded into a porous form. .

The turntable 3 has a flat surface 3a formed flat. The flat surface 3a has a round planar shape. The turntable 3 is provided rotatably about an axis P1 orthogonal to the flat surface 3a.

The fixed platen 4 has a flat surface 4a formed on a flat surface.
It has. The flat surface 4a has a round surface. The fixed platen 4 is arranged such that its flat surface 4a is opposed to the flat surface 3a of the turntable 3. The fixed platen 4 is guided by guide means (not shown) so as to be movable only in a direction along an axis P2 coaxial with the axis P1.

The rotary platen 3 and the fixed platen 4 are arranged such that their flat surfaces 3a, 4a are parallel to each other.
The flat surfaces 3a and 4a are surfaces of the rotating plate 3 and the fixed plate 4 that face each other. Although a rolling guide bearing is used as the guide means, it may be used for a sliding guide bearing or a hydrostatic guide bearing using oil or the like.

The driving means 5 rotates the rotating disk 3 about the axis P1. The driving means 5 drives the rotation of the motor and its rotating shaft directly or in combination with, for example, a bell and a pulley, or a reduction mechanism comprising a gear or the like. The rotating disk 3 is rotated via a transmission mechanism such as described above. The position control means 12 for holding the fixed platen 4 includes a drive motor 12c that can be rotated forward and backward, a ball screw 12a that is arranged in parallel with the axis P1 and is rotated by the drive motor 12c, and a number of unillustrated ball screws 12a. A nut 12b screwed through a ball, and the nut 12b is caused to stroke by rotation of the ball screw 12b. A connecting member 13 is provided on the nut 12b, and the connecting member 13
The fixed platen 4 is connected to the fixed platen 4 so that the fixed platen 4 can be moved toward the rotating platen 3 along the axis P2 to be adjusted and controlled to an arbitrary position.

The control by the position control means 12 is performed so that the polishing pad 7 gives an appropriate and appropriate working pressure to the sphere 10 as an elastic deformation amount, that is, a tool holding amount. That is, the support system for positioning the tool position by the drive motor 12c, the ball screw 12a and the nut 12b has sufficient mechanical rigidity to receive the processing reaction force generated in the machining unit 2. Further, the guide means has sufficient mechanical rigidity against a moment load acting to incline the fixed platen 4 with respect to the axis P2 due to the processing reaction force, so that such an inclination is prevented. I have.

The polishing pad 7 is attached to the flat surface 3a of the rotating disk 3 and the flat surface 4a of the fixed disk 4, for example. It has a plurality of grooves 11 formed concavely from each surface 7a. The concave groove 11 of the polishing pad 7 attached to the flat surface 3a of the turntable 3 and the concave groove 11 of the polishing pad 7 attached to the flat surface 4a of the fixed disk 4 are opposed to each other and coincide with each other. Are located in

Each of the concave grooves 11 has an arc-shaped or V-shaped cross section. Each groove 11
Is formed in an annular shape around the axes P1 and P2 in the flat surfaces 3a and 4a. The concave groove 11 of the polishing pad 7 affixed to the flat surface 3a of the turntable 3 and the concave groove 11 of the polishing pad 7 affixed to the flat surface 4a of the fixed disk 4 It is designed to be sandwiched.

When the ball screw 12a is rotated by driving the drive motor 12c of the position control means 12 and the nut 12b is moved to the left in the figure, the fixed plate 4 is moved in the same direction via the connecting member 12. That is, the fixed platen 4 is fixed at a position advanced in the direction of the rotary platen 3 by the amount of elastic deformation of the polishing pad 7 that applies an appropriate processing pressure to the sphere 10. In such a state, the sphere 10 is moved at a constant processing pressure determined by the positioning control in the concave groove 11 between the polishing pad 7 attached to the rotating plate 3 and the polishing pad 7 attached to the fixed plate 4. Rolling downward, the surface is stably mirror-finished by the working liquid and the polishing pad 7.

FIG. 2 shows a second embodiment, in which the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

The polishing apparatus 1 of the present embodiment comprises a position control means 1
This shows a form in which the conventional polishing apparatus is easily improved by combining the use of the pressing means 6 with a pressing means 6 such as a hydraulic cylinder. The position control means 12 in the present embodiment includes a ball screw 12a, a nut 12b, a drive motor 12c, and a stopper block 12d attached to the nut 12b. Fixed board 4
Is fixed to the extension block 4b.
The stopper block 12d is pressed against b in the direction opposite to the pressing direction.

The pressing plate 6 allows the fixed platen 4 of the tool unit 2
Thus, the polishing pad 7 attached to the fixed platen 4 is constantly pressed toward the polishing pad 7 attached to the rotating plate 3 in a direction to reduce the tool interval. The pressing force is the polishing pad
7 is a force that can sufficiently oppose the processing reaction force generated when the sphere 10 is sandwiched and is not pushed back. Then, the tool interval is restricted by the stopper system of the position control means 12, and the position can be controlled in a form opposing the pressing force.

Therefore, similarly to the first embodiment, the sphere 10
Is rolled under the constant processing pressure determined by the positioning control in the concave groove 11 between the polishing pad 7 attached to the rotating plate 3 and the polishing pad 7 attached to the fixed plate 4. The surface is stably mirror-finished by the working liquid and the polishing pad 7.

Here, the stopper system has sufficient rigidity to receive the pressing force and control the position. The guide means (not shown) has sufficient mechanical rigidity against a moment load acting to incline the fixed platen 4 with respect to the axis P2. In addition, since the stopper system receives a pressing force only in a fixed axial direction at the ball screw 12a to be position-controlled, it does not matter whether there is a gap or play between the ball screw 12a and the nut 12b. Therefore, the gap and the play can be offset by the pressing force. Therefore, if a necessary rigidity can be obtained without using a high-grade ball screw, it can be replaced with a general screw shaft and nut.

The position control means in each of the above embodiments is not limited to position control using a ball screw and a nut.
The motor may be driven by a rack, a pinion, and a linear motor, and the device used for driving is not limited.

[0029]

As described above, according to the present invention, since the position of the rotating plate and the fixed plate is mechanically controlled to be constant, when a polishing pad having elasticity is used, a spherical body is sandwiched. It has a mechanism that can always keep the amount of elastic deformation constant. Thereby, the processing pressure applied to the sphere as the workpiece can be controlled only by the position, and the processing pressure applied to one sphere as the workpiece can be kept constant. That is, even if the number of spheres inside the processing unit fluctuates,
No change in processing pressure per piece occurs. Therefore, a spherical polishing apparatus having a stable processing pressure adjusting mechanism when a polishing pad is used as a tool can be put to practical use.

In addition, by using a polishing pad having such elasticity as a tool, the surface roughness of a spherical body such as a silicon sphere or a ceramic used for a semiconductor circuit made of a brittle material can be adjusted with high precision and surface roughness. Center line average roughness Ra
In other words, processing that can improve the accuracy required for forming a semiconductor circuit on the surface can be put to practical use.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a part of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a side view in which a part of a polishing apparatus according to a second embodiment of the present invention is sectioned;

FIG. 3 is an overall configuration diagram of a conventional polishing apparatus.

FIG. 4 is a side view in which a part of a working unit of a conventional polishing apparatus is sectioned.

5A and 5B show a conventional machining unit, wherein FIG. 5A is a cross-sectional view showing a positional relationship between a rotary plate, a fixed plate and a polishing plate pad having a concave groove, and FIG. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Polishing apparatus 2 ... Work unit 3 ... Rotating disk 3a, 4a ... Flat surface 4 ... Fixed disk 5 ... Driving means 6 ... Pressing means 7 ... Polishing pad 7a ... Polishing pad surface 10 ... Ball 12 ... Position control means

Claims (1)

[Claims] 1. A rotary disk rotating about an axis and a fixed disk disposed opposite to the rotary disk, a sphere is interposed between the rotary disk and the fixed disk, and the rotary disk is rotated around the axis. In a polishing apparatus for polishing the surface of the sphere by rotating the polishing pad, the polishing pad having elasticity provided on at least one of the surfaces of the rotating plate and the fixed plate facing each other, and polishing the surface of the sphere, Position control means for controlling the distance between the rotary plate and the fixed plate, and adjusting the amount of elastic deformation of the polishing pad when a sphere is sandwiched between the two. .