JPH10291147A - Method and device for polishing plate glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for polishing plate glasses capable of efficiently providing approximately uniform and flat polishing surface by applying an Oscar polishing machine irrespective of the amount of polishing. SOLUTION: A polishing device for plate glass is provided with a lower surface plate 1 which is rotated with its upper surface as a polishing surface 1a, an upper surface plate 2 which is arranged opposedly over the lower surface plate 1 and holds a plate glass material 4, and a rotating arm 3 which supports the upper surface plate 2 rotatably through a supporting shaft 5 at its top end and grinds one surface of the plate glass material 4 by reciprocatedly rotating the upper surface plate 2 within the area around one side of the lower surface plate 1 except for its rotating center part with the position eccentric to one side relative to the rotating center O1 of the lower surface plate 1 taken as a center O2 . Also it polishes the plate glass material 4 efficiently within the area on the lower surface plate 1 where peripheral speed is high and less in peripheral speed difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat glass plate used for plate glass for plasma displays, glass substrates for liquid crystals, and various other electronic components requiring strict surface flatness. The present invention relates to a method and an apparatus for polishing a glass sheet.

[0002]

2. Description of the Related Art Generally, a formed glass sheet material has minute irregularities on its surface, and requires polishing for application to the above-mentioned applications. Therefore, conventionally, the surface of the sheet glass material has been polished using an Oscar type polishing apparatus.

As shown in FIG. 3, this Oscar-type polishing apparatus comprises a lower surface plate 10 having an upper surface as a polishing surface, and a lower surface plate 1
And an upper stool 12 for holding the sheet glass material 11. The upper stool 12 is
A slurry containing an abrasive such as cerium oxide is polished on the polishing surface 10a while the plate glass material 11 is pressed against the polishing surface 10a of the lower stool 10 while being rotatably supported on the lower end of the support shaft 14 hanging down at the tip of the substrate. The lower platen 10 is rotated at a constant speed while being supplied from above the lower platen 10, and the upper platen 12 is swung on the lower platen 10 by utilizing the rotation of the lower platen 10 or while being positively rotated. By doing so, one surface of the sheet glass material 11 is polished by the polishing surface 10a of the lower platen 10 and the polishing agent.

[0004]

However, in the conventional Oscar-type polishing apparatus, the swing range of the sheet glass material 11 which is swung by the swing arm 13 is lower than the lower platen 1.
Since it was set so as to pass through the rotation center point O of 0, polishing streaks were generated, and it was not possible to obtain a flat glass plate having a uniform and high-precision flat surface.

[0005] The reason is that when the swing range of the sheet glass material 11 swung by the swing arm 13 is set so as to pass through the rotation center point O of the lower platen 10, the sheet glass material 11 Move from the outer peripheral region of the lower surface plate 10 having a large peripheral speed, which is one end of the swing range, to the peripheral region having a large peripheral speed, which is the other end of the swing range, through the central region having a small peripheral speed. It is determined that polishing is performed while moving in such a direction as to repeat such reciprocation. In other words, the sheet glass material 11 repeats the operation of moving from the maximum peripheral speed region of the lower platen 10 to the peripheral speed maximum region through the point of zero peripheral speed (center point O), Along with such an operation, the sheet glass material 11 that is driven by the contact frictional force received from the lower platen 10 around the support shaft 14 at the tip end portion of the swing arm 13 or actively rotated by a motor or the like, The polishing amount in the center tends to be smaller (polishing streaks remain) than in the outer peripheral portion, and it is used for polishing (to produce a certain amount of polishing) to increase the surface accuracy after molding. In such a case, polishing unevenness occurs. Therefore, conventionally, the Oscar type polishing apparatus has been applied only to polishing with a relatively small polishing amount such as finish polishing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for polishing a glass sheet which can efficiently obtain a substantially uniform and flat polished surface with less polishing unevenness by using an Oscar type polishing apparatus regardless of the amount of polishing. To provide.

[0007]

In order to attain the above object, the method of the present invention comprises the steps of swinging a sheet glass material only on one side peripheral portion of a polishing surface of a lower platen which rotates with an upper surface as a polishing surface, except for a rotation center portion. The method is characterized in that one side of the glass sheet material is polished by setting a moving range.

[0008] When the swing range of the sheet glass material is set only on one side peripheral portion except for the rotation center of the polishing surface of the lower surface plate, and one surface of the sheet glass material is polished, the peripheral speed of the lower surface plate is reduced. Is efficiently polished in the peripheral area where
Moreover, since polishing is performed in a range where the peripheral speed difference is small, polishing unevenness is reduced, and polishing is performed substantially uniformly and flatly.

Further, the apparatus of the present invention comprises a lower stool rotating with the upper surface as a polishing surface, an upper stool which is disposed above the lower stool to hold a sheet glass material, and a support shaft at a tip end of the upper stool. The platen is rotatably supported, and the upper platen is reciprocally oscillated in a range around one side excluding the rotation center portion of the lower platen around a position offset to one side with respect to the rotation center of the lower platen. And a swinging arm for moving one side of the sheet glass material to be polished. With this configuration, the sheet glass material can be polished efficiently and substantially uniformly and flatly in a region where the peripheral speed of the lower platen is large and in a range where the peripheral speed difference is small.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a schematic plan view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic longitudinal sectional side view thereof, wherein 1 is a lower platen, 2 is an upper platen, 3 is a swing arm, and 4 is a sheet glass material. I have.

The lower surface plate 1 has a polishing surface 1a on the upper surface, is rotatably supported at a fixed position, and is driven to rotate at a constant rotation speed by a suitable driving means (not shown) such as a motor. The size of the polished surface 1a of the lower stool 1 is appropriately set according to the size of the glass sheet material 4, but the larger the better, the better the polishing efficiency.

The upper surface plate 2 is attached to the lower surface of the lower surface plate 1 with an appropriate adhesive 2a capable of peeling one surface of the sheet glass material 4 and pressed against the polishing surface 1a of the lower surface plate 1. Usually, the upper stool 2 is used to attach and detach the sheet glass material 4.
Is configured to be able to move up and down by a cylinder or the like, and to be able to apply a polishing pressure by an appropriate means.

The swinging arm 3 rotatably supports the upper stool 2 at the tip thereof via a support shaft 5, and shifts the position offset to one side with respect to the rotation center O ₁ of the lower stool 1. The upper surface plate 2 is reciprocally oscillated within a range of one side peripheral portion excluding the rotation center portion of the lower surface plate 1 as the center O ₂ to grind one surface of the sheet glass material 4. A base end of the swing arm 3 is connected to a swing applying mechanism 6. In the drawing, the swing applying mechanism 6 includes a motor 6a, a crank 6b rotated by the motor 6a, and a connecting rod 6c and a lever 6d connecting the base end of the swing arm 3 to the crank 6b. However, other configurations may be used. The swing range of the swing arm 3 is adjusted by changing the radius of the crank 6b or by adjusting the lever 6d.
This is done by changing the length.

Although the sheet glass material 4 is illustrated in the drawings as having a rectangular shape, it may have a circular shape or another shape.

Further, as shown by the two-dot chain line in FIG. 1, by using two upper platens 2 with respect to the lower platen 1, two sheet glass materials 4 can be polished simultaneously. In this case, it is preferable to share the drive source of the swing applying mechanism 6 of the swing arm 3.

The configuration of the apparatus according to the embodiment of the present invention is as described above, and the method invention is implemented using the above-described apparatus.
Next, the polishing operation of the sheet glass material 4 by the above-described apparatus will be described. First, the lower platen 1 is rotated, and one surface of a sheet glass material 4 is attached to the lower surface of the upper platen 2 to polish the polishing surface 1a of the lower platen 1.
, And while the polishing slurry is being supplied from above the polishing surface 1a, one side of the sheet glass material 4 is polished while the upper platen 2 is rocked by the rocking of the rocking arm 3 by the rocking application mechanism 6. In this case, the swing range of the sheet glass material 4, that is,
The swing range of the tip of the oscillating arm 3, by setting only one side periphery except for the rotation center O ₁ of the polishing surface 1a of the lower platen 1, by polishing the one surface of the glass sheet material 4, the glass sheet material No. 4 is polished efficiently in a peripheral area where the peripheral speed of the lower stool 1 is high, and is polished in a range where the peripheral speed difference is small. Is done.

[0017] The swing range of the front end of the swing arm 3 to be set as described above, as shown in FIG. 1, about the position offset to one side with respect to the rotation center O ₁ of the lower stool 1 O _The swing arm 3 may be swung as 2 so that the upper platen 2 is reciprocated and swung in a range of one side peripheral portion excluding the rotation center portion of the lower platen 1 to make the sheet glass material. 4 on one side, lower platen 1
In a region where the peripheral speed is large, and in a range where the peripheral speed difference is small, it is possible to perform polishing substantially uniformly, flatly and efficiently.

The lower surface plate 1 may have a polished surface 1a formed in a ring shape or a concave center of rotation.

[0019]

According to the method of the present invention, the sheet glass material is efficiently polished in the peripheral region where the peripheral speed of the lower platen is large, and is polished in a range where the peripheral speed difference is small. Polishing unevenness is reduced, and the polishing is performed substantially uniformly and flatly.

Further, according to the apparatus of the present invention, while the plate glass material is pressed against the polishing surface of the rotating lower surface plate by the upper surface plate, the rotation center of the lower surface plate is removed by swinging of the swing arm. One side of the sheet glass material can be polished approximately uniformly and flatly and efficiently by reciprocatingly swinging the sheet glass material in the range of one side peripheral portion, and the method invention can be easily carried out.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional side view of FIG.

FIG. 3 is a schematic plan view of a conventional Oscar-type polishing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower surface plate 1a Polishing surface 2 Upper surface plate 3 Oscillating arm 4 Sheet glass material 5 Support shaft 6 Oscillating mechanism

Claims (2)

[Claims] 1. A swinging range of a sheet glass material is set only on one side peripheral portion of a polishing surface of a lower platen which rotates with an upper surface as a polishing surface, except for a rotation center portion, and one surface of the sheet glass material is polished. A feature of the method for polishing plate glass. 2. A lower platen which rotates with the upper surface as a polishing surface;
An upper surface plate which is disposed above the lower surface plate and holds the sheet glass material, and rotatably supports the upper surface plate via a support shaft at a tip, and is biased to one side with respect to a rotation center of the lower surface plate. And a swing arm for polishing the one surface of the sheet glass material by reciprocatingly swinging the upper platen in a range of one side peripheral portion excluding a rotation center portion of the lower platen with the center as a center. Plate glass polishing equipment.