JP2013198974A - End face grinder of glass substrate, end face grinding method of glass substrate and manufacturing method of glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an end face grinder of a glass substrate which can grind the end face of the glass substrate into a desired shape even if the center of the end face of the glass substrate is displaced from a center position of a groove of a grinding stone of a primary end face grinding part, an end face grinding method of the glass substrate and a manufacturing method of the glass substrate.SOLUTION: There is provided an end face grinder of a glass substrate, which is characterized in that: the grinder has a primary end face grinding part and a secondary end face grinding part sequentially from the upstream side of a glass substrate conveyance route; columnar-shape grinding stones having grooves along circumferential directions at side faces are arranged at the primary end face grinding part and the secondary end face grinding part, respectively; cross section shapes of the grooves formed at the grinding stones have shapes which are gradually expanded toward surface sides of the grinding stones from bottom sides of the grooves; an opening angle of the groove formed at the grinding stone of the primary end face grinding part is formed larger than that of the groove formed at the end face grinding stone of the secondary end face grinding part; and the bottom of the groove formed at the grinding stone of the primary end face grinding part is formed into a protrusive curved line at the bottom side. There are also provided an end face grinding method of the glass substrate and a manufacturing method of the glass substrate.

Description

  The present invention relates to a glass substrate end surface grinding apparatus, a glass substrate end surface grinding method, and a glass substrate manufacturing method.

  A glass substrate such as a plate glass or a liquid crystal panel is cut into a predetermined size and then processed into a glass substrate having a product outer diameter by grinding and chamfering the end faces of the four sides.

  Grinding processing that performs grinding and chamfering is performed by rotating a cylindrical grindstone and transporting the glass substrate while applying the end surface of the glass substrate to be ground to the groove formed along the circumference on the side surface of the grindstone. By doing so, chamfering and grinding are performed according to the shape of the groove.

  In particular, in recent years, in order to increase the productivity of glass substrates, when grinding processing is performed, by placing a plurality of grindstones on the conveyance path of the glass substrates, the load on each grindstone is reduced and the feed rate of the glass substrates is increased. A method of speeding up is taken (for example, Patent Document 1).

JP 2006-247768 A

  Conventionally, when a plurality of grindstones are arranged on the glass substrate conveyance path as described above to grind the end surfaces of the glass substrates, the grooves formed on the side surfaces of the grindstones have the same shape.

  For this reason, for example, when the glass substrate end face is ground with the front-stage grindstone, if the center in the plate thickness direction of the glass substrate end face deviates from the center position in the grindstone thickness direction of the groove, the glass is ground even if grinding is performed with the rear-stage grindstone. In some cases, the grinding (working) surface at the previous stage remains on the end surface of the substrate, and the end surface shape deviates from the prescribed shape.

  In addition, if the grindstone groove position is periodically adjusted, it takes time to adjust, so that the operation rate of the end face grinding apparatus is lowered and there is a problem in productivity.

  Further, when the center of the glass substrate end face in the plate thickness direction is shifted from the center position of the groove in the grindstone thickness direction when the grinding process is performed with the preceding stage grindstone, if a corner remains on the end face of the glass substrate, the latter stage There was also a problem that the load on the grindstone increased and quality defects were likely to occur.

  In the present invention, in view of the problems of the above-described conventional technology, when the grinding process is performed on the end surface of the glass substrate with a plurality of grindstones, the center of the glass substrate end surface in the plate thickness direction is the front stage (primary end grinding portion) An object of the present invention is to provide a glass substrate end surface grinding apparatus capable of removing a corner portion of a glass substrate end surface even if the groove is deviated from the center position in the grinding wheel thickness direction, and capable of performing a grinding process into a predetermined shape.

  In order to solve the above-mentioned problems, the present invention has a primary end surface grinding portion and a secondary end surface grinding portion in order from the upstream side of the glass substrate transport path, and the primary end surface grinding portion and the secondary end surface grinding portion. Each of the sections is provided with a cylindrical grindstone in which a groove is formed on the side surface along the circumferential direction, and a cross section of the groove when the cylindrical grindstone is cut along a plane including the central axis thereof The shape has a shape that gradually widens from the bottom side of the groove to the grindstone surface side, and the opening angle of the groove formed in the grindstone of the primary end face grinding portion is that of the secondary end face grinding portion. A glass that is larger than a groove provided on a grindstone for end face grinding, and a groove provided on the grindstone of the primary end face grinding section has a convex curve on the bottom side. A substrate end surface grinding apparatus is provided.

  According to the glass substrate end surface grinding apparatus of the present invention, even if grinding processing is performed with the center in the plate thickness direction of the glass substrate end surface deviating from the center position in the grinding wheel thickness direction of the groove in the primary end surface grinding portion, The end surface grinding portion can be ground without leaving the ground surface ground by the primary end surface grinding portion. For this reason, it becomes possible to improve a yield compared with a prior art.

  In addition, since grinding can be performed without leaving the corners of the glass substrate end face in the primary end face grinding part, the load on the secondary end face grinding part can be reduced, and in this respect also the product yield can be improved. become.

  Furthermore, since it is not necessary to adjust the position of the grindstone of each of the primary end surface grinding part and the secondary end surface grinding part as accurately as in the prior art, and the time required for the position adjustment can be shortened, the operating rate of the end face grinding apparatus Can be increased.

The side view of the end surface grinding apparatus of the glass substrate in the 1st Embodiment of this invention The top view of the end surface grinding apparatus of the glass substrate in the 1st Embodiment of this invention The side view of the grindstone provided in the end surface grinding part in the end surface grinding apparatus of the glass substrate in the 1st Embodiment of this invention. Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in the 1st Embodiment of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in the 1st Embodiment of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in the 1st Embodiment of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in the 1st Embodiment of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in Example 1 of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side in Example 1 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 1 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 1 of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in Example 2 of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in Example 2 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 2 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 2 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 3 of this invention Explanatory drawing of the grinding state of the glass substrate end surface in Example 3 of this invention Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in the comparative example 1 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 1 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 1 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 2 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 2 Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in the comparative example 3 Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in the comparative example 3 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 3 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 3 Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in the comparative example 4 Explanatory drawing of the cross-sectional shape of the groove | channel formed in the grindstone side surface in the comparative example 4 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 4 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 4 Explanatory drawing of the grinding state of the glass substrate end surface in the comparative example 4

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and the following embodiments are not departed from the scope of the present invention. Various modifications and substitutions can be made.
[First Embodiment]
In the present embodiment, a glass substrate end surface grinding apparatus of the present invention will be described.

  First, a configuration example of a glass substrate end surface grinding apparatus will be described with reference to FIGS. 1a, 1b, and 2. FIG.

  1a and 1b are schematic views of a glass substrate end surface grinding apparatus 10, FIG. 1a is a side view, and FIG. 1b is a top view.

  A workpiece W (glass substrate) to be ground is detachably held on the holding means 11.

  Here, the material, manufacturing method, and plate thickness of the work W (glass substrate) are not particularly limited, and various glass substrates can be used. For example, as the material (material) of the work W, non-alkali glass, soda lime glass, quartz glass, or the like that does not substantially contain an alkali metal oxide for a glass substrate for a liquid crystal display can be used.

  Further, there is no limitation on the method of forming the glass substrate to be the workpiece W, and a glass substrate formed by a general method, for example, glass formed by a float method, a fusion down draw method, a slit down draw method, a redraw method, or the like. A substrate can be used.

  The plate thickness of the workpiece W (glass substrate) is not limited as long as the plate thickness of the workpiece W and the size and shape of the groove formed on the side surface of the grindstone are suitable. However, if it is too thick, it will be difficult to transport due to the load of the glass substrate, and if it is too thin, it will be easily damaged when transporting the glass substrate. Therefore, the thickness of the workpiece W is 0.3 mm or less and 6 mm or less. It is preferable that it is 0.3 mm or more and 3 mm or less.

  Next, the holding means 11 is disposed on the traveling body S that can move in the left-right direction in FIGS. 1a and 1b (the arrow direction in FIGS. 1a and 1b). Thus, the workpiece W can be conveyed in the left-right direction in the drawing. Moreover, the conveyance mechanism 12 can be comprised so that the conveyance speed (feeding speed) of the workpiece | work W can be controlled by the controller (control part) which is not shown in figure.

  The workpiece W held on the holding means 11 is transferred by the transfer mechanism 12 to a position where the primary end surface grinding portion 13 is installed, and grinding and chamfering processing (hereinafter simply referred to as grinding processing) is performed on both end surface portions. Is performed). Subsequently, it is conveyed to the position where the secondary end surface grinding section 23 is installed, and similarly, both ends of the workpiece W are ground.

  In FIG. 1b, an example is shown in which the primary end surface grinding portion 13 and the secondary end surface grinding portion 23 are arranged one by one on the left and right sides of the conveyance mechanism 12 (in the direction orthogonal to the conveyance direction of the workpiece W) (FIG. 1a). In FIG. 2, only one by one is shown for easy understanding of the structure), and further, an end surface polishing portion can be provided on the downstream side in the workpiece conveyance direction in order to perform mirror finishing on the end surface of the workpiece W.

  In FIGS. 1a and 1b, an example in which only the primary end surface grinding portion 13 and the secondary end surface grinding portion 23 for the end surfaces of two sides of the workpiece are described, but the remaining two sides are also ground. It can also be configured to perform processing. For example, a turntable that changes the orientation of the workpiece W upstream or downstream in the workpiece conveyance direction, and similarly, a primary end surface grinding portion and a secondary end surface grinding portion for the remaining two sides can be provided.

  As shown in FIG. 1 b, the primary end surface grinding unit 13 and the secondary end surface grinding unit 23 have cylindrical end surface grinding wheels (hereinafter also simply referred to as “grinding stones”) 132 and 232, respectively. Motors 131 and 231 for rotating the grindstones 132 and 232 with the central axis of the grindstones 132 and 232 as the rotation axis are disposed during the grinding process. Furthermore, at the time of grinding, the coolant supply mechanisms 14 and 24 for supplying coolant (coolant) to the periphery of the portion where the grindstones 132 and 232 and the workpiece W come into contact, and the suction mechanism 15 that draws in the used coolant via the duct L. , 25 can be connected to the respective end face grinding portions.

  About the kind of grindstone, it can select according to the grinding amount (processing amount) etc. which are requested | required. The roughness of the grindstone can also be selected depending on the ratio of the grinding amount required in the primary end surface grinding part and the secondary end surface grinding part, the surface roughness of the finished surface of the glass substrate, and the like. For example, if the grinding amounts in the primary end surface grinding part and the secondary end surface grinding part are approximately the same, the counts (roughness) of the two grinding stones can be made the same. In the glass substrate manufacturing process, generally, a grinding wheel with a larger grindstone (fine) is used to finish the grinding (polishing) surface to a smooth surface (mirror surface) as it goes downstream of the glass substrate processing process. Has been taken. For this reason, also in this invention, the count of the grinding wheel of a primary end surface grinding part can be made smaller than the count of the grinding wheel of a secondary end surface grinding part. That is, the grindstone of the secondary end surface grinding portion can be made finer than the primary end surface grinding portion.

  In the case of the present invention, even when the grindstone count is selected as described above, grinding can be performed at the secondary end face grinding portion without leaving the ground surface formed at the primary end face grinding portion, as will be described later. Therefore, it can be finished without leaving a surface with a rough surface as in the prior art.

  Grooves 133 and 233 are formed on the side surfaces (circumferential surfaces) of the grindstones 132 and 232 along the circumferential direction as can be seen from the side view of the grindstone shown in FIG. Grinding processing of the end surface of the workpiece W is performed by conveying the workpiece W while being in contact with the groove. At this time, the end face of the workpiece W is chamfered in accordance with the shape of the groove. FIG. 2 shows an example in which three grooves 133 and 233 are provided at predetermined intervals in the central axis direction (thickness direction of the grindstone), but this corresponds to the grinding amount (processing amount) without exchanging the grindstone. This is for grinding by changing the groove. The number of grooves is not limited and can be selected according to the size of the grindstone or the groove.

  Next, the shape of the groove formed on the side surface of the grindstone will be described with reference to FIGS. 3a to 3d.

  3A shows an example of the cross-sectional shape of the groove 133 formed on the side surface of the grindstone 132 of the primary end surface grinding portion, and FIGS. 3B to 3D show the cross section of the groove 233 formed on the side surface of the grindstone 232 of the secondary end surface grinding portion. Examples of shapes are shown respectively.

  The cross-sectional shape of the groove here means the cross-sectional shape of the groove when a cylindrical grindstone is cut at a plane including the central axis (a plane perpendicular to the tangent to the side of the grindstone) (the grindstone is cut in half). Yes. The central axis means a line (axis) connecting the centers of the circles on the upper surface and the bottom surface of the cylindrical grindstone.

  3A to 3D, the alternate long and short dash line shown in each groove indicates the center position (center portion) when viewed in the width direction of the groove (thickness direction of the grindstone) in the cross-sectional shape of each groove. In other drawings describing the groove, the center position is similarly indicated by a one-dot chain line.

  As is clear from the relationship with FIG. 2, the upper side where the opening is located is the grindstone surface (surface of the grindstone side surface) side, and the bottom side of the groove is arranged on the center side of the grindstone.

  As shown in FIGS. 3a to 3d, in both the primary and secondary end surface grinding portions, the cross-sectional shape gradually widens from the bottom side of the groove to the grindstone surface (the surface of the side surface portion of the grindstone). Shape).

  This is for chamfering the glass substrate, and the end portion of the glass substrate is inserted into the groove of the grindstone, and the corner portion of the end portion of the glass substrate is chamfered according to the shape of the groove formed on the grindstone.

  And the opening angle of the groove | channel (its cross-sectional shape) is larger in the groove | channel formed in the grindstone of a primary end surface grinding part than the groove | channel provided in the grindstone for end face grinding of a secondary end surface grinding part.

  Here, the opening angle of the groove is an angle represented by 31 in FIG. 3a and 32 in FIGS. 3b to 3d, and is an angle formed between both side portions of the groove.

  Since the opening angle satisfies the above relationship, for example, when comparing FIG. 3A and FIG. 3B, the inclination angle of the groove side surface of the primary end surface grinding portion is gentler than that of the secondary end surface grinding portion. For this reason, compared with the prior art in which the groove shape formed in the grindstone of the primary end face grinding part and the secondary end face grinding part is the same, the processed surface given to the end face of the glass substrate by the primary end face grinding part is secondary. It becomes possible to remove more reliably at the end grinding portion.

  Further, the groove (its cross-sectional shape) provided in the grindstone of the primary end surface grinding portion has a convex curve on the bottom side. That is, the cross-sectional shape of the groove is a concave curve, and as shown in FIG. 3A, the groove provided on the grindstone of the primary end face grinding portion can be, for example, a parabolic shape, a semicircular shape, or the like.

  The radius of curvature of the curve convex on the bottom side provided at the bottom of the groove is not particularly limited, and can be appropriately selected. For example, as shown in FIG. 3c, when the bottom portion of the grindstone of the secondary end surface grinding portion is similarly curved to the bottom side, the bottom of the grindstone groove of the secondary end surface grinding portion is It is preferable that the curvature radius of the curve at the bottom of the groove of the grindstone of the primary end face grinding portion is larger than the curvature radius of the curve.

  The center of the workpiece W end face in the plate thickness direction is shifted from the center position of the groove in the grinding wheel thickness direction when grinding is performed in the primary end face grinding portion by forming the groove of the grinding wheel of the primary end face grinding portion in the above shape. However, it is possible to reliably remove the corners of the end face of the workpiece W.

  The cross-sectional shape of the groove provided in the grindstone of the secondary end face grinding portion is not particularly limited as long as the above requirements are satisfied. As for the secondary end surface grinding portion, it is preferable to select the shape and size of the groove so as to have a shape required for the product or a shape close to that.

  Specifically, for example, the bottom of the groove can be flattened as shown in FIG. 3b.

  Also, as shown in FIG. 3c, a convex curve on the bottom side of the grindstone groove, that is, the shape of the groove can be a parabola shape, a semicircular shape, or the like, similar to the grindstone groove of the primary end face grinding portion. .

  And as shown in FIG. 3d, it is preferable that the cross-sectional shape of the groove | channel formed in the grindstone of a secondary end surface grinding part is a shape by which the notch part 33 was formed in the opening edge part.

  When grinding the end surface of the workpiece W as described above, grinding is performed while supplying coolant to the periphery of the portion where the grinding wheel and the workpiece W are in contact with each other. In particular, the grooves formed on the grinding wheel of the secondary end surface grinding portion are Since the opening angle is small, the coolant does not enter the groove sufficiently, and there is a risk of causing haze. For this reason, in order to make it easy to introduce a coolant into the groove formed in the grindstone of the secondary end face grinding portion, it is preferable to provide a notch portion at the opening end portion.

  The size of the notch is not particularly limited and should be selected in consideration of the width between grooves, the opening angle of the groove formed in the grinding wheel of the secondary end surface grinding part, the thickness of the workpiece W, etc. Can do. For example, the width 34 of the groove opening at the upper end of the notch is preferably 1.5 times or more and 2.5 times or less, and 1.8 times or more and 2.1 times or less the plate thickness of the workpiece W. It is more preferable that This is because when the size of the notch portion is within such a range, it is particularly easy to introduce the coolant into the groove, and the occurrence of burns can be suppressed low.

  The notch can be provided only at one end of the opening of the groove, but as shown in FIG. 3d, it is easier for the coolant to enter the groove more uniformly at both ends of the opening of the groove. More preferred.

  The specific shape of the notch is not limited, and may be a shape that facilitates entry of coolant. For example, an oblique cutout can be provided in the groove as shown in FIG. 3d. In this case, the inclination angle of the side surface portion of the groove changes in two stages. When the grindstone surface (surface of the grindstone side surface portion) is used as a reference, the inclination angle of the upper end side (notch portion) of the groove is It is preferable that the inclination angle is more gentle than the inclination angle on the bottom side. In this case, the opening angle of the groove formed on the grindstone of the primary end face grinding portion is larger than the opening angle of the groove on the bottom side among the two inclination angles of the grooves formed on the grindstone of the secondary end face grinding portion. It will be comprised so that it may also become large.

  Here, the description has been given of providing the notch in the grindstone groove of the secondary end face grinding part, but similarly, the notch part for facilitating introduction of the coolant into the grindstone groove of the primary end face grinding part is provided. Also good.

  According to the glass substrate end surface grinding apparatus of the present invention described above, the center in the plate thickness direction of the workpiece W (glass substrate) end surface is shifted from the central position in the grinding wheel thickness direction of the groove in the primary end surface grinding portion. The range in which the grinding process of the end face of the workpiece can be performed without leaving the grinding surface formed in the primary end face grinding part in the secondary end face grinding part (work in the primary end face grinding part) The allowable range of the deviation width between the center of the end face in the plate thickness direction and the center position of the groove in the thickness direction of the grindstone can be widened.

  In addition, since the grinding can be performed without leaving the corner portion of the workpiece end surface in the primary end surface grinding portion, the load on the secondary end surface grinding portion can be reduced. For these reasons, the product yield can be improved.

Furthermore, as described above, the workpiece end surface can be ground into a predetermined shape without adjusting the position of the grindstone of each of the primary end surface grinding portion and the secondary end surface grinding portion with as high accuracy as in the prior art. The time required for adjusting the position of the grindstone can be shortened. For this reason, it becomes possible to raise the operation rate of an end surface grinding apparatus.
[Second Embodiment]
In the present embodiment, an end surface grinding method for a glass substrate of the present invention will be described.

  The glass substrate end surface grinding method of the present invention is a glass substrate end surface grinding method in which an end surface of a glass substrate is ground in a primary end surface grinding portion and then ground in a secondary end surface grinding portion, wherein the primary end surface grinding is performed. Each of the portion and the secondary end surface grinding portion are provided with a cylindrical grindstone having grooves formed on the side surfaces along the circumferential direction, and the cylindrical grindstone is a surface including the central axis thereof. The cross-sectional shape of the groove when cut has a shape that gradually widens from the bottom side of the groove to the grindstone surface side, and the opening angle of the groove formed in the grindstone of the primary end surface grinding portion is greater The groove provided in the grindstone of the secondary end face grinding portion is larger than the groove provided in the grindstone of the primary end face grinding portion, and the bottom of the groove provided in the grindstone of the primary end face grinding portion has a convex curve on the bottom side. This is a method for grinding an end face of a glass substrate.

  According to the method for grinding an end face of a glass substrate of the present invention, even if a grinding process is performed with the center in the plate thickness direction of the workpiece W end face deviating from the center position in the grinding wheel thickness direction of the groove in the primary end face grinding portion. The range in which the end surface of the workpiece can be ground without leaving the ground surface formed in the primary end surface grinding portion in the secondary end surface grinding portion (the center in the thickness direction of the workpiece end surface in the primary end surface grinding portion) The allowable range of the deviation width from the center position of the groove in the thickness direction of the grindstone can be widened.

  Moreover, since grinding can be performed without leaving the corners of the glass substrate end face in the primary end face grinding part, the load on the secondary end face grinding part can be reduced. For these reasons, the product yield can be improved.

  Furthermore, as described above, the glass substrate end face can be ground into a predetermined shape without adjusting the positions of the grindstones of the primary end face grinding part and the secondary end face grinding part as accurately as in the prior art. Therefore, the time required for adjusting the position of the grindstone can be shortened. For this reason, it becomes possible to raise the operation rate of an end surface grinding apparatus.

  The glass substrate end surface grinding method can be carried out, for example, by the glass substrate end surface grinding apparatus described in the first embodiment. For this reason, since it overlaps with 1st Embodiment about the structure of an apparatus, it is abbreviate | omitted here, Especially the count of the grindstone of a primary end surface grinding part is smaller than the count of the grindstone of a secondary end surface grinding part. It is preferable to do. That is, it is preferable to make the grindstone of the secondary end face grinding portion finer than the primary end face grinding portion.

  This is because even when the count of the grindstone is selected as described above, grinding can be performed at the secondary end surface grinding portion without leaving the grinding surface formed at the primary end surface grinding portion. This is because the surface can be finished without leaving a rough surface. Further, by adopting such a configuration, a sufficient grinding amount (processing amount) can be secured in the primary end surface grinding portion, and the surface can be finished in the secondary end surface grinding portion, thereby increasing the efficiency of grinding. Can do.

  As described in the first embodiment, the grindstone count can be selected according to the grinding amount in the primary end face grinding portion and the secondary end face grinding portion. For example, the grindstone having the same count can be used. Is possible.

  In particular, as shown in FIG. 3d, it is preferable that the cross-sectional shape of the groove formed in the grindstone of the secondary end face grinding portion is a shape in which the notch 33 is formed at the opening end.

  In this case as well, as described in the first embodiment, when the end surface of the workpiece W (glass substrate) is ground, the grinding is performed while supplying the coolant around the grinding portion of the grindstone. Since the groove formed in the grindstone of the part has a small opening angle, the coolant does not sufficiently enter the groove, and there is a risk of burning. For this reason, it is preferable to provide a notch at the opening end so that coolant can be easily introduced into the groove formed in the grindstone of the secondary end face grinding portion.

  The size of the notch 33 is not particularly limited, and is selected in consideration of the width between the grooves, the opening angle of the groove formed in the grindstone of the secondary end surface grinding part, the thickness of the workpiece W, and the like. be able to. For example, the width 34 of the opening of the groove is preferably 1.5 to 2.5 times the plate thickness of the workpiece W, more preferably 1.8 to 2.1 times. preferable.

  Although the notch can be provided only at one end of the opening, it is preferable to provide the notch at both ends of the opening as shown in FIG.

  The specific shape of the notch is not limited, and may be a shape that facilitates entry of coolant. For example, an oblique cutout can be provided in the groove as shown in FIG. 3d. In this case, the inclination angle of the side surface portion of the groove changes in two stages. When the grindstone surface (surface of the grindstone side surface portion) is used as a reference, the inclination angle of the upper end side (notch portion) of the groove is It is preferable that the inclination angle is more gentle than the inclination angle on the bottom side. In this case, the opening angle of the groove formed on the grindstone of the primary end face grinding portion is larger than the opening angle of the groove on the bottom side among the two inclination angles of the grooves formed on the grindstone of the secondary end face grinding portion. It will be comprised so that it may also become large.

  Here, the description has been given of providing the notch in the grindstone groove of the secondary end face grinding part, but similarly, the notch part for facilitating introduction of the coolant into the grindstone groove of the primary end face grinding part is provided. Also good.

  And the end surface grinding method of the glass substrate demonstrated by this embodiment is preferably applicable to the end surface grinding process of the glass substrate in the manufacturing method of a glass substrate. That is, it can be set as the manufacturing method of the glass substrate using the end surface grinding method of the glass substrate demonstrated in 2nd Embodiment.

  According to the method for manufacturing a glass substrate, in the end surface grinding process of the glass substrate, the center in the plate thickness direction of the workpiece W end surface is shifted from the center position in the grindstone thickness direction of the groove in the primary end surface grinding portion. Even if it is performed, the range in which the grinding process of the end face of the workpiece can be performed without leaving the grinding surface formed in the primary end grinding section in the secondary end grinding section (the plate of the workpiece end face in the primary end grinding section) The allowable range of the deviation width between the center in the thickness direction and the center position of the groove in the thickness direction of the grindstone can be widened.

  Moreover, since grinding can be performed without leaving the corners of the glass substrate end face in the primary end face grinding part, the load on the secondary end face grinding part can be reduced.

  Furthermore, as described above, the glass substrate end face can be ground into a predetermined shape without adjusting the positions of the grindstones of the primary end face grinding part and the secondary end face grinding part as accurately as in the prior art. Therefore, the time required for adjusting the position of the grindstone can be shortened.

  For this reason, according to the manufacturing method of such a glass substrate, since the incidence rate of defective products can be reduced in the end surface grinding step, it is possible to improve the yield of products. In addition, since the time required for adjusting the end face grinding apparatus is less than before, the operating rate can be increased, and the productivity of the entire manufacturing process can be increased.

Specific examples and comparative examples will be described below, but the present invention is not limited to these examples.
[Example 1]
In the glass substrate end surface grinding apparatus shown in FIG. 1, a cylindrical grindstone in which grooves of the shapes shown in FIG. 4a and FIG. 4b are respectively formed on the side surfaces thereof as the grindstone of the primary end face grinding portion and the secondary end face grinding portion. Was used to grind the end face of the glass substrate.

  As shown in FIG. 4a, the groove formed on the grindstone of the primary end surface grinding portion gradually spreads from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion), and the bottom of the groove has a radius of curvature of 0.2 mm. It has a convex curve on the bottom side of 5 mm. The groove opening angle 41 was 75 degrees.

  As shown in FIG. 4b, the grooves formed on the grindstone of the secondary end face grinding portion gradually spread from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion), and a flat portion is provided on the bottom surface of the groove. Has the shape. The width 43 of the flat portion of the bottom surface was 32% of the thickness of the glass substrate to be ground, and the opening angle 44 of the groove formed in the grindstone of the secondary end surface grinding portion was 52 degrees. A notch 46 was provided at the upper end of the groove. The opening angle 45 at the notch portion of the grindstone of the secondary end surface grinding portion is 80 degrees.

  Then, as shown in FIG. 4c, the center in the thickness direction of the glass substrate end face in the primary end face grinding portion (hereinafter also simply referred to as “the center of the glass substrate end face”) is the thickness direction of the grindstone in the grindstone groove. The glass substrate end face was ground in a state shifted from the center position (hereinafter also simply referred to as “the groove center position”) to the left in the figure. In the drawing, the position of the glass plate when the center of the end surface of the glass plate is at the center of the groove of the grindstone is indicated by a dotted line. The deviation width 47 from the case where the center of the glass substrate end face is at the center of the groove is 14% of the thickness of the glass substrate. As can be seen from FIG. 4c, although the center of the glass substrate end face is shifted from the center position of the groove, the entire end face portion of the glass substrate is ground according to the shape of the groove, and the corners of the glass substrate are also ground. Has been.

Next, as shown in FIG. 4 d, the glass substrate subjected to the grinding process in the primary end face grinding part was ground in the secondary end face grinding part so that the predetermined grinding amount 48 was obtained. At this time, the grinding processing was performed in a state where the center position of the groove of the grindstone coincided with the center of the end face of the glass substrate. In FIG. 4d, 49 portions indicated by oblique lines are ground and removed by the secondary end surface grinding portion. That is, even if the center of the glass substrate end face does not coincide with the center position of the grindstone groove of the primary end face grinding portion, all the grinding surfaces formed by the primary end face grinding portion remain in the secondary end face grinding portion. It was confirmed that grinding was possible without any problems.
[Example 2]
In the present example, the groove formed on the side surface of the grinding wheel of the secondary end face grinding part was formed in the same manner as in Example 1 except that the shape of the groove was a parabolic groove like the grinding wheel of the primary end face grinding part. It was.

  Specifically, the grooves formed on the grindstone of the primary end face grinding portion have the same shape as in the first embodiment as shown in FIG. 5a, and the grindstone surface (the surface of the grindstone side surface portion) side from the groove bottom side. The bottom of the groove has a convex curve on the bottom side with a curvature radius 52 of 0.5 mm. The groove opening angle 51 was set to 75 degrees.

  As shown in FIG. 5b, the grooves formed on the grindstone of the secondary end surface grinding portion gradually spread from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion), and the curvature radius 54 of the groove bottom is 0.00. The curve is convex on the bottom side of 356 mm, and the groove opening angle 53 is 60 degrees.

  And as shown in FIG. 5c, the center of the glass substrate end face in the primary end face grinding portion is the center position of the grindstone groove (in the figure, the center of the glass plate end face is the center position of the grindstone groove of the glass plate). The glass substrate end face was ground in a state shifted from the position to the left side in the figure. The deviation width 55 from the case where the center of the glass substrate end face is at the center of the groove is 14% of the thickness of the glass substrate. As can be seen from FIG. 5c, even in the present embodiment, the entire end face portion is ground according to the shape of the groove, even though the center of the glass substrate end face is deviated from the center position of the groove. Is also ground.

Next, as shown in FIG. 5 d, the glass substrate subjected to the grinding process in the primary end surface grinding part was subjected to the grinding process in the secondary end surface grinding part so as to obtain a predetermined grinding amount 56. At this time, the grinding process was performed in a state where the center position of the groove of the grindstone and the center of the end face of the glass substrate coincided with each other. In FIG. 5d, the portion 57 indicated by oblique lines is ground and removed by the secondary end face grinding portion. That is, even if the center of the glass substrate end face does not coincide with the center position of the groove of the grindstone of the primary end face grinding portion, all the grinding surfaces formed by the primary end face grinding portion in this embodiment are also secondary end faces. It was confirmed that grinding was possible without remaining in the grinding part.
[Example 3]
In this example, the grindstone with the same groove as that of Example 2 was used as the grindstone of the primary end face grinding part and the secondary end face grinding part (that is, the grindstone of the primary end face grinding part is shown in FIG. 5a. The grindstone in which the groove | channel of FIG. 5b was formed was used for the grindstone of a secondary end surface grinding part.

  Then, as shown in FIG. 6a, the center of the glass substrate end face is the center position of the grindstone groove in the primary end face grinding portion (in the figure, the center of the glass plate end face is the center position of the grindstone groove of the glass plate. The glass substrate end face was ground in a state shifted from the position to the left side in the figure. In this case, the deviation width 61 from the case where the center of the glass substrate end face is at the center position of the groove is 21% of the plate thickness. As can be seen from FIG. 6a, although the end face of the glass substrate is displaced from the center position of the groove, the entire end face portion is ground according to the shape of the groove, and the corners of the glass substrate are also ground.

Next, as shown in FIG. 6 b, the glass substrate that was ground in the primary end face grinding portion was ground in the secondary end face grinding portion so that the predetermined grinding amount 62 was obtained. At this time, the grinding processing was performed in a state where the center position of the groove of the grindstone coincided with the center of the end face of the glass substrate. In FIG. 6b, the portion indicated by hatching 63 is ground and removed by the secondary end surface grinding portion. That is, even if the center of the glass substrate end face and the center position of the grindstone groove of the primary end face grinding portion do not coincide with each other, all the grinding surfaces formed by the primary end face grinding portion remain in the secondary end face grinding portion. It was confirmed that grinding was possible without any problems.
[Comparative Example 1]
In this comparative example, similarly to Example 1, the glass substrate end face was ground using the glass substrate end face grinding apparatus shown in FIG. As the grindstones of the primary end face grinding part and the secondary end face grinding part, the grinding process of the glass substrate end face was performed using a grindstone in which grooves having the shape shown in FIG.

  As shown in FIG. 7a, the grooves formed on the grindstone of the primary end surface grinding portion and the secondary end surface grinding portion gradually spread from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion) and are flat on the bottom Has a shape provided. The width 71 of the flat portion of the bottom surface was set to 32% of the thickness of the glass substrate, and the groove opening angle 72 was set to 52 degrees.

  And as shown in FIG. 7b, in the primary end face grinding portion, the center of the glass substrate is the center position of the grindstone groove (in the figure, the position of the glass plate when the center of the glass plate end face is at the center position of the grindstone groove). The edge of the glass substrate was ground in a state shifted to the left in the figure. The deviation width 73 from the case where the center of the glass substrate end face is at the center of the groove is 14% of the plate thickness.

  In this case, as can be seen from FIG. 7b, the glass substrate is ground at the end face according to the shape of the groove, and the corners of the glass substrate are also ground.

Next, as shown in FIG. 7 c, the glass substrate that was ground in the primary end face grinding portion was ground in the secondary end face grinding portion so that a predetermined grinding amount 74 was obtained. The grinding amount 74 was set so as to be the same as the grinding amount 48 of Example 1, and the grinding process was performed in a state where the center position of the grindstone groove and the center of the glass substrate end face coincided. In FIG. 7c, 75 portions indicated by oblique lines are ground and removed by the secondary end surface grinding portion. However, since the portion indicated by 76 of the end face of the glass substrate is not in contact with the groove of the grindstone with such grinding amount, it cannot be ground and the ground face formed by the primary end face grinding portion remains.
[Comparative Example 2]
In this comparative example, a grindstone in which the same groove as the groove formed in the secondary end face grinding portion of Example 2 was used as the grindstone of the primary end face grinding portion and the secondary end face grinding portion (that is, The grindstone in which the groove | channel of FIG. 5b was formed was used for the grindstone of a primary end surface grinding part and a secondary end surface grinding part.

  Then, as shown in FIG. 8a, the center of the glass substrate end face in the primary end face grinding portion is at the center position of the grindstone groove (in the figure, the center of the glass plate end face is at the center position of the grindstone groove) The glass substrate end face was ground in a state shifted from the position to the left side in the figure. In this case, the deviation width 81 from the case where the center of the glass substrate is at the center of the groove of the grindstone was 14% of the plate thickness. As can be seen from FIG. 8a, the end surface of the glass substrate is ground in accordance with the shape of the groove, and the corners of the glass substrate are also ground.

Next, as shown in FIG. 8 b, the glass substrate subjected to the grinding process in the primary end surface grinding part was subjected to the grinding process in the secondary end surface grinding part so as to obtain a predetermined grinding amount 82. The grinding amount 82 was set to be the same as the grinding amount 56 of Example 2, and the grinding process was performed in a state where the center position of the grindstone groove and the center of the glass substrate end face coincided. In FIG. 8b, the portion 83 indicated by oblique lines is ground and removed by the secondary end surface grinding portion. However, since the portion indicated by 84 in the end face of the glass substrate is not in contact with the grindstone groove with such a grinding amount, it cannot be ground and the ground face formed by the primary end face grinding portion remains.
[Comparative Example 3]
In this comparative example, the grinding process of the glass substrate end face is performed using a grindstone in which grooves having the shapes shown in FIGS. 9a and 9b are formed on the side surfaces thereof as the grindstone of the primary end face grinding section and the secondary end face grinding section. went.

  As shown in FIG. 9a, the groove formed on the grindstone of the primary end surface grinding portion gradually spreads from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion), and has a shape in which a flat portion is provided on the bottom surface. Have. The width 91 of the flat portion on the bottom surface is set to 61% of the plate thickness of the glass substrate, and the groove opening angle 92 is set to 60 degrees.

  And the groove | channel formed in the grindstone of a secondary end surface grinding part is gradually spreading from the bottom part side of a groove | channel to the grindstone surface (surface of the grindstone side part) side, as shown in FIG. 9b, and the flat part was provided in the bottom face. It has a shape. The width 93 of the flat portion on the bottom surface is set to 32% of the thickness of the glass substrate, and the groove opening angle 94 is set to 52 degrees.

  And as shown in FIG. 9c, the center of the glass substrate end face in the primary end face grinding portion is the center position of the grindstone groove (in the figure, the center of the glass plate end face is the center position of the grindstone groove of the glass plate The glass substrate end face was ground in a state shifted from the position to the left side in the figure. The deviation width 95 from the case where the center of the glass substrate is at the center of the groove of the grindstone was 14% of the plate thickness.

  In this case, as shown in FIG. 9c, the corner portion 96 of the glass substrate cannot be ground in the primary end face grinding portion, and when grinding is performed in the secondary end face grinding portion, the load on the grindstone becomes large. .

  Then, as shown in FIG. 9 d, the glass substrate subjected to the grinding process in the primary end surface grinding part was subjected to the grinding process in the secondary end surface grinding part so that the predetermined grinding amount 97 was obtained. The grinding amount 97 at this time is the same as the grinding amount 48 of Example 1, and the grinding process is performed in a state where the center position of the grindstone groove and the center of the glass substrate end face coincide. It was. In FIG. 9d, 98 portions indicated by oblique lines are ground and removed by the secondary end surface grinding portion.

In this comparative example, the secondary end surface grinding part can be ground without leaving the ground surface formed by the primary end face grinding part, but when the grinding process is performed in the primary end surface grinding part, glass is used. There is a problem that corners of the substrate remain. For this reason, when grinding is performed in the secondary end face grinding portion, a load is applied and a product with poor quality is likely to be generated, resulting in a decrease in yield.
[Comparative Example 4]
In this comparative example, the grinding process of the glass substrate end face is performed using a grindstone in which grooves having the shapes shown in FIGS. 10a and 10b are formed on the side surfaces thereof as the grindstone of the primary end face grinding section and the secondary end face grinding section. went.

  As shown in FIG. 10a, the groove formed on the grindstone of the primary end surface grinding portion has a shape gradually expanding from the bottom side of the groove to the grindstone surface (surface of the grindstone side surface portion), and the flat portion is formed on the bottom surface. It has a provided shape. Further, the width 101 of the flat portion of the bottom surface was 54% of the thickness of the glass substrate, and the groove opening angle 102 was 52 degrees.

  As shown in FIG. 10B, the grooves formed on the grinding wheel of the secondary end surface grinding part gradually spread from the bottom side of the groove to the grinding wheel surface (the surface of the grinding wheel side face part), and have a shape in which a flat part is provided on the bottom surface. Have. The width 103 of the flat portion of the bottom surface was 32% of the thickness of the glass substrate, and the groove opening angle 104 was 52 degrees.

  As shown in FIG. 10c, the center of the glass substrate end face in the primary end face grinding portion is the center position of the grindstone groove (in the figure, the position of the glass plate when the center of the glass plate end face is at the center position of the grindstone groove) The glass substrate end face was ground in a state of being shifted to the left in the figure from the dotted line). The deviation width 105 with respect to the case where the center of the glass substrate end face is at the center of the groove of the grindstone was 14% of the plate thickness.

  Then, as shown in FIG. 10 d, the glass substrate subjected to the grinding process in the primary end surface grinding part was subjected to the grinding process in the secondary end surface grinding part so as to obtain a predetermined grinding amount 106. At this time, grinding was performed in a state where the center position of the groove of the grindstone coincided with the center of the end face of the glass substrate. In FIG. 10d, a portion 107 indicated by hatching is ground and removed by the secondary end surface grinding portion.

  FIG. 10e shows an enlarged view of the portion indicated by the dotted line 109 in FIG. 10d in order to show the contact state between the surface of the grindstone groove and the glass substrate surface when grinding by the secondary end face grinding portion.

  As can be seen from FIG. 10e, in this comparative example, in the secondary end face grinding portion, a portion 108 of the ground surface formed by the primary end face grinding portion remained unground.

  In any of the above comparative examples, when the position of the glass substrate in the primary end face grinding portion is shifted to the same extent as in the embodiment, the ground surface formed by the primary end face grinding portion is also in the secondary end face grinding portion. It turns out that it cannot be ground and remains, or the corner | angular part of a glass substrate remains.

  On the other hand, according to the embodiment of the glass substrate end surface polishing apparatus and glass substrate end surface polishing method of the present invention, even if the center position of the glass substrate end surface is shifted from the center position of the grindstone groove in the primary end surface grinding portion, The end face of the glass substrate can be ground without leaving the ground surface formed by the primary end face grinding part in the secondary end face grinding part. For this reason, it becomes possible to improve a yield compared with a prior art.

  In addition, since grinding can be performed without leaving the corners of the glass substrate end face in the primary end face grinding part, the load on the secondary end face grinding part can be reduced, and in this respect also the product yield can be improved. become.

  Furthermore, in the present invention, it is not necessary to adjust the position of the grindstone of each of the primary end surface grinding part and the secondary end surface grinding part with higher accuracy than in the prior art, and the time required for position adjustment can be shortened. Therefore, it is possible to increase the operating rate of the end surface grinding apparatus.

13 Primary end face grinding part 23 Secondary end face grinding part 132, 232 Grinding stone 133, 233 Groove 33 Notch

Claims (7)

It has a primary end face grinding part and a secondary end face grinding part in order from the upstream side of the glass substrate transport path,
Each of the primary end face grinding part and the secondary end face grinding part is provided with a cylindrical grindstone in which grooves are formed on the side surfaces along the circumferential direction,
The cross-sectional shape of the groove when the cylindrical grindstone is cut along a plane including its central axis has a shape that gradually widens from the bottom side of the groove to the grindstone surface side, and the opening angle is the primary angle. The groove formed in the grindstone of the end face grinding part is larger than the groove provided in the grindstone for end face grinding of the secondary end face grinding part, and the groove provided in the grindstone of the primary end face grinding part Is a glass substrate end surface grinding device characterized in that its bottom is a convex curve on the bottom side.   The glass substrate end surface grinding apparatus according to claim 1, wherein a cross-sectional shape of a groove formed in the grindstone of the secondary end surface grinding portion is a shape in which a notch portion is formed at an opening end portion.   The glass substrate end face grinding apparatus according to claim 1 or 2, wherein the count of the grindstone of the primary end face grinding section is smaller than the count of the grindstone of the secondary end face grinding section. About the end face of the glass substrate, after grinding at the primary end face grinding part, grinding at the secondary end face grinding part, the end face grinding method of the glass substrate,
Each of the primary end face grinding part and the secondary end face grinding part is provided with a cylindrical grindstone in which grooves are formed on the side surfaces along the circumferential direction,
The cross-sectional shape of the groove when the cylindrical grindstone is cut along a plane including its central axis has a shape that gradually widens from the bottom side of the groove to the grindstone surface side, and the opening angle is the primary angle. The groove formed in the grindstone of the end face grinding portion is larger than the groove provided in the grindstone of the secondary end face grinding portion, and the groove provided in the grindstone of the primary end face grinding portion is the bottom thereof. Is a curved surface convex toward the bottom side.   5. The method for grinding an end face of a glass substrate according to claim 4, wherein a cross-sectional shape of a groove formed on the grindstone of the secondary end face grinding portion is a shape in which a notch portion is formed at an opening end portion.   The method for grinding an end face of a glass substrate according to claim 4 or 5, wherein the count of the grindstone of the primary end face grinding section is smaller than the count of the grindstone of the secondary end face grinding section.   A method for producing a glass substrate, wherein the method for grinding an end surface of a glass substrate according to any one of claims 4 to 6 is used.

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