JP5898984B2 - Hard brittle plate side processing equipment - Google Patents

Description

  The present invention relates to an apparatus for grinding a side of a hard brittle plate such as a glass plate, and particularly to an apparatus for grinding a cleaved side of a glass substrate for a display panel used in a portable terminal or the like with a rotating grindstone. .

  A glass substrate used for a display panel of a portable terminal or a television receiver is cut into a predetermined size by cleaving (breaking) using the brittleness of glass. The cleaving due to mechanical shock is a method called scribe break, for example, and the cleaving due to thermal shock is a method using laser beam, for example. A broken surface of a glass substrate cleaved by such a method has small irregularities, and the corners of the substrate surface and the cut surface become sharp edges and small chips can be formed. Therefore, in order to mainly remove such sharp edges and chips, side processing generally called chamfering is performed.

  The glass substrate is usually cleaved into a rectangular shape. As shown in FIG. 10, the side processing of the rectangular glass substrate is performed by fixing the glass substrate 1 to the table 2, fixing the rotating grindstones 3 and 3 arranged on both sides of the table to fixed positions, and the table 2. And the rotating grindstones 3 and 3 are moved relative to each other in a direction (Y-axis direction) parallel to the sides 11 and 11 of the glass substrate to be ground.

  FIG. 12 is a front view schematically showing an example of the side processing apparatus. A glass plate 1 serving as a workpiece (workpiece) is fixed on a table 2 by vacuum suction or the like. The table 2 is slidably mounted on a rail 21 in the direction perpendicular to the paper surface (Y-axis direction) in the drawing, and is connected via a ball nut 23 to a Y-axis feed screw 22 that is rotationally driven by an electric motor (not shown). Has been. The rotary grindstone 3, whose only one is shown in the figure, is attached to the tip of a grindstone shaft 32 that is integral with the rotor shaft of the grindstone motor 31 mounted on the tool table 4. The tool table 4 is mounted so as to be movable in the width direction of the workpiece 1 (X-axis direction which is the horizontal direction in the figure) by a linear guide 42 provided on the lifting table 41, and an X-axis feed motor (servo) mounted on the lifting table 41. A motor) 43 is connected to an X-axis feed screw 44 driven by a ball nut 45 (see FIG. 2). The lifting platform 41 is mounted on a column (not shown) so as to be movable in the vertical direction (Z-axis direction), and is connected to a Z-axis feed screw 47 driven by a lifting motor (servo motor) 46 via a ball nut (not shown). Has been. The X-axis feed motor 43 and the lift motor 46 are controlled by the NC device 5 via servo amplifiers 51 and 52, respectively.

  The side 11 of the glass substrate to be processed is fixed to the table 2 in the Y-axis direction, and the lifting table 41 and the tool table 4 are moved under the control of the NC device 5, whereby the side 11 of the glass substrate is moved. The relative position of the grindstone 3 in the Z-axis and X-axis directions is set and held at a fixed position, and the table 2 is moved in the Y-axis direction in this state, whereby the side 11 of the glass substrate is processed with the grindstone 3. In the example shown in the figure, the table 2 is driven, but a column supporting the tool table 4 with the table 2 fixed may be driven in the Y-axis direction. Moreover, you may provide the raising / lowering apparatus which raises / lowers the table 2 instead of providing the raising / lowering base 41 in the tool stand 4 side.

  As the grindstone 3, a grindstone called a general grindstone having a trapezoidal groove 33 on the outer periphery as shown in FIG. 12, or upper and lower grindstone shafts 32 parallel to the side 11 of the glass substrate, as shown in FIG. 11, A so-called multi-grinding wheel in which a plurality of disc-shaped grinding stones 34 are attached to 32 is often used.

  If the side grinding is performed with the rotary grindstone 3 as a tool fixed on the table 2 in the Z-axis direction and the X-axis direction perpendicular to the Y-axis direction, which is the relative feed direction, it is caused by cleaving. It can be processed into the side of an accurate straight line that is chamfered by removing unevenness and sharp edges.

  If the grindstone 12 is processed in the shape of a side grindstone, the bottom surface of the trapezoidal groove 33 is used. If the grindstone is a multiple grindstone, the disc grindstone 34 is biased upward or downward so that the disc grindstone. This is carried out by bringing a portion of the outer periphery of 34 in the vertical direction into contact with the fractured surface 12 of the glass substrate.

  The above is for a rectangular glass substrate, but for a rounded trapezoidal shape or a deformed glass substrate with curved sides, is it possible to move the grindstone around the glass substrate fixed in place? The processing is performed by controlling the position of the grindstone in the X-axis direction (the radial direction is centered on the turning center of the table) in synchronization with the turning around the vertical axis of the table to which the glass substrate is fixed.

  On the other hand, as for mobile phones, smartphones are becoming mainstream, and display panels are becoming larger even in small mobile terminals in which light weight is particularly important. In addition, touch panels with a touch sensor have become mainstream in portable terminals such as iPad (registered trademark) with a large display area, electronic books, and personal computer displays. Under these trends, small mobile terminals such as mobile phones and smartphones are focused on weight reduction and design, and display panels are becoming thinner. Emphasis is placed on how to avoid a decrease in strength due to crystallization. Further, in a display panel with a touch sensor, since the display panel is directly touched, the strength of the panel substrate is required, and it is important to increase the strength of the panel without impairing portability, that is, without increasing the thickness of the substrate. It has become an issue.

  Furthermore, in the touch panel, the cover glass with the touch sensor has been abolished, and technical progress has been made in the direction of providing the touch sensor directly on the display panel. The strength required for the substrate of the panel itself is increasing.

Japanese Patent Laid-Open No. 10-113855 JP 2000-52233 A JP 2006-305661 A

  In order to meet the above demands, if the glass substrate for display panels is made thinner, touch panels, and cover glass is abolished, there is a limit to increasing the strength by improving the material of the substrate. When the display panel is transported or assembled during manufacturing, and further, when used by the user, there is an increased risk of damage such as cracking in the panel.

  The present invention has been made with the object of reducing as much as possible the increase in cracks caused by thinning the display panel, etc., and the strength resulting from the side processing of the glass substrate for a display panel that has been overlooked in the past. It is an object to provide technical means for preventing the decrease.

  The present invention relates to the setting (positioning or feeding) of the grindstone 3 in the side processing of a hard brittle plate, particularly a glass substrate for a display panel. The above problem is solved by restricting the force. When the machining reaction force in the X-axis direction acting on the grindstone 3 (component force in the X-axis direction of the machining reaction force) exceeds the limited thrust, the grindstone 3 is pushed back in the direction away from the workpiece (reverse direction) following the load. Like that. When the load falls below the limited thrust, the original position commanded by the controller 5 is restored and the position is held.

  The side processing apparatus according to the present invention includes a table 2 for fixing a hard brittle plate 1 serving as a workpiece (work), and a rotation arranged at the side of the table 2 so as to be substantially flush with the upper surface of the table 2. The grindstone 3, position setting means for setting the position in the X-axis direction orthogonal to the side 11 of the workpiece to be machined with the rotary grindstone 3, the table 2 and the tool table 4 in a direction parallel to the side 11 of the workpiece Y-axis feeding devices 22 and 23 that move relative to each other.

  The position setting means sets the position of the grindstone 3 relative to the workpiece 1 using the X-axis feed motor 43 whose rotation angle or stroke is controlled by the NC device 5 as a drive source. The position setting means according to the present invention regulates the advance position of the grindstone 3 to a position corresponding to the command value of the NC device 5 and presses the grindstone 3 toward the regulated position with a predetermined urging force. The position of 3 is set. Whether the predetermined urging force is registered in advance in the NC device 5 or the urging force of the urging device 6 is set by a pressure setting device, a current setting device, or the like according to the material of the workpiece to be processed, the plate pressure, and the processing mode. Depending on whether the elastic force of the spring or the elastic bodies 35 and 36 is selected or the like, the thrust of the grindstone in the advancing direction facing the workpiece is limited to a predetermined value.

  Note that the X axis is a direction orthogonal to the side of the plate material that is actually being processed, and in an apparatus that moves and processes the grindstone in one direction in synchronization with the rotation around the vertical axis of the table to which the glass plate material is fixed. The radial direction is centered on the center of rotation of the plate material. As shown in FIG. 10, when a plurality of grindstones 3 are provided and their positions and feeds are individually controlled, the control direction of the other grindstone corresponding to the X-axis direction of one grindstone is sometimes referred to as the U-axis direction. The X-axis in this specification includes the U-axis in such a case.

  In the conventional apparatus that performs side processing while holding the relative positional relationship between the table 2 that fixes the substrate 1 to be processed and the grindstone 3 that processes the side 11 of the substrate at the set position, the substrate side caused by cleaving When the convex part of the fine unevenness of the side and the corner part of the chip enter the contact part with the grindstone 3, the fluctuation of the machining resistance suddenly occurs, the fluctuation of the machining force on the grinding surface after the side machining, In particular, it is presumed that minute cracks that could not be visually recognized occurred in the portion where the processing force increased rapidly. Then, it is considered that the minute cracks grew due to bending stress acting on the substrate at the time of transportation and assembly or bending stress generated by touching the substrate at the time of use, resulting in a large crack leading to damage to the substrate.

  On the other hand, according to the present invention, when a convex portion or a chipped corner portion where the processing load increases suddenly enters the contact portion with the grindstone 3, the increase in the processing load is alleviated. Since the grindstone 3 is pushed back in the direction away from the substrate, the occurrence of micro cracks due to a sudden change in the processing load is prevented, the apparent strength of the substrate is increased, the display panel is thinned and the touch panel is touched. It is possible to respond to the demands of computerization.

  According to the present invention, since the substrate side is processed at a predetermined processing load or less set in the biasing device or the NC device, even if there are irregularities or chips on the processed substrate side, the processing side exceeds the predetermined processing load. Since no force is applied to the substrate, the processing is close to polishing, the surface roughness of the processed surface is improved, and the occurrence of minute cracks is prevented.

  The apparent strength of the substrate processed on the side by the apparatus of the present invention is higher than that of the same material and processed on the side by the conventional apparatus. Therefore, it can improve the strength against external force generated by touching the substrate during side processing, during transportation, assembly, or use. The panel strength can be improved.

Schematic front view showing the main part of the embodiment Schematic front view showing the main part of Reference Example 1 Plan view Partial cross-sectional view of the part provided with play Schematic front view showing the main part of Reference Example 2 Plan view The perspective view which shows the principal part of the reference example 3 The perspective view which shows the principal part of the reference example 4 Front view showing essential parts of Reference Example 5 Perspective view showing an example of side processing Front view showing another example of a rotating whetstone Schematic front view showing the main part of the side processing device

Referring to FIG. 1, it will be specifically described embodiments of the present invention. The components already described in FIG. 12 are denoted by the same reference numerals as those in FIG. In the side processing apparatus of the present invention, a processing reaction force in the X-axis direction exceeding a predetermined value registered in the controller 5 in advance is applied to the grindstone 3 in which the relative position and relative movement with respect to the substrate 1 to be processed by the controller 5 are set. The grindstone 3 moves in a direction away from the work 1.

  The side processing apparatus shown in FIG. 1 controls the position of the grindstone 3 by applying different torques or thrust limits to the X-axis feed motor 43 in the advance direction and the reverse direction of the grindstone 3. How much force the grindstone 3 is held at the set position against the machining reaction force is determined by a current value applied to the X-axis feed motor 43 when the position is held. Therefore, the feedback signal is set so as to resist with a weak current value in the direction in which the grindstone 3 is moved backward and with a strong current value in the direction in which the grindstone 3 moves forward.

  The NC device 5 controls the X-axis feed motor 43 via the servo amplifier 51, and the feedback signal b of the rotation angle of the X-axis feed motor 43 is given to the servo amplifier 51. The servo amplifier 51 controls the current applied to the X-axis feed motor 43 so that the feedback signal b coincides with the command value a from the NC device 5, so that the rotation angle of the X-axis feed motor 43, and hence the grinding wheel 3. Holds the position. When a processing reaction force in the direction of retracting the grindstone 3 acts during the processing of the substrate 1, the servo amplifier 51 applies torque in the direction of advancing the grindstone 3 to the X-axis feed motor 43 to command the grindstone 3. Try to hold on.

  Therefore, the maximum torque of the X-axis feed motor 43 can be limited by providing a maximum current setter 53 that limits the current applied to the X-axis feed motor 43 and limiting the maximum value of the current flowing in the direction in which the grindstone 3 is advanced. For example, when a machining reaction force of a predetermined value or more corresponding to the maximum torque acts on the grindstone 3 set at the commanded position, the X-axis feed motor 43 generates a torque sufficient to resist the machining reaction force. Therefore, the X-axis feed motor 43 is forcibly rotated by the processing reaction force, and the grindstone 3 is moved away from the substrate 1 to prevent an excessive processing load from acting on the substrate 1. It is possible to prevent cracks from occurring on the ground surface.

Reference example

  2-9 is a figure which shows a reference example. In the reference examples shown in FIGS. 2 to 6, a clearance δ is provided at a position from the feed motor 43 in the X-axis direction to the grindstone 3 or in the middle of the feed transmission system, and the grindstone 3 is attached to the substrate 1 with a predetermined force. An urging device 6 is provided.

  In the reference examples shown in FIGS. 7 to 9, elastic bodies 35 and 36 that allow the grindstone 3 to move in the direction away from the work 1 are interposed in the middle of the transmission system from the tool table 4 on which the grindstone is mounted to the grindstone 3. In this case, a metal grindstone excellent in rigidity and wear resistance can be used as the grindstone 3. Further, it is preferable to use an anisotropic elastic body that prevents or reduces deformation in the advance direction of the grindstone 3 as the elastic bodies 35 and 36 or to provide a stopper that prevents deformation in the advance direction of the grindstone 3.

  Also in the following description of the reference example, the components already described in FIG. 12 are denoted by the same reference numerals as those in FIG. 2 to 4 are diagrams showing Reference Example 1. FIG.

  In Reference Example 1, an axial clearance δ of the X-axis feed screw 44 is provided between a ball nut 45 that is screwed to the feed screw 44 in the X-axis direction and a bracket 55 that is fixed to the tool table 4. . A ball nut 45 screwed into the X-axis feed screw 44 without a gap is inserted into a fitting hole 56 in a direction parallel to the X-axis feed screw 44 provided in the bracket 55 so as to be freely movable in the axial direction. A key 57 or spline for fixing the relative rotation is provided. A clearance δ is formed between the flange 58 on the ball nut 45 side and the stopper 59 on the bracket 55 side. That is, the bracket 55 fixed to the tool base 4 and the ball nut 45 are connected in the axial direction of the X-axis feed screw 44 so as to be movable in the axial direction and not relatively rotatable in the gap δ. The clearance δ is a clearance sufficiently larger than the size of the unevenness that may occur on the side 11 of the workpiece to be processed.

  In this way, an air cylinder 6 is provided to urge the tool table 4 connected to the X-axis feed screw 44 toward the substrate 1. The air cylinder 6 is mounted on the lifting table 41 with the rod 61 moving forward and backward in the axial direction of the X-axis feed screw 44, the tip of the cylinder rod 61 is connected to the tool table 4, and the tool table is placed on the head end side of the cylinder. Therefore, pressurized air for biasing the grindstone 3 toward the substrate 1 is supplied. The stroke of the cylinder rod 61 is larger than the movement stroke of the tool table 4 by the X-axis feed motor 43 by a margin.

  In the reference example 1 configured as described above, the bracket 55 is pushed to the substrate 1 side by the urging force of the air cylinder 6, and the stopper 59 of the bracket 55 and the flange 58 of the ball nut 45 are pressed against each other. The tool base 4, and thus the grindstone 3, is set. In this state, the substrate 1 is moved relative to the grindstone 3 to process the side 11 of the substrate. If a reaction force exceeding a predetermined force determined by the pressure of the pressurized air supplied to the air cylinder 6 is applied from the substrate 1 to the grindstone 3 during this processing, the cylinder rod 61 is pushed back, and the tool table 4, and thus the tool table 4. The grindstone 3 moves away from the side 11 of the substrate, and the processing load acting on the substrate is relaxed. This prevents a large processing load from acting on the ground surface of the substrate and prevents the occurrence of cracks due to a rapid increase in the processing load.

  5 and 6 are views showing Reference Example 2 of the present invention. The reference example 2 is an example in which a clearance δ is provided between the tool base 4 and the grindstone motor 31, and the grindstone motor 31 has a short stroke corresponding to the clearance δ in the X-axis direction provided on the tool base 4. The tool base 4 is mounted via a linear guide 48. The grindstone motor 31 is connected to a rod 61 of a short stroke air cylinder 6 mounted on the tool base 4, and the grindstone motor 31 with a predetermined urging force and thus the pressurized air supplied to the head end side of the air cylinder. The grindstone 3 is biased toward the substrate 1.

  In the reference example 2 configured as described above, the grindstone motor 31 and thus the grindstone 3 are positioned in a state where the grindstone motor 31 is pushed to the stroke end on the substrate 1 side of the linear guide 48 by the urging force of the air cylinder 6. Thus, the side 11 of the substrate is processed. If a reaction force exceeding a predetermined force determined by the pressure of the pressurized air supplied to the air cylinder 6 is applied from the substrate 1 to the grindstone 3 during this machining, the cylinder rod 61 is pushed back, and the grindstone motor 31 and thus the grindstone motor 31. The grindstone 3 moves away from the side edge 11 of the substrate, the processing load acting on the substrate is relaxed, and the generation of cracks due to a sudden increase in the processing load is prevented.

  In the reference examples 1 and 2, an air cylinder is used as the urging device, but an elastic body such as a spring or a magnet attracting force can be used.

  In the reference examples 1 and 2, the rotation motor 43 is used as the X-axis feed motor. However, the position of the grindstone 3 in the X-axis direction can be set using a linear motor. By adopting the same means, the same effects as described above can be obtained.

  FIG. 7 is a view showing Reference Example 3 of the present invention. In the reference example 3, the grindstone motor 31 is mounted on the tool table 4 via the plate-like elastic body 35. The other structure is the same as that of the conventional apparatus shown in FIG. When an excessive processing reaction force is applied from the substrate 1 to the grindstone 3 set at a predetermined position by the X-axis feed motor 43, the elastic body 35 is deformed, and the grindstone 3 moves away from the substrate 1 along with the deformation. . By this movement, it is possible to prevent an excessive processing load from acting on the substrate 1 and to prevent a crack from occurring on the ground surface of the substrate. In Reference Example 3, the direction in which the grindstone leaves when an excessive machining load is applied does not necessarily match the X-axis direction that is the feed direction of the grindstone 3 by the X-axis feed motor 43. If the elastic body 35 is an isotropic elastic body, the grindstone 3 moves in the direction in which the processing reaction force acts, and the processing load is reduced.

  FIG. 8 is a diagram showing Reference Example 4. In Reference Example 4 and Reference Example 5 shown in FIG. 9, an elastic body 36 is interposed on the grindstone shaft 32. In Reference Example 4 shown in FIG. 8, the grindstone 3 is mounted in a cantilever manner on a grindstone shaft 32 that is integral with the rotor shaft of the grindstone motor 31, and an elastic body 36 is interposed on the grindstone shaft 32.

  On the other hand, in Reference Example 5 in FIG. 9, the grindstone 3 is pivotally supported by bearings provided on both sides thereof, and the elastic body 36 is interposed between the bearing and the grindstone 3. In other words, the grindstone 3 is pivotally supported at both ends with the elastic body 36 interposed between both sides of the grindstone shaft 32.

  In any case of Reference Examples 4 and 5, when an excessive processing reaction force is applied to the grindstone 3, the elastic body 36 is deformed and the grindstone 3 moves away from the substrate 1, and the side edge 11 of the substrate. This prevents a local excessive machining load from acting on the ground surface and prevents cracks from occurring on the ground surface.

1 Workpiece (substrate)
2 Table 3 Rotary grindstone 4 Tool stand 5 NC unit 6 Air cylinder
11 Side of workpiece
22,23 Y-axis feeder
31 Wheel motor
35,36 elastic body
43 X-axis feed motor
44 X-axis feed screw
45 Ball nut
48 Straight guide
51 Servo amplifier
53 Maximum current setting device

Claims (1)

A table for fixing a plate of hard brittle material, which is a workpiece, a rotating grindstone arranged at the side of the table at substantially the same height as the upper surface of the table, and a side of the plate material to be worked on the grindstone In a side processing apparatus for a hard brittle plate, comprising: a position setting means for setting a position in an orthogonal X-axis direction; and a Y-axis feeding device that relatively moves the table and tool table in a direction parallel to the side.
The position setting means limits the maximum torque or thrust of the X-axis feed motor controlled by the NC device and the X-axis feed motor in the direction in which the grindstone moves away from the workpiece to be lower than the maximum torque or thrust in the advancing direction. With a maximum current setter,
While restricting the advanced position of the grinding wheel at a position corresponding to the command value of the NC device, and sets the position of the grinding wheel by pressing a predetermined biasing force toward a position of the grinding wheel and the regulating Side processing equipment for hard and brittle plates.

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