CH670790A5 - - Google Patents

Description

DESCRIPTION

The invention relates to a glass plate grinding machine according to the preamble of claim 1, in particular a glass plate grinding machine with a numerical control system for grinding the peripheral edges of glass plates during the movement of grinding wheels along the peripheral edges of these glass plates. The movements of the grinding wheels are numerically controlled.

Known numerically controlled glass plate grinding machines for grinding the peripheral edges of glass plates do not work satisfactorily because it is very difficult to readjust the position of the grinding wheel when the grinding wheel is ground, because the grinding wheel is usually rigidly mounted, and because in known machines the exact positioning of the glass plates is extremely difficult Support organs during or after the supply to these support organs is difficult to accomplish.

The object of the invention is to improve a numerically controlled glass plate grinding machine in that

that these disadvantages are avoided, namely that the grinding wheel can be easily readjusted when the wheel is ground if its diameter has decreased as a result of wear.

Another object of the invention is to improve a machine of the generic type in such a way that the glass pane to be processed is positioned more easily and more precisely on the support members after they have been transported to them.

The characterizing features of patent claim 1 serve to solve these tasks.

The first part of the object of the invention is therefore achieved by a numerically controlled glass plate grinding machine, with a machine bed, with a plurality of stands mounted on the machine bed, all of which serve to support a glass plate to be ground, with grinding wheels for grinding the glass plate, with a plurality of Grinding heads, each of which carries an associated grinding wheel at one end, and which are each arranged above the associated stand such that the grinding head can be rotated about an axis which is perpendicular to the plane of the glass plate and through a grinding point (A) which passes through during the grinding operation the point of contact of the surface of the grinding wheel with the peripheral edge of the glass plate is defined, with means for rotating the grinding heads around said axis, with displacement means for displacing these grinding heads with respect to said stands in two mutually perpendicular directions, and with control means, which are operatively connected to the numerical control and the displacement means, in such a way that each of these grinding heads can be moved along the peripheral edge of the glass plate carried by the stands and grinds this peripheral edge, said control means also having the means for rotating the grinding heads are linked to the effect that a straight line from the named grinding point (A) to the axis of rotation of the grinding wheel coincides with the normal straight line of the peripheral edge at the grinding point (A). According to the invention, each of the grinding wheels mentioned is able to carry out the same machining operation, and the glass plate grinding machine comprises setting means for setting the position of each of these grinding wheels. namely individually and independently of one another and with reference to said assigned grinding head in a direction that runs parallel to said straight line.

The second part of the object of the invention is achieved with a glass plate grinding machine, with a machine bed, with support means mounted on the machine bed for supporting a glass plate to be ground, with a first. arranged on one side of the support means for transporting the glass plate in a position that corresponds to that of the support means, and with a first transfer device for transferring the glass plate from that position to the support means. According to the invention, the first transport member for receiving the glass plate has a plurality of rollers which are rotatably mounted on the machine bed in such a way that an imaginary plane which runs through a plurality of contact areas between the rollers and the glass plate has an inclination with respect to a horizontal plane and a vertical plane in which an axis of rotation of the rollers lies, and that in the vicinity of the lowermost part of those contact regions, a belt is provided for supporting the glass plate carried by the rollers along one of its peripheral edges, this belt conveying the glass plate in one direction which runs perpendicular to the axis of rotation mentioned, lying in that imaginary plane.

Further developments of the subject matter of the invention or preferred embodiments thereof are defined in the dependent claims.

The invention is explained in more detail below using an exemplary embodiment; show it:

Figure 1 is a front view of a grinding machine;

Figure 2 is a plan view of the grinding machine;

Figure 3 is a side view of the grinding machine;

Figure 4 is an enlarged side view of part of the grinding machine;

Figure 5 is an enlarged front view of part of the grinding machine;

Figure 6 is an enlarged plan view of part of the grinding machine; and

Figure 7 is an electrical and pneumatic circuit diagram of a fluid actuator.

FIGS. 1, 2 and 3 show the device according to the invention in the form of a grinding machine main body 1 for grinding the peripheral edges of glass plates with numerically controlled movement of the grinding wheels 7. and there is also shown a feeding device 2 for feeding the glass plates to the grinder main body 1 and an output device 3 for discharging the cut glass plates, each mounted on a machine bed 4.

The grinding machine main body 1 is suitable for grinding the peripheral edges of glass plates 8 in that each grinding head 5 in the direction of an axis X in FIG. 2 from left to right and vice versa and in that a table 6 can be moved back and forth in the direction of an axis Y, at the same time each of the grinding wheels 7 is moved along the peripheral edge of the glass plate 8, while each grinding wheel 7 is rotated about an axis which is perpendicular to the plane of the glass plate 8 and passes through the grinding point A (FIG. 4) of the grinding wheel 7.

The table 6 mounted on the machine bed 4 can move in the Y direction and carries stands 9, five of which are arranged in a row in order to hold the glass plates 8 to be ground. These stands 9 can Glas5

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Hold plates 8 by means of a vacuum clamping device. For this purpose, each stand 9 is connected to a vacuum pump, not shown, via pipes and valves. The table 6 has sliding elements 10 in the middle and at its two ends, which run parallel to one another in the direction Y, and lies on sliding rails 11, in which the sliding elements 10 engage. Since these slide rails 11 are arranged parallel to one another in the Y direction on the machine bed 4, the table 6 can be moved on the machine bed 4 in the Y direction.

A servomechanism for the movement in the direction Y has three groups of screw spindles 12, which are arranged along the sliding elements 10, gear 13 and a shaft 14 connected to the screw spindles 12 and a Y-axis servo motor 16, which drives the shaft 14 via a belt 15 drives. Each of the screw spindles 12 has ball threads 17 and an adjusting nut 18, and each ball thread 17 is fastened to the machine bed 4 via a bearing 19. while the adjusting nut 18 is attached under the table 6. The ball screws 17 are connected to the gears 13 on the machine bed 4 and the gears 13 are in turn connected to one another by the shaft 14. The shaft 14 is supported at various points on the machine bed 4 by bearings 20. The belt drives 15 expediently comprise a V-belt and pulleys.

A support frame 22 is held by supports 21 above the table 6, which are arranged on both sides of the machine bed 4. Two groups of slide rails 23 are arranged parallel to the axis X on the front of the support frame 22. The slide rails 23 have a rail body 24, which lies on the support frame 22, and a number of slide elements 25, which move on the rail body 24, and furthermore, an engine block 26 is fastened to the slide elements 25. Accordingly, the engine block 26 can be moved in the X direction by the slide rails 23.

The servomechanism acting in the X direction has screw spindles 27, which are arranged between the two groups of slide rails 23, and an X-axis servo motor 28, which is usually coupled to the screw spindles 27 by a belt or the like. The screw spindle 27 has a ball screw 29 and an adjusting nut 30. the ball screw 29 is fastened to the supporting frame 22 by a bearing 78 and the adjusting nut 30 to the engine block 26.

The engine block 26 shown in FIG. 4 is equipped with five grinding heads 31 such that they are arranged above the respective stands 9 on the table 6 and that each of the grinding heads 31 has a mounting device 32, a grinding head 5 hanging on the mounting device 32 and one with the Holding device 32 connected rotary drive 33. Each of the grinding heads 31 is fastened to the engine block 26 via the mounting device 32.

According to FIGS. 4 to 6, the grinding head 5 has a spindle motor 34 and a displacement adjustment device 35 with a cutting direction adjustment guide 42. a transverse guide 43 and a vertical guide 79 in order to position the spindle motor 34 in the vertical direction and in two perpendicular to each other in the horizontal plane Directions. The grinding wheel 7 is attached to the shaft of the spindle motor 34. The holding device 32 has a rotatable shaft 36. A number of bearings (not shown) for supporting the shaft 36 and a housing 37 for holding the bearings. The mounting device 32 is attached to the engine block 26 through the housing 37. The entire grinding head 5 is suspended to hold the displacement adjuster 35 on the lower part of the rotatable shaft 36 and a bevel gear 38 is arranged on the upper part of the rotatable shaft 36 to form the rotary drive 33. The grinding head 5 can be rotated about the rotatable shaft 36 of the holding device 32 as an axis of rotation.

In FIGS. 1 and 2, the servomechanism for transmitting the rotary movement has the rotary drive 33 consisting of the bevel gear 38 at the upper end of the rotatable shaft 36 of the holding device 32, a drive shaft 39 connecting the rotary drive 33 with the respective grinding head device 31 and one with the drive shaft 39 connected servo motor 40 for turning on. The drive shaft 39 is driven by the servo motor 40, as a result of which the grinding head 5 and thus the grinding wheel are rotated simultaneously in each grinding head device 31 by the respective rotary drive 33.

If the center of rotation for the grinding wheel 7 is set such that it coincides with the grinding point A of the grinding wheel 7 in relation to the glass plate 8, according to FIG. 4, namely by the displacement adjustment device 35 of each grinding head 5, then the grinding wheel 7 will move due to a numerical control a rotational movement and moves along the peripheral edge of the glass plate 8, which is held on each of the stands 9, according to the numerically controlled movement of the table 6 and the engine block 26 and thereby grinds so that the grinding point A is always at one is held in a constant position.

In the following, an explanation is given for the principle according to which the grinding wheel 7 carries out the grinding, during which a rotary movement takes place according to numerical control, and the advantages achieved thereby are explained with reference to FIGS. 4 to 6.

The grinding wheel 7 is held during the movement along the circumferential edge of the glass plate 8 in such a way that the grinding head 5 performs a rotary movement about an axis, which takes place through the grinding point A of the grinding wheel 7 and perpendicular to the plane of the glass plate 8. The angle of rotation of the grinding wheel 7 is subject to numerical control such that the normal line on the profile of the peripheral edge of the glass plate 8 is aligned with a straight line connecting the grinding point A with the center of rotation 41 of the grinding wheel 7. With such a structure, when the diameter of the grinding wheel 7 is reduced due to abrasion, the holding position for the grinding wheel 7 can be set by moving the grinding wheel 7 in only one direction, specifically by the cutting direction setting guide 42 in such a way that the grinding point A is aligned with the axis of rotation 36 of the grinding wheel 7. This means an essential advantage for the glass plate grinding machine if a number of glass plates 8 are ground simultaneously by a number of grinding wheels 7. Since the drive of the grinding wheels 7 can be determined beforehand, the grinding point A for the grinding wheel 7 can easily be aligned with respect to the axis of rotation 36 of the grinding wheel 7 by simply moving the cutting direction setting guides 42 by the desired dimension. The movement of each cutting direction setting guide 42 is expediently effected by a numerically controlled displacement servo motor 44 as shown in FIG. 6.

The control mechanism for the grinding contact pressure is explained below with reference to FIGS. 4 to 6.

In FIGS. 4 to 6, the same parts have the same reference symbols as in FIGS. 1 to 3.

In these figures, the displacement adjustment device 35 has a cutting direction adjustment guide 42, a transverse guide 43 and a vertical guide 79. A shift control device 45. with a spindle motor

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34 and a fluid actuator 46 is attached to the cutting direction setting guide 42. The displacement control device 45 is arranged such that its direction of movement is parallel to the direction of movement of the cutting direction setting guide 42. The fluid actuator 46 can move the spindle motor 34 and thus the grinding wheel 7 back and forth in the direction of movement of the displacement control device 45 and thus change the contact pressure of the grinding wheel 7 on the glass plate 8. A ball guide bearing is expediently used for the displacement control device 45 in such a way that the fluid actuator 46 can be moved with a low actuation force. Furthermore, an air cylinder is expediently used as the fluid actuator 46.

To control the actuating force for the fluid actuator 46, a primary air pressure is supplied to an electropneumatic converter 47 and a secondary air pressure controlled by the electropneumatic converter 47 is transmitted to the fluid actuator 46 in order to control the pressing force for the fluid actuator according to FIG. The electro-pneumatic converter 47 is constructed in such a way that the delivered pneumatic pressure is changed in relation to the electrical current fed in.

On the other hand, the current signal input to the electropneumatic converter 47 is generated by a current converter 48. The current transformer 48 is coupled to an auxiliary function part of a numerical control device 49 which controls the grinder main body 1 and which is designed to generate a number of input current pulses while generating a number of auxiliary function signals from that numerical control device 49 receives. The current converter 48 is usually constructed as a variable resistor or as a digital / analog converter system. Furthermore, the electropneumatic converter 47 can be connected to a separate control device, to a setting instrument or to a functional amplifier, so that it does not have to be operated in connection with the numerical control device 49.

While an air cylinder is commonly used as the fluid actuator 46, the secondary air pressure generated by the electropneumatic converter 47 can be connected to a hydraulic pressure converter and converted into a fluid pressure corresponding to the secondary air pressure, and the hydraulic pressure can be supplied to the fluid actuator 46.

In this way, the electropneumatic converter 47 changes the secondary air pressure supplied to the fluid actuator 46 by the signal from the numerical control device 49 such that the grinding wheel 7 grinds the glass plate 8 in a controlled manner with regard to its contact force. The contact pressure is expediently controlled so that the grinding wheel 7 presses more strongly against the circumference of the glass plate 8 in the straight part of the glass plate and less strongly at the corners. At a corner where the radius of curvature is extremely small, the feed speed of the grinding wheel 7 is usually reduced compared to the glass plate 8 and at the same time the above-mentioned secondary air pressure is reduced. The grinding can therefore be uniform, since the anchor pressure force can be reduced at points where the grinding wheel 7 on the glass plate 8 could grind too much material.

The range of the change in the secondary air pressure ranges from 0.3 bar to 1.5 bar in the case of a fluid actuator 46 with a diameter of 40 mm.

1 to 3, the feeding device 2 is divided into respective blocks 50A to 50E corresponding to the respective stand 9 of the grinding machine main body 1, and each of the blocks 50A to 50E is provided with a feeding device 51 for feeding the glass plates 8 and with a position detector 52 to stop the glass plate fed from the feeder 51 at the position corresponding to one stand 9 each. Furthermore, the feed device 2 has a lifting device 53 for lifting the feed device 51 on each of the blocks 50A to 50E.

The feed device 51 has a roller conveyor 54 for moving the glass plates 8 and a belt conveyor 55 for transporting the glass plates 8. The roller conveyor 54 has a frame part 56 and roller groups 57, which are arranged in the frame part 56, the frame part 56 being held on the machine bed 4 via a shaft 58. The roller conveyor 54 can be pivoted vertically upwards relative to the stand 9 about the shaft 58 as a center line. Furthermore, the belt conveyor 55 is attached to the frame part 56 and has a plate 59, a pulley 60, a belt 61 and a drive 62. According to FIG. 3, the frame part 56 is tilted when the feed device 51 feeds the glass plate 8, the latter sliding on the roller conveyor 54 due to the frictional force together with the movement of the belt 61, the frictional force due to the abutment of the peripheral edge of the glass plate 8 on the belt

61 is caused. Under each feed device 51, the associated lifting device 53 is arranged as the first lifting device, which controls each frame part 56 of the feeding device 51 into a raised position in which the frame is inclined with respect to the horizontal plane, expediently at an angle of 38 ° when feeding the glass plate 8 , and also controls each frame portion 56 of the feeder 51 to a lowered position in which the frame is lowered substantially horizontally as the glass plate 8 is transferred from the feeder 51 to the stand 9.

In this way, the glass plates 8, which are cut to a desired shape in a preliminary stage for the grinding work, are successively brought from a receiving conveyor 81 to the feed device 51 of the feed device 2. In this case, the belt conveyor 55 is driven by one drive means for each of the blocks 50A-50E

62 operated and the first glass plate 8 is conveyed to the outermost end block 50A. Then, when the correct position detector 52 attached to the frame member 56 of the block 50A detects the arrival of the glass plate 8 to the block 50A, the belt conveyor 55 of the block 50A is stopped and the frame member 56 is caused to wait in the raised position. In the same manner, glass plates 8 are fed from the blocks 50B to 50E and stopped one by one. In this case, the table 6 moved in the direction Y toward the feeder 51 waits under each of the feeders 51. The respective feeders 51 which were held in the raised position are simultaneously lowered by the lifting devices 53, whereby the respective glass plates 8 simultaneously on the respective stand 9 placed and held there by negative pressure. The table 6 receiving the glass plate 8 is then moved against the main body 1 of the grinding machine for the purpose of grinding.

The output device 3 has a belt conveyor 63 as a transport member for receiving the glass plate 8 from each of the stands 9 and moves the plate in the direction of the axis Y; it also has a lifting device 64 as a second lifting device for raising the belt conveyor 63, a roller conveyor 65 as a transfer device for transferring the glass plate and a drive device 66 for driving the roller conveyor 65.

A belt 67 of the belt conveyor 63 is guided around pulleys 69 and 70, which are arranged in a support frame 68 of the lifting device 64, the pulley 70

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connected to a drive device 71 and driven by this via a suitable transmission device. The support frame 68 of the lifting device 64 is supported by a shaft 72 on the machine bed 4 and can be pivoted vertically with respect to the stand 9 about the shaft 72 as the center, specifically under the influence of a drive device 73. The roller conveyor 65 has a frame part 74 and a group of rollers 75 arranged on the frame part 74; each of the rollers is connected to and driven by the drive device 66 via a chain drive.

In this way, the table 6, which carries the glass plate 8 that has been finished by the grinding machine main body 1, is moved in the direction Y to the dispensing device 3 and waits at the transfer position B according to FIG. 3. At this time, the support frame 68 of the lifting device 64 is in FIG a substantially horizontal, lowered position. At the same time, each of the stands 9 stops sucking the glass plates 8, the support frame 68 of the lifting device 64 is raised, and the glass plate 8

is handed over to the belt conveyor 63. Furthermore, the belt conveyor 63, which carries the glass plate 8, is moved in the direction Y by the drive device 71, and when the glass plate 8 arrives at the delivery position C according to FIG. 3, the support frame 68 of the lifting device 64 is lowered in order to move the glass plate 8 to the roller conveyor To pass 65. The glass plate 8 is then moved on by the roller conveyor 65 and transferred to an output conveyor 77. The table 6, which has passed the glass plate 8 to the dispensing device 3, is immediately reversed, moved in the direction of the feeding device 2 and repeats the work sequence described above.

In the numerically controlled grinding machine described above, the position of the grinding wheel can be easily adjusted by moving in one direction when the diameter of the grinding wheel is reduced due to wear. Furthermore, the glass plate can be easily brought into the required position, namely on support members which support the plate during processing, and are precisely aligned there for processing.

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Claims (12)

670 790 PATENT CLAIMS 1. Numerically controlled glass plate grinding machine with a machine bed (4), with a plurality of stands (9) mounted on the machine bed (4), all of which serve to support a glass plate (8) to be ground, with grinding wheels (7) for grinding the Glass plate (8), with a plurality of grinding heads (5), each of which carries an associated grinding wheel (7) at one end and which are each arranged above the associated stand (9) such that the grinding head (5) can be rotated about an axis which runs perpendicular to the plane of the glass plate (8) and through a grinding point (A), which is defined during the grinding operation by the contact point of the surface of the grinding wheel (7) with the peripheral edge of the glass plate (8), with means for rotating the Grinding heads (5) around said axis, with displacement means for displacing these grinding heads (5) with respect to said stands (9) in two mutually perpendicular directions, and with control means, i ie are operatively connected to the numerical control and the displacement means, such that each of these grinding heads (5) can be moved along the peripheral edge of the glass plate (8) carried by the stands (9) and grinds this peripheral edge, said control means also are so functionally connected with the said means for rotating the grinding heads that a straight line from said grinding point (A) to the axis of rotation of the grinding wheel (7) coincides with the normal straight line of the peripheral edge in the grinding point (A), characterized in that each of the mentioned grinding wheels (7) is able to carry out the same machining operation and that the glass plate grinding machine comprises adjusting means (44) for adjusting the position of each of these grinding wheels (7), individually and independently of one another and with reference to the associated one Grinding head (5) in a direction parallel to the straight line ve runs. 2. Grinding machine according to claim 1, characterized in that each of said setting means comprises a servo motor (44) for automatically adjusting the grinding head (5). 3. Grinding machine according to claim 1, characterized in that each of said adjustment means comprises a manually operated adjustment screw, by means of which the grinding head (5) is manually adjustable. 4. Grinding machine according to one of claims 1 to 3, characterized in that it further comprises pressure means (46) for pressing the grinding wheel (7) along said straight line against the glass plate (8), and in that said control means (49) are also included the pressure means (46) are functionally connected in such a way that the grinding wheel (7) rests against the peripheral edge of the glass plate (8) with sufficient force to produce a uniform grinding depth of the glass plate (8). 5. Glass plate grinding machine according to claim 1, in which support means (9) for supporting a glass plate (8) to be ground are mounted on the machine bed (4), with a first transport element (51) arranged on one side of the support means for Transporting the glass plate into a position that corresponds to that of the support means and with a first transfer device for transferring the glass plate from that position to the support means, characterized in that the first transport member (51) for receiving the glass plate (8) has a plurality of Has rollers (57) which are rotatably mounted on the machine bed (4) such that an imaginary plane which passes through a plurality of contact areas between the rollers (57) and the glass plate (8) has an inclination with respect to a horizontal plane and a vertical plane in which an axis of rotation of the rollers (57) lies and that in the vicinity of the lowermost part of those contact areas a belt (61) is closed r support of the glass plate (8) carried by the rollers (57) is provided along one of their peripheral edges, this belt (61) conveying the glass plate (8) in a direction perpendicular to the said axis of rotation lying in that imaginary plane . 6. Grinding machine according to claim 5, characterized in that the support means comprise a plurality of stands (9) which are arranged in a row, and that that conveying direction runs along this row. 7. Grinding machine according to claim 6, characterized in that it has a position detector (52) which interrupts the movement of the belt (61) when the glass plate (8) has reached a predetermined position. 8. Grinding machine according to claim 7, characterized in that the highest part of those contact areas is opposite said stands (9). 9. Grinding machine according to claim 8, characterized in that the rollers (57) are mounted on the machine bed (4) with the aid of shafts (54), in addition that first transfer device comprises a first lifting device (53) on which these shafts (54 ) and said belt (61) are mounted, each of these shafts (54) being arranged between the uprights (9) and perpendicular to their row, furthermore said first lifting device (53) those shafts (54) and said belt ( 61) pivoted about an axis (58), which runs parallel to the row of stands (9), in such a way that said imaginary plane can be moved between a pivoted and a substantially horizontal position, and also adjustment means (16) for the stands (9) are provided, which are mounted on the machine bed (4) and support the stands (9) in order to bring the stands (9) into said position, and finally control elements for controlling the movement of the first lifting device (53) and the ver adjusting means (16) are provided, by means of which the imaginary plane is to be lowered into said horizontal position after the stands (9) have been moved into said position, around the glass plate (8) from the rollers (57) to the stands (9) to be handed over. 10. Grinding machine according to claim 5, characterized in that it has a second transport member (65) which is arranged on the other side of the support means (9) in order to transport the glass plate (8) and thus remove it from the support means (9) , and that a second transfer device (63) is provided, which transfers the glass plate (8) from the support means (9) to said second transport member (65). 11. Grinding machine according to claim 10, characterized in that said support means (9) comprise a plurality of stands (9) which are arranged along a row, and that the second transport member (65) has a roller conveyor (65) which is extends along this row. 12. Grinding machine according to claim 11, characterized in that the second transfer device (63) comprises a plurality of belt conveyors (63) to convey the glass plate (8) from one end to its other end, in a direction that runs perpendicular to said row of stands (9), said belt conveyors (63) being supported at the other end by a second lifting device (64) and being arranged at that one end opposite the stands (9), furthermore that each of the belt conveyors (63) with respect to said vertical direction between said stands (9), and that said second lifting device (64) determines said second belt conveyors (63) to be displaced in this way 2nd 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 3rd 670 790 is. that they are either above a position in which the glass plate (8) comes from the stands (9) to said one end of the belt conveyors (63), or below a position in which the glass plate (8) from said other end the belt conveyor (63) arrives at the roller conveyor (65).