KR20210152941A - Grinding apparatus - Google Patents

Abstract

The present invention aims to configure a grinding apparatus at a low cost. An air nozzle (7) placed on the grinding apparatus (1), which grinds and processes a subject to be processed (14), sprays air, rotates a grinding wheel (36) at a low speed (for instance, 10 rpm), detects a segment stone (360) by using a front end detecting means (5), and counts the number of the segment stones (360) and the like by using a counter (60). In addition, by comparing the counted value counted by the counter (60) with the number of segment stones (360) pre-memorized by a determination unit (61), the grinding apparatus determines whether the segment stones (360) are falling or not. As such, the grinding apparatus (1) can be configured at a low cost since the grinding apparatus (1) does not need to have a motor for rotating the grinding wheel (36) at a low speed or the like.

Description

grinding device {GRINDING APPARATUS}

The present invention relates to a grinding device.

As disclosed in Patent Document 1, a grinding wheel attached to a grinding device for grinding a workpiece includes a base and a plurality of segment grindstones arranged in an annular shape with a gap therebetween.

At the time of grinding a to-be-processed object, while rotating a grinding wheel, the chuck table holding a to-be-processed object is rotated, and a segment grindstone is made to enter toward the center from the outer periphery of a to-be-processed object.

When a segment grindstone approaches from the outer periphery of a to-be-processed object, a segment grindstone may fall off from a base by the impact etc. received by the segment grindstone.

When the grinding wheel has a portion in which the segment grindstone has fallen off, there is a problem that an arc shape of a portion not ground to be ground is formed on the surface to be ground, and a thickness difference occurs in the portion of the shape.

Therefore, as disclosed by patent document 2, there exists invention which detects drop-off|omission of a segment grindstone.

Japanese Laid-Open Patent Publication No. 2003-089065 Japanese Laid-Open Patent Publication No. 2017-127936

However, in order to enable the detection of drop-off of the segment grindstone, it is necessary to rotate the grinding wheel at a low speed of about 10 rpm. In order to rotate the grinding wheel at a low speed, an encoder that detects the rotation angle of the rotating shaft, a servo motor that rotates while feeding back the rotation angle detected by the encoder, and a control unit that rotates the servo motor at a predetermined rotation angle are required. It is expensive.

Therefore, a grinding apparatus does not have an expensive motor unit, but there exists a subject that a grinding wheel is rotated at low speed, and the fall-off|omission of a segment grindstone is detected.

The present invention is provided with a holding means for holding a workpiece on a holding surface, and a grinding wheel which is annularly disposed on a base and rotatable in a state in which a plurality of segment grindstones are provided with gaps on the base, and the workpiece held by the holding means. A grinding apparatus comprising: grinding means for grinding using the segment grindstone; grinding transfer means for moving the grinding means in a direction perpendicular to the holding surface; and tip detection means for detecting the tip of the segment grindstone. an air nozzle for rotating the grinding wheel at a speed detectable by the tip detecting means by spraying air to the grinding wheel positioned so that the tip detecting means can detect the tip of the segment grindstone; It is a grinding apparatus provided with the counter which counts the number of the said segment grindstone or the number of the said clearance gap, and the determination part which judges the drop-off|omission of the said segment grindstone based on the value of the said counter.

The tip detection means provided in the grinding device includes a translucent part for projecting measurement light, and the segment grindstone is disposed opposite the transmissive part so as to be able to enter between the translucent part, and the light projected from the translucent part It is preferable to include a light receiving unit for receiving measurement light, and a detecting unit for detecting the segment grindstone or the gap due to a change in the amount of light received by the light receiving unit due to the segment grindstone entering between the light transmitting unit and the light receiving unit.

It is preferable that the said air nozzle provided in the said grinding device is provided with the light-transmitting part air-injecting part which blows air out to the said light-transmitting part, and the light-receiving part air-injecting part which injects air into the said light receiving part.

ADVANTAGE OF THE INVENTION According to this invention, low-speed rotation of a grinding wheel is attained by blowing out air, without providing the special motor etc. which rotate a grinding wheel at low speed. Therefore, the low-cost grinding apparatus which can detect drop-off|omission of a segment grindstone can be comprised, and it is economical.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the whole grinding apparatus.
2 is a bottom view of the first grinding wheel;
3 is a front view illustrating a state in which light transmitted from a light transmitting unit passes through a gap.
Fig. 4 is a graph showing the change in voltage when the grinding wheel intermittently blocks measurement light from the light transmitting part.

1. Construction of grinding device

The grinding apparatus 1 shown in FIG. 1 is a grinding apparatus which grind-processes the to-be-processed object 14 using the grinding means 3 . Hereinafter, the structure of the grinding apparatus 1 is demonstrated.

As shown in FIG. 1 , the grinding apparatus 1 includes a base 10 installed extending in the Y-axis direction, and a column 11 standing on the +Y direction side on the base 10 . are being prepared

A grinding transfer means 4 supporting the grinding means 3 is disposed on the side surface of the column 11 on the -Y direction side. The grinding means 3 includes a spindle 30 having a rotation shaft 35 in the Z-axis direction, a housing 31 rotatably supporting the spindle 30, and a spindle 30 with the rotation shaft 35 as an axis. ), a motor 32 for rotationally driving, a mount 33 connected to the lower end of the spindle 30 , and a grinding wheel 36 attached to the lower surface of the mount 33 . The grinding wheel 36 is detachable with respect to the mount 33 , and other types of grinding wheels may be mounted on the mount 33 instead of the grinding wheel 36 .

The grinding wheel 36 includes a base 361 and a plurality of segment grindstones 360 having a substantially rectangular parallelepiped shape arranged in an annular shape on the lower surface of the base 361 .

As shown in FIG. 2, two adjacent segment grindstones 360 are arrange|positioned with the clearance gap 363, and all the segment grindstones 360 are arranged in an annular shape as a whole. Each segment grindstone 360 has a segment length 364 as a length in the circumferential direction. The lower surface 362 of the segment grindstone 360 serves as a grinding surface for grinding the workpiece 14 .

By using the motor 32 shown in FIG. 1 to rotate the spindle 30 about the rotating shaft 35 as an axis, it is mounted on the mount 33 and the mount 33 connected to the spindle 30 and The grinding wheel 36 is rotated about the rotation axis 35 in the Z-axis direction passing through the center of the base 361 as an axis.

The grinding transfer means 4 includes a ball screw 40 having a rotation axis 45 in the Z-axis direction, a pair of guide rails 41 arranged in parallel to the ball screw 40 , and a ball screw 40 . ) connected to the upper end of the Z-axis motor 42 for rotating the ball screw 40 with the rotating shaft 45 as the axis, and the nut inside is screwed to the ball screw 40, and the side is the guide rail 41 and a lifting plate 43 that is in sliding contact with the lifting plate 43 and a holder 44 connected to the lifting plate 43 and holding the spindle 30 .

By driving the ball screw 40 using the Z-axis motor 42 , when the ball screw 40 rotates about the rotating shaft 45 as an axis, the lifting plate 43 is guided to the guide rail 41 . It has a configuration in which the grinding means 3 held by the holder 44 moves in a direction perpendicular to the holding surface 200 (Z-axis direction) while being moved up and down in the Z-axis direction.

On the base 10 , the holding means 2 is arranged. The holding means 2 is provided with the disk-shaped suction part 20 and the annular frame 21 which supports the suction part 20. As shown in FIG. The suction unit 20 is a porous member having a large number of pores, and the upper surface of the suction unit 20 serves as a holding surface 200 on which the workpiece 14 is held by suction. The upper surface 210 of the frame 21 is formed in the same plane as the holding surface 200 .

A suction source (not shown) is connected to the holding surface 200 of the holding means 2 . For example, by operating the suction source in a state in which the workpiece 14 is placed on the holding surface 200 , the workpiece 14 can be sucked and held on the holding surface 200 .

In addition, a rotation mechanism (not shown) is disposed on the holding means 2 . By using the said rotation mechanism, the holding means 2 can be rotated.

A cover 28 is disposed around the holding means 2 , and the cover 28 is telescopically connected to the bellows 27 .

When the holding means 2 moves in the Y-axis direction, the cover 28 moves in the Y-axis direction integrally with the holding means 2, and the bellows 27 expands and contracts.

The tip detecting means 5 is disposed on the +Y direction side of the holding means 2 . The tip detection means 5 is fixed to the cover 28, for example, and is movable in the ±Y direction together with the holding means 2 . The tip detecting means (5) includes a base (53) and a light-transmitting element (54) disposed on the base (53). The light transmitting element 54 includes a light projecting unit 50 for projecting measurement light and a light receiving unit 51 for receiving the measurement light transmitted from the light projecting unit 50 . The light receiving unit 51 is disposed opposite to the light transmitting unit 50 . A recess 540 penetrating in the X-axis direction is formed between the light transmitting portion 50 and the light receiving portion 51 . The segment grindstone 360 can enter into the recessed part 540 .

Moreover, the tip detection means 5 is equipped with the detection part 55 which detects the segment grindstone 360 or the clearance gap 363. As shown in FIG. The detection unit 55 converts and measures the amount of light received by the light receiving unit 51 that changes when the segment grindstone 360 enters between the light projecting unit 50 and the light receiving unit 51 into a voltage value, and measures the voltage. It has a function of detecting the segment grindstone 360 or the gap 363 based on the change in .

As shown in Figs. 2 and 3, the grinding device 1 injects air into the grinding wheel 36 located at a position where the tip detecting means 5 can detect the tip of the segment grindstone 360. It is provided with the air nozzle 7 which says. The air nozzle 7 is provided with the light-transmitting part air-injection part 70 which ejects air to the light-transmitting part 50, and the light-receiving part air-injection part 71 which injects air to the light receiving part 51. As shown in FIG. The light-transmitting part air-injection part 70 and the light-receiving part air-injection part 71 are connected to the air source 72 .

As shown in FIG. 2 , the light transmitting part air jetting part 70 and the light receiving part air blowing part 71 rotate the segment grindstone 360 at the position where the air blows out from each direction and the air contact each other. The tangent directions of the orbits are arranged so that they are neither parallel nor perpendicular. In addition, in the position where the air is in contact with the segment grindstone 360 , the angle between the direction of the air ejected from the light-transmitting part air injection part 70 and the tangential direction of the rotation trajectory of the segment grindstone 360 is the light receiving part air injection part The angle between the direction of the air ejected from (71) and the tangential direction of the rotational orbit of the segment grindstone (360) is substantially the same. In addition, as shown in FIG. 3, in the light transmitting part air jetting part 70 and the light receiving part air blowing part 71, the direction of the air ejected from each and the lower surface 362 of the segment grindstone 360 are neither parallel nor perpendicular. It is placed in such a way that it is not done.

In addition, although the air nozzle 7 in the example of illustration is integrated with the front-end|tip detection means 5, you may comprise both as a separate body.

In a state where the grinding wheel 36 is positioned at a position where the tip detection means 5 can detect the tip of the segment grindstone 360, the light transmitting part air injection part 70 and the light receiving part air of the air nozzle 7 The grinding wheel 36 can be rotated by blowing air from the injection part 71 toward the inner surface 365 and the outer surface 366, and the lower surface 362 of the grinding wheel 36. Moreover, in the air nozzle 7, it is possible to adjust the rotation speed of the grinding wheel 36 by adjusting the flow volume of the air supplied from the air source 72. As shown in FIG.

In addition, the air nozzle 7 jets air from the light transmitting part air jetting part 70 and the light receiving part air jetting part 71 of the air nozzle 7 , and is positioned between the light transmitting part 50 and the light receiving part 51 . It has a function to remove the water droplets attached to it. That is, in the illustrated example, the light transmitting part air jetting part 70 and the light receiving part air blowing part 71 have the function of rotating the grinding wheel 36 and the function of removing a water droplet etc. at the same time. In addition, a separate nozzle is provided in addition to the light transmitting part air injection part 70 and the light receiving part air injection part 71, and the function of rotating the grinding wheel 36 and the function of removing water droplets, etc. are realized by different nozzles. good.

A counter 60 for counting the number of segment grindstones 360 or the number of gaps 363 during rotation of the grinding wheel 36 is connected to the tip detecting means 5 . Further, the counter 60 is connected to a determination unit 61 that judges the drop-off of the segment grindstone 360 based on the value of the counter 60 .

The counter 60 has a function of counting up the number whenever the detection unit 55 detects the segment grindstone 360 . Further, the counter 60 has a function of counting up the number whenever the detection unit 55 detects the gap 363 . For example, when the grinding wheel 36 is rotating at 10 rpm, which is a speed at which the tip detection means 5 can detect the segment grindstone 360 and the gap 363, the detection unit 55 detects the segment grindstone 360. is detected, the count value of the counter 60 increases. The counter 60 may count the number of the segment grindstones 360 detected by the detection unit 55 while the grinding wheel 36 rotates once, for example.

Moreover, the number of the segment grindstones 360 can be memorize|stored in the determination part 61 beforehand. By comparing the number of segment grindstones 360 per one revolution of the grinding wheel 36 counted by the counter 60 with the number of segment grindstones 360 stored in the determination unit 61, the segment grindstone 360 It can be judged whether or not this is falling out.

2. Operation of grinding device

(grinding)

The operation of the grinding apparatus 1 at the time of grinding the to-be-processed object 14 using the said grinding apparatus 1 is demonstrated.

When grinding the to-be-processed object 14 using the grinding apparatus 1, first, the to-be-processed object 14 shown in FIG. 1 is mounted on the holding surface 200 of the holding means 2 . Then, a suction source (not shown) connected to the holding means 2 is operated, and the generated suction force is transmitted to the holding surface 200 . Thereby, the to-be-processed object 14 is sucked and held by the holding surface 200 .

In a state in which the workpiece 14 is being sucked and held by the holding surface 200 , the holding means 2 is moved in the +Y direction using a Y-axis moving means not shown or the like, and the grinding means 3 is positioned below the grinding means 3 . placed in

Next, the holding means 2 is rotated using a rotation mechanism (not shown) to rotate the workpiece 14 held on the holding surface 200, and the motor 32 is used to rotate the rotating shaft ( 35) as an axis to rotate the segment grindstone 360.

In a state in which the workpiece 14 is rotating about the rotating shaft 25 as an axis and the segment grindstone 360 is rotating about the rotating shaft 35 as an axis, the grinding transfer means 4 is used for grinding. The means 3 is lowered in the -Z direction. By lowering the segment grindstone 360 in the -Z direction, the lower surface 362 of the segment grindstone 360 contacts the upper surface 140 of the workpiece 14 .

In the state where the lower surface 362 is in contact with the upper surface 140 of the to-be-processed object 14, the to-be-processed object 14 is grind|ground by further lowering the segment grindstone 360 in the -Z direction.

When the grinding process of the workpiece 14 is completed, the grinding means 3 is moved in the +Z direction using the grinding transfer means 4 to move the segment grindstone 360 from the upper surface 140 of the workpiece 14 . After being spaced apart, the to-be-processed object 14 is carried out from the holding surface 200 of the holding means 2 .

(judgment of dropping out of segment grindstone)

In the grinding apparatus 1, it is judged whether the segment grindstone 360 has dropped off before the grinding process of the to-be-processed object 14 etc. is carried out. Hereinafter, the operation|movement of the grinding apparatus 1 at the time of judging whether the segment grindstone 360 has dropped off is demonstrated.

When judging whether the segment grindstone 360 has fallen off, the tip detection means 5 shown in Fig. 1 is actuated to project the measurement light from the light projecting unit 50 toward the light receiving unit 51, and to concave. The tip detection means 5 is moved so that the rotation trajectory of the segment grindstone 360 is located above the part 540 .

Then, the grinding wheel 36 is lowered by an appropriate distance in the -Z direction using the grinding transfer means 4 . Then, the segment grindstone 360 enters the concave portion 540 of the light transmitting element 54, and the lower surface 362 of the segment grindstone 360 connects the light transmitting unit 50 and the light receiving unit 51 in a straight line. It is located below the height position of the through-light line 52 (refer FIG. 2).

Next, for example, by operating the air source 72 shown in FIG. 2 , air is supplied to the light transmitting unit air jetting unit 70 and the light receiving unit air jetting unit 71 . Thereby, air at a predetermined flow rate is sprayed from the light transmitting part air injection part 70 and the light receiving part air injection part 71 toward the both side surfaces 365 and 366 and the lower surface 362 of the grinding wheel 36, and the grinding wheel 36 ) rotates under the pressure of air. The rotation speed of the grinding wheel 36 is, for example, 10 rpm.

That is, since the air injection part 71 is arrange|positioned below the segment grindstone 360, and injects air diagonally upward, the grinding wheel 36 can be rotated along the injection direction of the air.

Here, in a state where the lower surface 362 of the segment grindstone 360 is located below the height of the light transmitting line 52 connecting the light transmitting part 50 and the light receiving part 51 in a straight line, the grinding wheel 36 When this rotation occurs, the state in which the segment grindstone 360 overlaps and blocks the light-transmitting line 52 and the state in which the segment grindstone 360 does not overlap and is not blocked by the light-transmitting line 52 are alternately repeated do.

In Fig. 4, when the state in which the measurement light projected from the light projection unit 50 is blocked by the rotating segment grindstone 360 and the state in which the light is not blocked are repeated, the change in the voltage detected by the detection unit 55 is measured A graph is shown.

A segment threshold 80 and a gap threshold 81 are previously set in the detection unit 55 . For example, when the measured light-receiving voltage is greater than the gap threshold 81 , the gap 363 is detected as that the measurement light projected from the light projecting unit 50 is not blocked. In addition, when the measured light-receiving voltage is smaller than the segment threshold value 80 , the segment grindstone 360 is detected as being blocked by the segment grindstone 360 from the measurement light projected from the light projecting unit 50 .

When the state in which the measurement light projected from the light projection unit 50 is blocked by the rotating segment grindstone 360 and the state in which the light is not blocked are repeated, as shown in FIG. 4 , for example, the first light receiving voltage 82 ) and the second light-receiving voltage 83 are alternately measured.

When the measured light reception voltage is the first light reception voltage 82 , the segment grindstone 360 is detected by the detection unit 55 because the first light reception voltage 82 is smaller than the segment threshold value 80 . Further, when the measured light-receiving voltage is the second light-receiving voltage 83 , the gap 363 is detected by the detection unit 55 because the second light-receiving voltage 83 is greater than the gap threshold 81 .

Accordingly, the segment grindstone 360 and the gap 363 are alternately detected by the detection unit 55 .

With the start of rotation of the grinding wheel 36 , the counting of the number of segment grindstones 360 by the counter 60 is started. Then, whenever the detection part 55 detects the segment grindstone 360, the count value of the counter 60 rises. And after counting the number of segment grindstones 360 detected by the detection unit 55 during one rotation of the grinding wheel 36 by the counter 60, while stopping the operation of the counter 60, air The jet of air from the nozzle 7 is stopped, and the rotational operation of the grinding wheel 36 is stopped.

Thereafter, the count value counted by the counter 60 during one rotation of the grinding wheel 36 is compared with the number of segment grindstones 360 previously stored in the determination unit 61 by the determination unit 61 . .

At this time, when the count value counted by the counter 60 during one rotation of the grinding wheel 36 coincides with the number of the segment grindstones 360 memorized in the judgment unit 61 in advance, the segment grindstones 360 ) is not considered to have been eliminated. On the other hand, when the count value counted by the counter 60 during one rotation of the grinding wheel 36 is less than the number of the segment grindstones 360 memorized in the determination unit 61 in advance, the segment grindstones 360 are considered to be dropping out.

In addition, as described above, instead of comparing the number of segment grindstones 360 to determine the drop-off of the segment grindstone 360, it is also possible to compare the number of gaps 363 to determine the drop-off of the segment grindstone 360. It is possible.

Specifically, the number of gaps 363 provided in the grinding wheel 36 is stored in the determination unit 61 in advance, and the segment grindstone 360 is positioned at an appropriate height position to enter the recess 540 . . Then, while projecting measurement light from the light projecting unit 50, air is sprayed from the light projecting unit air jet unit 70 of the air nozzle 7 to rotate the grinding wheel 36, and the detection unit 55 opens the gap 363 The number of gaps 363 is counted by the counter 60 each time it is detected. The number of gaps 363 detected by the detection unit 55 during one rotation of the grinding wheel 36 is counted, and the number of gaps 363 stored in the determination unit 61 and the counted gaps 363 By comparing the number of , it can be determined whether the segment grindstone 360 has fallen off.

In the grinding apparatus 1, when judging the drop-off|omission of the segment grindstone 360, since air is blown out using the air nozzle 7 and the grinding wheel 36 is rotated at a low speed of about 10 rpm, grinding A motor for rotating the wheel 36 at a low speed or a control unit for controlling the rotation are unnecessary and economical.

1: grinding device 10: base 11: column 14: workpiece 140: upper surface
2: holding means 20: suction part 200: holding surface
21: frame 210: upper surface of the frame 27: bellows 28: cover
3: grinding means 30: spindle 31: housing 32: motor
33: mount 35: axis of rotation 36: grinding wheel 360: segment grindstone
361: base 362: lower surface 363: gap 364: segment length
365: inner surface 366: outer surface
4: grinding transport means 40: ball screw 41: guide rail
42: Z-axis motor 43: lifting plate 44: holder 45: rotating shaft
5: Tip detecting means 50: Transmitting unit 51: Light receiving unit 52: Transmitting light line 53: Base
54: light-transmitting element 540: recessed part 55: detection part
60: counter 61: judgment unit
7: air nozzle 70: light transmitting unit air jetting unit 71: light receiving unit air jetting unit
72: air one 80: segment threshold 81: gap threshold
82: first light-receiving voltage 83: second light-receiving voltage

Claims (3)

holding means for holding the workpiece on the holding surface;
Grinding means for grinding the workpiece held by the holding means using the segment grindstone, comprising a plurality of segment grindstones arranged in an annular shape with gaps on the base and provided with a rotatable grinding wheel;
a grinding transfer means for moving the grinding means in a direction perpendicular to the holding surface;
A grinding device provided with a tip detecting means for detecting the tip of the segment grindstone,
an air nozzle for spraying air to the grinding wheel positioned at a position where the tip detection means can detect the tip of the segment grindstone to rotate the grinding wheel at a speed detectable by the tip detection means;
a counter for counting the number of the segment grindstones or the number of gaps during rotation of the grinding wheel;
Grinding apparatus provided with the determination part which judges drop-off|omission of the said segment grindstone based on the value of the said counter. The method of claim 1,
The tip detection means includes: a light projecting unit for projecting measurement light; a light receiving unit disposed opposite the light projecting unit to allow the segment grindstone to enter between the light projecting unit and receiving the measurement light projected from the light projecting unit; , A grinding device provided with a detection unit configured to detect the segment grindstone or the gap due to a change in the amount of light received by the light receiving unit due to the entry of the segment grindstone between the light projecting unit and the light receiving unit. 3. The method of claim 2,
The air nozzle is a grinding device provided with a light-transmitting part air-jet unit that ejects air to the light-transmitting unit, and a light-receiving unit air ejection unit that injects air into the light-receiving unit.

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