JPH03287372A - Rotating device of monocrystal ingot for peripheral face grinding device - Google Patents

Abstract

PURPOSE:To correctly conform the grinding rotary center of a rotating clamp shaft onto its rotary center line, by providing the mean which detects the position of the grinding rotary center to the rotary center line of the rotating clamp shaft based on an image signal. CONSTITUTION:A camera 84A outputting an image signal and the endoscope 82A whose based end 822 is arranged at the photographing lens 823 side of the camera and whose tip side is arranged with its insertion in a through hole 79A, are provided. The position of a grinding rotation center MA to the rotary center line of a rotating clamp shaft 70A is detected by a detection mean 90 based on this image signal. Consequently, the end face of a monocrystal ingot 10 can be observed from about the orthogonal direction therewith and the grinding rotary center MA can correctly be conformed onto the rotary center line of the rotating clamp shaft 70A of a monocrystal ingot rotating device.

Description

[Detailed description of the invention] [Industrial application field]

In order to grind the circumferential surface of a single crystal ingot, which has a grinding rotation center marked on both end faces, into a cylindrical shape, the circumferential surface of the single crystal ingot is pressed and held by a pair of clamp rotary shaft tip surfaces and rotated. This invention relates to a single crystal ingot rotating device for a grinding device.

[Conventional technology]

A single crystal ingot grown by the CZ method or the FZ method is made into a cylindrical shape through the following steps. (1) Both cone-shaped ends of the single crystal ingot are cut in a direction perpendicular to the axis to make the single crystal ingot into a substantially cylindrical shape. (2) Place the single crystal ingot on a cart and transport it manually.
An operator grips the single crystal ingot and holds the single crystal ingot on a rotating clamp shaft of a rotating device. The single crystal ingot is rotated by hand, and the worker's intuition determines the amount of deviation of the rotation center of the single crystal ingot from the rotation center of the rotating clamp shaft in order to maximize the diameter of the single crystal ingot after grinding. . The worker uses a hammer to tap the circumference of the single crystal ingot to eliminate this misalignment. (3) In this state, press the rotating clamp shaft even more strongly against the end face of the single crystal ingot. The single-crystal ingot is rotated, and a grindstone is pressed against the circumferential surface of the single-crystal ingot using a grindstone moving device, thereby grinding the single-crystal ingot into a cylindrical shape.

[Problem to be solved by the invention]

However, in the step (2) above, since the amount of deviation was determined by the operator's intuition, it was not possible to accurately match the two centers. For this reason, the shavings on the peripheral surface of the single crystal ingot became larger than necessary, resulting in waste. In view of these problems, the object of the present invention is to provide a single crystal ingot for a peripheral surface grinding device that allows the grinding rotation center to precisely align with the rotation center line of the rotating clamp shaft of the single crystal ingot rotating device. The purpose of the present invention is to provide a rotating device.

[Problem solving means and their effects]

In order to achieve this object, in the single crystal ingot rotating device for a double-sided grinding device according to the present invention, a through hole is formed in the shaft center of a pair of opposingly arranged rotational clamp shafts with their rotation center lines aligned with each other. a means for supporting the single-crystal ingot by pressing the tip end surface of the rotary clamp shaft against both end surfaces of the single-crystal ingot on which the center of rotation for grinding is marked; a means for rotationally driving the rotary clamp shaft; and a video signal. an endoscope whose base end is placed on the photographing lens side of the camera and whose distal end side is inserted into the through hole; means for detecting the position of the grinding rotation center with respect to the grinding rotation center. In the present invention, since the end face of the single crystal ingot can be observed from a direction substantially perpendicular to the end face, it is possible to precisely align the grinding rotation center with the rotation center line of the rotating clamp shaft of the single crystal ingot rotation device. becomes. Furthermore, the matching operation can be automated. The endoscope is, for example, a borescope equipped with a light guide, and a light source is attached to the proximal end of the light guide, and light from the light source is led out from the tip of the borescope to illuminate the end face of the single crystal ingot. It is configured to illuminate. According to this configuration, the grinding rotation center can be clearly observed even if the rotating clamp axis and the end face of the single crystal ingot are brought close to each other, so that the accuracy of the matching is further increased. For example, a bearing is attached to the outer peripheral surface of the borescope, and the bearing is inserted and supported in the through hole. According to this configuration, the optical axis of the borescope and the center line of the rotary clamp shaft can be made to coincide with each other by the insertion. Therefore, the process of detecting the position of the grinding rotation center with respect to the rotation center line of the rotary clamp shaft becomes easy. Furthermore, adjustment of the mounting position of the borescope becomes extremely easy. Furthermore, even if the rotary clamp shaft is mechanically vibrated or misaligned, the optical axis of the borescope and the center line of the rotary clamp shaft will always align, making it possible to ensure accurate alignment over a long period of time. can.

【Example】

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 shows a single crystal ingot conveying/periphery grinding device. A single crystal ingot 10 to be processed has both ends cut perpendicularly to the axial direction, so that it has a substantially cylindrical shape. This single crystal ingot 10 is mounted on a rotation center marker 12 by a transport robot (not shown). Rotation center marker 12
Measures the circumferential shape at multiple locations along the axial direction, and based on the measured shape, determines the center line of grinding rotation for making the single crystal ingot 10 into a cylindrical shape with the maximum diameter. Then, grinding center points MA and MB are marked at the intersections of this center line and both end faces of the single crystal ingot 10. This single crystal ingot 10 is
In the conveyor robot, the conveyor belt 1 of the conveyor 14
Support stands 142 attached at regular intervals on 41
(Fig. 4A). On the ceiling side of the factory, there are traveling rails 16A and 1 of the same shape.
6B are parallel to each other and perpendicular to the conveyor 14,
It is arranged. Single-crystal ingot transport/attitude adjustment devices 20Δ and 20B having the same configuration are respectively attached to the traveling rails 16A and 16B so as to be freely movable along the traveling rails 16A and 16B. On the other hand, on the floor of the factory, single-crystal ingot peripheral surface grinding devices 221A to 225A and 221B to 225B, each having the same configuration, are arranged side by side at regular intervals along running rails 16A and 16B. The single crystal ingot transport/attitude adjustment device 2OA and the single crystal ingot peripheral surface grinding devices 221A to 225A can communicate via the communication line i8A, and similarly, the single crystal ingot transport/attitude adjustment device 20B and the single crystal ingot peripheral surface grinding devices 221A to 225A can communicate with each other via the communication line i8A. A communication line 1 is connected between the crystal ingot peripheral surface grinding devices 221B to 225B.
Communication is possible via 8B. Between the communication line 18A and the single crystal ingot conveyance/attitude adjustment device 2OA, and between the communication line 18B and the single crystal ingot conveyance/attitude adjustment device 20
B is magnetically coupled in a non-contact manner. Since the single crystal ingot transport/attitude adjustment devices 2OA and 20B operate in the same way, the single crystal ingot transport/attitude adjustment devices 20A and 20B operate in the same manner, so the following description will explain
Only the attitude adjustment device 2OA will be explained. The single crystal ingot conveyance/attitude adjustment device 2OA conveys the single crystal ingot 10 on the conveyor 14 and supplies it to the single crystal ingot circumferential surface grinding devices 221Δ to 225A, and the single crystal ingot circumferential surface grinding devices 221A to 225A convert the single crystal ingot into a cylindrical shape. The single crystal ingot 11 that has been ground is placed on a conveyor 23 arranged parallel to the conveyor 14. FIG. 2 shows the transport processing procedure of the single crystal ingot transport/attitude adjustment device 2OA. (100) First, single crystal ingot peripheral surface grinding device 221
Since A to 225A do not have an object to be ground, the single crystal ingot conveyance/attitude adjustment device 20A is
The upper single crystal ingot 10 is transported and supplied to these single crystal ingot peripheral surface grinding devices 221A to 225A. (102) Single crystal ingot peripheral surface grinding device 22iA (
When any one of i=1 to 5) finishes grinding and issues a grinding end signal, the single crystal ingot transport/attitude adjustment device 2O
A receives this and proceeds to the next step 104. (104) Single crystal ingot transport/attitude adjustment device 2OA
travels to the single crystal ingot peripheral surface grinding device 22iAJ: which is the source of the grinding end signal. (106) Next, single crystal ingot circular grinding device 22
The cylindrical single crystal ingot 11 held by iA is grasped and taken out from the single crystal ingot peripheral surface grinding device 22iA. (10g) Travel to the top of the conveyor 23 in the state shown in FIG. (110) Place the held cylindrical single crystal ingot 11 on the conveyor 23. (112) Next, it travels up to the top of the conveyor 14. (114) Grasp the single crystal ingot 10 on the conveyor 14 and lift it up. (116) Travels to above the single crystal ingot peripheral surface grinding device 22iA, which is the source of the grinding end signal. (118) The single crystal ingot 10 is lowered and supplied to the single crystal ingot peripheral surface grinding device 22A. As a result, the single crystal ingot surface grinding device 22iA holds the single crystal ingot 10 and grinds the single crystal ingot 10.
The single crystal ingot 10 is made into a cylindrical shape by grinding the peripheral surface of the single crystal ingot 10. Here, the schematic configuration of the single crystal ingot conveyance/attitude adjustment device 2OA will be described based on FIG. 4A. This single crystal ingot conveyance/attitude adjustment device 2OA consists of components 201 to 207. The running section 201 is locked to the running rail 16A, and runs along the longitudinal direction of the running rail 16A by a motor M1. Further, the traveling section 201 drives a vertical arm 203 whose lower end is fixed to the upper end of the posture adjusting section 202 up and down using a motor M2. The vertical arm 203 and the traveling section 201 are coupled by, for example, a rack and pinion. At the bottom of the attitude adjustment unit 202 are two lists 2 with the same configuration.
04 is fixed, and hands 205 and 206 of the same configuration are attached to each of the wrists 204 and 204. The hands 205 and 206 are driven by torque motors M4 and M4 provided in each of the wrists 204 and 204 in vertically opposite directions by the same distance. For example, by rotating a vertically arranged feed screw with a right-hand thread on the upper part and a left-hand thread on the lower part with the torque motor M4, the hand 205 Move the .206 up and down. List 204.2
The reason why it is necessary to provide torque motors M4 and M4 for each of the single crystal ingots 10 and 04 is because the diameter of the single crystal ingot 10 differs depending on its location. Note that the attitude adjustment unit 202 has an X-Y-θ-φ
Four motors are mounted to drive the stage 24 and the XY-θ-φ stage 24. Next, the details of the above step 114 are shown in FIGS. 3 and 4A-4.
This will be explained based on the 4G diagram. Initially, the single crystal ingot conveyance/attitude adjustment device 20A,
As shown in FIG. 4A, the posture adjustment section 202 is connected to the traveling section 201.
side (upper limit). Also, hands 205 and 20
6 and are maximally separated from each other. (200) In this state, the traveling section 201
2 is lowered to the level of the single crystal ingot 10 on the conveyor 14 and stopped in the state shown in FIG. 4B. (202) The conveyor belt 141 is moved one step (distance between the single crystal ingots 10 on the conveyor 14) to position the single crystal ingots 10 between the hands 205 and 206, as shown in FIG. 4C. (204) The wrist 204 turns on the torque motor M3 and moves the hands 205 and 206 toward each other, resulting in the state shown in FIG. 4D. Torque motor M3 remains on. (206) The traveling unit 201 moves the posture adjusting unit 202 upward to the upper limit and stops it in the state shown in FIG. 4E. As described above, the process of step 114 shown in FIG. 2 is executed. The process of step 110 shown in FIG. 2 is executed by proceeding in the reverse direction from step 210 shown in FIG. 3 to step 200. Next, the single crystal ingot peripheral surface grinding device 221A shown in FIG. 1 will be explained based on FIGS. 5 to 7. The mechanical configuration of this single-crystal ingot peripheral surface grinding device 221A includes a separate single-crystal ingot rotating device 46 and a grindstone moving device 48. The grindstone moving device 48 has a well-known structure that moves the grindstone 49 back and forth and left and right with respect to the single crystal ingot 10 held and rotated by the single crystal ingot rotation device 46, and is omitted. The single crystal ingot rotating device 46 will be explained below. A leg plate 54A and two parallel rails 56 are fixed on a base plate 52 fixed on the base 50. A slider 58 is fitted onto the two rails 56, and the slider 58 is movable along the rails 56 in a direction perpendicular to the leg plate 54A. slider 58
A leg plate 54B is fixed on the top, facing the leg plate 54A. A hydraulic cylinder 60 is fixed on the leg plate 54B with its piston rod 62 parallel to the rail 56. The tip of the piston rod 62 is fixed to a stopper 64, a slider 65 is fixed to the lower surface of the stopper 64, and the slider 65 is fitted into the rail 56. The stopper 64 is
It is fixed to the rail 56 at an arbitrary position along the rail 56 by a screw 66 that holds it. As shown in FIG. 6, bearings 68A are fixed to both ends of a hole passing through the leg plate 54A, and a rotating clamp shaft 70A is fitted and supported in the bearings 68A. A rubber ring plate T2A is attached to the tip surface of the rotating clamp shaft 70A.
is pasted. Rotating clamp shaft protruding to the outside of the leg plate 54A? A spur gear 74 is fitted into the base end of 0A. On the other hand, a motor 76 is fixed to the leg plate 54A via a bracket (not shown), and a drive shaft 77 of the motor 76 is fixed to the leg plate 54A via a bracket (not shown).
A spur gear 78 that meshes with the spur gear 74 is fitted in the. Therefore, when the motor 76 is turned on, the rotating clamp shaft 70A rotates. The rotating clamp shaft 70A has a rotating clamp shaft at its core.
A through hole 79A is formed concentrically with the OA. Through hole? The distal end side of a borescope 82A having a bearing 80A fitted on its outer peripheral surface is inserted and supported within the borescope 9A. In the borescope 82A, the proximal end of a hard pipe 821 is attached to a base 822, and a CCD camera 8 is mounted on the base 822, facing an eyepiece 823 disposed inside the base 822.
4A is fixed. This base portion 822 is supported by the lower leg plate 54A via a bracket (not shown). A light source 86A is fixed to the base end of the pipe 821. Illumination light from the light source 86A passes through a light guide (optical fiber) 824 arranged on the inner peripheral surface of the vibrator 821, is led out from the tip of the borescope 82A, and illuminates the end face of the single crystal ingot 10. The reflected light from the end face of the single crystal ingot 10 passes through an objective lens 825 and a relay lens 826 arranged in a vibrator 821, and further passes through an eyepiece 823 to form an image on an image sensor (not shown) in a CCD camera 84A. be done. CCD camera 8
The video signal taken out from 4A is sent to monitor T for confirmation.
Supplied to V88A. - Therefore, the grinding center point image NA corresponding to the grinding center point MA marked on the end face of the single crystal insert foot 10 is displayed on the screen A of the monitor TV 88A. The XY orthogonal coordinates are also displayed on the monitor TV 88A, and the intersection point is the optical axis of the borescope 82A and the rotation clamp axis 7.
It corresponds to the rotation center line of 0A. FIG. 7 shows the configuration of the leg plate 54B side. This configuration is the same as that in FIG. 6 except that the rotating clamp shaft 70B rotates freely, and the same components are given the same numbers and the suffix B is added instead of , and the explanation thereof will be omitted. . In FIG. 5, since grinding debris and coolant are scattered during grinding, a slide cover (not shown) is provided to cover the top and front surfaces between the leg plates 54A and 54B so as to be slidable along the longitudinal direction of the base plate 52. , and the leg plate 5
The grindstone 49 covers the back surface between 4A and 54B and passes through it.
The grindstone moving device 48 is equipped with a slide sheet (not shown) that moves together with the grindstone 9. As shown in FIG. 8, the video signals from the CCD cameras 84Δ and 84B are also supplied to a position measuring device 90, and the position measuring device 90 detects the grinding center points MA and MB from the optical axes of the CCD cameras 84A and 84B. Displacement coordinates (△X A %△
YA) and (ΔXB%ΔYB) are determined and supplied to the controller 92. FIG. 13(A) does not show these coordinates for the grinding center point images NA and NB. con)o-
92 is a driver 94 provided in the attitude adjustment section 202.
The X stage 2 of the XY-θ-φ stage 24
6. Y stage 28, θ stage 30 and φ stage 3
2 to match the shift coordinates with the origin (0, O). The driver 94 and controller 92 are optically or magnetically coupled in a non-contact manner. Next, the configuration of the XY-θ-φ stage 24 will be explained based on FIGS. 9 and 10. Figure 10 is A- in Figure 9.
FIG. 3 is an enlarged sectional view taken along line A. Rails 251 are fixed to the base 25 on both sides of its lower surface in a direction perpendicular to the plane of the paper, and a feed screw 251 is fixed to the center of the lower surface.
52 is supported by a bearing (not shown) in a direction perpendicular to the plane of the paper, and is rotationally driven by a motor M5. On the other hand, a slider 261 into which the rail 251 is fitted is fixed to the upper surface of the X stage 26. Further, a nut 262 on which the feed screw 252 is screwed is fixed to the center of the upper surface of the X stage 26. Therefore, when motor M5 is turned on, X stage 2
6 moves relative to the base 25 in a direction perpendicular to the plane of FIG. Leg plates 264 are fixed to opposite sides of the lower surface of the X stage 26, and a feed screw 265 is rotatably supported by the leg plates 264. The feed screw 265 has a hand 2
Similar to the drive parts 05 and 206, the right male thread and the left male thread are formed symmetrically, and a nut 266 is screwed into both the male threads. This feed screw 265 is rotationally driven by a motor M6 fixed to the leg plate 264. The nut 266 is fixed to the center of the lower surface of the slide plate 267. A slider 269 is fixed to the upper side of the slide plate 267. This slider 269 is fitted into a rail 270 fixed to the lower surface of the X stage 26 in the left-right direction in FIG. A tapered block 268 is fixed to the lower side of the slide plate 267. A rail 271 is fixed to the lower surface (slanted surface) of the taper plotter 268.
The rail 271 is fitted into a guide 281 having the same shape as the slider 269, and the guide 281 is fixed to both sides of the upper surface of the Y stage 28 via a tapered block 282. Therefore, when the motor M6 is turned on, the taper blocks 268 move in opposite left and right directions, and at the same time, the Y stage 28 moves up and down in the direction of arrow Y with respect to the X stage 26. A connecting piece 283 is fixed to one end of the lower surface of the Y stage 28, and correspondingly a connecting piece 301 is fixed to one end of the upper surface of the θ stage 30, and a bottle 302 is passed through the connecting pieces 283 and 301. . A feed screw 303 is soldered at the other end of the θ stage 30, and a spur gear 304 is fitted to the base end of the feed screw 303.
is rotationally driven by a motor M7 fixed to the θ stage 30. The tip of the feed screw 303 presses against the horizontal portion of an L-shape 284 fixed to the side surface of the Y stage 28. Therefore, when motor M7 is turned on, θ stage 3
0 rotates with respect to the Y stage 28 in the direction of arrow θ with the bin 302 as the center. On the bottom surface of the θ stage 30, a worm wheel φ
A stage 32 is rotatably supported by a bin 322 via a spacer 321. A worm 323 supported by a bearing (not shown) is engaged with the φ stage 32, and this worm 323 is driven by a motor M8 fixed to the θ stage 30. Therefore, when motor M8 is turned on, φ stage 3
2 rotates relative to the θ stage 30 in the direction of the arrow φ about the bin 322. A wrist 204 shown in FIG. 4A is fixed to the φ stage 32 (not shown in FIG. 9). In FIG. 11, the directions in which the single crystal ingot 10 is moved by the X-Y-θ-φ stage 24 are indicated by X, Y, θ, and φ. θ
The rotation center of is parallel to the X axis, and the rotation center of φ is parallel to the Y axis. Next, based on FIG. 12 and FIG. 13, the posture adjustment section 2
The attitude adjustment operation of the XY-θ-φ stage 24 that is operated with the stage 24 lowered will be described. Initially, the grinding center point images NA and NB are as shown in FIG. (300) In this state, △x as shown in Figure 13 (B)
The φ stage 32 is rotated so that A-ΔXB. (Pin 302) Next, as shown in FIG. 13(C), ΔxA
The X stage 26 is moved so that =ΔX, =O. (Spur gear 304) Next, as shown in FIG. 13(D), ΔY
The θ stage 30 is rotated so that A=ΔYIl. (306) Next, as shown in FIG. 13(E), ΔYA=Δ
The Y stage 28 is moved so that Y,=0. In this way, the grinding center points MA and MB precisely coincide with the rotation center lines of the rotary clamp shafts 70A and 70B. In this state, the hydraulic cylinder 60 is turned on to hold the single crystal ingot 10 between the rotating clamp shafts 70A and 70B, the motor 76 is turned on and the single crystal ingot 10 is rotated, and the single crystal ingot 10 is moved by the grindstone moving device 48. Grind the peripheral surface. As a result, a cylindrical single crystal ingot 11 having a maximum diameter can be obtained. Note that the present invention includes various other modifications. For example, in the above embodiment, the borescope 8 is used as an endoscope.
2A has been described, but since it is sufficient to insert and support the distal end of the endoscope into the through hole 79A, for example, insert the base end of a metal pipe into the through hole 79A, and insert the base end of the endoscope into the through hole 79A. The end portion may be fixed to the leg plate 54A, and the distal end side of the flexible endoscope may be inserted and supported within the vibrator. In addition, the optical axis of the borescope 82A and the rotating clamp axis 70
The rotation center lines of A do not necessarily have to coincide.

[Brief explanation of the drawing]

Figures 1 to 13 relate to one embodiment of the present invention, with Figure 1 being a perspective view showing a schematic configuration of a single crystal ingot conveyance/periphery surface grinding device, and Figure 2 being a single crystal ingot conveyance/position adjustment device. 3 is a detailed flowchart of step 114 in FIG. 2; FIGS. 4A to 4E are explanatory diagrams of the operation of the single crystal ingot transport/attitude adjustment device 2OA corresponding to FIG. 3. , FIG. 5 is a perspective view of the single-crystal ingot peripheral surface grinding device 221A, FIG. 6 is a partial cross-sectional front view showing details of the vicinity of the leg plate 54A of FIG. 5, and FIG. 7 is a view of the vicinity of the leg plate 54B of FIG. 5. A partially cross-sectional front view showing details; FIG. 8 is a schematic view of the grinding center alignment part of the single crystal ingot conveyance/periphery surface grinding device; FIG. 9 is a front view of the X'-Y-θ-φ stage 24. , Figure 10 is an enlarged sectional view taken along line A-A in Figure 9. Figure 11 is an
FIG. 12 is a flow chart showing the processing procedure for aligning the grinding center by the controller 92; FIG.
FIG. 13 is a diagram showing the positions of the grinding center point images NA and NB on the monitor screen and B, corresponding to FIG. 12. In the figure, 10.11 is the rotation center marker 14 for the single crystal ingot 12. 23 is the conveyor 16A; 16B is the running rail 2OA, 20B is the single crystal ingot conveyance/attitude adjustment device 201, the running section 202 is the attitude adjustment section 203, and the vertical arm. 204 is the list 205, 206 is the hand 22iA, 22iB (i=1 to 5) is the single crystal ingot peripheral surface grinding device 24, and 24A is the X-Y-θ-φ stage 251.270.
．． 271.56 is the rail 26 is the X stage 84 A1 84B is the CCD camera 261.269.323.58.65 is the slide 6 A
1 86B is the light source 8 A1 88B is the monitor TV 262.266 is the nut 252.265.303.324 is the feed screw 264.5
4A, 54B are leg plates 267, 304, spur gears 268, 282, taper block 28, Y stage 281, guide 30, θ stage 32, φ stage 323, worm 46, single crystal ingot rotating device 48, grindstone moving device 60, hydraulic Cylinder? OA, 70B are rotating clamp shafts 74, 78 are spur gears 76, Ml-M8 are motors 82A, 82B are borescopes

Claims (1)

[Claims] 1) A single crystal ingot (10 ) for supporting the single crystal ingot by pressing the tip end surface of the rotary clamp shaft against both end surfaces of the
4B, 58-64), and means (68A, 68B, 74-78) for rotationally driving the rotating clamp shaft. Through holes (79A, 79B
) is formed and outputs a video signal (84A, 84B), and an endoscope (82A, 82B) whose base end is placed on the photographing lens side of the camera and whose distal end is inserted into the through hole. and means (90) for detecting the position of the grinding rotation center with respect to the rotation center line of the rotary clamp shaft based on the video signal.
A single crystal ingot rotating device for a peripheral surface grinding device, characterized in that it is equipped with the following. 2) The endoscope is a borescope (82A, 82B) equipped with a light guide (824), and a light source (86A, 86B) is attached to the proximal end of the light guide, and the light from the light source is directed to the target area. 2. The apparatus according to claim 1, wherein the apparatus is led out from the tip of a borescope to illuminate the end face of the single crystal ingot. 3), bearings (80A, 80
3. The device according to claim 2, wherein the ring B) is inserted into and supported by the through holes (79A, 79B).