Cylinder grinding machine

Abstract

The present invention is a cylindrical grinding machine comprising: a first detection unit and a second detection unit that detect, in a non-contact manner, one end of a crystal bar and the proximity of the other end to a main shaft and a countershaft; and a drive mechanism capable of changing and adjusting the movement speed of the second support unit on the countershaft side, the drive mechanism being adjusted so that the movement speed B is lower than the movement speed A during the contact support of the one end of the crystal bar and the countershaft, the movement speed B is the movement speed of the second support unit from the detection of the approach of the one end to the countershaft by the second detection unit until the contact support, and the movement speed A is the movement speed until the detection of the approach, and the movement speed B is the movement speed of the second support unit when the other end of the crystal bar is in the contact support with the main shaft. The drive mechanism is adjusted so that a movement speed D is lower than a movement speed C, the movement speed D being a movement speed from when the first detection unit detects that the other end approaches the main shaft until the other end contacts the support, and the movement speed C being a movement speed until the first detection unit detects that the other end approaches the main shaft. As a result, provided is a cylindrical grinding machine in which, in a loading step, breakage of the end of the crystal bar and the occurrence of mechanical positional displacement of the support unit can be suppressed, the time required for the step can be shortened, and the need for maintenance of a portion for detecting the positional relationship between the crystal bar and the spindle or the like can be reduced.

Description

Technical Field

[0001] The present invention relates to a cylindrical grinding machine which detects both ends (conical taper and tail) of a crystal rod in a preparation process (loading process) for longitudinal feed grinding of a crystal rod (single crystal silicon ingot, etc.), clamps the crystal rod in the axial direction using a main shaft and a secondary shaft, and performs support operations safely and in a short time. Background Art

[0002] In recent years, the diameter of the wafers used in the manufacture of semiconductor devices has been increasing in order to improve the performance and reduce the manufacturing cost of semiconductor devices. The wafers used in the manufacture of semiconductor devices are manufactured by the following process: a crystal rod with a conical taper and tail is made in front and behind the cylindrical straight body by the Czochralski method, etc., the outer circumference of the crystal rod is cylindrically ground with a cylindrical grinder, and then sliced ​​perpendicularly to the axial direction to cut out a plate shape, and manufactured by a grinding process. Therefore, with the increase in the number of wafers obtained from a crystal rod and the increase in the diameter of the wafer, the produced crystal rod also has a larger diameter and a higher weight.

[0003] When such a crystal ingot is cylindrically ground, a conventional cylindrical grinding machine is composed of a conveying unit for conveying the crystal ingot in and out of the machine, a supporting unit for supporting the crystal ingot in the machine, and a grinding unit for performing longitudinal feed grinding on the outer circumference of the crystal ingot.

[0004] exist Figure 8 2 shows a preparation step (loading step) of clamping the crystal ingot in the crystal axis direction by the conveying unit 38 and the supporting units 34 a and 34 b .

[0005] (Introduction of crystal rod)

[0006] The conveying unit 38 holding the crystal rod 7 in the diameter direction is moved so that the crystal axis center 10 coincides with the rotation center 9 of the main axis 33a and the auxiliary axis 33b. Figure 8 Process 1).

[0007] (Support of crystal rod)

[0008] Next, the crystal rod 7 is clamped by the support units 34a and 34b. In a cylindrical grinder, the support unit 34a on the main axis side is usually fixed, and the support unit 34b on the secondary axis side is moved by a drive mechanism such as a servo motor ( Figure 8 Process 2).

[0009] The holding portion (support device) 32b of the supporting unit 34b on the secondary shaft side, which is continuously moved toward the primary shaft side by the driving mechanism such as the servo motor, contacts the conical tail portion 12 of the crystal rod 7, and continues to move toward the primary shaft side together with the conveying unit 38 that clamps the crystal rod 7 in the diameter direction ( Figure 8 Process 3).

[0010] Then, through the above-mentioned continuous movement, the holding portion 32a of the supporting unit 34a on the main shaft side also contacts the conical taper portion 11 of the crystal rod 7. The crystal rod 7 is clamped and supported by the holding portion 32a on the main shaft side and the holding portion 32b on the secondary shaft side. However, when the cylindrical surface of the crystal rod 7 is ground by the grindstone of the grinding unit in the subsequent cylindrical grinding process, it is necessary to prevent the holding portions 32a, 32b and the taper portion 11 and the tail portion 12 from sliding by means of grinding resistance. Therefore, after the crystal rod 7 is clamped and supported by the holding portions 32a, 32b, the supporting unit 34b on the secondary shaft side continues to move further toward the main shaft side, thereby increasing the friction between the taper portion 11 of the crystal rod 7 and the holding portion 32a, and the friction between the tail portion 12 and the holding portion 32b ( Figure 8 Process 4).

[0011] (Conveyor unit retreat)

[0012] In the above process, after the crystal rod 7 is sandwiched by the support units 34a and 34b in the crystal axis direction, the transport unit 38 is separated from the crystal rod 7 and retreats ( Figure 8 Process 5).

[0013] Prior art literature

[0014] Patent Literature

[0015] Patent Document 1: Japanese Patent Application Publication No. 2010-221393 Summary of the invention

[0016] 1. Technical issues to be resolved

[0017] In the loading process as described above, the conical taper 11 and tail 12 of the crystal ingot 7 come into contact with the holding parts 32a and 32b by the operation of the support unit 34b on the secondary shaft side, so that the conical taper 11 and tail 12 of the crystal ingot 7 may be damaged by impact caused by the contact. In this case, in the cylindrical grinding process, when the cylindrical surface of the crystal ingot 7 is ground by the grindstone of the grinding unit, the crystal ingot may slide or shift in position due to grinding resistance, and the state of the ground cylindrical surface and the diameter accuracy may be poor, which may adversely affect the quality. Therefore, the support unit 34b on the secondary shaft side must be operated at a low speed.

[0018] On the other hand, if the supporting unit 34 b on the auxiliary shaft side is operated at a low speed in order to suppress damage due to the above-mentioned impact or the like, the loading process will take a long time.

[0019] In addition, Patent Document 1 discloses a technique of providing an ingot detection rod that can pass through an engagement hole of a holder (support device) and abut against the end (taper and tail) of an ingot (crystal rod). Fig. 9The contact detection technique shown in the middle shows the position of the existing crystal bar 7 just before it contacts the cage 45.

[0020] It can be easily imagined that the crystal bar 7 is clamped in the diameter direction by the conveying unit. After moving to make the center of the crystal axis coincide with the rotation centers of the main shaft and the sub-shaft ( Fig. 9 The upper figure here: The sub-shaft side is shown here), the ingot detection rod 46 (movable in the ingot detection rod movable device 50) that passes through the engaging hole of the cage 45 on the sub-shaft side that continuously moves toward the main shaft side by a driving mechanism such as a servo motor and is held by the sliding part 47 contacts the end part (tail part 12) of the crystal bar 7. When the end detection chuck (Japanese: end detection dog) 49 moves from the position of the sensor 48a and the sensor 48b becomes the detection state, the position just before the end part contacts the cage 45 can be grasped ( Fig. 9 The lower figure).

[0021] The contact detection technique including the ingot detection rod 46 as in Patent Document 1 can be said to be an effective means for detecting the positions of the end parts (conical parts and tail parts) of the crystal bar, but failures and aging of the constituent parts may occur. Specifically, it is also considered that the ingot detection rod 46 is held by the sliding part 47, and due to the entry of mist-like grinding powder for grinding the outer peripheral surface of the cylinder in the cylinder grinding process, etc., the sliding part 47 and the like are worn and sliding failure (operation failure) occurs, and regular maintenance is required.

[0022] Therefore, the present invention is made to solve the above problems, and its object is to provide a cylinder grinding machine that can suppress breakage of the end part of the crystal bar and mechanical position deviation of the support unit due to impacts caused by contact with the main shaft and the sub-shaft in the loading process, and can shorten the time consumed in the loading process. Furthermore, for the constituent parts for detecting the positional relationship between the crystal bar and the main shaft and the sub-shaft, the need for maintenance can be reduced.

[0023] (2) Technical solution

[0024] To achieve the above object, the present invention provides a cylinder grinding machine having: a conveying unit that holds and conveys a crystal bar; a pair of support units that clamp the crystal bar held by the conveying unit in the axial direction and enable it to rotate around the axis; and a grinding unit that longitudinally feeds and grinds the outer periphery of the crystal bar while moving along the axial direction of the crystal bar supported by the pair of support units.

[0025] The pair of support units has: a first support unit having a main shaft and a second support unit having a sub-shaft, and has a driving mechanism that can move the second support unit toward the first support unit.

[0026] The second supporting unit is moved toward the first supporting unit by the driving mechanism, so that one end of the crystal rod held by the conveying unit approaches and contacts the secondary axis of the second supporting unit and is supported, and then the other end of the crystal rod approaches and contacts the primary axis of the first supporting unit and is supported, and the crystal rod is supported by being sandwiched between the primary axis and the secondary axis.

[0027] The cylindrical grinder is characterized in that it further comprises: a first detection unit that detects the proximity of the other end of the crystal rod to the main shaft in a non-contact manner; and a second detection unit that detects the proximity of one end of the crystal rod to the secondary shaft in a non-contact manner.

[0028] The driving mechanism is capable of changing and adjusting the moving speed of the second supporting unit.

[0029] In the contact support between one end of the crystal ingot and the secondary shaft, the driving mechanism is adjusted so that a moving speed B is lower than a moving speed A, wherein the moving speed B is a moving speed of the second supporting unit from when the second detecting unit detects the approach of the one end of the crystal ingot and the secondary shaft until the contact support is achieved, and the moving speed A is a moving speed of the second supporting unit until the approach is detected, and

[0030] In the contact support between the other end of the crystal rod and the main shaft, the driving mechanism is adjusted so that the moving speed D is lower than the moving speed C, wherein the moving speed D is the moving speed of the second supporting unit from the time when the first detection unit detects the approach of the other end of the crystal rod and the main shaft until the contact support, and the moving speed C is the moving speed of the second supporting unit until the approach is detected.

[0031] If it is such a cylindrical grinder of the present invention, in the loading process, the above-mentioned driving mechanism is used to slow down the moving speed of the second support unit by detecting the proximity of the tail (one end) and the cone (the other end) of the crystal rod to the main shaft and the secondary shaft, so that the impact of the end of the crystal rod contacting the main shaft and the secondary shaft can be alleviated and the contact can be made safely. Therefore, the damage to the end of the crystal rod can be reduced, and the occurrence of mechanical position deviation of each support unit can be suppressed. Therefore, in the subsequent cylindrical grinding process, the grinding resistance will not cause the crystal rod to slide or produce position deviation, and the adverse effects on quality such as poor state of the cylindrical surface after grinding and poor diameter accuracy can be prevented.

[0032] In addition, the second support unit moves at a higher speed before the approach is detected, so the process time can be greatly shortened compared to the conventional cylindrical grinder that moves at a low speed from the beginning to the end of the loading process. Therefore, it is a cylindrical grinder with improved processing capacity and improved productivity.

[0033] Furthermore, since the aforementioned means for detecting proximity is not a contact type as in the prior art but a non-contact type, there will be no failure due to wear of components used for detection, and the frequency of maintenance can be reduced.

[0034] In this case, the main shaft and the auxiliary shaft may each include a holding portion that contacts and supports the crystal rod.

[0035] The first detection unit and the second detection unit are sensors respectively.

[0036] The sensor is arranged in a direction perpendicular to the main axis and the sub-axis and a detection line based on the sensor is provided inside each holding portion of the main axis and the sub-axis.

[0037] The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line.

[0038] The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

[0039] Alternatively, the main shaft and the auxiliary shaft may each include a holding portion that contacts and supports the crystal rod.

[0040] The first detection unit and the second detection unit are sensors respectively.

[0041] The sensor is connected to the first support unit and the second support unit via brackets, and is arranged outside each holding portion of the main shaft and the auxiliary shaft, and a detection line based on the sensor is provided on the outside.

[0042] The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line.

[0043] The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

[0044] By using the sensor disposed inside or outside the holding portion in this manner, it is possible to more easily detect the proximity of the end of the ingot to the main axis or the sub-axis.

[0045] Furthermore, the sensor may be designed as a photosensor or an image sensor having a light emitter and a light receiver.

[0046] Such a sensor can more reliably detect the proximity of the end of the ingot to the main axis or the sub-axis.

[0047] In addition, the moving speed A and the moving speed C of the second supporting unit may be set to 3,000 to 4,000 mm / min.

[0048] The moving speed B and the moving speed D of the second supporting unit are 50 to 200 mm / min.

[0049] With such a portion, the time required for the loading step can be more reliably shortened, and damage to the end of the ingot can be more reliably prevented.

[0050] (III) Beneficial effects

[0051] The cylindrical grinding machine of the present invention can prevent the end of the crystal rod from being damaged or misaligned during the loading process. In addition, the time required for the loading process can be greatly shortened. The need for maintenance can also be reduced. Furthermore, the quality of the crystal rod after cylindrical grinding and its productivity can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is an explanatory diagram showing an example of the cylindrical grinding machine of the present invention.

[0053] Figure 2 This is a flowchart showing the functions and cooperation of the detection unit and the drive unit in the loading process (first half).

[0054] Figure 3 This is a flowchart showing the functions and cooperation of the detection unit and the driving unit in the loading process (latter half).

[0055] Figure 4 This is an explanatory diagram showing an example (internal configuration) of the detection unit in the first embodiment.

[0056] Figure 5 This is an explanatory diagram showing an example of before and after detection of the approach of the end of the ingot and the secondary axis (holding portion) in the first embodiment.

[0057] Figure 6 This is an explanatory diagram showing an example (external configuration) of the detection unit in the second embodiment.

[0058] Figure 7 This is an explanatory diagram showing an example of before and after detection of the approach of the end of the ingot and the secondary axis (holding portion) in the second embodiment.

[0059] Figure 8 This is a flowchart showing an example of a conventional loading process.

[0060] Fig. 9 This is a flow chart showing a conventional contact detection technology for detecting the position of a crystal ingot immediately before it contacts a holder.

[0061] Fig.10 This is an explanatory diagram showing the relationship between the shape of the ingot detection rod and the end of the crystal ingot in a conventional device. DETAILED DESCRIPTION

[0062] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

[0063] exist Figure 1 The overall view of the cylindrical grinding machine 1 of the present invention is shown in FIG. Figure 1 As shown, the cylindrical grinder 1 first has a conveying unit 8, a pair of support units 4 and a grinding unit 5. It also has a non-contact detection unit 14.

[0064] First, the conveying unit 8 only needs to be able to hold and convey the crystal ingot 7. In addition, the grinding unit 5 has a grindstone 6, and can perform longitudinal feed grinding on the outer circumference of the crystal ingot 7 while moving along the axial direction of the crystal ingot 7 supported by a pair of supporting units 4. These conveying unit 8 and grinding unit 5 are equipped with a driving mechanism (not shown) to be movable, and can be set as units similar to existing units, for example.

[0065] Next, the pair of support units 4 will be described. The pair of support units 4 can clamp the crystal rod 7 held by the conveying unit 8 in the axial direction and rotate it around the axis, and has a first support unit 4a and a second support unit 4b. The first support unit 4a has a main shaft 3a, and the second support unit 4b has a secondary shaft 3b. In addition, the main shaft 3a has a holding portion 2a at the front end, and the secondary shaft 3b has a holding portion 2b at the front end. Therefore, the crystal rod 7 is supported by being clamped between the holding portion 2a of the main shaft 3a and the holding portion 2b of the secondary shaft 3b.

[0066] In addition, the example shown here is that the tail portion (one end) 12 of the crystal rod 7 is supported on the secondary axis 3b side and the tapered portion (the other end) 11 is supported on the primary axis 3a side, but the present invention is not limited to this, and the orientation of the crystal rod 7 may be reversed.

[0067] The other pair of support units 4 has a drive mechanism 13. In addition, for simplicity, the drive mechanism 13 is only shown in FIG. Figure 1 The driving mechanism 13 has, for example, a motor (servo motor, etc.), which can move the second supporting unit 4b toward the first supporting unit 4a. Of course, it can also be moved in the opposite direction to the first supporting unit 4a. By adjusting the rotation speed and rotation direction of the motor, the moving speed and moving direction of the second supporting unit 4b can be freely changed and adjusted. In addition, it can also be provided with a computer, etc., and in particular, it can be configured to automatically adjust the moving speed of the second supporting unit 4b in conjunction with the detection signal from the detection unit 14.

[0068] The detection unit 14 detects the proximity of the crystal ingot 7 to the pair of support units 4 in a non-contact manner. More specifically, it is composed of a first detection unit 14a for detecting the proximity of the other end 11 of the crystal ingot 7 to the main axis 3a and a second detection unit 14b for detecting the proximity of the one end 12 of the crystal ingot 7 to the auxiliary axis 3b.

[0069] Here, regarding the functions and cooperation of the detection unit 14 and the driving unit 13, in conjunction with the loading process ( Figure 2 :The first half, Figure 3 : The second half of the description is explained.

[0070] First, the basic flow of the loading process is similar to the general example above ( Figure 8 ). That is, after the crystal rod 7 is fed in, the second support unit 4b moves toward the first support unit 4a by the driving mechanism 13, whereby one end 12 of the crystal rod 7 held by the conveying unit 8 approaches and contacts the secondary shaft 3b (more specifically, the holding part 2b) of the second support unit 4b and is supported, and then the other end 11 of the crystal rod 7 approaches and contacts the main shaft 3a (more specifically, the holding part 2a) of the first support unit 4a and is supported, and the crystal rod 7 is sandwiched between the main shaft 3a (holding part 2a) and the secondary shaft 3b (holding part 2b) and is supported. Thereafter, the feeding unit 8 retreats.

[0071] However, in the cylindrical grinder 1 of the present invention, in the contact support between one end 12 of the crystal rod 7 and the secondary shaft 3b, and in the contact support between the other end 11 of the crystal rod 7 and the main shaft 3a, there is cooperation between the second detection part 14b and the driving mechanism 13, and cooperation between the first detection part 14a and the driving mechanism 13, respectively.

[0072] Each process is described below.

[0073] (Introduction of crystal rod)

[0074] The conveying unit 8 holding the crystal rod 7 in the diameter direction is moved so that the crystal axis center 10 coincides with the rotation center 9 of the main axis 3a and the auxiliary axis 3b. Figure 2 Process 1).

[0075] (Support of crystal rod)

[0076] Next, the first support unit 4a and the second support unit 4b clamp the crystal ingot 7, so the second support unit 4b moves toward the first support unit 4a by the driving mechanism 13. At this time, the second detection unit 14b is adjusted to move at a moving speed A (A) until the approach of the one end 12 of the crystal ingot 7 to the secondary shaft 3b is detected. Figure 2 of process 2 to process 3).

[0077] Then, when the second detection unit 14b detects the approach, the drive mechanism 13 automatically adjusts the movement at a lower speed B than the movement speed A from this point until the one end 12 contacts the auxiliary shaft 3b based on the detection signal. Figure 2 of process 3 to process 4).

[0078] After the one end 12 is in contact with the secondary shaft 3b, the second support unit 4b is further moved toward the first support unit 4a by the driving mechanism 13. At this time, the crystal rod 7, the conveying unit 8, and the second support unit 4b move as a whole. Then, the first detection unit 14a is adjusted to move at a moving speed C ( Figure 2 Process 4~ Figure 3 The moving speed C can be higher than the moving speed B, for example, it can be set to the same speed as the moving speed A. In addition, the change adjustment from the moving speed B to the moving speed C can also be performed manually by the operator by visually confirming the start of movement of the crystal rod 7 and the conveying unit 8, or it can be set as a mechanism that automatically changes and adjusts by transmitting the start of movement from the mechanism controlling the position of the conveying unit 8 to the driving mechanism 13.

[0079] Then, when the first detection unit 14a detects the approach, the drive mechanism 13 automatically adjusts the movement from this point until the other end 11 contacts the spindle 3a at a lower speed than the movement speed C ( Figure 3 The moving speed D can be set to the same speed as the moving speed B, for example.

[0080] Thus, the crystal ingot 7 is supported by being sandwiched between the main shaft 3a and the auxiliary shaft 3b. However, in the cylindrical grinding process of the subsequent process, when the cylindrical surface of the crystal ingot 7 is ground by the grinding stone of the grinding unit, in order to prevent the main shaft 3a, the auxiliary shaft 3b and the other end 11 and the one end 12 from sliding due to the grinding resistance, the second supporting unit 4b continues to move further toward the first supporting unit 4a (continuously pushes), thereby increasing the friction between the main shaft 3a and the auxiliary shaft 3b that are in contact with the other end 11 and the one end 12 of the crystal ingot 7 ( Figure 3 Step 6). In this way, the crystal rod 7 is clamped in the crystal axis direction by the first supporting unit 4a and the second supporting unit 4b. The time of completion of the clamping can be determined, for example, by visually confirming that the crystal rod 7 and the conveying unit 8 have stopped moving, or by confirming that the conveying unit 8 has stopped moving based on the position control mechanism of the conveying unit 8.

[0081] (Conveyor unit retreat)

[0082] After the crystal rod 7 is clamped in the above process, the conveying unit 8 is separated from the crystal rod 7 and retreats ( Figure 3 Process 7).

[0083] If the cylindrical grinder 1 of the present invention has such a detection unit 14 and a driving mechanism 13 that cooperate with each other, when the end of the crystal rod 7 approaches the main shaft 3a and the secondary shaft 3b, the moving speed of the second support unit 4b is slowed down, thereby preventing the end of the crystal rod 7 from being damaged or the mechanical position of the support unit 4 from being shifted due to the impact when they contact each other.

[0084] In addition, since the second supporting unit 4 b can be moved at high speed until it approaches, the time required for the loading process can be shortened.

[0085] Furthermore, as described above, in the contact-type detection unit such as Patent Document 1, wear of components related to detection occurs and maintenance is required. However, in the non-contact-type detection unit 14 of the present invention, such component wear does not occur and the need for maintenance can be reduced.

[0086] Furthermore, due to these excellent effects, a high-quality cylindrical ground material can be obtained, and the productivity is also excellent.

[0087] In addition, the specific setting value of the moving speed AD of the second support unit 4b is not particularly limited, but the moving speed A and the moving speed C can be set to, for example, 3,000 to 4,000 mm / min, and the moving speed B and the moving speed D can be set to, for example, 50 to 200 mm / min. If the setting value is selected from these numerical ranges, the loading process can be shortened more reliably, and the end of the crystal rod 7 can be prevented from being damaged.

[0088] As examples of the detection unit 14 (first detection unit 14a, second detection unit 14b), various sensors can be cited, for example, a photoelectric sensor and an image sensor can be used. In the case of a photoelectric sensor, it can be provided with a light transmitter and a light receiver. In addition, in the case of an image sensor, an image processor (computer, etc.) for processing the acquired image can be further used. Through these devices, the proximity of the crystal rod to the main axis and the secondary axis can be detected more reliably.

[0089] The following describes a specific form of the detection unit 14 (embodiments 1 and 2). In addition, the second detection unit 14b and the secondary shaft 3b (holding unit 2b) are described as an example, but the first detection unit 14a and the main shaft 3a (holding unit 2a) can also be configured in the same manner.

[0090] (Embodiment 1 of the detection unit: internal configuration)

[0091] exist Figure 4An example of the detection unit 14 (second detection unit 14b) is shown in FIG. This is a case where the detection unit 14 is arranged in a direction perpendicular to the secondary axis 3b inside the holding unit 2b. Figure 5 2 shows an example of detecting the approach of the end of the ingot 7 to the auxiliary shaft 3 b (holding portion 2 b ) before and after.

[0092] A through hole formed by a combination of a conical recess and a hole of a predetermined diameter is formed in the holding portion 2b that contacts and supports the tip of the secondary shaft 3b of the crystal rod 7. The end of the crystal rod 7 can be inserted and supported in the through hole.

[0093] In addition, the holding portion 2b is provided with a sensor installation hole 21, in which a conical portion detection sensor 22 is arranged as the second detection portion 14b, and a detection line 23 based on the conical portion detection sensor 22 is provided. The approach of the one end 12 of the crystal rod 7 to the secondary shaft 3b (holding portion 2b) is detected by the one end 12 of the crystal rod 7 passing through the detection line 23. With such a structure, the approach detection can be performed more simply.

[0094] In addition, by pre-setting a mechanism for allowing compressed air 24 to flow through the sensor setting hole 21, during the cylindrical grinding process, the cone detection sensor 22 can be prevented from being contaminated by the entry of misty grinding powder generated by grinding the cylindrical outer surface of the crystal rod 7, thereby reducing maintenance as much as possible.

[0095] In this case, since there is no contact point when detecting the end of the ingot 7 (because the detection unit 14 is non-contact), there is no limit to the distance of entry into the holding unit 2 b and the shape of the end.

[0096] In addition, the first detection unit 14a can also be configured in the same manner.

[0097] Regarding the shape restriction of the end of the crystal rod, the contact type example of Patent Document 1 will be examined. Fig.10 The relationship between the ingot detection rod 46 and the shape of the end of the crystal rod 7 is shown in the upper section: the state where the ingot detection rod is extended, the middle section: the shape of the end of the crystal rod is short, and the lower section: the shape of the end of the crystal rod is long.

[0098] The end portion (conical taper portion and tail portion) of the ingot 7 is supported by the holder 45 . Therefore, the distance that the end portion enters into the holder 45 must be small according to the allowable stroke (a) of the ingot detection rod 46 and the ingot detection rod movable device 50 .

[0099] exist Fig.10 In the middle section, the entry distance (b) is less than the allowable stroke (a), and the conical end of the crystal rod 7 is supported by the holder 45 without any problem. Fig.10In the lower section, the entry distance (c)> the allowable stroke (a), and it can be seen that the end of the crystal rod 7 cannot be properly supported by the holder 45. That is, in the case of the contact type detection part, it is limited by the shape of the end of the crystal rod 7, which is considered to be one of the disadvantages.

[0100] Thus, in the contact-type detection part, there is a situation where the end of the crystal rod 7 is blocked from entering, so the shape of the end of the crystal rod 7 must be considered. However, if it is a non-contact type such as the present invention, such consideration is not necessary and it is simpler.

[0101] (Embodiment 2 of the detection unit: external configuration)

[0102] exist Figure 6 2 shows another example of the detection unit 14 (second detection unit 14b). It is a case where it is arranged outside the holding unit 2b. By arranging the end detection sensor 25 as the second detection unit 14b outside the holding unit 2b, it is possible to detect the end of the crystal ingot 7 before it enters the holding unit 2b.

[0103] Since the relative position between the end detection sensor 25 and the holding portion 2b needs to be kept fixed, it is desirable that the end detection sensor 25 is completely fixed by being connected to the second support unit 4b (for example, the base portion 27b of the second support unit) via the bracket 28. In this way, the second support unit 4b on the secondary shaft side, which is moved toward the main shaft side by a driving mechanism such as a servo motor, can be moved synchronously with the end detection sensor 25.

[0104] In addition, a detection line 26 is provided by the end detection sensor 25. The approach of the end 12 to the auxiliary shaft 3b (holding portion 2b) is detected by the end 12 of the ingot 7 passing through the detection line 26. With such a configuration, the approach can be detected more easily.

[0105] In addition, the first detection unit 14a can also be configured in the same manner.

[0106] In addition, Figure 5 In the first embodiment, since the conical end of the crystal rod 7 needs to enter the interior of the holding portion 2b, it is impossible to detect when the end of the crystal rod 7 does not have a conical end. However, in the case of an external configuration, such as Figure 7 As shown, the end of the crystal rod 7 can be detected regardless of whether it is conical or flat.

[0107] As for the detection unit 14 that detects the proximity of the end of the crystal rod to the main axis and the secondary axis, it is not necessary to have a structure that contacts the crystal rod and the components used for detection contact each other as in Patent Document 1. As long as the structure can detect in a non-contact manner and can cooperate with the driving mechanism 13 as mentioned above, there is no special limitation.

[0108] As for preventing the end of the crystal rod from being damaged, in order to move the second support unit 4b at a low speed before the support unit 4 is about to contact the end of the crystal rod 7, it is necessary to detect the position where the support unit 4 is close to the end of the crystal rod 7. If it is a mechanism like the aforementioned embodiments 1 and 2, the proximity detection can be performed more simply.

[0109] Example

[0110] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0111] An automatic cylindrical grinder (comparative example) which does not detect the end portion (conical taper portion and tail portion) of the crystal ingot as a conventional technique and a non-contact detection unit are prepared. Figure 6 The end detection sensors 25 of the present invention are respectively provided outside the holding parts on the main shaft side and the auxiliary shaft side. Figure 1 ) (Example), use and compare the time required for the loading process respectively.

[0112] (Example)

[0113] The end detection sensor 25 is a conventional photoelectric sensor in which a light emitter and a light receiver are separated, and is completely fixed to the base portion 27b of the second support unit 4b via a bracket 28 on the secondary shaft 3b side in such a manner that a distance 29 between the optical axis of the photoelectric sensor and the end surface of the holding portion 2b is 100 mm and a spacing 30 between the light emitter and the light receiver is 450 mm. The same conditions are set on the main shaft 3a side.

[0114] The crystal rod 7 used had a diameter of 300 mm, a taper length of 150 mm, a straight body length of 1,000 mm, and a tail length of 250 mm.

[0115] like Figure 2 , Figure 3 The loading process is carried out in this way.

[0116] First, the crystal rod 7 is moved and fed in by the conveying unit 8 so that the crystal axis center 10 coincides with the rotation center 9 of the main axis 3a and the secondary axis 3b. Figure 2The time required for the process 1 is 30 seconds. In addition, by this feeding, the distance between the end surface of the secondary shaft 3b side and the tail (one end) 12, and the distance between the end surface of the main shaft 3a side and the tapered part (the other end) 11 are both 1,000 mm.

[0117] Before the tail 12 is detected, the second support unit 4b is continuously moved toward the main shaft 3a by the driving mechanism 13 ( Figure 2 The moving speed until the end detection sensor (second detection unit 14 b ) on the side of the secondary shaft 3 b detects the movement is set to 4,000 mm / min (hereinafter referred to as high speed), and the time required is about 15 seconds.

[0118] Next, the conical tail 12 of the crystal rod 7 is brought into contact with the interior of the holding portion 2b ( Figure 2 The moving speed before contact was set to 100 mm / min (hereinafter referred to as low speed), and the time required was about 48 seconds.

[0119] The holding portion 2 a on the spindle 3 a side and the conical tapered portion 11 of the crystal ingot 7 also operate in the same manner.

[0120] The end detection sensor (first detection unit 14a) on the main shaft 3a side before detecting the tapered portion 11 moves the second support unit 4b at a high speed ( Figure 2 Process 4~ Figure 3 Step 5). The time required is about 18 seconds.

[0121] The conical portion 11 of the crystal ingot 7 moves at a low speed before entering and contacting the inside of the holding portion 2a. After the crystal ingot 7 is sandwiched between the holding portion 2a and the holding portion 2b and supported, the second supporting unit 4b further moves toward the first supporting unit 4a to increase the friction between the conical portion 11 of the crystal ingot 7 and the holding portion 2a and the friction between the tail portion 12 and the holding portion 2b, and complete the sandwiching ( Figure 3 The time required is 78 seconds.

[0122] Thereafter, the transport unit 8 is separated from the crystal ingot 7 and withdrawn. The time required is 30 seconds.

[0123] (Comparative Example)

[0124] The crystal rod used was the same as that in the embodiment.

[0125] like Figure 8 The loading process is carried out in this way.

[0126] In addition, the feeding of the crystal rod ( Figure 8 Step 1) and the retraction of the conveying unit 8 ( Figure 8Step 5) is the same as in Example 1, and the time required is also the same as in Example 1, which is 30 seconds.

[0127] In addition, the supporting unit 4b on the secondary shaft side is moved by the driving mechanism so that the tail portion 12 of the crystal rod 7 contacts the holding portion of the secondary shaft of the supporting unit 4b ( Figure 8 In addition, the conical portion 11 of the crystal rod 7 is brought into contact with the holding portion of the secondary shaft of the supporting unit 4a on the main shaft side, thereby completing the clamping of the crystal rod 7 ( Figure 8 The moving speed of the support unit 4b in the steps 2 to 4 is all low at 100 mm / min, and the time required for the steps 2 to 3 and the steps 3 to 4 is 630 seconds and 663 seconds, respectively.

[0128] Table 1 summarizes the time required for each stage in the loading process in Examples and Comparative Examples.

[0129] The total time required for the loading process was 1,353 seconds in the comparative example, whereas it was 219 seconds in the example. Thus, the time required for the example was approximately 16% of that for the comparative example, and a significant reduction of approximately 84% in time was confirmed.

[0130] In an automatic cylindrical grinder, if it is considered that the cylindrical grinding time accounts for most of the time, and one crystal rod takes about 2 to 4 hours (depending on the length of the crystal rod, etc.), then in the overall process of cylindrical grinding including the loading process, the present invention can shorten the processing time by about 11 to 5%, thereby improving productivity.

[0131] Furthermore, even when the ingot is supported and cylindrically ground under the conditions of the embodiment, positional deviation does not occur, and the ground surface has the same surface state as under the conditions of the comparative example.

[0132] Table 1

[0133] (Unit: seconds)

[0134]

[0135] This specification includes the following methods.

[0136] [1]: A cylindrical grinding machine,

[0137] The invention comprises: a conveying unit for holding and conveying a crystal rod; a pair of supporting units for clamping the crystal rod held by the conveying unit in the axial direction and making it rotatable around the axis; and a grinding unit for performing longitudinal feed grinding on the outer circumference of the crystal rod while moving along the axial direction of the crystal rod supported by the pair of supporting units.

[0138] The pair of support units includes: a first support unit having a main shaft and a second support unit having a secondary shaft, and includes a driving mechanism capable of moving the second support unit toward the first support unit.

[0139] The second supporting unit is moved toward the first supporting unit by the driving mechanism, so that one end of the crystal rod held by the conveying unit approaches and contacts the secondary axis of the second supporting unit and is supported, and then the other end of the crystal rod approaches and contacts the primary axis of the first supporting unit and is supported, and the crystal rod is supported by being sandwiched between the primary axis and the secondary axis.

[0140] The cylindrical grinder further comprises: a first detection unit for detecting the proximity of the other end of the crystal rod to the main axis in a non-contact manner; and a second detection unit for detecting the proximity of one end of the crystal rod to the secondary axis in a non-contact manner.

[0141] The driving mechanism is capable of changing and adjusting the moving speed of the second supporting unit.

[0142] In the contact support between one end of the crystal ingot and the secondary shaft, the driving mechanism is adjusted so that a moving speed B is lower than a moving speed A, wherein the moving speed B is a moving speed of the second supporting unit from when the second detecting unit detects the approach of the one end of the crystal ingot and the secondary shaft until the contact support is achieved, and the moving speed A is a moving speed of the second supporting unit until the approach is detected, and

[0143] In the contact support between the other end of the crystal rod and the main shaft, the driving mechanism is adjusted so that the moving speed D is lower than the moving speed C, wherein the moving speed D is the moving speed of the second supporting unit from the time when the first detection unit detects the approach of the other end of the crystal rod and the main shaft until the contact support, and the moving speed C is the moving speed of the second supporting unit until the approach is detected.

[0144] [2]: According to the cylindrical grinding machine of [1] above,

[0145] The main shaft and the auxiliary shaft each have a holding portion that contacts and supports the crystal rod.

[0146] The first detection unit and the second detection unit are sensors respectively.

[0147] The sensor is arranged in a direction perpendicular to the main shaft and the sub-shaft and a detection line based on the sensor is provided inside each holding portion of the main shaft and the sub-shaft.

[0148] The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line.

[0149] The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

[0150] [3]: According to the cylindrical grinding machine of [1] above,

[0151] The main shaft and the auxiliary shaft each have a holding portion that contacts and supports the crystal rod.

[0152] The first detection unit and the second detection unit are sensors respectively.

[0153] The sensor is connected to the first support unit and the second support unit via brackets, and is arranged outside each holding portion of the main shaft and the auxiliary shaft, and a detection line based on the sensor is provided on the outside.

[0154] The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line.

[0155] The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

[0156] [4]: The cylindrical grinding machine according to [2] or [3] above,

[0157] The sensor is a photoelectric sensor or an image sensor having a light emitter and a light receiver.

[0158] [5]: A cylindrical grinding machine according to any one of [1] to [4] above,

[0159] The moving speed A and the moving speed C of the second support unit are 3,000 to 4,000 mm / min.

[0160] The moving speed B and the moving speed D of the second supporting unit are 50 to 200 mm / min.

[0161] The present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and any scheme having substantially the same structure and achieving the same function and effect as the technical concept described in the claims of the present invention is included in the technical scope of the present invention.

Claims

1. A cylindrical grinding machine, comprising: a conveying unit that holds and conveys a crystal rod; a pair of supporting units that clamp the crystal rod held by the conveying unit in the axial direction and enable it to rotate around the axis; and a grinding unit that performs longitudinal feed grinding on the outer circumference of the crystal rod while moving along the axial direction of the crystal rod supported by the pair of supporting units. The pair of support units includes a first support unit having a main shaft and a second support unit having a secondary shaft, and includes a drive mechanism capable of moving the second support unit toward the first support unit. The second supporting unit is moved toward the first supporting unit by the driving mechanism, so that one end of the crystal rod held by the conveying unit approaches and contacts the secondary axis of the second supporting unit and is supported, and then the other end of the crystal rod approaches and contacts the primary axis of the first supporting unit and is supported, and the crystal rod is supported by being sandwiched between the primary axis and the secondary axis. The cylindrical grinder is characterized in that it further comprises: a first detection unit that detects the proximity of the other end of the crystal rod to the main axis in a non-contact manner; and a second detection unit that detects the proximity of one end of the crystal rod to the secondary axis in a non-contact manner. The driving mechanism is capable of changing and adjusting the moving speed of the second supporting unit. In the contact support between one end of the crystal rod and the auxiliary shaft, the driving mechanism is adjusted so that the moving speed B is lower than the moving speed A, wherein: The moving speed B is the moving speed of the second support unit from the time when the second detection unit detects the approach of one end of the crystal rod and the secondary shaft until the contact support is reached, and the moving speed A is the moving speed of the second support unit until the approach is detected, and In the contact support between the other end of the crystal rod and the main shaft, the driving mechanism is adjusted so that the moving speed D is lower than the moving speed C, wherein the moving speed D is the moving speed of the second supporting unit from the time when the first detection unit detects the approach of the other end of the crystal rod and the main shaft until the contact support, and the moving speed C is the moving speed of the second supporting unit until the approach is detected.

2. The cylindrical grinding machine according to claim 1, characterized in that The main shaft and the auxiliary shaft each have a holding portion that contacts and supports the crystal rod. The first detection unit and the second detection unit are sensors respectively. The sensor is arranged in a direction perpendicular to the main shaft and the sub-shaft inside each holding portion of the main shaft and the sub-shaft, and a detection line based on the sensor is provided. The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line. The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

3. The cylindrical grinding machine according to claim 1, characterized in that The main shaft and the auxiliary shaft each have a holding portion that contacts and supports the crystal rod. The first detection unit and the second detection unit are sensors respectively. The sensor is connected to the first support unit and the second support unit via brackets, and is arranged outside each holding portion of the main shaft and the auxiliary shaft, and a detection line based on the sensor is provided on the outside. The first detection unit detects the proximity of the other end of the crystal rod to the main axis according to the other end of the crystal rod passing through the detection line. The second detection unit detects proximity of one end of the crystal ingot to the minor axis based on one end of the crystal ingot passing through the detection line.

4. The cylindrical grinding machine according to claim 2, characterized in that The sensor is a photoelectric sensor or an image sensor having a light emitter and a light receiver.

5. The cylindrical grinding machine according to claim 3, characterized in that The sensor is a photoelectric sensor or an image sensor having a light emitter and a light receiver.

6. The cylindrical grinding machine according to any one of claims 1 to 5, characterized in that The moving speed A and the moving speed C of the second support unit are 3,000 to 4,000 mm / min. The moving speed B and the moving speed D of the second supporting unit are 50 to 200 mm / min.

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