JPH10320053A - Detection and correction method for displacement angle and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently demonstrate a vibration isolation effect by detecting the storage amount of a displacement angle generated between the drive side of a shaft joint and a load side and correcting the displacement angle of the load side to the drive side of the shaft joint based on the storage amount. SOLUTION: By signals from a saddle type photosensor 90 inputted to a displacement amount detection part 100 at the point of time of being rotated and stabilized (5 rotations), synchronizing signals 103 are measured. Simultaneously, by the signals from the saddle type photosensor 91, the measurement of the synchronizing signals is stopped. The pulse number of the synchronizing signals 103 measured during the time is stored and the stored pulse number 106 is inputted to a displacement amount synthesis part 107, added to a normal rotation drive pulse 101 and turned to the normal rotation drive pulse 101A. That is, the stored pulse number 106 is added at the time of elevating an elevating and lowering block and subtraction is performed at the time of lowering the elevating and lowering block. By the constitution, for instance, even when the displacement angle by a smoothing device to the pulsation of the shaft joint 1 is generated, it is detected and corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to transmission of drive rotation between two shafts, and in a shaft coupling having a pulsation smoothing device therein, the drive of the shaft coupling due to a change in load on the load side of the shaft coupling. The present invention relates to a method for detecting and correcting a deflection angle of a load side with respect to a load side, and an apparatus for implementing the method.

[0002]

2. Description of the Related Art The prior art relating to a method and an apparatus for detecting and correcting the deviation angle of a shaft coupling between two shafts proposed by the present invention cannot be found at present.

[0003]

In a transfer device used for various processing of semiconductors and a transfer device used in a manufacturing apparatus, for example, when a wafer or the like is transferred, the vibration of the transfer device causes the mounted wafer to be moved. The position may fluctuate during the transfer, or the transfer of the wafer may be hindered. Further, when transferring the wafer, it is necessary to secure an accurate position.

An object of the present invention is to apply a drive rotation transmission between two shafts and, in a shaft joint provided with pulsation smoothing means therein, to produce a deviation between a driving side and a load side of the shaft joint. To provide a method of detecting the stored amount of angle and correcting the deviation angle of the load side with respect to the drive side of the shaft coupling based on the stored amount of the deviation angle, and an apparatus for implementing the method. is there.

[0005]

In order to achieve the above object of the present invention, the present invention is configured as described in the appended claims. That is, according to the present invention, a rotation detecting device for detecting rotation is provided on the driving side and the load side of the shaft coupling, respectively, and between the driving side and the load side of the shaft coupling. A method for detecting and correcting a deviation angle that detects and corrects a generated deviation angle, wherein measurement of the deviation angle is started using a rotation detection device that detects the rotation of the drive side, The measurement of the deviation angle by the rotation detection device that detects the rotation on the load side is stopped, and the stored amount of the deviation angle generated between the driving side and the load side is detected, and the deviation angle is detected. This is a method of detecting and correcting a deflection angle for correcting a deflection angle between a driving side and a load side of the shaft coupling based on the stored amount. With such a configuration, for example, even if a deviation angle due to the pulsation of the shaft coupling is generated by the smoothing device, it is easy to detect and correct the deviation angle.
It can also be used for vibration isolation of the entire servo motor, and has an effect of increasing the stability of transfer and transfer of wafers and the like, and enabling to produce high-quality products such as wafers with high yield. Further, according to the present invention, a rotation detecting device for detecting rotation is provided on the drive side and the load side of the shaft coupling, respectively, and between the drive side and the load side of the shaft coupling. A displacement angle detection and correction device for detecting and correcting a generated displacement angle, comprising: a shaft coupling connected to a shaft of an AC servomotor; and a photosensor for detecting a deviation angle on a driving side of the shaft coupling. And a photosensor for detecting a deflection angle of the shaft coupling on the load side, and a stored amount of the deviation angle generated between the driving side and the load side of the shaft coupling in forward (or reverse) driving. And a device for detecting and correcting a deviation angle comprising at least means for correcting the deviation angle between the drive side and the load side of the shaft coupling based on the stored amount of the deviation angle. Is what you do. According to a third aspect of the present invention, in the deviation angle detection and correction device according to the second aspect, the general control unit that performs overall control of the deviation angle detection and the correction includes: Means for inputting a normal rotation (or reverse rotation) drive pulse to a deflection amount synthesizing unit for synthesizing the angle deviation amount, and a normal rotation (or reverse rotation) for a deviation amount detection unit for detecting the deviation angle deviation amount. )
A means for inputting a synchronization signal synchronized with the drive pulse, a photosensor for detecting a driveside deflection angle of the shaft coupling, and a displacement amount of a deflection angle sent from a photosensor for detecting a load side deflection angle. The deviation amount is converted into a stored pulse number, and the deviation amount is converted into a forward (or reverse) drive pulse transmitted from the overall control unit by a deviation amount detection unit input to the deviation amount combination unit. (Or subtract) the number of stored pulses
The deviation angle detection and correction device includes at least an AC servomotor that rotates synchronously with the corrected forward (or reverse) drive pulse. In this way, by using the deviation angle detection and correction device according to claim 2 or 3, the same effect as that of claim 1 can be obtained, and the detection and correction of the deviation angle can be automatically performed. This makes it possible to perform control and immediately detect and correct even if a large amount of deflection angle occurs, so that the stability of transport and transfer of wafers and the like increases, and wafers of excellent quality can be obtained. And the like can be manufactured with a high yield.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of a shaft joint in which a deflection angle occurs will be described. FIG. 1 is a perspective view illustrating an example of the structure of the shaft coupling 1, and FIG. 2 is a schematic diagram illustrating a cross-sectional structure of a main part of the shaft coupling 1. The drive-side shaft coupling 2 is provided with a boss portion 3 for fixing the drive-side shaft A, and forms pressure applying portions 4 and 5 having required shapes in parallel with the axis and at symmetric positions. The pressure applying portions 4 and 5 have opposed surfaces 6 and 7 and 8 and 9 set at the center portion via openings, and further have tapped holes 10, 11, 12, and 13 (13 in the figure). (Not visible). The load-side shaft coupling 14 is provided with a boss 16 for connecting the load-side shaft B at the center of one surface of the disk 15,
On the other surface, pressure receiving portions 17 and 18 having a required shape are provided symmetrically. Each shallow spherical recess 19 is provided at a predetermined position on the plane forming the V-shape of the pressure receiving portions 17 and 18.
A required number of groups, 20, 20, 21 and 22 are provided. FIG.
As shown in the figure, the shaft coupling 1 has a shallow spherical depression 19,
Each of the groups 20, 21, and 22 includes balls 23, 24, which are made of urethane rubber having a required diameter and have high resilience.
Groups 25 and 26 are arranged with only the contact vertices glued. A group of shallow spherical depressions 27, 28, 29 and 30 are provided at the same position facing the groups of shallow spherical depressions 19, 20, 21 and 22. Pressure receiving relay plates 31, 32, 33 and 3
4 inserts one end of springs 39, 40, 41 and 42 into each of the spring counterbore 35, 36, 37 and 38 as shown. Springs 39, 40, 41 and 4
The other end of 2 is preloaded and has stepped washers 43, 4
The stepped bolts 47, 48, 49, and 50 (dotted lines) are arranged via 4, 45 (dotted lines) and 46 (dotted lines). Here, the description of the pulsation smoothing action of the shaft coupling 1 will be omitted. The springs 39, 40, 41 and 42
This is set based on the transmission horsepower of the shaft coupling 1, and a large angular deviation does not occur when the load fluctuates in a normal operation state. However, when accuracy is required, even a slight deviation causes a problem. Here, the worst excursion is considered. FIG.
In the case where the ball 23 is crushed, the angle 51 is 2.5 ° (degrees) and the angle 52 is 33 ° in actual measurement. However, since the spring 39 is inserted, it is considered that the 39 intervals are 4 ° because one interval is 4 °
× 5 = 20 °, and the crushed ball 23 is added,
20 ° + 4 ° = 24 ° at maximum. Although the above has been described with assumptions that are unlikely in practice, in practice,
The elevator, which is a transfer device, has its own weight, which is 50% of the motor output, but there is room for the motor output even when the actual load is loaded at 100%. For example, in an elevator having a motor rated output of 120 W, when the actual load is changed from 0% to 100%, the deviation angle of the shaft coupling is 2.
It changed by 7 °. Therefore, the deviation amount of the deviation angle of 2.7 ° is corrected. FIG. 3 is a perspective view schematically showing an embodiment in which the deviation angle of the shaft coupling 1 is extracted and corrected. The elevator 54 sandwiches and fixes the guide lots 57 and 57 with the base 55 and the support member 56, and lifts and lowers the block 59 via respective ball nuts 58.
Are held along the respective guide lots 57 so as to be able to move up and down smoothly. A ball nut 60 is attached to the center of the lifting block 59, and a ball screw 61 is engaged and in communication therewith. The lower end of the ball screw 61 is attached to the base 55 with the ball bearing 6.
2 and the upper part is rotatably suspended on a support member 56 via a bearing 63, and the bevel gear 6 is provided at the upper end.
4 is fixed. Mounting table 6 with cylindrical shape lying down
5 is a lifting block 5 via supporting arms 66 and 67.
9 is integrated. In the driving section 68, the AC servomotor 69 is fixedly attached to a support member 71 which is separated from the motor shaft 70, and a seat 73 of a shaft 72 is fixed to a lower portion of the support member 71. The lower end of the shaft 72 is received by a ball bearing 74 and is firmly attached to a bearing case 75 that houses the ball bearing 74. Axis 7
2, a worm wheel 76 is fixed, and a worm 77 that engages with the worm wheel 76 is provided with a servo motor 7.
8 is fixed to the shaft 79. The servomotor 78 may be a reversible motor having an encoder capable of servo control. Although not shown, a cam mechanism may be used instead of the worm 77 and the worm wheel 76. The hollow shaft 80 attached to the support member 71 is provided with a ball bearing 81, through which the fixed member 82 is set at a predetermined position, and the support member 71 is movable together with the ball bearing 74. At the same time, the AC servomotor 69 also makes the whole movable. The boss 3 of the shaft coupling 1 is firmly attached to the motor shaft 70. Furthermore, the boss 3 has
A disk 83 with a slit 84 is provided. A shaft 85 is fixed to the boss 16 of the shaft coupling 1, and the shaft 85 is rotatably supported by respective ball bearings 87 (one is not visible in FIG. 3) provided on both sides of the bearing block 86. . Axis 85
, A disk 89 provided with a slit 88 is fixed. Each disc 83 and 89 is provided with a respective saddle-shaped photosensor 90 and 91. The upper end of the shaft 85 is
To the input shaft 93. The shaft 95 passes through a ball bearing 97 provided on a support angle 96 fixed to the support member 56, and has one end connected to the output shaft of the speed reducer 92, and the other simply having a bevel gear 98 engaged with the bevel gear 64. Is fixed. Next, the overall operation of the deviation angle detection and correction device will be described. As shown in FIG. 3, when the servo motor 78 is stopped at a predetermined position, the worm wheel 76 is also stopped, so that the support member 71 does not move, and if a drive pulse is given to the AC servo motor 69, the motor shaft 70 , Shaft coupling 1,
The ball screw 61 is rotated via the shaft 85, the speed reducer 92, the shaft 95, the bevel gear 98 and the bevel gear 64, and the lifting block 5
9 is raised and lowered. Elevating block 59 of elevator 54
The relationship between the movement of the motor and the rotation speed of the AC servomotor 69 will be described. The lead of the ball screw 61 is 6 mm, that is, the amount of movement of the lifting block 59 by one rotation of the ball screw 61 is 6 mm. Since the bevel gears 64 and 98 have the same number of teeth, the reduction ratio is 1. The reduction ratio of the reduction gear 92 is 1
/ 20, so that when the shaft 95 makes one rotation, the shaft 85 becomes 20
Will rotate. That is, the shaft 70 of the AC servomotor 69 rotates 20 times. For example, if the amount of movement of the lifting block 59 is 4.5 mm each time, the number of rotations of the ball screw 61 every time is 4.5 / 6 =
The number of rotations of the AC servomotor 69 is 0.75 times, which is the reduction ratio of the speed reducer 92, that is, 0.75 × 20 = 15 rotations. The above condition is a state in which there is no load on the mounting table 65 integrated with the elevating block 59, and when a load of 100% is applied to this, the driving by the shaft coupling 1 is performed as described above. The deviation angle between the side shaft coupling 2 and the load side shaft coupling 14 is 2.7 °. Considering this deviation angle 2.7 ° with the ball screw 61, the change amount is 2.7 / 20 = 0.135 ° when first divided by the reduction ratio, and the ball screw 61 moves 6 mm in one rotation of 360 °. 6 × by proportional calculation
0.135 / 360 ≒ 0.0225 mm. Also,
When the AC servomotor 69 makes one rotation at 400 pulses, the number of 2.7 ° pulses corresponds to 360 ° at 400 pulses.
2.7 / 360 = 3 pulses. Therefore, it is necessary to perform a correction corresponding to the deviation angle of 2.7 °. There are a method of performing the correction electrically and a method of performing the correction mechanically, both of which will be described later. Next, a method for detecting the amount of deviation will be described. The control of the entire apparatus is omitted, and only the method of detecting the deviation angle will be described. From the overall control unit (general control unit) 99 in the block diagram of the method of detecting the amount of deviation shown in FIG.
The displacement amount detection unit 100 synchronizes with the forward drive pulse 101 and the reverse drive pulse 102 and
Are supplied with synchronization signals 103, 104, and 105. AC
In the servo motor 69, the forward rotation drive pulse 101 passes through the displacement amount synthesizing unit 107, and synchronous rotation starts with the forward rotation drive pulse 101A. As described above, while the lifting block 59 moves 4.5 mm, the AC servomotor 69
Requires 5 rotations. Therefore, at the time when the rotation is stabilized (5 rotations), the synchronization signal 103 is a signal from the saddle-shaped photosensor 90 input to the deviation amount detection unit 100.
At the same time, the measurement of the synchronizing signal is stopped by the signal from the saddle-shaped photosensor 91, the number of pulses of the synchronizing signal 103 measured during that time is stored, and the stored pulse number 106 is used as the displacement amount synthesizing unit. 107 and forward drive pulse 1
01 to obtain a normal rotation drive pulse 101A. That is, when the lifting block 59 is raised, the number of stored pulses 10
6 is added, and when the lifting block 59 is lowered, a subtraction is performed. At the time of reverse rotation driving, the number of stored pulses can be utilized as it is if the operation order of the saddle-shaped photosensors 90 and 91 is reversed. In the above case, the AC servomotor 69 is rotated including the correction.
When the servo motor 78 in FIG. 3 is driven, forward and reverse rotations are performed only with the number of stored pulses 106 of the deviation amount detection unit 100, and the AC servo motor 69 is turned around as a whole to reduce the deviation angle. Can be corrected. As mentioned above,
Even if a deviation angle of the shaft coupling occurs, it can be easily detected and corrected, so that not only the shaft coupling 1 but also AC
It can also be used for vibration isolation of the entire servo motor, and has the effect of increasing the stability of the transferred wafer. Further, correction can be easily performed even when a large amount of deviation occurs.

[0007]

According to the method and the apparatus for detecting and correcting the deviation angle of the present invention, even if the deviation angle is generated by the smoothing device with respect to the pulsation of the shaft coupling, the deviation can be easily corrected. The effect can be sufficiently exhibited, and there is an effect that the reliability of a transfer device for a wafer or the like can be further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure of a shaft coupling exemplified in an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a cross-sectional structure of a main part of the shaft coupling shown in FIG.

FIG. 3 is a perspective view showing a configuration of a device for detecting and correcting a deviation angle exemplified in the embodiment of the present invention.

FIG. 4 is a block diagram for detecting and correcting a deflection angle exemplified in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shaft coupling 2 ... Drive side shaft coupling 3 ... Boss part 4, 5 ... Pressure applying part 6, 7, 8, 9 ... Opposing surface 10, 11, 12, 13 ... Tapped hole 14 ... Load side shaft coupling 15 ... Circle Plate 16 ... Boss 17, 18 ... Pressure receiving portion 19, 20, 21, 22 ... Shallow spherical depression 23, 24, 25, 26 ... Ball 27, 28, 29, 30 ... Shallow spherical depression 31, 32, 33, 34 ... Pressure receiving Relay plates 35, 36, 37, 38 ... counterbore springs 39, 40, 41, 42 ... springs 43, 44, 45, 46 ... stepped washers 47, 48, 49, 50 ... stepped bolts 51, 52 ... corners 54 ... Elevator 55 ... Base 56 ... Supporting material 57 ... Guide lot 58 ... Ball nut 59 ... Elevating block 60 ... Ball nut 61 ... Ball screw 62 ... Ball bearing 63 ... Bearing part 64 ... Bevel gear 65 ... Placement table 66,67 ... Support arm 68 ... Driver 69 ... AC servo motor 70 ... Motor shaft 71 ... Support member 72 ... Shaft 73 ... Seat 74 ... Ball bearing 75 ... Bearing case 76 ... Worm wheel 77 ... Warm 78 ... AC servo motor 79 ... Shaft 80 ... hollow shaft 81 ... ball bearing 82 ... fixing member 83 ... disk 84 ... slit 85 ... shaft 86 ... bearing block 87 ... ball bearing 88 ... slit 89 ... disk 90, 91 ... saddle-shaped photo sensor 92 ... reduction gear 93 … Input shaft 94… hollow shaft 95… shaft 96… support angle 97… ball bearing 98… bevel gear 99… overall control unit (overall control unit) 100… deviation amount detection unit 101… forward rotation drive pulse 101 A… forward rotation drive Pulse 102: reverse rotation drive pulse 102A: reverse rotation drive pulse 103, 104, 105 ... same Period signal 106: Number of stored pulses 107: Deflection amount synthesizing unit A: Drive side axis B: Load side axis

Claims (3)

[Claims] 1. A rotation detecting device for detecting rotation is provided on each of a driving side and a load side of a shaft coupling, and a deviation angle generated between the driving side and the load side of the shaft coupling is detected and corrected. A method of detecting and correcting a deviation angle, wherein the measurement of the deviation angle is started using a rotation detection device that detects the rotation of the drive side, and then the rotation is detected to detect the rotation of the load side. Stop measuring the deflection angle by the motion detection device, detect the stored amount of the deflection angle generated between the driving side and the load side, and based on the stored amount of the deflection angle, A deviation angle between the driving side and the load side. 2. A rotation detecting device for detecting rotation is provided on each of a drive side and a load side of a shaft coupling, and a deviation angle generated between the drive side and the load side of the shaft coupling is detected and corrected. And a photo-sensor for detecting a deviation angle of a drive side of the shaft coupling, and a photo-sensor for detecting a deviation angle of a drive side of the shaft coupling. A photosensor for detecting a deviation angle, detecting a stored amount of the deviation angle generated between the driving side and the load side of the shaft coupling in the forward rotation (or reverse rotation) driving, and detecting the deviation angle. A device for correcting a deviation angle between the driving side and the load side of the shaft coupling based on the stored amount of the shaft coupling. 3. An apparatus for detecting and correcting a deflection angle according to claim 2, wherein a general control unit for performing overall control of the detection and correction of the deflection angle synthesizes a deflection amount of the deflection angle. A synchronization signal synchronized with the forward (or reverse) drive pulse is supplied to a means for inputting a forward (or reverse) drive pulse to the displacement synthesizer and a displacement detector for detecting the amount of deviation of the displacement angle. Means for inputting, by converting the deviation amount of the deviation angle sent from the photo sensor for detecting the deviation angle on the drive side of the shaft coupling and the photo sensor for detecting the deviation angle on the load side to the number of stored pulses, The number of stored pulses converted by the deviation amount synthesizing unit is added to the deviation amount detecting unit input to the deviation amount synthesizing unit and the normal rotation (or reverse rotation) driving pulse transmitted from the general control unit (or Subtraction), and the corrected forward (or reverse) drive pulse Detection and correction apparatus of deviation angle, characterized in that it comprises at least an AC servo motor for synchronizing rotation.