JP2004167631A - Method and apparatus for aligning gripping center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for aligning a gripping center which can easily and accurately align the gripping center axis of a gripping member for gripping a workpiece with a predetermined reference axis. <P>SOLUTION: The method for aligning the gripping central axis 4 of the gripping member for gripping a workpiece with the reference axis 6 of the apparatus 5 is characterized in that a short cylinder 1 having a screen 9 stuck on its end face or within the cylinder is gripped by the gripping member, a laser beam oscillator 7 rotatably mounted on the reference axis 6 is rotated, a circular trajectory of a beam spot is displayed on the screen 9 by radiating the laser beam toward the short cylinder 1, and the position of the gripping member is adjusted such that the center of the circular trajectory coincides with the center of the short cylinder 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for aligning a center of a gripping center for gripping a cylindrical or cylindrical object (hereinafter, simply referred to as a work) with a reference axis of the apparatus.
[0002]
[Prior art]
Conventionally, when gripping a workpiece with the center axis aligned with the reference axis of the device, if the reference axis of the device is vertical, a thread attached with a weight (swing down thread) is hung from the axis of the device and visually inspected. Accordingly, the adjustment is made such that the center of the swinging thread and the center of the gripper supporting the work are aligned. In this case, since the grip center is a virtual point that cannot be seen, adjustment by visual observation has a limit in accuracy.
[0003]
When the reference axis of the apparatus is the main axis of a lathe having centers on both ends, one small chuck holds a small laser beam oscillator, and a workpiece provided by a gripping member provided near the lathe holds the laser beam. The position of the gripping member has been adjusted such that the contact with the center of the end face of the work. In this case, it is necessary to match the main axis of the lathe with the laser beam in advance, and it takes time to perform the adjustment for that.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a method and an apparatus for centering a grip center, which can easily and highly accurately align a grip center axis of a grip member that grips a work with a predetermined reference axis. .
Note that the predetermined reference axis refers to, for example, a spindle rotation axis of a lathe or the like, or a vertical axis passing through the center of gravity when an object is suspended.
[0005]
[Means for Solving the Problems]
The centering method of the grip center of the present invention is a method of aligning the grip center axis of a grip member gripping a workpiece with a reference axis of the apparatus, and a short cylinder having a screen attached to an end surface or a cylinder thereof. Is gripped by a gripping member, an output beam oscillator is rotatably attached to the reference axis and rotated, and by projecting an output beam toward a short cylinder, a locus circle of a beam luminescent spot is drawn on the screen, The position of the gripping member is adjusted so that the center of the locus circle coincides with the center of the short cylinder.
[0006]
By drawing a plurality of circles concentric with the outer diameter of the short cylinder on a screen provided on the short cylinder, it is easily adjusted so that the concentric circle and the locus circle of the beam luminescent spot are concentric. be able to. Also, the trajectory circle of the beam luminescent spot projected on the screen is measured by an image sensor, and the adjustment amount is calculated from the deviation amount between the center of the short cylinder and the center of the trajectory circle to be displayed. It can also be controlled automatically to zero.
[0007]
Further, the grip center axis alignment apparatus of the present invention is an apparatus for aligning a grip center axis of a grip member for gripping a workpiece with a reference axis of the apparatus, and a short screen having a screen attached to an end face or a cylinder. A cylinder, a gripping member for gripping the short cylinder, an output beam oscillator rotatably mounted on a reference axis of the apparatus, and rotating the output beam oscillator to draw a locus circle of a beam luminescent spot on the screen. And a mechanism for adjusting the position of the gripping member so that the center of the locus circle coincides with the center of the short cylinder. Note that the gripping members include chucks and gripping rollers.
[0008]
In addition to the above, the grip center axis alignment device of the present invention calculates an adjustment amount from an amount of deviation between the center of the short cylinder and the center of the locus circle, or an image sensor that measures the locus circle of the beam luminescent spot. By providing the display device for displaying, the alignment of the axis becomes easier. In addition, based on the amount of deviation obtained by the calculation, the control device can also control the deviation to be zero.
In the present invention, a base material for an optical fiber is suitably used as the work.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The method and apparatus for centering the center of the grip of the present invention is to align the reference axis of the apparatus with the center axis of the gripping member that grips the workpiece before processing the workpiece using the target apparatus. In addition, the axis alignment is performed by causing the holding unit to hold a short cylinder instead of the work.
[0010]
The device of the present invention is an output beam oscillator for forming a small-diameter bright spot on a screen, for example, a laser beam oscillator, a mechanism for rotating the laser beam oscillator, a short cylinder having a screen attached to an end face or a cylinder, A gripping member and a mechanism for adjusting the position of the gripping member are provided.
On the screen attached to the short cylinder, draw a plurality of concentric circles concentrically with the outer diameter of the short cylinder, and when aligning the center of the grip center, hold the short cylinder with a gripping member and screen the short cylinder. The mounting position of the oscillator is adjusted so that the output beam of the laser beam oscillator hits the top.
[0011]
Thereafter, when the mounting jig of the laser beam oscillator is rotated about the reference axis, the bright spot of the laser beam rotates on the above-mentioned screen, so that the locus circle of the beam bright spot is drawn. By adjusting the position of the gripping member so as to be concentric with the upper concentric circle, the gripping center axis of the gripping member can be aligned with the reference axis of the apparatus. The deviation between the trajectory of the beam luminescent spot and the concentric circle on the screen must be visually checked and measured by an image sensor using a CCD camera, and the adjustment amount is calculated from the deviation amount and displayed to the operator. You can also.
[0012]
【Example】
The present invention will be described in more detail based on the following examples, but the present invention is not limited thereto, and various embodiments are possible.
[0013]
(Example 1)
In this embodiment, the reference axis of the apparatus is horizontal, and FIG. 1 shows a gripping mechanism for gripping a cylindrical work horizontally.
The short cylinder 1 is horizontally held by holding rollers 3a and 3b provided on the holding unit 2. In order to align the gripping center axis 4 of the short cylinder 1 with the reference axis 6 of the apparatus 5, the apparatus 5 is provided with a laser beam oscillator 7 which indicates the reference axis 6 by a laser beam. The small laser beam oscillator 7 is rotatably mounted around a reference axis 6 by a mounting jig 8.
[0014]
A screen 9 is attached to the end surface of the short cylinder 1, and a laser beam is projected on the screen, and a beam luminescent spot is visually recognized. When the small laser beam oscillator 7 is rotated around the reference axis 6 by the mounting jig 8, the beam luminescent spot projected on the screen 9 draws a circular locus about the intersection of the reference axis 6 and the screen 9.
[0015]
Therefore, if a concentric circle concentric with the outer diameter of the short cylinder 1 is drawn on the screen 9 at an appropriate pitch, the deviation between the concentric circle and the trajectory circle of the beam luminescent spot causes the grip center axis 4 and the reference axis 6 to shift. You can see the gap. By operating the position adjustment mechanism 10 while visually confirming the amount of the shift to adjust the positions of the gripping rollers 3a and 3b, the shift can be corrected.
[0016]
In addition, instead of adjusting the position by visual recognition, the position deviation of the short cylinder 1 is automatically controlled via the position adjustment mechanism 10 by measuring the beam luminescent spot projected on the screen with the image sensor 11 of the CCD camera system. be able to. It should be noted that the adjustment amount calculated from the deviation amount is displayed as a numerical value, and the operation can be performed based on the numerical value.
[0017]
(Example 2)
The present embodiment is an example in the case where the reference axis of the axis centering device at the grip center is vertical, and FIG. 2 is a schematic longitudinal sectional view showing the axis centering device of the present invention.
FIG. 2 shows a state in which the short cylinder 1 is gripped by gripping rollers 3 a and 3 b provided on the gripping unit 2, and the gripping center axis 4 of the short cylinder 1 is adjusted so as to coincide with the reference axis 6 on the device 5 side. Is shown.
Specifically, the short cylinder 1 is vertically gripped by a gripping member provided in the gripping unit 2, in this example, a pair of gripping rollers 3a, 3b.
[0018]
A disk 12 is disposed in the opening of the device 5 having a cylindrical upper end so as to fit at the inner peripheral edge of the opening. A gimbal mechanism 15 having two orthogonal axes configured to be movable in the X and Y directions is provided at the center of the disk 12, and the hollow shaft 13 is supported by the gimbal mechanism 15. A small laser beam oscillator 7 is mounted on the upper portion of the hollow shaft 13, and the output beam of the laser beam oscillator 7 is adjusted so as to be emitted from a small hole 14 formed at the center of the lower end of the hollow shaft 13. . Since the hollow shaft 13 is suspended in the direction of gravity by the action of the gimbal mechanism 15, the output beam of the laser beam oscillator 7 functions as a substitute for the conventional weight.
[0019]
Next, the short cylinder 1 is gripped by the pair of gripping rollers 3a and 3b instead of the work. An auxiliary bar 16 orthogonal to the short cylinder 1 to stabilize the holding state is placed on the holding rollers 3a and 3b to prevent the short cylinder 1 from falling down. The gripping unit 2 is a unit that grips the work, and includes a pair of gripping rollers 3a and 3b, and a position adjustment mechanism that opens and closes and adjusts the position of the gripping rollers, in addition to the auxiliary bar 16.
Further, a translucent screen 9 is provided inside the short cylinder 1 at a height position to be gripped by the gripping rollers 3a and 3b, and an output beam of the laser beam oscillator 7 hits the screen 9, and a beam luminescent spot is formed. Is generated.
[0020]
By measuring the position of the beam luminescent spot with an image sensor 11 having a CCD element provided at an appropriate distance from the screen 9, the shift amount and the direction of the shift of the beam luminescent spot from the holding center axis of the short cylinder 1 are measured. And the adjustment amount. By adjusting the position of the gripping unit 2 so that the displacement amount becomes zero, the gripping center axis 4 of the short cylinder 1 can be made to coincide with the reference axis 6 of the device 5.
[0021]
Note that the hollow shaft 13 may not correctly face the vertical direction due to an error of the gimbal mechanism 15 or other causes. In such a case, for example, a normal appropriate driving mechanism as shown in FIG. When the hollow shaft 13 is rotated by the motor 17, the rotation locus circle of the beam luminescent spot is drawn on the screen 9. Therefore, the center point is obtained, and this center point may be made to coincide with the center of the short cylinder 1.
[0022]
【The invention's effect】
By using the gripping center axis alignment method and apparatus of the present invention, it is not necessary to align the laser beam with the gripping center axis of the short cylinder, so there is no need to increase the mounting accuracy of the laser beam oscillator, and there is no skilled skill. However, the alignment can be performed in a short time. In addition, since the trajectory circle of the laser beam oscillator's beam luminescent spot is aligned with the concentric circle on the screen, multiple concentric circles are drawn on the screen with the required pitch and precision, so that highly accurate and reliable adjustment can be performed. Can be.
Further, by using a CCD camera image sensor to calculate the displacement of the beam luminescent spot on the screen from the grip center axis of the short cylinder, the amount of adjustment is calculated from the shift between the grip center axis and the reference axis. Can be accurately displayed in a short time even if the user is not an expert. In addition, the position of the short cylinder can be automatically adjusted.
[Brief description of the drawings]
FIG. 1 shows a gripping mechanism for horizontally gripping a work used in a first embodiment of the present invention.
FIG. 2 is a schematic vertical cross-sectional view showing a grip center centering device used in a second embodiment of the present invention.
[Explanation of symbols]
1. … A short cylinder,
2. … Grip unit,
3a, 3b. … Gripping roller,
4. … Grip center axis,
5. …apparatus,
6. … Reference axis,
7. … Laser beam oscillator,
8. … Mounting jig,
9. …screen,
10. … Position adjustment mechanism,
11. ... image sensor,
12. … A disk,
13. ... hollow shaft,
14． … A small hole,
15. … Gimbal mechanism,
16. ... Auxiliary bar,
17. …motor.

Claims (10)

This is a method of aligning the gripping center axis of a gripping member for gripping a workpiece with a reference axis of an apparatus, wherein a short cylinder having a screen attached to an end face or a cylinder is gripped by a gripping member and output to the reference axis. The beam oscillator is rotatably mounted and rotated, and the output beam is projected toward the short cylinder, thereby drawing a locus circle of the beam luminescent spot on the screen, and the center of the locus circle coincides with the center of the short cylinder. Adjusting the position of the gripping member so as to perform gripping. The method of claim 1, wherein the workpiece is a base material for an optical fiber. 3. A plurality of circles concentric with the outer diameter of the short cylinder are drawn on a screen provided on the short cylinder, and the concentric circle and the locus circle of the beam luminescent spot are adjusted to be concentric. 5. The method for centering the axis of the grip center described in 1. above. The gripping center according to any one of claims 1 to 3, wherein a locus circle of the beam luminescent spot is measured by an image sensor, and an adjustment amount is calculated and displayed from an amount of deviation between the center of the short cylinder and the center of the locus circle. Axis alignment method. 5. The method according to claim 4, wherein the control is performed automatically so that the displacement amount becomes zero. An apparatus for aligning a gripping center axis of a gripping member for gripping a workpiece with a reference axis of the apparatus, comprising: a short cylinder having a screen attached to an end face or a cylinder; a gripping member for gripping the short cylinder; An output beam oscillator rotatably mounted on a reference axis of the laser beam, and rotating the output beam oscillator to draw a locus circle of a beam luminescent spot on the screen, and the center of the locus circle coincides with the center of the short cylinder. A mechanism for adjusting the position of the gripping member as described above. The apparatus according to claim 6, wherein the workpiece is a base material for an optical fiber. The apparatus according to claim 6 or 7, wherein the gripping member is a chuck or a gripping roller. 9. The image sensor according to claim 6, further comprising: an image sensor that measures a locus circle of the beam bright spot; and a display device that calculates and displays an adjustment amount from a shift amount between the center of the short cylinder and the center of the locus circle. A gripping center axis aligning device according to any of the claims. The apparatus according to claim 9, further comprising a controller configured to control the displacement amount to be zero.

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