JP3941867B2 - Axis centering method and apparatus for gripping center - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an axis alignment method and apparatus for gripping centers, in which a gripping center for gripping a cylindrical or columnar object (hereinafter simply referred to as a workpiece) is aligned with a reference axis of the apparatus.
[0002]
[Prior art]
Conventionally, when gripping with the center axis of the work aligned with the reference axis of the device, if the reference axis of the device is vertical, a thread with a weight (swinging thread) is hung from the axis of the device and visually Thus, the adjustment is made so that the center of the swinging thread and the gripping portion that supports the workpiece coincide with each other. In this case, since it is a virtual point where the grip center is not visible, visual adjustment has a limit in accuracy.
[0003]
When the reference axis of the machine is a lathe spindle with centers at both ends, a small laser beam oscillator is gripped by one chuck, a workpiece is gripped by a gripping member provided near the lathe, and a laser beam The position of the gripping member has been adjusted so that the center of the workpiece is in contact with the center of the workpiece end surface. In this case, it is necessary to make the laser beam and the main axis of the lathe coincide with each other in advance, and it takes time for adjustment.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a gripping center axis alignment method and apparatus capable of easily and accurately aligning a gripping center axis of a gripping member that grips a workpiece with a predetermined reference axis. .
The predetermined reference axis refers to, for example, a spindle rotation axis such as a lathe or a vertical axis passing through the center of gravity when an object is suspended.
[0005]
[Means for Solving the Problems]
The gripping center axis alignment method of the present invention is a method of matching the gripping center axis of a gripping member that grips a workpiece with the reference axis of the apparatus, and a short cylinder having a screen attached to its end face or cylinder , The output beam oscillator is rotatably mounted on the reference axis and rotated, and the output beam is projected toward the short cylinder, thereby drawing a locus circle of the beam bright spot 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 concentric circles with the outer diameter of the short cylinder on the screen provided in the short cylinder, the concentric circle and the locus circle of the beam bright spot are easily adjusted to be concentric. be able to. In addition, the locus circle of the beam bright spot projected on the screen is measured with an image sensor, and the adjustment amount is calculated from the amount of deviation between the center of the short cylinder and the center of the locus circle, and displayed. It can also be automatically controlled so that it becomes zero.
[0007]
In addition, the gripping center axis alignment device of the present invention is a device for matching the gripping center axis of a gripping member that grips a workpiece with the reference axis of the device, and is a short screen with 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 attached to a reference axis of the apparatus, and rotating the output beam oscillator to draw a locus circle of a beam bright 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 examples of the gripping member include a chuck and a gripping roller.
[0008]
In addition to the above, the gripping center axis alignment device of the present invention calculates an adjustment amount from an image sensor that measures the locus circle of the beam bright spot and a deviation amount between the center of the short cylinder and the center of the locus circle. By providing a display device for display, it is easier to align the axes. In addition, on the basis of the amount of deviation obtained by calculation, the control device can also be controlled so that this becomes zero.
In the present invention, an optical fiber preform is preferably used as the workpiece.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The gripping center axis alignment method and apparatus according to the present invention aligns the reference axis of the apparatus with the gripping center axis of the gripping member that grips the work prior to processing the work using the target apparatus. Yes, this axial alignment is performed by holding the short cylinder by the holding unit instead of the workpiece.
[0010]
The apparatus of the present invention includes an output beam oscillator for producing a small-diameter luminescent 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, a plurality of concentric circles are drawn concentrically with the outer diameter of the short cylinder, and when aligning the axis of the grip center, the short cylinder is gripped with a gripping member. Above, the mounting position of the oscillator is adjusted so that the output beam of the laser beam oscillator hits.
[0011]
After that, when the laser beam oscillator mounting jig is rotated around the reference axis, the laser beam bright spot rotates on the above-mentioned screen. 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. In addition to visually confirming the deviation between the locus of the beam bright spot and the concentric circle on the screen, measure it with an image sensor using a CCD camera, calculate the adjustment amount from the deviation amount, and display it to the operator. You can also.
[0012]
【Example】
The present invention will be described in more detail based on the following examples. However, the present invention is not limited to these, and various modes are possible.
[0013]
Example 1
In this embodiment, the reference axis of the apparatus is horizontal, and FIG. 1 shows a gripping mechanism that grips a cylindrical workpiece horizontally.
The short cylinder 1 is gripped horizontally by gripping rollers 3 a and 3 b provided in the gripping unit 2. In order to align the grip center axis 4 of the short cylinder 1 with the reference axis 6 of the apparatus 5, a laser beam oscillator 7, which indicates the reference axis 6 with a laser beam, is attached to the apparatus 5. The small laser beam oscillator 7 is rotatably mounted around the reference axis 6 by a mounting jig 8.
[0014]
A screen 9 is affixed to the end face of the short cylinder 1, a laser beam is projected onto the screen, and a beam bright 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 bright spot projected on the screen 9 draws a circular locus around 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 gripping center axis 4 and the reference axis 6 are displaced from the deviation between the concentric circle and the locus circle of the beam bright spot. I understand the gap. By operating the position adjustment mechanism 10 while visually recognizing the amount of deviation and adjusting the positions of the gripping rollers 3a and 3b, the deviation can be corrected.
[0016]
Further, the positional deviation of the short cylinder 1 is automatically controlled via the position adjustment mechanism 10 by measuring the beam bright spot projected on the screen by the CCD camera type image sensor 11 instead of the position adjustment by visual recognition. be able to. It is also possible to display the adjustment amount calculated by calculating from the deviation amount as a numerical value and operate based on this numerical value.
[0017]
(Example 2)
The present embodiment is an example in which the reference axis of the axis alignment device at the grip center is vertical, and FIG. 2 is a schematic longitudinal sectional view showing the axis alignment device of the present invention.
In FIG. 2, the short cylinder 1 is gripped by the gripping rollers 3 a and 3 b provided in the gripping unit 2, and the grip center axis 4 of the short cylinder 1 is adjusted so as to coincide with the reference axis 6 on the apparatus 5 side. Is shown.
Specifically, the short cylinder 1 is gripped in the vertical direction by a gripping member provided in the gripping unit 2, in this example, a pair of gripping rollers 3a and 3b.
[0018]
A disc 12 is disposed in the opening of the device 5 whose upper end is cylindrical in shape so as to be fitted at the inner periphery of the opening. A gimbal mechanism 15 having two orthogonal axes configured to be movable in the X and Y directions is disposed at the center of the disc 12, and a hollow shaft 13 is supported by the gimbal mechanism 15. A small laser beam oscillator 7 is attached to the upper part 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 in 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 pair of gripping rollers 3a and 3b grip the short cylinder 1 instead of the workpiece. In the short cylinder 1, an auxiliary bar 16 orthogonal to the gripping state is placed on the gripping rollers 3a and 3b to prevent the short cylinder 1 from falling down. The gripping unit 2 is a unit for gripping a workpiece, and includes a pair of gripping rollers 3a and 3b and a position adjusting mechanism for opening and closing the gripping roller and adjusting the position in addition to the auxiliary bar 16.
Further, a translucent screen 9 is provided in the short cylinder 1 at a height position gripped by the gripping rollers 3a and 3b. The output beam of the laser beam oscillator 7 hits the screen 9, and the beam bright spot. Produce.
[0020]
The position of the beam bright spot is measured by an image sensor 11 having a CCD element disposed at an appropriate distance from the screen 9, thereby shifting the beam bright spot from the grip center axis of the short cylinder 1 and the direction of the shift. And the adjustment amount. By adjusting the position of the gripping unit 2 so that the amount of deviation 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 there may be a case where the hollow shaft 13 does not correctly face the vertical direction due to an error of the gimbal mechanism 15 or other causes, but in that case, for example, via a normal appropriate drive mechanism as shown in FIG. When the hollow shaft 13 is rotated by the motor 17, a rotation locus circle of the beam bright spot is drawn on the screen 9, so that the center point is obtained, and the center point and the center of the short cylinder 1 may be matched.
[0022]
【The invention's effect】
By using the gripping center axis alignment method and apparatus of the present invention, it is not necessary to make the laser beam coincide 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 skill required. However, the axis alignment can be performed in a short time. In addition, since the locus circle of the beam bright spot of the laser beam oscillator is aligned with the concentric circles on the screen, multiple highly concentric circles are drawn on the screen with the required pitch and accuracy to perform highly accurate and reliable adjustment. Can do.
Furthermore, the amount of adjustment is calculated from the amount of deviation between the grip center axis and the reference axis by calculating the positional deviation of the beam bright spot on the screen from the grip center axis of the short cylinder using an image sensor with a CCD camera. Therefore, even if it is not an expert, an axis alignment operation can be performed accurately in a short time. Further, 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 workpiece used in Embodiment 1 of the present invention.
FIG. 2 is a schematic longitudinal sectional view showing an axis alignment device for a gripping center used in Embodiment 2 of the present invention.
[Explanation of symbols]
1. ... short cylinder,
2. ... Grip unit,
3a, 3b. ... Gripping roller,
4). ... Gripping center axis,
5). …apparatus,
6). ... reference axis,
7). ... Laser beam oscillator,
8). ... Installation jig,
9. …screen,
Ten. ... Position adjustment mechanism,
11． ... Image sensor,
12． ... discs,
13. ... hollow shaft,
14. ... small holes,
15． ... Gimbal mechanism,
16． ... Auxiliary bar,
17． …motor.

Claims (10)

This is a method for matching the grip center axis of the gripping member that grips the workpiece with the reference axis of the device, and grips the short cylinder with the screen pasted on its end face or cylinder with the gripping member and outputs it to the reference axis A beam oscillator is rotatably mounted and rotated, and an output beam is projected toward the short cylinder, so that a locus circle of the beam bright spot is drawn on the screen, and the center of the locus circle coincides with the center of the short cylinder. A method for adjusting the axis of the gripping center, wherein the position of the gripping member is adjusted in such a manner. The method of claim 1, wherein the workpiece is an optical fiber preform. 3. A plurality of circles concentric with the outer diameter of the short cylinder are drawn on a screen provided in the short cylinder, and the concentric circle and the locus circle of the beam bright spot are adjusted to be concentric. A method for aligning the axis of the grip center as described in 1. 4. The gripping center according to claim 1, wherein the locus circle of the beam bright spot is measured by an image sensor, and an adjustment amount is calculated and displayed from a deviation amount between the center of the short cylinder and the center of the locus circle. The method of aligning the axis. The method of claim 4, wherein the grip center is automatically controlled so that the amount of deviation is zero. An apparatus for matching a grip center axis of a gripping member for gripping a workpiece with a reference axis of the apparatus, a short cylinder having a screen pasted on an end face or a cylinder, a gripping member for gripping the short cylinder, and an apparatus An output beam oscillator rotatably attached to the reference axis of the laser beam and rotating the output beam oscillator to draw a locus circle of the beam bright spot on the screen, the center of the locus circle being coincident with the center of the short cylinder A gripping center axis aligning device having a mechanism for adjusting the position of the gripping member as described above. The gripping center axis alignment device according to claim 6, wherein the workpiece is an optical fiber preform. The gripping center axis alignment device according to claim 6 or 7, wherein the gripping member is a chuck or a gripping roller. The image sensor for measuring a locus circle of the beam bright spot, and a display device for calculating and displaying an adjustment amount from a deviation amount between the center of the short cylinder and the center of the locus circle. The grip center-centering device according to claim 1. The gripping center axis alignment device according to claim 9, further comprising a control device that controls the deviation amount to be zero.

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