JP4046110B2 - Hole positioning method - Google Patents

Description

  The present invention relates to a hole positioning method in which the center position of a hole formed in a hemispherical surface is positioned and the axial direction of the hole coincides with the direction of the θ axis.

  As shown in FIG. 1, a visual device 1 that captures an image of the hemispherical surface of the object 5 to be positioned, a θ positioning part 2 that holds the object 5 and rotates only in the θ direction, and supports the θ positioning part. Using a hole positioning device composed of a φ positioning part 3 that rotates and moves only in the φ direction, and an XY table 4 that supports the φ positioning part and moves in the horizontal and vertical directions, The center position of the hole 51 formed on the hemispherical surface of the object 5 is positioned, and the axial direction of the hole 51 is made to coincide with the direction of the θ axis.

However, in the conventional hole positioning method, as shown in FIG. 5, the image center is obtained from the entire shape captured by the image of the visual device 1, and the angle of the hole center with respect to the image center, the image center, and the hole center are obtained. The angle on the φ axis of the hole 51 is obtained from the ideal spherical surface, and the angle obtained on the φ axis is rotated to position the hole in front of the visual device.
However, since the surface is actually deviated from the ideal spherical surface, high-precision positioning cannot be performed, and when machining with a machining allowance of 15 μm is performed, a surface that cannot be machined remains.
Moreover, the three-dimensional shape measuring machine and measuring method of patent document 1 are known as a prior art. In this Patent Document 1, the object to be measured having a spherical surface is placed on a table that can rotate around the rotation axis, and the displacement of the object to be measured in the direction of moving back and forth toward the rotation axis on a plane perpendicular to the rotation axis. The sensor is moved in a direction parallel to the rotation axis while the sensor is detected, the sensor is stopped at a position where the maximum displacement is given, the table is rotated while detecting the displacement of the object to be measured by the sensor in the stationary state, The mounting position of the object to be measured on the table is adjusted so that the detected displacement amount during the rotation is constant, and the spherical surface of the object to be measured is based on the constant sensor detected displacement amount after the adjustment. By determining the radius of curvature, it is intended to improve the measurement accuracy of the radius of curvature by reducing the influence of mechanical operating errors.
JP 2000-74606 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a hole positioning method capable of positioning a hole formed on a spherical surface of an object to be positioned with high accuracy even if the spherical surface is displaced. It is to be.

The present invention provides a hole positioning method according to the claims as a means for solving the problems.
The hole positioning method according to claim 1, wherein the hole formed on the hemispherical surface of the object to be positioned is positioned so that the hole is located at a front position of the visual device .
The object to be positioned is chucked by the holding portion , and the image of the hole formed in the hemispherical surface is captured by the visual device every 120 ° rotation about the θ rotation axis, and the object to be positioned is determined from the three images of the hole of the object to be positioned. Determination of θ rotation axis center as seen from the visual device direction, and rotated to the home position to the center of θ positioning portion when viewed from the visual device direction of the hole to be positioned object, and the φ positioning portion, the hole to be positioned object The rotation is such that the center viewed from the direction of the visual device is at a position directly above the center of the θ rotation axis .
In this way, by capturing an image of the hemisphere with a visual device every 120 ° rotation around the θ rotation axis, and obtaining the θ rotation axis center of the object to be positioned from the three images, the rotation center of the object to be positioned (θ axis) can be a determined with high accuracy, also determine the φ axis angle of the holes in an ideal spherical diameter from a distance of between θ rotation center and the hole, after rotational positioning, and about the θ rotation axis center of the hole By matching, the hole can be positioned with high accuracy without being affected by the shape error of the hemispherical surface of the object to be positioned.

  Hereinafter, a hole positioning method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an overall configuration of a hole positioning device for carrying out a hole positioning method according to an embodiment of the present invention. The hole positioning device of the present invention basically includes a visual device 1, a θ positioning portion 2, a φ positioning portion 3, and an XY table 4.

The visual device 1 captures the held hemispherical surface of the object to be positioned 5 as an image, and the captured image is sent to an image processing device 11 described later and stored therein as visual data.
The θ positioning unit 2 holds the object to be positioned 5 with a chuck or the like and can rotate and move only in the θ direction.
The φ positioning unit 3 supports the θ positioning unit 2 and can rotate and move only in the φ direction.
The XY table 4 supports the φ positioning unit 3 that supports the θ positioning unit 2 and can move in the horizontal and vertical directions.

  The operation (hole positioning method) of the hole positioning device of the present invention having the above configuration will be described. 2 is a diagram for explaining a hole positioning method according to an embodiment of the present invention, FIG. 3 is a block diagram for explaining the operation of the hole positioning device of the present invention, and FIG. 4 is a flowchart thereof. is there. That is, in this embodiment, as shown in FIG. 3, the image captured by the visual device 1 is sent to the image processing device 11 and stored as visual data, and from this stored visual data, the θ axis The angle of the φ axis from the center and the amount of deviation in the horizontal and vertical directions are calculated, and this data is sent to the control device 12. Based on this data, the control device 12 calculates the movement amounts of the θ, φ, X, and Y axes, and issues a movement command to each of the θ, φ, X, and Y axes.

  As shown in the flowchart of FIG. 4, first, in step S1, the object to be positioned 5 is chucked and attached to the θ positioning portion 2 of the hole positioning device. Next, in step S2, an image of the hole 51 of the object to be positioned 5 is captured by the visual device 1, and in step S3, the captured image is stored as a first image by the image processing device 11 (image of FIG. 2). 1). Next, in step S4, the object to be positioned 5 held by the θ positioning unit 2 is rotated by 120 ° in the θ direction, and in step S5, the image of the hole 51 of the object to be positioned 5 rotated by 120 ° is captured by the visual device 1. Similarly, in step S6, the captured image is stored as the second image in the image processing apparatus 11 (image 2 in FIG. 2). Further, in step S7, the object to be positioned 5 held by the θ positioning unit 2 is further rotated by 120 ° in the θ direction. In step S9, the captured image is stored as the third image in the image processing apparatus 11 (image 3 in FIG. 2).

  Next, from the three times of image data (images 1 to 3) stored in the image processing apparatus 11 in step S10, the centers of the images of the three holes 51 are obtained, the θ rotation axis is obtained, and the θ rotation axis position is obtained. Is stored (θ axis center). Next, in step S11, the image processing apparatus 11 calculates the φ axis angle of the hole 51 at the ideal spherical diameter from the distance between the center of the θ axis and the hole 51 of the object to be positioned 5, and stores this. In step S12, the θ-axis and φ-axis angles are output from the image processing apparatus 11 to the control apparatus 12. In step S13, the control apparatus 12 calculates the movement amounts of the θ and φ axes, and in step S14, the control apparatus 12 performs this movement. Based on the amount, a movement command is output to the θ and φ axes.

  Next, in step S15, the to-be-positioned object 5 is rotated by the θ positioning unit 2, and the center position of the hole 51 is rotated to a predetermined position (origin position) with respect to the θ axis center. Next, similarly, in step S16, the object to be positioned 5 is rotated by the φ positioning unit 3, the center position of the hole 51 is rotated to a position directly above the center of the θ axis, and the image of the hole 51 at this time is visually viewed in step S17. The image is captured by the apparatus 1, and the captured image is stored in the image processing apparatus 11 in step S18 (image 4 in FIG. 2).

Next, in step S19, the image processing device 11 calculates θ, horizontal (X), and vertical (Y) direction deviations from the image 4, and in step S20, the control device 12 determines θ, X, The movement amount of the Y axis is calculated and a movement command is output. In step S21, the center position of the hole 51 is corrected and moved to a predetermined position by the θ positioning unit 2 and the XY table 4 with respect to the positioning object 5. In this way, the positioning of the hole 51 of the object to be positioned 5 is completed in step S22.
By positioning the hole 51 of the positioning object 5 in this way, the center of the hole 51 can be accurately positioned without being influenced by the shape error of the spherical surface. In addition, the direction toward the center of the spherical surface of the hole can coincide with the center of the θ axis.

  As described above, in the present invention, the hemispherical surface of the object to be positioned is captured as an image by the visual device every 120 ° rotation around the θ axis, and the θ axis center of the object to be positioned is obtained from the three images, and the θ axis The hole formed in the spherical surface is obtained by determining the φ-axis angle of the hole at the ideal spherical diameter from the distance between the center and the hole formed in the hemispherical surface, rotating and positioning, and then aligning the center of the hole with the θ-axis center Can be positioned with high accuracy even if the spherical surface is displaced.

It is a schematic diagram which shows the whole structure of the hole positioning device used in enforcing the hole positioning method of embodiment of this invention. It is a figure explaining the positioning method of the hole of embodiment of this invention. It is a block diagram explaining the action | operation of the positioning device of the hole of FIG. It is a flowchart explaining the action | operation of the positioning device of the hole of FIG. It is a figure explaining the positioning method of the conventional hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Visual apparatus 11 Image processing apparatus 12 Control apparatus 2 (theta) positioning part 3 (phi) positioning part 4 XY table 5 Positioning object 51 hole

Claims (1)

A holding part for chucking an object to be positioned having a hemispherical surface in which a hole is formed;
A visual device that captures an image of the hemispherical surface of the object to be positioned held by the holding unit;
A θ positioning unit that rotates the object to be positioned around a θ rotation axis in the direction of the visual device;
A φ positioning portion that rotates the object to be positioned around a φ rotation axis in a direction perpendicular to the θ rotation axis and passing through the center of the hemisphere.
Wherein a hole positioning method of the positioning object formed in said semi-spherical hole to be positioned object is positioned such that the front position of the visual device,
Said object positioning was chuck by said holding unit, for each rotation 120 ° about said θ rotation axis and the θ positioning portion by the visual device, the capture three images of the hemisphere, said from said three image Obtaining the center of rotation of the θ viewed from the visual device direction of the object to be positioned;
An origin that allows the θ positioning portion to rotate the center of the hole of the object to be positioned as viewed from the visual device to a position directly above the θ rotation axis center viewed from the visual device direction by the φ positioning portion. Rotating to a position,
Characterized in that by the φ positioning unit, wherein rotating the object to be positioned object, the center as viewed from the visual device direction of said hole; and a step of rotating to come to a position directly over the θ rotation axis center The positioning method of the hole provided in the to-be-positioned object.

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