JPH07119586B2 - Work tilt angle measuring device for bending machine - Google Patents

Description

Description: [Object of the Invention] (Industrial field of application) The present invention relates to a measuring device for measuring an inclination angle of a workpiece bent by a bending machine such as a press brake.

(Prior Art) In a bending machine such as a press brake, generally, a work is clamped between an upper punch and a lower die to perform bending at a predetermined bending angle. Therefore, it is necessary to accurately measure the bending angle of this work. In other processing machines, it may be necessary to accurately measure the inclination angle of a certain processing surface.

However, conventionally, in such a processing machine, an angle measuring device that automatically and accurately measures the inclination angle of the surface to be measured of the object has not been known.

(Problems to be Solved by the Invention) As described above, conventionally, there has been known an angle measuring device that accurately and automatically measures the tilt angle of the surface to be measured of an object such as a workpiece in a processing machine. Absent.

The present invention has been made in view of such conventional problems, and provides a tilt angle measuring device capable of accurately and automatically measuring the tilt angle of a measurement target surface having a wide object. With the goal.

[Structure of the Invention] (Means for Solving Problems) In view of the conventional problems as described above, the present invention provides a tilt angle measuring device for measuring a tilt angle of a workpiece bent by a bending machine, The optical axis of a circular scan laser projector that projects a laser beam in a conical shape is provided vertically, and an imaging device that captures the image that appears on the work by the projection from this circular scan laser projector is provided, and an image is captured by the imaging device. A CPU is provided for calculating the inclination angle of the work from the relationship between the length of the major axis of the ellipse image and the inclination angle of the work.

(Embodiment) FIG. 1 is a block diagram of an embodiment of the present invention, which is equipped with a circular scan laser projector 1 for projecting a laser beam into a circular shape having a constant radius as a projecting means. The circular rotation of the circular scan laser projector 1 is controlled by a motor control 3. Further, as an image pickup means for picking up an image appearing on the surface to be measured by the light emitted from the circular scan laser light projector 1,
An imaging device 5 such as a CCD image sensor or PST is provided. The image pickup information from the image pickup device 5 is given to the main amplifier 7, the main amplifier 7 performs A / D conversion, and is given as digital data to the CPU 9 as a calculation means.

The CPU 9 has a calculation function for automatically calculating the tilt angle of the target surface from the imaged information, outputs the calculated tilt angle, and causes the display device (not shown) to display the angle, if necessary. .

FIG. 2 shows the circular scan laser projector 1 and the image pickup device 5.
Shows the mechanical configuration of. In this embodiment, the case where it is used to measure the bending angle of the work of the press brake is shown, but the circular scan laser projector 1 is used.
However, it is installed so as to project a laser beam LB in a circular shape from below on a work W which is clamped and bent between the punch 11 and the die 13 and around a vertical optical axis.

Further, the image pickup device 5 is installed on the lower surface of the work W, which is bent at various angles, so as to be able to pick up a wide range of images formed by the laser beam from the laser projector 1.

When the circular scan laser projector 1 projects the laser beam LB around a vertical axis so as to draw a circle with a predetermined radius,
The image drawn by the laser beam LB on the lower surface of the work W has various elliptical shapes with different ratios of the major axis and the minor axis depending on the tilt angle, as shown in FIG.

Therefore, the image pickup device 5 picks up an image of the laser beam appearing on the work W, gives the picked-up information to the main amplifier 7, where it is A / D converted and given to the CPU 9.

The elliptical image appearing on the work W has a one-to-one correspondence with the inclination angle of the work W. Therefore, in the CPU 9, the comparison table of the length of the long axis of the elliptic image and the inclination angle of the work is input in advance, the length of the long axis is determined based on the imaging data coming from the main amplifier 7, and the long axis The inclination angle of the work W can be calculated by extracting the inclination angle of the work corresponding to the length from the table.

The CPU 9 does not only determine the tilt angle of the work W using the above table, but also determines the tilt angle of the work W by substituting the data of the long axis and the short axis of the image that appears in the general formula. It is also possible to do so. The table and the general formula are determined by the place where the tilt angle measuring device is installed, the measurement object, the scan radius, and various other parameters, and can be experimentally determined according to the installation place. it can.

As can be understood from the above description, the circular scan laser projector 1 projects the laser beam LB in a conical shape as shown in FIG. The image appearing on the work W by the light is circular, and the image becomes elliptical as the work W is bent and gradually inclined.

As can be understood from FIGS. 2 and 3, the change rate of the major axis of the ellipse increases as the inclination angle of the work W increases, so that the final bending angle of the work should be detected more accurately. It is something that can be done.

[Effects of the Invention] As will be understood from the above description of the embodiments, in brief, the present invention provides a conical shape in a tilt angle measuring device for measuring a tilt angle of a work (W) bent by a bending machine. The optical axis of the circular scan laser projector (1) that projects the laser beam (LB) is set vertically, and the image that appears on the workpiece (W) is projected by the projection from the circular scan laser projector (11). A CPU (9) that is provided with the device (5) and that calculates the tilt angle of the work (W) from the relationship between the length of the long axis of the elliptic image captured by the imaging device (5) and the tilt angle of the work (W). ) Is provided.

As is apparent from the above configuration, in the present invention, the circular scan laser projector 1 projects the laser beam LB into a conical shape, and its optical axis is provided vertically.

Therefore, when the work W bent by the bending machine is horizontal, the image appearing on the work W by the light emitted from the circular scan laser projector 1 is circular, and as the work W is bent and inclined. It becomes an elliptical shape.

At this time, as the inclination angle of the workpiece W increases, the length of the elliptical major axis becomes longer, but since the laser beam LB is projected in a conical shape, the rate of change of the major axis is the inclination angle of the workpiece W. Is larger, the inclination angle of the work W, in other words, the final bending angle can be measured more accurately.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an explanatory view showing a mechanical structure of the circular scan laser projector and the image pickup apparatus of the above embodiment, and FIG. 3 is a schematic diagram of the circular scan laser projector. It is explanatory drawing which shows the image of the laser beam which appeared on the workpiece | work. 1 ... Circular scan laser projector 3 ... Motor control 5 ... Imaging device, 7 ... Main amplifier 9 ... CPU

Claims (1)

[Claims] 1. A tilting angle measuring device for measuring a tilting angle of a work (W) bent by a bending machine, wherein light of a circular scan laser projector (1) which projects a laser beam (LB) in a conical shape. An axis is provided vertically, and an image pickup device (5) for picking up an image appearing on the work (W) by light projection from the circular scan laser projector (11) is provided, and an elliptic image picked up by the image pickup device (5). And a workpiece inclination angle measurement for a bending machine, comprising a CPU (9) for calculating the inclination angle of the workpiece (W) from the relationship between the length of the long axis of the workpiece and the inclination angle of the workpiece (W). apparatus.