JP3592846B2 - Teaching method and apparatus for laser beam machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a teaching method and apparatus in a laser processing machine that performs teaching using an imaging means such as a CCD camera.
[0002]
[Prior art]
Conventionally, as teaching for laser processing, there is one performed using a visible light laser KLB as shown in FIG. In FIG. 8, for example, the visible light laser KLB is irradiated from the laser processing head 101, and the visible light laser KLB irradiated on the workpiece W when the operator visually observes the teaching is performed in accordance with the processing position. .
[0003]
However, when such a visible light laser KLB is used, there is a problem that it is difficult to visually recognize the visible light laser KLB with the eyes of the operator and the focus is not clear, so that accurate teaching cannot be performed. For this reason, there is a type that performs teaching by imaging a processing position by a CCD camera 103 as shown in FIG.
[0004]
In FIG. 9, for example, a CCD camera 103 is provided inside the laser processing head 105, and the surface of the workpiece W is focused and imaged through the condenser lens 107. From the image, the laser processing head 105 is aligned with the processing position and teaching is performed. Is to do.
[0005]
[Problems to be solved by the invention]
However, when teaching is performed using an image from the CCD camera 103, the condenser lens 107 is also an imaging lens of the CCD camera 103. Therefore, if the laser focal length is increased, the depth of focus of the camera is increased and the focus is not clear. There is a problem that proper teaching is difficult.
[0006]
An object of the present invention is made by paying attention to the conventional technology as described above, and an imaging means such as a CCD camera that can perform accurate teaching even in a laser processing machine using a long focus laser lens. It is an object of the present invention to provide a teaching method and apparatus for the laser beam machine used.
[0007]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and the invention according to claim 1 irradiates a processing position on a workpiece with a main laser beam through a condensing lens provided inside a laser processing head. A teaching method in a laser processing machine for performing laser processing by making an auxiliary laser beam incident on the condenser lens parallel to the optical axis from a position away from the optical axis of the main laser beam. Irradiating obliquely toward the processing position via the optical axis and imaging the work surface of the imaging target placed at a position overlapping the optical axis of the main laser beam via the condenser lens; and Adjusting the distance between the laser processing head and the workpiece so as to make the irradiation position of the workpiece surface displayed by irradiation coincide with the machining position; And the step of teaching by storing the position coordinates of the laser processing head after matching the irradiation position with the processing position, and if the irradiation position and the processing position do not match, This is a teaching method in a laser processing machine in which irradiation of the auxiliary laser beam is located outside the irradiation range of the main laser beam.
The invention according to claim 2 is a teaching apparatus in a laser processing machine that performs laser processing by irradiating a processing position on a workpiece through a condensing lens provided inside a laser processing head with a main laser beam, An auxiliary laser source that radiates the auxiliary laser beam to the condenser lens obliquely toward the processing position through the condenser lens by entering the auxiliary laser beam parallel to the optical axis from a position away from the optical axis of the main laser beam; By means of imaging means for imaging the workpiece surface of the imaging target placed at a position overlapping with the optical axis of the main laser beam through the condenser lens, display means for displaying the captured image, and the auxiliary laser beam The distance between the laser processing head and the workpiece is adjusted so that the irradiation position on the surface of the workpiece to be irradiated matches the processing position, and the irradiation A position detecting means for detecting a position coordinate of the laser processing head when a position is matched with the processing position, and a storage means for storing the position coordinate detected by the position detecting means, When the machining position does not coincide with the machining position, the teaching device is a teaching machine in a laser beam machine where the irradiation of the auxiliary laser beam is positioned outside the irradiation range of the main laser beam.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
Referring to FIG. 2, as a laser processing machine, for example, an articulated robot 3 is provided near a YAG laser oscillator 1. A laser processing head 9 connected to the YAG laser oscillator 1 and the optical fiber 7 is attached to the wrist portion 5 of the articulated robot 3.
[0010]
The articulated robot 3 is provided with a drive motor 11 (see FIG. 3) for driving each arm at each joint. The drive motor 11 is, for example, a rotary as position detecting means for measuring the angle of each arm. An encoder 13 (see FIG. 3) and the like are provided. The drive motor 11 and the rotary encoder 13 are connected to a robot controller 15.
[0011]
Accordingly, the robot controller 15 controls the drive motor 11 while detecting the angle of each arm by the rotary encoder 13, thereby moving and positioning the laser processing head 9 to a desired position to perform laser processing.
[0012]
Referring to FIG. 3, the robot controller 15 has a CPU 17 as a main control unit. The CPU 17 operates a teaching box 19 for moving the laser machining head 9 by operating the articulated robot 3 during teaching. Or, it has a CRT 21 as a display means for displaying an image projected by an imaging means described later. The rotary encoder 13 described above is connected to the CPU 17.
[0013]
Inside the robot controller 15, a memory 23 as storage means is connected to the CPU 17, and an axis control unit 25 that controls each drive motor 11 that operates the articulated robot 3 is provided.
[0014]
FIG. 1 shows a laser processing head 9. The optical fiber 7 is connected to the laser processing head 9, and a collimating lens 27 is attached in front of the tip of the optical fiber 7 inside the laser processing head 9 (right direction in FIG. 1). A semi-transparent mirror 29 having a predetermined transmittance is provided in front of the collimator lens 27, and a condenser lens 31 is provided below the semi-transparent mirror 29.
[0015]
Accordingly, since the main laser beam LB sent by the optical fiber 7 is directed downward by the semi-transparent mirror 29 and sent to the condenser lens 31, it is condensed on the focal point FP and laser processed on the workpiece W. Become.
[0016]
On the other hand, a CCD camera 33 as an imaging means is provided above the semi-transparent mirror 29, and an auxiliary laser that emits a visible light laser KLB as an auxiliary laser beam beside the CCD camera 33 (right side in FIG. 1). A visible light laser source 35 as a source is provided downward (downward in FIG. 1). A visible light laser collimating lens 37 is provided on the side of the semi-transparent mirror 29 below the visible light laser source 35.
[0017]
Accordingly, as shown in FIG. 1, since the visible light laser KLB emitted from the visible light laser source 35 is irradiated onto the surface of the workpiece W by the condenser lens 31 for laser processing, the focal point FP of the main laser beam LB. Condensed at the same position.
[0018]
Further, since the CCD camera 33 images the work W via the semi-transparent mirror 29 and the condenser lens 31 and follows the same path as the main laser beam LB, the imaging target TP (see FIG. 4) of the CCD camera 33 and visible light are visible. The point where the laser KLB intersects with the focal point FP of the main laser beam LB.
[0019]
4 and 5, when the focal point FP of the main laser beam LB is not on the surface of the workpiece W, the main laser beam LB is distributed in a certain range around the imaging target TP. The visible light laser KLB irradiates the outside of the main laser beam LB. This is the same not only when the focal point FP is below the workpiece W as shown in FIG. 5 but also when the focal point FP is above the workpiece W.
[0020]
Therefore, referring to FIGS. 6 and 7 together, when teaching is performed, the axis control unit 25 is directly controlled by the teaching box 19 while viewing the image 39 displayed on the CRT 21 to control the laser processing head 9. It is moved, and the imaging target TP of the CCD camera 33 and the visible light laser KLB are made coincident with each other and positioned on the welding line 41, which is a processing position, and the position of the laser processing head 9 at this time is detected by the rotary encoder 13. Teaching is performed by inputting to the memory 23.
[0021]
From the above results, by matching the imaging target TP with the visible light laser KLB, the focus of the main laser beam LB can be reliably adjusted to the processing position on the surface of the workpiece W, so that accurate teaching can be easily performed. it can.
[0022]
In addition, since the visible light laser KLB, which is an auxiliary laser, is arranged at a position shifted from the optical axis of the main laser beam LB and the common condensing lens 31 is used, even when the focal length of the condensing lens is long. A clear focus can be recognized and accurate teaching can be performed.
[0023]
The present invention is not limited to the above-described embodiment, and can be implemented in other modes by making appropriate modifications. That is, in the above-described embodiment, the three-dimensional laser processing machine using the articulated robot 3 has been described. However, the present invention is not limited to this, and can be applied to teaching in a very general two-dimensional laser processing machine. .
[0024]
In the above-described embodiment, the visible light laser source 35 is provided inside the laser processing head 9, but instead, the visible light laser source is provided outside the laser processing head 9 and guided by an optical fiber. But it is exactly the same.
[0025]
In the above-described embodiment, welding is taken as an example of laser processing, but the present invention can be similarly applied to cutting by laser.
[0026]
【The invention's effect】
As described above, in the teaching method in the laser processing machine according to the first aspect of the present invention, imaging is performed through the same condenser lens or irradiation of the auxiliary laser beam, so that both the imaging target and the auxiliary laser beam are the focal points of the main laser beam. Pass through. Therefore, the point where the auxiliary laser beam and the imaging target coincide with each other becomes the focal point of the main laser beam, so that the focal position of the main laser beam can be clearly detected. Accurate teaching can be performed by detecting and storing the coordinate value of the laser processing head at that time in accordance with the processing position on the surface. Further, since the same condenser lens is used, accurate teaching can be performed regardless of the focal length of the condenser lens.
In the teaching device in the laser beam machine according to the second aspect of the present invention, since the imaging of the workpiece surface by the imaging means and the auxiliary laser beam emitted from the auxiliary laser source pass through the same condenser lens, both the imaging target and the auxiliary laser beam are Passes the focal point of the main laser beam. Therefore, the point where the auxiliary laser beam and the imaging target coincide with each other becomes the focal point of the main laser beam, so that the focal position of the main laser beam can be clearly detected, and the auxiliary laser is viewed while viewing the image displayed by the display means. Accurate teaching can be performed by matching the point where the beam and the imaging target coincide with the machining position on the workpiece surface, detecting the coordinate value of the laser machining head at that time by the position detection means, and storing it by the storage means. Further, since the same condenser lens is used, accurate teaching can be performed regardless of the focal length of the condenser lens .
[Brief description of the drawings]
FIG. 1 is a sectional view showing a laser processing head used in a teaching device in a laser processing machine according to the present invention.
FIG. 2 is an overall view showing a teaching device in a laser beam machine according to the present invention.
FIG. 3 is a block diagram showing an internal configuration of a robot controller.
FIG. 4 is a display screen showing a state where the focal point does not coincide with the machining position.
5 is a cross-sectional view showing the state of FIG.
FIG. 6 is a display screen showing a proper teaching state in which the focal point coincides with the machining position.
7 is a cross-sectional view showing the state of FIG. 6. FIG.
FIG. 8 is an explanatory diagram showing a conventional teaching method using a visible light laser.
FIG. 9 is an explanatory diagram showing a conventional teaching method using a CCD camera.
[Explanation of symbols]
3 Articulated robot (laser processing machine)
9 Laser processing head 13 Rotary encoder (position detection means)
21 CRT (display means)
23 Memory (storage means)
31 Condensing lens 33 CCD camera (imaging means)
35 Visible laser source (auxiliary laser source)
W Work LB Main laser beam KLB Visible light laser (auxiliary laser beam)
TP imaging target

Claims (2)

A teaching method in a laser processing machine that performs laser processing by irradiating a processing position on a workpiece through a condensing lens provided inside a laser processing head with a main laser beam,
  An auxiliary laser beam is incident on the condenser lens from a position away from the optical axis of the main laser beam in parallel to the optical axis, and is irradiated obliquely toward the processing position via the condenser lens and the main laser beam. Imaging the workpiece surface of the imaging target placed at a position overlapping the optical axis of the optical axis through the condenser lens;
  Adjusting the distance between the laser processing head and the workpiece so as to match the irradiation position of the workpiece surface displayed by the irradiation of the auxiliary laser beam with the processing position;
  Furthermore, after matching the position of the irradiation with the processing position, teaching by storing the position coordinates of the laser processing head,
  A teaching method in a laser processing machine, wherein the irradiation of the auxiliary laser beam is positioned outside the irradiation range of the main laser beam when the irradiation position and the processing position do not coincide with each other. A teaching device in a laser processing machine that performs laser processing by irradiating a processing position on a workpiece through a condensing lens provided inside a laser processing head with a main laser beam,
  An auxiliary laser source that irradiates the converging lens with an auxiliary laser beam parallel to the optical axis from a position away from the optical axis of the main laser beam and obliquely irradiates the processing position through the condensing lens;
  Imaging means for imaging the workpiece surface of the imaging target placed at a position overlapping the optical axis of the main laser beam through the condenser lens;
  Display means for displaying the captured image;
  The laser when the distance between the laser processing head and the workpiece is adjusted so that the irradiation position of the workpiece surface irradiated by the auxiliary laser beam matches the processing position and the irradiation position matches the processing position. Position detecting means for detecting the position coordinates of the machining head;
  Storage means for storing the position coordinates detected by the position detection means,
  A teaching apparatus in a laser processing machine, wherein the irradiation of the auxiliary laser beam is located outside the irradiation range of the main laser beam when the irradiation position and the processing position do not coincide with each other.

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