JPS6393493A - Laser beam machine - Google Patents

Abstract

PURPOSE:To facilitate processing with high accuracy without necessitating mechanical correction of an optical path by correcting the deviation quantity by the mis-alignment of the optical axis of an incident beam in a projection position and mechanism rotating shaft by the movement control of a parallel movement driving means. CONSTITUTION:An theta axis motor driving switch 20 is turned on to run an thetaaxis motor 14 so that the spot of a laser beam is projected to the inside surface of a work 5 from the top end nozzle 7 of a processing lens 3. The inside surface of the work 5 is cut and the beta angle of the turning angle position of a rotating cylinder 12 at which the max. mis-alignment DELTAL arises is obtd. The max. mis- alignment DELTAL and the theta angle in the turning angle position of the theta axis at which DELTAL arises are inputted to ten keys 19 to calculate Ftheta=DELTAL.cos(theta-beta). Reading of the angle theta is executed by a sensor 17 for angle detection and a Z-axis motor 11 is run to move a Z-axis cylinder 9 by the moving distance G=-F(theta)=-DELTAL.cos(theta-beta). The laser beam processing in the Z-axis direction is thus executed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a laser processing device that focuses a laser beam to process a three-dimensional workpiece, and particularly relates to a laser processing device that focuses a laser beam to process a three-dimensional workpiece. This invention relates to position correction of focused laser beams that are separated from each other.

[Prior art] Conventional known technologies of this type are listed in patent publications such as JP-A-60-24295 and JP-A-60-121411.
No. 61-1494, Japanese Patent Application Laid-open No. 61-4
There are publications such as No. 6390.

This type of laser processing device has three parallel movement axes, the Y-axis, Y-axis, and Z-axis, which are orthogonal to each other. Y
Regarding the axes, those that move the workpiece, those that move the laser beam, or those that move the workpiece with either the X@ or Y axis and the other axis that moves the laser beam. etc.

In this way, in a laser processing device that performs three-axis drive control, the fifth
This will be explained using the developed explanatory diagram of processing using a uniaxial laser beam shown in the figure.

In the figure, (1) is a laser oscillator, (2) is a reflecting mirror that deflects the laser beam, (3) is a processing lens that focuses the laser beam, and (4) is a workpiece. The reflecting mirror (2) and the processing lens (3) are moved relative to the surface of the workpiece (4), ie parallel to XlN1.

A laser beam output from a laser oscillator (1) is focused by an optical system consisting of a reflecting mirror (2) and a processing lens (3) and irradiates the workpiece (4) with a laser beam spot. At this time, if an angle α occurs due to a misalignment between the optical axis and the mechanical axis of the incident beam, the incident beam enters the reflecting mirror (2) and the processing lens (3) along the path shown by the broken line in the figure, and the movement stroke From the mechanical reference position A1 or A2 for the amount of L [m], Ll [m] or L2 is approximately proportional to the angle α and the optical path length from the laser oscillator (1) to the processing lens (3). The surface of the workpiece (4) is irradiated with a deviation of [m]. However, the focal length of the processed lens (3) is f [m].

Therefore, in actual processing, the control command value of the laser beam spot must be changed in advance by anticipating a certain amount of deviation Wi Ll~m2 [m], or,
The workpiece (4) may be moved in the direction of the deviation amount L1 to L2 [TrL].

[Problems to be solved by the invention] However, when the mechanical axis of the laser beam and the optical axis of the actual incident beam are misaligned, the laser beam is deflected by a reflecting mirror and focused by a processed lens. Accuracy problems arise when optical system means for irradiating a workpiece with a spot of a laser beam processes a three-dimensional three-dimensional object that rotates around the mechanical axis of the laser beam.

That is, as shown in the explanatory diagram of the case in which a uniaxial laser beam rotates and performs turning processing in Fig. 6, a vertical laser beam output from a laser oscillator (1) is turned horizontally by a reflecting mirror (2). The beam is changed to irradiate the cylindrical workpiece (5) through the processing lens (3). Foul'i! 1. (2) and processing lens (3) are laser beam incident optical axis (Z-axis direction)
The machine is configured to rotate around the cylindrical workpiece (5). At this time, the laser beam output from the laser oscillator (1) is approximately α
There is a deviation by the angle, and the reflector (2
) and the processing lens (3), the irradiation spot position will be in the direction of deviation of the laser beam from the processing lens (3).
When it comes, and when it comes 180 degrees in the opposite direction,
-L[m] and +L[ from mechanical reference position B, respectively
m] deviation occurs.

For example, FIG. 7 shows the locus of the deviation L [m] when a cylindrical workpiece (5) is actually machined. As shown in the figure, the maximum deviation ffl+L [m] and the minimum deviation fJi-L [m] with respect to the brutal reference position B.
As a result, the problem that machining accuracy was disturbed was a rare problem.

As a method for solving the above-mentioned problems, there is a method of making the deviation between the optical axis and the mechanical rotation axis the same.

For this purpose, a laser emitter (1) or a reflector in the optical path (
Although it is possible to correct the deviation by the adjustment in 2), it has not always been easy to make these adjustments in devices that have a complicated optical path or a complicated drive system. In addition, in the case of far-infrared rays or CO2 lasers, there are problems such as the lack of appropriate detection and measurement means, making it impossible to detect the position of the laser beam spot with high precision. This is hindering high precision.

Therefore, the present invention was made to solve the above-mentioned problems, and aims to provide a laser processing device that facilitates high-precision processing without mechanically correcting the optical path. .

[Means for Solving the Problems] A laser processing apparatus according to the present invention includes a rotation drive means that rotates the direction of the incident beam as a rotation axis, and a parallel drive means that drives a translation axis parallel to the direction of the incident beam. By driving the movement drive means and the rotation drive means, the amount of deviation due to the deviation between the optical axis and the mechanical rotation axis of the incident beam at the irradiation position where the focused laser beam is irradiated onto the workpiece is adjusted in the direction of the incident beam. and control means for controlling as a movement variable of a parallel movement driving means that drives parallel translation axes.

[Function] In the present invention, when the reflecting mirror that deflects the laser beam is rotated by the rotation driving means, the optical axis of the incident beam at the irradiation position and the mechanical rotation axis of the focused laser beam at the irradiation position to irradiate the workpiece are adjusted. A deviation amount due to the shift occurs in the axial direction of the rotation drive means, that is, in the direction of the translation axis parallel to the incident beam direction.

Therefore, as the movement variable of the translation drive means that drives the parallel translation axis parallel to the incident beam direction, the deviation amount due to the deviation between the optical axis and the mechanical rotation axis is set to control the translation drive means 31). For example, it is possible to compensate for the amount of deviation due to the misalignment between the optical axis and the mechanical rotation axis.

[Embodiment] FIG. 1 is a diagram showing the basic main parts and configuration of a laser processing apparatus according to an embodiment of the present invention.

In the figure, (1) is a laser oscillator that oscillates and outputs a laser, (2) is a reflector (6) that changes the vertically downward laser beam to a horizontal direction, and (3) is a reflector ( This is a processing lens that focuses the laser beam changed horizontally in step 2) and irradiates a spot on the cylindrical workpiece (5).The laser beam is sent from the nozzle (7) at the tip of the processing lens (3). , the inner surface of the cylindrical workpiece (5) is irradiated and cut. (6) is the laser oscillator (1) described above.
), (8) is the processing table on which the workpiece (5) is placed, and (9) is the slider (1) of the processing table (8).
0) and vertically slid by the Z-axis motor (11); inner bearing (13
) and is a rotating cylinder that is rotated around the Z-axis by a θ-axis motor (14). (15) is the Z-axis motor (
11), which is attached to a Z-axis tube (9) that slides in the vertical direction, and the cord disk (15) is equipped with a senna (16) for detecting the starting point of the rotation of the Z-axis tube (9). It also has an angle detection sensor (17) that detects angles by 1 degree. The starting point detection sensor (16) and the angle detection sensor (17) are made of photocouplers, and detect the position and number of slits provided in code=<15>. (18) is the Z-axis motor (11),
This is an NC control device equipped with a microcomputer CPU as a control circuit that simultaneously controls the θ-axis motor (14), and the circuit diagram thereof is shown in FIG. This NC control D device (1
8) includes a numeric keypad (19) for inputting the maximum deviation iL[mE and the angle at that time, a θ-axis motor drive switch (20>) that drives the θ-axis motor (14>), and a Z@motor (11).
It has a 7-axis motor drive switch (21) that drives the 7-axis motor drive switch (21), and other control-related switches and display means that are not the subject matter of this invention.

The principle operation of the laser processing apparatus of this embodiment configured as described above will be explained with reference to the detailed explanatory diagram of the present invention shown in FIG.

First, the shaft that is vertically slid by the Z-axis motor (11) of the drive system is the Z-axis, and the rotary cylinder (12) is rotated around the Z-axis by the θ-axis motor (14) of the drive system. Let the axis be the θ axis.

When the laser beam output from the laser oscillator (1) is separated by the reflecting mirror (6) and enters the reflecting mirror (2) and the processing lens (3) at an angle α with respect to the Z axis, the processing lens Assuming that the focal length in (3) is f[TrL] and there is no angular deviation of the laser beam with respect to the rotational direction of the axis,
When the Z-axis operation is stopped and processing is performed only by rotating the θ-axis, the laser beam rotates around the θ-axis to produce the developed view of the cylindrical workpiece shown in the explanation of the conventional example in Fig. 7. Follow the dashed line and proceed along the route.

That is, the spot of the focused laser beam can vary by up to ±1. A deviation of -[TrL] occurs, resulting in a sinusoidal deviation, and the deviation is expressed as a function of the rotation angle of the θ axis. Therefore, the maximum deviation ± l [m
] The relationship between the rotation angle of the θ-axis at which this occurs, that is, the rotation angular position (θ°) of the rotary cylinder (12), and the deviation F(θ) is as follows: F(θ) = 1-cosθ = 1-φCOSω , ω is the rotational angular velocity of 0 chapters, t is time, and becomes.

This (Dfz large'fn+L [m3 or -L[7n
] By measuring θ-axis motor (14), the relationship between the rotation angle position of the θ-axis motor (14) and the above-mentioned deviation F(θ) can be determined as F(θ)=
It can be expressed as L-CO5ω↑, and this F(θ) is the deviation in the Z-axis direction.

Therefore, the shift in the Z-axis direction caused by one vertical movement by the Z-axis motor (11) of the drive system is compensated for by ) is set as G=-F(θ) =-[・COSθ=-1-cosωt, then the rotation angle position (θ°) of the rotary cylinder (12) resulting in the deviation in the Z-axis direction is and the above deviation F(θ)-1-co
sωt can be canceled out.

Therefore, Z
The Z-axis cylinder (
If the moving path idG in 9) is set as G=-L-CO8θ, the laser beam output from the laser beam unit (1) is deflected by the reflecting mirror (6), and the angle α with respect to the Z axis is
It is possible to correct the deviation in the case where the light is incident on the reflecting mirror (2> and the processing lens (3)) with a deviation by a certain amount.

Or, the rotation angle position of the θ-axis motor (14) and the Z@tube (9) rotated in the vertical direction by the Z-axis motor (11).
If the moving distance G of is in a synchronous state and the machining rotational angular velocity of the θ-axis motor (14) is ω, then the moving rotational angular velocity of the Z-axis motor (11) is ω, and the moving distance G of the Z-axis cylinder (9) is By setting G=-LψCOSωt, the laser beam output from the laser oscillator (1) is deflected by the reflecting mirror (6), and is shifted by an angle α with respect to Z@ and is directed to the reflecting mirror (2) and processing lens (3). ), it is possible to correct the deviation when the beam is incident on the

Next, the deviation of the angle α with respect to the Z axis of the lifting platform that controls the processing of the laser 7JO machining device according to the embodiment of the present invention is corrected.
The process control correction routine will be explained using the flowchart shown in FIG.

First, the Z@motor drive switch (21) that drives the Z-axis motor (11) is turned off, and the θ of the NC control device (18) is turned off.
θ-axis motor drive switch (
20> is turned on, the θ-axis motor (14) is rotated, and a laser beam is applied from the nozzle (7) at the tip of the processing lens (3) to the inner surface of the cylindrical workpiece (5). The spot is irradiated to cut the inner surface of the cylindrical workpiece (5), and the rotation angle position of the rotary cylinder (12) at which the maximum deviation L [m] occurs is set to 1 degree β. .

Then, in step S1, input the maximum deviation L [m] using the numeric keypad (19), and in step S2, input the maximum deviation L [m].
Enter the β degree of the rotation angle position of the θ axis where m] occurs on the numeric keypad (1
9). In step S3, F(θ)=Sh・cos(θ−B) is calculated, and F(1), F(2>,...
・.

Store F (360) in memory. In step S4, θ
The shaft motor (14) is rotated, the angle θ is read by the angle detection sensor (17) in step S5, and the angle θ is read in step S5.
6, the Z-axis motor (11) is rotated and moved in the Z-axis direction as follows: G=-F (θ) =-L-CO3 (θ-β) to perform laser processing in the Z-axis direction. Note that when the laser processing control in the Z-axis direction is g(t), G=cx(↑
)-F(θ) =g(t)-L'CO6(θ-β) to perform laser processing in the Z-axis direction.

Further, the processes from step S4 to step S7 are repeated until a laser processing end signal is received in step S7, and in response to the laser processing end signal, the θ-axis motor (14) is stopped in step S8, and the Z-axis motor (14) is stopped in step S9. (11)
stop.

As described above, in the laser processing apparatus of this embodiment, the anti-copper mirror (2) that deflects the laser beam is rotated by the θ-axis motor (
14); and a Z-axis for driving the Z-axis of the parallel movement axis parallel to the incident beam direction of the laser beam.
A parallel movement drive means consisting of a shaft motor (11), and an optical system that irradiates the workpiece (5) with a laser beam that is deflected by a reflecting mirror (2) that deflects the laser beam and focused by a processing lens (3). By driving the system means and the rotation driving means, the optical system means directs the focused laser beam to the workpiece (5).
) of the incident beam at the irradiation position due to the deviation of the angle α between the optical axis and the mechanical axis of rotation, the movement variable of the translation driving means that drives the translation axis parallel to the direction of the incident beam. Microcomputer CP to control as
NC control device equipped with tJ as a control circuit (18)
and a control means consisting of:

Particularly, in this embodiment, by driving the rotation drive means consisting of the θ-axis motor (14), the optical system means is aligned with the optical axis of the incident beam at the irradiation position where the focused laser beam is irradiated onto the workpiece (5). The amount of deviation due to the deviation of the angle α of the mechanical rotation axis is corrected for each rotation angle of the rotating cylinder (12) that is rotationally driven around the Z-axis by the θ-axis motor (14). The relationship between the rotation of the rotary tube (12) that is rotationally driven around the Z-axis by the shaft motor (14) and the movement of the Z-axis motor (11) is expressed as follows:
12), that is, the rotational angular velocity ω of the θ-axis motor (14), the rotational angular velocity of the rotating cylinder (12) which causes a deviation in the Z-axis direction.
) rotation angle position (θ°) and the deviation F(θ) are F(θ) = L-003wt, so the ZNI motor (11) rotates t in the vertical direction.
If the moving distance G of the Z-axis cylinder (9) that is moved by J is set as G=-[・COSωt in a synchronous state with no rotational angular velocity ω and phase difference, then as in the case of the previous embodiment, the optical axis It is possible to correct the amount of deviation due to the deviation of the angle α between the mechanical rotation axis and the mechanical rotation axis. Note that the above state is based on the synchronized state with no phase difference, or even if the phase difference is constant and does not change,
It can be corrected by the rotational angular velocity ω.

In the above embodiment, the cylindrical workpiece (5
) to obtain the rotation angular position β of the rotating cylinder (12) on the θ axis where the maximum deviation L [m] occurs, but by reducing the output of the laser emitting device (1), Maximum deviation l [711] and maximum deviation I [m] in dimensional image element
By detecting the rotation angle position β of the θ axis where
The rotation angle position β of the θ axis at which the maximum deviation L[TrL] and the maximum deviation L[711] occur can be obtained.

[Effects of the Invention] As described above, the laser processing apparatus of the present invention includes a rotation driving means for rotationally driving a reflecting mirror that deflects a laser beam about a rotation axis, and a parallel movement driving means for driving in the incident beam direction of the laser beam. , an optical system means for irradiating the workpiece with a laser beam focused by a processing lens, and an incident beam at an irradiation position for irradiating the workpiece with the laser beam focused by the optical system means that changes by driving the rotation drive means. The laser beam focused by the optical system means is equipped with a control means for controlling the amount of deviation due to the misalignment between the optical axis and the mechanical rotation axis as a movement variable of the parallel movement drive means for driving in the direction of the incident beam. Since the amount of deviation due to the deviation between the optical axis and the mechanical rotation axis of the incident beam at the irradiation position at which the beam is irradiated onto the workpiece can be corrected by controlling the movement of the parallel movement drive means, it is possible to mechanically correct the optical path. High-precision machining is facilitated without the need for

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of the main parts of a laser processing apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the principle of a laser processing apparatus according to an embodiment of this invention, and FIG. 90
FIG. 4 is a circuit diagram of the control means of the processing device; FIG. 4 is a flowchart of the "processing control correction routine" for correcting the laser processing device according to the embodiment of the present invention; FIG. 5 is an explanatory diagram of processing using a single-axis laser beam; The figure is an explanatory diagram of the principle when a uniaxial laser beam rotates and performs turning 7J[], and FIG. 7 is a developed explanatory diagram showing the trajectory of the amount of deviation when machining a cylindrical workpiece. In the figure, 2: nonconforming mirror, 3: processing lens, 4.5: workpiece, 11: Z-axis motor, 12: rotating cylinder,
14: θ-axis motor, 18: NC control device. In addition, in the figures, the same reference numerals and the same symbols do not indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] Rotating drive means for rotating a reflecting mirror that deflects a laser beam with the direction of the incident beam as a rotation axis; and translation drive means for driving a parallel axis parallel to the direction of the incident beam of the laser beam. an optical system means for irradiating the workpiece with a laser beam that is deflected by a reflecting mirror that deflects the laser beam and focused by a processing lens; and a laser beam focused by the optical system means by driving the rotation drive means. The amount of deviation due to the deviation between the optical axis and the mechanical rotation axis of the incident beam at the irradiation position where the beam is irradiated onto the workpiece is controlled as a movement variable of a parallel movement drive means that drives a parallel movement axis parallel to the direction of the incident beam. A laser processing device comprising: a control means for controlling; and a laser processing device.