JP2773932B2 - Processing head of laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a processing head of a laser processing apparatus that performs cutting, heat treatment, welding, and the like using a laser beam, and particularly to three-dimensional processing. The present invention relates to a one-point directivity type three-dimensional processing head.

(Prior Art) As a three-dimensional processing means by a laser processing apparatus, a distance between a laser beam nozzle and a processing surface of a workpiece, that is, a nozzle gap is detected by a sensor, and the laser beam nozzle is moved in an optical axis direction in accordance with the distance. In many cases, it is known to move the laser beam nozzle in the vertical direction (Z-axis direction) and to freely change the direction and orientation of the laser beam nozzle three-dimensionally using three-dimensional moving means such as a robot arm. I have.

In the former three-dimensional processing means, the laser beam nozzle only moves in the direction of the optical axis, and depending on the movement, the position of the laser beam emitted by the laser beam nozzle is shifted in the X-axis and Y-axis directions. That is, it does not fluctuate in the plane direction, but cannot irradiate the laser beam nozzle to a vertical plane extending in the Z-axis direction, and there is a limit to a shape that can be three-dimensionally processed.

On the other hand, in the latter case, the above-described problem does not occur, but the coordinate position of the laser beam emission port provided at the tip of the laser beam nozzle with the change in the direction and orientation is changed in the X-axis direction and the Y-axis direction. And the Z-axis direction, the laser beam emission position by the laser beam nozzle fluctuates including the plane direction. Therefore, it is very difficult to control the processing position to compensate for the fluctuation. Control technology is required.

In view of the drawbacks described above, a first rotating optical path means rotatable around a vertical axis aligned with a laser beam emitting port of a laser beam nozzle, and inclined at an angle of 45 degrees with respect to the optical axis of the laser beam nozzle. Using a second rotating optical path means rotatable around an inclined axis aligned with the nozzle tip, and using the four reflecting mirrors to pass the laser beam from the first rotating optical path means through the second rotating optical path means The laser beam nozzle is guided to the laser beam nozzle without changing the coordinate position of the laser beam emission port by rotating the first rotary optical path means and the second rotary optical path means around their own axes. A three-dimensional machining head that changes the direction and orientation of the three-dimensional shape is considered.

(Problems to be Solved by the Invention) In the three-dimensional processing head as described above, even if the direction and orientation of the laser beam nozzle are three-dimensionally changed, the coordinate position of the laser beam emission port does not change, and one point is always obtained. However, this processing head is considerably limited in design due to the method of turning the laser beam back by the reflecting mirror and the focal length of the lens, and in this processing head,
Since the optical axis is two-dimensionally folded on one vertical plane formed by the Y axis and the Z axis, an optical path of a right-angled isosceles triangle is formed in the rotating portion to establish the second rotating optical path means. If necessary, this results in a considerable overhang of the optical path, which results in a very large processing head.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a three-dimensional processing head for a one-point-oriented laser processing apparatus, which has excellent design flexibility and can be designed to be miniaturized.

[Means for Solving the Problems] In view of the above-described conventional problems, the present invention provides a first rotating optical path means provided on a vertical vertical optical path member so as to be rotatable around a vertical axis. A first reflecting mirror for reflecting a laser beam traveling vertically downward in the vertical optical path member in a direction inclined with respect to the horizontal, and reflecting the laser beam reflected by the first reflecting mirror downward. A second reflecting mirror that reflects the laser beam reflected by the second reflecting mirror in a direction intersecting an extension of the vertical axis and 45 ° downward to the first reflecting mirror. The laser beam reflected by the third reflecting mirror is provided in the rotating optical path means, and the laser beam reflected by the third reflecting mirror is provided in a direction intersecting with an extension of the vertical axis and a fourth reflecting mirror for reflecting the laser beam upward. Laser beam reflected A second rotating optical path means having a fifth reflecting mirror capable of reflecting vertically downward at a position coinciding with an extension of the vertical axis, and a laser beam reflected by the third reflecting mirror. A lens holder sleeve provided rotatably about an inclined axis having the same axis and provided with a condenser lens for condensing the laser beam reflected by the fifth reflecting mirror; And a nozzle member provided at the tip of the lens holder sleeve.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a laser processing apparatus provided with a processing head according to the present invention. In FIG. 1, reference numeral 1 denotes a laser beam generator including an oscillator and the like, and a laser beam LB generated by the laser beam generator 1 is shown.
Passes through the horizontal optical path 5 through the shutter device 3 to the reflecting mirror 7, is refracted at a right angle by the reflecting mirror 7, and reaches the processing head 11 through the vertical optical path 9. The horizontal optical path 5 and the vertical optical path 9 are fixed to a main body frame (not shown) of the laser processing apparatus.

The processing head 11 has a laser beam nozzle 13 having a laser beam emission port 13a at the tip, and a first rotating optical path means rotatably supported by the main body frame around the nozzle tip, that is, a vertical axis aligned with the laser beam emission port 13a. 15 and a second rotating optical path means 17 rotatably provided with respect to the first rotating optical path means 15 around an inclined axis A which supports the laser beam nozzle 13 at the tip and aligns with the nozzle tip. ing. The tilt axis A extends to align with the tip of the laser beam nozzle 13 at an angle of 45 degrees with respect to the optical axis N of the laser beam nozzle 13. The first circuit light path means 15 and the second rotating light path means 17 are aligned.
Is an inclined optical path cooperating with each other and concentric with the inclined axis A.
In order to form the structure 19 between the vertical optical path 9 and the laser beam nozzle 13, it is bent three-dimensionally into a pentagonal shape in three directions of the X-axis direction, the Y-axis direction and the Z-axis direction.

The first rotating optical path means 15 is rotatable with respect to the main body frame around a vertical axis aligned with the above-described nozzle tip by a rotating connecting portion 21 provided at one end thereof. The second rotating optical path means 17 has one end thereof and the first rotating optical path means.
At a portion of the inclined optical path 19 formed by the other end of the optical path 15, a rotation connection portion 23 provided at the portion enables rotation about the inclined axis A with respect to the first rotating optical path means 15.

The first rotating optical path means 15 has three bent parts, and the second rotating optical path means 17 has two bent parts three-dimensionally. , The second reflecting mirror 27, the third reflecting mirror 29, the fourth reflecting mirror 31, and the fifth reflecting mirror 33 are arranged with their mounting angles adjusted three-dimensionally.

Since the reflecting mirrors 25 to 33 are disposed at the bent portions of the first rotating optical path means 15 and the second rotating optical path means 17 as described above, the laser beam LB from the vertical optical path 9 is The laser beam passes through the respective optical paths of the rotating optical path means 15 and the second rotating optical path means 17 to reach the laser beam nozzle 13, passes through the condenser lens 35, and is emitted from the laser beam emitting port 13a to the surface of the workpiece. Will be.

As shown in FIG. 2, the laser beam nozzle 13 has a lens holder sleeve 37 for supporting the condenser lens 35.
And a nozzle member 3 having a laser beam emission port 13a at the tip
9, both of which are screw-connected by screws 41 so that the length can be adjusted. When the nozzle member 39 is rotated with respect to the lens holder sleeve 37, the nozzle member 39 is moved up and down with respect to the lens holder sleeve 37 by the lead of the screw 41 so as to change the distance L between the condenser lens 35 and the laser beam emission port 13a. It has become.

Thereby, the relative position between the focal position of the laser beam and the laser beam emission port 13a is adjusted.

The nozzle member 39 is fixed to the lens holder sleeve 37 by a lock nut 43.

As shown in FIG. 2, a distance between the tip of the laser beam nozzle 13 and the processing surface of the workpiece, that is, a capacitance for detecting a nozzle gap, is provided at the tip of the laser beam nozzle 13. A distance sensor 45 such as a mold is provided.

According to the configuration as described above, the second rotating optical path means 17 is rotated around the tilt axis A with the laser beam nozzle 13, so that the laser beam nozzle 13 can move the coordinate position of the laser beam emitting port 13a to any position. Without being displaced also in the axial direction, the tilt is made between the vertical posture shown by the solid line in the figure and the horizontal posture shown by the virtual line in the figure. The first rotating optical path means 15 is the second rotating optical path means.
By rotating around the vertical axis together with the laser beam nozzle 17 and the laser beam nozzle 13, the laser beam nozzle 13 rotates around the laser beam emission port 13a, and the radiation direction of the laser beam from the laser beam emission port 13a is around the Z axis line. It will change.

This causes the first rotating optical path means 15 to rotate around the vertical axis,
By rotating the second rotary optical path means 17 around the tilt axis A, three-dimensional laser processing can be performed on a workpiece including a horizontal plane and a vertical plane.

For example, when laser processing is performed on each surface of the workpiece W as shown in FIG. 3, the laser beam nozzle 13 is set in a horizontal posture from point a to point b, and manually stopped at point b. Control, manually change the laser beam nozzle 13 from the horizontal position to the vertical position, and then manually restart the laser processing.From the point b, to the point c, and manually again at the point c. Stop control, laser beam nozzle
It is sufficient that the laser beam 13 is manually returned from the vertical posture to the horizontal posture, the laser processing is manually restarted again, and the processing from the point c to the point d proceeds.

Note that all of this control may be automated by program control.

As described above, when the directional attitude of the laser beam nozzle 13 is tilted and changed between the vertical attitude and the horizontal attitude, the laser beam LB may be erroneously irradiated from the laser beam emission port 13a of the laser beam nozzle 13. Distance sensor
When the nozzle gap detected by 45 becomes a predetermined value or more, the shutter device 3 is closed and the laser beam emission is automatically stopped, assuming that the laser beam emission port 13a does not face the processing surface. It may be.

The laser beam nozzle 13 including the condenser lens 35 and the nozzle member 39 has a control system independent of NC control according to the nozzle gap detected by the distance sensor 45.
It may be moved up and down in a feedback control manner in the axial direction, so that it can be moved vertically by springback at points a and b, b and c, c and d in FIG. As shown by the imaginary line in the drawing, the focal position of the condenser lens 35 with respect to the surface to be processed may be changed due to the movement of the laser beam nozzle 13 in the Z-axis direction, as shown by a virtual line in the drawing. Laser processing can be performed satisfactorily in a state where a predetermined nozzle gap is maintained.

Also, when performing two-dimensional processing, that is, when only planar processing is required, the first reflecting mirror and the fifth reflecting mirror are set in a state where the optical axis of the laser beam nozzle is perpendicular. What is necessary is just to remove the laser beam LB from the vertical optical axis and directly reach the laser beam nozzle. In this case, laser processing can be performed without causing power down due to the turning of the laser beam LB to the reflecting mirror.

FIG. 4 shows the side of the optical path between the case where the optical path is bent three-dimensionally in a pentagonal shape and the case where the optical path forms a two-dimensional right-angled isosceles triangle, as in the processing head according to the present invention. Are shown in comparison. In FIG. 4,
Components in the processing head according to the present invention are designated by the same reference numerals as those shown in FIG. 1, and reference numeral M denotes a reflecting mirror arranged in a two-dimensional optical path.

From FIG. 4, in the processing nozzle according to the present invention,
It will be understood that the amount of overhang to the side of the optical path, that is, in the Y-axis direction, is almost half as compared with that using the two-dimensional optical path as shown by the dashed line.

FIGS. 5 and 6 show one embodiment of a reflector mounting device provided with a three-dimensional reflector mounting angle adjusting device required in the optical path configuration of the processing head in the present invention. ing. The reflecting mirrors 25 to 33 are respectively fixed to a mirror mount assembly 51 of a mirror mount block 47 and a mirror set plate 49, and the mirror mount assembly 51 is provided with three follower sets which are spaced apart from each other around its own center. It is mounted on the mount cover 61 by a screw 55, a hexagon bolt 57, and a compression coil spring 59 in a floating manner so that the mounting direction can be set. The mount cover 61 is connected to a first rotating optical path means by a mounting screw (not shown) mounted in the bolt through hole 63.
15 or the second rotary optical path means 17 is fixedly mounted on the bent portion. The mounting direction of the reflecting mirrors 25 to 33, in other words, the three-dimensional mounting angle adjustment,
Screw the round-point wing bolt 67 into the screw hole 65 provided at the center of the mirror mount block 47 so that the round-pointed part comes into contact with the back of the mirror mount block 47. By adjusting the screwing amount of the hexagonal bolt 57, the reflecting mirrors 25 to 33 are three-dimensionally tilted around the center of the reflecting mirror 25 to 33 together with the mirror mount assembly 51 around the contact point with the round-point wing bolt 67 as a pivot point. Thus, the three-dimensional angle adjustment is performed without changing the center position of the reflecting mirror. After the adjustment is completed, follow-up set screw 55
Is screwed, so that the reflecting mirror is fixed with the adjusted stop angle. After the adjustment,
The round head wing bolt 67 is removed from the screw hole 65.
In this case, another follower set screw 55 may be screwed in instead of the round-point wing bolt 67.

Mirror mount assembly 51 carrying reflectors 25-35
Is located in the optical path and is not exposed to the outside when the mount cover 61 is attached to the rotating optical path means, so that this does not fluctuate due to external factors and the angle of the reflecting mirror can be easily adjusted. There is no shift.

In the three-dimensional machining head having the above configuration,
It is necessary to strictly align the rotation axis and the optical axis in the rotating optical path so that they are coaxial with each other. If this alignment is incomplete, the rotation of the rotating optical path causes the relative position between the optical path and the optical axis. The relationship fluctuates and the laser beam
There is a possibility that the LB may not reach the proper position of the laser beam nozzle 13.

This alignment may be performed using cylindrical target-like alignment jigs 69 and 71 as shown in FIG. 7 or FIG. Each of the alignment jigs 69 and 71 has a cylindrical body 69a or 71a inserted into the optical path as shown in FIG. 9, and in the alignment jig 69, both ends of the cylindrical body 69a are at 45 degrees to each other. With a phase angle of rotation
On the other hand, in another alignment jig 71, an end plate 71c having a hole 71b having a diameter of about 1 mm on the same axis is attached to both ends of the cylindrical body 71a. Have been.

The optical axis alignment using the alignment jig 69 or 71 as described above is first performed by the oscillator of the laser generator 3 so that the regular laser light and the He-Ne light, which is a red visible light, are coaxial with each other. After the coaxial adjustment, the adjustment is performed by emitting only He-Ne light. If the rotation axis and the optical axis in the optical path are coaxial, in the alignment jig 69, the center of the cross-shaped target 69b projected on a blank sheet or the like matches the center of the cross at each end. In the other alignment jig 71, light should enter from one of the fine holes 71b, light should come out of the other fine hole 71b, and pass through it.
Therefore, otherwise, the optical axis adjustment is insufficient. In this case, the alignment of the optical axes may be performed by adjusting the mounting angles of the respective reflecting mirrors as described above.

In the processing head according to the present invention, since the optical path distance between the respective reflecting mirrors is short due to its compact design, the cylindrical body 69a of the alignment jig 69 or 71 is separate from this optical path length. , 71a may be made sufficiently long, and the longer this is, the more the alignment accuracy is improved.

Cooling of the reflecting mirrors 25 to 33 in each optical path may be performed by supplying dry air into the optical path, and this dry air may also perform a function of removing dust blowout in the optical path in addition to cooling the reflecting mirror. become.

The supply of the assist gas and the cooling air to the nozzle tip is performed through a hole-shaped passage provided on the outer wall of the first rotating optical path means 15 and the second rotating optical path means 17 from the side of the main body frame. Just do it. In this case, in the rotary connection portion 21 or 23, a rotation joint structure as shown in FIGS. 10 and 11 is used to transmit the assist gas or the cooling air. I just need. FIG. 10 and FIG.
2 shows one embodiment of a rotary connection mechanism for the assist gas in the section of FIG. The first rotary optical path means 15 and the second rotary optical path means 17 are fitted into each other in a cylindrical manner so as to be rotatable with each other by a ball bearing 73, and an annular gap 75 therebetween is formed in the axial direction. A closed chamber 75a is provided between the two seal members 77 arranged at a distance from each other.
With 5a, the assist gas can be transmitted from the gas passage 79 of the first rotating optical path means 15 to the gas passage 81 of the second rotating optical path means 17 irrespective of their relative rotational displacement.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to this, and various embodiments can be made within the scope of the present invention. It will be clear to those skilled in the art.

[Effects of the Invention] As can be understood from the above description of the embodiments, in short, the present invention relates to a first rotating optical path means (15) provided on a vertical vertical optical path member so as to be rotatable around a vertical axis. , A laser beam (L) traveling vertically downward in the vertical optical path member.
A first reflecting mirror (25) for reflecting B) in a direction inclined to the horizontal and a second reflecting mirror for reflecting the laser beam (LB) reflected by the first reflecting mirror (25) downward. (27), a third reflecting mirror (45) that reflects the laser beam (LB) reflected by the second reflecting mirror (27) downward in a direction intersecting the extension of the vertical axis and at an angle of 45 °. 29) is provided in the first rotating optical path means (15), and the laser beam (LB) reflected by the third reflecting mirror (29) is provided.
A fourth reflector (31) that reflects upward and in a direction intersecting with an extension of the vertical axis, and a laser beam (LB) reflected by the fourth reflector (31),
A second rotating optical path means (17) provided with a fifth reflecting mirror (33) capable of reflecting vertically downward at a position coinciding with an extension of the vertical axis is reflected by the third reflecting mirror (29). The laser beam (LB) is provided so as to be rotatable around an inclined axis (A) having the same axis as the laser beam (LB), and for condensing the laser beam (LB) reflected by the fifth reflecting mirror (33). A lens holder sleeve (37) provided with a condenser lens (35) is provided on the second rotating optical path means (17), and a nozzle member (39) is provided at the tip of the lens holder sleeve (37). Things.

As is clear from the above configuration, in the present invention, the first reflecting mirror 25 provided in the first rotating optical path means 15 inclines the laser beam LB traveling vertically downward in the vertical optical path member with respect to the horizontal. The laser beam reflected by the first reflecting mirror 25 is reflected downward by the second reflecting mirror 27, and the laser beam LB reflected by the second reflecting mirror 27 is reflected by the third reflecting mirror 29. Is reflected 45 ° downward.

Therefore, as is apparent from the comparison of FIG. 4, the amount of lateral projection from the vertical optical path can be reduced as compared with the configuration in which the laser beam LB is reflected horizontally by the first reflecting mirror 25. It is. Therefore, the rotational moment about the vertical axis can be reduced, and the size can be easily reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an optical system of one embodiment of a processing head of a laser processing apparatus according to the present invention.
The figure is a longitudinal sectional view showing an example of a laser beam nozzle suitable for use in the processing head of the laser processing apparatus according to the present invention,
FIG. 3 is an explanatory view showing a processing example using the processing head of the laser processing apparatus according to the present invention, and FIG. 4 is an optical path structure of the processing head of the laser processing apparatus according to the present invention and a conventional three-dimensional processing head. FIG. 5 is a longitudinal sectional view showing an apparatus for mounting a reflecting mirror which is incorporated in a processing head according to the present invention, FIG. 6 is a rear view thereof, and FIG. 8 is a perspective view showing an example of an alignment jig suitable for use in optical axis alignment in a processing head according to the present invention, and FIG. 9 is a jig shown in FIG. 7 or FIG. FIG. 10 is a schematic configuration diagram showing a working state of optical axis alignment using alignment, FIG. 10 is a longitudinal sectional view showing a rotational connection structure of an assist gas at a rotational connection portion of a processing head according to the present invention, and FIG. Line XI-XI in the figure
FIG. DESCRIPTION OF SYMBOLS 1 ... Laser beam generator 3 ... Shutter device, 11 ... Processing head 13 ... Laser beam nozzle 15 ... First rotating optical path means 17 ... Second rotating optical path means 25-33 ... Reflector

Claims (1)

(57) [Claims] A first rotating optical path means (15) provided on a vertical vertical optical path member so as to be rotatable around a vertical axis, applies a laser beam (LB) traveling vertically downward in the vertical optical path member. First mirror (25) that reflects in the direction inclined to the horizontal
And a second reflecting mirror (27) for reflecting the laser beam (LB) reflected by the first reflecting mirror (25) downward, and the laser beam reflected by the second reflecting mirror (27). A third reflector (29) for reflecting (LB) downward in a direction intersecting the extension of the vertical axis and at an angle of 45 °.
Is provided in the first rotating optical path means (15), and the laser beam (LB) reflected by the third reflecting mirror (29) is reflected upward in a direction intersecting with an extension of the vertical axis. A fourth reflecting mirror (31) that reflects the laser beam (LB) reflected by the fourth reflecting mirror (31) in a vertically downward direction at a position that coincides with an extension of the vertical axis. The second rotating optical path means (17) provided with the five reflecting mirrors (33) is moved around the inclined axis (A) whose axis coincides with the laser beam (LB) reflected by the third reflecting mirror (29). A lens holder sleeve (37) provided rotatably on the second lens and provided with a condenser lens (35) for condensing the laser beam (LB) reflected by the fifth reflecting mirror (33). Provided in the rotating optical path means (17), and at the tip of the lens holder sleeve (37) Nozzle member section (39)
A processing head for a laser processing apparatus, comprising: