JPH06677A - Laser machining head - Google Patents

Abstract

(57) [Summary] [Purpose] A laser that can perform highly accurate small circle machining with a simple structure
The processing head is provided. A rotating cylinder 14 is concentrically and rotatably attached to an introducing cylinder 8 into which laser light is introduced, and the laser light from the introducing cylinder 8 is transmitted through the rotating cylinder 14 so that the optical axis is changed. A window 15 that can be decentered in parallel is provided so as to be tiltable.
A lens holder 16 holding a lens 17 is attached to the rotary cylinder 14 so as to be movable in the eccentric direction of the optical axis. By moving the lens holder 16, the center of the lens is decentered by the radius R of the circle to be processed, and the window 15 is moved so that the lens center and the eccentric optical axis from the window 15 substantially coincide with each other. It is tilted by a predetermined angle θ. [Effect] By rotating the rotary cylinder 14, a relatively small circle can be accurately processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus and, more particularly, to a laser processing head capable of processing small circles.

[0002]

2. Description of the Related Art Conventionally, in laser processing, for example, X,
In addition to the three axes of Y and Z, a multi-joint type processing machine with a plurality of axes provided on the head is used, and three-dimensional processing of flat plate or three-dimensional work is performed based on a processing program.

In the circle processing, a predetermined pattern program for drawing a circle locus is created by using a composite vector of a plurality of axes, and the pattern program is performed based on the pattern program.

[0004]

However, in the above-mentioned conventional method, control is complicated and complicated movement is caused by a plurality of control axes, and there is a problem of interference with the work especially in a three-dimensional work. . Moreover, since the control is performed by calculation, there is a problem that a continuous and precise circular locus cannot be obtained.

In order to solve such a problem, for example, as shown in JP-A-63-76784, another rotating shaft is added to the head, and the reflecting mirror is moved in the radial direction from the center thereof. By using a head that is equipped with a slide mechanism that expands and contracts the optical axis and also moves the condensing part together with the mirror, a method is also adopted in which a circular process with a desired radius is performed only by the rotation of the rotary shaft depending on the slide amount. Has been. However, in the head using the slide cylinder as described above, the size of the head itself becomes large and the manufacturing cost becomes high. In addition, alignment adjustment is difficult due to the structure of the mirror for reflection.

For this reason, as a further solution, there is one disclosed in Japanese Patent Laid-Open No. 2-169195. There, a method is adopted in which another rotating shaft is added to the head and the condensing lens is moved in the radial direction from the center to decenter the condensing point in the same manner as described above. In this case, the straight line connecting the incident point of the laser optical axis to the lens and the condensing point has an angle with the rotation axis, and the work cut surface is not perpendicular to the work upper surface and the cutting accuracy There is a problem that is bad.

Therefore, according to the present invention, instead of expanding and contracting the optical axis in the radial direction, by providing a laser light transmitting medium that decenters the laser optical axis in parallel with the incident light inside the head as the lens moves. An object of the present invention is to provide a laser processing head capable of highly accurate small circle processing with a simple structure.

[0008]

That is, according to the present invention, a rotating cylinder is concentrically and rotatably attached to an introducing cylinder into which laser light is introduced from a laser oscillator through a laser optical path. A window capable of transmitting laser light from the introduction cylinder and decentering its optical axis in parallel with the incident light is provided in the rotating cylinder in a tiltable manner, and the lens holder is arranged in the eccentric direction of the optical axis with respect to the rotating cylinder. The lens holder is movably mounted, and the lens center supported by the lens holder is decentered by the radius of the circle to be processed by the movement of the lens holder, and the lens center and the eccentric optical axis from the window are substantially aligned with each other. By inclining the window and rotating the rotary cylinder, a relatively small circle can be easily formed.

[0009]

The lens holder is moved by the lens driving unit to decenter the lens supported by the lens holder by the radius of the circle to be machined, and at the same time, the lens center and the eccentric optical axis from the window are interlocked with the interlocking means. Adjust the tilt angle of the window so that and are approximately the same.

By simply positioning the head in a predetermined processing position at a predetermined processing position and irradiating the laser light while rotating the rotary cylinder by the rotation drive section in that state, the laser light is emitted. The focal point is moved while drawing a circular locus of a predetermined radius around the center of rotation of the rotary cylinder, and small circle machining such as cutting with laser light can be easily performed.

[0011]

EXAMPLES Specific examples of the present invention will be described below. 1 is a sectional view showing an embodiment of a laser processing head of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a sectional view taken along the line BB of FIG. 2, and FIG. 5 is a sectional view taken along line CC of FIG. 5, FIG. 5 is a side view of a main part of FIG. 1 taken in the direction of an arrow D, FIG. 6 is a front view showing an example of a laser processing apparatus to which the laser processing head of the present invention is attached, and FIG. a)
(B) is a schematic diagram of circle processing.

The laser processing head 1 of the present invention is shown in FIG.
It is attached to the laser processing apparatus shown in FIG. Fixed column 2
On the other hand, the movable table 3 is provided movably in the X-axis direction, and the column 2 is provided with the Y-axis saddle 4 movably in the Y-axis direction. Further, a Z-axis saddle 5 is provided on the Y-axis saddle 4 so as to be movable in the Z-axis direction.
The laser processing head 1 is mounted on the head support 6 attached to the shaft saddle 5.

The laser processing head 1 has a first rotating bracket 7 which is rotated about an α axis which coincides with the optical axis of the laser light from the head support 6, and β with respect to the first bracket 7. A second bracket 8 which is rotated about an axis.
That is, the three-dimensional control of the X, Y, and Z axes determines the three-dimensional position of the head support 6, and the two axes of α and β are added to determine the attitude of the head 1. ing. .

When the laser light is oscillated from the laser oscillator 9 provided on the side of the column 2, the laser light passes through a plurality of mirrors and forms a Y-axis duct 11 which forms a laser light path. , The Z-axis duct 12 and the first bracket 7 to be introduced into the second bracket 8. The second bracket 8 corresponds to the introducing cylinder in the present invention, and FIGS. 1 to 5 show the head structure at the tip thereof.

In FIG. 1, a slide cylinder 13 is slidably attached to the leading end of the introducing cylinder 8 along the optical axis of the incident laser, and a rotary cylinder 14 is attached to the slide cylinder 13 about the optical axis.
Is rotatably supported. Inside the rotary cylinder 14, a window 15 that can transmit the incident laser light from the introduction cylinder 8 and decenter its output optical axis in the radial direction parallel to the input optical axis is tiltable with respect to the optical axis direction. It is provided. A lens holder 16 is slidably attached to the lower end surface of the rotary cylinder 14 in the same direction as the eccentric direction of the optical axis. The lens holder 16 faces the lower end opening 14 a of the rotary cylinder 14 and faces the window 15 a.
It supports a lens 17 that transmits the laser light from the lens and focuses it on the focal point F. Further, an inverted conical nozzle 18 is mounted coaxially with the lens 17 at the lower end of the lens holder 16.

The slide cylinder 13 has a bush 19 on the introduction cylinder 8.
A support rod 20 is slidably attached in the axial direction via a support rod 20 protruding upward from one side. The support rod 20 is inserted into a guide cylinder 21 provided on the side of the introduction cylinder 8 and is connected to a gap control lift drive unit 22 at its upper end. The elevating / lowering drive unit 22 is composed of a motor 23 with a speed reducer provided on the upper portion of the introducing cylinder 8 and a swing arm 24 having one end fixed to an output shaft 23a of the motor 23. The swing end of the arm 24 engages with the engagement groove 20a formed in the support rod 20, and the movement of the swing arm 24 causes the support rod 20 to move up and down.

The nozzle 18 attached to the lens holder 16 is provided with an electrostatic capacitance sensor (not shown) for detecting the gap amount between the nozzle tip and the work W. Based on the detection signal, the electrostatic capacitance sensor is provided. The head 23 is controlled so that the head portion on the front end side is slightly moved from the slide cylinder 13 in the optical axis direction, so that a constant gap amount is always maintained.

A motor 25 for rotation driving is mounted on the slide cylinder 13, and the output shaft 2 of the motor 25 is mounted.
A gear 26 is attached to 5a. Rotating cylinder 14
Are rotatably supported by the slide cylinder 13 via bearings 27. The driven gear 2 is provided on the outer circumference of the rotary cylinder 14.
8 is fixed and meshed with the gear 26 of the motor 25. Therefore, the motor 25, the gear 26, and the driven gear 28 constitute a rotary drive unit of the rotary cylinder 14.

As shown in FIGS. 2 and 3, the rotary cylinder 14
A window supporting shaft 29 is rotatably mounted in the inside of the casing in a direction orthogonal to the incident optical axis, and the window 15 is held on the shaft 29 via a holder 30. The window 15 is opposed to a position where the laser light from the introduction tube 8 is incident, and has a substantially oval shape so that all incident light can be transmitted even if it is swung about the shaft 29 within a certain angle. Has become.

The window 15 uses a material having a very high transmittance of laser light, for example, a parallel plate such as ZnSe. Then, by changing the angle θ of the window 15 with respect to the incident parallel light as shown by, for example, a two-dot chain line in FIG. 1, the emission optical axis transmitted through the window 15 is parallel to the incident optical axis and is straight. The R amount can be eccentric in the direction.

The lens holder 16 is slidably supported in the left-right direction in FIG. 1 along a guide 31 formed on the lower end surface of the rotary cylinder 14. The lens 17 is held inside the lens holder 16 via the lens mount 32, and the lens center is moved integrally with the movement of the lens holder 16.

Next, the lens holder 16 and the drive mechanism for the window 15 will be described.

As shown in FIGS. 3 to 5, a motor 33 is attached to one side of the rotary cylinder 14 on the outside thereof.
A pulley 34 is attached to the output shaft 33a of No. 3.
Further, the lens holder 16 fixed to the lower end of the rotary cylinder 14
A screw shaft 36 in the feed direction of the lens holder 16 is rotatably supported by a bracket 35 provided opposite to the bracket 35. A ball screw 37 is formed at the tip of the screw shaft 36 and is screwed into a nut 38 fixed to the lens holder 16.
A pulley 39 is attached to the outer end of the screw shaft 36, and rotation is transmitted from the motor 33 via a timing belt 40 wound between the pulley 34 and the lens holder 34 by screw feeding. 16 is given a linear motion.

Further, as shown in FIGS. 2 and 3, the lens holder 16 is provided with a rack plate 41 projecting upward one side, and a rack 42 in the same direction as the moving direction of the lens holder 16 is provided at the upper end thereof. Has been formed. A pinion 43 integrally attached to one end of the window support shaft 29 is meshed with the rack 42. That is, the shaft 29 is rotated via the rack 42 and the pinion 43 in association with the movement of the lens holder 16, and the swing motion is given to the window 15.

In this way, the window 15 and the lens holder 16 are mechanically connected to each other so that they are synchronously operated by one driving source. That is, the motor 33 and the pulley 3
4, timing belt 40, pulley 39, ball screw 3
7 and the nut 38 constitute a holder drive section, and the rack 42 and the pinion 43 constitute interlocking means of the window 15. The outsides of all of these mechanical parts are covered with a cover 44 to protect them from laser light and spatter.

Further, in this case, the window 1 is obtained from the relationship between the incident angle of the laser light transmitted through the window 15 and the refractive index.
The relationship between the inclination angle θ of 5 and the eccentricity of the outgoing optical axis is calculated in advance, and the configuration conditions such as the diameter of the pinion 43 are set so that the eccentricity substantially matches the movement amount R of the lens center from the rotation cylinder rotation center L. To decide.

By moving the lens holder 16 to decenter the lens center supported by the lens holder 16 by the radius R of the circle to be machined, the center of the lens and the eccentric optical axis from the window 15 are substantially formed. The angle θ of the window 15 is adjusted so as to match.

For example, as shown in FIGS. 7 (a) and 7 (b), the motor 3 is selected according to the radii R1 and R2 of the circles O1 and O2 to be machined.
By controlling 3 to move the lens centers L1 and L2 from the rotation center L of the rotary cylinder 14 by radii R1 and R2, the window 15 is tilted at the corresponding angles θ1 and θ2, and the output optical axis of the lens 15 is changed to the lens. It can be aligned with the centers L1 and L2.

Then, according to the machining program, X, Y,
The head 1 is positioned at a predetermined processing position and a predetermined processing posture by simultaneously controlling the Z axis and the α and β axes. By irradiating the laser light while driving the motor 25 and rotating the rotary cylinder 14 in the state as it is, the circular machining of the desired radius can be easily performed without moving the other control shafts.

Further, the rotation axis of the rotary cylinder 14 is the U axis, and the drive axes of the lens 17 and the window 15 are the V axis.
In addition to the control axis, both axes can be automatically controlled by a machining program. In this case, the optical axis feeding from piercing to circular machining can be performed simply by controlling the U and V axes without moving the X, Y and Z axes.

Alternatively, it is possible to perform not only a perfect circle but also various shapes such as an ellipse and a rectangle by adding a machining program organization or additional software.

In the above embodiment, the window 1
5 is mechanically interlocked with the same drive source as the drive unit of the lens 17, but not limited to this, a drive source is provided for each, and for example, the lens drive axis is the VL axis and the window drive axis is the VW axis. It is also possible to individually control the drive in association with the motor rotation amount.

Further, the laser processing head of the present invention is not limited to the laser processing machine as shown in FIG. 6, but may be used in other articulated robots for laser processing or laser processing machines for flat plate processing. Can also be attached.

[0034]

According to the present invention, the lens inside the head is moved laterally in accordance with the radius of the circle to be processed, and at the same time the laser is moved.
By tilting the window of the light transmission medium, the laser optical axis entering the lens is decentered parallel to the rotation axis and aligned with the center of the lens, making it a simple structure and requiring no complicated control. Can perform small circle processing.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a laser processing head according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a side view taken along the arrow D in FIG.

FIG. 6 is a front view showing an example of a laser processing apparatus to which a laser processing head of the present invention is attached.

FIG. 7 is a schematic diagram illustrating a positional relationship between a lens and a window during circular processing.

[Explanation of symbols]

1 Laser Processing Head 8 Introducing Tube 9 Laser Oscillator 11, 12, 7 Duct and Bracket Constituting Laser Optical Path 14 Rotating Tube 15 Window 16 Lens Holder 17 Lens 25 Motor Constituting Rotation Driving Section 29 Window support shaft 33 Motors 42, 43 constituting holder driving unit Rack, pinion constituting interlocking means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanori Nishi Nishi No. 2 Kurosaki Shiroishi, Yawatanishi-ku, Kitakyushu, Fukuoka Prefecture (72) In Yaskawa Electric Hachiman Factory (72) Masahiko Okura No. 2 Kurosaki Shiroishi, Hachiman Nishi-ku, Kitakyushu, Fukuoka Prefecture No. 1 Yasukawa Electric Co., Ltd. Hachiman factory

Claims (1)

[Claims] 1. A laser from a laser oscillator through a laser optical path.
An introduction cylinder into which the laser light is introduced, a rotary cylinder attached to the tip of the introduction cylinder so as to be rotatable about the incident optical axis of the laser light, a rotary drive unit for imparting a rotary motion to the rotary cylinder, A window that is rotatably supported in the rotating cylinder about an axis orthogonal to the incident optical axis and that can transmit the laser light from the introducing cylinder and decenter its outgoing optical axis in parallel to the incident optical axis. A lens holder that is linearly movable in the eccentric direction of the emission optical axis with respect to the rotary cylinder; and a lens that is supported by the lens holder and that transmits laser light from the window and focuses it on a focus. A holder driving unit that linearly drives the lens holder, and interlocking means that is connected to the holder driving unit and that rotates the window so that the optical axis of the light emitted from the window substantially coincides with the center of the lens. Les characterized in that was - The processing head.