JPH11788A - Laser beam machining method and nozzle of laser beam machine using this machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining method saving the quantity of gas usage and capable of blowing molten metal away in the optional direction so as to improve stability at the time of starting cutting and the nozzle of the laser beam machine using this machining method. SOLUTION: The nozzle 1 having an eccentric hole is rotationally controlled making a laser beam LB the rotational axis with a rotational dividing mechanism 13, whereby the area of the hole existing in the front side in the cutting direction of the laser beam LB and the area of the hole existing in the back side in the cutting direction are regulated. By this way, the jetting quantity of an assist gas in the front side in the cutting direction of the laser beam LB and the jetting quantity of the assist gas in the back side in the cutting direction are regulated. The nozzle 1 may be relatively and rotationally dividable with respect to a laser machining head 3, or the nozzle 1 fixed to the tip end of the laser machining head 3 may be rotationally divided by rotationally dividing the laser machining head 3 with the rotational dividing mechanism 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method and a nozzle of a laser processing machine used in the laser processing method, and more particularly, to a laser processing for adjusting a positional relationship between a nozzle hole and a laser beam during laser processing. The present invention relates to a method and a nozzle of a laser processing machine used for the processing method.

[0002]

2. Description of the Related Art Conventionally, when performing a cutting process using a laser processing machine, an assist gas is ejected simultaneously with a laser beam. The assist gas has a role to blow away and remove the molten metal generated at the time of cutting, or to cause a chemical reaction depending on the type of gas to utilize the heat.

[0003] The assist gas may need a flow rate according to the content of cutting, but at present, this is handled by changing the diameter (small diameter or large diameter) of the nozzle hole for ejecting the assist gas. .

Further, when piercing is performed by aligning a laser beam with the center of a nozzle, it is general that spatter adheres uniformly in all directions around the piercing hole.

[0005]

Referring to FIG. 7, in such a conventional technique, since the flow rate of the assist gas is adjusted by the diameter of the nozzle hole 101, a large flow rate is required. Use a nozzle having a large-diameter hole 101. At this time, since the gas is also ejected from the front side of the laser beam LB in the hole 101 in the direction 103 irrespective of the action thereof, the amount of gas used is increased, and there is a problem in terms of cost.

[0008] As shown in FIG. 8, particularly when the pierce 105 is processed on a thick plate, there is a problem that a cutting defect is likely to occur at the start of cutting because the amount of spatter SP attached becomes large.

[0009] As shown in FIG. 9, in the application of the marking by the laser beam LB, when the output is increased from the time of the marking and the V-groove 107 is to be processed, the sputter SP returns to the upper surface and the material surface There is a problem that V-groove processing cannot be performed in a good state because of sticking to the surface.

An object of the present invention is to pay attention to the above-mentioned prior art, and to reduce the amount of gas used and to improve the stability at the start of cutting by moving molten metal in an arbitrary direction. It is an object of the present invention to provide a laser processing method that can be blown off at a time and a nozzle of a laser processing machine used for the processing method.

[0009]

According to a first aspect of the present invention, there is provided a laser processing method comprising: irradiating a workpiece with a laser beam from a nozzle provided at a tip of a laser processing head; In the laser processing method for performing the above, the nozzle provided with a hole for laser light irradiation having a center at a position eccentric from the optical axis of the laser light at its tip is rotated and indexed with the optical axis of the laser light as a rotation axis. Then, the area of the hole on the front side in the cutting direction of the laser beam and the area of the hole on the rear side in the cutting direction are controlled.

Therefore, when irradiating a workpiece with laser light from a hole of a nozzle mounted on the tip of a laser processing head and performing laser processing, a nozzle having an eccentric hole is rotated about the optical axis of the laser light as a rotation axis. By controlling, the area of the hole on the front side in the cutting direction of the laser beam and the area of the hole on the rear side in the cutting direction are adjusted. Thus, the amount of assist gas ejected before the cutting direction of the laser beam and the amount of assist gas ejected behind the cutting direction are adjusted.

[0011] The nozzle of the laser processing machine according to the invention according to claim 2 is a nozzle of a laser processing machine that performs laser processing by irradiating a workpiece with a laser beam from a nozzle provided at the tip of a laser processing head, A laser light irradiation hole provided at a position eccentric from the optical axis of the laser light at the tip of the laser light, and a rotation / indexing mechanism for rotating / indexing the nozzle with the optical path of the laser light as a rotation axis. It is characterized by becoming.

Therefore, when irradiating a laser beam to a work through a hole of a nozzle mounted on the tip of a laser processing head and performing laser processing, a nozzle having an eccentric hole is rotated and indexed by a laser beam. Rotation control is performed using the axis as a rotation axis to adjust the area of the hole on the front side in the cutting direction of the laser beam and the area of the hole on the rear side in the cutting direction. Thus, the amount of assist gas ejected before the cutting direction of the laser beam and the amount of assist gas ejected behind the cutting direction are adjusted.

According to a third aspect of the present invention, there is provided a nozzle of a laser processing machine, wherein the nozzle according to the second aspect is rotatable and indexable relative to the laser processing head. .

Therefore, the nozzle is rotated / indexed relative to the laser processing head by the rotation / indexing mechanism.

According to a fourth aspect of the present invention, there is provided a nozzle of a laser processing machine, wherein the nozzle according to the second aspect is fixedly provided at a tip of the laser processing head which is rotatable and indexable. Things.

Accordingly, by rotating / indexing the laser processing head by the rotation / indexing mechanism, the rotation / indexing of the nozzle fixed to the tip of the laser processing head is indirectly performed.
Make an index.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a laser processing head 3 equipped with a nozzle 1 of a laser processing machine according to the present invention. The nozzle 1 is rotatably provided at the tip of the laser processing head 3, and a belt-shaped gear 7 is provided on the outer peripheral surface 5 of the nozzle 1.

The belt-shaped gear 7 is provided on the laser processing head 3.
A motor 13 having a drive gear 9 which is a flat gear meshing with a shaft of the rotary shaft 11 is attached. At the center of the laser processing head 3, an optical axis (optical path) of the laser light LB is provided in a downward direction in FIG.

Therefore, when the motor 13 rotates, the driving gear 9 drives the belt-shaped gear 7 to rotate, so that the nozzle 1 moves relative to the laser processing head 3 about the optical axis of the laser beam LB which is the center of the laser processing head 3. Rotate relatively.

On the other hand, referring to FIG. 2, a circular hole 17 provided at the tip 15 of the nozzle 1 is positioned eccentrically with respect to the laser processing head 3 and the optical axis of the laser beam LB which is the center of the nozzle 1. It is provided in. Therefore, nozzle 1
Is rotated, the hole 17 rotates eccentrically about the optical axis of the laser beam LB. Therefore, the large-diameter portion LR is disposed on the front side of the laser beam LB, and the small-diameter portion SR is disposed on the rear side. It is possible to freely arrange the large-diameter portion LR on the side and the small-diameter portion SR on the front side.

Here, referring to FIG. 3, the laser beam LB
The metal melted by the sputtering is blown out to the outside by the assist gas AG spouting radially from the center of the hole 17, so that the spatter SP is blown off to the small diameter portion SR side.

That is, when the small-diameter portion SR is arranged on the rear side in the cutting direction of the laser beam LB, the sputter SP is blown off on the rear side in the cutting direction. Conversely, if the small-diameter portion SR is arranged on the front side in the cutting direction of the laser beam LB, the sputter SP will be blown off on the front side in the cutting direction.

Referring to FIG. 4, consider the case where the direction of the cutting path TR changes, for example. In this case, at the start of cutting, it is preferable to blow off the sputter, which is a molten metal, in the direction opposite to the cutting direction as shown in FIG. Rotate the nozzle 1 so that the small diameter portion SR comes
Index.

Then, at the time of cutting, as shown in FIG. 4, the dross-free (good cutting) becomes possible by blowing off the molten metal by an efficient gas action on the cut portion.
When V-groove machining is performed, as shown in FIG. 6, the sputter is blown off in the traveling direction, and the motor 13 is rotated to prevent the molten metal from adhering to the material surface.
Then, the nozzle 1 is rotated via the belt-shaped gear 7 to rotate and index so that the small-diameter portion SR of the hole 17 comes to the front side in the traveling direction of the laser beam LB. Thereby, the clean V groove 19
Can be formed.

From the above results, by shifting the center of the hole 17 of the nozzle 1 from the irradiation position of the laser beam LB and controlling the directions of the large diameter portion LR and the small diameter portion SR of the hole 17,
Both the effect when the nozzle hole 17 has a large diameter and the effect when the nozzle hole 17 has a small diameter can be obtained. This makes it possible to blow off the sputter SP in the direction in which it is desired to blow off, so that it is possible to improve the stability of the processing at the start of the cutting processing and to perform a clean V-groove processing.
Further, it is possible to reduce the amount of the assist gas AG to reduce the cost in the cutting process.

The present invention is not limited to the above-described embodiment, but can be embodied in other forms by making appropriate changes. That is, in the above-described embodiment, only the nozzle 1 is rotatable and indexable with respect to the laser processing head 3, but the nozzle 1 is fixed to the laser processing head 3 and the entire laser processing head 3 is already in use. The same operation and effect can be obtained even if the drive unit is rotatable and indexable by a known drive motor and a drive unit including a plurality of gear mechanisms.

The nozzle 1 rotates as a rotating mechanism.
Although the flat gear is used as the drive gear 9 meshing with the belt-shaped gear 7 mounted on the outer periphery of the drive gear 9, the drive gear 9 may be a worm gear.

Further, a nozzle 1 rotatable and indexable with respect to the laser processing head 3 may be further provided at the tip of the laser processing head 3 which is rotatable and indexable as described above. This ratio has the additional effect that the nozzle 1 can be rotated at high speed.

[0030]

As described above, in the laser processing method according to the first aspect of the present invention, when performing laser processing by irradiating a workpiece with laser light from a hole of a nozzle mounted on the tip of a laser processing head, By controlling the rotation of the nozzle having the eccentric hole using the optical axis of the laser beam as the rotation axis, the area of the hole on the front side in the cutting direction of the laser beam and the area of the hole on the rear side in the cutting direction can be adjusted. This makes it possible to adjust the ejection amount of the assist gas at the front side in the cutting direction of the laser light and the ejection amount of the assist gas at the rear side in the cutting direction, so that the molten metal generated during laser processing can be blown in a desired direction. As it becomes possible,
The cost of laser processing can be reduced by eliminating waste of the assist gas.

According to a second aspect of the present invention, there is provided a nozzle of a laser processing machine, wherein a laser beam is irradiated from a hole of a nozzle mounted on a tip of a laser processing head onto a workpiece to perform laser processing. Can be controlled by the rotation / indexing mechanism with the optical axis of the laser beam as the rotation axis, so that the area of the hole on the front side in the cutting direction of the laser beam and the area of the hole on the rear side in the cutting direction can be adjusted. This makes it possible to adjust the ejection amount of the assist gas at the front side in the cutting direction of the laser light and the ejection amount of the assist gas at the rear side in the cutting direction, so that the molten metal generated during laser processing can be blown in a desired direction. This makes it possible to reduce the cost of laser processing by eliminating waste of assist gas.

In the laser processing machine nozzle according to the third aspect of the present invention, the nozzle can be rotated and indexed relative to the laser processing head by the rotation and indexing mechanism.

In the nozzle of the laser processing machine according to the fourth aspect of the present invention, the laser processing head is rotated by the rotation / indexing mechanism.
By indexing, the nozzle fixed to the tip of the laser processing head can be rotated and indexed.

[Brief description of the drawings]

FIG. 1 is a front view showing a nozzle and a laser processing head of a laser processing machine according to the present invention.

FIG. 2 is an enlarged view showing the position of a hole at the tip of the nozzle as viewed from the II-II direction in FIG.

FIG. 3 is an explanatory view showing a state of occurrence of spatter due to a positional relationship between a large diameter portion and a small diameter portion in a nozzle hole and a laser beam.

FIG. 4 is a plan view showing a rotation state of a nozzle hole when a cutting direction changes.

FIG. 5 is a plan view showing a relationship between a nozzle hole and a laser beam at the start of cutting.

FIG. 6 is a plan view showing a relationship between a nozzle hole and a laser beam during V-groove processing.

FIG. 7 is a plan view showing a portion for ejecting useless assist gas during conventional cutting.

FIG. 8 is a plan view showing a defective cutting portion when cutting is started from conventional piercing.

FIG. 9 is a plan view showing generation of spatter during conventional V-groove processing.

[Explanation of symbols]

 Reference Signs List 1 nozzle 3 laser processing head 13 motor (rotation / indexing mechanism) 17 hole W work LB laser light

Claims (4)

[Claims] 1. A laser processing method for performing laser processing by irradiating a workpiece with a laser beam from a nozzle provided at the tip of a laser processing head, wherein the laser beam has a center at a position decentered from the optical axis of the laser beam. The nozzle provided with a hole for irradiation at the tip is rotated and indexed with the optical axis of the laser beam as the rotation axis, and the area of the hole on the front side in the cutting direction of the laser beam and the rear side on the cutting direction are A laser processing method comprising controlling the area of a hole. 2. A nozzle of a laser processing machine for performing laser processing by irradiating a workpiece with a laser beam from a nozzle provided at the tip of a laser processing head, wherein the nozzle is eccentric from the optical axis of the laser beam at the tip of the nozzle. And a rotation / indexing mechanism for rotating / indexing the nozzle using the optical axis of the laser beam as a rotation axis. Nozzle. 3. The nozzle according to claim 2, wherein the nozzle is rotatable and indexable relative to the laser processing head. 4. The nozzle according to claim 2, wherein the nozzle is fixedly provided at a tip of the laser processing head which is rotatable and indexable.