JP3761687B2 - Method for removing material adhering melt during piercing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a material surface adhering melt removal method during piercing in laser processing of a plate material or the like.
[0002]
[Prior art]
In laser processing of a plate material or the like, it is usual to perform piercing processing that penetrates a minute hole at the start of cutting processing.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned conventional example, while the materials and processing methods are diversified, it is a problem that occurs more or less regardless of the type of material, but especially during piercing processing of aluminum material, stainless steel material At the time of piercing in the clean cut processing of the metal melt, the metal melt adheres to the periphery of the piercing hole as if it swelled in a bowl shape (hereinafter referred to as a whisker shape) or a mountain shape, and (1) the sensor nozzle and metal melt Contact and electrical continuity, abnormal sensing of the scanning sensor, (2) change in plate thickness, (3) material change on the cutting path, etc. cause processing errors such as defective cutting, and piercing. There is also a method of increasing the pressure of the assist gas during processing and spraying it on the metal melt adhesion part, but it becomes a form of pressing from above and the assist gas escapes from the pierced hole, which is effective. In addition, even if it tries to blow away from the scanning sensor nozzle from the lateral direction by the air blow nozzle from the side, it is effective on the front side of the pierced hole, but it is not effective on the opposite side, and further before piercing processing However, there is a case where oil is applied to the piercing point of the workpiece to reduce the adhesion of the metal melt, but there is a problem that the problem has not yet been solved.
[0004]
The present invention has been made by paying attention to the above-mentioned points, and applies a circular motion to the nozzle of the machining head, controls the output of the laser beam and the assist gas, and removes the metal melt generated during the piercing process. An object of the present invention is to provide a material surface adhesion melt removal method during piercing which can reduce or prevent the processing defect rate.
[0005]
[Means for Solving the Problems]
The present invention can solve the above problems by providing the following configuration.
(1) In laser processing of plate materials, etc., metal fusion that adheres to the material surface that occurs during piercing when the cutting head is started by turning the nozzle of the processing head by controlling the laser light output and assist gas pressure A material surface adhering melt removal method during piercing processing, wherein a nozzle operating method of a processing head that enables removal of an object is incorporated in a processing step.
[0006]
(2) The nozzle of the machining head is a metal that adheres to the surface of the material by giving a swirl circular motion larger than the outer peripheral edge of the melted deposit to the nozzle of the machining head around the piercing position and injecting an assist gas at a high pressure. The material surface adhesion melt removal method at the time of the piercing process according to item (1), wherein the melt is blown off and removed.
[0007]
(3) The nozzle operation method of the machining head is such that a minute swirl circular motion is given to the nozzle of the machining head around the piercing position, and the laser beam output is suppressed and controlled to cut only the metal melt near the piercing. The material surface adhering melt removing method during piercing as described in (1) above, wherein the metal melt is blown off by controlling the injection pressure of the assist gas.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0009]
FIG. 1 is a piercing process and a metal melt deposit removal flowchart according to the present invention, FIG. 2 is a side sectional view showing a main part configuration of the machining head and the situation during piercing, and FIG. 3 is a normal machining starting from a piercing hole. 4A is a plan view showing an example of the path, FIG. 4A is an enlarged side cross-sectional view showing the adhesion state of the whisker-like melt and the flow state of the assist gas, and FIG. 4B is a diagram showing the trajectory of the swirling circular motion of the nozzle. The enlarged cross-sectional side view showing the situation where the whisker-like melt by the assist gas is blown off and removed, and (c) shows the trajectory of the swirling circular movement of the nozzle from the outer circumference of the melt. FIG. 5A is an enlarged plan view showing a case where a large circle is formed. FIG. 5A is an enlarged side cross-sectional view showing a trace of the fine swirl circle movement of the nozzle and a situation in which the molten deposit is blown off and removed. Is an enlarged plan view showing the size of FIG. FIG 6 (a), (b) is an explanatory diagram showing the external side and the operating shaft Examples of the laser processing head.
[0010]
Referring to the drawings, 1 is a machining head, 2 is a sensor nozzle, L is a condenser lens, and a laser beam LB propagated from an oscillator (not shown) is converged by the condenser lens L to be machined. The assist gas G is introduced from the connecting portion of the processing head, and injected so as to wrap the laser beam LB irradiated to the processing point. g is a gap and indicates a set distance between the workpiece W and the tip of the sensor nozzle unit 2.
[0011]
The sensor nozzle unit 2 has a function of adjusting assist gas narrowing and the like and detecting and adjusting a nozzle gap with the workpiece W.
[0012]
Example 1
The metal melt generated at the time of piercing that is the starting point of the cutting process forms a welded portion at the inner peripheral edge of the pierced hole, and adheres in a whisker shape (FIG. 4A) or a mountain shape.
[0013]
In order to remove the metal melt deposit, the scanning sensor is turned off or the sensor alarm is ignored, and the sensor nozzle portion 2 is pierced as shown in the swirl circular movement locus of the nozzle in FIG. Melting by rotating the assist gas at a high pressure while making a circular motion around the pierce hole along a circle larger than the outer peripheral edge of the melted adhering material adhering to the vicinity of the peripheral edge A high-pressure gas in a reverse flow (FIG. 4 (a)) flows from the outer periphery toward the center of the piercing hole with respect to the deposit, and the molten deposit can be easily removed and removed (see FIG. 4 (b)). Then, the cutting sensor can be turned on to perform normal cutting.
[0014]
(Example 2)
The scanning sensor is turned off or the sensor alarm is ignored, and the sensor nozzle 2 is turned around the pierced hole around the pierced hole as shown in the laser head path of FIG. 5B. A micro circular motion is made, and the laser beam LB is irradiated with a low output of the degree of scribing in the vicinity of the weld that becomes the root of the melt adhering to the periphery of the pierce hole after making a round circle trajectory. The assist gas G is sprayed while cutting, and the cut welding pieces and the remaining fine pieces can be blown off and removed (see FIGS. 5A and 5B).
[0015]
In the same manner as described above, the copying sensor can be turned on to perform normal cutting.
[0016]
Next, the operation will be described according to the piercing process and the metal melt deposit removal flowchart shown in FIG.
[0017]
S1 is a step of performing piercing, and piercing is performed at the set gap g. In step S2, it is determined whether there is a molten deposit at the piercing point, and it is determined that there is a molten deposit. If this is the case, the process proceeds to step S3, the Z-axis (up-down direction of the machining head) scanning sensor is set to OFF, and the nozzle of the machining head 1 is moved along the Z-axis to prevent contact between the nozzle and the molten deposit in step S4. If it is determined that the laser beam is not output when it is determined whether the laser beam is output by proceeding to step S5, the type and pressure of the assist gas G are set in step S6. Is usually set to high pressure. Next, in step S7, the turning circle motion of the nozzle is set. In this case, the turning radius is set so as to turn around the pierced hole with a circle larger than the outer peripheral edge of the molten deposit. In step S8, the high-pressure gas is injected while turning the nozzle, and the deposit is blown off by the gas flow that makes a round and flows backward from the outer peripheral side of the melt deposit toward the center of the pierce hole, and the operation for removing the melt deposit is completed. The output of the laser beam LB stopped in the next step S9 is restored, and the process proceeds to the next step S15, where the nozzle is returned to the piercing processing point, the Z-axis scanning sensor is turned ON in step S16, and the processing head Taking advantage of the scanning sensor function of 1 in the vertical direction, in the next step S17, the routine shifts from the normal approach processing to the path cutting operation and proceeds to the next step.
[0018]
On the other hand, if the laser beam LB is output in step S5, the process proceeds to step S10, and the laser beam LB output is set to a low level of scribing to cut only the melted deposit. In step S11, the type and pressure of the assist gas G are set. In this case as well, in the same manner as in step S6 described above, the pressure is set slightly higher, and in step S12, the swirling circular movement of the nozzle is set. When the melted deposit is whisker-shaped, the welding part is located at the upper peripheral edge of the pierced hole, so that a small turning radius is set around the pierced hole so that the welded part is turned slightly larger than the size of the pierced hole. Then, in the next step S13, the nozzle of the machining head 1 makes a small turn while making the assist gas G and irradiating the low-power laser beam LB, and cutting and blowing off the deposits. When the removal operation for removing the adhered matter is completed, the output of the laser LB is returned to the original in step S14, and the process proceeds to the next step S15 as described above, where the nozzle is returned to the piercing point, and in step S16. The Z-axis scanning sensor is turned ON, and the vertical scanning sensor function of the machining head 1 is utilized to move from the normal approach machining to the path cutting operation in the next step S17, and proceed to the next process.
[0019]
During continuous wave (CW) piercing processing of SS materials, etc., there are cases in which deposits can be removed by blowing assist gas, and beard-like deposits, mountain-like deposits, etc. can be melted. The turning radius of the nozzle that forms the path of the laser beam LB, the output of the laser beam LB, the type of assist gas (usually air is sufficient), and the pressure can be selected on a case-by-case basis depending on the degree of deposits. Of course.
[0020]
【The invention's effect】
According to the present invention, a turning circular motion is given to the nozzle of the processing head, the output of the laser beam and the assist gas is controlled, and the metal melt generated during the piercing processing can be removed, thereby reducing or preventing the processing defect rate. It has the effect of being able to.
[Brief description of the drawings]
FIG. 1 is a piercing process and a metal melt deposit removal flowchart according to the present invention. FIG. 2 is a side sectional view showing the main part configuration of the machining head and the situation at the time of piercing. FIG. 4 is a plan view showing an example of the path. FIG. 4A is an enlarged side cross-sectional view showing the state of adhesion of the whisker-like melt and the flow of the assist gas, and FIG. 4B is the trajectory of the swirling circular motion of the nozzle. An enlarged side cross-sectional view showing a situation in which the whisker-like melt by the assist gas is blown away and removed, and (c) a circle having a trajectory of the swirling circular motion of the nozzle larger than the outer circumference of the melt. [FIG. 5] (a) An enlarged side sectional view showing a trace of a fine swirl circular movement of a nozzle and a situation in which a molten deposit is blown off and removed, (b) FIG. Plane enlargement showing the size of (a) 【 6] (a), (b) diagram illustrating the external side and the operating shaft Examples of the laser processing head EXPLANATION OF REFERENCE NUMERALS
1 Processing Head 2 Sensor Nozzle G Assist Gas g Gap LB Laser Light L Condensing Lens W Workpiece

Claims (3)

In laser processing of plate materials, etc., the laser beam output and assist gas pressure are controlled, and the nozzle of the processing head is turned to remove the metal melt adhering to the material surface that is generated during piercing when starting cutting. A material surface adhering melt removal method during piercing, which incorporates a nozzle operation method of a machining head into a machining process. The nozzle of the processing head is operated by giving a swirl circular motion larger than the outer peripheral edge of the molten deposit to the nozzle of the processing head around the piercing position, and ejecting the assist gas at a high pressure to cause the metal melt to adhere to the material surface. The material surface adhesion melt removal method at the time of piercing processing according to claim 1, wherein the material is removed by blowing away. The nozzle of the processing head is operated by giving a fine swirl circular motion to the nozzle of the processing head around the piercing position, and suppressing and controlling the output of the laser beam to cut only the metal melt in the vicinity of the piercing. The material surface adhesion melt removal method at the time of piercing processing according to claim 1, wherein the metal melt is blown off by controlling an injection pressure.

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