JP2800946B2 - Laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a laser processing apparatus that determines the material and optimizes laser processing conditions by observing the state of occurrence of spatter. .

(Prior Art) As a conventional laser processing apparatus, a list of laser processing conditions is created in advance based on experimental data, and this is registered as table data, and data corresponding to the material and the thickness of the workpiece is stored. There is an example in which a laser output condition such as a laser power, a pulse frequency, and a duty ratio, and a laser processing condition including an assist gas type, a processing speed, and the like are determined by searching for.

On the other hand, the laser processing conditions set in this way also
At present, the optimum laser processing conditions are not always set for a work material for which the condition data is insufficient or the material is not specified, and a processing defect may occur.

Also, if the optimum laser processing conditions are not set, spatter due to thermal fusing scatters from the workpiece during laser processing, and this spatter cools and becomes dust, adheres to various members, and is exposed to machinery and parts. , Which may interfere with machine operation.

As a specific example, for example, in a laser / punch combined processing machine, if dust generated during the thermal cutting process scatters on the upper surface of the die of the punching portion, the lower surface of the workpiece during the punching process causes a product defect. In addition, in a turret station where a mold is not mounted, when the mold is mounted, if the dust is attached, the mold sometimes causes a galling phenomenon in the station.

Therefore, when dust generated during the thermal cutting process is scattered and adheres to the turret centering seat, etc., air is blown from the air nozzle formed on the shot pin to the shot pin hole on the outer periphery of the turret, or the air is sucked. Means to blow off or suck the dust.

(Problems to be Solved by the Invention) As described above, in the conventional laser processing apparatus, the laser processing conditions are set by the data table, but the data may be insufficient, and the optimum laser processing conditions are not necessarily set. Was.

Further, when the optimum laser processing conditions are not set, there is a problem that a large amount of spatter is scattered, and the machine and the product are contaminated.

Therefore, an object of the present invention is to provide a laser processing apparatus capable of setting optimum laser processing conditions by effectively utilizing sputtering and observing the state of occurrence.

[Means for Solving the Problems] The present invention for solving the above-mentioned problems is directed to a laser processing machine which irradiates a workpiece with a laser beam and thermally cuts the workpiece. A data table that determines laser processing conditions according to a material and a plate thickness; a laser processing condition setting unit that sets laser processing conditions retrieved from the data table according to a material and a plate thickness of the workpiece; A sputter color detecting means for detecting a color of spatter output from the workpiece during execution; a sputter intensity detecting means for detecting an intensity of spatter output from the workpiece during laser processing; Material discriminating means for discriminating the material of the workpiece from the color of the sputter detected by the sputter color detecting means, and from the sputter strength detected by the sputter strength detecting means Characterized by comprising a processing condition optimizing means for shifting the over The processing conditions more optimal direction.

Further, the sputter strength detecting means is constituted by an illuminance sensor or an infrared sensor.

Further, the sputter strength detecting means is provided at different positions on the circumference of the work with respect to the laser center.

(Operation) Since the laser processing apparatus of the present invention has the above configuration, the material can be determined from the sputter color, and the optimum laser processing conditions can be estimated from the sputter strength.

When a sensor that detects illuminance or an amount of infrared light is used as the spatter intensity detection means, more appropriate laser processing conditions can be set by using, for example, fuzzy inference using the detection results of both sensors. Becomes

When detecting the spatter intensity at two different positions, for example, both detection results are compared with respective threshold values,
By determining whether each detection result exceeds each threshold, the offset amount toward the optimal direction can be changed,
Optimal laser processing conditions can be quickly found according to each intensity detection result.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 2, a combined punch / laser machine 1 as an example of a laser machine according to an embodiment of the present invention.
Is a lower frame 3, side frames 5R and 5L erected on both sides of the lower frame 3, and
It is composed of a gate-shaped frame composed of an upper frame 7 provided on 5R and 5L.

In the gap between the lower frame 3 and the upper frame 7, a punching section 9 and a laser processing section 11 are provided in proximity to the punching section 9. That is, the punching section 9 includes an upper turret 15 mounted on a rotating shaft 13 rotatably supported on the upper frame 7, a lower turret 19 mounted on a rotating shaft 17 rotatably supported on the lower frame 3, and the like. It is composed of

The upper turret 15 and the lower turret 19 were formed in a disk shape, and were provided to face each other. A plurality of punches (not shown) are mounted on the circumference of the upper turret 15 at appropriate intervals, and a plurality of dies (not shown) are provided on the circumference of the lower turret 19 at positions corresponding to the punches. (Not shown). The upper turret 15 and the lower turret 19 are rotated synchronously by a drive device (not shown), and a desired punch and die are indexed from a plurality of punches and dies to a processing position indicated by a dashed line and positioned. It is supposed to be.

That is, the upper turret 15 and the lower turret 19 are always rotated and indexed as if they are integral, and the positioning of the center of the punch and the center of the die is performed as shown in FIGS. 3 and 4. Is secured by a shot pin 21 provided to be able to enter and exit from the upper frame 7 side and a centering seat 23 of the upper turret 15.

The shot pin 21 has a tapered tapered shape with a short length, and a plurality of centering seats 23 formed on the side surface of the upper turret 15.
A bush 25 having a tapered groove matching the shape of the shot pin 21 is fitted to the bush 25.

Further, in FIG. 2, although not shown, the upper frame 7 at the processing position indicated by the dashed line is provided with a striker for pressing the punch and a drive device for moving the striker up and down. .

With the above configuration, the work W is punched by the cooperation of the punch and the die indexed to the processing position.

A work table 27 is provided on the right side of the lower frame 3. A work base 27 is provided on the work table 27 so as to be movable in the Y-axis direction (the left-right direction in FIG. 2).

The carriage base 29 is provided with a plurality of parallel guide rails 31 extending in the X-axis direction (a direction orthogonal to the paper surface in FIG. 2).

A carriage 35 is attached to the guide rail 31 via a guide member 33 so as to be movable in the X-axis direction. A work clamp 37 for clamping the work W is fixed to the carriage 35.

With the above configuration, the carriage base 29 is moved in the Y-axis direction by a drive motor (not shown), and the carriage 35 is moved in the X-axis direction while being guided by the guide rail 31 by a drive motor (not shown).

Thereby, the work W clamped by the work clamp 37 is moved in the X-axis and Y-axis directions, and the desired position of the work W is positioned at the processing position of the punching processing section 9.
Next, the work is punched at a desired position of the work W by cooperation between the punch and the die.

The laser oscillator 39 of the laser processing unit 11 is provided on the left side of the side frame 5L of the portal frame. An optical axis frame 41 extending in the Y-axis direction is attached to the upper part of the laser oscillator 39 in a cantilever manner.

A bend mirror 43 is provided in the distal end of the optical axis frame 41. The lower part of the tip of the optical axis frame 41 has a Z
A laser processing head 45 extending in the axial direction (the vertical direction in FIG. 3) is provided. In addition, a nozzle 47 is mounted on the lower end of the laser processing head 45.

With the above configuration, the laser beam LB oscillated by the laser oscillator 39 passes through the optical axis frame 41, is bent by the bend mirror 43, and passes through the nozzle 47 attached to the lower end of the laser processing head 45 to assist gas (inert gas). At the same time, the work W clamped by the work clamp 37 is irradiated to be cut into a desired shape by heat.

When the workpiece W is irradiated with the laser beam LB and subjected to thermal cutting, spattering occurs to a greater or lesser extent. In order to remove dust as a result of cooling the spatter, a dust cleaning device 49 is provided in the laser processing head 45 near the punching section 9.

More specifically, as shown in FIG. 1, on the side wall of the laser processing head 45, a brush positioning cylinder 51 is provided.
A flange 53 formed at the rear end of the piston rod 57 is hinged by a pin 55, and the distal end of the piston rod 57 is attached to a mounting seat 61 provided on an upper portion of an air motor mounting bracket 59.
Are mounted in a hinge shape by pins 63.

The rear end of the air motor mounting bracket 59 is hinged to the side wall of the laser processing head 45 by pins 65.

An air motor 67 is fixed to the tip of the air motor mounting bracket 59, and a dust removal brush 71 is mounted on a rotating shaft 69 of the air motor 67.

During the laser processing operation, the dust cleaning device 49 is held vertically by the laser processing head 45 as shown by a two-dot chain line.

Since the dust processing device 49 is configured as described above, if dust generated during laser processing adheres to the centering seat 23, the dust processing device 49 is inserted into a program during automatic operation to remove the dust, and the operation is performed. Is stopped, the machine is returned to the origin, the cylinder 51 for brush positioning is started to extend the piston rod 57, and the bracket 59 for air motor mounting is stopped.
Is tilted in a cantilever manner with the pin 55 as an axis, and is brought into a state shown by a solid line in FIG. At this time, the operation of the brush positioning cylinder 51 is adjusted so that the dust removing bush 71 matches the position of the centering seat 23.

When the position of the dust removing brush 71 is determined, the operation of the brush positioning cylinder 51 is stopped, the air motor 67 is started, and the dust removing brush 71 is rotated, thereby turning the upper turret.
The dust is removed by grinding the inner surface of the bush 25 fitted to the mating seat 23 of the fifteen.

When the dust removal of one concentric seat 23 is completed, the turret is rotated to remove the dust of the next concentric seat 23, and when the front end is completed, the dust cleaning device 49 is operated in the reverse of the above to operate the dust cleaning device 49. To the position.

Then, the interrupted program operation is restarted.

The operation of the dust cleaning device 49 will be described with reference to FIG. 5. First, in step 501, a mode selection switch on an operation panel (both not shown) of the NC device is turned on, an automatic operation mode is set, and automatic operation is started. Here, usually, automatic processing is performed.

In step 502, in the laser cutting operation, the time is measured by the integrating time meter of the program, and when the integrated time reaches the set time, the process proceeds to the next step 503.

At step 503, the operation is stopped by interrupting the program during automatic operation, the machine is returned to the origin, and the laser processing head 45 is lowered.

In step 504, the brush positioning cylinder 51 is operated, the dust cleaning device 49 is tilted in a cantilever manner, and the dust cleaning device 49 is aligned with the centering seat 23 of the upper turret 15 while being adjusted, and the air motor 67 is started, and the centering seat is started. The inner surface of the bush 25 fitted to the 23 is automatically cleaned by a dust removing brush 71.

Next, in step 505, all the bushes 25 of all the mating seats 23 of the mold and turret are cleaned.

In step 506, when all the operations are completed, the operation is reversed to return to the original position of the dust cleaning device 49, the interrupted program operation is restarted, and the laser cutting operation is continued.

Referring again to FIG. 1, in this example, arms 75 and 77 extending outward from the laser center 73 of the laser processing head 45 by distances L1 and L2 are provided, and a spectroanalysis sensor S1 for detecting a sputter 79 is provided at the tip thereof. Sensor S2, infrared sensor
A sensor group consisting of S3 is provided. The distance L1 is, for example, 200 mm, L
2 is, for example, 300 mm.

The group of sensors attached to the tip of the arm 75 having a length L1 is referred to as Group 1, and the group of sensors attached to the tip of the arm 75 having a distance L2 is referred to as Group 2. Sensor GS1, G of each group
A plurality (for example, three) of S2 are provided around the laser processing head 45, respectively. Each of the sensors S1, S2, S3 is capable of detecting the state of the sputter 79 arriving immediately below itself.

The distance L1 is a distance allowed even if the spatter scatters. The distance L2 is a distance indicating a boundary indicating a state where the spatter is excessively scattered.

The spectrum analysis sensor S1 detects the color of the sputter 79 and determines the material of the currently cut workpiece. The illuminance sensor S2 detects the brightness of the sputter 79. The infrared sensor S3 detects the size of the spatter from the amount of infrared light of the spatter.

Each of the sensors S1, S2, S3 is connected to an NC device via an amplifier.

In the sensors S1, S2, and S3 having the above-described configurations, in this example, the detection results of the illuminance sensor S2 and the infrared sensor S2 are compared with threshold values set for themselves, and when the detection value is larger than the threshold value. , On-state signals are output.

FIG. 6 shows a processing flow for setting optimum laser processing conditions.

First, in step 601, when the sensor power is turned on in the NC operation panel and the automatic mode (tape memory) is set, the process proceeds to step 602, the automatic operation and the laser mode are determined, and the process proceeds to step 603 in the laser mode.

In step 603, it is determined whether or not the material to be actually processed and the plate thickness are specified. If not, the process proceeds to step 604.

In Step 604, the temporary material or the temporary plate thickness is determined, and the process proceeds to the next Step 605, where the temporarily determined material,
The laser processing conditions are provisionally determined according to the plate thickness. In the provisional determination of the plate thickness, a larger plate thickness is determined.

In step 606, a trial cutting is performed under the temporarily determined laser processing conditions. At this time, next, in step 607, the material is determined by the spectrum analysis sensor S1, and if it can be optimized by the laser processing conditions in the material group according to the spectrum analysis state, the process proceeds to step 608, and the laser in the same material group is used. Modify the processing conditions.

If the material can be determined in step 607 and relatively good laser processing conditions can be set, the process proceeds to step 610.

On the other hand, if the material and plate thickness are specified in step 603, the process proceeds to step 609, where the laser processing conditions are set by searching the data table, and the process proceeds to step 610.

In step 610, the illuminance sensor S2 and the infrared sensor S3 of the first group of sensors G1 for detecting spatter intensity
It is determined whether or not both are turned on. If either is turned off or both are turned off, the process proceeds to step 611, and the cutting is continued under this condition. If the laser processing condition under the current work condition has not been registered, the data is written into the optimum condition table to supplement the data table.

Next, if both the sensors GS1 of the first group are ON at step 610, the process proceeds to step 612, where the next determination process is performed, since a large amount of spatter has been scattered.

In step 612, among the sensors GS2 of the second group,
It is determined whether or not both the illuminance sensor S2 and the infrared sensor S3 are on. If one or both of them are off, it is rarely determined that there is too much spatter, and the process proceeds to step 613. The laser processing conditions of the candidate are set, a cutting trial is performed, and the process returns to step 610.

Further, if both sensors S2 and S3 of the second group are turned on in step 612, the next candidate laser processing condition is set assuming that the spatter is scattered more,
Try cutting and return to step 610.

The next candidate set in steps 613 and 614 is one laser processing condition in which it is estimated that spatter will not be scattered up to the distance L1, depending on the current state of both steps.

Therefore, in this example, the distances L1 and L2 shown in FIG.
By making the thresholds compared by each sensor S2 and S3 appropriate, the laser processing conditions where spatters are scattered far beyond the distance L2 can be quickly changed to laser processing conditions that keep the spatters within the distance L1. Can be optimized.

In the above process, the spatter intensity was determined based on whether or not both the illuminance sensor S2 and the infrared sensor S3 were on.However, the on / off of the illuminance sensor S2 and the on / off of the infrared sensor S3 were separately determined, and the smaller. The next candidate of the laser processing condition may be selected for each of the divided intensity regions.

Further, as shown in FIG. 1, the number of sensor groups is two. However, the number of groups is made larger, and the optimum laser processing conditions are set for each combination by the combination of the comparison results by the sensors of each group. It may be.

Furthermore, in the above embodiment, the detection value of each sensor is compared with the threshold value, and the current state is determined by the ON signal, but the detection value of each sensor is used as it is, and the optimal laser processing condition is estimated by fuzzy inference. You may make it.

In the above embodiment, the arm is attached to the laser processing head 45.
Although the sensors S1, S2, and S3 are provided by providing the sensors 75 and 77, the mounting location of the sensors is not limited thereto.

The present invention is not limited to the above embodiments, but can be implemented in an appropriate mode by making appropriate design changes.

[Effects of the Invention] As described above, since the present invention is a laser processing apparatus as described in the claims, the optimum laser processing conditions are automatically set by detecting the color and intensity of sputter. be able to.

[Brief description of the drawings]

FIG. 1 is an enlarged front view of a portion viewed in the direction of arrow I in FIG. 2, FIG. 2 is a front view of a laser / punch combined machine as one embodiment of the laser machining apparatus of the present invention, and FIG. FIG. 4 is a partially cutaway plan view showing a shot pin for positioning the center of the die and a concentric seat, FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3, FIG. 5 is a flowchart of a bush cleaning process, and FIG. It is a flowchart which shows the setting processing method of a processing condition. 1 ... Punch / Laser combined processing machine 9 ... Punching processing part 11 ... Laser processing part, 15 ... Upper turret 19 ... Lower turret, 23 ... Center seat 25 ... Bushing, 45 ... Laser processing head 47 ... Nozzle, 49 ... Dust cleaning device 71 ... Dust removal brush W ... Work, LB ... Laser beam GS1 ... Sensor of the first group GS2 ... Sensor of the second group S1 ... Spectrum analysis sensor S2 ... Illuminance sensor S3 ... Infrared sensor

Claims (3)

(57) [Claims] 1. A laser processing machine for irradiating a workpiece with a laser beam and thermally cutting the workpiece, comprising: a data table for determining laser processing conditions in accordance with a material and a thickness of the workpiece; A laser processing condition setting means for setting a laser processing condition retrieved from the data table according to a material and a plate thickness of the material; and a sputter for detecting a color of a sputter output from the workpiece during the execution of the laser processing. A color detection unit, a spatter intensity detection unit that detects the intensity of spatter output from the workpiece during execution of the laser processing, and a material of the workpiece based on a sputter color detected by the sputter color detection unit. Material discriminating means for discriminating, and processing condition optimizing means for shifting laser processing conditions in a more optimal direction from the sputter strength detected by the sputter strength detecting means. Laser processing apparatus, characterized in that was e. 2. A laser processing apparatus according to claim 1, wherein said spatter intensity detecting means comprises an illuminance sensor or an infrared sensor. 3. A laser processing apparatus according to claim 1, wherein said sputter strength detecting means is provided at different positions on the circumference of the workpiece with respect to the laser center.