JP3687814B2 - Laser processing machine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a laser processing machine, and more particularly to a laser processing machine that performs piercing (drilling) at a required position of a workpiece and starts laser processing from there.
[0002]
[Prior art]
Conventionally, a laser processing machine having the following configuration is known. That is, a laser oscillator that oscillates a laser beam, a processing head that irradiates a workpiece with a laser beam oscillated from the laser oscillator, a drive source that relatively moves the processing head and the workpiece, the laser oscillator, and A control device that controls the operation of the drive source and the distance between the machining head and the workpiece are detected and transmitted to the control device when laser machining is performed by relatively moving the machining head and the workpiece. And a sensor for detecting when the processing head comes into contact with an obstacle and transmitting the detected head to the control device, the control device based on the distance detection signal transmitted from the sensor. There is known a laser processing machine configured to perform a required laser processing on a workpiece while maintaining a constant distance between the workpiece and a processing head by controlling the operation of the above.
[0003]
[Problems to be solved by the invention]
In the conventional laser processing machine described above, piercing (perforation) is performed by irradiating a laser beam to a required position of the workpiece before laser processing. In some cases, the melt was scattered on the surface of the workpiece around the piercing site, which solidified as a small arch.
When an arched solid is generated around the piercing portion in this manner, the lower end portion of the machining head comes into contact with the arched solid when laser processing is started after piercing. Then, this is detected by the sensor and transmitted to the control device. In this case, conventionally, the laser processing is stopped by stopping all the operations of the laser oscillator and the driving source by the control device. In other words, laser processing is stopped even when the solidified product that does not interfere with contact with the processing head comes into contact.
In addition, when laser processing is started after piercing, and the processing head does not come into contact with the arched solidified material immediately after the start of laser processing, and the processing head passes near the piercing part when laser processing has progressed to some extent There is. At that time, when the sensor detects the distance between the solidified material and the machining head and transmits it to the control device, the control device calculates the distance between the machining head and the solidified material based on the distance detection signal transmitted from the sensor. The drive source is controlled to be constant. For this reason, in the machining area where the sensor detects the solidified material, the distance between the machining head and the surface of the work piece is poor, and thus the laser processing is incomplete in that machining area. is there.
[0004]
[Means for Solving the Problems]
In view of such circumstances, the present invention provides a laser oscillator that oscillates a laser beam, a machining head that irradiates a workpiece with the laser beam oscillated from the laser oscillator, and a relative movement between the machining head and the workpiece. A driving source to be operated, a control device for controlling the operation of the laser oscillator and the driving source, and the laser beam is moved between the machining head and the workpiece while the machining head and the workpiece are relatively moved. A sensor that detects the distance and transmits it to the control device, and detects that the machining head contacts the obstacle and transmits it to the control device. The control device outputs a distance detection signal transmitted from the sensor. Laser processing that is configured to perform the required laser processing on the workpiece while maintaining the distance between the workpiece and the processing head constant by controlling the operation of the drive source and the laser oscillator. In,
When the sensor detects that the machining head has come into contact with the obstacle during laser machining and transmits this to the control device, the control device increases the height of the machining head for a predetermined time T1. It is configured to maintain the height at the time of contact with an obstacle.
[0005]
[Action]
According to the above-described configuration, the workpiece has an arch-like solidified product generated during piercing, and the machining head contacts the solidified product during laser processing, which is detected by the sensor and transmitted to the control device. Then, the control device maintains the height of the machining head constant for the predetermined time T1. Therefore, the processing is continued while the height of the processing head is kept constant, and the solidified material is destroyed when the processing head collides with the solidified material. Since the solidified material is brittle and brittle, even if the machining head collides with the solidified material, the machining head is not damaged. Therefore, even in a processing region where a solidified material exists, laser processing is performed while maintaining a constant height from the original surface of the workpiece to the processing head.
Therefore, even if there is an arch-like solidified product generated in piercing, a good laser processing can be performed on the workpiece regardless of this. Therefore, good laser processing can be performed on the workpiece without causing processing defects.
[0006]
【Example】
Hereinafter, the present invention will be described with reference to the illustrated embodiment. In FIG. 1, reference numeral 1 denotes a laser processing machine. A processing head 4 that condenses the laser beam L and irradiates the workpiece 3 with a plate shape is provided.
The machining head 4 is attached to a portal frame (not shown) and can move in the X direction in conjunction with a motor (not shown).
The workpiece 3 is placed on a processing table 5, and the processing table 5 is moved in the Y direction orthogonal to the X direction in conjunction with a motor (not shown).
As described above, the machining head 4 and the machining table 5 are linked to motors (not shown) as drive sources, and the operation of these motors is controlled by the control device 6. Therefore, by controlling the operation of each motor by the control device 6, the workpiece 3 placed on the machining table 5 and the machining head 5 are moved relative to each other in the XY directions, so that the workpiece 3 has a required shape. It can be cut into two.
Further, the machining head 4 is provided so as to be movable up and down on the portal frame described above, and is interlocked with a motor 7 provided on the portal frame so as to face vertically downward. The operation of the motor 7 is also controlled by the control device 6.
Furthermore, a conventionally known capacitance sensor 8 is attached to the lower end of the machining head 4. The capacitance sensor 8 can detect the distance between the surface of the workpiece 3 and the lower end of the machining head 4. The surface of the workpiece 3 detected by the capacitance sensor 8 and the machining head. The distance from the lower end of 4 is converted into a signal and transmitted to the control device 6. Further, when the machining head 4 comes into contact with any obstacle while performing laser machining by moving the machining head 4 and the workpiece 3 relative to each other in the XY directions, the capacitance sensor 8 indicates that. Is supposed to be detected. Also in this case, a detection signal indicating that the machining head 4 has contacted the obstacle is transmitted from the capacitance sensor 8 to the control device 6.
When cutting the workpiece 3, first, as shown in FIG. 2, the laser beam L is irradiated toward the required position of the workpiece 3 before piercing (piercing) as shown in FIG. )I do. Then, a motor (not shown) is operated by the control device 6 to move the machining head 4 and the workpiece 3 relative to each other in the XY directions and start cutting from the pierced portion 3A. Further, during the cutting process, the control device 6 rotates the motor 7 in the forward and reverse directions based on the distance detection signal transmitted from the capacitance sensor 8, thereby processing the head 4 (the condensing lens 11). ) And the surface of the workpiece 3 are controlled to be constant. The control device 6 includes a motor and motor 7 in the X and Y directions (not shown), and a first control unit 6A that controls the operation of the laser oscillator 2. The first control unit 6A receives a motor from the second control unit 6B. When the scanning command is transmitted so that the distance between the head 7 and the processing head 4 (the condensing lens 11) is controlled to be constant, the motor 7 is rotated in the forward and reverse directions so that the processing head 4 and the workpiece 3 are rotated. The distance is controlled to be constant.
The above configuration is the same as that of the conventionally known laser beam machine 1.
By the way, although cutting is performed after piercing the workpiece 3 as described above, as shown in FIG. 2, when the piercing is performed, the molten material scatters to the surroundings from the portion 3A to be pierced, The melt may solidify as a small thread-like arch around the portion 3A where piercing occurs (FIG. 2). When such a solidified product 3B is present around the piercing portion 3A, the capacitance sensor 8 detects the arched solidified product 3B during the cutting process, and transmits the detection signal to the control device 6. . Then, the control device 6 moves the machining head 4 up and down following the arch of the solidified material 3 </ b> B transmitted from the capacitance sensor 8. Then, since the distance between the processing head 4 (the condensing lens 11) and the original surface of the workpiece 3 varies, the cutting process is poor in the processing region where the capacitance sensor 8 detects the solidified material 3B. become. Therefore, the present embodiment is an improvement of the control device 6 so that the workpiece 3 can be satisfactorily cut even when the solidified product 3B is present around the piercing portion 3A. is there.
That is, when the workpiece 3 is pierced, a plurality of solidified and arched solids 3B are generated around the pierced portion 3A as shown in FIG. Then, it is assumed that cutting processing is started on the workpiece 3 from the piercing portion 3B, and the solidified material 3B is not detected by the capacitance sensor 8 immediately after the cutting is started. In this case, the control device 6 of this embodiment controls the operation of the motors and motors 7 in the X and Y directions (not shown) as the drive source and the laser oscillator 2 by performing the following processing.
That is, as shown in FIG. 3, during the cutting process, the control device 6 first checks whether or not a copying command is transmitted from the second control unit 6B to the first control unit 6A (S1). In other words, the control device 6 issues a copying command so that the distance between the motor 7 and the processing head 4 (the condensing lens 11) is controlled from the second control unit 6B to the first control unit 6A. Check if it is communicated.
Here, when it is confirmed that the copying command is transmitted to the first control unit 6A, the process proceeds to the next S2. On the other hand, when it is confirmed in S1 that the copying command is not transmitted to the first control unit 6A, the process immediately shifts to the end.
Next, in S <b> 2, the control device 6 checks whether or not a signal indicating that the machining head 4 is in contact with an obstacle is currently transmitted from the capacitance sensor 8 to the control device 6. Here, when it is confirmed that a signal indicating contact with the obstacle has not been transmitted from the capacitance sensor 8 to the control device 6, the process proceeds to the next S3.
On the other hand, if it is confirmed in S2 that a signal indicating that the sensor has contacted the obstacle is transmitted from the capacitance sensor 8 to the control device 6, the process proceeds to S5.
In S5, the control device 6 ignores the copying command, and instead, from the second control unit 6B to the first control unit, issues a height maintenance command for maintaining the machining head 4 on the workpiece 3 at a constant height. Processing to be transmitted to 6A is performed. As a result, the height of the machining head 4 is kept constant even though a signal indicating that an obstacle has been contacted is transmitted from the capacitance sensor 8 to the control device 6.
The processing in S5 takes into account the case where the solidified material 3B and the processing head 4 shown in FIG. 2 are in contact with each other during the cutting process, and this is detected by the capacitance sensor 8 and transmitted to the control device 6. It is. In this case, in S5, the control device 6 ignores the scanning command, and instead transmits a height maintenance command to the first control unit 6A, so that the machining head 4 contacts the solidified product 3B without changing the height. As a result, they move relative to each other in the XY directions, whereby the solidified product 3B collides with the machining head 4 and is broken into a plurality of pieces. In this case, the solidified product 3B is thread-like and easily breaks, so there is no problem even if the machining head 4 collides with the solidified product 3B.
After the process of S5, the process proceeds to the end, and thereafter, the control device 6 performs the process shown in FIG. 4 to be described later, and then returns to the start process shown in FIG. Thereafter, the process proceeds from S1 to S2 again. In S2, the contact signal from the capacitance sensor 8 is not transmitted to the control device 6 because the solidified material 3B is destroyed. The process proceeds to S3.
Then, in S3, the control device 6 checks whether or not 1 second has elapsed since the height maintenance command was transmitted to the first control unit 6A in S5. Here, when it is confirmed that one second has not elapsed, the process immediately shifts to the end. On the other hand, when it is confirmed that one second has elapsed, the process proceeds to S4, and in S4, the control device 6 performs a process of canceling the height maintenance command. As a result, the process proceeds from S4 to END.
Of course, in S2, during the normal cutting process in which the contact signal is not transmitted to the control device 6 by the capacitance sensor 8 from the beginning, the process proceeds from S2 to S3, and immediately proceeds from S3 to the end. Then, the process proceeds to the processing step shown in FIG.
The processing by the control device 6 shown in FIG. 3 will be described more simply. In a normal processing state in which the capacitance sensor 8 does not transmit a contact signal to the control device 6 during cutting processing, the control device 6 has S1, S2, and S2. Processing is performed in the order of S3 to end. In other words, the first control unit 6A executes a copying command via the motor 7 so that the distance between the surface of the workpiece 3 and the processing head 4 is constant.
On the other hand, when the capacitance sensor 8 transmits a contact signal to the control device 6 during the cutting process, the process proceeds from S2 to S5. Execute a height maintenance command to keep the height constant. This is the case, for example, when the machining head 4 comes into contact with the solidified product 3B, is detected by the capacitance sensor 8, and is transmitted to the control device 6. In this case, since the solidified product 3B is in the form of a thread, the solidified product 3B is instantaneously destroyed when the processing head 4 contacts the solidified product 3B. On the other hand, if the copying command is executed at this time, the machining head 4 is raised along the arch of the solidified product 3B detected by the capacitance sensor 8 even though the solidified product 3B is destroyed. Thus, the cutting process in that region becomes defective. In the present embodiment, such a situation does not occur.
According to the process of the present embodiment described above, the solidified material 3B is present, and even if the processing head comes into contact therewith, the region where the solidified material 3B is present can be cut without being affected by it. Good cutting can be performed without causing cutting failure.
Next, the processing of the control device 6 performed after the processing shown in FIG. 3 will be described with reference to FIG. First, in S11, the control device 6 confirms whether or not a copying command is transmitted from the second control unit 6B to the first control unit 6A during the cutting process. Here, if it is confirmed that the copying command is not transmitted, the process immediately shifts to the end.
On the other hand, when it is confirmed in S11 that the copying command is transmitted from the second control unit 6B to the first control unit 6A, the process proceeds to the next S12.
In S <b> 12, the control device 6 confirms whether or not a detection signal indicating that the machining head 4 has contacted any obstacle is transmitted from the capacitance sensor 8 to the control device 6. Here, when it is confirmed that the contact signal is not transmitted, the process immediately shifts to the end.
On the other hand, when it is confirmed in S12 that the contact signal is transmitted to the control device 6, the process proceeds to the next S13.
In S <b> 13, the control device 6 confirms whether or not 0.3 seconds have elapsed since the contact signal was transmitted to the control device 6. Here, when it is confirmed that 0.3 second has not elapsed, the process immediately shifts to the end.
On the other hand, in S13, when it is confirmed that 0.3 second has passed and the contact signal is continuously transmitted to the control device 6, the control device 6 proceeds to the next processing of S14. Transition.
In S <b> 14, the control device 6 stops the laser oscillator 2 and the motors for XY direction operation, retracts the machining head by the operation of the motor 7, and stops the cutting process. The stop process is the same as that of a conventional laser processing machine.
If the process in S13 and S14 is supplementarily described, the process in S13 and S14 is performed by the capacitance sensor 8 detecting the contact between the solidified product 3B and the machining head 4 as described with reference to FIG. Thus, the case of transmission to the control device 6 is taken into consideration. In this case, in the process using FIG. 3, the solidified body 3B is destroyed by maintaining the height of the machining head after the machining head 4 and the solidified body 3B come into contact with each other. The contact signal from the capacitive sensor to the control device 6 disappears instantaneously and does not continue. Therefore, in such a case, since it is not necessary to stop the cutting process, the cutting process is continued when the contact signal disappears before 0.3 seconds elapses in S13.
On the other hand, the fact that 0.3 second has elapsed in S13 means that the machining head 4 is not in contact with the solidified substance but is in contact with some obstacle other than the solidified substance. Is to stop the cutting process in S14. This prevents the machining head 4 from colliding with a large obstacle or the like and being damaged.
Note that the control device 6 circulates and repeats the process shown in FIG. 4 after the process shown in FIG.
In the above-described embodiment, the process in the case where the contact signal is transmitted to the control device 6 by the capacitance sensor 8 after the cutting process has progressed to some extent after the cutting process is started has been described. Even when the contact signal is transmitted to the control device 6 by the capacitance sensor 8 near the time or near the end of cutting, the same processing as described above is performed.
Furthermore, the predetermined times T1 and T2 are not limited to 1 second and 0.3 seconds, respectively, and may be changed as appropriate.
[0007]
【The invention's effect】
As described above, according to the present invention, even if there is an arch-like solidified product that has occurred during piercing, an effect is obtained that good laser processing can be performed without causing processing defects.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a state after piercing the workpiece 3. FIG. 3 is a process performed by the control device shown in FIG. The figure which shows a process. [FIG. 4] The figure which shows the process process by the control apparatus shown in FIG.
DESCRIPTION OF SYMBOLS 1 Laser processing machine 2 Laser oscillator 3 Work piece 4 Processing head 6 Control apparatus 8 Capacitance sensor L Laser beam

Claims (2)

A laser oscillator that oscillates a laser beam, a machining head that irradiates a workpiece with a laser beam oscillated from the laser oscillator, a drive source that relatively moves the machining head and the workpiece, and the laser oscillator and the drive source A control device that controls the operation of the machine, and when the laser beam machining is performed by relatively moving the machining head and the workpiece, the distance between the machining head and the workpiece is detected and transmitted to the control device , A sensor for detecting when the processing head comes into contact with an obstacle and transmitting it to the control device. The control device operates the drive source and the laser oscillator based on a distance detection signal transmitted from the sensor. In a laser processing machine configured to perform a required laser processing on the workpiece while maintaining a constant distance between the workpiece and the processing head,
When the sensor detects that the machining head has come into contact with the obstacle during laser machining and transmits this to the control device, the control device increases the height of the machining head for a predetermined time T1. A laser processing machine characterized by maintaining the height at the time of contact with an obstacle. When laser processing is being performed, the sensor has transmitted to the control device that the machining head has come into contact with the obstacle, and after the detection signal is transmitted from the sensor to the control device, it continues even after the elapse of a predetermined time T2. When the same detection signal is transmitted to the control device, the control device stops the laser processing by stopping all the operations of the laser oscillator and the driving source,
When laser processing is transmitted from the sensor to the control device that the machining head has come into contact with the obstacle, a detection signal is transmitted from the sensor, and after the elapse of a predetermined time T2, the same detection as described above is performed from the sensor. When the signal is not transmitted, the control device is configured to continue the laser processing by continuously operating the laser oscillator and the driving source,
2. The laser beam machine according to claim 1, wherein the predetermined time T2 is set to be equal to or shorter than the predetermined time T1.

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