JPH1034362A - Method and equipment for laser beam machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the cutting with excellent cut section without generating any inconveniences in machining caused by insufficient or excessive heat input at the machining start point. SOLUTION: In the initial irradiation of the laser beam 1, the irradiation power is rapidly transferred to the prescribed value by controlling the irradiation power through the control of the current of PW, etc., in order to charge the irradiation power capable of instantaneously burning and removing a work 9 so as to prevent the work 9 from being carbonized, and in order to complete holding of a working hole 6, the material of the work 9 is removed to the depth of 1/3 to 2/3 of its thickness with irradiation by the initial laser beam 1. The second and subsequent laser beam irradiation power is set to be lower than the previous value, and the irradiation power is controlled so that the residual part at the work starting point of the work with reduced heat capacity is drilled down without giving excessive heat input.

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 laser processing apparatus for cutting a workpiece by laser processing, and more particularly to a cutting process from a drilling operation at a processing start point to a next process. TECHNICAL FIELD The present invention relates to a laser processing method and an apparatus for changing a processing condition at the time of moving to (1).

[0002]

2. Description of the Related Art In general, when a metal material is cut using a laser beam, a laser beam is irradiated once at a processing start point, and a drilling operation is performed. The process is shifted from the starting point to the cutting process. However, in the case of cutting a material such as a combustible material, which is easily combustible, if the process shifts to cutting after performing a drilling operation at a processing start point by one laser beam irradiation. When shifting to cutting, processing defects may occur. For example, this defect may include a residue at the processing start point due to insufficient heat input,
Conversely, as a problem that occurs when preventing a problem due to insufficient heat input, there is an abnormal spread of the bottom of the hole at the processing start point due to excessive heat input that occurs when the irradiation power of the laser beam is set high.

FIGS. 8A and 8B are explanatory views of a conventional laser processing method for cutting a workpiece due to insufficient heat input by laser processing. FIG. 8A is a sectional view and FIG. 8B is a bottom view. FIGS. 9A and 9B are explanatory views of a conventional laser processing method for cutting a workpiece by excessive heat input by laser processing. FIG. 9A is a sectional view and FIG. 9B is a bottom view. 8 and 9, 1
Is a laser beam having a low irradiation power and insufficient heat input, 2 is a condensing lens as a condensing optical component for condensing the laser beam 1, A is a processing start point, and B is a processing end point including during processing. 5, a remaining portion at the bottom of the processing start portion near the processing start point A; 6, a processing start hole generated at the processing start point A; 7, a moving direction of the laser beam 1; The area 9 is a workpiece made of a flammable material.

As shown in FIG. 8, in laser processing due to insufficient heat input, a processing start hole 6 is formed at a processing start point A, the laser beam 1 moves in the moving direction 7 side, and then a processing end point. Assume that the processing is stopped at B. In the laser processing due to insufficient heat input, the laser beam 1 is moved in the moving direction 7 after the processing start hole 6 is drilled near the processing start point A. Since the laser beam 1 moves in the state described above, the remaining portion 5 is formed near the lower portion of the processing start hole 6. That is, when the processing start hole 6 is formed, the laser beam 1 does not enter heat in the moving direction 7. Therefore, when the laser beam 1 moves, the lower part of the processing start hole 6 enters. Since heat is input in the moving direction 7 of the other laser beam 1 in a state of insufficient heat, the remaining portion 5 is generated due to insufficient energy near the lower portion of the processing start hole 6. Conversely, when the heat input becomes excessive, as shown in FIG. 9, the processing start hole 6 is formed at the processing start point A by the laser processing by the excessive heat input, and the laser beam 1 moves in the moving direction 7 side. Then, it is assumed that the machining is stopped at the machining end point B. In the laser processing by excessive heat input, a processing start hole 6 is formed around the processing start point A, but in the laser processing by excessive heat input, the hole bottom side on the side opposite to the incident surface side of the laser beam 1 expands, Its diameter increases. Thereafter, the laser beam 1 is moved in the moving direction 7, but compared with the processing width at this time, the bottom of the processing start hole 6 is widened, and the cut removal area 8 having a uniform width cannot be obtained, resulting in a poor finish. .

[0005]

As described above, according to the conventional laser processing method, even when the work material 9 such as a combustible material is used as the work material 9, the cutting method is not limited to the case of cutting the metal material. Similarly to the above, the drilling operation of the processing start point A is performed by one laser beam irradiation. Therefore, if the laser input power is set high for the purpose of preventing the occurrence of an uncut portion at the processing start point A due to insufficient heat input, or the excessive heat input, the bottom of the processing start hole 6 may expand abnormally due to excessive heat input. Or inconvenience.

Accordingly, the present invention has been made to solve the above-mentioned problems, and there is no problem in processing due to insufficient heat input or excessive heat input at the processing start point, and the cutting processing has a good cross section. It is an object of the present invention to provide a laser processing method that can realize the above.

[0007]

According to a first aspect of the present invention, there is provided a laser processing method for processing a work material, such as a combustible material, which is easily combustible by using a heat source that focuses a laser beam at a high energy density. In the processing method, in the vicinity of the processing start point of the workpiece, a laser beam moved a predetermined distance along the processing path from the processing start point, repeatedly reciprocating along the processing path a plurality of times, After penetrating the machining start hole, the process shifts to the next cutting operation.

According to a second aspect of the present invention, in the laser processing method, the laser beam focusing point is displaced upward or downward by an arbitrary predetermined amount with respect to the surface of the workpiece after penetrating the processing start hole. Then, the workpiece is irradiated with a laser beam to form a cut groove of the workpiece in a desired shape.

According to a third aspect of the present invention, there is provided a laser processing method comprising: performing the reciprocating operation a plurality of times along the processing path according to the first or second aspect; To change it.

According to a fourth aspect of the present invention, in the laser processing method, the reciprocating operation performed a plurality of times along the processing path according to any one of the first to third aspects is performed by using the irradiation power of the first laser beam. A method of removing the workpiece to a depth of about 1/3 to 2/3 of the plate thickness, setting the irradiation power of the second and subsequent laser beams lower than the first irradiation power, and removing the remaining portion. It is.

According to a fifth aspect of the present invention, there is provided a laser processing apparatus for processing a work material which is easily combustible, such as a combustible material, by using a heat source which focuses a laser beam at a high energy density. In the vicinity of the processing start point of the processing material, the laser beam moved a predetermined distance along the processing path from the processing start point is repeatedly reciprocated a plurality of times along the processing path to penetrate the processing start hole. After that, the process moves to the next cutting operation and cuts.

According to a sixth aspect of the present invention, in the laser processing apparatus, the laser beam condensing point is displaced upward or downward by an arbitrary predetermined amount with respect to the surface of the workpiece after penetrating the processing start hole. Then, the workpiece is irradiated with a laser beam to form a cut groove of the workpiece in a desired shape.

According to a seventh aspect of the present invention, a laser processing apparatus according to the fifth or sixth aspect performs the reciprocating operation a plurality of times along the processing path, and performs the first and second and subsequent irradiation powers of the laser beam. Things that change.

According to an eighth aspect of the present invention, in the laser processing apparatus, the reciprocating plural times reciprocating operation performed along the processing path according to any one of the fifth to seventh aspects is performed by using the irradiation power of the first laser beam. A method of removing the workpiece to a depth of about 1/3 to 2/3 of the plate thickness, setting the irradiation power of the second and subsequent laser beams lower than the first irradiation power, and removing the remaining portion. It is.

According to a ninth aspect of the present invention, there is provided a laser processing apparatus according to any one of the fifth to eighth aspects, wherein the irradiation power of the first laser beam and the second and subsequent laser beams are performed along the processing path. Is performed by pulse oscillation control.

[0016]

Embodiments of the present invention will be described below. FIG. 1 is an overall configuration diagram of a laser beam machine according to one embodiment of the present invention, and FIG. 2 is a control circuit diagram of a control system for controlling a laser beam of the laser beam machine according to one embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a bed serving as a base of a mechanical system of a laser processing machine; 12 denotes a main table mounted on the bed 11 and allowed to move only with the bed 11 in the X-axis direction; Is the main table 12
And is allowed to move only in the Y-axis direction with the main table 12. Also, 14 is the main table 12 with respect to the bed 11 X
An X-axis drive motor 15 composed of a servomotor or the like that moves in the axial direction, and 15 is a Y motor composed of a servomotor that moves the sub-table 13 in the Y-axis direction with respect to the main table 12.
It is a shaft drive motor. Reference numeral 9 denotes a workpiece made of a flammable material, which is fixed on the sub-table 13 with a fixture (not shown). Reference numeral 16 denotes a laser oscillator for oscillating a laser, 17 denotes a pipeline of the laser beam 1, and 18 denotes a processing machine main body. Reference numeral 19 denotes a Z-axis drive motor including a servomotor for moving a processing head 20 described later up and down, that is, moving the processing head 20 with respect to the main table 12 and the sub-table 13 in the Z-axis direction.
Mounted on Reference numeral 20 denotes a processing head which is moved in the Z-axis direction by a Z-axis drive motor 19. Reference numeral 2 denotes a condenser lens as a condenser optical component. Reference numeral 30 denotes a control / power supply device including a computer or the like,
The main table 12 is connected to the bed 11 in the X-axis direction, and the sub-table 13 is connected to the main table 12 by program control. To move the processing head 20 in the Z-axis direction with respect to the main table 12. Also,
It outputs a current for causing the laser oscillator 16 to continuously oscillate (CW) or pulse (PW).

In FIG. 2, reference numeral 16 denotes the above-described laser oscillator, 25 denotes a partial reflection mirror, 26 denotes a total reflection mirror, and 27 denotes a mirror.
Is a discharge electrode, 28 is a mixed gas of a laser medium sealed in a resonator, 1 is a laser beam emitted (output) from the laser oscillator 16, and 30 performs the above-described continuous oscillation (CW) or pulse oscillation (PW). And output the current
A control / power supply device for performing position control by the X-axis drive motor 14, the Y-axis drive motor 15, and the Z-axis drive motor 19;
Is a main power supply circuit of the control / power supply device 30, which functions as a constant current source when continuous oscillation is selected as its output. In addition, an analog gate that outputs a rectangular wave pulse by directly or indirectly cutting off the constant current output is connected to the inside thereof. When pulse oscillation is selected, a rectangular wave current is output from the constant current source. Output pulse. Although not described in detail here, the main power supply circuit 32 includes a trigger transformer for generating a high voltage when the discharge electrode 27 is first turned on, and a trigger transformer necessary for maintaining lighting of the discharge electrode 27 after lighting. A circuit for supplying a minimum current (hereinafter referred to as "simmer current") is also provided. 31 is a main control circuit for program-controlling a main power supply circuit 32 of a control / power supply device 30 composed of a microcomputer or the like;
Is a peak current setting device that determines the peak of the output current of the pulse output and the constant current output, and is composed of a potentiometer.
Similarly, 30B is a pulse output frequency setting device, and 30C is a pulse output duty ratio setting device, both comprising potentiometers. Reference numeral 30D denotes a continuous oscillation / pulse oscillation switch (hereinafter simply referred to as "CW / PW switch") which switches between continuous oscillation for selecting a constant current output and pulse oscillation for selecting a pulse output, and is constituted by a changeover switch. Note that 33
Is a keyboard, and 34 is a display.

Next, the operation of the power supply of the control / power supply device 30 will be described. When the mixed gas 28 of the laser medium is irradiated by the excitation light of the discharge electrode 27 of the excitation light source of the laser oscillator 16, the mixed gas 28 of the laser medium is excited, and the partial reflecting mirror provided so as to sandwich the mixed gas 28 of the laser medium. The laser beam 1 is oscillated by the mirror 25 and the total reflection mirror 26. The laser beam 1 is output from the partial reflection mirror 25 by this oscillation, and is used as a heat source for laser processing.
At this time, the control / power supply device 30 supplies power to the discharge electrode 27 serving as an excitation light source of the laser oscillator 16, and in this embodiment using a discharge lamp as the excitation light source, the control / power supply device 30 is used as a constant current type. doing. Desired processing conditions, in other words, parameters that determine the current waveform (peak current value, repetitive pulse frequency, duty ratio)
Are the peak current setting device 30A and the frequency setting device 3
0B, the main control circuit 31 based on the duty ratio setting device 30C.
Here, a desired current command value signal is generated and output to the main power supply circuit 32. When the current command value signal is input to the main power supply circuit 32, the main power supply circuit 32 supplies a desired current value to the discharge electrode 27 based on the command value of the current command value signal. Note that the current command value signal output from the main control circuit 31 is based on the peak output of the constant current source and the PWM signal.
It controls the opening and closing of the analog gate of the main power supply circuit 32 as a signal.

When the laser oscillator 16 is used as a heat source for laser processing or the like, continuous oscillation (CW) or pulse oscillation (PW) is selected and used according to the type and purpose of the processing, and the continuous oscillation is used. A CW / PW switch 30D is provided as a switch for selecting pulse oscillation. When the CW side of the CW / PW switch 30D is selected, only the peak current value set by the peak current setter 30A is valid, and the frequency and duty ratio set by the frequency setter 30B and the duty ratio setter 30C are used. Is activated by the main control circuit 31. When the PW side is selected, the peak current setting device 30A and the frequency setting device 30
B. The main control circuit 31 operates so that all the duty ratio setting devices 30C are valid. FIG. 3 is a schematic diagram showing a cut section at a processing start point of the laser processing method according to one embodiment of the present invention. In FIG. 3, 1 is a laser beam, 2 is a condensing lens as a condensing optical component for condensing the laser beam 1, 3 is a beam condensing point, 4 is a plate thickness of a workpiece, A is a processing start point, 5 is the remaining portion at the bottom position of the processing start portion near the processing start point A, and 6 is the processing start point A
, A moving direction of the laser beam 1, a cutting and removing area 8 by the laser beam 1, and a work material 9 made of a combustible material.

Next, the operation of the laser beam machine according to this embodiment will be described. First, as shown in FIG. 3, in order to cut the workpiece 9, a processing start hole 6 is formed at a processing start point A.
Perform the tasks to open the door. The operation irradiates the surface of the workpiece 9 with the laser beam 1 condensed by the condenser lens 2. At the same time, the laser beam 1 or the workpiece 9 is moved along the cutting path. The irradiation power of the laser beam 1 at this time is preferably such that an output capable of instantaneously burning and removing the workpiece 9 is input in a short time in order to suppress carbonization of the workpiece 9. In addition, in order to complete the penetration of the machining start hole 6 in a short time, the workpiece 9 is removed to a depth of about 被 of the plate thickness 4 of the workpiece 9 by the first irradiation of the laser beam 1. According to the experiments by the inventors, a preferable treatment was possible if the workpiece 9 was removed to a depth of about １ ／ to ／ of the thickness 4 of the workpiece 9 by the first irradiation of the laser beam 1. Further, the irradiation power of the laser beam 1 can be easily controlled, and cutting and removal can be performed with high efficiency. By this cutting operation, a cut removal area 8 is formed in the workpiece 9 shown in FIG.

In this embodiment, the main power supply circuit 32
In order to improve the responsivity, the irradiation power of the laser beam 1 is controlled by current control such as PWM in the main control circuit 31, and the power is quickly shifted to a predetermined power by pulse oscillation. Thereafter, the laser beam 1 is moved along the cutting path in a state where the laser beam 1 is cut off, returns to the machining start hole 6 at the machining start point A previously drilled, and receives the laser beam 1 collected by the condenser lens 2 again. The laser beam 1 or the workpiece 9 is moved along the cutting path while irradiating the surface of the workpiece 9. These operations are performed a plurality of times in the vicinity of the processing start point A, and the cut removal area 8 gradually advances to the bottom of the workpiece 9, and finally the processing start hole 6 is formed.

At this time, the second and subsequent laser beams 1
Is set to a lower irradiation power than that of the first irradiation, and the processing start hole 6 of the workpiece 9 having a reduced heat capacity is set.
Is irradiated on the remaining portion 5. The depth to be dug down by the irradiation of the laser beam 1 from the second time on is to prevent the combustion of the work material 9 due to heat conduction from progressing. Remaining part 5 of 1
It is preferable to remove with an irradiation power that leaves about / 2.
By such a repetitive operation, the machining start hole 6 is penetrated without the occurrence of an uncut portion due to insufficient heat input or an abnormal spread at the bottom of the machining start hole 6 due to excessive heat input.
After the machining start hole 6 is formed, the beam focusing point 3 moves by an arbitrary predetermined amount with reference to the surface of the workpiece 9. At this time, the beam focusing point 3 can be moved to a predetermined position while being displaced upward or downward.

This control is controlled by the main control circuit 31 as shown in FIG. FIG. 4 is a flowchart for performing program control for drilling a machining start hole of the laser beam machine according to one embodiment of the present invention. The program for drilling the machining start hole is called during the processing of the main routine, and the cutting and removing operation is continuously performed. First, in step S1, the material and thickness of the workpiece 9 stored in the memory in advance are displayed on the display 34, and the material and thickness of the workpiece 9 are selected from the keyboard 34 and set there. In step S2, the cutting path is input using the keyboard 33. Based on the material and thickness of the workpiece 9 selected in step S3, the initial irradiation power of the laser beam 1 is selected according to a table already stored in the memory. The initial irradiation power is controlled by the work material 9 to suppress carbonization of the work material 9.
In order to make an output capable of instantaneously burning and removing the crushed gas in a short time, and to complete the penetration of the machining start hole 6 in a short time,
By the first irradiation of the laser beam 1, the thickness 4 of the workpiece 9
The duty ratio is the peak current value of the ability to remove to a depth of about ３ to ／. The moving distance L is calculated from the route input in step S4. That is, in this embodiment, since the cutting groove is formed instead of the machining start hole 6, the cutting groove is made to match the cutting direction in advance. In step S5, the counter N for counting the number of repetitions is cleared. In step S6, it is determined whether a key operation for starting processing is performed, and the process stops in step S6 until the key operation for starting processing is performed.

If it is determined in step S6 that a key operation for starting processing has been performed, the processing is started at a processing start point A with an initial irradiation power of 100% irradiation power of the laser beam 1 in step S7. Is determined, the completion of the movement of the movement distance L is determined in step S9, and the routine from step S7 to step S9 is repeatedly executed until the completion of the movement of the movement distance L is determined in step S9.
When the completion of the movement of the movement distance L is determined in step S9,
In step S10, the initial irradiation of the laser beam 1 is stopped, and in step S11, the processing is returned from the moving distance L to the processing start point A. In step S12, it is determined whether the process has returned to the processing start point A, and the routine from step S10 to step S12 is repeatedly executed until it is determined in step S12 that the process has returned to the processing start point A.

When it is determined in step S12 that the processing has returned to the processing start point A, the irradiation power for the second and subsequent irradiations is applied as the laser beam 1 in step S13. This irradiation power is set lower than that of the first irradiation. In particular, the second laser beam 1 remains in the first irradiation of the laser beam 1 so that the burning of the workpiece 9 by heat conduction does not progress. The irradiation power is set to such an extent that half of the remaining portion 5 of the workpiece 9 is left. That is, the duty ratio of the peak current value of the ability to remove the remaining portion 5 of the plate thickness 4 of the workpiece 9 to a depth of about １ ／ by the first irradiation of the laser beam 1 is used. In step S14, the counter N for counting the number of repetitions is incremented. In step S15, it is determined whether the counter N for counting the number of repetitions is "3", and the steps from step S10 are repeated until the counter N is determined to be "3". The routine of S15 is repeatedly executed. When the counter N is determined to be “3”, the machining start hole 6 is formed through. After the processing start hole 6 is formed through, the beam focusing point 3
Moves by an arbitrary predetermined amount based on the surface of the workpiece 9. At this time, the initial irradiation power of the laser beam 1 is increased to a predetermined value at an irradiation power of 100%. Alternatively, it moves along a predetermined cutting path while displacing the beam focusing point 3 upward or downward.

As described above, as shown in FIG. 3, when the work for drilling the processing start hole 6 at the processing start point A is performed, the laser beam 1 condensed by the condenser lens 2 is applied to the surface of the workpiece 9. At the same time, the laser beam 1 or the workpiece 9 is moved along the cutting path. The irradiation power of the laser beam 1 at this time is preferably such that an output capable of instantaneously burning and removing the workpiece 9 is input in a short time in order to suppress carbonization of the workpiece 9. In addition, in order to complete the penetration of the processing start hole 6 in a short time, it is preferable to remove the workpiece 9 to a depth of about 〜 to の of the thickness 4 of the workpiece 9 by the first irradiation of the laser beam 1. . Of course, it is also possible to make the value smaller or larger than the above value. By this cutting operation, a cut removal area 8 is formed in the workpiece 9 shown in FIG. Thereafter, the laser beam 1 is moved along the cutting path in a state where the laser beam 1 is cut off, returns to the machining start hole 6 at the machining start point A previously drilled, and receives the laser beam 1 collected by the condenser lens 2 again. The laser beam 1 or the workpiece 9 is moved along the cutting path while irradiating the surface of the workpiece 9. At this time, the beam focusing point 3 can be moved by an arbitrary predetermined amount based on the surface of the workpiece 9 to form a predetermined cutting groove. These operations are performed at the processing start point A
Is performed a plurality of times in the vicinity of, and the cutting removal area 8 is gradually advanced to the bottom of the workpiece 9, and finally the processing start hole 6 is formed. The irradiation power of the laser beam 1 in the second and subsequent times is set to one of the remaining portions 5 of the workpiece 9 remaining in the first or previous irradiation of the laser beam 1 so that the combustion of the workpiece 9 due to heat conduction does not progress. It is preferable to remove with an irradiation power that leaves about / 2. By such a repetitive operation, the machining start hole 6 is penetrated without the occurrence of an uncut portion due to insufficient heat input or an abnormal spread at the bottom of the machining start hole 6 due to excessive heat input.

After cutting in this manner, for example, a cutting tool or the like is inserted into the formed groove in the cut removal area 8 and used as a simple punching die. At this time, the constraint force of the insert changes greatly depending on the groove shape. Next, the groove shape of the cut removal area 8 will be described. FIG. 5 is a schematic view showing a cross section when a laser beam is focused on a surface of a workpiece by a laser processing method according to an embodiment of the present invention;
FIG. 6 is a schematic view showing a cross section when a laser beam is focused on the surface of a workpiece by a laser processing method according to an embodiment of the present invention, and FIG. 7 is a laser according to an embodiment of the present invention. It is a schematic diagram which shows the cutting cross section when the focal point of the laser beam by the processing method is below the surface of the workpiece. In the case of the laser cutting, the grooves are roughly classified into three patterns as shown in FIG. 5, FIG. 6, and FIG. In order to form the groove shape of the cut section shown in FIG. 5, the beam focusing point 3 is set on the surface of the workpiece 9. In order to form the groove shape shown in FIG. 6, the beam focusing point 3 is set above the surface of the workpiece 9. Then, in order to form the groove shape of FIG. 7, the beam focusing point 3 is set below the surface of the workpiece 9. For example, when a cutting tool or the like is inserted into a cutting groove and used as a simple punching die, an appropriate groove shape is narrow on the surface of the workpiece 9,
It is preferable that the cross-section hollow portion shown in FIG. 5, which expands at the center portion of the plate thickness 4 and narrows again at the back surface of the workpiece 9, has a substantially drum shape. That is, it becomes easy to insert a blade into the narrowed surface of the workpiece 9 and use the blade as a fulcrum to separate the blade. In order to obtain a desired cross section as such a groove shape,
After the penetration of the machining start hole 6, the process proceeds to the cutting process, and the focal point 3 of the laser beam 1 is moved up and down with respect to an appropriate position, for example, the surface of the workpiece 9 or the workpiece 9 is moved.
By moving along a plane at a predetermined position from the surface of the substrate, cutting and removing are performed.

As described above, the laser processing apparatus according to the present embodiment converts the work material 9 which is easily combustible like a combustible material into
In a laser processing apparatus that processes a laser beam 1 using a heat source condensed to a high energy density, a predetermined distance L from a processing start point A along a processing path near a processing start point A of a workpiece 9. Is reciprocated a plurality of times along the machining path, and the machining start hole 6 is moved.
After cutting through the workpiece 9, the process moves to the next cutting operation and cuts.
, The laser beam 1 moved a predetermined distance L from the processing start point A along the processing path is repeatedly reciprocated several times along the processing path to penetrate the processing start hole 6, It is also possible to adopt a laser processing method in which a transition is made to the next cutting operation and cutting is performed.

That is, in the above-described embodiment, in the first irradiation of the laser beam 1, the carbonization of the workpiece 9 is prevented, and the irradiation power capable of instantaneously burning and removing the workpiece 9 is applied in a short time. Power is executed by current control, and
By the first irradiation of the laser beam 1, at least the workpiece 9
The laser irradiation power for the second and subsequent times is set lower than that of the previous irradiation, and the processing start point A of the work material 9 having a reduced heat capacity remains. The irradiation power is controlled so that the portion 5 is dug down without giving excessive heat input. But,
In practicing the present invention, the reciprocating operation is repeated a plurality of times along the machining path with uniform irradiation power so that the drilling operation at the machining start point A is completed a plurality of times in advance. It can also penetrate. Therefore, even in the case of cutting the workpiece 9 which is easily combustible such as a combustible material, the drilling operation at the processing start point A is executed by one irradiation of the laser beam 1 as in the conventional laser processing method. However, since the drilling operation is performed at the processing start point A by irradiating the laser beam 1 a plurality of times, the processing of cutting with a good cross section can be performed without occurrence of processing defects due to insufficient heat input or excessive heat input.

The laser processing apparatus according to the present embodiment
After penetrating the processing start hole 6, the laser beam 1 is irradiated by displacing the focusing point 3 of the laser beam 1 upward or downward by an arbitrary predetermined amount with respect to the surface of the workpiece 9;
The cutting groove of the workpiece 9 is controlled to have a desired shape. After the groove is made to penetrate the processing start hole 6, the laser beam 1 is arbitrarily applied to the surface of the workpiece 9 by an arbitrary predetermined amount. A laser processing method in which the focusing point 3 is displaced upward or downward to irradiate the laser beam 1 and the cut groove of the workpiece 9 is controlled to a desired shape can be provided. Accordingly, a desired cross-sectional shape of the cut groove is obtained, and cutting and removing according to the cutting form of the work material 9 that is easily combustible like a combustible material can be performed.

In the laser processing apparatus of the present embodiment, the reciprocating multiple reciprocating operations performed along the processing path changes the irradiation power of the laser beam 1 from the first time to the second and subsequent times. This can be a laser processing method. That is, in the irradiation of the laser beam 1 a plurality of times, the irradiation power of the first and second and subsequent irradiations is changed. For example, in the first irradiation of the laser beam 1, the workpiece 9 is prevented from being carbonized. In order to supply irradiation power capable of instantaneously burning and removing the irradiation power in a short period of time, the irradiation power is executed by current control such as PW, and the transition to a predetermined irradiation power is promptly performed. In order to complete the penetration in a short time, the first irradiation of the laser beam 1 removes the workpiece 9 at least to a depth of about ９ of the thickness of the workpiece 9, and the second and subsequent laser irradiation powers are used for the previous irradiation. The irradiation power is controlled such that the power is set lower than that of the workpiece 9 and the remaining portion 5 of the processing start point A of the work material 9 having a reduced heat capacity is dug down without giving excessive heat input. More efficient Good cutting is possible.

Further, the laser processing apparatus of the present embodiment
The reciprocating multiple reciprocating operations performed along the processing path is performed by using the irradiation power of the first laser beam 1 at 初 回 of the plate thickness of the workpiece.
The laser beam is removed to a depth of about 2/3, and the irradiation power of the second and subsequent laser beams 1 is set lower than the irradiation power of the first time to remove the remaining portion. It can also be. Therefore, in the first irradiation of the laser beam 1, the irradiation power is set to P in order to quickly apply irradiation power capable of instantaneously burning and removing the work 9 in order to prevent carbonization of the work 9.
In order to quickly execute the transition to the predetermined irradiation power and complete the penetration of the machining start hole 6 in a short time, at least the irradiation with the first laser beam 1 is performed. The workpiece 9 having a reduced heat capacity is removed by removing the workpiece material 9 to a depth of about １ ／ to ／ of the plate thickness and setting the second and subsequent laser irradiation powers lower than the previous irradiation. The irradiation power is controlled so that the remaining portion 5 of the processing start point A is dug down without giving excessive heat input, and more excellent cutting can be performed.

Further, in the laser processing apparatus of the present embodiment, the irradiation power of the first laser beam 1 and the irradiation power of the second and subsequent laser beams in the reciprocating reciprocating operation performed a plurality of times along the processing path are: The response is determined by the pulse oscillation control, and the response can improve the followability even when moving at high speed.

In this embodiment, the case where the irradiation power of the first laser beam 1 and the irradiation power of the second and subsequent laser beams 1 are changed has been described. However, the present invention can also be realized by changing the cutting movement speed. it can. However, changing the irradiation power of the laser beam 1 described in the present embodiment is easier and more efficient in control. Also,
In the present embodiment, after the first irradiation of the laser beam 1,
Although the second and subsequent irradiations of the laser beam 1 at the processing start point A are performed in a state where the emission of the laser beam 1 is turned off, when the present invention is implemented, the irradiation is gradually performed in the state of continuous irradiation. It can be performed while reducing the power, and can be returned at an extremely low irradiation power. In the present embodiment, after the first irradiation of the laser beam 1, the irradiation of the laser beam 1 for the second and subsequent times at the processing start point A is the same irradiation distance L. However, when the present invention is implemented, However, the moving distance can be gradually narrowed or conversely widened.

[0035]

As described above, the laser processing method according to the first aspect is intended for processing a work material which is easily combustible, such as a flammable material, using a heat source which focuses a laser beam at a high energy density. Near the processing start point of the workpiece,
The laser beam moved a predetermined distance along the processing path from the processing start point is repeatedly reciprocated a plurality of times along the processing path, and after penetrating the processing start hole, the process proceeds to the next cutting processing operation. Is what you do. Therefore, even in the case of cutting a combustible material such as a combustible material, a drilling operation at a processing start point is not performed by one laser beam irradiation as in the conventional laser processing method, but a plurality of cutting operations are performed. Since the drilling work is performed at the processing start point by performing the laser beam irradiation twice, there is no occurrence of a processing defect due to insufficient heat input or excessive heat input, and a cutting process with a good cut cross section can be performed.

According to a second aspect of the present invention, in the laser processing method, after passing through the processing start hole according to the first aspect, the laser beam converging point is shifted upward or downward by an arbitrary predetermined amount with respect to the surface of the workpiece. Displace it down and irradiate it with a laser beam,
The cutting groove of the workpiece is controlled to have a desired shape. In addition to the effect of claim 1, a desired cutting groove cross-sectional shape is obtained, and the cutting groove is easily combustible like a combustible material. The cutting material can be cut and removed according to the cutting form.

According to a third aspect of the present invention, in the laser processing method, the reciprocating operation performed a plurality of times along the processing path according to the first or second aspect is performed by changing the irradiation power of the laser beam for the first time and the second and subsequent times. In addition to the effects described in claim 1 or claim 2, the irradiation power of the first and second and subsequent irradiations is changed in a plurality of laser beam irradiations, and the irradiation power is changed in the first irradiation of the laser beam. In order to prevent carbonization of the work material, the irradiation power capable of instantaneously burning and removing the work material is applied in a short time, and the laser irradiation power for the second and subsequent times is set lower than the previous irradiation to reduce the heat capacity. The remaining portion at the processing start point of the processed workpiece is dug down without giving excessive heat input, so that more efficient cutting with a good cross section can be performed.

According to a fourth aspect of the present invention, there is provided a laser processing method, wherein the reciprocating plural times reciprocating operation performed along the processing path according to any one of the first to third aspects is performed by the irradiation power of the first laser beam. After removing to a depth of about 1/3 to 2/3 of the plate thickness of the work material, the remaining portion is removed by setting the irradiation power of the second and subsequent laser beams lower than the first irradiation power. In addition to the effects described in any one of claims 1 to 3, the work material can be instantaneously burned and removed in the first laser beam irradiation to prevent carbonization of the work material. In order to quickly switch to the prescribed irradiation power by applying a short irradiation power in a short time, and to complete the penetration of the machining start hole in a short time, at least 1/3 to 2 / of the thickness of the material The laser irradiation power for the second and subsequent times is set lower than that of the previous irradiation, and the remaining part at the processing start point of the work material having a reduced heat capacity is not given excessive heat input. The irradiation power is controlled in such a way as to dig deeper, so that the cutting with a better cross section can be performed.

According to a fifth aspect of the present invention, there is provided a laser processing apparatus for processing a work material which is easily combustible, such as a combustible material, using a heat source which focuses a laser beam at a high energy density. In the vicinity of the start point, the laser beam moved a predetermined distance along the processing path from the processing start point, repeatedly reciprocating multiple times along the processing path,
After penetrating the machining start hole, the process moves to the next cutting operation and cuts. Therefore, even in the case of cutting a combustible material such as a combustible material, a drilling operation at a processing start point is not performed by one laser beam irradiation as in the conventional laser processing method, but a plurality of cutting operations are performed. Since the drilling work is performed at the processing start point by performing the laser beam irradiation twice, there is no occurrence of a processing defect due to insufficient heat input or excessive heat input, and a cutting process with a good cut cross section can be performed.

According to a sixth aspect of the present invention, in the laser processing apparatus, after passing through the processing start hole according to the fifth aspect, the laser beam condensing point is shifted upward or downward by an arbitrary predetermined amount with respect to the surface of the workpiece. Displace it down and irradiate it with a laser beam,
Since the cut groove of the workpiece is controlled to a desired shape, in addition to the effect of claim 5, a desired cut groove cross-sectional shape is obtained, and it is easy to burn like a combustible material. Cutting and removing can be performed according to the cutting form of the workpiece.

According to a seventh aspect of the present invention, in the laser processing apparatus according to the fifth or sixth aspect, the reciprocating operation performed a plurality of times along the processing path changes the irradiation power of the laser beam for the first time and the second and subsequent times. Therefore, in addition to the effects of claim 5 or claim 6, the irradiation power of the first and second and subsequent irradiations is changed in a plurality of irradiations of the laser beam, and in the first irradiation of the laser beam, the workpiece is processed. In order to prevent carbonization of the material, the irradiation power that can instantaneously burn and remove the work material is applied in a short time, and the laser irradiation power for the second and subsequent times is made lower than the previous irradiation to reduce the heat capacity. The remaining portion at the processing start point of the processed material is dug down without giving excessive heat input, thereby enabling more efficient cutting with a better cut cross section.

In the laser processing apparatus according to the present invention, the reciprocating plural times reciprocating operation performed along the processing path according to any one of claims 5 to 7 is performed by the irradiation power of the first laser beam. The removal is performed to a depth of about 1/3 to 2/3 of the thickness of the work material, and the remaining portion is removed by setting the irradiation power of the second and subsequent laser beams lower than the first irradiation power. Therefore, in addition to any one of claims 5 to 7, in order to prevent carbonization of the workpiece in the first laser beam irradiation, the irradiation power capable of instantaneously burning and removing the workpiece is set. In a short time, the transition to the predetermined irradiation power is performed promptly, and in order to complete the penetration of the processing start hole in a short time, at least the thickness of the workpiece is reduced by the first laser beam irradiation. 1/3 to 2/3 of the depth The second and subsequent laser irradiation powers are set lower than those of the previous irradiation, and the remaining part of the processing start point of the work material having a reduced heat capacity is dug down without giving excessive heat input. In this way, the irradiation power is controlled in such a manner that the cutting section can be cut more favorably.

According to a ninth aspect of the present invention, there is provided the laser processing apparatus according to any one of the fifth to eighth aspects, wherein the irradiation power of the first laser beam and the second laser beam irradiation power in the reciprocating plural times reciprocating operation performed along the processing path Since the irradiation power of the laser beam after the first time is determined by the pulse oscillation control, high-speed movement is performed by the responsiveness in addition to the effect according to any one of claims 5 to 8. Even so, the followability can be improved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a laser processing machine according to an embodiment of the present invention.

FIG. 2 is a control circuit diagram of a control system for controlling a laser beam of the laser beam machine according to one embodiment of the present invention.

FIG. 3 is a schematic view showing a cut section at a processing start point of a laser processing method according to an embodiment of the present invention.

FIG. 4 is a flowchart for performing a program control for drilling a machining start hole of the laser beam machine according to the embodiment of the present invention.

FIG. 5 is a schematic view showing a cut section when a laser beam is focused on a surface of a workpiece by a laser processing method according to an embodiment of the present invention.

FIG. 6 is a schematic view showing a cross section when a laser beam is focused on an upper surface of a workpiece by a laser processing method according to an embodiment of the present invention.

FIG. 7 is a schematic view showing a cut cross section when a laser beam is focused on a lower portion of the surface of a workpiece by a laser processing method according to an embodiment of the present invention.

FIG. 8 is an explanatory view of a conventional laser processing method for performing cutting processing of a workpiece due to insufficient heat input by laser processing;
(A) is a sectional view, and (b) is a bottom view.

FIG. 9 is an explanatory view of a conventional laser processing method for cutting a workpiece by excessive heat input by laser processing;
(A) is a sectional view, and (b) is a bottom view.

[Explanation of symbols]

1 laser beam, 2 condenser lens, 3 focal point, 4 plate thickness, 5 remaining part, 6 processing start hole, 7 laser beam moving direction, 8 cutting removal area, 9 work material.

Claims (9)

[Claims] 1. A laser processing method for processing a workpiece such as a combustible material that is easily combustible by using a heat source that focuses a laser beam at a high energy density, in the vicinity of a processing start point of the workpiece. In, the laser beam moved a predetermined distance along the processing path from the processing start point, repeatedly reciprocating multiple times along the processing path,
A laser processing method characterized by shifting to the next cutting operation after penetrating the processing start hole. 2. After passing through the machining start hole,
A laser beam is irradiated by displacing a laser beam focusing point upward or downward by an arbitrary predetermined amount with respect to a surface of a workpiece, and a cutting groove of the workpiece is formed in a desired shape. The laser processing method according to claim 1. 3. The laser according to claim 1, wherein the reciprocating operation performed a plurality of times along the processing path changes the irradiation power of the laser beam for the first time and the second and subsequent times. Processing method. 4. The method according to claim 1, wherein the reciprocating operation performed a plurality of times along the processing path includes removing the workpiece to a depth of about 1/3 to 2/3 of the thickness of the workpiece by the irradiation power of the first laser beam. 4. The laser processing method according to claim 1, wherein the remaining portion is removed by setting the irradiation power of the laser beam after the first irradiation to be lower than the irradiation power of the first time. 5. 5. A laser processing apparatus for processing a work material, such as a combustible material, which is easily combustible by using a heat source that focuses a laser beam at a high energy density, in the vicinity of a processing start point of the work material. In, the laser beam moved a predetermined distance along the processing path from the processing start point, repeatedly reciprocating multiple times along the processing path,
A laser processing apparatus characterized in that after a processing start hole is penetrated, a transition is made to a next cutting processing operation and cutting is performed. 6. Further, after penetrating the machining start hole,
A laser beam is irradiated by displacing a laser beam focusing point upward or downward by an arbitrary predetermined amount with respect to a surface of a workpiece, and a cutting groove of the workpiece is formed in a desired shape. The laser processing apparatus according to claim 5, wherein 7. The laser according to claim 5, wherein the reciprocating operation performed a plurality of times along the machining path changes the irradiation power of the laser beam for the first time and the second and subsequent times. Processing equipment. 8. The reciprocating plural times reciprocating operation performed along the processing path includes removing the workpiece to a depth of about １ ／ to ／ of the plate thickness of the workpiece by the irradiation power of the first laser beam, The laser processing apparatus according to any one of claims 5 to 7, wherein the remaining portion is removed by setting the irradiation power of the laser beam after the first irradiation to be lower than the irradiation power of the first time. 9. The irradiation power of the first laser beam and the irradiation power of the second and subsequent laser beams in the reciprocating plural reciprocating operations performed along the machining path are determined by pulse oscillation control. The laser processing apparatus according to any one of claims 5 to 8.