JP6393555B2 - Laser processing machine and laser cutting processing method - Google Patents

Description

  The present invention relates to a laser processing machine and a laser cutting processing method for cutting a workpiece using energy of laser light emitted from an output end of a transmission fiber.

  In recent years, the development of cutting technology using the energy of laser light emitted from a transmission fiber has become active, and the cutting technology will be briefly described as follows.

  That is, laser light emitted from the exit end of the transmission fiber is converted into parallel light by a collimator lens, condensed by a condensing lens, and irradiated toward a cut portion of the workpiece. Further, simultaneously with the laser light irradiation, the assist gas is jetted toward the work to be cut. Thereby, it is possible to cut the workpiece while melting the portion to be cut of the workpiece and removing the melt using the energy of the laser beam. A series of cutting processes can be performed on a plurality of workpieces by continuously repeating the above-described operation. The collimating lens and the condensing lens are provided in a processing head in the laser processing machine.

  Here, the processing forms can be divided into non-oxidizing processing (inert gas processing) using an inert gas such as nitrogen as the assist gas and oxygen processing using oxygen as the assist gas. Non-oxidation processing can melt the workpiece only by the energy of the laser beam and prevent oxidation of the cut surface of the workpiece. The thickness of stainless steel, copper, copper alloy, aluminum, aluminum alloy, mild steel, etc., for example, 3 mm or less Suitable for high-speed cutting of workpieces made of thin plates. Oxygen processing can melt a workpiece by oxidation reaction heat in addition to laser beam energy, and is suitable for cutting a workpiece made of a thick plate of mild steel having a thickness of, for example, 6 mm or more. In addition, a general-purpose condenser lens is used for non-oxidation processing, whereas in the case of oxygen processing, a ring-shaped laser beam (ring beam) can be formed to prevent burning (abnormal combustion). A special condensing lens incorporating a special axicon lens is used (see Patent Document 1 and Patent Document 2).

  In addition to Patent Literature 1 and Patent Literature 2, there are those shown in Patent Literature 3 as prior art related to the present invention.

JP 2013-75331 A WO2010 / 095744 A1 JP 2000-227576 A

  By the way, during a series of cutting processes, the processing form may be changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing by changing the material and thickness of the workpiece. In such a case, it is necessary to replace the laser processing machine, for example, by temporarily cutting the cutting process and changing from a general-purpose condenser lens to a special condenser lens. For this reason, there is a problem that the work of the cutting process becomes complicated, the work efficiency is lowered, the interruption time of the cutting process becomes long, and the productivity of the cutting process cannot be sufficiently increased.

  Therefore, an object of the present invention is to provide a laser processing machine and a laser processing method having a novel configuration that can solve the above-described problems.

  The inventor of the present invention, as a result of repeated trial and error in order to solve the above-mentioned problems, has changed the outer layer portion of the laser light by the aperture provided in the middle of the optical path between the output end of the transmission fiber and the collimating lens. By cutting off under an appropriate cutting rate (blocking rate), even if a special condensing lens incorporating an axicon lens is not used, for workpieces made of mild steel with a thickness of 6 mm or more, for example. A novel finding that oxygen processing can be performed while preventing burning has been obtained, and the present invention has been completed (see Examples described later). This is considered to be because the outer layer portion of the laser beam, in other words, the low energy portion that does not contribute to melting (cutting) in the laser beam is sufficiently suppressed from being irradiated to the cut portion of the workpiece. Here, the appropriate cut rate by the aperture means 2% or more.

  The first feature of the present invention is that a laser beam machine that cuts a workpiece using the energy of the laser beam emitted from the exit end of the transmission fiber can irradiate the tip side with the laser beam and assists it. A cylindrical laser processing head (laser processing head main body) having a nozzle capable of ejecting gas, connected to the output end of the transmission fiber, and internally connected to an assist gas supply source, and inside the laser processing head A collimating lens that converts laser light emitted from the exit end of the transmission fiber into parallel light, and is provided between the collimating lens and the nozzle in the laser processing head and converted into parallel light. A condensing lens for condensing laser light, and an optical axis direction between the output end of the transmission fiber and the collimating lens in the laser processing head The outer layer portion of the laser light emitted from the emission end of the transmission fiber (the portion located on the outer peripheral side) is provided so that its position can be adjusted (movable) in the direction and has a circular opening for transmitting the laser light. ), An actuator for adjusting the position of the aperture in the direction of the optical axis, and a laser beam cut rate by the aperture (cut rate of the aperture) is a cut rate according to processing conditions. Thus, the gist is provided with an actuator control means for controlling the actuator. More specifically, the actuator control means has a laser beam cut rate of 2% or more (preferably 2) when the processing form as the processing condition is oxygen processing using oxygen as an assist gas. % To 20%), and when the processing mode is non-oxidation processing using an inert gas as an assist gas, the laser beam cut rate by the aperture is 8% or less. Thus, the actuator is controlled.

  Here, in the specification and claims of the present application, “provided” means not only directly provided but also indirectly provided via another member. The “cutting rate of laser light by the aperture” refers to the ratio of the power intensity of the laser light blocked (cut) by the aperture to the power intensity of the laser light emitted from the exit end of the transmission fiber. Furthermore, the “processing conditions” means the material of the workpiece, the thickness of the workpiece, the processing mode (oxygen processing or non-oxidizing processing), the processing speed, and the like.

  According to the first feature of the present invention, when the processing form is oxygen processing, the actuator is controlled so that the laser beam cut rate by the aperture is 2% or more. When applied, it is possible to perform cutting by oxygen processing while preventing burning of a workpiece made of a thick steel plate having a thickness of, for example, 6 mm or more, without using a special condenser lens. In addition, when the processing form is non-oxidation processing, the actuator is controlled so that the laser beam cut rate by the aperture is 8% or less. It is possible to reduce the reflected light while securing the cutting speed during the non-oxidation processing at a high speed. Thereby, the processing form can be changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing only by adjusting the position of the aperture in the optical axis direction during a series of cutting processes.

  The second feature of the present invention is that the laser light emitted from the exit end of the transmission fiber is converted into parallel light by a collimator lens, condensed by a condenser lens, and irradiated toward the cut portion of the workpiece. By injecting an assist gas toward the workpiece to be cut, the energy of the laser beam is used to melt the workpiece to be cut and remove the melt while cutting the workpiece. In the laser cutting processing method, a circular opening is provided between the emission end of the transmission fiber and the collimating lens so that the position can be adjusted (movable) in the optical axis direction and the laser beam is transmitted. An aperture that cuts off (cuts off) the outer layer portion (portion located on the outer peripheral side) of the laser beam emitted from the emission end of the transmission fiber is used. Adjust position to direction, it is summarized in that to set the cut rate of the aperture by the laser beam cut rate corresponding to machining conditions (cut rate of the aperture). Specifically, when the processing mode in the processing conditions is oxygen processing using oxygen as an assist gas, the aperture is adjusted in the optical axis direction, and the laser beam cut rate by the aperture is adjusted. Is set to 2% or more (preferably 2 to 20%), and when the processing form in the processing conditions is non-oxidation processing using an inert gas as an assist gas, the aperture is moved in the optical axis direction. By adjusting the position, the cut rate of the laser beam by the aperture is set to 8% or less.

  According to the second feature of the present invention, when the processing form is oxygen processing, the position of the aperture is adjusted in the direction of the optical axis, and the cut rate of the laser light by the aperture is set to 2% or more, By applying the above-described novel knowledge, it is possible to perform cutting by oxygen processing while preventing burning on a workpiece made of a thick steel plate having a thickness of 6 mm or more without using a special condensing lens. . In addition, when the processing form is non-oxidation processing, the position of the aperture is adjusted in the optical axis direction, and the laser beam cut rate by the aperture is set to 8% or less. Therefore, it is possible to reduce the reflected light while maintaining a sufficient cutting speed during the non-oxidation processing. Thereby, the processing form can be changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing only by adjusting the position of the aperture in the optical axis direction during a series of cutting processes.

  According to the present invention, the processing mode can be changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing by simply adjusting the position of the aperture in the optical axis direction during a series of cutting processes. Therefore, it is possible to suppress the complication of the cutting process, improve the work efficiency, shorten the interruption time of the cutting process as much as possible, and sufficiently increase the productivity of the cutting process.

FIG. 1 is a schematic diagram of a laser beam machine according to an embodiment of the present invention. FIG. 2 is a control block diagram showing a control unit according to the embodiment of the present invention. FIG. 3 is a diagram for explaining a table showing the relationship between the processing conditions and the aperture cut rate (the laser beam cut rate by the aperture). FIG. 4 is a diagram showing the relationship between the distance from the output end of the transmission fiber to the aperture and the power transmittance of the laser beam that passes through the aperture of the aperture. FIG. 5A is a diagram for explaining a laser cutting method according to an embodiment of the present invention. As a processing condition, the workpiece is made of a thick steel plate having a thickness of, for example, 6 mm or more, and the processing form is oxygen processing. FIG. 5B shows a distribution of power intensity of laser light emitted from the aperture. FIG. 6A is a diagram for explaining a laser cutting processing method according to an embodiment of the present invention. As a processing condition, the workpiece is made of a thin plate having a thickness of a highly reflective material, for example, 3 mm or less, and the processing form is non-oxidized. FIG. 6B shows a distribution of power intensity of laser light emitted from the aperture. FIG. 7A is a diagram for explaining a laser cutting processing method according to an embodiment of the present invention. As a processing condition, the workpiece is made of a thin plate having a thickness of a material other than a highly reflective material, for example, 3 mm or less, and a processing mode. FIG. 7B shows a distribution of power intensity of laser light emitted from the aperture. In addition, FIG. 8 (a) is a table showing the relationship between the aperture cut rate and the presence or absence of burning when oxygen processing is performed on a workpiece made of mild steel, and FIG. 8 (b) shows the transmission fiber. It is a figure which shows the relationship between the distance from an output end to an aperture, and the reflection level of reflected light.

  An embodiment of the present invention will be described with reference to FIGS.

  Hereinafter, the configuration of the fiber laser processing machine according to the embodiment of the present invention, the laser cutting processing method according to the embodiment of the present invention, and the like will be sequentially described with reference to the drawings.

  As shown in FIG. 1, a fiber laser processing machine (an example of a laser processing machine) 1 according to an embodiment of the present invention uses a laser beam LB emitted from an emission end 3e of a transmission fiber (process fiber) 3. , An apparatus for cutting the workpiece W. Here, the transmission fiber 3 transmits the laser light L having a wavelength of 1 μm band oscillated from the fiber laser oscillator 5.

  The fiber laser processing machine 1 includes a processing table (support frame) 7 that supports the workpiece W by point contact, and the processing table 7 includes a fixture (not shown) that fixes the workpiece W. Further, a cylindrical (hollow) laser processing head (laser processing head main body) 9 is provided above the processing table 7 via a movable frame (not shown) and the like. A nozzle 11 capable of irradiating the laser beam LB and ejecting the assist gas is provided on the front end side (lower end side). The laser processing head 9 is movable relative to the processing table 7 in the X-axis direction, the Y-axis direction, and the Z-axis direction (vertical direction) via a movable frame or the like. The base end (upper end) of the laser processing head 9 is connected to the output end 3 e of the transmission fiber 3. Further, the inside of the laser processing head 9 can be connected to a gas cylinder 15 as an assist gas supply source via a gas supply pipe 13 or the like. The gas cylinder 15 can be appropriately replaced according to the processing form.

  A collimating lens 17 is provided in the laser processing head 9 via an upper lens holder 19, and the collimating lens 17 converts the laser light LB emitted from the emission end 3 e of the transmission fiber 3 into parallel light. Is. Further, the position of the collimating lens 17 in the optical axis direction (Z-axis direction) is set so that the focal position of the collimating lens 17 coincides with the position of the emission end 3 e of the transmission fiber 3. And the condensing lens 21 is provided between the collimating lens 17 and the nozzle 11 in the laser processing head 9 via the lower lens holder 23, and this condensing lens 21 was converted into parallel light. The laser beam LB is condensed.

  An aperture 25 is provided between the exit end 3e of the transmission fiber 3 and the collimating lens 17 in the laser processing head 9 so as to be adjustable (movable) in the optical axis direction (Z-axis direction). Is for blocking (cutting) the outer layer portion (portion located on the outer peripheral side) LBo of the laser beam LB emitted from the emission end 3 e of the transmission fiber 3. The aperture 25 is made of a material having high thermal conductivity and has a circular opening 27 for transmitting the laser beam LB. The material having high thermal conductivity refers to, for example, aluminum, aluminum alloy, copper, or copper alloy.

  A servo motor (actuator) 29 for adjusting the position of the aperture 25 in the optical axis direction is provided at an appropriate position of the laser processing head 9. A ball screw 31 extending in the optical axis direction is interlocked with an output shaft (not shown) of the servo motor 29, and a nut member 33 screwed to the ball screw 31 is provided in the aperture 25.

  Here, the distance (length in the optical axis direction) S from the exit end 3e of the transmission fiber 3 to the aperture 25 and the power transmittance of the laser beam LB that passes through the opening 27 of the aperture 25 (the opening 27 of the aperture 25). The relationship with the power transmittance of the laser beam LB is as shown in FIG. The cut rate (cutoff rate) of the laser beam LB by the aperture 25 is a value obtained by subtracting the power transmittance of the laser beam LB from the opening 27 of the aperture 25 from 100%.

  As shown in FIG. 2, the fiber laser processing machine 1 includes a control device 35 that controls the fiber laser oscillator 5 and the servo motor 29 based on a processing program, and is connected to the control device 35 and processing conditions (work W And an input unit 37 for inputting a material, a thickness of the workpiece W, a processing form, a processing speed, and the like. The control device 35 includes a memory that stores a machining program and the like, and a CPU that interprets and executes the machining program. The memory of the control device 35 has a function as the table storage unit 39, and the CPU of the control device 35 has a function as the cut rate selection unit 41 and a function as the motor control unit (actuator control means) 43. doing.

  Here, the table storage unit 39 stores a table (see FIG. 3) indicating the relationship between the processing conditions and the laser beam cut rate by the aperture 25 (cut rate of the aperture 25), and is set in advance. In addition, the cutting rate selection unit 41 refers to the processing conditions such as the material of the workpiece W to be processed, the thickness of the workpiece, and the like stored in the table storage unit 39 based on the processing conditions specified by the processing program. The cutting rate corresponding to the is selected. The motor control unit 43 controls the servo motor 29 so that the cut rate selected by the cut rate selection unit 41 is obtained. The specific control of the servo motor 29 will be described later.

  Subsequently, with respect to the laser cutting processing method according to the embodiment of the present invention, while including the operation of the fiber laser processing machine 1, FIGS. 1 to 3 and FIGS. 5 (a) (b) to 7 (a) (b). Will be described with reference to FIG. In FIGS. 5A, 6A, and 7A, the laser beam LB is more densely hatched at higher power intensity, and FIGS. 5B and 6B. ), The power intensity of the laser beam LB blocked by the aperture 25 is hatched.

  As shown in FIG. 1, the laser machining head 9 is moved relative to the machining table 7 in the Z-axis direction to adjust the focal position of the laser beam LB. Then, the fiber laser oscillator 5 is operated to emit the laser light LB from the emission end 3 e of the transmission fiber 3, so that the laser light LB is converted into parallel light by the collimator lens 17 and condensed by the condenser lens 21. Then, the laser beam LB is irradiated from the nozzle 11 toward the cut portion Wa of the workpiece W. Further, simultaneously with the irradiation with the laser beam LB, the assist gas is supplied from the gas cylinder 15 into the laser processing head 9 to inject the assist gas from the nozzle 11 toward the cut portion Wa of the workpiece W. Further, in the state where the laser beam LB is irradiated from the nozzle 11 toward the cut portion Wa of the workpiece W and the assist gas is ejected, the laser processing head 9 is moved along the cut portion Wa of the workpiece W along the X axis direction and the Y axis. It moves relative to the processing table 7 in at least one of the axial directions. Accordingly, the workpiece W can be cut while melting the portion to be cut Wa of the workpiece W and removing the melt using the energy of the laser beam LB condensed at high density. . A series of cutting processes can be performed on a plurality of workpieces W by repeating the above-described operation continuously. During the cutting process, the aperture 25 is water cooled by a chiller (not shown).

  Before cutting the workpiece W, as shown in FIG. 2 and FIG. 3, the processing conditions include the material of the workpiece W, the thickness of the workpiece W, the processing mode (oxygen processing or assist using oxygen as an assist gas) Non-oxidation processing using an inert gas as a gas), processing speed, and the like are input in advance by the input unit 37. And when a processing form is oxygen processing, the cut rate of the laser beam LB by the aperture 25 will be set in the range of 2 to 20%. Further, when the processing form is non-oxidizing processing, the cut rate of the laser beam LB by the aperture 25 is set within a range of 0 to 8% and stored in the table storage unit 39. Then, the cut rate selection unit 41 selects a cut rate according to the processing conditions while referring to the table stored in the table storage unit 39 based on the processing conditions specified by the processing program. Then, the motor control unit 43 controls the servo motor 29 so that the cut rate selected by the cut rate selection unit 41 is obtained. If the cutting rate is wrong when inputting the processing conditions and the cutting rate by the input unit 37, for example, 1% outside the range of 2 to 20% is temporarily input even though the processing form is oxygen processing. When stored in the storage unit 39, the CPU of the control device 35 can notify the operator by displaying an alarm or the like outside the set range. Alternatively, when the servo motor 29 is controlled by the control device 35 during machining based on the machining program, the CPU of the control device 35 determines that the setting is out of the predetermined range, and for example, 1% set incorrectly. Alternatively, the servo motor 29 can be controlled by changing it to 2% close to 1% of 2 to 20% within a predetermined range.

  Specifically, as shown in FIG. 3, as processing conditions, the material of the workpiece W is mild steel (one of materials other than the highly reflective material), the thickness of the workpiece W is 6 mm, and the processing mode is oxygen. In the case of machining, the position of the aperture 25 is adjusted in the optical axis direction by driving the servo motor 29, and the cut rate of the laser beam LB by the aperture 25 is set to 3% within the range of 2 to 20%. As a result, as shown in FIGS. 5A and 5B, the outer layer portion LBo of the laser beam LB by the aperture 25, in other words, a low energy portion that does not contribute to melting (cutting) in the laser beam LB is formed on the workpiece W. Irradiation to the part to be cut Wa can be sufficiently suppressed. Here, the reason why the cut rate of the laser beam LB by the aperture 25 is set to 2% or more is that the low energy portion of the laser beam LB is irradiated to the cut portion Wa of the workpiece W when it is less than 2%. This is because it becomes difficult to sufficiently suppress this. On the other hand, the reason why the cut rate of the laser beam LB by the aperture 25 is set to 20% or less is that when it exceeds 20%, the power intensity of the laser beam LB at the cut portion Wa of the workpiece W as a processing point decreases. . The high reflection material means copper, copper alloy, aluminum, aluminum alloy, or mirror-finished stainless steel, and the material other than the high reflection material means normal stainless steel, mild steel, or the like.

  Further, as shown in FIG. 3, when the workpiece W is made of normal stainless steel and the workpiece W has a thickness of 2 mm and is non-oxidizing, the aperture is driven by the servo motor 29. 25 is adjusted in the optical axis direction, and the cut rate of the laser beam LB by the aperture 25 is set to 0%. As a result, it becomes as shown in FIGS. In the case of stainless steel processing, if the cut rate is as low as possible (0%), high-speed processing is possible while maintaining the power intensity of the laser beam LB. However, when the cut rate is increased, the low-energy portion of the laser beam LB is suppressed from being irradiated onto the cut portion Wa of the workpiece W, and the reflected light LB ′ toward the laser processing head 9 is sufficiently reduced. This makes it possible to perform stable machining, but the power strength is reduced by the amount of reduction in the cutting rate, so the machining speed needs to be reduced in accordance with the reduction in power strength.

  In particular, in the case of a highly reflective material, the influence of the reflected light is particularly great, and the cut rate is required to some extent instead of 0%. For example, as shown in FIG. 3, when the workpiece W is made of a copper alloy (an example of a highly reflective material), the workpiece W has a thickness of 1 mm, and the machining mode is non-oxidation machining as shown in FIG. The position of the aperture 25 is adjusted in the optical axis direction by driving the servo motor 29, and the cut rate of the laser light LB by the aperture 25 is set to 5% within the range of 3 to 8%. As a result, as shown in FIGS. 6A and 6B, the low-energy portion of the laser beam LB is suppressed from being irradiated to the cut portion Wa of the workpiece W, and the laser processing head 9 is moved toward the laser processing head 9 side. The reflected light LB ′ can be sufficiently reduced, and the power intensity of the laser light LB in the cut portion Wa of the workpiece W as a processing point is sufficiently secured to suppress a reduction in productivity during non-oxidation processing and to reduce the cutting speed. High speed can be maintained. Here, a reduction in productivity during non-oxidation processing can be suppressed and a high cutting speed can be maintained. Here, it is desirable that the cut rate of the aperture 25 is large when the influence of the reflected light LB ′ is considered. However, the cut rate of the laser beam LB by the aperture 25 is 8% or less. As a result, the power intensity of the laser beam LB at the cut portion Wa of the workpiece W as the lowering of the workpiece W is reduced, the cutting speed during the non-oxidation processing cannot be maintained at a high speed, and the cutting speed must be reduced, and the productivity is reduced. It is.

  Then, the effect | action and effect of embodiment of this invention are demonstrated.

  When the processing form is oxygen processing, the position of the aperture 25 is adjusted in the optical axis direction, and the cut rate of the laser light LB by the aperture 25 is set to 2 to 20%. Even without using a special condensing lens, a sufficient work strength of the laser beam LB at the cut portion Wa of the workpiece W as a processing point is ensured, and the workpiece is made of a thick plate having a thickness of mild steel, for example, 6 mm or more. Cutting by oxygen processing can be performed while preventing burning of W. Further, when the processing form is non-oxidizing processing, the cut rate of the laser beam LB by the aperture 25 is set to 8% or less, so the reflected light LB ′ is reduced and the cutting speed during non-oxidizing processing is high. Therefore, the power intensity of the laser beam LB in the part Wa to be cut of the workpiece W can be sufficiently secured, and the speed can be increased while maintaining the cutting speed during the non-oxidizing process. Thereby, the processing mode can be changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing only by adjusting the position of the aperture 25 in the optical axis direction during a series of cutting processes.

  In particular, when the workpiece W is made of a thin plate having a thickness of a highly reflective material, for example, 3 mm or less, and the processing form is non-oxidizing, the laser processing head 9 is set by setting the cut rate of the laser beam LB by the aperture 25 Since the reflected light LB ′ to the side can be sufficiently reduced, it is possible to sufficiently prevent the condensing lens 21, the collimating lens 17, and the emission end 3e of the transmission fiber 3 from being burned out. In particular, since the aperture 25 can block the reflected light LB ', it is possible to more sufficiently prevent the emission end 3e of the transmission fiber 3 from being burned out.

  Therefore, according to the embodiment of the present invention, the processing mode is changed from non-oxidation processing to oxygen processing or from oxygen processing to non-oxidation processing by simply adjusting the position of the aperture 25 in the optical axis direction during a series of cutting processes. Since it can be changed, the complexity of the cutting process can be suppressed, the work efficiency can be improved, the interruption time of the cutting process can be shortened as much as possible, and the productivity of the cutting process can be sufficiently increased.

  In particular, even when the workpiece W is made of a thin plate with a thickness of 3 mm or less, and the processing form is non-oxidizing, burnout of the condenser lens 21 and the like can be sufficiently prevented. As a result, the work efficiency can be further improved.

  The present invention is not limited to the description of the above-described embodiment. For example, instead of using the fiber laser processing machine 1, a YAG laser processing machine or a solid-state laser of a type that transmits the laser light LB through the transmission fiber 3 is used. The present invention can be implemented in various other modes such as using a processing machine and a carbonic acid laser processing machine. Further, the scope of rights encompassed by the present invention is not limited to the above-described embodiment.

  An embodiment of the present invention will be described with reference to FIGS.

  When oxygen processing is performed on a workpiece made of mild steel using a general-purpose condensing lens, the relationship between the aperture cut rate and the presence or absence of occurrence of burning is summarized as shown in FIG. The result was. That is, by setting the aperture cut rate to 2% or more, it was confirmed that oxygen processing was performed while preventing burning on a workpiece made of a thick steel plate having a thickness of 6 mm or more. Note that “◯” in FIG. 8A indicates that there was no burning, and “X” in FIG. 8A indicates that burning occurred. .

  When a laser beam reflection test is performed on a workpiece made of a copper alloy and the relationship between the distance from the output end of the transmission fiber to the aperture and the reflection level of the reflected light is summarized, the result shown in FIG. 8B is obtained. Became. That is, when the distance from the output end of the transmission fiber to the aperture becomes longer and the cutting rate increases, the reflected light level tends to decrease. It was confirmed that the reflection level of the reflected light can be sufficiently reduced when the rate becomes a certain cut rate (3%) or more.

LB Laser light LBo Outer layer portion LB 'Reflected light W Work Wa Cut part 1 Fiber laser processing machine 3 Transmission fiber 3e Output end 5 Fiber laser oscillator 7 Processing table 9 Laser processing head (laser processing head main body)
11 Nozzle 13 Gas supply pipe 15 Gas cylinder 17 Collimating lens 19 Upper lens holder 21 Condensing lens 23 Lower lens holder 25 Aperture 27 Opening 29 Servo motor (actuator)
31 Ball screw 33 Nut member 35 Control device 37 Input unit 39 Table storage unit 41 Cut rate selection unit 43 Motor control unit (actuator control means)

Claims (10)

In a laser processing machine that performs cutting processing on a workpiece using the energy of laser light emitted from the exit end of the transmission fiber,
A cylindrical laser processing head having a nozzle capable of irradiating a laser beam on the tip side and capable of ejecting an assist gas, connected to the output end of the transmission fiber, and internally connected to an assist gas supply source;
A collimating lens that is provided in the laser processing head and converts the laser light emitted from the emission end of the transmission fiber into parallel light;
A condensing lens that is provided between the collimating lens and the nozzle in the laser processing head and condenses the laser light converted into parallel light;
The laser processing head is provided between the exit end of the transmission fiber and the collimating lens so as to be adjustable in position in the optical axis direction, and has a circular opening for transmitting laser light. An aperture that blocks the outer layer portion of the laser beam emitted from the emission end;
An actuator for adjusting the position of the aperture in the optical axis direction;
Actuator control means for controlling the actuator so that the cut rate of the laser beam by the aperture becomes a cut rate according to the processing conditions. A table storage unit for storing a table showing the relationship between the processing conditions and the cutting rate;
A cutting rate selection unit that selects a cutting rate according to processing conditions while referring to the table stored in the table storage unit,
The laser processing machine according to claim 1, wherein the actuator control unit controls the actuator so that the cut rate selected by the cut rate selection unit is obtained. In a laser processing machine that performs cutting processing on a workpiece using the energy of laser light emitted from the exit end of the transmission fiber,
A cylindrical laser processing head having a nozzle capable of irradiating a laser beam on the tip side and capable of ejecting an assist gas, connected to the output end of the transmission fiber, and internally connected to an assist gas supply source;
A collimating lens that is provided in the laser processing head and converts the laser light emitted from the emission end of the transmission fiber into parallel light;
A condensing lens that is provided between the collimating lens and the nozzle in the laser processing head and condenses the laser light converted into parallel light;
The laser processing head is provided between the exit end of the transmission fiber and the collimating lens so as to be adjustable in position in the optical axis direction, and has a circular opening for transmitting laser light. An aperture that blocks the outer layer portion of the laser beam emitted from the emission end;
An actuator for adjusting the position of the aperture in the optical axis direction;
Actuator processing means for controlling the actuator so that the cut rate of laser light by the aperture is 2 to 20% when the processing form as processing conditions is oxygen processing using oxygen as an assist gas. laser machine you characterized in that the. In a laser processing machine that performs cutting processing on a workpiece using the energy of laser light emitted from the exit end of the transmission fiber,
A cylindrical laser processing head having a nozzle capable of irradiating a laser beam on the tip side and capable of ejecting an assist gas, connected to the output end of the transmission fiber, and internally connected to an assist gas supply source;
A collimating lens that is provided in the laser processing head and converts the laser light emitted from the emission end of the transmission fiber into parallel light;
A condensing lens that is provided between the collimating lens and the nozzle in the laser processing head and condenses the laser light converted into parallel light;
The laser processing head is provided between the exit end of the transmission fiber and the collimating lens so as to be adjustable in position in the optical axis direction, and has a circular opening for transmitting laser light. An aperture that blocks the outer layer portion of the laser beam emitted from the emission end;
Actuator processing means for controlling the actuator so that the cut rate of the laser beam by the aperture is 8% or less when the processing form as the processing condition is non-oxidation processing using an inert gas as an assist gas ; laser machine characterized by comprising a. In a laser processing machine that performs cutting processing on a workpiece using the energy of laser light emitted from the exit end of the transmission fiber,
A cylindrical laser processing head having a nozzle capable of irradiating a laser beam on the tip side and capable of ejecting an assist gas, connected to the output end of the transmission fiber, and internally connected to an assist gas supply source;
A collimating lens that is provided in the laser processing head and converts the laser light emitted from the emission end of the transmission fiber into parallel light;
A condensing lens that is provided between the collimating lens and the nozzle in the laser processing head and condenses the laser light converted into parallel light;
The laser processing head is provided between the exit end of the transmission fiber and the collimating lens so as to be adjustable in position in the optical axis direction, and has a circular opening for transmitting laser light. An aperture that blocks the outer layer portion of the laser beam emitted from the emission end;
As processing conditions, when the workpiece material is a highly reflective material and the processing form is non-oxidation processing using an inert gas as an assist gas, the laser light cut rate by the aperture is 3 to 8% . laser machine you characterized by comprising the actuator control means, the controlling said actuator so. Laser light emitted from the output end of the transmission fiber is converted into parallel light by a collimating lens, condensed by a condensing lens, and irradiated toward the workpiece to be cut, while assisting toward the workpiece to be cut. In the laser cutting processing method of performing cutting processing on a work while injecting gas and using the energy of laser light to melt the work to be cut and remove the melt,
Between the exit end of the transmission fiber and the collimating lens, the position is adjustable in the optical axis direction, and a circular opening for transmitting the laser light is provided and emitted from the exit end of the transmission fiber. Using an aperture that blocks the outer layer of the laser beam,
A laser cutting processing method characterized in that the position of the aperture is adjusted in the optical axis direction, and the cut rate of the laser light by the aperture is set to a cut rate according to a processing condition. Laser light emitted from the output end of the transmission fiber is converted into parallel light by a collimating lens, condensed by a condensing lens, and irradiated toward the workpiece to be cut, while assisting toward the workpiece to be cut. In the laser cutting processing method of performing cutting processing on a work while injecting gas and using the energy of laser light to melt the work to be cut and remove the melt,
Between the exit end of the transmission fiber and the collimating lens, the position is adjustable in the optical axis direction, and a circular opening for transmitting the laser light is provided and emitted from the exit end of the transmission fiber. Using an aperture that blocks the outer layer of the laser beam,
When the processing form as the processing condition is oxygen processing using oxygen as an assist gas, the position of the aperture is adjusted in the optical axis direction, and the cut rate of the laser light by the aperture is set to 2 to 20%. laser cutting how to characterized in that. Laser light emitted from the output end of the transmission fiber is converted into parallel light by a collimating lens, condensed by a condensing lens, and irradiated toward the workpiece to be cut, while assisting toward the workpiece to be cut. In the laser cutting processing method of performing cutting processing on a work while injecting gas and using the energy of laser light to melt the work to be cut and remove the melt,
Between the exit end of the transmission fiber and the collimating lens, the position is adjustable in the optical axis direction, and a circular opening for transmitting the laser light is provided and emitted from the exit end of the transmission fiber. Using an aperture that blocks the outer layer of the laser beam,
When the processing form as the processing condition is non-oxidation processing using an inert gas as an assist gas, the position of the aperture is adjusted in the optical axis direction so that the laser light cut rate by the aperture is 8% or less. laser cutting way to and sets. Laser light emitted from the output end of the transmission fiber is converted into parallel light by a collimating lens, condensed by a condensing lens, and irradiated toward the workpiece to be cut, while assisting toward the workpiece to be cut. In the laser cutting processing method of performing cutting processing on a work while injecting gas and using the energy of laser light to melt the work to be cut and remove the melt,
Between the exit end of the transmission fiber and the collimating lens, the position is adjustable in the optical axis direction, and a circular opening for transmitting the laser light is provided and emitted from the exit end of the transmission fiber. Using an aperture that blocks the outer layer of the laser beam,
As a processing condition, when the work material is a highly reflective material and the processing form is non-oxidation processing using an inert gas as an assist gas, the aperture is adjusted in the optical axis direction to adjust the aperture. laser cutting how to, characterized in that by setting the cut of the laser beam to 3-8%.   10. The laser according to claim 6, wherein the transmission fiber is for transmitting laser light having a wavelength of 1 μm band oscillated from a fiber laser oscillator. 10. Cutting method.