WO2019058520A1 - Laser machining device and laser machining method - Google Patents

Abstract

A laser machining device (1) is provided with: a laser oscillator (2) that oscillates a laser beam (L); and a light collecting optical system (4) that collects the laser beam (L) to a light collecting position (11). The laser machining device (1) is also provided with a moving mechanism (5) and a controller (7), which are adjustment units that adjust the light collecting position (11) by detecting a relative displacement quantity to the light collecting position (11) from a machining point of a workpiece (8), i.e., a subject to be machined by means of irradiation of the laser beam (L), said light collecting position being adjusted while the workpiece (8) is being machined.

Description

Laser processing apparatus and laser processing method

The present invention relates to a laser processing apparatus and a laser processing method for processing a workpiece by irradiation of a laser beam.

There is known a laser processing apparatus which processes a workpiece by irradiating a laser beam while repeatedly scanning the same line of the workpiece.

Patent Document 1 discloses a technique of cutting a reinforcing fiber base by irradiating a laser beam a plurality of times at a cutting line of the reinforcing fiber base which is a workpiece. The irradiation of the laser beam in the first scan at the cutting line brings the reinforcing fiber base into a state where the processing has advanced to an intermediate position in the thickness direction of the reinforcing fiber base. The irradiation of the laser beam by scanning at the cutting line is repeated, and the processing point reaches the surface on the back side of the reinforcing fiber base from the incident side of the laser beam, whereby the reinforcing fiber base is the cutting line. It is cut at.

Unexamined-Japanese-Patent No. 2015-214771

According to the technique of Patent Document 1, when the focusing position of the laser beam at the time of processing is fixed, the processing proceeds in the thickness direction of the workpiece, thereby causing a shift of the focusing position from the processing point. As the deviation amount of the light collecting position from the processing point increases, the cross-sectional area of the laser beam at the processing point increases, and the power density of the laser beam at the processing point decreases. As described above, in the technique of Patent Document 1, efficient processing of a workpiece may be difficult.

The present invention has been made in view of the above, and it is an object of the present invention to obtain a laser processing apparatus capable of processing with high efficiency.

In order to solve the problems described above and achieve the object, a laser processing apparatus according to the present invention includes a laser oscillator that oscillates a laser beam, a focusing optical system that focuses the laser beam at a focusing position, and a laser An adjustment unit configured to detect a relative displacement amount from the processing point of the workpiece to the focusing position during processing of the workpiece by irradiation of the beam and adjust the focusing position;

The laser processing apparatus according to the present invention has the effect of enabling processing with high efficiency.

The figure which shows the structure of the laser processing apparatus concerning Embodiment 1 of this invention. A first diagram for explaining light emitted from a workpiece in processing by the laser processing apparatus shown in FIG. 1 The second figure explaining the light emitted from the work in the processing by the laser processing apparatus shown in FIG. 1 A block diagram showing an example of the hardware configuration of the controller shown in FIG. 1 Flowchart showing control procedure of laser processing apparatus according to the first embodiment The figure which shows the structure of the laser processing apparatus concerning Embodiment 2 of this invention. FIG. 7 shows a first configuration example of the beam shaping unit shown in FIG. 6 The figure which shows the 2nd structural example of the beam shaping part shown in FIG. The figure which shows the structure of the laser processing apparatus concerning Embodiment 3 of this invention. The figure which shows the structure of the laser processing apparatus concerning Embodiment 4 of this invention. The figure which shows the structure of the laser processing apparatus concerning Embodiment 5 of this invention. Flowchart showing control procedure of laser processing apparatus according to the fifth embodiment The figure which shows the structure of the laser processing apparatus concerning Embodiment 6 of this invention. The figure which shows the structure of the laser processing apparatus concerning Embodiment 7 of this invention. The figure which shows the structure of the laser processing apparatus concerning Embodiment 8 of this invention.

Hereinafter, a laser processing apparatus and a laser processing method according to an embodiment of the present invention will be described in detail based on the drawings. The present invention is not limited by the embodiment.

Embodiment 1
FIG. 1 is a view showing the configuration of a laser processing apparatus 1 according to a first embodiment of the present invention. The laser processing apparatus 1 includes a laser oscillator 2 that oscillates a laser beam L, a focusing optical system 4 that focuses the laser beam L at a focusing position 11, a moving mechanism 5, and a controller 7. The laser processing apparatus 1 processes the workpiece 8 which is a workpiece by irradiation of the laser beam L condensed at the condensing position 11 by the condensing optical system 4. The moving mechanism 5 and the controller 7, which are adjustment units, gathers from the processing point due to the displacement of the processing point of the work 8 in the direction of the optical axis AX of the focusing optical system 4 during processing of the work 8 by irradiation of the laser beam L. The relative shift amount to the light position 11 is detected to adjust the condensing position 11. The condensing position 11 is a position at which the beam diameter of the laser beam L is minimum. The condensing position 11 may coincide with a focal position at which light transmitted through the condensing optical system 4 is condensed at one point when parallel light is incident on the condensing optical system 4.

In FIG. 1, the X axis and the Y axis are two axes parallel to the horizontal direction and perpendicular to each other. The Z axis is an axis parallel to the vertical direction and perpendicular to the X axis and the Y axis. The work 8 is placed on the stage 9 in a plane parallel to the X axis and the Y axis.

The laser oscillator 2 emits a laser beam L by pulse oscillation. The laser oscillator 2 is a gas laser such as a CO ₂ laser and a CO laser, or a solid laser or a fiber laser. Examples of the wavelength of the laser beam L are 10.6 μm, 9.3 μm, 5 μm, 1.06 μm, 1.03 μm, 532 nm, 355 nm and 266 nm.

The mirror 3 reflects the laser beam L from the laser oscillator 2 toward the focusing optical system 4 to bend the optical path of the laser beam L. The condensing optical system 4 includes one or more condensing lenses. The optical axis AX of the focusing optical system 4 is parallel to the Z axis. The moving mechanism 5 adjusts the focusing position 11 of the focusing optical system 4 in the Z-axis direction by moving one or more focusing lenses of the focusing optical system 4 in the Z-axis direction which is the optical axis direction. Do. In one example, the moving mechanism 5 includes a motor and a mechanism that converts the rotational motion of the motor into a linear motion. In FIG. 1, the illustration of the motor and the mechanism is omitted.

The mirror 3, the focusing optical system 4, and the moving mechanism 5 are accommodated in the processing head 10. The processing head 10 is movable in the Y-axis direction. The processing head 10 may be movable in the X-axis direction, or may be movable in the X-axis direction and the Y-axis direction.

The laser processing apparatus 1 further includes an optical sensor 6 that is a sensor that detects light emitted from a processing point. The light sensor 6 receives light to output a signal of a level according to the light amount. The light sensor 6 is a light receiving element having sensitivity to a wavelength range including the wavelength of the laser beam L. One example of the light sensor 6 is a photodiode.

The controller 7 controls the entire laser processing apparatus 1. The controller 7 controls the laser oscillation of the laser oscillator 2 and the drive of the processing head 10. Further, the controller 7 receives the signal from the light sensor 6 and controls the driving of the moving mechanism 5. The moving mechanism 5 moves the condensing optical system 4 under the control of the controller 7.

Examples of the work 8 are composite materials such as carbon fiber reinforced plastics (CFRP), glass fiber reinforced plastics (Glass Fiber Reinforced Plastics (GFRP)) and aramid fiber reinforced plastics (Aramid Fiber Reinforced Plastics (AFRP), semiconductor thin film , And glass material. In one example, the laser processing apparatus 1 performs processing for cutting the workpiece 8 by irradiation of the laser beam L.

The laser processing apparatus 1 repeatedly scans the same line of the workpiece 8 and irradiates the position on the line with the laser beam L multiple times. By repeating the irradiation of the laser beam L in the line and causing the processing point to reach the surface on the back side of the workpiece 8 to the laser beam L incident side, the laser processing apparatus 1 works the workpiece along the line. Cut 8

In addition to the cutting, the laser processing apparatus 1 may perform groove processing for forming a groove or hole processing for forming a hole. The material of the work 8 is not limited to the above-described material as long as the processing is performed by multiple irradiation of the laser beam L. The stage 9 may be movable in a direction parallel to the X axis and the Y axis. The laser processing apparatus 1 displaces the incident position of the laser beam L on the workpiece 8 by moving one or both of the processing head 10 and the stage 9.

FIG. 2: is a 1st figure explaining the light radiate | emitted from the workpiece | work 8 in the process by the laser processing apparatus 1 shown in FIG. In FIG. 2, the divergent light 12 emitted from the processing point of the workpiece 8 at the start of processing and the divergent light 12 emitted from the processing point at the processing start from the processing start are schematically shown. It shows. In FIG. 2, the processing point is a position at which the laser beam L has reached the work 8. The curve shown below the workpiece 8 in FIG. 2 is a graph showing the relationship between the distance from the center O of the laser beam L in the X-axis direction and the Y-axis direction, and the intensity of the laser beam L.

In one example, the laser beam L is a Gaussian beam in which the intensity distribution in the X and Y directions at the work 8 is a normal distribution. The laser beam L may also be a top-hat-type intensity distribution beam whose intensity is constant in a range of a fixed distance from the center O. Alternatively, the laser beam L may be a beam having a ring-like intensity distribution whose intensity is higher at the periphery than at the center O. The beam having a ring-like intensity distribution may be obtained by shaping using an axicon lens, or may be light of higher order mode. The components for shaping the laser beam L may be provided either inside or outside of the laser oscillator 2.

The example shown in FIG. 2 shows the case where the condensing position 11 of the laser beam L is constant from the time when the processing is started. When the processing is started, the condensing position 11 is on the surface of the work 8 on which the laser beam L is incident, and coincides with the processing point. At this time, since the power of the laser beam L is concentrated at the processing point, processing with good processing efficiency is performed on the work 8.

Here, processing efficiency represents the progress degree of processing per time. The processing efficiency can be expressed as the amount of removed material removed from the workpiece 8 per time or the amount of change in the distance from the processing start position to the processing point per time. The higher the processing efficiency, the shorter the time required to process the workpiece 8. The lower the processing efficiency, the longer the time required to process the workpiece 8.

In the process in which the processing proceeds downward to the work 8 after the start of the processing, the bottom portion of the processing groove 13 formed in the work 8 becomes a processing point. While the condensing position 11 is at a constant position from the time when the processing is started, the processing position moves downward as the processing progresses, so that the condensing position 11 from the processing point is Misalignment occurs. The cross-sectional area of the laser beam L at the processing point increases as the displacement amount of the light collecting position 11 from the processing point increases, so the power density of the laser beam L at the processing point decreases. The peak of the intensity of the laser beam L is lower than when processing is started. The amount of processing per irradiation of the laser beam L is smaller than when the power is concentrated at the processing point.

In general, when the processing with high power is performed, the light amount of the diverging light 12 becomes large, and the light amount of the diverging light 12 becomes smaller as the power decreases. For this reason, the shift of the condensing position 11 from the processing point appears as a decrease in the light amount of the diverging light 12. In the first embodiment, the controller 7 detects the relative displacement amount from the processing point to the condensing position 11 based on the change in the light amount of light detected by the light sensor 6. The moving mechanism 5 adjusts the condensing position 11 so that the detected displacement amount becomes zero.

FIG. 3 is a second diagram for explaining light emitted from the work 8 in the processing by the laser processing apparatus 1 shown in FIG. In the example shown in FIG. 3, the case where the condensing position 11 is moved downward is shown. The controller 7 instructs the moving mechanism 5 to move the condensing optical system 4 downward when determining that the light amount of the diverging light 12 detected by the light sensor 6 is reduced. As described above, the controller 7 detects the shift amount of the condensing position 11 from the processing point due to the displacement of the processing point in the direction parallel to the optical axis AX based on the change in the light quantity of the diverging light 12 The adjustment of the focusing position 11 by 5 is controlled. In one example, the controller 7 instructs the movement of the focusing optical system 4 when the light amount of the diverging light 12 detected by the light sensor 6 becomes smaller than a preset threshold. The controller 7 moves the condensing optical system 4 so that the light amount of the diverging light 12 becomes the same as when the condensing position 11 coincides with the processing point, the focusing position 11 from the processing point Adjustment may be performed such that the amount of deviation is zero.

The moving mechanism 5 adjusts the condensing position 11 by moving the condensing optical system 4 in accordance with an instruction from the controller 7. By bringing the condensing position 11 closer to the processing point, the cross-sectional area of the laser beam L at the processing point is reduced, and the power density of the laser beam L at the processing point is improved. The peak of the intensity of the laser beam L is higher than before the focusing position 11 is adjusted. The processing efficiency can be improved by improving the power density at the processing point. In addition, the processing amount per one irradiation of the laser beam L can be increased.

The higher the efficiency of the processing, the greater the light intensity of the diverging light 12. The controller 7 may monitor the amount of light detected by the light sensor 6 and move the condensing optical system 4 by an arbitrary amount of movement so that the amount of light detected becomes large.

The laser processing apparatus 1 can process the workpiece 8 with high efficiency by matching the condensing position 11 to the processing point. The laser processing apparatus 1 determines the possibility of adjustment of the condensing position 11 at the time of processing of the work 8 in order to grasp the relative displacement amount from the processing point to the condensing position 11 from the light amount change of the diverging light 12 be able to.

Temporarily, when the condensing position 11 is set based on the result of pre-processing before main processing of the work 8, it is processing by performing several times processing, changing the condensing position 11, by pre-processing. The optimal condensing position 11 is determined. In this case, it is difficult to adjust the light collecting position 11 corresponding to the individual difference of the work 8 in the main processing. In addition, the productivity of the work 8 is reduced by requiring a large amount of processing in pre-processing.

According to the first embodiment, the laser processing apparatus 1 makes it possible to adjust the light collecting position 11 corresponding to the individual difference of the work 8 by making it possible to adjust the light collecting position 11 in the main processing of the work 8. Become. Moreover, the laser processing apparatus 1 can avoid the productivity fall of the workpiece | work 8 by pre-processing being unnecessary.

Further, the light amount of the diverging light 12 detected by the light sensor 6 rapidly decreases when the processing of the work 8 is completed. The controller 7 may determine that the processing of the workpiece 8 is completed when the amount of light to be detected suddenly decreases, and may control the operation of the laser processing apparatus 1 based on the determination.

In one example, the light sensor 6 is disposed between the focusing optical system 4 and the work 8. The position of the light sensor 6 may be any position where the diverging light 12 can reach. The light sensor 6 may detect a component of the diverging light 12 returned from the processing point to the condensing optical system 4. The light sensor 6 may be disposed between the focusing optical system 4 and the mirror 3.

The mirror 3 may be a mirror whose curvature can be changed by deformation of a curved surface which is a reflective surface. The laser processing apparatus 1 may adjust the condensing position 11 by changing the curvature of the mirror 3 in addition to the movement of the position of the condensing optical system 4.

In one example, the laser oscillator 2 reciprocates laser light amplified by a laser medium between a total reflection mirror and an output mirror that transmits a part of incident light. In the first embodiment, illustration of the total reflection mirror and the output mirror is omitted.

The control function by the controller 7 is realized using a hardware configuration. FIG. 4 is a block diagram showing an example of the hardware configuration of the controller 7 shown in FIG. One example of a hardware configuration is a microcontroller. The functions of the controller 7 are executed on a program analyzed and executed by the microcontroller. A part of the functions of the controller 7 may be executed on hardware by wired logic.

The controller 7 includes a processor 14 that executes various processes, and a memory 15 in which programs for various processes are stored. The processor 14 and the memory 15 are connected to each other via a bus 16. The processor 14 develops the loaded program to execute various processes for controlling the laser processing apparatus 1. The processing executed by the processor 14 includes processing for capturing the detection result of the light sensor 6 and operating the moving mechanism 5 according to the change in light quantity.

In the first embodiment, the controller 7 is based on means for controlling the entire laser processing apparatus 1 including the laser oscillator 2 and the processing head 10 and a change in the light quantity of the diverging light 12 detected by the optical sensor 6. It also serves as means for operating the moving mechanism 5. The means for the operation of the moving mechanism 5 based on the light amount change and the means for the control of the laser processing apparatus 1 in general other than the operation of the moving mechanism 5 may be provided independently of each other.

FIG. 5 is a flowchart showing a control procedure of the laser processing apparatus 1 according to the first embodiment. FIG. 5 shows an example of a procedure for adjusting the condensing position 11 when processing the workpiece 8.

After processing of the work 8 is started, the optical sensor 6 detects the divergent light 12 generated by the processing in step S1 which is a light detection process. In step S2, the controller 7 determines whether the amount of light detected by the light sensor 6 is less than a threshold. When the light amount detected by the light sensor 6 is equal to or more than the threshold (No in step S2), the laser processing apparatus 1 continues the processing of the work 8 and the detection of the diverging light 12 by the light sensor 6 in step S1. .

If the amount of light detected by the optical sensor 6 is less than the threshold (Yes in step S2), the controller 7 determines that a deviation of the condensing position 11 from the processing point has occurred based on the change in the amount of light Then, the movement mechanism 5 is instructed to move the focusing optical system 4. In step S3 which is an adjustment process, the moving mechanism 5 moves the condensing position 11 by moving the condensing optical system 4 in the optical axis direction according to the instruction from the controller 7. The moving mechanism 5 adjusts the condensing position 11 so that the shift amount of the condensing position 11 from the processing point detected based on the light amount change of the diverging light 12 becomes zero. Thus, the laser processing apparatus 1 ends the procedure shown in FIG. The laser processing apparatus 1 repeats the operation from step S1 while the processing of the workpiece 8 is continued even after the condensing position 11 is adjusted once. The condensing position 11 may be adjusted each time a scan on the same line is performed, or may be adjusted during the scan.

When the processing of a plurality of workpieces 8 which are the same product is continuously performed, the adjustment of the condensing position 11 according to the procedure shown in FIG. 5 may be performed in the processing of the first workpiece 8. In the processing of the second and subsequent workpieces 8, the focusing position 11 is adjusted at the same timing as the adjustment of the focusing position 11 of the first workpiece 8 regardless of the detection result of the optical sensor 6. As well. In addition, the movement amount of the focusing optical system 4 in the processing of the second and subsequent workpieces 8 may be the same as in the case of the first workpiece 8.

According to the first embodiment, the laser processing apparatus 1 detects the relative shift amount from the processing point to the light collecting position 11 from the change in the light amount of light detected by the light sensor 6 to determine the light collecting position 11. adjust. The laser processing apparatus 1 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. Thus, the laser processing apparatus 1 has an effect of enabling processing with high efficiency.

Second Embodiment
FIG. 6 is a view showing the configuration of a laser processing apparatus 20 according to a second embodiment of the present invention. The laser processing apparatus 20 is provided with a beam shaping unit 21 instead of the moving mechanism 5 of the first embodiment. The same parts as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The beam shaping unit 21 and the controller 7, which are adjustment units, operate from the processing point due to the displacement of the processing point of the work 8 in the direction of the optical axis AX of the focusing optical system 4 during processing of the work 8 by irradiation of the laser beam L. The amount of deviation of the light collecting position 11 is detected to adjust the light collecting position 11. The beam shaping unit 21 is disposed between the laser oscillator 2 and the mirror 3. The beam shaping unit 21 adjusts the beam diameter of the laser beam L to be advanced to the mirror 3 and the focusing optical system 4. The beam shaping unit 21 adjusts the focusing position 11 by changing the beam diameter of the laser beam L incident on the focusing optical system 4. The beam shaping unit 21, the mirror 3, and the focusing optical system 4 are accommodated in the processing head 10.

The controller 7 receives the signal from the light sensor 6 and controls the driving of the beam shaping unit 21. The beam shaping unit 21 adjusts the beam diameter of the laser beam L according to the control of the controller 7.

FIG. 7 is a diagram showing a first configuration example of the beam shaping unit 21 shown in FIG. The beam shaping unit 21 according to the first configuration example includes three lenses 22, 23 and 24. The lenses 22 and 23 are convex lenses. The lens 24 is a concave lens. The lenses 22, 23, 24 are arranged in the X-axis direction. Note that FIG. 7 shows the beam shaping unit 21 and the focusing optical system 4, and the mirror 3 between the beam shaping unit 21 and the focusing optical system 4 and the folding of the laser beam L by the mirror 3. Illustration is omitted.

The beam shaping unit 21 moves the lenses 22, 23, 24 in the X-axis direction. The beam shaping unit 21 changes the divergence angle or the beam diameter of the laser beam L emitted from the beam shaping unit 21 by adjusting the position of each of the lenses 22, 23 and 24 individually. The beam shaping unit 21 adjusts the beam diameter of the laser beam L in the focusing optical system 4 by changing the divergence angle or the beam diameter of the laser beam L. In one example, the beam shaping unit 21 includes a motor and a mechanism for converting rotational motion of the motor into linear motion of the lenses 22, 23, 24. In FIG. 7, illustration of the motor and the mechanism is omitted. The number and type of lenses included in the beam shaping unit 21 are not limited to those shown in the first configuration example, and are arbitrary.

FIG. 8 is a diagram showing a second configuration example of the beam shaping unit 21 shown in FIG. The beam shaping unit 21 according to the second configuration example includes a convex mirror 25 and a concave mirror 26. The convex mirror 25 reflects the laser beam L incident on the beam shaping unit 21 toward the concave mirror 26. The concave mirror 26 reflects the laser beam L from the convex mirror 25 and causes the beam shaping unit 21 to emit the laser beam L.

The beam shaping unit 21 changes the divergence angle of the laser beam L emitted from the beam shaping unit 21 by moving the convex mirror 25 and the concave mirror 26 in the X-axis direction. The beam shaping unit 21 adjusts the beam diameter of the laser beam L in the focusing optical system 4 by changing the divergence angle of the laser beam L. In one example, the beam shaping unit 21 includes a motor and a mechanism for converting the rotational movement of the motor into linear movement of the convex mirror 25 and the concave mirror 26. In FIG. 8, the illustration of the motor and the mechanism is omitted. The number and type of mirrors included in the beam shaping unit 21 are not limited to those shown in the second configuration example, and are arbitrary. The beam shaping unit 21 may include a lens included in the first configuration example and a mirror included in the second configuration example.

The mirror 3 shown in FIG. 6 may be a mirror whose curvature can be changed by deformation of a curved surface which is a reflection surface. In addition to the adjustment of the beam diameter by the beam shaping unit 21, the laser processing apparatus 20 may adjust the focusing position 11 by changing the curvature of the mirror 3.

In one example, the laser oscillator 2 reciprocates laser light amplified by a laser medium between a total reflection mirror and an output mirror that transmits a part of incident light. In the second embodiment, the total reflection mirror and the output mirror are not shown.

In the second embodiment, the controller 7 is based on means for controlling the entire laser processing apparatus 20 including the laser oscillator 2 and the processing head 10 and a change in the light quantity of the diverging light 12 detected by the optical sensor 6. It also serves as means for operating the beam shaping unit 21. The means for the operation of the beam shaping unit 21 based on the light amount change and the means for the control of the laser processing apparatus 20 in general other than the operation of the beam shaping unit 21 may be provided independently of each other. .

According to the second embodiment, the laser processing apparatus 20 detects the relative displacement amount from the processing point to the condensing position 11, and adjusts the condensing position 11 by adjusting the beam diameter in the beam shaping unit 21. Do. The laser processing apparatus 20 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. As a result, the laser processing apparatus 20 has an effect of enabling processing with high efficiency.

Third Embodiment
FIG. 9 is a diagram showing the configuration of a laser processing apparatus 30 according to a third embodiment of the present invention. The laser processing apparatus 30 includes a galvano scanner 31 and a beam shaping unit 21 similar to that of the second embodiment. The same parts as in the first and second embodiments will be assigned the same reference numerals and overlapping explanations will be omitted.

The galvano scanner 31 is disposed between the beam shaping unit 21 and the focusing optical system 4. The position of the galvano scanner 31 is set to the position of the entrance pupil of the focusing optical system 4. The galvano scanner 31 deflects the laser beam L in the Y-axis direction. The galvano scanner 31 displaces the incident position of the laser beam L on the work 8 in the Y-axis direction by the rotation of the reflecting surface that reflects the laser beam L. The controller 7 controls the rotational drive of the galvano scanner 31.

The focusing optical system 4 may be an fθ lens having a focusing position 11 of the laser beam L at a position of fθ obtained by multiplying the focal distance f of the focusing optical system 4 by the deflection angle θ of the galvano scanner 31. good. The laser processing apparatus 30 may include a galvano scanner that deflects the laser beam L in the X-axis direction. The laser processing apparatus 30 may be capable of displacing the laser beam L in the X and Y directions by a galvano scanner that deflects the laser beam L in the X axis direction and a galvano scanner 31 that deflects the laser beam L in the Y axis direction. The position of the entrance pupil of the focusing optical system 4 may be set at an intermediate position between the two galvano scanners.

The laser processing apparatus 30 may deflect the laser beam L using components other than the galvano scanner 31. The laser processing apparatus 30 replaces the galvano scanner 31 with an acousto-optic deflector (Acousto-Optic Deflector, AOD) that deflects light using an acousto-optic effect, or electricity that deflects light using an electro-optic effect. An optical deflector (Electro-Optic Deflector, EOD) may be provided.

According to the third embodiment, the laser processing apparatus 30 deflects the laser beam L that has undergone the adjustment of the beam diameter in the beam shaping unit 21. The laser processing apparatus 30 adjusts the focusing position 11 by adjusting the beam diameter in the beam shaping unit 21. The laser processing apparatus 30 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. Thereby, the laser processing apparatus 30 has an effect that processing can be performed with high efficiency.

The laser processing apparatus 30 may adjust the focusing position 11 by the moving mechanism 5 similar to that of the first embodiment, instead of the beam shaping unit 21. In this case, the laser processing apparatus 30 moves the galvano scanner 31 in the Z-axis direction in conjunction with the movement of the focusing optical system 4 by the moving mechanism 5. Thereby, the laser processing apparatus 30 can adjust the condensing position 11 while keeping the positional relationship between the condensing optical system 4 and the galvano scanner 31 constant.

Fourth Embodiment
FIG. 10 is a diagram showing the configuration of a laser processing apparatus 40 according to a fourth embodiment of the present invention. The laser processing device 40 adjusts the condensing position 11 in accordance with the change in the amount of light detected by the light sensor 6 and the amount of change in the distance detected by the distance sensor 41. The laser processing apparatus 40 has the same configuration as the laser processing apparatus 30 of the third embodiment except that a distance sensor 41 is added. The same parts as those in the first to third embodiments are given the same reference numerals, and duplicate explanations are omitted.

The distance sensor 41 detects the distance between the workpiece 8 and the focusing optical system 4. In one example, the distance sensor 41 is a non-contact distance sensor that performs distance detection at a position away from the workpiece 8 as an object. The distance sensor 41 may be a contact type distance sensor that performs distance detection based on contact with the workpiece 8.

In the fourth embodiment, the height in the Z-axis direction of the surface of the work 8 on which the laser beam L is incident changes depending on the position in the X and Y directions. The work 8 may have an uneven surface on the surface on which the laser beam L is incident. The controller 7 performs control to adjust the condensing position 11 including the variation of the distance detected by the distance sensor 41.

When processing at a position lower than the position at the start of processing, the distance from the condensing optical system 4 to the processing point is extended. In this case, the beam shaping unit 21 detects the diverging light 12 detected by the light sensor 6 including the amount of downward movement of the light collecting position 11 as the distance from the light collecting optical system 4 to the processing point increases. Adjustment of the condensing position 11 is performed according to the light amount change.

On the other hand, when processing at a position higher than the position at the start of processing, the distance from the condensing optical system 4 to the processing point is shortened. In this case, the beam shaping unit 21 detects the diverging light 12 detected by the light sensor 6 including the amount of upward movement of the light collecting position 11 corresponding to the reduction of the distance from the light collecting optical system 4 to the processing point. Adjustment of the condensing position 11 is performed according to the light amount change. The laser processing apparatus 40 can perform adjustment for bringing the condensing position 11 closer to the processing point in the work 8 including the distribution of the height at each position in the X and Y directions.

The laser processing apparatus 1 of the first embodiment or the laser processing apparatus 20 of the second embodiment adjusts the focusing position 11 including the variation of the distance detected by the distance sensor 41 as in the fourth embodiment. You may The distance sensor 41 may be provided in the laser processing apparatus 1, 20.

According to the fourth embodiment, the laser processing apparatus 40 can improve the processing efficiency by adjusting the condensing position 11 to coincide with the processing point for the workpiece 8 including the distribution of height. Thereby, the laser processing apparatus 40 has an effect that processing with high efficiency becomes possible.

Embodiment 5
FIG. 11 is a view showing the configuration of a laser processing apparatus 50 according to a fifth embodiment of the present invention. The laser processing apparatus 50 has the same configuration as the laser processing apparatus 1 of the first embodiment except that a sound sensor 51 is provided instead of the light sensor 6. The same parts as those in the first to fourth embodiments are given the same reference numerals, and duplicate explanations are omitted.

The sound sensor 51 is a sensor that detects a processing sound generated from a processing point. By receiving the sound, the sound sensor 51 outputs a signal of a level according to the volume. One example of the sound sensor 51 is a microphone. The controller 7 receives the signal from the sound sensor 51 and controls the driving of the moving mechanism 5.

Usually, when the processing is performed with high power, the volume of the processed sound becomes large, and the volume of the processed sound becomes smaller as the power decreases. For this reason, the reduction of the processing efficiency due to the reduction of the power density appears as the reduction of the volume of the processing sound. In the fifth embodiment, the controller 7 detects the relative displacement amount from the processing point to the condensing position 11 based on the volume change of the sound detected by the sound sensor 51. The moving mechanism 5 adjusts the condensing position 11 so that the detected displacement amount becomes zero.

When it is determined that the volume of the processed sound detected by the sound sensor 51 has become small, the controller 7 instructs the moving mechanism 5 to move the condensing optical system 4 downward. In one example, the controller 7 instructs the movement of the focusing optical system 4 when the volume of the processed sound detected by the sound sensor 51 becomes less than a preset threshold. The controller 7 shifts the focusing position 11 from the processing point by moving the focusing optical system 4 so that the volume of the processed sound is the same as when the focusing position 11 matches the processing point. Adjustment may be made so that the amount is zero. The moving mechanism 5 adjusts the condensing position 11 by moving the condensing optical system 4 in accordance with an instruction from the controller 7. Thereby, the laser processing apparatus 50 improves the power density at the processing point and improves the processing efficiency.

The higher the efficiency of processing, the higher the volume of the processed sound. The controller 7 may monitor the volume detected by the sound sensor 51 and move the focusing optical system 4 by an arbitrary amount of movement so that the detected volume is increased.

The laser processing apparatus 50 can process the workpiece 8 with high efficiency by matching the condensing position 11 to the processing point. The laser processing apparatus 50 can determine whether the adjustment of the condensing position 11 can be performed at the time of processing of the work 8 because the laser processing device 50 grasps the shift amount of the condensing position 11 from the processing point from the volume change of the processing sound.

In addition, the volume of the processed sound detected by the sound sensor 51 sharply decreases when the processing of the work 8 is completed. The controller 7 may determine that the processing of the workpiece 8 is completed when the detected volume suddenly decreases, and may control the operation of the laser processing apparatus 50 based on the determination.

In one example, the sound sensor 51 is disposed between the focusing optical system 4 and the work 8. The position of the sound sensor 51 may be any position at which the processing sound can reach. Further, in the fifth embodiment, the controller 7 is based on means for controlling the entire laser processing apparatus 50 including the laser oscillator 2 and the processing head 10 and a change in volume of the processing sound detected by the sound sensor 51. Also serves as means for operating the moving mechanism 5. The means for the operation of the moving mechanism 5 based on the volume change and the means for controlling the laser processing apparatus 50 in general other than the operation of the moving mechanism 5 may be provided independently of each other.

FIG. 12 is a flowchart showing the control procedure of the laser processing apparatus 50 according to the fifth embodiment. FIG. 12 shows an example of a procedure for adjusting the light collecting position 11 when processing the workpiece 8.

After the processing of the work 8 is started, the sound sensor 51 detects a processing sound generated by the processing in step S11, which is a sound detection process. In step S12, the controller 7 determines whether the volume detected by the sound sensor 51 is less than a threshold. When the sound volume detected by the sound sensor 51 is equal to or higher than the threshold (No in step S12), the laser processing device 50 continues the processing of the work 8 and the detection of the processed sound by the sound sensor 51 in step S11.

If the volume detected by the sound sensor 51 is less than the threshold (Yes in step S12), the controller 7 determines that a deviation of the light collecting position 11 from the processing point has occurred based on the change in the volume. Then, the movement mechanism 5 is instructed to move the focusing optical system 4. In step S13, which is an adjustment process, the moving mechanism 5 moves the condensing position 11 by moving the condensing optical system 4 in the optical axis direction according to the instruction from the controller 7. The moving mechanism 5 adjusts the light collecting position 11 so that the shift amount of the light collecting position 11 from the processing point detected based on the volume change of the processing sound becomes zero. Thus, the laser processing apparatus 50 ends the procedure shown in FIG. The laser processing apparatus 50 repeats the operation from step S11 while the processing of the workpiece 8 is continued even after the condensing position 11 is adjusted once. The condensing position 11 may be adjusted each time a scan on the same line is performed, or may be adjusted during the scan.

When the processing of a plurality of workpieces 8 which are the same product is continuously performed, the adjustment of the condensing position 11 according to the procedure shown in FIG. 12 may be performed in the processing of the first workpiece 8. In the processing of the second and subsequent workpieces 8, the focusing position 11 is adjusted at the same timing as the adjustment of the focusing position 11 of the first workpiece 8 regardless of the detection result of the sound sensor 51. As well. In addition, the movement amount of the focusing optical system 4 in the processing of the second and subsequent workpieces 8 may be the same as in the case of the first workpiece 8.

According to the fifth embodiment, the laser processing apparatus 50 detects the relative shift amount from the processing point to the light collecting position 11 from the volume change of the sound detected by the sound sensor 51 to determine the light collecting position 11. adjust. The laser processing apparatus 50 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. Thereby, the laser processing apparatus 50 has an effect that processing can be performed with high efficiency.

Sixth Embodiment
FIG. 13 is a diagram showing the configuration of a laser processing apparatus 60 according to a sixth embodiment of the present invention. The laser processing apparatus 60 has the same configuration as the laser processing apparatus 20 of the second embodiment except that a sound sensor 51 is provided instead of the light sensor 6. The same parts as those in the first to fifth embodiments are given the same reference numerals, and duplicate explanations are omitted.

The controller 7 receives the signal from the sound sensor 51 and controls the driving of the beam shaping unit 21. The beam shaping unit 21 adjusts the beam diameter of the laser beam L according to the control of the controller 7.

According to the sixth embodiment, the laser processing apparatus 60 detects the relative shift amount from the processing point to the light collecting position 11 based on the volume change of the sound detected by the sound sensor 51, and the beam shaping unit At 21 the beam diameter is adjusted. The laser processing apparatus 60 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. Thus, the laser processing apparatus 60 has an effect of enabling processing with high efficiency.

Embodiment 7
FIG. 14 is a view showing the configuration of a laser processing apparatus 70 according to a seventh embodiment of the present invention. The laser processing apparatus 70 has the same configuration as the laser processing apparatus 30 of the third embodiment except that a sound sensor 51 is provided instead of the light sensor 6. The same parts as those in the first to sixth embodiments are denoted by the same reference numerals, and redundant description will be omitted.

According to the seventh embodiment, the laser processing apparatus 70 detects the relative shift amount from the processing point to the light collecting position 11 based on the volume change of the sound detected by the sound sensor 51, and the beam shaping unit At 21 the beam diameter is adjusted. The laser processing apparatus 70 improves processing efficiency by adjusting the condensing position 11 to coincide with the processing point. Thus, the laser processing apparatus 70 has an effect of enabling processing with high efficiency.

Eighth Embodiment
FIG. 15 is a view showing the configuration of a laser processing apparatus 80 according to an eighth embodiment of the present invention. The laser processing apparatus 80 has the same configuration as the laser processing apparatus 40 of the fourth embodiment except that a sound sensor 51 is provided instead of the light sensor 6. The same parts as in the first to seventh embodiments will be assigned the same reference numerals and overlapping explanations will be omitted.

The controller 7 performs control to adjust the condensing position 11 including the variation of the distance detected by the distance sensor 41. The laser processing device 80 adjusts the light collecting position 11 in accordance with the volume change of the processing sound detected by the sound sensor 51 and the change amount of the distance detected by the distance sensor 41.

According to the eighth embodiment, the laser processing apparatus 80 can improve the processing efficiency by adjusting the condensing position 11 to coincide with the processing point for the workpiece 8 including the distribution of height. Thereby, the laser processing apparatus 80 has an effect that processing with high efficiency becomes possible.

The configuration shown in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and one of the configurations is possible within the scope of the present invention. Parts can be omitted or changed.

1, 20, 30, 40, 50, 60, 70, 80 laser processing apparatus, 2 laser oscillators, 3 mirrors, 4 focusing optical systems, 5 moving mechanisms, 6 optical sensors, 7 controllers, 8 works, 9 stages, DESCRIPTION OF SYMBOLS 10 processing head, 11 condensing position, 12 diverging light, 13 processing groove, 14 processors, 15 memory, 16 buses, 21 beam shaping part, 22, 23, 24 lens, 25 convex mirror, 26 concave mirror, 31 galvano scanner, 41 distance sensor, 51 sound sensor, AX optical axis, L laser beam, O center.

Claims (11)

A laser oscillator that oscillates a laser beam;
A focusing optical system for focusing the laser beam at a focusing position;
An adjustment unit configured to detect a relative displacement amount from the processing point of the workpiece to the focusing position during processing of the workpiece by irradiation of the laser beam, and adjust the focusing position;
A laser processing apparatus comprising: The said adjustment part adjusts the said condensing position so that the said deviation | shift amount may become zero, The laser processing apparatus of Claim 1 characterized by the above-mentioned. A sensor for detecting light emitted from the processing point;
The laser processing apparatus according to claim 1, wherein the adjustment unit detects the amount of deviation based on a change in the amount of light detected by the sensor. It has a sensor that detects the sound generated from the processing point,
The laser processing apparatus according to claim 1, wherein the adjustment unit detects the amount of deviation based on a change in volume of the sound detected by the sensor. The said adjustment part adjusts the said condensing position by moving the said condensing optical system in an optical axis direction, The laser processing apparatus as described in any one of Claim 1 to 4 characterized by the above-mentioned. The laser according to any one of claims 1 to 4, wherein the adjustment unit adjusts the condensing position by changing a beam diameter of the laser beam incident on the condensing optical system. Processing equipment. A distance sensor for detecting a distance between a workpiece and the focusing optical system;
The said adjustment part adjusts the said condensing position including the variation | change_quantity of the distance detected with the said distance sensor, The laser processing apparatus as described in any one of Claim 1 to 6 characterized by the above-mentioned. A laser processing method for processing a workpiece by irradiation of a laser beam condensed at a condensing position by a condensing optical system,
An adjustment step of detecting a relative displacement amount from the processing point of the workpiece to the focusing position during processing of the workpiece by irradiation of the laser beam, and adjusting the focusing position; Laser processing method characterized by 9. The laser processing method according to claim 8, wherein the focusing position is adjusted so that the deviation amount becomes zero in the adjustment step. Including a light detection step of detecting light emitted from the processing point;
10. The laser processing method according to claim 8, wherein the deviation amount is detected based on a change in the light amount of the light detected in the light detection step in the adjustment step. Including a sound detection step of detecting a sound generated from the processing point;
10. The laser processing method according to claim 8, wherein in the adjusting step, the amount of deviation is detected based on a change in volume of the sound detected in the sound detecting step.

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