Incidence angle calculation device and computer-readable storage medium

Abstract

This incidence angle calculation device generates information for controlling a laser processing machine in accordance with a processing program, acquires control information that includes a trajectory for a processing point that is based on the processing program and a nozzle vector and a focal distance for a processing head of the laser processing machine, acquires beam shape information that is for calculating a beam shape, and calculates a beam incidence angle that is the angle formed by a side surface of a beam and a workpiece surface from the control information and the beam shape information.

Description

Angle of incidence calculation device and a computer-readable storage medium

[0001] This disclosure relates to an incident angle calculation device and a computer-readable storage medium.

[0002] Conventionally, laser processing machines exist that use laser energy for processing. A laser processing machine consists of a laser oscillator, a galvanometer scanner, a laser processing head, and other components. The control unit analyzes the processing program, NC data, etc., and controls the laser processing machine.

[0003] In laser processing, numerous factors such as laser output, laser movement speed, oscillation state, and frequency affect processing quality. Engineers adjust the processing program and parameters while monitoring data indicating the processing status.

[0004] A method for visualizing the laser energy distribution to assist engineers in making adjustments is disclosed. For example, Patent Document 1.

[0005] International Publication No. 2020-069266

[0006] In the field of laser processing, there is a need to use laser information to assist in adjusting processing programs and parameters.

[0007] The incident angle calculation device according to this disclosure comprises: an analysis unit that generates information for controlling a laser processing machine according to a processing program; a control information acquisition unit that acquires control information including the trajectory of a processing point based on the processing program, the nozzle vector and focal length of the processing head of the laser processing machine; a beam information acquisition unit that acquires beam shape information for calculating the beam shape; and an incident angle calculation unit that calculates the beam incident angle, which is the angle between the side surface of the beam and the workpiece surface, from the control information and the beam shape information.

[0008] This is a block diagram of the incident angle calculation device of the first embodiment. This diagram illustrates beam shape information. This diagram illustrates the beam parameter product. This diagram illustrates the beam incident angle. This is an example of a display screen for the beam incident angle. This is an example of a display screen for the beam incident angle. This is a block diagram of the incident angle calculation device of the second embodiment. This diagram illustrates the correction of the beam incident angle. This is a block diagram of the incident angle calculation device of the third embodiment. This diagram shows an example of a multimode laser. This is a hardware configuration diagram of the incident angle calculation device.

[0009] Embodiments of this disclosure will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted.

[0010] In this application, "based on XX" means "based on at least XX," and includes cases where it is based on another element in addition to XX. Furthermore, "based on XX" is not limited to cases where XX is used directly, but also includes cases where it is based on something that has been calculated or processed. "XX" is any element (for example, any information).

[0011] The incident angle calculation device 100 of this embodiment can be applied to information processing devices such as numerical control devices and industrial PCs (personal computers). Specifically, it can be applied to actual machining, CAM (Computer-Aided Machining), simulations, and the like.

[0012] [First Embodiment] Figure 1 is a block diagram of the incident angle calculation device 100 of the first embodiment. The incident angle calculation device 100 comprises an analysis unit 11, a control information acquisition unit 12, a beam information acquisition unit 13, an incident angle calculation unit 14, an incident angle storage unit 15, and an incident angle display unit 16.

[0013] The analysis unit 11 analyzes the machining program and NC data, calculates the trajectory (coordinates) of the machining points, and creates control information for the mechanical and optical systems of the laser machining machine. The trajectory includes the program trajectory, command trajectory, and actual trajectory. The program trajectory is the shape data specified by the machining program. The command trajectory is an interpolated trajectory based on the command position and machine configuration information. The actual trajectory is a trajectory generated by connecting actual coordinates, for example, with straight lines.

[0014] The mechanical components include a galvanometer scanner for adjusting the beam angle, a stage for placing the workpiece, an axis for horizontally moving the machining head, and a robot for spatially moving the machining head. The analysis unit 11 generates commands to control each drive unit, such as galvanometer commands, stage commands, and robot commands.

[0015] The optical system includes components such as collimator lenses and focusing lenses. The laser beam generated by the oscillator is parallelized by the collimator lens and then focused by the focusing lens. The beam moves along a trajectory commanded by the processing program.

[0016] Information relating to the control of the laser processing machine by the analysis unit 11 is called control information. The control information includes at least the position and orientation of the processing head nozzle (called the nozzle vector) and the focal length of the focusing lens.

[0017] The control information acquisition unit 12 acquires control information. The control information acquisition unit 12 may also acquire information regarding the laser trajectory.

[0018] The beam information acquisition unit 13 acquires parameters for calculating the beam shape. Parameters that affect the beam shape are called beam shape information. The beam shape information includes the beam divergence angle θ. ｃ Beam West ω ０ , beam oscillation wavelength, M ２ These include factors, beam parameter products, etc. ２ The factors show a comparison between the actual beam shape and the ideal Gaussian beam shape, and the beam parameter product (BPP) defines the effect of the lens on the divergence and focusing of the laser beam. ２ The factor is expressed by the following formula.

[0019]

[0020] In the above formula, ω ０ is the beam waist, θ ｃ is the divergence angle of the laser, and λ is the oscillation wavelength. The divergence angle θ ｃ of the Gaussian beam is determined by the following formula.

[0021]

[0022] The M ２ factor may be referred to the specification, or may be actually measured with a beam profiler or the like. The divergence angle θ ２ can be calculated from the M ｃ factor. The shape of the beam is as shown in FIG. 2. FIG. 2 is a cross-sectional view of the beam. The actual shape of the beam is close to a conical shape with the outer periphery of a circle with a radius ω(z) (z is the distance from ω ０ as the side surface. ω ０ is called the beam waist and is the minimum value of the beam radius. The beam irradiates the work surface from the direction of the nozzle vector. The laser output from the nozzle converges at the divergence angle θ ｃ and the beam has a shape close to a cone with a divergence angle θ ｃ .

[0023] The beam parameter product (BPP) will be described with reference to FIG. 3. The beam parameter product is an expression that defines the influence of a lens on the spread and convergence of laser light. The beam parameter product can be expressed by the radius ω ０ of the beam waist and the full width at half maximum θ ｃ of the divergence angle of the beam. When converged by a focusing lens, there is the following relationship between the spot diameter and the divergence angle after the lens focus point.

[0024]

[0025] From this formula, it can be seen that deeper and faster processing can be achieved by reducing the beam waist and the convergence angle to reduce the beam parameter product.

[0026] The incident angle calculation unit 14 calculates the beam incident angle at each machining point based on the above-described formula. The incident angle calculation unit 14 calculates the beam incident angle θ ｂ from the nozzle vector and the beam shape. The cutting plane for calculating the beam incident angle θ ｂ is, for example, a plane perpendicular to the traveling direction of the beam. Referring to FIG. 4, the beam incident angle θ ｂ will be described. The beam incident angle is the angle formed by the workpiece surface and the side surface of the beam. The beam incident angle θ ｂ can be calculated from the angle θ ａ formed by the nozzle vector and the workpiece surface and the divergence angle θ of the beam. The beam incident angle θ ｂ is the value obtained by subtracting θ from θ ａ .

[0027] The incident angle storage unit 15 stores the beam incident angle at the machining point. By referring to the stored beam incident angle, the machining program and parameters can be adjusted.

[0028] The incident angle display unit 16 displays the beam incident angle at the machining point. The means for displaying the beam incident angle is not particularly limited. FIGS. 5 and 6 are examples of the display screen. FIG. 5 is a three-dimensional image. In the three-dimensional image of FIG. 5, the laser trajectory and the beam shape are superimposed and displayed. The three-dimensional image displays at least one of the trajectory (program trajectory, command trajectory, actual trajectory), the optical axis of the beam when passing through the trajectory, the beam shape, and the beam incident angle. The shape of the beam inside the workpiece is also displayed. The engineer can visually confirm the beam incident angle.

[0029] FIG. 6 is an image of the cutting plane of the beam. In the image of FIG. 6, the optical axis of the beam, the beam shape, the beam incident angle, and the shape of the workpiece are displayed. The shape of the beam inside the workpiece is also displayed. The engineer can visually confirm the beam incident angle. In the simulation, other processing conditions such as the type of beam and the laser mode may also be simulated and displayed considering the influence of the processing conditions. Other processing conditions will be described in the third embodiment.

[0030] [Second Embodiment] FIG. 7 is a block diagram of an incident angle calculation device 100 according to the second embodiment. The incident angle calculation device 100 according to the second embodiment includes a selection unit 17 and an incident angle correction unit 18. The selection unit 17 accepts the selection of a processed product or a waste material. The incident angle correction unit 18 calculates a correction value for correcting the deviation of the incident angle. Alternatively, it presents the deviation of the incident angle to an engineer and accepts the correction of the deviation by the engineer. In the second embodiment, the same configuration as that in the first embodiment is omitted from the description.

[0031] The selection unit 17 accepts the selection of the part that becomes a processed product and the part that becomes a waste material after cutting. Note that it may be automatically determined even if not selected by an engineer.

[0032] The analysis unit 11 analyzes the machining program and NC data and generates a command for controlling the laser processing machine. Here, an example is shown in which the nozzle vector is controlled so that the cut surface of the processed product is perpendicular so that the processed product does not have a taper. A processed product is a part that is used as a product after processing. A part that is not used as a product after processing is called a waste material.

[0033] Referring to FIG. 8, the shape of the beam, the inclination of the beam, and the correction of the beam incident angle will be described. In FIG. 8, the side surface of the beam is controlled to be perpendicular to the workpiece surface. That is, the beam is inclined toward the waste material side by the divergence angle θ.

[0034] The incident angle correction unit 18 calculates a correction value for the nozzle vector from the beam incident angle θ ｂ For example, if the angle of the ideal cut surface is 90°, the correction value is calculated so that the difference between the angle of the ideal cut surface and the beam incident angle θ ｄ becomes zero. The analysis unit 11 generates a command so that the nozzle vector is corrected by the correction value.

[0035] In FIG. 8, the beam incident angle θ ｄ is 80°. Assuming that the angle of the ideal cut surface is 90°, the correction value is calculated so that the beam incident angle θ ｄ becomes 90°.

[0036] [Third Embodiment] Figure 9 shows the incident angle calculation device 100 of the third embodiment. The incident angle calculation device 100 of the third embodiment includes a processing condition acquisition unit 19. The processing condition acquisition unit 19 acquires processing conditions that affect the beam incident angle. The incident angle calculation unit 14 calculates the beam shape based on beam shape information, taking the processing conditions into account.

[0037] The processing condition acquisition unit 19 acquires processing conditions from the analysis unit 11. Processing conditions include beam type, laser mode, oscillation state, frequency, duty cycle, assist gas type, assist gas pressure, workpiece information, gap amount with workpiece, nozzle diameter, nozzle shape, lens F value, spot diameter, etc.

[0038] Beam type, laser mode, oscillation state, frequency, and duty cycle are processing conditions related to oscillation. Processing conditions related to oscillation affect the shape of the beam. Beam types include Gaussian beams and Bessel beams. The beam type affects the spot diameter. There are two types of laser modes: single-mode and multi-mode. In single-mode, the beam shape is circular and the power is concentrated at its center. Multi-mode lasers can consist of multiple circles. A ring-mode laser, one type of multi-mode laser, is composed of two beams, a center beam and a ring beam, as shown in Figure 11. In this case, the incident angle calculation unit 14 calculates the beam incident angle of at least one of the two beams. Oscillation states include pulse oscillation, which repeats emission at regular intervals, and continuous oscillation, which continuously oscillates with a constant output. The frequency is determined by the oscillation medium. The duty cycle is related to energy.

[0039] The assist gas type and assist gas pressure are processing conditions related to the assist gas. Processing conditions related to the assist gas affect the cut surface of the workpiece. The assist gas type affects processing quality and processing capacity. The assist gas pressure affects the discharge of metal molten by the laser beam from the cutting groove.

[0040] Workpiece information includes the material, thickness, and surface condition of the workpiece. The material, thickness, and surface condition of the workpiece also affect the cut surface of the workpiece.

[0041] The gap between the workpiece and the nozzle affects both the assist gas and the laser power. Machining conditions related to the nozzle affect the cut surface of the workpiece. Nozzle diameter and nozzle shape are machining conditions related to the nozzle of the machining head. The molten metal discharge capacity depends on the assist gas pressure, but nozzle diameter and nozzle shape also play a role.

[0042] Lens f-number and spot diameter are manufacturing conditions related to the lens. The lens f-number is the value obtained by dividing the lens's focal length by its effective aperture. The spot diameter is determined by the lens specifications, and the shorter the focal length lens, the smaller the diameter.

[0043] The incidence angle calculation unit 14 calculates the beam incidence angle by taking into account the beam shape information acquired by the beam information acquisition unit 13, the processing conditions that affect the beam shape, and the processing conditions that affect the processed surface of the workpiece. Simulation or the like is used to calculate the beam incidence angle that takes processing conditions into account.

[0044] The hardware configuration of the incident angle calculation device 100 to which this disclosure is applied will be described below. Figure 11 is a hardware configuration diagram of the incident angle calculation device 100. As shown in Figure 11, the incident angle calculation device 100 includes a CPU 111 that controls the incident angle calculation device 100 as a whole, a ROM 112 that stores programs and data, and a RAM 113 for temporarily expanding data. The CPU 111 reads the system program stored in the ROM 112 via a bus.

[0045] The non-volatile memory 114 is backed up, for example, by a battery (not shown), so that its stored state is maintained even when the incident angle calculation device 100 is turned off. The non-volatile memory 114 stores various data, such as programs read from an external device 120 via interfaces 115, 118, and 119, and operation inputs input via the input device 20. The non-volatile memory 114 may also store programs and data for running the incident angle calculation device 100 of this embodiment.

[0046] Interface 115 is an interface for connecting the incident angle calculation device 100 to an external device 120 such as an adapter. Programs and various parameters are read from the external device 120. Interface 118 is an interface for connecting the incident angle calculation device 100 to a display device 30 such as a liquid crystal display. The display device 30 displays data read into memory, data obtained as a result of executing programs, etc. Interface 119 is an interface for connecting the incident angle calculation device 100 to an input device 20 such as a keyboard or pointing device. The input device 20 passes commands, data, etc. based on operator operations to the CPU 111 via interface 119.

[0047] While embodiments of this disclosure have been described in detail above, this disclosure is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the spirit of the invention or from the idea and intent of this disclosure derived from the claims and their equivalents. For example, the order of operations and processes in the embodiments described above are shown as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0048] The following are appendices to embodiments of the present disclosure. (Appendix 1) An incident angle calculation device (100) according to one aspect of the present disclosure includes: an analysis unit (11) that generates information for controlling a laser processing machine according to a processing program; a control information acquisition unit (12) that acquires control information including the trajectory of processing points based on the processing program, the nozzle vector and focal length of the processing head of the laser processing machine; a beam information acquisition unit (13) that acquires beam shape information for calculating the beam shape; and an incident angle calculation unit (14) that calculates the beam incident angle, which is the angle between the side surface of the beam and the work surface, from the control information and the beam shape information. (Appendix 2) The incident angle calculation device (100) includes an incident angle display unit (16) that displays the beam incident angle. (Appendix 3) The incident angle display unit (16) displays the beam incident angle to the workpiece as an image. (Note 4) The incident angle calculation device (100) includes an incident angle correction unit (18) that causes the analysis unit (11) to generate control information to correct the beam incident angle so that the difference between the angle of the ideal cut surface of the workpiece and the beam incident angle becomes small. (Note 5) The incident angle correction unit (18) corrects the beam incident angle so that the cut surface of the workpiece is perpendicular. (Note 6) It includes a processing condition acquisition unit (19) that acquires processing conditions that affect the beam incident angle, and the incident angle calculation unit (14) calculates the beam incident angle based on the control information, the beam shape information and the processing conditions. (Note 7) Computer-readable storage media (112, 113, 114) record a program that causes the computer to operate as an analysis unit (11) that generates information to control the laser processing machine according to a processing program; a control information acquisition unit (12) that acquires control information including the trajectory of processing points based on the processing program and the nozzle vector and focal length of the processing head of the laser processing machine; a beam information acquisition unit (13) that acquires beam shape information for calculating the beam shape; and an incidence angle calculation unit (14) that calculates the beam incidence angle, which is the angle between the side surface of the beam and the work surface, from the control information and the beam shape information.

[0049] 100 Incidence angle calculation device 11 Analysis unit 12 Control information acquisition unit 13 Beam information acquisition unit 14 Incidence angle calculation unit 15 Incidence angle storage unit 16 Incidence angle display unit 18 Incidence angle correction unit 19 Processing condition acquisition unit 111 CPU 112 ROM 113 RAM 114 Non-volatile memory

Claims

1. An incident angle calculation device comprising: an analysis unit that generates information for controlling a laser processing machine according to a processing program; a control information acquisition unit that acquires control information including the trajectory of the processing point based on the processing program, the nozzle vector and focal length of the processing head of the laser processing machine; a beam information acquisition unit that acquires beam shape information for calculating the beam shape; and an incident angle calculation unit that calculates the beam incident angle, which is the angle between the side surface of the beam and the work surface, from the control information and the beam shape information.

2. The incident angle calculation device according to claim 1, further comprising an incident angle display unit for displaying the beam incident angle.

3. The incident angle display unit displays the beam incident angle to the workpiece as an image, the incident angle calculation device according to claim 2.

4. The incident angle calculation device according to claim 1, further comprising an incident angle correction unit that generates control information for correcting the beam incident angle so that the difference between the angle of the ideal cut surface of the workpiece and the beam incident angle becomes small.

5. The incident angle calculation device according to claim 4, wherein the incident angle correction unit corrects the beam incident angle so that the cut surface of the workpiece is perpendicular.

6. The incident angle calculation device according to claim 1, comprising a processing condition acquisition unit that acquires processing conditions that affect the beam incident angle, wherein the incident angle calculation unit calculates the beam incident angle based on the control information, the beam shape information, and the processing conditions.

7. A computer-readable storage medium that records a program causing the computer to operate as: an analysis unit that generates information to control a laser processing machine according to a processing program; a control information acquisition unit that acquires control information including the trajectory of the processing point based on the processing program, the nozzle vector and focal length of the processing head of the laser processing machine; a beam information acquisition unit that acquires beam shape information for calculating the beam shape; and an incidence angle calculation unit that calculates the beam incidence angle, which is the angle between the side surface of the beam and the workpiece surface, from the control information and the beam shape information.

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