Laser irradiation system and laser irradiation method

Abstract

The problem that this invention aims to solve is to provide a laser irradiation system and a laser irradiation method that can set the range and conditions of laser irradiation according to the surface irregularities of an additively manufactured object. [Solution] In order to achieve the above objectives, the laser irradiation system of this embodiment is characterized by comprising: an additive manufacturing information input unit for inputting information of an additive manufacturing product; a surface treatment request value input unit for inputting a surface treatment request value which is a request value for determining whether to perform surface treatment by laser irradiation on the surface roughness of the additive manufacturing product; a surface condition confirmation unit for measuring the surface roughness of the additive manufacturing product; and a surface condition comparison unit for comparing the surface treatment request value with the measured value of the surface roughness.

Description

Technical Field

[0001]

[0001] The present invention relates to a laser irradiation system and a laser irradiation method.

Background Art

[0002] A metal 3D printer is a device that laminates and shapes metal based on digital data, and laminates and shapes it into a predetermined shape by melting or sintering a metal material with a laser or an electron beam. The metal 3D printer can laminate and shape metal parts and molds with complex shapes, and can also laminate and shape metal parts and molds having high strength, high heat resistance, and high thermal conductivity.

[0003] In this metal 3D printer, since a metal material is melted or sintered to laminate and shape it into a predetermined shape, surface irregularities may occur due to the remaining unmelted metal material on the surface of the laminated and shaped object. In particular, the more complex the shape of the laminated and shaped object is, the greater the surface irregularities generated in the laminated and shaped object, and there is a risk that the dimensional accuracy of the laminated and shaped object will decrease. On the other hand, as one means for improving the surface irregularities generated in the laminated and shaped object, a surface treatment technique by laser irradiation is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the surface treatment technique by laser irradiation, control for setting the range and conditions of laser irradiation according to the surface irregularities of the laminated and shaped object has not yet been proposed.

[0006] The present invention addresses these circumstances, and the problem that the present invention aims to solve is to provide a laser irradiation system and a laser irradiation method that can set the range and conditions of laser irradiation according to the surface irregularities of an additively manufactured object. [Means for solving the problem]

[0007] The laser irradiation device according to this embodiment is characterized by comprising: an additive manufacturing information input unit for inputting information of an additive manufacturing product; a surface treatment request value input unit for inputting a surface treatment request value which is a request value for determining whether to perform surface treatment by laser irradiation on the surface roughness of the additive manufacturing product; a surface condition confirmation unit for measuring the surface roughness of the additive manufacturing product; and a surface condition comparison unit for comparing the surface treatment request value with the measured value of the surface roughness.

[0008] The laser irradiation method according to this embodiment is characterized by including the steps of: inputting information of a laminated product; inputting a surface treatment request value, which is a request value for determining whether to perform surface treatment by laser irradiation on the surface roughness of the laminated product; measuring the surface roughness of the laminated product; and comparing the surface treatment request value with the measured value of the surface roughness. [Effects of the Invention]

[0009] Embodiments of the present invention have been made to solve the above-mentioned problems, and allow the range and conditions of laser irradiation to be set according to the surface irregularities of the additively manufactured object. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic side view showing the configuration of a laser irradiation device according to the first embodiment. [Figure 2] A block diagram showing the system configuration of the laser irradiation system according to the first embodiment. [Figure 3] A diagram showing an example of data related to material properties. [Figure 4] A diagram showing an example of data illustrating the relationship between laser power and removal amount. [Figure 5] A plan view showing an example of the trajectory of laser irradiation by a laser irradiation device. [Figure 6] (a) to (f) are side views illustrating examples of the operation of a laser irradiation device. [Figure 7] A flowchart of the laser irradiation method according to the first embodiment. [Figure 8] (a) to (e) are side views illustrating examples of the operation of a laser irradiation device. [Figure 9] A schematic side view showing the configuration of a laser irradiation device according to the second embodiment. [Figure 10] An explanatory diagram showing an example of a distribution map in a grid-like layered fabricated object. [Figure 11] A flowchart of the laser irradiation method according to the third embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, a laser irradiation apparatus and a laser irradiation method according to embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments shown below are illustrative examples of embodiments of the present invention and are not intended to limit the scope of the invention. Furthermore, in the drawings referenced in the embodiments, the same or similar reference numerals are used for identical parts or parts having similar functions, and their descriptions may be omitted. Also, the dimensional ratios in the drawings may differ from the actual ratios, and some components may be omitted from the drawings.

[0012] (First embodiment) The laser irradiation device 1 according to the first embodiment will be described with reference to Figure 1. Figure 1 is a schematic side view showing the configuration of the laser irradiation device 1 according to the first embodiment. Figure 1 shows the laser irradiation device 1 according to the first embodiment irradiating the irradiation position 4 on the surface irregularities 3 of the additively manufactured object 2 with a laser. As shown in Figure 1, the laser irradiation device 1 comprises a laser oscillator 10, a laser optical path mechanism 20, and a focusing lens unit 30.

[0013] The laser oscillator 10 is a device that oscillates a pulsed laser 11. The laser oscillator 10 oscillates a pulsed laser 11 for surface treatment by laser irradiation, for example. The laser oscillator 10 is appropriately selected according to the application. For example, when laser irradiation is performed on a metal material, a laser oscillator 10 that oscillates a Nd:YAG laser with a wavelength of 1064 nm or 532 nm and a pulse width of several ns to several tens of ns may be selected. Also, for example, when laser irradiation is performed on a material such as an aluminum alloy or resin, a laser oscillator 10 that oscillates a Nd:YAG laser with a wavelength of 1064 nm or 532 nm and a pulse width of several hundred fs to several ps may be selected. Note that the present invention is not limited to this example, and any laser oscillator that can oscillate a pulsed laser capable of performing surface treatment on the surface of the laminated object 2 when laser irradiation is performed may be used.

[0014] The laser optical path mechanism 20 is a mechanism that serves as the optical path of the pulsed laser 11 irradiated from the laser oscillator 10. The laser optical path mechanism 20 includes at least two mirrors as an optical system for reflecting the pulsed laser 11. In the first embodiment, the laser optical path mechanism 20 includes a first mirror 21 and a second mirror 22. The first mirror 21 is installed at a position and angle capable of reflecting the pulsed laser 11 irradiated from the laser oscillator 10 toward the second mirror 22. The second mirror 22 is installed at a position and angle capable of reflecting the pulsed laser 11 reflected by the first mirror 21 toward the condenser lens unit 30. Also, at least the second mirror 22 is configured to be able to change its angle in order to adjust the irradiation position 4 of the pulsed laser 11 on the laminated object 2. That is, the laser optical path mechanism 20 is configured to be able to irradiate the pulsed laser 11 at a predetermined irradiation position 4 on the laminated object 2 by changing at least the angle of the second mirror 22.

[0015] The laser optical path mechanism 20 also includes an attenuator 23 and a shutter 24. The attenuator 23 is provided between the laser oscillator 10 and the condenser lens unit 30. In the first embodiment, the attenuator 23 is provided between the laser oscillator 10 and the first mirror 21. The attenuator 23 is an optical system for adjusting the energy of the pulsed laser 11 irradiated on the laminated object 2. The shutter 24 is provided between the laser oscillator 10 and the condenser lens unit 30. In the first embodiment, the shutter 24 is provided between the second mirror 22 and the condenser lens unit 30. The shutter 24 is a mechanism for blocking the optical path of the pulsed laser 11.

[0016] The condenser lens unit 30 is an optical system that condenses the pulsed laser 11 that has passed through the laser optical path mechanism 20. The condenser lens unit 30 is configured to be able to condense the pulsed laser 11 that has passed through the laser optical path mechanism 20 into a predetermined spot diameter toward the irradiation position 4 on the laminated object 2. Specifically, the condenser lens unit 30 includes at least two lenses as an optical system for condensing the pulsed laser 11. In the first embodiment, the condenser lens unit 30 includes a first lens 31 and a second lens 32. At least one of the first lens 31 and the second lens 32 is configured to be able to change the distance between the lenses in order to adjust the focal length of the pulsed laser 11. That is, the condenser lens unit 30 is configured to be able to condense the pulsed laser 11 into a predetermined spot diameter at the irradiation position 4 on the laminated object 2 by changing the distance between the first lens 31 and the second lens 32. Although the spot diameter of the pulsed laser 11 can be changed by the condenser lens unit 30, it is necessary to set at least the spot diameter at which ablation plasma is generated at the irradiation position 4 of the pulsed laser 11.

[0017] With this configuration, the pulsed laser 11 emitted from the laser oscillator 10 is irradiated onto the additively manufactured object 2 via the laser optical path mechanism 20 and the focusing lens unit 30. At this time, by changing the angle of at least the second mirror 22, the pulsed laser 11 can be irradiated onto the additively manufactured object 2 at a predetermined irradiation position 4. Furthermore, by changing the distance between the first lens 31 and the second lens 32, the pulsed laser 11 irradiated onto the additively manufactured object 2 at the predetermined irradiation position 4 can be set to a predetermined spot diameter.

[0018] Next, the laser irradiation system 40 according to the first embodiment will be described using Figure 2. Figure 2 is a block diagram showing the system configuration of the laser irradiation system 40 according to the first embodiment. The laser irradiation system 40 is a system that controls the laser irradiation device 1. The laser irradiation system 40 is realized by executing a software program and / or instruction set stored in memory or HDD by one or more processors. As shown in Figure 2, the laser irradiation system 40 includes an additive manufacturing information input unit 41, a surface treatment request value input unit 42, a surface condition confirmation unit 43, a surface condition comparison unit 44, a surface treatment area setting unit 45, a laser irradiation condition setting unit 46, a database unit 47, a device control unit 48, an information input unit 49, a display output unit 50, and a main control unit 51.

[0019] The additive manufacturing object information input unit 41 is a means for inputting information about the additive manufacturing object 2 that is to be irradiated with a laser. The information about the additive manufacturing object 2 that is to be irradiated with a laser, as referred to here, refers to design information that includes at least one of the materials used for the additive manufacturing object 2 and the dimensions of the additive manufacturing object 2. This design information may also include design information such as the roughness and tolerances of the additive manufacturing object 2. For example, 3D-CAD drawings can be input into the manufacturing unit information input unit 41.

[0020] The surface treatment requirement input unit 42 is a means for inputting the surface treatment requirement for the additively manufactured object 2 that is to be laser-irradiated. The surface treatment requirement here refers to the requirement value used to determine whether or not to perform surface treatment by laser irradiation on the surface roughness of the additively manufactured object 2. The surface roughness here refers to the difference in the direction of the normal vector of the actual surface (magnitude of surface irregularities) when compared with the design (ideal surface) of the additively manufactured object 2 input in the additively manufactured object information input unit 41. For example, the target maximum height roughness value and the centerline average roughness value can be input as surface treatment requirement values.

[0021] The surface condition confirmation unit 43 is a means for confirming the surface roughness of the additively manufactured object 2 that is to be irradiated with a laser. The surface condition confirmation unit 43 measures the surface roughness of the additively manufactured object 2. Specifically, the surface condition confirmation unit 43 controls a non-contact surface roughness measuring instrument using a pulsed laser or a surface roughness measuring instrument built into a laser microscope to measure the surface roughness of the additively manufactured object 2. For example, if a dichroic mirror is used as the first mirror 21 to reflect the wavelength of the pulsed laser 11 irradiated from the laser oscillator 10 and transmit other wavelengths, the surface condition confirmation unit 43 measures the surface roughness of the additively manufactured object 2 by controlling a means for confirming images, such as a CCD camera (see reference numeral 43a in Figure 1). The surface condition confirmation unit 43 may also create a distribution map of the surface roughness of the additively manufactured object 2 based on the surface roughness measurement values ​​at each measurement point.

[0022] The surface condition comparison unit 44 is a means for comparing the surface treatment request value entered in the surface treatment request value input unit 42 with the surface roughness measurement value measured by the surface condition confirmation unit 43. Specifically, the surface condition comparison unit 44 determines whether the surface roughness measurement value exceeds the surface treatment request value. Furthermore, if the surface roughness measurement value exceeds the surface treatment request value, the surface condition comparison unit 44 may calculate the difference between the surface roughness measurement value and the surface treatment request value. For example, if the target maximum height roughness value is entered as the surface treatment request value in the surface treatment request value input unit 42, the surface condition comparison unit 44 determines whether the surface roughness measurement value exceeds the target maximum height roughness value. Then, if the surface roughness measurement value exceeds the target maximum height roughness value, the surface condition comparison unit 44 may calculate the difference between the surface roughness measurement value and the target maximum height roughness value. For example, if the target centerline average roughness value is entered as the surface treatment request value in the surface treatment request value input unit 42, the surface condition comparison unit 44 will determine whether the measured surface roughness value exceeds the target centerline average roughness value. If the measured surface roughness value exceeds the target centerline average roughness value, the surface condition comparison unit 44 may calculate the difference between the measured surface roughness value and the target centerline average roughness value. The surface condition comparison unit 44 may also compare the surface treatment request value entered in the surface treatment request value input unit 42 with the distribution diagram created by the surface condition confirmation unit 43.

[0023] The surface treatment area setting unit 45 is a means for setting areas on the additively fabricated object 2 to be subjected to laser irradiation surface treatment. Specifically, the surface treatment area setting unit 45 sets areas where the surface roughness measurement value is determined by the surface condition comparison unit 44 to exceed the surface treatment requirement value as areas to be subjected to laser irradiation surface treatment. At this time, the surface treatment area setting unit 45 may set one area or multiple areas.

[0024] The laser irradiation condition setting unit 46 is a means for setting the conditions for performing surface treatment on the additively fabricated object 2 by laser irradiation. The conditions for surface treatment by laser irradiation referred to here are the energy of the pulsed laser 11, the spot diameter, the coverage, and the scanning direction and pitch direction. The laser irradiation condition setting unit 46 comprises an energy setting unit 46a, a spot diameter setting unit 46b, a coverage setting unit 46c, and a direction setting unit 46d.

[0025] The energy setting unit 46a is a means for setting the energy of the pulsed laser 11 when performing surface treatment by laser irradiation.

[0026] The spot diameter setting unit 46b is a means for setting the spot diameter of the pulsed laser 11 when performing surface treatment by laser irradiation.

[0027] The coverage setting unit 46c is a means for setting the coverage, which is the coverage rate of the pulsed laser 11 when performing surface treatment by laser irradiation. The coverage referred to here can also be a standard that represents the number of laser irradiations per unit length or unit area.

[0028] The direction setting unit 46d is a means for setting the scanning direction and pitch direction of the pulse laser 11 when performing surface treatment by laser irradiation.

[0029] The laser irradiation condition setting unit 46 sets the conditions for performing surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45, based on the surface treatment request value entered in the surface treatment request value input unit 42 and the surface roughness measurement value measured by the surface condition confirmation unit 43. For example, the laser irradiation condition setting unit 46 sets conditions suitable for performing surface treatment by laser irradiation using data stored in the database unit 47, with the difference between the surface roughness measurement value calculated by the surface condition comparison unit 44 and the surface treatment request value as the amount to be removed by surface treatment. If it is not possible to set conditions that satisfy the surface treatment request value using the data stored in the database unit 47, the surface treatment request value entered in the surface treatment request value input unit 42 may be reviewed.

[0030] The database unit 47 is a means for storing and retrieving data. The database unit 47 stores data on various materials, as well as data on the results of surface treatment of various materials by laser irradiation under various conditions.

[0031] For example, the database unit 47 stores data on material properties as shown in Figure 3. Figure 3 is a diagram illustrating an example of data on material properties. Figure 3 illustrates a case where the database unit 47 stores data on material properties for stainless steels such as SUS316L and 12Cr steel, pure aluminum (Al), and nickel alloys such as Alloy625, Alloy718, and Alloy600. However, it is not limited to this case, and the database unit 47 may also store data on material properties for other materials.

[0032] For example, the database unit 47 stores data showing the relationship between laser power and removal amount, as shown in Figure 4. Figure 4 is a diagram showing an example of data showing the relationship between laser power and removal amount. In Figure 4, the horizontal axis shows the laser power (W) of the pulsed laser 11, and the vertical axis shows the amount of material removed from the additively fabricated object 2 (mg) as a percentage of the laser power of the pulsed laser 11, assuming that the spot diameter and coverage of the pulsed laser 11 are constant. Figure 4 also illustrates data showing the relationship between laser power and removal amount when the metal material SUS316L is irradiated with a laser under the conditions of pulse energy 300mJ, spot diameter 1.0mm, and coverage 95% (hereinafter referred to as condition A), and data showing the relationship between laser power and removal amount when the metal material SUS316L is irradiated with a laser under the conditions of pulse energy 70mJ, spot diameter 0.7mm, and coverage 90% (hereinafter referred to as condition B). Under condition A, for example, when the frequency of the laser oscillator 10 is 300Hz, the laser power is 90W (=300mJ × 300Hz). In this case, the amount of material removed from the additively manufactured object 2 when irradiated with a laser under condition A is calculated to be 1mg. Under condition B, for example, when the frequency of the laser oscillator 10 is 400Hz, the laser power is 28W (=70mJ × 400Hz). In this case, the amount of material removed from the additively manufactured object 2 when irradiated with a laser under condition B is calculated to be 0.2mg.

[0033] In this way, the laser irradiation condition setting unit 46 uses the data stored in the database unit 47 to set the optimal laser irradiation conditions according to the material of the additively fabricated object 2, using the difference between the surface roughness measurement value calculated by the surface condition comparison unit 44 and the surface treatment requirement value as the amount to be removed by surface treatment.

[0034] The device control unit 48 controls the laser irradiation device 1 and performs surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45. The device control unit 48 controls the laser irradiation device 1 based on the conditions set by the laser irradiation condition setting unit 46. Specifically, the device control unit 48 adjusts the energy, spot diameter, coverage, scanning direction, and pitch direction of the pulsed laser 11 based on the conditions set by the laser irradiation condition setting unit 46. For example, the device control unit 48 adjusts the energy of the pulsed laser 11 by controlling the laser oscillator 10, attenuator 23, or shutter 24. Alternatively, the device control unit 48 adjusts the spot diameter of the pulsed laser 11 by controlling the focusing lens unit 30.

[0035] Here, using Figure 5, we will explain an example of the control of the laser irradiation device 1 by the device control unit 48 for one region C set by the surface treatment region setting unit 45. Figure 5 is a plan view showing an example of the trajectory of laser irradiation by the laser irradiation device 1.

[0036] As shown in Figure 5, the device control unit 48 controls the laser irradiation device 1 to scan the pulsed laser 11 in the scanning direction (X direction) of one region C set by the surface treatment region setting unit 45. As a result, multiple irradiation spots D are formed aligned along the scanning direction. At this time, the number of irradiation spots D varies depending on the coverage. After scanning in the scanning direction, the device control unit 48 controls the laser irradiation device 1 to shift the irradiation position of the pulsed laser 11 in the pitch direction (Y direction) and scan again in the scanning direction. By repeating this, the irradiation spots D in region C trace a trajectory E. In other words, the device control unit 48 controls the laser irradiation device 1 so that in region C, rows of multiple irradiation spots aligned along the scanning direction are aligned in the pitch direction.

[0037] In this example, the additively manufactured object 2 is fixed, and the laser irradiation device 1 is moved relative to the additively manufactured object 2 in the scanning direction or pitch direction. However, the explanation is not limited to this case. For example, the laser irradiation device 1 may be fixed, and the additively manufactured object 2 may be moved relative to the laser irradiation device 1 in the scanning direction or pitch direction. Alternatively, for example, both the laser irradiation device 1 and the additively manufactured object 2 may be moved in different directions.

[0038] The information input unit 49 is a means for inputting predetermined information to the laser irradiation device 1 and the laser irradiation system 40 through user operation. The information input unit 49 is, for example, an input device such as a mouse or keyboard.

[0039] The display output unit 50 is a means for outputting the results obtained from the laser irradiation device 1 and the laser irradiation system 40. The display output unit 50 is, for example, an output device such as a display or a printer.

[0040] The main control unit 51 is a means for comprehensively controlling the laser irradiation system 40.

[0041] Based on the above configuration, the laser irradiation device 1 performs a series of operations, such as those shown in Figure 6, under the control of the laser irradiation system 40. Figures 6(a) to (f) are side views showing examples of the operation of the laser irradiation device 1. In Figure 6, an example is shown in which, within one region of the additively fabricated object 2 set by the surface treatment area setting unit 45, there are surface irregularities 3 that exceed the surface treatment request value input unit 42, and these include a surface irregularity 3a with relatively small surface roughness and a surface irregularity 3b with relatively large surface roughness.

[0042] As shown in Figure 6(a), the laser irradiation device 1 is controlled to irradiate the surface irregularities 3 of the additively manufactured object 2 with a laser under conditions set by the laser irradiation condition setting unit 46. At this time, the focal length of the pulsed laser 11 is adjusted by the focusing lens unit 30 so that the spot diameter at the irradiation position 4 is set by the laser irradiation condition setting unit 46. In the surface irregularities 3 that overlap with the irradiation position 4 of the pulsed laser 11, ablation plasma is generated, thereby performing surface treatment by laser irradiation. The laser irradiation device 1 is controlled to move in direction F relative to the additively manufactured object 2.

[0043] As shown in Figure 6(b), when the laser irradiation device 1 irradiates the surface uneven portion 3a with a laser, a surface unevenness removal portion 3c is formed on the surface uneven portion 3a. As a result, the surface roughness of the surface uneven portion 3a is reduced compared to before laser irradiation. Next, the laser irradiation device 1 irradiates the surface uneven portion 3b with a laser. However, if the laser irradiation is performed in the same manner as for the surface uneven portion 3a, the distance from the focusing lens unit 30 to the irradiation position 4 becomes shorter, and the spot diameter of the pulsed laser 11 becomes larger, resulting in a decrease in the accuracy of the surface treatment.

[0044] In contrast, as shown in Figure 6(c), the laser irradiation device 1 is controlled to adjust the focal length of the pulsed laser 11 by changing the distance between the lenses of the focusing lens unit 30. This allows the laser irradiation device 1 to irradiate surface irregularities 3b with different surface roughnesses under the conditions set by the laser irradiation condition setting unit 46. However, this is not limited to this case, and in order to enhance the effect of surface treatment on surface irregularities 3b, different conditions from those for surface irregularities 3a may be set by the laser irradiation condition setting unit 46 for laser irradiation of surface irregularities 3b.

[0045] As shown in Figure 6(d), when the laser irradiation device 1 irradiates the surface irregularities 3b with a laser, a surface irregularity removal area 3c is formed on the surface irregularities 3b. As a result, the surface roughness of the surface irregularities 3b is reduced compared to before laser irradiation. However, in areas with relatively large surface roughness, such as the surface irregularities 3b, a single laser irradiation may not be sufficient for surface treatment. In other words, after a single laser irradiation, the surface roughness of the surface irregularities 3b may still exceed the required surface treatment value.

[0046] Therefore, as shown in Figure 6(e), the laser irradiation device 1 measures the surface roughness of the additively fabricated object 2 again using the surface condition confirmation unit 43, and controls the device to irradiate the area (in this example, the surface irregularities 3b) that the surface condition comparison unit 44 determines still exceeds the required surface treatment value with the laser again. The conditions for the second and subsequent laser irradiations may be the same as those for the previous laser irradiations, or they may be set again by the laser irradiation condition setting unit 46.

[0047] As shown in Figure 6(f), the laser irradiation device 1 is controlled to repeat surface treatment by laser irradiation until the surface roughness of the surface irregularities 3 on the surface of the additively fabricated object 2 becomes less than or equal to the surface treatment requirement value. Alternatively, the laser irradiation device 1 may be controlled to irradiate the area set by the surface treatment area setting unit 45 with laser a predetermined number of times.

[0048] Next, the laser irradiation method 100 according to the first embodiment will be described using Figure 7. Figure 7 is a flowchart of the laser irradiation method 100 according to the first embodiment.

[0049] First, the user inputs information about the additively manufactured object 2 to be irradiated with the laser into the additively manufactured object information input unit 41 (step S101).

[0050] Next, the user inputs the surface treatment requirement values ​​for the additively manufactured object 2 to be laser-irradiated into the surface treatment requirement value input unit 42 (step S102).

[0051] Next, the surface condition confirmation unit 43 measures the surface roughness of the additively fabricated object 2 that is to be irradiated with the laser (step S103).

[0052] Next, the surface condition comparison unit 44 compares the surface treatment request value input in the surface treatment request value input unit 42 with the surface roughness measurement value measured by the surface condition confirmation unit 43, and determines whether the surface roughness measurement value exceeds the surface treatment request value (step S104).

[0053] If the surface roughness measurement value exceeds the surface treatment requirement value (if the answer to step S105 is YES), the process proceeds to step S106. On the other hand, if the surface roughness measurement value does not exceed the surface treatment requirement value (if the answer to step S105 is NO), the process proceeds to step S113, and the surface treatment by the laser irradiation method 100 is terminated.

[0054] Next, the surface treatment area setting unit 45 sets the areas where the surface roughness measurement value determined by the surface condition comparison unit 44 exceeds the surface treatment requirement value as areas to be treated by laser irradiation (step S106).

[0055] Next, the laser irradiation condition setting unit 46 sets the conditions for performing surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45 (step S107). For example, the laser irradiation condition setting unit 46 sets conditions suitable for performing surface treatment by laser irradiation using data stored in the database unit 47, with the difference between the surface roughness measurement value calculated by the surface condition comparison unit 44 and the surface treatment request value as the amount to be removed by surface treatment.

[0056] If it is possible to set conditions that satisfy the surface treatment requirements using the data stored in the database unit 47 (if the answer to step S108 is YES), the process proceeds to step S109. On the other hand, if it is not possible to set conditions that satisfy the surface treatment requirements using the data stored in the database unit 47 (if the answer to step S108 is NO), the process returns to step S102, and the surface treatment requirements to be entered into the surface treatment requirement input unit 42 are reviewed.

[0057] Next, the device control unit 48 controls the laser irradiation device 1 based on the conditions set by the laser irradiation condition setting unit 46 and performs surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45 (step S109).

[0058] Next, after performing surface treatment by laser irradiation, the surface condition confirmation unit 43 measures the surface roughness of the additively fabricated object 2 again (step S110).

[0059] Next, the surface condition comparison unit 44 compares the surface treatment request value input in the surface treatment request value input unit 42 with the remeasured surface roughness value measured again by the surface condition confirmation unit 43, and determines again whether the remeasured surface roughness value exceeds the surface treatment request value (step S111).

[0060] If the remeasured surface roughness value exceeds the surface treatment requirement value (if the answer to step S112 is YES), the process returns to step S106 and repeats from step S106 onward. On the other hand, if the remeasured surface roughness value does not exceed the surface treatment requirement value (if the answer to step S112 is NO), the process proceeds to step S113 and the surface treatment by the laser irradiation method 100 is terminated. In the case of YES in step S112, the laser irradiation may be repeated a predetermined number of times. In either case, the area irradiated with laser and the remeasured surface roughness value after laser irradiation may be output.

[0061] As described above, according to the first embodiment, by controlling the laser irradiation device 1 with the laser irradiation system 40, the range and conditions of laser irradiation can be set according to the surface roughness of the additively manufactured object 2. This makes it possible to effectively perform surface treatment by laser irradiation on the surface roughness of the additively manufactured object 2.

[0062] In the first embodiment, Figure 6 illustrates the case where the laser irradiation device 1 irradiates the upper surface of the additively manufactured object 2 with a laser, but the embodiment is not limited to this case. For example, as shown in Figure 8, the laser irradiation device 1 may irradiate the side surface of the additively manufactured object 2 with a laser.

[0063] Figures 8(a) to 8(e) are side views showing examples of the operation of the laser irradiation device 1. As shown in Figures 8(a) to 8(e), the laser irradiation device 1 may be controlled to irradiate the surface irregularities 3 on the side surface of the additively manufactured object 2 with a laser under conditions set by the laser irradiation condition setting unit 46. In this case, the laser irradiation device 1 may adjust the laser irradiation angle by tilting the entire laser irradiation device 1 in order to irradiate the side surface of the additively manufactured object 2 with a laser. Alternatively, the laser irradiation angle may be adjusted by adjusting the angle of the first mirror 21, the second mirror 22, or the focusing lens unit 30. Note that the explanation of the series of operations using Figure 8 is the same as the explanation of the series of operations using Figure 6, except for the difference between laser irradiation to the top surface or laser irradiation to the side surface of the additively manufactured object 2, so it will be omitted.

[0064] Furthermore, in the first embodiment, Figure 7 illustrates a flowchart relating to the laser irradiation method 100 in which each step is executed in series, but the embodiment is not limited to this case. For example, the order of some steps may be reversed. Also, for example, some steps may be executed in parallel with other steps.

[0065] (Second Embodiment) The laser irradiation device 200 according to the second embodiment will be described using Figure 9. Figure 9 is a schematic side view showing the configuration of the laser irradiation device 200 according to the second embodiment. Hereafter, the differences from the first embodiment will be described, and parts that are the same as in the first embodiment will be given the same figure numbers and their descriptions will be omitted.

[0066] As shown in Figure 9, the laser irradiation device 200 comprises a laser oscillator 10, a laser optical path mechanism 20, a focusing lens unit 30, and a fluid supply mechanism 210. In other words, the laser irradiation device 200 differs from the laser irradiation device 1 according to the first embodiment in that it further comprises a fluid supply mechanism 210. This laser irradiation device 200 is controlled by a laser irradiation system 40.

[0067] The fluid supply mechanism 210 is a device that supplies fluid 215 to the additively manufactured object 2 that is to be laser-irradiated. The fluid supply mechanism 210 is configured to adjust the flow rate and pressure of the fluid 215 supplied to the additively manufactured object 2. The fluid 215 can be water, water mixed with a rust inhibitor, ammonia water, alkaline ionized water, or rust-preventive oil. For example, when water is used as the fluid 215, laser irradiation can be performed while suppressing losses in the water. Also, for example, when water mixed with a rust inhibitor or ammonia water is used as the fluid 215, laser irradiation can be performed while suppressing rust formation on the additively manufactured object 2.

[0068] Furthermore, the fluid supply mechanism 210 supplies fluid 215 to the additively fabricated object 2 that is to be laser-irradiated, enabling the laser irradiation device 200 to perform laser irradiation in the presence of fluid 215. Therefore, the laser irradiation device 200 may also function as a laser peening device. Laser peening, as used here, is a technique that imparts compressive residual stress to a metal material by the shock wave of plasma generated by irradiating the surface of the metal material with a laser in the presence of fluid 215.

[0069] This laser peening process can improve the strength of metallic materials. Specifically, when a laser is shone onto the surface of a metallic material, a plasma of atoms constituting the metallic material is instantaneously generated. If a fluid 215 is present around the generated plasma, its expansion is hindered. Then, a shock wave is generated by the mechanical reaction of this plasma expansion, and this shock wave propagates through the metallic material, imparting compressive residual stress to it. This imparting of compressive residual stress to the metallic material has the effect of preventing stress corrosion cracking or fatigue cracking of the metallic material.

[0070] The fluid supply mechanism 210 includes a supply unit 220, a flow path 230, and a nozzle 240.

[0071] The supply unit 220 stores the fluid 215 to be supplied to the additively fabricated object 2 that is to be irradiated with the laser. The supply unit 220 is connected to one end of the flow path 230 and supplies the fluid 215 to the flow path 230.

[0072] The flow path 230 is connected at one end to the supply unit 220 and at the other end to the nozzle 240. The flow path 230 guides the fluid 215 supplied from the supply unit 220 to the nozzle 240. The flow path 230 is provided with an opening / closing mechanism 235 that adjusts the flow rate and pressure of the fluid 215 supplied to the additively fabricated object 2. The opening / closing mechanism 235 is, for example, a valve or a pump.

[0073] The nozzle 240 extends taperingly from the focusing lens unit 30 toward the additively manufactured object 2, along the direction in which the pulsed laser 11 is focused. The opening 245 at the tip of the nozzle 240 faces the additively manufactured object 2. The other end of the flow channel 230 is connected to the side of the nozzle 240. The nozzle 240 supplies the fluid 215 guided from the flow channel 230 to the additively manufactured object 2.

[0074] As described above, the second embodiment exhibits the same functions and effects as the first embodiment, and by further including a fluid supply mechanism 210, it is possible to supply fluid 215 to the additively manufactured object 2 that is the target of laser irradiation simultaneously with the laser irradiation. This makes it possible to perform laser peening in addition to surface treatment by laser irradiation.

[0075] (Third embodiment) The laser irradiation system 40 and laser irradiation method 400 according to the third embodiment will be described with reference to Figures 10 and 11. Figure 10 is an explanatory diagram showing an example of surface roughness in a grid-like additively fabricated object 300. Figure 11 is a flowchart of the laser irradiation method 400 according to the third embodiment. Hereafter, the differences from the first embodiment will be described, and parts that are the same as in the first embodiment will be given the same figure numbers and their descriptions will be omitted.

[0076] The surface condition confirmation unit 43 measures the external dimensions of the additively manufactured object 300 that is to be irradiated with the laser. The surface condition confirmation unit 43 also measures the surface roughness of the additively manufactured object 300 that is to be irradiated with the laser. Figure 10 shows an example of a distribution map of the grid-shaped additively manufactured object 300 that is to be irradiated with the laser, created by the surface condition confirmation unit 43.

[0077] The surface condition comparison unit 44 compares the design information of the additively manufactured object 300 input to the additively manufactured object information input unit 41 with the external dimension measurement values ​​measured by the surface condition confirmation unit 43. Based on this comparison, the surface condition comparison unit 44 determines whether or not there are at least manufacturing defects 310, as shown in Figure 10. Here, manufacturing defects 310 refer to protrusions formed during additive manufacturing. For example, the surface condition comparison unit 44 determines the presence or absence of manufacturing defects 310 by checking whether the difference between the design information of the additively manufactured object 300 and the external dimension measurement values ​​exceeds a predetermined dimensional tolerance. Here, predetermined dimensional tolerance refers to a predetermined dimensional tolerance that serves as a standard when determining manufacturing defects. In this way, the surface condition comparison unit 44 first determines whether or not there are obvious manufacturing defects 310 in the additively manufactured object 300. The surface condition comparison unit 44 may also compare the design information of the additively manufactured object 300 input to the additively manufactured object information input unit 41 with the outline drawing created by the surface condition confirmation unit 43.

[0078] Next, the surface condition comparison unit 44 may compare the surface treatment request value input to the surface treatment request value input unit 42 with the surface roughness measurement value measured by the surface condition confirmation unit 43. Based on this comparison, the surface condition comparison unit 44 determines whether the surface roughness measurement value exceeds the surface treatment request value. For example, as shown in Figure 10, the surface condition comparison unit 44 identifies a region 320 with relatively low surface roughness and a region 330 with relatively high surface roughness. Alternatively, the surface condition comparison unit 44 may compare the surface treatment request value input to the surface treatment request value input unit 42 with a distribution map created by the surface condition confirmation unit 43.

[0079] The surface treatment area setting unit 45 sets areas where the difference between the design information of the additively manufactured object 300 and the external dimension measurement value is determined by the surface state comparison unit 44 to exceed a predetermined dimensional tolerance as areas to be treated by laser irradiation.

[0080] The laser irradiation condition setting unit 46 uses data stored in the database unit 47 to set conditions suitable for surface treatment by laser irradiation, determining that the difference between the design information of the additively manufactured object 300 and the external dimension measurement value, which exceeds a predetermined dimensional tolerance, should be removed by surface treatment.

[0081] Next, a laser irradiation method 400 according to the third embodiment will be described using Figure 11.

[0082] First, the user inputs the design information of the additively manufactured object 300 to be laser-irradiated into the additively manufactured object information input unit 41 (step S401).

[0083] Next, the user may input the surface treatment requirement values ​​for the additively manufactured object 300 to be laser-irradiated into the surface treatment requirement value input unit 42 (step S402).

[0084] Next, the surface condition confirmation unit 43 measures the external dimensions of the additively fabricated object 300 that is to be irradiated with the laser (step S403).

[0085] Next, the surface condition comparison unit 44 compares the design information of the additively manufactured object 300 input by the additively manufactured object information input unit 41 with the external dimension measurement values ​​measured by the surface condition confirmation unit 43, and determines whether or not there are any manufacturing defects on the surface of the additively manufactured object 300 based on whether or not the difference between the design information of the additively manufactured object 300 and the external dimension measurement values ​​exceeds a predetermined dimensional tolerance (step S404).

[0086] If there are manufacturing defects on the surface of the additively manufactured object 300 (if the answer to step S405 is YES), the process proceeds to step S406. On the other hand, if there are no manufacturing defects on the surface of the additively manufactured object 300 (if the answer to step S405 is NO), the process proceeds to step S412, and then to the laser irradiation method 100 shown in Figure 7.

[0087] Next, the surface treatment area setting unit 45 sets the areas where the difference between the design information of the additively manufactured object 300 and the external dimension measurement value is determined by the surface condition comparison unit 44 to exceed a predetermined dimensional tolerance (areas on the surface of the additively manufactured object 300 where it is determined that there are manufacturing defects) as areas to be treated by laser irradiation (step S406).

[0088] Next, the laser irradiation condition setting unit 46 sets the conditions for performing surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45 (step S407). For example, the laser irradiation condition setting unit 46 uses data stored in the database unit 47 to set conditions suitable for performing surface treatment by laser irradiation, determining that the difference between the design information of the additively manufactured object 300 and the external dimension measurement value, which exceeds a predetermined dimensional tolerance, should be removed by surface treatment.

[0089] Next, the device control unit 48 controls the laser irradiation device 1 based on the conditions set by the laser irradiation condition setting unit 46, and performs surface treatment by laser irradiation on the area set by the surface treatment area setting unit 45 (step S408).

[0090] Next, after performing surface treatment by laser irradiation, the surface condition confirmation unit 43 measures the external dimensions of the additively fabricated object 300 again (step S409).

[0091] Next, the surface condition comparison unit 44 compares the design information of the additively manufactured object 300 input by the additively manufactured object information input unit 41 with the remeasured external dimensions measured again by the surface condition confirmation unit 43, and determines again whether there are any manufacturing defects on the surface of the additively manufactured object 300 based on whether the difference between the design information of the additively manufactured object 300 and the remeasured external dimensions exceeds a predetermined dimensional tolerance (step S410).

[0092] If there are manufacturing defects on the surface of the additively manufactured object 300 (if the answer to step S411 is YES), the process returns to step S406 and repeats from step S406 onward. On the other hand, if there are no manufacturing defects on the surface of the additively manufactured object 300 (if the answer to step S411 is NO), the process proceeds to step S412 and then to the laser irradiation method 100 shown in Figure 7.

[0093] As described above, the third embodiment exhibits the same functions and effects as the first embodiment, and first allows for surface treatment of the molding defects 310 of the additively manufactured object 300 by laser irradiation. This makes it possible to perform surface treatment of the surface roughness of the additively manufactured object 300 by laser irradiation more effectively.

[0094] In the third embodiment, Figure 11 illustrates a flowchart relating to the laser irradiation method 400 in which each step is executed in series, but the embodiment is not limited to this case. For example, the order of some steps may be reversed. Also, for example, some steps may be executed in parallel with other steps.

[0095] Furthermore, the third embodiment illustrates a case where the laser irradiation method 400 shown in Figure 11 is followed by the laser irradiation method 100 shown in Figure 7, but the embodiment is not limited to this case. For example, the laser irradiation method 400 and the laser irradiation method 100 may be performed as a single procedure. That is, instead of performing surface treatment for surface roughness exceeding the surface treatment requirement value after surface treatment for molding defects, the surface treatment for molding defects and surface roughness exceeding the surface treatment requirement value may be performed as a single procedure.

[0096] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, modifications, and combinations are possible without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as described in the claims. [Explanation of Symbols]

[0097] 1...Laser irradiation device, 2...Layer-formed object, 3...Surface irregularities, 3c...Surface irregularity removal unit, 4...Irradiation position, 10...Laser oscillator, 11...Pulsed laser, 20...Laser optical path mechanism, 21...First mirror, 22...Second mirror, 23...Attenuator, 24...Shutter, 30...Focusing lens unit, 31...First lens, 32...Second lens, 40...Laser irradiation system, 41...Layer-formed object information input unit, 42...Surface treatment request value input unit, 43...Surface condition confirmation unit, 44...Surface condition comparison unit, 45...Surface treatment area setting unit, 46...Laser irradiation condition setting unit, 46a...Energy setting unit, 46b...Spot diameter setting unit, 46c...Coverage setting unit, 46d...Direction setting unit, 47...Database unit, 48...Device control unit, 49...Information input unit, 50...Display output unit, 51...Main control unit, 100...Laser irradiation method, 200...Laser irradiation device, 210...Fluid supply mechanism, 215...Fluid, 220...Supply unit, 230...Flow path, 235...Opening / closing mechanism, 240...Nozzle, 245...Opening, 300...Additive-formed object, 310...Formation defect, 400...Laser irradiation method.

Claims

1. A layered material information input unit for inputting information about layered material, A surface treatment request value input unit inputs a surface treatment request value, which is a required value for determining whether to perform surface treatment by laser irradiation on the surface roughness of the aforementioned additively manufactured object. A surface condition confirmation unit for measuring the surface roughness of the additively manufactured object, A surface condition comparison unit that compares the surface treatment requirement value with the measured surface roughness value, A laser irradiation system characterized by having the following features.

2. The laser irradiation system according to claim 1, characterized in that the information is design information including at least one of the material used for the additively manufactured object and the dimensions of the additively manufactured object.

3. A surface treatment area setting unit sets the area in which the measured value of the surface roughness is determined to exceed the surface treatment requirement value as the area to be treated, A laser irradiation condition setting unit that sets the conditions for performing laser irradiation on the aforementioned region, A device control unit that controls the execution of the surface treatment on the region based on the above conditions, The laser irradiation system according to claim 1, further comprising the features described above.

4. The laser irradiation system according to claim 3, characterized in that the conditions are set using data stored in the database based on the measured value of the surface roughness and the surface treatment request value.

5. The laser irradiation condition setting unit is, An energy setting unit for setting the energy of the laser irradiation, A spot diameter setting unit for setting the spot diameter of the laser irradiation, A coverage setting unit for setting the coverage of the laser irradiation, A direction setting unit for setting the scanning direction and pitch direction of the laser irradiation, The laser irradiation system according to claim 3, characterized by comprising the features.

6. Steps include inputting information about the additively manufactured object, The steps include: inputting a surface treatment request value, which is a request value for determining whether or not to perform surface treatment by laser irradiation on the surface roughness of the additively manufactured object; A step of measuring the surface roughness of the additively manufactured object, A step of comparing the surface treatment requirement value with the measured surface roughness value, A laser irradiation method characterized by including the following:

7. The laser irradiation method according to claim 6, characterized in that the information is design information including at least one of the material used for the additively manufactured object and the dimensions of the additively manufactured object.

8. The steps include setting the region in which the measured value of the surface roughness is determined to exceed the surface treatment requirement as the region to be subjected to the surface treatment, The steps include setting the conditions for performing laser irradiation on the region, A step of controlling the execution of the surface treatment on the region based on the above conditions, The laser irradiation method according to claim 6, further comprising:

9. The laser irradiation method according to claim 8, characterized in that the conditions are set using data stored in the database based on the measured value of the surface roughness and the surface treatment request value.

10. After performing the surface treatment, the surface roughness of the additively manufactured object is measured again. A step of comparing the surface treatment requirement value with the remeasured surface roughness value, The laser irradiation method according to claim 8, further comprising:

11. The steps include measuring the external dimensions of the additively fabricated object, A step of comparing the information of the additively manufactured object with the measured value of the external dimensions, The steps include setting the area where the difference between the information of the additively manufactured object and the measured value of the external dimensions exceeds a predetermined dimensional tolerance, and where it is determined that there is a manufacturing defect on the surface of the additively manufactured object, as the area to be subjected to surface treatment, A laser irradiation method according to any one of claims 6 to 10, further comprising:

Images