Additive manufacturing apparatus and additive manufacturing method

Abstract

An additive manufacturing device (100) is provided with: a shaping unit (30) having a material supply unit for supplying a material to a workpiece, a heat source output unit for outputting a heat source for melting the material, and a drive unit for moving the heat source and the material supply unit, the shaping unit (30) forming a weld bead by using the material melted by the heat source; an operation amount adjustment unit that adjusts the amount of material supplied by the material supply unit or the heat source output by the heat source output unit on the basis of the shape error of the bead; and an operation amount readjustment unit (33) that sets an appropriate range, which is the range of the value of the material supply amount with respect to the value of the heat source output when the weld bead can be appropriately formed, and that readjusts the amount of the material supply amount when the value of the material supply amount adjusted by the operation amount adjustment unit deviates from the appropriate range with respect to the value of the heat source output. One of a material supply amount and a heat source output is selected as an operation amount for prioritizing adjustment, and the selected operation amount is readjusted preferentially.

Description

Technical Field

[0001] The present invention relates to an additive manufacturing apparatus and an additive manufacturing method for manufacturing a three-dimensional shaped object. Background Art

[0002] As one of the techniques for manufacturing a three-dimensional shaped object, a technique of additive manufacturing (AM) is known. According to the directed energy deposition (DED) method, which is one of the plurality of methods in the additive manufacturing technique, an additive manufacturing apparatus forms a weld bead while supplying a material to a designated position and irradiating a light beam onto the material and the workpiece. The weld bead is a solidified product obtained by solidifying the molten material at the workpiece. The additive manufacturing apparatus manufactures a shaped object by sequentially laminating the weld beads.

[0003] In additive manufacturing, due to various reasons, an error with respect to a target shape sometimes occurs in the shape of the formed weld bead. Therefore, various methods for reducing the shape error by controlling the additive manufacturing apparatus have been proposed in the past. In Patent Document 1, the following technique is proposed, that is, with respect to a shape error in which an error with respect to a target height occurs in the height of the weld bead, the amount of the material supplied to the processing point is corrected based on the measurement result of the height of the weld bead.

[0004] Patent Document 1: Japanese Patent No. 6765569 Summary of the Invention

[0005] In additive manufacturing, the amount of the material that can be melted at the processing point is determined based on the output value of the heat source that melts the material. When correcting the amount of the material supplied to the processing point, if an appropriate amount of the material cannot be melted, it is difficult to continue the processing. As described above, in the case of additive manufacturing, even if the manipulated variable to be controlled is corrected, the limit for continuing the processing may sometimes not be satisfied. Therefore, according to the prior art described in Patent Document 1, there is a problem that it is sometimes difficult to manufacture a shaped object with reduced errors.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to obtain an additive manufacturing apparatus capable of manufacturing a shaped object with reduced errors.

[0007] In order to solve the above problems and achieve the object, the additive manufacturing apparatus according to the present invention includes: a shaping unit having a material supply unit that supplies a material to a workpiece, a heat source output unit that outputs a heat source for melting the material, and a drive unit that moves the heat source and the material supply unit, and forming a weld bead by using the material melted by the heat source; an operation amount adjustment unit that adjusts the material supply amount of the material supply unit or the heat source output of the heat source output unit based on the shape error of the weld bead; and an operation amount readjustment unit that sets a range, i.e., an appropriate range, of the value of the material supply amount with respect to the value of the heat source output when the weld bead can be appropriately formed, and when the value of the adjusted material supply amount with respect to the value of the heat source output in the operation amount adjustment unit deviates from the appropriate range, selecting one of the material supply amount and the heat source output as the operation amount to which adjustment is prioritized, and preferentially readjusting the selected operation amount.

[0008] Effect of the Invention

[0009] The additive manufacturing apparatus according to the present invention has an effect of being able to manufacture a shaped object with reduced errors. Description of the Drawings

[0010] Figure 1 FIG. is an example of an additive manufacturing apparatus according to Embodiment 1.

[0011] Figure 2 FIG. is an example of the functional structure of the additive manufacturing apparatus according to Embodiment 1.

[0012] Figure 3 FIG. is a first diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus according to Embodiment 1.

[0013] Figure 4 FIG. is a second diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus according to Embodiment 1.

[0014] Figure 5 FIG. is a third diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus according to Embodiment 1.

[0015] Figure 6 FIG. is an example of a diagram showing the relationship between the material supply amount and the laser output obtained by positioning the tip of the wire at an appropriate position in the additive manufacturing apparatus according to Embodiment 1.

[0016] Figure 7 FIG. is a first diagram for explaining the selection of the operation amount to which adjustment is prioritized implemented by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0017] Figure 8 FIG. 2 is a diagram for explaining the selection of the operation amount that prioritizes adjustment performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0018] Figure 9 FIG. 3 is a diagram for explaining the selection of the operation amount that prioritizes adjustment performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0019] Figure 10 FIG. 1 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0020] Figure 11 FIG. 2 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0021] Figure 12 FIG. is a diagram for explaining the readjustment of the operation amount in the case where a tolerance amount is set in Embodiment 1.

[0022] Figure 13 FIG. is a flowchart showing an example of the processing sequence performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 1.

[0023] Figure 14 FIG. is a diagram for explaining the selection of the operation amount that prioritizes adjustment performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 2.

[0024] Figure 15 FIG. 1 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 2.

[0025] Figure 16 FIG. 2 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 2.

[0026] Figure 17 FIG. is a diagram for explaining the readjustment of the operation amount in the case where a tolerance amount is set in Embodiment 2.

[0027] Figure 18 FIG. is a flowchart showing an example of the processing sequence performed by the operation amount readjustment unit of the additive manufacturing apparatus according to Embodiment 2.

[0028] Figure 19 FIG. is a diagram for explaining the relationship between the tolerance amount in the additive manufacturing apparatus according to Embodiment 2 and the occurrence of defects in the formed object.

[0029] Figure 20 This is a diagram showing an example of the functional structure of the additive manufacturing apparatus according to Embodiment 3.

[0030] Figure 21 This is the first diagram for explaining the relationship between the correction of the processing point and the formation of the bead in the additive manufacturing apparatus according to Embodiment 3.

[0031] Figure 22 This is the second diagram for explaining the relationship between the correction of the processing point and the formation of the bead in the additive manufacturing apparatus according to Embodiment 3.

[0032] Figure 23 This is a diagram for explaining the correction of the bead width in the additive manufacturing apparatus according to Embodiment 3.

[0033] Figure 24 This is a diagram for explaining the correction amount calculated by the bead width correction amount calculation unit of the additive manufacturing apparatus according to Embodiment 3.

[0034] Figure 25 This is a flowchart showing an example of the processing sequence implemented by the position correction unit, the position correction amount adjustment unit, and the bead width correction amount calculation unit of the additive manufacturing apparatus according to Embodiment 3.

[0035] Figure 26 This is a diagram showing an example of the structure of the control circuit according to Embodiments 1 to 3.

[0036] Figure 27 This is a diagram showing an example of the structure of the dedicated hardware circuit according to Embodiments 1 to 3. Detailed Embodiment

[0037] Hereinafter, the additive manufacturing apparatus and the additive manufacturing method according to the embodiment will be described in detail with reference to the drawings.

[0038] Embodiment 1.

[0039] Figure 1 This is a diagram showing an example of the additive manufacturing apparatus 100 according to Embodiment 1. The additive manufacturing apparatus 100 is an additive manufacturing apparatus of the DED method. The additive manufacturing apparatus 100 supplies a material to the workpiece 19 and stacks beads 16 formed of the material melted by using a light beam to manufacture a shaped object 17. The light beam is a heat source for melting the material, and is a laser beam L or an electron beam or the like. The heat source is not limited to the light beam, and may also be an arc. In Embodiment 1, the case where the heat source is the laser beam L is taken as an example. Further, in Embodiment 1, the material is set to be a metal wire 14. The material is not limited to the wire 14, and may also be powder.

[0040] The additive manufacturing apparatus 100 forms a weld bead 16 by supplying a wire 14 to a specified position while irradiating the wire 14 and the workpiece 19 with a laser beam L. The weld bead 16 is formed in a molten pool 15. The molten pool 15 is a pool of molten metal that appears by melting the workpiece 19 and the wire 14 by the irradiation of the laser beam L.

[0041] On the base material 18, a layer of the weld beads 16 is formed by arranging a plurality of the weld beads 16. By laminating the layers of the weld beads 16, a deposit of the weld beads 16, i.e., a shaped object 17, is formed. As described above, the additive manufacturing apparatus 100 manufactures the shaped object 17 as a three-dimensional shaped object by laminating the weld beads 16. Figure 1 The illustrated base material 18 is a plate. The base material 18 may also be an object other than a plate. The workpiece 19 is an object to which a material to be melted is added, and includes the base material 18 and the shaped object 17 being shaped. The shaped object 17 is formed on the base material 18.

[0042] The X-axis, Y-axis, and Z-axis are three mutually perpendicular axes. The X-axis and Y-axis are two horizontal axes. The Z-axis is a vertical axis. In each of the X-axis direction, Y-axis direction, and Z-axis direction, the direction indicated by the arrow is defined as positive, and the direction opposite to the arrow is defined as negative. The positive Z direction is the vertically upward direction. The weld beads 16 are laminated in the positive Z direction.

[0043] The additive manufacturing apparatus 100 includes a numerical control (NC) device 1, a laser oscillator 2, an axis drive device 3, a gas supply device 4, a material supply device 5, an analysis device 6, a camera 7, a processing head 8, a PC (Personal Computer) 10, and a worktable 21. The base material 18 is fixed to the worktable 21. The laser oscillator 2, the axis drive device 3, the gas supply device 4, the material supply device 5, the processing head 8, and the worktable 21 constitute a shaping unit 30, which manufactures the shaped object 17 by laminating the weld beads 16 formed of a material melted using the laser beam L.

[0044] The laser oscillator 2 as a light beam source outputs the laser beam L. The laser oscillator 2 is an example of a heat source output unit that outputs a heat source. The laser beam L output by the laser oscillator 2 is transmitted in an optical fiber cable 20 as an optical transmission path and is incident on the processing head 8. An optical system such as a collimation optical system or a focusing optical system is disposed inside the processing head 8. The illustration of the optical system is omitted. The laser oscillator 2, the optical fiber cable 20, and the processing head 8 constitute an irradiation unit that irradiates the workpiece 19 with the laser beam L.

[0045] The processing head 8 is provided with: a beam nozzle through which the laser beam L emitted from the processing head 8 toward the processing point passes; and a gas nozzle 9 that jets a protective gas G toward the processing point. The central axis of the beam nozzle coincides with the optical axis of the optical system. The central axis of the beam nozzle also coincides with the Z-axis. The center line of the laser beam L irradiated on the workpiece 19 coincides with the Z-axis. The laser beam L passes through the optical system inside the processing head 8 and is emitted from the processing head 8 through the beam nozzle. The processing point is the irradiation position of the laser beam L on the workpiece 19 and is the area where the additional wire 14 is attached. The additive manufacturing apparatus 100 moves the processing point along the movement path during the additive processing of adding and melting the material. The position of the processing point is the position where the heat source and the material are supplied and is the position on the central axis of the beam nozzle.

[0046] The gas supply device 4 supplies the protective gas G from the gas supply source to the gas nozzle 9. An example of the gas supply source is a gas cylinder. The gas supply source is connected to the gas nozzle 9 via a pipe. The illustration of the gas supply source and the pipe is omitted. The gas supply device 4 can change the flow rate of the protective gas G based on the gas supply instruction from the NC device 1. By jetting the protective gas G, the oxidation of the material and the workpiece 19 is reduced, and the shaped object 17 is cooled. The protective gas G is preferably an inert gas such as argon.

[0047] The material supply device 5 as the material supply unit supplies the wire 14 toward the processing point. The material supply device 5 has a material supply source 12 and a material supply nozzle 13. The material supply device 5 supplies the wire 14 drawn from the material supply source 12 to the processing point through the material supply nozzle 13. In Figure 1 An example of the side supply method of supplying the wire 14 from the material supply nozzle 13 arranged obliquely above the processing point is shown. The material supply device 5 may not be the side supply method but the center supply method of supplying the wire 14 from the material supply nozzle 13 arranged directly above the processing point. The material supply device 5 can be operated by a servo motor and change the supply speed of the wire 14 based on the material supply instruction from the NC device 1.

[0048] The axis drive device 3 moves the machining head 8, the material supply device 5, and the measuring device 11 in the X-axis direction, Y-axis direction, and Z-axis direction based on the movement speed command from the NC device 1. The positional relationship among the machining head 8, the material supply device 5, and the measuring device 11 is fixed. An example of the axis drive device 3 is a servo motor that moves the machining head 8, the material supply device 5, and the measuring device 11 in the X-axis direction, a servo motor that moves the machining head 8, the material supply device 5, and the measuring device 11 in the Y-axis direction, and a servo motor that moves the machining head 8, the material supply device 5, and the measuring device 11 in the Z-axis direction. The illustration of each servo motor is omitted. The additive manufacturing device 100 can move the irradiation position of the laser beam L, the supply position of the wire 14, and the measurement position of the measuring device 11 to any position within the stroke ranges of the machining head 8, the material supply device 5, and the measuring device 11 by operating each servo motor.

[0049] The camera 7 is a photographing device that photographs the area including the machining point among the workpieces 19 from vertically above. As an example, the camera 7 acquires an image of the area including the machining point and outputs the acquired image to the analysis device 6.

[0050] The measuring device 11 measures the height of the weld bead 16 formed in the molten pool 15 in the Z-axis direction, that is, the weld bead height. As an example, the measuring device 11 is a laser displacement sensor. The measuring device 11 is arranged at a position where it can be moved in the X-axis direction, Y-axis direction, and Z-axis direction by the axis drive device 3. The measuring device 11 outputs the measurement result of the weld bead height to the analysis device 6.

[0051] The analysis device 6 analyzes the image input from the camera 7, thereby measuring the width of the weld bead 16 formed in the molten pool 15, that is, the weld bead width. In addition, the analysis device 6 calculates the error in the width of the formed weld bead 16, that is, the weld bead width error. The analysis device 6 calculates the difference between the measured value of the weld bead width and the target value of the weld bead width, thereby obtaining the weld bead width error. The analysis device 6 outputs the value of the weld bead width error, that is, the weld bead width error amount, to the NC device 1.

[0052] The analysis device 6 calculates the error in the height of the formed weld bead 16, that is, the weld bead height error. The analysis device 6 calculates the difference between the weld bead height measured by the measuring device 11 and the target value of the weld bead height, thereby obtaining the weld bead height error. The analysis device 6 outputs the value of the weld bead height error, that is, the weld bead height error amount, to the NC device 1.

[0053] The NC device 1 is a control device that controls the entire additive manufacturing device 100. The NC device 1 controls the additive manufacturing device 100 according to a machining program and machining conditions. The machining program describes movement commands for moving the machining head 8 and the material supply device 5 along a preset path. The machining conditions include information required for forming the bead 16, such as the output of the laser beam L generated by the laser oscillator 2, i.e., the laser output, the speed at which the irradiation position of the laser beam L and the supply position of the wire 14 are moved, i.e., the moving speed, the amount of the wire 14 supplied by the material supply device 5, i.e., the material supply amount, and the flow rate of the shielding gas G, i.e., the gas flow rate. In addition, in the following description, the laser output is referred to as the heat source output. The material supply amount in the following description is also renamed as the material supply speed.

[0054] The NC device 1 outputs a position command corresponding to the machining program to the axis drive device 3, thereby controlling the axis drive device 3 according to the machining program. The axis drive device 3 moves the machining head 8 and the material supply device 5 along a preset movement path according to the position command.

[0055] The NC device 1 outputs a laser output command to the laser oscillator 2 according to the machining conditions, thereby controlling the laser oscillator 2. The laser oscillator 2 outputs the laser beam L according to the laser output command. The NC device 1 outputs a material supply command to the material supply device 5 according to the machining conditions, thereby controlling the material supply device 5. The material supply device 5 supplies the wire 14 in the material supply amount according to the material supply command. The NC device 1 outputs a moving speed command to the axis drive device 3 according to the machining conditions. The axis drive device 3 moves the irradiation position of the laser beam L and the supply position of the wire 14 at the moving speed according to the moving speed command. The NC device 1 outputs a gas supply command to the gas supply device 4 according to the machining conditions, thereby controlling the gas supply device 4. The gas supply device 4 supplies the shielding gas G at the gas flow rate according to the gas supply command.

[0056] Values of various parameters related to the control of the additive manufacturing device 100 are input by the user of the additive manufacturing device 100 into the PC 10. The PC 10 outputs the input information to the NC device 1. In addition, the PC 10 displays an operation screen for operating the additive manufacturing device 100.

[0057] In addition, Figure 1 The NC device 1 and the PC 10 shown are built into the additive manufacturing device 100. That is, the NC device 1 and the PC 10 are components of the additive manufacturing device 100. At least one of the NC device 1 and the PC 10 may also be a device external to the additive manufacturing device 100.

[0058] Next, an outline of the operation of the additive manufacturing apparatus 100 will be described. After the base material 18 is fixed to the workbench 21, the laser oscillator 2, the axis drive device 3, the gas supply device 4, and the material supply device 5 are operated according to the control performed by the NC device 1. The additive manufacturing apparatus 100 operates the laser oscillator 2, whereby the laser beam L is irradiated onto the processing point. The additive manufacturing apparatus 100 operates the material supply device 5, whereby the wire material 14 is supplied to the processing point. The additive manufacturing apparatus 100 operates the gas supply device 4, whereby the protective gas G is jetted onto the processing point. The additive manufacturing apparatus 100 operates the axis drive device 3, whereby the processing point is moved on the movement path.

[0059] By the irradiation of the laser beam L, a molten pool 15 is formed on the workpiece 19. The processing point moves as the molten pool 15 is formed, whereby a weld bead 16 is formed. By laminating the weld beads 16, a shaped object 17 is formed.

[0060] Next, a function for reducing the shape error of the weld bead 16 will be described. The additive manufacturing apparatus 100 has a function for reducing the shape error of the weld bead 16. Figure 2 FIG. is an example showing the functional structure of the additive manufacturing apparatus 100 according to the first embodiment. In Figure 2 an example of the functional structure related to the function for reducing the shape error of the weld bead 16 is shown.

[0061] The NC device 1 includes a weld bead width correction control unit 31, a weld bead height correction control unit 32, and an operation amount readjustment unit 33. The weld bead width correction control unit 31 and the weld bead height correction control unit 32 function as operation amount adjustment units that adjust the material supply amount of the material supply device 5 or the heat source output of the laser oscillator 2 based on the shape error of the weld bead 16. In the first embodiment, the weld bead width error and the weld bead height error are each the shape error of the weld bead 16.

[0062] The weld bead width error amount calculated by the analysis device 6 is input to the weld bead width correction control unit 31. If the weld bead width error amount is input to the weld bead width correction control unit 31, the laser output shown in the laser output command generated by the processing conditions is adjusted based on the weld bead width error amount. The weld bead width correction control unit 31 controls the correction of the weld bead width by adjusting the laser output based on the weld bead width error amount. The weld bead width correction control unit 31 outputs the adjusted laser output value to the operation amount readjustment unit 33.

[0063] The bead height error amount calculated by the analysis device 6 is input to the bead height correction control unit 32. If the bead height error amount is input to the bead height correction control unit 32, the bead height correction control unit 32 adjusts the material supply amount indicated by the material supply command generated based on the processing conditions based on the bead height error amount. The bead height correction control unit 32 controls the correction of the bead height by adjusting the material supply amount based on the bead height error amount. The bead height correction control unit 32 outputs the value of the adjusted material supply amount to the operation amount readjustment unit 33.

[0064] The PC 10 has a parameter input unit 34 for inputting values of various parameters. Values of various parameters are input, for example, by a user operation. One of the parameter values, namely, the allowable error amount, is input to the parameter input unit 34. In the first embodiment, the allowable error amount is the value of the bead height error that can be tolerated. By inputting the allowable error amount to the parameter input unit 34, the allowable error amount is set in the additive manufacturing apparatus 100. The parameter input unit 34 functions as an allowable error amount setting unit for setting the allowable error amount. The parameter input unit 34 outputs the input allowable error amount to the NC device 1.

[0065] The operation amount readjustment unit 33 performs readjustment of the laser output or the material supply amount. Here, readjustment means that when the laser output is adjusted by the bead width correction control unit 31 or when the material supply amount is adjusted by the bead height correction control unit 32, the operation amount readjustment unit 33 further adjusts at least one of the laser output and the material supply amount. Details of the readjustment performed by the operation amount readjustment unit 33 will be described later.

[0066] When the operation amount readjustment unit 33 performs readjustment of the laser output, the laser output command indicating the value of the readjusted laser output is output to the laser oscillator 2. When the operation amount readjustment unit 33 does not perform readjustment of the laser output, the laser output command indicating the value of the laser output input from the bead width correction control unit 31 is output to the laser oscillator 2. When the operation amount readjustment unit 33 performs readjustment of the material supply amount, the material supply command indicating the value of the readjusted material supply amount is output to the material supply device 5. When the operation amount readjustment unit 33 does not perform readjustment of the material supply amount, the material supply command indicating the value of the material supply amount input from the bead height correction control unit 32 is output to the material supply device 5.

[0067] Next, the relationship between the correction of the bead width and the correction of the bead height will be described. The correction of the bead width is mainly achieved by adjusting the heat source output. The correction of the bead height is mainly achieved by adjusting the material supply amount. When correcting the bead width or the bead height, sometimes one of the heat source output and the material supply amount is restricted according to the relationship between the heat source output and the material supply amount.

[0068] Figure 3 FIG. 1 is a diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus 100 according to the first embodiment. Figure 4 FIG. 2 is a diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus 100 according to the first embodiment. Figure 5 FIG. 3 is a diagram for explaining the relationship between the laser output and the material supply amount in the additive manufacturing apparatus 100 according to the first embodiment.

[0069] In Figures 3 to 5 the case where the wire 14 enters the laser beam L is shown. At the tip of the wire 14 sent out from the material supply nozzle 13, the temperature of the wire 14 reaches the melting point of the wire 14. In Figure 3 the state where the tip of the wire 14 is near the center line CN of the laser beam L is shown. The position of the tip of the wire 14 is determined by the laser output and the material supply amount. Figure 3 The double-headed arrow shown in

[0070] shows the case where the position of the tip of the wire 14 changes according to the laser output and the material supply amount. Figure 4 In the case where the material supply amount is too small relative to the laser output, the position of the tip of the wire 14 gradually approaches the material supply nozzle 13. That is, the tip of the wire 14 retreats. In

[0071] The left part of Figure 4 shows the case where the tip of the wire 14 retreats to the vicinity of the boundary where the wire 14 enters the laser beam L. In this case, sometimes the molten material does not adhere to the workpiece 19 and accumulates at the tip of the wire 14, so that the droplet phenomenon of the molten material block, that is, the droplet 41 remains on the wire 14. When the droplet phenomenon occurs, it is difficult for the additive manufacturing apparatus 100 to continue the processing by appropriately forming the bead 16.

[0071] To avoid Figure 4 the droplet phenomenon as shown in the left part of Figure 4 compared with the state shown in the left part of Figure 4When the dashed line 48 shown on the right side is in a position closer to the negative X direction side, it is difficult to appropriately form the bead 16. In this case, it is necessary to set limits on the material supply amount or the laser output so that the position of the tip of the wire 14 is on the positive X direction side compared to the dashed line 48.

[0072] On the other hand, when the material supply amount is too large relative to the laser output, the position of the tip of the wire 14 gradually approaches in the direction opposite to the material supply nozzle 13. That is, the tip of the wire 14 advances. If the advancement of the tip of the wire 14 continues, the wire 14 passes through the laser beam L without melting. In Figure 5 the left part shows a situation where the wire 14 has passed through the laser beam L. In this case, a stub phenomenon may occur where the wire 14 before melting collides with the workpiece 19. In the case where the stub phenomenon occurs, it is difficult for the additive manufacturing apparatus 100 to continue the processing by appropriately forming the bead 16.

[0073] To avoid Figure 5 the stub phenomenon as shown in the left part of Figure 5 it is necessary to reduce the material supply amount or increase the laser output compared to the state shown in the left part of Figure 5 For example, when the position of the tip of the wire 14 is on the positive X direction side compared to the dashed line 49 shown on the right side of

[0074] Figure 6 it is difficult to appropriately form the bead 16. In this case, limits are set on the material supply amount or the laser output so that the position of the tip of the wire 14 is on the negative X direction side compared to the dashed line 49.

[0074] Figure 6 is a diagram showing an example of the relationship between the material supply amount and the laser output obtained by placing the tip of the wire 14 in an appropriate position in the additive manufacturing apparatus 100 according to the first embodiment. The appropriate position of the tip of the wire 14 is the position of the tip of the wire 14 when the processing can be continued. For example, it is Figure 4 the position between the dashed line 48 shown in Figure 5 and the dashed line 49 shown in

[0075] In Figure 6 the relationship between the material supply amount and the laser output is graphically represented. In Figure 6 the vertical axis represents the material supply amount, and the horizontal axis represents the laser output. Figure 6 The straight line 42 shown in Figure 6 represents the relationship between the laser output and the maximum value of the wire speed when the bead 16 can be appropriately formed. Figure 6In [the figure], the region between straight line 42 and straight line 43 represents the range of the value of the material supply amount with respect to the value of the laser output when the bead 16 can be properly formed, that is, the appropriate range. The appropriate range can be said to be the range of the value of the laser output with respect to the value of the material supply amount when the bead 16 can be properly formed.

[0076] Next, the processing performed by the operation amount readjustment unit 33 in the first embodiment will be described. In the operation amount readjustment unit 33, the range of the value of the material supply amount with respect to the value of the laser output when the bead 16 can be properly formed, that is, the appropriate range, is set. When the value of the adjusted material supply amount with respect to the value of the laser output in the operation amount adjustment unit deviates from the appropriate range, the operation amount readjustment unit 33 selects one of the material supply amount and the laser output as the operation amount to which adjustment is prioritized, and re-adjusts the selected operation amount preferentially. That is, the operation amount readjustment unit 33 preferentially re-adjusts the selected operation amount when the value of the material supply amount with respect to the value of the laser output deviates from the appropriate range after the adjustment of the laser output in the bead width correction control unit 31 or after the adjustment of the material supply amount in the bead height correction control unit 32. Further, when an allowable error amount is set in the parameter input unit 34, the operation amount readjustment unit 33 re-adjusts the laser output and the material supply amount in consideration of the set allowable error amount.

[0077] In the first embodiment, when the material supply amount becomes too large with respect to the laser output by the adjustment of the laser output in the bead width correction control unit 31 or the adjustment of the material supply amount in the bead height correction control unit 32, the operation amount readjustment unit 33 selects the operation amount to which adjustment is prioritized and re-adjusts the selected operation amount.

[0078] Figure 7 FIG. 1 is a diagram for explaining the selection of the operation amount to which adjustment is prioritized performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the first embodiment. In Figure 7 [the figure], similar to Figure 6 [the above], the relationship between the material supply amount and the laser output is graphically represented. Figure 7 The points shown in the graph of

[0079] Figure 7 represent the set of the value of the laser output and the value of the material supply amount. The point 44 shown in Figure 7In [the figure], point 44 is above the straight line 42. This indicates that the value of the material supply amount exceeds the maximum value of the material supply amount when the bead 16 can be properly formed.

[0080] In order to converge the values of the laser output and the material supply amount to an appropriate range, for example, regarding the set of values of the laser output and the material supply amount, readjustment from point 44 to point 45 or readjustment from point 44 to point 46 is considered. The conversion from point 44 to point 45 means increasing the laser output without changing the material supply amount. The conversion from point 44 to point 46 means decreasing the material supply amount without changing the laser output.

[0081] Figure 8 FIG. 2 is a diagram for explaining the selection of the operation amount that gives priority to adjustment implemented by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to Embodiment 1. Here, a first example of a phenomenon that may occur when readjustment is performed to decrease the material supply amount without increasing the laser output is described. If the material supply amount is decreased, the error in the bead height cannot be corrected, and the error in the bead height will increase as the machining continues.

[0082] In Figure 8 is schematically shown the situation when unevenness is generated on the upper surface of the workpiece 19 due to the error in the bead height. Since the unevenness is generated, a portion inclined with respect to the horizontal direction is generated on the upper surface of the workpiece 19. If this inclination is greater than the inclination of the wire 14 with respect to the horizontal direction, as Figure 8 shown, interference of the wire 14 or the material supply nozzle 13 with the workpiece 19 may occur. If interference of the wire 14 or the material supply nozzle 13 with the workpiece 19 occurs, the machining tends to become unstable.

[0083] Figure 9 FIG. 3 is a diagram for explaining the selection of the operation amount that gives priority to adjustment implemented by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to Embodiment 1. Here, a second example of a phenomenon that may occur when readjustment is performed to decrease the material supply amount without increasing the laser output is described. In Figure 9 also similar to the situation shown in Figure 8 , it is assumed that unevenness has been generated on the upper surface of the workpiece 19. In Figure 9 is schematically shown the irradiation of the laser beam L in each of the portions having different magnitudes of inclination with respect to the horizontal direction.

[0084] As Figure 9As shown, between parts with different inclinations and different sizes, the area of the molten part in the workpiece 19 changes. The greater the inclination, the larger the area of the molten part becomes. If the area of the molten part changes during the formation of the bead 16, the machining is likely to become unstable. When adjusting the width of the laser beam L so that the area of the molten part is constant, the variation in the laser output becomes large.

[0085] As described above, in the additive manufacturing apparatus 100, when the material supply amount is excessive relative to the laser output, if readjustment is performed by reducing the material supply amount without increasing the laser output, the machining is likely to become unstable. Since the machining of the additive manufacturing apparatus 100 becomes unstable, it is sometimes difficult to continue the machining.

[0086] On the other hand, when performing readjustment by increasing the laser output without reducing the material supply amount, the width of the bead becomes larger by increasing the laser output. In this case, a phenomenon that makes it difficult to continue the machining can be avoided. In addition, if the width of the bead becomes larger, the shape of the formed object may sometimes be larger than the target shape. In this case, the shape of the formed object can be corrected by the cutting process performed after the additive manufacturing process.

[0087] As described above, the operation amount readjustment unit 33 prioritizes the adjustment of increasing the laser output over the adjustment of reducing the material supply amount in the case where the material supply amount becomes excessive relative to the laser output. That is, when the value of the material supply amount is greater than the maximum value of the appropriate range, the operation amount readjustment unit 33 selects the laser output as the operation amount for prioritizing the adjustment.

[0088] For example, the operation amount readjustment unit 33 does not perform Figure 7 the readjustment of converting from the point 44 to the point 46 in Figure 7 but performs the readjustment of converting from the point 44 to the point 45 in

[0089] Figure 10 FIG. 1 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to Embodiment 1. The operation amount readjustment unit 33 performs readjustment of the laser output, which is the operation amount for prioritizing the adjustment. In Figure 10 an example in which the allowable bead height error, that is, the allowable error amount, is not set is described. That is, in the example shown in Figure 10 , the operation amount readjustment unit 33 performs readjustment of the laser output so that the bead height error is zero.

[0090] In Figure 10In (a), the state before the bead 16 is formed in the workpiece 19 is shown. In Figure 10 On the upper surface of the workpiece 19 shown in (a), unevenness caused by the error in the bead height has occurred. The bead height correction control unit 32 adjusts the material supply amount indicated by the material supply command based on the bead height error amount, and outputs the value of the adjusted material supply amount to the operation amount readjustment unit 33. The bead width correction control unit 31 outputs the value of the laser output indicated by the laser output command to the operation amount readjustment unit 33.

[0091] Here, it is assumed that the value of the material supply amount input to the operation amount readjustment unit 33 is greater than the maximum value of the appropriate range. The operation amount readjustment unit 33 determines that the value of the material supply amount is greater than the maximum value of the appropriate range, and thus selects the laser output as the operation amount for which adjustment is prioritized. The operation amount readjustment unit 33 performs readjustment to increase the selected operation amount, that is, the laser output. Specifically, the operation amount readjustment unit 33 performs readjustment to increase the laser output in the portion surrounded by the ellipse in Figure 10 (a), that is, in the concave portion, in such a way that a large amount of molten material is supplied. In this case, the adjustment performed by the operation amount readjustment unit 33 is an adjustment that prioritizes bringing the bead height closer to the target value over bringing the laser width closer to the target value.

[0092] In Figure 10 (b), the state after the bead 16 is formed in the workpiece 19 starting from the state shown in Figure 10 (a) is shown. In Figure 10 (b), the XZ cross-section of the workpiece 19 and the bead 16 and the XY plane of the bead 16 are shown. In Figure 10 the XZ cross-section shown in (b), the height of the upper surface of the bead 16 is flattened to the target value of the bead height, that is, H. The additive manufacturing apparatus 100 can make the bead height error zero through readjustment of the laser output in the operation amount readjustment unit 33.

[0093] In addition, in Figure 10 (b), the laser output in the portion surrounded by the ellipse increases, and thus the width in the Y direction in this portion of the XY plane of the bead 16 expands. In Figure 10 the XY plane of the bead 16 shown in (b), the width in the Y direction in this portion is greater than the target value of the bead width, that is, W.

[0094] In Figure 10 (c), the state after the bead 16 is subjected to cutting processing starting from the state shown in Figure 10 (b) is shown. In Figure 10 (c), an example in which the portion of the bead 16 whose width exceeds W is removed by cutting processing is shown. Figure 10 The dashed line shown in (c) representsFigure 10 The profile of the weld bead 16 before cutting as shown in (b) above. As described above, the shape of the shaped object 17 can be corrected by cutting as a subsequent process. In addition, in Figure 10 (c), an example is shown in which the weld bead 16 is cut so that the width of the weld bead 16 becomes W, but the cutting method is arbitrary. The cutting only needs to correct the profile of the shaped object 17 obtained by additive manufacturing. As described above, the additive manufacturing apparatus 100 can prevent the continuation of processing from becoming difficult and can manufacture the shaped object 17 with reduced shape error.

[0095] Figure 11 FIG. 2 is a diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the first embodiment. In Figure 11 , an example in the case where an allowable weld bead height error, that is, an allowable error amount, is set is explained. In the example shown in Figure 11 , the operation amount readjustment unit 33 readjusts the material supply amount so that the weld bead height error matches the allowable error amount, and based on the readjusted material supply amount, readjusts the laser output. The operation amount readjustment unit 33 not only readjusts the operation amount with priority adjustment, that is, the laser output, but also readjusts the operation amount other than the operation amount with priority adjustment, that is, the material supply amount.

[0096] In Figure 11 , in the example shown, the operation amount readjustment unit 33 reduces the priority of adjusting the weld bead height compared to the case shown in Figure 10 , and thus, compared to the case shown in Figure 10 , the increase amount of the laser output is reduced. The reduction of the increase amount of the laser output alleviates the widening of the weld bead width caused by the readjustment of the laser output compared to the case shown in Figure 10 . Through the adjustment as described above, the additive manufacturing apparatus 100 can converge the weld bead height error to the allowable error amount. In addition, corresponding to the alleviation of the widening of the weld bead width, the cutting amount in the cutting process can be reduced. Since the cutting amount can be reduced, the time required for the cutting process can be shortened.

[0097] In Figure 11 (a), a state before forming the weld bead 16 in the workpiece 19 is shown. It is assumed that unevenness due to an error in the weld bead height has occurred on the upper surface of the workpiece 19 shown in Figure 11 (a). The weld bead height correction control unit 32 adjusts the material supply amount indicated by the material supply command based on the weld bead height error amount, and outputs the value of the adjusted material supply amount to the operation amount readjustment unit 33. The weld bead width correction control unit 31 outputs the value of the laser output indicated by the laser output command to the operation amount readjustment unit 33.

[0098] Here, it is assumed that the value of the material supply amount input to the operation amount readjustment unit 33 is greater than the maximum value of the appropriate range. The operation amount readjustment unit 33 determines that the value of the material supply amount is greater than the maximum value of the appropriate range, and thus selects the laser output as the operation amount that gives priority to adjustment, in the same manner as in the case shown in Figure 10 .

[0099] In the example shown in Figure 11 , the allowable error amount set in the parameter input unit 34 is input to the operation amount readjustment unit 33. The operation amount readjustment unit 33 readjusts the material supply amount so that the bead height error coincides with the allowable error amount. In addition, the operation amount readjustment unit 33 readjusts to increase the value of the laser output so that the value of the readjusted material supply amount is less than or equal to the maximum value of the appropriate range in relation to the laser output. In the above manner, the operation amount readjustment unit 33 readjusts the laser output and the material supply amount in consideration of the set allowable error amount.

[0100] In Figure 11 (b), the situation after the bead 16 is formed on the workpiece 19 from the state shown in Figure 11 (a) is shown. In Figure 11 (b), the XZ cross-section of the workpiece 19 and the bead 16 and the upper surface of the bead 16 are shown. In the XZ cross-section shown in Figure 11 (b), the height error of the upper surface of the bead 16, that is, the bead height error, coincides with the allowable error amount, that is, EH. As described above, by readjusting the material supply amount in the operation amount readjustment unit 33, a bead height error corresponding to the allowable error amount remains in the bead 16.

[0101] In addition, in the portion surrounded by the ellipse in Figure 11 (b), the laser output increases, and thus the width in the Y direction in this portion of the XY plane of the bead 16 expands. However, the increase amount of the laser output is less than that in the case shown in Figure 10 (b), so the degree of expansion of the bead width is smaller than that in the case shown in Figure 10 (b). Figure 11 The dotted line shown in Figure 10 (b) shows the contour of the bead 16 in the case shown in

[0102] as a reference. Figure 11 In Figure 11 (c), the situation after the bead 16 is subjected to cutting processing from the state shown in Figure 11 (b) is shown. In Figure 11The dashed line shown in (c) indicates Figure 11 the profile of the weld bead 16 before cutting shown in (b). In Figure 11 the example shown, compared with the example shown in Figure 10 the widening of the weld bead width is alleviated, and accordingly, the amount of cutting in the cutting process becomes smaller.

[0103] Figure 12 FIG. is a diagram for explaining the readjustment of the operation amount in the case where the allowable error amount is set in Embodiment 1. In Figure 12 it, similar to Figure 6 the relationship between the material supply amount and the laser output is graphically represented. Figure 12 The points shown in the graph represent the sets of the values of the laser output and the values of the material supply amount.

[0104] Figure 12 The point 51 shown in FIG. represents an example of the set of the value of the laser output after the adjustment in the weld bead width correction control unit 31 or the value of the material supply amount after the adjustment in the weld bead height correction control unit 32. In the set represented by the point 51, the value of the material supply amount exceeds the maximum value of the material supply amount when the weld bead 16 can be properly formed.

[0105] Figure 12 The point 53 shown in FIG. represents an example of the set of the value of the laser output and the value of the material supply amount after the readjustment in the case where the allowable error amount of the beam height error is not set. Figure 12 The conversion from the point 51 to the point 53 in FIG. represents the readjustment of increasing the laser output without changing the material supply amount.

[0106] Figure 12 The point 52 shown in FIG. represents an example of the set of the value of the laser output and the value of the material supply amount after the readjustment in the case where the allowable error amount of the beam height error is set. Figure 12 The conversion from the point 51 to the point 52 in FIG. represents the readjustment of decreasing the material supply amount and increasing the laser output. The increase amount of the laser output in the conversion from the point 51 to the point 52 is smaller than the increase amount of the laser output in the conversion from the point 51 to the point 53. As described above, the additive manufacturing apparatus 100 sets the allowable error amount of the weld bead height error, thereby reducing the increase amount of the laser output. The additive manufacturing apparatus 100 reduces the increase amount of the laser output, thereby being able to alleviate the widening of the weld bead width.

[0107] The additive manufacturing apparatus 100 can reduce the bead height error in any case where a tolerance amount is set and where no tolerance amount is set. When no tolerance amount is set, the additive manufacturing apparatus 100 can make the bead height error zero. When a tolerance amount is set, the additive manufacturing apparatus 100 can converge the bead height error to the tolerance amount and can mitigate the widening of the bead width.

[0108] Next, the order of the processes performed by the operation amount readjustment unit 33 will be described. Figure 13 It is a flowchart showing an example of the order of the processes performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the first embodiment. In Figure 13 an example of the order of the processes in the case where a tolerance amount for the beam height error is set is shown.

[0109] The bead width correction control unit 31 adjusts the laser output based on the bead width error. The bead width correction control unit 31 outputs the value of the laser output. The bead height correction control unit 32 adjusts the material supply amount based on the bead height error. The bead height correction control unit 32 outputs the value of the material supply amount. The value of the laser output and the value of the material supply amount are input to the operation amount readjustment unit 33.

[0110] In step S11, the operation amount readjustment unit 33 determines whether the material supply amount is excessive relative to the laser output. The operation amount readjustment unit 33 determines that the material supply amount is excessive relative to the laser output when the value of the material supply amount is greater than the maximum value of the appropriate range. When it is determined that the material supply amount is excessive relative to the laser output (step S11, Yes), the operation amount readjustment unit 33 advances the order to step S12. On the other hand, when it is determined that the material supply amount is not excessive relative to the laser output (step S11, No), the operation amount readjustment unit 33 advances the order to step S14.

[0111] In step S12, the operation amount readjustment unit 33 adjusts the material supply amount in accordance with the tolerance amount of the bead height error with respect to the target value of the bead height. The operation amount readjustment unit 33 makes an adjustment to reduce the material supply amount so that the bead height error coincides with the tolerance amount.

[0112] In step S13, the operation amount readjustment unit 33 adjusts the laser output in accordance with the material supply amount adjusted in step S12. The operation amount readjustment unit 33 makes an adjustment to increase the laser output so that the value of the material supply amount is less than or equal to the maximum value of the appropriate range in the relationship between the laser output and the material supply amount.

[0113] In step S14, the operation amount readjustment unit 33 outputs the operation amount. That is, the operation amount readjustment unit 33 outputs the value of the laser output as the operation amount and the value of the material supply amount as the operation amount. The operation amount readjustment unit 33 outputs a laser output command indicating the value of the laser output after readjustment to the laser oscillator 2. The operation amount readjustment unit 33 outputs a material supply command indicating the value of the material supply amount after readjustment to the material supply device 5. Above, the operation amount readjustment unit 33 ends Figure 13 the processing related to the sequence shown

[0114] In the above description, when the value of the material supply amount input to the operation amount readjustment unit 33 is greater than the maximum value of the appropriate range, the operation amount readjustment unit 33 gives priority to the laser output over the material supply amount for readjustment. That is, the adjustment implemented by the operation amount readjustment unit 33 is an adjustment that gives priority to making the bead height closer to the target value compared to making the bead width closer to the target value. In Embodiment 1, the operation amount readjustment unit 33 can give priority to the material supply amount over the laser output for readjustment when the value of the material supply amount input to the operation amount readjustment unit 33 is greater than the maximum value of the appropriate range. That is, the adjustment implemented by the operation amount readjustment unit 33 can be an adjustment that gives priority to making the bead width closer to the target value compared to making the bead height closer to the target value. For example, by setting an overly large value as the allowable error amount of the bead height, that is, the allowable error quantity, the operation amount readjustment unit 33 can perform only the readjustment of the material supply amount without performing the readjustment of the laser output. The additive manufacturing device 100 can arbitrarily adjust the ratio of the adjustment of the bead height and the adjustment of the bead width by arbitrarily setting the allowable error amount.

[0115] According to Embodiment 1, when the value of the material supply amount in the operation amount adjustment unit or the value of the material supply amount after the adjustment of the laser output deviates from the value of the laser output within the appropriate range, the operation amount readjustment unit 33 selects one of the material supply amount and the laser output as the operation amount to be prioritized for adjustment. The operation amount readjustment unit 33 preferentially readsjusts the selected operation amount. When the value of the material supply amount is greater than the maximum value of the appropriate range, the operation amount readjustment unit 33 selects the laser output as the operation amount to be prioritized for adjustment. The additive manufacturing device 100 can reduce the shape error of the bead 16 through the adjustment of the material supply amount or the laser output in the operation amount adjustment unit, and can prevent the continuation of processing from becoming difficult through the readjustment of the operation amount in the operation amount readjustment unit 33. Above, the additive manufacturing device 100 has the effect of being able to manufacture a shaped object 17 with reduced errors.

[0116] Embodiment 2.

[0117] In Embodiment 1, a case where the material supply amount becomes excessive relative to the laser output due to the adjustment of the laser output in the bead width correction control unit 31 or the adjustment of the material supply amount in the bead height correction control unit 32 was described. In Embodiment 2, the processing of the operation amount readjustment unit 33 in a case where the material supply amount becomes too small relative to the laser output due to the adjustment of the laser output in the bead width correction control unit 31 or the adjustment of the material supply amount in the bead height correction control unit 32 will be described.

[0118] The additive manufacturing apparatus 100 according to Embodiment 2 has the same structure as the Figure 1 additive manufacturing apparatus 100 shown. Further, the additive manufacturing apparatus 100 according to Embodiment 2 has the same functional structure as the Figure 2 functional structure shown. In Embodiment 2, the same constituent elements as those in the above-described Embodiment 1 are denoted by the same reference numerals, and mainly the structures different from those in Embodiment 1 will be described.

[0119] In Embodiment 2, in a case where the material supply amount becomes too small relative to the laser output due to the adjustment of the laser output in the bead width correction control unit 31 or the adjustment of the material supply amount in the bead height correction control unit 32, the operation amount readjustment unit 33 selects an operation amount that gives priority to adjustment and readjusts the selected operation amount.

[0120] Further, when an allowable error amount is set in the parameter input unit 34, the operation amount readjustment unit 33 readsjusts the laser output and the material supply amount in consideration of the set allowable error amount. In Embodiment 2, the allowable error amount is a value of an allowable bead width error. In Embodiment 2, a value of an allowable bead width error is input to the parameter input unit 34. By inputting the allowable error amount to the parameter input unit 34, the allowable error amount is set in the additive manufacturing apparatus 100.

[0121] Figure 14 FIG. is for explaining the selection of an operation amount that gives priority to adjustment performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to Embodiment 2. In Figure 14 it, similar to Figure 6 , the relationship between the material supply amount and the laser output is graphically represented. Figure 14 The points shown in the graph of FIG. represent sets of values of the laser output and the material supply amount.

[0122] Figure 14The indicated point 54 represents an example of a set of values of the laser output after adjustment in the bead width correction control unit 31 or values of the material supply amount after adjustment in the bead height correction control unit 32. The values of the laser output and the material supply amount indicated by point 54 are outside the appropriate range. In Figure 14 , point 54 is below the straight line 43. This indicates that the value of the material supply amount is less than the minimum value of the material supply amount when the bead 16 can be appropriately formed.

[0123] In order to converge the values of the laser output and the material supply amount to the appropriate range, for example, with respect to the set of values of the laser output and the material supply amount, readjustment from point 54 to point 55 or readjustment from point 54 to point 56 is considered. The conversion from point 54 to point 55 means not changing the laser output and increasing the material supply amount. The conversion from point 54 to point 56 means not changing the material supply amount and decreasing the laser output.

[0124] When the material supply amount is too small relative to the laser output, if the laser output is decreased, the bead width becomes too small, and thus defects may sometimes occur in the shaped object 17. In additive manufacturing, it may be difficult to continue processing due to defects compared to the error in the remaining bead height. In the second embodiment, the operation amount readjustment unit 33 gives priority to the adjustment of increasing the material supply amount over the adjustment of decreasing the laser output in the case where the material supply amount becomes too small relative to the laser output. That is, when the value of the material supply amount is less than the minimum value of the appropriate range, the operation amount readjustment unit 33 selects the material supply amount as the operation amount for which adjustment is prioritized.

[0125] For example, the operation amount readjustment unit 33 does not perform Figure 14 the readjustment of the conversion from point 54 to point 56 in Figure 14 but performs the readjustment of the conversion from point 54 to point 55 in

[0126] Figure 15 is the first diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the second embodiment. The operation amount readjustment unit 33 performs readjustment of the operation amount, that is, the material supply amount, for which adjustment is prioritized. In Figure 15 an example in the case where the allowable bead width error, that is, the allowable error amount, is not set is explained. That is, in Figure 15 the example shown, the operation amount readjustment unit 33 performs readjustment of the laser output so that the bead width error is zero.

[0127] InFigure 15 shows the situation after the bead 16 is formed on the workpiece 19. In Figure 15 shows the XY plane of the bead 16 and the XZ cross-section of the bead 16. In Figure 15 In the XY plane of the bead 16 shown, the width of the bead 16 is leveled by the target value of the bead width, i.e., W. The additive manufacturing apparatus 100 can make the bead width error zero by readjusting the laser output in the operation amount readjustment unit 33.

[0128] In addition, the material supply amount increases, and thus in Figure 15 in the XZ cross-section shown, a portion where the bead 16 is higher than the target value of the bead height, i.e., H, is generated. If the bead height error becomes large, the machining tends to become unstable as described in the first embodiment. The operation amount readjustment unit 33 can prevent the bead height error from becoming large by setting the allowable bead width error, i.e., the allowable error amount.

[0129] Figure 16 is a second diagram for explaining the readjustment of the operation amount performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the second embodiment. In Figure 16 an example in the case where the allowable bead width error, i.e., the allowable error amount, is set is described. In Figure 16 in the example shown, the operation amount readjustment unit 33 readsjusts the laser output so that the bead width error coincides with the allowable error amount, and performs readjustment of the material supply amount based on the readjusted laser output. The operation amount readjustment unit 33 performs readjustment not only on the operation amount with priority in adjustment, i.e., the material supply amount, but also on the operation amount other than the operation amount with priority in adjustment, i.e., the laser output.

[0130] In Figure 16 in the example shown, the operation amount readjustment unit 33 Figure 15 compared with the case shown in Figure 15 reduces the priority of adjusting the bead width, and thus Figure 15 compared with the case shown in

[0131] In Figure 16 shows the situation after the bead 16 is formed on the workpiece 19. In Figure 16 shows the XY plane of the bead 16 and the XZ cross-section of the bead 16. In Figure 16The upper surface of the bead 16 shown, the error in the width of the bead 16, i.e., the bead width error, coincides with the allowable error amount, i.e., EW. As described above, by readjusting the laser output in the operation amount readjustment unit 33, a bead width error corresponding to the allowable error amount remains in the bead 16.

[0132] In addition, the material supply amount is readjusted, whereby the degree of expansion of the bead height becomes smaller than Figure 15 the case shown. Figure 16 The dashed line in the XZ cross-section shown represents Figure 15 the upper surface of the bead 16 in the case shown. The additive manufacturing apparatus 100 reduces the degree of expansion of the bead height, whereby the bead height error can be reduced.

[0133] Figure 17 is a diagram for explaining the readjustment of the operation amount in the case where the allowable error amount is set in the second embodiment. In Figure 17 , similar to Figure 6 , the relationship between the material supply amount and the laser output is represented graphically. Figure 17 The points shown in the graph represent sets of values of the laser output and the material supply amount.

[0134] Figure 17 The point 54 shown is set to be the same as the point 54 shown in Figure 14 . Figure 17 The point 58 shown represents an example of a set of values of the laser output and the material supply amount after readjustment in the case where the allowable error amount of the bead width error is not set. Figure 17 The transition from the point 54 to the point 58 in represents a readjustment in which the laser output is not changed and the material supply amount is increased.

[0135] Figure 17 The point 57 shown represents an example of a set of values of the laser output and the material supply amount after readjustment in the case where the allowable error amount of the bead width error is set. Figure 17 The transition from the point 54 to the point 57 in represents a readjustment in which the material supply amount is increased and the laser output is decreased. The increase amount of the material supply amount in the transition from the point 54 to the point 57 is smaller than the increase amount of the material supply amount in the transition from the point 54 to the point 58. The additive manufacturing apparatus 100 reduces the increase amount of the material supply amount, whereby by setting the allowable error amount of the bead width error, the expansion of the bead height can be alleviated.

[0136] The additive manufacturing apparatus 100 can reduce the bead width error in any case where an allowable error amount is set and where no allowable error amount is set. When no allowable error amount is set, the additive manufacturing apparatus 100 can make the bead width error zero. When an allowable error amount is set, the additive manufacturing apparatus 100 can converge the bead width error to the allowable error amount and can reduce the bead height error.

[0137] Next, the order of the processing performed by the operation amount readjustment unit 33 will be described. Figure 18 It is a flowchart showing an example of the order of the processing performed by the operation amount readjustment unit 33 of the additive manufacturing apparatus 100 according to the second embodiment. In Figure 18 an example of the processing order in the case where an allowable error amount of the bead width error is set is shown.

[0138] The bead width correction control unit 31 adjusts the laser output based on the bead width error. The bead width correction control unit 31 outputs the value of the laser output. The bead height correction control unit 32 adjusts the material supply amount based on the bead height error. The bead height correction control unit 32 outputs the value of the material supply amount. The value of the laser output and the value of the material supply amount are input to the operation amount readjustment unit 33.

[0139] In step S21, the operation amount readjustment unit 33 determines whether the material supply amount is too small relative to the laser output. The operation amount readjustment unit 33 determines that the material supply amount is too small relative to the laser output when the value of the material supply amount is less than the minimum value of the appropriate range. When it is determined that the material supply amount is too small relative to the laser output (step S21, Yes), the operation amount readjustment unit 33 advances the sequence to step S22. On the other hand, when it is determined that the material supply amount is not too small relative to the laser output (step S21, No), the operation amount readjustment unit 33 advances the sequence to step S24.

[0140] In step S22, the operation amount readjustment unit 33 adjusts the laser output in accordance with the allowable amount of the bead width error with respect to the target value of the bead width. The operation amount readjustment unit 33 performs an adjustment to lower the laser output so that the bead width error coincides with the allowable error amount.

[0141] In step S23, the operation amount readjustment unit 33 adjusts the material supply amount in accordance with the laser output adjusted in step S22. The operation amount readjustment unit 33 performs an adjustment to increase the material supply amount so that the value of the material supply amount is greater than or equal to the minimum value of the appropriate range in the relationship between the laser output and the material supply amount.

[0142] In step S24, the operation amount readjustment unit 33 outputs the operation amount. That is, the operation amount readjustment unit 33 outputs the value of the laser output as the operation amount and the value of the material supply amount as the operation amount. The operation amount readjustment unit 33 outputs a laser output command indicating the value of the readjusted laser output to the laser oscillator 2. The operation amount readjustment unit 33 outputs a material supply command indicating the value of the readjusted material supply amount to the material supply device 5. Thus, the operation amount readjustment unit 33 finishes Figure 18 the processing related to the sequence shown.

[0143] In the above description, when the value of the material supply amount input to the operation amount readjustment unit 33 is less than the minimum value of the appropriate range, the operation amount readjustment unit 33 preferentially readjusts the material supply amount compared to the laser output. That is, the adjustment performed by the operation amount readjustment unit 33 is an adjustment that gives priority to approaching the bead width to the target value compared to approaching the bead height to the target value. In Embodiment 2, the operation amount readjustment unit 33 can preferentially readjust the laser output compared to the material supply amount when the value of the material supply amount input to the operation amount readjustment unit 33 is less than the minimum value of the appropriate range. That is, the adjustment performed by the operation amount readjustment unit 33 can be an adjustment that gives priority to approaching the bead height to the target value compared to approaching the bead width to the target value. For example, by setting an overly large value as the allowable error amount of the bead width, that is, the allowable error, the operation amount readjustment unit 33 can perform only the readjustment of the laser output without performing the readjustment of the material supply amount. The additive manufacturing apparatus 100 can arbitrarily adjust the ratio of the adjustment of the bead width and the adjustment of the bead height by arbitrarily setting the allowable error amount.

[0144] In addition, in actual additive manufacturing, even when the bead width is less than the target value, defects do not necessarily occur in the shaped object 17. By appropriately setting the allowable error amount of the bead width error, defects can be avoided even when the bead width is less than the target value.

[0145] Figure 19 is a diagram for explaining the relationship between the allowable error amount in the additive manufacturing apparatus 100 according to Embodiment 2 and the occurrence of defects in the shaped object 17. In the following description, the width of the overlapping portion between adjacent beads 16 is referred to as the overlapping amount. The width of the overlapping portion between the beads 16 is the width in the direction in which the beads 16 are arranged. In addition, the distance between the center positions of one of the adjacent beads 16 and the center position of the other is referred to as the bead center-to-center distance. The bead center-to-center distance is specified in advance by a machining program or the like.

[0146] The overlapping amount can be calculated by the following formula.

[0147] Overlapping amount

[0148] = (Actual bead width) - (Distance between bead centers)

[0149] = (Target value of bead width) - (Allowable error amount of bead width error) - (Distance between bead centers)

[0150] In Figure 21 Examples of the arrangement of two adjacent beads 16 are shown in (a), (b), and (c) of Figure 21 P shown in (a), (b), and (c) of represents the distance between bead centers. When the overlap amount O is greater than zero, the two beads 16 overlap each other and no defects occur.

[0151] In Figure 21 In the case shown in (a) of , the bead width of each bead 16 is consistent with the target value, i.e., W. That is, the actual bead width of each bead 16 is W. In Figure 21 In the case shown in (a) of , the allowable error amount of bead width error, i.e., EW, is set to zero. In Figure 21 In the case shown in (a) of , since the overlap amount O is greater than zero, no defects occur.

[0152] In Figure 21 In the case shown in (b) of , the bead width of each bead 16, i.e., W', is less than the target value, i.e., W, and the allowable error amount of bead width error, i.e., EW, is set. In Figure 21 In the case shown in (b) of , 0 < EW < W - P holds. In this case, since the overlap amount O is greater than zero, no defects occur.

[0153] In Figure 21 In the case shown in (c) of , the bead width of each bead 16, i.e., W', is less than the target value, i.e., W, and the allowable error amount of bead width error, i.e., EW, is set. In Figure 21 In the case shown in (c) of , 0 < W - P < EW holds. In this case, since the overlap amount O is less than zero, i.e., the two beads 16 do not overlap each other, defects occur.

[0154] As described above, the allowable error amount of bead width error satisfies the following condition, whereby the additional manufacturing apparatus 100 can avoid the occurrence of defects.

[0155] (Allowable error amount of bead width error) < (Target value of bead width) - (Distance between bead centers)

[0156] According to Embodiment 2, when the material supply amount in the operation amount adjustment unit or the adjusted material supply amount value after the adjustment of the laser output deviates from the appropriate range with respect to the laser output value, the operation amount readjustment unit 33 selects one of the material supply amount and the laser output as the operation amount to be preferentially adjusted. The operation amount readjustment unit 33 preferentially readjusts the selected operation amount. When the value of the material supply amount is less than the minimum value of the appropriate range, the operation amount readjustment unit 33 selects the material supply amount as the operation amount to be preferentially adjusted. The additive manufacturing apparatus 100 can reduce the shape error of the bead 16 by adjusting the material supply amount or the laser output in the operation amount adjustment unit, and can prevent the continuation of processing from becoming difficult by readjusting the operation amount in the operation amount readjustment unit 33. As described above, the additive manufacturing apparatus 100 has the effect of being able to manufacture a shaped object 17 with reduced error.

[0157] The additive manufacturing apparatus 100 can perform both the processing described in Embodiment 1 and the processing described in Embodiment 2. That is, when the material supply amount is too large with respect to the appropriate range, the additive manufacturing apparatus 100 can perform the processing described in Embodiment 1, and when the material supply amount is too small with respect to the appropriate range, the additive manufacturing apparatus 100 can perform the processing described in Embodiment 2.

[0158] Embodiment 3.

[0159] In additive manufacturing, due to thermal deviation, an error relative to the target position sometimes occurs at the center position of the bead 16 to be formed. The influence of this error spreads to the shape of the shaped object 17, and thus the shape of the shaped object 17 may be different from the target shape. In the case of correcting the position of the processing point based on the result of measuring the error of the center position of the bead 16, if the position correction amount is too large, the bead 16 may be formed at a position separated from the base material 18 or the shaped object 17 on the base material 18. If the position correction amount is too large, it is difficult to continue processing if the bead 16 cannot be brought into contact with the base material 18 or the shaped object 17. In addition, if only a limit is set on the position correction amount, it is difficult to obtain a shaped object 17 having the target shape.

[0160] In Embodiment 3, when the position correction amount is limited, correction for making the shape of the shaped object 17 approach the target shape is performed by increasing the adjustment of the bead width, that is, by increasing the adjustment of the laser output.

[0161] Figure 20 FIG. is an example showing the functional configuration of the additive manufacturing apparatus 100A according to Embodiment 3. In Figure 20 an example of the functional configuration related to the function of reducing the error of the center position of the bead 16, that is, the bead position error, is shown. In addition, inFigure 20 In the example shown, it has, together with Figure 2 a structure identical to the structure shown, that is, a functional structure related to the function of reducing the shape error of the bead 16. In Embodiment 3, the same reference numerals are assigned to the constituent elements identical to those in Embodiment 1 or 2 above, and mainly the structures different from those in Embodiment 1 or 2 will be described.

[0162] The additive manufacturing apparatus 100A is different from Figure 1 the additive manufacturing apparatus 100 shown in that the NC apparatus 1 is replaced with an NC apparatus 1A. The structure of the additive manufacturing apparatus 100A other than the NC apparatus 1A is the same as Figure 1 the additive manufacturing apparatus 100 shown.

[0163] The NC apparatus 1A is a control apparatus that controls the entire additive manufacturing apparatus 100A. The NC apparatus 1A has a bead width correction control unit 31, a bead height correction control unit 32, an operation amount readjustment unit 33, a position correction unit 61, a position correction amount adjustment unit 62, and a bead width correction amount calculation unit 63.

[0164] The analysis device 6 analyzes the image input from the Figure 1 camera 7 shown, and thereby obtains the bead position error. The analysis device 6 outputs the value of the bead position error, that is, the beat position error amount, to the NC apparatus 1A.

[0165] The bead position error amount calculated by the analysis device 6 is input to the position correction unit 61. If the bead position error amount is input to the position correction unit 61, the position correction unit 61 obtains the correction amount of the processing point based on the bead position error amount. The position correction unit 61 outputs the obtained value of the correction amount to the position correction amount adjustment unit 62.

[0166] A value representing an appropriate correction range is input to the parameter input unit 34 as a parameter value. The appropriate correction range is the range of the values of the correction amount of the processing point when the bead 16 can be appropriately formed. By inputting the value representing the appropriate correction range to the parameter input unit 34, the appropriate correction range is set in the additive manufacturing apparatus 100. The parameter input unit 34 outputs the value representing the appropriate correction range to the NC apparatus 1A.

[0167] When the value of the correction amount obtained by the position correction unit 61 deviates from the appropriate correction range indicated by the value input from the parameter input unit 34, the position correction amount adjustment unit 62 adjusts the value of the correction amount to a value included in the appropriate correction range. The position correction amount adjustment unit 62 corrects the position indicated by the position command based on the adjusted correction amount. The position correction amount adjustment unit 62 outputs the corrected position command to the axis drive device 3.

[0168] The position correction amount adjustment unit 62 determines whether the shape of the formed object 17 can be set to the target shape by the adjusted correction amount. When the value of the correction amount obtained by the position correction unit 61 deviates from the appropriate correction range, the position correction amount adjustment unit 62 determines that the shape of the formed object 17 cannot be set to the target shape. The position correction amount adjustment unit 62 calculates the difference between the shape of the formed object 17 and the target shape when the processing points are corrected by the correction amount adjusted by the position correction amount adjustment unit 62. The position correction amount adjustment unit 62 outputs the value representing the difference obtained to the bead width correction amount calculation unit 63.

[0169] If the bead width correction amount calculation unit 63 is input with the value representing the difference, it calculates the correction amount of the bead width based on the value representing the difference. That is, the bead width correction amount calculation unit 63 calculates the correction amount of the bead width, namely the bead width correction amount, based on the difference between the shape of the formed object 17 and the target shape when the processing points are corrected by the correction amount adjusted by the position correction amount adjustment unit 62. The bead width correction amount calculation unit 63 outputs the calculated correction amount value to the bead width correction control unit 31 and the bead height correction control unit 32 respectively.

[0170] Similar to Embodiment 1 or 2, if the bead width correction control unit 31 is input with the bead width error amount, it adjusts the laser output indicated by the laser output command based on the bead width error amount. In addition, the bead width correction control unit 31 corrects the laser output based on the correction amount value input from the bead width correction amount calculation unit 63. If the bead height correction control unit 32 is input with the bead height error amount, it adjusts the material supply amount indicated by the material supply command based on the bead height error amount. In addition, the bead height correction control unit 32 corrects the material supply amount based on the correction amount value input from the bead width correction amount calculation unit 63. The operation amount adjustment unit corrects at least one of the laser output and the material supply amount based on the bead width correction amount. Through the correction of the laser output in the bead width correction control unit 31 and the correction of the material supply amount in the bead height correction control unit 32, the bead width of the bead 16 to be formed is corrected.

[0171] Next, the relationship between the correction of the processing points corresponding to the bead position error and the formation of the bead 16 will be described. Figure 21 This is the first diagram for explaining the relationship between the correction of the processing points and the formation of the bead 16 in the additive manufacturing apparatus 100A according to Embodiment 3. In Figure 21 (a), a situation where the bead 16 is formed in the workpiece 19 is illustrated. In Figure 21 (a), the processing direction is set to the Y-axis direction. The processing point is the position on the central axis of the beam nozzle. CX1 is set to beFigure 21 The position of the central axis of the beam nozzle in the state shown in (a) of

[0172] Figure 21 In the region 65 at the outer edge of the workpiece 19 where the bead 16 shown in (a) of

[0173] is Figure 21 to be formed. The center position of the formed bead 16 deviates from the center position of the region 65. If the bead position error of the bead 16 to be formed becomes too large, defects will occur in the formed object 17. If defects occur in the formed object 17, it may be difficult to continue the processing. Figure 21 Figure 21 In (b) of

[0174] Figure 21 is illustrated the case where the correction of the bead position error as shown in (a) of

[0175] Figure 22 Figure 22 is carried out only by correcting the processing point. CX2 is Figure 22 the position of the central axis of the beam nozzle in the state shown in (b) of Figure 21 The distance between CX1 and CX2 corresponds to the correction amount of the processing point, that is, ΔCX.

[0176] Figure 22 In (b) of

[0177] is illustrated the state where the gap between the workpiece 19 and the corrected processing point is too large and the bead 16 cannot be formed on the workpiece 19. In addition, in the part of the workpiece 19 where the bead 16 is to be formed, there may be a region 66 where the laser beam L cannot irradiate. As described above, it is sometimes difficult to continue the processing because the bead 16 cannot be formed on the workpiece 19 only by correcting the processing point.

[0177] is Figure 22In the state shown in (b), the correction amount of the processing point is limited to an appropriate correction range, and thus the shape of the shaped object 17 does not satisfy the target shape. As Figure 22 shown in (c), the bead width of the bead 16 to be formed is corrected to W' which is larger than the target value W. The additive manufacturing apparatus 100A corrects the bead width by the bead width correction amount calculation unit 63, and thus can make the shape of the shaped object 17 coincide with the target shape.

[0178] Figure 23 This is a diagram for explaining the correction of the bead width in the additive manufacturing apparatus 100A according to the third embodiment. In Figure 23 (a), an example of the bead 16 before correcting the bead width by the bead width correction amount calculated by the bead width correction amount calculation unit 63 is shown. Figure 23 The bead width of the bead 16 shown in (a) is the target value of the bead width, that is, W. Figure 23 The bead height of the bead 16 shown in (a) is the target value of the bead height, that is, H.

[0179] In Figure 23 (b), an example of the bead 16 in the case where only the bead width is corrected from the state shown in (a) is shown. The bead width correction amount calculation unit 63 calculates ΔW as the bead width correction amount based on the difference between the shape of the shaped object 17 and the target shape when the processing point is corrected by the correction amount adjusted by the position correction amount adjustment unit 62. The bead width correction control unit 31 increases the laser output based on the value of the bead width correction amount input from the bead width correction amount calculation unit 63. Figure 23 (b), the bead width of the bead 16 shown is W + ΔW. However, if the laser output increases but the material supply amount cannot be changed, the bead height of the bead 16 to be formed does not satisfy the target value H. Figure 23 (b), the bead width of the bead 16 shown is W + ΔW. However, if the laser output increases but the material supply amount cannot be changed, the bead height of the bead 16 to be formed does not satisfy the target value H.

[0180] In Figure 23 (c), an example of the bead 16 in the case where the bead width and the bead height are corrected from the state shown in (a) is shown. The bead height correction control unit 32 increases the material supply amount based on the value of the bead width correction amount input from the bead width correction amount calculation unit 63. Thus, the additive manufacturing apparatus 100A forms a bead 16 having a bead width of W + ΔW and a bead height of H as shown in Figure 23 (c). Figure 23 (c), a bead 16 having a bead width of W + ΔW and a bead height of H is formed.

[0181] Figure 24 This is a diagram for explaining the correction amount calculated by the bead width correction amount calculation unit 63 of the additive manufacturing apparatus 100A according to the third embodiment. In Figure 24Among them, the bead 16 in which a bead position error has occurred and the contour shape 67 that is the target shape of the shaped object 17 are illustrated. The bead width of the bead 16 is set to W. The correction amount ΔW calculated by the bead width correction amount calculation unit 63 corresponds to the difference between the contour shape 67 and the formed bead 16. The bead width correction amount calculation unit 63 outputs the calculated value of the bead width correction amount to each of the bead width correction control unit 31 and the bead height correction control unit 32.

[0182] Next, the order of the processes performed by the position correction unit 61, the position correction amount adjustment unit 62, and the bead width correction amount calculation unit 63 will be described. Figure 25 It is a flowchart showing an example of the order of processes performed by the position correction unit 61, the position correction amount adjustment unit 62, and the bead width correction amount calculation unit 63 of the additive manufacturing apparatus 100A according to Embodiment 3.

[0183] In step S31, the position correction unit 61 obtains a correction amount for the processing point based on the bead position error. The position correction unit 61 outputs the obtained value of the correction amount to the position correction amount adjustment unit 62.

[0184] In step S32, the position correction amount adjustment unit 62 determines whether the value of the correction amount obtained by the position correction unit 61 in step S31 deviates from the appropriate correction range. When it is determined that the value of the correction amount deviates from the appropriate correction range (step S32, Yes), the position correction amount adjustment unit 62 advances the sequence to step S33.

[0185] In step S33, the position correction amount adjustment unit 62 adjusts the value of the correction amount to a value included in the appropriate correction range. The position correction amount adjustment unit 62 outputs the position command corrected based on the adjusted correction amount to the axis drive device 3. The position correction amount adjustment unit 62 obtains the difference between the shape of the shaped object 17 and the target shape when the processing point is corrected by the correction amount adjusted in step S33. The position correction amount adjustment unit 62 outputs the value indicating the obtained difference to the bead width correction amount calculation unit 63.

[0186] In step S34, the bead width correction amount calculation unit 63 calculates the correction amount of the bead width based on the difference between the shape of the shaped object 17 and the target shape when the processing point is corrected by the correction amount adjusted in step S33. The bead width correction amount calculation unit 63 outputs the calculated value of the correction amount to the bead width correction control unit 31 and the bead height correction control unit 32, respectively.

[0187] If step S34 is completed, the position correction unit 61, the position correction amount adjustment unit 62, and the bead width correction amount calculation unit 63 end Figure 25The processing involved in the order shown. Alternatively, when it is determined that the value of the correction amount does not deviate from the appropriate correction range (step S32, No), the position correction unit 61, the position correction amount adjustment unit 62, and the bead width correction amount calculation unit 63 end Figure 25 The processing involved in the order shown.

[0188] In addition, the additive manufacturing apparatus 100A, together with the processing described in Embodiment 3, executes the processing described in Embodiment 1 or the processing described in Embodiment 2. The additive manufacturing apparatus 100A may also execute both the processing described in Embodiment 1 and the processing described in Embodiment 2, together with the processing described in Embodiment 3.

[0189] According to Embodiment 3, when the value of the correction amount of the bead position error deviates from the appropriate correction range, the position correction amount adjustment unit 62 adjusts the value of the correction amount to a value included in the appropriate correction range. The bead width correction amount calculation unit 63 calculates the correction amount of the bead width based on the difference between the shape of the shaped object 17 and the target shape when the processing point is corrected with the correction amount adjusted by the position correction amount adjustment unit 62. The additive manufacturing apparatus 100A can correct the bead position error and prevent the continuation of processing from becoming difficult due to an excessive correction amount. The additive manufacturing apparatus 100A can reduce the shape error of the bead 16 by correcting the bead width. As described above, the additive manufacturing apparatus 100A has the effect of being able to manufacture a shaped object 17 with reduced errors.

[0190] Next, the hardware configurations of the NC devices 1 and 1A according to Embodiments 1 to 3 will be described. The NC devices 1 and 1A are implemented by a processing circuit. The processing circuit may be a circuit in which a processor executes software, or may be a dedicated circuit.

[0191] When the processing circuit is implemented by software, the processing circuit is, for example, Figure 26 the control circuit 70 shown. Figure 26 FIG. is a diagram showing a structural example of the control circuit 70 according to Embodiments 1 to 3. The control circuit 70 includes an input unit 71, a processor 72, a memory 73, and an output unit 74.

[0192] The input unit 71 is an interface circuit that receives data input from the outside of the control circuit 70 and supplies it to the processor 72. The output unit 74 is an interface circuit that transmits data from the processor 72 or the memory 73 to the outside of the control circuit 70. When the processing circuit is Figure 26In the case of the control circuit 70 shown, the processor 72 reads out and executes the program stored in the memory 73, thereby implementing the functions of the NC devices 1 and 1A. The memory 73 is also used as a temporary memory in each process implemented by the processor 72.

[0193] In the case where the processing circuit is Figure 26 the control circuit 70 shown, the NC devices 1 and 1A are implemented by software, firmware, or a combination of software and firmware. The software or firmware is described as a program and stored in the memory 73. The processing circuit reads out and executes the program stored in the memory 73 by the processor 72, thereby implementing the respective functions of the NC devices 1 and 1A. That is, the processing circuit has a memory 73 that stores the program for which the processing of the NC devices 1 and 1A is finally executed. In addition, these programs can be said to cause a computer to execute the sequence and method of the NC devices 1 and 1A.

[0194] The processor 72 is a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor). The memory 73 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a floppy disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc).

[0195] Figure 26 is an example of the hardware in the case where the NC devices 1 and 1A are implemented by a general-purpose processor 72 and a memory 73, and the NC devices 1 and 1A can be implemented by a dedicated hardware circuit. Figure 27 is a diagram showing a structural example of the dedicated hardware circuit 75 according to Embodiments 1 to 3.

[0196] The dedicated hardware circuit 75 has an input section 71, an output section 74, and a processing circuit 76. The processing circuit 76 is a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a circuit obtained by combining them. In addition, the NC devices 1 and 1A can also be implemented by combining the control circuit 70 and the hardware circuit 75.

[0197] In Embodiments 1 to 3, the PC 10 is implemented by the same hardware as the Figure 26 hardware shown. The function of the parameter input section 34 is implemented by the input section 71. In addition, the PC 10 has an input device operated by the user and a display device for displaying a screen. The input device includes, for example, a keyboard, a mouse, a keypad, or a touch panel. The display device is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) display.

[0198] The specific manner of dispersion or integration of the components of the NC devices 1 and 1A described in Embodiments 1 to 3 is not limited to the descriptions in Embodiments 1 to 3. All or part of the components of the NC devices 1 and 1A can be functionally or physically dispersed or integrated in any unit to form the devices.

[0199] The structures shown in the above embodiments illustrate an example of the content of the present invention. The structures of the embodiments can be combined with other known technologies. The structures of the embodiments can also be appropriately combined with each other. Without departing from the gist of the present invention, a part of the structure of each embodiment can be omitted or changed.

[0200] Description of Reference Numerals

[0201] 1. 1A NC device, 2 laser oscillator, 3 axis drive device, 4 gas supply device, 5 material supply device, 6 analysis device, 7 camera, 8 processing head, 9 gas nozzle, 10 PC, 11 measuring device, 12 material supply source, 13 material supply nozzle, 14 wire, 15 molten pool, 16 weld bead, 17 shaped object, 18 base material, 19 workpiece, 20 optical cable, 21 workbench, 30 shaping unit, 31 weld bead width correction control unit, 32 weld bead height correction control unit, 33 operation amount readjustment unit, 34 parameter input unit, 41 molten droplet, 42, 43 straight lines, 44, 45, 46, 51, 52, 53, 54, 55, 56, 57, 58 points, 48, 49 dashed lines, 61 position correction unit, 62 position correction amount adjustment unit, 63 weld bead width correction amount calculation unit, 65, 66 regions, 67 contour shape, 70 control circuit, 71 input unit, 72 processor, 73 memory, 74 output unit, 75 hardware circuit, 76 processing circuit, 100, 100A additive manufacturing device.

Claims

1. An additive manufacturing device, characterized in that, comprising: a shaping unit having a material supply unit for supplying a material to a workpiece, a heat source output unit for outputting a heat source that melts the material, and a drive unit for moving the heat source and the material supply unit, and forming a weld bead by using the material melted by the heat source; an operation amount adjustment unit that adjusts the material supply amount of the material supply unit or the heat source output of the heat source output unit based on the shape error of the weld bead; and an operation amount readjustment unit that sets a proper range, which is a range of the value of the material supply amount with respect to the value of the heat source output when the weld bead can be properly formed, and when the value of the material supply amount with respect to the value of the heat source output deviates from the proper range after adjustment in the operation amount adjustment unit, selects one of the material supply amount and the heat source output as the operation amount to be preferentially adjusted, and preferentially readjusts the selected operation amount.

2. The additive manufacturing apparatus according to claim 1, wherein the operation amount adjustment unit has: a weld bead width correction control unit that adjusts the heat source output based on an error in the width of the formed weld bead, i.e., a weld bead width error, thereby controlling the correction of the weld bead width; and a weld bead height correction control unit that adjusts the material supply amount based on an error in the height of the formed weld bead, i.e., a weld bead height error, thereby controlling the correction of the weld bead height, the operation amount readjustment unit preferentially readjusts the selected operation amount when the value of the material supply amount with respect to the value of the heat source output deviates from the proper range after the adjustment of the heat source output in the weld bead width correction control unit or after the adjustment of the material supply amount in the weld bead height correction control unit.

3. The additive manufacturing apparatus according to claim 2, wherein the operation amount readjustment unit selects the heat source output as the operation amount to be preferentially adjusted when the value of the material supply amount is greater than the maximum value of the proper range.

4. The additive manufacturing apparatus according to claim 3, wherein it has a tolerance amount setting unit that sets a value of the weld bead height error that can be tolerated, i.e., a tolerance amount, the operation amount readjustment unit readjusts the heat source output and the material supply amount in consideration of the set tolerance amount.

5. The additive manufacturing apparatus according to claim 2, wherein the operation amount readjustment unit selects the material supply amount as the operation amount to be preferentially adjusted when the value of the material supply amount is less than the minimum value of the proper range.

6. The additive manufacturing apparatus according to claim 5, wherein it has a tolerance amount setting unit that sets a value of the weld bead width error that can be tolerated, i.e., a tolerance amount, the operation amount readjustment unit readjusts the material supply amount and the heat source output in consideration of the set tolerance amount.

7. The additive manufacturing apparatus according to any one of claims 1 to 6, characterized in that, comprising: A position correction unit that obtains a correction amount for a processing point to which the heat source and the material are supplied based on an error in the center position of the bead to be formed, i.e., the bead position error; A position correction amount adjustment unit that sets a range of values of the correction amount when the bead can be appropriately formed, i.e., the appropriate correction range, and adjusts the value of the correction amount to a value included in the appropriate correction range when the value of the correction amount obtained by the position correction unit deviates from the appropriate correction range; and A bead width correction amount calculation unit that calculates a correction amount for the bead width, i.e., the bead width correction amount, based on the difference between the shape of the formed object and the target shape when the processing point is corrected with the correction amount adjusted by the position correction amount adjustment unit; The operation amount adjustment unit corrects at least one of the heat source output and the material supply amount based on the bead width correction amount.

8. An additive manufacturing device, characterized in that, Having: A forming unit that has a material supply unit that supplies a material to a workpiece, a heat source output unit that outputs a heat source that melts the material, and a drive unit that moves the heat source and the material supply unit, and forms a bead by using the material melted by the heat source; A position correction unit that obtains a correction amount for a processing point to which the heat source and the material are supplied based on an error in the center position of the bead to be formed, i.e., the bead position error; A position correction amount adjustment unit that sets a range of values of the correction amount when the bead can be appropriately formed, i.e., the appropriate correction range, and adjusts the value of the correction amount to a value included in the appropriate correction range when the value of the correction amount obtained by the position correction unit deviates from the appropriate correction range; and A bead width correction amount calculation unit that calculates a correction amount for the bead width based on the difference between the shape of the formed object and the target shape when the processing point is corrected with the correction amount adjusted by the position correction amount adjustment unit.

9. An additive manufacturing method, characterized in that, Including the following steps: Adjusting the value of the material supply amount of the material supply unit that supplies the material to the workpiece or the heat source output of the heat source output unit that outputs a heat source that melts the material based on the shape error of the bead formed by using the material melted by the heat source; And Setting a range of values of the material supply amount with respect to the heat source output when the bead can be appropriately formed, i.e., the appropriate range, and when the value of the material supply amount with respect to the heat source output deviates from the appropriate range after the adjustment of the material supply amount or the heat source output, selecting one of the material supply amount and the heat source output as an operation amount to which the adjustment is prioritized, and re-adjusting the selected operation amount preferentially.

10. An additive manufacturing method, characterized in that, Including the following steps: Based on the error in the center position of the bead formed by using the material melted by the heat source, i.e., the bead position error, obtaining a correction amount for the processing point to which the heat source and the material are supplied; Set a range of values for the correction amount when the bead can be properly formed, that is, an appropriate correction range. When the value of the obtained correction amount deviates from the appropriate correction range, adjust the value of the correction amount to a value included in the appropriate correction range; and Based on the difference between the shape of the formed object and the target shape when the processing point is corrected by the adjusted correction amount, calculate the correction amount for the bead width, that is, the bead width correction amount.

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