Additive processing method, additive processing device, and additive processing program

Abstract

Provided is a lamination processing technology that can suppress the generation of burrs in cutting or removal processing after lamination processing. [Solution] A method for additive processing of a workpiece includes the steps of lowering the floor surface of a processing area of ​​the workpiece, spreading a metal powder material in the processing area after lowering the floor surface of the processing area, irradiating the metal powder material spread in the processing area with a laser beam, and layering a workpiece of a predetermined shape onto a plate attached to the floor surface by repeating the lowering step, the layering step, and the irradiating step. The workpiece includes a processing surface on which cutting or removal processing is to be performed after layering processing of the workpiece of the predetermined shape is completed, and a workpiece portion continuous with the processing surface. The layering processing step includes a step of layering the workpiece such that the width of the workpiece portion in a direction parallel to the processing surface increases the farther it is from the processing surface.

Description

[Technical Field]

[0001] The present disclosure relates to an additive processing method, an additive processing device, and an additive processing program. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2022-33955 (Patent Document 1) discloses an additive manufacturing device that performs additive manufacturing using the SLM (Selective Laser Melting) method. The SLM method achieves additive manufacturing by irradiating a metal powder material spread in a processing area with laser light, locally melting and solidifying the metal powder material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-33955 Summary of the Invention [Problem to be solved by the invention]

[0004] After the lamination process, some cutting or removal process may be performed. Patent Document 1 does not disclose the cutting or removal process performed after the lamination process. Burrs may be generated by the cutting or removal process performed after the lamination process.

[0005] The present disclosure has been made to solve the above-mentioned problems, and in one aspect, an object is to provide an additive processing technology that can suppress the generation of burrs in cutting or removal processes that are performed after additive processing. [Means for solving the problem]

[0006] In one example of the present disclosure, a method for additive machining of a workpiece is provided. The additive machining method includes the steps of lowering a floor surface of a machining area of ​​the workpiece, spreading a metal powder material in the machining area after lowering the floor surface of the machining area, irradiating the metal powder material spread in the machining area with a laser beam, and layering a workpiece of a predetermined shape on a plate attached to the floor surface by repeating the lowering, layering, and irradiating steps. The workpiece includes a processing surface on which cutting or removal processing is to be performed after layering processing of the workpiece of the predetermined shape is completed, and a workpiece portion connected to the processing surface. The layering processing step includes layering the workpiece such that the width of the workpiece portion in a direction parallel to the processing surface increases as the workpiece moves away from the processing surface.

[0007] In one example of the present disclosure, the surface to be machined of the workpiece includes a contact surface with the plate.

[0008] In one example of the present disclosure, the cutting process includes wire electrical discharge machining to separate the workpiece from the plate.

[0009] In one example of the present disclosure, the work portion has a tapered shape in which the width increases as the work portion moves away from the intended processing surface.

[0010] In one example of the present disclosure, the surface to be machined of the workpiece includes a surface to be machined by a milling cutter.

[0011] Another example of the present disclosure provides an additive processing apparatus. The additive processing apparatus includes a recoater for spreading metal powder material in a processing area of ​​a workpiece, a lifting mechanism configured to raise and lower the floor surface of the processing area, a plate configured to be detachable from the floor surface, an irradiation mechanism capable of performing layering processing on the workpiece by irradiating laser light onto the metal powder material spread in the processing area, and a control unit capable of performing layering processing on a workpiece of a predetermined shape in the processing area by repeating the recoater's supply of metal powder material to the processing area, the lifting mechanism's lowering of the floor surface, and the irradiation mechanism's irradiation of laser light. The workpiece includes a processing surface that is to be cut or removed after layering processing of the workpiece of the predetermined shape is completed, and a workpiece portion that is continuous with the processing surface. The control unit performs layering processing so that the width of the workpiece portion in a direction parallel to the processing surface increases as it moves away from the processing surface.

[0012] In another example of the present disclosure, a program for additive machining of a workpiece is provided. The additive machining program causes a computer to execute the steps of lowering a floor surface of a machining area for the workpiece, spreading a metal powder material in the machining area after lowering the floor surface of the machining area, irradiating the metal powder material spread in the machining area with a laser beam, and stacking a workpiece of a predetermined shape on a plate attached to the floor surface by repeating the lowering, spreading, and irradiating steps. The workpiece includes a processing surface on which cutting or removal processing is to be performed after stacking of the workpiece of the predetermined shape is completed, and a workpiece portion connected to the processing surface. The stacking step includes stacking the workpiece such that the width of the workpiece portion in a direction parallel to the processing surface increases as the workpiece portion moves away from the processing surface.

[0013] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram showing an example of the device configuration of the additive processing device. [Figure 2] It is a diagram showing the SLM-based layer processing steps in chronological order. [Figure 3] It is a diagram showing the layer processing steps according to the embodiment in chronological order. [Figure 4] It is a diagram showing an example of a workpiece formed on a base plate. [Figure 5] It is a diagram showing the cross-section of the workpiece along the V-V line shown in FIG. 4 from the positive side in the Z-axis direction. [Figure 6] It is a diagram showing an example of the drive mechanism of the additive processing device. [Figure 7] It is a diagram showing an example of the hardware configuration of the control unit. [Figure 8] It is a flowchart showing the flow of the layer processing by the additive processing device.

Modes for Carrying Out the Invention

[0015] Hereinafter, each embodiment according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. In addition, each embodiment and each modification described below may be selectively combined as appropriate.

[0016] <A. Additive Processing Device 100> First, referring to FIG. 1, the additive processing device 100 according to the embodiment will be described. FIG. 1 is a diagram showing an example of the device configuration of the additive processing device 100.

[0017] For the sake of convenience of explanation, hereinafter, the direction parallel to the gravitational direction is also referred to as the "Z-axis direction". The Z-axis direction corresponds to the vertical direction. Also, the downward direction (gravitational direction) is also referred to as the positive side of the Z-axis direction, and the upward direction is also referred to as the negative side of the Z-axis direction.

[0018] The direction on a horizontal plane perpendicular to the Z-axis direction is also referred to as the "X-axis direction." The X-axis direction corresponds to the left-right direction when the additional processing device 100 is viewed from the front. The right direction when the additional processing device 100 is viewed from the front is also referred to as the X-axis positive side, and the left direction when the additional processing device 100 is viewed from the front is also referred to as the X-axis negative side.

[0019] Furthermore, the direction on a horizontal plane perpendicular to both the X-axis and Z-axis directions is also referred to as the "Y-axis direction." In Fig. 1, the Y-axis direction indicates the front-to-back direction on the paper. The back side of the additional processing device 100 when viewed from the front side is also referred to as the Y-axis positive side, and the front side of the additional processing device 100 is also referred to as the Y-axis negative side.

[0020] The additive processing device 100 is a processing machine capable of layer-by-layer processing of a workpiece using the SLM method. The additive processing device 100 irradiates a spread metal powder material with laser light, locally melting and solidifying the metal powder material, thereby layer-by-layer processing the workpiece.

[0021] The additional processing device 100 includes a lifting mechanism 130 , a lifting mechanism 140 , a recoater 150 , and a laser irradiation mechanism 160 .

[0022] A storage area AR1 for metal powder material PM is provided inside the additive processing apparatus 100. The metal powder material PM is the material of the workpiece W. Any metal powder that can be melted by the laser light LS can be used as the metal powder material PM.

[0023] The storage area AR1 is defined by, for example, an elevator mechanism 130 and a wall surface 132. The wall surface 132 is configured to surround the upper surface of the elevator mechanism 130 in a top view.

[0024] The upper surface of the lifting mechanism 130 forms the floor surface of the storage area AR1. The upper surface of the lifting mechanism 130 is configured to be able to move up and down in the Z-axis direction. The lifting mechanism 130 is raised and lowered, for example, by a motor 212Z (see FIG. 6), which will be described later. The top of the storage area AR1 is open, and as the lifting mechanism 130 rises, the metal powder material PM is pushed out of the storage area AR1.

[0025] Furthermore, a processing area AR2 for the workpiece W is provided inside the additional processing device 100. The processing area AR2 is defined by, for example, an elevating mechanism 140 and a wall surface 142. The wall surface 142 is configured to surround the upper surface of the elevating mechanism 140 in a top view.

[0026] The upper surface of the lifting mechanism 140 forms the floor surface of the processing area AR2. The lifting mechanism 140 is configured to be able to move up and down in the Z-axis direction. The lifting mechanism 140 is moved up and down by, for example, a motor 222Z (see FIG. 6), which will be described later. The top of the processing area AR2 is open.

[0027] A base plate 144 may be attached to the upper surface of the lifting mechanism 140. The base plate 144 may be fixed to the lifting mechanism 140 by, for example, a chuck mechanism (not shown) or the like. The base plate 144 is fixed to the lifting mechanism 140 before the additive processing apparatus 100 starts the layer processing.

[0028] The recoater 150 is configured to spread the metal powder material PM extruded from the storage area AR1 into the processing area AR2. The recoater 150 is configured with a blade, a roller, or the like.

[0029] More specifically, the recoater 150 extends in the Y-axis direction. The width of the recoater 150 in the Y-axis direction is longer than the width of the storage area AR1 in the Y-axis direction, and is also longer than the width of the processing area AR2 in the Y-axis direction.

[0030] Further, the recoater 150 is configured to be drivable in the X-axis direction. The driving of the recoater 150 is realized, for example, by a motor 232X (see FIG. 6) described later. The recoater 150 is configured to be at least passable through a storage area AR1 and a processing area AR2 in a top view. When the recoater 150 is driven in the negative X-axis direction, the metal powder material PM extruded from the upper surface of the storage area AR1 is transported to the processing area AR2. Thereby, the metal powder material PM is supplied from the storage area AR1 to the processing area AR2.

[0031] The laser irradiation mechanism 160 irradiates the laser light LS on the metal powder material PM spread in the processing area AR2, and selectively melts and solidifies the metal powder material PM. As an example, the laser irradiation mechanism 160 is composed of a laser oscillator, an optical system, and a laser scanner.

[0032] The laser oscillator is a device that generates high-energy laser light. The optical system condenses the laser light generated by the laser oscillator to generate the laser light LS. For the laser scanner, for example, a galvanometer scanner is used. The galvanometer scanner is composed of a galvanometer mirror for deflecting the laser light LS in the X-axis direction and a galvanometer mirror for deflecting the laser light LS in the Y-axis direction. The additive processing apparatus 100 irradiates the laser light LS at an arbitrary position on the XY plane by controlling the driving of the two galvanometer mirrors.

[0033] <B. Laminated Processing Step> Next, referring to FIG. 2, the laminated processing step of the SLM method will be described. FIG. 2 is a diagram showing the laminated processing step of the SLM method in chronological order.

[0034] In step S1, the additive processing apparatus 100 raises the lifting mechanism 130. The lifting width of the lifting mechanism 130 is preset. When the lifting mechanism 130 rises, the metal powder material PM is extruded from the storage area AR1.

[0035] Further, the additive processing apparatus 100 lowers the lifting mechanism 140. The lowering width of the lifting mechanism 140 is preset. The lowering width corresponds to the thickness of one layer of the workpiece W. Thereby, a space where no metal powder material PM exists is formed in the processing area AR2.

[0036] In step S2, the additive processing apparatus 100 drives the recoater 150, which is waiting at a predetermined position, in the negative X-axis direction. At this time, the additive processing apparatus 100 drives the recoater 150 so that the recoater 150 passes through the storage area AR1 and the processing area AR2 in this order in a top view. Thereby, the recoater 150 evenly spreads the metal powder material PM extruded from the storage area AR1 over the processing area AR2. Thereafter, the additive processing apparatus 100 returns the recoater 150 to a predetermined standby position.

[0037] In step S3, the additive processing apparatus 100 controls the laser irradiation mechanism 160 according to an additive processing program and irradiates the metal powder material PM spread over the processing area AR2 with laser light LS. At this time, the laser light LS is irradiated onto the metal powder material PM on the base plate 144. The metal powder material PM at the irradiated portion of the laser light LS melts and solidifies. Thereby, the first layer SL1 of the workpiece W is formed.

[0038] Thereafter, the additive processing apparatus 100 forms a workpiece W having a predetermined shape on the base plate 144 mounted on the floor surface of the processing area AR2 by repeating the processes of steps S1 to S3.

[0039] <C. Outline> In a post-process of the laminated processing, some cutting or removing process may be performed on the workpiece W. Examples of the cutting process in the post-process of the laminated processing include wire electrical discharge machining for separating the workpiece W from the base plate 144. Examples of the removing process in the post-process of the laminated processing include cutting (e.g., milling) for shaping the workpiece W.

[0040] Burrs may occur when cutting or removing is performed on the workpiece W in a later process. Therefore, the additive processing device 100 according to the embodiment performs lamination processing so as to prevent burrs from occurring in the cutting or removing process in the later process.

[0041] The lamination process according to the embodiment will be described below with reference to Fig. 3. Fig. 3 is a diagram showing the lamination process according to the embodiment in chronological order.

[0042] In the following, the work surface to be subjected to cutting or removal processing in a post-lamination process will be referred to as the “surface to be processed SF.” Examples of the surface to be processed SF include the contact surface between the base plate 144 and the workpiece W, and the surface to be processed by a milling cutter.

[0043] Furthermore, hereinafter, the portion of the workpiece W that is continuous with the to-be-processed surface SF will be referred to as the "workpiece portion WP." If a cross section that is a predetermined distance away from the to-be-processed surface SF in the perpendicular direction to the to-be-processed surface SF is defined as the workpiece cross section, the workpiece portion WP corresponds to the portion of the workpiece W between the to-be-processed surface SF and the workpiece cross section.

[0044] In step S11, the additional processing apparatus 100 executes the lamination processing of steps S1 to S3 described above in Fig. 2. As a result, the additional processing apparatus 100 forms the first layer SL1 on the base plate 144. The lower surface of the layer SL1 is the surface to be processed SF.

[0045] In step S12, the additional processing apparatus 100 again executes the layering processing of steps S1 to S3 described above in Fig. 2. As a result, the additional processing apparatus 100 forms the second layer SL2 on the base plate 144. At this time, the additional processing apparatus 100 makes the width ΔD2 of the second layer SL2 longer than the width ΔD1 of the surface SF to be processed in the direction parallel to the surface SF to be processed.

[0046] In step S13, the additional processing apparatus 100 again executes the layering processing of steps S1 to S3 described above in Fig. 2. As a result, the additional processing apparatus 100 forms a third layer SL3 on the base plate 144. At this time, the additional processing apparatus 100 makes the width ΔD3 of the third layer SL3 longer than the width ΔD2 of the second layer in the direction parallel to the surface to be processed SF.

[0047] As described above, the additive processing device 100 performs layer processing so that the width of the workpiece portion WP in the direction parallel to the surface to be processed SF increases the further away from the surface to be processed SF. Note that in the example of Fig. 3, the outer shape of the workpiece portion WP is shown as a stepped structure, but the thickness of each layer is very thin, for example, 20 to 100 µm. Therefore, the workpiece portion WP appears to have a tapered shape in which the width increases the further away from the surface to be processed SF.

[0048] Fig. 4 is a view showing the workpiece W formed on the base plate 144 from the Y direction. Fig. 5 is a view showing a cross section of the workpiece W taken along line VV shown in Fig. 4, from the positive side in the Z axis direction.

[0049] The workpiece W shown in Figures 4 and 5 is an example of a workpiece formed by additive machining processing using the additive machining apparatus 100. In the example of Figures 4 and 5, additive machining is performed so that the workpiece portion WP has a tapered shape. This makes it less likely that burrs will be generated on the workpiece W when the workpiece W is separated from the base plate 144. Separation of the workpiece W from the base plate 144 is performed, for example, by a wire electric discharge machine separate from the additive machining apparatus 100.

[0050] 4 and 5 show an example in which the shape of the workpiece portion WP is linearly tapered, but the shape of the workpiece portion WP is not limited to this. As another example, the shape of the workpiece portion WP may be exponentially tapered or parabolic tapered. Furthermore, the workpiece portion WP does not necessarily have to be tapered, and may have an inverted pyramid shape whose width increases as it moves away from the surface to be processed SF.

[0051] In addition, in the above description, an example where the planned machining surface SF is the contact surface between the workpiece W and the base plate 144 has been described. However, the planned machining surface SF is not limited to such a contact surface. The planned machining surface SF may be a portion to be machined by cutting in a post-process of the laminated machining. Examples of such a portion include, for example, a workpiece portion where milling is planned.

[0052] <D. Driving Mechanism of Additional Machining Device 100> Next, referring to FIG. 6, the driving mechanism in the additional machining device 100 will be described. FIG. 6 is a diagram showing an example of the driving mechanism of the additional machining device 100.

[0053] As shown in FIG. 6, the additional machining device 100 includes a control unit 50, the above-described elevating mechanisms 130 and 140, the above-described recliner 150, the above-described laser irradiation mechanism 160, and driving units 210, 220, 230, and 240.

[0054] The control unit 50 controls various devices within the additional machining device 100. The device configuration of the control unit 50 is arbitrary. The control unit 50 may be composed of a single control unit or a plurality of control units. As an example, the control unit 50 includes at least one of a CNC (Computer Numerical Control) and a PLC (Programmable Logic Controller).

[0055] The driving unit 210 is a driving mechanism for driving the above-described elevating mechanism 130. The driving unit 210 may be composed of a single driving unit or a plurality of driving units. In the example of FIG. 6, the driving unit 210 is composed of a motor driver 211Z and a motor 212Z.

[0056] The motor driver 211Z sequentially receives input of target positions for the lifting mechanism 130 from the control unit 50, and outputs a current corresponding to the target positions to the motor 212Z. As a result, the motor 212Z moves the lifting mechanism 130 to any position in the Z-axis direction. The motor 212Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0057] The drive unit 220 is a drive mechanism for driving the above-described lifting mechanism 140. The drive unit 220 may be configured with a single drive unit or multiple drive units. In the example of Fig. 6, the drive unit 220 is configured with a motor driver 221Z and a motor 222Z.

[0058] The motor driver 221Z sequentially receives input of target positions for the lifting mechanism 140 from the control unit 50, and outputs a current corresponding to the target positions to the motor 222Z. As a result, the motor 222Z moves the lifting mechanism 140 to any position in the Z-axis direction. The motor 222Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0059] The drive unit 230 is a drive mechanism for driving the recoater 150. The drive unit 230 may be configured with a single drive unit or multiple drive units. In the example of Fig. 6, the drive unit 230 is configured with a motor driver 231X and a motor 232X.

[0060] The motor driver 231X sequentially receives input of target positions for the recoater 150 from the control unit 50, and outputs a current corresponding to the target positions to the motor 232X. As a result, the motor 232X moves the recoater 150 to any position in the X-axis direction. The motor 232X may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0061] The drive unit 240 is a drive mechanism for rotationally driving the galvanometer mirrors 162A and 162B in the laser irradiation mechanism 160. The drive unit 240 may be composed of a single drive unit or a plurality of drive units. In the example of FIG. 6, the drive unit 240 is composed of motor drivers 241A and 241B and motors 242A and 242B.

[0062] The motor driver 241A sequentially receives an input of the target rotation angle or the target rotation speed of the galvanometer mirror 162A centered on the X-axis direction from the control unit 50, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 242A. The motor 242A drives the galvanometer mirror 162A to pivot about the X-axis direction. The additional processing apparatus 100 can irradiate the laser light LS at an arbitrary position in the X-axis direction by reflecting the laser light LS generated by the laser irradiation mechanism 160 with the galvanometer mirror 162A. The laser light LS reflected by the galvanometer mirror 162A is guided to the galvanometer mirror 162B. <B

[0063] The motor driver 241B sequentially receives an input of the target rotation angle or the target rotation speed of the galvanometer mirror 162B centered on the Y-axis direction from the control unit 50, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 242B. The motor 242B drives the galvanometer mirror 162B to pivot about the Y-axis direction. The additional processing apparatus 100 can irradiate the laser light LS at an arbitrary position in the Y-axis direction by reflecting the laser light LS generated by the laser irradiation mechanism 160 with the galvanometer mirror 162B.

[0064] <E. Hardware Configuration of Control Unit 50> Next, referring to FIG. 7, the hardware configuration of the control unit 50 shown in FIG. 6 will be described. FIG. 7 is a diagram showing an example of the hardware configuration of the control unit 50.

[0065] As described above, the control unit 50 may be a CNC or a PLC. Fig. 7 shows the hardware configuration of the control unit 50 as a CNC.

[0066] The control unit 50 includes, for example, a control circuit 101, a read only memory (ROM) 102, a random access memory (RAM) 103, a communication interface 104, and an auxiliary storage device 120. These components are connected to an internal bus 109.

[0067] The control circuit 101 is configured, for example, by at least one integrated circuit. The integrated circuit may be configured, for example, by at least one central processing unit (CPU), at least one graphics processing unit (GPU), at least one application specific integrated circuit (ASIC), at least one field programmable gate array (FPGA), or a combination thereof.

[0068] The control circuit 101 controls the operation of the control unit 50 by executing various programs such as an additive machining program 122. The additive machining program 122 is a program for realizing the various processes described in this specification. Upon receiving an execution command for the additive machining program 122, the control circuit 101 reads the additive machining program 122 from the ROM 102 to the RAM 103. The RAM 103 functions as a working memory and temporarily stores various data required for executing the additive machining program 122.

[0069] The communication interface 104 is an interface for realizing communication with various devices. The additional processing device 100 communicates with, for example, various drive units (such as the above-mentioned drive units 210, 220, 230, and 240) for realizing additional processing of a workpiece via the communication interface 104.

[0070] The auxiliary storage device 120 is a storage medium such as a hard disk or a flash memory. The auxiliary storage device 120 stores an additive processing program 122, three-dimensional data 124, and the like. The additive processing program 122 is generated in advance from the three-dimensional data 124 of a workpiece W, for example. The additive processing device 100 executes the additive processing program 122 to form a workpiece W having the shape indicated by the three-dimensional data 124.

[0071] The storage location of the additional processing program 122 and the three-dimensional data 124 is not limited to the auxiliary memory device 120, but may also be stored in a memory area (e.g., cache memory) of the control circuit 101, ROM 102, RAM 103, an external device (e.g., a server), etc.

[0072] Furthermore, the additive processing program 122 may be provided not as a standalone program but as part of an arbitrary program. In this case, various processes according to this embodiment are realized in cooperation with the arbitrary program. Even a program that does not include some of these modules does not deviate from the spirit of the additive processing program 122 according to this embodiment. Furthermore, some or all of the functions provided by the additive processing program 122 may be realized by dedicated hardware. Furthermore, the control unit 50 may be configured in the form of a so-called cloud service in which at least one server executes part of the processing of the additive processing program 122.

[0073] <F.フローチャート> Next, the control flow of the additional processing device 100 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the flow of the laminating process by the additional processing device 100.

[0074] 8 is realized, for example, by the control unit 50 of the additional processing apparatus 100 executing the above-described additional processing program 122. In another aspect, some or all of the processing may be performed by circuit elements or other hardware.

[0075] In step S110, the control unit 50 initializes a variable "N" for managing the number of layers of the workpiece W. "N" is a natural number. The initial value of "N" is "1."

[0076] In step S112, the control unit 50 raises the above-mentioned lifting mechanism 130. The lifting amount of the lifting mechanism 130 is set in advance. As a result, the metal powder material PM is pushed out of the storage area AR1.

[0077] In step S114, the control unit 50 lowers the above-mentioned lifting mechanism 140. The lowering width of the lifting mechanism 140 is set in advance. The lowering width corresponds to the thickness of one layer of the workpiece W. As a result, a space where the metal powder material PM does not exist is formed in the processing area AR2.

[0078] In step S116, the control unit 50 drives the recoater 150, which is waiting at a predetermined position, to the negative side in the X-axis direction. At this time, the control unit 50 drives the recoater 150 so that, when viewed from above, the recoater 150 passes through the storage area AR1 and the processing area AR2 in that order. This causes the metal powder material PM to be supplied from the storage area AR1 to the processing area AR2. Thereafter, the control unit 50 returns the recoater 150 to the predetermined waiting position.

[0079] In step S118, the control unit 50 controls the laser irradiation mechanism 160 in accordance with the additive processing program 122 to irradiate the metal powder material PM spread in the processing area AR2 with the laser light LS. At this time, the control unit 50 performs the layering processing so that the width of the workpiece portion WP continuing from the to-be-processed surface SF increases with increasing distance from the to-be-processed surface SF.

[0080] In step S120, the control unit 50 determines whether a predetermined termination condition is satisfied. As an example, the termination condition is satisfied when the variable "N" is equal to or greater than a predetermined value. If the control unit 50 determines that the predetermined termination condition is satisfied (YES in step S120), it terminates the processing shown in FIG. 8. If not (NO in step S120), the control unit 50 switches control to step S122.

[0081] In step S122, the control unit 50 increments "N." That is, the control unit 50 adds 1 to "N." After that, the control unit 50 returns the process to step S112.

[0082] In this way, the control unit 50 executes the lamination processing of the workpiece W. After lamination processing in the additional processing device 100 is completed, the workpiece W is subjected to a post-processing cutting or removal process. The post-processing cutting or removal process may be executed by the additional processing device 100, or may be executed by a processing machine other than the additional processing device 100.

[0083] As an example, wire electric discharge machining is performed as a post-process cutting process to separate the workpiece W from the base plate 144. In this case, the worker carries the workpiece W, which has been subjected to additive machining by the additive machining device 100, together with the base plate 144 to the wire electric discharge machine. Thereafter, the wire electric discharge machine performs wire electric discharge machining along the to-be-machined surface SF of the workpiece W, and separates the workpiece W from the base plate 144.

[0084] As another example, finishing processing of the workpiece W is performed as a post-process removal processing. In this case, the worker carries the workpiece W, which has completed the additive processing by the additive processing device 100, to a machine tool. The machine tool then performs milling or the like on the to-be-processed surface SF of the workpiece W to shape the workpiece W.

[0085] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0086] 50 control unit, 100 additional processing device, 101 control circuit, 102 ROM, 103 RAM, 104 communication interface, 109 internal bus, 120 auxiliary storage device, 122 additional processing program, 124 three-dimensional data, 130 lifting mechanism, 132 wall surface, 140 lifting mechanism, 142 wall surface, 144 base plate, 150 recoater, 160 laser irradiation mechanism, 162A galvanometer mirror, 162B galvanometer mirror, 210 drive unit, 211Z motor driver, 212Z motor, 220 drive unit, 221Z motor driver, 222Z motor, 230 drive unit, 231X motor driver, 232X motor, 240 drive unit, 241A motor driver, 241B motor driver, 242A motor, 242B motor, AR1 Storage area, AR2 processing area, LS laser light, PM metal powder material, SF surface to be processed, SL1 layer, SL2 layer, SL3 layer, W workpiece, WP workpiece part.

Claims

1. A method for additive machining of a workpiece, comprising: A step of lowering a floor surface of a workpiece processing area; After lowering the floor surface of the processing area, spreading metal powder material in the processing area; irradiating the metal powder material spread in the processing area with a laser beam; a step of laminating workpieces into a predetermined shape on a plate attached to the floor surface by repeating the lowering step, the spreading step, and the irradiating step; The workpiece after completion of the lamination process of the predetermined shape is a processing plane on which cutting or removal processing is to be performed; a workpiece portion connected to the planned machining plane, the planned processing plane includes a contact surface with the plate, the workpiece portion is a portion between the planned processing plane and a layer that is a predetermined distance away from the planned processing plane in a direction perpendicular to the planned processing plane, An additive processing method, wherein the layer processing step includes a step of layer processing the work portion so that the width of the work portion in a direction parallel to the planned processing plane becomes longer from the planned processing plane toward the layer.

2. The additive machining method according to claim 1 , wherein the cutting process comprises wire electrical discharge machining to separate the workpiece from the plate.

3. The additional machining method according to claim 1 or 2, wherein the workpiece portion has a tapered shape in which the width increases as the workpiece portion moves away from the planned machining plane.

4. The additional machining method according to claim 1 or 2, wherein the planned machining plane of the workpiece includes a surface to be machined by a milling cutter.

5. A recoater for spreading metal powder material over the workpiece processing area; a lifting mechanism configured to be able to lift and lower the floor surface of the processing area; a plate configured to be detachable from the floor surface; an irradiation mechanism capable of performing layer processing of the workpiece by irradiating a laser beam onto the metal powder material spread in the processing area; a control unit that executes a process of laminating a workpiece into a predetermined shape on a plate attached to the floor surface by repeating the supply of metal powder material to the processing area by the recoater, the lowering of the floor surface by the lifting mechanism, and the irradiation of laser light by the irradiation mechanism, The workpiece after completion of the lamination process of the predetermined shape is a processing plane on which cutting or removal processing is to be performed; a workpiece portion connected to the planned machining plane, the planned processing plane includes a contact surface with the plate, the workpiece portion is a portion between the planned processing plane and a layer that is a predetermined distance away from the planned processing plane in a direction perpendicular to the planned processing plane, The additive processing device, wherein the layering process includes a process of layering the workpiece portion so that the width of the workpiece portion in a direction parallel to the planned processing plane becomes longer from the planned processing plane toward the layer.

6. An additive machining program for a workpiece, The additive processing program is installed in a computer. A step of lowering a floor surface of a workpiece processing area; After lowering the floor surface of the processing area, spreading metal powder material in the processing area; irradiating the metal powder material spread in the processing area with a laser beam; repeating the lowering step, the spreading step, and the irradiating step, thereby executing a step of laminating workpieces into a predetermined shape on the plate attached to the floor surface; The workpiece after completion of the lamination process of the predetermined shape is a processing plane on which cutting or removal processing is to be performed; a workpiece portion connected to the planned machining plane, the planned processing plane includes a contact surface with the plate, the workpiece portion is a portion between the planned processing plane and a layer that is a predetermined distance away from the planned processing plane in a direction perpendicular to the planned processing plane, An additive processing program, wherein the layer processing step includes a step of layer processing the work portion so that the width of the work portion in a direction parallel to the planned processing plane becomes longer from the planned processing plane toward the layer.

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