Additional processing device, additional processing method, and additional processing program

Abstract

We provide technology to suppress spatter that occurs during layer processing using the DED (Directed Energy Deposition) method. [Solution] An additive processing device performs additive processing on a base material. The base material is a material containing zinc or a nitrided and quenched material. The additive processing device includes a laser head that supplies a metal material to the base material and irradiates the base material with laser light to melt the metal material on the base material, thereby performing additive processing on the base material, and a control unit that controls the additive processing on the base material based on set control parameters. The control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material. The control unit adjusts the first parameter so that the amount of heat during additive processing on the Nth layer (N is a natural number) and below is greater than the amount of heat during additive processing on the N+1th layer and beyond.

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2019-90072 (Patent Document 1) discloses a manufacturing device that performs additive processing using the SLM (Selective Laser Melting) method. The SLM method is a method of achieving additive processing by irradiating a spread metal powder with laser light and locally melting and solidifying the metal powder.

[0003] The manufacturing apparatus disclosed in Patent Document 1 aims to suppress evaporation of metal and scattering of spatter during irradiation with laser light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-90072 Summary of the Invention [Problem to be solved by the invention]

[0005] In addition to SLM, there is also the Directed Energy Deposition (DED) method as an additive manufacturing method. DED is a method of forming a workpiece by melting supplied metal material with laser light and layering it. When additive manufacturing using DED is performed on a base material that contains a substance with a low boiling point, spatter may occur. When spatter occurs, the accuracy of the additive manufacturing process decreases.

[0006] In view of the above, a technology to suppress spatter generated during lamination processing using the DED method is desired. [Means for solving the problem]

[0007] In one example of the present disclosure, there is provided an additive processing apparatus capable of performing additive processing on a base material. The base material is a zinc-containing material or a nitride-quenched material. The additive processing apparatus includes a laser head capable of supplying a metal material to the base material and irradiating the base material with a laser beam to melt the metal material on the base material, thereby performing additive processing on the base material, and a control unit for controlling additive processing on the base material based on set control parameters. The control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material. The control unit adjusts the first parameter so that the amount of heat during additive processing on the Nth layer (N is a natural number) and below is greater than the amount of heat during additive processing on the N+1th layer and beyond.

[0008] In one example of the present disclosure, N is 1.

[0009] In one example of the present disclosure, the first parameter includes at least one of a parameter related to an output level of the laser light emitted from the laser head and a parameter related to a feed speed of the laser head.

[0010] In one example of the present disclosure, the control parameters include a second parameter for adjusting a discharge rate of the metal material from the laser head, and the control unit adjusts the second parameter so that the discharge rate during lamination processing of the Nth layer or less is smaller than the discharge rate during lamination processing of the N+1th layer or later.

[0011] In one example of the present disclosure, the metal with the highest content in the base material is brass.

[0012] In one example of the present disclosure, the laser head is configured to selectively supply a first type of metallic material and a second type of metallic material. The control parameters include a third parameter for specifying the type of metallic material supplied from the laser head. The control unit adjusts the third parameter so that the first type of metallic material is supplied from the laser head during lamination processing of the Mth layer or less (M is a natural number), and adjusts the third parameter so that the second type of metallic material is supplied from the laser head during lamination processing of the Mth layer and thereafter.

[0013] In one example of the present disclosure, the metal most abundant in the first type of metallic material is nickel, and the metal most abundant in the second type of metallic material is iron.

[0014] In one example of the present disclosure, the metal material is a powder material or a wire material.

[0015] Another example of the present disclosure provides an additive processing method executed by an additive processing device capable of performing additive processing on a base material. The base material is a material containing zinc or a nitride-quenched material. The additive processing device includes a laser head capable of supplying a metal material to the base material and irradiating the base material with a laser beam to melt the metal material on the base material, thereby performing additive processing on the base material. The additive processing method includes a step of controlling additive processing on the base material based on set control parameters. The control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material. In the controlling step, the first parameter is adjusted so that the amount of heat during additive processing on the Nth layer (N is a natural number) and below is greater than the amount of heat during additive processing on the N+1th layer and beyond.

[0016] Another example of the present disclosure provides an additive processing program executed by an additive processing device capable of performing additive processing on a base material. The base material is a zinc-containing material or a nitride-quenched material. The additive processing device includes a laser head capable of supplying a metal material to the base material and irradiating the base material with a laser beam to melt the metal material on the base material, thereby performing additive processing on the base material. The additive processing program causes the additive processing device to execute a process for controlling additive processing on the base material based on set control parameters. The control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material. In the control process, the first parameter is adjusted so that the amount of heat during additive processing on the Nth layer (N is a natural number) and below is greater than the amount of heat during additive processing on the N+1th layer and beyond.

[0017] 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 explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a diagram showing an example of the appearance of an additional processing device. [Figure 2] FIG. 2 is a diagram illustrating an example of a device configuration of an additional processing device. [Figure 3] FIG. 2 is a diagram illustrating an example of a drive mechanism of an additional processing device. [Figure 4] FIG. 2 illustrates an example of a hardware configuration of a control unit. [Figure 5] 1 shows a cross-sectional view of a laser head during additive processing. [Figure 6] 10A and 10B are diagrams illustrating a lamination process for a base material as viewed from above. [Figure 7] 7 is a cross-sectional view of the work taken along line VII-VII in FIG. 6, showing a lamination process for a base material. [Figure 8] FIG. 10 is a diagram for explaining control parameters to be adjusted. [Figure 9]It is a flowchart showing the flow of the additional processing. [Figure 10] It is a diagram showing control parameters according to the first modification example. [Figure 11] It is a diagram showing a cross section of a workpiece generated based on control parameters according to the first modification example. [Figure 12] It is a diagram showing an example of the device configuration of an additional processing device according to the second modification example. [Figure 13] It is a diagram showing an example of a workpiece generated by an additional processing device according to the second modification example.

Embodiments for Carrying Out the Invention

[0019] 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. Note that each embodiment and each modification example described below may be selectively combined as appropriate.

[0020] <A. Appearance of the Additional Processing Device 200> First, referring to FIG. 1, the additional processing device 200 according to the embodiment will be described. FIG. 1 is a diagram showing an example of the appearance of the additional processing device 200.

[0021] The additional processing device 200 is a processing machine capable of performing additional processing (AM (Additive manufacturing) processing) on a workpiece. The additional processing device 200 performs additional processing by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam.

[0022] The additional processing device 200 includes, for example, a cover body 230 and an operation panel 300.

[0023] The cover body 230 is a mechanism for protecting the components provided inside the additional processing device 200. A door DR is provided on the cover body 230. The door DR is, for example, a slide-type door. The door DR may be configured to be opened and closed by a drive source such as a motor, or may be configured to be manually opened and closed.

[0024] The operation panel 300 is a general-purpose computer and has a display for displaying various information related to processing. The display is, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or other display device. Further, the display includes a touch panel and accepts various operations on the additional processing device 200 by touch operation.

[0025] Note that the additional processing device 200 may be a processing machine capable of not only additional processing of a workpiece but also subtractive processing (SM (Subtractive manufacturing)) of the workpiece. Examples of the subtractive processing function include a milling function and a turning function.

[0026] <B. Additional Processing Device 200> Next, referring to FIG. 2, the device configuration of the additional processing device 200 shown in FIG. 1 will be described. FIG. 2 is a diagram showing an example of the device configuration of the additional processing device 200.

[0027] The additional processing device 200 is, for example, a processing machine capable of additional processing of a workpiece and subtractive processing of the workpiece. The subtractive processing function possessed by the additional processing device 200 includes, for example, at least one of a milling function and a turning function using a fixed tool. Note that the additional processing device 200 may be a device without a subtractive processing function.

[0028] The additional processing device 200 includes a machine bed 211. A swivel table 212 is provided on the machine bed 211. The swivel table 212 has a rotary table 213. The rotary table 213 is rotatably attached to the swivel table 212.

[0029] A holding mechanism 213A is clamped on the rotary table 213. The holding mechanism 213A is a fixing mechanism for holding the workpiece W to be machined. As an example, the holding mechanism 213A is a chuck.

[0030] The additional processing device 200 has, for example, two axes (a swivel axis and a rotation axis) that can be controlled regarding the rotation of the holding mechanism 213A clamped on the rotary table 213. The swivel axis is an axis parallel to the upper surface of the machine bed 211. The rotation axis is an axis perpendicular to the upper surface of the rotary table 212. The rotary table 213 is configured to be rotatable around the swivel axis and the rotation axis.

[0031] The additional processing device 200 also has a first slide mechanism 214. The first slide mechanism 214 is disposed on a machine column on the rear side of the machine bed 211. The first slide mechanism 214 is configured to be movable along a slide guide attached to the machine column.

[0032] The additional processing device 200 also has a second slide mechanism 215. The second slide mechanism 215 is configured to be movable along a slide guide attached to the first slide mechanism 214. The slide guide for the second slide mechanism 215 is provided on the first slide mechanism 214 so as to be perpendicular to the slide guide for the first slide mechanism 214. As a result, the second slide mechanism 215 is configured to be movable in a direction perpendicular to the movement direction of the first slide mechanism 214.

[0033] The additional processing device 200 also has a removal processing head 216. The removal processing head 216 is configured to be movable along a slide guide attached to the second slide mechanism 215. The slide guide for the removal processing head 216 is provided on the second slide mechanism 215 so as to be perpendicular to both the slide guide for the first slide mechanism 214 and the slide guide for the second slide mechanism 215. As a result, the removal processing head 216 is configured to be movable in a direction perpendicular to both the movement direction of the first slide mechanism 214 and the movement direction of the second slide mechanism 215.

[0034] The additional processing device 200 drives the removal processing head 216 to any position by controlling the driving of the first slide mechanism 214, the driving of the second slide mechanism 215, and the driving of the removal processing head 216. Each of the first slide mechanism 214, the second slide mechanism 215, and the removal processing head 216 is driven by, for example, a servo motor or the like.

[0035] The additive machining device 200 also has a magazine 218 that stores various units such as a tool 218A, and an automatic tool changer (ATC) 219. When not in use, the tool 218A is stored in the magazine 218. Upon receiving a tool change instruction, the automatic tool changer 219 pulls out the unit to be attached from the magazine 218 and attaches the unit to a spindle 224 provided in the removal machining head 216.

[0036] The additive processing device 200 further includes a laser head 231 for performing additive processing by the DED method. The laser head 231 supplies a metal material to the workpiece W during additive processing, and irradiates the workpiece surface with laser light. The metal material may be a powder material, a wire material, or any other type of material that can be melted by laser light.

[0037] The laser head 231 has a head body 232 and a laser nozzle 236. A metal material is supplied to the head body 232 via a cable CB. The laser nozzle 236 irradiates a workpiece with laser light and defines an irradiation area of the laser light on the workpiece. The metal material supplied to the laser head 231 is discharged toward the workpiece W through the laser nozzle 236.

[0038] The laser head 231 is provided on a third slide mechanism 234. The third slide mechanism 234 is provided on a slide guide 233. Thus, the third slide mechanism 234 is configured to be movable along the slide guide 233. During additional processing, the laser head 231 is driven to be positioned below the main shaft 224 and is attached to the main shaft 224. The laser head 231 attached to the main shaft 224 is driven to an arbitrary position in conjunction with the removal processing head 216.

[0039] <Definition of C Direction> For the sake of convenience of explanation, hereinafter, the direction parallel to the axial direction of the main shaft 224 is also referred to as the "Z-axis direction". Also, one side in the Z-axis direction is also referred to as the "positive Z-axis side", and the other side in the Z-axis direction is also referred to as the "negative Z-axis side". In the example of FIG. 2, the direction of gravity corresponds to the "positive Z-axis side". Also, in the example of FIG. 2, the upward direction corresponds to the "negative Z-axis side".

[0040] Furthermore, one direction on the horizontal plane orthogonal to the Z-axis direction is also referred to as the "Y-axis direction". Also, one side in the Y-axis direction is also referred to as the "positive Y-axis side", and the other side in the Y-axis direction is also referred to as the "negative Y-axis side". In the example of FIG. 2, the back side when looking into the additive processing apparatus 200 from the door DR (front) of the additive processing apparatus 200 corresponds to the "positive Y-axis side". Also, in the example of FIG. 2, the front side when looking into the additive processing apparatus 200 from the door DR corresponds to the "negative Y-axis side".

[0041] Furthermore, the direction orthogonal to both the Y-axis direction and the Z-axis direction is referred to as the "X-axis direction". Also, one side of the X-axis direction is also referred to as the "positive side of the X-axis direction", and the other side of the X-axis direction is also referred to as the "negative side of the X-axis direction". In the example of FIG. 2, the left side when looking inside the additional processing device 200 from the door DR of the additional processing device 200 corresponds to the "positive side of the X-axis direction". Also, in the example of FIG. 2, the right side when looking inside the additional processing device 200 from the door DR corresponds to the "negative side of the X-axis direction".

[0042] <D. Driving mechanism of the additional processing device 200> Next, referring to FIG. 3, the driving mechanism in the additional processing device 200 will be described. FIG. 3 is a diagram showing an example of the driving mechanism of the additional processing device 200.

[0043] As shown in FIG. 3, the additional processing device 200 includes a control unit 50, a swivel table 212, a rotary table 213, a spindle 224, and driving units 310, 320, 330A, 330B. The control unit 50 realizes layer processing by controlling various devices in the additional processing device 200 according to the additional processing program 122 and the set control parameters 124.

[0044] 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).

[0045] The driving unit 310 is a driving mechanism for swiveling the above-described swivel table 212. The driving unit 310 may be composed of a single driving unit or a plurality of driving units. In the example of FIG. 3, the driving unit 310 is composed of a motor driver 311A and a motor 312A.

[0046] The motor driver 311A ​​sequentially receives input of the target rotation angle or target rotation speed of the turntable 212 from the control unit 50, and outputs a current corresponding to the target rotation angle or target rotation speed to the motor 312A. As a result, the motor 312A drives and turns the turntable 212 around a rotation axis centered in the X-axis direction. The motor 312A may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0047] The driving unit 320 is a driving mechanism for rotating the above-mentioned turntable 213. The driving unit 320 may be composed of a single driving unit or multiple driving units. In the example of Fig. 3, the driving unit 320 is composed of a motor driver 321C and a motor 322C.

[0048] The motor driver 321C sequentially receives input of the target rotation angle or target rotation speed of the turntable 213 from the control unit 50, and outputs a current corresponding to the target rotation angle or target rotation speed to the motor 322C. This causes the motor 322C to rotate the turntable 213 around a rotation axis centered in the Z-axis direction. The motor 322C may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0049] The driving unit 330A is a driving mechanism for moving the main shaft 224. The above-mentioned laser head 231 is driven by being attached to the main shaft 224. The driving unit 330A may be configured with a single driving unit or may be configured with multiple driving units. In the example of Fig. 3, the driving unit 330A is configured with motor drivers 331X to 331Z and motors 332X to 332Z.

[0050] The motor driver 331X sequentially receives input of target positions of the spindle 224 in the X-axis direction from the control unit 50, and outputs a current corresponding to the target positions to the motor 332X. This causes the motor 332X to drive the spindle 224 to any position in the X-axis direction. The motor 332X may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0051] The motor driver 331Y sequentially receives input of target positions of the spindle 224 in the Y-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 332Y. This causes the motor 332Y to drive the spindle 224 to any position in the Y-axis direction. The motor 332Y may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0052] The motor driver 331Z sequentially receives input of target positions of the spindle 224 in the Z-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 332Z. This causes the motor 332Z to move the spindle 224 to any position in the Z-axis direction. The motor 332Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0053] The drive unit 330B is a drive mechanism for rotating the main shaft 224. The drive unit 330B may be composed of a single drive unit or multiple drive units. In the example of Fig. 3, the drive unit 330B is composed of motor drivers 331A and 331B and motors 332A and 332B.

[0054] The motor driver 331A sequentially receives an input of a target rotation angle or a target rotation speed of the main shaft 224 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 332A. The motor 332A drives the main shaft 224 to rotate centered on the X-axis direction. The motor 332A may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0055] The motor driver 331B sequentially receives an input of a target rotation angle or a target rotation speed of the main shaft 224 centered on the axial direction of the main shaft 224 from the control unit 50, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 332B. The motor 332B rotates the main shaft 224 centered on the axial direction of the main shaft 224. The motor 332B may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0056] <E. Hardware Configuration of Control Unit 50> Next, referring to FIG. 4, the hardware configuration of the control unit 50 shown in FIG. 3 will be described. FIG. 4 is a diagram showing an example of the hardware configuration of the control unit 50.

[0057] As described above, the control unit 50 may be a CNC or a PLC. FIG. 4 shows the hardware configuration of the control unit 50 as a CNC.

[0058] The control unit 50 includes, for example, a control circuit 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a communication interface 104, and an auxiliary storage device 120. These components are connected to an internal bus 109.

[0059] 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.

[0060] 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.

[0061] The communication interface 104 is an interface for realizing communication with various devices. The additional processing device 200 communicates with, for example, various drive units (such as the above-mentioned drive units 310, 320, 330A, and 330B) for realizing additional processing of the workpiece via the communication interface 104.

[0062] The auxiliary storage device 120 is a storage medium such as a hard disk or flash memory. The auxiliary storage device 120 stores an additional machining program 122, control parameters 124, and the like. The control parameters 124 may be included in the additional machining program 122, or may be separate data. The storage location of the additional machining program 122 and the control parameters 124 is not limited to the auxiliary storage device 120, and may be stored in a storage area of ​​the control circuit 101 (for example, cache memory), the ROM 102, the RAM 103, an external device (for example, a server), or the like.

[0063] In addition, the additional processing program 122 may be provided not as a single program but incorporated into a part of an arbitrary program. In this case, various processes according to the present embodiment are realized in cooperation with an arbitrary program. Even a program that does not include such a part of the module does not deviate from the gist of the additional processing program 122 according to the present embodiment. Further, part or all of the functions provided by the additional processing program 122 may be realized by dedicated hardware. Further, the control unit 50 may be configured in a form such as a so-called cloud service in which at least one server executes part of the processing of the additional processing program 122.

[0064] <F. Principle of Layered Processing> Next, referring to FIG. 5, the mode of additional processing by the additional processing apparatus 200 will be described. FIG. 5 shows a cross-sectional view of the laser head 231 during additional processing.

[0065] Hereinafter, the raw material before the additional processing apparatus 200 performs additional processing is also referred to as a base material W0. Further, a laminated object including the base material W0 and a layer SL laminated by additional processing on the base material W0 is also referred to as a work W.

[0066] The laser head 231 irradiates the surface of the base material W0 with laser light LS while moving on the base material W0. As a result, the base material W0 melts at the irradiated portion of the laser light LS, and a molten pool MP is formed on the surface of the base material W0.

[0067] In parallel, the laser head 231 supplies the metal material PM to the molten pool MP. The metal material PM is guided to the molten pool MP by the gas GS discharged from the laser head 231. As a result, the metal material PM melts and liquefies in the molten pool MP. Thereafter, when the molten pool MP solidifies, a layer SL is formed on the base material W0. The gas GS also has a function as a shielding gas and prevents oxidation of the work W.

[0068] The additive processing device 200 can form workpieces W of various shapes by controlling the laser head 231 according to the above-mentioned additive processing program 122 (see FIG. 3) and the above-mentioned control parameters 124 (see FIG. 3). Examples of the types of additive processing include lamination processing and coating processing. Lamination processing is a process of forming a workpiece W by stacking layers SL on a base material W0. Coating processing is a process of forming a workpiece W by covering the surface of the base material W0 with a layer SL.

[0069] <G. Lamination processing> Next, referring to FIGS. 6 and 7, the lamination processing by the additive processing device 200 will be described. FIG. 6 is a top view showing the lamination processing steps for the base material W0. FIG. 7 is a cross-sectional view of the workpiece W along the line VII-VII in FIG. 6, showing the lamination processing steps for the base material W0.

[0070] The base material W0 to be additively processed may contain a substance with a low boiling point. An example of the low-boiling-point substance contained in the base material W0 is zinc. The boiling point of zinc is 907°C. On the other hand, the boiling point of copper is 2571°C, and the boiling point of iron is 2863°C.

[0071] Another example of the low-boiling-point substance contained in the base material W0 is nitrogen. Nitrogen is contained, for example, in a nitride-hardened base material W0.

[0072] Hereinafter, the description will be given by taking the base material W0 containing zinc as an example, but the low-boiling-point substance contained in the base material W0 is not limited to zinc.

[0073] When lamination processing is performed on the base material W0 containing zinc, zinc evaporates during the lamination processing, and spatter scatters. When the scattered spatter hits the optical system of the laser head 231, the laser head 231 may be damaged.

[0074] In addition, the workpiece surface may become rough due to spattering, or the scattered spatter may remain on the workpiece surface as foreign matter. As a result, the bonding strength between the previously formed layer and the layer formed in the subsequent process may be insufficient, or the density of each layer may become uneven. In this way, spattering also affects the accuracy of additional processing of the workpiece W.

[0075] Therefore, the additional processing device 200 according to the embodiment increases the amount of heat supplied from the laser head 231 to the base material W0 during stacking processing of the Nth layer (N is a natural number) or below, and keeps the amount of heat supplied from the laser head 231 to the base material W0 at the normal level during stacking processing of the N+1th layer and beyond.

[0076] This allows the additive processing device 200 to evaporate the zinc component that has dissolved from the base material W0 during the lamination processing of the first layer, reducing the amount of zinc transferred from the base material W0 to the first layer compared to normal. As a result, the amount of spatter generated is significantly reduced during lamination processing of the second and subsequent layers, and the amount of spatter generated throughout the lamination processing is reduced compared to normal. As a result, damage to the laser head 231 is prevented. Furthermore, suppressing the generation of spatter improves the processing quality of the workpiece W.

[0077] For ease of explanation, hereinafter, the lamination processing performed by the additional processing device 200 by supplying a larger amount of heat than usual when laminating the Nth layer or below will also be referred to as "high-heat lamination processing." In contrast, the lamination processing performed by the additional processing device 200 normally when laminating the Nth layer or above will also be referred to as "normal lamination processing."

[0078] In layers deposited by high-temperature lamination processing, the concentration of sputter-causing substances contained in the base material W0 is lower than in layers deposited by normal lamination processing. In this way, high-temperature lamination processing has the effect of diluting the sputter-causing substances. Therefore, to distinguish from normal layers deposited by normal lamination processing, layers formed by high-temperature lamination processing can also be referred to as "diluted layers."

[0079] If high-temperature lamination processing is performed at least during lamination processing of the first layer, the zinc component of the low-boiling-point substance will evaporate, so the above N may be equal to or greater than 1. Preferably, the above N is 1. In other words, the additive processing device 200 forms the first layer by high-temperature lamination processing, and forms the second and subsequent layers by normal lamination processing.

[0080] 6 and 7, in step S11, the additive processing device 200 forms a first layer SL1 on the base material W0 by high-temperature lamination processing. Next, in step S12, the additive processing device 200 forms a second layer SL2 on the layer SL1 by normal lamination processing.

[0081] The high-temperature lamination process is realized by adjusting the above-mentioned control parameters 124 (see FIG. 4). FIG. 8 is a diagram for explaining the control parameters 124 to be adjusted.

[0082] As described above, in the high-temperature lamination process, the laser head 231 is controlled so that a larger amount of heat than usual is supplied to the base material W0. Examples of the heat amount parameter P1 (first parameter) for adjusting the amount of heat supplied from the laser head 231 to the base material W0 include parameters P1A to P1C shown in FIG.

[0083] The parameter P1A is a parameter for adjusting the output level of the laser light LS from the laser head 231. The additional processing device 200 increases the amount of heat supplied to the base material W0 per unit time by increasing the output level of the laser head 231 higher than normal during high-temperature lamination processing.

[0084] The parameter P1B is a parameter for adjusting the feed speed of the laser head 231. The additional processing device 200 can increase the amount of heat supplied to the base material W0 per unit time as the feed speed of the laser head 231 is slowed down.

[0085] The parameter P1C is a parameter for adjusting the energy density supplied to the base material W0 from the laser head 231. As an example, the additive processing device 200 sets the parameter P1C to "50.0 J / mm" during high-temperature lamination processing. 2 " and for normal lamination processing, parameter P1C is set to "40.0 J / mm 2 Note that the adjustment of the energy density can also be achieved by adjusting the parameters P1A and P1B, so the heat quantity parameter P1 to be adjusted does not need to include the parameter P1C.

[0086] The additional processing device 200 does not need to adjust all of the parameters P1A to P1C during high-temperature lamination processing, but it is sufficient to adjust at least one of the parameters P1A to P1C.

[0087] Preferably, the additional processing device 200 adjusts not only the heat quantity parameter P1 but also a discharge amount parameter P2 (second parameter) for adjusting the discharge amount of the metal material PM from the laser head 231. More specifically, the additional processing device 200 adjusts the discharge amount parameter P2 so that the discharge amount of the metal material PM during high-temperature lamination processing is smaller than the discharge amount of the metal material PM during normal heat lamination processing.

[0088] By reducing the amount of metal material PM discharged during lamination processing of the first layer compared to lamination processing of the second and subsequent layers, the additive processing device 200 can suppress spatter while reducing consumption of the metal material PM. Furthermore, if no metal material PM is supplied at all during lamination processing of the first layer, there is a possibility that the laser light LS reflected by the workpiece W will directly strike the laser head 231. In contrast, by supplying even a small amount of metal material PM during lamination processing of the first layer, the metal material PM after discharge acts as a floating barrier near the laser irradiation point. Therefore, the laser light LS reflected by the workpiece W is less likely to directly strike the laser head 231. As a result, the laser light LS reflected by the workpiece W does not directly strike the laser head 231, or strikes the laser head 231 only in an attenuated state after being reflected and scattered by the metal material PM, thereby preventing damage to the laser head 231.

[0089] This effect is particularly pronounced when the base material W0 is made of a metal with high reflectivity, such as brass. Brass is an alloy of copper and zinc. In this case, the main component of the base material W0 is brass. In other words, the metal with the highest content in the base material W0 is brass. As an example, the content of brass in the base material W0 is 50% or more. The content may be an index based on mass, a index based on volume, or another index.

[0090] Note that the additional processing device 200 may set the discharge amount of the metal material PM to zero during high-temperature layer processing, for example, in cases where the laser light LS reflected by the workpiece W does not enter the laser head 231, or where even if it does enter, it causes almost no problems. This allows the additional processing device 200 to further reduce the consumption of the metal material PM.

[0091] Further, the additional processing device 200 makes the parameters related to the flow rate of the gas GS (see FIG. 5) discharged from the laser head 231 the same during high-temperature lamination processing and normal lamination processing. As an example, the additional processing device 200 maintains the discharge amount of the carrier gas from the laser head 231 at "6 L / min" both during high-temperature lamination processing and normal lamination processing. Also, the additional processing device 200 maintains the discharge amount of the shielding gas from the laser head 231 at "5 L / min" both during high-temperature lamination processing and normal lamination processing.

[0092] <H. Control Flow of Additional Processing> Next, referring to FIG. 9, the control flow of the additional processing will be described. FIG. 9 is a flowchart showing the flow of the additional processing.

[0093] The process shown in FIG. 9 is realized, for example, when the control unit 50 of the additional processing device 200 executes the above-described additional processing program 122. In other aspects, part or all of the process may be executed by circuit elements or other hardware.

[0094] In step S210, the control unit 50 initializes the variable "n" for counting the current layer number. The variable "n" is initialized to, for example, "1".

[0095] In step S212, the control unit 50 controls the above-described automatic tool changer 219 so as to mount the laser head

[0096] In step S220, the control unit 50 determines whether the current layer number "n" is less than or equal to a predetermined value "N". The predetermined value "N" may be set in advance or may be arbitrarily set by the user. The predetermined value "N" is, for example, 1. Alternatively, the predetermined value "N" may be a value of 2 or more.

[0097] If the control unit 50 determines that the current number of layers "n" is equal to or less than the predetermined value "N" (YES in step S220), the control unit 50 switches the control to step S230. Otherwise (NO in step S220), the control unit 50 switches the control to step S240.

[0098] In step S230, the control unit 50 acquires the control parameters 124 related to the high-temperature lamination process and updates the current setting parameters with the acquired control parameters 124. The control parameters 124 related to the high-temperature lamination process may be determined in advance, or may be calculated during execution of step S230 by multiplying the control parameters 124 related to the normal lamination process by a predetermined ratio. The control parameters 124 related to the high-temperature lamination process are as described in FIG. 8, and therefore will not be described again.

[0099] Thereafter, the control unit 50 drives the laser head 231 in accordance with the drive path for the nth layer of the laser head 231. The drive path of the laser head 231 for the nth layer is defined, for example, in the additive processing program 222. In parallel, the control unit 50 controls the laser head 231 in accordance with the control parameters 124 for high-temperature additive processing to supply the metal material PM to the base material W0 and irradiate it with the laser light LS. As a result, the nth layer of the workpiece W is formed on the base material W0.

[0100] In step S232, the control unit 50 increments the variable “n.” That is, the control unit 50 adds “1” to the variable “n.” After that, the control unit 50 switches the control to step S250.

[0101] In step S240, the control unit 50 acquires the control parameters 124 related to the normal lamination processing, and updates the current setting parameters with the acquired control parameters 124. The control parameters 124 related to the normal lamination processing are defined in advance. The control parameters 124 related to the normal lamination processing are as described in FIG. 8, and therefore, description thereof will not be repeated.

[0102] After that, the control unit 50 drives the laser head 231 according to the drive path of the n-th layer related to the laser head 231. The drive path of the laser head 231 in the n-th layer is defined, for example, in the additional processing program 222. In parallel, the control unit 50 controls the laser head 231 according to the control parameter 124 related to normal lamination processing, supplies the metal material PM to the base material W0, and irradiates the laser light LS. Thereby, the n-th layer of the workpiece W is formed on the base material W0.

[0103] In step S242, the control unit 50 increments the variable "n". That is, the control unit 50 adds "1" to the variable "n". After that, the control unit 50 switches the control to step S250.

[0104] In step S250, the control unit 50 determines whether a predetermined end condition is satisfied. As an example, the end condition is satisfied when the variable "n" is greater than or equal to a predetermined value. The predetermined value is a natural number greater than the above "N". When the control unit 50 determines that the predetermined end condition is satisfied (YES in step S250), it ends the process shown in FIG. 9. Otherwise (NO in step S250), the control unit 50 switches the control to step S252.

[0105] <I. First Modified Example> Next, referring to FIGS. 10 and 11, a lamination processing method according to the first modified example will be described. FIG. 10 is a diagram showing the control parameter 124 according to the modified example.

[0106] In the above example, the additive processing apparatus 200 performed lamination processing on the base material W0 using one type of metal material PM. In contrast, the additive processing apparatus 200 according to this modified example performs lamination processing on the base material W0 using a plurality of types of metal materials PM.

[0107] More specifically, the additive processing device 200 includes at least two hoppers, each containing a different type of metal powder, and a powder feeder that delivers the metal material from each hopper. By controlling the supply speed and supply ratio of the metal material for each powder feeder, the additive processing device 200 can change the supply ratio between the metal material from the first hopper and the metal material from the second hopper, or switch between the types of metal material delivered from the first and second hoppers. The metal material delivered from the first and second hoppers is supplied to the laser head 231. As a result, the laser head 231 is configured to selectively deliver the metal material stored in the first hopper and the metal material stored in the second hopper.

[0108] The first hopper contains, for example, a first type of metallic material. The main component of the first type of metallic material is, for example, nickel. In other words, the metal with the largest content in the first type of metallic material is nickel. As an example, the nickel content in the first type of metallic material is 50% or more. The content may be an index based on mass, a index based on volume, or an index based on some other standard. Hereinafter, the metallic material contained in the first hopper will also be referred to as a "nickel-based metallic material." An example of a nickel-based metallic material is Inconel (registered trademark) 625.

[0109] The second hopper contains, for example, a second type of metallic material. The main component of the second type of metallic material is, for example, iron. In other words, the metal with the largest content in the second type of metallic material is iron. As an example, the iron content in the second type of metallic material is 50% or more. The content may be an index based on mass, a index based on volume, or an index based on some other standard. Hereinafter, the metallic material contained in the second hopper will also be referred to as an "iron-based metallic material." An example of an iron-based metallic material is Rockit (registered trademark) 401.

[0110] The additional processing device 200 according to this modified example not only adjusts the heat quantity parameter P1 described above, but also adjusts a material parameter P3 (third parameter) for specifying the type of metal material supplied from the laser head. More specifically, the additional processing device 200 adjusts the material parameter P3 (third parameter) so that a first type of metal material is supplied from the laser head 231 during lamination processing of the Mth layer (M is a natural number) and below. On the other hand, the additional processing device 200 adjusts the material parameter P3 so that a second type of metal material is supplied from the laser head 231 during lamination processing of the Mth layer and beyond.

[0111] The timing for switching the type of material may be the same as or different from the timing for switching from high-temperature lamination processing to normal lamination processing described above. That is, the above "M" may be the same as or different from "N" described in step S220 in FIG. 9. In the example of control parameters 124 shown in FIG. 10, "M" is 2 and "N" is 1. That is, the additive processing device 200 switches from high-temperature lamination processing to normal lamination processing when laminating from the first layer to the second layer, and switches the type of metal material to be supplied when laminating from the second layer to the third layer.

[0112] FIG. 11 is a diagram showing a cross section of a workpiece W generated based on the control parameters 124 shown in FIG. 10. In the workpiece W shown in FIG. 11, layers SL1 and SL2 are formed on a base material W0 having the highest brass content. The layers SL1 and SL2 are layers formed using a nickel-based metal material. The layer SL1 is a layer formed by high-temperature lamination processing. On the other hand, the layer SL2 is a layer formed by normal lamination processing.

[0113] Furthermore, layers SL3 and SL4 are formed on the nickel-based layer SL2. The layers SL3 and SL4 are made of an iron-based metal material and are typically formed by lamination processing.

[0114] Thus, the additive processing apparatus 200 according to this modification forms nickel-based layers SL1 and SL2 as intermediate layers between the base material W0 and the iron-based layers SL3 and SL4. Nickel is a material that easily bonds with both copper and iron. Therefore, the iron-based layers SL3 and SL4 are more firmly bonded to the base material W0 through the nickel-based layers SL1 and SL2. Also, since the base material W0 is coated with the iron-based layers SL3 and SL4, the strength of the workpiece W becomes higher.

[0115] <J. Second Modification>

[0116] (J1. Additive Processing Apparatus 200A) Next, referring to FIG. 12, the additive processing apparatus 200A according to the second modification will be described. FIG. 12 is a diagram showing an example of the apparatus configuration of the additive processing apparatus 200A.

[0117] The additive processing apparatus 200 according to the above-described embodiment performed lamination processing on the base material W0 fixed on the table. In contrast, the additive processing apparatus 200A according to the second modification holds the base material W0 with respect to a workpiece spindle configured to be rotatable, and performs lamination processing on the base material W0 while rotating the workpiece spindle.

[0118] More specifically, the additive processing apparatus 200A includes a cover body 230. The cover body 230 forms the appearance of the additive processing apparatus 200A and partitions and forms a processing area AR for performing additive processing on the workpiece W.

[0119] The additive processing apparatus 200A also includes a bed 11, a tool rest 16, a first support portion 21, a second support portion 24, a spindle 224 as a tool spindle, and a laser head 231.

[0120] The bed 11 is a base member for supporting various devices within the additive machining apparatus 200A. In the example of Fig. 12, the bed 11 supports the tool rest 16, the first support portion 21, the second support portion 24, the spindle 224, and the laser head 231. The bed 11 is installed on the floor of a factory or the like. The bed 11 is made of metal such as cast iron.

[0121] The tool rest 16 has a turret 18. The turret 18 is configured to be rotatable about a rotation axis AX1. The turret 18 holds a plurality of tools spaced apart in the circumferential direction around the rotation axis AX1. The tool rest 16 is also configured to be movable in the X-axis and Y-axis directions by various drive mechanisms such as motors. The tool rest 16 performs turning by bringing a fixed tool held by the turret 18 into contact with the workpiece W, which is rotated by a first support portion 21.

[0122] The first support part 21 is configured to support one side of the workpiece W in the direction of the rotation axis AX2. The rotation axis AX2 is in the axial direction of the first support part 21. The first support part 21 is configured to be rotatable about the rotation axis AX2 in the axial direction. The first support part 21 is rotationally driven by a drive mechanism such as a motor (not shown), for example.

[0123] Any mechanism can be adopted as the support mechanism for the workpiece W by the first support part 21. FIG. 12 shows a workpiece spindle 22 as an example of the first support part 21. The workpiece spindle 22 is provided with a chuck mechanism 23 for gripping one side of the workpiece W. The chuck mechanism 23 is a mechanism for fixing the workpiece W to the workpiece spindle 22.

[0124] The second support part 24 is disposed opposite to the first support part 21 in the axial direction of the rotation axis AX2 or the rotation axis AX3. The rotation axis AX3 is in the axial direction of the first support part 21 and is coaxial with the rotation axis AX2. In other words, the second support part 24 is configured to support the other side of the workpiece W in the direction of the rotation axis AX3.

[0125] The rotation axis AX3 is a direction along the axial direction of the second support part 24. The second support part 24 is configured to be rotatable about the rotation axis AX3 along the axial direction. The second support part 24 is configured to rotate, for example, in response to the rotation of the first support part 21.

[0126] Any mechanism may be adopted as the support mechanism for the workpiece W by the second support portion 24. FIG. 12 shows an opposing workpiece spindle 25 as an example of the second support portion 24. The opposing workpiece spindle 25 is provided with a chuck mechanism 26 for gripping the other side of the workpiece W. The chuck mechanism 26 is a mechanism for fixing the workpiece W to the opposing workpiece spindle 25.

[0127] As another example, the second support portion 24 may be a tailstock (not shown). The tailstock is provided with a tailstock mechanism for supporting the other side of the workpiece W. In this case, the tailstock is provided with a center pin (not shown) instead of the chuck mechanism 26. The center pin has a pin shape that extends in the direction of the rotation axis AX3. As a result, the center pin tailstocks the end face of the workpiece W from the side opposite to the first support portion 21.

[0128] The following description will be given on the assumption that the first support portion 21 is the work spindle 22, but the first support portion 21 is not limited to the work spindle 22. The following description will be given on the assumption that the second support portion 24 is the opposing work spindle 25, but the second support portion 24 is not limited to the opposing work spindle 25.

[0129] The spindle 224 is provided, for example, at a position higher than the workpiece spindle 22 and the counter workpiece spindle 25. The spindle 224 is configured to allow tools and a laser head 231 to be detachably attached. Fig. 12 shows an example in which the laser head 231 is attached to the spindle 224.

[0130] The laser head 231 can be attached to and detached from the spindle 224 by, for example, an automatic tool changer (ATC). The additional processing device 200A attaches the laser head 231 to the spindle 224 when performing additional processing on the workpiece W. On the other hand, the additional processing device 200A attaches a tool to the spindle 224 when performing subtractive processing on the workpiece W.

[0131] An example of the removal process is milling, in which a rotating tool is brought into contact with the workpiece W fixed to the workpiece spindle 22. Another example of the removal process is turning, in which a tool is pressed against the workpiece W rotating about the rotation axis AX2.

[0132] The laser head 231 performs additional processing by the DED method while attached to the main shaft 224. The laser head 231 has a head main body 232 and a laser nozzle 236 as a mechanism for realizing the additional processing.

[0133] The metal material PM is supplied to the head main body 232 via a cable (not shown). The laser nozzle 236 irradiates the workpiece W with laser light and determines the irradiation area of ​​the laser light on the workpiece W. The metal material supplied to the laser head 231 is discharged toward the workpiece W through the laser nozzle 236.

[0134] (J2. Lamination Processing) Next, the laminating process according to the second modified example will be described with reference to Fig. 13. Fig. 13 is a diagram showing an example of the workpiece W produced by the additional processing apparatus 200A shown in Fig. 12.

[0135] In this modified example, the laser head 231 irradiates the rotating workpiece W with laser light LS while being fed in a direction parallel to the rotation axis AX2 of the workpiece spindle 22. As a result, the portion irradiated with the laser light LS melts, and a molten pool is formed on the rotating workpiece W. In addition, the laser head 231 supplies metal material PM to the rotating workpiece W in parallel with the irradiation of the laser light LS.

[0136] The additive processing device 200A forms the first layer using the high-temperature lamination process described above, and then forms the second and subsequent layers using the normal lamination process described above. The workpiece W thus formed is shown in FIG. 13. In the example of FIG. 13, a layer SL1 that has been subjected to the high-temperature lamination process is formed on the outer periphery of a cylindrical base material W0. Furthermore, a layer SL2 that has been subjected to the normal lamination process is formed on the outer periphery of layer SL1.

[0137] 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]

[0138] 11 bed, 16 tool rest, 18 turret, 21 first support part, 22 workpiece spindle, 23 chuck mechanism, 24 second support part, 25 opposing workpiece spindle, 26 chuck mechanism, 50 control part, 101 control circuit, 102 ROM, 103 RAM, 104 communication interface, 109 internal bus, 120 auxiliary storage device, 122 additional processing program, 124 control parameters, 200 additional processing device, 200A additional processing device, 211 machine bed, 212 swivel table, 213 rotary table, 213A holding mechanism, 214 first slide mechanism, 215 second slide mechanism, 216 removal processing head, 218 magazine, 218A tool, 219 automatic tool changer, 222 additional processing program, 224 spindle, 230 cover body, 231 laser head, 232 Head body, 233 slide guide, 234 third slide mechanism, 236 laser nozzle, 300 operation panel, 310 drive unit, 311A ​​motor driver, 312A motor, 320 drive unit, 321C motor driver, 322C motor, 330A drive unit, 330B drive unit, 331A motor driver, 331B motor driver, 331X motor driver, 331Y motor driver, 331Z motor driver, 332A motor, 332B motor, 332X motor, 332Y motor, 332Z motor, AR processing area, AX1 rotation axis, AX2 rotation axis, AX3 rotation axis, CB cable, DR door, GS gas, LS laser light, MP molten pool, P1 heat amount parameter, P1A parameter, P1B parameter, P1C parameter, P2 Discharge rate parameters, P3 material parameters, PM metal material, SL layer, SL1 layer, SL2 layer, SL3 layer, SL4 layer, W workpiece, W0 base material.

Claims

1. An additive processing device capable of performing additive processing on a base material, The base material is a zinc-containing material or a nitrided and quenched material, a laser head capable of supplying a metal material to the base material and irradiating the base material with laser light to melt the metal material on the base material and perform lamination processing on the base material; a control unit for controlling lamination processing of the base material based on set control parameters, the control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material; The control unit adjusts the first parameter so that the amount of heat during stacking processing of the Nth layer (N is a natural number) or below is greater than the amount of heat during stacking processing of the N+1th layer or later.

2. The additive processing apparatus according to claim 1 , wherein N is 1.

3. 3. The additional machining device according to claim 1, wherein the first parameter includes at least one of a parameter relating to an output level of the laser light emitted from the laser head and a parameter relating to a feed speed of the laser head.

4. the control parameters include a second parameter for adjusting the discharge amount of the metal material from the laser head; 3. The additional processing device according to claim 1, wherein the control unit adjusts the second parameter so that the discharge amount during lamination processing of the Nth layer or less is smaller than the discharge amount during lamination processing of the N+1th layer or more.

5. The additive processing device according to claim 4 , wherein the metal contained in the base material at the highest concentration is brass.

6. the laser head is configured to be able to selectively supply a first type of metal material and a second type of metal material; the control parameters include a third parameter for specifying a type of metal material supplied from the laser head; The control unit adjusting the third parameter so that the first type of metal material is supplied from the laser head during lamination processing of an Mth layer (M is a natural number) or less; 3. The additional processing device according to claim 1, wherein the third parameter is adjusted so that the second type of metal material is supplied from the laser head during lamination processing of the Mth layer and thereafter.

7. The metal contained in the first type of metallic material most abundantly is nickel, The additive processing apparatus according to claim 6 , wherein the metal contained in the second type of metallic material is iron.

8. The additive processing apparatus according to claim 1 or 2, wherein the metal material is a powder material or a wire material.

9. An additive processing method performed by an additive processing device capable of performing additive processing on a base material, The base material is a zinc-containing material or a nitrided and quenched material, the additive processing device includes a laser head capable of supplying a metal material to the base material and irradiating the base material with laser light to melt the metal material on the base material and perform additive processing on the base material; The additive processing method includes a step of controlling an additive process for the base material based on set control parameters, the control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material; In the controlling step, the first parameter is adjusted so that the amount of heat during lamination processing of the Nth layer (N is a natural number) or less is greater than the amount of heat during lamination processing of the N+1th layer or later.

10. An additive processing program executed by an additive processing device capable of performing additive processing on a base material, The base material is a zinc-containing material or a nitrided and quenched material, the additive processing device includes a laser head capable of supplying a metal material to the base material and irradiating the base material with laser light to melt the metal material on the base material and perform additive processing on the base material; the additive processing program causes the additive processing device to execute a process of controlling a lamination process on the base material based on set control parameters; the control parameters include a first parameter for adjusting the amount of heat supplied from the laser head to the base material; In the control process, the first parameter is adjusted so that the heat quantity during stacking processing of the Nth layer (N is a natural number) or below is greater than the heat quantity during stacking processing of the N+1th layer or later.

Images