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

Abstract

To provide a technology that suppresses heat accumulation in a workpiece during coating processing more than conventional technology. [Solution] The additive processing device includes a workpiece spindle that rotates a workpiece having a portion symmetrical with respect to the rotation axis around the rotation axis, a material supply mechanism that supplies material to the workpiece, a laser head that performs additive processing by irradiating the workpiece with laser light, and a drive unit that drives and feeds the laser head relative to the workpiece. The additive processing method includes a step of forming a coating layer on the surface of the workpiece using the additive processing device. In the forming step, a processing step is repeatedly performed in which additive processing is performed on the rotating workpiece while driving and feeding the laser head to one side of the rotation axis, and a stopping step is repeatedly performed in which the additive processing is stopped and the laser head is driven and fed to the other side of the rotation axis. Each time the processing step is performed, a spiral layer is formed on the surface of the workpiece. The coating layer is made up of multiple spiral layers.

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] JP 2023-537010 A (Patent Document 1) discloses a coating process in which a spiral wire is wound around a workpiece such as a shaft in advance, and the spiral wire is melted with a high-power laser.

[0003] In addition to the above methods, there is also a coating process using the DED (Directed Energy Deposition) method. Additive processing equipment that uses the DED method is equipped with a laser head. The laser head moves relative to the workpiece, ejecting powder material onto the workpiece and irradiating the workpiece with laser light. This melts the area on the workpiece that is irradiated with the laser light. The powder material is supplied to this melted area, where it melts and solidifies, and is then layered on the workpiece. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2023-537010 Summary of the Invention [Problem to be solved by the invention]

[0005] In the coating process disclosed in Patent Document 1, the laser unit irradiates the spiral wire with laser light while being driven along the longitudinal direction of the rotating workpiece. When the laser light is concentrated on the spiral wire, the workpiece becomes very hot. As a result, radiant heat from the workpiece may damage internal components. Furthermore, when the workpiece becomes hot, it expands. As a result, the material powder may not be supplied to the intended position, which may result in a problem of reduced accuracy in additional processing of the workpiece.

[0006] In view of the above, there is a need for a technology that can reduce heat accumulation in a workpiece during coating processing more than ever before. [Means for solving the problem]

[0007] In one example of the present disclosure, a method for additive machining of a workpiece using an additive machining apparatus is provided. The additive machining apparatus includes a workpiece spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis, a material supply mechanism for supplying material to the workpiece, a laser head capable of performing additive machining by irradiating the workpiece with laser light, and a drive unit for feeding and driving the laser head relative to the workpiece. The additive machining method includes a step of forming a coating layer on the surface of the workpiece by the additive machining. The coating layer forming step repeatedly includes a processing step of performing the additive machining on the rotating workpiece while feeding and driving the laser head on one side of the rotation axis, and a stopping step of stopping the additive machining and feeding and driving the laser head on the other side of the rotation axis. Each time the processing step is performed, a spiral layer is formed on the surface of the workpiece. The coating layer is made up of multiple spiral layers.

[0008] In one example of the present disclosure, in the processing step, the feed drive of the laser head is started from a predetermined start position, and in the stopping step, the laser head is fed and driven to the predetermined start position.

[0009] In one example of the present disclosure, execution of the machining step is started with the rotation angle of the work spindle about the rotation axis set to a predetermined target angle, which is incremented by a predetermined angle each time the machining step is executed.

[0010] In one example of the present disclosure, in the machining step, the laser head is driven to feed at a constant feed rate, and the workpiece spindle is driven to rotate at a constant rotational speed.

[0011] In one example of the present disclosure, the additive processing method further includes a step of acquiring the temperature of the workpiece while the additive processing is being performed, and a step of outputting a warning based on the temperature of the workpiece exceeding a predetermined value.

[0012] Another example of the present disclosure provides an additive processing apparatus. The additive processing apparatus includes a workpiece spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis, a material supply mechanism for supplying material to the workpiece, a laser head capable of performing additive processing by irradiating the workpiece with laser light, a drive unit for driving the laser head to feed relative to the workpiece, and a control unit. The control unit executes a process for forming a coating layer on the surface of the workpiece by the additive processing. The process for forming the coating layer repeatedly includes a process for performing the additive processing on the rotating workpiece while driving the laser head to feed on one side of the rotation axis, and a stop process for stopping the additive processing and driving the laser head to feed on the other side of the rotation axis. Each time the process is executed, a spiral layer is formed on the surface of the workpiece. The coating layer is composed of multiple spiral layers.

[0013] Another example of the present disclosure provides a program for additive machining of a workpiece by an additive machining apparatus. The additive machining apparatus includes a workpiece spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis, a material supply mechanism for supplying material to the workpiece, a laser head capable of performing additive machining by irradiating the workpiece with laser light, and a drive unit for feeding and driving the laser head relative to the workpiece. The additive machining program causes the additive machining apparatus to execute a process for forming a coating layer on the surface of the workpiece by the additive machining. The process for forming the coating layer includes a process for performing the additive machining on the rotating workpiece while feeding and driving the laser head on one side of the rotation axis, and a stop process for stopping the additive machining and feeding and driving the laser head on the other side of the rotation axis, which are repeatedly executed. Each time the processing is executed, a spiral layer is formed on the surface of the workpiece. The coating layer is composed of multiple spiral layers.

[0014] 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]

[0015] [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] 1 shows a cross-sectional view of a laser head during additive processing. [Figure 4] FIG. 1 is a diagram showing an embodiment of coating processing. [Figure 5] FIG. 10 is a diagram schematically illustrating a first processing step. [Figure 6] FIG. 10 is a diagram schematically illustrating a first stopping step. [Figure 7] FIG. 10 is a diagram schematically illustrating the second processing step. [Figure 8]It is a diagram schematically showing the state of the second stop step. [Figure 9] It is a diagram showing a workpiece after a plurality of machining steps and stop steps have been executed. [Figure 10] It is a diagram showing an example of control parameters referred to during the execution of the coating process. [Figure 11] It is a diagram showing an example of a warning screen. [Figure 12] It is a diagram showing an example of a drive mechanism of an additional processing device. [Figure 13] It is a diagram showing an example of the hardware configuration of a control unit. [Figure 14] It is a flowchart showing the flow of an additional processing.

Mode for Carrying Out the Invention

[0016] 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 described below may be selectively combined as appropriate.

[0017] <A. Appearance of the Additional Processing Device 100> First, referring to FIG. 1, the additional processing device 100 according to the embodiment will be described. FIG. 1 is a diagram showing an example of the appearance of the additional processing device 100.

[0018] The additional processing device 100 is a processing machine capable of performing additional processing (AM (Additive manufacturing) processing) on a workpiece. The additional processing device 100 performs additional processing by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam.

[0019] Note that the additive processing device 100 may be a processing machine capable of not only additive processing of a workpiece but also subtractive processing (SM (Subtractive manufacturing)) of the workpiece. Examples of the subtractive processing functions include a milling function and a turning function.

[0020] The additive processing device 100 includes, for example, a cover body 130 and an operation panel 200.

[0021] The cover body 130 is a mechanism for protecting the components provided inside the additive processing device 100. A door DR is provided on the cover body 130. 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 opened and closed manually.

[0022] The operation panel 200 is a general-purpose computer and has a display for displaying various pieces of 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 additive processing device 100 by touch operations.

[0023] <B. Device Configuration of Additive Processing Device 100> Next, referring to FIG. 2, the device configuration of the additive processing device 100 will be described. FIG. 2 is a diagram showing an example of the device configuration of the additive processing device 100. In FIG. 2, as an example of the additive processing device 100, an AM / SM hybrid processing machine capable of both additive processing and subtractive processing of a workpiece is shown.

[0024] As described above, the additive processing device 100 includes a cover body 130. The cover body 130 forms the exterior of the additive processing device 100 and partitions and forms a processing area AR for performing additive processing of the workpiece W.

[0025] The additional machining device 100 also includes a bed 11, a tool rest 16, a first support portion 21, a second support portion 24, a tool spindle 30, and a laser head 140.

[0026] For ease of explanation, the rotation axis direction of the first support part 21 and the second support part 24 will also be referred to as the "Z-axis direction." In the example of FIG. 2, the Z-axis direction is a direction parallel to the rotation axes AX1 to AX3. One side in the Z-axis direction will also be referred to as the "Z-axis positive side," and the other side in the Z-axis direction will also be referred to as the "Z-axis negative side." In the example of FIG. 2, the right side when viewing the processing area AR from the door DR is the "Z-axis positive side," and the left side when viewing the processing area AR from the door DR is the "Z-axis negative side."

[0027] Furthermore, one direction on a horizontal plane perpendicular to the Z-axis direction is also referred to as the "Y-axis direction." One side in the Y-axis direction is also referred to as the "Y-axis positive side," and the other side in the Y-axis direction is also referred to as the "Y-axis negative side." In the example of FIG. 2, the front side when viewing the processing area AR from the door DR is the "Y-axis positive side," and the back side when viewing the processing area AR from the door DR is the "Y-axis negative side."

[0028] Furthermore, the direction perpendicular to both the Y-axis and Z-axis directions is also referred to as the "X-axis direction." One side of the X-axis direction is also referred to as the "X-axis positive side," and the other side of the X-axis direction is also referred to as the "X-axis negative side." In the example of Figure 2, the sky direction corresponds to the "X-axis positive side," and the direction of gravity corresponds to the "X-axis negative side."

[0029] The bed 11 is a base member for supporting various devices within the additive machining apparatus 100. In the example of FIG. 2, the bed 11 supports the tool rest 16, the first support portion 21, the second support portion 24, the tool spindle 30, and the laser head 140. 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.

[0030] 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.

[0031] 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, for example, by a motor 212C (see FIG. 12) described below.

[0032] Any mechanism may be adopted as the support mechanism for the workpiece W by the first support part 21. In FIG. 2, a workpiece spindle 22 is shown 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.

[0033] 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.

[0034] 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.

[0035] Any mechanism may be adopted as the support mechanism for the workpiece W by the second support portion 24. FIG. 2 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.

[0036] 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.

[0037] 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.

[0038] The tool spindle 30 is provided, for example, at a position higher than the workpiece spindle 22 and the counter workpiece spindle 25. The tool spindle 30 is configured to allow tools and a laser head 140 to be detachably attached. Fig. 2 shows an example in which the laser head 140 is attached to the tool spindle 30.

[0039] The laser head 140 can be attached to and detached from the tool spindle 30 by, for example, an automatic tool changer (ATC). The additional machining device 100 attaches the laser head 140 to the tool spindle 30 when performing additional machining of the workpiece W. On the other hand, the additional machining device 100 attaches a tool to the tool spindle 30 when performing subtractive machining of the workpiece W.

[0040] As an example of removal machining, there is milling in which a rotating tool is brought into contact with a workpiece W fixed to the workpiece spindle 22. As another example of removal machining, there is turning in which a tool is pressed against a workpiece W rotating about the rotation axis AX2.

[0041] The laser head 140 performs additive machining by the DED (Direct Energy Deposition) method while being mounted on the tool spindle 30. As a mechanism for realizing additive machining, the laser head 140 has a head body 142 and a laser nozzle 146.

[0042] Powder material is supplied to the head body 142 via a cable (not shown). The supplied powder material may be metal powder, resin powder, or other types of powder that melt upon irradiation with laser light.

[0043] The laser nozzle 146 irradiates the workpiece W with laser light and defines the laser light irradiation region on the workpiece W. The powder material supplied to the laser head 140 is discharged toward the workpiece W through the laser nozzle 146. In the present embodiment, the laser head 140 supplies powder material, but for example, it may supply a wire-shaped material to the laser irradiation point. That is, the supplied material is not limited to powder material. Also, the laser head 140 and the mechanism for supplying the material may be an integral configuration, or the laser head 140 and the material supply mechanism for supplying the material may be provided separately.

[0044] <C. Outline of coating machining> Next, referring to FIGS. 3 and 4, the additive machining by the laser head 140 will be described in more detail. FIG. 3 shows a cross-sectional view of the laser head 140 during additive machining. FIG. 4 is a diagram showing the mode of coating machining.

[0045] While at least one of the laser head 140 and the workpiece W is being driven, the laser head 140 irradiates the surface of the workpiece W with laser light LS. As an example, the laser head 140 is driven to be fed in the direction of the rotation axis AX2 of the workpiece spindle 22 (for example, the negative side in the Z-axis direction) while irradiating the laser light LS onto the workpiece W rotating around that axial direction. As a result, the workpiece W melts in the area irradiated with the laser light LS, and a molten pool MP is formed on the surface of the workpiece W.

[0046] The laser head 140 supplies powder material PM to the molten pool MP in parallel with the irradiation of the laser beam LS. The powder material PM is guided to the molten pool MP by gas GS discharged from the laser head 140. As a result, the powder material PM is supplied to the position where the laser beam LS is irradiated on the workpiece W, and melts and liquefies in the molten pool MP. The molten pool MP then solidifies, forming a layer SL0 on the surface of the workpiece W. The gas GS also functions as a shielding gas, preventing oxidation of the workpiece W, which is a laminated structure.

[0047] More specifically, the additional processing device 100 first rotates the workpiece W, which is axially symmetrical with respect to the rotation axis AX2, on the workpiece spindle 22. As a result, the workpiece W rotates about the rotation axis AX2. Next, the additional processing device 100 performs additional processing on the rotating workpiece W while feeding and driving the laser head 140 in the direction of the rotation axis AX2 while maintaining a constant distance between the irradiation port of the laser light LS from the laser head 140 and the surface of the workpiece W. As a result, the surface of the workpiece W is covered with a coating layer SL.

[0048] The shape of the workpiece W is, for example, cylindrical. The diameter of the workpiece W is, for example, 350 mm. The coating width in the longitudinal direction of the workpiece W (i.e., the Z-axis direction) is 2000 mm.

[0049] In addition, in FIG. 4, a cylindrical workpiece W is shown as an example of the workpiece W that is axially symmetric with respect to the rotation axis AX2, but the shape of the workpiece W is not particularly limited. As an example, the shape of the workpiece W may be a frustum of a cone or a tapered shape. Further, the workpiece W may have a hollow shape.

[0050] Also, the workpiece W may partially include a shape that is axially symmetric with respect to the rotation axis AX2, and the shape of the other parts is not particularly limited.

[0051] Furthermore, the number of coating layers SL formed on the surface of the workpiece W may be one layer or two or more layers.

[0052] <D. Details of Coating Process> As described above, the additive processing apparatus 100 performs a coating process for forming a coating layer SL on the surface of the workpiece W by additive processing. At this time, the coating process includes a "processing step" of performing additive processing on the rotating workpiece W while feeding and driving the laser head 140 to one side of the rotation axis AX2 (for example, the negative side in the Z-axis direction), and a "stop step" of stopping the additive processing and feeding and driving the laser head 140 to the other side of the rotation axis AX2 (for example, the positive side in the Z-axis direction). This is realized by repeatedly executing these steps.

[0053] The additive processing apparatus 100 according to the present embodiment forms a spiral layer on the surface of the workpiece W each time the processing step is executed. Then, the additive processing apparatus 100 forms the above-described coating layer SL by covering the surface of the workpiece W with a plurality of spiral layers. That is, the coating layer SL is composed of a plurality of spiral layers arranged in the direction of the rotation axis AX2. In one processing step, the spiral layer is formed so as not to overlap in the direction of the rotation axis AX2. That is, each part of the spiral layer is separated from other adjacent parts in the direction of the rotation axis AX2.

[0054] The coating process according to the embodiment will be described below with reference to Figures 5 to 9. Figure 5 is a diagram schematically showing the first processing step S1A.

[0055] More specifically, first, the additional processing device 100 holds the workpiece W by the workpiece spindle 22 and the counter workpiece spindle 25. Next, the additional processing device 100 controls the workpiece spindle 22 to rotate the workpiece W. As a result, the workpiece W rotates about the rotation axis AX2.

[0056] Thereafter, the additional processing device 100 moves the position PH of the laser head 140 to a predetermined start position SP while controlling the attitude of the laser head 140 so that the laser beam LS is irradiated in the vertical direction (i.e., the negative side in the X-axis direction). Thereafter, the additional processing device 100 starts irradiating the laser beam LS and supplying the powder material PM, and drives and feeds the laser head 140 along a predetermined drive path PSH. As a result, the laser head 140 moves from the start position SP indicated by the drive path PSH to the end position EP indicated by the drive path PSH.

[0057] In Figure 5, the trajectory of the laser beam LS passing over the surface of the workpiece W in the first processing step S1A is shown as a coating path PSL1. The coating path PSL1 is both the trajectory of the laser beam LS on the surface of the workpiece W and the trajectory of the powder material PM on the surface of the workpiece W. The coating path PSL1 is a spiral path having a predetermined pitch ΔP in the direction of the rotation axis AX2. As a result, a first spiral layer is formed on the surface of the workpiece W along the coating path PSL1. The length of the pitch ΔP is set so that the spiral layers do not overlap in the direction of the rotation axis AX2.

[0058] 6 is a diagram schematically illustrating the first stopping step S1B. More specifically, after the first processing step S1A is completed, the additional processing apparatus 100 stops emitting the laser beam LS and supplying the powder material PM. This stops the additional processing. At this time, the rotation of the workpiece spindle 22 may or may not be stopped.

[0059] Next, the additional processing device 100 returns the laser head 140 to the start position SP of the drive path PSH. As a result, the laser head 140 is driven and fed from the end position EP of the drive path PSH to the start position SP indicated by the drive path PSH.

[0060] 7 is a diagram schematically illustrating the second machining step S2A. More specifically, the additional machining device 100 rotationally drives the workpiece spindle 22 so that the rotation angle of the workpiece spindle 22 becomes a predetermined target angle. This target angle is, for example, a value obtained by adding a predetermined value to the rotation angle of the workpiece spindle 22 at the start of execution of the first machining step S1A.

[0061] Thereafter, the additive processing device 100 starts irradiating the laser beam LS and supplying the powder material PM, and drives and feeds the laser head 140 along a predetermined drive path PSH, thereby moving the laser head 140 from the start position SP indicated by the drive path PSH to the end position EP indicated by the drive path PSH.

[0062] In Figure 7, the trajectory of the laser beam LS passing over the surface of the workpiece W in the second processing step S2A is shown as a coating path PSL2. The coating path PSL2 is a spiral path having a predetermined pitch ΔP in the direction of the rotation axis AX2. As a result, a second spiral layer is formed on the surface of the workpiece W along the coating path PSL2. The length of the pitch ΔP is determined so that the second spiral layers do not overlap in the direction of the rotation axis AX2.

[0063] The coating passes PSL1 and PSL2 have the same shape and are offset from each other by a predetermined angle in the rotation direction around the rotation axis AX2. That is, the pitch ΔP of the coating pass PSL2 is equal to the pitch ΔP of the coating pass PSL1. The rotation direction of the coating pass PSL2 is the same as the rotation direction of the coating pass PSL1.

[0064] Furthermore, the first spiral layer formed along coating pass PSL1 and the second spiral layer formed along coating pass PSL2 may or may not be adjacent to each other. "Adjacent" means that one side of the first spiral layer on the rotation axis AX2 overlaps with the other side of the second spiral layer on the rotation axis AX2. "Not adjacent" means that the first and second spiral layers do not overlap.

[0065] 8 is a diagram schematically illustrating the second stopping step S2B. More specifically, the additive processing apparatus 100 stops emitting the laser beam LS and supplying the powder material PM. This stops the additive processing. At this time, the rotation of the workpiece spindle 22 may or may not be stopped.

[0066] Next, the additional processing device 100 returns the laser head 140 to the start position SP of the drive path PSH. As a result, the laser head 140 is driven and fed from the end position EP of the drive path PSH to the start position SP indicated by the drive path PSH.

[0067] As described above, the additive processing device 100 sequentially executes the processing step and the stopping step repeatedly to sequentially form spiral layers on the surface of the workpiece W. The processing step and the stopping step are repeated until the spiral layers cover the surface of the workpiece W.

[0068] As an example, the processing step and the stopping step are each performed multiple times (for example, N times) to form a coating layer SL shown in Fig. 4 on the surface of the workpiece W. N is, for example, an integer of 2 or more.

[0069] Fig. 9 is a diagram showing the workpiece W after the processing step and the stopping step have each been performed N times. In the example of Fig. 9, N spiral coating passes PSL are shown on the surface of the workpiece W. The spiral layer along each coating pass PSL covers the surface of the workpiece W, thereby forming the coating layer SL shown in Fig. 4.

[0070] As described above, by irradiating the laser beam LS at a pitch ΔP, heat accumulation in the workpiece W during coating processing is suppressed. As a result, thermal expansion of the workpiece W is suppressed, and the additive processing device 100 can deposit the powder material PM at the intended position on the surface of the workpiece W. This allows the additive processing device 100 to improve the accuracy of coating processing on the workpiece W.

[0071] Furthermore, by irradiating the laser beam LS at a pitch ΔP, the amount of radiant heat that the laser head 140 receives from the workpiece W is reduced. This allows the additional processing device 100 to prevent damage to components that configure the laser head 140 (for example, the protective glass and the collimation lens).

[0072] Furthermore, the additional processing device 100 can ensure time for cooling the workpiece W by performing a stop step between processing steps. This allows the additional processing device 100 to further reduce heat accumulation in the workpiece W during coating processing. As a result, thermal expansion of the workpiece W is reduced, and the accuracy of coating processing on the workpiece W is improved.

[0073] In addition, the shape of the spiral layer formed in one processing step is not particularly limited as long as it can suppress the heat accumulation of the workpiece during the coating process more effectively than before. In the above description, an example in which a spiral layer is formed on the cylindrical workpiece W has been described. However, the workpiece W only needs to have a part that is axially symmetric with respect to the rotation axis AX. For example, the workpiece W may be a polygonal prism. Thus, the shape of the spiral layer only needs to be such that each part does not overlap with other adjacent parts in the direction of the rotation axis AX2.

[0074] <E. Control Parameters> FIG. 10 is a diagram showing an example of the control parameter 124 referred to when the coating process described in FIGS. 5 to 9 is executed. Hereinafter, an example of the control parameter 124 will be described.

[0075] The control parameter 124 includes the drive parameters of the laser head 140 and the drive parameters of the workpiece spindle 22. The drive parameters of the laser head 140 and the drive parameters of the workpiece spindle 22 are defined, for example, for each of the processing steps executed from the first to the Nth time.

[0076] As shown in FIG. 10, the start position of the laser head 140 at the start of the execution of the processing step is constant regardless of the number of executions. Also, the end position of the laser head 140 at the end of the execution of the processing step is constant regardless of the number of executions. Further, the feed rate of the laser head 140 during the execution of the processing step is constant regardless of the number of executions of the processing step. Furthermore, the rotation speed of the workpiece spindle 22 during the execution of the processing step is constant regardless of the number of executions.

[0077] On the other hand, the rotation start angle of the workpiece spindle 22 at the start of the execution of the processing step varies depending on the number of executions. In the example of FIG. 10, the rotation start angles of the workpiece spindle 22 at the execution of the first to Nth processing steps are shown as the target rotation angles "θ1" to "θN". The target rotation angle "θ(n)" at the start of the nth execution is calculated, for example, based on the following formula (1).

[0078] θ(n)=θ0+(n-1)·360° / N···(1) Here, "n" in equation (1) is an integer greater than or equal to 1 and less than or equal to N. "θ0" is a preset constant. "θ0" is, for example, 0°. "N" indicates the number of times the processing step needs to be performed, and is the total number of coating passes PSL required to form one coating layer on the workpiece W.

[0079] "N" is calculated, for example, by the following procedure. First, the additive processing device 100 receives input of the diameter "D" of the workpiece W, the step-over width "ΔS", and the above-mentioned pitch "ΔP". "D", "ΔS", and "ΔP" may be input by the user or may be determined in advance at the time of design. The step-over width "ΔS" corresponds to the overlap width of the spiral layer formed along each coating pass PSL. The additive processing device 100 calculates the provisional required number of executions "N'" based on the following formula (2):

[0080] N'=ΔS / cos{atan(ΔP / D·π)}···(2) Thereafter, the additional processing device 100 calculates the required number of executions "N" by rounding off the provisional required number of executions "N'".

[0081] As an example, assume that the diameter "D" of the workpiece W is 293 mm, the step-over width "ΔS" is 1.5 mm, and the pitch "ΔP" is 412 mm. In this case, the required number of executions "N" is 251, and the additional processing device 100 adds 1.434° (=360° / 251 times) to the target rotation angle "θ(n)" each time a processing step is executed.

[0082] The method for calculating θ(n) is not limited to the above formula (1). As another example, the target rotation angle θ(n) at the start of the nth execution may be calculated based on the following formula (3).

[0083] θ(n)=θ0+(n - 1)·(360° / N + Δθ)···(3) "Δθ" shown in Equation (3) is a preset constant. "Δθ" may be 45°, 60°, 90°, or 180°. By setting "Δθ", the spiral layer formed in the (n - 1)-th processing step and the spiral layer formed in the n-th processing step do not overlap. As a result, heat accumulation in the workpiece W is further suppressed.

[0084] <F. Temperature Monitoring Function> The additional processing device 100 has a function of monitoring the temperature of the workpiece W during the additional processing of the workpiece W. The means for detecting the temperature of the workpiece is not particularly limited. As an example, a thermographic camera may be provided inside the additional processing device 100, or a temperature sensor may be provided near the workpiece W.

[0085] The additional processing device 100 acquires the temperature of the workpiece W during the execution of the coating process on the workpiece W. The temperature is acquired, for example, at regular intervals. Then, the additional processing device 100 outputs a warning based on the acquired temperature exceeding a predetermined temperature. FIG. 11 is a diagram showing an example of a warning screen IM.

[0086] The warning screen IM includes, for example, a warning message MS indicating that the temperature of the workpiece W has exceeded the threshold value. The output destination of the warning screen IM may be the display of the additional processing device 100, or the display of a terminal different from the additional processing device 100 (for example, a management device or a server).

[0087] In the coating processing method described in FIGS. 5 to 9 above, heat accumulation in the workpiece W is suppressed. Therefore, the number of times the warning screen IM is output decreases.

[0088] <G. Drive Mechanism of Additional Processing Device 100> Next, a drive mechanism in the additional processing device 100 will be described with reference to Fig. 12. Fig. 12 is a diagram showing an example of a drive mechanism of the additional processing device 100.

[0089] As shown in FIG. 12, the additional processing device 100 includes a control unit 50 and drive units 210, 220, 230A, 230B, and 240.

[0090] The control unit 50 controls various devices within the additional processing apparatus 100. The control unit 50 may have any configuration. The control unit 50 may be configured as a single control unit or may be configured as multiple 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). Furthermore, the control unit 50 may include at least one of motor drivers 211C, 221Z, 231X to 231Z, 231A, 231B, 241Y, 241Z, and 241C shown in FIG. 12.

[0091] The drive unit 210 is a drive mechanism for rotationally driving the workpiece spindle 22. The drive unit 210 may be composed of a single drive unit or multiple drive units. In the example of Fig. 12, the drive unit 210 is composed of a motor driver 211C and a motor 212C.

[0092] The motor driver 211C sequentially receives input of the target rotation angle or target rotation speed of the work spindle 22 from the control unit 50, and outputs a current corresponding to the target rotation angle or target rotation speed to the motor 212C. This causes the work held by the work spindle 22 to rotate around the Z-axis direction as the center of rotation. The motor 212C may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0093] The drive unit 220 is a drive mechanism for driving the opposing workpiece spindle 25. The drive unit 220 may be composed of a single drive unit or multiple drive units. In the example of Fig. 12, the drive unit 220 is composed of a motor driver 221Z and a motor 222Z.

[0094] The motor driver 221Z sequentially receives input of target positions for the counter work spindle 25 from the control unit 50 and outputs a current corresponding to the target positions to the motor 222Z. This causes the motor 222Z to move the counter work spindle 25 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.

[0095] The drive unit 230A (feed drive unit) is a drive mechanism for moving the position of the tool spindle 30. The above-mentioned laser head 140 is driven by being attached to the tool spindle 30. The drive unit 230A may be configured with a single drive unit or may be configured with multiple drive units. In the example of FIG. 12, the drive unit 230A is configured with motor drivers 231X to 231Z and motors 232X to 232Z.

[0096] The motor driver 231X sequentially receives input of target positions of the tool spindle 30 in the X-axis direction from the control unit 50, and outputs a current corresponding to the target positions to the motor 232X. As a result, the motor 232X drives the tool spindle 30 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.

[0097] The motor driver 231Y sequentially receives input of target positions of the tool spindle 30 in the Y-axis direction from the control unit 50, and outputs a current corresponding to the target positions to the motor 232Y. In this way, the motor 232Y drives the tool spindle 30 to any position in the Y-axis direction. The motor 232Y may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0098] The motor driver 231Z sequentially receives input of target positions of the tool spindle 30 in the Z-axis direction from the control unit 50, and outputs a current corresponding to the target positions to the motor 232Z. This causes the motor 232Z to move the tool spindle 30 to any position in the Z-axis direction. The motor 232Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0099] The drive unit 230B is a drive mechanism for rotationally driving the tool spindle 30. The drive unit 230B may be configured with a single drive unit or multiple drive units. In the example of Fig. 12, the drive unit 230B is configured with motor drivers 231A and 231B and motors 232A and 232B.

[0100] The motor driver 231A sequentially receives input of a target rotation angle or a target rotation speed of the tool spindle 30 about 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 232A. The motor 232A drives the tool spindle 30 to rotate about the Y-axis direction. The motor 232A may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0101] The motor driver 231B sequentially receives input of a target rotation angle or a target rotation speed of the tool spindle 30 around the axial direction of the tool spindle 30 as a rotation center from the control unit 50, and outputs a current according to the target rotation angle or the target rotation speed to the motor 232B. The motor 232B drives the tool spindle 30 to rotate around the axial direction of the tool spindle 30 as a rotation center. The motor 232B may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0102] The drive unit 240 is a drive mechanism for driving the tool post 16 and the turret 18. The drive unit 240 may be composed of a single drive unit or multiple drive units. In the example of Fig. 12, the drive unit 240 is composed of motor drivers 241C, 241Y, and 241Z and motors 242C, 242Y, and 242Z.

[0103] The motor driver 241C receives an input of a target value for the rotation angle of the turret 18 about the Z-axis direction, and outputs a current corresponding to the target value to the motor 242C. In this way, the motor driver 241C controls the rotation angle of the turret 18 about the Z-axis direction as the center of rotation. The motor 242C may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0104] The motor driver 241Y sequentially receives input of target positions of the tool post 16 in the Y-axis direction from the control unit 50, and outputs a current corresponding to the target positions to the motor 242Y. This causes the motor 242Y to move the tool post 16 to any position in the X-axis direction. The motor 242Y may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0105] The motor driver 241Z sequentially receives the input of the target position of the tool post 16 in the Z-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 242Z. Thereby, the motor 242Z moves the tool post 16 to an arbitrary position in the Z-axis direction. The motor 242Z may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0106] In the above description, the drive unit 230A for driving the laser head 140 has been described. However, the laser head 140 may be configured to be relatively feed-driven with respect to the workpiece. As another example, instead of the laser head 140, the workpiece spindle 22 may be configured to be feed-driven. In this case, the drive unit 230A does not necessarily have to be provided in the additional processing device 100.

[0107] <H. Hardware Configuration of Control Unit 50> Next, referring to FIG. 13, the hardware configuration of the control unit 50 shown in FIG. 12 will be described. FIG. 13 is a diagram showing an example of the hardware configuration of the control unit 50.

[0108] As described above, the control unit 50 may be a CNC or a PLC. FIG. 13 shows the hardware configuration of the control unit 50 as a CNC.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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, 230A, 230B, and 240) for realizing additional processing of the workpiece via the communication interface 104.

[0113] The auxiliary storage device 120 is a storage medium such as a hard disk or flash memory. The auxiliary storage device 120 stores the additional processing program 122 and the above-mentioned control parameters 124. The storage location of the additional processing program 122 and the control parameters 124 is not limited to the auxiliary storage device 120, and may be stored in a storage area (e.g., cache memory) of the control circuit 101, the ROM 102, the RAM 103, an external device (e.g., a server), or the like.

[0114] In addition, the additional processing program 122 may be provided by being incorporated into a part of an arbitrary program instead of being provided as a single 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. Furthermore, part or all of the functions provided by the additional processing program 122 may be realized by dedicated hardware. Furthermore, the control unit 50 may be configured in a form such as a so-called cloud service in which at least one server executes a part of the processing of the additional processing program 122.

[0115] <I. Control Flow of Additional Processing> Next, referring to FIG. 14, the control flow of the additional processing will be described. FIG. 14 is a flowchart showing the flow of the additional processing.

[0116] The processing shown in FIG. 14 is realized, for example, when the control unit 50 of the additional processing device 100 executes the above-described additional processing program 122. In other aspects, part or all of the processing may be executed by circuit elements or other hardware.

[0117] In step S110, the control unit 50 causes the work spindle 22 and the opposing work spindle 25 to support the work W. Thereby, the work W is disposed between the work spindle 22 and the opposing work spindle 25.

[0118] In step S112, the control unit 50 initializes a variable “n” for managing the number of executions of the above-described processing steps. At this time, the variable “n” is initialized to “1”.

[0119] In step S114, the control unit 50 refers to the above-mentioned control parameters 124 (see FIG. 10) to acquire parameters corresponding to the "n"th execution count. As a result, the control unit 50 acquires the drive start position "SP" of the laser head 140, the drive end position "EP" of the laser head 140, the rotation start angle "θ(n)" of the workpiece spindle 22, the feed speed "V1" of the laser head 140, and the rotation speed "V2" of the workpiece spindle 22.

[0120] In step S116, the control unit 50 executes the above-described machining steps in accordance with the drive parameters acquired in step S114. More specifically, the control unit 50 controls the rotation angle of the workpiece spindle 22 so that the angle of the workpiece spindle 22 becomes the rotation start angle "θ(n)," and drives the laser head 140 to the start position "SP." Next, the control unit 50 starts irradiating the laser beam LS, supplying the powder material PM, driving the laser head 140 at the feed speed "V1," and rotating the workpiece spindle 22 at the rotation speed "V2."

[0121] In step S118, the control unit 50 determines whether the current position of the laser head 140 has reached the end position "EP" acquired in step S114. If the control unit 50 determines that the current position of the laser head 140 has reached the end position "EP" (YES in step S118), the control unit 50 switches the control to step S120. If not (NO in step S118), the control unit 50 executes the process of step S118 again.

[0122] In step S120, the control unit 50 executes the above-mentioned stopping step. More specifically, the control unit 50 stops the irradiation of the laser light LS and the supply of the powder material PM. At this time, the rotation of the workpiece spindle 22 may or may not be stopped. Next, the control unit 50 starts driving the laser head 140 to feed toward the start position "SP."

[0123] In step S122, the control unit 50 determines whether the current position of the laser head 140 has reached the start position "SP" acquired in step S114. If the control unit 50 determines that the current position of the laser head 140 has reached the start position "SP" (YES in step S122), the control unit 50 switches the control to step S130. If not (NO in step S122), the control unit 50 executes the process of step S122 again.

[0124] In step S130, the control unit 50 determines whether the variable "n" has reached the predetermined required number of executions "N". As an example, if the variable "n" is equal to or greater than "N", the control unit 50 determines that the variable "n" has reached the required number of executions "N". The method for calculating "N" is as described above, and therefore the description thereof will not be repeated. If the control unit 50 determines that the variable "n" has reached the predetermined required number of executions "N" (YES in step S130), the control unit 50 ends the processing shown in FIG. 14. If not (NO in step S130), the control unit 50 switches control to step S132.

[0125] In step S132, the control unit 50 increments the variable "N." That is, the control unit 50 adds "1" to the variable "N."

[0126] 14 is executed, whereby one layer of coating is applied to the workpiece W. When multiple layers of coating are applied to the workpiece W, the control unit 50 can realize coating of the second and subsequent layers by changing the drive start position "SP" of the laser head 140 and the drive end position "EP" of the laser head 140 according to the current number of layers.

[0127] Preferably, the control unit 50 monitors the temperature of the workpiece W during the coating process shown in Fig. 14. The function of monitoring the temperature of the workpiece W has been described above, and therefore, the description thereof will not be repeated.

[0128] 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]

[0129] 11 bed, 16 tool rest, 18 turret, 21 first support unit, 22 workpiece spindle, 23 chuck mechanism, 24 second support unit, 25 opposing workpiece spindle, 26 chuck mechanism, 30 tool spindle, 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 control parameters, 130 cover body, 140 laser head, 142 head body, 146 laser nozzle, 200 operation panel, 210 drive unit, 211C motor driver, 212C motor, 220 drive unit, 221Z motor driver, 222Z motor, 230A drive unit, 230B drive unit, 231A motor driver, 231B Motor driver, 231X motor driver, 231Y motor driver, 231Z motor driver, 232A motor, 232B motor, 232X motor, 232Y motor, 232Z motor, 240 drive unit, 241C motor driver, 241Y motor driver, 241Z motor driver, 242C motor, 242Y motor, 242Z motor, AR machining area, AX1 rotary axis, AX2 rotary axis, AX3 rotary axis, DR door, EP end position, GS gas, IM warning screen, LS laser beam, MP molten pool, MS warning message, PM powder material, PSH drive path, PSL coating path, PSL1 coating path, PSL2 coating path, SL coating layer, SL0 layer, SP start position, W workpiece, ΔP pitch.

Claims

1. A method for additionally processing a workpiece using an additional processing device, comprising: The additional processing device is a work spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis; a material supply mechanism for supplying material to the workpiece; a laser head capable of performing additional processing by irradiating the workpiece with laser light; a drive unit for driving the laser head to feed relative to the workpiece, The additive processing method includes a step of forming a coating layer on a surface of the workpiece by the additive processing, In the step of forming the coating layer, a processing step of performing the additional processing on the rotating workpiece while feeding and driving the laser head to one side of the rotation axis; a stopping step of stopping the additional processing and feeding and driving the laser head to the other side of the rotary shaft; Each time the processing step is performed, a spiral layer is formed on the surface of the workpiece; The additive manufacturing method, wherein the coating layer is composed of a plurality of the spiral layers.

2. In the processing step, the feed drive of the laser head is started from a predetermined start position, The additive machining method according to claim 1 , wherein in the stopping step, the laser head is driven to the predetermined start position.

3. The execution of the machining step is started in a state where the rotation angle of the work spindle around the rotation axis is set to a predetermined target angle, The additional machining method according to claim 2 , wherein the predetermined target angle is incremented by a predetermined angle each time the machining step is executed.

4. In the processing step, The laser head is driven to feed at a constant feed rate, The additional machining method according to any one of claims 1 to 3, wherein the workpiece spindle is rotationally driven at a constant rotational speed.

5. The additive processing method further comprises: acquiring a temperature of the workpiece during the execution of the additional machining; The additive machining method according to any one of claims 1 to 3, further comprising a step of outputting a warning based on the temperature of the workpiece exceeding a predetermined value.

6. a work spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis; a material supply mechanism for supplying material to the workpiece; a laser head capable of performing additional processing by irradiating the workpiece with laser light; a drive unit for driving the laser head to feed relative to the workpiece; a control unit; the control unit executes a process of forming a coating layer on the surface of the workpiece by the additional processing; In the process of forming the coating layer, a processing step of feeding and driving the laser head to one side of the rotation axis and performing the additional processing on the workpiece while the workpiece is rotating; a stop process of stopping the additional processing and feeding and driving the laser head to the other side of the rotation shaft is repeatedly executed; Each time the processing is performed, a spiral layer is formed on the surface of the workpiece; The coating layer is composed of a plurality of the spiral layers.

7. An additive processing program for a workpiece by an additive processing device, The additional processing device is a work spindle capable of rotating a workpiece having a portion symmetrical with respect to a rotation axis about the rotation axis; a material supply mechanism for supplying material to the workpiece; a laser head capable of performing additional processing by irradiating the workpiece with laser light; a drive unit for driving the laser head to feed relative to the workpiece, the additional processing program causes the additional processing device to execute a process of forming a coating layer on the surface of the workpiece by the additional processing; In the process of forming the coating layer, a processing step of feeding and driving the laser head to one side of the rotation axis and performing the additional processing on the workpiece while the workpiece is rotating; a stop process of stopping the additional processing and feeding and driving the laser head to the other side of the rotation shaft is repeatedly executed; Each time the processing is performed, a spiral layer is formed on the surface of the workpiece; The coating layer is composed of a plurality of the spiral layers.

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