Method and machine tool for machining a workpiece

Abstract

The method for processing a workpiece comprises the following steps: performing additive processing on a first region (460) of a workpiece (400); and performing additive processing on a second region (470) of the workpiece (400) having a width smaller than that of the first region (460). The step of performing additive processing on the first region (460) comprises the following steps: arranging the additive processing head (21) and the workpiece (400) so that a first distance (La) exists between the workpiece (400) and a laser emitting portion in the additive processing head (21). The step of performing additive processing on the second region (470) comprises the following steps: arranging the additive processing head (21) and the workpiece (400) so that a second distance (Lb) exists between the workpiece (400) and the laser emitting portion in the additive processing head (21) which is smaller than the first distance (La).

Description

Technical Field

[0001] This invention relates to a method for machining a workpiece and a machine tool. Background Technology

[0002] For example, International Patent Publication No. 2018 / 211594 (Patent Document 1) discloses an additive manufacturing head comprising: a laser forming section having a first-axis conical lens and a second-axis conical lens arranged opposite to each other, and a convex lens disposed between the first-axis conical lens and the second-axis conical lens, the laser forming section causing the laser incident on the first-axis conical lens to become an annular laser and exit from the second-axis conical lens; and a lens moving mechanism section that moves the convex lens in the direction of the optical axis of the laser.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2018 / 211594 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] As disclosed in Patent Document 1 above, there is a known additive manufacturing method in which a ring-shaped laser is emitted toward a workpiece while material powder is supplied from the inside of the ring-shaped laser toward the surface of the workpiece. In such an additive manufacturing method, the area on the surface of the workpiece to be additively manufactured is varied, and therefore, there is a requirement to control the size (spot diameter) of the laser irradiation area in accordance with the area on the workpiece surface.

[0008] On the other hand, in the additive processing head disclosed in Patent Document 1, the size of the laser irradiation area formed on the workpiece surface is controlled by changing the distance between the first-axis conical lens and the convex lens in the direction of the laser optical axis through the movement of the convex lens at the laser forming section. However, the optical components provided inside the additive processing head are very precise, so there is also a requirement to minimize the driving of the optical components.

[0009] Therefore, the object of the present invention is to solve the above-mentioned problems and to provide a workpiece processing method and a machine tool for performing such workpiece processing method, which can control the size of the laser irradiation area in accordance with the area on the surface of the workpiece to be additively processed using a simple method.

[0010] Solution for solving the problem

[0011] This invention relates to a method for processing a workpiece, wherein an additive processing head and a workpiece are moved relative to each other, and a ring-shaped laser is emitted from the additive processing head toward the workpiece, with material powder ejected from the inner side of the ring-shaped laser, thereby performing additive processing on the workpiece. The additive processing head has a laser emitting section that emits the ring-shaped laser toward the workpiece. The workpiece processing method includes the following steps: performing additive processing on a first region of the workpiece; and performing additive processing on a second region of the workpiece. The width of the first region in a direction orthogonal to the relative movement direction of the additive processing head and the workpiece and the central axis direction of the ring-shaped laser is smaller than the width of the second region in a direction orthogonal to the relative movement direction of the additive processing head and the workpiece and the central axis direction of the ring-shaped laser. The step of performing additive processing on the first region includes the following step: positioning the additive processing head and the workpiece relative to each other at a first distance between the workpiece and the laser emitting section. The steps for performing additive manufacturing on the second region include the following steps: configuring the additive manufacturing head and the workpiece to be positioned such that the distance between the workpiece and the laser emission part is a second distance smaller than the first distance.

[0012] According to the processing method for this type of workpiece, when the first region, which has a relatively small width, is the target for additive processing, the distance between the workpiece and the laser emission unit is set to a first distance larger than a second distance, thereby reducing the irradiation area of ​​the annular laser on the workpiece surface. This allows for precise additive processing of the first region of the workpiece. Conversely, when the second region, which has a relatively large width, is the target for additive processing, the distance between the workpiece and the laser emission unit is set to a second distance smaller than the first distance, thereby increasing the irradiation area of ​​the annular laser on the workpiece surface. This allows for efficient additive processing of the second region of the workpiece. Therefore, the size of the laser irradiation area can be controlled in a simple way, corresponding to the region on the workpiece surface that is the target of additive processing.

[0013] Furthermore, preferably, the additive processing head is capable of rotating around a predetermined axis orthogonal to the central axis of the annular laser. The workpiece processing method includes, between the step of additive processing on the first region and the step of additive processing on the second region, the following step: rotating the additive processing head around the predetermined axis, thereby changing the posture of the additive processing head.

[0014] According to the processing method of the workpiece thus constructed, the rotation of the additive processing head can be used to change the position of the additive processing head to be suitable for emitting a ring laser towards the first and second regions that are the objects to be processed.

[0015] Furthermore, it is preferable that, in the step of performing additive processing on the second region, the position of the additive processing head is maintained such that the central axis of the ring laser extends in the horizontal direction.

[0016] In processing methods for workpieces with this configuration, when the central axis of the annular laser extends horizontally, material powder ejected from the inside of the annular laser towards the workpiece may fall downwards due to gravity. Therefore, by setting a relatively small second distance between the workpiece and the laser emission point, the material powder can reach the workpiece before it falls downwards significantly. This improves the utilization efficiency of the material powder.

[0017] Alternatively, preferably, the workpiece is a turbine blade having a leading edge, a trailing edge, an airfoil extending between the leading and trailing edges, and a planar side surface disposed at the end of the airfoil, the turbine blade being repaired using additive manufacturing. The leading or trailing edge includes a first region. The side surface includes a second region.

[0018] By reducing the irradiation area of ​​the annular laser on the workpiece surface using this machining method, precision additive machining can be performed on defects such as those occurring at the leading or trailing edges of turbine blades. Conversely, by increasing the irradiation area of ​​the annular laser on the workpiece surface, efficient additive machining can be performed on full-surface wear occurring on the sides of turbine blades.

[0019] Alternatively, the workpiece is preferably a turbine blade having a leading edge, a trailing edge, an airfoil extending between the leading and trailing edges, and a planar side surface disposed at the end of the airfoil, the turbine blade being repaired using additive manufacturing. The airfoil includes a first region and a second region.

[0020] By reducing the irradiation area of ​​the annular laser on the workpiece surface using this machining method, it is possible to perform precise additive machining on smaller cracks and other defects on the turbine blade surface. Conversely, by increasing the irradiation area of ​​the annular laser on the workpiece surface, it is possible to perform efficient additive machining on larger pits and other defects on the turbine blade surface.

[0021] Furthermore, preferably, the additive manufacturing head is capable of rotating around a predetermined axis extending in the horizontal direction. The workpiece processing method includes the following steps prior to the steps of additive manufacturing on the first region and on the second region: using a spindle having a rotation axis extending in the horizontal direction and orthogonal to the predetermined axis, the workpiece is held such that its leading edge, trailing edge, and wing surface are positioned radially outward from the rotation axis, and its side surface is positioned axially towards the rotation axis.

[0022] Based on the processing method of the workpiece thus constructed, the leading edge, trailing edge, airfoil and side surface of the turbine blade can be continuously processed by using the rotation of the additive processing head and the rotation of the spindle.

[0023] This invention relates to a machine tool that performs a method for machining a workpiece as described in any of the preceding claims. The machine tool comprises: an additive machining head having a laser emission section; a workpiece holding section for holding a workpiece; and a moving mechanism section for moving the additive machining head and the workpiece holding section relative to each other.

[0024] With a machine tool configured in this way, the size of the laser irradiation area can be controlled in accordance with the area on the surface of the workpiece that is the object of additive processing.

[0025] Furthermore, it is preferable that the additive processing head has an optical lens. The optical lens is fixed inside the additive processing head in such a way that the distance from the laser emission section to the focal point of the ring laser is constant.

[0026] Machine tools configured in this way can maintain the reliability of the optical system in additive manufacturing heads.

[0027] The effects of the invention

[0028] As explained above, according to the present invention, a method for machining a workpiece and a machine tool for performing such a method can be provided, which can control the size of the laser irradiation area in accordance with the area on the surface of the workpiece to be additively processed using a simple method. Attached Figure Description

[0029] Figure 1 This represents the front view of the machine tool.

[0030] Figure 2 It means in Figure 1 A three-dimensional view of the machining area during additive manufacturing on a machine tool.

[0031] Figure 3 It means Figure 1 and Figure 2 A diagram showing the internal structure of the additive manufacturing head.

[0032] Figure 4 It is a cross-sectional view of the workpiece surface during additive manufacturing.

[0033] Figure 5 This is a perspective view showing the first step of the workpiece processing method in Embodiment 1 of the present invention.

[0034] Figure 6 This is a perspective view showing the second step of the workpiece processing method in Embodiment 1 of the present invention.

[0035] Figure 7 It means Figure 5 A top view of the workpiece surface during the steps of the workpiece processing method.

[0036] Figure 8 It means Figure 6 A top view of the workpiece surface during the steps of the workpiece processing method.

[0037] Figure 9 This is a three-dimensional diagram representing turbine blades.

[0038] Figure 10 It means maintenance Figure 9 A flowchart illustrating the overall process of turbine blade manufacturing.

[0039] Figure 11 This is a flowchart illustrating the steps of the workpiece processing method in Embodiment 2 of the present invention.

[0040] Figure 12 This is a front view showing the first step of the workpiece processing method in Embodiment 2 of the present invention.

[0041] Figure 13 This is a front view showing the second step of the workpiece processing method in Embodiment 2 of the present invention.

[0042] Figure 14 This is a front view showing the third step of the workpiece processing method in Embodiment 2 of the present invention.

[0043] Figure 15 This is a front view showing the steps for maintenance, with the turbine side as the first area.

[0044] Figure 16 This is a front view showing the steps for maintenance, with the turbine side as the second area.

[0045] Figure 17 This is a flowchart illustrating the steps of the workpiece processing method in Embodiment 3 of the present invention.

[0046] Figure 18 This is a front view showing the first step of the workpiece processing method in Embodiment 3 of the present invention.

[0047] Figure 19 This is a front view showing the second step of the workpiece processing method in Embodiment 3 of the present invention. Detailed Implementation

[0048] Embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings referred to below, the same or equivalent components are labeled with the same reference numerals.

[0049] (Implementation Method 1)

[0050] Figure 1 This represents the front view of the machine tool. Figure 1In this design, the interior of the machine tool is shown through a transparent enclosure that forms the exterior of the machine tool. Figure 2 It means in Figure 1 A three-dimensional view of the machining area during additive manufacturing on a machine tool.

[0051] Reference Figure 1 and Figure 2 Machine tool 100 is an AM / SM hybrid machining center capable of performing both additive manufacturing (AM) and subtractive manufacturing (SM) machining of workpieces. Machine tool 100 has both turning (using fixed tools) and milling (using rotary tools) functions as SM machining. Machine tool 100 is an NC (Numerically Controlled) machine tool that automates various workpiece machining actions through computer numerical control.

[0052] In this specification, the axis parallel to the left-right direction (width direction) of the machine tool 100 and extending horizontally is called the "Z-axis," the axis parallel to the front-back direction (depth direction) of the machine tool 100 and extending horizontally is called the "Y-axis," and the axis extending vertically is called the "X-axis." Figure 1 The right direction in the equation is called the "+Z-axis direction", and the left direction is called the "-Z-axis direction". Figure 1 The direction closest to the paper in the image is called the "+Y axis direction," and the direction furthest into the image is called the "-Y axis direction." Figure 1 The upward direction is called the "+X-axis direction", and the downward direction is called the "-X-axis direction".

[0053] First, the structure of the machine tool 100 used to perform the workpiece machining method in this embodiment will be described. The machine tool 100 includes a machine base 136, a first spindle table 111, a second spindle table 116, a tool spindle 121, and a tool post 131.

[0054] The base 136 is a base component for supporting the first spindle head 111, the second spindle head 116, the tool spindle 121, and the lower tool post 131, and is installed on the ground in a factory or similar facility. The first spindle head 111 (the first spindle 112 described later), the second spindle head 116, the tool spindle 121, and the lower tool post 131 are located in the machining area 200 defined by the splash guard 205.

[0055] The processing area 200 is a space for removing and additively processing workpieces. The processing area 200 is sealed to prevent foreign matter such as chips, cutting oil or fumes generated during the processing of these workpieces from leaking out of the processing area 200.

[0056] The first spindle stage 111 and the second spindle stage 116 are arranged opposite to each other in the Z-axis direction. The first spindle stage 111 and the second spindle stage 116 each have a first spindle 112 and a second spindle 117 for rotating the workpiece during turning operations using a fixed tool, and for holding the workpiece during milling operations using a rotary tool or during removal operations. The first spindle 112 is configured to rotate about a central axis 201 parallel to the Z-axis, and the second spindle 117 is configured to rotate about a central axis 202 parallel to the Z-axis. The first spindle 112 and the second spindle 117 are provided with removable holding disc mechanisms for holding the workpiece.

[0057] In this embodiment, the workpiece is held by the first spindle 112 of the first spindle stage 111 (corresponding to the "spindle" and "workpiece holding part" in this invention). Furthermore, the "workpiece holding part" in this invention is not limited to a workpiece spindle capable of rotating the workpiece; for example, it may be a tray mounted on the stage.

[0058] The second spindle stage 116 is configured to move in the Z-axis direction using various conveying mechanisms, guiding mechanisms, servo motors, etc. Alternatively, the second spindle stage 116 can also be fixed.

[0059] The tool spindle (upper tool post) 121 rotates the rotary tool during milling operations. The tool spindle 121 is configured to rotate about a central axis 203 parallel to the X-axis. A clamping mechanism is provided on the tool spindle 121 to hold the rotary tool in a detachable manner.

[0060] The tool spindle 121 is supported on the machine base 136 by a column (not shown). The tool spindle 121 is configured to move in the X-axis, Y-axis, and Z-axis directions using various conveying mechanisms, guiding mechanisms, servo motors, etc., provided on the column. The machining position of the rotary tool mounted on the tool spindle 121 can move in three dimensions.

[0061] The tool spindle 121 is also configured to rotate around a rotation center axis 204 parallel to the Y-axis (B-axis rotation). The rotation range of the tool spindle 121 is with the spindle end face 123 of the tool spindle 121 facing downwards. Figure 1 The rotation range of the tool spindle 121 is preferably ±120°, based on the posture shown. Figure 1 The posture shown is within a range of ±90° or more. (Hereinafter, it will also be...) Figure 1 The posture of the tool spindle 121 shown is called the "reference posture".

[0062] In addition, although Figure 1Not shown, but around the first spindle 111 are provided: an automatic tool changer (ATC) for automatically changing the tool mounted on the tool spindle 121; and a tool magazine for storing the replacement tool mounted on the tool spindle 121.

[0063] The lower tool post 131 is used to mount multiple fixed tools for turning. The lower tool post 131 is a so-called turret shape, with multiple fixed tools mounted radially for rotary indexing.

[0064] More specifically, the lower tool post 131 has a rotating section 132. The rotating section 132 is configured to rotate about a central axis 206 parallel to the Z-axis. Multiple tool holders for holding and fixing tools are installed at circumferentially spaced positions about the central axis 206. The rotation of the rotating section 132 about the central axis 206 causes the fixed tool held in the tool holders to move circumferentially, indexing the fixed tool used for turning operations.

[0065] The lower tool post 131 is supported on the machine base 136 by a saddle (not shown). The lower tool post 131 is configured to move in the X-axis and Z-axis directions using various conveying mechanisms, guiding mechanisms, servo motors, etc., provided on the saddle, etc.

[0066] The machine tool 100 also includes an additive processing head 21. The additive processing head 21 supplies material powder to the workpiece and irradiates it with a laser to perform additive processing (directed energy deposition). For example, metal powders such as stainless steel, cobalt-based alloys, nickel-based alloys, or titanium can be used as the material powder. Furthermore, the material powder is not limited to metal powders.

[0067] The additive manufacturing head 21 is detachably mounted on the tool spindle 121. During additive manufacturing, the additive manufacturing head 21 is mounted on the tool spindle 121. The tool spindle 121 moves in the X-axis, Y-axis, and Z-axis directions, thereby causing the additive manufacturing position of the additive manufacturing head 21 to shift three-dimensionally. Furthermore, the tool spindle 121 rotates around the rotation center axis 204, so the additive manufacturing head 21 also rotates integrally with the tool spindle 121 around the rotation center axis 204 (corresponding to the "prescribed axis" in this invention). This allows the orientation (the direction of laser irradiation relative to the workpiece) of the additive manufacturing head 21 to be freely varied.

[0068] During the removal process, the additive manufacturing head 21 separates from the tool spindle 121 and is stored in a head storage device (not shown).

[0069] A clamping mechanism is provided on the tool spindle 121. When the additive machining head 21 is installed onto the tool spindle 121, the clamping mechanism is activated, thereby connecting the additive machining head 21 to the tool spindle 121. As an example of the clamping mechanism, a mechanism that uses elastic force to obtain a clamping state and uses hydraulic pressure to obtain a releasing state can be listed.

[0070] The machine tool 100 also includes a powder feeder 70, a laser oscillation device 76, and a cable 24.

[0071] The powder feeder 70 introduces additive manufacturing material powder into the additive manufacturing head 21 within the processing area 200. The powder feeder 70 has a powder hopper 72 and a mixing section 71. The powder hopper 72 forms a sealed space for containing the additive manufacturing material powder. The mixing section 71 mixes the material powder contained in the powder hopper 72 with a gas used as a carrier for the material powder.

[0072] The laser oscillation device 76 oscillates the laser used in additive manufacturing. The cable 24 includes an optical fiber for guiding the laser from the laser oscillation device 76 toward the additive manufacturing head 21, piping for guiding material powder from the powder feeder 70 toward the additive manufacturing head 21, air piping serving as an air flow path, gas piping serving as a flow path for inactive gases, cooling piping serving as a flow path for refrigerants, electrical wiring, and conduit components housing these components.

[0073] Next, the structure of the additive manufacturing head 21 will be described in detail. Figure 3 It means Figure 1 and Figure 2 A diagram showing the internal structure of the additive manufacturing head.

[0074] Reference Figure 3 The additive manufacturing head 21 has a laser collimation section 31, an annular laser forming section 32, a laser guiding section 33, and a laser emitting section 34 as an optical system for emitting externally introduced lasers toward the workpiece.

[0075] The laser collimation section 31, the annular laser forming section 32, the laser guiding section 33, and the laser emitting section 34 are arranged in the listed order from the upstream side to the downstream side of the laser optical path in the additive manufacturing head 21.

[0076] From cable 24 (reference) Figure 1 and Figure 2 The laser light is introduced into the laser collimation section 31 via the optical fiber 41. The laser collimation section 31 has a collimating lens 42. The collimating lens 42 is disposed on the axis of the central axis 102. The laser collimation section 31 uses the collimating lens 42 to make the laser light input from the optical fiber 41 parallel light and deliver it toward the annular laser forming section 32.

[0077] The annular laser forming unit 32 includes an axial conical lens 43 and an axial conical lens 45, and a spherical lens 44. The axial conical lens 43, the spherical lens 44, and the axial conical lens 45 are arranged in the listed order from the upstream side to the downstream side of the laser optical path in the additive manufacturing head 21. The axial conical lens 43, the spherical lens 44, and the axial conical lens 45 are disposed on the axis of the central axis 102.

[0078] Axicon lens 43 has one side 43m formed by a conical surface and another side 43n formed by a plane. Axicon lens 45 has one side 45m formed by a conical surface and another side 45n formed by a plane. Axicon lenses 43 and 45 are arranged such that one side 43m of axial conic lens 43 faces the other side 45m of axial conic lens 45.

[0079] The annular laser forming unit 32 uses an axial conical lens 43, a spherical lens 44, and an axial conical lens 45 to form the laser input from the laser collimator 31 into a ring shape. The laser output from the annular laser forming unit 32 has a ring shape; in other words, it has a shape that wraps around the axis of the central axis 102 when cut by a plane orthogonal to the direction of laser travel. In this embodiment, the annular laser forming unit 32 forms the laser input from the laser collimator 31 into a circular ring shape. The annular laser emitted from the annular laser forming unit 32 travels axially around the central axis 102.

[0080] The laser guiding section 33 includes a guide mirror 46 and a guide mirror 47. The guide mirrors 46 and 47 are arranged in the listed order from upstream to downstream of the laser beam path in the additive manufacturing head 21. The guide mirror 46 is positioned on the axis of the central axis 102. The guide mirror 46 is inclined relative to the central axis 102. The guide mirror 47 is positioned on the axis of the central axis 101, which is parallel to the central axis 102. The guide mirror 47 is inclined relative to the central axis 101.

[0081] The laser guide unit 33 guides the annular laser input from the annular laser forming unit 32 toward the laser emission unit 34 by using the reflection of the guide mirrors 46 and 47. The annular laser output from the laser guide unit 33 travels axially around the central axis 101.

[0082] The laser emission section 34 includes a condenser lens 51, a condenser lens 54, and a protective lens 56. The condenser lens 51, condenser lens 54, and protective lens 56 are arranged in the listed order from upstream to downstream of the laser beam path in the additive manufacturing head 21. The condenser lens 51, condenser lens 54, and protective lens 56 are located on the axis of the central axis 101.

[0083] The laser emitting section 34 emits a ring-shaped laser beam input from the laser guide section 33 toward the workpiece. The laser emitting section 34 uses a focusing lens 51 and a focusing lens 54 to focus the ring-shaped laser beam emitted toward the workpiece. The ring-shaped laser beam emitted from the laser emitting section 34 travels axially around the central axis 101. The protective lens 56 is provided to protect the lens system built into the additive manufacturing head 21 from the influence of the external atmosphere.

[0084] also, Figure 1 The rotation center axis 204 shown is orthogonal to the direction of the central axis of the ring laser (the axial direction of the central axis 101) and to the rotation center axis 201, which serves as the rotation axis of the first main axis 112. The additive processing head 21 can rotate around the rotation center axis 204.

[0085] The additive manufacturing head 21 has a material powder supply section 61 as a mechanism for supplying material powder to the workpiece.

[0086] The material powder supply unit 61 is composed of a tube capable of discharging material powder. The material powder supply unit 61 is arranged along the axis of the central axis 101. (Source: cable 24, see reference) Figure 1 and Figure 2 Material powder is introduced into the material powder supply unit 61. The material powder supply unit 61 has a nozzle 62. The nozzle 62 is an opening of the material powder supply unit 61 for ejecting material powder. The material powder supply unit 61 ejects material powder from the nozzle 62 toward the workpiece. The nozzle 62 has a circular opening shape.

[0087] The nozzle 62 is positioned inside the annular laser emitted from the laser emission section 34. Therefore, the material powder supply section 61 ejects material powder from inside the annular laser emitted from the laser emission section 34. The nozzle 62 is positioned on the axis of the central axis 101. The supply of material from the nozzle 62 towards the workpiece and the emission of the annular laser from the laser emission section 34 towards the workpiece are both on the axis of the central axis 101 and are coaxial.

[0088] The nozzle 62 is positioned downstream of the condenser lens 51 and condenser lens 54 in the optical path of the laser in the additive processing head 21. The nozzle 62 is also positioned downstream of the protective lens 56 in the optical path of the laser in the additive processing head 21.

[0089] A through hole 48 is formed in the guide mirror 47. The through hole 48 is formed so as to pass through the guide mirror 47 along the axis of the central axis 101. The through hole 48 has an opening surface larger than the cross-section of the material powder supply section 61 when cut by a plane orthogonal to the central axis 101. The material powder supply section 61 passes through the through hole 48.

[0090] Through holes 52, 55, and 57 are formed in the condenser lens 51, condenser lens 54, and protective lens 56, respectively. Through holes 52, 55, and 57 are formed such that they pass through the condenser lens 51, condenser lens 54, and protective lens 56 along the axis of the central axis 101. When cut by a plane orthogonal to the central axis 101, the through holes 52, 55, and 57 have an opening surface larger than the cross-section of the material powder supply section 61. The material powder supply section 61 is penetrated through the through holes 52, 55, and 57.

[0091] The additive manufacturing head 21 has a housing 26. The housing 26 has a shell shape, forming a space for accommodating a condenser lens 51, a condenser lens 54, and a protective lens 56. An opening 27 is formed in the housing 26. The opening 27 is disposed on the axis of the central axis 101. The opening 27 is positioned to face the workpiece surface during additive manufacturing. The opening 27 communicates between the space accommodating the condenser lens 51, the condenser lens 54, and the protective lens 56 and the external space. An annular laser beam is emitted from the laser emission section 34 through the opening 27 into the external space.

[0092] The nozzle 62 is preferably positioned axially along the central axis 101, protruding outwards from the opening 27. In this case, the nozzle 62 can be positioned closer to the workpiece.

[0093] Furthermore, the nozzle 62 can be disposed axially on the central axis 101 at a position overlapping with the opening 27, or it can be disposed inside the cover 26. In addition, the position of the nozzle 62 is not particularly limited as long as it is inside the annular laser emitted from the laser emission section 34, and it can also be disposed at a position deviating from the axis of the central axis 101.

[0094] The material powder supply section 61 may also be composed of multiple tubes. Furthermore, the nozzle 62 is not limited to a circular opening shape; for example, it may have a circular annular opening shape. In this case, the nozzle 62 ejects material powder in an annular shape from the inside of the annular laser emitted from the laser emission section 34, and the material powder ejected from the nozzle 62 is supplied to an annular area on the workpiece surface. Alternatively, the material powder may be ejected in a manner where the diameter of the annular laser decreases as it moves further away from the laser emission section 34.

[0095] Next, the processing method of the workpiece in this embodiment will be described. Figure 4 This is a cross-sectional view showing the surface of the workpiece during additive manufacturing. Furthermore, in Figure 4 The figure shows curve 410, which represents the normalized laser density distribution on the workpiece surface.

[0096] Reference Figures 1-4 In the workpiece processing method of this embodiment, while the additive processing head 21 and the workpiece 400 are moved relative to each other, an annular laser 311 is emitted from the additive processing head 21 toward the workpiece 400 and material powder is sprayed from the inside of the annular laser 311, thereby performing additive processing on the workpiece 400.

[0097] In this embodiment, such as Figure 4 As indicated by arrow 210, the tool spindle 121 on which the additive machining head 21 is mounted is moved, thereby causing the additive machining head 21 and the workpiece 400 to move relative to each other. Alternatively, as a method for moving the additive machining head 21 and the workpiece 400 relative to each other, the first spindle 112 holding the workpiece 400 on the first spindle stage 111 can be rotated, or both the movement of the additive machining head 21 and the rotation of the first spindle 112 can be performed.

[0098] The various conveying mechanisms, guiding mechanisms, servo motors, and motors that allow the tool spindle 121 to move in the X-axis, Y-axis, and Z-axis directions constitute a moving mechanism that allows the additive manufacturing head 21 and the first spindle 112 to move relative to each other.

[0099] A ring-shaped laser 311 is emitted from the additive manufacturing head 21 toward the workpiece 400, thereby forming a ring-shaped laser irradiation area 312 on the workpiece surface. Furthermore, material powder is ejected from the inner side of the ring-shaped laser 311 toward the workpiece 400, supplying material powder to a region on the workpiece surface that includes an area inward from the outer periphery 312p of the laser irradiation area 312. This causes the material powder to be deposited onto the workpiece surface.

[0100] Figure 5 and Figure 6 This is a perspective view showing the steps of the workpiece processing method in Embodiment 1 of the present invention. Figure 7 It means Figure 5 A top view of the workpiece surface during the steps of the workpiece processing method. Figure 8 It means Figure 6 A top view of the workpiece surface during the steps of the workpiece processing method.

[0101] Reference Figures 5-8The workpiece processing method includes two steps: additive processing of the first region 460 of the workpiece 400 and additive processing of the second region 470 of the workpiece 400. The width Wa of the first region 460 in the direction orthogonal to the relative movement direction of the additive processing head 21 and the workpiece 400 (the movement direction of the additive processing head 21 as shown by arrow 210) and the direction orthogonal to the central axis direction of the annular laser 311 (the axial direction of the central axis 101) (the direction shown by arrow 220) is smaller than the width Wb of the second region 470 in the direction orthogonal to the relative movement direction of the additive processing head 21 and the workpiece 400 (the movement direction of the additive processing head 21 as shown by arrow 210) and the direction orthogonal to the central axis direction of the annular laser 311 (the axial direction of the central axis 101) (the direction shown by arrow 220) (Wa < Wb).

[0102] like Figure 5 As shown, the steps for performing additive manufacturing on the first region 460 include arranging the additive manufacturing head 21 and the workpiece 400 such that a first distance La is formed between the workpiece 400 and the laser emission unit 34. Figure 6 As shown, the steps of performing additive processing on the second region 470 include arranging the additive processing head 21 and the workpiece 400 together in such a way that the distance between the workpiece 400 and the laser emission unit 34 is a second distance Lb (Lb < La) smaller than the first distance La.

[0103] Region 1 460 and Region 2 470 are distinct regions on the workpiece surface. Region 1 460 and Region 2 470 can also be discontinuously arranged regions on the workpiece surface. Region 1 460 and Region 2 470 can also be regions on the workpiece surface facing different directions. The shape of the workpiece surface at Region 1 460 and Region 2 470 can be either planar or curved. The shape of the workpiece surface at Region 1 460 can be the same as or different from the shape of the workpiece surface at Region 2 470.

[0104] As the additive manufacturing head 21 and the workpiece 400 move relative to each other, the width Wa of the first region 460 can be either constant or variable. Similarly, the width Wb of the second region 470 can also be either constant or variable as the additive manufacturing head 21 and the workpiece 400 move relative to each other. Even when the width Wa of the first region 460 and / or the width Wb of the second region 470 change with the relative movement of the additive manufacturing head 21 and the workpiece 400, the relationship Wa < Wb is satisfied.

[0105] The area of ​​region 470 projected onto a plane orthogonal to the central axis of the annular laser 311 (the axial direction of central axis 101) is larger than the area of ​​region 460 projected onto a plane orthogonal to the central axis of the annular laser 311 (the axial direction of central axis 101). The area of ​​region 470 projected onto a plane orthogonal to the central axis of the annular laser 311 can also be equal to or smaller than the area of ​​region 460 projected onto a plane orthogonal to the central axis of the annular laser 311.

[0106] There is no particular limitation on the order of the additive manufacturing steps performed on the first region 460 of workpiece 400 and the second region 470 of workpiece 400.

[0107] During the step of additive manufacturing on the first region 460 of workpiece 400, the relative movement direction between the additive manufacturing head 21 and workpiece 400 can be constant, continuously changing, or intermittently changing. During the step of additive manufacturing on the second region 470 of workpiece 400, the relative movement direction between the additive manufacturing head 21 and workpiece 400 can be constant, continuously changing, or intermittently changing.

[0108] During the step of additive processing of the first region 460 of workpiece 400, the first distance La between workpiece 400 and laser emission unit 34 can be constant or variable. During the step of additive processing of the second region 470 of workpiece 400, the second distance Lb between workpiece 400 and laser emission unit 34 can be constant or variable. Even when the first distance La and / or the second distance Lb varies, the relationship Lb < La is satisfied.

[0109] During the step of additive processing of the first region 460 of workpiece 400, the emission of the annular laser 311 from the additive processing head 21 and the emission of material powder from the additive processing head 21 can be performed continuously or intermittently. During the step of additive processing of the second region 470 of workpiece 400, the emission of the annular laser 311 from the additive processing head 21 and the emission of material powder from the additive processing head 21 can be performed continuously or intermittently.

[0110] Between the step of performing additive processing on the first region 460 of workpiece 400 and the step of performing additive processing on the second region 470 of workpiece 400, the processing conditions of additive processing (such as the type of material powder, the oscillation energy of the laser, or the relative moving speed of the additive processing head 21 and the workpiece 400 (the conveying speed of the additive processing head 21)) can be the same or different.

[0111] Between the steps of additive processing of the first region 460 of workpiece 400 and additive processing of the second region 470 of workpiece 400, the following step may also be included: stopping the emission of the annular laser 311 from the additive processing head 21 and the emission of material powder from the additive processing head 21, and moving the additive processing head 21 and workpiece 400 relative to each other. In this case, the step of moving the additive processing head 21 and workpiece 400 relative to each other may also include moving the additive processing head 21 about the rotation center axis 204 (see reference). Figure 1 and Figure 2 The steps are centered on the rotation.

[0112] like Figure 5 and Figure 7 As shown, when the first region 460 with a relatively small width Wa on the workpiece surface is the object of additive manufacturing, the distance between the workpiece 400 and the laser emission section 34 is set to a first distance La that is larger than the second distance Lb, thereby reducing the diameter (spot diameter) Da of the annular laser irradiation area 312 on the workpiece surface. This allows for precise additive manufacturing of the first region 460 of the workpiece 400.

[0113] like Figure 6 and Figure 8 As shown, when the second region 470 with a relatively large width Wb on the workpiece surface is the target for additive manufacturing, the distance between the workpiece 400 and the laser emission section 34 is set to a second distance Lb that is smaller than the first distance La, thereby increasing the diameter Db of the annular laser irradiation area 312 (spot diameter) on the workpiece surface. This allows for efficient additive manufacturing of the second region 470 of the workpiece 400.

[0114] When using a ring laser in additive manufacturing of workpieces based on directional energy deposition, the following characteristics are observed: even if the spot diameter on the workpiece surface increases, the laser intensity distribution does not decrease significantly, and the temperature of the molten pool formed on the workpiece surface can be maintained at a high level. Therefore, even when the diameter Db of the laser irradiation area 312 (spot diameter) is large, efficient deposition of material powder supplied to the workpiece surface is possible.

[0115] As explained above, according to the workpiece processing method in this embodiment, the size of the laser irradiation area can be controlled in a simple way in accordance with the area on the surface of the workpiece that is the object of additive processing.

[0116] Reference Figure 3 As a method to change the diameter of the laser irradiation area 312 on the workpiece surface, for example, there is a method of driving the optical lens in the annular laser forming section 32 in the direction of the laser's optical axis. In this case, it is necessary to provide a driving device for the optical lens in the additive processing head 21. Therefore, there is a possibility that the structure of the additive processing head 21 becomes complicated and the reliability of the optical system in the additive processing head 21 is compromised.

[0117] On the other hand, regarding the workpiece processing method in this embodiment, the distance between the workpiece 400 and the laser emission section 34 is adjusted to change the diameter of the laser irradiation area 312 on the workpiece surface. Therefore, the optical lenses (axial conical lens 43, spherical lens 44, and axial conical lens 45) in the annular laser forming section 32 are fixed within the additive processing head 21 in such a way that the distance from the laser emission section 34 to the focal point of the annular laser 311 remains constant. Thus, the additive processing head 21 can be simplified in construction while maintaining the reliability of the optical system within it.

[0118] Furthermore, this embodiment describes an AM / SM hybrid machining center based on a multi-functional machining center with both turning and milling capabilities, but it is not limited to this structure. For example, the machine tool may also be an AM / SM hybrid machining center based on a milling function, or it may be an AM machining center capable only of additive manufacturing.

[0119] (Implementation Method 2)

[0120] In this embodiment, a machining method for repairing turbine blades using machine tool 100 and additive manufacturing will be described. The machining method in this embodiment has essentially the same structure as the machining method in Embodiment 1. Repeated structures will not be described again below.

[0121] Figure 9 This is a three-dimensional diagram showing turbine blades. (See reference...) Figure 9 First, the structure of the turbine blade 500 repaired using the workpiece processing method in this embodiment will be described.

[0122] The turbine blade 500 has a leading edge 510, a trailing edge 520, an airfoil 540, and a pair of turbine sidewalls 530.

[0123] The leading edge 510 is the front end of the blade where air or other fluids flow in as the turbine blade 500 rotates, and it has an edge shape. The trailing edge 520 is the rear end of the blade where fluids flow out as the turbine blade 500 rotates, and it also has an edge shape.

[0124] Airfoil 540 extends between leading edge 510 and trailing edge 520. Airfoil 540 extends while curving between leading edge 510 and trailing edge 520. As turbine blade 500 rotates, fluid flowing in through leading edge 510 flows on airfoil 540 towards trailing edge 520. Airfoil 540 has a positive pressure surface 540P and a negative pressure surface 540N. The positive pressure surface 540P experiences relatively high pressure due to the fluid flowing on airfoil 540, while the negative pressure surface 540N experiences relatively low pressure due to the fluid flowing on airfoil 540.

[0125] A pair of turbine sidewalls 530 are respectively disposed at both ends of the airfoil 540. The turbine sidewalls 530 are composed of planes. The turbine sidewalls 530 are composed of planes orthogonal to the extending directions of the leading edge 510 and the trailing edge 520.

[0126] Turbine blades 500 are formed, for example, from nickel-based alloys or metallic materials such as Ti-6Al-4V.

[0127] If the turbine blade 500 is used more frequently, defects may occur at the leading edge 510 or trailing edge 520, wear may occur on the turbine side 530, or small cracks or large pits may occur on the airfoil 540. Turbine blades 500 that have developed such defects should be repaired.

[0128] Figure 10 It means maintenance Figure 9 A flowchart illustrating the overall process of turbine blade manufacturing.

[0129] Reference Figure 9 and Figure 10 The overall process of repairing turbine blade 500 is explained below. First, turbine blade 500 is held by the first main shaft 112 of the first main shaft table 111 (S101).

[0130] In this step, the turbine blade 500 is held such that the leading edge 510, trailing edge 520, and airfoil 540 are arranged radially outward from the central axis 201, which serves as the axis of rotation of the first main shaft 112, and the turbine sidewall 530 is arranged axially towards the central axis 201 (see below). Figure 12 wait).

[0131] Next, the turbine blade 500 is measured before maintenance (S102). In this step, the shape of the turbine blade 500 is measured using a measuring probe held on the tool spindle 121 to determine the maintenance location of the turbine blade 500. Furthermore, the measurements of the turbine blade 500 in S102 and S106 (described later) can also be performed non-contactly. The measurements of the turbine blade 500 in S102 and S106 (described later) can also be performed by a dedicated measuring device instead of the machine tool 100.

[0132] Next, the turbine blade 500 is subjected to machining before additive manufacturing (S103). In this step, the cracked parts are removed and the surface shape is adjusted to be suitable for additive manufacturing at the repair area of ​​the turbine blade 500 determined in the previous step.

[0133] Next, the turbine blade 500 is subjected to additive manufacturing (S104). In this step, additive manufacturing is performed using the same material powder as the metal material constituting the turbine blade 500, thereby thickening the repair area of ​​the turbine blade 500.

[0134] Next, the turbine blade 500 is subjected to machining after additive manufacturing (S105). In this step, the thickened portion that was added to the turbine blade 500 in the previous step is machined to finish the surface of the turbine blade 500.

[0135] Next, measurements are taken of the turbine blade 500 (S106). In this step, the shape of the turbine blade 500 that has been repaired is finally confirmed.

[0136] Furthermore, in the steps for repairing turbine blade 500 described above, the machining steps of turbine blade 500 in S103 and S105 and the measurement steps of turbine blade 500 in S102 and S106 are not required to be performed.

[0137] The workpiece processing method in this embodiment applies the workpiece processing method of the present invention to the additive manufacturing of the turbine blade 500 in S104 described above. The workpiece processing method in this embodiment will be described in detail below.

[0138] Figure 11 This is a flowchart illustrating the steps of the workpiece processing method in Embodiment 2 of the present invention. Figures 12-14 This is a front view illustrating the steps of the workpiece processing method in Embodiment 2 of the present invention. Figures 12-14 The diagram schematically shows the turbine blades 500 held on the first main shaft 112 of the first main shaft platform 111 and the defects 511 and 521 produced on the turbine blades 500. (The text abruptly ends here.) Figure 10In the case of machining before additive manufacturing in S103, defects 511 and 521 correspond to machining marks formed by machining the defective part.

[0139] Reference Figure 11 and Figure 12 First, the additive manufacturing head 21 is positioned opposite the trailing edge 520 (S110).

[0140] In this step, the first spindle 112 is rotated so that the trailing edge 520 is positioned above the central axis 201. The tool spindle 121 is set to a reference position, and the additive manufacturing head 21 mounted on the tool spindle 121 is positioned upwards from the defect 521 generated at the trailing edge 520. At this time, the distance in the X-axis direction between the laser emission section 34 and the defect 521 is set as L1.

[0141] Next, the defect 521 (first region 460) generated at the trailing edge 520 is repaired (S120). This step corresponds to the "step of performing additive processing on the first region of the workpiece" in this invention.

[0142] In this step, while maintaining the distance L1 between the laser emission section 34 and the defect 521, the additive processing head 21 is moved along the Z-axis. The annular laser 311 is emitted from the additive processing head 21 toward the defect 521, and material powder is ejected from the inner side of the annular laser 311.

[0143] Using the additive manufacturing process described above, a metal layer formed by melting and depositing material powder is thickened over the defect 521 generated at the trailing edge 520. After the required additive manufacturing is completed for the trailing edge 520, the emission of the annular laser 311 from the additive manufacturing head 21 and the ejection of material powder are stopped.

[0144] Reference Figure 11 and Figure 13 Next, the additive manufacturing head 21 is positioned opposite the leading edge 510 (S130).

[0145] In this step, the first spindle 112 is rotated 180°. With the tool spindle 121 in a reference position, the additive manufacturing head 21 mounted on the tool spindle 121 is positioned upwards, separate from the defect 511 generated at the leading edge 510. At this time, the distance in the X-axis direction between the laser emission section 34 and the defect 511 is set as L2. The relationship between distances L1 and L2 is not particularly limited. Distances L1 and L2 can also be equal values.

[0146] Next, the defect 511 (first region 460) generated at the leading edge 510 is repaired (S140). This step corresponds to the "step of performing additive processing on the first region of the workpiece" in this invention.

[0147] In this step, while maintaining the distance L2 between the laser emission section 34 and the defect 511, the additive processing head 21 is moved along the Z-axis. The annular laser 311 is emitted from the additive processing head 21 toward the defect 511, and material powder is ejected from the inner side of the annular laser 311.

[0148] Using the additive manufacturing process described above, a metal layer formed by melting and depositing material powder is thickened over the defect 511 generated at the leading edge 510. After the required additive manufacturing is completed for the leading edge 510, the emission of the annular laser 311 from the additive manufacturing head 21 and the ejection of material powder are stopped.

[0149] Reference Figure 11 and Figure 14 Next, the additive manufacturing head 21 is positioned opposite the turbine side 530 (S150).

[0150] In this step, the tool spindle 121 is rotated 90° clockwise from its reference position. The additive machining head 21 and the tool spindle 121 are rotated together around the rotation center axis 204, thereby changing the posture of the additive machining head 21. The additive machining head 21, mounted on the tool spindle 121, is positioned separately from the turbine side 530 in the +Z axis direction. At this time, the distance in the Z-axis direction between the laser emission section 34 and the turbine side 530 is set as L3. The distance L3 is smaller than the distance L1 and smaller than the distance L2 (L3 < L1, L3 < L2).

[0151] Next, the repair resulted in wear on the entire turbine side surface 530 (second region 470) (S160). This step corresponds to the "step of performing additive manufacturing on the second region of the workpiece" in this invention.

[0152] In this step, while maintaining the distance L3 between the laser emission section 34 and the turbine side surface 530, the additive processing head 21 is moved back and forth along the X-axis (or Y-axis). The annular laser 311 is emitted from the additive processing head 21 toward the turbine side surface 530, and material powder is ejected from the inner side of the annular laser 311.

[0153] Using the additive manufacturing process described above, a metal layer formed by fused material powder is deposited on the turbine side surface 530, which has undergone full-surface wear. After the required additive manufacturing process is completed on the turbine side surface 530, the emission of the annular laser 311 from the additive manufacturing head 21 and the ejection of the material powder are stopped.

[0154] Based on this structure, precision additive machining can be performed on defects 511 and 521 generated at the leading edge 510 and trailing edge 520, and efficient additive machining can be performed on the wear on the entire surface generated on the turbine side 530.

[0155] Furthermore, by rotating the first spindle 112 that holds the turbine blade 500 and rotating the additive machining head 21 around the rotation center axis 204, the leading edge 510, trailing edge 520 and turbine side 530 can be continuously machined while the turbine blade 500 is held by the first spindle 112.

[0156] Figure 15 This is a front view showing the steps for maintenance, with the turbine side as the first area. Figure 16 This is a front view showing the steps for maintenance, with the turbine side as the second area.

[0157] Reference Figure 15 and Figure 16 During the maintenance of the turbine side 530, the central axis 101 of the annular laser 311 emitted from the additive processing head 21 extends in the horizontal direction, and the material powder ejected from the additive processing head 21 travels along the central axis 101 extending in the horizontal direction toward the turbine side 530.

[0158] like Figure 15 As shown, when additive processing is performed with the turbine side 530 as the first region 460, the distance La between the laser emission section 34 and the turbine side 530 is set to a relatively large value (La > Lb). Therefore, it is possible that the material powder ejected from the additive processing head 21 will fall away from the additive processing head 21 under the action of gravity and be supplied to the region that is offset relative to the laser irradiation region 312 formed on the surface of the turbine side 530.

[0159] like Figure 16 As shown, in contrast, when additive processing is performed with the turbine side 530 as the second region 470, the distance Lb between the laser emission section 34 and the turbine side 530 is set to a relatively small value (Lb < La). This suppresses the amount of material powder sag from the additive processing head 21 and directs it towards the laser irradiation area 312. Figure 8 More material powder is supplied to the inner side of the outer periphery (312p). As a result, the utilization efficiency of the material powder can be improved.

[0160] The processing method for the workpiece in Embodiment 2 of the present invention, which is configured in this way, can achieve the same effects as described in Embodiment 1.

[0161] (Implementation Method 3)

[0162] The workpiece processing method in this embodiment has essentially the same structure as the workpiece processing method in Embodiment 2. Repeated structures will not be described again below.

[0163] Figure 17 This is a flowchart illustrating the steps of the workpiece processing method in Embodiment 3 of the present invention. Figure 18 and Figure 19 This is a front view illustrating the steps of the workpiece processing method in Embodiment 3 of the present invention. Figure 18 and Figure 19 The diagram schematically shows the turbine blade 500 held on the first main shaft 112 of the first main shaft platform 111, as well as the cracks 541 and pits 542 formed on the turbine blade 500. (The text abruptly ends here.) Figure 10 In the case of machining before additive manufacturing in S103, cracks 541 and pits 542 correspond to machining marks formed by machining the cracked and pitted portions.

[0164] Reference Figure 17 and Figure 18 First, the additive manufacturing head 21 is positioned opposite to the negative pressure surface 540N of the wing surface 540 (S210).

[0165] In this step, the first spindle 112 is rotated so that the negative pressure surface 540N of the wing surface 540 is positioned above the central axis 201. The tool spindle 121 is set to a reference position, and the additive machining head 21 mounted on the tool spindle 121 is positioned upwards, separate from the crack 541 generated on the negative pressure surface 540N. At this time, the distance in the X-axis direction between the laser emission section 34 and the crack 541 is set to L4.

[0166] Next, the crack 541 (first region 460) generated on the negative pressure surface 540N is repaired (S220). This step corresponds to the "step of performing additive processing on the first region of the workpiece" in this invention.

[0167] In this step, while maintaining the distance L4 between the laser emission section 34 and the crack 541, the additive processing head 21 is moved along the Z-axis. The annular laser 311 is emitted from the additive processing head 21 toward the crack 541, and material powder is ejected from the inside of the annular laser 311.

[0168] Using the above additive processing, the metal layer formed by melting and depositing material powder is thickened over the crack 541 generated on the negative pressure surface 540N. After the required additive processing is completed on the negative pressure surface 540N, the emission of the annular laser 311 from the additive processing head 21 and the ejection of material powder are stopped.

[0169] Reference Figure 17 and Figure 19 Next, the additive manufacturing head 21 is positioned opposite to the positive pressure surface 540P of the wing surface 540 (S230).

[0170] In this step, the first spindle 112 is rotated 180°. With the tool spindle 121 in a reference position, the additive manufacturing head 21 mounted on the tool spindle 121 is positioned upwards from the recess 542 created on the positive pressure surface 540P. At this time, the distance in the X-axis direction between the laser emission section 34 and the recess 542 is set to L5. The distance L5 is smaller than the distance L4 (L5 < L4).

[0171] Next, the pit 542 (second region 470) generated on the positive pressure surface 540P is repaired (S240). This step corresponds to the "step of performing additive processing on the second region of the workpiece" in this invention.

[0172] In this step, while maintaining the distance L5 between the laser emission section 34 and the recess 542, the additive processing head 21 is moved back and forth along the Z-axis. The annular laser 311 is emitted from the additive processing head 21 toward the recess 542, and material powder is ejected from the inner side of the annular laser 311.

[0173] Using the additive manufacturing process described above, a metal layer formed by melting and depositing material powder is thickened over the pit 542 created on the positive pressure surface 540P. After the required additive manufacturing process is completed on the positive pressure surface 540P, the emission of the annular laser 311 from the additive manufacturing head 21 and the ejection of material powder are stopped.

[0174] With this structure, precise additive machining can be performed on the cracks 541 generated on the negative pressure surface 540N, and efficient additive machining can be performed on the pits 542 generated on the positive pressure surface 540P. Furthermore, by rotating the first main shaft 112 that holds the turbine blade 500, the negative pressure surface 540N and the positive pressure surface 540P of the airfoil 540 can be continuously machined while the turbine blade 500 is held by the first main shaft 112.

[0175] Furthermore, the workpiece processing method of the present invention can also be applied to situations where cracks and pits have occurred on the same surface of the airfoil 540, and can also be applied to situations where pits of varying sizes have occurred on the airfoil 540. The steps for repairing turbine blades described in Embodiment 2 and the steps for repairing turbine blades described in this embodiment can also be appropriately combined.

[0176] The processing method of the workpiece in Embodiment 3 of the present invention, which is configured in this way, can achieve the same effect as described in Embodiment 1.

[0177] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the invention is defined not by the foregoing description but by the claims, and is intended to include all modifications of the same meaning and scope as the claims.

[0178] Industrial availability

[0179] This invention is mainly applied to additive manufacturing of workpieces.

[0180] Explanation of reference numerals in the attached figures

[0181] 21. Additive processing head; 24. Cable; 26. Cover; 27. Opening; 31. Laser collimation section; 32. Annular laser forming section; 33. Laser guiding section; 34. Laser emitting section; 41. Optical fiber; 42. Collimating lens; 43, 45. Axial cone lens; 43m, 45m, one side; 43n, 45n, the other side; 44. Spherical lens; 46, 47. Guide mirror; 48, 52, 55, 57. Through hole; 51, 54. Condensing lens; 56. Protective lens; 61. Material powder supply section; 62. Spray nozzle; 70. Powder feeder; 71. Mixing section; 72. Powder hopper; 76. Laser oscillation device; 100. Machine tool; 101, 102, 201, 202, 203, 20 6. Central axis; 111. First spindle table; 112. First spindle; 116. Second spindle table; 117. Second spindle; 121. Tool spindle; 123. Spindle end face; 131. Tool holder; 132. Rotating part; 136. Machine base; 200. Machining area; 204. Rotation center axis; 205. Anti-splash component; 311. Ring laser; 312. Laser irradiation area; 312p. Outer perimeter; 400. Workpiece; 410. Curve; 460. First area; 470. Second area; 500. Turbine blade; 510. Leading edge; 511. 521. Defect; 520. Trailing edge; 530. Turbine side; 540. Airfoil; 540N. Negative pressure surface; 540P. Positive pressure surface; 541. Crack.

Claims

1. A method for processing a workpiece, wherein an additive processing head and a workpiece are moved relative to each other while an annular laser is emitted from the additive processing head toward the workpiece and material powder is ejected from the inner side of the annular laser, thereby performing additive processing on the workpiece, wherein... The additive manufacturing head has a laser emission section that emits the annular laser toward the workpiece. The additive manufacturing head has an optical lens. The optical lens is fixed inside the additive manufacturing head at a fixed distance from the laser emission section to the focal point of the annular laser. The processing method includes the following steps: Additive processing is performed on the first region of the workpiece; and Additive processing is performed on the second region of the workpiece. The width of the first region in the direction orthogonal to the relative movement direction of the additive manufacturing head and the workpiece and the direction of the central axis of the annular laser is smaller than the width of the second region in the same direction. The step of performing additive manufacturing on the first region includes the following steps: configuring the additive manufacturing head and the workpiece to be positioned such that a first distance exists between the workpiece and the laser emission unit. The step of performing additive processing on the second region includes the following steps: configuring the additive processing head and the workpiece to be positioned such that the distance between the workpiece and the laser emission part is a second distance smaller than the first distance.

2. The workpiece processing method according to claim 1, wherein, The additive manufacturing head can rotate around a predetermined axis orthogonal to the central axis of the annular laser. The processing method for the workpiece further includes the following step between the step of performing additive processing on the first region and the step of performing additive processing on the second region: rotating the additive processing head around the predetermined axis, thereby changing the posture of the additive processing head.

3. The workpiece processing method according to claim 2, wherein, In the step of performing additive processing on the second region, the position of the additive processing head is maintained such that the central axis of the annular laser extends in the horizontal direction.

4. The method for processing a workpiece according to any one of claims 1 to 3, wherein, The workpiece is a turbine blade, which has a leading edge, a trailing edge, an airfoil extending between the leading edge and the trailing edge, and a planar side surface disposed at the end of the airfoil. The turbine blade is repaired using additive manufacturing. The leading edge or the trailing edge includes the first region. The side includes the second region.

5. The method for processing a workpiece according to any one of claims 1 to 3, wherein, The workpiece is a turbine blade, which has a leading edge, a trailing edge, an airfoil extending between the leading edge and the trailing edge, and a planar side surface disposed at the end of the airfoil. This turbine blade is repaired using additive manufacturing. The wing surface includes the first region and the second region.

6. The workpiece processing method according to claim 4, wherein, The additive manufacturing head is capable of rotating around a predetermined axis extending in the horizontal direction. The processing method for the workpiece includes the following steps prior to the steps of additive processing with the first region as the object and additive processing with the second region as the object: using a spindle having a rotation axis extending in the horizontal direction and orthogonal to the predetermined axis, the workpiece is held such that the leading edge, the trailing edge, and the wing surface are arranged outward in the radial direction of the rotation axis, and the side surface is arranged axially toward the rotation axis.

7. The workpiece processing method according to claim 5, wherein, The additive manufacturing head is capable of rotating around a predetermined axis extending in the horizontal direction. The processing method for the workpiece includes the following steps prior to the steps of additive processing with the first region as the object and additive processing with the second region as the object: using a spindle having a rotation axis extending in the horizontal direction and orthogonal to the predetermined axis, the workpiece is held such that the leading edge, the trailing edge, and the wing surface are arranged outward in the radial direction of the rotation axis, and the side surface is arranged axially toward the rotation axis.

8. A machine tool that performs a method for machining a workpiece according to any one of claims 1 to 3, wherein, This machine tool has the following features: The additive manufacturing head has the laser emission section; Workpiece holding part, which is used to hold the workpiece; and The moving mechanism moves the additive processing head and the workpiece holding part relative to each other.

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