Molding apparatus and molding method

Abstract

To provide a shaping device and a shaping method capable of forming on an object surface a three-dimensional shaped object having good machining accuracy.SOLUTION: A shaping device includes a beam shaping system 500 having a beam irradiating section 520 including a condensing optical system 82 for emitting a beam, and a material processing section 530 for supplying a shaping material irradiated with the beam from the beam irradiating section 520, and a control device for controlling a workpiece moving system and the beam shaping system 500 based on 3D data of a three-dimensional shaped object to be formed on the target surface so that a target site TA on the target surface is shaped by supplying the shaping material from the material processing section 530 while relatively moving the target surface TAS on a workpiece or table 12 and the beam from the beam irradiating section 520. In addition, the intensity distribution of the beam in the forming surface MP on the exit surface side of the condensing optical system can be changed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a fabrication apparatus and a fabrication method, and more particularly to a fabrication apparatus and a fabrication method for forming a three-dimensional object on a target surface. The fabrication apparatus and fabrication method according to the present invention can be suitably used for forming three-dimensional objects by rapid prototyping (sometimes called 3D printing, additive manufacturing, or direct digital manufacturing). [Background technology]

[0002] The technology of directly generating 3D (three-dimensional) shapes from CAD data is called rapid prototyping (sometimes called 3D printing, additive manufacturing, or direct digital manufacturing, but hereafter referred to collectively as rapid prototyping), and has contributed to the production of prototypes primarily for shape verification in extremely short lead times. When classifying 3D printing equipment that forms three-dimensional objects using rapid prototyping, such as 3D printers, by the materials they handle, they can be broadly divided into those that handle resin and those that handle metal. Unlike resin objects, metal three-dimensional objects produced by rapid prototyping are primarily used as actual parts. That is, they are not prototype parts for shape verification, but rather function as part of an actual mechanical structure (whether it is a mass-produced item or a prototype). Two types of existing metal 3D printers (hereinafter abbreviated as M3DP (Metal 3D Printer)) are well known: PBF (Powder Bed Fusion) and DED (Directed Energy Deposition).

[0003] In a PBF (Plant-Based Fabrication) process, a thin layer of sintered metal powder is deposited onto a bed on which the workpiece is mounted. A high-energy laser beam is then scanned over the powder using a galvanometer mirror or similar device, melting and solidifying the areas where the beam hits. Once one layer is completed, the bed is lowered by the thickness of that layer, and another layer of sintered metal powder is spread onto it. The process is then repeated, layer by layer, to obtain the desired three-dimensional shape.

[0004] Due to its manufacturing principle, PBF inherently has several problems, including (1) insufficient manufacturing precision of parts, (2) poor surface finish, (3) slow processing speed, and (4) the cumbersome and time-consuming handling of sintered metal powder.

[0005] DED employs a method of adhering molten metal material to the workpiece. For example, powdered metal is sprayed near the focal point of a laser beam focused by a focusing lens. The powdered metal then melts into a liquid state due to the laser irradiation. If the workpiece is located near the focal point, the liquefied metal adheres to the workpiece, cools, and solidifies again. This focal point acts like a pen tip, allowing for the drawing of "lines with thickness" on the surface of the workpiece. The desired shape is formed by the appropriate relative movement of either the workpiece or the processing head (laser and powder spray nozzle, etc.) relative to the other based on CAD data (see, for example, Patent Document 1).

[0006] As can be seen from this, with DED, powder material is ejected from the processing head only as needed and in the required amount, so there is no waste and there is no need to process with a large amount of excess powder.

[0007] As mentioned above, DED has been improved compared to PBF in terms of handling the raw material, powdered metal, but there are still many areas that need improvement.

[0008] Against this backdrop, there is a strong desire to improve the convenience of manufacturing equipment used to create three-dimensional objects as machine tools, and ultimately to improve the economic rationality of manufacturing. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] U.S. Patent Application Publication No. 2003 / 0206820 [Overview of the project]

Means for Solving the Problem

[0010] According to a first aspect of the present invention, there is provided a shaping apparatus for forming a three-dimensional shaped object on a target surface, comprising: a moving system for moving the target surface; a beam irradiation unit including a condensing optical system for emitting a beam; and a material processing unit for supplying a shaping material irradiated with the beam from the beam irradiation unit. A control device is provided for controlling the moving system and the beam shaping system based on 3D data of the three-dimensional shaped object to be formed on the target surface such that shaping is performed on a target site on the target surface by supplying the shaping material from the material processing unit while relatively moving the target surface and the beam from the beam irradiation unit. A shaping apparatus is provided in which the intensity distribution of the beam within a predetermined plane on the emission surface side of the condensing optical system can be changed.

[0011] Here, the target surface is a surface on which a target site for shaping is set, and the predetermined plane may be a virtual plane with which the target surface should be aligned during shaping. The predetermined plane may be, for example, a plane perpendicular to the optical axis of the condensing optical system. The predetermined plane may also be the rear focal plane of the condensing optical system or a plane in the vicinity thereof.

[0012] According to this, it becomes possible to form a three-dimensional shaped object with good processing accuracy on the target surface.

[0013] According to a second aspect of the present invention, there is provided a shaping method for forming a three-dimensional shaped object on a target surface, comprising controlling at least one of the movement of the target surface, the emission state of the beam from the beam irradiation unit, and the supply state of the shaping material based on 3D data of the three-dimensional shaped object to be formed on the target surface such that shaping is performed on a target site on the target surface by supplying the shaping material irradiated with the beam while relatively moving the beam emitted from the beam irradiation unit including the condensing optical system and the target surface. A shaping method is provided in which the intensity distribution of the beam within a predetermined plane on the emission surface side of the condensing optical system can be changed.

[0014] This makes it possible to form three-dimensional objects with good processing accuracy on the target surface. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block diagram showing the overall configuration of a molding apparatus according to one embodiment. [Figure 2] This diagram schematically shows the configuration of the mobile system along with the measurement system. [Figure 3] This is a perspective view showing a mobile system with a workpiece mounted on it. [Figure 4] This diagram shows a beam lithography system along with a table on which the workpiece is mounted. [Figure 5] This figure shows an example of the configuration of a light source system that constitutes part of the beam irradiation section of a beam lithography system. [Figure 6] This figure shows a state in which a parallel beam from a light source system is irradiated onto a mirror array, and the incident angle of the reflected beam from each of the multiple mirror elements to the focusing optical system is individually controlled. [Figure 7] This shows the material processing unit of the beam fusion system, along with the focusing optical system. [Figure 8] This figure shows a plurality of supply ports formed in the nozzle of a material processing unit, and an opening / closing member that opens and closes each of the plurality of supply ports. [Figure 9] Figure 9(A) is a magnified view of the area within circle A in Figure 4, and Figure 9(B) is a diagram showing the relationship between the single character area shown in Figure 9(A) and the scanning direction. [Figure 10] This figure shows an example of the beam irradiation area formed on the fabrication surface. [Figure 11] This is a block diagram showing the input / output relationships of the control device, which is the central component of the control system for a molding machine. [Figure 12] Figures 12(A) and 12(B) are diagrams illustrating one effect of a molding apparatus according to one embodiment, in comparison with the prior art. [Figure 13]This diagram illustrates an example of performing additional machining on a workpiece using three single-line beams, each formed in a separate single-line region. [Figure 14] This figure shows the relationship between the arrangement of the three single-character regions shown in Figure 13 and the scanning direction. [Figure 15] Figures 15(A) and 15(B) illustrate an example of increasing the thickness of the coating layer by slightly widening the width of the single-character area. [Modes for carrying out the invention]

[0016] The following description of one embodiment will be based on Figures 1 to 15(B). Figure 1 shows the overall configuration of the molding apparatus 100 according to one embodiment in a block diagram.

[0017] The molding device 100 is a DED-type M3DP. The molding device 100 can be used to form three-dimensional objects on the table 12, which will be described later, by rapid prototyping, but it can also be used to perform additive processing on a workpiece (for example, an existing part) by three-dimensional molding. In this embodiment, the explanation will focus on the latter case of performing additive processing on a workpiece. In actual manufacturing, it is common to repeatedly process parts produced by different manufacturing methods, different materials, or different machine tools to create the desired part, and the demand for additive processing by three-dimensional molding is potentially the same.

[0018] The 3D printing apparatus 100 includes a moving system 200, a measuring system 400, and a beam 3D printing system 500, as well as a control device 600 that includes these systems and controls the entire 3D printing apparatus 100. Of these, the measuring system 400 and the beam 3D printing system 500 are arranged separately in a predetermined direction. For convenience, in the following description, the measuring system 400 and the beam 3D printing system 500 will be assumed to be arranged separately in the X-axis direction (see Figure 2), as will be described later.

[0019] Figure 2 schematically shows the configuration of the moving system 200 together with the measurement system 400. Figure 3 shows the moving system 200 with the workpiece W mounted on it in a perspective view. In the following explanation, the left-right direction within the plane of Figure 2 will be referred to as the Y-axis direction, the direction perpendicular to the plane of the paper as the X-axis direction, and the direction perpendicular to the X and Y axes as the Z-axis direction. The rotation (tilting) directions around the X, Y, and Z axes will be referred to as the θx, θy, and θz directions, respectively.

[0020] The moving system 200 changes the position and orientation of the surface to be molded (here, the surface on the workpiece W where the target part TA is set) TAS (see, for example, Figures 4 and 9(A)). Specifically, the position of the surface to be molded is changed in the six degrees of freedom directions (X-axis, Y-axis, Z-axis, θx, θy, and θz directions) by driving the workpiece having the surface to be molded and the table on which the workpiece is mounted, as described later. In this specification, the positions in the three degrees of freedom directions of θx, θy, and θz are collectively referred to as "orientation" for the table, workpiece, or surface to be molded, and the positions in the remaining three degrees of freedom directions (X-axis, Y-axis, and Z-axis directions) are collectively referred to as "position".

[0021] The moving system 200 includes a Stewart platform-type 6-degree-of-freedom parallel link mechanism as an example of a drive mechanism for changing the position and orientation of the table. However, the moving system 200 is not limited to those capable of driving the table in 6 degrees of freedom directions.

[0022] The moving system 200 (excluding the stator of the planar motor described later) is positioned on a base BS installed on the floor F so that its upper surface is approximately parallel to the XY plane, as shown in Figure 2. The moving system 200, as shown in Figure 3, has a slider 10 that is a regular hexagon in plan view and constitutes the base platform, a table 12 that constitutes the end effector, six retractable rods (links) 141 to 146 that connect the slider 10 and the table 12, and telescopic mechanisms 161 to 166 (not shown in Figure 3, see Figure 11) provided on each of the rods 141 to 146 to extend and retract each rod. The moving system 200 has a structure that allows the movement of the table 12 to be controlled in three-dimensional space with 6 degrees of freedom by independently adjusting the length of each of the rods 141 to 146 with the telescopic mechanisms 161 to 166. The moving system 200 is equipped with a Stewart platform-type 6-degree-of-freedom parallel link mechanism as the drive mechanism for the table 12, and therefore has features such as high precision, high rigidity, large support capacity, and ease of inverse kinematics calculation.

[0023] In the molding apparatus 100 according to this embodiment, the position and orientation of the workpiece (table 12) are controlled in relation to the beam molding system 500, more specifically, in relation to the beam from the beam irradiation unit described later, in order to form an object of a desired shape on the workpiece during additional processing of the workpiece. In principle, the opposite is also possible: the beam from the beam irradiation unit may be movable, or both the beam and the workpiece (table) may be movable. As described later, the beam molding system 500 has a complex configuration, so it is simpler to move the workpiece.

[0024] Table 12, in this case, consists of a plate member shaped like an equilateral triangle with each vertex cut off. The workpiece W to be processed is mounted on the top surface of table 12. Table 12 is provided with a chuck mechanism 13 (not shown in Figure 3, see Figure 11) for fixing the workpiece W. For example, a mechanical chuck or a vacuum chuck can be used as the chuck mechanism 13. Note that table 12 is not limited to the shape shown in Figure 3, but can be any shape, such as a rectangular plate or a disc.

[0025] In this case, as is clear from Figure 3, each of the rods 141 to 146 is connected to the slider 10 and the table 12, respectively, at both ends via the universal joint 18. Furthermore, rods 141 and 142 are connected near the location of one vertex of the triangle formed by the table 12, so that the slider 10 and these rods 141 and 142 form a roughly triangular structure. Similarly, rods 143, 144, and rods 145 and 146 are connected near the locations of the remaining vertices of the triangle formed by the table 12, so that the slider 10 and rods 143, 144, and rods 145 and 146 form a roughly triangular structure, respectively.

[0026] Each of these rods 141 to 146 has a first axial member 20 and a second axial member 22 that are relatively movable in their respective axial directions, as is typically shown for rod 141 in Figure 3. One end (lower end) of the first axial member 20 is attached to the slider 10 via a universal joint 18, and the other end (upper end) of the second axial member 22 is attached to the table 12 via a universal joint.

[0027] A stepped cylindrical hollow section is formed inside the first shaft member 20, and a bellows-type air cylinder, for example, is housed at the lower end of this hollow section. A pneumatic circuit and a pneumatic source (neither of which are shown) are connected to this air cylinder. By controlling the air pressure of the compressed air supplied from the pneumatic source via the pneumatic circuit, the internal pressure of the air cylinder is controlled, causing the piston of the air cylinder to reciprocate in the axial direction. In the air cylinder, the return stroke utilizes gravity acting on the piston when it is incorporated into a parallel link mechanism.

[0028] Furthermore, an armature unit (not shown) consisting of multiple armature coils arranged in a axial direction is positioned at the upper end of the hollow portion of the first shaft member 20.

[0029] On the other hand, one end (lower end) of the second shaft member 22 is inserted into the hollow portion of the first shaft member 20. A small-diameter portion is formed at one end of the second shaft member 22, which has a smaller diameter than the rest of the part, and a cylindrical movable element yoke made of a magnetic material is provided around this small-diameter portion. A hollow cylindrical magnet body, i.e., a cylindrical magnet body made of multiple permanent magnets of the same dimensions, is provided on the outer circumference of the movable element yoke. In this case, the movable element yoke and the magnet body constitute a hollow cylindrical magnet unit. In this embodiment, a shaft motor, which is a type of electromagnetic linear motor, is configured by the armature unit and the magnet unit. In the shaft motor configured in this way, by supplying a sinusoidal drive current of a predetermined period and amplitude to each coil of the armature unit, which is the stator, the second shaft member 22 is driven axially relative to the first shaft member 20 by the Lorentz force (driving force) generated by the electromagnetic interaction, which is a type of electromagnetic interaction between the magnet unit and the armature unit.

[0030] In other words, in this embodiment, the aforementioned telescopic mechanisms 161 to 166 (see Figure 11) are configured to extend and retract the rods 141 to 146, respectively, by driving the first shaft member 20 and the second shaft member 22 relative to each other in the axial direction using the air cylinder and shaft motor described above.

[0031] Furthermore, the magnet unit, which is the movable element of the shaft motor, is supported non-contact with the armature unit, which is the stator, via an air pad provided on the inner circumferential surface of the first shaft member 20.

[0032] Although not shown in Figure 3, each of the rods 141 to 146 is provided with an absolute-type linear encoder 241 to 246 that detects the axial position of the second shaft member 22 relative to the first shaft member 20. The outputs of these linear encoders 241 to 246 are supplied to the control device 600 (see Figure 11). The axial position of the second shaft member 22 detected by the linear encoders 241 to 246 corresponds to the respective lengths of the rods 141 to 146.

[0033] Based on the outputs of linear encoders 241 to 246, the telescopic mechanisms 161 to 166 are controlled by the control device 600 (see Figure 11). Details of the configuration of a parallel link mechanism similar to that of the moving system 200 in this embodiment are disclosed, for example, in U.S. Patent No. 6,940,582, and the control device 600 controls the position and orientation of the table 12 via the telescopic mechanisms 161 to 166 using inverse kinematic calculations in a manner similar to that disclosed in the above U.S. Patent.

[0034] In the moving system 200, the telescopic mechanisms 161 to 166 provided on rods 141 to 146 each have air cylinders and shaft motors, which are a type of electromagnetic linear motor, arranged in series (or parallel) with each other. Therefore, the control device 600 can drive the table 12 roughly and broadly by pneumatic control of the air cylinders, and finely move it using the shaft motors. As a result, it becomes possible to control the position (i.e., position and orientation) of the table 12 in all six degrees of freedom directions accurately in a short amount of time.

[0035] Furthermore, since each of the rods 141 to 146 has an air pad that non-contactively supports the magnet unit, which is the movable element of the shaft motor, with respect to the armature unit, which is the stator, friction, which is a nonlinear component when controlling the extension and retraction of the rods by the telescopic mechanism, can be avoided, thereby enabling more precise control of the position and orientation of the table 12.

[0036] Furthermore, in this embodiment, a shaft motor is used as the electromagnetic linear motor constituting the telescopic mechanism 161-166. In this shaft motor, a magnetic unit with a cylindrical magnet on the movable element side is used, so magnetic flux (magnetic field) is generated in all directions of the radial direction of the magnet, and this magnetic flux in all directions can be used to generate a Lorentz force (driving force) due to electromagnetic interaction. This allows for the generation of a significantly larger thrust compared to, for example, a conventional linear motor, and is easier to miniaturize compared to hydraulic cylinders, etc.

[0037] Therefore, a moving system 200 in which each rod includes a shaft motor can simultaneously achieve miniaturization, weight reduction, and improved output, making it suitable for application to a molding device 100.

[0038] Furthermore, the control device 600 can suppress low-frequency vibrations by controlling the air pressure of the air cylinders that constitute each of the telescopic mechanisms, and isolate high-frequency vibrations by controlling the current to the shaft motor.

[0039] The moving system 200 is further equipped with a planar motor 26 (see Figure 11). A movable element of the planar motor 26, consisting of a magnet unit (or coil unit), is provided on the bottom surface of the slider 10, and correspondingly, a stator of the planar motor 26, consisting of a coil unit (or magnet unit), is housed inside the base BS. Multiple air bearings (hydrostatic air bearings) are provided on the bottom surface of the slider 10, surrounding the movable element, and the slider 10 is supported by these multiple air bearings, floating on the upper surface (guide surface) of the base BS, which is finished to a high degree of flatness, with a predetermined clearance (gap or gap). The slider 10 is driven in the XY plane without contact with the upper surface of the base BS by the electromagnetic force (Lorentz force) generated by the electromagnetic interaction between the stator and movable element of the planar motor 26. In this embodiment, as shown in Figure 1, the moving system 200 allows the table 12 to move freely between the positions of the measurement system 400, the beam shaping system 500, and the workpiece transport system 300 (not shown in Figure 1, see Figure 11). The moving system 200 may also have multiple tables 12, each carrying a workpiece W. For example, while processing is being performed on a workpiece held on one of the tables using the beam shaping system 500, measurement may be performed on a workpiece held on another table using the measurement system 400. In such a case, it is sufficient that each table can move freely between the positions of the measurement system 400, the beam shaping system 500, and the workpiece transport system 300 (not shown in Figure 1, see Figure 11). Alternatively, if a configuration is adopted in which a table is provided to hold the workpiece when measuring using the measurement system 400 and another table is provided to hold the workpiece when processing using the beam shaping system 500, and the loading and unloading of workpieces to and from these two tables is possible by a workpiece transport system, then each slider 10 may be fixed on the base BS. Even if multiple tables 12 are provided, each table 12 is movable in six degrees of freedom directions, and its position in those six degrees of freedom directions can be controlled.

[0040] Furthermore, the planar motor 26 is not limited to an air levitation type; a magnetic levitation type planar motor may also be used. In the latter case, it is not necessary to provide an air bearing in the slider 10. In addition, either a moving magnet type or a moving coil type planar motor 26 can be used.

[0041] The control device 600 can freely drive the slider 10 in the X and Y two-dimensional directions on the base BS by controlling at least one of the magnitude and direction of the current supplied to each coil of the coil unit constituting the planar motor 26.

[0042] In this embodiment, the moving system 200 includes a position measurement system 28 (see Figure 11) that measures positional information of the slider 10 in the X-axis and Y-axis directions. A two-dimensional absolute encoder can be used as the position measurement system 28. Specifically, a two-dimensional scale having a strip-shaped absolute code of a predetermined width extending along the entire length in the X-axis direction is provided on the upper surface of the base BS, and correspondingly, an X-head and a Y-head are provided on the bottom surface of the slider 10, each consisting of a light source such as a light-emitting element and a one-dimensional photodetector array arranged in the X-axis direction and a one-dimensional photodetector array arranged in the Y-axis direction, respectively, which receive reflected light from the two-dimensional scale illuminated by the light beam emitted from the light source. As the two-dimensional scale, for example, one is used in which a plurality of square reflective parts (marks) are arranged in two dimensions at a constant period along two mutually orthogonal directions (X-axis direction and Y-axis direction) on a non-reflective substrate (reflectance 0%), and the reflective characteristics (reflectance) of the reflective parts have gradations according to a predetermined rule. As a two-dimensional absolute encoder, for example, a configuration similar to the two-dimensional absolute encoder disclosed in U.S. Patent Application Publication No. 2014 / 0070073 may be adopted. An absolute two-dimensional encoder with a configuration similar to that of U.S. Patent Application Publication No. 2014 / 0070073 enables measurement of two-dimensional position information with the same high accuracy as a conventional incremental encoder. Because it is an absolute encoder, unlike an incremental encoder, origin detection is not required. The measurement information from the position measurement system 28 is sent to the control device 600.

[0043] In this embodiment, as will be described later, the measurement system 400 measures positional information (shape information in this embodiment) in three-dimensional space of at least a portion of the target surface (e.g., the top surface) on the workpiece W mounted on the table 12, and additional processing (shaping) is performed on the workpiece W after the measurement. Therefore, when the control device 600 measures the shape information of at least a portion of the target surface on the workpiece W, it associates the measurement result with the measurement results of the linear encoders 241 to 246 provided on the rods 141 to 146 and the measurement results of the position measurement system 28 at the time of measurement, thereby associating the position and orientation of the target surface on the workpiece W mounted on the table 12 with the reference coordinate system of the shaping device 100 (hereinafter referred to as the table coordinate system). As a result, thereafter, position control of the target surface TAS on the workpiece W with respect to the target value is possible in the six degrees of freedom directions by open-loop control of the position of the table 12 in the six degrees of freedom directions based on the measurement results of the linear encoders 241 to 246 and the position measurement system 28. In this embodiment, absolute type encoders are used as linear encoders 241-246 and position measurement system 28, so resetting is easy as there is no need to set the origin. The aforementioned three-dimensional spatial position information to be measured by the measurement system 400, which is used to enable position control in the six degrees of freedom directions with respect to the target value of the target surface on the workpiece W by open-loop control of the position of the table 12 in the six degrees of freedom directions, is not limited to the shape, but is sufficient if it is three-dimensional position information of at least three points corresponding to the shape of the target surface.

[0044] In the above embodiment, a planar motor 26 was described as the drive device for driving the slider 10 in the XY plane, but a linear motor may be used instead of the planar motor 26. In this case, instead of the two-dimensional absolute encoder described above, a position measurement system that measures the position information of the slider 10 may be configured using an absolute type linear encoder. Furthermore, the position measurement system that measures the position information of the slider 10 may be configured using an interferometer system, not limited to an encoder.

[0045] Furthermore, in the above embodiment, an example was given of a mechanism for driving the table using a planar motor that drives a slider in the XY plane and a Stewart platform type 6-degree-of-freedom parallel link mechanism in which the slider forms the base platform. However, the invention is not limited to this, and a mechanism for driving the table may be configured using other types of parallel link mechanisms or mechanisms other than parallel link mechanisms. For example, a slider that moves in the XY plane and a Z-tilt drive mechanism that drives the table 12 on the slider in the Z-axis direction and in the tilt direction relative to the XY plane may be employed. An example of such a Z-tilt drive mechanism is a mechanism that supports the table 12 from below at each vertex of a triangle via, for example, a universal joint or other joint, and has three actuators (such as a voice coil motor) that can drive each support point independently in the Z-axis direction. However, the configuration of the mechanism that drives the table of the moving system 200 is not limited to these, and any configuration that can drive the table (movable member) on which the workpiece is placed in at least 5 degrees of freedom directions, namely the 3 degrees of freedom directions in the XY plane, the Z axis direction, and the inclination direction relative to the XY plane, is sufficient, and it does not need to include a slider that moves in the XY plane. For example, the moving system may be composed of a table and a robot that drives this table. In any configuration, resetting can be made easier if the measurement system for measuring the position of the table is configured using a combination of absolute linear encoders, or a combination of such linear encoders and absolute rotary encoders.

[0046] Alternatively, instead of the moving system 200, a system capable of driving the table 12 in at least five degrees of freedom directions—three degrees of freedom in the XY plane, the Z-axis direction, and the tilt direction (θx or θy) relative to the XY plane—may be employed. In this case, the table 12 itself may be supported by air levitation or magnetic levitation, floating above the upper surface of a support member such as a base BS with a predetermined clearance (gap or gap) (non-contact support). Adopting such a configuration is extremely advantageous in terms of positioning accuracy because the table moves without contact with the member supporting it, and greatly contributes to improving molding accuracy.

[0047] The measurement system 400 measures the three-dimensional position information of a workpiece, for example, its shape, in order to associate the position and orientation of the workpiece mounted on the table 12 with the table coordinate system. As shown in Figure 2, the measurement system 400 is equipped with a laser non-contact three-dimensional measuring machine 401. The three-dimensional measuring machine 401 comprises a frame 30 installed on a base BS, a head unit 32 attached to the frame 30, a Z-axis guide 34 mounted on the head unit 32, a rotation mechanism 36 provided at the lower end of the Z-axis guide 34, and a sensor unit 38 connected to the lower end of the rotation mechanism 36.

[0048] The frame 30 consists of a horizontal member 40 extending in the Y-axis direction and a pair of column members 42 that support the horizontal member 40 from below at both ends in the Y-axis direction.

[0049] The head unit 32 is attached to the horizontal member 40 of the frame 30.

[0050] The Z-axis guide 34 is mounted on the head unit 32 so as to be movable in the Z-axis direction and is driven in the Z-axis direction by a Z-drive mechanism 44 (not shown in Figure 2, see Figure 11). The position of the Z-axis guide 34 in the Z-axis direction (or displacement from the reference position) is measured by a Z-encoder 46 (not shown in Figure 2, see Figure 11).

[0051] The rotation mechanism 36 continuously rotates the sensor unit 38 around a rotation center axis parallel to the Z-axis within a predetermined angular range (for example, 90 degrees (π / 2) or 180 degrees (π)) relative to the head unit 32 (Z-axis guide 34) (or in predetermined angular steps). In this embodiment, the rotation center axis of the sensor unit 38 by the rotation mechanism 36 coincides with the central axis of the line light emitted from the illumination unit, which will be described later, that constitutes the sensor unit 38. The rotation angle of the sensor unit 38 from the reference position by the rotation mechanism 36 (or the position of the sensor unit in the θz direction) is measured by a rotation angle sensor 48 (not shown in Figure 2, see Figure 11), such as a rotary encoder.

[0052] The sensor unit 38 mainly consists of an irradiation unit 50 that irradiates a line of light onto the object to be inspected (workpiece W in Figure 2) placed on the table 12 to perform optical cutting, and a detection unit 52 that detects the surface of the object to be inspected where an optical cutting surface (line) appears due to the irradiation of the line of light. In addition, a calculation processing unit 54 that determines the shape of the object to be inspected based on the image data detected by the detection unit 52 is connected to the sensor unit 38. In this embodiment, the calculation processing unit 54 is included in the control device 600 that comprehensively controls each component of the molding apparatus 100 (see Figure 11).

[0053] The irradiation unit 50 is composed of a cylindrical lens (not shown) and a slit plate with a narrow strip-shaped cutout, and receives illumination light from a light source to generate a fan-shaped line of light 50a. As the light source, an LED, laser light source, or SLD (superluminescent diode) can be used. If an LED is used, the light source can be formed inexpensively. If a laser light source is used, since it is a point light source, it can produce line light with little aberration, has excellent wavelength stability and a small FWHM, and a filter with a small FWHM can be used to cut stray light, thus reducing the influence of disturbances. If an SLD is used, in addition to the characteristics of a laser light source, its coherence is lower than that of laser light, so the generation of speckle on the surface of the object under test can be suppressed. The detection unit 52 is for imaging the line of light 50a projected onto the surface of the object under test (work W) from a direction different from the light irradiation direction of the irradiation unit 50. The detection unit 52 is composed of an imaging lens and CCD (not shown), and as described later, the table 12 is moved to image the object under test (work W) each time the line of light 50a is scanned at predetermined intervals. The positions of the irradiation unit 50 and the detection unit 52 are determined such that the incident direction of the line light 50a on the surface of the object to be inspected (workpiece W) to the detection unit 52 and the light irradiation direction of the irradiation unit 50 form a predetermined angle θ. In this embodiment, the predetermined angle θ is set to, for example, 45 degrees.

[0054] Image data of the object under test (work W) captured by the detection unit 52 is sent to the arithmetic processing unit 54, where predetermined image calculation processing is performed to calculate the height of the surface of the object under test (work W) and to determine the three-dimensional shape (surface shape) of the object under test (work W). The arithmetic processing unit 54 calculates the height of the surface of the object under test (work W) from a reference plane using the principle of triangulation for each pixel in the longitudinal direction to which the light cross-section (line) (line light 91a) extends, based on the position information of the light cross-section (line) formed by the line light 50a which is deformed according to the unevenness of the object under test (work W) in the image of the object under test (work W), and performs calculation processing to determine the three-dimensional shape of the object under test (work W).

[0055] In this embodiment, the control device 600 moves the table 12 in a direction approximately perpendicular to the longitudinal direction of the line light 50a projected onto the workpiece (work W), thereby scanning the surface of the workpiece (work W) with the line light 50a. The control device 600 detects the rotation angle of the sensor unit 38 with the rotation angle sensor 48, and moves the table 12 in a direction approximately perpendicular to the longitudinal direction of the line light 50a based on the detection result. Thus, in this embodiment, the table 12 is moved when measuring the shape of the workpiece (work W), so as a prerequisite, when the workpiece W is held and moved below the sensor unit 38 of the measurement system 400, the position and orientation (position in the 6 degrees of freedom directions) of the table 12 are always set to a predetermined reference state. The reference state is, for example, when rods 141 to 146 are all at the length corresponding to the neutral point (or minimum length) of the extension stroke range. In this state, the positions of table 12 in the Z-axis, θx, θy, and θz directions (Z, θx, θy, θz) = (Z0, 0, 0, 0). In this reference state, the position (X,Y) of table 12 in the XY plane coincides with the X,Y positions of slider 10 measured by the position measurement system 28.

[0056] Subsequently, the aforementioned measurements of the workpiece (work W) are initiated. During and after these measurements, the position of the table 12 in the six degrees of freedom directions is managed by the control device 600 on the table coordinate system. Specifically, the control device 600 controls the position of the table 12 in the six degrees of freedom directions by controlling the planar motor 26 based on the measurement information from the position measurement system 28, and by controlling the telescopic mechanisms 161-166 based on the measurement values ​​from the linear encoders 241-246.

[0057] Incidentally, when using the light section method as in the three-dimensional measuring machine 401 according to this embodiment, it is desirable to position the line light 50a irradiated from the irradiation unit 50 of the sensor unit 38 onto the workpiece (work W) in a direction perpendicular to the relative movement direction between the sensor unit 38 and the table 12 (workpiece (work W)). For example, in Figure 2, if the relative movement direction between the sensor unit 38 and the workpiece (work W) is set to the Y-axis direction, it is desirable to position the line light 50a along the X-axis direction. This is because, during measurement, relative movement with respect to the workpiece (work W) can be performed using the entire range of the line light 50a, and the shape of the workpiece (work W) can be measured optimally. A rotation mechanism 36 is provided so that the direction of the line light 50a and the relative movement direction described above can always be perpendicular.

[0058] The three-dimensional measuring machine 401 described above is configured similarly to the shape measuring device disclosed in, for example, U.S. Patent Application Publication No. 2012 / 0105867. However, the scanning of the line light with respect to the object in directions parallel to the X and Y planes is performed by the movement of the sensor unit in the device described in U.S. Patent Application Publication No. 2012 / 0105867, whereas in this embodiment, it is performed by the movement of the table 12. In this embodiment, when scanning the line light with respect to the object in directions parallel to the Z axis, either the Z-axis guide 34 or the table 12 may be driven.

[0059] In the measurement method using the three-dimensional measuring machine 401 according to this embodiment, a linear projection pattern consisting of a single line of light is projected onto the surface of the object to be examined using the light section method. Each time the linear projection pattern is scanned over the entire surface of the object to be examined, the linear projection pattern projected onto the object is imaged from an angle different from the projection direction. Then, the height of the object's surface from a reference plane is calculated for each pixel in the longitudinal direction of the linear projection pattern using the principle of triangulation or the like, and the three-dimensional shape of the object's surface is determined.

[0060] In addition, as a three-dimensional measuring machine constituting the measurement system 400, a device with a configuration similar to that of the optical probe disclosed in U.S. Patent No. 7,009,717 can also be used. This optical probe consists of two or more optical groups and includes two or more field directions and two or more projection directions. Each optical group includes one or more field directions and one or more projection directions, with at least one field direction and at least one projection direction differing between optical groups, and the data obtained by the field directions is generated only from patterns projected by the projection directions of the same optical group.

[0061] The measurement system 400 may include, in place of, or in addition to, the three-dimensional measuring machine 401 described above, a mark detection system 56 (see Figure 11) for optically detecting alignment marks. The mark detection system 56 can, for example, detect alignment marks formed on a workpiece. The control device 600 calculates the position and orientation of the workpiece (or table 12) by accurately detecting the center positions (three-dimensional coordinates) of at least three alignment marks using the mark detection system 56. Such a mark detection system 56 may be configured to include, for example, a stereo camera. The mark detection system 56 may also optically detect at least three alignment marks that have been pre-formed on the table 12.

[0062] In this embodiment, the control device 600 scans the surface (target surface) of the workpiece W using the three-dimensional measuring machine 401 as described above and acquires its surface shape data. The control device 600 then uses this surface shape data to perform least-squares processing and associates the three-dimensional position and orientation of the target surface on the workpiece with respect to the table coordinate system. Here, including during the measurement of the object under test (workpiece W) as described above, the position of the table 12 in the six degrees of freedom directions is managed by the control device 600 on the table coordinate system. Therefore, after the three-dimensional position and orientation of the workpiece are associated with the table coordinate system, including during additional processing by three-dimensional molding, the control of the position (i.e., position and orientation) of the workpiece W in the six degrees of freedom directions can all be performed by open-loop control of the table 12 according to the table coordinate system.

[0063] Figure 4 shows the beam fusion system 500 together with the table 12 on which the workpiece W is mounted. As shown in Figure 4, the beam fusion system 500 includes a light source system 510, a beam irradiation unit 520 that emits a beam, a material processing unit 530 that supplies powdered fusion material, and a water shower nozzle 540 (not shown in Figure 4, see Figure 11). Note that the beam fusion system 500 does not necessarily have to include the water shower nozzle 540.

[0064] As shown in Figure 5, the light source system 510 includes a light source unit 60, a light guide fiber 62 connected to the light source unit 60, a double fly-eye optical system 64 positioned on the exit side of the light guide fiber 62, and a condenser lens system 66.

[0065] The light source unit 60 comprises a housing 68 and a plurality of laser units 70 housed inside the housing 68 and arranged in a matrix parallel to each other. As the laser units 70, various lasers that perform pulsed or continuous wave oscillation can be used, such as carbon dioxide lasers, Nd:YAG lasers, fiber lasers, or GaN-based semiconductor lasers.

[0066] The light guide fiber 62 is a fiber bundle composed of a large number of optical fiber strands randomly bundled together, and has a plurality of entrance ports 62a individually connected to the exit ends of a plurality of laser units 70, and an exit section 62b having a number of exit ports greater than the number of entrance ports 62a. The light guide fiber 62 receives the plurality of laser beams (hereinafter abbreviated as "beams" as appropriate) emitted from each of the plurality of laser units 70 through each entrance port 62a and distributes them to a plurality of exit ports, and emits at least a portion of each laser beam from a common exit port. In this way, the light guide fiber 62 mixes and emits the beams emitted from each of the plurality of laser units 70. As a result, the total output can be increased in proportion to the number of laser units 70 compared to when a single laser unit is used. However, if sufficient output can be obtained with a single laser unit, it is not necessary to use multiple laser units.

[0067] Here, the ejection section 62b has a cross-sectional shape similar to the overall shape of the incident end of the first fly-eye lens system, which constitutes the incident end of the double fly-eye optical system 64 described next, and the ejection ports are provided within its cross-section at a nearly uniform arrangement. For this reason, the light guide fiber 62 also serves as a shaping optical system that shapes the beam mixed as described above so that it resembles the overall shape of the incident end of the first fly-eye lens system.

[0068] The double fly-eye optical system 64 is designed to uniformize the cross-sectional illuminance distribution (cross-sectional intensity distribution) of the beam (illumination light), and consists of a first fly-eye lens system 72, a lens system 74, and a second fly-eye lens system 76, which are sequentially arranged on the beam path (optical path) of the laser beam behind the light guide fiber 62. An aperture is provided around the second fly-eye lens system 76.

[0069] In this case, the incident surface of the first fly-eye lens system 72 and the incident surface of the second fly-eye lens system 76 are optically conjugate to each other. Furthermore, the exit-side focal plane of the first fly-eye lens system 72 (where a surface light source described later is formed), the exit-side focal plane of the second fly-eye lens system 76 (where a surface light source described later is formed), and the pupil plane (entry pupil) PP of the condensing optical system 82 described later are optically conjugate to each other. In this embodiment, the pupil plane (entry pupil) PP of the condensing optical system 82 coincides with the front-side focal plane (see, for example, Figures 4, 6, and 7).

[0070] The beam mixed by the light guide fiber 62 is incident on the first fly-eye lens system 72 of the double fly-eye optical system 64. This forms a surface light source, i.e., a secondary light source consisting of numerous light source images (point light sources), at the exit-side focal plane of the first fly-eye lens system 72. Laser light from each of these numerous point light sources is incident on the second fly-eye lens system 76 via the lens system 74. This forms a surface light source (tertiary light source) at the exit-side focal plane of the second fly-eye lens system 76, in which numerous minute light source images are uniformly distributed within a predetermined shaped region.

[0071] The condenser lens system 66 emits the laser light emitted from the tertiary light source as a beam with a uniform illuminance distribution.

[0072] Furthermore, by optimizing the area of ​​the incident end of the second fly-eye lens system 76 and the focal length of the condenser lens system 66, the beam emitted from the condenser lens system 66 can be considered a parallel beam.

[0073] The light source system 510 of this embodiment includes an illumination uniformization optical system comprising a light guide fiber 62, a double fly-eye optical system 64, and a condenser lens system 66. Using this illumination uniformization optical system, beams emitted from multiple laser units 70 are mixed to generate a parallel beam with a uniform cross-sectional illumination distribution.

[0074] Furthermore, the illumination uniformity optical system is not limited to the configuration described above. For example, an illumination uniformity optical system may be constructed using a rod integrator, a collimator lens system, or the like.

[0075] The light source unit 60 of the light source system 510 is connected to the control device 600, and the control device 600 individually controls the on / off state of the multiple laser units 70 that make up the light source unit 60. This adjusts the amount of light (laser output) of the laser beam irradiated from the beam irradiation unit 520 onto the workpiece W (the target surface above).

[0076] Furthermore, the molding apparatus 100 does not necessarily have to be equipped with a light source unit 60, or a light source unit 60 and an illumination uniformity optical system. For example, a parallel beam having the desired light quantity (energy) and desired illumination uniformity may be supplied to the molding apparatus 100 from an external device.

[0077] As shown in Figure 4, the beam irradiation unit 520 includes a light source system 510, a beam cross-sectional intensity conversion optical system 78 sequentially arranged on the optical path of the parallel beam from the light source system 510 (condenser lens system 66), a mirror array 80 which is a type of spatial light modulator (SLM), and a focusing optical system 82 which focuses the light from the mirror array 80. Here, a spatial light modulator is a general term for an element that spatially modulates the amplitude (intensity), phase, or polarization state of light traveling in a predetermined direction.

[0078] The beam cross-sectional intensity conversion optical system 78 converts the intensity distribution of the cross-section of the parallel beam from the light source system 510 (condenser lens system 66). In this embodiment, the beam cross-sectional intensity conversion optical system 78 converts the parallel beam from the light source system 510 into a donut-shaped (ring-shaped) parallel beam in which the intensity in the region including the center of the cross-section is approximately zero. In this embodiment, the beam cross-sectional intensity conversion optical system 78 is composed of, for example, a convex cone reflector and a concave cone reflector sequentially arranged on the optical path of the parallel beam from the light source system 510. The convex cone reflector has a conical reflective surface on its outer circumferential surface facing the light source system 510, and the concave cone reflector is made of an annular member whose inner diameter is larger than the outer diameter of the convex cone reflector, and has a reflective surface on its inner circumferential surface that faces the reflective surface of the convex cone reflector. In this case, when viewed in any cross-section passing through the center of the concave cone reflector, the reflective surface of the convex cone reflector and the reflective surface of the concave cone reflector are parallel. Therefore, the parallel beam from the light source system 510 is reflected radially by the reflective surface of the convex cone mirror, and this reflected beam is then reflected by the reflective surface of the concave cone mirror, converting it into an annular parallel beam.

[0079] In this embodiment, the parallel beam that passes through the beam cross-sectional intensity conversion optical system 78 is irradiated onto the workpiece via the mirror array 80 and the focusing optical system 82, as described later. By converting the cross-sectional intensity distribution of the parallel beam from the light source system 510 using the beam cross-sectional intensity conversion optical system 78, it is possible to change the intensity distribution of the beam incident on the pupil surface (entry pupil) PP of the focusing optical system 82 from the mirror array 80. Furthermore, by converting the cross-sectional intensity distribution of the parallel beam from the light source system 510 using the beam cross-sectional intensity conversion optical system 78, it is also possible to substantially change the intensity distribution of the beam emitted from the focusing optical system 82 at the exit surface of the focusing optical system 82.

[0080] Furthermore, the beam cross-sectional intensity conversion optical system 78 is not limited to a combination of a convex conical reflector and a concave conical reflector, but may also be configured using a combination of a diffractive optical element, an afocal lens, and a conical axicon system, for example, as disclosed in U.S. Patent Application Publication No. 2008 / 0030852. The beam cross-sectional intensity conversion optical system 78 only needs to convert the cross-sectional intensity distribution of the beam, and various configurations are possible. Depending on the configuration of the beam cross-sectional intensity conversion optical system 78, it is possible to make the intensity of the parallel beam from the light source system 510 less than the intensity in the region including the center of its cross-section (the optical axis of the focusing optical system 82), rather than being nearly zero.

[0081] In this embodiment, the mirror array 80 comprises a base member 80A having a surface on one side that forms a 45-degree angle (π / 4) with respect to the XY and XZ planes (hereinafter referred to as the reference plane for convenience), and, for example, M (=P×Q) mirror elements 81 arranged in a matrix of, for example, P rows and Q columns on the reference plane of the base member 80A. p,q (p=1~P, q=1~Q) and each mirror element 81 p,q The mirror array 80 has a drive unit 87 (not shown in Figure 4, see Figure 11) which includes M actuators (not shown) that individually drive the mirrors. p,q By adjusting the inclination of the element with respect to the reference plane, it is possible to substantially form a large reflective surface parallel to the reference plane.

[0082] Each mirror element 81 of the mirror array 80 p,q For example, each mirror element 81 p,q It is configured to be rotatable around a rotation axis parallel to one of the diagonals, and the inclination angle of its reflective surface relative to the reference plane can be set to any angle within a predetermined angle range. The angle of the reflective surface of each mirror element is detected by a sensor that detects the rotation angle of the rotation axis, such as a rotary encoder 83. p,q (Not shown in Figure 4, see Figure 11) is used for measurement.

[0083] The drive unit 87 includes, for example, an electromagnet or a voice coil motor as an actuator, and individual mirror elements 81 p,qIt is driven by an actuator and operates with very high responsiveness.

[0084] Among the multiple mirror elements that make up the mirror array 80, the mirror element 81 illuminated by the annular parallel beam from the light source system 510 p,q Each of these emits a reflected beam (parallel beam) in a direction corresponding to the inclination angle of its reflective surface and directs it into the focusing optical system 82 (see Figure 6). The reasons for using the mirror array 80 and directing an annular parallel beam into the mirror array 80 will be explained later, but it is not necessary to make it annular. The cross-sectional shape (cross-sectional intensity distribution) of the parallel beam incident on the mirror array 80 may be different from an annular shape, and the beam cross-sectional intensity conversion optical system 78 may not be provided.

[0085] The focusing optical system 82 is a low-aberration optical system with a high numerical aperture (NA) of, for example, 0.5 or more, preferably 0.6 or more. Because the focusing optical system 82 has a large aperture, low aberration, and high NA, it can focus multiple parallel beams from the mirror array 80 onto the rear focal plane. As will be described in detail later, the beam irradiation unit 520 can focus the beam emitted from the focusing optical system 82 into, for example, a spot or slit shape. Furthermore, since the focusing optical system 82 is composed of one or more large-diameter lenses (Figure 4, etc., typically shows one large-diameter lens), the area of ​​incident light can be increased, thereby allowing for the capture of a larger amount of light energy compared to when a focusing optical system with a small numerical aperture (NA) is used. Therefore, the beam focused by the focusing optical system 82 according to this embodiment is extremely sharp and has a high energy density, which directly leads to improved processing accuracy in additive manufacturing.

[0086] In this embodiment, as will be described later, the case in which the beam and the workpiece W having the target surface TAS at its upper end are scanned in the scanning direction (scanning direction) while the table 12 is moved in a scanning direction parallel to the XY plane (in Figure 4, the Y-axis direction as an example) is manufactured (processing). It goes without saying that during manufacturing, the table 12 may be moved in at least one of the X-axis direction, Z-axis direction, θx direction, θy direction, and θz direction while the table 12 is moving in the Y-axis direction. Furthermore, as will be described later, the powdered manufacturing material (metal material) supplied by the material processing unit 530 is melted by the energy of the laser beam. Therefore, as mentioned above, if the total amount of energy taken in by the focusing optical system 82 increases, the energy of the beam emitted from the focusing optical system 82 increases, and the amount of metal that can be melted per unit time increases. By increasing the supply amount of manufacturing material and the speed of the table 12 accordingly, the throughput of the manufacturing process by the beam manufacturing system 500 can be improved.

[0087] However, even if the total output of the laser can be greatly increased by the method described above, in reality, it is not possible to make the scanning operation of the table 12 infinitely fast, and therefore it is not possible to achieve a throughput that fully utilizes the laser power. To solve this, in the molding apparatus 100 of this embodiment, as will be described later, a slit-shaped beam irradiation area (hereinafter referred to as a single-line area (see the symbol LS in Figure 9(B))) is formed on a predetermined surface (hereinafter referred to as the molding surface) MP (see, for example, Figures 4 and 9(A)) where the target surface TAS to be molded should be aligned, rather than a spot-shaped beam irradiation area, and molding (processing) can be performed while relatively scanning the workpiece W in a direction perpendicular to its longitudinal direction with respect to the beam (hereinafter referred to as the single-line beam) that forms the single-line area LS. As a result, a significantly larger area (for example, several to tens of times larger) can be processed at once compared to when scanning the workpiece with a spot-shaped beam. As will be described later, in this embodiment, the above-mentioned molding surface MP is the rear focal plane of the focusing optical system 82 (see, for example, Figures 4 and 9(A)), but the molding surface may be a plane in the vicinity of the rear focal plane. Also, in this embodiment, the molding surface MP is perpendicular to the optical axis AX on the exit side of the focusing optical system 82, but it does not have to be perpendicular.

[0088] As a method for setting or changing the beam intensity distribution on the fabrication surface MP (for example, the method for forming a single-line region as described above), one can employ a method of controlling the incident angle distribution of multiple parallel beams incident on the focusing optical system 82. In a lens system that focuses parallel light to a single point, such as the focusing optical system 82 of this embodiment, the focusing position on the rear focal plane (focusing plane) is determined by the incident angle of the parallel beam LB (see, for example, Figures 4 and 6) at the pupil plane (entry pupil) PP. Here, the angle of incidence is determined by a. the angle α (0≦α<90 degrees (π / 2)) that the parallel beam incident on the pupil plane PP of the focusing optical system 82 makes with respect to an axis parallel to the optical axis AX of the focusing optical system 82, and b. the angle β (0≦β<360 degrees (2π)) on the reference axis (for example, the X axis (X≧0)) in the two-dimensional Cartesian coordinate system (X,Y) when a two-dimensional Cartesian coordinate system (X,Y) is set with a point on the optical axis AX as the origin and perpendicular to the optical axis AX on the pupil plane PP (XY coordinate plane). For example, a beam incident perpendicularly (parallel to the optical axis) to the pupil plane PP of the focusing optical system 82 will focus on the optical axis AX, and a beam slightly inclined relative to the focusing optical system 82 (relative to the optical axis AX) will focus at a position slightly off from the optical axis AX. Using this relationship, the parallel beam from the light source system 510 When the beam is reflected and incident on the focusing optical system 82, by appropriately distributing the incident angles (incidence directions) of the multiple parallel beams LB incident on the pupil plane PP of the focusing optical system 82, it is possible to arbitrarily change at least one of the beam intensity distributions within the fabrication surface MP, such as the position, number, size, and shape of the irradiation area on the fabrication surface MP. Therefore, for example, a single-line area, a triple-row area, a missing single-line area (see Figure 10), etc. can be easily formed, and it is also easy to form a spot-shaped irradiation area. Here, the incident angle (incidence direction) has been explained using angles α and β, but it goes without saying that there are various ways to express the incident angle (incidence direction), and the control of the incident angle (incidence direction) of the parallel beam incident on the pupil plane PP is not limited to controlling it using angles α and β as parameters.

[0089] Note that the condenser optical system 82 of the present embodiment is configured such that its pupil plane (entrance pupil) PP coincides with the front focal plane. Therefore, by changing the incident angles of the plurality of parallel beams LB using the mirror array 80, the condensing positions of the plurality of parallel beams LB can be accurately and easily controlled. However, the pupil plane (entrance pupil) of the condenser optical system 82 does not necessarily have to coincide with the front focal plane.

[0090] Further, if the shape and size of the irradiation region formed on the shaping surface are not made variable, a solid mirror having a desired shape can be used to control the incident angle of one parallel beam incident on the pupil plane of the condenser optical system 82, thereby changing the position of the irradiation region.

[0091] However, when performing additional processing (shaping) on the workpiece, the region of the target surface on which the target portion of the shaping is set is not always a flat surface. That is, relative scanning of a single-character beam is not always possible. In the vicinity of the contour edge of the workpiece or in the vicinity of the boundary between the solid region and the hollow region, the boundary is inclined, narrow, or has a radius, making it difficult to apply relative scanning of a single-character beam. For example, with a wide brush, it is difficult to cover such places, so a brush with a narrow width or a thin pencil corresponding thereto is required. That is, it is desired to be able to freely use the wide brush and the thin pencil in real time and continuously as needed. Similarly, in the vicinity of the contour edge of the workpiece or in the vicinity of the boundary between the solid region and the hollow region, there is a demand to change the width of the scanning direction (relative movement direction) of the beam irradiation region, or to change the size (e.g., the length of a single-character beam), the number, or the position (the position of the beam irradiation point) of the irradiation region.

[0092] Therefore, in the present embodiment, the mirror array 80 is adopted, and the control device 600 controls each mirror element 81 p,qBy operating with very high response, the incident angles of multiple parallel beams LB incident on the pupil surface PP of the focusing optical system 82 are controlled. This sets or changes the beam intensity distribution on the build surface MP. In this case, the control device 600 can change at least one of the beam intensity distribution on the build surface MP, such as the shape, size, and number of beam irradiation areas, during the relative movement of the beam and the target surface TAS (the surface on which the target area TA for build is set, and in this embodiment, the surface on the workpiece W). In this case, the control device 600 can change the beam intensity distribution on the build surface MP continuously or intermittently. For example, it is also possible to continuously or intermittently change the width of the linear region in the relative movement direction during the relative movement of the beam and the target surface TAS. The control device 600 can also change the beam intensity distribution on the build surface MP according to the relative position of the beam and the target surface TAS. The control device 600 can also change the beam intensity distribution on the build surface MP according to the required build accuracy and throughput.

[0093] Furthermore, in this embodiment, the control device 600 controls the rotary encoder 83 described above. p,q By using this method to detect the state of each mirror element (in this case, the tilt angle of the reflective surface), the state of each mirror element is monitored in real time, allowing for precise control of the tilt angle of the reflective surface of each mirror element in the mirror array 80.

[0094] As shown in Figure 7, the material processing unit 530 includes a nozzle unit 84 having a nozzle member (hereinafter abbreviated as nozzle) 84a provided below the ejection surface of the focusing optical system 82, a material supply device 86 connected to the nozzle unit 84 via piping 90a, and a plurality of powder cartridges 88A and 88B, respectively, connected to the material supply device 86 via piping. Figure 7 shows the portion below the focusing optical system 82 in Figure 4 as viewed from the -Y direction.

[0095] The nozzle unit 84 includes a nozzle 84a that extends in the X-axis direction below the focusing optical system 82 and has at least one supply port for supplying the molding material powder, and a pair of support members 84b and 84c that support both longitudinal ends of the nozzle 84a and whose upper ends are connected to the housing of the focusing optical system 82. One end (lower end) of the material supply device 86 is connected to one of the support members 84b via a pipe 90a, and a supply passage is formed inside that connects the pipe 90a and the nozzle 84a. In this embodiment, the nozzle 84a is positioned directly below the optical axis of the focusing optical system 82, and a plurality of supply ports, which will be described later, are provided on its lower surface (bottom surface). Note that the nozzle 84a does not necessarily have to be positioned on the optical axis of the focusing optical system 82, and may be positioned slightly offset to one side in the Y-axis direction from the optical axis.

[0096] Piping 90b and 90c are connected to the other end (upper end) of the material supply device 86 as supply routes to the material supply device 86, and powder cartridges 88A and 88B are connected to the material supply device 86 via piping 90b and 90c, respectively. One powder cartridge 88A contains powder of a first molding material (e.g., titanium). The other powder cartridge 88B contains powder of a second molding material (e.g., stainless steel).

[0097] In this embodiment, the molding apparatus 100 is equipped with two powder cartridges to supply two types of molding materials to the material supply device 86, but the molding apparatus 100 may be equipped with only one powder cartridge.

[0098] The supply of powder from powder cartridges 88A and 88B to the material supply device 86 may be provided by having each of the powder cartridges 88A and 88B have a function to forcibly supply powder to the material supply device 86. However, in this embodiment, the material supply device 86 has a function to switch between piping 90b and 90c, as well as a function to suck powder from either powder cartridge 88A or 88B using vacuum. The material supply device 86 is connected to the control device 600 (see Figure 11). During molding, the control device 600 switches between piping 90b and 90c using the material supply device 86, and powder of the first molding material (e.g., titanium) from powder cartridge 88A and powder of the second molding material (e.g., stainless steel) from powder cartridge 88B are selectively supplied to the material supply device 86. From the material supply device 86, powder of either molding material is supplied to the nozzle 84a via piping 90a. Furthermore, by changing the configuration of the material supply device 86, it is also possible to simultaneously supply the first molding material from powder cartridge 88A and the second molding material from powder cartridge 88B to the material supply device 86 when necessary, and to supply a mixture of the two molding materials to the nozzle 84a via the piping 90a. In addition, a nozzle that can be connected to powder cartridge 88A and another nozzle that can be connected to powder cartridge 88B are provided below the light-gathering optical system 82, and powder may be supplied from either one of the nozzles or from both nozzles during molding.

[0099] Furthermore, the control device 600 can adjust the amount of molding material supplied per unit time from the powder cartridges 88A and 88B to the nozzle 84a via the material supply device 86. For example, the amount of molding material supplied per unit time to the nozzle 84a via the material supply device 86 can be adjusted by adjusting the amount of powder supplied from at least one of the powder cartridges 88A and 88B to the material supply device 86. For example, the amount of molding material supplied per unit time to the nozzle 84a can be adjusted by adjusting the level of vacuum used for supplying powder from the powder cartridges 88A and 88B to the material supply device 86. Alternatively, the amount of molding material supplied per unit time to the nozzle 84a can be adjusted by providing a valve that adjusts the amount of powder supplied from the material supply device 86 to the piping 90a.

[0100] Although not shown in Figure 7, in reality, the lower (bottom) surface of the nozzle 84a has multiple, for example, N supply ports 91, as shown in Figure 8. i (i=1~N) are formed at equal intervals in the X-axis direction, and each supply port 91 i The opening / closing member 93 i It can be opened and closed individually by [this method]. Note that in Figure 8, for illustrative purposes, the supply port 91 i In this example, 12 supply ports are shown, and both are illustrated to show the relationship between the supply port and the opening / closing member. However, in reality, more than 12 supply ports are formed, and the partitions between adjacent supply ports are narrower. However, the number of supply ports can be any number, as long as they are arranged along almost the entire length of the nozzle 84a in the longitudinal direction. For example, the supply port may be a single slit-shaped opening that extends almost the entire length of the nozzle 84a in the longitudinal direction.

[0101] Opening / closing member 93 i The k-th opening / closing member 93 is shown in Figure 8. k As typically shown with arrows, it is slidable in the +Y and -Y directions, and the supply port 91 i Opens and closes. Opening / closing member 93 iThis mechanism is not limited to sliding drive; it may also be configured to rotate in the tilt direction around one end.

[0102] Each opening / closing member 93 i The beam is driven and controlled by the control device 600 via an actuator (not shown). The control device 600 controls multiple supply ports 91, for example, N ports, depending on the setting (or modification) of the beam intensity distribution on the build surface, such as the shape, size, and arrangement of the beam irradiation area formed on the build surface. i Each of these, each opening / closing member 93 i The opening and closing is controlled using this. This controls the supply operation of the molding material by the material processing unit 530. In this case, the control device 600 controls the opening and closing of multiple supply ports 91 i At least one of the supply ports is selected, and the opening / closing member 93 closes the selected at least one supply port. i Only the opening control is performed, for example, by driving in the -Y direction. Therefore, in this embodiment, there are multiple, for example, N supply ports 91 i Only a portion of these sources can supply the molding materials.

[0103] Furthermore, the control device 600 controls the amount of molding material supplied per unit time to the nozzle 84a via the aforementioned material supply device 86, and also controls the opening and closing of arbitrary opening and closing members 93 i At least one of the following is opening and closing control using the opening and closing member 93 i The supply port 91 is opened and closed. i It is also possible to adjust the amount of material supplied per unit time from the molding process. The control device 600 can adjust any supply port 91 according to the setting (or change) of the beam intensity distribution on the molding surface, such as the shape, size, and arrangement of the beam irradiation area formed on the molding surface. i The amount of molding material supplied per unit time from each supply port 91 is determined. The control device 600 determines, for example, the width of the scanning direction of the single character area described above, for each supply port 91 i Determine the amount supplied per unit time from [source].

[0104] Note that each opening / closing member 93 i Therefore, each supply port 91 iThe opening degree may be configured to be adjustable. In this case, the control device 600 controls, for example, the width of the single character area in the scanning direction according to each opening / closing member 93 i Alternatively, the opening degree of each supply port may be adjusted accordingly.

[0105] In addition, at least one supply port for supplying the molding material powder may be movable. For example, a slit-shaped supply port extending in the X-axis direction may be formed on the lower surface of the nozzle 84a, and the nozzle 84a may be configured to be movable in at least one of the X-axis and Y-axis directions relative to a pair of support members 84b and 84c, and the control device 600 may move the nozzle 84a with the supply port formed on its lower surface in response to a change in the beam intensity distribution on the molding surface, i.e., a change in the shape, size, and position of the beam irradiation area. The nozzle 84a may also be movable in the Z-axis direction.

[0106] Alternatively, the nozzle 84a may consist of a main body and at least two movable members that are movable relative to the main body, for example, in the XY plane in at least one of the X-axis and Y-axis directions, and have a supply port formed on their bottom surface, and the control device 600 may move at least a part of the movable members in accordance with a change in the beam intensity distribution on the build surface. In this case as well, at least a part of the movable members may be movable in the Z-axis direction.

[0107] Furthermore, the supply port may be configured so that one of the supply ports is relatively movable to another. Alternatively, for example, the Y-axis position of one supply port may be different from the Y-axis position of another supply port. Alternatively, the Z-axis position of one supply port may be different from the Z-axis position of another supply port.

[0108] Furthermore, the movement of at least one supply port may be performed not only in accordance with the setting or modification of the beam intensity distribution, but also for other purposes.

[0109] As mentioned above, the nozzle 84a has multiple supply ports 91 iThese are arranged at equal intervals along the entire length of the nozzle 84a in the X-axis direction, perpendicular to the optical axis of the focusing optical system 82, and adjacent to the supply port 91 i There is only a small gap between them. Therefore, as shown by the black arrows in Figure 9(A), the nozzle 84a has multiple supply ports 91 i If powdered molding material PD is supplied directly downward from each of these nozzles along the Z-axis parallel to the optical axis AX of the focusing optical system 82, the molding material PD will be supplied to the aforementioned linear region LS (irradiation area of ​​the linear beam) directly below the optical axis AX of the focusing optical system 82. In this case, the molding material PD from the nozzle 84a can be supplied using the weight of the molding material PD itself, or by spraying it with a small amount of spraying pressure. Therefore, complex mechanisms such as a gas flow generation mechanism to guide the supply of the molding material, as would be required when supplying the molding material from an oblique direction to the surface to be molded, are unnecessary. Furthermore, being able to supply the molding material perpendicularly at close range to the workpiece, as in this embodiment, is extremely advantageous in ensuring processing accuracy during molding.

[0110] Furthermore, a gas supply port may be provided in the nozzle 84a. The gas supplied from this gas supply port may be used to guide the supply of the molding material, or it may be used for other purposes, such as providing gas that contributes to the molding process.

[0111] In this embodiment, since an annular parallel beam is irradiated onto the mirror array 80, the reflected beam from the mirror array 80 is incident on a partial region (a partial region with a large NA) near the periphery of the focusing optical system 82, and is focused onto the fabrication surface MP of the focusing optical system 82 (which in this embodiment coincides with the rear focal plane of the focusing optical system 82) via the peripheral region away from the optical axis of the terminal lens located at the exit end of the focusing optical system 82, i.e., the exit end of the beam irradiation section 520 (see Figure 4). In other words, a single-line beam is formed by light passing through the same peripheral region of the focusing optical system 82. For this reason, it is possible to form a high-quality beam spot compared to the case where light from separate optical systems is focused onto the same region to form a beam spot (laser spot). Furthermore, in this embodiment, it is possible to limit the irradiation of the beam to the nozzle 84a provided below the center of the exit surface (lower end surface) of the focusing optical system 82. Therefore, in this embodiment, it becomes possible to utilize all of the reflected beam from the mirror array 80 for spot formation, and it becomes unnecessary to provide a light-shielding member or the like to limit the beam from irradiating the nozzle 84a in the portion of the focusing optical system 82 corresponding to the nozzle 84a on the incident surface side. For this reason, the mirror array 80 is illuminated by an annular parallel beam.

[0112] Furthermore, the optical element located at the exit end of the focusing optical system 82 only needs to have an optical surface formed in a region away from the optical axis of at least its exit-side surface, so that the beam can be focused onto the fabrication surface (rear focal plane) through this optical surface. Therefore, in the region including the optical axis, at least one of the exit surface and the incident surface of this optical element may be a plane perpendicular to the optical axis of the focusing optical system 82, or a hole may be formed in the region including the optical axis. The optical element located at the exit end of the focusing optical system 82 may also be configured as a donut-shaped focusing lens with a hole in the central region including the optical axis.

[0113] Furthermore, in order to limit the beam incident from the focusing optical system 82 to the nozzle 84a, a limiting member 85, for example, shown by the dashed line in Figure 7, may be provided on the incident surface side (e.g., pupil surface PP) of the focusing optical system 82. The limiting member 85 restricts the incident beam from the focusing optical system 82 to the nozzle 84a. A light-shielding member may be used as the limiting member 85, or a light-reducing filter may be used. In this case, the parallel beam incident on the focusing optical system 82 may be a parallel beam with a circular cross-section, or a parallel beam with an annular cross-section. In the latter case, since the beam does not irradiate the limiting member 85, it becomes possible to utilize all of the reflected beam from the mirror array 80 for spot formation.

[0114] It is not necessarily required to completely shield the beam incident from the focusing optical system 82 to the nozzle 84a. However, in order to prevent the beam from the focusing optical system 82 from entering the nozzle 84a, the beam may be emitted only from separate peripheral regions (e.g., two arc regions) on both sides of the optical axis with respect to the Y-axis direction of the emission surface of the terminal lens of the focusing optical system 82.

[0115] The water shower nozzle 540 (see Figure 11) is used during the hardening process. The water shower nozzle 540 has a supply port for supplying coolant (cooling water) and sprays the coolant onto the object to be cooled. The water shower nozzle 540 is connected to the control device 600 (see Figure 11). During hardening, the control device 600 controls the light source unit 60 to adjust the thermal energy of the beam from the beam irradiation unit 520 to a value appropriate for hardening. The control device 600 then irradiates the surface of the workpiece with the beam to raise the temperature, and then sprays coolant onto the high-temperature area via the water shower nozzle 540 to rapidly cool it, thereby performing hardening. In this case, it is also possible to perform the hardening process simultaneously with additive processing of the workpiece by three-dimensional molding. When performing the hardening process simultaneously with additive processing, it is desirable to use a metal with good hardenability as the molding material.

[0116] In this embodiment, during additional processing of the workpiece, as shown in Figure 4 and Figure 9(A), which shows an enlarged view of the area within circle A in Figure 4, the beam (shown as beams LB11 and LB12 for convenience in Figure 9(A)) passing near the periphery of the focusing optical system 82 and through the optical paths on the +Y and -Y sides of the nozzle 84a (forward and backward in the scanning direction of the workpiece W (table 12)) is focused directly below the nozzle 84a, forming a linear region LS on the build surface with its longitudinal direction in the X-axis direction (the direction perpendicular to the plane of the paper in Figure 9(A)) (see Figure 9(B)). The multiple supply ports 91 of the nozzle 84a supply the linear beam that forms this linear region LS. i The powdered molten material PD is supplied via the nozzle 84a along the Z-axis parallel to the optical axis AX of the focusing optical system 82 (along the XZ plane including the optical axis AX). This forms a linear molten pool WP extending in the X-axis direction directly below the nozzle 84a. The formation of this molten pool WP is performed while scanning the table 12 in the scanning direction (the +Y direction in Figure 9(A)). This makes it possible to form a bead (molten and solidified metal) BE of a predetermined width along the length of the linear beam (molten pool WP) in the longitudinal direction (X-axis direction). The beams LB11 and LB12 shown in Figure 9(A) are different mirror elements 81 of the mirror array 80. p.q These may be separate parallel beams that are reflected and incident on the pupil plane PP of the focusing optical system 82 at different incident angles, or they may be part of the same parallel beam, for example, a parallel beam with an annular cross-section.

[0117] When multiple parallel beams are incident on the pupil plane PP of the focusing optical system 82, for example, if the incident angles of the multiple parallel beams LB incident on the focusing optical system 82 are adjusted so that the width of the single beam in the X-axis direction, or the width in the Y-axis direction, or both, gradually narrows without reducing the number of parallel beams LB incident on the focusing optical system 82, the beam focusing density (energy density) will increase. Accordingly, by increasing the supply amount of powder (forming material) per unit time and increasing the scanning speed of the target surface TAS, it becomes possible to maintain a constant thickness of the formed bead BE layer and maintain a high level of throughput. However, the thickness of the formed bead BE layer can also be maintained at a constant level using other adjustment methods, not limited to this method. For example, the laser output (energy amount of the laser beam) of at least one of the multiple laser units 70 may be adjusted according to the width of the single beam in the X-axis direction, or the width in the Y-axis direction, or both, or the number of parallel beams LB incident on the focusing optical system 82 from the mirror array 80 may be changed. In this case, the throughput is somewhat lower compared to the adjustment method described above, but the adjustment is simpler.

[0118] Figure 11 shows a block diagram illustrating the input / output relationships of the control device 600, which forms the core of the control system for the molding apparatus 100. The control device 600 includes a workstation (or microcomputer), etc., and provides comprehensive control for all components of the molding apparatus 100.

[0119] The basic function of the molding apparatus 100 according to this embodiment, configured as described above, is to add a desired shape to an existing part (workpiece) by three-dimensional molding. The workpiece is fed into the molding apparatus 100, and after the desired shape is accurately added, it is discharged from the molding apparatus 100. At this time, the actual shape data of the added shape is sent from the apparatus to an external device, such as a higher-level device. The series of operations performed by the molding apparatus 100 are roughly as follows.

[0120] First, when the table 12 is in a predetermined loading / unloading position, the workpiece W is loaded onto the table 12 by the workpiece transport system 300. At this time, the table 12 is in the aforementioned reference state (Z, θx, θy, θz) = (Z0, 0, 0, 0), and its XY position matches the X and Y positions of the slider 10 measured by the position measurement system 28.

[0121] Next, the control device 600 moves the table 12, on which the workpiece W is mounted, downwards from the measurement system 400. The movement of the table 12 is performed by the control device 600 controlling the planar motor 26 based on the measurement information from the position measurement system 28 to drive the slider 10 on the base BS in the X-axis direction (and Y-axis direction). During this movement, the table 12 maintains the aforementioned reference state.

[0122] Next, the control device 600 uses the measurement system 400 to measure the positional information (shape information in this embodiment) of at least a portion of the target surface TAS on the workpiece W on the table 12 in a reference state within three-dimensional space. From this point onward, based on these measurement results, the position of the target surface TAS on the workpiece W in the six degrees of freedom directions can be managed by open-loop control on the table coordinate system (reference coordinate system).

[0123] Next, the control device 600 moves the table 12, on which the workpiece W has been mounted after the measurement of shape information of at least a portion of the target surface TAS has been completed, below the beam shaping system 500.

[0124] Next, additive processing is performed on the workpiece on table 12 using three-dimensional modeling to add a shape corresponding to the 3D data. This additive processing is carried out as follows.

[0125] In other words, the control device 600 converts the three-dimensional CAD data of the shape to be added by additive processing (the shape obtained by removing the shape of the workpiece to be processed from the shape of the object to be created after additive processing) into, for example, STL (Stereo Lithography) data as data for three-dimensional modeling, and further generates data for each layer sliced ​​in the Z-axis direction from this three-dimensional STL data. Then, based on the data of each layer, the control device 600 controls the moving system 200 and the beam modeling system 500 to perform additive processing on each layer of the workpiece, repeatedly performing the formation of the aforementioned single-line region and the formation of a linear (slit-shaped) molten pool by supplying modeling material from the nozzle 84a to the single-line beam, while scanning the table 12 in the scanning direction. Here, the position and orientation of the target surface on the workpiece during additive processing are controlled considering the shape information of the target surface measured earlier.

[0126] Here, the above explanation assumes that the target surface (e.g., the top surface) TAS on which the target area TA for additional processing of the workpiece W is set is a plane that is perpendicular to the optical axis of the focusing optical system 82 (a plane parallel to the XY plane) by adjusting the inclination of the table 12, and that the molding is performed with a scanning operation of the table 12. However, the target surface on which the target area for additional processing of the workpiece is set is not necessarily a plane on which a straight beam can be used. Therefore, the molding apparatus 100 according to this embodiment is equipped with a moving system 200 that can arbitrarily set the position of the table 12 on which the workpiece is mounted in the six degrees of freedom directions. Therefore, in such a case, the control device 600 controls the moving system 200 and the beam irradiation unit 520 of the beam molding system 500 based on the three-dimensional shape of the workpiece measured using the measurement system 400, adjusting the width in the X-axis direction of the beam irradiation area on the molding surface MP to such an extent that the target surface (e.g., the top surface) on the workpiece W that is aligned with the molding surface MP can be considered a flat surface that can be further processed within the beam irradiation area on the molding surface MP, while also controlling each opening / closing member 93 of the nozzle 84a i via each supply port 91 iThe opening and closing operation is performed to supply the molding material to the beam irradiating the irradiation area from the required supply port. This allows molding to be performed on the desired area even if the workpiece surface (target surface) is not flat.

[0127] Furthermore, when performing bead layering for fabrication, it is also possible to perform additional processing (bead formation) using a beam with a small width in the X-axis direction of the irradiation area on the fabrication surface to form a relatively large area plane, and then perform additional processing (bead formation) on that plane using a straight beam with a larger width in the X-axis direction of the irradiation area on the fabrication surface. For example, when fabricating on an uneven surface, it is also possible to perform additional processing (bead formation) to fill in depressions using a beam with a small width in the X-axis direction of the irradiation area on the fabrication surface to form a plane, and then perform additional processing (bead formation) on that plane using a straight beam with a larger width in the X-axis direction of the irradiation area on the fabrication surface MP. In such cases, it goes without saying that the fabrication material powder is supplied from one or more supply ports selected according to the change in the size (width) of the beam irradiation area on the fabrication surface MP.

[0128] After the additional processing of the workpiece W is completed, the control device 600 moves the table 12 on which the processed workpiece W is mounted to the aforementioned loading / unloading position.

[0129] Next, the control device 600 instructs the workpiece transport system 300 to unload the workpiece. In response to this instruction, the workpiece transport system 300 removes the processed workpiece W from the table 12 and transports it outside the molding device 100. Then, the control device 600 sets the table 12 of the moving system 200 to its standard state. As a result, the moving system 200 waits in the loading / unloading position, ready to receive the next workpiece.

[0130] As described in detail above, according to the molding apparatus 100 and the molding method performed by the molding apparatus 100 according to this embodiment, the beam intensity distribution within the molding surface MP can be continuously changed as needed, not only before the start of molding due to the relative movement between the beam and the target surface TAS, but also during the relative movement between the beam and the target surface TAS, and can be changed according to the relative position between the target surface TAS and the beam, and according to the required molding accuracy and throughput. As a result, the molding apparatus 100 can form a molded object on the target surface TAS of the workpiece W with high processing accuracy and high throughput, for example, by rapid prototyping.

[0131] Furthermore, in the molding apparatus 100 and the molding method performed by the molding apparatus 100, when performing additional processing (molding) over a relatively large area on a flat target surface TAS, a method is employed in which powdered molding material PD is supplied from the nozzle 84a to the aforementioned single-line beam to form a linear molten pool WP directly below the nozzle 84a, and the formation of this molten pool WP is performed while scanning the table 12 in the scanning direction (+Y direction in Figure 4). With this method, shapes that could not be generated with conventional 3D printers, etc., by making dozens of passes of a spot-shaped beam, as shown in Figure 12(B), can be generated with just a few passes of the table 12 to the single-line beam, as shown in Figure 12(A). According to this embodiment, it is possible to form a molded object on the target surface of a workpiece in a significantly shorter time compared to conventional molding with a spot-shaped beam, which is like a single-stroke molding. In other words, throughput can be improved in this respect as well.

[0132] Furthermore, according to the molding apparatus 100 and the molding method performed with the molding apparatus 100 according to this embodiment, the intensity distribution of the beam within the molding surface of the focusing optical system 82 is changed by changing the inclination angle of the reflective surface of each mirror element of the mirror array 80. As a result of changing the intensity distribution, at least one of the position, number, size, and shape of the beam irradiation area within the molding surface can be easily changed. Therefore, for example, by setting the irradiation area to a spot shape, slit shape (line shape), etc., and performing three-dimensional molding on the target surface of the workpiece using the method described above, it becomes possible to form a highly accurate three-dimensional object.

[0133] Furthermore, the molding apparatus 100 according to this embodiment has a plurality of powder cartridges, for example, two powder cartridges 88A and 88B, each containing powder of a first molding material (e.g., titanium) and powder of a second molding material (e.g., stainless steel). During additive processing (molding), the control device 600 switches the powder supply path, i.e., the piping 90b and 90c, to the nozzle unit 84 using the material supply device 86. As a result, the first molding material (e.g., titanium) powder from powder cartridge 88A and the second molding material (e.g., stainless steel) powder from powder cartridge 88B are supplied to the nozzle unit 84 selectively. Therefore, by simply switching the powder material supplied by the control device 600 according to the part, it is possible to easily create a joint shape of dissimilar materials. Moreover, this switching can be done almost instantaneously. Furthermore, by mixing and supplying dissimilar materials, it is possible to create an "alloy" on the spot, or to change its composition depending on the location or create a gradient.

[0134] In the above embodiment, the beam fusion system 500 formed an irradiation area of ​​a single linear beam (single-line beam), and the case in which the workpiece W was scanned in the scanning direction (for example, the Y-axis direction) relative to the single-line beam was described. However, as mentioned above, the beam fusion system 500 can freely change the beam intensity distribution on the fusion surface MP by appropriately distributing the incidence angles of the multiple parallel beams LB incident on the focusing optical system 82. Therefore, the fusion apparatus 100 can change at least one of the position, number, size, and shape of the beam irradiation area on the fusion surface MP, and as mentioned above, it is possible to form, for example, a single-line area, a triple-line area, a missing single-line area, etc. (see Figure 10) as the beam irradiation area.

[0135] Figure 13 shows, as an example, how additional processing is performed on a workpiece W using three single-line beams, each irradiated onto one of the three single-line regions that make up the aforementioned three-row region. As shown in Figure 13, beams LB11 and LB12, which pass near the periphery of the focusing optical system 82 and through the optical paths in front of and behind the workpiece W (table 12) in the scanning direction relative to the nozzle 84a, are focused directly below the nozzle 84a (or its multiple supply ports), forming a slit-shaped (line-shaped) first single-line region LS1 on the build surface with the X-axis direction (the direction perpendicular to the plane of the paper in Figure 13) as its longitudinal direction. At this time, the target surface TAS, where the target area TA of the workpiece W is set, is aligned with the build surface MP. Furthermore, beams LB21 and LB22, which pass near the periphery of the focusing optical system 82 and take an optical path behind the nozzle 84a in the scanning direction, are focused to form a second single-character region LS2, which extends in the X-axis direction parallel to the first single-character region LS1 and has the same length as the first single-character region LS1, at a predetermined distance behind the first single-character region LS1 in the scanning direction. Also, beams LB31 and LB32, which pass near the periphery of the focusing optical system 82 and take an optical path in front of the nozzle 84a in the scanning direction, are focused to form a third single-character region LS3, which extends in the X-axis direction parallel to the first single-character region LS1 and has the same length as the first single-character region LS1, at a predetermined distance in front of the first single-character region LS1 in the scanning direction. Figure 14 shows the relationship between the three single-character regions LS1, LS2, and LS3 shown in Figure 13 and the scanning direction in the XY plane.

[0136] Note that the beams LB11, LB12, LB21, LB22, LB31, and LB32 shown in Figure 13 are schematic representations, and the optical path of at least one beam incident on each single-letter region, the number of beams, etc., can be set and changed, for example, by controlling the mirror array 80.

[0137] As described above, powdered molding material PD is supplied from nozzle 84a to the first single-character beam (hereinafter referred to as the first single-character beam for convenience) formed by the first single-character region LS1, which is located in the center of the scanning direction of table 12 among the three single-character regions LS1, LS2, and LS3. This forms a linear molten pool WP directly below the multiple supply ports of nozzle 84a, and the formation of this molten pool WP is performed while scanning the workpiece W (table 12) in the scanning direction (the +Y direction in Figure 13).

[0138] The second linear beam (hereinafter referred to as the second linear beam for convenience), which forms the second linear region LS2 located behind the scanning direction (rear in the direction of travel) of the table 12 relative to the first linear region LS1, plays a role in preheating the surface of the workpiece W (target area of ​​the target surface) before the molding process begins (heating it to a suitable temperature). If such preheating is not performed, the large temperature difference between the high-temperature metal molten by the laser beam and the low-temperature workpiece (target surface) causes rapid cooling of the molten metal, resulting in instantaneous solidification and a crumbly mass. This is a major factor in deteriorating the surface accuracy and roughness of the processed surface (surface of the molded area). In contrast, by preheating the surface of the workpiece W (target surface) with the second linear beam, the temperature difference between the molten metal and the workpiece W (target surface) is reduced, slowing down the solidification speed of the molten metal on the workpiece W (target surface). This provides sufficient time for the molten metal to spread and settle on the surface of the workpiece W (target surface) due to surface tension. As a result, excellent surface precision and surface roughness can be achieved.

[0139] A single-line beam (hereinafter referred to as the third single-line beam for convenience) that forms a third single-line region LS3 located in front of the scanning direction (forward in the direction of travel) of the table 12 relative to the first single-line region LS1, for example, has the effect of laser polishing the surface of the molded material (metal material) that has adhered to and solidified on the surface of the workpiece W (target area of ​​the surface), i.e., the surface of the bead BE. While surface polishing with a laser beam is a well-known general technique, the third single-line beam can immediately polish the surface, achieving a level of surface accuracy and roughness that cannot normally be obtained in a single additional processing (molding) step.

[0140] In particular, in the additional processing of the workpiece W shown in Figure 13, the above-mentioned preheating of the surface of the workpiece W (table 12), formation of molten pools and beads on the workpiece, and laser polishing of the formed bead surface can be performed while the workpiece W (table 12) is scanned once in the scanning direction. Note that the second linear beam in the case of Figure 13 may be used for purposes other than preheating. Similarly, the third linear beam may be used for purposes other than laser polishing. For example, three nozzles may be provided corresponding to the arrangement of the first, second, and third linear regions LS1, LS2, and LS3, and three linear pools of a predetermined width may be simultaneously formed on the molding surface of the workpiece W using the first, second, and third linear beams.

[0141] Conversely to Figure 13, if the scanning direction of the workpiece W (table 12) is set in the -Y direction, the third horizontal beam will play the role of heating the surface temperature of the workpiece W to a suitable temperature before the molding process begins, and the second horizontal beam will play the role of laser polishing the surface of the metal material that has adhered to the surface of the workpiece W and solidified.

[0142] In the above explanation, we described a case where, in addition to the irradiation area of ​​the first straight beam used for forming a molten pool on the workpiece (first straight beam region), the irradiation area of ​​the second straight beam used for preheating the surface of the workpiece W (second straight beam region), and the irradiation area of ​​the third straight beam used for laser polishing the formed bead surface (third straight beam region) are formed separately from each other on the fabrication surface. However, for example, the first straight beam region and the second straight beam region may overlap in at least part. Also, at least one of the second straight beam region LS2 and the third straight beam region LS3 may differ from the first straight beam region LS1 in at least one of its shape and size. Furthermore, at least one of the second straight beam and the third straight beam is not necessarily used, and therefore it is not necessary to form at least one of the second straight beam region and the third straight beam region on the fabrication surface.

[0143] Previously, explanations assumed a usage scenario where the thickness controllability of the molten pool (coated layer) was maximized by making the single-character region as thin and sharp as possible, thereby rapidly reducing the energy density of the beam irradiating that region when defocused. However, in this case, the thickness of the coated layer becomes very thin, and when adding layers of the same thickness, the addition process (shaping) must be performed in many separate layers (requiring multiple coats), which is disadvantageous from a productivity standpoint.

[0144] Therefore, considering the balance between the required molding accuracy and throughput, there may be cases where it is desirable to increase the thickness of the coated layer. In such cases, the control device 600 changes the beam intensity distribution within the molding surface according to the required molding accuracy and throughput, specifically each mirror element 81 of the mirror array 80 p,q The width of the single-character region can be slightly increased by controlling the tilt angle. For example, the single-character region LS shown in Figure 15(B) changes to the single-character region LS'. In this way, the change in energy density when defocusing becomes more gradual, and as shown in Figure 15(A), the thickness h of the high-energy area in the vertical direction increases. This allows for a thicker layer to be generated in a single scan, thereby improving productivity.

[0145] As described above, the molding apparatus 100 according to this embodiment is characterized by having numerous advantages and solutions that meet the requirements of actual processing sites, compared to conventional 3D printers for metal.

[0146] In the above embodiment, the case in which a mirror array 80 is used as a spatial light modulator was described. However, instead, a large-area digital mirror device consisting of a large number of Digital Micromirror Devices (DMD®) fabricated by MEMS technology arranged in a matrix may be used. In such a case, it becomes difficult to measure the state of each mirror element (e.g., tilt angle) with an encoder or the like. In such a case, a detection system may be used that irradiates the surface of the large-area digital mirror device with detection light, receives the reflected light from the numerous mirror elements constituting the digital mirror device, and detects the state of each mirror element based on the intensity distribution. In this case, the detection system may detect the state of each of the numerous mirror elements based on image information obtained by capturing an image formed by the digital mirror device with an imaging means.

[0147] In addition, in the molding apparatus 100 according to the above embodiment, the rotary encoder 83 p,q In addition, a detection system 89, shown by dashed lines in Figure 11, may also be used. This detection system 89 may consist of, for example, a number of mirror elements 81 that make up a mirror array 80. p,q The reflected light from is received via a beam splitter placed between the mirror array 80 and the focusing optical system 82, and based on its intensity distribution, each mirror element 81 p,q A detection system can be used to detect the state of [the system]. For example, a system with a configuration similar to that disclosed in U.S. Patent No. 8,456,624 can be used as the detection system.

[0148] Furthermore, in the above embodiment, each mirror element 81 p,qThe example given uses a mirror array 80 of which the inclination angle of the reflective surface with respect to the reference plane can be changed. However, the example is not limited to this, and a mirror array may be adopted in which each mirror element is tiltable with respect to the reference plane and displaceable in a direction perpendicular to the reference plane. Furthermore, each mirror element does not necessarily have to be tiltable with respect to the reference plane. Such a mirror array that is displaceable in a direction perpendicular to the reference plane is disclosed, for example, in U.S. Patent No. 8,456,624. In addition, a type of mirror array may be adopted in which each mirror element is rotatable around two mutually orthogonal axes parallel to the reference plane (i.e., the inclination angle in the two orthogonal directions can be changed). Such a mirror array in which the inclination angle in two orthogonal directions can be changed is disclosed, for example, in U.S. Patent No. 6,737,662. In these cases as well, the state of each mirror element can be detected using the detection system disclosed in U.S. Patent No. 8,456,624.

[0149] Furthermore, detection light is irradiated onto the surface of the mirror array 80, and the numerous mirror elements 81 that constitute the mirror array 80 are detected. p,q A detection system that receives reflected light from the mirrors may be used. Alternatively, as a detection system, sensors that individually detect the tilt angle and spacing of each mirror element relative to the reference plane (base) may be provided on the mirror array (optical device).

[0150] In the above embodiment, the case in which the beam intensity distribution on the build surface is changed by individually controlling the incident angles of multiple parallel beams incident on the pupil of the focusing optical system 82 was described. However, it is not necessary for all incident angles of the multiple parallel beams incident on the pupil of the focusing optical system 82 to be controllable (changeable). Therefore, in cases where the incident angles of parallel beams incident on the focusing optical system 82 are controlled using a mirror array, similar to the above embodiment, it is not necessary for all mirror elements to be able to change the state of their reflective surfaces (at least one of the position and tilt angle of the reflective surface). Also, in the above embodiment, the case in which a mirror array 80 is used to control the incident angles of multiple parallel beams incident on the focusing optical system 82, that is, to change the beam intensity distribution on the build surface was described. However, instead of a mirror array, a spatial light modulator (non-emitting image display element) described below may be used. Examples of transmissive spatial light modulators include not only transmissive liquid crystal displays (LCDs) but also electrochromic displays (ECDs). In addition to the micromirror arrays mentioned above, other examples of reflective spatial light modulators include reflective liquid crystal display elements, electrophoretic displays (EPDs), electronic paper (or electronic ink), and grating light valves. Furthermore, while the above embodiment described the use of a mirror array (a type of spatial light modulator) to change the beam intensity distribution on the fabrication surface, spatial light modulators may be used for other purposes as well.

[0151] Furthermore, as mentioned above, it is desirable for the focusing optical system 82 to have a large aperture, but a focusing optical system with a numerical aperture (NA) smaller than 0.5 may also be used.

[0152] Furthermore, in the above embodiment, the fabrication apparatus 100 may be equipped with a sensor capable of positioning a light-receiving unit at or near the rear focal plane of the focusing optical system 82 in order to manage the beam intensity distribution. For example, it is desirable to mount a CCD image sensor on the table 12 and to use the CCD image sensor to calibrate the beam intensity distribution (intensity distribution within the irradiation area on the fabrication surface) at an appropriate frequency. In this case, the measurement may be taken with the light-receiving unit of the sensor (e.g., the table 12) stationary, or a scan measurement may be performed to receive the beam from the focusing optical system 82 while the light-receiving unit of the sensor (e.g., the table 12) is moving. By performing the measurement while moving the light-receiving unit of the sensor, the influence of a finite number of pixels such as a CCD or mirror array can be eliminated, and correct measurement results can be obtained. In this way, by measuring the beam intensity distribution with a sensor that receives the beam from the focusing optical system 82, it becomes possible to manage the beam intensity distribution while taking into account fluctuating factors such as thermal aberration of the focusing optical system 82. Furthermore, by controlling the mirror array 80 and the like based on the results, the beam intensity distribution at the rear focal plane of the focusing optical system 82 can be precisely set to a desired state.

[0153] In the above embodiment, examples were given of using titanium and stainless steel powders as the molding material. However, it is also possible to use iron powder and other metal powders, as well as non-metallic powders such as nylon, polypropylene, and ABS. Furthermore, the molding apparatus 100 according to the above embodiment can also be applied when using materials other than powder, such as filler wire used for welding. In this case, however, a wire feeding device or the like would be provided instead of the powder supply system, such as a powder cartridge and nozzle unit.

[0154] Furthermore, in the above embodiment, the nozzle 84a has multiple supply ports 91 i The explanation described the case where powdered shaping material PD is supplied from each of the following sources along the Z-axis direction parallel to the optical axis AX of the focusing optical system 82. However, the explanation is not limited to this, and the shaping material (powder) may also be supplied from a direction inclined with respect to the optical axis AX. Furthermore, the shaping material (powder) may also be supplied from a direction inclined with respect to the vertical direction.

[0155] In addition, in the molding apparatus 100 of the above embodiment, the nozzle 84a provided in the material processing unit 530 may have a collection port (suction port) for collecting unmelted powdered molding material, as well as the aforementioned material supply port for molding material.

[0156] Up to this point, we have described an example of adding a shape to an existing workpiece, but the uses of the molding apparatus 100 according to this embodiment are not limited to this. Similar to a normal 3D printer, it is also possible to generate a three-dimensional shape from nothing on the table 12 by molding. In this case, it is nothing more than adding processing to a workpiece that is "nothing". When molding a three-dimensional object on the table 12 in this way, the control device 600 uses the mark detection system 56 (see Figure 11) of the measurement system 400 to optically detect at least three alignment marks that have been formed in advance on the table 12, thereby obtaining positional information in the six degrees of freedom directions of the target surface to be molded on the table 12. Based on this result, the control device 600 can perform three-dimensional molding while controlling the position and orientation of the target surface on the table 12 with respect to the beam (irradiation area).

[0157] In the above embodiment, as an example, a case was described in which the control device 600 controls the components of the mobile system 200, the measurement system 400, and the beam fusion system 500. However, the control device for the fusion system may be configured with multiple hardware components, each including a processing unit such as a microprocessor. In this case, each of the mobile system 200, the measurement system 400, and the beam fusion system 500 may have its own processing unit, or it may be a combination of a first processing unit that controls two of the mobile system 200, the measurement system 400, and the beam fusion system 500, and a second processing unit that controls the remaining system. In either case, each processing unit will be responsible for a part of the functions of the control device 600 described above. Alternatively, the control device for the fusion system may be configured with multiple processing units such as microprocessors and a host computer that comprehensively manages these processing units.

[0158] At least some of the constituent elements of each embodiment described above can be appropriately combined with at least some other constituent elements of each embodiment described above. Some of the constituent elements of each embodiment described above do not need to be used. Furthermore, to the extent permitted by law, all published gazettes and U.S. patent disclosures relating to exposure apparatus, etc., cited in each embodiment described above shall be incorporated into the text. [Industrial applicability]

[0159] As described above, the molding apparatus and molding method according to the present invention are suitable for forming three-dimensional objects. [Explanation of symbols]

[0160] 12...Table, 62...Light guide fiber, 64...Double fly-eye optics, 66...Condenser lens system, 70...Laser unit, 78...Beam cross-sectional intensity conversion optics, 80...Mirror array, 81...Mirror element, 82...Focusing optics, 83...Rotary encoder, 85...Limiting member, 89...Detection system, 91...Supply port, 100...Building device, 200...Movement system, 500...Beam building system, 520...Beam irradiation unit, 530...Material processing unit, 540...Water shower nozzle, 600...Control device, BS...Base, PD...Building material, LS...Single character area, LS1...First single character area, LS2...Second single character area, LS3...Third single character area, MP...Building surface, TA...Target area, TAS...Target surface, W...Workpiece, WP...Molten pool.

Claims

1. A fabrication device for creating three-dimensional objects, A material processing unit equipped with a nozzle member that supplies molding material to the surface to be molded, A beam irradiation unit that irradiates the surface to be fabricated with a beam to form a molten pool on the surface to be fabricated, A moving device that moves the molding surface and the nozzle member relative to each other along the direction of movement, Control device and Equipped with, The nozzle member supplies the molding material from a plurality of material supply ports arranged in a direction intersecting the direction of movement to the beam irradiation position on the molding surface, thereby forming a material supply region extending in the intersecting direction. The material processing unit includes a material supply control member that controls the supply operation of the molding material from the plurality of material supply ports by the control device. Modeling equipment.

2. The molding material is supplied from the nozzle member by pressurized ejection. The molding apparatus according to claim 1.

3. The molding material is supplied using its own weight. The molding apparatus according to claim 1.

4. The molding material from the nozzle member is supplied directly downwards. A molding apparatus according to any one of claims 1 to 3.

5. The nozzle member supplies the molding material from an inclined direction. A molding apparatus according to any one of claims 1 to 3.

6. The nozzle member is equipped with a gas supply port. A molding apparatus according to any one of claims 1 to 5.

7. The nozzle member includes a gas supply port for supplying gas that guides the supply of the molding material. A molding apparatus according to any one of claims 1 to 6.

8. The beam irradiation unit comprises a mirror element into which a beam from a light source is incident, an actuator for changing the tilt angle of the mirror element, and a focusing optical system into which the beam reflected by the mirror element is incident. A molding apparatus according to any one of claims 1 to 7.

9. The actuator changes the angle of incidence of the beam entering the focusing optical system by changing the tilt angle of the mirror element. The molding apparatus according to claim 8.

10. The tilt angle of the mirror element is changed to alter the position of the beam irradiated onto the surface to be fabricated. The molding apparatus according to claim 9.

11. The beam irradiation unit makes the irradiation area on the surface to be molded into a spot shape or a slit shape. The molding apparatus according to claim 10.

12. The beam irradiation unit and the material supply control member change the width of the bead in the direction intersecting the direction of movement. A molding apparatus according to any one of claims 1 to 11.

13. The material supply control member supplies the molding material from one or more material supply ports selected from the plurality of material supply ports. The molding apparatus according to claim 12.

14. The nozzle member is provided with a suction port. A molding apparatus according to any one of claims 1 to 13.

15. The nozzle member is provided with a recovery port for recovering the molding material that was not melted. A molding apparatus according to any one of claims 1 to 14.

16. A method for creating three-dimensional objects, Supplying the molding material from the nozzle member to the surface to be molded, The beam is irradiated onto the surface to be fabricated to form a molten pool on the surface to melt the fabrication material, The molding surface and the nozzle member are moved relative to each other along the direction of movement, Controlling the supply operation of the molding material from a plurality of material supply ports formed on the nozzle member in a direction intersecting the aforementioned direction of movement. Includes, Supplying the molding material from the nozzle member includes supplying the molding material from the nozzle member to the beam irradiation position on the surface to be molded. Modeling method.

17. The molding material is supplied from the nozzle member by pressurized ejection. The molding method according to claim 16.

18. The molding material is supplied using its own weight. The molding method according to claim 16.

19. The molding material from the nozzle member is supplied directly downwards. The molding method according to any one of claims 16 to 18.

20. The nozzle member supplies the molding material from an inclined direction. The molding method according to any one of claims 16 to 18.

21. The nozzle member supplies gas that guides the supply of the molding material. The molding method according to any one of claims 16 to 20.

22. This includes changing the tilt angle of a mirror element into which a beam from a light source is incident, thereby changing the incident angle of the beam incident on the focusing optical system, and thus changing the position of the beam irradiating the surface to be fabricated. The molding method according to any one of claims 16 to 21.

23. The irradiation area on the surface to be molded is made into a spot shape or a slit shape. The molding method according to claim 22.

24. By forming the molten pool and controlling the supply operation, the width of the bead in the direction intersecting the direction of movement is changed. The molding method according to any one of claims 16 to 23.

25. Controlling the supply operation includes selecting one or more material supply ports for supplying the molding material. The molding method according to claim 24.

26. The unmelted molding material is recovered using the recovery port provided in the nozzle member. The molding method according to any one of claims 16 to 25.

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