Molding apparatus and molding method

Abstract

To provide a shaping device and a shaping method for forming a three-dimensional shaped object having improved convenience and economic rationality.SOLUTION: A shaping device includes: a beam shaping system 500 having a beam irradiation section 520 that includes a condensing optical system 82 which emits a beam and a material processing section 530 which supplies a shaping material irradiated by the beam from the beam irradiation section 520; and a controller which, on the basis of 3D data of a three-dimensional shaped object to be formed on a target surface, controls a workpiece movement system and the beam shaping system 500 such that a target portion TA on the target surface is shaped by supplying the shaping material from the material processing section 530 while moving the beam from the beam irradiation section 520 and the target surface TAS on a workpiece W (or a table 12) relative to each other. Further the intensity distribution of the beam in the shaping plane MP facing the emitting surface of the condensing optical system can be modified. Consequently, it becomes possible for three-dimensional shaped objects with excellent processing accuracy to be formed on the target surface.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] The technology to generate 3D (three-dimensional) shapes directly from CAD data is called rapid prototyping (sometimes called 3D printing, additive manufacturing, or direct digital manufacturing, but hereafter, rapid prototyping will be used as a general term), and has contributed to the production of prototypes with an extremely short lead time, mainly for the purpose of confirming the shape. When modeling devices that form three-dimensional objects by rapid prototyping, such as 3D printers, are classified according to the material they handle, they can be broadly divided into those that handle resin and those that handle metal. Unlike resin-made three-dimensional objects, metal three-dimensional objects produced by rapid prototyping are used exclusively as actual parts. In other words, they function not as prototype parts for shape confirmation, but as part of an actual mechanical structure (whether it is a mass-produced product or a prototype). There are two well-known types of existing metal 3D printers (hereafter, abbreviated as M3DP (Metal 3D Printer)): PBF (Powder Bed Fusion) and DED (Directed Energy Deposition).

[0003] In PBF, sintered metal powder is thinly layered on the bed on which the workpiece is placed, and a high-energy laser beam is scanned over it using a galvanometer mirror or similar device, melting and solidifying the areas where the beam hits. When drawing of one layer is completed, the bed is lowered by the thickness of one layer, and sintered metal powder is spread over that area again, and the same process is repeated. In this way, the desired 3D shape is obtained by repeating the process of forming one layer at a time.

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

[0005] DED uses a method in which molten metal material is attached to the workpiece. For example, powdered metal is sprayed near the focal point of a laser beam focused by a condenser lens. The powdered metal is then melted and liquefied by 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 becomes a kind of pen tip, and "lines with thickness" can be drawn one after another on the surface of the workpiece. The desired shape is formed by appropriately moving one of the workpiece and the processing head (laser, 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 in the amount required when needed, eliminating waste and the need to process in the midst of large amounts of excess powder.

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

[0008] In light of this background, there is a strong demand for improving the convenience of machine tools used by modeling devices that form three-dimensional objects, and ultimately improving the economic rationality of manufacturing. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US Patent Application Publication No. 2003 / 0206820 Summary of the Invention [Means for solving the problem]

[0010] According to a first aspect of the present invention, there is provided a modeling apparatus that forms a three-dimensional object on a target surface, the modeling system having a moving system that moves the target surface, a beam modeling system having a beam irradiation unit including a focusing optical system that emits a beam, and a material processing unit that supplies modeling material to be irradiated with the beam from the beam irradiation unit, and a control device that controls the moving system and the beam modeling system based on 3D data of a three-dimensional object to be formed on the target surface so that a target portion on the target surface is modeled by supplying the modeling material from the material processing unit while moving the target surface and the beam from the beam irradiation unit relatively, and the modeling apparatus is capable of changing the intensity distribution of the beam within a specified plane on the exit surface side of the focusing optical system.

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

[0012] This makes it possible to form a three-dimensional object on the target surface with good processing accuracy.

[0013] According to a second aspect of the present invention, there is provided a modeling method for forming a three-dimensional object on a target surface, the modeling method comprising controlling, based on 3D data of a three-dimensional object to be formed on the target surface, the movement of the target surface and at least one of the emission state of the beam from the beam irradiation unit and the supply state of the modeling material, so that a target portion on the target surface is modeled by supplying modeling material to be irradiated with a beam emitted from a beam irradiation unit including a focusing optical system while moving the beam emitted from the beam irradiation unit relative to the target surface, and capable of changing the intensity distribution of the beam within a specified plane on the emission surface side of the focusing optical system.

[0014] This makes it possible to form a three-dimensional object on the target surface with good processing accuracy. [Brief description of the drawings]

[0015] [Figure 1] 1 is a block diagram showing an overall configuration of a molding apparatus according to an embodiment; [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration of a moving system together with a measurement system. [Diagram 3] FIG. 2 is a perspective view showing a moving system on which a workpiece is mounted. [Figure 4] FIG. 2 is a diagram showing the beam shaping system together with a table on which a workpiece is placed. [Diagram 5] FIG. 2 is a diagram showing an example of a configuration of a light source system that constitutes a part of a beam irradiation unit included in the beam shaping system. [Figure 6] 1 is a diagram showing 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 a plurality of mirror elements with respect to a focusing optical system is individually controlled. [Figure 7] 1 shows a material processing section of a beam shaping system together with a focusing optical system. [Figure 8] 1 is a diagram showing a plurality of supply ports formed in a nozzle of a material processing section and opening / closing members for opening and closing each of the plurality of supply ports. FIG. [Figure 9] 9A is an enlarged view of the inside of circle A in FIG. 4, and FIG. 9B is a diagram showing the relationship between the one-character region shown in FIG. 9A and the scanning direction. [Figure 10] 1 is a diagram showing an example of a beam irradiation area formed on a modeling surface. FIG. [Figure 11] 2 is a block diagram showing input / output relationships of a control device that is a central component of a control system of the molding apparatus. FIG. [Figure 12] 12A and 12B are views for explaining one effect of the modeling apparatus according to one embodiment in comparison with the conventional technology. [Figure 13]13 is a diagram for explaining an example of performing additional machining on a workpiece using three single-character beams formed in three single-character regions, respectively. FIG. [Figure 14] FIG. 14 is a diagram showing the relationship between the arrangement of the three character regions shown in FIG. 13 and the scanning direction. [Figure 15] 15(A) and 15(B) are diagrams for explaining an example in which the thickness of the coating layer is increased by slightly increasing the width of the single character region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, one embodiment will be described with reference to Fig. 1 to Fig. 15(B) Fig. 1 shows in block diagram the overall configuration of a molding apparatus 100 according to one embodiment.

[0017] The modeling apparatus 100 is a DED type M3DP. The modeling apparatus 100 can be used to form a three-dimensional object on a table 12, which will be described later, by rapid prototyping, but can also be used to perform additional processing on a workpiece (e.g., an existing part) by three-dimensional modeling. In this embodiment, the latter case of performing additional processing on a workpiece will be mainly described. In actual manufacturing sites, it is common to further repeatedly process parts created by a different manufacturing method, a different material, or a different machine tool to create a desired part, and the requirements for additional processing by three-dimensional modeling are potentially the same.

[0018] The modeling apparatus 100 includes a moving system 200, a measuring system 400, a beam modeling system 500, and a control device 600 that includes these systems and controls the entire modeling apparatus 100. Among these, the measuring system 400 and the beam modeling system 500 are arranged separately in a predetermined direction. In the following description, for convenience, the measuring system 400 and the beam modeling system 500 are assumed to be arranged separately in the X-axis direction (see FIG. 2) described later.

[0019] Fig. 2 shows a schematic configuration of the moving system 200 together with the measurement system 400. Fig. 3 shows a perspective view of the moving system 200 on which the workpiece W is mounted. In the following description, the left-right direction in the plane of Fig. 2 is defined as the Y-axis direction, the direction perpendicular to the plane of the plane is defined as the X-axis direction, the direction perpendicular to the X-axis and Y-axis is defined as the Z-axis direction, and the directions of rotation (tilt) about the X-axis, Y-axis, and Z-axis are defined as the θx, θy, and θz directions, respectively.

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

[0021] The moving system 200 includes a Stewart platform type parallel link mechanism with six degrees of freedom as an example of a driving mechanism for changing the position and attitude of the table. Note that the moving system 200 is not limited to a mechanism that can drive the table in six degrees of freedom.

[0022] The moving system 200 (excluding the stator of the planar motor described later) is placed on a base BS that is installed on a floor F so that its upper surface is approximately parallel to the XY plane, as shown in Fig. 2. As shown in Fig. 3, the moving system 200 has a slider 10 that is a regular hexagon in a plan view and constitutes a base platform, a table 12 that constitutes an end effector, six extendable rods (links) 141-146 that connect the slider 10 and the table 12, and telescopic mechanisms 161-166 (not shown in Fig. 3, see Fig. 11) that are provided on the rods 141-146 and extend or retract the rods. The moving system 200 is structured so that the movement of the table 12 can be controlled with six degrees of freedom in a three-dimensional space by independently adjusting the lengths of the rods 141-146 with the telescopic mechanisms 161-166. The moving system 200 is equipped with a Stewart platform type six-degree-of-freedom parallel link mechanism as a drive mechanism for the table 12, and is therefore characterized by high precision, high rigidity, large support force, and easy inverse kinematics calculation.

[0023] In the modeling apparatus 100 according to this embodiment, in order to form a modeled object of a desired shape on the workpiece during additional processing or the like on the workpiece, the position and posture of the workpiece (table 12) are controlled relative to the beam modeling system 500, more specifically, the beam from the beam irradiation unit described below. In principle, the beam from the beam irradiation unit may be movable, or both the beam and the workpiece (table) may be movable. As described below, the beam modeling system 500 has a complex configuration, so it is simpler to move the workpiece.

[0024] Here, the table 12 is made of a plate member shaped like an equilateral triangle with each apex cut off. A workpiece W to be subjected to additional processing is placed on the upper surface of the table 12. The table 12 is provided with a chuck mechanism 13 (not shown in FIG. 3, see FIG. 11) for fixing the workpiece W. As the chuck mechanism 13, for example, a mechanical chuck or a vacuum chuck is used. Note that the shape of the table 12 is not limited to that shown in FIG. 3, and may be any shape such as a rectangular plate or a disk.

[0025] 3, both ends of each of the rods 141 to 146 are connected to the slider 10 and the table 12, respectively, via the universal joint 18. The rods 141 and 142 are connected to the vicinity of one vertex of the triangle of the table 12, and are arranged such that the slider 10 and the rods 141 and 142 roughly form a triangle. Similarly, the rods 143 and 144 and the rods 145 and 146 are connected to the vicinity of the remaining vertices of the triangle of the table 12, and are arranged such that the slider 10 and the rods 143 and 144 and the rods 145 and 146 roughly form a triangle.

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

[0027] A stepped cylindrical hollow portion is formed inside the first shaft member 20, and a bellows-type air cylinder, for example, is housed at the lower end side of this hollow portion. A pneumatic circuit and an air pressure source (neither shown) are connected to this air cylinder. The internal pressure of the air cylinder is controlled by controlling the air pressure of the compressed air supplied from the air pressure source via the pneumatic circuit, thereby causing a 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 the air cylinder is incorporated into a parallel link mechanism.

[0028] Furthermore, an armature unit (not shown) made up of a plurality of armature coils arranged side by side in the axial direction is disposed on the upper end side within 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 part of the first shaft member 20. A small diameter part having a smaller diameter than the other parts is formed at one end of the second shaft member 22, and a cylindrical mover yoke made of a magnetic material is provided around the small diameter part. A hollow cylindrical magnet body made of a plurality of permanent magnets of the same size is provided on the outer periphery of the mover yoke. In this case, a hollow cylindrical magnet unit is formed by the mover yoke and the magnet body. In this embodiment, a shaft motor, which is a kind of electromagnetic linear motor, is formed by the armature unit and the magnet unit. In the shaft motor configured in this way, a sinusoidal driving current with a predetermined period and a predetermined amplitude is supplied to each coil of the armature unit, which is a stator, and the second shaft member 22 is driven axially relative to the first shaft member 20 by the Lorentz force (driving force) generated by electromagnetic interaction, which is a kind of electromagnetic interaction between the magnet unit and the armature unit.

[0030] That is, in this embodiment, the above-mentioned air cylinder and shaft motor are used to relatively drive the first shaft member 20 and the second shaft member 22 in the axial direction to form the aforementioned extension / retraction mechanisms 161-166 (see FIG. 11) that extend and retract each of the rods 141-146.

[0031] Also, the magnet unit, which is the mover of the shaft motor, is supported in a non-contact manner with respect to the armature unit, which is the stator, via air pads provided on the inner circumferential surface of the first shaft member 20.

[0032] 3, absolute type linear encoders 241-246 are provided on the rods 141-146, respectively, for detecting the axial position of the second shaft member 22 relative to the first shaft member 20, and the outputs of these linear encoders 241-246 are supplied to the control device 600 (see FIG. 11). The axial position of the second shaft member 22 detected by the linear encoders 241-246 corresponds to the length of each of the rods 141-146.

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

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

[0035] In addition, each of the rods 141 to 146 has an air pad that supports the magnet unit, which is the movable part of the shaft motor, without contacting the armature unit, which is the stator. This makes it possible to avoid friction, which becomes a nonlinear component when controlling the extension and retraction of the rod by the extension and retraction mechanism, and thereby makes it possible to control the position and posture of the table 12 with even greater precision.

[0036] In addition, in this embodiment, a shaft motor is used as the electromagnetic linear motor that constitutes the extension and contraction mechanisms 161 to 166, and in this shaft motor, a magnet unit using a cylindrical magnet on the movable member side is used, so that magnetic flux (magnetic field) is generated in all directions in the radial direction of the magnet, and this omnidirectional magnetic flux can be contributed to the generation of Lorentz force (driving force) by electromagnetic interaction. For example, a clearly larger thrust can be generated compared to a normal linear motor, etc., and it is easier to make it smaller than a hydraulic cylinder, etc.

[0037] Therefore, according to the movement system 200 in which each rod includes a shaft motor, it is possible to simultaneously achieve a small size and light weight while improving output, and thus the movement system 200 can be suitably applied to the molding apparatus 100.

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

[0039] The movement system 200 further includes a planar motor 26 (see FIG. 11). A mover of the planar motor 26, which is made up of a magnet unit (or a coil unit), is provided on the bottom surface of the slider 10, and a stator of the planar motor 26, which is made up of a coil unit (or a magnet unit), is accommodated inside the base BS corresponding to the mover. A plurality of air bearings (hydrostatic air bearings) are provided on the bottom surface of the slider 10 surrounding the mover, and the slider 10 is supported by the plurality of air bearings in a floating manner with a predetermined clearance (gap or space) on the top surface (guide surface) of the base BS, which is finished to a high degree of flatness. The slider 10 is driven in the XY plane without contact with the top surface of the base BS by an electromagnetic force (Lorentz force) generated by electromagnetic interaction between the stator and mover of the planar motor 26. In this embodiment, as shown in Fig. 1, the moving system 200 can freely move the table 12 between the positions of the measurement system 400, the beam shaping system 500, and the workpiece transport system 300 (not shown in Fig. 1, see Fig. 11). The moving system 200 may include multiple tables 12, each of which carries a workpiece W. For example, while processing a workpiece held on one of the multiple tables using the beam shaping system 500, measurement of a workpiece held on another table using the measurement system 400 may be performed. Even in this case, it is sufficient that each table can be freely moved between the positions of the measurement system 400, the beam shaping system 500, and the workpiece transport system 300 (not shown in Fig. 1, see Fig. 11). Alternatively, when a table for holding a workpiece during measurement using the measurement system 400 and a table for holding a workpiece during processing using the beam shaping system 500 are provided, and a workpiece can be carried in and out of the two tables by a work transport system or the like, each slider 10 may be fixed on the base BS. Even when multiple tables 12 are provided, each table 12 is movable in six degrees of freedom, and the position in the six degrees of freedom can be controlled.

[0040] Planar motor 26 is not limited to an air levitation type, and a magnetic levitation type planar motor may be used. In the latter case, there is no need to provide an air bearing on slider 10. Planar motor 26 may be of either a moving magnet type or a moving coil type.

[0041] In the control device 600, by controlling at least one of the magnitude and direction of the current supplied to each coil of the coil unit that constitutes the planar motor 26, the slider 10 can be freely driven in two dimensions, X and Y, on the base BS.

[0042] In this embodiment, the moving system 200 includes a position measuring system 28 (see FIG. 11) that measures position information of the slider 10 in the X-axis direction and the Y-axis direction. A two-dimensional absolute encoder can be used as the position measuring system 28. Specifically, a two-dimensional scale having a strip-shaped absolute code of a predetermined width over 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 of which is composed of a light source such as a light emitting element, and a one-dimensional light receiving element array arranged in the X-axis direction and a one-dimensional light receiving element array arranged in the Y-axis direction, 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, a non-reflective base material (reflectance 0%) is used in which a plurality of square reflective parts (marks) are two-dimensionally arranged at a constant period along two mutually orthogonal directions (X-axis direction and Y-axis direction), and the reflective characteristics (reflectance) of the reflective parts have gradations according to a predetermined rule. The two-dimensional absolute encoder may have a configuration similar to that of the two-dimensional absolute encoder disclosed in, for example, US Patent Application Publication No. 2014 / 0070073. An absolute type two-dimensional encoder having a configuration similar to that of US Patent Application Publication No. 2014 / 0070073 enables measurement of two-dimensional position information with high accuracy equivalent to that of a conventional incremental encoder. Since it is an absolute encoder, it does not require origin detection, unlike an incremental encoder. Measurement information from the position measurement system 28 is sent to the control device 600.

[0043] In this embodiment, as described later, the measurement system 400 measures position information (shape information in this embodiment) of at least a part of a target surface (e.g., an upper surface) on the workpiece W mounted on the table 12 in a three-dimensional space, 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 part of the target surface on the workpiece W, the control device 600 can associate the position and orientation of the target surface on the workpiece W mounted on the table 12 with the reference coordinate system (hereinafter referred to as the table coordinate system) of the molding apparatus 100 by associating the measurement result with the measurement results of the linear encoders 241-246 provided on the rods 141-146 and the measurement result of the position measurement system 28 at the time of the measurement. As a result, it is possible to control the position of the target surface TAS on the workpiece W in the six degrees of freedom directions relative to the target value 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 241-246 and the position measurement system 28. In this embodiment, absolute type encoders are used as the linear encoders 241-246 and the position measurement system 28, so resetting is easy since there is no need to return to the origin. Note that the above-mentioned position information in the three-dimensional space to be measured by the measurement system 400, which is used to enable position control in six degrees of freedom directions relative to target values ​​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, and three-dimensional position information of at least three points according to the shape of the target surface is sufficient.

[0044] In the above embodiment, the planar motor 26 is used as a 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 above-mentioned two-dimensional absolute encoder, a position measurement system for measuring the position information of the slider 10 may be configured using an absolute linear encoder. Also, the position measurement system for measuring the position information of the slider 10 is not limited to an encoder, and may be configured using an interferometer system.

[0045] In the above embodiment, the mechanism for driving the table is configured using a planar motor that drives the slider in the XY plane and a Stewart platform type six-degree-of-freedom parallel link mechanism in which the slider forms a base platform. However, the present invention is not limited to this, and the mechanism for driving the table may be configured using other types of parallel link mechanisms or mechanisms other than the parallel link mechanism. 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 with respect to the XY plane may be adopted. One example of such a Z-tilt drive mechanism is a mechanism that supports the table 12 from below at each apex position of a triangle via, for example, a universal joint or other joint, and has three actuators (such as voice coil motors) that can drive each support point independently in the Z-axis direction. However, the configuration of the mechanism for driving the table of the moving system 200 is not limited to these, and any configuration is sufficient as long as it can drive the table (movable member) on which the workpiece is placed in at least five degrees of freedom, i.e., three degrees of freedom in the XY plane, the Z-axis direction, and the inclination direction relative to the XY plane, and does not need to include a slider that moves within the XY plane. For example, the moving system may be composed of a table and a robot that drives the table. In either configuration, resetting can be made easier by configuring the measurement system that measures the position of the table using a combination of an absolute type linear encoder, or a combination of the linear encoder and an absolute type rotary encoder.

[0046] Alternatively, instead of the moving system 200, a system capable of driving the table 12 in at least five degrees of freedom, i.e., 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 (supported in a non-contact manner) by air levitation or magnetic levitation via a predetermined clearance (gap or space) on the upper surface of a support member such as the base BS. When such a configuration is employed, the table moves in a non-contact manner relative to the member supporting it, which is extremely advantageous in terms of positioning accuracy and contributes greatly to improving the molding accuracy.

[0047] The measurement system 400 measures three-dimensional position information of a workpiece, for example, a shape, for associating the position and posture of the workpiece mounted on the table 12 with a table coordinate system. The measurement system 400 includes a laser non-contact three-dimensional measuring device 401, as shown in Fig. 2. The three-dimensional measuring device 401 includes a frame 30 placed on a base BS, a head unit 32 attached to the frame 30, a Z-axis guide 34 attached to 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 is made up of a horizontal member 40 extending in the Y-axis direction, and a pair of column members 42 supporting the horizontal member 40 from below at both ends in the Y-axis direction.

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

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

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

[0052] The sensor unit 38 is mainly composed of an irradiation unit 50 that irradiates a line light for performing optical sectioning on a test object (workpiece W in FIG. 2) placed on the table 12, and a detection unit 52 that detects the surface of the test object on which an optical section surface (line) appears as a result of the irradiation of the line light. In addition, a calculation processing unit 54 that determines the shape of the test object based on 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 a control device 600 that comprehensively controls each component of the molding apparatus 100 (see FIG. 11).

[0053] The irradiation unit 50 is composed of a cylindrical lens (not shown) and a slit plate having a thin strip-shaped notch, and generates a fan-shaped line light 50a by receiving illumination light from a light source. As the light source, an LED, a laser light source, an SLD (super luminescent diode), or the like can be used. When an LED is used, the light source can be formed inexpensively. When a laser light source is used, since it is a point light source, it is possible to create a line light with little aberration, and since it has excellent wavelength stability and a small half-width, and a filter with a small half-width can be used to cut stray light, the influence of disturbance can be reduced. When an SLD is used, in addition to the characteristics of the laser light source, the coherence is lower than that of laser light, so the generation of speckles on the surface of the test object can be suppressed. The detection unit 52 is for imaging the line light 50a projected on the surface of the test object (workpiece 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, a CCD, and the like (not shown), and is configured to image the test object (workpiece W) every time the line light 50a is scanned at a predetermined interval by moving the table 12 as described later. The positions of the irradiation unit 50 and the detection unit 52 are determined so that the incident direction of the line light 50a on the surface of the test object (workpiece W) to the detection unit 52 forms a predetermined angle θ with the light irradiation direction of the irradiation unit 50. In this embodiment, the predetermined angle θ is set to, for example, 45 degrees.

[0054] The image data of the test object (workpiece W) captured by the detection unit 52 is sent to the calculation processing unit 54, where a predetermined image calculation process is performed to calculate the height of the surface of the test object (workpiece W) and obtain the three-dimensional shape (surface shape) of the test object (workpiece W). The calculation processing unit 54 calculates the height of the test object (workpiece W) surface from a reference plane for each pixel in the longitudinal direction along which the light section (line) (line light 91a) extends using the principle of triangulation based on position information of the light section (line) by the line light 50a deformed in accordance with the unevenness of the test object (workpiece W) in the image of the test object (workpiece W), and performs calculation process to obtain the three-dimensional shape of the test object (workpiece 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 test object (workpiece W), thereby causing the line light 50a to scan the surface of the test object (workpiece W). The control device 600 detects the rotation angle of the sensor unit 38 by 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. In this manner, in this embodiment, the table 12 is moved when measuring the shape of the test object (workpiece W), and therefore, as a prerequisite, when the table 12 holds the workpiece W and moves below the sensor unit 38 of the measurement system 400, the position and attitude (position in the six degrees of freedom direction) of the table 12 are always set to a predetermined reference state. The reference state is, for example, a state in which the rods 141-146 all have a length (or a minimum length) corresponding to the neutral point of the extension stroke range, and at this time, the positions of the table 12 in the Z axis, θx, θy, and θz directions are (Z, θx, θy, θz)=(Z0, 0, 0, 0). Also, in this reference state, the position (X, Y) of the table 12 in the XY plane coincides with the X, Y positions of the slider 10 measured by the position measurement system 28.

[0056] Thereafter, the above-mentioned measurement of the test object (workpiece W) is started, and the position of table 12 in the six degrees of freedom directions, including during this measurement, is managed on the table coordinate system by control device 600. That is, control device 600 controls planar motor 26 based on measurement information from position measurement system 28, and controls extension mechanisms 161-166 based on measurement values ​​from linear encoders 241-246, thereby controlling the position of table 12 in the six degrees of freedom directions.

[0057] Incidentally, when using the light cutting method as in the three-dimensional measuring device 401 according to this embodiment, it is desirable to arrange the line light 50a irradiated from the irradiation unit 50 of the sensor unit 38 to the test object (workpiece W) in a direction perpendicular to the relative movement direction between the sensor unit 38 and the table 12 (test object (workpiece W)). For example, in FIG. 2, when the relative movement direction between the sensor unit 38 and the test object (workpiece W) is set to the Y-axis direction, it is desirable to arrange the line light 50a along the X-axis direction. This is because, during measurement, relative movement with respect to the test object (workpiece W) can be performed by effectively utilizing the entire area of ​​the line light 50a, and the shape of the test object (workpiece W) can be optimally measured. The rotation mechanism 36 is provided so that the direction of the line light 50a and the above-mentioned relative movement direction can always be perpendicular to each other.

[0058] The above-mentioned three-dimensional measuring machine 401 is configured similarly to the shape measuring machine disclosed in, for example, US Patent Application Publication No. 2012 / 0105867. However, the difference is that the scanning of the test object with the line light in a direction parallel to the XY plane is performed by moving the sensor unit in the machine described in US Patent Application Publication No. 2012 / 0105867, whereas in this embodiment, the scanning is performed by moving the table 12. Note that in this embodiment, either the Z-axis guide 34 or the table 12 may be driven when scanning the test object with the line light in a direction parallel to the Z axis.

[0059] In the measurement method using the three-dimensional measuring device 401 according to this embodiment, a light-section method is used to project a line-shaped projection pattern consisting of a single line of light onto the surface of the test object, and each time the line-shaped projection pattern is scanned over the entire surface of the test object, the line-shaped projection pattern projected onto the test object is imaged from an angle different from the projection direction. Then, from the image of the test object surface that has been imaged, the height of the test object surface from a reference plane is calculated for each pixel in the longitudinal direction of the line-shaped projection pattern using the principle of triangulation or the like, and the three-dimensional shape of the test object surface is obtained.

[0060] Alternatively, a device having a similar configuration to the optical probe disclosed in U.S. Patent No. 7,009,717 may be used as the three-dimensional measuring machine constituting the measurement system 400. This optical probe is composed of two or more optical groups and includes two or more viewing directions and two or more projection directions. One optical group includes one or more viewing directions and one or more projection directions, at least one viewing direction and at least one projection direction are different between the optical groups, and data obtained from a viewing direction is generated only from a pattern projected by a projection direction of the same optical group.

[0061] The measurement system 400 may include a mark detection system 56 (see FIG. 11) for optically detecting an alignment mark instead of the above-mentioned three-dimensional measuring machine 401 or in addition to the above-mentioned three-dimensional measuring machine. The mark detection system 56 can detect an alignment mark formed on a workpiece, for example. The control device 600 calculates the position and attitude 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. The mark detection system 56 can be configured to include, for example, a stereo camera. The mark detection system 56 may optically detect at least three alignment marks formed in advance 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 device 401 as described above, and acquires the surface shape data. Then, the control device 600 performs least squares processing using the surface shape data, and associates the three-dimensional position and orientation of the target surface on the workpiece with the table coordinate system. Here, since the position of the table 12 in the six degrees of freedom directions is managed on the table coordinate system by the control device 600, including during the above-mentioned measurement of the test object (workpiece W), after the three-dimensional position and orientation of the workpiece are associated with the table coordinate system, all control of the position of the workpiece W in the six degrees of freedom directions (i.e., position and orientation) can be performed by open-loop control of the table 12 according to the table coordinate system, including during additional processing by three-dimensional modeling.

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

[0064] As shown in FIG. 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's eye optical system 64 arranged on the exit side of the light guide fiber 62, and a condenser lens system 66.

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

[0066] The light guide fiber 62 is a fiber bundle formed by randomly bundling a number of optical fiber strands, and has a number of entrances 62a individually connected to the exit ends of the laser units 70, and an exit portion 62b having a number of exits greater than the number of entrances 62a. The light guide fiber 62 receives a number of laser beams (hereinafter, abbreviated as "beams") emitted from the laser units 70 through the entrances 62a, distributes the beams to a number of exits, and emits at least a part of each laser beam from a common exit. In this way, the light guide fiber 62 mixes and emits the beams emitted from the laser units 70. This allows the total output to be increased according to the number of laser units 70, compared to the case where a single laser unit is used. However, if a sufficient output can be obtained from a single laser unit, it is not necessary to use multiple laser units.

[0067] Here, the exit portion 62b has a cross-sectional shape similar to the overall shape of the entrance end of a first fly-eye lens system constituting the entrance end of the double fly-eye optical system 64 described below, and the exit ports are provided at approximately equal intervals within the cross section. Therefore, the light guide fiber 62 also serves as a shaping optical system that shapes the beam mixed as described above so that it becomes similar to the overall shape of the entrance end of the first fly-eye lens system.

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

[0069] In this case, the entrance surface of the first fly-eye lens system 72 and the entrance surface of the second fly-eye lens system 76 are set optically conjugate to each other. Also, 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 a pupil plane (entrance pupil) PP of the focusing optical system 82 described later are set optically conjugate to each other. In this embodiment, the pupil plane (entrance pupil) PP of the focusing optical system 82 coincides with the front focal plane (see, for example, FIG. 4, FIG. 6, FIG. 7, etc.).

[0070] The beam mixed by the light guide fiber 62 enters a first fly-eye lens system 72 of the double fly-eye optical system 64. As a result, a surface light source, i.e., a secondary light source consisting of a large number of light source images (point light sources), is formed on the exit-side focal plane of the first fly-eye lens system 72. Laser light from each of these large number of point light sources enters a second fly-eye lens system 76 via a lens system 74. As a result, a surface light source (tertiary light source) in which a large number of tiny light source images are uniformly distributed within an area of ​​a predetermined shape is formed on the exit-side focal plane of the second fly-eye lens system 76.

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

[0072] By optimizing the area of ​​the entrance end of the second fly-eye lens system 76, the focal length of the condenser lens system 66, and the like, the beam emerging from the condenser lens system 66 can be regarded as a parallel beam.

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

[0074] The illuminance uniformizing optical system is not limited to the above-mentioned configuration, and may be configured using, for example, 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 a control device 600, and the control device 600 individually controls the on / off of the multiple laser units 70 constituting the light source unit 60. This adjusts the amount of light (laser output) of the laser beam irradiated from the beam irradiation section 520 to the workpiece W (upper target surface).

[0076] The modeling apparatus 100 does not necessarily have to include the light source unit 60, or the light source unit 60 and an illuminance uniformizing optical system. For example, a parallel beam having a desired light amount (energy) and a desired illuminance uniformity may be supplied to the modeling apparatus 100 from an external device.

[0077] 4, the beam irradiation unit 520 has, in addition to the light source system 510, a beam cross-sectional intensity conversion optical system 78 and a mirror array 80, which is a type of spatial light modulator (SLM), sequentially arranged on the optical path of the parallel beam from the light source system 510 (condenser lens system 66), and a focusing optical system 82 that focuses the light from the mirror array 80. Here, the 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 (annular) parallel beam in which the intensity of the area including the center of the cross section is almost zero. In this embodiment, the beam cross-sectional intensity conversion optical system 78 is composed of, for example, a convex conical reflector and a concave conical reflector arranged in sequence on the optical path of the parallel beam from the light source system 510. The convex conical reflector has a conical reflecting surface on the outer circumferential surface on the light source system 510 side, and the concave conical reflector is made of an annular member whose inner diameter is larger than the outer diameter of the convex conical reflector, and has a reflecting surface facing the reflecting surface of the convex conical reflector on its inner circumferential surface. In this case, when viewed in any cross section passing through the center of the concave conical reflector, the reflecting surface of the convex conical reflector and the reflecting surface of the concave conical reflector are parallel. Therefore, the parallel beam from the light source system 510 is radially reflected by the reflecting surface of the convex conical reflector, and this reflected beam is then reflected by the reflecting surface of the concave conical reflector, thereby being converted into an annular parallel beam.

[0079] In this embodiment, the parallel beam that has passed through the beam cross-sectional intensity conversion optical system 78 is irradiated onto a workpiece via a mirror array 80 and a focusing optical system 82, as described below. 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 a pupil plane (entrance pupil) PP of the focusing optical system 82 from the mirror array 80. In addition, 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 on the exit surface of the focusing optical system 82.

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

[0081] In this embodiment, the mirror array 80 includes a base member 80A having a surface (hereinafter, for convenience, referred to as a reference surface) that forms an angle of 45 degrees (π / 4) with respect to the XY plane and the XZ plane, and, for example, M (=P×Q) mirror elements 81 arranged in a matrix of, for example, P rows and Q columns on the reference surface of the base member 80A. p,q (p=1 to P, q=1 to Q) and each mirror element 81 p,q The mirror array 80 includes a number of mirror elements 81 and a driving unit 87 (not shown in FIG. 4, see FIG. 11) including M actuators (not shown) for individually driving the mirror elements 81. p,q By adjusting the inclination of the reflector with respect to the reference plane, it is possible to form a large reflecting surface that is substantially 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 The angle of the reflecting surface of each mirror element is rotatable about a rotation axis parallel to one of the diagonals, and the inclination angle of the reflecting surface with respect to the reference surface can be set to any angle within a predetermined angle range. The angle of the reflecting surface of each mirror element is detected by a sensor, such as a rotary encoder 83, which detects the rotation angle of the rotation axis. p,q (not shown in FIG. 4, see FIG. 11).

[0083] The driving unit 87 includes, for example, an electromagnet or a voice coil motor as an actuator, and drives each of the mirror elements 81 p,qis driven by an actuator and operates with extremely high response.

[0084] Among the multiple mirror elements constituting 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 the reflecting surface, and causes the reflected beam to enter the light-collecting optical system 82 (see FIG. 6). Note that, in this embodiment, the reason for using the mirror array 80 and the reason for causing annular parallel beams to enter the mirror array 80 will be described later, but the beam does not necessarily have to be annular, and the cross-sectional shape (cross-sectional intensity distribution) of the parallel beam entering the mirror array 80 may be made different from the annular shape, and the beam cross-sectional intensity conversion optical system 78 may not be provided.

[0085] The focusing optical system 82 is an optical system with a high numerical aperture NA of, for example, 0.5 or more, preferably 0.6 or more, and low aberration. The focusing optical system 82 has a large aperture, low aberration, and high NA, so that it can focus a plurality of parallel beams from the mirror array 80 on the rear focal plane. Although the details will be described later, the beam irradiation unit 520 can focus the beam emitted from the focusing optical system 82, for example, in a spot shape or a slit shape. In addition, since the focusing optical system 82 is composed of one or more lenses with a large aperture (one lens with a large aperture is representatively illustrated in FIG. 4 and the like), the area of ​​the incident light can be increased, and thus a larger amount of light energy can be taken in compared to the case where 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 an improvement in the processing accuracy of the additional processing by molding.

[0086] In this embodiment, as described later, a case will be described in which the table 12 is moved in a scanning direction parallel to the XY plane (in FIG. 4, the Y-axis direction is an example) to relatively scan the beam and the workpiece W having the target surface TAS of the modeling at its upper end in the scanning direction (scanning direction) to perform modeling (processing). It goes without saying that during modeling, the table 12 may be moved in at least one direction of the X-axis direction, the Z-axis direction, the θx direction, the θy direction, and the θz direction while the table 12 is moving in the Y-axis direction. Also, as described later, the powdered modeling material (metal material) supplied by the material processing unit 530 is melted by the energy of the laser beam. Therefore, as described 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. If the supply amount of modeling material and the speed of the table 12 are increased accordingly, the throughput of modeling processing by the beam modeling system 500 is improved.

[0087] However, even if the total output of the laser is greatly increased by the above-mentioned method, the scanning operation of the table 12 cannot be made infinitely fast in reality, so that a throughput that fully utilizes the laser power cannot be realized. To solve this problem, in the modeling apparatus 100 of this embodiment, as described later, a slit-shaped beam irradiation area (hereinafter referred to as a single character area (see symbol LS in FIG. 9(B))) is formed on a predetermined surface (hereinafter referred to as a modeling surface) MP (see, for example, FIGS. 4 and 9(A)) to which the target surface TAS of modeling should be aligned, and modeling (processing) can be performed while scanning the workpiece W relatively in a direction perpendicular to the longitudinal direction of the beam (hereinafter referred to as a single character beam) that forms the single character area LS. This makes it possible to process a much larger area (for example, an area several times to several tens of times larger) at once compared to the case of scanning the workpiece with a spot-shaped beam. As described later, in this embodiment, the above-mentioned printing surface MP is the rear focal plane of the focusing optical system 82 (see, for example, Figs. 4 and 9(A)), but the printing surface may be a surface in the vicinity of the rear focal plane. Also, in this embodiment, the printing 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 intensity distribution of the beam on the printing surface MP (for example, a method for forming a single character region as described above), for example, a method for controlling the incidence angle distribution of multiple parallel beams entering the focusing optical system 82 can be adopted. 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 back focal plane (light focusing surface) is determined by the incidence angle of the parallel beam LB (see, for example, FIGS. 4 and 6, etc.) on the pupil plane (entrance 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)) with respect to a reference axis (e.g., X-axis (X≧0)) on the two-dimensional orthogonal coordinate system (X,Y) of the orthogonal projection onto the pupil plane PP (XY coordinate plane) of the parallel beam incident on the pupil plane PP when a point on the optical axis AX is set as the origin on the pupil plane PP and the two-dimensional orthogonal coordinate system (X,Y) perpendicular to the optical axis AX is set. For example, a beam that is perpendicular to the pupil plane PP of the focusing optical system 82 (parallel to the optical axis) is focused on the optical axis AX, and a beam that is slightly inclined with respect to the focusing optical system 82 (with respect to the optical axis AX) is focused at a position slightly shifted from the optical axis AX. By utilizing this relationship, the parallel beam from the light source system 510 is focused on the pupil plane PP (XY coordinate plane). When the beam is reflected and made to enter the focusing optical system 82, the beam intensity distribution in the printing surface MP, for example, at least one of the position, number, size, and shape of the irradiation area on the printing surface MP can be arbitrarily changed by providing an appropriate distribution to the incidence angle (incident direction) of the multiple parallel beams LB incident on the pupil plane PP of the focusing optical system 82. Therefore, for example, a one-character area, a three-row area, a missing one-character area, etc. (see FIG. 10) can be easily formed, and it is also easy to form a spot-shaped irradiation area. Here, the incidence angle (incident direction) has been described using the angle α and the angle β, but various ways of expressing the incidence angle (incident direction) are possible, and it goes without saying that the incidence angle (incident direction) of the parallel beam incident on the pupil plane PP is not limited to the control using the angle α and the angle β as parameters.

[0089] In addition, since the focusing optical system 82 of this embodiment is configured so that its pupil plane (entrance pupil) PP coincides with the front focal plane, the focusing position of the multiple parallel beams LB can be accurately and easily controlled by changing the incident angle of the multiple parallel beams LB using the mirror array 80, but the pupil plane (entrance pupil) of the focusing optical system 82 does not have to be configured so that it coincides with the front focal plane.

[0090] Furthermore, if the shape and size of the irradiation area formed on the modeling surface are not variable, a solid mirror of the desired shape can be used to control the angle of incidence of a single parallel beam entering the pupil plane of the focusing optical system 82, thereby changing the position of the irradiation area.

[0091] However, when performing additional processing (shaping) on ​​a workpiece, the area of ​​the target surface where the target part of the shaping is set is not always a flat surface. In other words, it is not always possible to perform relative scanning with a single character beam. In the vicinity of the contour edge of the workpiece or the boundary between the solid area and the hollow area, the boundary is slanted, narrow, or has an R, making it difficult to apply relative scanning with a single character beam. For example, it is difficult to fill such an area with a wide brush, so a narrow brush or a thin pencil is required accordingly, so it is desirable to be able to freely use a brush and a thin pencil in real time and continuously. Similarly, in the vicinity of the contour edge of the workpiece or the boundary between the solid area and the hollow area, there is a demand to change the width of the beam irradiation area in the scanning direction (relative movement direction), or to change the size (for example, the length of the single character beam), number, or position (position of the beam irradiation point) of the irradiation area.

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

[0093] In this embodiment, the control device 600 also controls the rotary encoder 83 p,q is used to detect the state of each mirror element (here, the tilt angle of the reflective surface), thereby monitoring the state of each mirror element in real time, allowing the tilt angle of the reflective surface of each mirror element in mirror array 80 to be accurately controlled.

[0094] As shown in Fig. 7, the material processing section 530 has a nozzle unit 84 having a nozzle member (hereinafter, abbreviated as nozzle) 84a provided below the emission surface of the light collecting optical system 82, a material supply device 86 connected to the nozzle unit 84 via a pipe 90a, and a plurality of, for example, two powder cartridges 88A, 88B each connected to the material supply device 86 via a pipe. Fig. 7 shows the portion below the light collecting optical system 82 in Fig. 4 as viewed from the -Y direction.

[0095] The nozzle unit 84 includes a nozzle 84a extending in the X-axis direction below the condensing optical system 82 and having at least one supply port for supplying the powder of the modeling material, and a pair of support members 84b, 84c supporting both ends of the nozzle 84a in the longitudinal direction and having their upper ends connected to the housing of the condensing optical system 82. One of the support members 84b is connected to one end (lower end) of a material supply device 86 via a pipe 90a, and a supply path communicating the pipe 90a and the nozzle 84a is formed inside. In this embodiment, the nozzle 84a is disposed directly below the optical axis of the condensing optical system 82, and a plurality of supply ports, which will be described later, are provided on the lower surface (bottom surface). The nozzle 84a does not necessarily need to be disposed on the optical axis of the condensing optical system 82, and may be disposed at a position slightly shifted from the optical axis to one side in the Y-axis direction.

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

[0097] In this embodiment, the modeling apparatus 100 includes two powder cartridges for supplying two types of modeling materials to the material supply device 86, but the modeling apparatus 100 may include only one powder cartridge.

[0098] Regarding the supply of powder from the powder cartridges 88A and 88B to the material supply device 86, each of the powder cartridges 88A and 88B may have a function of forcibly supplying powder to the material supply device 86. In this embodiment, however, the material supply device 86 has a function of switching between the pipes 90b and 90c and a function of sucking powder from one of the powder cartridges 88A and 88B using a vacuum. The material supply device 86 is connected to the control device 600 (see FIG. 11). During modeling, the control device 600 switches between the pipes 90b and 90c using the material supply device 86, and the powder of the first modeling material (e.g., titanium) from the powder cartridge 88A and the powder of the second modeling material (e.g., stainless steel) from the powder cartridge 88B are alternatively supplied to the material supply device 86, and the powder of one of the modeling materials is supplied to the nozzle 84a from the material supply device 86 via the pipe 90a. In addition, by changing the configuration of the material supplying device 86, the first modeling material from the powder cartridge 88A and the second modeling material from the powder cartridge 88B may be simultaneously supplied to the material supplying device 86 when necessary, and a mixture of the two modeling materials may be supplied to the nozzle 84a via the piping 90a. In addition, a nozzle connectable to the powder cartridge 88A and another nozzle connectable to the powder cartridge 88B may be provided below the condensing optical system 82, and powder may be supplied from either one of the nozzles or from both nozzles during modeling.

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

[0100] Although not shown in FIG. 7, in reality, the nozzle 84a has a plurality of, for example, N supply ports 91 on the lower surface (bottom surface) as shown in FIG. i (i=1 to N) are formed at equal intervals in the X-axis direction, and each supply port 91 i Opening and closing parts 93 i In FIG. 8, for convenience of illustration, the supply port 91 is shown as i As an example, twelve supply ports are shown, and both are shown so that the relationship between the supply ports and the opening / closing member can be understood. However, in reality, more than twelve supply ports are formed, and the partitions between adjacent supply ports are narrower. However, as long as the supply ports are arranged over almost the entire length of the nozzle 84a in the longitudinal direction, any number of supply ports may be used. For example, the supply port may be a single slit-shaped opening that extends over almost the entire length of the nozzle 84a in the longitudinal direction.

[0101] Opening and closing parts 93 i In FIG. 8, the k-th opening / closing member 93 k As shown by the arrows, the supply port 91 can be slid in the +Y direction and the -Y direction. i The opening and closing member 93 iThe tilting mechanism is not limited to a sliding mechanism, and may be configured to be rotatable in the tilt direction around one end.

[0102] Each opening and closing member 93 i The control device 600 controls the supply ports 91, for example, N supply ports 91, in accordance with the intensity distribution of the beam on the modeling surface, for example, the setting (or change) of the shape, size, arrangement, etc. of the irradiation area of ​​the beam formed on the modeling surface. i Each of the opening and closing members 93 i In this case, the control device 600 controls the opening and closing of the plurality of supply ports 91. i At least one supply port is selected, and an opening / closing member 93 is closing the selected at least one supply port. i Therefore, in this embodiment, a plurality of, for example, N supply ports 91 are driven to open, for example, in the -Y direction. i The building material can be supplied from only a portion of the

[0103] The control device 600 also controls the supply amount per unit time of the modeling material supplied to the nozzle 84a via the material supply device 86 and the opening and closing member 93. i and at least one of the opening and closing control using the opening and closing member 93 i Supply port 91 opened and closed by i The control device 600 can adjust the supply amount of the modeling material per unit time from any of the supply ports 91 according to the intensity distribution of the beam on the modeling surface, for example, the setting (or change) of the shape, size, arrangement, etc. of the irradiation area of ​​the beam formed on the modeling surface. i The control device 600 determines the supply amount of the modeling material per unit time from each of the supply ports 91 based on, for example, the width of the one character region in the scanning direction. i Determine the amount of supply per unit time from

[0104] In addition, each opening and closing member 93 i Therefore, each supply port 91 iIn this case, the control device 600 may adjust the opening degree of each opening / closing member 93 in accordance with, for example, the width of the one character region in the scanning direction. i The opening degree of each supply port may be adjusted by the pressure sensor.

[0105] In addition, at least one supply port for supplying the powder of the modeling material 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 direction and the Y-axis direction relative to the pair of support members 84b and 84c, and the control device 600 may move the nozzle 84a having the supply port formed on the lower surface according to a change in the intensity distribution of the beam on the modeling surface, that is, a change in the shape, size, and position of the irradiation area of ​​the beam. The nozzle 84a may be movable in the Z-axis direction.

[0106] Alternatively, the nozzle 84a may be composed of a main body and at least two movable members that are movable in at least one of the X-axis direction and the Y-axis direction in the XY plane relative to the main body and have a supply port formed on their bottom surfaces, and at least a part of the movable members may be moved by the control device 600 in response to a change in the intensity distribution of the beam on the modeling surface. In this case, at least a part of the movable members may also be movable in the Z-axis direction.

[0107] Also, one of the multiple supply ports may be configured to be relatively movable with respect to another supply port. Alternatively, for example, the position of the one supply port in the Y-axis direction may be different from the position of the other supply port in the Y-axis direction. Alternatively, the position of the one supply port in the Z-axis direction may be different from the position of the other supply port in the Z-axis direction.

[0108] At least one supply port may be moved not only in accordance with the setting or change of the beam intensity distribution, but also for another purpose.

[0109] As described above, the nozzle 84a has a plurality of supply ports 91. iare 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 each other. i Therefore, as shown by the black arrows in FIG. i If the powdered modeling material PD is supplied directly below from each of the nozzles 84a along the Z-axis direction parallel to the optical axis AX of the focusing optical system 82, the modeling material PD will be supplied to the single-character region LS (the irradiation region of the single-character beam) directly below the optical axis AX of the focusing optical system 82. In this case, the modeling material PD can be supplied from the nozzle 84a by using the weight of the modeling material PD or by ejection with a slight ejection pressure. Therefore, a complex mechanism such as a gas flow generating mechanism for guiding the supply of the modeling material is not required, as in the case of supplying the modeling material from an oblique direction to the target surface of the modeling. In addition, being able to supply the modeling material vertically at close range to the workpiece as in this embodiment is extremely advantageous in ensuring the processing accuracy in the modeling.

[0110] In addition, the nozzle 84a may be provided with a gas supply port. The gas supplied from the gas supply port may be supplied to guide the supply of the modeling material, or may be supplied for another purpose, such as a gas that contributes to modeling.

[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 condensed onto the modeling surface MP of the focusing optical system 82 (which coincides with the rear focal plane of the focusing optical system 82 in this embodiment) 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 unit 520 (see FIG. 4). That is, for example, a single character beam is formed only by the light passing through the portion near the periphery of the same focusing optical system 82. Therefore, it is possible to form a high-quality beam spot compared to the case where light passing through separate optical systems is condensed onto the same region to form a beam spot (laser spot). In addition, 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. For this reason, in this embodiment, it is possible to use all of the reflected beams from the mirror array 80 to form spots, and it is not necessary to provide a light-shielding member or the like for restricting the beam from being irradiated onto the nozzle 84a in the portion corresponding to the nozzle 84a on the incident surface side of the focusing optical system 82. For these reasons, the mirror array 80 is illuminated with an annular parallel beam.

[0112] The optical member located at the exit end of the focusing optical system 82 may have an optical surface formed at least in a region away from the optical axis of the exit side surface, and may focus a beam on the modeling surface (rear focal plane) via the optical surface. Therefore, in a region including the optical axis, at least one of the exit surface and the entrance surface of this optical member 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 member located at the exit end of the focusing optical system 82 may be configured by a donut-shaped focusing lens with a hole in the central region including the optical axis.

[0113] In order to limit the beam incident from the focusing optical system 82 to the nozzle 84a, for example, a limiting member 85 shown by a two-dot chain line in FIG. 7 may be provided on the entrance surface side (for example, pupil surface PP) of the focusing optical system 82. The limiting member 85 limits the beam from the focusing optical system 82 from being incident on the nozzle 84a. The limiting member 85 may be a light blocking member, or a neutral density filter or the like. In such a case, the parallel beam incident on the focusing optical system 82 may be a parallel beam having a circular cross section, or may be an annular parallel beam. In the latter case, since the beam is not irradiated on the limiting member 85, it becomes possible to use all of the reflected beam from the mirror array 80 to form a spot.

[0114] It is not necessary to completely block the beam entering the nozzle 84a from the focusing optical system 82, but 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 in the Y-axis direction of the exit surface of the terminal lens of the focusing optical system 82.

[0115] The water shower nozzle 540 (see FIG. 11) is used in so-called hardening. The water shower nozzle 540 has a supply port for supplying a cooling liquid (cooling water) and sprays the cooling liquid onto the object to be cooled. The water shower nozzle 540 is connected to the control device 600 (see FIG. 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 can perform hardening by irradiating the surface of the workpiece with a beam to heat it to a high temperature, and then spraying the cooling liquid onto the high-temperature part through the water shower nozzle 540 to rapidly cool it. In this case, it is also possible to perform the hardening process simultaneously with the additional processing of the workpiece by three-dimensional modeling. When the hardening process is performed simultaneously with the additional processing, it is preferable to use a metal with good hardenability as the modeling material.

[0116] In this embodiment, during additional processing of the workpiece, as shown in FIG. 4 and FIG. 9(A) which shows an enlarged view of circle A in FIG. 4, a beam (shown as beams LB11 and LB12 in FIG. 9(A) for the sake of convenience) that passes through the vicinity of the peripheral portion of the focusing optical system 82 and passes through an optical path on the +Y side and -Y side (front and rear in the scanning direction of the workpiece W (table 12)) of the nozzle 84a is focused directly below the nozzle 84a, and a single character area LS with the X-axis direction (direction perpendicular to the paper surface in FIG. 9(A)) as the longitudinal direction is formed on the printing surface (see FIG. 9(B)). i Powdered modeling material PD is supplied 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) via the nozzle 84a. As a result, a linear molten pool WP extending in the X-axis direction is formed directly below the nozzle 84a. The molten pool WP is formed while the table 12 is scanned in the scan direction (+Y direction in Figure 9(A)). This makes it possible to form a bead (molten and solidified metal) BE of a predetermined width that spans the length of the linear beam (molten pool WP) in the longitudinal direction (X-axis direction). Note that the beams LB11 and LB12 shown in Figure 9(A) are irradiated by different mirror elements 81 of the mirror array 80. p.q These may be separate parallel beams that are reflected by the focusing optical system 82 and incident on the pupil plane PP of the focusing optical system 82 at different angles of incidence, or they may be parts of the same parallel beam, for example, a parallel beam having an annular cross section.

[0117] In the case where a plurality of parallel beams are incident on the pupil plane PP of the focusing optical system 82, for example, if the angle of incidence of the plurality of parallel beams LB incident on the focusing optical system 82 is adjusted so that the width of the single character beam in the X-axis direction, the width of the single character beam 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) increases. Therefore, by increasing the supply amount of powder (modeling material) per unit time and increasing the scanning speed of the target surface TAS accordingly, it is possible to keep the thickness of the layer of the bead BE formed constant and to keep the throughput at a high level. However, this adjustment method is not limited to this, and other adjustment methods can also be used to keep the thickness of the layer of the bead BE formed constant. For example, the laser output (energy amount of the laser beam) of at least one of the plurality of laser units 70 may be adjusted according to the width of the single character beam in the X-axis direction, the width of the Y-axis direction, or both widths, 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 than in the above-mentioned adjustment method, but the adjustment is simpler.

[0118] 11 is a block diagram showing the input / output relationship of a control device 600 that centrally configures the control system of the molding apparatus 100. The control device 600 includes a workstation (or a microcomputer) and the like, and controls each component 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 modeling. The workpiece is input into the molding apparatus 100, and after the desired shape has been accurately added, it is removed from the molding apparatus 100. At this time, actual shape data of the added shape is sent from the apparatus to an external device, for example, a higher-level device. The series of operations performed by the molding apparatus 100 is 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 above-mentioned reference state (Z, θx, θy, θz)=(Z0, 0, 0, 0), and its XY position coincides with the X, Y position of the slider 10 measured by the position measurement system 28.

[0121] Next, the control device 600 moves the table 12 with the workpiece W mounted thereon to below the measurement system 400. The control device 600 controls the planar motor 26 based on the measurement information of the position measurement system 28 to move the table 12 in the X-axis direction (and Y-axis direction) on the base BS. Even during this movement, the table 12 maintains the above-mentioned reference state.

[0122] Next, the control device 600 uses the measurement system 400 to measure position information (shape information in this embodiment) in three-dimensional space of at least a portion of the target surface TAS on the workpiece W placed on the table 12 in the reference state. After this, based on the 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 carrying the workpiece W, on which measurement of shape information of at least a portion of the target surface TAS has been completed, to below the beam shaping system 500.

[0124] Next, additional processing is performed by three-dimensional modeling, which adds a shape corresponding to the 3D data to the workpiece on the table 12. This additional processing is performed as follows.

[0125] That is, the control device 600 converts three-dimensional CAD data of the shape to be added by the additive processing (the shape obtained by subtracting the shape of the workpiece to be added from the shape of the object created after the additive processing) into, for example, STL (Stereo Lithography) data as data for three-dimensional modeling, and further generates data of each layer sliced ​​in the Z-axis direction from this three-dimensional STL data. Then, the control device 600 controls the movement system 200 and the beam modeling system 500 to perform additive processing of each layer on the workpiece based on the data of each layer, and repeats the formation of the above-mentioned single character area and the formation of a linear (slit-shaped) molten pool by supplying modeling material from the nozzle 84a to the single character beam while scanning the table 12 in the scan direction for each layer. Here, the position and attitude of the target surface on the workpiece during the additive processing are controlled in consideration of the shape information of the target surface measured previously.

[0126] Here, in the above explanation, it is assumed that the target surface (e.g., the upper surface) TAS on which the target area TA of the workpiece W for additional processing is set is a plane that is set to a plane 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 modeling is performed with the scanning operation of the table 12. However, the target surface on which the target area of ​​the workpiece for additional processing is set is not necessarily a plane on which a single character beam can be used. Therefore, the modeling apparatus 100 according to this embodiment is equipped with a movement system 200 that can arbitrarily set the position of the table 12 on which the workpiece is mounted in six degrees of freedom. In this case, the control device 600 controls the movement system 200 and the beam irradiation unit 520 of the beam forming system 500 based on the three-dimensional shape of the workpiece measured using the measurement system 400, and adjusts the width of the beam irradiation area on the forming surface MP in the X-axis direction so that the target surface (e.g., the upper surface) of the workpiece W aligned with the forming surface MP can be considered as flat enough to be additionally processed within the beam irradiation area on the forming surface MP, while controlling each opening / closing member 93 of the nozzle 84a. i Each supply port 91 iBy opening and closing the opening, the modeling material is supplied from the necessary supply port to the beam irradiated in the irradiation area. This makes it possible to model the required area even if the top surface of the workpiece (target surface) is not flat.

[0127] In addition, when performing modeling by laminating beads, additional processing (bead formation) may be performed with a beam having a small width in the X-axis direction of the irradiation area on the modeling surface to form a relatively large surface area, and then additional processing (bead formation) may be performed on the surface using a single-character beam having a larger width in the X-axis direction of the irradiation area on the modeling surface. For example, when performing modeling on a target surface with irregularities, additional processing (bead formation) may be performed to fill in the recesses using a beam having a small width in the X-axis direction of the irradiation area on the modeling surface to form a surface, and then additional processing (bead formation) may be performed on the surface using a single-character beam having a larger width in the X-axis direction of the irradiation area on the modeling surface MP. Even in such a case, it goes without saying that the powder of the modeling material is supplied from one or more supply ports selected according to the change in the size (width) of the irradiation area of ​​the beam on the modeling surface MP.

[0128] After the additional processing of the workpiece W is completed, the control device 600 moves the table 12 on which the additionally processed workpiece W is placed to the above-mentioned 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 workpiece W that has been subjected to additional processing from the table 12 and transports it to the outside of the molding apparatus 100. Then, the control device 600 sets the table 12 of the moving system 200 to the reference state. As a result, the moving system 200 waits at the loading / unloading position in preparation for the delivery of the next workpiece.

[0130] As described above in detail, according to the modeling apparatus 100 and the modeling method performed by the modeling apparatus 100 according to this embodiment, the intensity distribution of the beam in the modeling surface MP can be changed continuously, if necessary, not only before modeling by relative movement between the beam and the target surface TAS begins, but also during the relative movement between the beam and the target surface TAS, according to the relative position between the target surface TAS and the beam, and according to the required modeling accuracy and throughput. This makes it possible for the modeling apparatus 100 to form a model on the target surface TAS of the workpiece W with high processing accuracy and high throughput, for example, by rapid prototyping.

[0131] In addition, in the modeling apparatus 100 and the modeling method performed by the modeling apparatus 100, when additional processing (modeling) of a relatively wide area is performed on a flat target surface TAS, a method is adopted in which a powdered modeling material PD is supplied from the nozzle 84a to the one-character beam described above to form a linear molten pool WP directly below the nozzle 84a, and the molten pool WP is formed while scanning the table 12 in the scan direction (+Y direction in FIG. 4). With this method, a shape that could not be generated by a conventional 3D printer or the like without making a spot-shaped beam go back and forth dozens of times as shown in FIG. 12(B) can be generated by making the table 12 go back and forth several times with respect to the one-character beam as shown in FIG. 12(A). According to this embodiment, it is possible to form a model on the target surface of the workpiece in a significantly shorter time than in the case of modeling by a conventional spot-shaped beam, which is a one-stroke modeling. That is, in this respect as well, it is possible to improve the throughput.

[0132] Furthermore, according to the modeling apparatus 100 and the modeling method performed by the modeling apparatus 100 of this embodiment, the beam intensity distribution in the modeling surface of the focusing optical system 82 is changed by changing the inclination angle of the reflecting surface of each mirror element of the mirror array 80, and therefore, as a change in the intensity distribution, at least one of the position, number, size, and shape of the irradiation area of ​​the beam in the modeling surface can be easily changed. Therefore, for example, by setting the irradiation area to a spot shape, a slit shape (line shape), or the like, and performing three-dimensional modeling on the target surface on the work by the above-mentioned method, it becomes possible to form a highly accurate three-dimensional object.

[0133] Moreover, the modeling apparatus 100 according to this embodiment has a plurality of, for example, two, powder cartridges 88A and 88B, and powder of a first modeling material (for example, titanium) and powder of a second modeling material (for example, stainless steel) are stored inside the powder cartridges 88A and 88B, respectively. Then, during additional processing (modeling), the control device 600 switches the supply path of the powder to the nozzle unit 84 using the material supply device 86, that is, the piping 90b and 90c. As a result, the powder of the first modeling material (for example, titanium) from the powder cartridge 88A and the powder of the second modeling material (for example, stainless steel) from the powder cartridge 88B are alternatively supplied to the nozzle unit 84. Therefore, by simply switching the powder material supplied by the control device 600 according to the part, it is possible to easily generate a joint shape of different materials. Moreover, the switching can be performed almost instantly. Furthermore, it is possible to mix and supply different materials to create an "alloy" on the spot, or to change the composition depending on the location or to create a gradation.

[0134] In the above embodiment, the case has been described where the beam shaping system 500 forms an irradiation area of ​​a single linear beam (single character beam) and scans the workpiece W in the scanning direction (e.g., Y-axis direction) with the single character beam. However, as described above, in the beam shaping system 500, the beam intensity distribution on the printing surface MP can be freely changed by appropriately distributing the incidence angles of the multiple parallel beams LB incident on the focusing optical system 82. Therefore, in the printing apparatus 100, at least one of the position, number, size, and shape of the beam irradiation area on the printing surface MP can be changed, and it is also possible to form, for example, a single character area, a three-row area, a missing single character area, etc. (see FIG. 10) as the beam irradiation area.

[0135] Fig. 13 shows, as an example, a state in which additional processing is performed on the workpiece W using three single-character beams that are irradiated to the three single-character regions that make up the three-row region described above. As shown in Fig. 13, the beams LB11 and LB12 that pass near the peripheral portion of the focusing optical system 82 and pass through the optical paths in front and rear of the nozzle 84a in the scanning direction of the workpiece W (table 12) are focused directly under the nozzle 84a (its multiple supply ports), and a slit-shaped (linear) first single-character region LS1 with the X-axis direction (direction perpendicular to the paper surface in Fig. 13) as the longitudinal direction is formed on the printing surface. At this time, the target surface TAS on which the target portion TA of the workpiece W is set is aligned with the printing surface MP. Also, the beams LB21 and LB22 passing near the periphery of the focusing optical system 82 and passing through the optical path behind the nozzle 84a in the scanning direction are focused to form a second character region LS2 that is parallel to the first character region LS1 and has the same length as the first character region LS1 at a position a predetermined distance behind the first character region LS1 in the scanning direction. Also, the beams LB31 and LB32 passing near the periphery of the focusing optical system 82 and passing through the optical path ahead of the nozzle 84a in the scanning direction are focused to form a third character region LS3 that is parallel to the first character region LS1 and has the same length as the first character region LS1 at a position a predetermined distance ahead of the first character region LS1 in the scanning direction. FIG. 14 shows the relationship between the three character regions LS1, LS2, and LS3 shown in FIG. 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 shown diagrammatically, and the optical path of at least one beam incident on each character area, the number of beams, etc. can be set and changed, for example, by controlling the mirror array 80.

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

[0138] The single-character beam (hereinafter, for convenience, referred to as the second single-character beam) that forms the second single-character area LS2 located behind the first single-character area LS1 in the scanning direction (behind the traveling direction) of the table 12 plays a role of preheating (heating to a suitable temperature) the surface of the workpiece W (the target part of the target surface) before shaping, for example. If such preheating is not performed, the molten metal will be rapidly cooled due to the large temperature difference between the high-temperature metal melted by the laser beam and the low-temperature workpiece (target surface), and will instantly solidify into a crumbly mass. This is a major factor that deteriorates the surface accuracy and surface roughness of the processed surface (the surface of the shaping part). In contrast, by heating the surface of the workpiece W (target surface) in advance with the second single-character beam and reducing the temperature difference between the molten metal and the workpiece W (target surface), the solidification speed of the molten metal on the workpiece W (target surface) will be slowed down, and the molten metal will spread on the surface of the workpiece W (target surface) due to the action of surface tension, and there will be enough time for it to become familiar with the surface. As a result, excellent surface precision and surface roughness can be achieved.

[0139] The single-character beam (hereinafter, for convenience, referred to as the third single-character beam) that forms the third single-character area LS3 located forward in the scanning direction (forward in the traveling direction) of the table 12 with respect to the first single-character area LS1 has the effect of laser polishing, for example, the surface of the bead BE, that is, the molding material (metal material) that has adhered to and solidified (hardened) on the surface (target portion of the target surface) of the workpiece W. Surface polishing with a laser beam is a well-known general technique, but good surface precision and surface roughness that cannot normally be obtained by one additional processing (molding) can be achieved by instantly polishing with the third single-character beam.

[0140] In particular, in the additional processing of the workpiece W shown in FIG. 13, the above-mentioned preheating of the surface of the workpiece W, formation of a molten pool and a bead 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. The second single character beam in the case of FIG. 13 may be used for other purposes other than preheating. Similarly, the third single character 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 single character regions LS1, LS2, and LS3, and three linear molten pools of a predetermined width may be simultaneously formed on the printing surface of the workpiece W by the first, second, and third single character beams.

[0141] In addition, when the scanning direction of the workpiece W (table 12) is set in the -Y direction, opposite to Figure 13, the third character beam plays a role in heating the surface temperature of the workpiece W to an appropriate temperature before shaping is performed, and the second character beam plays a role in laser polishing the surface of the metal material that has adhered to the surface of the workpiece W and once solidified.

[0142] In the above description, in addition to the irradiation area (first character area) of the first character beam used to form a molten pool on the workpiece, the irradiation area (second character area) of the second character beam used to preheat (preheat) the surface of the workpiece W, and the irradiation area (third character area) of the third character beam used to laser polish the formed bead surface are formed apart from each other on the forming surface. However, for example, the first character area and the second character area may at least partially overlap. Also, at least one of the second character area LS2 and the third character area LS3 may be different from the first character area LS1 in at least one of the shape and size. Also, at least one of the second character beam and the third character beam does not necessarily have to be used, and therefore at least one of the second character area and the third character area does not necessarily have to be formed on the forming surface.

[0143] Up until now, explanations have been given on the premise that by making the character area as thin and sharp as possible, the energy density of the beam irradiated to that character area drops sharply when it is defocused, and this is used to maximize the controllability of the thickness of the molten pool (coating layer).However, in this case, the thickness of the coating layer becomes very thin, and when adding a layer of the same thickness, the additive processing (shaping) must be performed in many separate layers (repeated multiple times), which is disadvantageous in terms of productivity.

[0144] Therefore, there may be cases where the thickness of the coating layer is desired to be thicker, taking into consideration the balance between the required modeling accuracy and throughput. In such a case, the control device 600 changes the intensity distribution of the beam within the modeling surface in accordance with the required modeling accuracy and throughput. Specifically, the control device 600 controls each mirror element 81 of the mirror array 80 to change the intensity distribution of the beam within the modeling surface in accordance with the required modeling accuracy and throughput. p,q By controlling the tilt angle of the laser beam, the width of the character region can be made slightly wider. For example, the character region LS shown in Fig. 15(B) changes to the character region LS'. In this way, the change in energy density when defocused becomes gentler, and the thickness h of the high energy area in the vertical direction becomes thicker as shown in Fig. 15(A). This makes it possible to increase the thickness of the layer that can be produced in one scan, thereby improving productivity.

[0145] As described above, the molding apparatus 100 according to this embodiment has a major feature in that it provides many conveniences and solutions that meet the requirements of actual processing sites, compared to conventional metal 3D printers.

[0146] In the above embodiment, the mirror array 80 is used as the spatial light modulator. Alternatively, a large-area digital mirror device may be used that is made up of a large number of digital micromirror devices (DMD (registered trademark)) fabricated by MEMS technology arranged in a matrix. In such a case, it is difficult to measure the state (e.g., tilt angle) of each mirror element using 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 reflected light from the many mirror elements that make up 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 many mirror elements based on image information obtained by capturing an image formed by the digital mirror device using an imaging means.

[0147] In the molding apparatus 100 according to the above embodiment, the rotary encoder 83 p,q 11. The detection system 89 may be, for example, a system for detecting the number of mirror elements 81 constituting the mirror array 80. p,q The reflected light from the mirror array 80 is received via a beam splitter disposed between the mirror array 80 and the focusing optical system 82, and each mirror element 81 is divided into two groups based on the intensity distribution. p,q A detection system for detecting the above-mentioned state can be used. As the detection system, for example, a system having a configuration similar to that disclosed in U.S. Patent No. 8,456,624 can be used.

[0148] In the above embodiment, each mirror element 81 p,qThe mirror array 80 is of a type that can change the inclination angle of the reflecting surface with respect to the reference plane, but the present invention is not limited to this. Alternatively, a mirror array having a structure in which each mirror element can be inclined with respect to the reference plane and displaced in a direction perpendicular to the reference plane may be adopted. Also, each mirror element does not necessarily have to be inclined with respect to the reference plane. A mirror array displaceable in a direction perpendicular to the reference plane in this way is disclosed in, for example, U.S. Patent No. 8,456,624. In addition, a mirror array in which each mirror element can rotate around two mutually perpendicular axes parallel to the reference plane (i.e., the inclination angle in two perpendicular directions can be changed) may be adopted. A mirror array in which the inclination angle in two perpendicular directions can be changed in this way is disclosed in, for example, U.S. Patent No. 6,737,662. In these cases, the state of each mirror element can be detected using the detection system disclosed in U.S. Patent No. 8,456,624.

[0149] In addition, detection light is irradiated onto the surface of the mirror array 80, and a large number of mirror elements 81 constituting the mirror array 80 are p,q Alternatively, the detection system may be a mirror array (optical device) provided with sensors that individually detect the tilt angle and spacing of each mirror element relative to a reference surface (base).

[0150] In the above embodiment, the incident angles of the parallel beams incident on the pupil plane of the focusing optical system 82 are individually controlled to change the intensity distribution of the beams on the printing surface. However, it is not necessary that all the incident angles of the parallel beams incident on the pupil plane of the focusing optical system 82 can be controlled (changed). Therefore, in the case of controlling the incident angle of the parallel beams incident on the focusing optical system 82 using a mirror array as in the above embodiment, it is not necessary that all the mirror elements can change the state of the reflecting surface (at least one of the position and the inclination angle of the reflecting surface). In the above embodiment, the incident angle of the parallel beams incident on the focusing optical system 82 is controlled, that is, the intensity distribution of the beams on the printing surface is changed. However, instead of the mirror array, a spatial light modulator (non-emissive image display element) described below may be used. Examples of the transmissive spatial light modulator include an electrochromic display (ECD) in addition to a transmissive liquid crystal display element (LCD). In addition to the above-mentioned micromirror array, examples of the reflective spatial light modulator include a reflective liquid crystal display element, an electrophoretic display (EPD: Electro Phonetic Display), electronic paper (or electronic ink), a grating light valve, etc. In the above embodiment, a mirror array (a type of spatial light modulator) is used to change the intensity distribution of a beam on a modeling surface, but the spatial light modulator may be used for other purposes.

[0151] As described above, it is desirable for the light collecting optical system 82 to have a large aperture, but a light collecting optical system with a numerical aperture NA smaller than 0.5 may also be used.

[0152] In the above embodiment, the modeling apparatus 100 may include a sensor capable of arranging a light receiving portion on or near the rear focal plane of the focusing optical system 82 in order to manage the intensity distribution of the beam. For example, it is desirable to mount a CCD image sensor on the table 12 and calibrate the intensity distribution of the beam (intensity distribution in the irradiation area on the modeling surface) at an appropriate frequency using the CCD image sensor. In this case, the measurement may be performed with the light receiving portion of the sensor (e.g., the table 12) stationary, but the light receiving portion of the sensor (e.g., the table 12) may move while performing a scan measurement in which the light receiving portion receives the beam from the focusing optical system 82. By performing the measurement while moving the light receiving portion of the sensor, it is possible to eliminate the influence of a finite number of pixels such as a CCD or a mirror array, and obtain a correct measurement result. In this way, by measuring the intensity distribution of the beam with a sensor that receives the beam from the focusing optical system 82, it is possible to manage the intensity distribution of the beam taking into account fluctuation factors such as thermal aberration of the focusing optical system 82. Furthermore, by controlling the mirror array 80 etc. based on the result of the calculation, the beam intensity distribution on the rear focal plane of the focusing optical system 82 etc. can be set to a desired state with high precision.

[0153] In the above embodiment, the case where titanium and stainless steel powders are used as the modeling material is exemplified, but it is also possible to use powders of iron and other metals, as well as powders of nylon, polypropylene, ABS, and other non-metallic materials. The modeling apparatus 100 according to the above embodiment can also be applied when a material other than powder, such as a filler wire used in welding, is used as the modeling material. In this case, however, a wire feeding device or the like is provided instead of a powder supply system such as a powder cartridge and a nozzle unit.

[0154] In the above embodiment, the nozzle 84a has a plurality of supply ports 91. i In the above description, the powdered molding material PD is supplied from each of the nozzles 81 and 82 in the Z-axis direction parallel to the optical axis AX of the focusing optical system 82, but the invention is not limited to this, and the molding material (powder) may be supplied from a direction inclined with respect to the optical axis AX. Also, the molding material (powder) may be supplied from a direction inclined with respect to the vertical direction.

[0155] In addition, in the modeling apparatus 100 of the above embodiment, the nozzle 84a provided in the material processing unit 530 may have, in addition to the above-mentioned modeling material supply port, a recovery port (suction port) for recovering the powdered modeling material that has not been melted.

[0156] Up to this point, an example of adding a shape to an existing workpiece has been described, but the use of the modeling apparatus 100 according to this embodiment is not limited to this, and it is also possible to generate a three-dimensional shape from nothing on the table 12 by modeling, similar to a normal 3D printer. In this case, it is nothing other than performing additional processing on a workpiece that is "nothing." When modeling such a three-dimensional object on the table 12, the control device 600 optically detects at least three alignment marks formed in advance on the table 12 using the mark detection system 56 (see FIG. 11 ) provided in the measurement system 400, thereby obtaining position information in six degrees of freedom directions of the target surface of the modeling set on the table 12, and based on this result, the control device 600 performs three-dimensional modeling while controlling the position and attitude of the target surface on the table 12 relative to the beam (irradiation area).

[0157] In the above embodiment, the control device 600 controls each of the components of the moving system 200, the measuring system 400, and the beam shaping system 500. However, the present invention is not limited to this. The control device of the shaping system may be configured by a plurality of hardware devices each including a processing device such as a microprocessor. In this case, the moving system 200, the measuring system 400, and the beam shaping system 500 may each include a processing device, or a combination of a first processing device that controls two of the moving system 200, the measuring system 400, and the beam shaping system 500 and a second processing device that controls the remaining system may be used. In either case, each processing device will take on part of the functions of the control device 600. Alternatively, the control device of the shaping system may be configured by a plurality of processing devices such as microprocessors and a host computer that collectively manages these processing devices.

[0158] At least a part of the components of each of the above-described embodiments can be appropriately combined with at least a part of other components of each of the above-described embodiments. Some of the components of each of the above-described embodiments may not be used. In addition, to the extent permitted by law, the disclosures of all publications and U.S. patents related to the exposure apparatus and the like cited in each of the above-described embodiments are incorporated by reference into the present description. [Industrial Applicability]

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

[0160] 12...table, 62...light guide fiber, 64...double fly's eye optical system, 66...condenser lens system, 70...laser unit, 78...beam cross-sectional intensity conversion optical system, 80...mirror array, 81...mirror element, 82...focusing optical system, 83...rotary encoder, 85...limiting member, 89...detection system, 91...supply port, 100...modeling device, 200...movement system, 500...beam modeling system, 520...beam irradiation unit, 530...material processing unit, 540...water shower nozzle, 600...control device, BS...base, PD...modeling material, LS...single character area, LS1...first single character area, LS2...second single character area, LS3...third single character area, MP...modeling surface, TA...target part, TAS...target surface, W...work, WP...molten pool.

Claims

1. A modeling apparatus for forming a three-dimensional object by a DED method, comprising: a beam shaping system including a beam irradiating unit capable of irradiating a plurality of beams, a material processing unit that supplies a modeling material to an area irradiated with the plurality of beams from the beam irradiating unit, and a moving device that relatively moves the beam and a target surface irradiated with the beam; the beam irradiation unit includes at least a plurality of mirrors that reflect the plurality of beams, The beam shaping system includes: During the relative movement, moving the mirrors to change the exit angles of the beams; The modeling material supplied from the material processing unit is melted by the plurality of beams. Modeling equipment.

2. The mirrors can be moved to move the beams during the relative movement. The molding apparatus according to claim 1 .

3. the beam irradiation unit includes a focusing optical system that emits the plurality of beams, By moving the mirrors, the angles of incidence of the beams into the focusing optical system can be changed during the relative movement. The molding apparatus according to claim 2 .

4. The incident angles of the beams with respect to the pupil plane of the focusing optical system are different from each other. The molding apparatus according to claim 3 .

5. The irradiation angles of the beams are changed by the mirrors, thereby changing the irradiation positions of the beams within the target surface. The molding apparatus according to claim 2 .

6. A measurement system for measuring a shape of a workpiece having the target surface is further provided, The motion of the mirrors during the relative movement is controlled based on the measurement results of the measurement system. The molding apparatus according to claim 2 .

7. Each of the beams is reflected by a different mirror. The molding apparatus according to claim 2 .

8. The plurality of beams are irradiated at positions spaced apart in a direction intersecting a direction in which the beams and a target surface irradiated with the beams move relatively to each other. The molding apparatus according to claim 2 .

9. The width of the beam can be changed by controlling the plurality of mirrors. The molding apparatus according to claim 2 .

10. The shape of the beam can be changed by controlling the plurality of mirrors. The molding apparatus according to claim 2 .

11. The position of the beam can be changed by controlling the plurality of mirrors. The molding apparatus according to claim 2 .

12. A method for forming a three-dimensional object by a DED method, comprising the steps of: Irradiating a plurality of beams; supplying a build material to an area irradiated with the plurality of beams; Relatively moving the beam and a target surface onto which the beam is irradiated; During the relative movement, moving at least a plurality of mirrors that reflect the plurality of beams to change the emission angles of the plurality of beams. Including, The irradiating step includes melting the building material supplied to the target surface with the multiple beams.

13. and moving the plurality of beams during the relative movement by moving the plurality of mirrors. The method of claim 12.

14. and changing angles of incidence of the plurality of beams into a focusing optical system that emits the plurality of beams during the relative movement by moving the plurality of mirrors. The method of claim 13.

15. The incident angles of the beams with respect to the pupil plane of the focusing optical system are different from each other. The method of claim 14.

16. and changing the irradiation angles of the beams by the mirrors to change the irradiation positions of the beams within the target surface. The molding apparatus according to any one of claims 13 to 15.

17. and controlling the movement of the plurality of mirrors during the relative movement based on a measurement result of a measurement system that measures a shape of a workpiece having the target surface. The method according to any one of claims 13 to 15.

18. Each of the beams is reflected by a different mirror. The method according to any one of claims 13 to 15.

19. The plurality of beams are irradiated at positions spaced apart in a direction intersecting a direction in which the beams and a target surface irradiated with the beams move relatively to each other. The method according to any one of claims 13 to 15.

20. Varying the width of the beam by controlling the plurality of mirrors. The method according to any one of claims 13 to 15.

21. and modifying the shape of the beam by controlling the plurality of mirrors. The method according to any one of claims 13 to 15.

22. and varying the position of the beam by controlling the plurality of mirrors. The method according to any one of claims 13 to 15.

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