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

Abstract

Provided is a technique for improving the additional processing accuracy of a workpiece compared to the prior art. 【Solution means】The additive processing apparatus includes a laser head capable of performing additive processing on a workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam, a drive unit for driving the laser head, and a control unit for controlling the additive processing apparatus. The control unit executes a process of generating a drive path of the laser head based on three-dimensional data defining the shape of the added portion of the workpiece, a process of expanding the generated drive path in the horizontal direction of the added portion, and a process of driving the laser head according to the expanded drive path to perform additive processing on the workpiece.

Description

Technical Field

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

Background Art

[0002] Japanese Patent Application Laid-Open No. 2023-125537 (Patent Document 1) discloses a processing machine capable of maintaining high machining accuracy in additive processing of a workpiece using a directed energy deposition method. The processing machine includes an additive processing head that supplies a powder material to the workpiece and irradiates the workpiece with laser light, and a first holding portion and a second holding portion for rotatably holding the workpiece. The first holding portion and the second holding portion are provided to face each other in the direction of the rotation axis of the workpiece, and are configured to hold the workpiece from both sides.

[0003] When the workpiece is irradiated with laser light, the workpiece thermally expands (see paragraph

[0005] ). Therefore, when performing additive processing on the workpiece, the processing machine relatively moves the first holding portion and the second holding portion in a direction away from each other. Thereby, the processing machine suppresses the surface of the workpiece from being distorted between the first holding portion and the second holding portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] During additive processing, the workpiece thermally expands due to the irradiation of laser light, but contracts after the completion of additive processing. Due to such size changes, the workpiece may not be additively processed into the intended shape.

[0006] In view of the above points, a technique for improving the additional processing accuracy of a workpiece more than before is desired.

Means for Solving the Problem

[0007] In an example of the present disclosure, an additional processing apparatus includes a laser head capable of performing additional processing on a workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam, a drive unit for driving the laser head, and a control unit for controlling the additional processing apparatus. The control unit executes a process of generating a drive path of the laser head based on three-dimensional data defining the shape of an additional portion of the workpiece, a process of expanding the generated drive path in the horizontal direction of the additional portion, and a process of driving the laser head according to the expanded drive path to perform additional processing on the workpiece.

[0008] In an example of the present disclosure, the additional processing apparatus further includes a workpiece spindle for holding one side of the workpiece and rotating the workpiece about a predetermined axis, and a center rest mechanism for centering the other side of the workpiece. In the process of performing the additional processing, the control unit executes in parallel a process of rotating the workpiece by the workpiece spindle and a process of driving the laser head according to the expanded drive path.

[0009] In an example of the present disclosure, the center rest mechanism includes a center pin configured to be movable forward and backward in the direction of the predetermined axis, and an elastic member for pressing the center pin against the workpiece.

[0010] In an example of the present disclosure, the expanding process includes a process of expanding the generated drive path in the direction of the predetermined axis.

[0011] In an example of the present disclosure, the expanding process includes a process of expanding the generated drive path at least on the installation side of the center rest mechanism.

[0012] In an example of the present disclosure, the expanding process includes a process of increasing the expansion distance of the driving path in the expanding process as the position of the additional portion is closer to the core pressing mechanism.

[0013] In another example of the present disclosure, an additional processing method by an additional processing device is provided. The additional processing device includes a laser head capable of performing additional processing on the workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam, and a driving unit for driving the laser head. The additional processing method includes a step of generating a driving path of the laser head based on three-dimensional data defining the shape of the additional portion of the workpiece, a step of expanding the generated driving path in the horizontal direction of the additional portion, and a step of driving the laser head according to the expanded driving path to perform additional processing on the workpiece.

[0014] In another example of the present disclosure, an additional processing program by an additional processing device is provided. The additional processing device includes a laser head capable of performing additional processing on the workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam, and a driving unit for driving the laser head. The additional processing program causes the additional processing device to execute a process of generating a driving path of the laser head based on three-dimensional data defining the shape of the additional portion of the workpiece, a process of expanding the generated driving path in the horizontal direction of the additional portion, and a process of driving the laser head according to the expanded driving path to perform additional processing on the workpiece.

[0015] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention understood in connection with the accompanying drawings.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0017] Hereinafter, each embodiment according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that each embodiment and each modification described below may be selectively combined as appropriate.

[0018] [First Embodiment] [A. Appearance of the Additional Processing Device 100] First, referring to FIG. 1, an additive processing apparatus 100 according to an embodiment will be described. FIG. 1 is a diagram showing an example of the appearance of the additive processing apparatus 100.

[0019] The additive processing apparatus 100 is a processing machine capable of performing additive processing (AM (Additive manufacturing) processing) on a workpiece. The additive processing apparatus 100 performs additive processing by supplying a powder material to the workpiece and irradiating the workpiece with a laser beam.

[0020] Note that the additive processing apparatus 100 may be a processing machine capable of not only additive processing of a workpiece but also subtractive processing (SM (Subtractive manufacturing)) of the workpiece. Examples of the subtractive processing function include a milling function and a turning function.

[0021] The additive processing apparatus 100 includes, for example, a cover body 130 and an operation panel 200.

[0022] The cover body 130 is a mechanism for protecting the components provided inside the additive processing apparatus 100. A door DR is provided in the cover body 130. The door DR is, for example, a slide-type door. The door DR may be configured to be openable and closable by a drive source such as a motor, or may be configured to be openable and closable manually.

[0023] The operation panel 200 is a general-purpose computer and has a display for displaying various information related to processing. The display is, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or other display device. Further, the display is provided with a touch panel and accepts various operations on the additive processing apparatus 100 by touch operation.

[0024] <B. Device Configuration of Additive Processing Apparatus 100> Next, with reference to FIG. 2, the device configuration of the additive processing device 100 will be described. FIG. 2 is a diagram showing an example of the device configuration of the additive processing device 100. In FIG. 2, as an example of the additive processing device 100, an AM / SM hybrid processing machine capable of both additive processing and removal processing of a workpiece is shown.

[0025] As described above, the additive processing device 100 includes a cover body 130. The cover body 130 forms the exterior of the additive processing device 100 and partitions and forms a processing area AR for performing additive processing on the workpiece W.

[0026] The additive processing device 100 further includes a bed 11, a tool rest 16, a workpiece spindle 22, a centering mechanism 25, a tool spindle 30, and a laser head 140.

[0027] For the convenience of explanation, hereinafter, the rotational axis direction of the workpiece spindle 22 will also be referred to as the "Z-axis direction". The Z-axis direction is parallel to the rotational axes AX1 and AX2 shown in FIG. 2. Also, one direction on the horizontal plane orthogonal to the Z-axis direction will also be referred to as the "X-axis direction". The direction orthogonal to both the X-axis direction and the Z-axis direction is referred to as the "Y-axis direction". In the example of FIG. 2, the Y-axis direction corresponds to the direction of gravity.

[0028] The bed 11 is a base member for supporting various devices within the additive processing device 100. In the example of FIG. 2, the bed 11 supports the tool rest 16, the workpiece spindle 22, the centering mechanism 25, the tool spindle 30, and the laser head 140. The bed 11 is installed on the floor surface of a factory or the like. The bed 11 is formed of a metal such as cast iron.

[0029] The tool post 16 has a turret 18. The turret 18 is configured to be rotatable about the rotation axis AX1. The turret 18 holds a plurality of tools at intervals in the circumferential direction about the rotation axis AX1. Further, the tool post 16 is configured to be movable in the X-axis direction and the Y-axis direction by various drive mechanisms such as a motor. The tool post 16 performs turning by bringing a fixed tool held by the turret 18 into contact with a workpiece W that is rotationally driven by a workpiece spindle 22.

[0030] The workpiece spindle 22 is configured to be rotatable while holding one side of the workpiece W. More specifically, a chuck mechanism 23 is provided on the workpiece spindle 22. The chuck mechanism 23 is a mechanism for fixing the workpiece W to the workpiece spindle 22. Further, the workpiece spindle 22 is configured to be rotatable about a rotation axis AX2 along its axial direction.

[0031] The steady rest mechanism 25 is configured to support the workpiece W from the side opposite to the workpiece spindle 22 so as not to inhibit the rotation of the workpiece W by the workpiece spindle 22. Further, the steady rest mechanism 25 is configured to be movable in the direction of the rotation axis AX2 by various drive mechanisms such as a motor. Thereby, the steady rest mechanism 25 steady rests the long workpiece W from the side opposite to the workpiece spindle 22.

[0032] The configuration for realizing the steady rest is not particularly limited. As an example, the steady rest mechanism 25 includes a center pin 26 and an elastic member 27.

[0033] The center pin 26 is configured to be movable forward and backward in the direction of the rotation axis AX2 (predetermined axis). As an example, the center pin 26 has a pin shape extending in the direction of the rotation axis AX2. Thereby, the center pin 26 steady rests the end face of the workpiece W from the side opposite to the workpiece spindle 22.

[0034] The elastic member 27 is built into the center punch mechanism 25 and is a member that presses the center pin 26 toward the workpiece W. That is, the elastic member 27 generates an elastic force for pressing the center pin 26 toward the workpiece. Thereby, the center punch mechanism 25 can absorb the thermal expansion of the workpiece W generated during the additional processing of the workpiece W while stably supporting the workpiece W. As an example, the elastic member 27 is a coil spring extending around the rotation axis AX2.

[0035] The tool spindle 30 is provided, for example, at a position higher than the workpiece spindle 22 and the center punch mechanism 25. Further, the tool spindle 30 is configured to be detachable from a tool or a laser head 140. FIG. 2 shows an example in which the laser head 140 is attached to the tool spindle 30.

[0036] The attachment and detachment of the laser head 140 to and from the tool spindle 30 are realized, for example, by an automatic tool changer (ATC). When the additive processing apparatus 100 executes the additive processing of the workpiece W, the laser head 140 is attached to the tool spindle 30. On the other hand, when the additive processing apparatus 100 executes the removal processing of the workpiece W, a tool is attached to the tool spindle 30.

[0037] As an example of the removal processing, there is milling processing in which a rotating tool is brought into contact with the workpiece W fixed to the workpiece spindle 22. As another example of the removal processing, there is turning processing in which a tool is pressed against the workpiece W rotating around the rotation axis AX2.

[0038] The laser head 140 performs additive processing by the DED (Direct Energy Deposition) method while being attached to the tool spindle 30. As a mechanism for realizing the additive processing, the laser head 140 includes a head body 142 and a laser nozzle 146.

[0039] Powder material is supplied to the head body 142 via a cable (not shown). The supplied powder material may be metal powder, resin powder, or other types of powder that melt upon irradiation with laser light.

[0040] The laser nozzle 146 irradiates the workpiece W with laser light and defines the irradiation area of the laser light on the workpiece W. The powder material supplied to the laser head 140 is discharged toward the workpiece W through the laser nozzle 146.

[0041] <C. Additional Processing> Next, with reference to FIGS. 3 and 4, the additional processing by the laser head 140 will be described in more detail. FIG. 3 is a view showing the state of additional processing of the workpiece W by the laser head 140 from the Z-axis direction.

[0042] The additional processing apparatus 100 is configured, for example, to enable high-speed additional processing. As an example, as the high-speed additional processing technology, EHLA (Extreme High-speed Laser Application) can be mentioned.

[0043] More specifically, while the laser head 140 moves in the direction of the rotation axis AX2 of the workpiece spindle 22 (i.e., the Z-axis direction), the laser head 140 irradiates the workpiece W that is rotationally driven by the workpiece spindle 22 with the laser light LS. As a result, the irradiated portion of the laser light LS melts, and a molten pool MP is formed on the workpiece W.

[0044] Also, the laser head 140 supplies the powder material PM to the workpiece W in parallel with the irradiation of the laser light LS. Since the focus F of the laser light LS is located above the surface of the workpiece W, the supplied powder material PM melts before reaching the surface of the workpiece W by the laser light LS. As a result, the molten powder material PM is introduced into the molten pool MP. When the molten pool MP hardens on the workpiece W, it becomes a layer SL.

[0045] Laminating is achieved by repeatedly forming layer SL on work W. FIG. 4 is a diagram for explaining the lamination process for work W. FIG. 4 shows a cross-sectional view of work W along the XY plane.

[0046] In the example of FIG. 4, a flange-shaped additional part PB is formed on the base material part PA of work W. The additional part PB is formed by stacking a plurality of layers SL1 to SL4 in order.

[0047] More specifically, first, the additive processing device 100 drives the laser head 140 to the start position of the additive processing in the first layer SL1. After that, the additive processing device 100 executes in parallel the rotation process of work W by the work spindle 22, the driving process of the laser head 140 in the positive Z-axis direction, the irradiation process of the laser light LS by the laser head 140, and the supply process of the powder material PM. Based on the laser head 140 reaching the end position of the additive processing of layer SL1, the additive processing device 100 stops the irradiation process of the laser light LS by the laser head 140 and the supply process of the powder material PM. Thereby, layer SL1 is formed on work W.

[0048] After that, the additive processing device 100 drives the laser head 140 to the start position of the additive processing in the second layer SL2. Next, the additive processing device 100 executes in parallel the rotation process of work W by the work spindle 22, the driving process of the laser head 140 in the positive Z-axis direction, the irradiation process of the laser light LS by the laser head 140, and the supply process of the powder material PM. Based on the laser head 140 reaching the end position of the additive processing of layer SL2, the additive processing device 100 stops the irradiation process of the laser light LS by the laser head 140 and the supply process of the powder material PM. Thereby, layer SL2 is formed on work W.

[0049] By repeating the above processes, the additive processing device 100 can perform additive processing of additional parts PB with various shapes on the base material part PA of work W.

[0050] Note that the formation of the additional portion PB does not necessarily have to be achieved by high-speed additive processing. As an example, the additive processing apparatus 100 may form the additional portion PB by additive processing that rotates the work spindle 22 at a low speed. In this case, the additive processing apparatus 100 forms the additional portion PB with the focus F of the laser beam LS positioned on the surface of the work W.

[0051] <D. Expansion Function of Drive Path>

[0052] (D1. Overview) Next, an overview of the process for expanding the drive path of the laser head 140 will be described.

[0053] The additive processing apparatus 100 generates a drive path for the laser head 140 based on three-dimensional data that defines the shape of the additional portion PB of the work W. Then, the additive processing apparatus 100 drives the laser head 140 according to the generated drive path to form the additional portion PB on the work W.

[0054] At this time, the work W thermally expands due to the irradiation of the laser beam during additive processing and contracts after the completion of additive processing. Therefore, the additional portion PB of the work W may become smaller than the intended size.

[0055] Therefore, the additive processing apparatus 100 according to the present embodiment expands the drive path generated from the three-dimensional data in the horizontal direction of the additional portion PB. As a result, the additive processing apparatus 100 forms an additional portion PB having a size larger than the additional portion PB defined in the three-dimensional data on the work W. Since the additional portion PB returns to room temperature after the additive processing of the work W, it contracts. As a result, the additional portion PB becomes the intended size. As a result, the additive processing accuracy of the work is improved compared to the conventional case.

[0056] (D2. Specific Example) Next, a specific example of the process for expanding the drive path of the laser head 140 will be described with reference to FIGS. 5 and 6. FIG. 5 is a diagram schematically showing the expansion process of the drive path.

[0057] As shown in step S1, the additive processing apparatus 100 first acquires three-dimensional data 124 including the added portion PB of the workpiece W. The three-dimensional data 124 is, for example, data designed by CAD (Computer Aided Design). The three-dimensional data 124 includes at least data indicating the shape of the added portion PB. Note that the three-dimensional data 124 may include the shape of the base material portion PA forming the added portion PB.

[0058] In step S2, the additive processing apparatus 100 generates a drive path R of the laser head 140 based on the three-dimensional data 124. The drive path R is a command value that defines the path of the laser head 140 when forming the added portion PB on the workpiece W.

[0059] The drive path R is generated by any method. As an example, the drive path R may be designed by a designer. As another example, the drive path R may be automatically generated by CAM (Computer Aided Manufacturing). CAM is a tool for automatically generating an NC (Numerically Control) program necessary for processing by the additive processing apparatus 100 based on the three-dimensional data 124 created by CAD.

[0060] The NC program generated by CAM includes the drive path R of the laser head 140. In addition, the NC program may also include the posture (e.g., angle, etc.) of the laser head 140 during additive processing, the speed of the laser head 140 during additive processing, the laser light irradiation command (e.g., ON / OFF command) of the laser head 140 during additive processing, and the supply command (e.g., ON / OFF command) of the powder material PM of the laser head 140 during additive processing.

[0061] Note that the NC program generated by CAM may include not only command values related to the laser head 140 but also command values related to the workpiece spindle 22. As an example, the NC program may include the rotational speed of the workpiece spindle 22 during additive processing.

[0062] The drive path R is generated, for example, for each layer to be formed. In the example of step S2 in FIG. 5, drive paths R1 to RN for forming each of the first to Nth layers (N is a natural number of 2 or more) are shown.

[0063] The drive path R1 includes the start position SP1 of the laser head 140 during the additional processing of the first layer and the end position EP1 of the laser head 140 during the additional processing of the first layer. The drive path R2 includes the start position SP2 of the laser head 140 during the additional processing of the second layer and the end position EP2 of the laser head 140 during the additional processing of the second layer. The drive path RN includes the start position SPN of the laser head 140 during the additional processing of the Nth layer and the end position EPN of the laser head 140 during the additional processing of the Nth layer.

[0064] In step S3, the additive processing apparatus 100 extends the drive path R generated from the three-dimensional data 124 in the direction of the rotation axis AX2 (i.e., the Z-axis direction) to generate an extended drive path R'.

[0065] In the example of FIG. 5, the additive processing apparatus 100 extends the drive paths R1 to RN respectively to generate drive paths R1' to RN'. At this time, the additive processing apparatus 100 may extend the drive paths R1 to RN on one side of the rotation axis AX2, or may extend the drive paths R1 to RN on both sides of the rotation axis AX2.

[0066] As an example, the additive processing apparatus 100 moves the start positions SP1 to SPN of the drive paths R1 to RN to the negative side in the Z-axis direction. As a result, the start positions SP1 to SPN are updated to the start positions SP1' to SPN'. As a result, drive paths R1' to RN' extended to the negative side in the Z-axis direction are generated.

[0067] As another example, the additive processing apparatus 100 moves the end positions EP1 to EPN of the drive paths R1 to RN in the positive Z-axis direction. As a result, the end positions EP1 to EPN are updated to the end positions EP1' to EPN'. As a result, the drive paths R1' to RN' extended in the positive Z-axis direction are generated.

[0068] As yet another example, the additive processing apparatus 100 moves the start positions SP1 to SPN of the drive paths R1 to RN in the negative Z-axis direction and moves the end positions EP1 to EPN of the drive paths R1 to RN in the positive Z-axis direction. As a result, the start positions SP1 to SPN are updated to the start positions SP1' to SPN', and the end positions EP1 to EPN are updated to the end positions EP1' to EPN'. As a result, the drive paths R1' to RN' extended on both sides in the Z-axis direction are generated.

[0069] Thereafter, the additive processing apparatus 100 drives the laser head 140 according to the extended drive path R' to form the added portion PB on the workpiece W. At this time, as described with reference to FIG. 2, the additive processing apparatus 100 performs additive processing while holding the workpiece W with the workpiece spindle 22 and the centering mechanism 25. Since the centering mechanism 25 has an elastic member 27 for absorbing thermal expansion, the size of the workpiece W changes in the direction of the rotation axis AX2 during the additive processing. In accordance with this change, the additive processing apparatus 100 extends the drive path R generated from the three-dimensional data 124 in the direction of the rotation axis AX2. Therefore, even if the workpiece W contracts to room temperature after the additive processing is completed, the added portion PB has the intended size in the direction of the rotation axis AX2. As described above, the processing accuracy of the added portion PB in the direction of the rotation axis AX2 is improved.

[0070] Note that the size of the workpiece W is more likely to change on the installation side of the centering mechanism 25 having an elastic function than on the installation side of the workpiece spindle 22. Therefore, preferably, the additive processing apparatus 100 extends at least the drive path R generated from the three-dimensional data 124 on the installation side of the centering mechanism 25.

[0071] Hereinafter, with reference to FIG. 6, the extension method will be described. FIG. 6 is a diagram schematically showing the process of extending the drive path R shown in FIG. 5 to the drive path R'.

[0072] Note that FIG. 6 shows an example in which one drive path R is extended. Typically, however, the additional processing device 100 applies the extension process shown in FIG. 6 to each of the drive paths R1 to RN shown in FIG. 5.

[0073] In this example, the additional processing device 100 extends the drive path R by an extension distance ΔE1 on the installation side of the work spindle 22 and extends the drive path R by an extension distance ΔE2 on the installation side of the center rest mechanism 25. At this time, the additional processing device 100 makes the extension distance ΔE2 on the installation side of the center rest mechanism 25 longer than the extension distance ΔE1 on the installation side of the work spindle 22. Thereby, the additional processing device 100 can further improve the additional processing accuracy of the work W.

[0074] Note that the extension distance ΔE1 on the installation side of the work spindle 22 may be 0. That is, the additional processing device 100 may extend the drive path R only on the installation side of the center rest mechanism 25.

[0075] Further, the additional portion PB is more likely to thermally displace in the direction of the rotation axis AX2 as it is closer to the center rest mechanism 25. Therefore, the additional processing device 100 may change the extension distances ΔE1 and ΔE2 according to the position of the additional portion PB with respect to the work W. In this case, the additional processing device 100 makes the extension distances ΔE1 and ΔE2 longer as the position of the additional portion PB is closer to the center rest mechanism 25. Thereby, the additional processing device 100 can further improve the additional processing accuracy of the work W.

[0076] Note that the extension distance of the drive path R can be determined by various factors other than the above. As an example, the additional processing device 100 makes the extension distances ΔE1 and ΔE2 longer as the width of the work W in the direction of the rotation axis AX2 is longer. In other words, the additional processing device 100 makes the extension distances ΔE1 and ΔE2 shorter as the width of the work W in the direction of the rotation axis AX2 is shorter.

[0077] As another example, the additional processing device 100 increases the expansion distances ΔE1 and ΔE2 as the temperature of the workpiece W during additional processing is higher. In other words, the additional processing device 100 decreases the expansion distances ΔE1 and ΔE2 as the temperature of the workpiece W during additional processing is lower. The temperature of the workpiece W during additional processing may be measured by a temperature sensor or may be estimated based on the irradiation intensity of the laser light irradiated from the laser head 140.

[0078] <E. Driving mechanism of the additional processing device 100> Next, with reference to FIG. 7, the driving mechanism in the additional processing device 100 will be described. FIG. 7 is a diagram showing an example of the driving mechanism of the additional processing device 100.

[0079] As shown in FIG. 7, the additional processing device 100 includes a control unit 50 and driving units 210, 220, 230A, 230B, and 240.

[0080] The control unit 50 controls various devices in the additional processing device 100. The device configuration of the control unit 50 is arbitrary. The control unit 50 may be composed of a single control unit or may be composed of a plurality of control units. As an example, the control unit 50 includes at least one of a CNC (Computer Numerical Control) and a PLC (Programmable Logic Controller).

[0081] The driving unit 210 is a driving mechanism for rotationally driving the workpiece spindle 22. The driving unit 210 may be composed of a single driving unit or may be composed of a plurality of driving units. In the example of FIG. 7, the driving unit 210 is composed of a motor driver 211C and a motor 212C.

[0082] The motor driver 211C sequentially receives an input of a target rotation angle or a target rotation speed of the work spindle 22 from the control unit 50, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 212C. Thereby, the work held by the work spindle 22 rotates about the Z-axis direction as the rotation center. The motor 212C may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0083] The drive unit 220 is a drive mechanism for driving the center drill mechanism 25. The drive unit 220 may be composed of a single drive unit or a plurality of drive units. In the example of FIG. 7, the drive unit 220 is composed of a motor driver 221Z and a motor 222Z.

[0084] The motor driver 221Z sequentially receives an input of a target position regarding the work spindle 22 from the control unit 50, and outputs a current corresponding to the target position to the motor 222Z. Thereby, the motor 222Z moves the center drill mechanism 25 to an arbitrary position in the Z-axis direction. The motor 222Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0085] The drive unit 230A is a drive mechanism for moving the position of the tool spindle 30. The above-described laser head 140 is driven by being attached to the tool spindle 30. The drive unit 230A may be composed of a single drive unit or a plurality of drive units. In the example of FIG. 7, the drive unit 230A is composed of motor drivers 231X to 231Z and motors 232X to 232Z.

[0086] The motor driver 231X sequentially receives the input of the target position of the tool spindle 30 in the X-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 232X. Thereby, the motor 232X drives the tool spindle 30 to an arbitrary position in the X-axis direction. The motor 232X may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0087] The motor driver 231Y sequentially receives the input of the target position of the tool spindle 30 in the Y-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 232Y. Thereby, the motor 232Y drives the tool spindle 30 to an arbitrary position in the Y-axis direction. The motor 232Y may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0088] The motor driver 231Z sequentially receives the input of the target position of the tool spindle 30 in the Z-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 232Z. Thereby, the motor 232Z moves the tool spindle 30 to an arbitrary position in the Z-axis direction. The motor 232Z may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0089] The drive unit 230B is a drive mechanism for rotationally driving the tool spindle 30. The drive unit 230B may be composed of a single drive unit or a plurality of drive units. In the example of FIG. 7, the drive unit 230B is composed of the motor drivers 231A, 231B and the motors 232A, 232B.

[0090] The motor driver 231A sequentially receives from the control unit 50 an input of a target rotation angle or a target rotation speed of the tool spindle 30 centered on the X-axis direction, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 232A. The motor 232A drives the tool spindle 30 to rotate about the X-axis direction. The motor 232A may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0091] The motor driver 231B sequentially receives from the control unit 50 an input of a target rotation angle or a target rotation speed of the tool spindle 30 centered on the axial direction of the tool spindle 30, and outputs a current corresponding to the target rotation angle or the target rotation speed to the motor 232B. The motor 232B drives the tool spindle 30 to rotate about the axial direction of the tool spindle 30. The motor 232B may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0092] The drive unit 240 is a drive mechanism for driving the tool rest 16 and the turret 18. The drive unit 240 may be composed of a single drive unit or a plurality of drive units. In the example of FIG. 7, the drive unit 240 is composed of the motor drivers 241C, 241Y, 241Z and the motors 242C, 242Y, 242Z.

[0093] The motor driver 241C receives an input of a target value regarding the turning angle of the turret 18 centered on the Z-axis direction, and outputs a current corresponding to the target value to the motor 242C. Thereby, the motor driver 241C controls the turning angle of the turret 18 centered on the Z-axis direction. The motor 242C may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0094] The motor driver 241Y sequentially receives the input of the target position of the tool post 16 in the Y-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 242Y. Thereby, the motor 242Y moves the tool post 16 to an arbitrary position in the Y-axis direction. The motor 242Y may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0095] The motor driver 241Z sequentially receives the input of the target position of the tool post 16 in the Z-axis direction from the control unit 50, and outputs a current corresponding to the target position to the motor 242Z. Thereby, the motor 242Z moves the tool post 16 to an arbitrary position in the Z-axis direction. The motor 242Z may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0096] <F. Hardware Configuration of Control Unit 50> Next, with reference to FIG. 8, the hardware configuration of the control unit 50 shown in FIG. 7 will be described. FIG. 8 is a diagram showing an example of the hardware configuration of the control unit 50.

[0097] As described above, the control unit 50 may be a CNC or a PLC. FIG. 8 shows the hardware configuration of the control unit 50 as a CNC.

[0098] The control unit 50 includes, for example, a control circuit 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a communication interface 104, and an auxiliary storage device 120. These components are connected to an internal bus 109.

[0099] The control circuit 101 is constituted by, for example, at least one integrated circuit. The integrated circuit can be constituted by, for example, at least one CPU (Central Processing Unit), at least one GPU (Graphics Processing Unit), at least one ASIC (Application Specific Integrated Circuit), at least one FPGA (Field Programmable Gate Array), or a combination thereof.

[0100] The control circuit 101 controls the operation of the control unit 50 by executing various programs such as the machining program 122. The machining program 122 is a program for realizing the various processes described in this specification. Based on receiving an execution instruction of the machining program 122, the control circuit 101 reads the machining program 122 from the ROM 102 into the RAM 103. The RAM 103 functions as a working memory and temporarily stores various data necessary for the execution of the machining program 122.

[0101] The communication interface 104 is an interface for realizing communication with various devices. The additional processing device 100 communicates with various drive units (for example, the above-described drive units 210, 220, 230A, 230B, 240, etc.) for realizing the additional processing of the workpiece via the communication interface 104, for example.

[0102] The auxiliary storage device 120 is a storage medium such as a hard disk or a flash memory, for example. The auxiliary storage device 120 stores the machining program 122 and the above-described three-dimensional data 124, etc. The storage locations of the machining program 122 and the three-dimensional data 124 are not limited to the auxiliary storage device 120 and may be stored in the storage area (for example, cache memory) of the control circuit 101, the ROM 102, the RAM 103, an external device (for example, a server), etc.

[0103] Further, the machining program 122 may be provided not as a single program but incorporated into a part of any program. In this case, various processes according to the present embodiment are realized in cooperation with any program. Even a program that does not include such a part of the module does not deviate from the gist of the machining program 122 according to the present embodiment. Further, part or all of the functions provided by the machining program 122 may be realized by dedicated hardware. Further, the control unit 50 may be configured in a form such as a so-called cloud service in which at least one server executes a part of the processing of the machining program 122.

[0104] <G. Control Flow of Additional Machining> Next, with reference to FIG. 9, the control flow of additional machining will be described. FIG. 9 is a flowchart showing the flow of the additional machining process.

[0105] The process shown in FIG. 9 is realized, for example, when the control unit 50 of the additional machining apparatus 100 executes the above-described machining program 122. In other aspects, part or all of the process may be executed by circuit elements or other hardware.

[0106] In step S110, the control unit 50 acquires three-dimensional data 124 including the additional part PB of the workpiece W.

[0107] In step S112, the control unit 50 generates an NC program that defines a drive command for the laser head 140 based on the three-dimensional data 124 acquired in step S110. The NC program includes a drive path of the laser head 140 for forming the additional part PB. The NC program may also include the posture (such as an angle) of the laser head 140 during additional machining, the speed of the laser head 140, an irradiation command for the laser light from the laser head 140, a supply command for the powder material PM from the laser head 140, and the like. Further, the NC program may include command values such as the rotation speed of the workpiece spindle 22.

[0108] In step S114, the control unit 50 extends the drive path of the laser head 140 defined in the NC program generated in step S112. Since the extension process of the drive path is as described above, the description thereof will not be repeated.

[0109] In step S116, the control unit 50 controls the laser head 140 according to the NC program after the extension process in step S114. Thereby, the additional processing device 100 forms an additional portion PB on the workpiece W.

[0110] In the above description, an example in which the processes of steps S110, S112, S114, and S116 are continuously executed has been described. However, these processes do not necessarily have to be continuously executed. As an example, the generation process of the NC program shown in steps S110, S112, and S114 and the additional processing process shown in step S116 may be executed at different timings. In this case, these processes may be executed by the same device or by different devices.

[0111] [Second Embodiment] <H. Overview> Next, the additional processing device 100 according to the second embodiment will be described.

[0112] The additional processing device 100 according to the first embodiment described above extended the drive path of the laser head 140 in consideration of the thermal expansion of the workpiece during additional processing. Thereby, the additional processing device 100 improved the additional processing accuracy of the workpiece.

[0113] On the other hand, the additional processing device 100 according to the second embodiment improves the additional processing accuracy of the workpiece in different processing modes. Specifically, when the powder material PM is supplied to the end of the additional portion PB, a part of the powder material PM may fall from the end of the additional portion PB. As a result, the width of the additional portion PB may become shorter than intended. This becomes more prominent as the number of stacked layers increases.

[0114] Therefore, when the additional processing device 100 according to the second embodiment performs additional processing on the horizontal end of the additional portion PB, the laser head 140 is driven such that the optical axis of the laser head 140 faces the end from the outside of the additional portion PB in a top view. Here, the optical axis refers to a straight line connecting the center of the emission port of the laser light LS in the laser head 140 and the focal point F (see FIG. 3) of the laser light LS. By driving the laser head 140 such that the optical axis is inclined with respect to the gravitational direction, the powder material PM is more likely to enter the inside of the workpiece W. As a result, the fall of the powder material PM from the end of the workpiece W is suppressed, and the additional processing accuracy is improved.

[0115] In the following, the differences between the additive manufacturing apparatus 100 according to the first embodiment and the additive manufacturing apparatus 100 according to the second embodiment will be described, and the common points thereof will be omitted.

[0116] <I. Driving mode of the laser head 140> Next, with reference to FIGS. 10 to 12, the driving mode of the laser head 140 during additive manufacturing according to the present embodiment will be described.

[0117] FIG. 10 is a diagram showing the additive manufacturing process S10 of the layer SL4. FIG. 11 is a diagram showing the additive manufacturing process S11 of the layer SL4 following FIG. 10. FIG. 12 is a diagram showing the additive manufacturing process S12 of the layer SL4 following FIG. 11.

[0118] In the following, the angle formed by the optical axis AXL of the laser head 140 and the orthogonal plane SF of the rotation axis AX2 is defined as the tilt angle θ of the laser head 140.

[0119] Also, the end portion of the additional portion PB in the direction of the rotation axis AX2 is defined as the end portion E. The end portion E is, for example, a portion of the additional portion PB included at a predetermined distance from the end surface of the additional portion PB in the direction of the rotation axis AX2. Also, one side of the end portion E in the direction of the rotation axis AX2 is referred to as the end portion E1, and the other side of the end portion E in the direction of the rotation axis AX2 is referred to as the end portion E2.

[0120] In the additional processing step S10, it is assumed that the additional processing of the layer SL4 is started. Based on this, the additive processing apparatus 100 drives the laser head 140 so that the inclination angle θ becomes larger than 0°. At this time, the additive processing apparatus 100 tilts the laser head 140 so that the optical axis AXL faces the end E1 from the outside of the additional portion PB in a top view. The inclination angle θ in the additional processing step S10 is, for example, 10° or more and 45° or less.

[0121] In the additional processing step S11, it is assumed that the additional processing position has passed the end E1. During the additional processing other than the end E1, the additive processing apparatus 100 drives the laser head 140 while maintaining the state where the optical axis AXL is parallel to the gravitational direction. At this time, the optical axis AXL becomes parallel to the orthogonal plane SF, and the inclination angle θ becomes 0°. As a result, the powder material PM is supplied in the gravitational direction (that is, the positive side of the Y-axis direction). Thereafter, the additive processing apparatus 100 drives the laser head 140 in the positive direction of the Z-axis while maintaining the inclination angle θ at 0°.

[0122] In the additional processing step S12, it is assumed that the additional processing position has reached the end E2. Based on this, the additive processing apparatus 100 drives the laser head 140 so that the inclination angle θ becomes larger than 0°. At this time, the additive processing apparatus 100 tilts the laser head 140 so that the optical axis AXL faces the end E2 from the outside of the additional portion PB in a top view. That is, in the additional processing step S12, the additive processing apparatus 100 tilts the laser head 140 in the opposite direction to the additional processing step S10. The inclination angle θ of the laser head 140 in the additional processing step S12 is, for example, 10° or more and 45° or less.

[0123] Preferably, the additive processing apparatus 100 maintains a constant separation distance from the laser head 140 to the additive portion PB during the additive processing steps S10 to S12. As an example, the separation distance is the distance in the direction of the optical axis AXL. In this case, the additive processing apparatus 100 maintains a constant distance from the laser head 140 to the additive portion PB in the direction of the optical axis AXL during the additive processing steps S10 to S12. Thereby, the focal position of the laser beam with respect to the additive portion PB is less likely to fluctuate, and the quality of the additive processing is stabilized.

[0124] As another example, the separation distance is the distance in the direction of gravity. In this case, the additive processing apparatus 100 performs the additive processing in the additive processing steps S10 to S12 while maintaining the position of the laser head 140 in the direction of gravity.

[0125] Note that the additive processing apparatus 100 may change the inclination angle θ stepwise or maintain the inclination angle θ constant during the additive processing of the end portion E. Preferably, the additive processing apparatus 100 increases the inclination angle θ as the additive processing position approaches the outermost end of the additive portion PB in the direction of the rotation axis AX2. In other words, the additive processing apparatus 100 decreases the inclination angle θ as the additive processing position moves toward the inside of the additive portion PB in the direction of the rotation axis AX2. Thereby, the additive processing apparatus 100 can reduce the amount of powder material PM falling from the end portion E and make the quality of the additive processing more stable.

[0126] Also, in the above description, the additive processing steps S10 to S12 of the layer SL4 have been described. However, the additive processing apparatus 100 may make the inclination angle θ greater than 0° during the additive processing of each end portion E of the layers SL1 to SL4. At this time, the inclination angle θ at each end portion E of the layers SL1 to SL4 may be constant or may be changed for each layer. Preferably, the additive processing apparatus 100 drives the laser head 140 so that the inclination angle θ at the end portion E of the upper layer is greater than the inclination angle θ at the end portion E of the lower layer.

[0127] FIG. 13 is a diagram showing the mode of additional processing of the end portion E2 in different layers SL3 and SL4. In FIG. 13(A), the inclination angle θ of the laser head 140 during the additional processing of the end portion E2 of the layer SL3 is shown as "θ1". In FIG. 13(B), the inclination angle θ of the laser head 140 during the additional processing of the end portion E2 of the layer SL4 is shown as "θ2".

[0128] As shown in FIG. 13, the additive manufacturing apparatus 100 makes the inclination angle θ2 during the additive manufacturing of the layer SL4 larger than the inclination angle θ1 during the additive manufacturing of the lower layer SL3. As a result, the powder material PM is supplied more obliquely from the side toward the end portion E in the upper layer. As a result, the additive manufacturing apparatus 100 can reliably stack the powder material PM layer by layer, and can improve the additive manufacturing accuracy.

[0129] <J. Control Flow of Additive Manufacturing> Next, with reference to FIG. 14, the control flow of additive manufacturing according to the second embodiment will be described. FIG. 14 is a flowchart showing the flow of the additive manufacturing process according to the present embodiment.

[0130] The process shown in FIG. 14 is realized, for example, when the control unit 50 of the additive manufacturing apparatus 100 executes the above-described machining program 122. In other aspects, part or all of the process may be executed by circuit elements or other hardware.

[0131] In step S210, the control unit 50 initializes the variable "N". At this time, the variable "N" is initialized to "1".

[0132] In step S212, the control unit 50 acquires the drive path of the laser head 140 in the Nth layer, and moves the laser head 140 to the start position defined in the drive path.

[0133] In step S214, the control unit 50 drives the laser head 140 to be in an inclined posture such that the above-described inclination angle θ (see FIG. 10) is greater than 0°. Thereafter, the control unit 50 starts the irradiation of the laser beam by the laser head 140 and the supply of the powder material by the laser head 140, and drives the laser head 140 according to the drive path acquired in step S212.

[0134] In step S220, the control unit 50 determines whether or not the current additional processing position has passed the above-described end portion E1 (see FIG. 10). When the control unit 50 determines that the current additional processing position has passed the end portion E1 (YES in step S220), the control is switched to step S222. Otherwise (NO in step S220), the control unit 50 executes the process of step S220 again.

[0135] In step S222, during the additional processing between the end portions E1 and E2, the control unit 50 drives the laser head 140 to be in an upright posture such that the above-described inclination angle θ (see FIG. 11) is 0°. Thereafter, the control unit 50 continues the additional processing according to the drive path acquired in step S212.

[0136] In step S230, the control unit 50 determines whether or not the current additional processing position has reached the above-described end portion E2 (see FIG. 12). When the control unit 50 determines that the current additional processing position has reached the end portion E2 (YES in step S230), the control is switched to step S232. Otherwise (NO in step S230), the control unit 50 executes the process of step S230 again.

[0137] In step S232, the control unit 50 drives the laser head 140 to be in an inclined posture such that the above-described inclination angle θ (see FIG. 12) is greater than 0°, and continues the additional processing according to the drive path acquired in step S212.

[0138] In step S240, the control unit 50 determines whether the current position of the laser head 140 has reached the end position defined in the drive path acquired in step S212. When it is determined that the current position of the laser head 140 has reached the end position (YES in step S240), the control is switched to step S242. Otherwise (NO in step S240), the control unit 50 executes the process of step S240 again.

[0139] In step S242, the control unit 50 stops the additional processing. That is, the control unit 50 stops the irradiation of the laser light LS by the laser head 140 and the supply of the powder material PM by the laser head 140.

[0140] In step S250, the control unit 50 determines whether a predetermined end condition is satisfied. As an example, the end condition is satisfied when the variable "N" is greater than or equal to a predetermined value. The predetermined value is a natural number of 1 or more. When the control unit 50 determines that the predetermined end condition is satisfied (YES in step S250), the process shown in FIG. 14 is terminated. Otherwise (NO in step S250), the control unit 50 switches the control to step S252.

[0141] In step S252, the control unit 50 increments the variable "N". That is, the control unit 50 adds "1" to the variable "N".

[0142] <K. Others> The above first and second embodiments may be selectively combined as appropriate. Also, the ideas of the above first and second embodiments can be variously improved and modified. Hereinafter, modified examples of the above first and second embodiments will be described.

[0143] In the above description, the explanation has been made on the premise of the additional processing device 100 including the work spindle 22 and the center pushing mechanism 25. However, the technical idea described in this specification can also be applied to the additional processing device 100 that does not include the work spindle 22 and the center pushing mechanism 25. The additional processing device 100 forms the additional portion PB by sequentially forming layers on the non-rotating work W. The technical idea described in this specification can also be applied to such an additional processing device 100.

[0144] It should be considered that all the embodiments disclosed this time are illustrative and not restrictive in all respects. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all changes within the meaning and scope equivalent to the claims are included.

Explanation of reference signs

[0145] 11 Bed, 16 Tool rest, 18 Turret, 22 Work spindle, 23 Chuck mechanism, 25 Center punch mechanism, 26 Center pin, 27 Elastic member, 30 Tool spindle, 50 Control unit, 100 Additional processing device, 101 Control circuit, 102 ROM, 103 RAM, 104 Communication interface, 109 Internal bus, 120 Auxiliary storage device, 122 Processing program, 124 Three-dimensional data, 130 Cover body, 140 Laser head, 142 Head body, 146 Laser nozzle, 200 Control panel, 210 Drive unit, 211 C motor driver, 212 C motor, 220 Drive unit, 221 Z motor driver, 222 Z motor, 230A Drive unit, 230B Drive unit, 231A Motor driver, 231B Motor driver, 231X Motor driver, 231Y Motor driver, 231Z Motor driver, 232A Motor, 232B Motor, 232X Motor, 232Y Motor, 232Z Motor, 240 Drive unit, 241C Motor driver, 241Y Motor driver, 241Z Motor driver, 242C Motor, 242Y Motor, 242Z Motor, AR processing area, AX1 Rotation axis, AX2 Rotation axis, AXL Optical axis, DR Door, E End, E1 End, E2 End, EPN End position, EP1 End position, EP1' End position, EP2 End position, F Focus, LS Laser beam, MP Molten pool, PA Base material part, PB Added part, PM Powder material, R Drive path, R1 Drive path, R1' Drive path, R2 Drive path, RN Drive path, R' Drive path, SF Orthogonal plane, SL Layer, SL1 Layer, SL2 Layer, SL3 Layer, SL4 Layer, SPN Start position, SP1 Start position, SP1' Start position, SP2 Start position, W Workpiece, ΔE1 Expansion distance, ΔE2 Expansion distance, θ Tilt angle, θ1 Tilt angle, θ2 Tilt angle.

Claims

1. An additional processing device, A laser head capable of performing additional processing on a workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser light; A drive unit for driving the laser head; a work spindle for holding one side of the work and rotating the work around a predetermined axis; a tailstock mechanism for tailstocking the other side of the workpiece; A control unit for controlling the additional processing device, The control unit is generating a drive path for the laser head based on three-dimensional data defining a shape of the additional portion of the workpiece; extending the generated driving path in the horizontal direction of the added portion; Drive the laser head according to the expanded drive path to perform additional machining on the workpiece; An additional machining device, wherein in the additional machining process, a process of rotating the workpiece by the work spindle and a process of driving the laser head according to the expanded drive path are performed in parallel.

2. The tailstock mechanism includes: a center pin configured to be movable in the direction of the predetermined axis; The additional processing device according to claim 1 , further comprising: an elastic member for pressing the center pin toward the workpiece.

3. The additional processing apparatus according to claim 1 or 2, wherein the expanding process includes a process of expanding the generated drive path in a direction of the predetermined axis.

4. The additional machining apparatus according to claim 3 , wherein the expanding process includes a process of expanding the generated drive path at least on a side where the tailstock mechanism is installed.

5. The additional machining apparatus according to claim 1 or 2, wherein the expanding process includes a process of increasing an expanding distance of a drive path in the expanding process as the position of the additional portion is closer to the tailstock mechanism.

6. An additional processing method using an additional processing device, The additional processing device is A laser head capable of performing additional processing on a workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser light; A drive unit for driving the laser head; a work spindle for holding one side of the work and rotating the work around a predetermined axis; a tailstock mechanism for tailstocking the other side of the workpiece, The additive processing method includes: generating a drive path of the laser head based on three-dimensional data defining a shape of the additional portion of the workpiece; extending the generated driving path in a horizontal direction of the additional portion; and driving the laser head according to the expanded drive path to additionally machine the workpiece. An additional machining method, wherein in the additional machining step, a process of rotating the workpiece by the work spindle and a process of driving the laser head according to the expanded drive path are performed in parallel.

7. An additional processing program for an additional processing device, The additional processing device is A laser head capable of performing additional processing on a workpiece by supplying a powder material to the workpiece and irradiating the workpiece with a laser light; A drive unit for driving the laser head; a work spindle for holding one side of the work and rotating the work around a predetermined axis; a tailstock mechanism for tailstocking the other side of the workpiece, The additional processing program is configured to: generating a drive path for the laser head based on three-dimensional data defining a shape of the additional portion of the workpiece; extending the generated driving path in the horizontal direction of the added portion; and driving the laser head according to the expanded drive path to perform additional machining on the workpiece. An additional machining program in which, in the additional machining process, a process of rotating the workpiece by the work spindle and a process of driving the laser head according to the expanded drive path are executed in parallel.

Images