Stacked manufacturing method

Abstract

To form a good-quality three-dimensional molding by suppressing the influence of drooping when metal layers are laminated by welding.SOLUTION: A laminate molding method for forming a three-dimensional molding by sequentially laminating a plurality of metal layers carries out repeatedly a unit process including a step of laminating metal layers made of welding beads to form a laminate molding and a step of shaving off a molding side surface directed in a second direction intersecting a first direction in which the metal layers are laminated in the laminate molding to form a processed side surface. In the step of forming the processed side surface, the molding side surface is shaved off so as to form a reception part projecting in the second direction with respect to the processed side surface on the uppermost layer of the laminate molding in the first direction. When the unit process is repeated, in the step of forming the laminate molding, a new metal layer is laminated so as to be superposed on the upper surface of the reception part in the first direction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a layered manufacturing method.

Background Art

[0002] For example, Patent Document 1 discloses a configuration in which metal layers composed of weld beads formed by arc welding are sequentially laminated as a layered manufacturing method for manufacturing a three-dimensional object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration as disclosed in Patent Document 1, when the thickness of the already laminated metal layer is small, by laminating a new metal layer by arc welding, the end portion of the already laminated metal layer may melt and sag together with the new metal layer. This is because the already laminated metal layer melts due to the heat of the molten welding material for laminating the new metal layer. Such a phenomenon significantly affects the end portion of the metal layer. As a result, in the process of laminating the metal layers, the shape of the side surface, which is the end portion of the metal layer, may collapse due to sagging, and it may not be possible to accurately laminate the next metal layer.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a layered manufacturing method capable of suppressing the influence of sagging when laminating a metal layer by welding and forming a three-dimensional object with good quality.

Means for Solving the Problems

[0006] In order to solve the above problems, a laminated manufacturing method according to the present disclosure is a laminated manufacturing method for manufacturing a three-dimensional object formed by sequentially laminating a plurality of metal layers, the method including: a step of laminating metal layers composed of weld beads to form a laminated manufacturing part; and a step of cutting a side surface of the manufacturing part facing a second direction intersecting a first direction in which the metal layers are laminated in the laminated manufacturing part to form a processed side surface. The unit steps including these steps are repeatedly performed. In the step of forming the processed side surface, the side surface of the manufacturing part is cut so as to form a receiving part that protrudes in the second direction with respect to the processed side surface on the uppermost layer in the first direction of the laminated manufacturing part. When the unit steps are repeated, in the step of forming the laminated manufacturing part, a new metal layer is laminated so as to overlap the upper surface of the receiving part in the first direction. , the shaped object is formed in a cylindrical shape centered on an axis extending in the first direction, and fluid can flow inside. In the step of forming the processed side surface, the side surface facing the inner side in the radial direction of the shaped object is formed by the processed side surface, and the processed side surface is formed by scraping the shaped part side surface in the flow direction of the fluid flowing inside the shaped object. .

Advantages of the Invention

[0007] According to the laminated manufacturing method of the present disclosure, when laminating metal layers by welding, the influence of sag can be suppressed, and a three-dimensional object with good quality can be formed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments for carrying out the additive manufacturing method according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to only this embodiment.

[0010] As shown in FIG. 1, in the additive manufacturing method S10 according to the embodiment of the present disclosure, a three-dimensional shaped object 100 is shaped. The shaped object 100 shaped by the additive manufacturing method S10 of the present embodiment is, for example, a component constituting a rotating machine such as a turbine or a compressor. More specifically, examples of the shaped object 100 to be shaped include a nozzle, an impeller, and a casing. In the present embodiment, as the shaped object 100, a cylindrical nozzle extending in the first direction D1 around the axis O is shaped. In the completed nozzle (shaped object 100), a fluid such as steam or air, which is a gas, can flow as a working fluid inside so that the first direction D1 is the flow direction F1 (see FIG. 4).

[0011] In the additive manufacturing method S10, a plurality of metal layers 101 are stacked on the support surface 5f of the table 5 to form a shaped object 100 with a predetermined shape. The additive manufacturing method S10 is implemented by an NC (Numerical Control) machine tool to which a welding torch or a processing tool is attached. One metal layer 101 is composed of a welding bead 102. The welding bead 102 is generated by arc welding performed with the welding torch of the NC machine tool. The support surface 5f of the table 5 forms a surface orthogonal to the first direction D1. In the present embodiment, the first direction D1 is set to coincide with the vertical direction Dv. Thereby, the plurality of metal layers 101 are stacked on the support surface 5f from the first side D1a (the side approaching the support surface 5f with respect to the metal layer 101) to the second side D1b (the side away from the support surface 5f with respect to the metal layer 101) in the first direction D1. That is, the first direction D1 is the direction in which the metal layers 101 are stacked. Note that the first direction D1 may be a direction inclined with respect to the vertical direction Dv as long as it is not orthogonal to the vertical direction Dv.

[0012] As shown in FIG. 2, the additive manufacturing method S10 of the present embodiment mainly includes a step S20 of forming the additive manufacturing part 105, a step S30 of forming the processed side surface 103, a step S40 of determining the number of times of forming the additive manufacturing part 105, and a step S50 of performing the final processing.

[0013] As shown in FIG. 3, in step S20 of forming the laminated forming portion 105, a laminated forming portion 105 having a predetermined height H1 in the first direction D1 is formed. The laminated forming portion 105 constitutes a partial region of the formed object 100. As shown in FIG. 2, step S20 of forming the laminated forming portion 105 includes a step S21 of laminating the metal layer 101, a step S22 of cooling the metal layer 101, a step S23 of measuring the temperature, a step S24 of determining the temperature, and a step S25 of determining the number of laminations. Step S20 of forming the laminated forming portion 105 repeatedly performs step S21 of laminating the metal layer 101, step S22 of cooling the metal layer 101, step S23 of measuring the temperature, step S24 of determining the temperature, and step S25 of determining the number of laminations a preset number of times. In step S20 of forming the laminated forming portion 105, a predetermined number of metal layers 101 are laminated in the first direction D1 to form a laminated forming portion 105 having a predetermined height H1. The laminated forming portion 105 having the predetermined height H1 has a forming portion side surface 106 facing the second direction D2 intersecting the first direction D1 in a cross section parallel to the axis O. In the present embodiment, the laminated forming portion 105 is formed in a cylindrical shape extending in the first direction D1. Further, the second direction D2 of the present embodiment is a direction orthogonal to the first direction D1 and is the radial direction (width direction) Dr of the laminated forming portion 105. Therefore, the laminated forming portion 105 has, as the forming portion side surface 106, an inner forming portion side surface 106s facing the inner side Dri in the radial direction Dr (second direction D2) and an outer forming portion side surface 106t facing the outer side Dro in the radial direction Dr. That is, the inner forming portion side surface 106s is the inner peripheral surface of the laminated forming portion 105 facing the axis O in the radial direction Dr. Further, the outer forming portion side surface 106t is the outer peripheral surface of the laminated forming portion 105 facing the side opposite to the axis O in the radial direction Dr.

[0014] As shown in FIG. 3, in the step S21 of laminating the metal layer 101, the metal layer 101 composed of the weld bead 102 formed by arc welding is laminated. In the step S21 of laminating the metal layer 101, first, the weld bead 102 is formed by arc welding on the support surface 5f of the table 5. In the step S21 of laminating the metal layer 101, the weld bead 102 is formed based on the shape data of the object 100 input in advance. In the step S21 of laminating the metal layer 101 of the present embodiment, a plurality of passes of weld beads 102 are continuously formed by arc welding in the second direction D2 orthogonal to the first direction D1, thereby constituting one layer of the metal layer 101. In the step S21 of laminating the metal layer 101, it is preferable to form the weld bead 102 by high-speed welding such as rotary arc welding.

[0015] Note that the metal layer 101 is not limited to being constituted by one layer of a plurality of passes of weld beads 102 as in the present embodiment, and may be constituted by one layer of a weld bead 102 of only one pass.

[0016] In the step S22 of cooling the metal layer 101, a refrigerant is supplied to the surface of the uppermost metal layer 101 laminated in the step S21 of laminating the metal layer 101 to cool the metal layer 101. The uppermost metal layer 101 is the metal layer 101 located on the most second side D1b in the first direction D1. That is, the uppermost metal layer 101 is the metal layer 101 that forms the top of the laminated molding portion 105. In the step S22 of cooling the metal layer 101 of the present embodiment, a liquid refrigerant is directly supplied to the surface of the uppermost metal layer 101. In the step S22 of cooling the metal layer 101, for example, cutting oil or air is supplied as the refrigerant. Thereby, when the step S21 of laminating the metal layer 101 is repeated, a new metal layer 101 is laminated on the surface of the uppermost metal layer 101 cooled in the step S22 of cooling the metal layer 101.

[0017] In the process S22 of cooling the metal layer 101 of the present embodiment, for example, the uppermost metal layer 101 may be subjected to processing other than cooling. For example, in the process S22 of cooling the metal layer 101, impurities on the surface of the uppermost metal layer 101 laminated in the process S21 of laminating the metal layer 101 may be removed. The removal of impurities is to scrape off and remove the impurities adhering to the surface and periphery of the metal layer 101 by a cutting tool or a polishing tool attached to an NC processing machine as a processing tool. Here, the impurities are foreign substances generated on the surface and its periphery of the weld bead 102 that causes welding defects. Specifically, examples of the impurities include spatter, slag, and fume. Spatter is metal particles scattered around the weld bead 102. Slag is a foreign substance composed of an intermetallic compound generated from the base material or the welding material. Specific examples of slag include, for example, glassy substances with a low melting point. Fume is mineral dust adhering to the periphery of the weld bead 102. Fume is composed of components contained in the base material or the welding material, but the ratio of each component is significantly different from that of the original material.

[0018] In the process S23 of measuring the temperature, the temperature on the surface of the uppermost metal layer 101 laminated in the process S21 of laminating the metal layer 101 is measured. In the process S23 of measuring the temperature, a thermosensor or a non-contact thermometer is used to obtain temperature information on the surface of the metal layer 101 without touching the metal layer 101. The acquired temperature information is sent to a control device (not shown) and then displayed on a monitor or used for processing by an NC processing machine.

[0019] In the step S24 of determining the temperature, it is determined whether the temperature of the surface of the metal layer 101 measured is lower than a predetermined reference temperature. Here, the reference temperature is a temperature at which a welding bead 102 can be newly formed without causing a decrease in welding quality on the metal layer 101, and is a temperature at which the refrigerant supplied to the surface of the metal layer 101 can be considered to have evaporated. Therefore, the reference temperature is, for example, about 100°C. In the step S24 of determining the temperature, when it is determined that the measured temperature is lower than the reference temperature, the process proceeds to the step S25 of determining the number of layers. Also, in the step S24 of determining the temperature, when it is determined that the temperature measured in the step S23 of measuring the temperature exceeds the reference temperature, the step S23 of measuring the temperature again is performed after a predetermined time has elapsed.

[0020] In the step S25 of determining the number of layers, it is determined whether the metal layer 101 has been laminated a predetermined number of times. Here, the predetermined number of times is the number of metal layers 101 required to form a laminated modeling part 105 having a predetermined height H1, and is determined based on the shape data of the modeled object 100. In the step S25 of determining the number of layers, when it is determined that the metal layer 101 has not been laminated the predetermined number of times, the process returns to the step S21 of laminating the metal layer 101. In the step S21 of laminating the metal layer 101 after the step S25 of determining the number of layers, a new metal layer 101 is formed on the metal layer 101 on which the temperature has been measured. In the step S25 of determining the number of layers, when it is determined that the metal layer 101 has been laminated the predetermined number of times, the process proceeds to the step S30 of forming the machined side surface 103.

[0021] In the step S30 of forming the machined side surface 103, the modeling part side surface 106 of the laminated modeling part 105 formed at a predetermined height H1 is cut. As shown in FIG. 4, in the step S30 of forming the machined side surface 103, at least a part of the modeling part side surface 106 in the laminated modeling part 105 is cut, and the machined side surface 103 is formed.

[0022] The machined side surface 103 is formed by cutting a predetermined dimension from the shaped part side surface 106 so as to be recessed in the radial direction Dr. The machined side surface 103 is formed as a smooth surface with a smaller surface roughness than the shaped part side surface 106. The machined side surface 103 is formed by removing the surplus part 105z of the laminated shaped part 105. The surplus part 105z is a part formed in a region larger than the shape of the shaped object 100 in the laminated shaped part 105, and includes the sag generated during welding. Further, the machined side surface 103 of the present embodiment constitutes the side surface of the product. That is, the machined side surface 103 is a part of the inner peripheral surface or the outer peripheral surface of the shaped object 100 in a cross section parallel to the axis O.

[0023] In the present embodiment, in the laminated shaped part 105, an inner machined side surface 103s is formed on the inner shaped part side surface 106s facing the inner side Dri in the radial direction Dr. Further, in the present embodiment, an outer machined side surface 103t is further formed on the outer shaped part side surface 106t facing the outer side Dro in the radial direction Dr.

[0024] Further, in the step S30 of forming the machined side surface 103, the machined side surface 103 is formed such that a receiving part 107 that protrudes in the second direction D2 with respect to the machined side surface 103 remains at the end 105e of the second side D1b of the uppermost layer in the first direction D1 of the laminated shaped part 105. The end 105e is a corner of the uppermost layer of the laminated shaped part 105. In the present embodiment, the receiving part 107 has an inner receiving part 107s that protrudes from the inner machined side surface 103s to the inner side Dri in the radial direction Dr and an outer receiving part 107t that protrudes from the outer machined side surface 103t to the outer side Dro in the radial direction Dr.

[0025] The thickness T of the receiving part 107 in the first direction D1 is preferably equal to or greater than the penetration dimension of the welding bead 102 with respect to the receiving part 107. The thickness T of the receiving part 107 is preferably, for example, 2 times or more and 5 times or less with respect to the penetration dimension of the welding bead 102. The penetration dimension is the length in the first direction D1 of the part that melts when the welding bead is formed. The receiving part 107 of the present embodiment is formed leaving the shaped part side surface 106 at least in a part of the first direction D1. Note that the receiving part 107 may be formed without leaving the shaped part side surface 106.

[0026] Further, the inner receiving portion 107s is formed such that the thickness T gradually decreases from the outer side Dro in the radial direction Dr toward the inner side Dri. The outer receiving portion 107t is formed such that the thickness T gradually decreases from the inner side Dri in the radial direction Dr toward the outer side Dro. Note that the inner receiving portion 107s and the outer receiving portion 107t may have a constant thickness T in the radial direction Dr. The inner receiving portion 107s and the outer receiving portion 107t preferably have similar shapes such that the cross-sectional shape parallel to the axis O is nearly line-symmetric.

[0027] In the step S30 of forming the machining side surface 103, when forming the machining side surface 103, it is preferable that the tool is moved in the first direction D1 by an NC machine while the shaping portion side surface 106 is being cut. That is, the machining side surface 103 is formed by cutting the shaping portion side surface 106 in the flow direction F1. As a result, a plurality of machining marks 109 extending in the first direction D1 are formed in the circumferential direction Dc centered on the axis O on the machining side surface 103. Thereby, the machining marks 109 extend along the flow direction F1 of the fluid flowing inside the completed shaped article 100.

[0028] Here, after completion of the step S30 of forming the machining side surface 103, the shape (dimensions) of the formed machining side surface 103 may be measured. The shape of the machining side surface 103 is measured, for example, by contact or being contacted using a three-dimensional measuring instrument. Specifically, when measuring the shape of the machining side surface 103 non-contact, for example, laser light, pattern light, or an arc sensor is used. Further, when measuring the shape of the machining side surface 103 by contact, for example, a touch sensor is used. After measuring the shape of the machining side surface 103, it is determined whether or not the measured shape of the machining side surface 103 deviates from a predetermined standard. Here, the predetermined standard is determined according to the allowable dimensions with respect to the shape of the final shaped article 100. For example, as the standard, a value obtained by considering a certain dimensional tolerance in the shape data of the shaped article 100 can be mentioned. When it is determined that the shape of the machining side surface 103 deviates from the standard, additional processing may be performed until it no longer deviates from the standard.

[0029] In this way, in the step S30 of forming the machined side surface 103, by forming the inner machined side surface 103s and the outer machined side surface 103t, one unit step S60 is completed. As shown in FIG. 2, the unit step S60 is a step including a step S20 of forming the laminated formation part 105 and a step S30 of forming the machined side surface 103. In the laminated forming method S10, the unit step S60 is repeatedly executed. When one unit step S60 is completed, the process proceeds to a step S40 of determining the number of times the laminated formation part 105 is formed.

[0030] In the step S40 of determining the number of times the laminated formation part 105 is formed, it is determined whether the laminated formation part 105 has been formed the predetermined number of times. Here, the predetermined number of times is the number of laminated formation parts 105 required to form the shaped object 100, and is determined based on the shape data of the shaped object 100. In the step S40 of determining the number of times the laminated formation part 105 is formed, when it is determined that the laminated formation part 105 has not been formed the predetermined number of times, the above unit step S60 is repeated. In the step S40 of determining the number of times the laminated formation part 105 is formed, when it is determined that the laminated formation part 105 has been formed the predetermined number of times, the process proceeds to a step S50 of performing the final machining.

[0031] When repeating the unit process S60, the process returns to step S21 of forming the metal layer 101. As shown in FIG. 5, when the unit process S60 is repeated (when the second and subsequent unit processes S60 are performed), in the process S20 of forming the laminated molding part 105, a new metal layer 101 is laminated so as to overlap the upper surface (the surface of the uppermost layer) of the receiving part 107 in the first direction D1. Specifically, the metal layer 101 newly formed when additionally forming the laminated molding part 105 is formed so as to overlap the receiving part 107 on the surface of the metal layer 101 of the uppermost layer of the already formed laminated molding part 105. The receiving part 107 protrudes in the second direction D2 with respect to the processing side surface 103. For this reason, as the metal layers 101 of the laminated molding parts 105 newly added and formed are sequentially laminated, the surplus part 105z of the additionally formed laminated molding part 105 is formed on the receiving part 107. When a new metal layer 101 is laminated on the upper surface of the receiving part 107, the heat energy due to the melting of the welding bead 102 and the heat of the welding bead 102 itself in the portion where the surplus part 105z is formed is absorbed by the receiving part 107.

[0032] Also, in the process S30 of forming the processing side surface 103 in the second and subsequent unit processes S60, the molding part side surface 106 of the newly formed laminated molding part 105 is cut. At that time, as shown in FIG. 6, the processing side surface 103 is formed so that a receiving part 107 protruding in the second direction D2 remains at the end 105e of the newly formed laminated molding part 105. Also, the receiving part 107 of the already formed laminated molding part 105 is cut. Thereby, the processing side surfaces 103 (the inner processing side surface 103s and the outer processing side surface 103t) of the already formed laminated molding part 105 and the processing side surfaces 103 (the inner processing side surface 103s and the outer processing side surface 103t) of the newly formed laminated molding part 105 are formed as smooth surfaces continuous in the first direction D1.

[0033] In step S50 of performing the final machining after the stacked forming portions 105 are stacked a predetermined number of times, as shown in FIG. 7, the forming portion side surfaces 106 (inner forming portion side surface 106s and outer forming portion side surface 106t) of the stacked forming portion 105 that are located on the most second side D1b in the first direction D1 and are formed last are machined away, and the machining side surfaces 103 (inner machining side surface 103s and outer machining side surface 103t) are formed. At this time, it is not necessary to form the receiving portion 107 in the last-formed stacked forming portion 105. Thereby, the machining side surface 103 of the already formed stacked forming portion 105 and the machining side surface 103 of the last-formed stacked forming portion 105 form a smooth surface that is continuous in the first direction D1.

[0034] Also, in step S50 of performing the final machining, the surface (upper surface of the formed object 100) of the stacked forming portion 105 that is located on the most second side D1b in the first direction D1 may be machined away to form a plane 105f orthogonal to the first direction D1. Also, in step S50 of performing the final machining, machining such as forming a groove portion 105k for welding the formed object 100 to other components may be performed at the corner portions of the formed object 100. Further, in step S50 of performing the final machining, finishing machining may be performed on the outer machining side surface 103t with a predetermined machining accuracy so as to further reduce the surface roughness of the surface of the outer machining side surface 103t facing the outer side Dro in the radial direction Dr of the plurality of stacked forming portions 105. When step S50 of performing the final machining is completed, the forming of the formed object 100 with a predetermined dimension is completed.

[0035] (Function and Effect) In the additive manufacturing method S10 with the above configuration, in the step S30 of forming the machined side surface 103, the machined side surface 103 is formed such that the receiving portion 107 remains on the uppermost layer of the additive manufacturing portion 105. The receiving portion 107 protrudes in the second direction D2 with respect to the machined side surface 103. When the unit process S60 is repeated, a new metal layer 101 is laminated on the receiving portion 107, so that when the weld bead 102 is laminated, the heat energy due to the penetration of the weld bead 102 and the heat influence of the weld bead 102 can be absorbed by the receiving portion 107. Thereby, the receiving portion 107 can suppress the adhesion of the molten metal drip to the machined side surface 103 and the collapse of the shape of the machined side surface 103. As a result, the influence of the metal drip can be suppressed during the lamination of the metal, and a three-dimensional shaped object 100 with good quality can be formed.

[0036] Also, the metal layer 101 is laminated in the first direction D1 to form the additive manufacturing portion 105. By cutting the shaped portion side surface 106 for each formed additive manufacturing portion 105, the machined side surface 103 is formed. The additive manufacturing portion 105 is sequentially laminated in the first direction D1 by repeatedly performing the unit process S60. At this time, when a plurality of additive manufacturing portions 105 are laminated in the first direction D1 to approach the shape of the final shaped object 100, it may be difficult for the tool for machining to access the shaped portion side surface 106. However, in the present embodiment, the machined side surface 103 is formed for each formed additive manufacturing portion 105. That is, since the shaped portion side surface 106 of the additive manufacturing portion 105 is cut for each unit process S60, the tool does not become difficult to access the shaped portion side surface 106. As a result, all the side surfaces of the shaped object 100, which is the final finished product, can be made into the machined side surfaces 103 with the intended shape.

[0037] Also, by making the thickness T of the receiving part 107 in the first direction D1 equal to or greater than the penetration dimension of the welding bead 102 with respect to the receiving part 107, the heat energy due to the penetration of the welding bead 102 and the heat of the welding bead 102 itself can be sufficiently absorbed by the receiving part 107. As a result, it is possible to stably suppress the metal from dripping and adhering to the processed side surface 103 when forming the metal layer 101. Therefore, the already formed processed side surface 103 can be maintained in the intended shape, and a three-dimensional shaped object 100 with better quality can be formed.

[0038] Also, by forming the receiving part 107 while leaving the shaped part side surface 106, a certain thickness can be ensured for the receiving part 107 from the root to the tip in the second direction D2. As a result, the receiving part 107 can stably receive the welding bead 102 for forming a new metal layer 101. Thereby, it is possible to more effectively suppress the occurrence of metal dripping during metal lamination.

[0039] Also, in the cylindrical shaped object 100, for each unit process S60, an inner processed side surface 103s is formed on the inner shaped part side surface 106s of the laminated shaping part 105. Thereby, even in the case of the cylindrical shaped object 100, while suppressing hindrance to access by tools or the like, the inner peripheral surface of the shaped object 100 can be processed well. Similarly, an outer processed side surface 103t is formed on the outer shaped part side surface 106t facing the outside Dro in the radial direction Dr of the shaped object 100. Thereby, together with the inner processed side surface 103s, the outer peripheral surface of the cylindrical shaped object 100 can be processed well.

[0040] Also, the surface of the uppermost metal layer 101 is cooled. By being cooled, the temperature of the uppermost metal layer 101 decreases. When laminating the metal layers 101, if a new metal layer 101 is laminated on the metal layer 101 in a state where the temperature is too high, the welding quality may deteriorate. However, by cooling the uppermost metal layer 101, it is possible to prevent a new metal layer 101 from being laminated on the metal layer 101 in a high-temperature state. Furthermore, compared to simply leaving the metal layer 101 to cool, the waiting time for welding until the formation of a new metal layer 101 starts can be shortened.

[0041] Also, by measuring the temperature of the uppermost metal layer 101 in the temperature measurement step S23, it is possible to prevent with high accuracy a new metal layer 101 from being laminated on the metal layer 101 with a high temperature. Therefore, a decrease in the welding quality of the new metal layer 101 can be stably suppressed. From this, a decrease in the strength of the finally manufactured shaped object 100 can be further suppressed.

[0042] Also, in the step S30 of forming the processed side surface 103, the shaped part side surface 106 is cut along the flow direction of the fluid flowing through the shaped object 100. As a result, the processing marks 109 formed on the processed side surface 103 are formed along the flow direction F1 of the fluid flowing through the shaped object 100. By aligning the processing marks 109 along the flow of the fluid, when the fluid flows, it is less likely for disturbances such as vortices to occur due to the processing marks 109. Thereby, the influence of the processing marks 109 on the fluid flow can be suppressed. Therefore, even if the surface state of the processing marks 109 is somewhat rough, it is less likely for losses to occur in the fluid flow. Thereby, the processing for forming the processed side surface 103 can be performed more simply and in a shorter time.

[0043] As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0044] Note that, in the above-described embodiment, in the laminated manufacturing method S10, the receiving portion 107 is formed on the side surfaces 106 of the forming portions at both ends in the second direction D2, but the present invention is not limited to such a configuration. The receiving portion 107 may be formed on only one of the side surfaces 106 of the forming portion in the second direction D2. Further, when the receiving portions 107 are formed on the side surfaces 106 of the forming portions on both sides in the second direction D2, the present invention is not limited to the structure in which the receiving portions 107 are formed in the same shape as in the present embodiment, and the shape and size of the receiving portion 107 may be changed depending on the position where the receiving portion 107 is formed.

[0045] Further, in the above-described embodiment, the shaped object 100 is formed in a cylindrical shape, but the present invention is not limited to this. The shape and configuration of the shaped object 100 may be other appropriate configurations such as a wall shape, for example.

[0046] Further, in the above-described embodiment, the outer processing side surface 103t is formed on the laminated forming portion 105 having a predetermined height H1 for each unit process S60, but the present invention is not limited to this. Even if the shaped object 100 is cylindrical, the outer processing side surface 103t may not cause any problem in processing by performing processing from the outside Dro in the radial direction Dr. In such a case, instead of forming the outer processing side surface 103t every time the laminated forming portion 105 having a predetermined height H1 is formed (for each unit process S60), the outer processing side surface 103t may be formed collectively in the final processing step S50. Further, even when both the inner processing side surface 103s and the outer processing side surface 103t are formed in the step S30 of forming the processing side surface 103, the number of times of forming the outer processing side surface 103t may be reduced compared to the number of times of forming the inner processing side surface 103s.

[0047] Further, the procedure of the laminated manufacturing method S10 is not limited to that described above, and changes such as changing the order, omitting some steps, or adding other steps may be made. For example, the steps S22 of cooling the metal layer 101, the step S23 of measuring the temperature, and the step S24 of determining the temperature may not be performed. Further, in the step S20 of forming the laminated forming portion 105, the present invention is not limited to forming a plurality of layers of the metal layer 101. That is, in the step S21 of laminating the metal layer 101, only one layer of the metal layer 101 may be formed, and the step S30 of forming the processing side surface 103 may be performed.

[0048] <Supplementary Note> (1) The layered manufacturing method S10 according to the first aspect is a layered manufacturing method S10 for manufacturing a three-dimensional shaped object 100 formed by sequentially laminating a plurality of metal layers 101. The method includes a step S20 of laminating a metal layer 101 composed of a welding bead 102 to form a layered manufacturing part 105, and a step S30 of cutting a shaped part side surface 106 facing a second direction D2 intersecting a first direction D1 in which the metal layer 101 is laminated in the layered manufacturing part 105 to form a processed side surface 103. A unit step S60 including these steps is repeatedly performed. In the step S30 of forming the processed side surface 103, the shaped part side surface 106 is cut so as to form a receiving part 107 protruding in the second direction D2 with respect to the processed side surface 103 on the uppermost layer of the layered manufacturing part 105 in the first direction D1. When the unit step S60 is repeated, in the step S20 of forming the layered manufacturing part 105, a new metal layer 101 is laminated so as to overlap the upper surface of the receiving part 107 in the first direction D1. Examples of the shaped object 100 include parts constituting a rotating machine such as a turbine or a compressor. Specifically, a nozzle, an impeller, and a casing can be mentioned.

[0049] In this layered manufacturing method S10, when the unit step S60 is repeated, a new metal layer 101 is laminated on the receiving part 107, so that when the welding bead 102 is laminated, the heat energy due to the penetration of the welding bead 102 and the heat influence of the welding bead 102 can be absorbed by the receiving part 107. Thereby, the receiving part 107 can suppress the adhesion of the molten metal drip to the processed side surface 103 and the collapse of the shape of the processed side surface 103. As a result, the influence of the metal drip during metal lamination can be suppressed, and a three-dimensional shaped object 100 with good quality can be formed.

[0050] (2) The layered manufacturing method S10 according to the second aspect is the layered manufacturing method S10 of (1), wherein a thickness T of the receiving part 107 in the first direction D1 is equal to or greater than a penetration dimension of the welding bead 102 with respect to the receiving part 107.

[0051] As a result, the heat energy due to the penetration of the welding bead 102 and the heat of the welding bead 102 itself can be sufficiently absorbed by the receiving portion 107. As a result, it is possible to stably suppress the dripping of the metal onto the processed side surface 103 when the metal layer 101 is formed. Therefore, the already formed processed side surface 103 can be maintained in the intended shape, and a three-dimensional shaped object 100 with better quality can be formed.

[0052] (3) The additive manufacturing method S10 according to the third aspect is the additive manufacturing method S10 of (1) or (2), wherein the receiving portion 107 is formed at least in a part of the first direction D1, leaving the shaped portion side surface 106.

[0053] As a result, a certain thickness can be ensured for the receiving portion 107. As a result, the receiving portion 107 can stably receive the welding bead 102 for forming a new metal layer 101. Thereby, it is possible to more effectively suppress the dripping of the metal during the lamination of the metal.

[0054] (4) The additive manufacturing method S10 according to the fourth aspect is any one of the additive manufacturing methods S10 of (1) to (3), wherein in the step S20 of forming the additive manufacturing portion 105, after supplying a refrigerant to the surface of the metal layer 101 forming the uppermost layer in the first direction D1 to cool the metal layer 101, a new metal layer 101 is laminated on the surface of the cooled metal layer 101.

[0055] As a result, the surface of the uppermost metal layer 101 is cooled by the refrigerant and the temperature decreases. Therefore, it is possible to prevent a new metal layer 101 from being laminated on the metal layer 101 in a high-temperature state. Furthermore, the waiting time for welding until the formation of a new metal layer 101 is started can be shortened compared to the case where the metal layer 101 is simply left to cool.

[0056] (5) The additive manufacturing method S10 according to the fifth aspect is any one of the additive manufacturing methods S10 from (1) to (4), wherein the object 100 is formed in a cylindrical shape centered on an axis O extending in the first direction D1, and fluid can flow inside. In the step of forming the machined side surface 103, the side surface facing the inner side Dri in the radial direction Dr of the object 100 is formed by the machined side surface 103, and the machined side surface 103 is formed by shaving the shaped part side surface 106 in the flow direction of the fluid flowing inside the object 100.

[0057] As a result, the shaped part side surface 106 is shaved along the flow direction of the fluid flowing through the object 100. As a result, the machining marks 109 formed on the machined side surface 103 are formed along the flow direction F1 of the fluid flowing through the object 100. By aligning the machining marks 109 with the flow of the fluid, when the fluid flows, it is less likely for disturbances such as vortices to occur due to the machining marks 109. As a result, the influence of the machining marks 109 on the fluid flow can be suppressed. Therefore, even if the surface state of the machining marks 109 is somewhat rough, it is less likely for losses to occur in the fluid flow. As a result, the machining for forming the machined side surface 103 can be performed more simply and in a shorter time.

Explanation of Reference Numerals

[0058] 5…Table 5f…Support Surface 100…Object 101…Metal Layer 102…Weld Bead 103…Machined Side Surface 103s…Inner Machined Side Surface 103t…Outer Machined Side Surface 105…Additively Manufactured Part 105e…End 105f…Plane 105k…Groove Tip 105z…Excess Metal Part 106…Shaped Part Side Surface 106s…Inner Shaped Part Side Surface 106t…Outer Shaped Part Side Surface 107…Receiving Part 107s…Inner Receiving Part 107t... Outer receiving part 109... Processing marks D1... First direction D1a... First side D1b... Second side D2... Second direction Dc... Circumferential direction Dr... Radial direction Dri... Inner side Dro... Outer side Dv... Vertical direction F1... Flow direction of fluid H1... Height of the laminated forming part O... Axis S10... Laminated forming method S20... Step of forming the laminated forming part S21... Step of laminating the metal layer S22... Step of cooling the metal layer S23... Step of measuring the temperature S24... Step of determining the temperature S25... Step of determining the number of laminations S30... Step of forming the processed side surface S40... Step of determining the number of times of forming the laminated forming part S50... Step of performing the final processing S60... Unit process T... Thickness

Claims

1. A laminated manufacturing method for manufacturing a three-dimensional object formed by sequentially laminating a plurality of metal layers, comprising: a step of laminating metal layers composed of welding beads to form a laminated manufacturing part; a step of machining a side surface of the manufacturing part facing a second direction intersecting a first direction in which the metal layers are laminated in the laminated manufacturing part to form a machined side surface; a unit process including the above steps is repeatedly performed; in the step of forming the machined side surface, the side surface of the manufacturing part is machined so as to form a receiving part protruding in the second direction with respect to the machined side surface on the uppermost layer in the first direction of the laminated manufacturing part; when the unit process is repeated, in the step of forming the laminated manufacturing part, a new metal layer is laminated so as to overlap the upper surface of the receiving part in the first direction; the object is formed in a cylindrical shape centered on an axis extending in the first direction, and fluid can flow inside; in the step of forming the machined side surface, a side surface facing the inner side in the radial direction of the object is formed by the machined side surface; the machined side surface is formed by machining the side surface of the manufacturing part in the flow direction of the fluid flowing inside the object.

2. The laminated manufacturing method according to claim 1, wherein the thickness of the receiving part in the first direction is equal to or greater than the penetration dimension of the welding bead with respect to the receiving part.

3. The laminated manufacturing method according to claim 1 or 2, wherein the receiving part is formed by leaving at least a part of the side surface of the manufacturing part in at least a part of the first direction.

4. In the step of forming the laminated manufacturing part, after supplying a refrigerant to the surface of the metal layer forming the uppermost layer in the first direction to cool the metal layer, a new metal layer is laminated on the cooled surface of the metal layer. The laminated manufacturing method according to any one of claims 1 to 3.

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