FORMED ARTICLE AND METHOD FOR MANUFACTURING FORMED ARTICLE

Abstract

To provide a molded article which is formed by a rotary body having a passage and inhibits stress concentration, and to provide a method for manufacturing the molded article.SOLUTION: A molded article W has a plurality of blades 55 molded from a welding metal in the surroundings of a shaft body 51 made of a metal matrix and is provided with a hollow cooling passage 61 located therein and formed by a rotary body which is rotated around an axis Ax of the shaft body 51. The cooling passage 61 has: blade-part passages 63 provided within the blades 55 and extending in parallel to the blades 55; and a communication passage 65 that extends in a direction intersecting the blades 55 at ends of the blades 55. The communication passage 65 communicates alternately with the adjacent blade-part passage 63, and a path of the cooling passage 61 is folded back at the ends of the blades 55.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a shaped object and a method for manufacturing a shaped object. [Background technology]

[0002] In recent years, there has been an increasing need for 3D printers as a means of production, and research and development is being conducted for practical use in the aircraft industry, etc., particularly in the case of application to metallic materials. 3D printers that use metallic materials use a heat source such as a laser or arc to melt metal powder or metal wire, and then layer the molten metal to create a model.

[0003] For example, one technique for manufacturing a rotor having a blade is to form a blade by laminating welding beads around a shaft body that serves as a central axis (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-155463 A Summary of the Invention [Problem to be solved by the invention]

[0005] As an example of further increasing functionality, the above-mentioned molding method can be used to mold a rotating body with a cooling function by forming a cooling flow path inside it. However, a rotating body with a cooling flow path requires a balance between mechanical strength and a moldable structure.

[0006] For example, in a rotating body having an internal cooling channel, as shown in Fig. 9, the stress concentration coefficient of the cooling channel 1 varies depending on the R shape of the corners and the ratio of height h to width w when viewed in a cross section parallel to the expected load direction F. For this reason, when molding a rotating body having a cooling channel 1, it is preferable to design it so that the stress concentration coefficient is low, assuming that the principal stress will occur in the axial direction, from the viewpoint of fatigue strength, etc. However, if the width w or the R shape of the corners is simply increased, the number of beads in the overhanging parts will increase when the cooling channel 1 is molded by stacking beads, and detailed adjustment of the molding conditions will be required to form the R shape.

[0007] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a shaped object which is made of a rotating body having a flow path and in which stress concentration is suppressed, and a method for manufacturing the shaped object. [Means for solving the problem]

[0008] The present invention comprises the following configurations. (1) A structure comprising a rotor having a plurality of blades formed from welded metal around a shaft body made of a base metal, a hollow flow passage provided therein, and rotated about the axis of the shaft body, The flow path is A plurality of blade flow passages are provided within the blade portion and extend parallel to the blade portion; A connecting flow passage extending in a direction intersecting the wing portion at an end of the wing portion; having The connecting flow passages are alternately connected to the adjacent wing flow passages, and the paths of the flow passages are turned back at the ends of the wing portions. Sculpture. (2) A method for producing a shaped object according to (1) above, comprising the steps of: A wing portion forming process includes forming the wing portion by laminating a weld bead formed by melting and solidifying a filler material on an outer periphery of the shaft while rotating the shaft, In the wing portion forming step, a flow passage forming step is performed in which the weld bead is extended in parallel along the path of the wing portion flow passage to be continuous with the portion along the connecting flow passage and laminated to form the flow passage. A method for manufacturing a sculpture. Effect of the Invention

[0009] According to the present invention, it is possible to provide a shaped object which is made of a rotor having a flow passage and in which stress concentration is suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view of a shaped object according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a cooling channel in a shaped object of the present invention. [Diagram 3] 4 is a schematic cross-sectional view of a blade illustrating the arrangement of cooling channels in the blade. FIG. [Figure 4] FIG. 4 is a cross-sectional view of a blade flow passage illustrating the cross-sectional shape of a cooling flow passage. [Diagram 5] FIG. 1 is a schematic diagram illustrating the configuration of a manufacturing system for manufacturing a shaped object. [Figure 6] 13(A) and 13(B) are side views of a partly molded object illustrating how a blade flow path is formed in the blade molding process. [Figure 7] 10(A) and 10(B) are cross-sectional views of a part of a blade in the process of being formed, illustrating how a blade flow passage is formed in the blade forming process. [Figure 8] 1A and 1B are diagrams illustrating the wing flow passage in the molded object of this example, where (A) is a schematic diagram of the wing flow passage, (B) is a cross-sectional view taken along line VIIIB-VIIIB in (A), and (C) is a cross-sectional view taken along line VIIIC-VIIIC in (A). [Figure 9] FIG. 4 is a cross-sectional view showing a schematic view of a cooling flow passage to which a load is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a perspective view of a shaped object W of the present invention. Fig. 2 is a schematic diagram showing a cooling passage 61 in the shaped object W of the present invention. Fig. 3 is a schematic cross-sectional view of a blade 55 illustrating the arrangement of the cooling passage 61 in the blade 55.

[0012] As shown in FIG. 1, the shaped object W has a shaft body 51 and a shaped portion 53 shaped on the outer periphery of the shaft body 51, and the shaped portion 53 has a blade (wing portion) 55 formed thereon.

[0013] The shaft body 51 is, for example, a round bar with a circular cross section, such as a steel bar. The blade 55 of the shaping portion 53 provided on the outer periphery of the shaft body 51 is formed so that the portion protruding toward the outer periphery is twisted in a spiral shape toward the axial direction. The shaping portion 53 having the blade 55 is shaped by forming and layering a weld bead around the shaft body 51. The surface of the shaping portion 53 shaped by the weld bead is then cut to a target shape.

[0014] 2 and 3, the object W has therein a cooling flow path 61. This cooling flow path 61 is a flow path through which a cooling medium such as cooling water flows, and by flowing the cooling medium through this cooling flow path 61, the object W is cooled.

[0015] The cooling passage 61 has a vane passage 63, a connecting passage 65, and an axial passage 67. The vane passages 63 are formed in a set of three on each blade 55. These three vane passages 63 extend in parallel along the blade 55.

[0016] Moreover, the inner surfaces 63a of the blade passages 63 on the outer surface 55a side of the blade 55 are arranged parallel to the outer surface 55a of the blade 55. Furthermore, the three blade passages 63 provided on each blade 55 are arranged at equal distances from the outer surface 55a of the blade 55.

[0017] The connecting passages 65 are formed at both ends of the blade 55. These connecting passages 65 extend in a direction intersecting the blade 55 at the end of the blade 55, and are alternately connected to the adjacent blade passages 63. As a result, the cooling passage 61 is a path in which the blade passages 63 are folded back by the connecting passages 65 at the end of the blade 55. The axial passage 67 is formed in the center of the shaft body 51. One end of the axial passage 67 is connected to one of the blade passages 63 via the connecting passage 65.

[0018] The cooling passage 61 has a start end 61S at an end of the axial passage 67 opposite to the side communicating with the blade passage 63, and a finish end 61E at an end of the blade passage 63 that is not communicating with the connecting passage 65. The cooling passage 61 is continuous from the start end 61S to the finish end 61E. In other words, the cooling passage 61 runs from the start end 61S of the axial passage 67 at one end of the shaft body 51, alternately through the blade passage 63 and the connecting passage 65, turns around at the end of the blade 55, and reaches the finish end 61E at the end of the blade passage 63.

[0019] FIG. 4 is a cross-sectional view of a blade flow passage 63 for explaining the cross-sectional shape of the cooling flow passage 61. As shown in FIG. 4, the corners of the blade flow passages 63 of the cooling passage 61 are formed in an arc shape in a cross section perpendicular to the extension direction. This reduces stress concentration at the corners of the cooling passage 61. For example, when forming the cooling passage 61 by stacking the weld beads B, fillet welds Bs are applied to the corners between the sidewall portions and the bottom portion to form an R-shape, or when forming the ceiling portion that closes the upper part of the sidewall portions, the weld beads B are stacked to overhang so that the corners between the sidewall portions and the ceiling portion have an R-shape.

[0020] Next, a description will be given of a manufacturing system 100 for manufacturing the above-mentioned object W. FIG.

[0021] As shown in FIG. 5, the manufacturing system 100 for a shaped object having this configuration includes a welding robot 11, a robot controller 13, a filler metal supply unit 15, a welding power source 19, and a control unit 21.

[0022] The welding robot 11 is an actuator consisting of an articulated robot, and a torch 23 is supported on the tip shaft. The position and posture of the torch 23 can be set arbitrarily in three dimensions within the range of the degrees of freedom of the robot arm. The torch 23 holds a linear filler metal (welding wire) M, which is continuously supplied from a filler metal supply unit 15, in a state where it protrudes from the tip of the torch.

[0023] The torch 23 has a shield nozzle (not shown) through which a shield gas is supplied to the welded portion. The arc welding method may be either a consumable electrode type such as shielded metal arc welding or carbon dioxide gas arc welding, or a non-consumable electrode type such as TIG welding or plasma arc welding, and is appropriately selected depending on the object to be produced.

[0024] For example, in the case of a consumable electrode type, a contact tip is disposed inside the shield nozzle, and a filler material M to which a melting current is supplied is held by the contact tip. The torch 23 holds the filler material M and generates an arc from the tip of the filler material M in a shielding gas atmosphere. The filler material M is fed to the torch 23 by a feeding mechanism (not shown) attached to a robot arm or the like. Then, as the torch 23 moves, the continuously fed filler material M is melted and solidified, and a weld bead B, which is a molten and solidified body of the filler material M, is formed.

[0025] The heat source for melting the filler material M is not limited to the above-mentioned arc. For example, other types of heat sources may be used, such as a heating method using both an arc and a laser, a heating method using plasma, or a heating method using an electron beam or a laser. When heating with an electron beam or a laser, the amount of heat can be controlled more precisely, and the state of the weld bead B can be more appropriately maintained, which contributes to further improving the quality of the molded object W.

[0026] Any commercially available welding wire can be used as the filler metal M. For example, wires specified in MAG and MIG welding solid wires for mild steel, high tensile steel and low temperature steel (JIS Z 3312), arc welding flux-cored wires for mild steel, high tensile steel and low temperature steel (JIS Z 3313), etc. can be used.

[0027] An active metal such as titanium can be used as the filler metal M. In that case, it is necessary to place the weld in a shielding gas atmosphere to prevent oxidation and nitridation due to reaction with the atmosphere during welding.

[0028] The robot controller 13 receives instructions from the control unit 21 to drive each part of the welding robot 11 and controls the output of the welding power source 19 as necessary.

[0029] The control unit 21 is configured by a computer device equipped with a CPU, memory, storage, etc., and executes a driving program prepared in advance or a driving program created under desired conditions to drive each part such as the welding robot 11.

[0030] In the manufacturing system 100 configured as described above, the welding robot 11 drives the torch 23 to move along a movement trajectory of the torch 23 generated from the set layer shape data, and the shaft body 51 is rotated about its axis while the torch 23 deposits a weld bead B made of molten filler material M around the shaft body 51. In this way, a molded object W is manufactured in which a molded portion 53 made of the weld bead B is formed on the outer periphery of the shaft body 51. Both ends of the shaft body 51 are supported by supports 49 provided on the base 47 so as to be rotatable.

[0031] Next, a method for producing a shaped object according to the present invention will be described. (Axial channel formation process) First, a hole is drilled from one end in the center of the shaft body 51 to form the axial passage 67. Furthermore, a hole is formed in the radial direction near the other end of the shaft body 51 to form a part of the connecting passage 65 connected to the axial passage 67.

[0032] (Wing modeling process) While rotating the shaft body 51, a molded portion 53 having a blade 55 is molded on the outer periphery of the shaft body 51. Specifically, a weld bead B is repeatedly formed along the extension direction of the blade 55 to be molded. In this way, the weld beads B are layered on the outer periphery of the shaft body 51 to mold the molded portion 53 having the blade 55.

[0033] At this time, when the blade 55 is shaped, a flow passage forming process is performed in which a gap is provided between the weld beads B to form a hollow portion, thereby forming the blade flow passage 63 and the connecting flow passage 65 surrounded by the weld beads B. In this way, a cooling flow passage 61 is formed as a continuous path from the starting end 61S, which is the inlet, to the ending end 61E, which is the outlet.

[0034] Here, a method for forming the blade flow passages 63 in the flow passage forming step will be described by taking as an example the case of forming the blade flow passages 63 in the outermost peripheral portion of the blade 55. Fig. 6 is a side view of a part of a model W in the process of being formed, illustrating how the blade flow passage 63 is formed in the blade-forming process. Fig. 7 is a cross-sectional view of a part of a blade 55 in the process of being formed, illustrating how the blade flow passage 63 is formed in the blade-forming process.

[0035] As shown in Figures 6(A) and 7(A), the weld bead B is extended in parallel along the path of the blade flow passage 63. This forms a groove G in the path of the blade flow passage 63. At this time, fillet welds Bs are applied to the corners between both side wall portions and the bottom of the groove G to form an R shape (see Figure 4).

[0036] Next, as shown in Fig. 6(B) and Fig. 7(B), a plurality of welding beads B are formed on the upper edge of the groove G along the groove G so as to close the upper part of the groove G. Specifically, the welding beads B are repeatedly stacked to overhang from the upper edge of the groove G to form a ceiling portion, which forms the blade flow passage 63. At this time, the corners of the blade flow passage 63 are formed in an arc shape in a cross section perpendicular to the extension direction (see Fig. 4). Also, the welding beads B are stacked so that the inner surface 63a of the blade flow passage 63 on the side of the outer surface 55a of the blade 55 is parallel to the outer surface 55a of the blade 55, thereby forming the blade 55 (see Fig. 3).

[0037] In the object W thus formed, the cooling medium is fed from the starting end 61S to the axial passage 67, flows alternately through the connecting passage 65 and the blade passage 63, and is discharged from the ending end 61E (see FIG. 2). As a result, the object W is cooled by the cooling medium flowing through the cooling passage 61.

[0038] Incidentally, in the case of a structure W, which is a rotating body rotating around an axis Ax (see Figure 2), when a bending load acts on the structure W, a principal stress consisting of a tensile force is generated along the axis Ax in the part on the outside of the bend, and the principal stress is maximum in the central part in the axial direction.

[0039] In the object W of this configuration, the wing passage 63 of the cooling passage 61 has a width dimension Wc in a cross section perpendicular to the extension direction as shown in Figures 8(A) and 8(B), and a width dimension WAx in a cross section along the axis Ax as shown in Figures 8(A) and 8(C) that is larger than the width dimension Wc in a cross section perpendicular to the extension direction.

[0040] In this manner, in the molded object W of this configuration, the blade passage 63 of the cooling passage 61 has a large width dimension WAx in a cross section along the axis Ax, and therefore has a small stress concentration factor. Therefore, even in the central portion in the axial direction where the principal stress is maximum when a bending load is applied, the effect of the principal stress can be suppressed.

[0041] As described above, according to the present configuration of the molded object W and the manufacturing method of the molded object W, the cooling passages 61 are provided in which the plurality of blade portion passages 63 extending parallel to the blades 55 are connected to the connecting passages 65 at the ends of the blades 55 and are folded back, so that it is possible to increase the area of ​​the inner surface of the cooling passages 61 within the blades 55. This makes it possible to increase the efficiency of heat exchange with the blades 55 when a cooling medium is flowed through the cooling passages 61, and to obtain a molded object W with excellent cooling capacity.

[0042] Furthermore, the blade passage 63 extending parallel to the blade 55 has a large width dimension WAx in a cross section along the axis Ax, which is the principal stress direction, so that stress concentration can be alleviated when stress acts in the axial direction due to bending load.

[0043] Moreover, the cooling flow passage 61 is formed as a continuous path from the start end 61S, which is the inlet, to the end end 61E, which is the outlet. This makes it easy to determine whether or not the cooling flow passage 61 is clogged by circulating the cooling medium through the cooling flow passage 61.

[0044] Furthermore, when forming a blade 55 having a cooling passage 61 by stacking weld beads B, the weld beads B can be formed continuously along the path of the blade passage 63, thereby reducing the start and end points of the weld beads B and increasing productivity.

[0045] Furthermore, the corners of the cooling flow passage 61 are formed in an arc shape in a cross section perpendicular to the extension direction, so that stress concentration at the corners of the cooling flow passage 61 can be alleviated.

[0046] Also, the inner surface 63a of the blade passage 63 on the outer surface 55a side of the blade 55 is arranged parallel to the outer surface 55a of the blade 55. This makes it possible to make the thickness between the outer surface 55a of the blade 55 and the blade passage 63 uniform, and when a cooling medium is caused to flow through the cooling passage 61, the outer surface 55a of the blade 55 can be cooled in a balanced manner.

[0047] Moreover, the plurality of vane passages 63 provided in the blade 55 are disposed at equal distances from the outer surface 55a of the blade 55. Therefore, when a cooling medium is caused to flow through the cooling passages 61, the entire blade 55 can be cooled in a balanced manner by the plurality of vane passages 63 provided in the blade 55.

[0048] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates mutual combinations of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the descriptions in the specification and well-known technologies, and these are included in the scope of protection sought.

[0049] As described above, the present specification discloses the following: (1) A structure comprising a rotor having a plurality of blades formed from welded metal around a shaft body made of a base metal, a hollow flow passage provided therein, and rotated about the axis of the shaft body, The flow path is A plurality of blade flow passages are provided within the blade portion and extend parallel to the blade portion; A connecting flow passage extending in a direction intersecting the wing portion at an end of the wing portion; having A shaped object, wherein the connecting flow passages are alternately connected to adjacent wing flow passages, and the paths of the flow passages are folded back at the ends of the wing portions. In the object of this configuration, the blade passages extending parallel to the blade are connected to the connecting passage at the end of the blade to provide a passage that turns back, so that the area of ​​the inner surface of the passage within the blade can be increased, thereby increasing the efficiency of heat exchange with the blade when a cooling medium is passed through the passage, and resulting in an object with excellent cooling capacity. Furthermore, the blade flow passage extending parallel to the blade portion has a large width dimension in a cross section along the axis, which is the principal stress direction, so that stress concentration when stress acts in the axial direction due to bending load can be alleviated.

[0050] (2) The object according to (1), wherein the flow path is formed as a continuous path from the inlet to the outlet. In a molded object having this configuration, the flow path is formed as a continuous route from the inlet to the outlet, so that by circulating the cooling medium through the flow path, it is possible to easily determine the presence or absence of a blockage in the flow path. In addition, when forming a wing portion having a flow passage by stacking weld beads, the weld beads can be formed continuously along the path of the wing portion flow passage, thereby reducing the start and end points of the weld beads and increasing productivity.

[0051] (3) The object according to (1) or (2), wherein the flow path has corners formed in an arc shape in a cross-sectional view perpendicular to the extension direction. In a shaped object having this configuration, the corners of the flow passage are formed in an arc shape, so that it is possible to reduce stress concentration at the corners of the flow passage.

[0052] (4) The shaped object according to any one of (1) to (3), wherein the inner surface of the blade flow passage on the outer surface side of the blade is arranged parallel to the outer surface of the blade. In the case of a molded product having this configuration, the inner surface of the blade passage on the outer surface side of the blade is arranged parallel to the outer surface of the blade, which makes it possible to make the thickness between the outer surface of the blade and the blade passage uniform, and enables the outer surface of the blade to be cooled in a balanced manner when a cooling medium is flowed through the passage.

[0053] (5) The object according to any one of (1) to (3), wherein the plurality of blade flow passages provided in the blade are each disposed at an equal distance from an outer surface of the blade. According to a molded object having this configuration, when a cooling medium is caused to flow through the flow passages, the entire blade can be cooled in a balanced manner by the plurality of blade flow passages provided in the blade.

[0054] (6) A method for producing a shaped object according to any one of (1) to (5), comprising the steps of: A wing portion forming process includes forming the wing portion by laminating a weld bead formed by melting and solidifying a filler material on an outer periphery of the shaft while rotating the shaft, A method for manufacturing a molded object, in which, in the wing portion forming process, a flow path forming process is performed in which the weld bead is extended parallel to the path of the wing portion flow path, so as to be continuous with the portion along the connecting flow path, and laminated to form the flow path. According to the manufacturing method of the molded object having this configuration, when molding the wing portion, it is possible to form a flow path having a plurality of wing portion flow paths that turn back at a connecting flow path at the end. Also, when molding the wing portion having a flow path by stacking weld beads, it is possible to form the weld beads continuously, which reduces the start and end points of the weld beads and increases productivity.

[0055] (7) The method for manufacturing a shaped object according to (6), wherein in the flow path forming step, the weld bead is formed so that a portion that becomes a corner in a cross-sectional view perpendicular to an extension direction of the flow path has an arc shape. According to the manufacturing method of a shaped object having this configuration, a flow path can be formed with arc-shaped corners, and stress concentration at the corners of the flow path can be alleviated.

[0056] (8) A method for manufacturing a molded object according to (6) or (7), wherein in the wing portion forming process, the weld beads are stacked so that the inner surface of the wing portion on the outer surface side in the wing portion flow path is parallel to the outer surface of the wing portion to form the wing portion. According to this method for manufacturing a molded object, the inner surface of the blade passage on the outer surface side of the blade is arranged parallel to the outer surface of the blade, which makes it possible to make the thickness between the outer surface of the blade and the blade passage uniform, and allows the outer surface of the blade to be cooled in a balanced manner when a cooling medium is passed through the passage. [Explanation of symbols]

[0057] 51 Shaft body 55 Blade (wing) 55a outer surface 61 Cooling channel (channel) 61S Beginning (entrance) 61E Termination (exit) 63 Wing passage 63a Inside 65 Connecting Channel B Weld bead W sculpture

Claims

1. A molded object is a rotor having a plurality of wing portions formed from a welded metal around a shaft body made of a metal base material, a hollow flow passage provided therein, and rotated around an axis of the shaft body, The wing portion is formed such that a protruding portion on an outer circumferential side of the shaft body extends in an axial direction of the shaft body in a spiral twisted shape, The flow path is A plurality of blade flow passages are provided within the blade portion and extend parallel to the blade portion; A connecting flow passage extending in a direction intersecting the wing portion at an end of the wing portion; having The connecting flow passages are alternately connected to the adjacent wing flow passages, and the paths of the flow passages are turned back at the ends of the wing portions. Sculpture.

2. The flow path is formed as a continuous path from the inlet to the outlet. The shaped object according to claim 1 .

3. The flow path has a corner formed in an arc shape in a cross-sectional view perpendicular to the extension direction. The shaped object according to claim 1 or 2.

4. The blade flow passage has an inner surface on the outer surface side of the blade, the inner surface being arranged parallel to the outer surface of the blade. The shaped object according to any one of claims 1 to 3.

5. The plurality of blade flow passages provided in the blade are disposed at equal distances from an outer surface of the blade. The shaped object according to any one of claims 1 to 3.

6. A method for producing a shaped object according to any one of claims 1 to 5, comprising the steps of: A wing portion forming process includes forming the wing portion by laminating a weld bead formed by melting and solidifying a filler material on an outer periphery of the shaft while rotating the shaft, In the wing portion forming step, a flow passage forming step is performed in which the weld bead is extended in parallel along the path of the wing portion flow passage to be continuous with the portion along the connecting flow passage and laminated to form the flow passage. A method for manufacturing a sculpture.

7. In the flow channel forming step, the weld bead is formed so that a corner portion in a cross-sectional view perpendicular to an extension direction of the flow channel has an arc shape. The method for producing a shaped object according to claim 6 .

8. In the blade portion forming step, the weld beads are laminated to form the blade portion such that an inner surface of the blade portion in the blade portion flow path on the outer surface side of the blade portion is parallel to an outer surface of the blade portion. The method for producing a shaped object according to claim 6 or 7.

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