JP6783964B1 - Manufacturing method of laminated model - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated model, which can accurately form a welded bead while suppressing the generation of an unwelded portion to produce a high-quality model. SOLUTION: This is a method for manufacturing a laminated shaped object in which a welded bead B obtained by melting and solidifying a filler metal M is laminated to form a shaped object, and a frame portion forming step of forming a frame portion 53 with the welded bead B1. And, the welded bead B2 along the first direction X is continuously formed from both sides in the frame portion 53 toward the inside while being folded back at the end portions 53A and 53B of the frame portion 53, and the welded bead B2 is formed in the first direction X. The internal modeling process in which two modeling portions 57A and 57B lined up in the second direction Y intersecting with each other with a gap G between them are formed, and the first direction in the gap G between the two modeling portions 57A and 57B in the frame portion 53. It includes a filling step of forming a welded bead B3 along X and filling a gap G between the two modeling portions 57A and 57B. [Selection diagram] FIG. 2D

Description

The present invention relates to a method for producing a laminated model.

In recent years, the needs for 3D printers as a means of production have been increasing, and research and development have been carried out for practical use in the aircraft industry and the like, especially for application to metal materials. A 3D printer using a metal material melts a metal powder or a metal wire by using a heat source such as a laser or an arc, and laminates the molten metal to form a modeled object.

In Patent Document 1, a first pass along the first direction and a second pass along a second direction different from the first direction are repeated to fill the frame with beads, and between the first pass and the second pass. In, it is described that a folding path extending in a direction away from the second path and folding back in a direction toward the second path is provided.

Further, in Patent Document 2, when a metal material is filled with a filling pattern having a waveform having a certain wavelength inside the contour made by laminated molding to form a modeled object, the filling pattern intersects the contour. It is stated that the welding speed is reduced.

JP-A-2018-86664 Japanese Unexamined Patent Publication No. 2019-111582

For example, when a bead is formed in the inner region of the frame portion to form a modeled object, unwelding occurs at the start end and the end of the bead, which may lead to quality deterioration. In particular, when a plurality of beads are formed in parallel in the plane direction in the frame portion, the number of start ends and ends of the beads increases, and unwelded is likely to occur.

As in Patent Documents 1 and 2, if the beads are folded back or filled with a filling pattern of a certain wavelength, the number of start ends and ends of the beads can be reduced, but the beads are folded in the width direction at the folded back portion. It overhangs in the height direction, and the dimensions of the shaped part formed by the bead fluctuate. That is, it has been difficult to accurately form a bead in an internal region such as a frame portion to produce a high-quality model.

Therefore, an object of the present invention is to provide a method for producing a laminated model, which can accurately form a welded bead while suppressing the generation of an unwelded portion to produce a high-quality model.

The present invention has the following configuration.
It is a method for manufacturing a laminated model, in which weld beads obtained by melting and solidifying a filler metal are laminated to form a model.
The frame part molding process of forming the frame part by the welding bead and
Welded beads along the first direction from both sides in the frame portion are continuously formed inward while being folded back at the end of the frame portion, and the welded beads are arranged in the second direction intersecting the first direction. The internal modeling process, which creates the two modeling parts with a gap between them,
A filling step of forming a welding bead along the first direction in the gap between the two shaped portions in the frame portion to fill the gap between the two shaped portions.
including,
A method for manufacturing a laminated model.

According to the present invention, it is possible to accurately form a welded bead while suppressing the generation of an unwelded portion to produce a high-quality modeled product.

It is a schematic schematic block diagram of the manufacturing system which manufactures a laminated model by the manufacturing method of embodiment of this invention. It is a top view of the laminated model in the process of manufacturing which shows the manufacturing process of the laminated model. It is a top view of the laminated model in the process of manufacturing which shows the manufacturing process of the laminated model. It is a top view of the laminated model in the process of manufacturing which shows the manufacturing process of the laminated model. It is a top view of the laminated model in the process of manufacturing which shows the manufacturing process of the laminated model. It is sectional drawing of AA in FIG. 2A. FIG. 2B is a sectional view taken along line BB in FIG. 2B. FIG. 2C is a cross-sectional view taken along the line CC in FIG. 2C. FIG. 2 is a cross-sectional view taken along the line DD in FIG. 2D. It is a schematic plan view at the corner of the frame part which becomes the start end of the welding bead in an internal molding process. It is a schematic vertical sectional view of the manufactured laminated model. It is a schematic vertical sectional view of another laminated model. It is a figure explaining the method of setting the formation direction of the welding bead in an internal molding process, and (a) and (b) are schematic plan views of the frame part respectively. It is a figure explaining the modification of the internal molding process and the filling process, (a) is a plan view, (b) is the EE sectional view in (a). It is a schematic plan view of the frame part which shows another example of the formation direction of the welding bead in an internal molding process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of a manufacturing system used for manufacturing a laminated model of the present invention.
The laminated model manufacturing system 100 having this configuration includes a laminated modeling device 11, a controller 13 that controls the laminated modeling device 11, and a power supply device 15.

The laminated modeling device 11 includes a welding robot 19 provided with a torch 17 on a tip shaft, and a filler material supply unit 21 that supplies a filler metal (welding wire) M to the torch 17.

The welding robot 19 is an articulated robot, and the filler metal M is continuously supplied to the torch 17 attached to the tip shaft of the robot arm. The position and posture of the torch 17 can be arbitrarily set three-dimensionally within the range of the degree of freedom of the robot arm.

The torch 17 has a shield nozzle (not shown), and shield gas is supplied from the shield nozzle. The arc welding method may be either a consumable electrode type such as shielded metal arc welding or carbon dioxide arc welding, or a non-consumable electrode type such as TIG welding or plasma arc welding, and is appropriately selected according to the laminated model to be manufactured. Weld.

For example, in the case of the consumable electrode type, the contact tip is arranged inside the shield nozzle, and the filler metal M to which the melting current is supplied is held by the contact tip. The torch 17 generates an arc from the tip of the filler metal M in a shield gas atmosphere while holding the filler metal M. The filler metal M is fed from the filler metal supply unit 21 to the torch 17 by a feeding mechanism (not shown) attached to a robot arm or the like. Then, when the filler metal M that is continuously fed is melted and solidified while moving the torch 17, a linear welded bead B that is a molten solidified body of the filler metal M is formed on the base plate 51. A laminated model W composed of a welded bead B is modeled.

The controller 13 includes a CAD / CAM unit 31, an orbit calculation unit 33, a storage unit 35, and a control unit 37 to which these are connected.

The CAD / CAM unit 31 inputs or creates shape data (CAD data, etc.) of the laminated model W to be produced, and cooperates with the trajectory calculation unit 33 to represent a welding bead B representing a modeling procedure of the laminated model. Generate a stacked model of. That is, the shape data is divided into a plurality of layers to generate layer shape data representing the shape of each layer. Then, the movement locus of the torch 17 is determined based on the layer shape data of the generated laminated model. The CAD / CAM unit 31 generates a drive program for the welding robot 19 and the power supply device 15 that move the torch 17 to form a welding bead based on the generated layer shape data and data such as the movement locus of the torch 17. .. Various data such as the generated drive program are stored in the storage unit 35.

The control unit 37 executes a drive program stored in the storage unit 35 to drive the welding robot 19, the power supply device 15, and the like. That is, the welding robot 19 moves the torch 17 along the trajectory of the torch 17 generated by the trajectory calculation unit 33 by a command from the controller 13, and melts the filler metal M with an arc to melt the base plate 51. A welded bead B is formed on the top.

The base plate 51 is made of a metal plate such as a steel plate, and is basically a base plate 51 larger than the bottom surface (bottom layer surface) of the laminated model W. The base plate 51 is not limited to a plate shape, and may be a base having another shape such as a block body or a rod shape.

As the filler metal M, any commercially available welding wire can be used. For example, it is defined by MAG welding and MIG welding solid wire for mild steel, high-strength steel and low-temperature steel (JIS Z 3312), and arc welding flux-welded wire for mild steel, high-strength steel and low-temperature steel (JIS Z 3313). Wire can be used.

In the laminated model manufacturing system 100 having the above configuration, when the shape data (CAD data or the like) of the laminated model W to be modeled is input to the control unit 37, the control unit 37 stacks based on the input shape data. A laminated model of welded beads B representing the modeling procedure of the modeled object W is generated.

This laminated model is analytically obtained from the input shape data based on an appropriate algorithm so that it can be efficiently laminated based on various conditions such as its shape, material, and heat input. As a result, an orbital plan, which is a plan for the stacking procedure and shape of the welded bead B, is obtained, and the orbit (moving locus) of the torch 17 is obtained based on this orbital plan. Then, the CAD / CAM unit 31 generates a drive program based on the obtained trajectory of the torch 17 and the trajectory plan of the welded bead B.

According to the drive program, the control unit 37 melts the filler metal M protruding from the tip of the torch 17 by an arc to form a linear weld bead B on the base plate 51. Then, by laminating the welded beads B, the laminated model W is modeled.

Next, a method of manufacturing a laminated model by the above-mentioned manufacturing system 100 will be described.
2A to 2D are plan views of the laminated model in the process of manufacturing showing the manufacturing process of the laminated model. 3A to 3D are cross-sectional views of FIGS. 2A to 2D, respectively. FIG. 4 is a plan view of a corner portion of the frame portion in an enlarged view. FIG. 5 is a schematic vertical sectional view of the manufactured laminated model.

(Frame molding process)
As shown in FIGS. 2A and 3A, the filler metal M is melted while the torch 17 of the laminated modeling apparatus 11 is moved by the drive of the welding robot 19. Then, the welded bead B1 made of the molten filler M is supplied onto the base plate 51, and a frame portion 53 having a substantially rectangular shape in a plan view made of the welded bead B1 is formed on the base plate 51. At this time, as shown in FIG. 4, an overhanging portion 55 projecting inward is formed at least at a corner portion of the frame portion 53 which is formed at least in the internal molding step described later.

(Internal modeling process)
As shown in FIGS. 2B and 3B, a welded bead B2 along the first direction X is continuously formed inward from one side portion in the frame portion 53 while being folded back at the end portion of the frame portion 53 (. See middle arrow α in FIG. 2B). Specifically, the welding bead B2 is formed by starting from the corner where the overhanging portion 55 on the one end 53A side of the frame portion 53 is formed and extending toward the other end 53B side on the opposite side of the frame portion 53 to form the frame. Fold back at the other end 53B side of the portion 53. Further, the frame portion 53 is stretched toward one end 53A side and folded back at one end 53A side of the frame portion 53. After that, it is stretched toward the other end 53B side of the frame portion 53, reaches the frame portion 53, and is welded to the inner surface of the frame portion 53. As a result, the molding portion 57A in which the welding beads B2 along the first direction X are lined up in the second direction Y intersecting the first direction X is formed.

Further, as shown in FIGS. 2C and 3C, a welded bead B2 along the first direction X is continuously formed inward from the other side portion in the frame portion 53 while being folded back at the end portion of the frame portion 53. (See arrow β in FIG. 2B). Specifically, the welding bead B2 is formed by starting from the corner where the overhanging portion 55 on the other end 53B side of the frame portion 53 is formed and extending toward one end 53A side on the opposite side of the frame portion 53 to form the frame. Fold back at one end 53A side of the portion 53. Further, it is stretched toward the other end 53B side of the frame portion 53 and folded back at the other end 53B side of the frame portion 53. After that, one end of the frame portion 53 is stretched toward the 53A side, reaches the frame portion 53, and is welded to the inner surface of the frame portion 53. As a result, the molding portion 57B in which the welded beads B2 along the first direction X are lined up in the second direction Y intersecting the first direction X is formed.

At this time, the two modeling portions 57A and 57B formed in the frame portion 53 by the welding bead B2 are formed with a gap G between them.

(Filling process)
As shown in FIGS. 2D and 3D, a welded bead B3 along the first direction X is formed in the gap G between the two modeling portions 57A and 57B in the frame portion 53, and these two modeling portions 57A and 57B are connected to each other. The gap G is filled with the welded bead B3. The formation of the welded bead B3 starts from, for example, one end 53A side of the frame portion 53, reaches the other end 53B of the frame portion 53, and is welded to the inner surface of the frame portion 53 (see arrow γ in FIG. 2D). The welding bead B3 may be formed by starting from the other end 53B side of the frame portion 53 and reaching one end 53A of the frame portion 53 to weld it to the inner surface of the frame portion 53.

By performing the above steps, as shown in FIG. 5, a molding composed of a welded bead B2 in which a gap G is filled by a welded bead B3 inside a frame portion 53 in which a welded bead B1 is laminated on a base plate 51. A laminated model W in which parts 57A and 57B are laminated is formed.

As described above, according to the method for manufacturing a laminated model according to the present embodiment, the frame portion 53 is molded and the inside of the frame portion 53 is filled with the weld beads B2 and B3. Therefore, for example, a large cross-sectional area is formed. The inside of the frame portion 53 can be efficiently filled with the weld beads B2 and B3. Further, a welded bead B2 along the first direction X is continuously formed from both insides in the frame portion 53 while being folded back at the end of the frame portion 53, and the welded bead B2 intersects the first direction X in the second direction Y. Since the two modeling portions 57A and 57B arranged side by side are formed, the number of start ends and ends of the welded bead B2 that fills the inside of the frame portion 53 can be reduced. Thereby, the generation of the unwelded portion can be suppressed. Further, since the welded bead B2 is folded back at the end of the frame portion 53 to be continuously formed, a high-quality lamination is performed while improving the production efficiency as compared with the case where a plurality of welded beads are formed and arranged in the same direction. The modeled object can be manufactured efficiently.

In this way, the weld bead B3 along the first direction X is formed in the gap G between the two modeling portions 57A and 57B to fill the gap G between the modeling portions 57A and 57B, so that the width of the welding bead B3 is adjusted. By doing so, the inside of the frame portion 53 can be satisfactorily filled by flexibly responding to the gap G that changes due to the change of the width dimension of the frame portion 53 and the fluctuation of the width dimension of both the modeling portions 57A and 57B.

For example, as shown in FIG. 6, the gap G also increases as the width dimension of the frame portion 53 increases, but even in this case, the gap G does not change the welding conditions of the welded beads B2 that form the modeling portions 57A and 57B. The welding conditions of the welded bead B3 that fills G can be easily dealt with simply by adjusting the welding conditions so that the required welding cross-sectional area can be obtained without finely controlling the height and width.

In the internal molding step, the first direction X, which is the stretching direction of the weld beads B2 and B3, is preferably set by the aspect ratio of the frame portion 53.

FIG. 7 is a diagram for explaining how to set the forming direction of the welded bead in the internal molding process, and FIGS. 7A and 7B are schematic plan views of the frame portion, respectively.

As shown in FIG. 7A, if the vertical dimension l and the horizontal dimension w of the frame portion 53 are l> w, the vertical direction is set to the first direction X and the horizontal direction is set to the second direction Y. Set. On the other hand, as shown in FIG. 7B, if the vertical dimension l and the horizontal dimension w of the frame portion 53 are l <w, the horizontal direction is set to the first direction X and the vertical direction is set. Set to the second direction Y.

As described above, if the first direction X, which is the stretching direction of the weld beads B2 and B3, is set to be longer by comparing the vertical dimension l and the horizontal dimension w of the frame portion 53, the welding formed in the internal molding process is performed. The number of turns of the bead B2 can be reduced, and the work efficiency can be improved. Further, since the number of folded portions of the welded bead B2 is reduced, it is possible to suppress the occurrence of unwelded portions between the frame portion 53 and the folded portions.

Next, a modified example will be described.
8A and 8B are views for explaining a modification of the internal molding step and the filling step, where FIG. 8A is a plan view and FIG. 8B is a sectional view taken along line EE in FIG. 8A.

As shown in FIGS. 8A and 8B, in the modified example, in the internal molding step, the welded beads B2 for molding the respective molding portions 57A and 57B are slightly folded back inward from both ends in the gap G. It is stretched and its end is arranged in the gap G. At this time, the end surface B2e at the end of the weld bead B2 is formed on an inclined surface that gradually inclines downward toward the end. In this way, in order to form the end surface B2e at the end of the weld bead B2 on the inclined surface, for example, the arc is appropriately held before the arc is cut and the welding is stopped. In this way, the end surface B2e of the welded bead B2 is formed on an inclined surface without a dent. Then, in the filling step, a welding bead B3 for filling is formed between the ends of the welding beads B2 in the gap G.

According to this modification, since the start and end ends of the welded bead B3 filled in the gap G are located away from the frame portion 53, the unwelded portion between the frame portion 53 and the start and end ends of the welded bead B3. Can be avoided. Further, the interference between the torch 17 forming the welded bead B3 and the frame portion 53 can be suppressed, and the filling process can be smoothly performed.

Further, by forming the end surface B2e of the end of the weld bead B2 on an inclined surface that gradually inclines downward toward the end, the end of the weld bead B3 and the end surface of the weld bead B3 are formed with respect to the weld bead B2 that forms the modeling portions 57A and 57B. The start ends can be connected well without any gaps.

The forming direction of the welded bead B2 in the internal molding step is not limited to the above embodiment. For example, as shown in FIG. 9, each welded bead B2 for modeling the modeling portions 57A and 57B may be started from one end 53A side of the frame portion 53, folded back at the other end 53B, and further folded back at one end 53A. (See arrows α1 and α2 in FIG. 9). When the welded bead B2 is formed in this way, the molding portions 57A and 57B can be shaped symmetrically at the center in the width direction to fill the inside of the frame portion 53 in a well-balanced manner.

As described above, the present invention is not limited to the above-described embodiment, and can be modified or applied by those skilled in the art based on the combination of the configurations of the embodiments with each other, the description of the specification, and the well-known technique. This is also the subject of the present invention and is included in the scope for which protection is sought.

As described above, the following matters are disclosed in this specification.
(1) A method for manufacturing a laminated model in which a welded bead obtained by melting and solidifying a filler metal is laminated to form a model.
The frame part molding process of forming the frame part by the welding bead and
Welded beads along the first direction from both sides in the frame portion are continuously formed inward while being folded back at the end of the frame portion, and the welded beads are arranged in the second direction intersecting the first direction. The internal modeling process, which creates the two modeling parts with a gap between them,
A filling step of forming a welding bead along the first direction in the gap between the two shaped portions in the frame portion to fill the gap between the two shaped portions.
A method for manufacturing a laminated model, including.

According to the method for manufacturing a laminated model having the configuration of (1) above, the frame portion is shaped and the inside of the frame portion is filled with the welded bead. Therefore, for example, the inside of the frame portion can be efficiently filled with the welded bead having a large cross-sectional area. it can. In addition, welded beads along the first direction from both insides in the frame are continuously formed while being folded back at the ends of the frame, and two shaped portions in which the weld beads intersect the first direction are formed. Therefore, the number of start ends and ends of the welded beads that fill the frame portion can be reduced, and the occurrence of unwelded portions can be suppressed. In addition, since the welded beads are folded back at the end of the frame portion to be continuously formed, a high-quality laminated modeled product while improving production efficiency as compared with the case where a plurality of welded beads are formed and arranged in the same direction. Can be efficiently manufactured.
Moreover, since a welded bead along the first direction is formed in the gap between the two shaped parts to fill the gap between the shaped parts, the width of the frame part can be changed by adjusting the width of the welded bead. It is possible to satisfactorily fill the inside of the frame by flexibly responding to the gap that changes due to the fluctuation of the width dimension of the modeled portion.

(2) The method for manufacturing a laminated model according to (1), wherein in the frame portion modeling step, an overhanging portion that projects inward is formed at least at a corner portion that is the starting end of the welded bead in the internal modeling step.

According to the method for manufacturing a laminated model having the configuration of (2) above, it is possible to suppress the formation of a gap with the frame portion at the start end of the welded bead for modeling the modeled portion, and it is possible to suppress the occurrence of the unwelded portion. ..

(3) In the internal modeling step, the vertical dimension and the horizontal dimension of the frame portion are compared, the longer one is set in the first direction, and the shorter one is set in the second direction, (1) or (2). ). The method for manufacturing a laminated model.

According to the method for manufacturing a laminated model having the configuration of (3) above, the number of times the weld bead formed in the internal modeling step is folded back can be reduced, and the work efficiency can be improved. Further, by reducing the number of folded portions of the welded bead, it is possible to suppress the occurrence of an unwelded portion with the frame portion.

(4) In the internal modeling step, the welded bead for modeling each of the modeling portions is folded back at the gap and the end is arranged in the gap.
The method for producing a laminated model according to any one of (1) to (3), wherein in the filling step, a welded bead is filled between the ends in the gap.

According to the method for manufacturing a laminated model having the configuration of (4) above, the start end and the end of the welded bead to be filled in the gap are located away from the frame part, so that there is no gap between the frame part and the start end and the end. The generation of welded parts can be avoided. In addition, interference between the torch forming the weld bead and the frame portion can be suppressed, and the filling process can be smoothly performed.

(5) The method for manufacturing a laminated model according to (4), wherein in the internal modeling step, the end surface of the end of the weld bead is formed on an inclined surface that gradually inclines downward toward the end.

According to the method for manufacturing a laminated model having the configuration of (5) above, the weld bead is formed by forming the end face of the end of the weld bead into an inclined surface that gradually inclines downward toward the end. On the other hand, the end and start ends of the welded beads that fill the gaps between the shaped portions can be satisfactorily connected without any gaps.

53 Frame part 55 Overhang part 57A, 57B Modeling part B, B1, B2, B3 Welded bead B2e End face G Gap M filler metal W Laminated model X First direction Y Second direction l Vertical dimension w Horizontal dimension

Claims (5)

It is a method for manufacturing a laminated model, in which a welded bead obtained by melting and solidifying a filler metal is laminated to form a model.
The frame part molding process of forming the frame part by the welding bead and
Welded beads along the first direction from both sides in the frame portion are continuously formed inward while being folded back at the end of the frame portion, and the welded beads are arranged in the second direction intersecting the first direction. The internal modeling process, which creates the two modeling parts with a gap between them,
A filling step of forming a welding bead along the first direction in a gap between two molding portions in the frame portion to fill the gap between the two molding portions.
including,
A method for manufacturing a laminated model. In the frame portion molding step, an overhanging portion that projects inward is formed at least at a corner portion that is the starting end of the welding bead in the internal molding step.
The method for manufacturing a laminated model according to claim 1. In the internal modeling step, the vertical dimension and the horizontal dimension of the frame portion are compared, the longer one is set in the first direction, and the shorter one is set in the second direction.
The method for manufacturing a laminated model according to claim 1 or 2. In the internal modeling step, the welded bead that models each of the modeling portions is folded back in the gap and the end is arranged in the gap.
In the filling step, a welded bead is filled between the ends in the gap.
The method for manufacturing a laminated model according to any one of claims 1 to 3. In the internal molding step, the end face of the end of the weld bead is formed into an inclined surface that gradually inclines downward toward the end.
The method for manufacturing a laminated model according to claim 4.

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