JP7193423B2 - Laminate-molded article manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a layered product.

In recent years, the need for 3D printers as a means of production has increased, and research and development are being carried out for practical application in the aircraft industry, etc., especially for application to metal materials. A 3D printer using a metal material melts metal powder or metal wire using a heat source such as a laser or an arc, and laminates the molten metal to form a modeled object.

Regarding the technique of forming a weld bead, Patent Document 1 describes a control method for detecting a welding groove gap in arc welding, selecting an amplitude corresponding to the detected groove gap, and performing weaving. Further, in Patent Document 2, according to the increase in the gap width at the groove bottom detected by the visual sensor, the average welding current is decreased stepwise, and at the same time, the welding speed is decreased and the weaving width is increased. is described. Furthermore, in Patent Document 3, in a system that irradiates an energy beam downstream of arc welding, porosity in at least one surface of a weld puddle and a weld bead formed by the weld puddle is detected, and the detected porosity is Altering the operation of the energy beam in response is described.

JP-A-63-72480 Japanese Patent No. 4500489 JP 2014-531325 A

By the way, when forming a layered product by further laminating a welding bead layer on a welding bead layer in which a plurality of welding beads are arranged, there is no welding at the narrow boundary between adjacent welding beads in each welding bead layer. part may occur. As a result, weld defects such as blowholes and cracks may occur in the completed laminate-molded article, and desired mechanical strength may not be obtained.

The possibility of the occurrence of an unwelded portion at the boundary of this adjacent weld bead is caused by controlling weaving by detecting the welding groove gap of arc welding and the gap width at the groove bottom as in Patent Documents 1 and 2. , is difficult to reliably eliminate by simply changing the behavior of the energy beam.

The present invention has been made in view of the above matters, and its object is to suppress the occurrence of unwelded parts at the boundaries between adjacent welding beads and obtain a high-quality laminate-molded article. It is to provide a manufacturing method of

The present invention consists of the following configurations.
A method for manufacturing a laminate-molded article, in which welding beads obtained by melting and solidifying a filler material are placed adjacent to each other to form a welding bead layer, and the following welding bead layer is repeatedly laminated on the formed welding bead layer to form a laminate model. and
a groove forming step of forming a groove by forming weld beads on both sides of the boundary between adjacent weld beads in the previous weld bead layer when forming the next weld bead layer;
a high-melt weld bead forming step of forming a high-melt weld bead having a deep penetration depth in the groove portion.

ADVANTAGE OF THE INVENTION According to this invention, generation|occurrence|production of the unwelded part in the boundary part of adjacent welding beads can be suppressed, and a high-quality laminate-molded article can be obtained.

It is a lineblock diagram of a manufacturing system used for manufacture of a laminate-molded article. It is a schematic sectional drawing of the laminate-molded article in the middle of manufacture which shows the manufacturing procedure of a laminate-molded article. It is a schematic sectional drawing of the laminate-molded article in the middle of manufacture which shows the manufacturing procedure of a laminate-molded article. FIG. 3 is a schematic plan view of a laminate-molded article in the middle of production for explaining a melting position determination step in the method for producing a laminate-molded article of the present invention. It is a schematic plan view of the laminate-molded article in the middle of manufacture for explaining the groove forming step in the method for manufacturing the laminate-molded article of the present invention. FIG. 2 is a schematic plan view of a laminate-molded article in the process of production, for explaining a high-melt welding bead forming step in the method for producing a laminate-molded article of the present invention. FIG. 4 is a schematic plan view of a laminate-molded article in the process of manufacturing, for explaining a step of forming a welding bead in the method for producing a laminate-molded article of the present invention. 3B is a schematic cross-sectional view along A1-A1 in FIG. 3A; FIG. FIG. 3B is a schematic cross-sectional view along A2-A2 in FIG. 3B; FIG. 3C is a schematic cross-sectional view along A3-A3 in FIG. 3C; 3C is a schematic cross-sectional view along A4-A4 in FIG. 3D; FIG. It is a schematic sectional drawing of the laminate-molded article in the middle of manufacture explaining the high melting welding bead formation process in the manufacturing method of the laminate-molded article of this invention. It is a schematic sectional drawing of the laminate-molded article in the middle of manufacture explaining another high-melting welding bead formation process.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a manufacturing system used for manufacturing a laminate-molded article of the present invention.
A manufacturing system 100 for a laminate-molded article having this configuration includes a laminate-molding apparatus 11 , a controller 13 that performs integrated control of the laminate-molding apparatus 11 , and a power supply device 15 .

The layered manufacturing apparatus 11 includes a welding robot 19 having a torch 17 on its tip axis, and a filler material supply section 21 that supplies a filler material (welding wire) M to the torch 17 . A laser irradiator 23 and a detection sensor 25 are provided along with the torch 17 on the distal end shaft of the welding robot 19 .

The welding robot 19 is a multi-joint robot, and the torch 17 attached to the tip shaft of the robot arm is supported so that the filler material M can be continuously supplied. The position and posture of the torch 17 can be arbitrarily set three-dimensionally within the range of degrees of freedom of the robot arm.

The torch 17 has a shield nozzle (not shown), and a shield gas is supplied from the shield nozzle. The arc welding method may be a consumable electrode type such as coated arc welding or carbon dioxide gas arc welding, or a non-consumable electrode type such as TIG welding or plasma arc welding. be.

For example, in the case of the consumable electrode type, a contact tip is arranged inside the shield nozzle, and the contact tip holds the filler material M to which the melting current is supplied. The torch 17 holds the filler material M and generates an arc from the tip of the filler material M in a shield gas atmosphere. The filler material M is fed from the filler material supply unit 21 to the torch 17 by a feeding mechanism (not shown) attached to a robot arm or the like. When the continuously fed filler material M is melted and solidified while the torch 17 is moving, a linear welding bead B, which is a melted and solidified body of the filler material M, is formed on the base plate 51 .

The laser irradiator 23 irradiates by condensing a laser oscillated from a laser oscillator with a condensing optical system. Examples of the laser include a CO ₂ laser and a YAG laser. The detection sensor 25 is a sensor that measures the shape of the laminate-molded article W in the process of being molded. As the detection sensor 25, for example, a laser sensor that acquires the reflected light of the irradiated laser light as height data is used.

The controller 13 has a CAD/CAM section 31, a trajectory calculation section 33, a storage section 35, and a control section 37 to which these are connected.

The CAD/CAM unit 31 inputs or creates shape data (CAD data, etc.) of the laminate-molded object to be manufactured, and cooperates with the trajectory calculation unit 33 to determine the welding bead B representing the procedure for forming the laminate-molded object. Generate a laminate model. 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 locus of movement of the torch 17 is determined based on the layer shape data of the generated layered model. The CAD/CAM unit 31 generates a drive program for the welding robot 19 and the power supply device 15 that moves the torch 17 to form a weld bead based on the generated layer shape data and data such as the movement trajectory of the torch 17. . Various data such as the generated drive program are stored in the storage unit 35 .

The control unit 37 executes the 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 in accordance with the command from the controller 13, melts the filler material M with an arc, and melts the base plate 51. A weld bead B is formed thereon.

The base plate 51 is made of a metal plate such as a steel plate, and is basically larger than the bottom surface (lowermost layer surface) of the laminate-molded article W. Note that the base plate 51 is not limited to a plate-like shape, and may be a block-like or rod-like base.

As filler material M, any commercially available welding wire can be used. For example, MAG welding and MIG welding solid wires for mild steel, high-strength steel and low-temperature steel (JIS Z 3312), arc welding flux-cored wires for mild steel, high-strength steel and low-temperature steel (JIS Z 3313), etc. wire can be used.

In the laminate-molded article manufacturing system 100 configured as described above, when the shape data (such as CAD data) of the laminate-molded article W to be modeled is input to the control unit 37, the control unit 37 performs lamination based on the input shape data. A lamination model of the welding bead B representing the molding procedure of the object W is generated.

This lamination model is analytically determined based on an appropriate algorithm based on various conditions such as the shape, material, and heat input from the input shape data so that lamination can be efficiently performed. As a result, a trajectory plan, which is a plan for the lamination procedure and shape of the welding bead B, is obtained, and the trajectory (moving trajectory) of the torch 17 is obtained based on this trajectory plan. Then, the CAD/CAM unit 31 generates a driving program based on the determined trajectory of the torch 17 and the trajectory plan of the welding bead B. FIG.

The controller 37 melts the filler material M projecting from the tip of the torch 17 with the arc Ac to form a linear welding bead B on the base plate 51 according to the drive program, as shown in FIG. 2A. Then, a plurality of weld beads B are formed adjacent to each other on the base plate 51 to shape the first weld bead layer 53 .

Next, as shown in FIG. 2B, the control unit 37 forms a plurality of welding beads B adjacent to each other on the welding bead layer 53 of the first layer, and welds the second layer, which is the next layer. A bead layer 53 is laminated. By repeating the lamination of the welding bead layers 53, the laminate-molded article W is formed.

By the way, when forming the welding bead layer 53 with the welding beads B adjacent to each other, there is a possibility that an unwelded portion may be formed in a narrow boundary portion between adjacent welding beads B in each welding bead layer 53 . As a result, weld defects such as blowholes and cracks may occur in the completed laminate-molded article W, and desired mechanical strength may not be obtained.

In the present embodiment, the laminate-molded article W is manufactured while suppressing the occurrence of unwelded portions at narrow boundaries between adjacent welding beads B. FIG. Hereinafter, the method for manufacturing the laminate-molded article W according to this embodiment will be described in detail.

3A to 3D are schematic plan views of a laminate-molded article in the process of manufacturing, showing the manufacturing procedure of the laminate-molded article. 4A to 4D are schematic cross-sectional views along the width direction of the laminate-molded article during manufacturing, showing the manufacturing procedure of the laminate-molded article. FIG. 5 is a schematic cross-sectional view along the welding direction of the laminate-molded product in the process of manufacturing, for explaining the high-melt welding bead forming process.

(Melting position specifying step)
As shown in FIGS. 3A and 4A, after forming the first welding bead layer 53 on the base plate 51, the first welding bead layer 53 is detected based on the detection data from the detection sensor 25. to estimate the width and depth of the gap at the boundary 55 of the adjacent welding beads B. For example, the control section 37 estimates the width and depth of the boundary section 55 by the optical section method using the height data from the detection sensor 25 consisting of a laser sensor.

The control unit 37 determines whether or not the estimated width and depth of the gap at the boundary 55 exceed preset threshold values. Note that the threshold value used for determination is a value at which an unwelded portion may occur due to the large width and depth of the gap at the boundary portion 55 of the adjacent welding beads B, and is preset and stored in the storage unit 35. ing. When the controller 37 determines that the width and depth of the gap at the boundary 55 between the adjacent welding beads B exceed preset threshold values, the controller 37 specifies the melting position P, which is the position.

(Groove forming process)
After specifying the melting position P, the control unit 37 corrects the trajectory plan created using the shape data of the laminate-molded article W. FIG. Based on the corrected trajectory plan, the control unit 37 forms the welding bead B on the first welding bead layer 53 .

As a result, as shown in FIGS. 3B and 4B, on both sides of the boundary portion 55 having the melting position P of the adjacent welding bead B in the welding bead layer 53 of the first layer, based on the corrected trajectory plan A welding bead B is formed, and a groove portion 57 is formed on the boundary portion 55 by the welding bead B constituting the second welding bead layer 53 .

The welding bead B formed by the corrected trajectory plan for shaping the groove portion 57 has, for example, a narrower width than the welding bead B in the created trajectory plan. are shifted in the direction of separation. When forming the groove portion 57, the groove portion 57 may be formed by shifting the trajectory (moving trajectory) of the welding bead B in a direction to separate them from each other without changing the width.

(High-melt welding bead forming process)
After forming the groove portion 57, a high-melting welding bead BH is formed in the groove portion 57 as shown in FIGS. 3C and 4C. This high-melting weld bead BH is a weld bead that penetrates deeper into the substrate than the normal weld bead B. As shown in FIG.

In order to form this high-melting welding bead BH, as shown in FIG. A workpiece M is melted by an arc Ac. Then, in the groove portion 57, the portion where the welding bead is formed by the arc Ac with the low energy density is previously irradiated with the laser L with the high energy density, thereby supplementing the amount of heat input to the portion where the welding bead is formed. In other words, the boundary portion 55 in the groove portion 57 is melted by the laser L, and further, a welding bead is embedded in the melted portion by the arc AC, thereby forming a high melting welding bead BH with a deep penetration depth into the base. It is formed. By forming this high-melting weld bead BH in the groove portion 57, the penetration depth is deep at the boundary portion 55 between the adjacent weld beads B in the first weld bead layer 53, which is the front layer. It is remelted by the melt weld bead BH. Thereby, the gap at the boundary portion 55 is eliminated. For the groove portion 57 , the welding bead B formed by the torch 17 may be irradiated with the laser L. In this way, the welding bead B formed in the groove portion 57 is pushed into the boundary portion 55 by the laser L, thereby forming a high-melting welding bead BH having a deep penetration into the substrate.

As shown in FIGS. 3D and 4D , in the first welding bead layer 53 , a welding bead B is formed based on the trajectory plan above the boundary portion 55 where the required melting position P is not specified. As a result, the second welding bead layer 53 formed by the welding beads B including the high-melting welding bead BH is laminated on the first welding bead layer 53 .

When forming the groove portion 57 to form the high-melt weld bead BH, the high-melt weld bead BH is added to the trajectory plan for forming the laminate-molded article W as a new weld bead element.

As described above, according to the manufacturing method described above, a high-melting weld bead BH having a deep penetration depth is formed at the boundary 55 between adjacent weld beads B in the weld bead layer 53 of the front layer. As a result, the boundary portion 55 of the welding bead B can be melted again by the high-melting welding bead BH to eliminate unwelded parts, and there are no weld defects such as blowholes and cracks, and the desired mechanical strength can be obtained. A quality laminate-molded article W can be manufactured.

In addition, since the welding beads B are formed on both sides of the welding bead layer 53 of the front layer sandwiching the boundary portion 55 of the adjacent welding beads B and the groove portion 57 is formed, the high-melting welding bead BH is formed. It is possible to dam the molten metal that is generated at the time and prevent it from spreading and flowing out to the surroundings. As a result, the high-melting weld bead BH can be smoothly formed at the boundary portion 55 of the weld bead B of the previous weld bead layer 53 .

Moreover, the melting position P where the high-melt welding bead BH needs to be formed is specified based on the width and depth of the gap in the boundary portion 55, and the groove portion 57 is formed at this melting position P to perform high-melting welding. Form a bead BH. As a result, the formation of the high-melt welding bead BH can be minimized, and the laminate-molded article W of high quality can be manufactured with high manufacturing efficiency.

In addition, in the high-melt welding bead forming step, the laser L is irradiated to the welding bead formation location to make the welding bead a high-melting welding bead BH with a deep penetration depth. It can be easily formed.

In addition, since the groove portion 57 is formed by correcting the lamination procedure of the welding bead B and the trajectory plan of the shape, it is possible to eliminate the trouble of newly creating the trajectory plan of the welding bead B for forming the groove portion 57. . Thereby, a high-quality laminate-molded article W can be efficiently manufactured.

In the above example, the high melting welding bead BH was formed by irradiating the laser L to deepen the penetration depth of the welding bead. For example, plasma welding may be used. With plasma welding, the arc is converged by the nozzle and cooling gas, so it is easy to achieve deep penetration.

For example, by generating the arc Ac irradiated by the torch 17 at a high current value, the groove portion 57 may be intensively irradiated with the arc Ac to form a high melting welding bead BH with a deep penetration depth.

Further, as shown in FIG. 6, by weaving the torch 17 along the welding direction (reciprocating movement in the direction of arrow X in FIG. 6) at the groove portion 57, the arc Ac is repeatedly irradiated to increase the penetration depth. A deep high-melt welding bead BH may be formed.

As a detection sensor for detecting the shape of the boundary portion 55 of the adjacent welding bead B, an ultrasonic sensor or the like receives an ultrasonic wave propagated from a transmitting probe with a receiving probe and detects a diffracted wave. various known sensors can be used. For example, when an ultrasonic sensor is used, the controller 37 estimates the shape of the boundary portion 55 by a TOF (Time of Flight) method using diffracted waves from the ultrasonic sensor.

In the above example, the high-melting weld bead BH is formed over the entire length at the boundary 55 of the welding bead B having the melting position P of the front welding bead layer 53. It may be formed only at the position P and its surroundings.

As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make modifications and applications by combining each configuration of the embodiments with each other, based on the description of the specification and well-known techniques. It is also contemplated by the present invention that it falls within the scope of protection sought.

As described above, this specification discloses the following matters.
(1) A laminate-molded article manufactured by forming a weld bead layer by placing weld beads obtained by melting and solidifying a filler material adjacent to each other, and repeatedly laminating the next layer of the weld bead layer on the formed weld bead layer. A manufacturing method of
a groove forming step of forming a groove by forming weld beads on both sides of the boundary between adjacent weld beads in the previous weld bead layer when forming the next weld bead layer;
a high-melt weld bead forming step of forming a high-melt weld bead having a deep penetration depth in the groove portion.
According to the method for manufacturing a laminate-molded article having the above configuration (1), a high-melting weld bead having a deep penetration depth is formed at the boundary between adjacent weld beads in the previous weld bead layer. As a result, the boundary of the welding bead can be re-melted with a high-melting welding bead to eliminate unwelded parts, and there are no weld defects such as blowholes or cracks, and a high-quality laminate with the desired mechanical strength can be obtained. Modeled objects can be manufactured.
In addition, since the welding beads are formed on both sides of the welding bead layer of the previous layer sandwiching the boundary portion of the adjacent welding beads and the groove portion is formed, the molten metal generated when forming the high-melting welding bead is reduced. It can be dammed to suppress the spread and outflow to the surroundings. As a result, a high-melting weld bead can be smoothly formed at the boundary between the weld beads in the previous weld bead layer.

(2) When forming the welding bead layer of the next layer, the width and depth of the gap at the boundary portion of the welding bead layer of the previous layer are estimated, and based on the estimated width and depth of the gap, the height including a melting position specifying step of specifying a melting position to form a melt welding bead;
The method for manufacturing a laminate-molded article according to (1), wherein the bevel forming step and the high-melting weld bead forming step are performed on the required melting position specified in the melting position specifying step.
According to the method for manufacturing a laminate-molded article having the configuration of (2) above, a melting position where a high-melting welding bead needs to be formed is specified based on the width and depth of the gap at the boundary, and the melting position is The bevel is shaped to form a high-melt weld bead. As a result, the formation of high-melt welding beads can be minimized, and a high-quality laminate-molded article can be manufactured with high manufacturing efficiency.

(3) The lamination according to (1) or (2), wherein in the high-melting weld bead forming step, a laser is irradiated to the weld bead formation location to make the weld bead a high-melt weld bead with a deep penetration depth. A method of manufacturing a modeled object.
According to the method for manufacturing a laminate-molded article having the above configuration (3), a high-melting weld bead with a deep penetration depth is easily formed by irradiating a laser beam to a portion where the weld bead is formed to form the weld bead. be able to.

(4) The method according to (1) or (2), wherein in the step of forming a high-melt weld bead, plasma welding is performed on the weld bead formation location to make the weld bead a high-melt weld bead with a deep penetration depth. A method for producing a laminate-molded article.
According to the method for manufacturing a laminate-molded article having the configuration (4), the arc is converged by the nozzle and the cooling gas, so that deep penetration can be easily achieved.

(5) In the high-melt weld bead forming step, the weld bead is formed into a high-melt weld bead with a deep penetration depth by generating an arc at a high current value to form a weld bead, (1) or ( 2) The method for producing a laminate-molded article according to 2).
According to the method for manufacturing a laminate-molded article having the configuration of (5) above, a high-melting weld bead with a deep penetration depth can be easily formed by intensively irradiating the arc with a high current value to the weld bead formation location. can do.

(6) In the step of forming a high-melt weld bead, the weld bead is formed by weaving a torch and repeatedly irradiating an arc to form a weld bead having a deep penetration depth, (1) Or the manufacturing method of the laminate-molded article as described in (2).
According to the method for manufacturing a laminate-molded article having the configuration (6) above, by repeatedly irradiating the arc by weaving the torch, a high-melting welding bead with a deep penetration depth can be easily formed.

(7) further comprising a trajectory planning step of creating a trajectory plan for the lamination procedure and shape of the welding bead using the shape data of the laminate-molded article;
In the groove part forming step, by correcting the trajectory plan and forming the welding bead, a gap that will be the groove part is opened between the welding beads constituting the welding bead layer of the next layer, (1) ~ (6) The method for producing a laminate-molded article according to any one of the above items.
According to the method for manufacturing a layered product having the above configuration (7), when forming the next layer of the welding bead layer, the trajectory plan is corrected to reduce the width dimension of the welding bead, or the welding bead is formed. A gap is created between the weld beads by shifting the travel path of the torch. As a result, it is possible to form a bevel portion by the welding bead of the next layer formed with a gap above the boundary portion between adjacent welding beads in the welding bead layer of the previous layer. In this way, since the bead is formed by correcting the welding bead stacking procedure and shape trajectory plan, it is possible to eliminate the need to create a new welding bead trajectory plan for forming the bead. Thereby, a high-quality laminate-molded article can be efficiently manufactured.

53 Welding bead layer 55 Boundary part 57 Groove part Ac Arc B Welding bead BH High-melting welding bead P L Laser M Filler material W Laminated object

Claims (6)

A method for manufacturing a laminate-molded article, in which welding beads obtained by melting and solidifying a filler material are placed adjacent to each other to form a welding bead layer, and the following welding bead layer is repeatedly laminated on the formed welding bead layer to form a laminate model. and
When forming the welding bead layer of the next layer, the width and depth of the gap at the boundary between adjacent welding beads in the welding bead layer of the previous layer are estimated, and based on the estimated width and depth of the gap, the penetration a melting position specifying step of specifying a melting position to form a deep high-melting welding bead;
A groove forming step of forming a groove by forming a weld bead on both sides of the weld bead layer of the previous layer with the boundary portion sandwiched therebetween when forming the weld bead layer of the next layer;
a high-melt weld bead forming step of forming the high-melt weld bead in the groove;
including
Performing the groove forming step and the high-melt welding bead forming step for the melting position specified in the melting position specifying step,
A method for manufacturing a laminate-molded article. 2. The method of manufacturing a laminate-molded article according to claim 1 , wherein in the high-melt welding bead forming step, a laser is irradiated to a portion where the welding bead is formed to make the welding bead a high-melting weld bead having a deep penetration depth. 2. The method of manufacturing a laminate-molded article according to claim 1 , wherein in the high-melt welding bead forming step, plasma welding is performed to the weld bead formation location to make the weld bead a high-melt weld bead with a deep penetration depth. Laminate manufacturing according to claim 1 , wherein in the high-melt welding bead forming step, the welding bead is formed by generating an arc with a high current value to make the welding bead a high-melting welding bead with a deep penetration depth. A method of making things. 2. The high-melt weld bead according to claim 1 , wherein in the high-melt weld bead forming step, the weld bead is formed by weaving a torch and repeatedly irradiating an arc to form a weld bead having a deep penetration depth. A method for producing a laminate-molded article. Further comprising a trajectory planning step of creating a trajectory plan for the lamination procedure and shape of the welding bead using the shape data of the laminate-molded article,
Claims 1 to 3, wherein in the groove portion forming step, a gap that becomes the groove portion is provided between the weld beads that constitute the next layer of the weld bead layer by correcting the trajectory plan and forming the weld bead. 6. The method for producing a laminate-molded article according to any one of 5 .

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