JP2020192605A - Laminate molding method - Google Patents

Abstract

To provide a laminate molding method capable of forming a laminate molded object at a high speed and with high quality.SOLUTION: A laminate molding method includes: a bead laminating step of laminating beads 53A, 53B, 53C, 53D along a bead formation locus determined by a lamination plan; and a slag removing step of removing, by using a slag removing tool, slag generated in a plurality of V groove portions 61A, 61B, 61C formed between the adjacent beads. In the slag removing step, the V groove portion in which a dimensional ratio H/W of a bead height H to a bead width W of the beads forming the V groove portions 61A, 61B, 61C exceeds 0.2 is extracted from lamination plan information as a removal candidate place, and slag in the extracted removal candidate place is removed.SELECTED DRAWING: Figure 3

Description

The present invention relates to a laminated modeling method for forming a laminated model in which beads are laminated.

A laminated modeling method is known in which beads obtained by sintering metal powder with a laser beam are laminated to perform three-dimensional modeling. This method has been partially applied to the small-scale production of products using relatively high-grade metals. On the other hand, for industries such as the modeling of machine parts, a process that can perform modeling at higher speed and guarantee internal quality is expected. As such a modeling technique, a method of laminating molten metal (beads) by moving a torch for arc welding that supplies a filler material to produce a modeled object is known (see, for example, Patent Document 1). ).

Japanese Patent No. 3784539 Japanese Patent No. 2974305 Japanese Patent No. 5883700

However, slag that reacts with the deoxidizing material and oxygen is generated on the surface of the formed bead, and when the bead is further laminated on the slag, the instability of the arc increases and welding failure due to slag entrainment also occurs. .. Slag entrainment is a phenomenon in which oxides are trapped in the molten metal and solidify, and since the bonding strength between the slag and the metal is small, the strength and durability of the laminated model are reduced.

As a technique for removing slag generated during welding, for example, Patent Document 2 discloses a robot that removes slag after welding, and Patent Document 3 discloses a type used in place of a torch and an additional attachment to the torch. A type of slag remover is disclosed. However, in the techniques disclosed in Patent Documents 2 and 3, slag removal is performed without considering whether or not slag entrainment is a concern, so that the removal work becomes complicated and a lot of time is required. It takes. Therefore, it has been difficult to manufacture a laminated model at high speed and with high quality.

In view of such conventional problems, an object of the present invention is to provide a laminated modeling method capable of forming a laminated model at high speed and with high quality.

The present invention has the following configuration.
A laminated molding method in which a bead obtained by melting and solidifying a filler metal is laminated on the surface of a base material according to a lamination plan in which the formation order of the bead is determined to form a laminated model.
A bead laminating step of laminating the beads along a bead forming trajectory determined by the laminating plan,
A slag removing step of removing slag generated in a plurality of V-grooves formed between adjacent beads by using a slag removing tool, and
Have,
The slag removing step is
From the bead shape of the stacking plan and the information of the bead forming orbit, the dimensional ratio H / W of the bead height H and the bead width W of the bead forming the V groove portion in the orbital direction vertical cross section orthogonal to the bead forming orbit. Seeking,
Of the plurality of V-grooves, V-grooves having a dimensional ratio H / W of more than 0.2 are extracted as removal candidate sites.
The extracted slag at the removal candidate site is removed.
Laminated modeling method.

According to the present invention, it is possible to form a laminated model at high speed and with high quality by removing slag with priority given to a portion where slag entrainment is a concern.

FIG. 1 is a schematic configuration diagram of a laminated modeling system. FIG. 2 is a cross-sectional view showing a schematic example of a laminated model formed by the laminated modeling system shown in FIG. FIG. 3 is an explanatory diagram showing a procedure for determining a slag removal candidate location and a slag removing tool abutting direction. (A) to (C) of FIG. 4 are process explanatory views stepwise showing a process of modeling the laminated model shown in FIG. (A) to (D) of FIG. 5 are process explanatory views stepwise showing a process of modeling the laminated model shown in FIG. 6 (A) and 6 (B) are explanatory views showing the opening angles of the V-groove portions according to the order of bead formation. FIG. 7 is an explanatory diagram illustrating problems in the conventional method. FIG. 8 is an explanatory diagram showing a method of abutting the slag removing tool for solving the problem described with reference to FIG. 7. FIG. 9 is an enlarged view of the portion of the slag and the V-groove portion in FIG. 8 and is an explanatory view for explaining the state before removing the slag. FIG. 10 is an enlarged view of the slag and the portion of the V-groove portion in FIG. 8 and is an explanatory view for explaining the state after removing the slag.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Structure of laminated modeling system>
As shown in FIG. 1, the laminated modeling system 100 for forming the laminated model of the present embodiment is a controller 15 that collectively controls the laminated modeling device 11, the slag removing device 13, the laminated modeling device 11, and the slag removing device 13. And.

The laminated modeling device 11 includes a welding robot 19 having 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 torch 17 holds the filler metal M in a state of protruding from the tip.

The welding robot 19 is an articulated robot, and the filler metal M is continuously supplied to the torch 17 provided on the tip shaft. 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 used in this configuration 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 used for the laminated model to be manufactured. It will be selected as appropriate.

For example, in the case of the consumable electrode type, a 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 M that is continuously fed is melted and solidified while moving the torch 17, a linear bead 53 that is a molten solidified body of the filler M is formed on the base material 51 described later. Torch.

The heat source for melting the filler metal M is not limited to the above-mentioned arc. For example, a heat source by another method such as a heating method using both an arc and a laser, a heating method using plasma, and a heating method using an electron beam or a laser may be adopted. When heating with an electron beam or a laser, the amount of heating can be controlled more finely, the state of the welded bead can be maintained more appropriately, and the quality of the laminated model can be further improved.

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.

The slag removing device 13 includes a general-purpose robot 41. The general-purpose robot 41 is an articulated robot like the welding robot 19, and a slag removing tool 45 is attached to the tip of the tip arm 43. In the general-purpose robot 41, the position and posture of the slag removing tool 45 can be arbitrarily set three-dimensionally within the range of the degree of freedom of the tip arm 43 by a command from the controller 15.

The general-purpose robot 41 removes the slag generated on the bead 53 laminated on the base material surface 51a by the welding robot 19 of the laminated modeling device 11 by using the slag removing tool 45. Examples of the slag removing tool 45 include a chisel mechanism (see, for example, Japanese Patent No. 2974305) in which a chisel member is abutted against the slag and vibrated to hit the slag. The chisel member is composed of a bundle of multi-core wire members, and the tip of the bundle is formed into a flat shape, a curved convex shape, or the like, but the shape is not limited to this. Here, the slag to be removed is a slag existing in the V groove portion between the beads 53 adjacent to each other.

Further, the general-purpose robot 41 preferably has a tool changer function, and in that case, includes a well-known changer unit 47 for tool replacement. The changer unit 47 is detachably provided with a metal processing tool 49 such as an end mill or a grinding wheel.

As a result, either the slag removing tool 45 or the metal processing tool 49 can be attached to the tip of the tip arm 43 of the general-purpose robot 41 as needed. Similar to the slag removing tool 45, the position and posture of the metal processing tool 49 can be arbitrarily set three-dimensionally within the range of the degree of freedom of the tip arm 43.

Further, the surface shape measuring device 48 for measuring the surface shape of the bead 53 may be arranged above the base material 51. As the surface shape measuring device 48, it is sufficient that the shape of the bead 53 can be measured, and a device using a well-known shape measuring method can be adopted. For example, an illuminating unit that irradiates the surface of the bead 53 with slit light, an imaging unit that images the surface of the bead 53 irradiated with slit light, and an image obtained by the imaging unit is analyzed to form a cross section of the surface of the bead 53. It may be configured to include a shape measuring unit for measuring the shape. The measurement data by the surface shape measuring device 48 is input to the controller 15.

The surface shape measuring device 48 may be fixed to an appropriate frame member (not shown), but is not limited to this, and may be attached to a general-purpose robot 41 or a welding robot 19.

The controller 15 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 creates shape data of the laminated model to be manufactured, and then divides the data into a plurality of layers to generate layer shape data representing the shape of each layer. The orbit calculation unit 33 obtains the movement locus of the torch 17 and the movement locus of the slag removing tool 45 and the metal processing tool 49 by the general-purpose robot 41 based on the generated layer shape data. The trajectories of the slag removing tool 45 and the metal processing tool 49 are obtained by giving an offset according to the tool shape to the trajectories of the torch 17 based on the lamination plan.

The storage unit 35 stores data such as shape data of the laminated model, generated layer shape data, movement locus of the torch 17, and movement locus of the slag removing tool 45 and the metal processing tool 49.

The control unit 37 drives the welding robot 19 by executing a drive program according to the layer shape data stored in the storage unit 35 and the movement locus of the torch 17. That is, the welding robot 19 moves the torch 17 while melting the filler metal M with an arc according to the movement locus of the torch 17 generated by the trajectory calculation unit 33 in response to a command from the controller 15. As a result, the bead 53 is formed (bead laminating step).

Further, the control unit 37 executes a drive program based on the shape data stored in the storage unit 35 and the movement locus of the slag removing tool 45 to drive the general-purpose robot 41. As a result, the slag removing tool 45 provided on the tip arm 43 of the general-purpose robot 41 removes the slag of the V-groove portion formed between the beads (slag removing step).

Further, although the details will be described later, the control unit 37 determines the slag removal candidate location and the abutting direction of the bead 53 of the slag removing tool 45 with respect to the V groove portion, and if necessary, the measurement result by the surface shape measuring device 48. The trajectory and abutting direction of the slag removing tool 45 are corrected accordingly.

<First laminated modeling method>
Next, the procedure of the laminated modeling method using the laminated modeling system 100 of FIG. 1 will be described. FIG. 2 is a cross-sectional view showing a schematic example of a laminated model formed by the laminated modeling system 100 shown in FIG.

In FIG. 2, four beads 53A to 53D are formed on the upper surface of the base material 51 as the first layer beads along the depth direction of the drawing according to the command of the control unit 37 (see FIG. 1), and the first layer is formed. A state in which the second layer beads 53E to 53G are laminated on the eye beads 53A to 53D is shown. In this case, the trapezoidal three-dimensional model 57 indicated by the dotted line DL can be obtained by cutting and removing the bead region outside the dotted line DL of the laminated model 55 composed of the seven beads 53A to 53G.

The laminated model 55 is formed by laminating seven beads 53A, 53B, 53C, 53D, 53E, 53F, and 53G in this order. In this laminated molding method, there is a step of removing slag from the slag removal candidate locations R1 to R4 shown by the black circles in FIG. 2 before laminating the next bead on the already formed bead. The non-candidate portion P indicated by the white circle in FIG. 2 is a portion where the slag does not need to be removed. In this way, the removal of the slag is selectively carried out by the command of the control unit 37.

(Determination of candidate locations for slag removal)
FIG. 3 is an explanatory diagram showing a procedure for determining a slag removal candidate location and a slag removing tool abutting direction.
As shown in FIG. 3 during the bead formation, valley V-groove portions 61A, 61B, and 61C are continuously formed between the beads adjacent to each other along the bead formation direction.

Of the plurality of V-groove portions, the control unit 37 is a V-groove portion arranged inside the modeled object excluding the outer surface of the completed laminated modeled object, and only the portion where slag is likely to remain is set as a removal candidate portion. Extract.

Here, removing the V-groove portion on the outer surface of the completed laminated model is that in the case of the laminated model 55 shown in FIG. 2, after the second layer beads 53E, 53F, 53G are formed, the beads 53E, 53F are removed. , 53G means that the V-groove portions K1, K2, K3, and K4 formed on the outer surface are removed from the removal candidate locations. Further, the V-grooves arranged inside the modeled object are the removal candidate points R1 to R4 surrounded by the beads and the non-candidates in the bead arrangement direction (horizontal direction) and the bead stacking direction (vertical direction) shown in FIG. It means the location P. The portion where the slag is likely to remain is a V-groove portion having a small opening angle in which the slag floating on the surface of the molten bead when the bead is formed accumulates without flowing out to the side of the molten bead. Specifically, it is a V-groove portion having an opening angle θ of less than 130 °, preferably less than 120 °, and more preferably less than 100 ° in a vertical cross section in the orbit direction orthogonal to the bead forming orbit.

Here, the opening angle θ of the V-groove portion is the outside of one bead 53B extending from the bottom of the V-groove portion 61B and forming the V-groove portion 61B when the V-groove portion 61B is shown as an example in the vertical cross section in the orbital direction shown in FIG. It is an angle formed by the tangent line L1 of the surface 63a and the tangent line L2 of the outer surface 63b of the other bead 53C.

The magnitude of the opening angle θ of the V-groove portion can be roughly estimated from the bead height and the bead width of the beads forming the V-groove portion. In addition, the bead height and the bead width often have a good correspondence between the dimensions modeled based on the design plan and the dimensions when the beads are actually formed. On the other hand, the opening angle θ often does not always match the angle obtained by the above model and the actual angle. Therefore, in order to determine the size of the opening angle θ of the V-groove portion from the information of the design plan, it is preferable to judge from the bead height and the bead width.

Therefore, the control unit 37 sets a predetermined threshold value for the dimensional ratio H / W of the bead height H and the bead width W of the beads forming the V-grooves with respect to the plurality of V-grooves formed between the beads. Whether or not it exceeds the threshold value is determined, and the V-groove portion exceeding the threshold value is extracted as a slag removal candidate location. The bead for which the dimensional ratio H / W is obtained may be one of the pair of beads forming the V-groove portion, and when both beads are used, the average value, the minimum value, and the minimum value of each bead are used. It may be determined by the maximum value or the like. The predetermined threshold value of the dimensional ratio H / W can be set to, for example, 0.2, preferably 0.5, and more preferably 0.7.

As a result, in the case of the laminated model 55 shown in FIG. 2, the control unit 37 extracts R1 to R4 as removal candidate locations among the plurality of V-groove portions, and P has a large opening angle, so that slag is generated. Judge that it does not accumulate and make it a non-candidate place.

Further, the control unit 37 sets the abutting direction of the slag removing tool in the slag removing step within a range of ± 1/4 of the opening angle θ around the bisector N of the opening angle θ of the V groove portion. To do.

(Bead forming process and slag removing process)
Next, the bead forming step and the slag removing step will be described with reference to FIGS. 4 and 5.
(A) to (C) of FIG. 4 and (A) to (D) of FIG. 5 stepwise show a series of steps from the bead laminated state shown in FIG. 3 to the bead laminated state shown in FIG. It is a process explanatory drawing.

As described above, the control unit 37 (see FIG. 1) extracts the removal candidate points of the V-groove portion formed in the laminated model based on the preset stacking plan. Then, a bead shape step for forming the bead and a slag removing step for removing the slag at the removal candidate portion are carried out. The following steps are carried out by driving the welding robot 19 and the general-purpose robot 41 in response to a command from the control unit 37 shown in FIG.

First, as shown in FIG. 4A, the first layer beads 53A, 53B, 53C, 53D are formed in this order on the substrate surface 51a. Then, the slag SL remains in the V groove portion 61A (removal candidate location R1) between the bead 53A and the bead 53B and the V groove portion 61B (removal candidate portion R2) between the bead 53B and the bead 53C. It becomes.

Next, before forming the bead of the second layer, as shown in FIG. 4B, the slag removing tool 45 is arranged at the position of the V groove portion 61A, and the V groove portion 61A is hit by the impact of the slag removing tool 45. Removes the slag SL. After that, as shown in FIG. 4C, a torch (not shown) is arranged in the V-groove portion 61A to form the bead 53E. Then, the slag SL remains in the V-groove portion 61D (removal candidate portion R3) newly formed between the bead 53E and the bead 53B. Further, although the slag SL remains in the V groove portion K1 between the bead 53E and the bead 53A, the remaining slag SL does not matter because the V groove portion K1 is not covered with the bead.

Note that FIGS. 4 and 5 below particularly show the tip of the slag removing tool 45, and this tip, the so-called chipper, corresponds to the above-mentioned chisel (see, for example, Japanese Patent No. 2974305). The chisel corresponding to the tip of the slag removing tool 45 is composed of a bundle of multi-core wire members, and the tip of the bundle can be formed into a flat shape, a curved convex shape, or the like, but the shape is not limited to this.

Next, as shown in FIG. 5A, the slag removing tools 45 are sequentially arranged at the positions of the V-groove portion 61B (removal candidate portion R2) and the V-groove portion 61D (removal candidate portion R3), respectively. The slag SL is removed from the V-groove portions 61B and 61D.

After that, as shown in FIG. 5B, a torch (not shown) is arranged in the vicinity of the V-groove portions 61B and 61D to form the bead 53F. Then, the slag SL remains in the V-groove portion 61F (removal candidate portion R4) newly formed between the bead 53F and the bead 53C. Although the slag SL remains in the V-groove portion K2 newly formed between the bead 53F and the bead 53E, it does not cause a problem like the V-groove portion K1.

Next, as shown in FIG. 5 (C), the slag removing tools 45 are sequentially arranged at the positions of the V-groove portion 61F (removal candidate portion R4) to remove the slag SL from the V-groove portion 61F. The V-groove portion 61C has a large opening angle and is a portion that was not extracted as a removal candidate location. Therefore, there is almost no slag remaining in the V-groove portion 61.

After that, as shown in FIG. 5D, a torch (not shown) is arranged in the vicinity of the V-groove portions 61F and 61C to form the bead 53G. Then, the slag SL remains in the V-groove portions K4 and K3 newly formed between the bead 53G and the bead 53D and between the bead 53G and the bead 53F, but it does not cause a problem like the V-groove portion K1. ..

By carrying out the above bead forming step and slag removing step, a laminated model 55 in which seven beads 53A to 53G are laminated on the base material surface 51a is formed.

Here, in any of the slag removing steps of FIG. 4B, FIG. 5A and FIG. 5, the opening angle θ of the V groove portion of the removal candidate portion is small, and the torch 17 and slag shown in FIG. 1 are formed. When there is a possibility that the removal tool 45 interferes, it is preferable to cut the portion so that the opening angle becomes large. The threshold angle of the opening angle θ of the V-groove portion determined to require cutting is set according to the size of the torch 17 and various tools, and is, for example, less than 100 °, preferably less than 90 °, more preferably less than 80 °. Can be set to the angle of.

When cutting the V-groove portion, after removing the slag, the slag removing tool 45 attached to the tip arm 43 of the general-purpose robot 41 shown in FIG. 1 is replaced with the metal processing tool 49 held by the changer unit 47. .. Then, the metal processing tool 49 is moved to the V-groove portion to be cut by the drive of the general-purpose robot 41, and the metal processing tool is used for cutting.

As described above, according to this laminated molding method, slag entrainment is performed by removing the slag formed on the surface of the already formed bead before laminating the next bead on the already formed bead. By preventing this, the strength and durability of the laminated model 55 can be improved.

Further, in this laminated molding method, slag removal candidate locations R1 to R4 are extracted from a plurality of V-groove portions based on a predetermined laminating plan, and slag is removed only from these removal candidate locations R1 to R4. To do. Therefore, the slag in the portion where slag entrainment is a concern can be preferentially removed, and the tact time can be shortened and the productivity can be improved as compared with the case where the slag is removed in all the V-groove portions. Therefore, the laminated model 55 can be formed at high speed and with high quality.

Further, according to this laminated molding method, the trajectory of slag removal by the slag removing tool 45 can be accurately set by a simple process of giving an offset to the trajectory at the time of laminated molding. Therefore, the trajectory calculation of the slag removing tool 45 in the slag removing step is not complicated, and the man-hours for removing the slag can be easily estimated. In addition, the conditions for removing slag can be easily set.

Further, when the opening angle θ of the V-groove portion is less than a predetermined threshold angle (for example, 100 °), the opening angle θ of the V-groove portion is increased by cutting with a metal processing tool or the like to increase the opening angle θ of the torch. 17. The gap with the slag removing tool 45 can be increased. As a result, interference with the torch 17 and the slag removing tool 45 can be avoided, and the generation of voids in the laminated model 55 can be prevented.

Although the slag removing step for the V-groove portion on the outer surface of the laminated model 55 is omitted in the above-mentioned laminated modeling method, slag removal may be performed. In that case, slag removal is also performed on the V-groove portion formed between the base material 51 and the bead of the first layer. According to this, the post-treatment for performing the surface treatment or the like after the formation of the laminated model 55 can be unnecessary or simplified, so that the productivity can be further improved.

<Second laminated modeling method>
In the first laminated molding method described above, slag removal candidate locations are extracted based on a preset lamination plan, and a bead forming step and a slag removing step of the extracted removal candidate locations are carried out. However, in this laminated molding method, the removal candidate location is determined by actually measuring the bead shape.

In this laminated modeling method, the shape of the formed bead is measured by the surface shape measuring device 48 shown in FIG. The surface shape measuring device 48 measures the bead width W, bead height H (see FIG. 3), bead position, and the like of the bead formed by the movement of the torch 17 by the welding robot 19, and the measurement result is measured by the control unit 37. Output to.

The control unit 37 compares the measured bead shape and bead position with the bead shape and bead formation trajectory predicted based on the stacking plan from the input bead measurement result, and removes the slag of the V-groove portion. The conditions for extracting the removal candidate locations, the offset value for determining the trajectory of the slag removal tool 45, and the like are corrected as necessary.

Then, the control unit 37 uses the corrected extraction conditions, the offset value, and other correction information to model the laminated model in the same manner as in the first laminated modeling method described above.

According to this laminated molding method, removal candidate locations and offset values are determined according to the beads actually formed, so that accurate bead formation and optimum slag removal can be realized, and the quality of the laminated model can be improved. You can be more productive.

<Third laminated molding method>
In the first and second laminated molding methods described above, the bead stacking order basically starts the formation of the upper layer after the formation of the lower layer is completed. However, even if the outer shape of the laminated model 55 obtained by laminating the beads is the same, a problem may occur depending on the step of laminating the beads. For example, when the filler material melted during bead formation is affected by gravity such as dripping, it is recommended to first form a bead laminate consisting of a plurality of beads extending in one direction to prevent dripping. preferable. In that case, even if a flowable filler melt is generated during the bead formation after the bead laminate is formed, the bead laminate formed below the melt blocks the flow of the melt, causing dripping. Can be prevented.

In such a case, since the definition of the opening angle θ of the V-groove portion described above is different, the conditions of the removal candidate location for removing the slag and the abutting direction of the slag removing tool are the above-mentioned first and second laminated molding. Different from the method. That is, as shown in FIG. 6A, when the first layer bead 54A, the bead 54B, the second layer bead 54C, and the bead 54D are formed on the substrate surface 51a in this order, the V-groove portion 62 The opening angle θ is represented by the angle formed by the tangents L1 and L2 on the outer surface of the bead 54C and the bead 54D.

On the other hand, as shown in FIG. 6B, when the bead laminate (wall body) in which the beads are laminated in the vertical direction is first formed, that is, the first layer on the substrate surface 51a. When the bead 54A, the bead 54B of the second layer, the bead 54C of the second layer, and the bead 54D of the first layer are formed in this order, the opening angle θ of the V groove portion 62 is the stacking direction of the beads 54A, 54B, 54C. It is represented by the angle formed by the LN and the tangent line L2 on the outer surface of the bead 54D.

As described above, since the opening angle θ of the V-groove portion differs depending on how the beads are laminated, the slag removing step changes depending on the contents of the lamination plan even if the laminated objects have the same shape. For example, in the case shown in FIG. 6A, since the space around the V-groove portion is secured, it is easy to access the slag removing tool, the metal processing tool, etc., but it is shown in FIG. 6B. In this case, the bead laminate composed of beads 54A, 54B, 54C becomes a wall, and access to the tool is restricted.

Therefore, in this laminated molding method, the opening angle θ of the V-groove portion is appropriately obtained according to the stacking order of the beads defined in the lamination plan, and the slag removal candidate location is determined accordingly. According to this, the slag removing tool 45, the metal processing tool, and the like can be appropriately accessed without interfering with the V-groove portion.

<Fourth laminated modeling method>
The above-mentioned first and second laminated molding methods basically target a case where the slag removing tool reaches the slag of the V-groove portion. However, depending on the surface shape of the beads, the laminated state, etc., the slag may accumulate in a place where the slag removing tool cannot reach. For example, if the V-groove is too small for the diameter of the tip of the slag removal tool, even if the slag removal tool is lowered vertically to hit the surface of the slag, it will not hit the deep part of the V-groove and the slag will not hit. Leftovers can occur.

FIG. 7 shows a case where the relationship between the bead width W and the diameter (tip diameter) d of the tip of the slag removing tool 45 is, for example, W / d <1/2, that is, the slag removing tool 45 is compared with the bead width W. The case where the tip diameter d is large is shown (the tip diameter d is larger than twice the bead width W). In such a case, unless the tip of the slag removing tool 45 is processed into a special shape, it is difficult for the tip to reach the V-groove portion 61, and it is difficult to remove the slag SL. The tip (chipper) of the slag removing tool 45 may be composed of, for example, a multi-core chisel as described above, that is, a bundle of wire members. In such an example, the diameter of the tip of the slag removing tool 45 (chipper) ( Tip diameter) d means the diameter of a bundle of wire members.

In such a case, the problem is the size of the V-groove portion 61. The size of the V-groove portion 61 depends on factors such as the shape of the bead alone, the amount of overlap with the adjacent bead, and the state at the time of welding. However, by comparing the values such as the bead width W, the bead height H, and the tip diameter d of the slag removing tool 45, it is possible to foresee a case where it is difficult to remove the slag as described above.

That is, when the feature amount calculated by using at least two of the bead width W, the bead height H, and the tip diameter d deviates from the predetermined reference range, it is determined that the slag removal is difficult. Specifically, when at least one of d / W, H / Wd, W / H, and d / W ² is larger than a predetermined reference value, the slag removing tool 45 is used in a usual manner. However, it is judged that slag removal is difficult.
If it is determined that slag removal is difficult, the slag removing tool 45 is tilted from the vertical direction in this method. Specifically, while tilting the slag removing tool 45 as shown in FIG. 8, the inclined tip of the slag removing tool 45 is brought into contact with the V-groove portion 61 to bring the tip and the slag SL as close as possible. The tip of the slag removing tool 45 of the present embodiment is machined so that at least two surfaces are in contact with the V-groove 61 between the two beads 53 when tilted. That is, at least two surfaces existing at the tip of the slag removing tool 45 are abutted against the V-groove portion 61 to carry out the slag removing step. In this state, even if the tip of the slag removing tool 45 does not reach the slag SL directly, the slag removing tool 45 is vibrated to float the slag SL, so that the slag SL can be smoothly removed. Further, the slag removing step is carried out by moving the slag removing tool 45 along the bead forming trajectory while applying the tip of the slag removing tool 45 to the side of the V-groove portion 61.

9 and 10 show an enlarged view of the portion of the slag SL and the V-groove portion 61 in FIG. In the present embodiment, the tip 46 of the slag removing tool 45 includes a plurality of surfaces of the first surface 46a, the second surface 46b, and the third surface 46c, at least as shown in the illustration. When the tip 46 is composed of a bundle of wire members, such a plurality of surfaces can be provided at the tip by adjusting the length of each wire member (position of the tip of the wire member). In this example, the tip 46 is C-cut, the first surface 46a is the side surface, the third surface 46c is the top surface of the C-cut, and the second surface 46b is the first surface 46a and the third surface 46c. It is a connecting surface.

In FIG. 9, the tip 46 of the slag removing tool 45 does not reach the slag SL, and the slag SL remains. As shown in FIG. 8, the slag removing tool 45 is tilted, and when the tip 46 advances as indicated by an arrow due to vibration as shown in FIG. 10, the first surface 46a and the second surface 46b reach the slag SL. Then, the slag SL at the removal candidate locations R5 and R6 is smoothly removed. When the V-groove portion 61 is smaller than the slag removing tool 45 (tip 46), it is generally difficult to remove the slag SL at the removal candidate locations R5 and R6. In this example, the tip 46 is processed so as to have a plurality of surfaces, and the slag removing tool 45 is arranged so as to challenge the V-groove portion 61 in a state of being tilted at an angle, thereby removing the slag SL in a portion that is difficult to remove. It becomes possible to do.

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 well-known techniques. It is the planned invention and is included in the scope of seeking protection.

For example, in the above embodiment, the case where the beads are laminated on the plate-shaped base material 51 to form a laminated model is shown, but the shape of the base material 51 is not limited to the plate shape, but is cylindrical or cylindrical. It may have other shapes such as a conical or polygonal prism or pyramid.

As described above, the following matters are disclosed in this specification.
(1) A laminated molding method in which a bead obtained by melting and solidifying a filler metal is laminated on the surface of a base material according to a lamination plan in which the formation order of the bead is determined to form a laminated model.
A bead laminating step of laminating the beads along a bead forming trajectory determined by the laminating plan,
It has a slag removing step of removing slag generated in a plurality of V-grooves formed between beads adjacent to each other by using a slag removing tool.
The slag removing step is
From the bead shape of the stacking plan and the information of the bead forming orbit, the dimensional ratio H / W of the bead height H and the bead width W of the bead forming the V groove portion in the orbital direction vertical cross section orthogonal to the bead forming orbit. Seeking,
Of the plurality of V-grooves, V-grooves having a dimensional ratio H / W of more than 0.2 are extracted as removal candidate sites.
The extracted slag at the removal candidate site is removed.
Laminated modeling method.
According to this laminated molding method, slag at a portion where slag entrainment is a concern can be preferentially removed, and a high-speed and high-quality laminated molded product can be stably produced.

(2) The laminated modeling method according to (1), wherein the removal candidate portion is extracted from a V-groove portion arranged inside the modeled object excluding the outer surface of the laminated modeled object.
According to this laminated molding method, by excluding the V-groove portion that does not affect the strength from the slag removal candidate locations, the number of times the slag is removed can be suppressed, and the productivity can be improved.

(3) The V-groove portion to be a candidate for removal extends from the bottom of the V-groove portion in the vertical cross section in the orbital direction, and is tangent to the outer surface of one bead forming the V-groove portion and the outside of the other bead. The laminated molding method according to (2), wherein the opening angle formed by the tangents on the surface is less than 120 °.
According to this laminated molding method, since the location where the slag is removed is directly determined from the opening angle of the V-groove portion, the location where the slag remains can be accurately determined.

(4) The slag removing tool has a chisel mechanism that abuts a chisel member against the slag and vibrates it to hit the slag.
The crossing angle between the axis in the abutting direction of the chisel member and the bisector of the opening angle of the V-groove portion is set within a range of ± 1/4 of the opening angle (3). Laminated molding method.
According to this laminated molding method, the abutting direction of the slag removing tool to the V-groove portion is set to the center side of the opening angle, so that the slag removing tool is less likely to interfere with the beads around the V-groove portion.

(5) The laminated molding method according to (3) or (4), wherein the slag removing step moves the slag removing tool along a moving track in which an offset is applied to the bead forming track.
According to this laminated molding method, the trajectory and the abutting angle of the slag removing tool can be easily set by using the bead forming trajectory.

(6) The slag removing step is
A step of measuring the surface shape of the bead formed in the bead laminating step and a step of measuring the surface shape of the bead.
A step of correcting at least one of the opening angle and the offset according to the measurement result of the surface shape, and
The laminated modeling method according to (5).
According to this laminated molding method, slag removal candidate locations can be extracted according to the actually formed bead shape. Therefore, the removal candidate portion can be extracted more accurately, and it is possible to prevent omission of slag removal and unnecessary removal processing.

(7) Prior to carrying out the slag removing step, the surface of the bead having an opening angle of less than 100 ° of the V-groove portion is cut to further increase the opening angle (1) to (5). ). The laminated molding method according to any one of.
According to this laminated molding method, in a place where the opening angle of the V-groove portion is small, even if the slag is removed, a gap may be generated after the bead is formed. In such a place, the V-groove of the bead is cut to increase the opening angle so that the torch can be sufficiently brought into the groove of the V-groove so that a gap is generated after the bead is formed. Can be prevented.

(8) In the slag removing step, the slag in the V groove portion between the bead unit in which the beads are laminated in a plurality of stages and the bead formed adjacent to the bead unit after the formation of the bead unit is removed. Including the process of
The bead height and the bead width corresponding to the bead unit are one bead constituting the bead unit, and the bead height and the bead width of the same layer as the bead formed adjacent to the bead unit. The laminated molding method according to any one of (1) to (7).
According to this laminated molding method, by determining a plurality of beads as one bead unit, a V-groove portion for which slag should be appropriately removed can be appropriately removed even when the surrounding conditions of bead formation differ depending on the bead formation order. Can be selected.

(9) When the feature amount calculated by using at least two of the bead height H, the bead width W, and the tip diameter of the slag removing tool deviates from a predetermined reference range, the slag removing tool is used. The laminated molding method according to any one of (1) to (8), wherein at least two surfaces existing at the tip are abutted against the V-groove portion to carry out the slag removing step.
According to this laminated molding method, it is possible to foresee cases where it is difficult to remove slag and remove slag smoothly.

(10) When the feature amount calculated by using at least two of the bead height H, the bead width W, and the tip diameter of the slag removing tool deviates from a predetermined reference range, the slag removing tool is used. The slag removing step is carried out by moving the slag removing tool along the bead forming trajectory while applying at least two surfaces existing at the tip portion to the side of the V groove portion (1) to The laminated molding method according to any one of (8).
According to this laminated molding method, it is possible to foresee cases where it is difficult to remove slag and remove slag smoothly.

11 Laminated molding device 13 Slag removal device 15 Controller 17 Torch 19 Welding robot 21 filler metal supply unit 31 CAD / CAM unit 33 Trajectory calculation unit 35 Storage unit 37 Control unit 41 General-purpose robot 43 Tip arm 45 Slag removal tool 47 Changer unit 48 Surface shape measuring device 49 Metal processing tool 51 Base material 51a Surface 53, 53A, 53B, 53C, 53D, 53E, 53F, 53G Bead 55 Laminated model 57 Three-dimensional model 61A, 61B, 61C V groove 63a Outer surface 63b Outside Surface 100 Laminated modeling system R1, R2, R3, R4 Candidate points for removal

Claims (10)

A laminated molding method in which a bead obtained by melting and solidifying a filler metal is laminated on the surface of a base material according to a lamination plan in which the formation order of the bead is determined to form a laminated model.
A bead laminating step of laminating the beads along a bead forming trajectory determined by the laminating plan,
A slag removing step of removing slag generated in a plurality of V-grooves formed between adjacent beads by using a slag removing tool, and
Have,
The slag removing step is
From the bead shape of the stacking plan and the information of the bead forming orbit, the dimensional ratio H / W of the bead height H and the bead width W of the bead forming the V groove portion in the orbital direction vertical cross section orthogonal to the bead forming orbit. Seeking,
Of the plurality of V-grooves, V-grooves having a dimensional ratio H / W of more than 0.2 are extracted as removal candidate sites.
The extracted slag at the removal candidate site is removed.
Laminated modeling method. The laminated modeling method according to claim 1, wherein the removal candidate portion is extracted from a V-groove portion arranged inside the modeled object excluding the outer surface of the laminated modeled object. The V-groove portion, which is a candidate for removal, extends from the bottom of the V-groove portion in the vertical cross section in the orbital direction, and is tangent to the outer surface of one bead forming the V-groove portion and the outer surface of the other bead. The laminated molding method according to claim 2, wherein the opening angle formed by the two is less than 120 °. The slag removing tool has a chisel mechanism that abuts a chisel member against the slag and vibrates it to hit the slag.
The third aspect of the present invention, wherein the intersection angle between the axis in the abutting direction of the chisel member and the bisector of the opening angle of the V-groove portion is set within a range of ± 1/4 of the opening angle. Laminated molding method. The laminated molding method according to claim 3 or 4, wherein the slag removing step moves the slag removing tool along a moving track in which the bead forming track is offset. The slag removing step is
A step of measuring the surface shape of the bead formed in the bead laminating step and a step of measuring the surface shape of the bead.
A step of correcting at least one of the opening angle and the offset according to the measurement result of the surface shape, and
The laminated modeling method according to claim 5, further comprising. Any one of claims 1 to 5, further comprising a cutting step of cutting the surface of the bead having an opening angle of less than 100 ° in the V-groove portion to increase the opening angle before carrying out the slag removing step. The laminated molding method described in the section. The slag removing step is a step of removing slag in a V-groove portion between a bead unit in which the beads are laminated in a plurality of stages and a bead formed adjacent to the bead unit after the bead unit is formed. Including
The bead height and bead width corresponding to the bead unit are the bead height and bead width of one bead constituting the bead unit and the same layer as the bead formed adjacent to the bead unit. The laminated molding method according to any one of claims 1 to 7. When the feature amount calculated using at least two of the bead height H, the bead width W, and the tip diameter of the slag removing tool deviates from a predetermined reference range, it exists at the tip of the slag removing tool. The laminated molding method according to any one of claims 1 to 8, wherein the slag removing step is carried out by abutting at least two surfaces to the V-groove portion. When the feature amount calculated by using at least two of the bead height H, the bead width W, and the tip diameter of the slag removing tool deviates from a predetermined reference range, the tip of the slag removing tool is used. Any of claims 1 to 8, wherein the slag removing step is carried out by moving the slag removing tool along the bead forming trajectory while applying at least two existing surfaces to the sides of the V-groove portion. The laminated molding method according to item 1.

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