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EP-4375000-B1 - TRAJECTORY PLAN CREATION ASSISTANCE METHOD FOR ASSISTING CREATION OF A TRAJECTORY PLAN FOR FORMING A WELD BEAD DURING AN ADDITIVE MANUFACTURING

EP4375000B1EP 4375000 B1EP4375000 B1EP 4375000B1EP-4375000-B1

Inventors

  • CHIKAGUCHI, SATOSHI
  • HUANG, SHUO

Dates

Publication Date
20260506
Application Date
20220720

Claims (14)

  1. A trajectory plan creation assistance method for assisting creation of a trajectory plan for forming a weld bead (B) during additive manufacturing, the trajectory plan including a bead formation trajectory (PS1, PS2, PSa, PSb, PSc) for forming the weld bead (B) when melting and solidifying a filler metal (M) held by a manipulator (17) while moving the filler metal (M) by the manipulator (17) to form the weld bead (B) and laminating the formed weld bead (B) to produce a manufacturing object (W), the trajectory plan creation assistance method comprising: receiving (S1) operator inputs of shape data of the manufacturing object (W); generating (S2) a three-dimensional shape model (Mw) of the manufacturing object (W) based on the received shape data and decomposing the three-dimensional shape model (Mw) into bead layers (BL) according to a height of the weld bead (B); decomposing (S3) each bead layer (BL) in accordance with a bead width (Wb) of the weld bead (B) into a plurality of bead models (PM) having a rectangular cross section, such that the bead model (PM) is arranged along the bead formation trajectory (PS1, PS2, PSa, PSb, PSc), which is the bead longitudinal direction; approximating the cross-sectional shape of the bead models (PM) to a polygon corresponding to the weld bead (B); setting (S5) a bead formation locus (PS) on which the weld bead (B) is formed along the bead model (PM) and the bead formation trajectory (PS1, PS2, PSa, PSb, PSc) including a lamination order of the weld bead (B); generating (S6) a plurality of polygonal columnar unit blocks (UB) obtained by dividing the bead model (PM) into unit lengths along the set bead formation locus (PS); increasing or decreasing a volume of the columnar unit block (UB) depending on a travel speed when forming the weld bead (B) and a feeding speed of the filler metal (M); and creating the trajectory plan by simulating (S7) the formation of the weld bead (B) for each of the unit blocks (UB) by simulation.
  2. The trajectory plan creation assistance method according to claim 1, further comprising: receiving (S8) a correction condition for correcting the trajectory plan depending on a simulation result; and correcting (S9) the trajectory plan by repeatedly executing the simulation based on the correction condition.
  3. The trajectory plan creation assistance method according to claim 1, wherein the unit block (UB) is a columnar body in which a portion simulating the weld bead (B) has at least a pair of opposing surfaces having a trapezoidal shape, and a portion simulating a part of a base metal (29) on which the weld bead (B) is laminated is a columnar body having a polygon having eight or more vertexes (P1-P8) on a pair of opposing surfaces.
  4. The trajectory plan creation assistance method according to claim 1, wherein the unit block (UB) of a truncated polygonal pyramid having a bottom surface facing a bead formation direction is arranged on at least one of a start part and an end part of the bead formation locus (PS).
  5. The trajectory plan creation assistance method according to claim 1, wherein a height position of each of the plurality of unit blocks (UB) along the continuous bead formation locus (PS) is smoothed and a height change is distributed along the continuous bead formation locus (PS) in accordance with a change in a formation condition or a lamination position of the weld bead (B).
  6. The trajectory plan creation assistance method according to claim 1, wherein when the polygonal columnar unit block (UB) is generated, at least one vertex (P1-P8) of the polygonal column is moved according to an interval from a vertex (P1-P8) of another bead model (PM) adjacent to the polygonal bead model (PM).
  7. The trajectory plan creation assistance method according to claim 1, wherein in a cross section obtained by cutting a unit block group (GUB) in which the plurality of unit blocks (UB) are arranged along the bead formation trajectory (PS1, PS2, PSa, PSb, PSc) in any direction, block cut surface information representing a positional relation between a plurality of unit blocks (UB) overlapping one another is generated.
  8. The trajectory plan creation assistance method according to claim 7, wherein the block cut surface information is displayed on a display unit (33).
  9. The trajectory plan creation assistance method according to claim 7, wherein a narrow portion (71) in which surfaces of the unit blocks (UB) adjacent to each other intersect at an angle less than a predetermined limit angle is extracted from the block cut surface information.
  10. The trajectory plan creation assistance method according to claim 9, wherein the narrow portion (71) is displayed on the display unit (33).
  11. The trajectory plan creation assistance method according to any one of claims 1 to 10, wherein at least one of a block side length of the unit block (UB) and a number of interior angles of the polygon is changed depending on a direction of the bead formation trajectory (PS1, PS2, PSa, PSb, PSc).
  12. The trajectory plan creation assistance method according to any one of claims 1 to 10, wherein a shape of the unit block (UB) is made to have a constant thickness in the direction along the bead formation trajectory (PS1, PS2, PSa, PSb, PSc).
  13. The trajectory plan creation assistance method according to any one of claims 1 to 10, wherein a thickness of the unit block (UB) in the direction along the bead formation trajectory (PS1, PS2, PSa, PSb, PSc) is made to have a thickness depending on a curvature of the bead formation trajectory (PS1, PS2, PSa, PSb, PSc).
  14. The trajectory plan creation assistance method according to any one of claims 1 to 10, wherein when a number of interior angles of the polygon is five, the cross-sectional shape of the bead model (PM) is divided into a trapezoid and a triangle, such that unit blocks (UB) including hexahedral sub-unit blocks and pentahedral sub-unit blocks are generated, and when the number of interior angles of the polygon is six or more and eight or less, the cross-sectional shape of the bead model (PM) is divided into a trapezoid and a triangle or a trapezoid and a quadrilateral, such that the unit blocks (UB) including a plurality of hexahedral sub-unit blocks or a plurality of hexahedral sub-unit blocks and pentahedral sub-unit blocks are generated.

Description

TECHNICAL FIELD The present invention relates to a trajectory plan creation assistance method, a trajectory plan creation assistance device, an additive manufacturing method, an additive manufacturing device, and a program. BACKGROUND ART In recent years, needs for manufacturing using a 3D printer as a means of production are increased, and research and development have been carried out toward a practical use of manufacturing using metal materials. As a technique for producing a three-dimensional manufacturing object using metal materials, for example, there is a method of laminating weld beads in a desired shape, the weld beads being formed by melting and solidifying a filler metal (welding wire) using a heat source such as an arc. There is a technique of modeling a cross-sectional shape of the weld beads for the purpose of computer-aided design support or automated control when producing such a manufacturing object (for example, Patent Literature 1). Patent Literature 1 describes that manufacturing conditions are changed using an elliptical shape bead model such that a difference between a target shape of the manufacturing object and a shape predicted from measured value database is equal to or less than an allowable value. US 2021/114112A1 describes a method for depositing an additively-manufactured object using three-dimensional shape data indicating a shape of the additively-manufactured object, wherein the method includes dividing the shape of the additively-manufactured object of the three-dimensional shape data, into a plurality of polygon faces, extracting a column of plural polygon faces and sequentially providing index numbers from a start polygon face, detecting a terminal polygon face based on directions of a pair of adjacent polygon faces, providing a bead formation ON flag to polygon faces other than the terminal polygon face, and a bead formation OFF flag to the terminal polygon face, producing a bead map in which the index numbers and the flags provided to the polygon faces are associated with one another; referring to the bead map to obtain a bead continuous formation pass, and continuously forming the bead along the bead continuous formation pass. CITATION LIST PATENT LITERATURE Patent Literature 1: JP2018-27558A SUMMARY OF INVENTION TECHNICAL PROBLEM In additive manufacturing, in which the weld beads made by melting and solidifying the filler metal are laminated, complicated three-dimensional shapes are often produced, and a trajectory plan for forming the weld beads is preferably determined using a three-dimensional bead formation path instead of a plan based on two dimensions in the related art. In particular, in order to correctly evaluate an influence of the trajectory of each bead formation path on a manufacturing result, it is essential to make the trajectory plan three-dimensional. However, when the trajectory plan is made three-dimensional, the trajectory plan becomes more complicated than a two-dimensional one, and thus it may become difficult to evaluate the plan per se. In addition, it is considered to finely adjust a shape of a bead model based on formation conditions of the weld beads, but calculation processing becomes complicated, and depending on a scale of the manufacturing object, it is not possible to create a trajectory plan in a realistic time. Here, an object of the present invention is to provide additive manufacturing method comprising a trajectory plan creation assistance method capable of correctly evaluating a suitability of a trajectory plan of a manufacturing object without requiring a complicated calculation process even when the trajectory plan is expanded from two-dimensional to three-dimensional, thereby creating the trajectory plan in which high reproducibility of the manufacturing object is obtained. SOLUTION TO PROBLEM The object of the present invention is solved by the subject-matter having the features of independent claim 1. Additional embodiments are defined in the dependent claims. ADVANTAGEOUS EFFECTS OF INVENTION According to the present invention, it is possible to correctly evaluate a suitability of a trajectory plan of a manufacturing object without requiring a complicated calculation process even when the trajectory plan is expanded from two-dimensional to three-dimensional. Accordingly, it is possible to create the trajectory plan in which high reproducibility of the manufacturing object is obtained. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an overall configuration diagram of an additive manufacturing device.FIG. 2 is a schematic configuration diagram of a control unit.Fig. 3 is a schematic functional block diagram of the control unit.FIG. 4 is a flowchart illustrating a procedure for determining a trajectory plan when a manufacturing object is manufactured.(A) to (C) of FIG.5 are process explanatory diagrams illustrating a state in which a three-dimensional shape model of the manufacturing object is decomposed into bead models in a stepwis