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EP-4306321-B1 - ADDITIVE MANUFACTURING METHOD, ADDITIVE MANUFACTURING APPARATUS, AND PROGRAM FOR MANUFACTURING ADDITIVELY MANUFACTURED ARTICLE

EP4306321B1EP 4306321 B1EP4306321 B1EP 4306321B1EP-4306321-B1

Inventors

  • YOSHIKAWA, Akinori

Dates

Publication Date
20260506
Application Date
20220413

Claims (11)

  1. An additively manufacturing method in which, while moving a welding torch having a tip portion to which a filler metal is supplied, the supplied filler metal is melted and solidified to form a weld bead, and plural layers of the weld beads are deposited to build an additively manufactured object, the additively manufacturing method comprising: a step of measuring a filler metal feed speed at which the filler metal is fed to the welding torch during the formation of the weld bead; a step of acquiring a reference welding speed that is a moving speed of the welding torch corresponding to the measured filler metal feed speed; a step of measuring a height of the formed weld bead; a step of acquiring a welding speed correction value with which the height of the weld bead to be formed is adjusted for reducing a difference between the measured actual height of the weld bead and a height of a tip of the filler metal that protrudes from the tip of the welding torch corresponding to a planned height of the weld bead; a step of correcting the reference welding speed with the welding speed correction value and determining a welding speed at which the weld bead is formed; and a step of forming the weld bead at the determined welding speed, wherein the welding speed is determined by adding an amount of the welding speed that is adjusted to increase or decrease to compensate for the difference between the planned height and the measured height of the weld bead to the reference welding speed at least in any one portion of a starting edge portion and an end edge portion of a formation path of the weld bead.
  2. The additively manufacturing method according to claim 1, wherein the reference welding speed is set to a speed for reducing a difference between a predetermined planned height of the weld bead and an estimated height of the weld bead that is estimated from the measured filler metal feed speed.
  3. The additively manufacturing method according to claim 2, wherein the difference between the planned height and the estimated height is generated by a difference between the set value of the filler metal feed speed and the measured filler metal feed speed.
  4. The additively manufacturing method according to claim 2, wherein the difference between the planned height and the estimated height is acquired from an average height of the weld bead in the same layer.
  5. The additively manufacturing method according to claim 3, wherein the difference between the planned height and the estimated height is acquired from an average height of the weld bead in the same layer.
  6. The additively manufacturing method according to claim 2, wherein the difference between the planned height and the estimated height is acquired for each layer of the weld bead or for each bead formation path.
  7. The additively manufacturing method according to claim 3, wherein the difference between the planned height and the estimated height is acquired for each layer of the weld bead or for each bead formation path.
  8. The additively manufacturing method according to any one of claims 1 to 7, wherein the welding speed correction value is set to a value for reducing a difference between a predetermined planned height of the weld bead and the measured actual height of the weld bead.
  9. The additively manufacturing method according to claim 8, wherein the difference between the planned height and the actual height is acquired from at least any one portion of a starting edge portion and an end edge portion of a formation path of the weld bead
  10. An additive manufacturing device in which, while moving a welding torch having a tip portion to which a filler metal is supplied, the supplied filler metal is melted and solidified to form a weld bead, and plural layers of the weld beads are deposited to build an additively manufactured object, the additive manufacturing device comprising: a filler metal feed speed measuring unit configured to measure a filler metal feed speed at which the filler metal is fed to the welding torch during the formation of the weld bead; a reference welding speed setting unit configured to acquire a reference welding speed that is a moving speed of the welding torch corresponding to the measured filler metal feed speed; a bead height measuring unit configured to measure a height of the formed weld bead; a correction value setting unit configured to acquire a welding speed correction value with which the height of the weld bead to be formed is adjusted for reducing a difference between the measured actual height of the weld bead and a height of a tip of the filler metal that protrudes from the tip of the welding torch corresponding to a predetermined planned height of the weld bead; a welding speed determination unit configured to correct the reference welding speed with the welding speed correction value and to determine a welding speed at which the weld bead is formed; and a bead forming unit configured to form the weld bead at the determined welding speed, wherein the welding speed is determined by adding an amount of the welding speed that is adjusted to increase or decrease to compensate for the difference between the planned height and the measured height of the weld bead to the reference welding speed at least in any one portion of a starting edge portion and an end edge portion of a formation path of the weld bead; a control unit configured to integrally control each of the units of the additive manufacturing device.
  11. A program causing the control unit of the additive manufacturing device of claim 10 to execute an additively manufacturing procedure in which, while moving a welding torch having a tip portion to which a filler metal is supplied, the supplied filler metal is melted and solidified to form a weld bead, and plural layers of the weld beads are deposited to build an additively manufactured object, the additive manufacturing procedure comprising: a function of measuring a filler metal feed speed at which the filler metal is fed to the welding torch during the formation of the weld bead; a function of acquiring a reference welding speed that is a moving speed of the welding torch corresponding to the measured filler metal feed speed; a function of measuring a height of the formed weld bead; a function of acquiring a welding speed correction value with which the height of the weld bead to be formed is adjusted for reducing a difference between the measured actual height of the weld bead and a height of a tip of the filler metal that protrudes from the tip of the welding torch corresponding to a predetermined planned height of the weld bead; a function of correcting the reference welding speed with the welding speed correction value and determining a welding speed at which the weld bead is formed; and a function of forming the weld bead at the determined welding speed, wherein the welding speed is determined by adding an amount of the welding speed that is adjusted to increase or decrease to compensate for the difference between the planned height and the measured height of the weld bead to the reference welding speed at least in any one portion of a starting edge portion and an end edge portion of a formation path of the weld bead.

Description

TECHNICAL FIELD The present invention relates to an additively manufacturing method, an additive manufacturing device, and a program for building an additively manufactured object. BACKGROUND ART In recent years, there is an increasing need for shaping using a 3D printer as means for production, and research and development are proceeding toward practical use of shaping using a metal material. A 3D printer that builds a metal material uses a heat source such as laser beams, electron beams, and arcs to melt a metal powder or a metal wire, and deposits the molten metal to create an additively manufactured object. For example, Patent Literature 1 describes a technique in which, when an additively manufactured object is manufactured by depositing weld beads obtained by melting and solidifying a wire-like metallic material (filler metal), a welding output current and a filler metal feed speed are sampled, a distance from a contact tip of a welding torch to a welding base material is estimated based on the sampled information, and a welding speed and a filler metal feed speed are adjusted such that error of a bead height is small. CITATION LIST PATENT LITERATURE Patent Literature 1: JP2018-158382A SUMMARY OF INVENTION TECHNICAL PROBLEM However, the adjustment of the height of the weld layer described in Patent Literature 1 is not always appropriately performed. For example, when any variation occurs in welding conditions, an operation of adjusting the occurred variation may be performed by maintaining a set value of a specific welding condition that causes the variation as it is and changing set values of the other welding conditions. Here, an expected adjustment operation may not be performed. For example, regarding the filler metal feed speed at which the filler metal is supplied to the welding torch, a control system of the device during bead formation sets the speed to feed the filler metal. When the set values of the other welding conditions change depending on the filler metal feed speed, a command value set by the control is used for drive control in many cases assuming that the command value is the same as an actual filler metal supply speed. Therefore, when the command value of the control is different from the actual feed speed due to some factor, appropriate drive control is not performed. As a result, the height of the weld layer varies, and a shape error occurs in the additively manufactured object. Accordingly, an object of the present invention is to provide an additively manufacturing method, an additive manufacturing device, and a program form building an additively manufactured object in which a feed speed of a filler metal can be accurately grasped, a height of a weld bead can be more accurately managed, and a high-accuracy additively manufactured object can be obtained. SOLUTION TO PROBLEM The present invention has the following configurations. (1) An additively manufacturing method in which, while moving a welding torch having a tip portion to which a filler metal is supplied, the supplied filler metal is melted and solidified to form a weld bead, and plural layers of the weld beads are deposited to build an additively manufactured object, the additively manufacturing method including: a step of measuring a filler metal feed speed at which the filler metal is fed to the welding torch during the formation of the weld bead;a step of acquiring a reference welding speed that is a moving speed of the welding torch corresponding to the measured filler metal feed speed;a step of measuring a height of the formed weld bead;a step of acquiring a welding speed correction value with which the height of the weld bead to be formed is adjusted based on a difference between the measured height of the weld bead and a height of a tip of the filler metal that protrudes from the tip of the welding torch;a step of correcting the reference welding speed with the welding speed correction value and determining a welding speed at which the weld bead is formed; anda step of forming the weld bead at the determined welding speed.(2) An additive manufacturing device in which, while moving a welding torch having a tip portion to which a filler metal is supplied, the supplied filler metal is melted and solidified to form a weld bead, and plural layers of the weld beads are deposited to build an additively manufactured object, the additive manufacturing device including: a filler metal feed speed measuring unit configured to measure a filler metal feed speed at which the filler metal is fed to the welding torch during the formation of the weld bead;a reference welding speed setting unit configured to acquire a reference welding speed that is a moving speed of the welding torch corresponding to the measured filler metal feed speed;a bead height measuring unit configured to measure a height of the formed weld bead;a correction value setting unit configured to acquire a welding speed correction value with which the height of t