Method For Calibrating A Device For Producing A Three-Dimensional Object And Device Configured For Implementing Said Method

Patent metadata

Field	Value
Publication number	US-2018093416-A1
Application number	US-201715714506-A
Country	US
Kind code	A1
Filing date	Sep 25, 2017
Priority date	Sep 30, 2016
Publication date	Apr 5, 2018
Grant date	—

Abstract

A calibration method serves for calibrating a manufacturing device for additively producing a three-dimensional object by applying layer by layer and selectively solidifying a building material. The manufacturing device comprises at least two scanning units, each of which is capable of directing a beam to different target points in the working plane, which are located within a scanning region assigned to the respective scanning unit, wherein the scanning regions region of the at least two scanning units overlap in an overlap area. At least a first of the at least two scanning units is assigned a first monitoring unit whose monitoring region extends to a target point of the first scanning unit and its proximity, wherein a change of a position of the monitoring region is carried out as a function of a change of a position of the target point.

First claim

1 . A calibration method for calibrating a manufacturing device for additively producing a three-dimensional object by applying layer by layer and selectively solidifying a building material, preferably a powder, within a build area in a working plane,
wherein the manufacturing device comprises at least two scanning units, each of which is capable of directing a beam to different target points in the working plane, which are located within a scanning region assigned to the respective scanning unit, wherein the scanning regions region of the at least two scanning units overlap in an overlap area, wherein at least a first of the at least two scanning units is assigned a first monitoring unit whose monitoring region extends to a target point of the first scanning unit and its proximity, wherein a change of a position of the monitoring region is carried out as a function of a change of a position of the target point, wherein the calibration method comprises the following steps: directing the monitoring region of the first monitoring unit to a region in the overlap area without a beam emanating from the first scanning unit, irradiating at least a portion of the monitoring region of the first monitoring unit with a beam via a second of the at least two scanning units, and evaluating an output signal of the first monitoring unit.

2 . Calibration method according to claim 1 , wherein the second scanning unit is assigned a second monitoring unit whose monitoring region extends to a target point of the second scanning unit and its proximity, wherein a change of a position of the monitoring region of the second monitoring unit is carried out as a function of a change of a position of the target point of the second scanning unit,
and the calibration method comprises a step of evaluating an output signal of the second monitoring unit.

3 . Calibration method according to claim 1 , wherein the second scanning unit is assigned a second monitoring unit whose monitoring region extends to a target point of the second scanning unit and its proximity, wherein a change of a position of the monitoring region of the second monitoring unit is carried out as a function of a change of a position of the target point of the second scanning unit, and
the calibration method comprises the following steps: directing the monitoring region of the second monitoring unit to an area within the overlap area without a beam emanating from the second scanning unit, irradiating at least a portion of the monitoring region of the second monitoring unit with a beam via the first scanning unit, and evaluating an output signal of the second monitoring unit.

4 . Calibration method according to claim 1 , wherein the monitoring region of the first monitoring unit is limited to the target point of the first scanning unit and its proximity and/or
the monitoring region of the second monitoring unit is limited to the target point of the second scanning unit and its proximity

5 . Calibration method according to claim 1 , wherein the beam of a scanning unit is a beam of a radiation suited for solidifying the building material, and/or
the beam of a scanning unit is a target beam and/or a laser beam whose energy is not sufficient to solidify the building material.

6 . Calibration method according to claim 1 , wherein the monitoring region of the monitoring unit assigned to a scanning unit is irradiated by the beam of a different scanning unit in the form of scanning,
wherein said scanning is implemented preferably according to a predetermined pattern.

7 . Calibration method according to claim 1 , wherein the evaluation of the output signal includes determining an extreme value of the output signal and/or comparing a signal curve of the output signal with a predetermined comparison pattern.

8 . Calibration method according to claim 1 , wherein the calibration method is carried out for more than one region in the overlap area and/or
the calibration method is carried out several times in succession, and/or the calibration method is carried out dynamically by moving the beam of a scanning unit across the working plane, and the monitoring region of a monitoring unit assigned to a different scanning unit following said movement and/or by moving the monitoring region of a monitoring unit assigned to a scanning unit across the working plane, and the beam of a different scanning unit following said movement.

9 . Calibration method according to claim 1 , wherein a beam path of a radiation for monitoring the monitoring region of a monitoring unit is at least within a section thereof the same in a reversed direction as a beam path of a beam of a radiation suited to solidify the building material and/or of a target beam and/or of a laser beam whose energy is not sufficient to solidify the building material.

10 . Calibration method according to claim 1 , wherein correction data for positioning at least one of the beams is determined from the evaluation of the output signal,
wherein a difference between a wavelength of a radiation used for monitoring the monitoring region of a monitoring unit and a wavelength of a radiation suited for solidifying the building material and/or a target beam and/or a laser beam whose energy is not sufficient to solidify the building material is incorporated for determining said correction data.

11 . A production method for additively producing a three-dimensional object by applying layer by layer and selectively solidifying a building material, comprising the steps
applying a layer of the building material in a build area within a working plane, solidifying the layer of the building material at positions that correspond to the respective cross-section of the object by selective irradiation within the build area by at least two beams of a radiation suited for solidifying the building material, and repeating the steps of applying and solidifying until the three-dimensional object is completed, wherein a calibration method according to claim 1 is carried out at least once before the building process and/or during the building process.

12 . A computer program which can be loaded into a programmable control unit which comprises program code means for executing all the steps of a calibration method according to claim 1 and/or a production method according to claim 11 when the computer program is executed on the control unit.

13 . A control device for a manufacturing device for additively producing a three-dimensional object by applying layer by layer and selectively solidifying a building material, wherein the manufacturing device comprises:
an application device for applying a layer of the building material to a build area within a working plane and at least two scanning units, each of them being configured to direct a beam to different target points in the working plane, which target points are located within a scanning region assigned to a respective scanning unit, wherein the scanning regions of the at least two scanning units overlap in an overlap area, wherein at least a first of the at least two scanning units is assigned at least one monitoring unit whose monitoring region extends to a target point of the first scanning unit and its proximity, wherein a change of a position of the monitoring region is carried out as a function of a change of a position of the target point, wherein the control unit is configured to control the manufacturing device such that it: repeats the steps of applying and selectively solidifying until the object is completed and that it carries out a calibration method according to claim 1 least once before and/or during of buildi

Assignees

• Eos Gmbh Electro Optical Systems

Inventors

• Prexler Michael
• Schade Martin

Classifications

• B22F10/30

  Process control · CPC title

• B22F10/20

  Direct sintering or melting · CPC title

• B22F12/13

  to preheat the material · CPC title

• B22F10/25

  Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] · CPC title

• B22F10/366

  Scanning parameters, e.g. hatch distance or scanning strategy · CPC title