Quality estimation device for additive product

Patent metadata

Field	Value
Publication number	US-10994336-B2
Application number	US-202016892350-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Jun 25, 2019
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

A quality estimation device for an additive product includes an imaging device configured to illuminate a region including a molding surface during manufacturing of the additive product and image the region, when manufacturing the additive product at a molding position by irradiating with a light beam and a material powder melting and solidifying, a luminance acquisition unit acquires a luminance obtained by quantifying a brightness of a light reflected by at least the molding surface of the region in an image in which the imaging device images the region, and a molding density estimation unit estimates a molding density indicating a density of the material powder in a solidified state after melting based on the luminance of the molding surface acquired by the luminance acquisition unit. The material powder is supplied to the molding position.

First claim

What is claimed is:

1. A quality estimation device for an additive product comprising:
an imaging device configured to illuminate a region including a molding surface during manufacturing of the additive product and image the region, when manufacturing the additive product at a molding position by irradiating with a light beam and a material powder melting and solidifying;
a luminance acquisition unit acquires a luminance obtained by quantifying a brightness of a light reflected by at least the molding surface of the region in an image in which the imaging device images the region; and
a molding density estimation unit estimates a molding density indicating a density of the material powder in a solidified state after melting based on the luminance of the molding surface acquired by the luminance acquisition unit,
wherein the material powder is supplied to the molding position.

2. The quality estimation device for the additive product according to claim 1 , further comprising:
a luminance correction unit corrects the luminance of the molding surface acquired by the luminance acquisition unit,
wherein the molding density estimation unit estimates the molding density based on the luminance of the molding surface corrected by the luminance correction unit.

3. The quality estimation device for the additive product according to claim 2 ,
wherein the imaging device comprises:
an illumination unit configured to illuminate the region from a predetermined direction, and
an imaging unit configured to image the region illuminated by the illumination unit, and

wherein the luminance correction unit corrects the luminance in accordance with a scanning direction of the light beam on the molding surface with respect to the predetermined direction in which the illumination unit illuminates the area.

4. The quality estimation device for the additive product according to claim 3 ,
wherein the scanning direction of the light beam is changed for each of adjacent additive layers in the additive product.

5. The quality estimation device for the additive product according to claim 2 ,
wherein the luminance correction unit corrects peripheral luminance of a peripheral region other than the molding surface in the region to a preset reference luminance.

6. The quality estimation device for the additive product according to claim 1 ,
wherein the luminance of the molding surface is a single layer average luminance which is an average of unit area luminance per unit area in the image.

7. The quality estimation device for the additive product according to claim 6 ,
wherein the luminance of the molding surface is a multiple-layer average luminance obtained by averaging the single layer average luminances of the molding surfaces of a plurality of additive layers of the additive product.

8. The quality estimation device for the additive product according to claim 6 ,
wherein the molding density estimation unit estimates the molding density based on a correlation represented by a multiple regression equation, and
wherein the multiple regression equation includes the single layer average luminance and single layer standard deviation indicating variation in the unit area luminance in the single layer average luminance.

9. The quality estimation device for the additive product according to claim 7 ,
wherein the molding density estimation unit estimates the molding density based on a correlation represented by a multiple regression equation, and
wherein the multiple regression equation includes the multiple-layer average luminance and multiple-layer average standard deviation obtained by averaging a plurality of the single layer standard deviations indicating variation in the unit area luminance in the single layer average luminance.

10. The quality estimation device for the additive product according to claim 1 ,
wherein the imaging device configured to image the region after the molding surface is molded and before the material powder is newly supplied to the molding position.

11. The quality estimation device for the additive product according to claim 1 , further comprising:
a defect determination unit determining presence or absence of an internal defect which lowers a strength of the additive product as compared with that of a none-defective product, based on the molding density estimated by the molding density estimation unit.

12. The quality estimation device for the additive product according to claim 11 ,
wherein the defect determination unit determines that the internal defect is present inside the additive product, when the molding density estimated by the molding density estimation unit is equal to or less than a preset reference molding density.

13. The quality estimation device for the additive product according to claim 11 ,
wherein manufacturing of the additive product is stopped, when the defect determination unit determines that the internal defect is present inside the additive product.

14. The quality estimation device for the additive product according to claim 11 ,
wherein the additive product in which the defect determination unit determines that the internal defect is present, is sorted as a defective product.

15. The quality estimation device for the additive product according to claim 1 ,
wherein the material powder is aluminum or an alloy steel.

Assignees

• Jtekt Corp

Inventors

• Nagahama Takaya
• Hoshino Hiroyuki
• Mizoguchi Takashi
• Tano Makoto

Classifications

• G01N9/36 Primary

  Analysing materials by measuring the density or specific gravity, e.g. determining quantity of moisture (methods of measurement in general G01N9/02 - G01N9/32) · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/49

  Scanners · CPC title

• B22F12/22

  Driving means · CPC title

• B22F12/17

  to heat the build chamber or platform · CPC title