Granted Patent B2

US 12,654,260 · App. 17/664,065 · Granted Jun 16, 2026

Inventors: Koji Funami (Kyoto, JP); Kazuki Fujiwara (Osaka, JP); Izuru Nakai (Osaka, JP)

Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.

B23K26/707B23K26/0643B23K26/21

Abstract

Claims (43)

1 . A laser processing method for scanning over a first member in a first direction while irradiating the first member with a laser beam emitted from an oscillator, and joining the first member and a second member adjacent to the first member by a molten portion, the laser processing method comprising:

measuring, in each of a first measurement region, a second measurement region different from the first measurement region, and a third measurement region different from the first measurement region and the second measurement region, an intensity of a welding light radiated from at least one of the first member or the second member by irradiation with the laser beam, the welding light including at least one of a heat radiation light, a plasma light, or a reflected light; and

evaluating a state of a laser processing based on the intensity of the welding light measured in each of the first measurement region, the second measurement region, and the third measurement region,

wherein:

the first measurement region, the second measurement region, and the third measurement region are aligned adjacent to each other in a second direction intersecting the first direction;

the first measurement region is located in the molten portion, and sandwiched between the second measurement region and the third measurement region; and

the evaluating the state of the laser processing includes determining, based on a relative relationship between the intensities measured in adjacent measurement regions of the first, second, and third measurement regions, that a melting abnormality has occurred on one side of the molten portion in the second direction.

2 . The laser processing method according to claim 1 , wherein the measuring the intensity of the welding light includes:

condensing the welding light from the first measurement region on a first optical fiber using an optical system to measure, by a first sensor, the welding light transmitted by the first optical fiber; and

condensing the welding light from the second measurement region on a second optical fiber using the optical system to measure, by a second sensor, the welding light transmitted by the second optical fiber.

3 . The laser processing method according to claim 1 , wherein the second direction is orthogonal to the first direction.

4 . The laser processing method according to claim 1 , wherein:

during normal welding, the molten portion has a width in a direction orthogonal to the first direction;

each of the first measurement region and the second measurement region has a diameter less than or equal to the width of the molten portion; and

the first measurement region includes an irradiation position of the laser beam during normal welding.

5 . The laser processing method according to claim 4 , wherein the diameter of each of the first measurement region and the second measurement region is equal to the width of the molten portion.

6 . The laser processing method according to claim 1 , wherein the evaluating the state of the laser processing includes:

comparing a first signal intensity of the welding light measured in the first measurement region with a first threshold value;

comparing a second signal intensity of the welding light measured in the second measurement region with a second threshold value; and

comparing a third signal intensity of the welding light measured in the third measurement region with a third threshold value.

7 . The laser processing method according to claim 6 , wherein:

the first threshold value is a lower limit value, the second threshold value is an upper limit value, and the third threshold value is an upper limit value; and

the evaluating the state of the laser processing includes determining that the melting abnormality has occurred on the one side of the molten portion in the second direction when the first signal intensity is smaller than the first threshold value, the second signal intensity is smaller than the second threshold value, and the third signal intensity is larger than the third threshold value.

8 . The laser processing method according to claim 6 , wherein:

the first threshold value is an upper limit value, the second threshold value is an upper limit value, and the third threshold value is an upper limit value; and

the evaluating the state of the laser processing includes determining that a focal position of the laser beam is deviated along an irradiation direction of the laser beam when the first signal intensity is smaller than the first threshold value, the second signal intensity is larger than the second threshold value, and the third signal intensity is larger than the third threshold value.

9 . A laser processing device for scanning over a first member in a first direction while irradiating the first member with a laser beam, and joining the first member and a second member adjacent to the first member by a molten portion, the laser processing device comprising:

an oscillator configured to emit the laser beam;

an irradiation optical system configured to guide the laser beam to the first member;

a stage configured to move the first member and the second member relative to the laser beam to cause the laser beam to scan in the first direction;

a measurement optical system configured to guide, from each of a first measurement region, a second measurement region different from the first measurement region, and a third measurement region different from the first measurement region and the second measurement region, a welding light radiated from at least one of the first member or the second member by irradiation with the laser beam, the welding light including at least one of a heat radiation light, a plasma light, or a reflected light;

a first sensor configured to measure a first intensity of the welding light guided from the first measurement region to the measurement optical system;

a second sensor configured to measure a second intensity of the welding light guided from the second measurement region to the measurement optical system;

a third sensor configured to measure a third intensity of the welding light guided from the third measurement region to the measurement optical system; and

a determination unit configured to evaluate a state of a laser processing based on the first intensity, the second intensity, and the third intensity,

wherein:

the first measurement region, the second measurement region, and the third measurement region are aligned adjacent to each other in a second direction intersecting the first direction;

the first measurement region is located in the molten portion and sandwiched between the second measurement region and the third measurement region; and

the determination unit is further configured to determine that a melting abnormality has occurred on one side of the molten portion in the second direction based on a relative relationship between the intensities measured in adjacent measurement regions of the first, second, and third measurement regions.

10 . The laser processing device according to claim 9 , further comprising:

a first optical fiber configured to transmit, to the first sensor, the welding light guided from the first measurement region to the measurement optical system;

a second optical fiber configured to transmit, to the second sensor, the welding light guided from the second measurement region to the measurement optical system; and

a third optical fiber configured to transmit, to the third sensor, the welding light guided from the third measurement region to the measurement optical system.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (17)