US 12,076,817 B2
Laser welding device
Toru Sakai, Hyogo (JP); Atsuhiro Kawamoto, Hyogo (JP); Junji Fujiwara, Osaka (JP); and Michio Sakurai, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Oct. 9, 2020, as Appl. No. 17/066,913.
Application 17/066,913 is a continuation of application No. PCT/JP2019/011483, filed on Mar. 19, 2019.
Claims priority of application No. 2018-077702 (JP), filed on Apr. 13, 2018.
Prior Publication US 2021/0023656 A1, Jan. 28, 2021
Int. Cl. B23K 26/244 (2014.01); B23K 26/10 (2006.01); B23K 26/70 (2014.01)
CPC B23K 26/244 (2015.10) [B23K 26/103 (2013.01); B23K 26/705 (2015.10)] 7 Claims
OG exemplary drawing
 
1. A laser welding device configured to weld two overlapping workpieces by emitting a laser beam to the workpieces to form a weld bead, the laser welding device comprising:
an irradiation unit configured to emit, to the workpieces, the laser beam and a measurement beam having a wavelength different from a wavelength of the laser beam;
a measurement unit configured to measure a depth from a predetermined reference surface based on the measurement beam emitted by the irradiation unit and reflected from the workpieces;
an irradiation position switching part configured to switch an irradiation position of the measurement beam between a keyhole position coaxial with an optical axis of the laser beam and a weld bead position behind a center of the optical axis of the laser beam in a welding direction, wherein the weld bead has a surface where a recess is formed; and
a controller configured to determine an amount of a gap between the two workpieces based on a measured value of a recess depth measured at the weld bead position, by making a comparison with recess depth previously measured in a state where there is no gap between the two workpieces.