Abstract: A laser processing apparatus having high accuracy of measurement of reflected light is provided. A laser processing apparatus according to the present disclosure includes: a laser oscillator configured to emit a laser beam to a workpiece; a sensor configured to measure intensity of light reflected from the workpiece; and a plate-like member disposed in the middle of an optical path of the reflected light, in which a through-hole is formed at a place in the plate-like member through which the reflected light passes, and the sensor measures the intensity of the reflected light that has passed through the through-hole. Therefore, it is possible to prevent light reflected from any object or the like other than the surface of the workpiece from entering the sensor, and thereby to accurately measure the intensity of light reflected from the surface of the workpiece.

Abstract: A laser welding method for irradiating a plurality of stacked metal plates in an upright position with a laser beam to weld the plurality of stacked metal plates is provided. The laser welding method includes irradiating the plurality of metal plates with the laser beam to form a circular molten pool and scanning the laser beam once around an outer periphery of the molten pool to enlarge the molten pool. In the enlarging of the molten pool, a scanning start point of the laser beam is set within a range from 135 degrees to 315 degrees in a scanning direction of the laser beam, with 0 degrees directly above the molten pool in a vertical direction.

Abstract: A vibration device includes a quartz substrate including a first vibration section, a second vibration section, and a third vibration section, a pair of first excitation electrodes formed at two principal surfaces of the quartz substrate, a pair of second excitation electrodes so formed as to sandwich the second vibration section in the thickness direction of the quartz substrate, and a pair of third excitation electrodes so formed as to sandwich the third vibration section in the thickness direction of the quartz substrate. At least one of the pair of second excitation electrodes is formed at a first inclining surface that inclines with respect to the two principal surfaces. At least one of the pair of third excitation electrodes is formed at a second inclining surface that inclines with respect to the two principal surfaces. The second inclining surface inclines with respect to the first inclining surface.

Abstract: A laser processing device includes: an oscillator that oscillates laser light; a mirror in which second laser light that is another part of laser light is reflected while first laser light that is a part of laser light is transmitted through the mirror to irradiate a processing target portion with second laser light, and first reflected light that is a part of reflected light in which second laser light is reflected by the processing target portion is transmitted through the mirror; an absorption unit that receives and absorbs the first laser light until an amount of the first laser light becomes equal to or less than a predetermined light amount; a sensor unit that measures intensity of the first reflected light; and a quality evaluation unit that outputs an evaluation result representing the quality of the laser processing at the processing target portion based on a measurement result.

Abstract: A laser processing machine includes: a lens for condensing a laser beam; an actuator changing a relative position between the lens and a workpiece to change a focal position of the laser beam with respect to the workpiece; a protective glass disposed between the lens and the workpiece; a detector detecting a focal position of the laser beam; and a controller configured to control the actuator, the controller configured to obtain a current deviation amount of the focal position from a target position using the detector, the controller configured to obtain a relationship data, wherein the relationship data indicates relationship between a deviation amount of the focal position from the target position and a spot diameter of the laser beam on a surface of the workpiece when contaminant adheres the protective glass, the controller configured to estimate a current spot diameter of the laser beam on the surface using the current deviation amount and the relationship data, the controller configured to control the ac

Abstract: The laser beam machine includes: a laser emitting system for emitting a laser beam, wherein the laser emitting system has a protective glass capable of transmitting the laser beam; and a housing attached to the laser emitting system. The housing includes, a first end facing the laser emitting system, a second end opposite to the first end, and a first blowing portion located over an entire circumference of an interior of the first end. The first blowing portion blows a gas toward a central axis of the housing.

Abstract: A method of detecting center coordinates of a spot welding mark includes: a linear laser light emitting step of emitting a plurality of linear laser light components with a linear irradiation trace on a spot welding mark by emitting laser light through continuous output oscillation; a waveform acquiring step of acquiring a waveform of an intensity of return light which is light generated from a processing point; an outer edge position coordinates deriving step of deriving position coordinates of three or more points on an outer edge of the spot welding mark from a peak position of the intensity of the waveform of the return light; and a center coordinates calculating step of calculating center coordinates of the spot welding mark from the position coordinates of the three or more points on the outer edge derived in the outer edge position coordinates deriving step.

Abstract: A welding method for integrally welding three or more superposed metal plates includes a spot welding of joining the first vehicle body structure plate and the second vehicle body structure plate by spot welding in a plurality of places along an opening edge of the door opening portion in a state where each of the metal plates is superposed, and a laser welding of joining the surface plate and the first vehicle body structure plate in a plurality of places including a place between welding places of the spot welding after the spot welding. The joining being performed by emitting laser light to the surface plate and by scanning the laser light to stir a molten pool including a molten metal of the surface plate and the first vehicle body structure plate melted by the laser light.

Abstract: Provided is a laser welding method for performing lap welding on a plurality of laminated metal plates by applying a laser beam to the metal plates. The metal plates are constituted by n pieces of metal plates laminated in order from a first metal plate to an n-th metal plate, n being an integer not less than 2. The laser welding method includes: forming a recess serving as an escape route for gas by applying a first laser beam from the first metal plate side, the escape route penetrating through the first metal plate to an (n?1)th metal plate in the laminating direction to reach the n-th metal plate; and forming a welding pool around the recess so as to maintain the shape of the recess, the welding pool being formed by applying a second laser beam to the outside of the recess.

Abstract: A laser welding method and a welded structure are provided to improve joining strength by increasing the throat depth and to prevent cracks due to stress concentration by increasing an angle at the back of the throat. The laser welding method for lap welding of multiple layered steel plates by irradiation with a laser beam includes: a step of forming a molten pool penetrating the first steel plate in a layer direction and reaching the second steel plate by irradiating the first steel plate with a first laser beam LB1; and a step of melting an outer peripheral edge of the molten pool by irradiating an outer periphery of the molten pool on the first steel plate with a second laser beam LB2 having a spot diameter D2 larger than a spot diameter D1 of the first laser beam LB1.

Abstract: A welding method for integrally welding three or more superposed metal plates includes a spot welding of joining the first vehicle body structure plate and the second vehicle body structure plate by spot welding in a plurality of places along an opening edge of the door opening portion in a state where each of the metal plates is superposed, and a laser welding of joining the surface plate and the first vehicle body structure plate in a plurality of places including a place between welding places of the spot welding after the spot welding. The joining being performed by emitting laser light to the surface plate and by scanning the laser light to stir a molten pool including a molten metal of the surface plate and the first vehicle body structure plate melted by the laser light.