Abstract: [Problems] A laser beam irradiation apparatus which can accurately perform a linear welding with a uniform width on an irradiation portion even if the overlap ratio is lowered is provided. [Means for Solving the Problems] A laser beam irradiation apparatus includes laser beam generation means for emitting a laser beam, an optical fiber for transmitting the laser beam incident on an input side face to an output side face, an incident optical unit for introducing the laser beam emitted from the laser beam generation means to the input side face of the optical fiber, and an emission optical unit for applying the laser beam emitted from the output side face of the optical fiber to an irradiation portion, wherein the core cross section of the optical fiber is formed to be rectangular, preferably oblong, throughout the optical fiber or in a range at a predetermined distance from the output side face, and the length of the range where the core cross section is rectangular is preferably set to 3 m or above.

Abstract: An opto-isolator including a Faraday rotator comprised of a crystal cylinder formed into a cylinder using a crystal that rotates polarized light; an enclosing tube surrounding the crystal cylinder; two cooling tubes each sized and positioned to allow both ends of the outer peripheral surface of the crystal cylinder to be inscribed within the cooling tubes and both end sections of an inner peripheral surface of the enclosing tube to be circumscribed around the cooling tubes; passages formed within the cooling tubes; a cooling medium circulating through a space formed among the crystal cylinder, the enclosing tube, and the two cooling tubes, and the passages; and a magnet disposed in an outer periphery of the enclosing tube. The opto-isolator further includes two polarizers respectively disposed on the optical path of light entering the Faraday rotator and an optical path of the light exiting the Faraday rotator.

Abstract: A Faraday rotator of an opto-isolator in a laser processing apparatus includes a crystal cylinder that causes the Faraday effect, an enclosing tube, cooling tubes, and a magnet. The enclosing tube encases the crystal cylinder. The cooling tubes are sandwiched between the crystal cylinder and the enclosing tube at both ends of the crystal cylinder. The cooling tubes have passages through which a coolant flows. The coolant circulates through a space between the crystal cylinder and the enclosing tube, and the passages, thereby cooling the crystal cylinder.

Abstract: A fiber laser processing apparatus controls a LD drive current ILD in a power feedback control mode (FIG. 3E) such that output of a fiber laser beam FB rises substantially from zero or a value around zero to a preceding level having no substantial effect on laser processing and arrives at a desired level (PA) for the laser processing from a preceding level PB after a first time period (preceding pulse width TB) has elapsed (time point t2 of FIGS. 3A to 3F) from the start of the rising to the preceding level (time point t1 of FIGS. 3A to 3F), and this may effectively prevent occurrence of a high-peak pulse HP at the rising edge of the fiber laser beam FB (FIG. 3F).

Abstract: A fiber laser processing apparatus controls a LD drive current ILD in a power feedback control mode (FIG. 3E) such that output of a fiber laser beam FB rises substantially from zero or a value around zero to a preceding level having no substantial effect on laser processing and arrives at a desired level (PA) for the laser processing from a preceding level PB after a first time period (preceding pulse width TB) has elapsed (time point t2 of FIGS. 3A to 3F) from the start of the rising to the preceding level (time point t1 of FIGS. 3A to 3F), and this may effectively prevent occurrence of a high-peak pulse HP at the rising edge of the fiber laser beam FB (FIG. 3F).

Abstract: This laser beam processing apparatus includes a fiber laser oscillator, a laser beam branching unit, a laser beam injecting unit, a fiber transmission system, a laser beam irradiating unit, and a processing table. Based on a fiber laser beam, which is oscillation-outputted from the fiber laser oscillator, the laser beam branching unit executes simultaneous multi-branching from the fiber laser beam into a plurality of branched laser beams. The laser beam injecting unit injects the branched laser beams respectively into optical fibers for transmission and the laser beam irradiating units condense and apply the branched laser beams from the optical fibers for transmission respectively to processing points.

Abstract: A YAG pulse laser oscillator 10 oscillates/outputs pulse width-variable YAG fundamental pulse laser light LB, and a YAG pulse laser oscillator 12 oscillates/outputs pulse width-variable YAG second harmonic pulse laser light SHG. An emission unit 20 superposes the pulse laser light LB and the pulse laser light SHG on the same optical axis and focuses, and irradiates a welding point K on welding pieces (W1 and W2) with, the pulse laser light LB and the pulse laser light SHG. A control unit 18 controls the laser oscillation operation of the laser oscillators 10 and 12 so that the point in time when the laser output of the YAG second harmonic pulse laser light SHG reaches its peak is slightly earlier than the point in time when the laser output of the YAG fundamental pulse laser light LB reaches its peak.

Abstract: A laser weld monitoring system capable of assessing a weld quality of welding using a pulsed laser is provided. The system includes at least one sensor capable of capturing a weld characteristic of welding using said pulsed laser. The weld characteristic has multiple attributes. The system also includes data acquisition and processing equipment adapted for storing and analyzing the weld characteristic. A user first performs multiple welds to capture at least one weld characteristic for each weld. The user then determines the weld quality of each weld, and runs at least one of a library of algorithms associated with the attributes on said at least one weld characteristic for each weld to generate a single value output for the associated attribute. The user selects an attribute indicative of the weld quality by correlating the single value outputs of said at least one algorithm with the weld qualities of the welds.

Abstract: A pressure regulator system for a pneumatically- or hydraulically-actuated weld head. The weld head includes a switching valve comprising several ports: an inflow port attached to a source of pressurized gas, preferably air; an exhaust port; a first line port; and a second line port. Two-way valves are provided on the first line port and the second line port. A valve sensor connected to a switch for determining weld force in the weld head is connected to means for simultaneously closing the first line port valve and the second line valve port when a desired weld force is attained between one or more electrodes and a workpiece, thereby maintaining a constant, maximum pressure in the cylinder and consequently maintaining the desired weld force between the electrode(s) and the workpiece during the welding operation.

Abstract: A pressure regulator system for a pneumatically- or hydraulically-actuated weld head. The weld head includes a switching valve comprising several ports: an inflow port attached to a source of pressurized gas, preferably air; an exhaust port; a first line port; and a second line port. Two-way valves are provided on the first line port and the second line port. A valve sensor connected to a switch for determining weld force in the weld head is connected to means for simultaneously closing the first line port valve and the second line valve port when a desired weld force is attained between one or more electrodes and a workpiece, thereby maintaining a constant, maximum pressure in the cylinder and consequently maintaining the desired weld force between the electrode(s) and the workpiece during the welding operation.