Fanuc Corporation

Minoru Ando

Akira Egawa

Atsushi Mori

Hajime Ikemoto

Satoshi Kagiwada

Eiji Kobayashi

Takeshi Watanabe

Ryoma Okazaki

A laser () provided with a discharge activation power supply () supplied with power from a 3-phase AC power line, the discharge activation power supply () provided inside it with three first capacitors (, and), the laser () including an external ground fault protection device comprising a voltage measuring unit using the first capacitors (, and) to measure voltages between the phases of the 3-phase AC power line and the ground and a power breaking unit () comparing the values of voltages measured by the voltage measuring unit and a predetermined threshold and breaking the supply of power from the 3-phase AC power line to the power supply () when the value of a voltage exceeds the threshold.

Laser

A discharge excitation type gas laser oscillator has a discharge excitation unit for exciting a laser gas by discharge in a discharge tube to generate induced emission of laser light, a high-frequency power supply unit for supplying power to the discharge tube, and a controller unit for controlling output current of the high-frequency power supply unit. The laser oscillator further has an output detecting section that detects actual current value of the high-frequency power supply unit supplying power to the discharge tube at an arbitrary pressure lower than the high pressure during the steady-state operation, at the start of the laser oscillator, after the laser gas begins discharge excitation at a pressure lower than the high pressure during steady-state operation, an output comparison section that compares the detected actual current value with a normal current value that has been detected when the gas composition of the laser gas is normal at the same pressure as the actual current value is detected; and a power supply control section that discriminates, if the difference between the actual current value and the normal current value is equal to or greater than a preset value, that the gas composition of the laser gas is abnormal, and stops output of the high-frequency power supply unit.

Method for discriminating anomaly in gas composition and discharge excitation type gas laser oscillator

A high-frequency discharge excited gas laser oscillator receiving power from a laser power supply controlled by a pulse command, the high-frequency discharge excited gas laser oscillator provided with a power detecting section for detecting supply power from the laser power supply to a discharge tube and a pulse command control section positioned at an upstream side of the laser power supply, comparing an allowable upper limit value of supply power found from a relationship between a discharge tube temperature and supply power and an actual supply power detected by the power detecting section, stopping the pulse command value to the discharge tube when the supply power is higher than the allowable upper limit value, and setting a pulse command value based on the allowable upper limit value.

High frequency discharge excited gas laser oscillator

A laser cutting apparatus capable of properly cutting a workpiece having a large thickness with a laser beam. The laser cutting apparatus includes a gas laser oscillator; and an optical system including a collective lens and transmitting and collecting a laser beam generated in the gas laser oscillator to irradiate a workpiece with the laser beam. An index Mfor evaluating a beam quality of the laser beam emerging from the optical system, with which the workpiece is irradiated, is in a range of 2.8 to 4.5; while the index Mis defined by a formula: M=&#x3c0;&#xd7;(dm)/(4&#xd7;&#x3bb;&#xd7;Zr); in which &#x3bb; is a wavelength of the laser beam; dm is a minimum beam diameter of the laser beam in a predetermined optical-path range including a focal point of the collective lens; and Zr is a distance between a first position on an optical axis, at which the minimum beam diameter dm is established, and a second position on the optical axis, at which a beam diameter '2&#xd7;dm' is established, in the laser beam in the predetermined optical-path range.

Laser cutting apparatus with a high quality laser beam

A laser apparatus () for performing the laser machining operation by condensing the laser light output from a laser oscillator () is disclosed. A laser output value calculation unit calculates a laser output value (L) based on a command value (L) issued to a laser oscillator (). A temperature change estimating unit () estimates the temperature change or the temperature (Te) of specified component element(s) () of the laser apparatus based on the elapsed time (t) and the laser output value calculated by the laser output value calculation unit. An adjusting unit () adjusts the conditions for controlling the laser or the conditions for laser machining based on the temperature change or the temperature of the specified component element estimated by the temperature change estimating unit. A stable laser machining operation is performed without a temperature sensor. The laser output value (L) may be measured by a laser power sensor ().

Laser apparatus

A gas laser oscillator of easy maintenance which is capable of switching a beam mode at high speed. Electric discharge sections in which gas medium is flown are formed in an optical resonating space in an electric discharge tube between a rear mirror and an output mirror. Electrodes are connected to electric discharge power sources (alternating current or direct current power sources). Coils are wound around the electric discharge tube at the respective electric discharge sections and excited by coil excitation circuits. Directions and intensities of the excitation currents from the coil excitation circuits are controlled by a controller. Regions in which the electric discharge currents flow between the electrodes in the respective electric discharge sections are varied by magnetic fields generated by the coils in accordance with the directions and intensities of the excitation currents of the coils, to thereby control the beam mode.

Gas laser oscillator

A laser oscillator capable of preventing contamination of optical components by organic matter such as oil mist. Gas laser medium in an optical resonator constituted by optical components is pumped by an electric discharge generated in an electric discharge tube to produce a laser beam. The gas medium flows at high speed in the electric discharge tube incorporated in a circulating path including a blower. A part of lubrication oil of the blower is evaporated and mixed into the gas medium. Since the optical components are cooled by retaining mechanisms to prevent temperature rise of the components and a gas stagnation occurs between the optical component and the electric discharge tube, the evaporated oil mist tends to be congealed and adhered to a surface of the optical component. A photocatalyst arranged in the vicinity of the optical component effectively decomposes and removes the oil mist.

Growing community of inventors

Yamanashi, Japan

Minoru Ando