Laser processing machine

Patent metadata

Field	Value
Publication number	US-9520693-B2
Application number	US-201314081005-A
Country	US
Kind code	B2
Filing date	Nov 15, 2013
Priority date	May 19, 2011
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A laser processing machine includes a plurality of collimating lenses to convert a laser beam from a laser oscillator, which have been emerged from a point of emergence of a transmission optical fiber, into parallel rays of light, a condensing lens to condense the laser beam and then radiate it onto a work, and a nozzle positioned on one side of the work remote from the condensing lens. The distance from the point of emergence to the tip of the nozzle remains unchangeable. The collimating lenses are spaced from each other in a direction parallel to an optical axis. A switching device switches the position of each of the collimating lenses in the orthogonal direction so that the center of one of the collimating lenses may be aligned with a center of the laser beam. The collimating lenses have respective focal lengths that are different from each other.

First claim

What is claimed is:

1. A laser processing machine comprising:
a plurality of collimating lenses which convert a laser beam from a laser oscillator into parallel rays of light, the laser beam emerging from a point of emergence of a transmission optical fiber, the plurality of collimating lenses being spaced from each other in an orthogonal direction perpendicular to an optical axis;
a condensing lens operable to collect the laser beam, which has been converted into the parallel rays of light, and then to radiate the collected laser beam onto a work to be processed;
a nozzle positioned on one side of the work adjacent the condensing lens and operable to discharge an assist gas, a distance from the point of emergence to a tip of the nozzle being unchangeable; and
a switching device which switches a position of the plurality of collimating lenses in the orthogonal direction so that an arbitrarily chosen one of the plurality of the collimating lenses may have a lens center thereof coinciding with the center of the laser beam emitted from the point of emergence,
wherein the plurality of the collimating lenses have respective focal lengths that are different from each other.

2. The laser processing machine as claimed in claim 1 , further comprising:
a storage unit which stores a plurality of processing conditions corresponding to each of the plurality of collimating lenses;
a selecting unit which selects a collimating lens among the plurality of collimating lenses which meets the processing which correspond to a selected processing condition, upon checking the storage unit; and
a switching control unit which controls a drive source for the switching device so that one of the plurality of collimating lenses selected by the selecting unit may assume a position at which the laser beam emerging from the point of emergence is converted into parallel rays of light.

3. The laser processing machine as claimed in claim 1 , further comprising:
a detecting unit which detects a position of a collimating lens among the plurality of collimating lenses, of which a position in the orthogonal direction is switched by the switching device and which has been positioned on the optical axis of the laser beam; and
an emergency responsive unit which implements a predetermined emergency responsive measure in the event that a lens center of the collimating lens detected by the detecting unit does not coincide with a position of a center of the laser beam emerging from the point of emergence.

4. The laser processing machine as claimed in claim 1 , further comprising a focal position changing mechanism which alters a focal position of the laser beam by moving the condensing lens in a direction parallel to the optical axis of the laser beam.

5. The laser processing machine as claimed in claim 1 , further comprising a lens holder which holds the plurality of the collimating lenses,
wherein the switching device switches the position in the orthogonal direction by moving the lens holder in the orthogonal direction.

6. The laser processing machine as claimed in claim 1 , further comprising a lens holder which holds the plurality of the collimating lenses,
wherein the switching device switches the position in the orthogonal direction by rotating the lens holder about a rotation axis that lies parallel to the optical axis.

Assignees

• Murata Machinery Ltd

Inventors

• Matsumoto Keita

Classifications

• H01S3/005 Primary

  Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping (shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B) · CPC title

• G02B7/16

  Rotatable turrets · CPC title

• B23K26/1462

  Nozzles; Features related to nozzles · CPC title

• B23K26/0665

  by beam condensation on the workpiece, e.g. for focusing · CPC title

• B23K26/046

  Automatically focusing the laser beam · CPC title