JP3177775B2 - Photosynthesis method and synthetic emission optical system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam synthesizing method suitable for a laser processing apparatus for performing welding and cutting by a laser beam, and a synthetic emission optical system therefor.

[0002]

2. Description of the Related Art As a laser oscillator suitable for laser processing for performing welding and cutting by laser light, for example, CO ₂
Laser oscillators and YAG laser oscillators are known. When irradiating a processing point of a workpiece with laser light using such a laser oscillator, the laser output is limited to the output of the laser oscillator. On the other hand, recently, higher output of the laser is required. In response to such demands, a plurality of laser beams output from a plurality of laser oscillators are combined and condensed at a processing point of a work, and a high output that cannot be obtained with only one laser oscillator is obtained at the processing point. Has been proposed for this purpose.

[0003] As one example, a multi-raise method is known, which will be described with reference to FIG. FIG. 2A shows a case in which three laser beams are combined. Laser beams from three laser oscillators (not shown) are transmitted through three optical fibers 51, 52, and 53. The laser beams from the optical fibers 51 to 53 have the same size beam diameter by the collimating lenses 54, 55, and 56, respectively, and are introduced into the condenser lens 57. The laser beams that have passed through the condenser lenses 57 are condensed on the processing points through the cover slide glasses 58, respectively.

On the other hand, Japanese Patent Application Laid-Open No. H8-75947 discloses the following method for coupling an optical fiber that can couple a laser beam with a high energy density. This method is a method of coupling laser light emitted from a plurality of emission-side optical fibers to be incident on one incidence-side optical fiber. The laser light emitted from the optical fiber whose optical axis is parallel to the fiber is collimated by a collimator lens system, and the laser light emitted from the optical fiber whose optical axis intersects with the incident optical fiber among a plurality of emission optical fibers. The laser light is collimated by a collimator lens system and reflected by a reflection mirror to be in a parallel multilayer state without interfering with the laser light emitted from another optical fiber. The laser light is condensed by a condenser lens system and is incident on the incident side optical fiber in a state where all the optical axes are aligned.

[0005]

In the above-mentioned multi-raise method, three laser beams become one spot at a processing point (focal point). However, as shown in FIG. (A position shifted from the position), the combined spots are separated. For this reason, when the defocus position is on the processing surface, a desired uniform spot diameter cannot be obtained.

[0006] On the other hand, in the method of coupling optical fibers described above,
The conditions under which laser light re-enters the coupling system from each optical fiber are limited, so that the spot diameter cannot be changed freely at the processing point.

Further, since the laser light re-enters the optical fiber, the occurrence of output loss cannot be avoided.

Accordingly, an object of the present invention is to provide a photosynthesis method capable of combining a plurality of laser beams concentrically at a processing point and changing the spot diameter of each laser beam independently.

Another object of the present invention is to provide a combined emission optical system suitable for the above-described light combining method.

[0010]

According to the present invention, there is provided a photosynthesis method for concentrically combining a plurality of laser beams from a plurality of optical fibers and irradiating the laser beam to a processing point. Irradiating a laser beam to the processing point via a first collimating lens system and a condensing lens system,
The optical axis of the second laser light of the plurality of laser lights is changed through a second collimating lens system and a prism optical system that makes the laser light from the second collimating lens system ring-shaped. The first laser beam intersects with the optical axis of the first laser beam on the front side of the converging lens system, and the ring-shaped laser beam is reflected at the intersection portion toward the processing point; The second collimating lens system is movable in the optical axis direction to adjust the spot diameter of the laser beam at the processing point, and the prism optical system is movable in the optical axis direction to form a ring-shaped laser at the intersection. The inner diameter and the outer diameter of the light can be adjusted.

According to the present invention, in a combined emission optical system for combining a plurality of laser beams from a plurality of optical fibers concentrically and irradiating the laser beam to a processing point, the first laser beam among the plurality of laser beams is provided. A first collimating lens system and a condensing lens system as means for directing the light to irradiate the processing point; and a second laser beam of the plurality of laser beams is transmitted to the condensing lens system. Before the first
A plurality of synthesizing means for synthesizing the laser light from the collimating lens system, wherein each of the synthesizing means includes a second collimating lens system receiving the laser light from the optical fiber, and a second collimating lens system. A prism optical system that forms a laser beam into a ring shape so that the optical axis intersects the optical axis of the laser beam from the first collimating lens system; and the first collimating lens system disposed at the intersection. A perforated mirror having an aperture through which laser light from the lens can pass and reflecting a ring-shaped laser light from the prism optical system toward the processing point, the first and second collimating lenses The system is movable in the optical axis direction so that the spot diameter of the laser beam at the processing point can be adjusted, and the prism optical system is movable in the optical axis direction at the intersection. Synthesis emitting optical system, characterized in that the adjustable inner and outer diameters of ring-shaped laser beam can be obtained.

In any of the inventions, the prism optical system includes a first prism lens for receiving a laser beam from the second collimating lens system and turning it into a ring shape; Receiving the ring-shaped laser light from the prism lens, the inner diameter thereof is adjusted to an inner diameter substantially equal to the outer diameter of the laser light from the first collimating lens system, and movable in the optical axis direction for adjusting the outer diameter. And a second prism lens.

Preferably, each of the first and second prism lenses has a conical portion, and the conical portions are arranged so as to face in opposite directions.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, an embodiment of a synthetic emission optical system according to the present invention will be described. In FIG. 1, a case where two laser beams are combined will be described for simplicity. In other words, this combined emission optical system is composed of two optical fibers 11 and 12.
The two laser beams are concentrically combined and irradiated to the processing point P.

A first collimating lens system 13 and a condensing lens 14 are provided as means for irradiating a laser beam from the optical fiber 11 to the processing point P while traveling straight.
On the other hand, the laser light from the optical fiber
A combining means for combining the laser light from the first collimating lens system 13 with the laser light before the position 4 is provided.
The synthesizing means includes a second collimating lens system 15 that receives the laser light from the optical fiber 12, a ring-shaped laser light from the second collimating lens system 15, and an optical axis of which is formed by the first collimating lens system. A prism optical system 16 intersecting with the optical axis of the laser light from the first collimating lens system 13 and the first collimating lens system 13
Has an opening 17a through which the laser light from the laser beam can pass, and transmits the ring-shaped laser light from the prism optical system 16 to the processing point P.
And a perforated mirror 17 that reflects light toward the mirror.

The prism optical system 16 includes a first prism lens 16-1 for receiving a laser beam from the second collimating lens system 15 and forming the ring into a ring shape, and a first prism lens 16. -1 and receives the ring-shaped laser light from the first collimating lens system 13.
The second prism lens 16 for adjusting the inner diameter to be substantially equal to the outer diameter of the laser beam from
-2. The first and second prism lenses 16-1 and 16-2 each have a conical portion, and the conical portions are in opposite directions, that is, the conical portion of the first prism lens 16-1 is The conical portion of the second prism lens 16-2 on the incident side is arranged so as to face the exit side.

In particular, in the present invention, the spot diameter of the laser beam at the processing point P can be adjusted by moving the first and second collimating lens systems 13 and 15 in the optical axis direction. In addition, the second prism lens 16-2 is movable in the optical axis direction so that the inner diameter and the outer diameter of the ring-shaped laser light at the intersection can be adjusted. Although the structure for making the first and second collimating lens systems 13 and 15 and the second prism lens 16-2 movable is not shown in detail, the structure along the inner wall of the cylindrical casing accommodating them is not shown. It just needs to be able to slide. For example, in the case of the first collimating lens system 13, a plurality of lenses are mounted in a cylindrical body, and the cylindrical body is slidably assembled along the inner wall of the casing. An elongated hole is provided in the casing along the axial direction, and a screw or the like is screwed into the cylindrical body through the elongated hole, so that the axial position of the cylindrical body with respect to the inner wall of the casing can be adjusted and fixed. This is the same for the second collimating lens system 15 and the second prism lens 16-2. Of course, such a movable and adjustment mechanism is an example, and can be easily realized by using other well-known mechanisms.

Laser light A emitted from optical fiber 11
Is re-collimated by a collimating lens system 13, and is irradiated to a processing point P by a condenser lens 14. By moving the collimating lens system 13 in the optical axis direction, the spot diameter at the processing point (condensing point) P can be changed.

On the other hand, the laser beam B emitted from the optical fiber 12 is re-collimated by the collimating lens system 15 and
The first prism lens 16-1 and the second prism lens 16-2 form a ring-shaped laser beam. This ring-shaped laser light is turned back to the processing point P side by the perforated mirror 17, guided concentrically with the laser light A, and irradiated to the processing point P by the condenser lens 14. By moving the collimating lens system 15 in the optical axis direction also on the path of the laser light, the spot diameter of the laser light (concentric outside) at the processing point P can be changed. Also, by moving the second prism lens 16-2 in the optical axis direction,
The inner and outer diameters of the ring-shaped laser light can be changed.

With the above configuration, the laser light A and the laser light B are combined so that the laser light A surrounds the laser light A, and are condensed concentrically at the processing point P. By changing the spot diameter and the inner and outer diameters of the ring-shaped laser light, the beam mode at the processing point P can be variously changed. Moreover, since the combining is performed without waste, a combined laser beam having a value obtained by adding the output of the laser beam A and the output of the laser beam B is obtained. For example, 4k
The output of W and the output of 2 kW can be combined to obtain an output of 6 kW, and the output of 4 kW and the output of 4 kW can be combined to obtain an output of 8 kW. That is, the greater the output per laser oscillator, the greater the combined output.

In the above embodiment, two laser beams are combined. In the present invention, two or more laser beams are combined concentrically with the laser beam from the optical fiber 11. it can. For example, when combining two laser beams with the laser beam from the optical fiber 11, in addition to the first combining system including the second collimating lens system 15, the prism optical system 16, and the perforated mirror 17, A second combining system having a similar configuration may be disposed between the first combining system and the condenser lens 14. Of course, in this case, the inner diameter of the ring-shaped laser light by the prism optical system is made substantially equal to the outer diameter of the ring-shaped laser light by the first combining system.

The present invention can be generally used for welding, cutting, drilling, and surface treatment using laser light, and is applicable not only to laser light but also to synthesis of light that can be transmitted by an optical fiber.

[0023]

According to the present invention, when combining and condensing laser beams emitted from a plurality of optical fibers, the diameter of each converging spot can be changed independently.
The beam mode at the processing point can be changed in various ways. As a result, a high-power laser processing capability that cannot be obtained with a single laser oscillator can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a combined emission optical system according to the present invention.

FIG. 2 is a diagram for explaining an example of a conventional synthesis method.

[Explanation of symbols]

 11, 12 First and second optical fibers 13, 15 First and second collimating lens systems 14 Condensing lens 16 Prism optical system 16-1, 16-2 First and second prism lenses 17 Perforated mirror

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-75947 (JP, A) JP-A-5-56992 (JP, A) JP-A-5-69172 (JP, A) JP-A-57- 136444 (JP, A) JP-A-61-120110 (JP, A) JP-A-63-153514 (JP, A) JP-A-5-224082 (JP, A) Japanese Utility Model Laid-Open No. 63-82216 (JP, U) Japanese Patent Publication No. 58-55483 (JP, B2) Japanese Utility Model Publication No. 62-8953 (JP, Y2) Japanese Utility Model Publication No. 2-41607 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 26/06 B23K 26/08 G02B 19/00 G02B 21/06

Claims (5)

(57) [Claims] 1. A photosynthesis method for concentrically combining a plurality of laser beams from a plurality of optical fibers and irradiating the laser beam to a processing point, wherein a first laser beam of the plurality of laser beams is first collimated. The laser beam is irradiated to the processing point via a lens system and a condenser lens system, and a second laser beam of the plurality of laser beams is emitted from a second collimating lens system and the second collimating lens system. Through a prism optical system for making the laser light into a ring shape, the optical axis thereof intersects the optical axis of the first laser light on the near side of the condensing lens system, and the ring is formed at the intersection. Laser light is reflected toward the processing point, and the first and second collimating lens systems are respectively movable in the optical axis direction so that the spot diameter of the laser light at the processing point can be adjusted. And a prism optical system movable in an optical axis direction to adjust an inner diameter and an outer diameter of the ring-shaped laser light at the intersection. 2. The photosynthesis method according to claim 1, wherein the prism optical system receives a laser beam from the second collimating lens system and forms the first laser beam into a ring shape.
Receiving the ring-shaped laser light from the first prism lens and adjusting the inner diameter to be substantially equal to the outer diameter of the laser light from the first collimating lens system, and adjusting the outer diameter to A light combining method comprising: a second prism lens movable in an optical axis direction for adjustment. 3. A combined emission optical system for combining a plurality of laser beams from a plurality of optical fibers concentrically and irradiating the laser beam to a processing point, wherein a first laser beam of the plurality of laser beams is straightened. A first collimating lens system and a condensing lens system as means for irradiating the processing point with the second laser beam of the plurality of laser beams, A plurality of combining means for combining with laser light from the first collimating lens system, wherein each of the combining means receives a laser beam from the optical fiber;
And a prism optical system that makes the laser light from the second collimating lens system ring-shaped so that its optical axis intersects the optical axis of the laser light from the first collimating lens system. A hole that is disposed at the intersection and has an opening through which laser light from the first collimating lens system can pass, and that reflects a ring-shaped laser light from the prism optical system toward the processing point An aperture mirror, wherein the first and second collimating lens systems are respectively movable in an optical axis direction so that a spot diameter of a laser beam at the processing point can be adjusted, and the prism optical system is movable in an optical axis direction. Wherein the inner and outer diameters of the ring-shaped laser light at the intersection are adjustable. 4. A combined emission optical system according to claim 3, wherein said prism optical system is provided with a first prism lens for receiving a laser beam from said second collimating lens system and forming it into a ring shape. Receiving the ring-shaped laser light from the first prism lens, adjusting the inner diameter to be approximately equal to the outer diameter of the laser light from the first collimating lens system, and adjusting the outer diameter. A composite emission optical system, comprising: a second prism lens movable in an optical axis direction. 5. The combined emission optical system according to claim 4, wherein each of the first and second prism lenses has a conical portion, and the conical portions are arranged so as to face in opposite directions. A synthetic emission optical system.