CN219026290U - Beam shaping single lens group laser head light path device and laser cutting head - Google Patents

Abstract

The utility model relates to a laser head light path device of a beam shaping single lens group and a laser cutting head, wherein the laser head light path device of the beam shaping single lens group comprises: the spherical lens comprises a shell and an aspherical focusing lens, wherein one surface of the aspherical focusing lens is a plane, the other surface of the aspherical focusing lens is a convex aspherical surface, two sides of the edge of the convex aspherical surface of the aspherical focusing lens are shaft conical surfaces, the center of the shaft conical surface is an arc-shaped aspherical surface, the cone angle of the shaft conical surface is 3-6 degrees, the aperture of the central arc-shaped aspherical surface accounts for 60-90% of the aperture of the whole aspherical focusing lens, and the curvature radius of the central arc-shaped aspherical surface is 25-50mm. The beam shaping single lens group laser head light path device has the advantages that the curvature is larger, the focusing capability is stronger due to the adoption of the size parameters, the scattered light can be deflected into the converged light only through one aspheric focusing lens, the structure is simplified, the cost is reduced, and meanwhile, the single lens absorbs less heat, so that the optical lens is not easy to generate focus drift.

Description

Beam shaping single lens group laser head light path device and laser cutting head

Technical Field

The utility model relates to the technical field of laser cutting equipment, in particular to a laser head light path device of a beam shaping single lens group and a laser cutting head.

Background

The laser processing technology is a door processing technology for cutting, welding, surface treatment, punching, micro-processing and the like of materials (including metals and non-metals) by utilizing the interaction characteristic of laser beams and substances. Laser processing as an advanced manufacturing technique has been widely used in the national economy important departments of automobile, electronics, electrical appliances, aviation, metallurgy, mechanical manufacturing, and the like.

The optical fiber laser is matched with the laser cutting head for cutting metal, and has the advantages of high cutting speed, high precision and the like. The main light path of the conventional laser cutting head consists of two closely attached spherical collimating lenses and two closely attached spherical focusing lenses, and the position of a focus on an optical axis is changed by adjusting the position of the collimating lenses or the focusing lenses on the optical axis so as to adapt to cutting of plates with different thicknesses; meanwhile, the emergent beam of the conventional laser cutting head is a Gaussian beam output by a laser. The problems of the existing laser cutting head are as follows: (1) The existing laser cutting head has a plurality of optical lenses, complex structure and high cost; (2) The number of the optical lenses is large, so that the quantity of heat absorbed by the optical lenses is also large, the temperature of the optical lenses rises faster, and focus drift is easy to cause; (3) Gaussian beam cutting of thin plate metal has the advantage of high energy density, but cutting of thick plate metal has the defects of too thin cutting slits, stationary central overheating edge and low energy utilization rate; (4) The existing laser cutting head outputs laser beams to cut the plate, and the returned slag generated during the cutting of the plate easily enters the laser cutting head to burn out the optical lens.

Therefore, it is needed to provide a laser head light path device and a laser cutting head with a single lens group for beam shaping, which has a simple structure, low production cost and less heat absorption.

Disclosure of Invention

First, the technical problem to be solved

In view of the above-mentioned shortcomings and disadvantages of the prior art, the present utility model provides a beam shaping single lens laser head light path device and a laser cutting head, which solve the technical problems of complex structure, high cost, and more easily occurring focal point drift due to heat absorption of the existing laser cutting head.

(II) technical scheme

In order to achieve the above purpose, the main technical scheme adopted by the utility model comprises the following steps:

in a first aspect, an embodiment of the present utility model provides a beam shaping single lens group laser head optical path device, including: the device comprises a shell and an aspheric focusing lens, wherein the aspheric focusing lens is movably arranged in the shell and can move forwards and backwards along the axis of the shell so as to adjust the focal position of a laser beam;

one surface of the aspheric focusing lens is a plane, the other surface of the aspheric focusing lens is a convex aspheric surface, two sides of the edge of the convex aspheric surface of the aspheric focusing lens are axial conical surfaces, and the center of the convex aspheric surface of the aspheric focusing lens is an arc-shaped aspheric surface.

Optionally, the cone angle of the shaft conical surface is 3 degrees to 6 degrees, the aperture of the central arc-shaped aspheric surface accounts for 60% -90% of the aperture of the whole aspheric focusing lens, and the curvature radius of the central arc-shaped aspheric surface is 25-50mm.

Optionally, the cone angle of the shaft conical surface is 3.5 degrees to 5 degrees, the aperture of the central arc-shaped aspheric surface accounts for 65% -80% of the aperture of the whole aspheric focusing lens, and the curvature radius of the central arc-shaped aspheric surface is 25-39mm.

Optionally, the method further comprises: an aperture stop for filtering out stray light at the edge of the laser beam;

the aperture diaphragm is positioned at the front side of the aspheric focusing lens and is fixed in the shell;

the aperture diaphragm is annular, and a light passing hole is formed in the center of the aperture diaphragm.

Optionally, the diameter of the light-passing hole is 10-15mm.

Optionally, the method further comprises: a protection window for preventing the slag returning generated when the laser beam cuts the plate from burning the aspherical focusing mirror;

the protection window is positioned at the rear side of the aspheric focusing lens and is fixed in the shell.

Optionally, the protection window is a plane mirror, and the thickness of the protection window is less than 1/10 of the focal length of the light beam.

Optionally, the thickness of the protection window is 5-8mm.

In a second aspect, embodiments of the present utility model provide a laser cutting head comprising: the laser head light path device of the beam shaping single lens group.

Optionally, the laser cutting head further comprises: a water cooling assembly;

the water cooling assembly is arranged on the single lens group laser head light path device for beam shaping and is used for cooling the single lens group laser head light path device for beam shaping.

(III) beneficial effects

The beneficial effects of the utility model are as follows: the utility model relates to a laser head light path device of a beam shaping single lens group, which comprises: the device comprises a shell and an aspherical focusing lens, wherein the aspherical focusing lens is movably arranged in the shell and can move forwards and backwards along the axis of the shell so as to adjust the focus position of a laser beam; the aspherical focusing lens has a plane surface and a convex aspherical surface on the other side, the two sides of the edge of the convex aspherical surface of the aspherical focusing lens are axial conical surfaces, the center is an arc aspherical surface, the cone angle of the axial conical surface is 3-6 degrees, the aperture of the center arc aspherical surface accounts for 60-90% of the aperture of the whole aspherical focusing lens, the radius of curvature of the center arc aspherical surface is 25-50mm, the curvature is larger, the focusing capability is stronger, the scattered light can be deflected into converged light only through one aspherical focusing lens, compared with the prior art, the structure is simplified, the cost is reduced, meanwhile, the single lens absorbs less heat, the laser power loss is low, and the optical lens is not easy to generate focus drift. In addition, the convex surface of the aspheric focusing lens is formed by an axial conical surface and an arc aspheric surface, so that a Gaussian distribution laser beam can be converted into an approximate flat-top beam, the energy distribution of the approximate flat-top beam is more uniform, and the plate cutting effect is better.

Drawings

Fig. 1 is an optical element arrangement diagram of an embodiment 1 of a beam shaping single lens group laser head optical path device of the present utility model, in which the beam shaping single lens group laser head optical path device is shown to include: an aspherical focusing mirror, an aperture diaphragm and a protection window;

FIG. 2 is a schematic cross-sectional view of an aperture stop of an embodiment 1 of a beam shaping single lens laser head optical path apparatus of the present utility model;

FIG. 3 is a schematic top view of an aperture stop of an embodiment 1 of a beam shaping single lens laser head optical path apparatus according to the present utility model;

FIG. 4 is a schematic view of an aspherical focusing mirror of example 1 of the optical path apparatus of the laser head with a beam shaping single lens group according to the present utility model;

fig. 5 is a schematic view of a protection window of an optical path device of a laser head with a single lens group according to embodiment 1 of the present utility model.

FIG. 6 is a schematic view of the optical element position of the beam shaping single lens group laser head optical path device of FIG. 1 when it is Jiao Diaojiao;

fig. 7 is a schematic diagram of the positions of optical elements during negative focal focusing of the optical path device of the beam shaping single lens group laser head in fig. 1.

[ reference numerals description ]

1: a light outlet point; 2: an aperture stop; 3: an aspherical focusing mirror; 4: a protective window; 5: an arc-shaped aspherical surface; 6: and (5) a shaft conical surface.

Detailed Description

The utility model will be better explained by the following detailed description of the embodiments with reference to the drawings. In the present embodiment, the direction of the output of the optical fiber is "front" near the light exit point 1, and the direction of the output of the optical fiber is "rear" far from the light exit point 1.

Example 1:

referring to fig. 1 and 4, fig. 1 is a layout diagram of optical elements of a beam shaping single lens group laser head optical path device according to the present utility model, and fig. 4 is a schematic diagram of an aspherical focusing mirror of the beam shaping single lens group laser head optical path device according to the present utility model.

The embodiment provides a single mirror group laser head light path device of beam shaping, includes: the laser cutting device comprises a shell (not shown in the figure), wherein an aperture diaphragm 2 for filtering stray light at the edge of a laser beam, an aspheric focusing lens 3 for deflecting the laser beam and a protection window 4 for preventing slag generated when the laser beam cuts a plate from entering a laser cutting head to burn out the aspheric focusing lens 3 are sequentially arranged in the shell along the light emitting direction of the laser beam.

Specifically, the aspherical focusing mirror 3 has a plane on one side and a convex aspherical surface on the other side, and the aspherical focusing mirror 3 can be moved forward and backward along the axis of the housing to adjust the focal position of the laser beam.

Further, the two sides of the convex aspheric surface edge of the aspheric focusing mirror 3 are shaft conical surfaces 6, the center is an arc-shaped aspheric surface 5, the cone angle of the shaft conical surface 6 is 3 degrees to 6 degrees, the aperture of the center arc-shaped aspheric surface 5 accounts for 60% -90% of the aperture of the whole aspheric focusing mirror 3, and the curvature radius of the center arc-shaped aspheric surface 5 is 25-50mm. The radius of curvature of the central arc-shaped aspherical surface 5 is inversely proportional to the curvature, and the smaller the radius of curvature is, the larger the curvature of the central arc-shaped aspherical surface 5 is.

The beam shaping single lens group laser head light path device of this embodiment, because the above-mentioned dimensional parameter is adopted to the aspheric focusing lens 3, its camber is bigger, and the focusing ability is stronger, therefore can omit collimating mirror and focusing mirror, just can deflect the light that diverges into the light that gathers through an aspheric focusing lens 3, compared with prior art, it has simplified the structure, reduced the cost, single lens absorbs the heat less simultaneously, laser power loss is low to the optical lens also is difficult to take place focus drift.

In addition, the convex surface of the aspheric focusing lens 3 is composed of the axial conical surface 6 and the arc aspheric surface 5, so that a Gaussian distribution laser beam can be converted into an approximate flat-top beam, the energy distribution of the approximate flat-top beam is more uniform, and the plate cutting effect is better.

Specifically, the aspherical focusing mirror 3 operates as follows: the laser beam before the aspherical focusing mirror 3 is a spherical wave, that is, a diverging light reflected by a point light source, gradually expands outwards, and gradually weakens in intensity when propagating along a radius. When passing through the aspherical focusing mirror 3, the aspherical focusing mirror 3 divides the laser beam into two parts, wherein the first part is a central beam passing through the central arc-shaped aspherical surface 5, the central beam diverges after being focused by spherical waves (the spherical waves are still spherical waves after passing through the central arc-shaped aspherical surface 5) behind the aspherical focusing mirror 3, and the second part is a side beam passing through two side shaft conical surfaces 6, and the side beam is converted into a strip-shaped plane wave with fixed width by the shaft conical surfaces 6 to linearly propagate. After the focus of the central beam, the central beam is overlapped with the side Fang Guangshu to form approximately flat-top beam distribution, the intensity of the middle and the two sides of the beam is the same like plane waves, and the effect is better when the plate is cut.

Referring to fig. 2 and 3, fig. 2 is a schematic cross-sectional view of an aperture stop of the optical path device of the laser head with a beam shaping single lens set according to the present utility model, and fig. 3 is a schematic top view of the aperture stop of the optical path device of the laser head with a beam shaping single lens set according to the present utility model.

Specifically, the aperture diaphragm 2 is fixed inside the housing, and is annular, and a light-passing hole is formed in the center. When the laser beam emitted from the light emitting spot 1 passes through the aperture diaphragm 2 in use, the aperture diaphragm 2 blocks part of stray light at the edge of the laser beam outside a light path, so that the aspheric focusing mirror 3 is protected, and the aspheric focusing mirror 3 is prevented from absorbing a large amount of stray light to generate heat. The laser beam is then transmitted to the aspherical focusing mirror 3 and deflected by the aspherical focusing mirror 3.

Preferably, the diameter of the light passing hole is 10-15mm. The purpose of this arrangement is to avoid that too large a diameter of the light-passing hole of the aperture diaphragm 2 causes that the edge parasitic light in the laser beam is not filtered out, and also to avoid that too small a diameter of the light-passing hole of the aperture diaphragm 2 causes that the aperture diaphragm 2 absorbs too much heat to burn out.

Fig. 5 is a schematic diagram of a protection window of the optical path device of the laser head with a single lens group for beam shaping according to the present utility model.

Specifically, the protection window 4 is fixed inside the shell, is a plane mirror, has a thickness less than 1/10 of the focal length of the light beam, and is used for protecting the aspherical focusing lens 3 in the shell and preventing the aspherical focusing lens from being burnt out by slag generated when the aspherical focusing lens is used for cutting a plate.

Preferably, the thickness of the protective window 4 is 5-8mm. By the arrangement, the protective window 4 is not only prevented from being too thin and being easy to overheat and burn out, but also the focus offset and the cost and weight increase of the lens caused by too thick protective window 4 and too large deflection of the light beam position can be avoided.

Fig. 6 and 7 are schematic diagrams of optical element positions when the optical path device of the beam shaping single lens assembly laser head of the present utility model is positive Jiao Diaojiao, and fig. 7 is a schematic diagram of optical element positions when the optical path device of the beam shaping single lens assembly laser head of the present utility model is negative focal focusing.

The positional relationship of the beam convergence points on both sides of the aspherical focusing mirror 3 of the present embodiment is as follows:

wherein a is the distance from the light outlet point 1 of the laser optical fiber rod to the aspheric focusing mirror 3, b is the distance from the focal point of the laser head emergent light beam to the aspheric focusing mirror 3, and f is the equivalent focal length of the aspheric focusing mirror 3.

According to the formula, the aspheric focusing lens 3 can be moved backwards (namely away from the light outlet point 1), so that the focus of the laser beam is moved forwards (close to the light outlet point 1), and the cutting of the positive focal position of the laser cutting head is realized (refer to fig. 6);

similarly, the aspherical focusing mirror 3 can be moved forward (closer to the light exit point 1), so that the focal point of the laser beam is moved backward (i.e., away from the light exit point 1), and the laser head can cut at the negative focal position (see fig. 7).

Example 2:

the difference between the optical path device of the laser head of the single lens group for beam shaping and the optical path device of the laser head of the embodiment is that compared with the embodiment 1, both sides of the edge of the convex aspheric surface of the aspheric focusing lens 3 of the embodiment are provided with shaft conical surfaces 6, the center is an arc-shaped aspheric surface 5, the cone angle of the shaft conical surface 6 is 3.5-5 degrees, the aperture of the center arc-shaped aspheric surface 5 accounts for 65-80% of the aperture of the whole aspheric focusing lens 3, and the curvature radius of the center arc-shaped aspheric surface 5 is 25-39mm. The aspherical focusing mirror 3 of the present embodiment has a larger cone angle of the axial cone surface 6 and a smaller radius of curvature than that of embodiment 1, and thus the aspherical focusing mirror 3 has a larger curvature (i.e., the center portion of the aspherical focusing mirror 3 is thicker and the edge is thinner), and the focusing ability is stronger.

Other technical features similar to those of embodiment 1 are not described here.

Example 3:

the embodiment also provides a laser cutting head, which comprises the beam shaping single-lens laser head light path device in the embodiment 1;

further, the laser cutting head further includes: the water cooling assembly (not shown in the figure) is arranged on the laser head light path device of the beam shaping single lens group and is used for cooling the laser head light path device of the beam shaping single lens group to prevent focal drift caused by temperature rise of the aspheric focusing lens 3.

In the description of the present utility model, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; may be a communication between two elements or an interaction between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature is "on" or "under" a second feature, which may be in direct contact with the first and second features, or in indirect contact with the first and second features via an intervening medium. Moreover, a first feature "above," "over" and "on" a second feature may be a first feature directly above or obliquely above the second feature, or simply indicate that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is level lower than the second feature.

In the description of the present specification, the terms "one embodiment," "some embodiments," "examples," "particular examples," or "some examples," etc., refer to particular features, structures, materials, or characteristics described in connection with the embodiment or example as being included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that alterations, modifications, substitutions and variations may be made in the above embodiments by those skilled in the art within the scope of the utility model.

Claims (10)

1. The utility model provides a light beam shaping single mirror group laser head light path device which characterized in that: comprising the following steps: the device comprises a shell and an aspheric focusing lens (3), wherein the aspheric focusing lens (3) is movably arranged in the shell and can move forwards and backwards along the axis of the shell so as to adjust the focal position of a laser beam;

one surface of the aspheric focusing mirror (3) is a plane, the other surface of the aspheric focusing mirror is a convex aspheric surface, two sides of the edge of the convex aspheric surface of the aspheric focusing mirror (3) are axial conical surfaces (6), and the center of the aspheric focusing mirror is an arc-shaped aspheric surface (5).

2. The beam shaping single lens group laser head light path device as claimed in claim 1, wherein: the cone angle of the shaft conical surface (6) is 3-6 degrees, the aperture of the central arc-shaped aspheric surface (5) accounts for 60-90% of the aperture of the whole aspheric focusing lens (3), and the curvature radius of the central arc-shaped aspheric surface (5) is 25-50mm.

3. The beam shaping single lens group laser head optical path apparatus as claimed in claim 2, wherein: the cone angle of the shaft conical surface (6) is 3.5-5 degrees, the aperture of the central arc-shaped aspheric surface (5) accounts for 65-80% of the aperture of the whole aspheric focusing lens (3), and the curvature radius of the central arc-shaped aspheric surface (5) is 25-39mm.

4. The beam shaping single lens group laser head light path device as claimed in claim 3, wherein: further comprises: an aperture diaphragm (2) for filtering out the stray light at the edge of the laser beam;

the aperture diaphragm (2) is positioned at the front side of the aspheric focusing mirror (3) and is fixed inside the shell;

the aperture diaphragm (2) is annular, and a light passing hole is formed in the center of the aperture diaphragm.

5. The beam shaping single lens group laser head light path apparatus as claimed in claim 4, wherein: the diameter of the light-passing hole is 10-15mm.

6. The beam shaping single lens group laser head light path device as claimed in claim 3, wherein: further comprises: a protection window (4) for preventing the aspherical focusing mirror (3) from being burned out by the returned slag generated when the laser beam cuts the plate;

the protection window (4) is positioned at the rear side of the aspheric focusing mirror (3) and is fixed inside the shell.

7. The beam shaping single lens group laser head light path apparatus as claimed in claim 6, wherein: the protection window (4) is a plane mirror, and the thickness of the protection window is smaller than 1/10 of the focal length of the light beam.

8. The beam shaping single lens group laser head light path apparatus as claimed in claim 7, wherein: the thickness of the protection window (4) is 5-8mm.

9. A laser cutting head, characterized in that: comprising the following steps: the beam shaping single lens group laser head optical path apparatus as claimed in any one of claims 1 to 8.

10. The laser cutting head of claim 9, wherein: the laser cutting head further comprises: a water cooling assembly;

the water cooling assembly is arranged on the single lens group laser head light path device for beam shaping and is used for cooling the single lens group laser head light path device for beam shaping.

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