CN214815683U - Laser output head with controllable output light spot - Google Patents

Abstract

The utility model relates to a laser equipment technical field, in particular to controllable laser output head of output facula. The optical fiber transmission device comprises a crystal end cap, a main body and a transmission optical fiber, wherein an optical fiber accommodating cavity is formed in the main body along the axial direction; the transmission optical fiber is accommodated in the optical fiber accommodating cavity; the crystal end cap is embedded in the front end of the main body and is connected with the transmission optical fiber; the distance between the virtual focus of the light beam of the convex lens end cap and the end face of the convex lens end cap is greater than the length of the convex lens end cap. The utility model realizes the purposes of controllable adjustment of numerical aperture of output light spots and adjustment of size of light spots by controlling the curvature of the convex lens; by controlling the length of the convex lens end cap and the curvature of the convex lens and the design of the laser output head, the virtual focus position of the laser output head can be ensured to be unchanged, and the laser output head can be normally used for the existing laser application equipment.

Description

Laser output head with controllable output light spot

Technical Field

The utility model relates to a laser equipment technical field, in particular to controllable laser output head of output facula.

Background

With the continuous maturity of high-power fiber laser technology, the mainstream high-power fiber laser is generally realized by a larger-core-diameter fiber scheme, a main oscillation power amplification scheme or a high-power beam combination scheme at present, and consequently, the output performance of the laser is sacrificed to cause the output light spot to be enlarged or the output laser NA to be enlarged, but in practical application, the output performance of the laser is closely inseparable with the configuration requirements of a laser processing head or complete equipment, and the sacrifice of the laser output performance (the light spot size or the output laser divergence angle NA) can cause the abnormality of other system components, such as the heating of a nozzle of a cutting head, the heating of a collimating mirror, the poor cutting effect and the like. As shown in fig. 1, when the divergence angle NA of the light beam output through the transmission fiber 110 is large, the energy of the light beam may irradiate the edges of the collimating lens M and the focusing lens N, or even the inner wall of the cutting head, thereby causing adverse effects such as lens heating, heating of the inner wall of the cutting head, poor focusing of the light spot of the focusing point, and the like; meanwhile, a small-hole diaphragm with a millimeter-grade diameter is generally arranged near a focusing point Q on the cutting head, and when the beam divergence angle NA is large, the edge of a light beam can irradiate on the diaphragm, so that the diaphragm is heated and even damaged, and the cutting quality is influenced. The problem that light spots are large or NA is scattered can be solved to a certain extent by utilizing the convex lens imaging principle, but the problem that the focus or the virtual focus is deviated cannot be normally adjusted after the quartz end cap is assembled with a laser output head can be caused, and new troubles are brought to actual laser processing application.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a controllable laser output head of output facula can effectively solve high power fiber laser output facula big, the divergence angle is big, easily arouses cutting head or collimating mirror to generate heat, cuts the scheduling problem badly.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a laser output head with controllable output light spots comprises a crystal end cap, a main body and a transmission optical fiber, wherein an optical fiber accommodating cavity is formed in the main body along the axial direction; the transmission optical fiber is accommodated in the optical fiber accommodating cavity; the crystal end cap is embedded in the front end of the main body and is welded with the transmission optical fiber;

the crystal end cap is a convex lens end cap, and the distance between the virtual focus of the emission light beam of the convex lens end cap and the end face of the convex lens end cap is greater than the length of the convex lens end cap.

In one possible implementation, the convex end cap narrows the input light beam and outputs the narrowed input light beam.

In one possible implementation, the divergence angle of the emitted light beam is reduced by reducing the radius of curvature of the convex lens end cap.

In a possible implementation manner, the convex lens end cap includes an optical fiber fusion-splicing surface, a first conical surface, a second conical surface, a quartz cylindrical surface and a convex lens output surface, wherein the quartz cylindrical surface is of a cylindrical structure, the convex lens output surface is arranged at the front end of the quartz cylindrical surface, the second conical surface, the first conical surface and the optical fiber fusion-splicing surface are sequentially arranged at the rear end of the quartz cylindrical surface along the axial direction, and the optical fiber fusion-splicing surface is fused with the transmission optical fiber.

In one possible implementation, the convex lens output face is coated.

In a possible implementation manner, the rear end of the main body of the laser output head with controllable output light spots is connected with a supporting part, the supporting part is connected with an armor cable, and the other end of the transmission optical fiber penetrates through the supporting part and then enters the armor cable;

the rear end of the main body is connected with two water nozzles; the two water nozzles are respectively connected with the two water pipes, and the two water pipes penetrate through the supporting parts and then enter the armor cables.

In a possible implementation manner, the main body comprises an inner water pipe and a water nozzle fixing piece, wherein the center of the inner water pipe is the optical fiber accommodating cavity, and the optical fiber accommodating cavity is internally provided with a mechanical small hole which contracts along the radial direction; the front end of the main body is provided with a groove communicated with the optical fiber accommodating cavity, and the crystal end cap is embedded in the groove;

the side wall of the inner water pipe is internally provided with an interlayer cavity for injecting cooling medium; the water injection well choke mounting set up in the outside of interior water pipe for install two the water injection well choke, the water injection well choke with the intermediate layer chamber intercommunication of interior water pipe.

In one possible implementation manner, the supporting part comprises an internal supporting part, an armor fixing part and a plurality of supporting columns, wherein one end of the internal supporting part is connected with the rear end of the main body, and the other end of the internal supporting part is connected with the armor fixing part;

the plurality of supporting columns are circumferentially distributed on the outer side of the internal supporting piece, and two ends of each supporting column are respectively connected with the main body and the armor cable fixing piece;

the armor cable is connected with an armor cable fixing member.

In a possible implementation manner, a sleeve is arranged outside the supporting portion, and two ends of the sleeve are respectively connected with the main body and the armor cable.

In a possible implementation mode, the outer side of the main body is alternately sleeved with an insulating ring and an electrode ring at intervals, and the insulating ring and the electrode ring are fixed through a clamping piece in threaded connection with the main body.

The utility model has the advantages and beneficial effects that:

the embodiment of the utility model provides a controllable laser output head of output facula, according to convex lens imaging principle, through controlling convex lens camber realize the purpose that the output facula numerical aperture is adjusted controllable, facula size is adjusted; the design of combining convex lens end cap, laser output head and cutting head inside can guarantee that laser output head virtual focus position is unchangeable through the design of control convex lens end cap length and convex lens camber plus laser output head, can normally be used for current laser application equipment.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a beam of a conventional laser head when assembled with a cutting head;

fig. 2 is a schematic structural diagram of a laser output head with controllable output light spots in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a crystal end cap according to an embodiment of the present invention;

fig. 4 is a schematic structural view of the supporting portion in the embodiment of the present invention;

FIG. 5 is a schematic structural view of the main body of the present invention;

fig. 6 is the light beam schematic diagram of the laser output head when assembled with the cutting head.

In the figure: 101 is a crystal end cap, 1011 is an optical fiber fusion-connecting surface, 1012 is a first conical surface, 1013 is a second conical surface, 1014 is a quartz cylindrical surface, 1015 is a convex lens output surface, 102 is a main body, 1021 is an inner water pipe, 1022 is a water nozzle fixing piece I, 1023 is a water nozzle fixing piece II, 1024 is a mechanical small hole, 1025 is a welding point I, 1026 is a welding point II, 1027 is a groove, 103 is a clamping piece, 1041 is an electrode ring I, 1042 is an electrode ring II, 1051 is an insulating ring I, 1052 is an insulating ring II, 1053 is an insulating ring III, 106 is a water nozzle, 107 is a water pipe, 108 is an internal supporting piece, 109 is a sleeve, 110 is a transmission optical fiber, 111 is an armor fixing piece, 112 is an armor cable, 113 is a supporting column, M is a collimating lens, N is a focusing lens, and Q is a focusing point.

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are presented herein only to illustrate and explain the present invention, and not to limit the present invention.

An embodiment of the utility model provides a pair of controllable laser output head of output facula realizes the purpose that output facula numerical aperture adjusts controllable, facula size is adjusted through the convex lens camber of control crystal end cap. Referring to fig. 2 to 4, the laser output head with controllable output light spots includes a crystal end cap 101, a main body 102, and a transmission fiber 110, wherein a fiber accommodating cavity is axially disposed in the main body 102; the transmission fiber 110 is accommodated in the fiber accommodating cavity; the crystal end cap 101 is embedded in the front end of the main body 102 and is welded with the transmission fiber 110; the crystal end cap 101 is a convex lens end cap, and the distance L' between the virtual focus of the emission light beam of the convex lens end cap and the end face of the convex lens end cap is greater than the length L of the convex lens end cap. In particular, the focal point of the reverse extension of the emission beam is the virtual focal point of the emission beam.

In the embodiment of the utility model, the convex lens end cap narrows the input light beam and outputs the narrowed light beam, that is, the divergence angle NA of the emitted light beam is smaller than the divergence angle NA of the incident light beam, and the divergence angle NA of the emitted light beam is reduced by reducing the curvature radius of the convex lens end cap; that is, the divergence angle NA of the emission beam of the convex lens end cap decreases as the radius of curvature R of the convex lens end cap decreases, and the distance L' from the virtual focus of the emission beam to the end face of the convex lens end cap increases as the radius of curvature R of the convex lens end cap decreases.

In the embodiment of the utility model, the material of convex lens end cap adopts quartz crystal. Referring to fig. 3, the convex lens end cap includes an optical fiber fusion-splicing surface 1011, a first conical surface 1012, a second conical surface 1013, a quartz cylindrical surface 1014 and a convex lens output surface 1015, wherein the quartz cylindrical surface 1014 is a cylindrical structure, the convex lens output surface 1015 is disposed at the front end, the second conical surface 1013, the first conical surface 1012 and the optical fiber fusion-splicing surface 1011 are sequentially disposed at the rear end along the axial direction, and the optical fiber fusion-splicing surface 1011 is fusion-spliced with the transmission optical fiber 110. The input optical fiber fusion end cap can reduce the power density of the output end face and solve the problem of burning of the output optical fiber end face.

Further, the taper angle of the first taper surface 1012 is smaller than that of the second taper surface 1013. Specifically, the taper angle of the second tapered surface 1013 is 90 degrees, when the returning light enters the second tapered surface 1013 at a small angle approximate to parallel light, most of the light will form total reflection on the 45-degree tapered surface of the returning light, and after two reflections, the returning light is reflected back along the original light path approximately, so that the returning light can be effectively intercepted, and the high-returning-light resistance of the product is greatly improved.

Further, the convex lens output face 1015 is coated to reduce end face reflections of the crystal end cap 101. In this embodiment, the transmission fiber 110 may be a single mode fiber or a multimode fiber; or a single optical fiber, a plurality of optical fibers or a fused tapered optical fiber bundle; or solid optical fiber or hollow optical fiber; or may be passive or active. The transmission fiber 110 and the crystal end cap 101 are welded together by heating using oxyhydrogen flame, graphite wire, electrode or laser discharge. The welding of the transmission optical fiber 110 and the crystal end cap 101 can be homogenizing light spot welding, the homogenizing optical fiber realizes the uniform energy distribution, the convex lens end cap realizes the reduction of light spots and numerical aperture, and the problem of poor cutting is effectively solved.

Referring to fig. 2 and 4, in an embodiment of the present invention, the rear end of the main body 102 is connected to a supporting portion, the supporting portion is connected to the armor cable 112, and the other end of the transmission fiber 110 passes through the supporting portion and enters the armor cable 112; the rear end of the main body 102 is connected with two water nozzles 106; the two water nozzles 106 are respectively connected with two water pipes 107, and the two water pipes 107 penetrate through the supporting part and then enter the armor cable 112.

Referring to fig. 5, in an embodiment of the present invention, the main body 102 includes an inner water tube 1021 and a water nozzle fixing member, wherein the center of the inner water tube 1021 is an optical fiber accommodating cavity, and a mechanical small hole 1024 contracting along a radial direction is disposed in the optical fiber accommodating cavity; the front end of the main body 102 is provided with a groove 1027 communicated with the optical fiber accommodating cavity, and the crystal end cap 101 is embedded in the groove 1027; the side wall of the inner water pipe 1021 is internally provided with a sandwich cavity for injecting cooling medium; the water nozzle fixing piece is arranged on the outer side of the inner water pipe 1021 and used for installing two water nozzles 106, and the water nozzles 106 are communicated with an interlayer cavity of the inner water pipe 1021.

In the embodiment of the present invention, the supporting portion includes an inner supporting member 108, an armor fixing member 111, and a plurality of supporting posts 113, wherein one end of the inner supporting member 108 is connected to the rear end of the main body 102, and the other end is connected to the armor fixing member 111; a plurality of support columns 113 are circumferentially distributed on the outer side of the inner support member 108, and two ends of each support column 113 are respectively connected with the main body 102 and the armor fixing member 111; the armor cable 112 is connected to the armor fixing 111.

Further, a sleeve 109 is provided outside the support, both ends of the sleeve 109 are connected to the main body 102 and the sheath 112, respectively, and the sleeve 109 protects the support and the water pipe 107 therein.

The utility model discloses an in the embodiment, the outside interval of main part 102 is overlapped in turn and is equipped with insulator ring and electrode ring, and insulator ring and electrode ring are fixed through the fastener 103 with main part 102 threaded connection.

Specifically, the electrode ring comprises an electrode ring I1041 and an electrode ring II 1042, the insulating ring comprises an insulating ring I1051, an insulating ring II 1052 and an insulating ring III 1053, the insulating ring I1051 and the insulating ring III 1053 are respectively arranged on the outer sides of the electrode ring I1041 and the electrode ring II 1042, and the insulating ring II 1052 is arranged between the electrode ring I1041 and the electrode ring II 1042. The inner parts of the electrode rings are respectively and correspondingly connected with leads which are connected to an external circuit board, and when a laser head QBH is inserted into a laser processing head, the electrode rings and the laser processing head are respectively contacted to form a passage which can be normally used; when the QBH is inserted inside the laser machining head, the electrode ring is in contact with the laser machining head but does not form a passage, and the laser machining head will alarm. The electrode ring is a safety measure for judging the conduction.

In this embodiment, the convex lens end caps of different lengths and curvature radii may be made of high purity fused quartz, calcium fluoride, sapphire, calcium fluoride, magnesium fluoride or zinc selenide; the convex lens end cap shape can be realized by laser cutting, end face grinding or quartz growth; the convex lens end cap controls the length and the curvature radius of the convex lens according to the requirements of the emergent light beam, the incident light beam and the virtual focus.

Referring to fig. 3, the utility model discloses a main design idea is based on convex lens imaging principle, and R is the curvature radius of convex lens end cap, and L is the length of convex lens end cap, and d is the output facula radius of convex lens terminal surface, and L' is the length of transmission beam virtual focus distance convex lens end cap terminal surface. Specifically, the design of the convex lens end cap is as follows:

the table shows that by changing the radius of curvature of the convex end cap, the NA and virtual focus of the exiting light are changed for incident light of a certain divergence angle NA. In addition, for the same endcap length and radius of curvature, input beams of different NA will be narrowed, but the virtual focus position will not change. Example 1 illustrates: in the case of nos. 3 and 4, in the case of the same end cap length of 15mm and curvature radius of 14.58mm, the input beam of 0.22NA is narrowed to the output beam of 0.15NA after passing through the convex lens end cap, the input beam of 0.12NA is narrowed to the output beam of 0.0818NA after passing through the convex lens end cap, and the virtual focus position is not changed to 15.2 mm; example 2 illustrates that: as in the case of nos. 6 and 7, in the case of the same end cap length of 15mm and curvature radius of 10.556mm, the input beam with 0.22NA is narrowed to the output beam with 0.123NA after passing through the convex lens end cap, the input beam with 0.15NA is narrowed to the output beam with 0.084NA after passing through the convex lens end cap, and the virtual focus position is not changed to 18.5 mm. The two examples above illustrate that changing the radius of curvature of the convex end cap changes the compression ratio of the input and output beams, and changes the virtual focus position, which is important for improving the beam divergence angle (compression ratio) and the assembly of the output head (QBH for short) (virtual focus position). Example 3 illustrates: in both cases 8 and 9, the end cap length was 18mm and the radius of curvature was 5.6mm, giving collimated beams for both incident beams of different NA. Specifically, the convex lens end cap controls the length and the radius of curvature of the lens according to the requirements of the outgoing light beam, the incoming light beam and the virtual focus.

Fig. 6 is a schematic light beam diagram of the laser output head of the present invention when assembled with a cutting head; referring to fig. 6, because the crystal end cap 101 adopts the output head structure of the convex lens end cap, the large divergence angle light beam output by the transmission fiber 110 is compressed into the small divergence angle light beam by the crystal end cap 101 of the convex lens structure, the light beam energy does not irradiate the edges of the collimating lens M and the focusing lens N, and further does not irradiate the inner wall of the cutting head, so that the problems of heating of the nozzle of the cutting head, heating of the collimating lens, poor cutting effect and the like are not caused in the application of high-power laser. The size of the divergence angle NA (spot numerical aperture) of the emitted light beam can also be adjusted according to the internal structure of the cutting head by adjusting the divergence angle of the emitted light beam by changing the length and curvature radius of the crystal end cap 101, and by pressing the divergence angle of the narrow light beam, a focused spot of higher energy density can be obtained at the focusing point Q, which is advantageous for cutting thicker metal materials.

Output fiber fusion bonding end cap can reduce the power density of output end face to a great extent, solves the problem that output fiber end face burns, but output beam can arouse output facula grow because numerical aperture restriction, in high power laser application, easily arouses that the cutting head nozzle generates heat, the collimating mirror generates heat, the not good scheduling problem of cutting effect. The utility model realizes the purposes of controllable adjustment of numerical aperture of output light spots and adjustment of light spot size by controlling the length of the convex lens end cap and the curvature of the convex lens according to the convex lens imaging principle and by combining the quartz end cap, the laser output head and the internal design of the cutting head; meanwhile, the output surface 1015 of the convex lens is coated with a film, so that the end surface reflection of the quartz end cap is reduced, and the problems can be effectively solved. In addition, the virtual focus position of the laser output head can be ensured to be unchanged by controlling the length of the convex lens end cap and the curvature of the convex lens and the design of the laser output head, and the laser output head can be normally used for the existing laser application equipment. The utility model provides a laser output head, the design is simple, and compact structure can effectively solve high power fiber laser output facula big, the divergence angle easily arouses cutting head or collimating mirror to generate heat, cut bad scheduling problem greatly.

It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (10)

1. The laser output head with the controllable output light spot is characterized by comprising a crystal end cap (101), a main body (102) and a transmission optical fiber (110), wherein an optical fiber accommodating cavity is formed in the main body (102) along the axial direction; the transmission optical fiber (110) is accommodated in the optical fiber accommodating cavity; the crystal end cap (101) is embedded at the front end of the main body (102) and is welded with the transmission optical fiber (110);

the crystal end cap (101) is a convex lens end cap, and the distance between the virtual focus of the emission light beam of the convex lens end cap and the end face of the convex lens end cap is greater than the length of the convex lens end cap.

2. The output spot-controllable laser output head as claimed in claim 1, wherein the convex end cap narrows the input beam for output.

3. The output spot-controllable laser output head of claim 2, wherein the divergence angle of the emitted beam is reduced by reducing the radius of curvature of the convex end cap.

4. The output head of claim 2, wherein the convex lens end cap comprises an optical fiber fusion-splicing surface (1011), a first conical surface (1012), a second conical surface (1013), a quartz cylindrical surface (1014), and a convex lens output surface (1015), wherein the quartz cylindrical surface (1014) is a cylindrical structure, the front end of the quartz cylindrical surface is provided with the convex lens output surface (1015), the rear end of the quartz cylindrical surface is provided with the second conical surface (1013), the first conical surface (1012), and the optical fiber fusion-splicing surface (1011) in sequence along the axial direction, and the optical fiber fusion-splicing surface (1011) is fused with the transmission optical fiber (110).

5. The output spot controllable laser output head as claimed in claim 4, wherein the convex lens output face (1015) is coated.

6. The output laser head according to any one of claims 1 to 5, characterized in that the rear end of the main body (102) is connected with a support part, the support part is connected with an armor (112), and the other end of the transmission optical fiber (110) passes through the support part and enters the armor (112);

the rear end of the main body (102) is connected with two water nozzles (106); the two water nozzles (106) are respectively connected with two water pipes (107), and the two water pipes (107) penetrate through the supporting parts and then enter the armor cable (112).

7. The laser output head with controllable output light spots according to claim 6, characterized in that the main body (102) comprises an inner water pipe (1021) and a water nozzle fixing member, wherein the center of the inner water pipe (1021) is the optical fiber accommodating cavity, and the optical fiber accommodating cavity is provided with a mechanical small hole (1024) which is contracted along the radial direction; the front end of the main body (102) is provided with a groove (1027) communicated with the optical fiber accommodating cavity, and the crystal end cap (101) is embedded in the groove (1027);

the side wall of the inner water pipe (1021) is internally provided with a sandwich cavity for injecting cooling medium; the water nozzle fixing piece is arranged on the outer side of the inner water pipe (1021) and used for installing two water nozzles (106), and the water nozzles (106) are communicated with the interlayer cavity of the inner water pipe (1021).

8. The output spot-controllable laser output head according to claim 6, wherein the supporting part comprises an inner supporting member (108), a cable sheath holder (111) and a plurality of supporting posts (113), wherein one end of the inner supporting member (108) is connected to the rear end of the main body (102), and the other end is connected to the cable sheath holder (111);

a plurality of supporting columns (113) are circumferentially distributed on the outer side of the inner supporting piece (108), and two ends of each supporting column (113) are respectively connected with the main body (102) and the armor fixing piece (111);

the armor cable (112) is connected with an armor fixing member (111).

9. The output spot-controllable laser output head according to claim 6, characterized in that a sleeve (109) is provided outside the support, and both ends of the sleeve (109) are respectively connected with the main body (102) and the cable sheath (112).

10. The output laser head of claim 1, wherein the outer side of the main body (102) is alternately sleeved with an insulating ring and an electrode ring at intervals, and the insulating ring and the electrode ring are fixed by a clamping piece (103) in threaded connection with the main body (102).

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