CN113067236A

CN113067236A - Laser output head

Info

Publication number: CN113067236A
Application number: CN202110210013.1A
Authority: CN
Inventors: 赵文利; 沈翔; 李榕; 雷星; 谭徐; 鲁晓聪; 买一帆; 宋梁; 闫大鹏
Original assignee: Wuhan Raycus Fiber Laser Technologies Co Ltd
Current assignee: Wuhan Raycus Fiber Laser Technologies Co Ltd
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2021-07-02
Also published as: DE112021005991T5; WO2022179230A1

Abstract

The invention provides a laser output head, at least comprising: an end cap and a ferrule; the end cap is composed of a cylindrical output end and a frustum-shaped input end, the small-diameter end of the frustum-shaped input end is connected with the output end of the optical fiber, and the large-diameter end of the frustum-shaped input end is welded with one end of the cylindrical output end; the frustum angle of the frustum-shaped input end is larger than the laser divergence angle of laser transmitted in the end cap, and the diameter of the large-diameter end of the frustum-shaped input end is smaller than that of the cylindrical output end; the lock pin is positioned on the outer side of the end cap, and the inner wall of the lock pin is in clearance fit with the outer wall of the frustum-shaped input end. According to the laser output head provided by the invention, the structures of the end cap and the insertion core are improved, and the end cap is changed into a structure with one frustum-shaped end from a traditional cylindrical structure, so that the cooling area of the insertion core can be effectively extended, the cooling capacity of the whole laser output head is increased, and the output and application requirements of tens of thousands of watts of laser can be fully met.

Description

Laser output head

Technical Field

The invention relates to the technical field of lasers, in particular to a laser output head.

Background

In recent years, with the rapid development of the application field of laser processing, the types of lasers, especially fiber lasers, are increasing and the power is increasing. Especially, after the output power of the optical fiber laser breaks through ten thousand watts, tens of thousands of watts or even hundreds of thousands of watts of optical fiber lasers appear in the market quickly. In the current general technology, in order to realize high-power laser output of tens of thousands of watts, each large laser manufacturer carries out power beam combination through a plurality of laser modules, namely, a multi-module laser. After the laser beam combination, through laser transmission optical cable with laser output to processing end, processing equipment such as cutting head, welding head promptly. Generally, the part of the laser transmission cable used for connecting with the processing equipment is called a laser output head, and the output head comprises a mechanical shell and optical devices, wherein the optical devices comprise end caps, energy transmission optical fibers and the like.

In the processing process, the light is reflected by materials, the compatibility problem of the output head is solved, and larger return light is inevitably caused, and the return light can directly irradiate the outer shell of the output head and even enter the output head, which is also the reason that water cooling must be introduced into the output head of the high-power output optical cable. However, with the development of lasers, the output power is continuously increased, and the return light power is further increased. In the prior art, the general water cooling technology is difficult to meet the requirement, and the output head is often burnt due to overheating in the field of high-power lasers.

Because traditional end cap main part is cylindric, is subject to the end cap volume great, and the casing size is subject to the application end restriction, and the cooling casing is outside only passing the ability optic fibre generally, hardly extends to around the end cap, when return light shines near the end cap casing, can not in time dispel the heat by the heat after being absorbed and converted into heat energy by the casing, can lead to near the end cap, especially near the generating heat of passing ability optic fibre part serious.

In view of the above, the existing heat dissipation manner of the end cap is continuously improved to meet the output application requirement of high power laser.

Disclosure of Invention

Aiming at the defect that the end cap in the laser output head cannot be effectively cooled in the prior art, the embodiment of the invention provides a novel laser output head.

The invention provides a laser output head, at least comprising: an end cap and a ferrule; the end cap is composed of a cylindrical output end and a frustum-shaped input end, the small-diameter end of the frustum-shaped input end is connected with the output end of the optical fiber, and the large-diameter end of the frustum-shaped input end is welded with one end of the cylindrical output end; the frustum angle of the frustum-shaped input end is larger than the laser divergence angle of laser transmitted in the end cap, and the diameter of the large-diameter end of the frustum-shaped input end is smaller than that of the cylindrical output end; the lock pin is positioned on the outer side of the end cap, and the inner wall of the lock pin is in clearance fit with the outer wall of the frustum-shaped input end.

According to the laser output head provided by the invention, between the cylindrical output end and the frustum-shaped input end, the laser output head further comprises: attaching a cylindrical output end; the diameter of the additional cylindrical output end is smaller than that of the cylindrical output end and not smaller than that of the large-diameter end of the frustum-shaped input end.

According to the laser output head provided by the invention, the inner wall of the insertion core is attached to the outer wall of the additional cylindrical output end.

According to the laser output head provided by the invention, the insertion core comprises a cooling water channel or a cooling air channel.

According to the laser output head provided by the invention, under the condition that the insert core comprises the cooling water channels, the surface of the insert core is provided with the multi-water-channel backflow structure belts, and each backflow structure belt is embedded with the radiating fin.

According to the laser output head provided by the invention, the two connecting ends of the cooling water channel and the main body are sealed by adopting a laser welding process, and a welding groove is arranged at the welding position.

According to the laser output head provided by the invention, the laser output head also comprises a light mould stripper, a light reflecting pad and an optical fiber fixing joint which are sleeved on the optical fiber and coaxially arranged; the light stripping device is suspended between the small-diameter end of the frustum-shaped input end and the light reflecting pad; and the optical fiber stripping point of the optical stripper is positioned between the light reflecting pad and the optical fiber fixing joint.

According to the laser output head provided by the invention, the reflecting pad is made of metal or glass, and the surface of the reflecting pad is plated with the reflecting coating.

According to the laser output head provided by the invention, the inner wall of the ferrule is formed after sand blasting texturing treatment.

According to the laser output head provided by the invention, the armored sleeve is sleeved at the tail part of the optical fiber of the laser output head, and the armored sleeve and the main body are locked in a threaded screwing mode.

According to the laser output head provided by the invention, the structures of the end cap and the insertion core are improved, and the end cap is changed into a structure with one frustum-shaped end from a traditional cylindrical structure, so that the cooling area of the insertion core can be effectively extended, the cooling capacity of the whole laser output head is increased, and the output and application requirements of tens of thousands of watts of laser can be fully met.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a conventional endcap of the prior art;

FIG. 2 is one of the schematic structural illustrations of the endcap provided in the present invention;

FIG. 3 is one of the schematic illustrations of laser light delivery in an end cap provided by the present invention;

FIG. 4 is one of the schematic diagrams of the ferrule and the end cap cooperating to achieve laser transmission and heat dissipation;

FIG. 5 is a schematic diagram of a laser output head according to the present invention;

FIG. 6 is a second schematic structural view of an endcap according to the present invention;

FIG. 7 is a second schematic illustration of laser light delivery in an end cap provided by the present invention;

FIG. 8 is a second schematic diagram of the ferrule and the end cap cooperating to achieve laser transmission and heat dissipation;

FIG. 9 is a second schematic structural view of a laser output head according to the present invention;

FIG. 10 is a schematic perspective view of a laser output head provided in accordance with the present invention;

FIG. 11 is a schematic view of a water-cooled welded seal arrangement provided by the present invention;

FIG. 12 is one of the schematic diagrams of the welding grooves at the two ends of the water channel provided by the present invention;

fig. 13 is a second schematic view of the welding grooves at the two ends of the water channel provided by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that in the description of the embodiments of the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. The terms "upper", "lower", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may 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 meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the laser transmission optical cable, the main structure of the optical system is an end cap and an energy transmission optical fiber, wherein the energy transmission optical fiber is used for transmitting high-power laser, and the end cap is generally made of high-purity fused quartz. The function of the end cap is mainly two points: firstly, a high-transmittance film is plated on the output surface of the end cap to inhibit Fresnel reflection of the end surface; and secondly, the laser output by the energy transfer optical fiber is divergent light, so that the laser output surface is a large light spot, the power density can be reduced, and the probability of the end surface being damaged by the laser is reduced.

Fig. 1 is a schematic structural diagram of a conventional end cap in the prior art, and as shown in fig. 1, a main structure of an optical portion of a laser output head of a conventional laser transmission cable mainly includes: the optical fiber connector comprises an end cap arranged at the output end of the optical fiber and a core insert for radiating the end cap. The end cap is cylindrical, an antireflection film is plated at the laser output end of the end cap, and the surface is generally called a film coating surface; the other end of the end cap is connected to the energy transmitting fiber by fusion splicing, which is commonly referred to as the splice end.

Because the diameter of the end cap is much larger than the diameter of the optical fiber, the fusion splice is made easier by reducing the diameter of the fusion splice end, while the main body of the end cap remains cylindrical. As shown in FIG. 1, the divergence angle of the output laser light is θ₀The divergence angle of the laser transmitted in the end cap is theta₁，sinθ₀＝n*sinθ₁And n is the refractive index of the end cap material at the current output laser wavelength.

Because the main body of the end cap in the prior art is cylindrical, the size of the end cap is limited by the larger volume of the end cap, and the size of the laser output head shell is limited by the application end, the water-cooled (or air-cooled) shell can only extend to the outside of the energy transmission optical fiber generally and is difficult to extend to the periphery of the end cap. Therefore, when the return light irradiates the shell near the end cap and is absorbed and converted into heat energy by the shell, the part is not cooled by water, and the heat generation near the end cap is serious. In particular, the end cap is close to the part of the energy transmission fiber where the laser light is not transmitted, which does not play a role in the optical system, but the heat generation is particularly significant.

In view of the defects existing in the current general design of the end cap, the laser output head provided by the invention mainly realizes the purpose of extending the water cooling (or air cooling) of the ferrule to the film coating output end of the end cap by improving the structure of the end cap, so that the heat dissipation capacity of the shell near the end cap is greatly improved, and meanwhile, the diameter of the welding end is close to that of the energy transmission optical fiber, and the welding difficulty is not increased.

The specific structure of the laser output head provided by the embodiment of the present invention is described below with reference to fig. 2 to 13.

As an alternative embodiment, the present invention provides a laser output head, comprising at least: an end cap and a ferrule; the end cap is composed of a cylindrical output end and a frustum-shaped input end, the small-diameter end of the frustum-shaped input end is connected with the output end of the optical fiber, and the large-diameter end of the frustum-shaped input end is welded with one end of the cylindrical output end; the frustum angle of the frustum-shaped input end is larger than the laser divergence angle of laser transmitted in the end cap, and the diameter of the large-diameter end of the frustum-shaped input end is smaller than that of the cylindrical output end; the lock pin is positioned on the outer side of the end cap, and the inner wall of the lock pin is in clearance fit with the outer wall of the frustum-shaped input end.

Fig. 2 is a schematic structural diagram of the end cap provided by the present invention, and as shown in fig. 2, the end cap 120 provided by the present invention is designed into two parts based on the original cylindrical shape, wherein the part near the laser output end is still cylindrical output end, but near the fiber splicing end is designed into a frustum-shaped input end 119.

Fig. 3 is a schematic diagram of laser transmission in the end cap of the present invention, as shown in fig. 3, the large diameter end of the frustum-shaped input end 119 is fused with a cylindrical section of the cylindrical output end, and the small diameter end of the frustum-shaped input end 119 is fused with the output end of the optical fiber.

Note that, as shown in fig. 3, in order to ensure normal transmission of the laser light, the frustum angle θ of the frustum-shaped input end 119 is set₂Greater than the laser divergence angle theta of the laser light propagating in the end cap₁. And the diameter of the large-diameter end of the frustum-shaped input end is smaller than or equal to that of the cylindrical output end. On the whole light path, the output end of the optical fiber is connected with the small-diameter end of the frustum-shaped input end, the large-diameter end of the frustum-shaped input end is welded on one end face of the cylindrical output end, and the other end face of the cylindrical output end is plated with an antireflection film and used as the laser output end of the laser output head.

Optionally, the cylindrical output end and the frustum-shaped input end may be fused to form the end cap of the present invention, or may be integrally formed to form the end cap of the present invention.

Fig. 4 is one of schematic diagrams illustrating that the ferrule and the end cap cooperate with each other to achieve laser transmission and heat dissipation, as shown in fig. 4, since the frustum-shaped input end of the end cap is located near the fiber splicing end in the laser output head provided by the present invention, the ferrule used for cooling may extend the portion related to water cooling (or other cooling methods) to the film coating surface of the end cap without increasing the volume of the whole laser output head and affecting the optical performance of the whole end cap, for example: the inner wall of the ferrule is in clearance fit with the outer wall of the frustum-shaped input end, so that the heat dissipation capacity of the shell near the end cap is greatly improved, the diameter of the welding end of the end cap and the optical fiber is close to the diameter of the optical fiber, and the welding difficulty cannot be increased.

Fig. 5 is a schematic structural diagram of a laser output head provided by the present invention, and as shown in fig. 5, the laser output head provided by the present invention mainly includes, but is not limited to: an end cap 120, a ferrule 101, a body 102, a ferrule 103, a light reflecting pad 108, two water cooled

joints

112 and 113, locking caps 11 and 113 corresponding to the water cooled joints, an armor sleeve 105, a locking cap 106, an armor cable 107, an optical fiber 109, and the like. According to the laser output head provided by the invention, the end cap 120 is designed into a structure that the cylindrical output end close to the light-emitting surface is large and the end close to the fusion point is small and is fused with the frustum-shaped input end, so that the water-cooling area of the ferrule 101 can extend to the periphery of the end cap, the inner wall of the ferrule is ensured to be in clearance fit with the outer wall of the frustum-shaped input end, and further most of the axial area of the periphery of most of the end cap is covered.

Based on the content of the foregoing embodiment, as an optional embodiment, between the cylindrical output end and the frustum-shaped input end, the method further includes: attaching a cylindrical output end; the diameter of the additional cylindrical output end is smaller than that of the cylindrical output end and not smaller than that of the large-diameter end of the frustum-shaped input end.

Fig. 6 is a second schematic structural view of the end cap according to the present invention, and as shown in fig. 6, the end cap can be regarded as being composed of three parts in the laser output head according to the present invention. Specifically, a cylindrical output end, an additional cylindrical output end 100, and a frustum-shaped input end, which are sequentially welded on the optical path, are included.

Fig. 7 is a second schematic diagram illustrating laser transmission in the end cap of the present invention, and as shown in fig. 7, because the processing difficulty of the frustum-shaped input end located at the welding end of the end cap is high, the end cap of the present invention can be simplified into the structure shown in fig. 6 by introducing a diameter D between the cylindrical output end and the frustum-shaped input end₁The cylinder smaller than the diameter of the cylindrical output end simultaneously keeps a welding end with the diameter similar to that of the optical fiber on the basis of realizing the purpose of water-cooling forward movement of the inserting core.

Based on the content of the above embodiment, as an optional embodiment, the inner wall of the ferrule is attached to the outer wall of the additional cylindrical output end.

Fig. 8 is a second schematic diagram illustrating the mutual cooperation of the ferrule and the end cap to achieve laser transmission and heat dissipation, and as shown in fig. 8, the end cap provided by the present invention can be used to cool the ferrule towards the coating surface. Specifically, on the basis that the inner wall of the ferrule is in clearance fit with the outer wall of the frustum-shaped input end, the inner wall of the ferrule is further in clearance fit with the outer wall of the additional cylindrical output end 100, so that the heat dissipation capacity of the shell near the end cap is greatly improved, the diameter of the welding end of the end cap and the optical fiber is close to the diameter of the optical fiber, and the welding difficulty cannot be increased.

Fig. 9 is a second schematic structural diagram of the laser output head provided by the present invention, and fig. 10 is a schematic perspective view of the laser output head provided by the present invention, as shown in fig. 9 and fig. 10, the laser output head provided by the present invention mainly includes, but is not limited to: end cap 114, ferrule 101, body 102, ferrule 103, reflective gasket 108, two water cooled

fittings

112 and 113, locking caps 11 and 113 corresponding to the water cooled fittings, armor sleeve 105, locking cap 106, armor cable 107, and optical fiber 109, among others. According to the laser output head provided by the invention, the end cap 120 is designed into a structure that the cylindrical output end close to the light-emitting surface is large and the end close to the fusion point is small and is fused with the frustum-shaped input end, so that the water-cooling area of the ferrule 101 can extend to the periphery of the end cap, the inner wall of the ferrule is ensured to be in clearance fit with the outer wall of the frustum-shaped input end, and further most of the axial area of the periphery of most of the end cap is covered.

Based on the above description of the embodiments, as an alternative embodiment, the ferrule includes a cooling water channel or a cooling air channel.

Further, in the case where the ferrule includes a cooling water passage, the surface of the ferrule is provided with a multi-passage backflow structure belt 104, and a heat radiation fin is embedded on each backflow structure belt 104.

For example, as shown in fig. 5 or 9, when returning light enters the

end cap

114 or 120, the laser light transmitted through the

end cap

114 or 120 is scattered to the inner wall surface of the ferrule 101 in the form of scattered light, and the scattered light is absorbed by the ferrule 101 and then converted into heat, which is carried away by circulating cooling water on the outer surface of the ferrule 101.

Further, the surface of the ferrule 101 adopts a multi-channel backflow structure belt 104 with a plurality of fins to increase the heat dissipation area. The water-cooling

joints

110 and 112 adopt an inclined-through structure, and the closer the included angle between the water-cooling

joints

110 and 112 is to 0 degree, the more beneficial the flow is to be improved. The external water pipe and the water-cooling

joints

110 and 112 are locked by the locking caps 111 and 113 in a threaded and quick-screwing manner. Wherein, the water-cooling

joints

110 and 112 are used for externally connecting circulating water.

Further, under the condition that the surface of the ferrule 101 adopts an air-cooled heat dissipation device, the air-cooled heat dissipation device mainly comprises fins and at least one fan; the fins are embedded in the periphery of the inserting core, are in contact with the main body sleeve and are used for receiving heat conducted by the inserting core; the fan is fixedly arranged on the outer side of the fin and used for carrying out air cooling heat dissipation on the fin.

According to the laser output head provided by the invention, the surface of the insertion core is additionally provided with the water channel or the radiating fin so as to increase the radiating efficiency of the insertion core, thereby ensuring that the laser output head works at a normal temperature and avoiding the output head from being burnt out due to overheating.

Based on the content of the above embodiment, as an optional embodiment, the two connecting ends of the cooling water channel and the main body are sealed by a laser welding process, and a welding groove is arranged at the welding position.

Fig. 11 is a schematic view of a water-cooling welding sealing structure provided by the present invention, a sealing manner of two ends of a water channel of a ferrule of a conventional laser output head is generally a mechanical sealing manner using a rubber sealing member, and as shown in fig. 11, two ends of a water channel of a ferrule 101 provided by the present invention are sealed by using a laser welding process to reduce a heat affected zone.

Because laser welding can realize the connection of many types of materials, and laser welding usually has incomparable superiority with other fusion welding processes, for some thin-walled workpiece materials that are difficult to weld, the deformation after welding is little, can produce very high average temperature in very little area. The advantage of laser welding over mechanical seals is that it enables superior sealing with smaller wall thickness dimensions, increasing the pressure and temperature resistance of the

seal areas

115 and 117 without concern for seal aging. In addition, under the conditions of high temperature and low temperature, the welded structure is more difficult to deform compared with a mechanical sealing structure, so that sealing failure cannot be caused.

Furthermore, the ferrule 101 provided by the invention can be made of red copper or brass, the copper material adopted by the ferrule 101 has the advantages of higher reflectivity to laser and capability of avoiding local heat accumulation effect, and the main body 102 can be made of stainless steel. Because pure copper welding wires or stainless steel welding wires can generate heat cracks and embrittlement, a brazing process is required for welding two dissimilar metals, and a silver-based silver brazing filler metal is preferably adopted.

During operation, the ferrule 101 is heated to a temperature of the melting point of the silver solder and can be stuck, and then the welding gun swings to the main body 102. When the stainless steel body 102 is welded to the copper ferrule 101, since copper dissipates heat much faster than stainless steel, the arc must be deflected to the copper ferrule 101 side during welding.

Optionally, in order to improve the light-heat conversion absorption efficiency, the ferrule 101 may also be made of stainless steel, that is, the ferrule 101 and the main body 102 are made of the same stainless steel, so that the welding is easier and the welding strength is ensured.

If no filler wire welding is adopted and a thermal welding process is adopted, the fit clearance between the ferrule 101 and the two ends of the main body 102 is controlled within 0.05mm, and the thermal welding has the advantages of small influence on fit dimensional tolerance after welding and no need of any post-treatment process.

Before welding, the relative axial and radial positions and the accuracy of the ferrule 101 and the body 102 must be ensured, and the ferrule and the body must be used in a pre-tensioned state in order for the welding process to be carried out. In order to ensure the pre-tightening strength of the ferrule 101 and the body 102, the ferrule 103 shown in fig. 5 or 9 may be locked by means of a tool.

The specific method comprises the steps of connecting the clamping sleeve 103 with the main body 102, installing the ferrule 101 into the main body 102, adjusting the radial position of the ferrule 101, locking the clamping sleeve 103 by using a tool, and pressing the end part of the ferrule 101 through the end part of the tool to generate axial pretightening force, so that the ferrule 101 can be attached to the conical surface of the front end of the main body 102, and the assembly precision is guaranteed.

Fig. 12 is a schematic view of a welding groove at two ends of a water channel provided by the present invention, and fig. 13 is a schematic view of a welding groove at two ends of a water channel provided by the present invention, as shown in fig. 12 or fig. 13, a

certain welding groove

121 or 122 may be designed at two ends of a ferrule 101, and a gap formed by the

welding groove

121 or 122 can bear more solder, so that the base material is more easily welded through, the welding is more sufficient, and the welding strength is more easily ensured.

Based on the content of the above embodiments, as an alternative embodiment, as shown in fig. 5, 9 and 11, the laser output head further includes a stripper 116, a reflective pad 108 and a fiber fixing joint 118, which are coaxially disposed on the optical fiber 109; the optical stripper 116 is suspended between the small diameter end of the frustum-shaped input end and the reflective pad 108; the fiber stripping point of the stripper 116 is located between the light reflecting pad 108 and the fiber securing tab 118.

Further, the reflective pad 108 is made of metal or glass, and a reflective coating is plated on the surface of the reflective pad 108.

Specifically, the reflective pad 108 inside the ferrule 101 is made of a metal material or a glass material, and the surface of the reflective pad is plated with a reflective coating, so that the reflectivity is generally over 90%.

When the output head cuts a high-reflection material, return light is generated, the return light penetrating through the

end cap

114 or 120 and scattered light stripped by the optical fiber stripper can block laser under the action of the light reflecting pad 108, so that the laser irradiates the inner wall surface of the water cooling area of the ferrule 101, and the laser is prevented from entering a stripping point area at the rear end of the output head.

The reflective pad 108 has strict concentricity requirements with the

end cap

114 or 120 and thus can be assembled with the body 102 with an interference fit.

The reflective pad 108 has a coaxial aperture inside, which is the passage for the optical fiber 109, and for the return light, this aperture is also the aperture.

The region of the optical fiber 109 where the stripper 116 is located is suspended in the region between the fusion splice of the

end cap

114 or 120 and the light reflecting pad 108, which is very demanding in terms of processing and cleanliness. The optical fiber 109 is fixed by injecting glue through the optical fiber fixing joint 118, so that the mold stripper 116 is in a coaxial and stretched state, and the optical fiber stripping point is located between the light reflecting pad 108 and the glue dispensing opening of the optical fiber fixing joint 118.

The cylindrical output end of the

end cap

114 or 120 and the ferrule 101 have high-precision radial fit requirements, and the end of the

end cap

114 or 120 and the end of the ferrule 101 have axial limit positions, so that the coaxiality of the

end cap

114 or 120 is ensured, the angular offset error of the end cap is reduced, and the pointing error of a light beam is reduced.

The cylindrical output end of the

end cap

114 or 120 is fixed with the ferrule 101 by glue. The tail cone 119 or the tail post 100 of the

end cap

114 or 120 is in large clearance fit with the inner wall of the ferrule 101, is not in contact with the inner wall of the ferrule 101, and is in a suspended state.

The clamping sleeve 103 is connected with the main body 102 through a fastener, has high coaxiality requirement, is used for realizing mechanical matching with a cutting head or a welding head, and can realize self-centering by the conical surface so as to ensure the coaxiality requirement.

Based on the content of the above embodiment, as an alternative embodiment, the inner wall of the ferrule is formed after sand blasting texturing.

According to the laser output head provided by the invention, the inner wall of the ferrule 101 is designed with a texturing structure or is processed by a texturing process, so that the thermal distribution homogenization is facilitated, and the axial temperature gradient is further reduced.

Alternatively, the inner wall surface of the ferrule 101 may be machined into a threaded structure, and the threaded structure may be roughened to increase the laser absorption area and facilitate heat propagation.

Based on the content of the above embodiment, as an alternative embodiment, the armored sleeve 105 is sleeved on the tail portion of the optical fiber of the laser output head, and the armored sleeve 105 is locked with the main body 102 in a screwing manner.

In particular, the sheathing sleeve 105 is used to mechanically connect the sheathing 107 while using a threaded connection and seal with the body 102, and the locking cap 106 is used to seal the sheathing 107.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A laser output head, comprising at least: an end cap and a ferrule;

the end cap is composed of a cylindrical output end and a frustum-shaped input end, the small-diameter end of the frustum-shaped input end is connected with the output end of the optical fiber, and the large-diameter end of the frustum-shaped input end is welded with one end of the cylindrical output end;

the frustum angle of the frustum-shaped input end is larger than the laser divergence angle of laser transmitted in the end cap, and the diameter of the large-diameter end of the frustum-shaped input end is smaller than that of the cylindrical output end;

the insertion core is located on the outer side of the end cap, and the inner wall of the insertion core is in clearance fit with the outer wall of the frustum-shaped input end.

2. The laser output head as set forth in claim 1, further comprising, between the cylindrical output end and the frustum-shaped input end: attaching a cylindrical output end;

the diameter of the additional cylindrical output end is smaller than that of the cylindrical output end and not smaller than the diameter of the large-diameter end of the frustum-shaped input end.

3. The laser output head as set forth in claim 2, wherein the inner wall of the ferrule abuts the outer wall of the additional cylindrical output end.

4. The laser output head according to claim 1 or 2, wherein the ferrule includes a cooling water channel or a cooling air channel.

5. The laser output head according to claim 4, wherein, in the case where the ferrule includes cooling water channels, the surface of the ferrule is provided with multi-channel backflow structure strips, and a heat dissipation fin is embedded on each backflow structure strip.

6. The laser output head as claimed in claim 5, wherein the two connecting ends of the cooling water channel and the main body are sealed by laser welding, and a welding groove is provided at the welding position.

7. The laser output head as claimed in claim 1 or 2, further comprising a light stripping device, a light reflecting pad and a fiber fixing joint which are coaxially arranged and sleeved on the optical fiber;

the light stripping device is arranged between the small-diameter end of the frustum-shaped input end and the light reflecting pad in a hanging manner; and the optical fiber stripping point of the optical stripper is positioned between the light reflecting pad and the optical fiber fixing joint.

8. The laser output head according to claim 7, wherein the reflective pad is made of metal or glass, and a reflective coating is coated on the surface of the reflective pad.

9. The laser output head according to claim 1 or 2, wherein the inner wall of the ferrule is formed after a sand blasting texturing process.

10. The laser output head of claim 1 or 2, wherein an armored sleeve is sleeved on the tail of the optical fiber of the laser output head, and the armored sleeve is locked with the main body in a threaded manner.