WO2022179230A1

WO2022179230A1 - Laser output head

Info

Publication number: WO2022179230A1
Application number: PCT/CN2021/135069
Authority: WO
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: 武汉锐科光纤激光技术股份有限公司
Priority date: 2021-02-24
Filing date: 2021-12-02
Publication date: 2022-09-01
Also published as: CN113067236A; DE112021005991T5

Abstract

Provided is a laser output head, at least comprising: an end cap and an insert core, wherein the end cap is composed of a cylindrical output end and a frustum-shaped input end; the smaller-diameter end of the frustum-shaped input end is connected to the output end of an optical fiber, and the larger-diameter end of the frustum-shaped input end is fusion-welded to one end of the cylindrical output end; the angle of frustum of the frustum-shaped input end is greater than the angle of divergence of laser transmitted in the end cap, and the diameter of the larger-diameter end of the frustum-shaped input end is smaller than the diameter of the cylindrical output end; and the insert core is located on the outer side of the end cap, and an inner wall of the insert core is ensured to be in clearance-fit with an outer wall of the frustum-shaped input end. In the laser output head provided in the present application, the structure of the end cap and the insert core is improved to change the structure of the end cap from a conventional cylindrical structure to a structure having a frustum-shaped end, such that a cooling region of the insert core can be effectively extended, which increases the cooling capacity for the entire laser output head and can fully satisfy the requirements of output and application of a laser of tens of thousands of watts.

Description

Laser output head

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese patent application with the application number 202110210013.1 filed on February 24, 2021, and the invention title is "a laser output head", which is fully incorporated herein by reference.

technical field

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

Background technique

In recent years, with the rapid development of the application field of laser processing, the types of lasers, especially fiber lasers, have been continuously increased, and the power has been continuously improved. In particular, after the output power of fiber lasers exceeded 10,000 watts, tens of thousands or even 100,000 watts of fiber lasers soon appeared on the market. At present, in order to achieve high-power laser output of tens of thousands of watts, major laser manufacturers currently combine power through multiple laser modules, that is, multi-module lasers. After the laser beam is combined, the laser is output to the processing end through the laser transmission cable, that is, the cutting head, welding head and other processing equipment. Generally speaking, the part of the laser transmission cable used to connect the processing equipment is called the laser output head, and the output head contains the mechanical housing and optical devices, wherein the optical devices include end caps, energy transmission fibers, etc.

In the process of processing, due to the reflection of the material and the compatibility of the output head, a large return light is inevitably caused. This part of the return light will directly illuminate the outer shell of the output head, and even enter the inside of the output head, which is also high. The reason why water cooling must be introduced into the output head of the power output cable. However, with the development of lasers, the output power has been continuously improved, and the return optical power has been further improved. In the current technology, the general water cooling technology has been difficult to meet the demand, which also leads to the fact that in the field of high-power lasers, the output head often burns out due to overheating.

Since the main body of the traditional end cap is cylindrical, it is limited by the large volume of the end cap, and the size of the shell is limited by the application end. The cooling shell generally only extends outside the energy transmission fiber, and it is difficult to extend around the end cap. When there is a return When light is irradiated to the shell near the end cap, it cannot be dissipated in time after being absorbed and converted into heat energy by the shell, which will cause serious heat generation near the end cap, especially near the energy transfer fiber.

In view of this, the existing end cap heat dissipation methods continue to be improved to meet the output application requirements of high-power lasers.

SUMMARY OF THE INVENTION

Aiming at the defect in the prior art that the end cap in the laser output head cannot be effectively dissipated, the embodiment of the present application provides a new laser output head.

The application provides a laser output head, which at least includes: an end cap and a ferrule; the end cap is composed of a cylindrical output end and a frustoconical input end, the small diameter end of the frustoconical input end is connected to the output end of an optical fiber, and the frustoconical input end is connected to the output end of the optical fiber. The large-diameter end of the input end is welded with one end of the cylindrical output end; the frustum angle of the frustum-shaped input end is greater than the laser divergence angle transmitted by the laser in the end cap, and the diameter of the large-diameter end of the frustum-shaped input end is smaller than the The diameter of the cylindrical output end; the ferrule is located on the outside of the end cap, and the inner wall of the ferrule and the outer wall of the frusto-conical input end are guaranteed to fit in clearance.

According to a laser output head provided by the present application, between the cylindrical output end and the frustoconical input end, further comprising: an additional cylindrical output end; the diameter of the additional cylindrical output end is smaller than the diameter of the cylindrical output end, and Not less than the diameter of the large diameter end of the frustoconical input end.

According to a laser output head provided by the present application, the inner wall of the ferrule is abutted with the outer wall of the additional cylindrical output end.

According to a laser output head provided by the present application, the ferrule includes a cooling water channel or a cooling air channel.

According to a laser output head provided by the present application, when the ferrule includes cooling water channels, the surface of the ferrule is provided with multi-channel return structure strips, and heat dissipation fins are embedded on each return structure strip.

According to a laser output head provided by the present application, 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 provided at the welding place.

According to a laser output head provided by the present application, the laser output head further comprises an optical stripper, a reflective pad and an optical fiber fixed joint which are sheathed on the optical fiber and are arranged coaxially; between the small diameter end of the end and the reflective pad; the optical fiber stripping point of the optical stripper is located between the reflective pad and the optical fiber fixed joint.

According to a laser output head provided by the present application, the reflective pad is made of metal material or glass material, and a reflective coating is plated on the surface of the reflective pad.

According to a laser output head provided by the present application, the inner wall of the ferrule is formed by sandblasting and texturing.

According to a laser output head provided by the present application, an armored sleeve is sheathed at the optical fiber tail of the laser output head, and the armored sleeve and the main body are locked by screwing together.

In the laser output head provided by the present application, by improving the structure of the end cap and the ferrule, the end cap is changed from a traditional cylindrical structure to a truncated cone-shaped structure at one end, so that the cooling area of the ferrule can be effectively extended, increasing the The cooling capacity of the entire laser output head can fully meet the output and application requirements of tens of thousands of watts of laser light.

Description of drawings

In order to illustrate the technical solutions in the present application or the prior art more clearly, the following briefly introduces the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are the For some embodiments of the application, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the structural representation of the conventional end cap in the prior art;

Fig. 2 is one of the structural representations of the end cap provided by the application;

Fig. 3 is one of the schematic diagrams of laser transmission in the end cap provided by this application;

FIG. 4 is one of the schematic diagrams of the ferrule and the end cap provided by the present application to realize laser transmission and heat dissipation;

Fig. 5 is one of the structural schematic diagrams of the laser output head provided by the present application;

Fig. 6 is the second structural schematic diagram of the end cap provided by the present application;

Fig. 7 is the second schematic diagram of laser transmission in the end cap provided by this application;

FIG. 8 is the second schematic diagram of the ferrule and the end cap provided by the present application to realize laser transmission and heat dissipation;

FIG. 9 is the second schematic diagram of the structure of the laser output head provided by the present application;

Fig. 10 is the three-dimensional appearance schematic diagram of the laser output head provided by this application;

11 is a schematic diagram of a water-cooled welded sealing structure provided by the present application;

12 is one of the schematic diagrams of the welding grooves at both ends of the water channel provided by the application;

FIG. 13 is the second schematic diagram of the welding groove at both ends of the water channel provided by the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the accompanying drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application. , not all examples. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

It should be noted that, in the description of the embodiments of the present application, the terms "comprising", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements Not only those elements are included, but other elements not expressly listed or inherent to such a process, method, article or apparatus are also included. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or element must be It has a specific orientation, is constructed and operates in a specific orientation, and therefore should not be construed as a limitation of the present application. Unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, It can also be an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood 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 fiber. The energy transmission fiber is used to transmit high-power laser light, and the end cap is generally made of high-purity fused silica. When the laser is transmitted in the end cap , the loss is basically negligible, so the forward light is transmitted in the end cap and basically does not heat up. There are two main functions of setting the end cap: one is to coat the output surface of the end cap with a high-transmission film to suppress the Fresnel reflection of the end surface; It is a larger spot, which can reduce the power density and reduce the probability of the end face being damaged by the laser.

FIG. 1 is a schematic structural diagram of a conventional end cap in the prior art. As shown in FIG. 1 , the main structure of the optical part of the laser output head of the existing laser transmission optical cable mainly includes: an end cap arranged at the output end of the optical fiber and a heat dissipation for the end cap. the ferrule. Among them, the shape of the end cap is cylindrical, and the laser output end of the end cap is coated with an anti-reflection coating, which is generally referred to as the coating surface; the other end of the end cap is connected to the energy-transmitting optical fiber by welding, and this part is generally It is called the welded end.

Since the diameter of the end cap is much larger than the diameter of the optical fiber, the diameter of the fusion splicing end is reduced to make it easier to splicing, while the main part of the end cap is still cylindrical. As shown in Figure 1, the divergence angle of the output laser is θ ₀ , the laser divergence angle of the laser transmitted in the end cap is θ ₁ , sinθ ₀ =n*sinθ ₁ , where n is the end cap material at the current output laser wavelength refractive index.

Since the main body of the end cap in the prior art is cylindrical, it is limited by the large volume of the end cap, and the size of the shell of the laser output head is limited by the application end, and its water-cooled (or air-cooled) shell can generally only extend to It is difficult to extend around the end cap outside of the energy-transmitting fiber. Therefore, when the returning light irradiates the casing near the end cap and is absorbed and converted into heat energy by the casing, this part has no water cooling to dissipate heat, which will cause serious heat generation near the end cap. In particular, the end cap is close to the part of the energy transmission fiber, where the laser is not transmitted, and this part does not play a role in the optical system, but the heat generation is particularly significant.

In view of the defects in the current general design of the end cap, the laser output head provided by this application, by improving the structure of the end cap, mainly realizes the water cooling (or air cooling) of the ferrule to the coating output of the end cap. The end is extended, so that the heat dissipation capacity of the shell near the end cap is greatly improved, and the diameter of the fusion end is close to the diameter of the energy transmission fiber, which does not increase the difficulty of fusion.

The specific structure of the laser output head provided by the embodiments of the present application will be described below with reference to FIGS. 2 to 13 .

As an optional embodiment, the laser output head provided by the present application at least includes: an end cap and a ferrule; wherein, the end cap is composed of a cylindrical output end and a frustoconical input end, and the small diameter end of the frustoconical input end is The output end of the optical fiber is connected, and the large diameter end of the frustum input end is fused with one end of the cylindrical output end; the frustum angle of the frustum input end is greater than the laser divergence angle of the laser transmitted in the end cap, and the large diameter of the frustum input end is larger. The diameter of the radial end is smaller than the diameter of the cylindrical output end; the ferrule is located on the outside of the end cap, and the inner wall of the ferrule and the outer wall of the frusto-conical input end are guaranteed to fit in clearance.

Fig. 2 is one of the structural schematic diagrams of the end cap provided by the present application. As shown in Fig. 2, the end cap 120 provided by the present application is designed into two parts on the basis of the original cylindrical shape, and the part close to the laser output end It is still a cylindrical output end, but is designed as a frusto-conical input end 119 near the fiber fusion splicing end.

Fig. 3 is one of the schematic diagrams of laser transmission in the end cap provided by the present application. As shown in Fig. 3, the large diameter end of the frustoconical input end 119 is welded with a cylindrical section of the cylindrical output end, and the frustoconical input end 119 The small diameter end of the optic fiber is spliced with the output end of the fiber.

It should be noted that, as shown in FIG. 3 , in order to ensure the normal transmission of the laser, the frustum angle θ ₂ of the frustum input end 119 is greater than the laser divergence angle θ ₁ of the laser transmitted in the end cap. Moreover, the diameter of the large diameter end of the frustoconical input end is smaller than or equal to the diameter of the cylindrical output end. In the entire optical path, the output end of the optical fiber is connected to the small diameter end of the frustoconical input end, the large diameter end of the frustoconical input end is fused to one end face of the cylindrical output end, and the other end face of the cylindrical output end is plated with antireflection The film is used as the laser output end of the laser output head.

Optionally, the cylindrical output end and the frustoconical input end can be welded to form the end cap provided by the present application, or the end cap provided by the present application can be produced by an integral molding process.

Fig. 4 is one of the schematic diagrams of the ferrule and the end cap provided by the present application to realize laser transmission and heat dissipation. As shown in Fig. 4, because in the laser output head provided by the present application, the cone of the end cap is close to the fusion splicing end of the fiber. The table-type input end, so on the premise of not increasing the volume of the entire laser output head and not affecting the optical performance of the entire end cap, the ferrule used for cooling can direct the water cooling (or other cooling methods) related parts to the end cap. The coating surface is extended, for example, the inner wall of the ferrule and the outer wall of the frustum input end are gap-fitted, so that the heat dissipation capacity of the shell near the end cap is greatly improved, and the diameter of the fusion end of the end cap and the fiber is close to the diameter of the fiber. , will not increase the difficulty of welding.

FIG. 5 is one of the schematic structural diagrams of the laser output head provided by this application. As shown in FIG. 5 , the laser output head provided by this application mainly includes but is not limited to: an end cap 120 , a ferrule 101 , a main body 102 , and a ferrule 103 , reflective pad 108 , two water-cooled

joints

112 and 113 , locking caps 11 and 113 corresponding to the water-cooled joints, armored sleeve 105 , locking cover 106 , armored cable 107 and optical fiber 109 , etc. In the laser output head provided by the present application, the end cap 120 is designed to be a structure in which the end cap 120 is large at one end close to the light-emitting surface and a small cylindrical output end at the end close to the fusion point is fused with the frustoconical input end, so that the water cooling area of the ferrule 101 is formed. It can be extended to the periphery of the end cap to ensure that the inner wall of the ferrule and the outer wall of the frusto-conical input end are in clearance fit, thereby covering most of the peripheral axial area of the end cap.

Based on the content of the above embodiment, as an optional embodiment, between the cylindrical output end and the frustoconical input end, further includes: an additional cylindrical output end; the diameter of the additional cylindrical output end is smaller than the diameter of the cylindrical output end , and not less than the diameter of the large diameter end of the frustoconical input end.

FIG. 6 is the second structural schematic diagram of the end cap provided by the present application. As shown in FIG. 6 , in the laser output head provided by the present application, the end cap can be considered to be composed of three parts. Specifically, it includes a cylindrical output end, an additional cylindrical output end 100 and a frustoconical input end that are sequentially welded on the optical path.

Fig. 7 is the second schematic diagram of laser transmission in the end cap provided by the present application. As shown in Fig. 7, since the processing of the frusto-conical input end located at the welding end of the end cap is relatively difficult, the end cap provided by the present application can be The structure of the end cap is simplified to the structure shown in Figure 6. By introducing a cylinder with a diameter D ₁ smaller than the diameter of the cylindrical output end between the cylindrical output end and the frusto-conical input end, the water cooling of the ferrule can be achieved. On the basis of the purpose, at the same time, a fusion splicing end with a diameter similar to the fiber is retained.

Based on the content of the foregoing embodiment, as an optional embodiment, the inner wall of the ferrule is fitted with the outer wall of the additional cylindrical output end.

FIG. 8 is the second schematic diagram of the ferrule and the end cap provided by the present application to achieve laser transmission and heat dissipation. As shown in FIG. 8 , the end cap provided by the present application can be used to extend the water cooling of the ferrule to the coating surface. Specifically, based on the clearance fit between the inner wall of the ferrule and the outer wall of the frusto-conical input end, the inner wall of the ferrule can be further clearance-fitted with the outer wall of the additional cylindrical output end 100, so that the shell near the end cap can dissipate heat The ability is greatly improved, and the diameter of the fusion end of the end cap and the optical fiber is close to the diameter of the optical fiber, which will not increase the difficulty of fusion.

FIG. 9 is the second structural schematic diagram of the laser output head provided by the present application, and FIG. 10 is a schematic three-dimensional appearance of the laser output head provided by the present application. As shown in FIGS. 9 and 10 , the laser output head provided by the present application mainly includes But not limited to: end cap 114, ferrule 101, main body 102, ferrule 103, reflective pad 108, two

water cooling joints

112 and 113, locking caps 11 and 113 corresponding to the water cooling joints, armored sleeve 105, locking Cover 106, armored cable 107, optical fiber 109, etc. In the laser output head provided by the present application, the end cap 120 is designed to be a structure in which the end cap 120 is large at one end close to the light-emitting surface and a small cylindrical output end at the end close to the fusion point is fused with the frustoconical input end, so that the water cooling area of the ferrule 101 is formed. It can be extended to the periphery of the end cap to ensure that the inner wall of the ferrule and the outer wall of the frusto-conical input end are in clearance fit, thereby covering most of the peripheral axial area of the end cap.

Based on the content of the foregoing embodiment, as an optional embodiment, the ferrule includes a cooling water channel or a cooling air channel.

Further, in the case where the ferrule includes cooling water channels, the surface of the ferrule is provided with multi-channel backflow structure belts 104 , and heat dissipation fins are embedded on each of the backflow structure belts 104 .

Taking FIG. 5 or FIG. 9 as an example, once returning light enters the

end cap

114 or 120, the laser light passing through the

end cap

114 or 120 will be scattered to the inner wall of the ferrule 101 in the form of scattered light, and the scattered light will be absorbed by the ferrule. After 101 is absorbed, it is converted into heat and taken away by the circulating cooling water on the outer surface of the ferrule 101.

Further, the surface of the ferrule 101 adopts a multi-channel return structure belt 104 with a plurality of fins to increase the heat dissipation area. The water-cooling joints 110 and 112 adopt an oblique structure, and the closer the angle between the water-cooling joints 110 and 112 is to 0 degrees, the more favorable it is to increase the flow. The connection between the external water pipe and the water cooling joints 110 and 112 is fastened through the locking caps 111 and 113 by means of quick screwing. Among them, the water cooling joints 110 and 112 are used for external circulating water.

Further, when the surface of the ferrule 101 adopts an air-cooled heat dissipation device, the air-cooled heat dissipation device mainly includes fins and at least one fan; the fins are embedded in the outer circumference of the ferrule and are in contact with the main body sleeve for Receive the heat conducted by the ferrule; the fan is fixed on the outer side of the fins for air cooling and heat dissipation of the fins.

The laser output head provided by this application increases the heat dissipation efficiency of the ferrule by adding water channels or heat dissipation fins on the surface of the ferrule, thereby ensuring that the laser output head works at a normal temperature and avoids the output head being burned 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 provided at the welding place.

Figure 11 is a schematic diagram of the water-cooled welding sealing structure provided by the invention. The conventional sealing method of the two ends of the water channel of the ferrule of the laser output head generally uses rubber seals for mechanical sealing. As shown in Figure 11, the ferrule provided by this application is Both ends of the 101's waterway are sealed with a laser welding process to reduce the heat-affected zone.

Because laser welding can realize the connection of many types of materials, and laser welding usually has incomparable advantages over other fusion welding processes. produces a high average temperature. Therefore, compared with mechanical seals, the advantage of laser welding is that it can achieve better sealing with smaller wall thickness, which improves the pressure bearing capacity and temperature resistance capacity of the sealing

areas

115 and 117 without worrying about the aging of the seals. In addition, under high and low temperature conditions, the welded structure is less prone to deformation than the mechanical seal structure, thereby causing no seal failure.

Further, the material of the ferrule 101 provided in the present application can be made of red copper or brass. The advantage of using copper for the ferrule 101 is that the reflectivity of the laser is high, which can avoid local heat accumulation effect, and the main body 102 can be made of stainless steel. Since pure copper wire or stainless steel wire will produce hot cracks and embrittlement, the welding of two dissimilar metals must use a brazing process, preferably silver-based silver solder.

During the operation, the ferrule 101 should be heated first, and the temperature will reach the melting point of the silver solder before it can stick, and then the welding gun is swung toward the main body 102 . When the stainless steel body 102 and the copper ferrule 101 are welded, since the heat dissipation of copper is much faster than that of stainless steel, the arc must be deflected to the side of the copper ferrule 101 during welding.

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

If wire filler welding is not used, the thermal fusion welding process is used, and the fitting gap between the ferrule 101 and the main body 102 should be controlled within 0.05mm. post-processing process.

Before welding, the relative position and accuracy of the axial and radial directions of the ferrule 101 and the main body 102 must be guaranteed, and the ferrule and the main body must be in a preloaded state for the implementation of the welding process. In order to ensure the pre-tightening strength of the ferrule 101 and the main body 102 , the clamping sleeve 103 shown in FIG. 5 or FIG. 9 can be used for locking by means of a tool.

The specific method is as follows: firstly connect the ferrule 103 to the main body 102, install the ferrule 101 into the main body 102, adjust the radial position of the ferrule 101, use the tool to lock the ferrule 103, and press and insert the ferrule through the end of the tool. The end of the core 101 generates an axial pre-tightening force, so that the ferrule 101 and the tapered surface of the front end of the main body 102 can fit together, thereby ensuring the assembly accuracy.

12 is one of the schematic diagrams of the welding grooves at both ends of the water channel provided by the present application, and FIG. 13 is the second schematic diagram of the welding grooves at both ends of the water channel provided by the present application. As shown in FIG. 12 or FIG. Design a

certain welding groove

121 or 122, the gap formed by the

welding groove

121 or 122 can withstand more solder, make the base material easier to penetrate, and also make the welding more sufficient, and the welding strength is easier to ensure.

Based on the content of the foregoing embodiment, as an optional embodiment, as shown in FIG. 5 , FIG. 9 and FIG. 11 , the laser output head further includes an optical stripper that is sheathed on the optical fiber 109 and is coaxially arranged 116. The reflective pad 108 and the optical fiber fixing joint 118; the optical stripper 116 is suspended between the small diameter end of the cone-shaped input end and the reflective pad 108; the optical stripping point of the optical stripper 116 is located between the reflective pad 108 and the optical fiber fixed joint between 118.

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

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

When the output head is cutting the highly reflective material, return light will be generated. The return light passing through the

end cap

114 or 120 and the scattered light stripped by the fiber stripper can block the laser light under the action of the reflective pad 108, so that the laser light can be blocked. It is irradiated on the inner wall surface of the water cooling area of the ferrule 101, so as to avoid entering the peeling point area at the rear end of the output head.

The reflective pad 108 and the

end cap

114 or 120 have strict coaxiality requirements, so they can be assembled with the main body 102 by means of interference fit.

There is a coaxial small hole inside the reflective pad 108, which is the channel of the optical fiber 109. For the returning light, this small hole is also an aperture hole.

The area where the stripper 116 on the optical fiber 109 is located is located between the fusion point of the

end cap

114 or 120 and the reflective pad 108, and is in a suspended state. This area requires very high processing requirements and cleanliness. The optical fiber 109 is fixed by glue injection through the optical fiber fixing joint 118 , so that the stripper 116 is in a coaxial and straight state, and the optical fiber stripping point is located between the reflective pad 108 and the glue dispensing opening of the optical fiber fixing joint 118 .

There is a high-precision radial fit requirement between the cylindrical output end of the

end cap

114 or 120 and the ferrule 101, and the end of the

end cap

114 or 120 and the end of the ferrule 101 have an axial limit to ensure the end cap The coaxiality of 114 or 120 reduces the angle offset error of the end cap, thereby reducing the pointing error of the beam.

The cylindrical output end of the

end cap

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

end cap

114 or 120 and the inner wall of the ferrule 101 are fitted with a large gap, and are not in contact with the inner wall of the ferrule 101 and are in a suspended state.

The ferrule 103 and the main body 102 are connected by fasteners, and have high coaxiality requirements, which are used to achieve mechanical cooperation with the cutting head or welding head, and the tapered surface can realize self-centering to ensure the coaxiality requirements. .

Based on the content of the above embodiment, as an optional embodiment, the inner wall of the ferrule is formed after sandblasting and texturing.

In the laser output head provided by the present application, the inner wall of the ferrule 101 is designed with a textured structure or treated with a textured process, which is more conducive to the homogenization of heat distribution and further reduces the axial temperature gradient.

Optionally, the inner wall surface of the ferrule 101 can be processed into a threaded structure, and the threaded structure can be textured to increase the laser absorption area, which is more conducive to the spread of heat.

Based on the content of the above embodiment, as an optional embodiment, an armored sleeve 105 is sheathed at the end of the optical fiber located at the laser output head, and the armored sleeve 105 is locked with the main body 102 by screwing.

Specifically, the armored sleeve 105 is used to mechanically connect the armored cable 107 , and at the same time, the main body 102 is connected and sealed with a screw thread, and the locking cover 106 is used to seal the armored cable 107 .

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims

A laser output head, characterized in that it at least comprises: an end cap and a ferrule;

The end cap is composed of a cylindrical output end and a frustoconical input end, the small diameter end of the conical frustum input end is connected to the output end of the optical fiber, and the large diameter end of the conical frustum input end is connected to the cylindrical output end. One end is welded;

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

The ferrule is located on the outer side of the end cap, and ensures that the inner wall of the ferrule and the outer wall of the frusto-conical input end are in clearance fit.
The laser output head according to claim 1, characterized in that, between the cylindrical output end and the frustoconical input end, further comprising: an additional cylindrical output end;

The diameter of the additional cylindrical output end is smaller than the diameter of the cylindrical output end, and not smaller than the diameter of the large diameter end of the frustoconical input end.
The laser output head according to claim 2, wherein the inner wall of the ferrule is abutted with the outer wall of the additional cylindrical output end.
The laser output head according to claim 1 or 2, wherein the ferrule includes a cooling water channel or a cooling air channel.
The laser output head according to claim 4, wherein when the ferrule includes cooling water channels, the surface of the ferrule is provided with a multi-channel return structure strip, and each of the return structure strips Heat dissipation fins are embedded on it.
The laser output head according to claim 5, wherein 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 provided at the welding place.
The laser output head according to claim 1 or 2, characterized in that, the laser output head further comprises an optical stripper, a reflective pad and an optical fiber fixed joint which are sheathed on the optical fiber and are coaxially arranged;

The optical stripper is suspended between the small diameter end of the frusto-conical input end and the reflective pad; the optical fiber stripping point of the optical stripper is located between the reflective pad and the optical fiber fixed joint.
The laser output head according to claim 7, wherein the reflective pad is made of metal material or glass material, and a reflective coating is plated on the surface of the reflective pad.
The laser output head according to claim 1 or 2, wherein the inner wall of the ferrule is formed by sandblasting and texturing.
The laser output head according to claim 1 or 2, wherein an armored sleeve is sheathed at the end of the optical fiber located at the laser output head, and the armored sleeve and the main body are locked by screwing.