CN111375917A

CN111375917A - Optical internal wire feeding device for laser additive manufacturing

Info

Publication number: CN111375917A
Application number: CN202010368438.0A
Authority: CN
Inventors: 朱刚贤; 张劭铭; 赵亮; 王丽芳; 李广琪; 石世宏
Original assignee: Suzhou University
Current assignee: Kunshan Baojin Laser Tailor Welding Co Ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-07-07

Abstract

The invention relates to an optical internal wire feeding device for laser additive manufacturing, which comprises a sleeve, a wire feeding pipeline and a light path unit, wherein the light path unit comprises a laser connector, a light splitting module, a reflector module, a light path steering module and a focusing mirror module; the wire feeding pipeline comprises a wire feeding pipe and a wire feeding nozzle, wherein the wire feeding pipe sequentially penetrates through the light path steering module and the focusing lens module from top to bottom and avoids the reflecting lens module to reflect a light path to the light path steering module, the center of a focus formed by the focusing lens module is located on the central line of the wire feeding nozzle, and the focus is located below the wire discharging end of the wire feeding nozzle and is arranged close to the wire discharging end. The invention ensures that the light path and the wire feeding pipeline are not interfered with each other through the change of the light path, the laser focus is collinear with the center of the wire feeding pipeline, the deflection of the wire is prevented when the wire is sent out from the wire feeding nozzle, and meanwhile, the temperature of the optical lens is also reduced, the optical lens is prevented from being deformed to change the light path, the light beam and the wire are ensured to be coaxial when entering a molten pool, and the hot melting forming precision is improved.

Description

Optical internal wire feeding device for laser additive manufacturing

Technical Field

The invention belongs to the field of laser additive manufacturing equipment, and particularly relates to an optical internal wire feeding device for laser additive manufacturing.

Background

The laser additive manufacturing technology is an advanced manufacturing technology which takes powder or wire materials as raw materials and can directly manufacture metal parts with full compactness and excellent mechanical property by high-power laser melting/rapid solidification layer by layer accumulation, and has wide application prospect in the fields of aerospace, automobiles, ships, weaponry and the like. The synchronous additive manufacturing technology based on wire feeding has the advantages that the metal wire is conveyed in a rigid mode, so that the dispersibility is avoided, the material utilization rate is almost 100%, the energy is saved, the environment is protected, the roughness of the cladding surface is low, and the problem caused by powder feeding can be avoided. In addition, the wire material is relatively low in cost and easy to obtain, and meanwhile, the wire material has the advantages of easiness in realizing accurate control, high feeding speed and the like, and the wire feeding cladding is considered to have a great development space.

At present, the wire feeding mode mostly adopts a lateral 'light outside' wire feeding method, namely, a wire material is fed into a molten pool generated by laser through the outside of a laser beam, the method has the problems of limitation of scanning directionality, incapability of ensuring accurate coupling of light and the wire and the like, and the wide application of the 'light outside' wire feeding cladding technology is limited. In order to solve the problem of 'outside light' wire feeding, the Shishihong and the like propose a novel 'inside light' coaxial wire feeding cladding method. The method utilizes the characteristic of easy change of light beams to change incident solid circular laser beams in a spray head device, so that a hollow conical no-light area is formed inside focused laser beams projected onto a forming surface, and a single wire feeding nozzle can be arranged in the no-light area and is coaxial with the focused laser beams. The influence of scanning directivity of an 'optical outside' wire feeding method can be eliminated, and meanwhile, accurate coupling of light and wires can be realized.

However, there are some problems in the existing in-light wire feed additive manufacturing process, first: because the wire material is bent to transition and vertically enters the molten pool, the wire feeding angle is gradually changed in the wire material conveying process, certain deflection of the wire material is caused due to stress release after the wire material is separated from the wire feeding pipe, the molten pool is unstable, and the wire feeding forming quality is poor. Secondly, the method comprises the following steps: because errors exist in the assembling and machining processes, the optical fiber is possibly out of axis, and further the melting of the wire material is caused to be problematic, even the laser is interfered with a wire feeding pipe. Thirdly, the method comprises the following steps: if the optical lens is not cooled effectively, the optical element cannot dissipate heat in time after absorbing the heat of the laser, which may cause deformation of the optical lens and further change the optical path.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an improved optical internal wire feeding device for laser additive manufacturing.

In order to solve the technical problems, the invention adopts the following technical scheme:

an optical internal wire feeder for laser additive manufacturing comprises a sleeve, a wire feeding pipeline and a light path unit,

particularly, the light path unit comprises a laser connector arranged on one side of the sleeve, a light splitting module intercepted in a light path channel formed by the laser connector or at an outlet of the light path channel, reflector modules corresponding to light paths formed by the light splitting modules one by one, a light path turning module arranged at the top of the sleeve and used for reflecting light beams reflected by the reflector modules downwards, and a focusing mirror module which is positioned below the light path turning module and can converge the light beams into a solid circular focus;

the wire feeding pipeline comprises a wire feeding pipe and a wire feeding nozzle, wherein the wire feeding pipe sequentially penetrates through the light path steering module and the focusing lens module from top to bottom and avoids the reflecting light path of the reflecting lens module to the light path steering module, the wire feeding nozzle is arranged at the bottom of the wire feeding pipe, the inner diameter of the wire feeding nozzle is matched with that of a wire material, the wire feeding pipe can also avoid the light path focused downwards by the focusing lens module, the wire feeding nozzle is a straight pipe, the wire discharging end is positioned inside the outlet of the sleeve or the wire discharging end of the wire feeding nozzle is flush with the end of the outlet at the bottom of the sleeve, the center of the focus is positioned on the central line of the wire feeding nozzle,

the beam splitting module, the reflector module, the focusing mirror module and the light path steering module are all light mirror modules, and the wire feeding device in the light further comprises a cooling mechanism which cools the light mirror modules and cannot interfere with the light path and wire feeding.

Preferably, the light path channel is horizontally arranged, the laser beam horizontally enters the sleeve, and the wire feeding pipeline is arranged perpendicular to the horizontal plane and penetrates through the centers of the light path turning module and the focusing mirror module. Thus, the laser beam and the wire are arranged vertically.

According to a specific implementation and preferred aspect of the invention, the bottom surface of the light path turning module is a slope and is a reflecting mirror surface, wherein the slope has an angle of 45 ± 10 °, and the light path reflected from the reflecting mirror module is directed to the reflecting mirror surface, and the reflecting mirror surface reflects the light beam downward. The optimal oblique angle is 45 degrees, the light path steering effect is optimal at the moment, the focusing of the focusing mirror module is facilitated, and meanwhile, the interference of the wire feeding pipe cannot be caused.

Preferably, the light splitting module extends and intercepts at an outlet of the light path channel along the length direction of the wire feeding pipe, and two light splitting mirror surfaces extending from the middle part to two sides of the light path channel are formed, wherein the two light splitting mirror surfaces completely shield the light path channel, and the separated light paths respectively emit to the corresponding side mirror modules. In this case, the light beam is split into two paths due to the arrangement of the light splitting module, and meanwhile, the vertically arranged wire feeding pipe is avoided, so that the interference between the light path and the pipeline is avoided.

According to a specific implementation and preferred aspect of the invention, the wire feeding pipe comprises a plurality of branch pipes which are butted from the end parts, wherein the outer diameter of the branch pipes from top to bottom is gradually reduced, and the interior of each branch pipe is hollow. The benefits of this arrangement: 1. the practical processing and assembly are convenient (a single slender pipe is difficult to process, and the stability cannot be ensured), and the vertical feeding of the wire can be ensured; 2. due to the branch pipes with the light paths converging and gradually becoming smaller, avoidance is well formed, and the laser beams can be fully used for forming a molten pool.

Preferably, the top of the branch pipe at the uppermost end protrudes out of the top of the sleeve, and the top end face of the branch pipe at the uppermost end is closed, wherein a wire feeding hole and a shielding gas port are formed on the top end face, the wire feeding hole is located at the center of the top end face, and the shielding gas port is located on one side of the wire feeding hole. Due to the solid property that the wire is not dispersed, the protective air channel and the wire feeding pipe can be arranged in the same channel, so that the size of the wire feeding pipe module is reduced, the interference of the wire feeding pipe module and a laser beam is avoided, and meanwhile, an inert protective atmosphere can be formed during additive manufacturing.

Further, the internal light wire feeding device further comprises a center position calibration and positioning mechanism which is arranged at the top of the sleeve and can abut against the outer side of the branch pipe emerging from the top of the sleeve.

According to a specific implementation and preferred aspect of the invention, the central position calibration positioning mechanism comprises a centering positioning cylinder fixedly connected to the top of the sleeve, a plurality of adjusting screws uniformly distributed around the circumference of the centering positioning cylinder, and connecting sleeves arranged outside the branch pipes emerging from the top of the sleeve and corresponding to the adjusting screws one by one, wherein each adjusting screw penetrates from the centering positioning cylinder and extends into an end part to be correspondingly matched and connected with the connecting sleeve.

Preferably, four adjusting screws are provided, four connecting sleeves are correspondingly provided, and under the butt joint matching of the adjusting screws and the connecting sleeves, the positioning of the wire feeding pipeline is realized; and secondly, the four adjusting screws are adjusted relatively to adjust the coincidence of the central line of the wire feeding pipeline and the central line of the sleeve.

According to a specific implementation and preferred aspect of the present invention, the cooling mechanism includes a cooling jacket and/or a cooling pipeline, wherein the cooling jacket is sleeved on the periphery of the optical lens module, and a cooling medium capable of flowing is added inside the cooling jacket, and the cooling medium absorbs heat through heat exchange, so as to cool the optical lens module; the cooling pipeline is arranged inside the optical mirror module, and absorbs heat through cold heat exchange in the flowing of a cooling medium, so that the optical mirror module is cooled.

In this example, the focusing mirror, the spectroscope and the reflecting mirror adopt a cooling jacket mode; the light path steering module adopts a cooling pipeline mode.

In addition, the sleeve includes upper sleeve and lower sleeve, and upper sleeve and lower sleeve pass through flange and sealing washer and connect relatively, and the light path turns to module top and contradicts from the top and fix in upper sleeve's roof, and focus mirror module level interception sets up in telescopic flange connector department down.

Due to the implementation of the technical scheme, compared with the prior art, the invention has the following advantages:

the invention ensures that the light path and the wire feeding pipeline are not interfered with each other through the change of the light path, the laser focus is collinear with the center of the wire feeding pipeline, the deflection of the wire is prevented when the wire is sent out from the wire feeding nozzle, and meanwhile, the temperature of the optical lens is also reduced, the optical lens is prevented from being deformed to change the light path, the light beam and the wire are ensured to be coaxial when entering a molten pool, and the hot melting forming precision is improved.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic perspective view of an internal light wire feeding device according to the present invention;

FIG. 2 is a schematic front view of FIG. 1;

FIG. 3 is a schematic sectional view taken along line A-A in FIG. 2;

FIG. 4 is an exploded view of FIG. 1;

FIG. 5 is a schematic view of the optical path of the present invention;

1. a sleeve; 10. an upper sleeve; 11. a lower sleeve; j. an interface;

2. a wire feeding pipeline; 20. a wire feeding pipe; a. a branch pipe; s, wire feeding holes; q, a protective gas interface; 21. a wire feeding nozzle;

3. an optical path unit; 30. a laser connector; t, a light path channel; 31. a light splitting module; m, a beam splitting mirror surface; 32. a mirror module; 33. a light path turning module; 34. a focusing mirror module;

4. the central position calibrates the positioning mechanism; 40. centering and positioning the cylinder; 41. adjusting the screw rod; 42. connecting sleeves;

5. a cooling mechanism; 50. a cooling jacket; 51. and cooling the pipeline.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

In the description of the present application, 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," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

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 at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

As shown in fig. 1, the internal optical wire feeder for laser additive manufacturing includes a sleeve 1, a wire feeding pipeline 2, and an optical path unit 3.

Referring to fig. 2 and 3, the sleeve 1 includes an upper sleeve 10 and a lower sleeve 11, and the upper sleeve 10 and the lower sleeve 11 are connected to each other by a flange and a sealing ring.

The optical path unit 3 includes a laser connector 30 disposed at one side of the upper sleeve 10, a light splitting module 31 intercepting an exit of an optical path channel t formed by the laser connector, reflector modules 32 corresponding to optical paths formed by the light splitting modules 31 one by one, an optical path turning module 33 disposed at the top of the upper sleeve 10 and reflecting a light beam reflected by the reflector modules 32 downward, and a focusing mirror module 34 located below the optical path turning module 33 and capable of converging the light beam into a solid circular focus.

In this example, the top of the light path turning module 33 abuts against the top wall of the upper sleeve 10 from the top and is fixed in the upper sleeve 10, and the focusing lens module 33 is horizontally intercepted and disposed at the flange connection port of the lower sleeve 11.

The light splitting module 31 extends along the length direction of the wire feeding pipeline 2 and intercepts at the outlet of the light path channel t, and two light splitting mirror surfaces m extending from the middle part to the two sides of the light path channel are formed, wherein the two light splitting mirror surfaces m completely shield the light path channel t, and the separated light paths respectively emit to the corresponding side mirror modules 32. Here, formally, due to the arrangement of the light splitting module, the light beam is split into two paths, and meanwhile, the wire feeding pipeline 2 which is vertically arranged is also avoided, so that the interference between the light path and the pipeline is avoided.

The bottom surface of the light path turning module 33 is an inclined surface and is a reflection mirror surface, wherein the inclined angle of the inclined surface is 45 degrees, the light path reflected by the self-reflection mirror module is directly projected to the reflection mirror surface, the reflection mirror surface reflects the light beam downwards, the light path turning effect is optimal at the moment, the focusing of the focusing mirror module 34 is facilitated, and meanwhile, the interference of the wire feeding pipeline 2 cannot be caused.

The light path t is horizontally arranged, the laser beam horizontally enters the upper sleeve 10, and the wire feeding pipeline 2 is arranged perpendicular to the horizontal plane. Thus, the laser beam and the wire are arranged vertically.

Specifically, the wire feeding pipeline 2 comprises a wire feeding pipe 20 which sequentially passes through the light path steering module 33 and the focusing lens module 34 from top to bottom and avoids the reflecting lens module 32 to reflect the light path to the light path steering module 33, and a wire feeding nozzle 21 which is arranged at the bottom of the wire feeding pipe 20 and extends along the length direction of the wire feeding pipe 20, wherein the wire feeding pipe 20 can also avoid the light path focused downwards by the focusing lens module 34, the wire outlet end surface of the wire feeding nozzle 21 is flush with the end surface of the outlet at the bottom of the lower sleeve 11, the center of the focus is located on the central line of the wire feeding nozzle 21, and the focus is located outside the outlet at the bottom of the lower sleeve 11 and is arranged close to the outlet at the bottom of.

Specifically, the wire feeding pipe 20 includes a plurality of branch pipes a butted from the end, wherein the outer diameter of the branch pipe a from top to bottom is gradually reduced, and the inside of each branch pipe a is hollow. The benefits of this arrangement: 1. the practical processing and assembly are convenient (a single slender pipe is difficult to process, and the stability cannot be ensured), and the vertical feeding of the wire can be ensured; 2. due to the branch pipes with the light paths converging and gradually becoming smaller, avoidance is well formed, and the laser beams can be fully used for forming a molten pool.

The top of the branch pipe a at the uppermost end is set to protrude from the top of the upper sleeve 10, and the top end face of the branch pipe a at the uppermost end is closed, wherein a wire feeding hole s and a shielding gas port q are formed on the top end face, the wire feeding hole s is located at the center of the top end face, and the shielding gas port q is located at one side of the wire feeding hole s. Due to the solid property that the wire is not dispersed, the protective air channel and the wire feeding pipe can be arranged in the same channel, so that the size of the wire feeding pipe module is reduced, the interference of the wire feeding pipe module and a laser beam is avoided, and meanwhile, an inert protective atmosphere can be formed during additive manufacturing.

In order to solve the problem that the wire material generates certain deflection to cause instability of a molten pool and further poor wire feeding forming quality, in the embodiment, the branch pipe a at the lowest part is a conical pipe with the diameter gradually reduced from top to bottom, the wire feeding nozzle 21 is a straight pipe, a channel formed inside the straight pipe is matched with the outer diameter of the wire material, the wire feeding nozzle 21 is connected to the bottom of the conical pipe from the upper end part, and meanwhile, the central lines of the wire feeding nozzle 21 and the conical pipe are overlapped. Thus, the wire fed from the wire feeding nozzle 21 is not deflected, and the accurate coupling of light and wire is ensured.

In this embodiment, the wire outlet end surface of the wire feeding nozzle 21 is flush with the end surface of the bottom outlet of the lower sleeve 11, and the wire feeding pipeline 2 is protected by the lower sleeve 11 to prevent the occurrence of collision or center position shift in the transferring process of the internal wire feeding device; secondly, the wire feeding length can be accurately known, and the practical operation is convenient; finally, the bottom of the lower sleeve 11 is also provided with a frustum shape with gradually reduced diameter for convenient operation.

Referring to fig. 4, in this embodiment, the internal light wire feeding device further includes a center position calibration and positioning mechanism 4 disposed at the top of the upper sleeve 10 and capable of abutting against the outside of the branch pipe a protruding from the top of the upper sleeve 10.

The central position calibration positioning mechanism 4 comprises a centering and positioning cylinder 40 fixedly connected to the top of the upper sleeve 10, a plurality of adjusting screws 41 uniformly distributed around the circumference of the centering and positioning cylinder 40, and connecting sleeves 42 arranged outside the branch pipes a at the top of the upper sleeve 10 and corresponding to the adjusting screws 41 one by one, wherein each adjusting screw 41 penetrates from the outside of the centering and positioning cylinder 40 and extends into an end to be correspondingly matched and connected with the connecting sleeve 42.

Specifically, the adjusting screw 41 and the middle positioning cylinder 40 are in threaded fit, and the connecting sleeve 42 and the adjusting screw 41 are also in threaded fit.

In this example, there are four adjusting screws 41, four connecting sleeves 42 are correspondingly provided, and are uniformly distributed around the circumference, and under the butt-joint matching of the adjusting screws 41 and the connecting sleeves 42, firstly, the positioning of the wire feeding pipeline is realized; and secondly, the four adjusting screws are adjusted relatively to adjust the coincidence of the central line of the wire feeding pipeline and the central line of the sleeve.

In addition, the light splitting module 31, the reflector module 32, the focusing lens module 34 and the light path turning module 33 are all light mirror modules, and the wire feeding device in light further comprises a cooling mechanism 5 for cooling the light mirror modules without interfering the light path and the wire feeding

The cooling mechanism 5 comprises a cooling jacket 50 and/or a cooling pipeline 51, wherein the cooling jacket 50 is sleeved on the periphery of the optical lens module, a cooling medium capable of flowing can be added in the cooling jacket, and heat is absorbed by the cooling medium in a heat exchange manner, so that the optical lens module is cooled; the cooling pipeline 51 is arranged inside the optical lens module, and absorbs heat through cold heat exchange in the flowing of a cooling medium, so that the optical lens module is cooled. The purpose of the temperature reduction is to prevent the optical mirror from deforming and changing the optical path, thereby ensuring the stability of the molten pool.

In this example, the focusing mirror, the spectroscope and the reflecting mirror adopt a cooling jacket mode; the optical path turning module adopts a cooling pipeline mode, and therefore, a port j communicating with the cooling pipeline 51 is formed at one side of the upper sleeve 10.

The cooling jacket mode is a mode of directly contacting with the optical lens, so that cold and heat exchange is realized; the cooling pipeline is a cooling medium flow channel formed in the optical mirror, and the heat absorbed by the optical mirror is directly taken away by flowing cooling medium, so that the temperature is reduced.

As shown in fig. 5, the flow of the optical path direction in this embodiment is as follows:

the laser beam horizontally enters the upper sleeve 10, the left side and the right side of the laser beam are stacked into the set beam splitting mirror surfaces m, the light path is respectively emitted to the corresponding side reflector modules 32, the light beam is reflected to the 45-degree reflection inclined surface of the light path turning module 33 by the reflector modules 32, then the light beam is downwards reflected to the focusing mirror module 34 by the reflection inclined surface, the downwards light beam is focused into a solid circular focus by the focusing mirror module 34, and the focus is positioned on the central line of the wire material sent out from the wire feeding nozzle 21.

Therefore, the present embodiment has the following features:

1) keeping the wires to be vertically fed in the wire conveying process, and keeping the wires to vertically enter a molten pool in the whole hot melting process;

2) the laser beam with horizontal side direction is converted into the laser beam with vertical angle through the designed light path conversion unit, so that the optical fiber is ensured to be accurate and coaxial when entering a molten pool, the angle change in the wire feeding process is avoided, and the forming precision is improved;

3) designing a central position calibration positioning mechanism to avoid the phenomenon of non-coaxial optical fibers in the assembling process;

4) the optical element (optical mirror module) is cooled by cold cutting in two modes of the cooling sleeve and the cooling pipeline, so that the phenomenon of overheating is avoided, namely, the optical element is prevented from deforming and changing a light path.

The present invention has been described in detail above, but the present invention is not limited to the above-described embodiments. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. The utility model provides a wire drive feed unit in light that laser vibration material disk used, its includes the sleeve, send a pipeline and light path unit, its characterized in that:

the light path unit comprises a laser connector arranged on one side of the sleeve, a light splitting module intercepted in a light path channel formed by the laser connector or at an outlet of the light path channel, reflector modules in one-to-one correspondence with light paths formed by the light splitting modules, a light path steering module arranged at the top of the sleeve and used for reflecting light beams received from the reflector modules downwards, and a focusing mirror module which is positioned below the light path steering module and used for converging the light beams into a solid circular focus;

the wire feeding pipeline comprises a wire feeding pipe and a wire feeding nozzle, wherein the wire feeding pipe sequentially penetrates through the light path steering module and the focusing lens module from top to bottom and avoids the reflecting lens module to reflect the light path to the light path steering module, the wire feeding nozzle is arranged at the bottom of the wire feeding pipe, the inner diameter of the wire feeding nozzle is matched with that of a wire material, the wire feeding pipe can also avoid the light path focused downwards by the focusing lens module, the wire feeding nozzle is a straight pipe, the wire outlet end of the wire feeding nozzle is positioned in the sleeve outlet or the wire outlet end of the wire feeding nozzle is flush with the end of the sleeve bottom outlet, the center of the focus is positioned on the central line of the wire feeding nozzle, and the focus is positioned outside the sleeve bottom outlet and is arranged close to the sleeve bottom outlet,

the light splitting module, the reflector module, the focusing lens module and the light path steering module are light lens modules, and the wire feeding device in the light further comprises a cooling mechanism which cools the light lens modules and cannot interfere with the light path and the wire feeding.

2. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein: the light path channel is horizontally arranged, the laser beam horizontally penetrates into the sleeve, the wire feeding pipeline is perpendicular to the horizontal plane and penetrates through the centers of the light path steering module and the focusing lens module.

3. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein: the bottom surface of the light path turning module is an inclined surface and is a reflecting mirror surface, wherein the inclined angle of the inclined surface is 45 +/-10 degrees, the light path reflected by the reflecting mirror module is directly projected to the reflecting mirror surface, and the reflecting mirror surface reflects the light beam downwards.

4. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein: the light splitting module extends along the length direction of the wire feeding pipe and intercepts the outlet of the light path channel, two light splitting mirror surfaces extending from the middle part of the light path channel to two sides are formed, the two light splitting mirror surfaces completely shield the light path channel, and the separated light paths respectively emit to the reflector modules on the corresponding sides.

5. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein: the wire feeding pipe comprises a plurality of sections of branch pipes which are butted from the end part, wherein the outer diameter of the branch pipes from top to bottom is gradually reduced, and each section of the branch pipe is hollow.

6. The internal optical wire feeder for laser additive manufacturing according to claim 5, wherein: the top of the branch pipe positioned at the uppermost end part protrudes out of the top of the sleeve, the top end face of the branch pipe positioned at the uppermost end part is closed, a wire feeding hole and a protective gas interface are formed on the top end face, the wire feeding hole is positioned in the center of the top end face, and the protective gas interface is positioned on one side of the wire feeding hole.

7. The internal optical wire feeder for laser additive manufacturing according to claim 6, wherein: wire drive feed unit still is in including setting up sleeve top and can conflict emerge the sleeve top the central point in the branch pipe outside puts calibration positioning mechanism.

8. The internal optical wire feeder for laser additive manufacturing according to claim 7, wherein: central point put calibration positioning mechanism include fixed connection in the centering location section of thick bamboo at sleeve top, round many adjusting screw of the circumference evenly distributed of centering location section of thick bamboo and setting are emitting the sleeve top the branch pipe outside and with adjusting screw one-to-one's adapter sleeve, wherein every adjusting screw certainly centering location section of thick bamboo penetrate and stretch into the tip with the adapter sleeve corresponds the cooperation and is connected.

9. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein:

the cooling mechanism comprises a cooling sleeve and/or a cooling pipeline, wherein the cooling sleeve is sleeved on the periphery of the optical lens module, a cooling medium capable of flowing can be added into the cooling sleeve, and heat is absorbed by the cooling medium in a heat exchange manner, so that the optical lens module is cooled; the cooling pipeline is arranged inside the optical mirror module, and absorbs heat through cold heat exchange in the flowing of a cooling medium, so that the optical mirror module is cooled.

10. The internal optical wire feeder for laser additive manufacturing according to claim 1, wherein: the sleeve include sleeve and lower sleeve, last sleeve with lower sleeve passes through flange and sealing washer and connects relatively, the light path turns to the module top and contradicts from the top go up telescopic roof and fix go up in the sleeve, focus mirror module level interception setting be in lower telescopic flange joint department.