A powder feeding nozzle and laser cladding and additive manufacturing machining head

Abstract

The present application relates to laser cladding and additive manufacturing equipment technical field, and provide a kind of powder feeding nozzle and laser cladding and additive manufacturing processing head, the powder feeding nozzle includes inner nozzle, outer nozzle and powder feeding pipeline, the inner nozzle includes tapered portion, the outer nozzle is sleeved on the tapered portion, and the outer wall of tapered portion and / or the inner wall of the outer nozzle is equipped with multiple powder feeding channel structures arranged in annular interval, the bottom end of the powder feeding channel structure extends to the bottom end of the tapered portion, and powder feeding pipeline is worn in the side wall of the outer nozzle and is communicated with each powder feeding channel structure;In the present application, powder feeding channel structure extends to the bottom end of tapered portion, and the powder flowing in each powder feeding channel is simultaneously sent out from the bottom end of the powder feeding nozzle, and finally converges to form powder jet focal point, so that the powder in each powder feeding channel structure is more evenly distributed and the directivity is greatly improved, to improve the stability and focusing of powder sprayed by powder feeding nozzle, and there is no problem of powder falling.

Description

Technical Field

[0001] This invention relates to the field of laser cladding and additive manufacturing equipment technology, and more specifically, to a powder feeding nozzle and a laser cladding and additive manufacturing processing head. Background Technology

[0002] Laser cladding, also known as laser bonding or laser coating, is a novel surface modification technology. It involves adding cladding material to a substrate surface using a synchronous or pre-placed material approach, and then using a high-energy-density laser beam to fuse the cladding material with a thin layer on the substrate surface, forming a metallurgically bonded cladding layer. The powder feeding nozzle is a key component in the laser cladding process, determining powder flowability, aggregation, and the stability of the additive manufacturing process. Most powder feeding nozzles on the market form a ring of powder inside the nozzle and then eject it directly in that ring shape. While this method offers the highest powder feeding efficiency, when the nozzle is tilted beyond a certain angle, the stability and focusing of the powder feeding deteriorate due to the powder's own gravity, and powder shedding can occur, thus limiting its application in 3D laser additive manufacturing. Summary of the Invention

[0003] The problem addressed by this invention is how to design a powder feeding nozzle with high stability and focusing capability.

[0004] To address the aforementioned problems, the present invention provides a powder feeding nozzle, comprising an inner nozzle, an outer nozzle, and a powder feeding pipeline. The inner nozzle includes a conical portion, and the outer nozzle is sleeved outside the conical portion. The outer wall of the conical portion and / or the inner wall of the outer nozzle are provided with a plurality of powder feeding channel structures arranged in a ring at intervals. The bottom end of each powder feeding channel structure extends to the bottom end of the conical portion. The powder feeding pipeline passes through the side wall of the outer nozzle and communicates with each of the powder feeding channel structures.

[0005] Optionally, the external nozzle includes an interconnected cylindrical structure and an internally hollow conical structure. The outer wall of the conical portion and / or the inner wall of the conical structure are provided with a plurality of powder feeding channels arranged in a ring at intervals. The number of powder feeding channels is multiple, and the multiple powder feeding channels are arranged in a ring at intervals on the cylindrical structure.

[0006] Optionally, the inner nozzle further includes a concave portion connected to the conical portion. The vertical cross-section of the concave portion has a structure that gradually narrows and then expands from top to bottom. A mixing cavity is formed between the cylindrical structure and the concave portion. The plurality of powder feeding channel structures are respectively connected to the mixing cavity. The powder feeding pipeline passes through the cylindrical structure and is connected to the mixing cavity.

[0007] Optionally, the inner nozzle further includes a connecting portion connected to one end of the concave portion away from the conical portion, the connecting portion being a disc structure, and the cylindrical structure being sleeved outside the connecting portion.

[0008] Optionally, it further includes a first cooling structure, which is an annular structure with a first receiving cavity inside, the first receiving cavity being suitable for holding coolant; the annular structure is sleeved outside the connecting part.

[0009] Optionally, it further includes a second cooling structure, which is an annular structure with a second receiving cavity inside, the second receiving cavity being suitable for holding coolant; the annular structure is sleeved outside the outer nozzle.

[0010] Optionally, the powder feeding channel structure includes a protrusion structure disposed on the outer wall of the conical portion and / or the conical structure, a groove forming a powder feeding channel between two adjacent protrusion structures, the protrusion structure of the conical portion abutting against the inner wall of the conical structure, or the protrusion structure of the conical structure abutting against the outer wall of the conical portion, or the protrusion structure of the conical portion abutting against the protrusion structure of the conical structure, and a powder feeding channel forming between the groove and the conical structure.

[0011] Optionally, the powder feeding channel structure includes a groove structure disposed on the outer wall of the conical portion and / or the inner wall of the conical structure, serving as a powder feeding channel.

[0012] Compared with the prior art, the present invention provides multiple powder feeding channels arranged in a ring at intervals on the outer wall of the conical part of the inner nozzle and / or the inner wall of the outer nozzle. When the outer nozzle is fitted outside the conical part, since the multiple powder feeding channels are connected to the powder feeding pipeline, the powder in the powder feeding pipeline diffuses before entering each powder feeding channel. Compared with the prior art where funnel-shaped annular powder is directly formed in the powder feeding nozzle and the stability and focusing of the annular powder are poor when the powder feeding nozzle is tilted at a certain angle, the powder feeding channel structure in this application extends downward to the bottom of the conical part. This allows the powder flowing in each of the annularly spaced powder feeding channels to be simultaneously delivered from the bottom of the powder feeding nozzle, and finally converge at the bottom of the powder feeding nozzle to form the powder jet focus. Since the powder in the powder feeding pipeline enters each powder feeding channel structure, the powder distribution is more uniform and the guidance is greatly improved, thereby improving the stability and focusing of the powder ejected from the powder feeding nozzle, and eliminating the problem of powder shedding.

[0013] The present invention also provides a laser cladding and additive manufacturing head, including a laser head, a connecting tube, and a powder feeding nozzle as described above. The laser head includes a protective lens, which is embedded in the connecting tube. The connecting tube is connected to an inner nozzle in the powder feeding nozzle. A protective gas inlet is provided on the connecting tube, which is adapted to connect to a protective gas tube. The beneficial effects of the laser cladding and additive manufacturing head are the same as those of the powder feeding nozzle, and will not be repeated here.

[0014] Optionally, it also includes a set screw, and the outer wall of the connecting tube is provided with a recessed structure, the recessed structure being parallel to the vertical axis of the connecting tube, the set screw passing through the laser head and abutting against the recessed structure. Attached Figure Description

[0015] Figure 1 This is a partial structural schematic diagram of the laser cladding and additive manufacturing head in an embodiment of the present invention;

[0016] Figure 2 This is a partial cross-sectional structural diagram of the laser cladding and additive manufacturing head in an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of a partial exploded structure of the laser cladding and additive manufacturing head in an embodiment of the present invention;

[0018] Figure 4 This is one of the structural schematic diagrams of the internal nozzle in an embodiment of the present invention;

[0019] Figure 5 This is a second schematic diagram of the internal nozzle structure in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the movement trajectory of powder entering the inner nozzle in an embodiment of the present invention;

[0021] Figure 7 This is the third schematic diagram of the internal nozzle in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1-Powder delivery pipeline; 2-Inner nozzle; 21-Conical part; 211-Groove structure; 22-Inner recess; 23-Connecting part; 3-Outer nozzle; 31-Cylindrical structure; 32-Conical structure; 4-First cooling structure; 5-Second cooling structure; 6-Protruding structure; 7-Connecting pipe; 71-Protective air inlet; 72-Recessed structure; 8-Protective lens. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in sequences other than those illustrated or described herein.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0028] To solve the above technical problems, combined with Figures 1 to 3 As shown, an embodiment of the present invention provides a powder feeding nozzle, including an inner nozzle 2, an outer nozzle 3, and a powder feeding pipeline 1. The inner nozzle 2 includes a conical portion 21, and the outer nozzle 3 is sleeved on the outside of the conical portion 21. The outer wall of the conical portion 21 and / or the inner wall of the outer nozzle 3 are provided with a plurality of powder feeding channel structures arranged in a ring at intervals, and the bottom end of the powder feeding channel structure extends to the bottom end of the conical portion 21. The powder feeding pipeline 1 passes through the side wall of the outer nozzle 3 and communicates with each of the powder feeding channel structures.

[0029] It should be noted that, by providing multiple powder feeding channels arranged in a ring at intervals on the outer wall of the conical portion 21 of the inner nozzle 2 and / or the inner wall of the outer nozzle 3, when the outer nozzle 3 is fitted outside the conical portion 21, since the multiple powder feeding channels are respectively connected to the powder feeding pipeline 1, the powder in the powder feeding pipeline 1 first diffuses between the outer nozzle and the inner nozzle before flowing into each powder feeding channel. This is in contrast to the prior art where funnel-shaped annular powder is directly formed inside the powder feeding nozzle, and the annular powder is more concentrated when the powder feeding nozzle is tilted at a certain angle. In contrast to the poor stability and focusing, the powder feeding channel structure in this application extends downward to the bottom of the conical portion 21, so that the powder flowing in each powder feeding channel arranged in a ring at intervals is simultaneously delivered from the bottom of the powder feeding nozzle, and finally converges on the lower side of the powder feeding nozzle to form the powder jet focus. Since the powder in the powder feeding pipeline 1 enters each powder feeding channel structure, the powder distribution is more uniform and the guidance is greatly improved. This not only improves the stability and focusing of the powder ejected from the powder feeding nozzle and prevents powder drop, but also improves the powder feeding efficiency and powder utilization rate.

[0030] In one embodiment of the present invention, combined with Figure 1 and Figure 3 As shown, the outer nozzle 3 includes an interconnected cylindrical structure 31 and an internally hollow conical structure 32. The outer wall of the conical part 21 and / or the inner wall of the conical structure 32 are provided with a plurality of powder feeding channels arranged in a ring at intervals. The number of powder feeding pipes 1 is multiple, and the multiple powder feeding pipes 1 are arranged in a ring at intervals on the cylindrical structure 31.

[0031] It should be noted that the interiors of the cylindrical structure 31 and the conical structure 32 of the outer nozzle 3 are hollow, and the bottom end of the cylindrical structure 31 is connected to the end of the conical structure 32 with a larger diameter. Multiple powder feeding channels arranged in a ring-shaped interval are provided on the outer wall of the conical portion 21 and / or the inner wall of the conical structure 32. By installing multiple powder feeding pipes 1 arranged in a ring-shaped interval on the side wall of the cylindrical structure 31, and connecting the powder feeding pipes 1 to the powder feeding channel structures, not only is the amount of powder entering the powder feeding channel structures per unit time increased, but also, because the multiple powder feeding pipes 1 and the multiple powder feeding channel structures are arranged in a ring-shaped interval, the powder transported by the multiple powder feeding pipes 1 enters each powder feeding channel structure respectively, thereby improving the uniformity of the powder entering each powder feeding channel structure. In this embodiment, the size of the powder feeding pipe 1 is greater than or equal to the size of each powder feeding channel, thereby ensuring that the powder entering the powder feeding channel structure has a certain flow rate, and the number of powder feeding pipes 1 is less than the number of powder feeding channel structures.

[0032] In one embodiment of the present invention, the inner nozzle 2 further includes an inner recess 22 connected to the conical portion 21. The vertical cross-section of the inner recess 22 has a structure that gradually narrows and then expands from top to bottom. A mixing cavity is formed between the cylindrical structure 31 and the inner recess 22. The plurality of powder feeding channel structures are respectively connected to the mixing cavity. The powder feeding pipeline 1 passes through the cylindrical structure 31 and is connected to the mixing cavity.

[0033] It should be noted that, in combination Figure 2 , Figure 3 and Figure 4 As shown, the larger diameter end of the conical portion 21 is positioned on the upper side relative to the smaller diameter end. A concave portion 22 is also provided at the top of the conical portion 21. Since the vertical cross-section of the concave portion 22 has a structure that gradually narrows and then expands from top to bottom, the outer wall of the concave portion 22 resembles an hourglass structure. Furthermore, the circumferential outer wall of the concave portion 22 is a smooth concave surface. Therefore, when the cylindrical structure 31 of the outer nozzle 3 is fitted over the inner nozzle 2, a sealed mixing cavity is formed between the cylindrical structure 31 and the concave portion 22. Multiple powder delivery pipes 1 pass through the cylindrical structure 31. 1. Each of the multiple powder feeding pipes 1 is connected to the mixing chamber. The powder in each pipe first undergoes continuous and thorough mixing within the mixing chamber. Then, the mixed powder, under its own gravity and the velocity generated by its movement within the mixing chamber, continues to move downwards. It is divided into multiple paths by the annularly spaced powder feeding channels and enters each channel. The powder is then ejected from the powder feeding nozzle at a certain speed. Finally, the powder in each channel converges below the powder feeding nozzle to form the powder jet focus. The trajectory of the powder within the mixing chamber is as follows: Figure 6 As shown, where Figure 6 The arrows on the curves indicate the direction of powder flow.

[0034] In the above embodiments, the top of each powder feeding channel structure is lower than or flush with the top of the conical portion 21.

[0035] It should be noted that, in combination Figure 4 As shown, the top of each powder feeding channel structure is flush with the top of the conical part 21. Thus, when the conical structure 32 in the outer nozzle 3 is fitted outside the conical part 21 in the inner nozzle 2, the powder from the multiple powder feeding pipes 1 first enters the mixing chamber for thorough mixing. Then, the mixed powder, under its own gravity and the flow velocity generated by the movement of the powder in the mixing chamber, continues to move downwards and directly and quickly enters each of the powder feeding channel structures. This reduces the movement path between the inner nozzle 2 and the outer nozzle 3, thereby improving the powder feeding efficiency. Moreover, since the volume of the groove formed between two adjacent protrusions 6 in each powder feeding channel structure is smaller than the volume of the mixing chamber, the flow speed of the powder in each powder feeding channel can be further accelerated, thereby greatly improving the focusing and powder feeding efficiency of the powder in the powder feeding nozzle.

[0036] In another embodiment of the invention, combined with Figure 7 As shown, the top of each powder feeding channel structure is lower than the top of the conical part 21, that is, the length of the powder feeding channel structure is less than the length of the conical part 21. The powder feeding channel structure includes a protrusion structure 6 provided on the outer wall of the conical part 21. A groove is formed between two adjacent protrusion structures 6 to serve as a powder feeding channel. At this time, a gap is reserved between the groove and the top of the protrusion structure 6 and the top of the conical part 21. When the conical structure 32 in the outer nozzle 3 is sleeved outside the conical part in the inner nozzle 2, a powder acceleration zone is formed between the conical structure 32 and the conical part 21 on the upper side of the powder feeding channel structure. Thus, the powder from multiple powder feeding pipes 1 first enters the mixing chamber for thorough mixing. Then, the mixed powder, under its own gravity and the flow velocity generated by the movement of the powder in the mixing chamber, causes it to continue to move downwards into the powder acceleration zone. Since the volume of the mixing chamber is greater than the volume of the powder acceleration zone, the powder in the mixing chamber will be further accelerated after entering the powder acceleration zone before entering each of the powder feeding channel structures, thereby further accelerating the flow speed of the powder in the powder feeding nozzle. In addition, since a gap is reserved between the top of each powder feeding channel structure and the top of the cone 21, the volume of the cone structure 32 in the outer nozzle 3 is further reduced.

[0037] In one embodiment of the present invention, the inner nozzle 2 further includes a connecting portion 23 connected to one end of the concave portion 22 away from the conical portion 21. The connecting portion 23 is a disc structure, and the cylindrical structure 31 is sleeved on the outside of the connecting portion 23.

[0038] It should be noted that, in combination Figure 2 As shown, since the cylindrical structure 31 in the outer nozzle 3 is sleeved on the inner nozzle 2, the connecting part 23 is a disc structure, which facilitates the smooth sleeve of the top of the cylindrical structure 31 onto the disc structure connecting part 23. The cylindrical structure 31 can be directly sleeved on the outside of the connecting part 23, or it can be sleeved on the outside of the connecting part 23 by means of threads. That is, an internal thread is provided on the inner wall of the cylindrical structure 31, and an external thread is provided on the outside of the connecting part 23. The internal thread and the external thread are connected by threads, thereby realizing the detachable sleeve of the cylindrical structure 31 on the outside of the connecting part 23.

[0039] In this embodiment, the connecting plate includes a first connecting plate and a second connecting plate that are connected to each other. The bottom end of the first connecting plate and the top end of the second connecting plate are integrally formed or detachably connected. The first connecting plate and the second connecting plate are coaxially arranged. The diameter of the first connecting plate is larger than the diameter of the second connecting plate. The second connecting plate is connected to the concave portion 22. The cylindrical structure 31 is sleeved on the outside of the second connecting plate.

[0040] In one embodiment of the present invention, combined with Figure 1 , Figure 2 and Figure 3 As shown, the powder feeding nozzle also includes a first cooling structure 4, which is an annular structure with a first receiving cavity inside, and the first receiving cavity is suitable for holding coolant; the annular structure is sleeved on the outside of the connecting part 23.

[0041] It should be noted that both the first cooling structure 4 and the first receiving cavity are annular structures, and the first receiving cavity inside the annular structure is suitable for holding coolant. When the annular structure is fitted outside the second connecting plate in the connecting part 23, the coolant can cool the inner nozzle 2 to prevent the inner nozzle 2 from overheating. The first cooling structure 4 is also provided with an inlet and an outlet, which are connected to each other. An external liquid delivery device is connected to the inlet and outlet through a liquid delivery pipe and an outlet pipe, respectively, to deliver coolant into the first receiving cavity of the first cooling structure 4 through the liquid delivery pipe and the inlet. Then, the coolant flows in the first receiving cavity of the annular structure and returns to the liquid delivery device through the outlet pipe. This process is continuously circulated to remove the high temperature generated by the inner nozzle 2 during operation and achieve continuous cooling of the inner nozzle 2. The coolant can be cooling water, cooling oil, or other types of coolant. Any coolant that can cool the inner nozzle 2 is suitable for this technical solution and is not specifically limited here.

[0042] In one embodiment of the present invention, combined with Figures 1 to 3 As shown, the powder feeding nozzle also includes a second cooling structure 5, which is an annular structure with a second receiving cavity inside, and the second receiving cavity is suitable for holding coolant; the annular structure is sleeved on the outside of the outer nozzle 3.

[0043] It should be noted that the second cooling structure 5 has the same shape and structure as the first cooling structure 4. When the cylindrical structure 31 of the outer nozzle 3 is fitted onto the connecting part 23 of the inner nozzle 2, the laser emitted by the laser head passes through the laser channel of the inner nozzle 2. At this time, the inner nozzle 2 will generate high temperature and transfer the high temperature to the outer nozzle 3. The second cooling structure 5 is fitted onto the cylindrical structure 31 of the outer nozzle 3, thereby cooling the outer nozzle 3. The cooling principle of the second cooling structure 5 on the outer nozzle 3 is the same as the cooling principle of the first cooling structure 4 on the inner nozzle 2, and will not be repeated here.

[0044] In one embodiment of the present invention, combined with Figure 4As shown, the powder feeding channel structure includes a protrusion 6 disposed on the outer wall of the conical portion 21 and / or the conical structure 32. A groove is formed between two adjacent protrusions 6 to serve as a powder feeding channel. The protrusion 6 of the conical portion 21 abuts against the inner wall of the conical structure 32, or the protrusion 6 of the conical structure 32 abuts against the outer wall of the conical portion 21, or the protrusion 6 of the conical portion 21 abuts against the protrusion 6 of the conical structure 32. A powder feeding channel is formed between the groove and the conical structure 32.

[0045] It should be noted that multiple protrusions 6 arranged in a ring at intervals are provided on the circumferential outer wall of the conical part 21 in the inner nozzle 2. A groove is formed between two adjacent protrusions 6 to serve as a powder feeding channel. That is, the multiple grooves are also arranged in a ring at intervals. When the outer nozzle 3 is sleeved on the inner nozzle 2, the multiple protrusions 6 abut against the inner wall of the conical structure 32 of the outer nozzle 3. The multiple grooves arranged at intervals form multiple powder feeding channels between the conical structure 32 of the outer nozzle 3, thereby improving the powder feeding stability and focusing of the powder feeding nozzle.

[0046] In this embodiment, the size of the protruding structure 6 gradually decreases from top to bottom along the outer wall of the inner nozzle 2. This not only ensures that the surface of the protruding structure 6 abuts against the inner surface of the conical structure 32 of the outer nozzle 3, but also makes the size of the groove formed between two adjacent protruding structures 6 decrease accordingly. This makes the powder feeding channel gradually smaller, thereby improving the uniformity, flow rate and guiding properties of the powder in the powder feeding channel, and thus improving the powder focusing and powder utilization efficiency. Unlike the above embodiments, the powder feeding channel structure can also be set on the inner sidewall of the conical structure 32 of the outer nozzle 3. For example, multiple protrusions 6 are arranged in a ring-shaped interval on the inner sidewall of the conical structure 32. That is, the protrusions 6 extend downward to the bottom end of the conical part 21. A pit is formed between two adjacent protrusions 6 to serve as a powder feeding channel. When the outer nozzle 3 is sleeved outside the inner nozzle 2, the multiple protrusions 6 abut against the outer wall of the conical part 21 of the inner nozzle 2. Multiple powder feeding channels are formed between the multiple pits and the outer wall of the conical part 21. Thus, multiple powders can be sprayed out from between the conical part 21 and the conical structure 32. The effect is the same as the effect of setting multiple protrusions 6 on the outer wall of the conical part 21, which will not be described again here.

[0047] Unlike the above embodiments, the inner wall of the conical structure 32 in the outer nozzle 3 and the outer wall of the conical portion 21 in the inner nozzle 2 are provided with a plurality of protruding structures 6 arranged in a ring at intervals. When the outer nozzle 3 is sleeved on the inner nozzle 2, the protruding structures 6 on the conical structure 32 abut against the protruding structures 6 on the conical portion 21. At this time, a groove is formed between two adjacent protruding structures 6. The groove on the conical structure 32 and the groove on the conical portion 21 together form a plurality of powder feeding channels. The effect is the same as the effect of providing a plurality of protruding structures 6 on the outer wall of the conical portion 21, which will not be repeated here.

[0048] In one embodiment of the present invention, the powder feeding channel structure includes a groove structure 211 disposed on the outer wall of the conical portion 21 and / or the inner wall of the conical structure 32 and serving as a powder feeding channel.

[0049] It should be noted that, in combination Figure 5 As shown, multiple groove structures 211 arranged in a ring-shaped interval are opened on the circumferential outer wall of the conical part 21 in the inner nozzle 2. When the outer nozzle 3 is sleeved outside the inner nozzle 2, the inner wall of the conical structure 32 is in close contact with the outer wall of the conical part 21. At this time, multiple powder feeding channels are formed between the multiple groove structures 211 and the conical structure 32. The powder conveyed by the multiple powder feeding pipes 1 is mixed in the mixing chamber and then enters each powder feeding channel. Compared with the prior art where the annular powder is directly formed in the powder feeding nozzle and the stability and focusing of the annular powder are poor when the powder feeding nozzle is tilted at a certain angle, the powder in the multiple powder feeding channels of this application is ejected from the powder feeding nozzle between the conical part 21 of the inner nozzle 2 and the conical structure 32 of the outer nozzle 3. Finally, it converges on the lower side of the powder feeding nozzle to form the powder jet focus, thereby making the powder distribution in each powder feeding channel structure more uniform and greatly improving the guidance, so as to improve the stability and focusing of the powder ejected from the powder feeding nozzle.

[0050] In this embodiment, the size of the groove structure 211 gradually decreases from top to bottom along the outer wall of the inner nozzle 2, thereby gradually reducing the size of the multiple powder feeding channels formed between the multiple groove structures 211 and the inner wall of the conical structure 32 in the outer nozzle 3. This improves the uniformity and guidance of powder flow within the powder feeding channels, thereby enhancing powder focusing and utilization efficiency. Unlike the above embodiment, if multiple groove structures 211 are circumferentially spaced in a ring on the inner wall of the conical structure 32 in the outer nozzle 3, when the outer nozzle 3 is fitted over the inner nozzle 2, the inner wall of the conical structure 32 of the outer nozzle 3 is in close contact with the outer wall of the conical portion 21 of the inner nozzle 2. Multiple powder feeding channels are formed between the multiple groove structures 211 and the outer wall of the conical portion 21, thus allowing multiple powder streams to be ejected from between the conical portion 21 and the conical structure 32. The effect is the same as that of opening multiple groove structures 211 on the outer wall of the conical portion 21, which will not be elaborated further here.

[0051] Unlike the above embodiments, the inner wall of the conical structure 32 in the outer nozzle 3 and the outer wall of the conical portion 21 in the inner nozzle 2 are provided with multiple groove structures 211 arranged in a ring at intervals. The groove structures 211 on the conical structure 32 and the groove structures 211 on the conical portion 21 together form multiple powder feeding channels. The effect is the same as the effect of opening multiple groove structures 211 on the outer wall of the conical portion 21, which will not be repeated here.

[0052] Another embodiment of the present invention provides a laser cladding and additive manufacturing head, including a laser head, a connecting tube 7, and a powder feeding nozzle as described in the above embodiments. The laser head includes a protective lens 8, which is embedded in the connecting tube 7. The connecting tube 7 is connected to the inner nozzle 2 of the powder feeding nozzle. A protective gas inlet 71 is provided on the connecting tube 7, and the protective gas inlet 71 is adapted to connect to a protective gas tube.

[0053] It should be noted that, in combination Figure 1 , Figure 2 and Figure 3 As shown, the laser head (not shown) includes a laser emitting module and a protective lens 8. The laser emitting module (not shown) is positioned above the protective lens 8. The laser emitting module is existing technology for emitting laser beams and will not be described in detail here. A laser channel is formed along the vertical axis of the connecting portion 23, the recessed portion 22, and the conical portion 21 of the inner nozzle 2, facilitating the passage of the laser beam emitted by the laser emitting module in the laser head through the laser channel. The vertical cross-section of the laser channel is also conical, with the diameter at the top of the conical structure being larger than the diameter at the bottom, thus facilitating focusing of the laser beam during transport. An annular recess is formed inside the connecting tube 7 above the protective gas inlet 71, and the protective lens... 8 is placed on the annular platform; the protective gas pipe is used to deliver protective gas into the connecting pipe 7. The protective gas will move downward along the gap between the inner wall of the connecting pipe 7 and the connection part 23 of the inner nozzle 2, and act on the powder in the mixing chamber. This not only prevents the powder in the mixing chamber from moving upward to protect the lens 8, but also the protective gas is ejected from the powder feeding nozzle along the powder feeding channel with the powder. After the powder in each powder feeding channel is ejected from the powder feeding nozzle, it gathers below the powder feeding nozzle to form the powder jet focus. The laser generated by the laser emission module is ejected from the laser channel of the inner nozzle 2, which can melt the powder jet focus at high temperature and coat it onto the surface of the workpiece to be coated. At this time, the protective gas surrounds the powder jet focus, which can prevent the powder melted at high temperature from being oxidized.

[0054] In one embodiment of the present invention, combined with Figure 1 and Figure 3 As shown, the laser cladding and additive manufacturing head also includes a set screw. The outer wall of the connecting tube 7 is provided with a recessed structure 72. The recessed structure 72 is parallel to the vertical axis of the connecting tube 7. The set screw passes through the laser head and abuts against the recessed structure 72.

[0055] It should be noted that at least one recessed structure 72 is provided on the outer wall of the connecting tube 7. The recessed structure 72 is parallel to the vertical axis of the connecting tube 7. When the connecting tube 7 is connected to the laser head, that is, the connecting tube 7 is embedded in the laser head. It is inserted into the laser head by a set screw and abuts against the recessed structure 72 of the connecting tube 7. This not only realizes the quick and detachable connection between the connecting tube 7 and the laser head, but also allows the connection position between the connecting tube 7 and the laser head to be adjusted by manually adjusting the connection position of the set screw and the recessed structure 72, so as to adjust the height of the powder feeding nozzle.

[0056] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A powder feeding nozzle, characterized in that, The device includes an inner nozzle (2), an outer nozzle (3), and a powder feeding pipeline (1). The inner nozzle (2) includes a conical part (21) and an inner recess (22) connected to the conical part (21). The outer nozzle (3) is sleeved on the outside of the conical part (21). The outer nozzle (3) includes a cylindrical structure (31) and a hollow conical structure (32) connected to each other. The outer wall of the conical part (21) and / or the inner wall of the conical structure (32) are provided with a plurality of powder feeding channels arranged in a ring at intervals, and the bottom end of the powder feeding channel structure extends to the bottom end of the conical part (21). The vertical cross-section of the concave portion (22) has a structure that gradually narrows and then expands from top to bottom. A mixing cavity is formed between the cylindrical structure (31) and the concave portion (22). The multiple powder feeding channel structures are respectively connected to the mixing cavity. The powder feeding pipeline (1) passes through the cylindrical structure (31) and is connected to each of the powder feeding channel structures through the mixing cavity. The top of each of the powder feeding channel structures is lower than the top of the conical portion (21), and a powder acceleration zone is formed between the conical structure (32) and the conical portion (21) on the upper side of the powder feeding channel structure.

2. The powder feeding nozzle according to claim 1, characterized in that, The number of powder feeding pipes (1) is multiple, and the multiple powder feeding pipes (1) are arranged in a ring at intervals on the cylindrical structure (31).

3. The powder feeding nozzle according to claim 2, characterized in that, The inner nozzle (2) also includes a connecting part (23) connected to one end of the concave portion (22) away from the conical portion (21). The connecting part (23) is a disc structure, and the cylindrical structure (31) is sleeved on the outside of the connecting part (23).

4. The powder feeding nozzle according to claim 3, characterized in that, It also includes a first cooling structure (4), which is an annular structure with a first accommodating cavity inside, and the first accommodating cavity is suitable for holding coolant; the annular structure is sleeved outside the connecting part (23).

5. The powder feeding nozzle according to claim 2, characterized in that, It also includes a second cooling structure (5), which is an annular structure with a second accommodating cavity inside, and the second accommodating cavity is suitable for holding coolant; the annular structure is sleeved outside the outer nozzle (3).

6. The powder feeding nozzle according to any one of claims 2 to 5, characterized in that, The powder feeding channel structure includes a protrusion (6) disposed on the outer wall of the conical part (21) and / or the conical structure (32). A groove is formed between two adjacent protrusions (6) to serve as a powder feeding channel. The protrusion (6) of the conical part (21) abuts against the inner wall of the conical structure (32), or the protrusion (6) of the conical structure (32) abuts against the outer wall of the conical part (21), or the protrusion (6) of the conical part (21) abuts against the protrusion (6) of the conical structure (32). A powder feeding channel is formed between the groove and the conical structure (32).

7. The powder feeding nozzle according to any one of claims 2 to 5, characterized in that, The powder feeding channel structure includes a groove structure (211) disposed on the outer wall of the conical part (21) and / or the inner wall of the conical structure (32) and serving as a powder feeding channel.

8. A laser cladding and additive manufacturing head, characterized in that, The device includes a laser head, a connecting tube (7), and a powder feeding nozzle as described in any one of claims 1 to 7. The laser head includes a protective lens (8), which is embedded in the connecting tube (7). The connecting tube (7) is connected to the inner nozzle (2) of the powder feeding nozzle. A protective gas inlet (71) is provided on the connecting tube (7), and the protective gas inlet (71) is adapted to connect to a protective gas tube.

9. The laser cladding and additive manufacturing head according to claim 8, characterized in that, It also includes a set screw, and the outer wall of the connecting tube (7) is provided with a recessed structure (72). The recessed structure (72) is parallel to the vertical axis of the connecting tube (7), and the set screw passes through the laser head and abuts against the recessed structure (72).

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