Material conveying head and laser deposition machining head

Abstract

The invention relates to laser melting deposition equipment, in particular to a material conveying head and a laser deposition machining head. The material conveying head is integrally constructed to be in a long strip shape and is provided with a feeding end and a discharging end which are opposite, a material input port and at least two gas connectors are formed in the feeding end, a material output port is formed in the discharging end, the material input port is connected with a material guide shaft extending in the first direction in a sealed mode, and the material guide shaft is constructed to be of a straight-pipe-shaped structure with the two ends open. A long-strip-shaped cavity-shaped axial cavity is formed in the material conveying head, the axial cavity extends in the first direction and is coaxial with the material guide shaft, the axial cavity is communicated with the gas connectors and the inner side of the material guide shaft at the same time, and the other end of the axial cavity is communicated with the surface of the material conveying head to form a material output port. A laser deposition processing head includes such a material delivery head. The material conveying head can be compatible with deposition materials of various forms and specifications, can adapt to different working conditions, has high process applicability and achieves multiple purposes through one device.

Description

TECHNICAL FIELD

[0001] The present application relates to a laser melting deposition device, in particular to a material delivery head and a laser deposition processing head. BACKGROUND

[0002] Laser melting deposition (LMD) technology is an important branch of metal material additive manufacturing technology. According to the form of the feeding material, it is divided into two categories: powder feeding LMD and wire feeding LMD. The two technical routes have irreplaceable advantages in applicable scenarios, and the material delivery head structures suitable for the two technical routes are different. Because the preparation requirements of different parts of the same product are often suitable for powder feeding LMD and wire feeding LMD respectively, when preparing products by LMD technology, different deposition processing heads are often used in sequence, which leads to high equipment cost.

[0003] In order to reduce the equipment cost, the deposition processing head and the light source module are detachably connected in the prior art, so that the step of transferring different deposition processing heads is simplified to detach and replace the material delivery head, which simplifies the process, saves the time cost, and reduces the equipment cost.

[0004] However, preparing multiple different material delivery heads still requires high cost, and the practicability is still low. SUMMARY

[0005] The purpose of the present application is to provide a material delivery head and a laser deposition processing head which can be used for wire feeding processing and powder feeding processing.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme: A material delivery head, which is integrally configured in a strip shape and has opposite feeding ends and discharging ends, the feeding end is formed with a material input port and at least two gas interfaces, the discharging end is formed with a material output port, the material input port is hermetically connected with a material guide shaft extending in a first direction, the material guide shaft is configured in a straight pipe structure with both ends open, an axial cavity in a strip shape is formed in the material delivery head, the axial cavity extends in the first direction and is coaxial with the material guide shaft, the axial cavity is simultaneously communicated with each gas interface and the inside of the material guide shaft, and the other end is communicated with the surface of the material delivery head to form the material output port.

[0007] Optionally, the material delivery head further comprises a sleeve cavity, an annular cavity and a transfer cavity, the transfer cavity is adjacent to each of the gas interfaces, and each of the gas interfaces is communicated with the transfer cavity through a gas through hole, the sleeve cavity and the annular cavity are connected to the side of the transfer cavity away from the gas interface, the sleeve cavity extends along the first direction and the material guide shaft is coaxially sleeved in the sleeve cavity, one end of the sleeve cavity away from the transfer cavity is connected with the axial cavity, and the diameter of the sleeve cavity is larger than the axial cavity, the annular cavity is configured in an annular strip shape, surrounds the axial cavity and is communicated with the transfer cavity at one end.

[0008] Optionally, the material delivery head comprises an upper end cover, a lower end cover, a material chamber, a nozzle connecting column and a nozzle, the upper end cover is detachably connected to the lower end cover, the material input port and each of the gas interfaces are connected to the surface of the upper end cover away from the lower end cover, and the gas through hole is composed of through holes penetrating the upper end cover and the lower end cover respectively, the upper end cover is formed with a through hole corresponding to the position of the material input port, and the lower end cover is formed with a through mounting hole corresponding to the position of the material input port, one end of the material guide shaft is sleeved in the inside of the mounting hole and detachably and tightly connected with the inner wall of the mounting hole, the lower end cover is detachably connected to the material chamber, the surface of the material chamber and / or the lower end cover is formed with a groove structure, so that the material chamber and the surface of the lower end cover together enclose the transfer cavity, the sleeve cavity and the annular cavity are formed in the inside of the material chamber, and the annular cavity is adjacent to the outer wall of the material chamber, the nozzle connecting column is connected to the material chamber, and the nozzle is detachably connected to the nozzle connecting column, the axial cavity penetrates the material chamber, the nozzle connecting column and the nozzle.

[0009] The application further provides a laser deposition processing head, comprising a main material delivery head, the main material delivery head is the material delivery head described above.

[0010] Optionally, the laser deposition processing head further comprises a main body module and a secondary material feeding module, The main body module comprises an outer shell and a light path shaping mechanism arranged in the inside of the outer shell, the outer shell has a light source input port and a communication port, the light path shaping mechanism is used for shaping the solid incident light input from the light source input port to form laser beams transmitted from multiple positions around the molten pool to the molten pool respectively, the laser beams are output from the communication port, and the hollow area enclosed in the inside thereof is a light-free area; The main material delivery head penetrates the outer shell and is arranged in the light-free area, and is used for delivering the main material to the molten pool along the first direction, the main material is a wire material or a powder material; The sub-material feeding module comprises a ring-shaped supporting shell and a plurality of sub-material delivery heads mounted on the supporting shell, the supporting shell is detachably connected to the communicating port of the main body module, and a central axis cavity for the laser beam to pass through is formed in the middle part of the supporting shell, the plurality of sub-material delivery heads are circumferentially arranged and penetrate through the supporting shell, and each of the sub-material delivery heads is used for delivering sub-material from outside the laser beam to the molten pool, and the sub-material is a wire or a powder.

[0011] Optionally, the supporting shell comprises a fixing member, a longitudinal member and a transverse member, the fixing member is connected to the communicating port of the main body module, the longitudinal member is slidingly connected to the fixing member and is controllably moved along the first direction, and the transverse member is slidingly connected to the longitudinal member and is controllably slid in multiple directions in a plane perpendicular to the first direction, the central axis cavity is communicated with the outside through a protective gas port for the protective gas to pass through, and the plurality of sub-material delivery heads are carried on the transverse member.

[0012] Optionally, the longitudinal member is sleeved in the fixing member, and the outer wall of the longitudinal member and the inner wall of the fixing member are controllably slidingly connected through threads, a circular ring-shaped sliding groove is formed on the position of the longitudinal member away from the fixing member, the cross section of the sliding groove is rectangular, and the sliding groove comprises an inner abutting surface extending along the first direction, a circular ring-shaped connecting flange is partially embedded in the sliding groove, and the inner diameter of the connecting flange is larger than the inner abutting surface, so that the connecting flange is freely slid and rotated relative to the longitudinal member, the transverse member comprises a connecting part and a carrying part connected to each other, the connecting part of the transverse member is connected to the connecting flange and is sleeved on the outside of the longitudinal member, the inner wall diameter of the connecting part is larger than the outer wall diameter of the longitudinal member, at least three fine adjustment screws perpendicular to the first direction penetrate and are tightly connected to the connecting part of the transverse member, the fine adjustment screws are arranged around the longitudinal member and abut against the longitudinal member at the end part, for adjusting the position of the transverse member, and the plurality of sub-material delivery heads are carried on the carrying part of the transverse member.

[0013] Optionally, the sub-material delivery head comprises a feeding channel extending along a straight line, the feeding channel is communicated with the central axis cavity and is matched in diameter with the sub-material, a plurality of material head sockets are formed on the supporting shell, and the plurality of sub-material delivery heads are detachably connected to the material head sockets respectively.

[0014] Optionally, the sub-material feeding module further comprises a plurality of medium communicating ports and a cooling channel, the cooling channel is configured in a ring shape, is embedded in the supporting shell and is adjacent to the molten pool, each of the medium communicating ports is used for communicating the cooling channel with the surface of the supporting shell, and each of the sub-material delivery heads is adjacent to the cooling channel.

[0015] Optionally, the auxiliary material feeding module further comprises a sensor for collecting temperature data and / or image data around the molten pool.

[0016] According to the first aspect of the present application, the deposition material enters the material delivery head from the feeding end, and enters the axial cavity along the material guide shaft, and exits the material delivery head from the material output port. The protective gas enters the material delivery head from at least one gas interface, is ejected from the material output port along the axial cavity, and reaches the molten pool to protect the deposition material melted at high temperature. When the deposition material is a wire, the inner diameter of the material guide shaft is matched with the diameter of the wire, so as to ensure the wire to be fed in a straight line and reduce the risk of wire bending. When the wire enters the axial cavity, it is protected by the protective gas to prevent oxidation and denaturation due to the small distance between the axial cavity and the molten pool and the high temperature. When the deposition material is a powder, the inner diameter of the material guide shaft can be adjusted according to the particle size of the powder, and the inner diameter of the material guide shaft can be adjusted according to the size of the deposition target to improve the deposition quality. When the deposition material is a powder, the gas pressure can be adjusted by the connection mode of the gas interface. When the protective gas is introduced from each gas interface, it is helpful to improve the gas pressure when the powder is fed. This mode is suitable for powder beam strengthening when the processing head angle is greater than 0°, and prevents the powder beam from falling due to gravity and failing to reach the working area. When some gas interfaces are connected with the protective gas and the remaining gas interfaces are connected with the atmosphere, dynamic pressure regulation is realized, which ensures that the protective gas is delivered to the molten pool and prevents the protective gas from being too large to cause the powder to be dispersedly injected. Through the structural design of the material delivery head, it can adapt to deposition materials of different forms and specifications, and can adapt to various working conditions, has high universality, and reduces the equipment cost and time cost when preparing products with diversified structures.

[0017] Further, the protective gas first enters the sleeve cavity and then enters the axial cavity, which helps to guide the flow direction of the protective gas to flow in the first direction, reduces the loss of the powder flowing from the material guide shaft to the axial cavity, and helps to cool the material guide shaft to protect the deposition material. By providing the annular cavity surrounding the sleeve cavity, it also helps to reduce the temperature outside the material delivery head. By increasing the volume of the cavity in the material delivery head through the annular cavity and the transfer cavity, the stability of the gas pressure in the material delivery head is improved, thereby improving the stability of the deposition.

[0018] Further, the detachable connection and compression sealing of the material guide shaft are realized by the upper end cover and the lower end cover, which has a simple structure and is easy to construct and disassemble, and is helpful to simplify the operation.

[0019] According to the second aspect of the present application, the above-mentioned material delivery head is assembled into a laser deposition processing head, which helps to improve the universality of the laser deposition processing head.

[0020] Further, by constructing a coaxial laser deposition processing head structure, the annular laser beam and the main material conveying channel are highly integrated, realizing synchronous and accurate supply of light and material, and having the core advantages of compact structure, high energy utilization rate, strong material adaptability, good molten pool protection effect, and processing without directionality, which can significantly improve the efficiency, precision and material performance of additive manufacturing. Multiple annular auxiliary material conveying heads are coaxially arranged to accurately control the real-time proportioning and synchronous feeding of multiple deposition materials, facilitating the realization of composition gradient design and in-situ synthesis of composite reinforced phases, and significantly improving the designability of the material system. Through the dynamic mixing mechanism, the material flowability and molten pool wettability are improved, which can effectively reduce the porosity and refine the grain structure. The simultaneous feeding of multiple materials helps to combine the advantages of powder-fed LMD and wire-fed LMD, quickly switch material combinations to adapt to different working conditions, while maintaining high material utilization and deposition efficiency, providing an efficient integrated forming solution for the preparation of high-performance multifunctional metal components. By making the auxiliary material feeding module detachable, the structure can be adjusted according to actual needs, reducing the burden on the main module when auxiliary material feeding is not needed, improving the process accessibility of the laser deposition processing head, enabling it to enter narrower spaces for processing without interference and helping to extend the service life of the auxiliary material feeding module.

[0021] Further, the position of the transverse piece is adjustable, which facilitates adjusting the position of the intersection of the conveying channels of the multiple auxiliary material conveying heads according to the position of the molten pool set, thereby ensuring that each auxiliary material is accurately fed into the molten pool.

[0022] Further, the transverse piece can be freely rotated, which helps to adjust the setting direction of each auxiliary material conveying head in coordination with the moving direction of the laser deposition processing head. The main material and the auxiliary material are melted and mixed uniformly in the molten pool, forming a flow field in the molten pool. Due to the differences in nozzle processing precision and layout form, airflow field disturbance and powder particle size distribution, the flow field symmetry of different powder in the spot often deviates. When the cladding head moves relative to the workpiece, this deviation will couple with the motion direction, causing differences in powder deposition efficiency in different directions of travel. For example, if a certain material beam deviates to the front or rear of the spot, it will cause "front preheating-rear replenishment" differences along the direction of travel, affecting the molten pool shape and the actual capture rate of alloying elements. On the other hand, the physical properties of multiple materials deposited together are different, and the directional deviation in the molten pool will further amplify the capture rate difference, leading to local composition drift.

[0023] Further, according to the differences in the properties of the auxiliary materials and the deposition requirements, auxiliary material conveying heads with different feeding channels are selected to be installed on the support shell, which helps to further expand the design freedom of alloying, improve the universality of the laser deposition processing head, and improve the deposition quality.

[0024] Further, the cooling channel is formed adjacent to the molten pool of the support shell, and the circulation is formed by the cooling medium communication port and the external flow channel, which helps to continuously cool the support shell and the components carried thereby, reduces the damage to the structure of the main and auxiliary material feeding module caused by the high temperature radiation of the molten pool and the light reflection of the high reflectivity material, so as to adapt to the high-quality deposition of special materials with high melting point and high reflectivity, improve the stability of the deposition process, and prolong the service life of the main and auxiliary material feeding heads.

[0025] Further, the temperature and image of the molten pool and its surroundings are monitored in real time by the sensor, so as to monitor the deposition effect and realize process closed-loop control, thereby improving the product yield.

[0026] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and the content of the description can be implemented. The following is a detailed description of the preferred embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The structure schematic diagram of the laser deposition processing head shown in embodiment one of the present application is shown in the figure. Figure 2 The structure schematic diagram of the main material feeding head shown in embodiment one of the present application is shown in the figure. Figure 3 The cross-sectional structure schematic diagram of the auxiliary material feeding module shown in embodiment one of the present application is shown in the figure. Figure 4 The schematic diagram of the multiple setting directions of each auxiliary material feeding head shown in embodiment one of the present application is shown in the figure.

[0028] Legend: 1-main module, 11-outer shell, 111-communication port, 112-light source input port, 12-supporting seat, 2-main material feeding head, 201-feeding end, 202-discharging end, 21-upper end cover, 211-material input port, 212-gas interface, 213-gas through hole, 22-lower end cover, 221-mounting hole, 222-transferring cavity, 23-material chamber, 231-upper matching part, 232-annular cavity, 233-sleeve cavity, 234-temperature adjusting part, 235-lower matching part, 24-nozzle connecting column, 241-axial cavity, 25-nozzle, 251-material output port, 26-material guide shaft, 3-auxiliary material feeding module, 31-supporting shell, 311-middle shaft cavity, 32-fixing part, 321-fastening ring, 33-longitudinal part, 331-sliding groove, 332-abutting surface, 34-connection flange, 35-transverse part, 351-connection part, 352-bearing part, 353-fine adjustment screw, 354-cooling channel, 355-cooling medium interface, 356-protection part, 36-auxiliary material feeding head, 361-feeding channel, 37-probe insertion hole. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0033] The present application claims a material conveying head, which is in the overall structure of a long strip, has opposite feeding end 201 and discharging end 202, feeding end 201 is formed with material input port 211 and at least two gas interfaces 212, discharging end 202 is formed with material output port 251, material input port 211 is hermetically connected with material guide shaft 26 extending in the first direction, material guide shaft 26 is constructed as a straight pipe structure with both ends open, a long strip-shaped axial cavity 241 is formed inside the material conveying head, the axial cavity 241 extends in the first direction and is coaxial with the material guide shaft 26, the axial cavity 241 is simultaneously communicated with each gas interface 212 and the inside of the material guide shaft 26, and the other end is communicated with the surface of the material conveying head to form the material output port 251.

[0034] The deposition material enters the material delivery head from the feeding end 201, enters the axial cavity 241 along the material guide shaft 26, and exits the material delivery head from the material output port 251. The shielding gas enters the material delivery head from at least one gas interface 212, is ejected from the material output port 251 along the axial cavity 241, and reaches the molten pool, thereby protecting the deposition material from being oxidized at high temperature. When the deposition material is a wire, the inner diameter of the material guide shaft 26 is matched with the diameter of the wire, thereby ensuring that the wire is fed in a straight line and reducing the risk of wire bending. After the wire enters the axial cavity 241, it is protected by the shielding gas to prevent oxidation and denaturation due to the small distance between the axial cavity 241 and the molten pool and the high temperature. When the deposition material is a powder, the inner diameter of the material guide shaft can be adjusted according to the particle size of the powder, and the inner diameter of the material guide shaft can be adjusted according to the size of the deposition target to improve the deposition quality. The gas pressure can also be adjusted by the connection mode of the gas interface 212. When the shielding gas is introduced from each gas interface 212, it helps to increase the gas pressure when the powder is fed. This mode is suitable for powder beam strengthening when the processing head has an angle greater than 0°, preventing the powder beam from reaching the working area due to gravity. When some gas interfaces 212 are connected to the shielding gas, the remaining gas interfaces 212 are connected to the atmosphere and are provided with a flow control knob, which realizes dynamic pressure regulation, ensures that the shielding gas is delivered to the molten pool, and prevents the shielding gas from being dispersed due to excessive gas pressure. Through the structural design of the material delivery head, it can adapt to deposition materials of different forms and specifications, and can adapt to various working conditions, has high universality, and reduces the equipment cost and time cost when preparing products with diversified structures.

[0035] For details, please refer to the following examples.

[0036] Example 1 Please refer to Figure 1 The laser deposition processing head shown in a preferred embodiment of the present application includes a main body module 1 and a main material delivery head 2 and a secondary material feeding module 3 installed on the main body module 1.

[0037] The main body module 1 comprises an outer shell 11 and a light path shaping mechanism installed inside the outer shell 11. The outer shell 11 is configured as a hollow rectangular block, with a communication port 111 formed at the bottom and light source input ports 112 formed at any side. The communication port 111 is a through hole with a ring-shaped transparent protective lens installed to achieve light transmission and structural protection, and the light source input ports 112 are light-transmitting structures. The outer shell 11 is coaxially installed with a ring-shaped support seat 12 at the position corresponding to the communication port 111, which is used to connect the auxiliary material feeding module 3 and support the ring-shaped transparent protective lens. External laser light is input from the light source input ports 112 into the outer shell 11 to form a solid incident light, and the light path shaping mechanism shapes the incident light into a ring-cone-shaped laser beam, with the transmission direction of the laser beam parallel to the first direction and output from the communication port 111. The laser beam forms a hollow cone-shaped area inside, forming a dark zone, and the laser beam is focused into a molten pool. In some embodiments, the surface of the outer shell 11 is formed with a cooling and protective medium interface for passing cooling medium and inert gas to cool and prevent oxidation. Since the specific structure and principle of the light path shaping mechanism are prior art, they are not described here.

[0038] Please refer to Figure 1 and Figure 2 The main material feeding head 2 is connected to the outer shell 11 and disposed in the dark zone, used to feed the main material to the molten pool along the first direction. The main material feeding head 2 in this embodiment is configured as a long strip, with opposite feeding end 201 and discharging end 202, and comprises upper end cover 21, lower end cover 22, material chamber 23, nozzle connecting column 24 and nozzle 25 connected coaxially along the first direction, and material guide shaft 26. The upper end cover 21 forms the feeding end 201 of the main material feeding head 2, and the nozzle 25 forms the discharging end 202 of the main material feeding head 2.

[0039] The upper end cover 21 and the lower end cover 22 are both configured as circular plates with the same diameter. The surface of the upper end cover 21 is provided with a material input port 211 at the center and two gas interfaces 212 symmetrically arranged on both sides of the material input port 211, and the upper end cover 21 is formed with circular through holes corresponding to the positions of the material input port 211 and the gas interfaces 212. The lower end cover 22 is detachably connected to the side of the upper end cover 21 away from the gas interfaces 212, and is formed with circular through holes corresponding to the positions of the material input port 211 and the gas interfaces 212, thereby forming gas through holes 213 communicating with the gas interfaces 212. The through hole on the lower end cover 22 corresponding to the material input port 211 is a mounting hole 221, and the diameter of the mounting hole 221 is larger than that of the corresponding through hole on the upper end cover 21. A straight pipe-shaped material guide shaft 26 with both ends open is detachably connected to the mounting hole 221, one end of which is sleeved in the mounting hole 221, the outer wall is sealingly connected to the mounting hole 221 through a flexible sealing ring, and is tightly pressed under the action of the upper end cover 21, so that the material guide shaft 26 is sealingly connected to the material input port 211. The material guide shaft 26 extends in the first direction as a whole.

[0040] The material chamber 23 comprises an upper fitting portion 231, a temperature adjusting portion 234 and a lower fitting portion 235 connected coaxially in sequence, all of which are configured in a cylindrical shape and decrease in diameter. The diameter of the upper fitting portion 231 of the material chamber 23 is fitted to the lower end cover 22 and detachably connected coaxially to the material chamber 23. The side surface of the lower end cover 22 close to the material chamber 23 is formed with two gas through holes 213 and a circular groove coaxial with the lower end cover 22, so that the lower end cover 22 and the surface of the material chamber 23 enclose a circular and thin transfer cavity 222. The side surface of the material chamber 23 close to the lower end cover 22 is formed with a circular annular deep groove extending along the first direction, so as to enclose an annular cavity 232 with the lower end cover 22, which is communicated with the transfer cavity 222. The side surface of the material chamber 23 close to the lower end cover 22 is also formed with a long strip-shaped cavity extending along the first direction, so as to enclose a sleeving cavity 233 with the lower end cover 22, which is communicated with the transfer cavity 222. The annular cavity 232 and the sleeving cavity 233 are coaxial with the upper end cover 21. The end of the annular cavity 232 close to the transfer cavity 222 is expanded so that the diameter of the outer circle is larger, so as to realize buffering. The outer wall of the annular cavity 232 adjacent to the temperature adjusting portion 234 helps to reduce the influence of the temperature rise of the temperature adjusting portion 234 due to laser irradiation of the light path shaping mechanism on the sleeving cavity 233 around it. The diameter of the sleeving cavity 233 is fitted to the mounting hole 221 and is larger than the outer wall diameter of the material guide shaft 26. The material guide shaft 26 is sleeved in the sleeving cavity 233 and separated from the inner wall of the sleeving cavity 233. The sleeving cavity 233 penetrates the upper fitting portion 231 and the temperature adjusting portion 234 of the material chamber 23, and one end of the sleeving cavity 233 extends into the lower fitting portion 235. The nozzle connecting column 24 is connected to the lower fitting portion 235 of the material chamber 23, and the diameter is fitted to the lower fitting portion 235 of the material chamber 23. The nozzle 25 is a consumable part and is detachably connected to the nozzle connecting column 24. The end of the sleeving cavity 233 away from the lower end cover 22 is inwardly contracted and coaxially connected with an axial cavity 241, which is configured in a long strip shape and has a smaller diameter than the sleeving cavity 233. The end of the material guide shaft 26 away from the material input port 211 is adjacent to the end of the axial cavity 241 and separated from the axial cavity 241. The axial cavity 241 extends along the first direction to the surface of the lower fitting portion 235 of the material chamber 23, and penetrates the nozzle connecting column 24 and the nozzle 25, so as to form a material output port 251 at the end away from the upper end cover 21. In this embodiment, the upper fitting portion 231 of the material chamber 23 is supported on the top outer wall of the main shell, and the communication port 111 of the main shell corresponds to the position of the lower fitting portion 235 of the material chamber 23 adjacent to the nozzle connecting column 24.

[0041] The main material delivery head 2 can be used for the delivery of wire material or powder material. The main material enters the material delivery head from the feeding end 201, and enters the axial cavity 241 along the material guide shaft 26, and exits the material delivery head from the material output port 251. The shielding gas enters the material delivery head from at least one gas interface 212, and sequentially passes through the gas through hole 213, the transfer cavity 222, the sleeve cavity 233 and the axial cavity 241, and is sprayed out of the material delivery head from the material output port 251 to reach the molten pool, thereby protecting the main material from being oxidized and denatured at high temperature due to the small distance between the axial cavity 241 and the molten pool.

[0042] When the main material is wire material, the material guide shaft 26 with an inner diameter matched with the diameter of the wire material is selected to be installed on the lower end cover 22, and the nozzle 25 with a matched inner diameter is selected to be installed on the nozzle connecting column 24, so as to ensure that the wire material is fed in a straight line, reduce the risk of shaking and bending of the wire material, and improve the accuracy of the material output position. After the wire material enters the axial cavity 241, it is protected by the shielding gas, so as to prevent the wire material from being oxidized and denatured due to the small distance between the axial cavity 241 and the molten pool and the high temperature.

[0043] When the main material is powder material, the appropriate material guide shaft 26 and nozzle 25 are selected according to the particle size and the required deposition size, and the gas pressure is adjusted through the connection mode of the gas interface 212. When the shielding gas is introduced from each gas interface 212, it is helpful to improve the gas pressure when the powder material is fed. This mode is suitable for powder beam strengthening when the processing direction, i.e. the first direction, is inclined upward, so as to prevent the powder beam from falling and failing to reach the molten pool due to gravity. When one gas interface 212 introduces the shielding gas and the other gas interface 212 is connected with the atmosphere, dynamic pressure regulation is realized, which not only ensures that the shielding gas is delivered to the molten pool, but also prevents the shielding gas from being blown away due to excessive gas pressure, so that the powder material flows more gently and almost relies on the self-weight of the powder material to flow out of the nozzle 25. When both gas interfaces 212 introduce the shielding gas, the gas pressure should not be too large, otherwise the molten pool will be blown away. When only one gas interface 212 introduces the shielding gas, a larger gas flow can be used for input, so as to realize circulating air cooling.

[0044] When the material guide shaft 26 is used for a period of time, the inner wall will become rough due to the long-term impact of the wire material or powder flow, which will affect the quality of material delivery, such as powder scattering or powder blocking, and the wire material will not be output smoothly. At this time, the material guide shaft 26 needs to be replaced. Therefore, in the embodiment, the material guide shaft 26 is consumable, which is convenient for disassembly and assembly, and is also helpful to improve the deposition quality and prolong the service life.

[0045] The sub-material feeding module 3 comprises a ring-shaped support housing 31 and a plurality of sub-material delivery heads 36 mounted on the support housing 31, the support housing 31 extends in the first direction as a whole, is detachably connected to the communication port 111 of the main body module 1, and has a central axis cavity 311 formed in the middle portion for the laser beam to pass through, and the plurality of sub-material delivery heads 36 are circumferentially arranged and penetrate through the support housing 31, each of the sub-material delivery heads 36 is used for delivering sub-material from the outside of the laser beam to the molten pool, and the sub-material is a wire material or a powder material.

[0046] By constructing the coaxial laser deposition processing head structure, the annular laser beam and the main material delivery channel are highly integrated, the synchronous and precise coupling of light and material is realized, and the core advantages of compact structure, high energy utilization rate, strong material adaptability, good molten pool protection effect, excellent layer bonding quality, and no processing directionality are achieved, which can significantly improve the efficiency, precision and material performance of additive manufacturing. The multiple circumferential sub-material delivery heads 36 are coaxially arranged, which can precisely control the real-time proportioning and synchronous feeding of multiple deposition materials, facilitate the realization of composition gradient design and in-situ synthesis of composite reinforced phases, and significantly improve the designability of the material system. Through the dynamic mixing mechanism, the material flowability and molten pool wettability are improved, which can effectively reduce the porosity and refine the grain structure. The simultaneous feeding of multiple materials helps to compatible the advantages of powder feeding LMD and wire feeding LMD two technical routes, can quickly switch the material combination to adapt to different working condition requirements, while maintaining high material utilization rate and deposition efficiency, providing an efficient integrated forming scheme for preparing high-performance multifunctional metal components. By detachably connecting the sub-material feeding module 3, it is convenient to adjust the structure according to actual needs, reduce the burden of the main body module 1 when sub-material feeding is not needed, and increase the processing accessibility.

[0047] Please refer to Figure 2 and Figure 3The support shell 31 comprises a fixing part 32, a longitudinal part 33, a connecting flange 34 and a transverse part 35. One end of the fixing part 32 is detachably connected to the bottom of the support base 12 by screwing, so that the central axis cavity 311 is coaxial with the communication port 111 and communicates with each other. The longitudinal part 33 is sleeved in the fixing part 32, and a matching thread is formed between the outer wall of the longitudinal part 33 and the inner wall of the fixing part 32, so that the longitudinal part 33 is controllably lifted in the first direction with its rotation. The fixing part 32 further comprises a fastening ring 321 sleeved on the outside of the longitudinal part 33, which is arranged at the bottom of the fixing part 32, used to lock the longitudinal part 33 after positioning, to prevent the longitudinal part 33 from sliding down. A plurality of protective gas ports are formed on the support base 12, which penetrate the support base 12, and a long and narrow flow guide cavity is formed between the support base and the outer surface of the fixing part 32, which is used to introduce protective gas into the central axis cavity 311 while providing transverse air blowing for the protective lens to avoid splashing dust pollution to the protective lens. The protective gas ports are arranged in a circle, which are used to introduce protective gas into the central axis cavity 311. A circular sliding groove 331 is formed on the position of the longitudinal part 33 away from the fixing part 32. The cross section of the sliding groove 331 is rectangular, and the sliding groove 331 comprises an inner abutting surface 332 extending in the first direction. The connecting flange 34 is formed by splicing two half circular ring structures to reduce the structural damage caused by thermal stress. Part of the connecting flange 34 is embedded in the sliding groove 331, and the inner diameter of the connecting flange 34 is larger than the inner abutting surface 332. The transverse part 35 comprises a connecting part 351 and a bearing part 352 connected to each other. The top side of the connecting part 351 of the transverse part 35 is connected to the bottom surface of the connecting flange 34, and is sleeved on the outside of the longitudinal part 33. The inner wall diameter of the connecting part 351 is larger than the outer wall diameter of the longitudinal part 33, and the gap ring width between the connecting part 351 and the longitudinal part 33 is smaller than the gap between the connecting flange 34 and the inner abutting surface 332, so that the transverse part 35 is freely rotated relative to the longitudinal part 33 in the plane perpendicular to the first direction, and is freely slid within a certain range. Six fine adjustment screws 353 are uniformly arranged in a circle and perpendicular to the first direction, and are connected to the connecting part 351 of the transverse part 35, penetrating the connecting part 351 of the transverse part 35 and abutting to the longitudinal part 33 at the end, and are tightly connected with the connecting part 351 of the transverse part 35 through the thread on the surface. The transverse part 35 is controllably fine adjusted and freely rotated in the plane relative to the longitudinal part 33 by pushing the transverse part 35 from multiple directions through the fine adjustment screws 353. After adjusting the position in the plane and the rotation angle, the fine adjustment screws 353 are tightened to fix the position, so as to ensure that the transverse part 35 does not move relative to the longitudinal part 33 during operation.

[0048] The sub-material delivery head 36 is configured in a strip shape, and a feeding channel 361 extending in a straight line and penetrating through the sub-material delivery head 36 is formed inside. Different specifications of the sub-material delivery head 36 are matched with different diameters of the wire and powder according to the diameter of the feeding channel 361, and the outer wall structures of the sub-material delivery heads 36 of different specifications are the same. The transverse piece 35 is internally formed with a plurality of material head sockets penetrating through the transverse piece 35, the material head sockets are uniformly distributed in the circumferential direction, the extending directions are all the directions inclined to the first direction towards the central axis cavity 311, and the included angles with the first direction are the same. Each sub-material delivery head 36 is detachably inserted into each material head socket, so that one end of each sub-material delivery head 36 extends into the central axis cavity 311, so that the feeding channel 361 of each sub-material delivery head 36 is formed in a conical shape.

[0049] Please refer to Figure 4 By the structural design of the support shell 31, the positions and directions of the sub-material delivery heads 36 are easily adjusted, and the accurate delivery of the plurality of sub-materials to the molten pool by the sub-material delivery heads 36 is easily ensured. Since the main material and the sub-material are melted and mixed uniformly at the molten pool, a flow field is formed in the molten pool. Due to the machining precision and layout form of the nozzle, the disturbance of the airflow field, and the difference in powder particle size distribution, the flow field symmetry of different powder paths in the light spot often deviates. When the cladding head moves relative to the workpiece, this deviation will be coupled with the movement direction, resulting in differences in powder deposition efficiency in different directions of movement. For example, if a certain material beam deviates in front of or behind the light spot, it will cause a "front preheating-rear replenishment" difference along the direction of movement, affecting the shape of the molten pool and the actual capture rate of alloying elements. Among them, forward deviation is beneficial to the material entering the high temperature zone in advance, but it may cause some powder to rebound or splash loss with the movement of the workpiece. The material deviated backward is more likely to enter the tail of the molten pool, and the deposition efficiency is high, but it may cause uneven directionality of the molten pool flow and the organization solidification. If one of the three material paths deviates laterally from the movement direction, it will cause obvious asymmetry in the formed cross section, and for functional gradient materials or alloying design, this asymmetry will directly affect the composition gradient distribution accuracy. On the other hand, the physical properties of the multiple materials deposited together are different, and the directional deviation in the molten pool will further amplify the capture rate difference, causing local composition drift.

[0050] The sub-material feeding module 3 further comprises a cooling channel 354 embedded in the bearing part 352 of the transverse piece 35. The cooling channel 354 is configured in a circular ring shape coaxial with the central axis cavity 311, adjacent to the side of the transverse piece 35 away from the connecting flange 34, and adjacent to the outer wall of the transverse piece 35. Two medium communication openings respectively communicate the cooling channel 354 with the outer surface of the transverse piece 35, and the end of the medium communication opening away from the cooling channel 354 is connected with a cooling medium interface 355 for communicating with the external pipeline.

[0051] When the laser deposition processing head is working, the temperature near the transverse piece 35 adjacent to the molten pool is high, which can reach thousands of degrees Celsius. Strong heat radiation can easily cause damage to the secondary material feeding module 3. By introducing cooling medium into the cooling channel 354, the service life of the secondary material feeding module 3 can be prolonged. In this embodiment, circulating cooling water is used as the cooling medium, and the water forms a circulation with the external pipeline in the cooling channel 354.

[0052] In this embodiment, the transverse piece 35 is protruded in the middle of the side close to the molten pool to form a protection part 356. The protection part 356 is configured as a hollow circular table shape with both ends open, which is in communication with the central axis cavity 311 for the laser beam to pass through, and the diameter decreases towards the direction close to the molten pool, thereby reducing heat radiation, shielding light reflection, increasing the water cooling contact surface, and further protecting the nozzle 25 of the primary material feeding head 2 and the end of the secondary material feeding head 36, thereby prolonging the service life.

[0053] The secondary material feeding module 3 also includes a sensor. The sensor is configured as a long strip-shaped probe, which is detachably installed in the transverse piece 35 by being inserted into the probe insertion hole 37 penetrating through the transverse piece 35, and one end of the sensor is in communication with the central axis cavity 311, which is used to collect temperature data and images around the molten pool, thereby monitoring the temperature change of the molten pool and the transmission of various materials in real time, which helps to improve the deposition quality, and facilitates the adjustment of the overall position of the secondary material feeding module 3.

[0054] The laser deposition processing head in this embodiment also includes a primary feeding head protection cover. The primary feeding head protection cover is configured as a hollow circular table shape with both ends open, which is detachably and coaxially connected to the communication port of the main module, the cavity inside is for the laser beam to pass through, and the diameter decreases towards the direction close to the molten pool, which is used to protect the nozzle of the primary material feeding head. When the feeding of the secondary material is not needed during production, the secondary material feeding module is detached and the primary feeding head protection cover is installed, which helps to prolong the service life of the whole equipment. When working in an inert gas sealed cabin, the primary feeding head protection cover can also not be used when the secondary material feeding module is not used, so that the processing end only includes the nozzle connecting column 24 and the nozzle 25, which has the ability to penetrate into narrow spaces for cladding or depositing materials.

[0055] The technical features of the above-described embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure.

[0056] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A material conveying head, characterized in that, The overall structure is elongated and has a feed end (201) and a discharge end (202). The feed end (201) has a material input port (211) and at least two gas ports (212). The discharge end (202) has a material output port (251). The material input port (211) is sealed and connected to a material guide shaft (26) extending in a first direction. The material guide shaft (26) is a straight tube structure with open ends. An elongated hollow axial cavity (241) is formed inside the material conveying head. The axial cavity (241) extends in the first direction and is coaxial with the material guide shaft (26). The axial cavity (241) is connected to each of the gas ports (212) and the inside of the material guide shaft (26). The other end is connected to the surface of the material conveying head to form the material output port (251).

2. The material conveying head as described in claim 1, characterized in that, It also includes a sleeve cavity (233), an annular cavity (232), and a transfer cavity (222). The transfer cavity (222) is adjacent to each of the gas interfaces (212), and each of the gas interfaces (212) is connected to the transfer cavity (222) through a gas through-hole (213). The sleeve cavity (233) and the annular cavity (232) are both connected to the side of the transfer cavity (222) away from the gas interface (212). (233) The material guide shaft (26) extends along the first direction and is coaxially sleeved in the sleeve cavity (233). The end of the sleeve cavity (233) away from the transfer cavity (222) is connected to the axial cavity (241), and the diameter of the sleeve cavity (233) is larger than that of the axial cavity (241). The annular cavity (232) is constructed as an annular strip, surrounds the axial cavity (241), and one end is connected to the transfer cavity (222).

3. The material conveying head as described in claim 2, characterized in that, The assembly includes an upper end cover (21), a lower end cover (22), a material chamber (23), a nozzle connecting post (24), and a nozzle (25). The upper end cover (21) is detachably connected to the lower end cover (22). The material inlet (211) and each of the gas interfaces (212) are connected to the surface of the upper end cover (21) away from the lower end cover (22). The gas through hole (213) is composed of through holes that pass through the upper end cover (21) and the lower end cover (22). The upper end cover (21) has a through hole corresponding to the position of the material inlet (211), and the lower end cover (22) has a through mounting hole (221) corresponding to the position of the material inlet (211). One end of the material guide shaft (26) is sleeved inside the mounting hole (221) and is connected to the material inlet (25). The inner wall of the mounting hole (221) is detachably and sealed. The lower end cover (22) is detachably connected to the material chamber (23). The surface of the material chamber (23) and / or the lower end cover (22) is formed with a groove structure, so that the surface of the material chamber (23) and the lower end cover (22) together form the transfer cavity (222). The sleeve cavity (233) and the annular cavity (232) are both formed inside the material chamber (23), and the annular cavity (232) is adjacent to the outer wall of the material chamber (23). The nozzle connecting post (24) is connected to the material chamber (23), and the nozzle (25) is detachably connected to the nozzle connecting post (24). The axial cavity (241) extends into the material chamber (23) and penetrates the nozzle connecting post (24) and the nozzle (25).

4. A laser deposition processing head, characterized in that, Includes a main material conveying head (2), which is a material conveying head as described in any one of claims 1 to 3.

5. The laser deposition head as described in claim 4, characterized in that, It also includes the main module (1) and the auxiliary material feeding module (3). The main module (1) includes an outer shell (11) and an optical path shaping mechanism disposed inside the outer shell (11). The outer shell (11) has a light source input port (112) and a communication port (111). The optical path shaping mechanism is used to shape the solid incident light input from the light source input port (112) to form laser beams transmitted from multiple positions surrounding the molten pool toward the molten pool. The laser beams are output from the communication port (111), and the hollow area enclosed by the laser beams is a light-free area. The main material conveying head (2) is connected through the outer shell (11) and is located in the dark area, for conveying the main material to the molten pool along the first direction. The main material is wire or powder. The auxiliary material feeding module (3) includes an annular support housing (31) and a plurality of auxiliary material conveying heads (36) installed on the support housing (31). The support housing (31) is detachably connected to the communication port (111) of the main module (1) and has a central cavity (311) formed in the middle for the laser beam to pass through. The plurality of auxiliary material conveying heads (36) are arranged circumferentially and penetrate the support housing (31). Each auxiliary material conveying head (36) is used to convey auxiliary material from the outside of the laser beam to the molten pool. The auxiliary material is wire or powder.

6. The laser deposition head as described in claim 5, characterized in that, The supporting housing (31) includes a fixing member (32), a longitudinal member (33), and a transverse member (35). The fixing member (32) is connected to the communication port (111) of the main body module (1). The longitudinal member (33) is slidably connected to the fixing member (32) and can move controllably along the first direction. The transverse member (35) is slidably connected to the longitudinal member (33) and can slide controllably in multiple directions in a plane perpendicular to the first direction. The central cavity (311) is connected to the outside through a protective gas port for introducing protective gas. Multiple auxiliary material conveying heads (36) are all supported by the transverse member (35).

7. The laser deposition head as described in claim 6, characterized in that, The longitudinal member (33) is sleeved inside the fixing member (32), and the outer wall of the longitudinal member (33) and the inner wall of the fixing member (32) are slidably connected by threads. A circular sliding groove (331) is formed on the longitudinal member (33) away from the fixing member (32). The sliding groove (331) has a rectangular cross-section and includes an inner contact surface (332) extending along the first direction. A circular connecting flange (34) is partially embedded in the sliding groove (331), and the inner diameter of the connecting flange (34) is larger than the inner contact surface (332), allowing the connecting flange (34) to slide and rotate freely relative to the longitudinal member (33). The transverse member (33) 5) Includes a connecting part (351) and a bearing part (352) that are connected to each other. The connecting part (351) of the transverse member (35) is connected to the connecting flange (34) and sleeved on the outside of the longitudinal member (33). Its inner wall diameter is larger than the outer wall diameter of the longitudinal member (33). At least three fine-tuning screws (353) perpendicular to the first direction pass through and are fastened to the connecting part (351) of the transverse member (35). The fine-tuning screws (353) are arranged around the longitudinal member (33) and their ends abut against the longitudinal member (33) for adjusting the position of the transverse member (35). Multiple auxiliary material conveying heads (36) are all carried on the bearing part (352) of the transverse member (35).

8. The laser deposition head as described in claim 5, characterized in that, The auxiliary material conveying head (36) includes a feeding channel (361) extending in a straight line. The feeding channel (361) is connected to the central shaft cavity (311) and its diameter is matched with the auxiliary material. The support housing (31) has a plurality of material head inlets, and the plurality of auxiliary material conveying heads (36) are detachably connected to each of the material head inlets.

9. The laser deposition head as described in claim 5, characterized in that, The auxiliary material feeding module (3) also includes multiple media connection ports and cooling channels (354). The cooling channels (354) are annular in structure, embedded in the support shell (31) and adjacent to the molten pool. Each of the media connection ports is used to connect the cooling channels (354) with the surface of the support shell (31). Each of the auxiliary material conveying heads (36) is adjacent to the cooling channels (354).

10. The laser deposition head as described in claim 5, characterized in that, The auxiliary material feeding module (3) also includes a sensor for collecting temperature data and / or image data around the molten pool.

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