Laser welding powder feeding device

Abstract

The invention discloses a laser welding powder feeding device which comprises a powder storage unit, a powder feeding regulation and control unit, a powder mixing unit, a powder feeding unit and an air feeding unit. A powder storage bin is arranged in the powder storage unit, the powder feeding regulation and control unit comprises screws in one-to-one correspondence with the powder storage bin, the screws penetrate through a cover plate at the top of the powder storage bin and extend into the powder mixing unit after passing through the powder storage bin and a bottom plate, an annular powder mixing bin and stirring blades are arranged in the powder mixing unit, and the bottom of the powder mixing bin communicates with the powder feeding unit through a powder conveying pipe. A powder feeding bin is arranged in the powder feeding unit, the powder feeding unit is sleeved with an air feeding unit, and an annular air feeding bin is arranged in the air feeding unit. Through cooperative control of the multiple independent powder storage bins and the independent screw rods, compounding of multi-element powder in any proportion is achieved; a Venturi tube structure is integrated in the powder feeding bin, so that the powder flowability is remarkably improved, and the powder utilization rate is increased; the coaxial design of the powder flow of the air feeding unit and the powder feeding unit effectively inhibits splashing after powder is sent out, and the powder feeding precision and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding powder feeding, and in particular to a laser welding powder feeding device. Background Art

[0002] Currently, there are two main powder feeding methods for laser powder welding: coaxial feeding and lateral feeding. Coaxial feeding delivers powder into the molten pool through the center channel of the laser beam, which provides high powder feeding accuracy and powder utilization. Lateral feeding delivers powder into the molten pool from the side of the laser beam. This method provides a wide powder feeding range but relatively low powder feeding accuracy.

[0003] Existing research has developed an intelligent laser powder welding device based on multi-sensor online monitoring. This device utilizes multi-sensor monitoring equipment such as spectrometers, high-speed cameras, and infrared thermometers to obtain real-time information on the dynamic characteristics of the molten pool during the laser powder welding process. The control system then adjusts the powder feed rate and laser welding process parameters based on this data. Other studies have proposed a powder design method and device for laser powder welding with gradient microstructures. This method uses an autonomous optimization algorithm to screen suitable intermediate element powders, establishes a method for scanning the weld before welding to obtain dimensional information, and dynamically adjusts the powder ratio by breaking the whole into smaller parts. This method achieves laser powder welding joints with gradient composition changes, thereby improving joint performance. To further improve weld performance, some studies have added nanoparticles, such as TiC, SiC, TiN, and TiB, to the filler powder. These nanoparticles are then introduced into the weld through laser powder welding, thereby improving the weld's mechanical properties and porosity resistance.

[0004] However, existing powder feeders still have shortcomings in terms of powder feeding accuracy and stability. For example, the powder feeder's feeding speed can be affected by factors such as powder fluidity and blockage in the powder feed pipe, leading to fluctuations in the powder feed rate and thus affecting welding quality. Furthermore, the powder feeder's structure is complex and has high maintenance costs.

[0005] Although multi-sensor online monitoring technology can obtain dynamic feature information of the molten pool in real time during the welding process, the current monitoring system still has certain limitations in data processing and analysis. For example, the characteristic information of different materials generated during the welding process, such as spectral signals and temperature changes, differs greatly, and the monitoring system needs to conduct a large number of experiments and data accumulation for different materials in order to accurately identify and analyze these characteristic information. The laser powder filling welding powder design method for gradient microstructure can improve the joint performance, but the design and implementation process is complex, and a complex self-optimization algorithm and a system for dynamically adjusting the powder ratio need to be established, and the control requirements for the welding process parameters are high. The nano-particle enhanced laser powder filling welding technology can improve the performance of the weld, but there are still some problems in practical application. For example, the dispersibility of nano-particles is poor, which is easy to agglomerate during the welding process, affecting the performance of the weld. In addition, the addition of nano-particles may increase the welding cost.

[0006] In addition, although the existing technology improves the welding quality and efficiency to some extent, it still cannot completely avoid the generation of welding defects. For example, during the laser powder filling welding process, defects such as pores, cracks, and incomplete fusion may occur. These defects not only affect the mechanical properties of the weld, but also may cause the corrosion resistance and fatigue performance of the weld to decrease.

[0007] In summary, the existing powder feeding device has many problems in the multi-material composite welding scene, such as insufficient material composite capability, mixed precision and uniformity defects, powder spatter and oxidation pollution, and insufficient dynamic matching. These problems seriously restrict the further development of laser welding and cladding technology in the field of high-end manufacturing. Therefore, it is urgent to develop a new type of powder feeding device that can realize multi-material dynamic proportioning, gas-powder collaborative delivery and molten pool state self-adaptation, in order to break through the bottleneck of existing technology and meet the urgent needs of the aerospace, automobile manufacturing and other fields for high-quality and high-efficiency welding technology. SUMMARY

[0008] The present application provides a laser welding powder feeding device, which realizes arbitrary proportioning of multi-element powder through the collaborative control of multiple independent powder storage bins and independent screws, significantly improves powder flowability by integrating a Venturi tube structure inside the powder feeding bin, and improves powder utilization rate. The coaxial design of the powder flow of the gas feeding unit and the powder feeding unit effectively suppresses powder spatter after powder feeding, and improves powder feeding accuracy and stability.

[0009] To solve the above technical problems, the present application provides a laser welding powder feeding device, comprising a powder storage unit, a powder feeding control unit, a powder mixing unit, a powder feeding unit, and a gas feeding unit.

[0010] A plurality of independent powder storage bins are arranged in the powder storage unit, and a cover plate is arranged on the top of each powder storage bin and a bottom plate is arranged at the bottom of each powder storage bin.

[0011] The powder feeding control unit includes a screw corresponding to each powder storage bin. The screw passes through the cover plate on the top of the powder storage bin, passes through the powder storage bin and the bottom plate, and then extends into the powder mixing unit.

[0012] An annular powder mixing bin and stirring blades are provided in the powder mixing unit, and the bottom of the powder mixing bin is connected to the powder feeding unit through a plurality of powder conveying pipes;

[0013] A powder feeding bin is provided in the powder feeding unit, an air feeding unit is provided outside the powder feeding unit, an annular air feeding bin is provided in the air feeding unit, and the central axes of the powder outlet at the bottom of the powder feeding bin and the air outlet at the bottom of the air feeding bin coincide with each other.

[0014] The present invention utilizes multiple independent powder storage silos, enabling simultaneous delivery of multiple powders of varying compositions. By controlling the screw speed, dynamic proportioning of the multiple powders can be achieved, allowing precise control of the delivery rate of each powder. This eliminates the tedious process of frequent powder changes required by traditional single-silo powder feeding devices and allows for real-time adjustment of material proportions based on welding requirements, enabling dynamic composite deposition of gradient materials. This enables the device to meet the welding requirements of complex material systems in fields such as aerospace and automotive manufacturing. For example, in the manufacture of aerospace engine blades, dynamic adjustment of powder composition can be used to optimize material properties in different locations, thereby improving the overall performance and service life of the component.

[0015] The present invention installs an air supply unit on the periphery of the powder supply unit and adopts gas-powder coordinated conveying technology to form a gas barrier around the delivered powder, effectively suppressing powder splashing and effectively improving powder delivery accuracy. At the same time, it can effectively reduce powder waste and reduce the emission of harmful gases and dust generated during welding. At the same time, the air supply unit effectively prevents powder oxidation through gas, ensuring the purity of the powder during the conveying and welding process. By reducing powder splashing and oxidation pollution, it can significantly reduce the occurrence of welding defects and improve the performance and reliability of welded joints. For example, in automobile manufacturing, the quality of welded joints directly affects the safety and durability of the vehicle. This device can effectively improve welding quality and reduce after-sales maintenance costs.

[0016] Furthermore, adjacent powder storage bins in the powder storage unit are separated by detachable isolation plates, and the number of isolation plates can be adjusted according to actual needs, thereby adjusting the number of powder storage bins.

[0017] Furthermore, the powder feeding control unit also includes a fixed plate and a drive motor mounted on the fixed plate for driving the screw to rotate. The drive motor controls the screw speed, thereby controlling the powder feeding amount. The drive motors are controlled separately to achieve proportional control of the output of multiple powders.

[0018] Further, the powder mixing bin comprises an upper section mixing bin, a middle section mixing bin and a lower section mixing bin, the outer periphery of the upper section mixing bin and the lower section mixing bin is conical, the outer periphery of the middle section mixing bin is cylindrical, and the stirring blade is located in the middle section mixing bin. Through the conical mixing bin of the upper and lower sections and the forced shearing mixing of the high-speed rotation of the stirring blade of the middle section mixing bin, the problem of interlayer segregation of the powder flow is effectively solved, and it is ensured that the powder is uniformly distributed during the conveying process; such uniform powder flow can form a cladding layer with uniform composition, and significantly improve the mechanical properties and quality stability of the welded part.

[0019] Further, the powder feeding bin comprises a first powder feeding bin connected with the powder conveying pipe, the first powder feeding bin is connected to a conical annular second powder feeding bin through a Venturi tube, and the first powder feeding bin is connected with a carrier gas input pipe. The powder is driven to flow downward by the carrier gas, the powder flow is accelerated by the converging-diverging channel of the Venturi tube, and the conveying blockage is effectively prevented.

[0020] Further, the gas feeding unit further comprises a gas feeding pipe connected to the gas feeding bin for inputting the protective gas, the gas feeding bin comprises a pressure buffering bin close to the gas feeding port of the gas feeding pipe and a conical gas feeding bin connected with the pressure buffering bin. The gas flow distribution is balanced through the pressure buffering bin, the protective gas uniformly covers the laser molten pool, the carrier gas and the protective gas are sprayed out through different channels, and mutual interference is avoided.

[0021] Further, the number of the powder storage bins and the screw rods is 2-6.

[0022] Further, the laser unit sequentially passes through the axis of the powder feeding regulation unit, the powder storage unit, the powder mixing unit and the powder feeding unit from top to bottom, and the laser beam output by the laser unit is focused on the axis of the gas outlet of the gas feeding bin and the powder outlet of the powder feeding bin.

[0023] Further, the gas flow pressure of the gas feeding bin is 0.2-0.8 MPa.

[0024] Further, the ratio of the gas flow rate output by the gas feeding bin to the powder rate output by the powder feeding bin is (1.2-2):1.

[0025] The beneficial effects of the present application are as follows:

[0026] The present application adopts a plurality of independent powder storage bins, can simultaneously convey a plurality of powders with different components, realizes dynamic proportioning of a plurality of powders through control of the rotation speed of the screw rod, accurately controls the conveying amount of each powder, avoids the cumbersome operation of frequent replacement of powder in the traditional single powder bin powder feeding device, and can also adjust the material proportioning in real time according to the welding requirement, and realizes dynamic composite deposition of gradient materials.

[0027] The application sets a gas sending unit on the periphery of the powder sending unit, adopts gas-powder collaborative delivery technology, forms a gas barrier on the periphery of the sent powder, effectively suppresses powder splashing, effectively improves powder sending precision, and effectively reduces powder waste and harmful gas and dust emission generated in the welding process; meanwhile, the gas sending unit effectively prevents powder oxidation through gas, and ensures the purity of the powder in the delivery and welding process.

[0028] The powder sending bin utilizes the converging-diverging channel of the Venturi tube to accelerate powder flow, effectively prevents delivery blockage, and improves powder sending stability. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0030] Figure 1 is a structural schematic diagram of the laser welding powder sending device of the present application;

[0031] Figure 2 is Figure 1 is a cross-sectional view in the A-A direction in the present application;

[0032] Figure 3 is a structural schematic diagram of the powder storage unit of the present application;

[0033] Figure 4 is a cross-sectional schematic diagram of the powder sending unit and the gas sending unit of the present application;

[0034] Explanation of reference numerals in the drawings:

[0035] 1, powder storage unit, 11, powder storage bin, 12, cover plate, 13, isolation plate;

[0036] 2, powder sending control unit, 21, screw rod, 22, fixed plate, 23, driving motor;

[0037] 3, powder mixing unit, 31, stirring blade, 32, upper mixing bin, 33, middle mixing bin, 34, lower mixing bin;

[0038] 4, powder sending unit, 41, first powder sending bin, 42, Venturi tube, 43, second powder sending bin;

[0039] 5, gas sending unit, 51, gas sending pipe, 52, pressure relief bin, 53, conical gas sending bin;

[0040] 6, powder delivery pipe, 7, carrier gas input pipe;

[0041] 8, laser unit, 81, laser beam. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be described clearly and completely below in conjunction with specific embodiments of the present application. Obviously, the described embodiments are only some 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.

[0043] Referring to Figure 1-4 The embodiment provides a laser welding powder feeding device, which comprises a powder storage unit 1, a powder feeding control unit 2, a powder mixing unit 3, a powder feeding unit 4 and a gas feeding unit 5. Figure 3 The powder storage unit 1 is provided with a plurality of independent powder storage bins 11, the top of each powder storage bin 11 is provided with a cover plate 12, and the bottom of each powder storage bin 11 is provided with a bottom plate; the powder feeding control unit 2 comprises a screw 21 corresponding to each powder storage bin 11, the number of the powder storage bins 11 and the screws 21 is 2-6, each screw 21 penetrates the cover plate 12 at the top of the corresponding powder storage bin 11, extends into the powder mixing unit 3 through the powder storage bin 11 and the bottom plate; the powder mixing unit 3 is provided with an annular powder mixing bin and stirring blades 31, and the bottom of the powder mixing bin is connected to the powder feeding unit 4 through a plurality of powder conveying pipes 6. Figure 4 The powder feeding unit 4 is provided with a powder feeding bin, the powder feeding unit 4 is sleeved with the gas feeding unit 5, the gas feeding unit 5 is provided with an annular gas feeding bin, and the central axes of the powder outlet at the bottom of the powder feeding bin and the gas outlet at the bottom of the gas feeding bin coincide.

[0044] The embodiment adopts the design of a plurality of independent powder storage bins 11, can simultaneously convey a plurality of powders with different components, realizes dynamic proportioning of the powders by controlling the rotating speed of the screw 21, and accurately controls the conveying amount of each powder; not only avoids the cumbersome operation of frequent replacement of powder in the traditional single-powder-bin powder feeding device, but also can adjust the material proportioning in real time according to the welding requirement, realizes dynamic composite deposition of gradient materials, and makes the device meet the welding requirement of complex material systems in the fields of aerospace and automobile manufacturing. The gas feeding unit 5 is arranged on the outer periphery of the powder feeding unit 4, the gas-powder collaborative conveying technology is adopted, a gas barrier is formed on the outer periphery of the conveyed powder, powder splashing is effectively inhibited, powder conveying precision is effectively improved, powder waste is effectively reduced, harmful gas and dust emission generated in the welding process is reduced, the powder is effectively prevented from being oxidized by the gas, the purity of the powder in the conveying and welding process is ensured, the generation of welding defects is significantly reduced by reducing powder splashing and oxidation pollution, and the performance and reliability of the welding joint are improved. For example, in automobile manufacturing, the quality of the welding joint directly affects the safety and durability of the vehicle, the device can effectively improve the welding quality and reduce the after-sales maintenance cost.

[0045] Specifically, adjacent powder storage bins 11 in the powder storage unit 1 are separated by detachable isolation plates 13 , and the number of isolation plates 13 can be adjusted according to actual needs, thereby adjusting the number of powder storage bins 11 .

[0046] Specifically, the powder feeding control unit 2 further includes a fixed plate 22 and a drive motor 23 mounted on the fixed plate 22 for driving the screw 21. The drive motor 23 controls the speed of the screw 21, thereby controlling the powder feeding amount. The drive motor 23 is controlled separately to achieve proportional control of the output of multiple powders.

[0047] Specifically, the powder mixing chamber includes an upper mixing chamber 32, a middle mixing chamber 33, and a lower mixing chamber 34. The outer circumferences of the upper and lower mixing chambers 32 and 34 are both conical, while the outer circumference of the middle mixing chamber 33 is cylindrical. The stirring blades 31 are located within the middle mixing chamber 33. The upper and lower conical mixing chambers, combined with the high-speed rotation of the stirring blades 31 in the middle mixing chamber 33, effectively solve the problem of interlayer segregation in the powder flow and ensure that the powder remains evenly distributed during the conveying process. This uniform powder flow can form a cladding layer with uniform composition, significantly improving the mechanical properties and quality stability of the weldment.

[0048] Specifically, the powder feeding bin includes a first powder feeding bin 41 connected one-to-one with the powder conveying pipe 6. The first powder feeding bin 41 is connected to a conical, annular second powder feeding bin 43 via a Venturi tube 42. The first powder feeding bin 41 is also connected to the carrier gas inlet pipe 7. The carrier gas drives the powder downward, and the gradually converging and diverging channel of the Venturi tube 42 accelerates powder flow, effectively preventing conveying blockages.

[0049] Specifically, the gas supply unit 5 further includes a gas supply pipe 51 connected to a gas supply chamber for supplying shielding gas. The gas supply chamber includes a pressure relief chamber 52 near the gas supply port of the gas supply pipe 51 and a conical gas supply chamber 53 connected to the pressure relief chamber 52. The pressure relief chamber 52 evenly distributes the gas flow, ensuring that the shielding gas evenly covers the laser molten pool. The carrier gas and shielding gas are ejected from different channels to avoid mutual interference.

[0050] Specifically, it also includes a laser unit 8 that passes through the axes of the powder feeding control unit 2, the powder storage unit 1, the powder mixing unit 3 and the powder feeding unit 4 from top to bottom. The laser beam 81 output by the laser unit 8 is focused on the central axis of the air outlet of the air feeding bin and the powder outlet of the powder feeding bin.

[0051] Specifically, the air flow pressure of the air delivery bin is 0.2-0.8 MPa; the ratio of the air flow rate output from the air delivery bin to the powder output rate from the powder delivery bin is (1.2-2):1.

[0052] In summary, the present invention adopts a design of multiple independent powder storage bins, which can simultaneously convey powders of multiple different compositions. By controlling the screw speed, dynamic proportioning of multiple powders can be achieved, and the conveying amount of each powder can be accurately controlled; it not only avoids the tedious operation of frequently replacing powder materials in traditional single-powder bin powder feeding devices, but also can adjust the material ratio in real time according to welding requirements to achieve dynamic composite deposition of gradient materials; an air supply unit is set on the periphery of the powder feeding unit, and gas-powder coordinated conveying technology is adopted to form a gas barrier on the periphery of the delivered powder, effectively suppressing powder splashing, effectively improving the powder feeding accuracy, and at the same time effectively reducing powder waste and reducing harmful gas and dust emissions generated during welding; at the same time, the air supply unit effectively prevents powder oxidation through gas, ensuring the purity of the powder during transportation and welding; the powder feeding bin utilizes the gradually converging-expanding channel of the Venturi tube to accelerate powder flow, effectively prevent conveying blockage, and improve powder feeding stability.

[0053] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A laser welding powder feeding device, characterized in that: It includes powder storage unit, powder feeding control unit, powder mixing unit, powder feeding unit and air feeding unit; A plurality of independent powder storage bins are provided in the powder storage unit, and a cover plate is provided on the top of the powder storage bin and a base plate is provided on the bottom; The powder feeding control unit includes a screw corresponding to each powder storage bin. The screw passes through the cover plate on the top of the powder storage bin, passes through the powder storage bin and the bottom plate, and then extends into the powder mixing unit. An annular powder mixing bin and stirring blades are provided in the powder mixing unit, and the bottom of the powder mixing bin is connected to the powder feeding unit through a plurality of powder conveying pipes; A powder feeding bin is provided in the powder feeding unit, an air feeding unit is provided outside the powder feeding unit, an air feeding bin is provided in the air feeding unit, and a powder outlet at the bottom of the powder feeding bin and an air outlet at the bottom of the air feeding bin coincide with central axes.

2. The laser welding powder feeding device according to claim 1, characterized in that: Adjacent powder storage bins in the powder storage unit are separated by detachable isolation plates.

3. The laser welding powder feeding device according to claim 1, characterized in that: The powder feeding regulating unit further includes a fixed plate and a driving motor mounted on the fixed plate and used for driving the screw to rotate.

4. The laser welding powder feeding device according to claim 1, characterized in that: The powder mixing bin includes an upper mixing bin, a middle mixing bin and a lower mixing bin. The outer peripheries of the upper mixing bin and the lower mixing bin are both conical, the outer periphery of the middle mixing bin is cylindrical, and the stirring blades are located in the middle mixing bin.

5. The laser welding powder feeding device according to claim 1, characterized in that: The powder feeding bin includes a first powder feeding bin connected one-to-one with the powder conveying pipe, the first powder feeding bin is connected to a second annular powder feeding bin with a conical structure through a venturi tube; the first powder feeding bin is connected to a carrier gas input pipe.

6. The laser welding powder feeding device according to claim 1, characterized in that: The air supply unit further includes an air supply pipe connected to an air supply bin, and the air supply bin includes a pressure relief bin close to an air supply port of the air supply pipe and a conical air supply bin connected to the pressure relief bin.

7. The laser welding powder feeding device according to claim 1, characterized in that: The number of the powder storage bins and screws is 2-6.

8. The laser welding powder feeding device according to claim 1, characterized in that: It also includes a laser unit that passes through the axes of the powder feeding control unit, the powder storage unit, the powder mixing unit and the powder feeding unit from top to bottom. The laser beam output by the laser unit is focused on the axis of the air outlet of the air feeding bin and the powder outlet of the powder feeding bin.

9. The laser welding powder feeding device according to claim 1, characterized in that: The air flow pressure of the air delivery bin is 0.2-0.8 MPa.

10. The laser welding powder feeding device according to claim 1, characterized in that: The ratio of the air flow rate output from the air delivery bin to the powder output rate from the powder delivery bin is (1.2-2):1.

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