CN113198372B

CN113198372B - Powder mixing device, laser cladding powder feeding equipment and laser cladding equipment

Info

Publication number: CN113198372B
Application number: CN202110542128.0A
Authority: CN
Inventors: 黄河; 吴志玮; 蔡国双
Original assignee: Nanjing Huirui Photoelectric Technology Co ltd
Current assignee: Nanjing Huirui Photoelectric Technology Co ltd
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2023-05-26
Anticipated expiration: 2041-05-18
Also published as: CN113198372A

Abstract

The invention discloses a powder mixing device, laser cladding powder feeding equipment and laser cladding equipment, and relates to the technical field of additive manufacturing so as to improve the laser cladding effect. The powder mixing device includes: the powder conveying structures, the stirring structures, the mixing structures and the driving parts in driving connection with the stirring structures and the mixing structures. The upper surface of the mixing structure is provided with a plurality of protruding structures. The laser cladding powder feeding equipment comprises a powder mixing device, a plurality of powder conveying pipelines, a plurality of powder barrels and a controller. The laser cladding equipment comprises laser cladding powder feeding equipment. The powder mixing device provided by the invention is used for mixing the powder to be mixed conveyed by the powder conveying pipelines.

Description

Powder mixing device, laser cladding powder feeding equipment and laser cladding equipment

Technical Field

The invention relates to the technical field of additive manufacturing, in particular to a powder mixing device, laser cladding powder feeding equipment and laser cladding equipment.

Background

The laser cladding technology can obviously improve the wear resistance, corrosion resistance, heat resistance, oxidation resistance, electrical appliance characteristics and the like of the surface of the matrix material, so that the method is widely applied. At present, the metal powder material used for laser cladding is generally obtained by a traditional alloy ingot casting powder process. The design of traditional alloy components mainly aims at traditional metal processing technologies such as casting, forging, overlaying and the like, and the physical thermal process of laser cladding is greatly different from the traditional metal processing technologies, and the most obvious difference is extremely fast heating and cooling rates and repeated hot and cold circulation processes, if the traditional alloy components are not optimized, crack defects are easily generated in the cladding process. For the requirements of alloy composition optimization, it is sometimes necessary to mix different alloy powder materials, or to add some single element metal powder in one alloy powder material, or to add some heterogeneous materials, such as WC ceramic particles in nickel-based alloy powder, etc., in order to achieve some special cladding layer performance requirements.

In the prior art, if the mixed powder is required to be used for laser cladding, a premixing method is generally used, namely, the powder is weighed first, then mixed according to a certain proportion, a powder filling container is rolled/rocked by a mixer, so that the powder is mixed, and then the mixed powder is filled into a powder feeding device of laser cladding equipment. The method is difficult to mix the powder uniformly, and particularly, the powder with larger component proportion difference can lead to uneven distribution of elements in the final cladding layer; and the mixing process has more manual operation steps, so that the measurement accuracy is easily reduced, and impurities are introduced or powder oxidation pollution is caused. In addition, this method can be very time consuming and labor intensive if the powder composition needs to be changed or fine tuned more frequently, for example, where the alloy composition is to be optimally developed.

Therefore, a new powder mixing method is needed, which can rapidly, accurately and stably adjust the components of powder alloy materials used for laser cladding and meet the requirements of cladding layer quality optimization.

Disclosure of Invention

The invention aims to provide a powder mixing device, laser cladding powder feeding equipment and laser cladding equipment so as to improve the quality of laser cladding.

In a first aspect, the present invention provides a powder mixing device for mixing powders to be mixed conveyed by a plurality of powder conveying pipelines. The powder mixing device includes: the powder conveying structures, the stirring structures, the mixing structures and the driving parts in driving connection with the stirring structures and the mixing structures. The upper surface of the mixing structure is provided with a plurality of protruding structures.

Each powder conveying structure is communicated with a corresponding powder conveying pipeline and is used for conveying powder to be mixed conveyed by the powder conveying pipeline to the stirring structure.

The stirring structure is used for premixing powder to be mixed under the driving of the driving piece, and the premixed powder is conveyed to the central area of the upper surface of the mixing structure through the powder leakage hole of the stirring structure.

The mixing structure is used for mixing the premixed powder under the drive of the driving member and then is sent out from the edge area of the upper surface of the mixing structure.

By adopting the technical scheme, the powder mixing device provided by the invention comprises a plurality of powder conveying structures, a stirring structure, a mixing structure and a driving piece. Each powder conveying structure is communicated with a corresponding powder conveying pipeline and is used for conveying powder to be mixed conveyed by the powder conveying pipeline to the stirring structure. Can carry out premixing to the powder that waits to mix of carrying in the stirring structure through setting up stirring structure, realize the preliminary mixing of waiting to mix of carrying among the different pipelines for the powder of the downthehole output of hourglass powder of follow stirring structure is the powder after premixing between the powder of multiple difference, further reinforcing powder's mixed effect. On this basis, through setting up the mixed structure and further mixing the powder after will premixing, at this moment, owing to the upper surface of mixed structure is equipped with a plurality of protruding structures for after the protruding structure of the upper surface of mixed structure of powder contact mixed structure after carrying into mixed structure upper surface, produce irregular collision to different angles, make the direction of motion of this powder after premixing more disperse, the mixing effect is better. And the powder leakage holes are used for conveying the premixed powder to the central area of the upper surface of the mixing structure, so that the number of times of collision between the premixed powder and the convex structure on the mixing structure is increased, and finally, after multiple collisions, the fully mixed powder is sent out from the edge area of the upper surface of the mixing structure. Meanwhile, the powder leakage holes are used for conveying the premixed powder to the central area of the upper surface of the mixing structure, so that the fact that the partially premixed powder is directly sent out from the edge area of the upper surface of the mixing structure and the powder mixing effect of the powder mixing device is affected can be prevented.

Meanwhile, the powder mixing device provided by the embodiment of the invention realizes different mass ratios of different powders in the final mixed powder by adjusting the flow of each powder to be mixed. Compared with the unified pre-mixing powder in the traditional method, the powder mixing device provided by the invention is equivalent to dividing all the powder to be mixed into countless small parts for mixing, and each small part is uniformly mixed, so that macroscopic element uniform distribution of the cladding layer is finally realized. Based on the above, the powder mixing device provided by the embodiment of the invention can be used for mixing the powder to be mixed with larger mass ratio difference.

In conclusion, the powder mixing device can realize uniform mixing of powder with different mass ratios and precise control of cladding material components, so that the laser cladding effect is improved, and the phenomena of cracking and the like are reduced.

In a second aspect, the present invention provides a laser cladding powder feeding apparatus, including the powder mixing device, the plurality of powder conveying pipelines, the plurality of powder barrels and the controller described in the first aspect or any possible implementation manner of the first aspect. Each powder conveying pipeline is connected with a powder conveying structure of the corresponding powder mixing device and the corresponding powder barrel.

The laser cladding powder feeding equipment further comprises a gas flow sensor and a gas pressure sensor which are arranged on the powder conveying structures or the powder conveying pipelines or the powder barrels, and the controller is respectively in communication connection with the gas flow sensor and the gas pressure sensor.

The beneficial effects of the laser cladding powder feeding device provided in the second aspect are the same as those of the powder mixing device described in the first aspect or any possible implementation manner of the first aspect, and are not described herein.

In a third aspect, the present invention provides a laser cladding apparatus comprising a laser cladding powder delivery apparatus as described in the second aspect.

The beneficial effects of the laser cladding apparatus provided in the third aspect are the same as those of the powder mixing device described in the first aspect or any possible implementation manner of the first aspect, and are not described herein.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a laser cladding apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a powder mixing device according to an embodiment of the present invention;

FIG. 3 is a perspective view of a powder mixing apparatus according to an embodiment of the present invention;

FIG. 4 is a top view of a powder mixing apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic view of a part of a powder mixing apparatus according to an embodiment of the present invention;

in the figure: 1-a powder mixing device; 2-a powder conveying pipeline; 3-a powder barrel; 4-a powder feeding pipeline; 5-laser cladding head; 11-a powder conveying structure; 12-stirring structure; 13-hybrid structure; 14-a driving member; 15-an upper housing; 16-a lower housing; 17-an extension rod; 18-plugs; 19-a seal; 20-a throttle valve; 21-a filter; 111-a powder inlet joint; 112-a powder inlet channel; 121-powder leakage holes; 122-a premix chamber; 131-bump structure; 132-a powder mixing cavity; 133-a powder outlet hole; 151-drive closure; 161-mixing chamber; 1611-funnel-shaped structure.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that various schematic drawings of embodiments of the present invention are illustrated in the accompanying drawings, which are not drawn to scale. In which some details are exaggerated and possibly omitted for clarity. The shapes of the various regions, layers and relative sizes, positional relationships between them shown in the drawings are merely exemplary, may in practice deviate due to manufacturing tolerances or technical limitations, and one skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions as actually required.

In the present invention, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

The laser cladding technology is a technological method that selected coating materials are placed on the surface of a coated substrate in different filling ways, and are melted together with a thin layer on the surface of the substrate by laser irradiation, and the surface coating which has extremely low dilution and is metallurgically bonded with the substrate material is formed after rapid solidification, so that the wear resistance, corrosion resistance, heat resistance, oxidation resistance, electrical characteristics and the like of the surface of the substrate material are obviously improved. The synchronous powder feeding method has the advantages of easy realization of automatic control, high laser energy absorptivity, no internal air holes, particularly cladding of metal ceramic, capability of remarkably improving the cracking resistance of the cladding layer, capability of uniformly distributing the hard ceramic phase in the cladding layer, and the like. At present, the metal powder material used for laser cladding is generally obtained by a traditional alloy ingot casting powder process. The design of traditional alloy components mainly aims at traditional metal processing technologies such as casting, forging, overlaying and the like, and the physical thermal process of laser cladding is greatly different from the traditional metal processing technologies, and the most obvious difference is extremely fast heating and cooling rates and repeated hot and cold circulation processes, if the traditional alloy components are not optimized, crack defects are easily generated in the cladding process. For the requirements of alloy composition optimization, it is sometimes necessary to mix different alloy powder materials, or to add some single element metal powder in one alloy powder material, or to add some heterogeneous materials, such as WC ceramic particles in nickel-based alloy powder, etc., in order to achieve some special cladding layer performance requirements.

However, in the prior art, if the laser cladding is required to be performed by using mixed powder, a premixing method is generally used, that is, the powder is weighed first, then mixed according to a certain proportion, the powder is mixed by rolling/shaking a powder-filling container by a mixer, and then the mixed powder is filled into a powder-feeding device of the laser cladding equipment. The method is difficult to mix the powder uniformly, and particularly, the powder with larger component proportion difference can lead to uneven distribution of elements in the final cladding layer; and the mixing process has more manual operation steps, so that the measurement accuracy is easily reduced, and impurities are introduced or powder oxidation pollution is caused. In addition, this method can be very time consuming and labor intensive if the powder composition needs to be changed or fine tuned more frequently, for example, where the alloy composition is to be optimally developed.

In order to solve the technical problems, the embodiment of the invention provides laser cladding equipment which is used for carrying out laser cladding on the surface of a substrate to obtain a cladding layer with good surface forming and no air holes and cracks, and the cost is relatively low.

Fig. 1 illustrates a schematic structural diagram of a laser cladding apparatus according to an embodiment of the present invention. As shown in fig. 1, the laser cladding apparatus provided by the embodiment of the present invention includes a laser cladding powder feeding apparatus. The laser cladding equipment provided by the embodiment of the invention conveys the uniformly mixed powder to the laser cladding head 5 through the powder conveying pipeline 4 by the laser cladding powder conveying equipment for laser cladding so as to obtain a cladding layer with good surface forming and no air holes and cracks.

As shown in fig. 1, the laser cladding powder feeding device includes: a powder mixing device 1, a plurality of powder conveying pipelines 2, a plurality of powder barrels 3 and a controller (not shown in the figure). Each powder conveying pipeline 2 is connected with a powder conveying structure of the corresponding powder mixing device 1 and a powder barrel 3 of the corresponding powder feeder. The powder conveying structures or the powder conveying pipelines 2 or the powder barrels 3 are connected with a gas flow sensor (not shown in the figure) and a gas pressure sensor (not shown in the figure), and the controller is respectively in communication connection with the gas flow sensor and the gas pressure sensor. By arranging the gas flow sensor and the gas pressure sensor, the flow of the powder conveying gas and the pressure of the powder conveying gas in the powder conveying process can be independently controlled, so that the powder to be mixed in each powder conveying pipeline 2 can be conveyed into the powder mixing device 1 under the protection and driving of the powder conveying gas, and the flow of the gas for conveying the powder is ensured to meet the requirements of a laser cladding process. Meanwhile, each powder barrel 3 can adopt a rotary disc type powder feeding mode, so that the powder feeding range is wider, for example, the powder feeding quantity control of 0.5 g/min-100 g/min can be realized, and the mass ratio of the powder fed by each powder feeding pipeline 2 can be maximally 1:200. based on the above, the laser cladding powder feeding device provided by the embodiment of the invention can control the powder feeding amount of each powder feeding pipeline 2, so that the powder fed by different powder feeding pipelines 2 can be fully mixed together to obtain uniformly mixed powder, and therefore, the laser cladding powder feeding device provided by the embodiment of the invention can realize uniform mixing among the powder with larger component proportion difference.

In practical application, when the plurality of gas flow sensors and the gas pressure sensors are arranged on the plurality of powder barrels, powder to be mixed in each powder barrel is conveyed into the powder conveying pipeline under the driving of gas with pressure and certain flow rate, at the moment, before the powder to be mixed is conveyed, the gas flow sensors in each powder barrel convey the gas flow information in each powder barrel to the controller, the pressure sensors in each powder barrel convey the gas pressure information in each powder barrel to the controller, the controller receives the gas flow information and the gas pressure information, processes the gas flow information and the gas pressure information, judges whether the gas flow information and the gas pressure information meet preset values, and under the condition that the gas flow information and the gas pressure information meet the preset values, the gas with pressure is controlled to convey the powder to be mixed in each powder barrel into the powder conveying pipeline from the powder barrel. And adjusting the gas flow and the gas pressure when the gas flow information and the gas pressure information are determined to be not in accordance with the preset value.

Fig. 2 illustrates a schematic structure of a powder mixing apparatus according to an embodiment of the present invention. As shown in fig. 2, the powder mixing device 1 is used for mixing powders to be mixed, which are conveyed by a plurality of powder conveying pipelines 2. The powder mixing device includes: a plurality of powder conveying structures 11, a stirring structure 12, a mixing structure 13 and a driving piece 14 which is in driving connection with the stirring structure 12 and the mixing structure 13.

As shown in fig. 2, each of the above-mentioned powder conveying structures 11 communicates with the corresponding powder conveying pipe 2 for conveying the powder to be mixed conveyed by the powder conveying pipe 2 to the stirring structure 12. It should be understood that the number of powder conveying structures 11 is the same as the number of powder conveying pipelines 2, and are connected together in a one-to-one correspondence. The powder conveying pipeline 2 is used for conveying a fluid composed of gas and powder to be mixed. The gas is usually an inert gas commonly used for laser cladding, and protects the metal powder from oxidation when entering a cladding area for cladding. As for the number of the powder feeding structures 11, it may be set according to actual conditions. For example, the number of the powder conveying structures 11 can be set to be 4 so as to realize 4-path powder conveying mixing; can be set to 6 to realize 6 paths of powder feeding mixing; the number of the powder feeding devices can be 8 to realize 8-path powder feeding mixing and the like, and the powder feeding devices are not limited herein.

As shown in fig. 2, the stirring structure 12 is used for premixing powder to be mixed under the driving of the driving member 14, and the premixed powder is delivered to the central region of the upper surface of the mixing structure 13 through the powder leakage hole 121 of the stirring structure 12. It should be understood that the driving member 14 may be a driving motor, or may be a driving member 14 that can rotate by an oil cylinder or the like.

As shown in fig. 2, the mixing structure 13 is driven by the driving member 14 to mix the premixed powder, and then is fed out from an edge region of the upper surface of the mixing structure 13. Wherein the upper surface of the mixing structure 13 is provided with a plurality of protruding structures 131. Specifically, the protruding structures 131 are hard spheres or hard hemispheres. Wherein, the material of the hard sphere or the hard hemisphere is wear-resistant metal. The protruding structure 131 may be fixed to the upper surface of the hybrid structure 13 by welding or bonding.

Therefore, the powder mixing device provided by the invention comprises a plurality of powder conveying structures, a stirring structure, a mixing structure and a driving piece. Each powder conveying structure is communicated with a corresponding powder conveying pipeline and is used for conveying powder to be mixed conveyed by the powder conveying pipeline to the stirring structure. Can carry out premixing to the powder that waits to mix of carrying in the stirring structure through setting up stirring structure, realize the preliminary mixing of waiting to mix of carrying among the different pipelines for the powder of the downthehole output of hourglass powder of follow stirring structure is the powder after premixing between the powder of multiple difference, further reinforcing powder's mixed effect. On this basis, through setting up the mixed structure and further mixing the powder after will premixing, at this moment, owing to the upper surface of mixed structure is equipped with a plurality of protruding structures for after the protruding structure of the upper surface of mixed structure of powder contact mixed structure after carrying into mixed structure upper surface, produce irregular collision to different angles, make the direction of motion of this powder after premixing more disperse, the mixing effect is better. And the powder leakage holes are used for conveying the premixed powder to the central area of the upper surface of the mixing structure, so that the number of times of collision between the premixed powder and the convex structure on the mixing structure is increased, and finally, after multiple collisions, the fully mixed powder is sent out from the edge area of the upper surface of the mixing structure. Meanwhile, the powder leakage holes are used for conveying the premixed powder to the central area of the upper surface of the mixing structure, so that the fact that the partially premixed powder is directly sent out from the edge area of the upper surface of the mixing structure and the powder mixing effect of the powder mixing device is affected can be prevented.

Meanwhile, the powder mixing device provided by the embodiment of the invention can divide the powder with different mass ratios to be mixed into a plurality of small parts for mixing by adjusting the flow of the powder with different mass ratios to be mixed, so that the uniform mixing among the powder with different mass ratios is realized. Based on the above, the powder mixing device provided by the embodiment of the invention can be used for mixing the powder to be mixed with larger mass ratio difference.

As shown in fig. 2, the powder mixing device 1 further includes an upper housing 15 and a lower housing 16, the upper housing 15 and the lower housing 16 are connected together in a sealing manner, the driving member 14 is located in the upper housing 15, and an output shaft of the driving member 14 extends into the lower housing 16 and is in driving connection with the stirring structure 12 and the mixing structure 13 located in the lower housing 16, so that the stirring structure 12 and the mixing structure 13 can rotate under the driving of the driving member 14, thereby achieving the mixing of the powder.

As shown in fig. 2, in order to enhance the mixing effect of the powder, after the premixed powder is transferred from the powder leakage hole 121 to the central region of the upper surface of the mixing structure 13, there is a powder mixing chamber 132 between the stirring structure 12 and the mixing structure 13, which should have a sufficient mixing space so that the powder can be sufficiently moved, collided, and sufficiently mixed, and thus, the powder mixing device 1 may further include an extension rod 17 having one end connected to the output shaft of the driving member 14 and the other end connected to the mixing structure 13 for transmitting the driving force of the driving member to the mixing structure. The extension rod 17 drives the mixing structure 13 to move together under the drive of the driving member 14. The size of the powder mixing chamber 132 and the length of the extension rod 17 are designed according to practical situations, and are not limited herein.

As shown in fig. 2, the upper case 15 may further include a driving member cover 151, and the upper case 15 and the lower case 16 are hermetically connected together by the driving member cover 151. Wherein the driver 14 is sealingly connected to the driver cover 151. By providing the driver cover 151 and fixing the driver 14 to the driver cover 151, sealing of the driver 14 can be achieved as much as possible, and the situation that the driver 14 is damaged due to the fact that powder to be mixed enters the driver 14 in the powder mixing process can be prevented.

In practical applications, as shown in fig. 2, the powder mixing device 1 may further include a plug 18, and the driving member 14 may be a motor. Specifically, after the driving element 14 and the driving element cover 151 are fixed together, the top of the driving element 14 is sealed by using the plug 18, and the driving element 14 is sealed inside the upper housing 15, so as to protect the driving element 14 and prevent particles such as external dust from entering the driving element 14. The material of the plug 18 may be rubber or synthetic fiber, and is not limited thereto.

As shown in fig. 2, the powder mixing device 1 further comprises a plurality of seals 19 in order to achieve a sealed connection between the upper housing 15 and the lower housing 16 and a sealed connection between the driver 14 and the upper housing 15. At least one seal 19 is located at the junction of the driver 14 and the upper housing 15 to prevent powder-carrying gas from leaking out of the powder mixing device 1 through the mating surfaces of the driver 14 and the upper housing 15. At least one seal 19 is located at the junction of the upper housing 15 and the lower housing 16 to prevent powder-laden gas from leaking out of the powder mixing device 1 through the mating surfaces of the upper housing 15 and the lower housing 16. When the upper housing 15 further comprises a driver cover 151, the at least one seal 19 is located at the junction of the driver 14 and the driver cover 151 to prevent powder-laden gas from entering the mounting cavity of the driver 14, which has an effect on the performance of the driver 14.

Fig. 3 illustrates a perspective view of a powder mixing device according to an embodiment of the present invention, and fig. 4 illustrates a top view of a powder mixing device according to an embodiment of the present invention. As shown in fig. 2 to 4, the powder mixing apparatus 1 further includes a throttle valve 20 and a filter 21. The throttle valve 20 is communicated with the lower shell 16, and is used for adjusting the gas flow in the lower shell 16, and discharging the gas with redundant flow out of the powder mixing device 1, so that the flow of the gas finally entering the laser cladding head 5 through the powder outlet of the powder mixing device 1 meets the laser cladding process requirement. It should be understood that the number of the throttle valves 20 may be one or plural, and is not limited herein.

In order to further ensure that the flow rate of the gas entering the laser cladding head 5 from the powder outlet of the powder mixing device 1 meets the requirements of the laser cladding process, the powder mixing device 1 may further comprise a gas flow sensor (not shown in the figures). The gas flow sensor may be connected to the gas outlet of the throttle valve 20, and determines the flow rate of the gas entering the laser cladding head 5 from the powder outlet of the powder mixing apparatus 1 by determining the sum of the gas flows delivered to the powder mixing apparatus 1 by each powder delivery pipe 2 and the difference of the gas flows flowing out from the gas outlet of the throttle valve 20. Of course, the gas flow sensor can also be connected with the powder outlet of the powder mixing device 1, and the flow of the gas entering the laser cladding head 5 from the powder outlet of the powder mixing device 1 is ensured to meet the laser cladding process requirement by detecting the gas flow of the powder outlet of the powder mixing device 1. The gas flow rate sensor is a commercially available device, and the range of options is wide and is not limited thereto.

In practical applications, the powder mixing device 1 may further include a controller, where the controller is communicatively connected to the gas flow sensor and the throttle valve, and is configured to control the gas flow sensor to detect the gas flow and control the on/off of the throttle valve. The intelligent control can be realized by setting the controller, and the labor cost is reduced.

As shown in fig. 2 to 4, the filter 21 is at least partially located at the junction of the throttle valve 20 and the lower housing 16. The filter 21 may be a filter mesh or a filter element, the mesh number of the filter mesh or the filter element is 1000 mesh to 2500 mesh, for example, the mesh number of the filter mesh or the filter element is 1000 mesh, the mesh number of the filter mesh or the filter element is 1250 mesh, and the mesh number of the filter mesh or the filter element is 1500 mesh. By providing the filter 21, the mixed powder in the powder mixing device 1 can be isolated from the throttle 20, and the powder is prevented from being discharged out of the powder mixing device 1 along with the leakage gas.

As shown in fig. 2 to 4, the lower housing 16 may further have a mixing chamber 161, wherein the bottom of the mixing chamber 161 is a funnel-shaped structure 1611, the powder mixed in the powder mixing chamber 132 of the mixing structure 13 is sent out from the edge area of the upper surface of the mixing structure 13, enters the funnel-shaped structure 1611, flows out from the funnel-shaped structure 1611, is sent into the laser cladding head 5 after the powder outlet of the powder mixing device 1 converges, so as to improve the collection efficiency of the powder, and the powder can be mixed again after the powder outlet converges.

In practical application, as shown in fig. 2 to 4, the shape of the mixing structure 13 may be diamond, a gap is formed between the funnel-shaped structure 1611 and the side wall of the mixing structure 13, and the powder mixed by the mixing structure 13 flows out through the gap under the driving of self gravity and air pressure. At this time, the gap has a steady flow effect on the fluid composed of the mixed gas and powder, so that the fluid entering the laser cladding head 5 through the powder outlet of the powder mixing device 1 is more stable, the uniformity of the laser cladding powder is ensured, and the laser cladding effect is improved.

Fig. 5 illustrates a schematic partial structure of a powder mixing apparatus according to an embodiment of the present invention. As shown in fig. 2 to 5, each of the powder conveying structures 11 includes a powder inlet joint 111 and a powder inlet passage 112 communicating with the powder inlet joint 111. The powder inlet connector 111 is connected with the corresponding powder conveying pipeline 2 in a matched manner, and the powder inlet channel 112 is used for conveying the powder to be mixed conveyed by the powder conveying pipelines 2 into the stirring structure 12 so as to improve the powder conveying efficiency.

In practical application, as shown in fig. 2 to 5, each powder inlet channel 112 is located in the area where the stirring structure 12 is located, so that the powder conveyed by the powder inlet channels 112 can be accurately conveyed into the stirring structure 12, and after being premixed in the stirring structure 12, flows out from the powder leakage holes 121 of the stirring structure 12. Specifically, the number of the powder feeding structures 11 may be selected according to the kinds of powder to be mixed, and is not limited herein.

As shown in fig. 2 to 5, the stirring structure 12 may have a premixing chamber 122, and the premixing chamber 122 may have a funnel-like shape. The weeping hole 121 is located at the bottom of the premix chamber 122. Through setting up hourglass powder hole 121 in the bottom of premixing chamber 122 for after the powder that waits to mix can be rotated the mixture from the top of premixing chamber 122, under the drive of self gravity and gaseous pressure, gradually to the hourglass powder hole 121 in the bottom of premixing chamber 122, and follow hourglass powder hole 121 outflow, make this powder that waits to mix can more abundant premix. Note that the number of the powder leakage holes 121 may be selected according to practical situations, and is not limited herein. And in order to ensure that the stirring structure 12 can be rotated by the driving member 14, a gap is provided between the stirring structure 12 and the mixing chamber 161 of the lower housing 16, and in order to prevent the powder to be mixed from flowing out of the gap, the gap should be as small as possible. Specifically, the width of the gap may be selected according to practical situations, and is not limited herein.

As shown in fig. 2 to 5, the upper surface of the mixing structure 13 is a paraboloid or a conical surface. The vertex of the paraboloid or the vertex of the conical surface is arranged close to the stirring structure, so that the dispersing area and the dispersing direction among powder particles are increased, the uncertainty factor among powder collision is increased, and the mixing effect of the powder is better.

As shown in fig. 2 to 5, the edge region of the upper surface of the mixing structure 13 has a plurality of powder discharge holes 133, and the mixed powder flows out from the plurality of powder discharge holes 133. By arranging the plurality of powder outlet holes 133, when powder mixed on the upper surface of the mixing structure 13 is discharged, only part of the powder can flow out of the powder outlet holes 133 each time, and part of the powder continues to move under the driving of the mixing structure 13, so that the mixing uniformity of the powder is improved.

Although the invention is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the invention has been described in connection with specific features and embodiments thereof, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the invention. Accordingly, the specification and drawings are merely exemplary illustrations of the present invention as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A powder mixing device is used for mixing powder to be mixed conveyed by a plurality of powder conveying pipelines; characterized by comprising the following steps: the powder conveying structures, the stirring structures, the mixing structures and the driving pieces are in driving connection with the stirring structures and the mixing structures; the upper surface of the mixing structure is provided with a plurality of protruding structures;

each powder conveying structure is communicated with the corresponding powder conveying pipeline and is used for conveying powder to be mixed conveyed by the powder conveying pipeline to the stirring structure;

the stirring structure is used for premixing the powder to be mixed under the driving of the driving piece, and conveying the premixed powder to the central area of the upper surface of the mixing structure through the powder leakage hole of the stirring structure; the stirring structure is provided with a premixing cavity, and the shape of the premixing cavity is similar to a funnel shape; the powder leakage hole is positioned at the bottom of the premixing cavity;

the mixing structure is used for mixing the premixed powder and then sending out the mixed powder from the edge area of the upper surface of the mixing structure under the driving of the driving piece; the upper surface of the mixing structure is a paraboloid or a conical surface, and the vertex of the paraboloid or the vertex of the conical surface is close to the stirring structure;

the powder mixing device further comprises an upper shell and a lower shell, wherein the upper shell and the lower shell are connected together in a sealing way, the driving piece is positioned in the upper shell, and an output shaft of the driving piece extends into the lower shell and is in driving connection with the stirring structure and the mixing structure which are positioned in the lower shell;

the powder mixing device further comprises a throttle valve and a filter; the throttle valve is communicated with the lower shell and is used for adjusting the air pressure in the lower shell, and the filter piece is at least partially positioned at the joint of the throttle valve and the lower shell; the lower shell is provided with a mixing cavity, and the bottom of the mixing cavity is of a funnel-shaped structure;

the edge area of the upper surface of the mixing structure is provided with a plurality of powder outlet holes, and the mixed powder flows out of the powder outlet holes.

2. The powder mixing device of claim 1, further comprising a plurality of seals; at least one sealing element is positioned at the joint of the driving element and the upper shell, and at least one sealing element is positioned at the joint of the upper shell and the lower shell.

3. The powder mixing device of claim 1, wherein the filter element is a filter screen or a filter cartridge, and the mesh number of the filter screen or the filter cartridge is 1000 mesh to 2500 mesh.

4. The powder mixing device of claim 1, further comprising a gas flow sensor connected to the gas outlet of the throttle valve; and/or the gas flow sensor is connected with a powder outlet of the powder mixing device.

5. The powder mixing device according to any one of claims 1-4, wherein each powder conveying structure comprises a powder inlet connector and a powder inlet channel communicated with the powder inlet connector, the powder inlet connectors are connected with the corresponding powder conveying pipelines in a matched mode, and the powder inlet channels are used for conveying powder to be mixed conveyed by the powder conveying pipelines to the stirring structure.

6. The powder mixing device of any one of claims 1-4, wherein the protruding structures are rigid spheres or rigid hemispheres; wherein the material of the hard sphere or the material of the hard hemisphere is metal; and/or the number of the groups of groups,

the powder mixing device further comprises an extension rod, one end of the extension rod is connected with the output shaft of the driving piece, and the other end of the extension rod is connected with the mixing structure and used for transmitting the driving force of the driving piece to the mixing structure.

7. A laser cladding powder feeding device, which is characterized by comprising the powder mixing device, a plurality of powder conveying pipelines, a plurality of powder barrels and a controller according to any one of claims 1-6; each powder conveying pipeline is connected with a powder conveying structure of the corresponding powder mixing device and the corresponding powder barrel;

the laser cladding powder conveying equipment further comprises a plurality of gas flow sensors and a plurality of gas pressure sensors which are arranged on the powder conveying structures, the powder conveying pipelines or the powder barrels, and the controller is respectively in communication connection with the gas flow sensors and the gas pressure sensors.

8. A laser cladding apparatus comprising the laser cladding powder feeding apparatus of claim 7.