A laser cladding powder feeding device and a powder feeding method

Abstract

The present invention discloses a laser cladding powder feeding device and a powder feeding method, relating to the technical field of laser cladding, and aiming to solve the problems of non-real-time powder feeding, uneven powder mixing and complex structure. The laser cladding powder feeding device includes a powder supply unit, a static powder mixing unit, a powder distribution unit and a nozzle. The powder supply unit is used to supply at least two kinds of powders. The static powder mixing unit is connected with the powder supply unit and is used to receive and mix at least two kinds of powders. The powder distribution unit is connected with the static powder mixing unit and is used to evenly distribute the mixed powder. The nozzle is connected with the powder distribution unit and is used to spray and accumulate the mixed powder on the surface of the workpiece. The laser cladding powder feeding method includes the following steps: controllably supplying at least two kinds of powders from the powder supply unit to the static powder mixing unit; mixing at least two kinds of powders by using the static powder mixing unit; relieving the pressure of the mixed powder by using a pressure relief unit; evenly distributing the mixed powder by using the powder distribution unit; spraying and accumulating the mixed powder on the surface of the workpiece by using the nozzle.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cladding, and particularly to a laser cladding powder feeding device and a powder feeding method. Background Art

[0002] Laser cladding technology is a new workpiece surface modification technology that emerged in the 1970s with the development of high-power lasers. It adds a cladding material (usually powder) to the surface of a workpiece through a laser cladding nozzle, and uses a high-energy density laser beam to melt and solidify it together with a thin layer on the surface of the workpiece, forming a metallurgical-bonded filler cladding layer on the surface of the workpiece. This cladding layer can significantly improve the wear resistance, corrosion resistance, heat resistance, oxidation resistance and other properties of the workpiece surface.

[0003] With the expansion of application fields such as functional composite materials and functionally gradient materials, the industrial community has an increasing demand for laser cladding processing with multiple powders mixed. Due to differences in particle size, density, shape, etc. between different types of powders, there are major challenges in realizing the real-time transportation and uniform mixing of multiple powders.

[0004] In the prior art, there are mainly two methods for the mixed powder feeding of multiple powders. First, off-line stirring and mixing powder feeding. This method mainly uses manual stirring or machine stirring to mix different types of powders in a preset ratio and then transports them to the nozzle. Although the off-line stirring and mixing powder feeding method can obtain uniformly mixed powders, it cannot adjust the powder supply amount in real time and cannot transport the mixed powder in real time according to actual needs. Second, on-line stirring and mixing. This method mainly uses a stirring mechanism to stir the mixed powders on-line. Such a mixing device generally requires a power source (such as a motor), and uses the motor to drive the stirring blades to mix and stir the powders to improve the uniformity of powder mixing. Such devices are often equipped with different powder feeders. Although they can realize the real-time adjustment of the powder supply amount, the device structure is complex, the volume is large, an additional power source is required, and on-line splitting of the powder cannot be realized. In particular, due to the large cavity of the device, the response time of powder feeding is long, affecting the efficiency of laser cladding. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser cladding powder feeding device and a powder feeding method for transporting and adjusting the transport amounts of at least two powders in real time. By adopting a static powder mixing unit, the structure of the laser cladding powder feeding device is simplified and the volume of the device is reduced while the powders are uniformly mixed.

[0006] To achieve the above object, in a first aspect, the present invention provides a laser cladding powder feeding device, comprising: a powder feeding unit for supplying at least two kinds of powders, and the flow rate of each powder is adjustable; a static powder mixing unit communicating with the powder feeding unit for receiving and mixing at least two kinds of powders; a powder dividing unit communicating with the static powder mixing unit for equally dividing the mixed powder; and a nozzle communicating with the powder dividing unit for spraying and accumulating the mixed powder on the surface of a workpiece.

[0007] When the above technical solution is adopted, when the powder feeding unit supplies at least two kinds of powders, the flow rate of each kind of powder can be independently controlled, so as to realize the real-time adjustment of the conveying amount of each kind of powder, make the powder be conveyed according to actual needs, and avoid the waste of powder. At the same time, a variety of powders are conveyed according to a preset flow rate, avoiding the reduction of the functional characteristics of the laser cladding layer caused by the change of the powder ratio. The powder feeding unit conveys a variety of powders to the static powder mixing unit, and the a variety of powders are mixed in the static powder mixing unit. The static powder mixing unit can realize the full mixing of a variety of powders without an external power source, saving energy and equipment investment costs. When the static powder mixing unit is mixing powders, there is no change in the relative positions between components, the overall structure is simple, and the occupied space is small, enhancing the stability of the overall structure of the device and extending the service life of the device.

[0008] In a second aspect, the present invention further provides a laser cladding powder feeding method. The laser cladding powder feeding method comprises the following steps:

[0009] Controllably supplying at least two kinds of powders to the static powder mixing unit by using the powder feeding unit; mixing at least two kinds of powders by using the static powder mixing unit; relieving the pressure of the mixed powder by using a pressure relief unit; evenly distributing the mixed powder by using the powder dividing unit; and spraying and accumulating the mixed powder on the surface of the workpiece by using the nozzle.

[0010] Compared with the prior art, the beneficial effects of the laser cladding powder feeding method provided in the second aspect are the same as those of the laser cladding powder feeding device described in the first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings:

[0012] Figure 1 is a schematic diagram of the overall structure of the laser cladding powder feeding device provided by an embodiment of the present invention;

[0013] Figure 2 is a schematic diagram of the structure composed of the first spiral blade provided by an embodiment of the present invention;

[0014] Figure 3 Structural schematic diagram of the first impeller provided by an embodiment of the present invention;

[0015] Figure 4 Cross-sectional schematic diagram of a powder separation unit provided by an embodiment of the present invention;

[0016] Figure 5 Structural schematic diagram of another powder separation unit provided by an embodiment of the present invention.

[0017] Reference numerals:

[0018] 1—Powder supply unit, 11—Gas storage tank, 12—Powder feeder,

[0019] 121—Powder storage cylinder, 122—Powder supply chamber, 2—Static powder mixing unit,

[0020] 21—Primary powder mixing section, 212—First impeller, 2121—Arc-shaped blade,

[0021] 2122—Rotating shaft, 22—Secondary powder mixing section, 221—First chamber,

[0022] 222—Composed of first spiral blades, 2221—First spiral blade, 2222—Second spiral blade,

[0023] 3—Powder separation unit, 31—Cylinder body, 32—Powder passing member,

[0024] 321—First sealing portion, 322—Powder passing portion, 323—Powder passing chamber,

[0025] 33—Powder separating member, 331—Second sealing portion, 332—Powder separating portion,

[0026] 333—Powder separating groove, 334—Through hole, 34—Powder separating pipe,

[0027] 35—Composed of second spiral blades, 351—Third spiral blade, 352—Fourth spiral blade,

[0028] 36—Hollow base, 361—Second impeller, 362—Powder separating core,

[0029] 37—Powder outlet, 4—Nozzle, 5—Pressure relief unit. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined. "Several" means one or more unless otherwise specifically defined.

[0033] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention.

[0034] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Figure 1 The overall structural schematic diagram of the laser cladding powder feeding device provided by the embodiment of the present invention is shown in Figure 1As shown in the figure, the above-mentioned laser cladding powder feeding device includes a powder feeding unit 1, a static powder mixing unit 2, a powder dividing unit 3, and a nozzle 4. The powder feeding unit 1 is used to supply at least two kinds of powders, and the flow rate of each powder is adjustable. When the powder feeding unit 1 supplies at least two kinds of powders, the flow rate of each kind of powder can be adjusted separately to achieve the separate control and real-time adjustment of the conveying amount of each kind of powder. The multiple powders are conveyed according to the preset flow rate to avoid the reduction of the functional characteristics of the laser cladding layer due to the change of the powder ratio. It can be understood that when the laser cladding work is started, the powder feeding unit 1 supplies the powder. When the laser cladding work is paused and no powder supply is required, the powder feeding unit 1 pauses to supply the powder, so that the powder is conveyed according to the actual demand, avoiding the waste of powder, avoiding the idle running of the equipment, saving electric energy at the same time, and prolonging the service life of the equipment. The static powder mixing unit 2 is connected to the powder feeding unit 1 and is used to receive and mix at least two kinds of powders. The powder feeding unit 1 conveys multiple powders to the static powder mixing unit 2, and the multiple powders are mixed in the static powder mixing unit 2. The working principle of the static powder mixing unit 2 is the same as that of the static mixer in the prior art and is used to mix multiple powders. The static mixer is a high-efficiency mixing device without moving parts. Its basic working mechanism is to use the mixing unit (generally a spiral blade) fixed in the pipe to change the flow state of the fluid in the pipe to achieve good dispersion and full mixing between different fluids. The static powder mixing unit 2 can achieve the full mixing of multiple powders without an external power source, reducing the energy consumption of the equipment and saving the equipment input cost. When the static powder mixing unit 2 is mixing powders, there is no change in the relative positions between the components, the integrity of the equipment structure is increased, the overall structure is simple, and the occupied space is small. Based on this, the stability of the equipment is enhanced, which is conducive to prolonging the service life of the equipment. The powder dividing unit 3 is connected to the static powder mixing unit 2 and is used to evenly divide the mixed powder. The nozzle 4 is connected to the powder dividing unit 3 and is used to receive the evenly divided mixed powder and spray and agglomerate the mixed powder on the surface of the workpiece. The powder dividing unit 3 is used to evenly divide the mixed powder and evenly divide the mixed powder into multiple paths and convey it to the nozzle 4 to achieve the consistency of the powder output amount at the multiple outlets of the nozzle 4, so that the powder agglomerates evenly on the surface of the workpiece, improving the characteristics of the laser cladding layer and ensuring the quality of the laser cladding layer.

[0036] As a possible implementation, as Figure 1 shown, the static powder mixing unit 2 includes a primary powder mixing part 21 and a secondary powder mixing part 22. The primary powder mixing part 21 is connected to the powder feeding unit 1 and is used to receive and pre-mix at least two kinds of powders. The secondary powder mixing part 22 is connected to the primary powder mixing part 21 and is used to receive and mix the pre-mixed powders.

[0037] In practical applications, the powder supply unit 1 supplies at least two types of powders. The at least two types of powders are first conveyed to the primary powder mixing section 21, where the primary powder mixing section 21 pre-mixes the at least two types of powders. Then, they are conveyed to the secondary powder mixing section 22. The multiple powders that have been pre-mixed can be better mixed, increasing the uniformity of the mixing of the multiple powders. The multiple powders after pre-mixing are conveyed to the secondary powder mixing section 22 for thorough mixing, making the multiple powders thoroughly and evenly mixed and ensuring the quality of laser cladding.

[0038] In an alternative embodiment, as Figure 1 and Figure 2 shown, the secondary powder mixing section 22 includes a through first chamber 221 and a plurality of groups of first spiral blade assemblies 222 connected in sequence. The plurality of groups of first spiral blade assemblies 222 are arranged in the first chamber 221 along the powder conveying direction. Each group of first spiral blade assemblies 222 includes a first spiral blade 2221 and a second spiral blade 2222. The first spiral blade 2221 and the second spiral blade 2222 are each at least one of left-handed blades or right-handed blades. The first spiral blade 2221 and the second spiral blade 2222 have an included angle α in the circumferential direction, where 0° < α < 180°.

[0039] As Figure 2As shown, both the first helical blade 2221 and the second helical blade 2222 are left-handed blades or both are right-handed blades. Alternatively, one can be set as a left-handed blade and the other as a right-handed blade. Both the first helical blade 2221 and the second helical blade 2222 are formed by relatively twisting both ends of a plate-like material by a certain angle γ. The range of the twisting angle γ is from 170° to 190°, preferably 180°. Here, no specific limitation is made, as long as it can better disperse the powder and change the powder flow state. The first helical blade 2221 and the second helical blade 2222 are arranged alternately at intervals in sequence, and there is an included angle α between the first helical blade 2221 and the second helical blade 2222 in the circumferential direction, where 0° < α < 180°. For the purpose of better dispersing the powder and changing the powder flow state, in the embodiments provided by the present invention, α = 90° is preferably selected. When the powder pre-mixed by the primary powder mixing section 21 is transported into the first chamber 221, passing through the first helical blade 2221 and the second helical blade 2222 arranged at intervals in sequence, the mixed powder is divided once every time it passes through the end of a helical blade driven by the air flow. At the same time, the arc-shaped surface of the helical blade continuously changes the movement direction of the powder. Based on this, the powder is repeatedly dispersed, its flow direction is changed, and it is mixed multiple times under the action of the first helical blade 2221 and the second helical blade 2222, so that the powder is transported in a rotational flow manner, ultimately achieving the purpose of uniform mixing of the powder. Moreover, the powder is transported in a rotational flow manner, eliminating the phenomenon that the powder biases in one direction or at one angle due to the influence of gravity or the air flow angle, avoiding the accumulation of powder in the first chamber 221, wasting powder and causing powder blockage, which affects the efficiency and quality of laser cladding. Based on this, the mixed powder moves in a swirling flow state, eliminating the phenomenon that the powder biases in one direction or at one angle due to the influence of gravity or the air flow angle, so that the placement angle of the static powder mixing unit 2 is not limited to the vertical state. Especially in the case where the working space and angle are limited, the applicable range of the static powder mixing unit 2 is increased. During specific implementation, the number of the first helical blade 2221 and the second helical blade 2222 provided and whether they are arranged at intervals in sequence are determined according to the actual situation, and the angle set between every two adjacent helical blades can also be different, not limited to a certain angle, so that the powder forms an irregular flow path, and the powder movement and mixing method can be rotational mixing, flipping mixing, reverse flow mixing, cross mixing, etc.

[0040] In some examples, the inner wall of the first chamber 221 is made of polished stainless steel for the inner wall, and it can be either metal or non-metal. In the embodiments of the present invention, a metal material is preferably used. The inner wall of the first chamber 221 is polished, which is beneficial to reducing the friction between the powder and the inner wall, reducing the flow resistance of the powder, enhancing the fluidity of the powder, preventing the powder from accumulating on the inner wall of the first chamber 221, increasing the powder utilization rate, and improving the uniformity of mixing of various powders. The size of the first chamber 221, the number of the first spiral blade 2221 and the second spiral blade 2222 are set according to the actual situation and are not specifically limited herein.

[0041] As a possible implementation, as Figure 1 and Figure 3 shown, the primary powder mixing section 21 includes: a through second chamber, the second chamber is respectively communicated with the powder supply unit 1 and the first chamber 221; a first impeller 212 rotatably accommodated in the second chamber. The first impeller 212 includes a rotating shaft 2122 and a plurality of arc-shaped blades 2121 circumferentially arranged around the rotating shaft 2122. When the arc-shaped blades 2121 are in a static state, the surface of the arc-shaped blades 2121 near the end of the powder supply unit 1 has a certain angle with the powder conveying direction. The impact force of the powder air flow conveyed by the powder supply unit 1 acts on the surface of the arc-shaped blades 2121, and the arc-shaped blades 2121 can rotate driven by the powder impact force. While the plurality of arc-shaped blades 2121 rotate, the movement direction of the powder is changed, the powder is dispersed, and the flow state of the powder is changed. When various powders are output from the outlet end of the primary powder mixing section 21, preliminary mixing has been achieved, which is beneficial to increasing the mixing uniformity of various powders in the secondary powder mixing section 22. The material and number of the above arc-shaped blades 2121 are set according to the actual situation and are not specifically limited herein.

[0042] As an alternative, as Figure 1 shown, the powder supply unit 1 includes a gas storage tank 11 for storing compressed gas and a plurality of powder feeders 12. The pressure range of the above compressed gas is 0.1 - 5 MPa, and the gas flow range is 0.1 - 50 L / min. The pressure and flow rate of the compressed gas are set according to the actual powder demand. The plurality of powder feeders 12 are independently communicated with the gas storage tank 11 and the static powder mixing unit 2. According to the actual required powder ratio and conveying volume, the gas pressure and flow rate input to each powder feeder 12 can be adjusted separately. A plurality of inlet channels 23 are provided at the powder input end of the primary powder mixing section 21, and the powder supply unit 1 is communicated with the primary powder mixing section 21 through a ferrule joint, an air pipe and the inlet channels 23.

[0043] Each powder feeder 12 is connected to the gas storage tank 11 through a separate air pipe. Each type of powder corresponds to a conveying pipeline and an inlet channel 23, which facilitates the separate adjustment of the conveying amount and conveying rate of each type of powder. Driven by compressed gas, the powder is conveyed into the static powder mixing unit 2 for full mixing.

[0044] In some optional ways, such as Figure 1 shown, each powder feeder 12 includes: a powder storage cylinder 121 for storing powder and a powder supply chamber 122. The powder supply chamber 122 is simultaneously connected to the powder storage cylinder 121, the gas storage tank 11, and the static powder mixing unit 2. The gas storage tank 11 controllably supplies compressed gas to the powder supply chamber 122, and the powder storage cylinder 121 controllably supplies powder to the powder supply chamber 122. A variety of powders are respectively placed in independent powder storage cylinders 121. According to the actual laser cladding requirements, the pressure and flow rate of the compressed gas conveyed into the powder supply chamber 122 or the rotation speed of the powder feeding turntable of the powder storage cylinder 121 can be adjusted simultaneously, and finally the powder supply amount and supply rate of the powder feeder 12 are adjusted to meet the actual use requirements, avoid powder waste, enable a variety of powders to be mixed according to a preset ratio, and ensure the quality of laser cladding.

[0045] In one example, such as Figure 4 shown, the powder dividing unit 3 includes: a cylinder body 31, a powder passing member 32, and a powder dividing member 33. The cylinder body 31 has opposite first and second ends, and the cylinder body 31 penetrates from the first end to the second end. The powder passing member 32 has a first sealing portion 321 and a powder passing portion 322, and a powder passing cavity 323 is formed through the first sealing portion 321 and the powder passing portion 322. The first sealing portion 321 covers the first end, and the powder passing portion 322 is accommodated in a part of the cylinder body 31 close to the first end. The powder dividing member 33 has a second sealing portion 331 and a powder dividing portion 332. A plurality of powder dividing grooves 333 are formed on the outer wall of the powder dividing portion 332 along the length direction of the powder dividing portion 332, and a plurality of through holes 334 are formed through the second sealing portion 331. Each powder dividing groove 333 corresponds to and communicates with each through hole 334. The second sealing portion 331 covers the second end, and the powder dividing member 33 is accommodated in a part of the cylinder body 31 close to the second end. One end of the powder dividing member 33 away from the second sealing portion 331 abuts against the powder passing portion 322, and the openings of the plurality of powder dividing grooves 333 communicate with the powder passing cavity 323.

[0046] See Figure 4, the shapes, structures, materials, etc. of the above-mentioned cylinder body 31, powder-passing member 32, powder-passing part 322, powder-dividing member 33, and powder-dividing part 332 can be set according to actual situations and will not be specifically limited here. The sizes and shapes of the above-mentioned powder-passing cavity 323 and powder-dividing groove 333 can also be set according to actual situations. The number of powder-dividing grooves 333 formed on the powder-dividing part 332 can be set according to actual situations, such as two, three, four, etc. In the embodiment of the present invention, the above-mentioned cylinder body 31 is a cylindrical cylinder body. Four powder-dividing grooves 333 are formed on the above-mentioned powder-dividing part 332.

[0047] See Figure 4 , the shape of the first sealing part 321 of the above-mentioned powder-passing member 32 matches the shape of the first end of the cylinder body 31, so that the first sealing part 321 can cover the first end. It should be understood that there are various ways of covering, such as snap connection, threaded connection, or bolt connection, etc. Similarly, the shape of the second sealing part 331 of the powder-dividing member 33 matches the shape of the second end of the cylinder body 31, so that the second sealing part 331 can cover the second end. As for the covering method, reference can be made to the previous description.

[0048] See Figure 4 , in the powder-dividing unit provided by the embodiment of the present invention, since the above-mentioned powder-dividing groove 333 is formed on the outer wall of the powder-dividing part 332, at this time, not only can the side wall for transmitting powder in the powder-dividing groove 333 be clearly and intuitively observed, but also the side wall can be directly processed. During actual use, when a powder blockage problem occurs in the powder-dividing groove 333, only the powder-dividing member 33 in the powder-dividing unit needs to be taken out of the cylinder body 31, and then the blocked powder-dividing groove 333 can be directly cleaned. It should be understood that since the side wall of the powder-dividing groove 333 is completely exposed to the air, at this time, it is not only convenient for the staff to directly and quickly clean the blocked powder-dividing groove 333 without the assistance of other cleaning equipment. At the same time, it is also beneficial for the staff to clearly and intuitively determine the dredging situation of the powder-dividing groove 333, which is convenient and fast. In addition, it is also beneficial for the staff to monitor the wear condition of the powder-dividing groove 333 and repair the powder-dividing groove 333 in a timely manner. Based on this, the overall replacement of the powder-dividing member 33 can be avoided, thereby reducing the use cost of the powder-dividing unit and the laser cladding cost of the workpiece. Further, since the powder-dividing unit provided by the embodiment of the present invention only includes the cylinder body 31, the powder-passing member 32, and the powder-dividing member 33, the structure of the powder-dividing unit is simple, which is convenient for the staff to quickly assemble and use, saving working time.

[0049] As Figure 4 shown, the part where the above-mentioned powder-passing cavity 323 communicates with the powder-dividing groove 333 is a horn cavity section, and there is a gap between the inner wall of the horn cavity section and the inner wall of the powder-dividing groove 333. The width of the above-mentioned gap is greater than the maximum diameter of a single powder, so that the powder transmitted through the powder-passing cavity 323 can be transmitted to the powder-dividing groove 333 to achieve uniform distribution of the powder.

[0050] In another example, as Figure 5 shown, the powder dividing unit 3 includes: a through powder dividing pipe 34 and a plurality of groups of second spiral blade assemblies 35 connected in sequence. The plurality of groups of second spiral blade assemblies 35 are all arranged in the powder dividing pipe 34 along the conveying direction of the powder in the powder dividing pipe 34; each group of second spiral blade assemblies 35 includes a third spiral blade 351 and a fourth spiral blade 352. Both the third spiral blade 351 and the fourth spiral blade 352 are at least one of left-handed blades or right-handed blades; the third spiral blade 351 and the fourth spiral blade 352 have an included angle β in the circumferential direction, and 0° < β < 180°. A hollow base 36, one end of the hollow base 36 is communicated with the powder dividing pipe 34, and the other end is provided with a plurality of powder outlets 37; a rotatable second impeller 361 is arranged in the cavity of the hollow base 36 and close to one end of the powder dividing pipe 34; a powder dividing core 362 is arranged in the cavity of the hollow base 36 and close to the position of the powder outlet 37.

[0051] See Figure 1 and Figure 5 , the sizes and materials of the above-mentioned third spiral blade 351, fourth spiral blade 352, second impeller 361, and powder dividing core 362 can be set according to actual situations and will not be specifically limited here. The material and shape of the powder dividing pipe 34 are also set according to actual situations. The number of the powder outlets 37 can be set according to actual situations, such as two, three, or four, etc. In the embodiment of the present invention, the powder dividing pipe 34 is preferably a cylindrical pipe, and the material can be metal or non-metal, preferably a metal material, and the inner wall of the powder dividing pipe 34 is polished to facilitate reducing the friction between the powder and the inner wall of the powder dividing pipe 34, enhancing the fluidity of the powder, preventing the powder from accumulating on the inner wall of the powder dividing pipe 34, and increasing the utilization rate of the powder. The other end of the hollow base 36 is provided with four powder outlets 37.

[0052] As Figure 5 shown, both the third spiral blade 351 and the fourth spiral blade 352 are formed by relatively twisting both ends of a plate-shaped material by a certain angle δ. The range of the twisting angle δ is 170° to 190°, so as to better disperse the powder and change the powder air flow direction. Both the third spiral blade 351 and the fourth spiral blade 352 are left-handed blades or both are right-handed blades, or one of them can be set as a left-handed blade and the other as a right-handed blade. The third spiral blade 351 and the fourth spiral blade 352 have an included angle β in the circumferential direction, and 0° < β < 180°, also so as to better disperse the powder and change the powder air flow direction. In the embodiment of the present invention, the twisting angle δ is preferably set to 180°, and the included angle β between the third spiral blade 351 and the fourth spiral blade 352 is preferably 90°.

[0053] SeeFigure 5 Along the conveying direction of the powder in the powder distribution pipe 34, a plurality of third spiral vanes 351 and fourth spiral vanes 352 are arranged at intervals in sequence, and there is an included angle between the third spiral vane 351 and the fourth spiral vane 352. When the powder passes through the third spiral vane 351 and the fourth spiral vane 352 driven by the air flow, the powder is segmented by the end parts of the spiral vanes, and at the same time, the flow direction of the powder changes following the rotation angle of the spiral vanes, realizing that the powder advances in a swirling state when being conveyed inside the powder distribution pipe 34, thereby eliminating the phenomenon that the powder deviates to one direction or one angle due to the influence of gravity or the air flow angle. When the powder is conveyed in the powder distribution pipe 34, it is repeatedly dispersed, rotated, and mixed, and the powder will not be fixed at a fixed angle and orientation during conveyance, so that the setting angle of the powder distribution pipe 34 is not restricted. Especially in the case where the space and orientation are limited, it is convenient for the placement of the equipment, expanding the applicable range of the powder distribution unit and improving the applicability of the equipment. Moreover, after a variety of powders are mixed by the static mixing unit, arranging a plurality of third spiral vanes 351 and fourth spiral vanes 352 in the powder distribution pipe 34 also plays a role in remixing the powder, enabling a variety of powders to be mixed evenly according to a preset ratio and ensuring the quality of laser cladding. A rotatable second impeller 361 is arranged in the cavity of the hollow base 36. The second impeller 361 can rotate under the impact of the powder air flow, not only making the powder evenly distributed in the cavity of the hollow base 36 and facilitating the subsequent powder distribution work, but also when the powder air flow drives the second impeller 361 to rotate, part of the kinetic energy of the powder air flow is converted into the rotational kinetic energy of the second impeller 361, reducing the transmission speed of the powder air flow and realizing the buffering effect of the powder, avoiding the accumulation phenomenon of the powder at the powder distribution core 362. In addition, a plurality of powder outlets 37 are opened at one end of the hollow base 36, facilitating the powder to be evenly divided into multiple paths and conveyed to the laser cladding nozzle 4.

[0054] As an alternative, as Figure 1 shown, the laser cladding powder feeding device further includes a pressure relief unit 5 communicated with the static powder mixing unit 2 and the powder distribution unit 3. The pressure relief unit 5 is used for relieving the pressure of the mixed powder; the pressure relief unit 5 is a pressure relief valve. Driven by their respective compressed gases, a variety of powders are mixed in the static powder mixing unit 2. The total gas flow rate of the mixed powder may exceed the gas flow rate requirement at the laser cladding nozzle 4. Therefore, it is necessary to relieve the gas pressure of the mixed powder to avoid excessive accumulation of the powder on the surface of the workpiece, resulting in uneven laser cladding layers, wasting powder and affecting the aesthetics of the laser cladding layer and the quality of the workpiece.

[0055] In a second aspect, the present invention also provides a laser cladding powder feeding method, including the following steps: controllably supplying at least two kinds of powders from the powder supply unit 1 to the static powder mixing unit 2;

[0056] Mix at least two kinds of powders by using the static powder mixing unit 2;

[0057] Shunt the mixed powder by using the powder dividing unit 3;

[0058] Spray and agglomerate the mixed powder on the surface of the workpiece by using the nozzle 4.

[0059] The beneficial effects of the laser cladding powder feeding method provided by the embodiment of the present invention are the same as those of the laser cladding powder feeding device described in the above technical solution, and will not be elaborated here.

[0060] In the present invention, up to 16 kinds of powders with adjustable control of transportation can be used. For the sake of easy understanding, taking the example of mixing and transporting four kinds of powders and dividing the mixed powder into four paths by the powder dividing unit 3, the specific applications of the laser cladding powder feeding device and the powder feeding method are described. It should be understood that the specific applications of the present invention are not limited to this, and the examples here are only for illustration and not for limitation.

[0061] Such as Figure 1As shown, the four kinds of powders are stored in four powder storage cylinders 121 respectively. The four powder storage cylinders 121 respectively correspond to four powder supply chambers 122. It should be understood that four inlet channels 23 are correspondingly arranged at the powder conveying end of the primary powder mixing part 21. Each inlet channel 23 is communicated with the powder supply chamber 122 through an air pipe and a ferrule joint. The four powder storage cylinders 121 supply powders into the corresponding powder supply chambers 122, and the powder supply amount of the powder storage cylinders 121 can be adjusted according to the actual requirements during laser cladding. By adjusting the rotation speed of the powder feeding disc runner of the corresponding powder storage cylinder 121, the powder conveying amount can be adjusted, so as to achieve supply as needed and on demand. At the same time, each powder supply chamber 122 is communicated with the gas storage tank 11 and the static powder mixing unit 2. The gas storage tank 11 conveys compressed gas to the four powder supply chambers 122 through four air pipes respectively. The powders in the four powder supply chambers 122 enter the primary powder mixing part 21 of the static powder mixing unit 2 through the corresponding four inlet channels 23 respectively under the drive of the compressed gas. By adjusting the flow rate and pressure of the compressed gas input into the four powder supply chambers 122 respectively, the powder amount and the conveying rate conveyed by each powder supply chamber 122 can also be adjusted accordingly. The four powder airflows supplied by the powder supply chambers 122 are conveyed through the air pipes. First, they are transmitted to the primary powder mixing part 21 in the static powder mixing unit 2. The impact force of the four powder airflows acts on the arc-shaped blades 2121, causing the arc-shaped blades 2121 to rotate. While the arc-shaped blades 2121 rotate, the movement directions of the four powder airflows are changed, and the four powder airflows are dispersed and mixed together, thus realizing the preliminary mixing of the four kinds of powders in the second chamber for subsequent full mixing. Since the second chamber is communicated with the first chamber 221, the preliminarily mixed powders enter the first chamber 221 under the drive of the air flow. When the mixed powders pass through the first spiral blade 2221 and the second spiral blade 2222 which are sequentially and spacedly arranged in the first chamber 221, they are divided, changed in flow state and mixed multiple times. The arc-shaped surfaces of the first spiral blade 2221 and the second spiral blade 2222 and the set angle between the two make the powder airflow advance in a swirling state, not only realizing the full mixing of the four kinds of powders, but also preventing the mixed powders from moving in one direction due to the influence of gravity and the airflow angle. The fully mixed powders are conveyed to the pressure relief unit 5 through an air pipe. The pressure relief unit 5 uses a pressure relief valve to release the pressure of the mixed powders, preventing the mixed powders from having too much powder amount finally conveyed to the nozzle 4 due to too large gas flow rate, resulting in waste of powders and affecting the quality of the laser cladding layer. The mixed powders after pressure relief are conveyed to the powder distribution unit 3 through an air pipe, and the powder distribution unit 3 is used to shunt the mixed powders. When the mixed powders pass through the powder distribution pipe 34 and pass through the third spiral blade 351 and the fourth spiral blade 352 which are sequentially and spacedly arranged in the powder distribution pipe 34, they are divided, changed in flow direction and mixed multiple times, avoiding powder aggregation in the powder distribution unit 3, resulting in powder blockage and affecting the working efficiency.Meanwhile, the powder is mixed again to ensure the uniformity of the powder mixture. It can be understood that the setting of the powder dividing tube 34 provides a buffering effect for the subsequent powder dividing work, which is conducive to more accurate powder dividing. After passing through the powder dividing core 362, the powder is divided into four paths of powder by the four powder outlets 37, and is transmitted to the nozzle 4 through four air pipes and their corresponding ferrule joints and pneumatic quick connectors. The nozzle 4 sprays and accumulates the four paths of powder received on the surface of the workpiece.

[0062] In the description of the above embodiments, the specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0063] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A laser cladding powder feeding device, characterized in that, Comprising: A powder supply unit for supplying at least two kinds of powders, with the flow rate of each powder adjustable; A static powder mixing unit communicating with the powder supply unit for receiving and mixing at least two kinds of powders; A powder dividing unit communicating with the static powder mixing unit for equally dividing the mixed powder; A nozzle communicating with the powder dividing unit for spraying and accumulating the mixed powder on the surface of a workpiece; A primary powder mixing part communicating with the powder supply unit for receiving and pre-mixing at least two kinds of powders; A secondary powder mixing part communicating with the primary powder mixing part for receiving and mixing the pre-mixed powders; A first chamber that is through and a plurality of groups of first spiral blades connected in sequence, with the plurality of groups of first spiral blades arranged in the first chamber along the powder conveying direction; Each group of the first spiral blade assemblies includes a first spiral blade and a second spiral blade, and both the first spiral blade and the second spiral blade are at least one of left-handed blades or right-handed blades; The first spiral blade and the second spiral blade have an included angle α in the circumferential direction, where 0° < α < 180°; A through second chamber that communicates with the powder supply unit and the first chamber respectively; A first impeller rotatably accommodated in the second chamber; The powder dividing unit includes: A cylinder body having opposite first and second ends, and the cylinder body is through from the first end to the second end; A powder passing member having a first sealing part and a powder passing part, and a powder passing cavity is formed by penetrating through both the first sealing part and the powder passing part; the first sealing part covers the first end, and the powder passing part is accommodated in the part of the cylinder body close to the first end; A powder dividing member having a second sealing part and a powder dividing part, with a plurality of powder dividing grooves opened along the length direction of the outer wall of the powder dividing part, and a plurality of through holes are opened through the second sealing part, and each powder dividing groove communicates with each through hole correspondingly; the second sealing part covers the second end, and the powder dividing member is accommodated in the part of the cylinder body close to the second end; one end of the powder dividing member away from the second sealing part abuts against the powder passing part, and the openings of the plurality of powder dividing grooves communicate with the powder passing cavity; 2. The laser cladding powder feeding device according to claim 1, wherein The powder supply unit includes: An air storage tank for storing compressed gas; And a plurality of powder feeders independently communicating with the air storage tank and the static powder mixing unit.

3. The laser cladding powder feeding device according to claim 2, wherein Each powder feeder includes: A powder storage cylinder for storing the powder; A powder supply chamber communicating with the powder storage cylinder, the air storage tank and the static powder mixing unit at the same time; the air storage tank controllably supplies compressed gas to the powder supply chamber, and the powder storage cylinder controllably supplies the powder to the powder supply chamber.

4. The laser cladding powder feeding device according to claim 1, characterized in that, The laser cladding powder feeding device further includes a pressure relief unit communicating with the static powder mixing unit and the powder dividing unit, and the pressure relief unit is used for relieving the pressure of the mixed powder; the pressure relief unit is a pressure relief valve.

5. A laser cladding powder feeding device, characterized in that, Comprising: Powder supply unit, which is used to supply at least two kinds of powders, and the flow rate of each powder is adjustable; Static powder mixing unit, which is connected to the powder supply unit and is used to receive and mix at least two kinds of powders; Powder dividing unit, which is connected to the static powder mixing unit and is used to evenly divide the mixed powder; Nozzle, which is connected to the powder dividing unit and is used to spray and accumulate the mixed powder on the surface of the workpiece; Primary powder mixing part, which is connected to the powder supply unit and is used to receive and pre-mix at least two kinds of powders; Secondary powder mixing part, which is connected to the primary powder mixing part and is used to receive and mix the pre-mixed powders; It consists of a through first chamber and multiple groups of first spiral blade assemblies connected in sequence, and multiple groups of first spiral blade assemblies are arranged in the first chamber along the powder conveying direction; Each group of the first spiral blade assemblies includes a first spiral blade and a second spiral blade, and both the first spiral blade and the second spiral blade are at least one of left-handed blades or right-handed blades; The first spiral blade and the second spiral blade have an included angle α in the circumferential direction, and 0° < α < 180°; A through second chamber, which is respectively connected to the powder supply unit and the first chamber; A first impeller rotatably accommodated in the second chamber; The powder dividing unit includes: A through powder dividing pipe, Multiple groups of second spiral blade assemblies connected in sequence, and multiple groups of second spiral blade assemblies are all arranged in the powder dividing pipe along the powder conveying direction in the powder dividing pipe; each group of the second spiral blade assemblies includes a third spiral blade and a fourth spiral blade, and both the third spiral blade and the fourth spiral blade are at least one of left-handed blades or right-handed blades; the third spiral blade and the fourth spiral blade have an included angle β in the circumferential direction, and 0° < β < 180°; A hollow base, one end of which is connected to the powder dividing pipe, and the other end is provided with a plurality of powder outlets; a rotatable second impeller is arranged at one end of the cavity of the hollow base close to the powder dividing pipe; a powder dividing core is arranged at a position in the cavity of the hollow base close to the powder outlets.

6. A laser cladding powder feeding method, characterized in that Using the laser cladding powder feeding equipment according to any one of claims 1-5 for transporting powder during the laser cladding process, including the following steps: Controllably supply at least two kinds of powders from the powder supply unit to the static powder mixing unit; Mix at least two kinds of the powders by using the static powder mixing unit; Release the pressure of the mixed powder by using the pressure relief unit; Evenly distribute the mixed powder by using the powder dividing unit; Spray and accumulate the mixed powder on the surface of the workpiece by using the nozzle.

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