CN114231971B

CN114231971B - Laser cladding powder feeding equipment

Info

Publication number: CN114231971B
Application number: CN202111536485.2A
Authority: CN
Inventors: 谢寿春; 黄河; 陶鸣; 邓小松
Original assignee: Nanjing Huirui Photoelectric Technology Co ltd
Current assignee: Nanjing Huirui Photoelectric Technology Co ltd
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2023-06-30
Anticipated expiration: 2041-12-15
Also published as: CN114231971A

Abstract

The invention discloses laser cladding powder feeding equipment, which relates to the technical field of laser cladding, and converts a carrier gas powder feeding mode into a gravity powder feeding mode, so that the technical problem that flowing gas in the carrier gas powder feeding mode blows off powder on the surface of a workpiece is avoided, a mechanical arm does not need to bear a heavier powder feeder, the phenomena of unstable powder and deviation when a powder feeding nozzle discharges powder due to shaking of a powder feeding pipe when the mechanical arm moves are solved, and the cladding quality and efficiency are improved. The laser cladding powder feeding device comprises a powder feeding unit, a separation unit and a powder feeding nozzle, wherein the powder feeding unit is used for providing carrier gas powder. The separation unit is communicated with the powder supply unit and is used for receiving the carrier gas powder and separating the gas and the powder of the carrier gas powder. The powder feeding nozzle is communicated with the separation unit and is used for receiving the separated powder and gathering the powder on the surface of the workpiece, and the powder feeding nozzle is positioned below the separation unit.

Description

Laser cladding powder feeding equipment

Technical Field

The invention relates to the technical field of laser cladding, in particular to laser cladding powder feeding equipment.

Background

The laser cladding technology is a new workpiece surface modification technology which is developed along with the development of high-power lasers, and a cladding material (generally powder) is added on the surface of a workpiece through a laser cladding powder feeding nozzle, and a metallurgically bonded material-adding cladding layer is formed on the surface of the workpiece by utilizing a method of fusing the cladding material and a thin layer on the surface of the workpiece together by utilizing a laser beam with high energy density. The additive cladding layer can obviously improve the characteristics of wear resistance, corrosion resistance, heat resistance, oxidation resistance and the like of the surface of the workpiece.

In the prior art, two main methods exist for powder feeding in laser cladding processing, namely, the powder feeding is carried by adopting gas flow to carry powder to flow to reach a molten pool, and generally, a three-axis machine tool is combined for operation, a powder feeding nozzle and a laser head are carried by a mechanical arm, and the powder feeding method is not influenced by the height difference of a powder feeder and the powder feeding nozzle. However, due to the presence of the flowing gas, the powder is easily blown by the flowing gas when reaching the surface of the workpiece, and the quality of the laser cladding layer is affected while the powder is wasted. Secondly, gravity powder feeding is realized, namely powder flows through a powder feeding nozzle to be flatly paved on the surface of a workpiece by utilizing the self weight of the powder, and the method needs a certain height difference between a powder feeder and the powder feeding nozzle, so that the powder can fall freely. This method is generally applied to cladding operations requiring a large amount of powder, for example, wide spot cladding operations for large area planar, irregular surfaces. The gravity powder feeding is also combined with the three-axis machine tool to work, when the weight of the powder feeding device is heavy and the mechanical arm cannot bear the weight, the powder feeding device cannot be mounted on the mechanical arm, so that the powder feeding device cannot form a relatively static matching mode with the powder feeding nozzle. When the mechanical arm works, the powder feeding pipe can not avoid swinging and shifting, when powder is conveyed in the powder feeding pipe, the powder is guided by the change of the angle of the powder feeding pipe to flow direction, so that the powder is shifted when being output from the powder feeding nozzle, and a regular linear plane cannot be formed on the surface of a workpiece, and the laser cladding quality is affected.

Disclosure of Invention

The invention aims to provide laser cladding powder feeding equipment, which converts a carrier gas powder feeding mode into a gravity powder feeding mode, so that the technical problem that flowing gas existing in the carrier gas powder feeding mode blows off powder on the surface of a workpiece is avoided, a mechanical arm does not need to bear a heavier powder feeder, the phenomena of unstable powder and deviation when a powder feeding nozzle discharges powder due to shaking of a powder feeding pipe when the mechanical arm moves are solved, and the cladding quality and efficiency are improved.

In order to achieve the above purpose, the invention provides laser cladding powder feeding equipment, which comprises a powder feeding unit, a separation unit and a powder feeding nozzle, wherein the powder feeding unit is used for providing carrier gas powder. The separation unit is communicated with the powder supply unit and is used for receiving the carrier gas powder and separating the gas and the powder of the carrier gas powder. The powder feeding nozzle is communicated with the separation unit and is used for receiving the separated powder and gathering the powder on the surface of the workpiece, and the powder feeding nozzle is positioned below the separation unit.

By adopting the technical scheme, the powder supply unit is used for providing carrier gas powder to realize a carrier gas powder supply mode. The carrier gas powder feeding mode is not limited by the height difference between the powder feeder and the powder feeding nozzle, a certain distance is allowed between the powder feeder and the powder feeding nozzle, and the application universality of the laser cladding powder feeding equipment provided by the invention is improved. The separation unit is communicated with the powder supply unit and is used for receiving the carrier gas powder and separating the gas and the powder of the carrier gas powder. The powder feeding nozzle is positioned below the separating unit, and separated powder is received by the powder feeding nozzle and gathered on the surface of the workpiece. The powder feeding nozzle is positioned below the separation unit, so that powder separated by the separation unit is guaranteed to be conveyed to the powder feeding nozzle under the action of self gravity, and conditions are provided for realizing a gravity powder feeding mode. The arrangement of the separation unit effectively combines a carrier gas powder feeding mode and a gravity powder feeding mode, and solves the problem that powder is unstable and deviates when a powder feeding nozzle discharges powder due to shaking of a powder feeding pipe when the mechanical arm moves. Especially when carrying out wide facula cladding operation on large tracts of land plane, irregular surface, need not to set up heavier powder feeder on the arm, alleviateed the loading weight of arm, extension arm's life. In addition, the carrier gas powder conveyed by the carrier gas powder conveying mode is conveyed to the powder conveying nozzle after being separated, so that the technical problem that flowing gas existing in the carrier gas powder conveying mode blows off powder on the surface of a workpiece is avoided, the powder utilization rate is increased, and the laser cladding quality is ensured.

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 powder feeding device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a separating valve according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of A-A of FIG. 2;

FIG. 4 is a schematic cross-sectional view of B-B of FIG. 2;

FIG. 5 is a schematic diagram of another separating valve according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of C-C of FIG. 5;

FIG. 7 is a schematic view of a powder tube according to an embodiment of the present invention;

FIG. 8 is a schematic view of a ventilation board according to an embodiment of the present invention;

FIG. 9 is a schematic view of an upper cylinder according to an embodiment of the present invention;

FIG. 10 is a schematic cross-sectional view of D-D of FIG. 9;

reference numerals:

1-powder supply unit, 2-separating valve, 21-valve body, 211-first cavity body, 212-powder feeding hole,

22-ventilation part, 221-second cavity, 23-reversing part, 231-third cavity,

24-upper cylinder body, 241-first through hole, 242-fourth cavity body,

25-a lower cylinder body, 251-a fifth cavity body, 26-a powder tube, 261-a second through hole,

27-a ventilation plate 271-a third through hole, 3-a powder feeding nozzle and 4-a filtering unit.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise. The meaning of "a number" is one or more than one unless specifically defined otherwise.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

As shown in fig. 1, the invention provides a laser cladding powder feeding device, which comprises a powder feeding unit 1, a separation unit and a powder feeding nozzle 3, wherein the powder feeding unit 1 is used for providing carrier gas powder. The separation unit communicates with the powder supply unit 1 for receiving the carrier gas powder and separating the gas of the carrier gas powder from the powder. The powder feeding nozzle 3 is communicated with the separating unit and is used for receiving the separated powder and gathering the powder on the surface of the workpiece, and the powder feeding nozzle 3 is positioned below the separating unit.

Thus, the powder supply unit 1 is used for providing carrier gas powder, and realizes a carrier gas powder feeding mode. The carrier gas powder feeding mode is not limited by the height difference between the powder feeder and the powder feeding nozzle 3, a certain distance is allowed between the powder feeder and the powder feeding nozzle 3, and the application universality of the laser cladding powder feeding equipment provided by the embodiment of the invention is improved. The separation unit communicates with the powder supply unit 1 for receiving the carrier gas powder and separating the gas of the carrier gas powder from the powder. The powder feeding nozzle 3 is positioned below the separating unit, and the separated powder is received by the powder feeding nozzle 3 and accumulated on the surface of the workpiece. The powder feeding nozzle 3 is positioned below the separation unit, so that a height difference is formed between the powder feeding nozzle 3 and the separation unit at the height position, the powder separated by the separation unit is ensured to be conveyed to the powder feeding nozzle 3 under the action of self gravity, and conditions are provided for realizing a gravity powder feeding mode. The arrangement of the separation unit effectively combines a carrier gas powder feeding mode and a gravity powder feeding mode, and solves the problem that powder is unstable and deviates when the powder feeding nozzle 3 discharges powder due to shaking of the powder feeding pipe when the mechanical arm moves. Especially when carrying out wide facula cladding operation on large tracts of land plane, irregular surface, need not to set up heavier powder feeder on the arm, alleviateed the loading weight of arm, extension arm's life. In addition, the carrier gas powder conveyed by the carrier gas powder conveying mode is conveyed to the powder conveying nozzle 3 after being separated, so that the technical problem that the flowing gas in the carrier gas powder conveying mode blows off the powder on the surface of the workpiece is avoided, the powder utilization rate is increased, and the laser cladding quality is ensured.

It should be noted that the gas separated by the separation unit still contains a small amount of powder, and it should be noted that the content of the powder in the separated gas is within the process requirement range. In order to reduce the waste of the powder and increase the utilization rate of the powder, as a possible implementation manner, the laser cladding powder feeding device provided by the embodiment of the invention further comprises a filtering unit 4, wherein the filtering unit 4 comprises a filter, and the filtering unit 4 is communicated with the separating unit and is used for receiving the gas separated from the carrier gas powder and discharging the gas into the atmosphere after filtering without pollution. The powder filtered by the filtering unit 4 can be put into the powder feeder in the powder feeding unit 1 for further use. In practical cases, the carrier gas powder feeding mode can adopt air with certain pressure, and the pressure range of the air can be 0.4-0.6 megapascals.

In specific implementation, the powder supply unit 1 is communicated with the separation unit through a powder supply pipe and a clamping sleeve connector, and the powder supply nozzle 3 adopts a paraxial powder supply nozzle. The separating unit is communicated with the powder feeding nozzle 3 and the filtering unit 4 through a powder feeding pipe and a clamping sleeve joint. After being output from the powder supply unit 1, the carrier gas powder is conveyed to the separation unit through the powder conveying pipe and the clamping sleeve connector, and the carrier gas powder is separated into powder and gas by the separation unit, so that the pressure relief effect of the carrier gas powder conveyed in the carrier gas powder conveying mode is realized. The separated gas is conveyed to the filtering unit 4 through the powder conveying pipe and the cutting sleeve connector, and the gas with a small amount of powder is filtered and discharged through the filter exhaust port without pollution. The separated powder is conveyed to the powder feeding nozzle 3 through the powder feeding pipe and the clamping sleeve connector under the action of self gravity, and the powder is output by the output end of the powder feeding nozzle 3 and gathered on the surface of a workpiece, so that the purpose of gravity powder feeding is achieved, and a serial powder feeding exhaust and pressure relief system is formed. And the laser is laid on the surface of the workpiece on which the powder is gathered, so that the laser cladding operation is completed. It should be appreciated that when performing a wide spot cladding operation on a large area planar, irregular surface, a large amount of powder is required, and thus the overall weight of the powder feeder is heavy and the mechanical arm cannot carry. In the embodiment provided by the invention, during specific operation, the powder feeding nozzle 3 and the separating unit are placed on the mechanical arm, and when the mechanical arm moves, the powder feeding nozzle 3 and the separating unit synchronously move, so that the powder feeding nozzle 3 and the separating unit are in a relatively static state, and the phenomena of unstable powder and deviation when the powder feeding nozzle 3 discharges powder due to shaking of the powder feeding pipe caused by the mechanical arm during operation are avoided. The mechanical arm described in the invention can realize actions such as extension, shortening, turning and the like, so that the powder feeding nozzle 3 can reach a wider area, and the laser cladding efficiency is improved. The height and distance between the powder feeding unit 1 and the separation unit are not particularly limited, but the length of the powder feeding pipe between the powder feeding unit 1 and the separation unit should not exceed 15 meters to ensure normal transportation of the powder.

As a possible implementation, the separation unit is a separation valve 2.

In one example, as shown in fig. 2, 3 and 4, the separation valve 2 includes a valve body 21, a breather 22 and a reversing member 23, the valve body 21 having opposite first and second ends, the valve body 21 penetrating from the first end to the second end to form a first cavity 211. The position of the outer wall of the valve body 21, which is close to the first end, is provided with a powder feeding hole 212, the powder feeding hole 212 is communicated with a first cavity 211, the first cavity 211 is communicated with the powder feeding unit 1 through the powder feeding hole 212, and the second end is used for discharging powder. The ventilation member 22 includes a sealing portion and a ventilation portion, and a second cavity 221 is formed through the sealing portion and the ventilation portion, the sealing portion being provided at the first end, and the ventilation portion being accommodated in the first cavity 211. The reversing piece 23 is sleeved on the ventilation part, and an extension line of the central axis of the powder feeding hole 212 passes through between the outer wall of the reversing piece 23 and the inner wall of the valve body 21. The reversing element 23 has a gap with the inner wall of the valve body 21 to let the powder pass.

In particular, in this example, the powder supply unit 1 supplies carrier gas powder into the valve body 21 through the powder supply hole 212 in the valve body 21 via the powder supply pipe and the ferrule joint. The carrier gas powder is separated into powder and gas by the separation valve 2, and the gas separated by the separation valve 2 is discharged from the second chamber 221 of the ventilation member 22 and then sent to the filter unit 4 through the ferrule fitting and the powder feeding tube. The powder separated by the separating valve 2 is discharged through the second end of the valve body 21 and is conveyed to the powder feeding nozzle 3 through the ferrule joint and the powder feeding pipe. The materials, dimensions, etc. of the valve body 21, the ventilation member 22, and the reversing member 23 are set according to actual conditions, and are not particularly limited herein. The ventilation piece 22 is connected with the valve body 21 in a threaded mode, an inner thread is formed on the inner wall, close to the first end, of the valve body 21, an outer thread matched with the inner thread on the valve body 21 is formed on the outer wall of the sealing part of the ventilation piece 22, and the ventilation piece 22 is tightly connected with the valve body 21 through the matching of the inner thread and the outer thread. Similarly, the reversing element 23 and the ventilation portion are fixed by screw connection.

The carrier gas powder supplied from the powder supply unit 1 is supplied from the powder supply pipe, supplied into the first chamber 211 through the powder supply hole 212, and supplied from the powder supply hole 212 to the outside of the reversing member 23 through the inner wall of the valve body 21, with the central axis of the powder supply hole 212 being offset from the central axis of the reversing member 23. Thus, a portion of the powder impinges on the inner wall of the valve body 21 and another portion impinges on the outer wall of the reversing element 23, driven by the flowing gas, such that the carrier gas powder rotates around the reversing element 23 within the first chamber 211. Since the cap sealed by the sealing portion is provided at the first end of the valve body 21, and the self weight of the powder, the carrier gas powder moves downward along the gap between the direction changing member 23 and the inner wall of the valve body 21 while rotating around the direction changing member 23, flowing into the lower portion of the first chamber 211. At this time, since the density of the powder is greater than that of the gas used, i.e., air, the powder freely falls to the second end of the valve body 21 due to its own weight. In the first chamber 211 of the valve body 21, the gas is discharged from the separation valve 2 through the second chamber 221 of the barrier-free ventilation member 22 due to the interference and the obstruction of the powder at the second end. The function of the diverter 23 is that the carrier gas powder can be formed into a regular, and rotational flow pattern as it enters the first cavity 211. It will be appreciated that the irregular flow of carrier gas powder on the one hand results in a large amount of gas being carried over from the second end of the valve body 21, thereby failing to adequately achieve the venting effect. On the other hand, a large amount of powder is entrained in the gas discharged from the separation valve 2, so that the powder utilization rate is lowered. Under the interference of the direction changing member 23, the carrier gas powder is regularly rotated at the upper portion of the first chamber 211, and at this time, inertia of the carrier gas powder flowing in is eliminated by the rotating force, and the carrier gas powder flows into the lower portion of the first chamber 211 along the gap between the inner wall of the valve body 21 and the direction changing member 23 by the gravity. The powder falls to the second end under the action of self gravity, and gas is discharged from the separating valve 2 through the second cavity 221 upwards, and the discharged gas enters the filtering unit 4 and is discharged without pollution after being filtered by the filter element in the filter, so that the pressure release effect of carrier gas powder is realized, and the purpose of gravity powder feeding is achieved.

In an alternative manner, as shown in fig. 3 and 4, the reversing element 23 is in a frustum structure, a third cavity 231 with a horn shape is provided at the bottom of the frustum structure, the third cavity 231 is communicated with the second cavity 221, and an end of the ventilation element 22 near the second end is located in the third cavity 231. The minimum distance between the reversing element 23 and the inner wall of the valve body 21 is in the range of 0.5mm to 1mm.

In this way, the diameter from the upper end to the lower end of the reversing element 23 gradually increases, so that the gap between the reversing element 23 and the inner wall of the valve body 21 gradually decreases, thereby preventing the gas from rapidly impacting from the upper part of the first cavity 211 to the lower part of the first cavity 211, increasing the residence time of the gas in the upper part of the first cavity 211, providing conditions for the carrier gas powder to form a regular rotary flow mode, and reducing the amount of the gas flowing out from the second end. The minimum distance between the direction changing member 23 and the inner wall of the valve body 21, i.e., the distance between the lower end of the direction changing member 23 and the inner wall of the valve body 21 is in the range of 0.5mm to 1mm, and in the embodiment provided by the present invention, 0.75mm is preferable so that the powder can smoothly pass between the direction changing member 23 and the inner wall of the valve body 21. The bottom of the frustum structure is provided with the third cavity 231 in a horn shape, when the gas flows upwards, the powder mixed with the gas is impacted on the outer wall forming the third cavity 231, so that the powder falls reversely, and the amount of the powder flowing out of the second cavity 221 can be reduced. The end of the ventilation member 22 near the second end is located in the third cavity 231, rather than extending out of the third cavity 231, so that the upward flowing powder is prevented from directly entering the second cavity 221 before striking the outer wall forming the third cavity 231, and part of the powder is taken away when flowing out from the separating valve 2, so that the powder is easy to waste.

As a possible implementation, the inner diameter of the valve body 21 gradually decreases from the lower end to the second end of the reversing element 23. As shown in fig. 3, the inner diameter of the second end of the valve body 21 is matched with the ferrule joint, so that powder slides along the inner wall of the valve body 21, and the powder smoothly flows out of the separating valve 2.

The diameter of the first cavity 211, the inner diameter of the powder feeding tube connected to the ventilation member 22, and the specific size of the inner diameter of the second end of the valve body 21 are not required here, but the diameter of the first cavity 211 is required to be larger than the inner diameter of the powder feeding tube connected to the ventilation member 22 and larger than the inner diameter of the second end of the valve body 21, so that the compressed gas is more easily discharged. Meanwhile, the first cavity 211 should not be too small and narrow, and in particular, the distance between the lower end and the second end of the direction-changing member 23 should not be too small, otherwise, the gas and the powder of the carrier gas powder cannot be separated efficiently. For example, when the vertical distance from the lower end of the sealing portion of the ventilation member 22 to the second end is 44mm, the vertical distance from the lower end of the direction change member 23 to the second end is 27mm, which is, of course, merely illustrative, and not particularly limited, and is specific to practical situations.

In addition, in the embodiment provided by the present invention, the first chamber 211, the ventilation member 22, the direction changing member 23, the second chamber 221, and the third chamber 231 are preferably coaxially disposed to facilitate the flow of the powder and the gas and to allow the gas and the powder to be sufficiently separated.

In another example, referring to fig. 5 and 6, the separating valve 2 includes an upper cylinder 24, a lower cylinder 25, and a powder passing tube 26, the upper cylinder 24 having opposite third and fourth ends, and a fourth cavity 242 formed therethrough from the third end to the fourth end. The upper cylinder 24 is provided with a plurality of first through holes 241 near the third end, and the first through holes 241 are communicated with the fourth cavity. The lower cylinder 25 is disposed at the fourth end of the upper cylinder 24, the lower cylinder 25 has a fifth cavity 251 therethrough, and the fourth cavity 242 communicates with the fifth cavity 251. The powder tube 26 is used for conveying carrier gas powder, and has a connecting end and a closed free end, and the free end extends from the third end into the fourth cavity 242 and is accommodated in the fifth cavity 251. The powder tube 26 is provided with a plurality of second through holes 261 near the free end for the circulation of the carrier gas powder.

As a possible implementation manner, the separating valve 2 further comprises a ventilation plate 27, the ventilation plate 27 is tightly sleeved outside the powder through tube 26, and the ventilation plate 27 is located between the second through hole 261 and the first through hole 241. The ventilation plate 27 is provided with a plurality of third through holes 271 in the powder conveying direction.

In practical terms, in this example, the powder supply unit 1 is conveyed into the separating valve 2 through the third end of the upper cylinder 24 by a powder conveying pipe and a ferrule joint, the carrier gas powder is separated into powder and gas by the separating valve 2, and the gas separated by the separating valve 2 is finally discharged from the first through hole 241 and conveyed to the filtering unit 4 by the ferrule joint and the powder conveying pipe. The powder separated by the separating valve 2 is discharged through the lower end of the lower cylinder 25 and is conveyed to the powder feeding nozzle 3 through the cutting ferrule joint and the powder feeding pipe.

As shown in fig. 6, the upper cylinder 24 is tightly and sealingly connected to the lower cylinder 25. The connection end of the powder passing tube 26 is in sealing connection with the third end of the upper cylinder 24, and the carrier gas powder provided by the powder supply unit 1 flows along the length direction of the powder passing tube 26 through the connection end of the powder passing tube 26, and the powder passing tube 26 has the function of guiding the carrier gas powder to flow. The lower end of the powder tube 26 is a closed free end, and a plurality of second through holes 261 are formed at the position, close to the free end, of the powder tube 26, so that the carrier gas powder does not generate downward inertia impact force when flowing downwards and flows out of the lower end of the lower cylinder 25. When the carrier gas powder passes through the second through hole 261, the carrier gas powder flows out from the powder passing tube 26 through the second through hole 261, so that the flowing direction of the carrier gas powder is changed, and part of the powder drops downwards under the action of self gravity until the powder drops to the lowest end of the lower cylinder 25, namely the powder outlet end. Due to the interference and obstruction of the powder at the powder outlet end, the gas with the powder entrained therein flows upward in the fourth chamber 242 and the fifth chamber 251, and when striking the gas-permeable plate 27, a part of the powder is separated by the obstruction. The gas with a small amount of powder is further separated by blocking while passing through the upper part of the upper cylinder 24, and finally discharged from the first through hole 241 and enters the filtering unit 4 for filtering. The separated powder is collected downwards under the action of gravity, and is conveyed to a paraxial powder feeding nozzle through a powder outlet end of the lower cylinder 25, namely the lower end of the lower cylinder 25 by a powder feeding pipe.

It should be noted that the diameter of the first through hole 241, the diameter of the second through hole 261 and the diameter of the third through hole 271 formed in the upper cylinder 24 should not be too large, and the number should not be too small for ventilation and filtration. Meanwhile, the diameters and heights of the fourth cavity 242 and the fifth cavity 251 should be such that sufficient separation of powder and gas can be efficiently achieved. The distance of the closed free end of the powder tube 26 from the lower end of the lower cylinder 25 cannot be too short in order to sufficiently separate the powder and the gas. It is required that the distance between the ventilation plate 27 and the first through hole 241 is smaller than the distance between the ventilation plate 27 and the second through hole 261 located at the uppermost end. For example, the diameter of the first through hole 241 is preferably 5mm or more to facilitate the discharge of gas. The diameter of the second through hole 261 ranges from 3.5mm to 4.5mm, preferably 4mm. The diameter of the third through hole 271 is in the range of 1mm to 3mm, preferably 2.5mm. The diameter of the fourth cavity 242 is 35mm, the total height of the fourth cavity 242 and the fifth cavity 251 is 142mm, and the distance from the free end of the powder passing tube 26 to the lower end of the lower cylinder 25 is 49mm. The distance between the ventilation plate 27 and the first through hole 241 was 12.5mm. Of course, the method is only exemplified here, and is not particularly limited, so that the separation of the gas and the powder can be better performed, and the waste of the powder is reduced. In particular, the upper cylinder 24, the lower cylinder 25, the powder tube 26, the fourth cavity 242 and the fifth cavity 251 are preferably coaxially arranged to facilitate the flow of the powder and the gas and to allow the gas and the powder to be sufficiently separated.

As shown in fig. 6, the inner wall of the lower cylinder 25 is gradually reduced in the powder conveying direction. The inner diameter of the lower end of the lower cylinder 25 is matched with the cutting sleeve joint, so that powder can slide down along the inner wall of the lower cylinder 25, and the powder can smoothly flow out of the separating valve 2.

In the description of the above embodiments, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A laser cladding powder delivery device, comprising:

a powder supply unit for supplying carrier gas powder;

a separation unit, which is communicated with the powder supply unit, is used for receiving the carrier gas powder and separating the gas and the powder of the carrier gas powder;

the powder feeding nozzle is communicated with the separation unit and is used for receiving the separated powder and gathering the powder on the surface of the workpiece; the powder feeding nozzle is positioned below the separation unit;

the separation unit is a separation valve;

the separation valve includes:

the upper cylinder is provided with a third end and a fourth end which are opposite, and a fourth cavity is formed by penetrating the upper cylinder from the third end to the fourth end; a plurality of first through holes are formed in the position, close to the third end, of the upper cylinder body, and the first through holes are communicated with the fourth cavity;

the lower cylinder is arranged at the fourth end of the upper cylinder and is provided with a fifth cavity which is communicated with the lower cylinder, and the fourth cavity is communicated with the fifth cavity;

the powder passing pipe is used for conveying the carrier gas powder, and is provided with a connecting end and a closed free end, and the free end extends from the third end into the fourth cavity and then extends to be accommodated in the fifth cavity; the powder tube is provided with a plurality of second through holes close to the free end for the circulation of the carrier gas powder.

2. The laser cladding powder feeding device according to claim 1, wherein the separating valve further comprises a ventilation plate, the ventilation plate is fastened and sleeved outside the powder feeding pipe, and the ventilation plate is located between the second through hole and the first through hole; and a plurality of third through holes are formed in the ventilation plate along the powder conveying direction.

3. The laser cladding powder feeding apparatus according to claim 1, wherein an inner wall of the lower cylinder is tapered in a powder conveying direction.

4. The laser cladding powder feeding apparatus according to claim 1, further comprising a filter unit in communication with the separation unit for receiving the gas of the carrier gas powder and discharging the gas after filtering.