CN210215545U - Cold spray gun for spraying aluminum layer - Google Patents

Abstract

The utility model relates to a cold spray gun for spraying aluminum layer, which can comprise an air chamber structure, an air inlet pipe, a powder feeding core assembly and a cold spray pipe assembly, wherein the air chamber structure can comprise a conical air chamber shell, an air chamber cover, an upper air chamber partition plate and a lower air chamber partition plate; the upper air chamber partition plate and the lower air chamber partition plate are provided with at least one circle of air holes, and the sum of the sectional areas of the air holes of the upper air chamber partition plate is larger than that of the air holes of the lower air chamber partition plate; the air inlet pipe penetrates through the air chamber cover and enters the air chamber part above the upper air chamber partition plate; the powder feeding core assembly penetrates through the air chamber cover, the upper air chamber partition plate and the lower air chamber partition plate until the powder feeding core assembly is close to the lower opening; the cold spray pipe assembly is fixedly arranged on the lower opening. The upper and lower air chamber clapboards with different air-through sectional areas are arranged, so that the pressure fluctuation of the air chamber can be avoided, and the coating quality is improved.

Description

Cold spray gun for spraying aluminum layer

Technical Field

The utility model relates to a cold spraying equipment specifically relates to a cold spray gun for spraying aluminium lamination.

Background

Cold spraying is a new and advanced surface coating technique developed from thermal spraying. The cold spraying is based on the aerodynamic and high-speed collision dynamics principle, firstly, high-pressure gas is introduced into a contraction-expansion Laval nozzle, supersonic flow is generated after the gas flows through the throat part of the nozzle, then powder conveying gas is used for conveying spraying powder into airflow from the upstream of the nozzle along the axial direction, powder particles are accelerated to the high speed of more than 300-1200 m/s through the whole nozzle to form high-speed particle flow, and the high-speed particle flow collides with a substrate to generate severe plastic deformation so as to deposit and form a coating. In the process, the working gas is usually preheated, and the temperature is generally 100-800 ℃ according to different spraying materials, but is far lower than the melting point of the spraying materials. Because the spraying process adopts relatively low temperature, adverse effects such as oxidation (aiming at metal materials), phase change, decomposition, chemical reaction, grain growth (aiming at nano-structure materials) and the like in the thermal spraying process can be avoided. At present, cold spray techniques have been successfully used to prepare most pure metals, alloys, metal matrix composites, nanostructured metal coatings or blocks, and the like.

The air chamber structure of the existing cold spray gun for spraying the aluminum layer adopts a form of a pure cone-shaped air chamber structure. Because the sectional area of the gas-powder mixing pipe at the rear end of the gas chamber is fixed, the gas supply pressure of the gas chamber structure is easy to fluctuate due to fluctuation of the powder supply quantity, and the system needs to correspondingly adjust when monitoring the large fluctuation. However, a certain time is required from monitoring-system calculation-valve execution-to gas chamber-gas chamber feedback, and the gas flow can continuously fluctuate in the time. The flow and pressure adjusted by the time lag cannot meet the actual fluctuation amount, and the phenomenon of overshoot or undershoot occurs, so that the system is continuously adjusted to oscillate. The method has the advantages that the service life of system components is greatly influenced, the coating quality is seriously influenced, the binding force of the coating is high and low, the porosity is different, the powdering rate is different, and the surface of the coating is uneven. In addition, the cold spraying temperature is high, so that the requirement on the material of a Laval nozzle in a cold spray gun is high, the production cost is high, a sealing ring in the cold spray gun is easy to damage, the service life is short, the continuity of the spraying action is influenced, and the material waste is caused.

Disclosure of Invention

The utility model aims at providing a cold spray gun of spraying aluminium lamination to solve above-mentioned technical problem. Therefore, the utility model discloses a specific technical scheme as follows:

a cold spray gun for spraying an aluminum layer can comprise a gas chamber structure, an air inlet pipe, a powder feeding core assembly and a cold spray pipe assembly, wherein the gas chamber structure comprises a conical gas chamber shell, a gas chamber cover, an upper gas chamber partition plate and a lower gas chamber partition plate, the gas chamber shell comprises a cylindrical upper part and a conical lower part and is provided with an upper opening and a lower opening; the air chamber cover is hermetically arranged at the upper opening, and the upper air chamber partition plate and the lower air chamber partition plate are fixedly arranged in the air chamber shell and divide the air chamber into three parts, wherein the upper air chamber partition plate is positioned at the junction of the cylindrical upper part and the conical lower part, and the lower air chamber partition plate is positioned in the conical lower part; the upper air chamber partition plate and the lower air chamber partition plate are provided with at least one circle of air holes, and the sum of the sectional areas of the air holes of the upper air chamber partition plate is larger than that of the air holes of the lower air chamber partition plate; the air inlet pipe penetrates through the air chamber cover and enters the air chamber part above the upper air chamber partition plate; the powder feeding core assembly penetrates through central through holes of the air chamber cover, the upper air chamber partition plate and the lower air chamber partition plate until the powder feeding core assembly is close to the lower opening; the cold spray pipe assembly is fixedly mounted on the lower opening.

Further, the side surface of the lower air chamber partition plate has the same taper as the inner wall of the conical lower part.

Further, the air holes in the upper air chamber partition plate are straight holes; the air holes in the lower air chamber partition plate are inclined holes, and the inclination of the inclined holes is the same as the taper of the inner wall of the conical lower part.

Further, the number of the air holes in the upper air chamber partition plate is the same as that of the air holes in the lower air chamber partition plate.

Furthermore, the air chamber structure also comprises an air chamber inner sleeve and a plurality of top columns, and the upper air chamber partition plate and the lower air chamber partition plate are fixedly arranged in the air chamber shell through the air chamber inner sleeve and the plurality of top columns; the upper end of the air chamber inner sleeve is abutted against the air chamber cover, and the lower end of the air chamber inner sleeve is abutted against the upper air chamber partition plate; the upper end of the top column supports the upper air chamber partition plate, and the lower end of the top column is fixed on the lower air chamber partition plate.

Further, the top pillar has an upper end with a smaller diameter, the upper air chamber partition plate has a through hole, and the upper air chamber partition plate is sleeved on the upper end through the through hole and supported by the top pillar; the lower end of the top column is fixedly connected with the lower air chamber partition plate through threads.

Further, the air chamber cover is further provided with a temperature sensor and a pressure sensor, and the temperature sensor and the pressure sensor are respectively used for measuring the temperature and the pressure in the air chamber part above the upper air chamber partition plate.

Furthermore, send powder core subassembly to establish including sending powder core and cover send the powder core sleeve pipe on the powder core, send the powder core sleeve pipe to be equipped with the cooling water sleeve on corresponding to the entrance point position of sending the powder core, be equipped with radial opposition's water inlet and delivery port on the lateral wall of cooling water sleeve, the water inlet is used for connecting cooling water source.

Further, the cold spray pipe assembly comprises a spray pipe seat, an inner spray pipe, an outer sleeve and a cooling water return pipe, wherein the spray pipe seat is provided with a water inlet channel and a water outlet channel, a cooling water channel is formed between the inner spray pipe and the outer sleeve, one end of the water inlet channel is communicated with a water outlet of the cooling water sleeve, the other end of the water inlet channel is communicated with the cooling water channel, the cooling water return pipes are arranged beside the outer sleeve side by side, the lower end of the cooling water return pipe is communicated with the cooling water channel, and the upper end of the cooling water return pipe is communicated with.

Further, the inner spray pipe comprises an upper inner spray pipe section and a lower inner spray pipe section which are butted together, the inner diameter of the upper inner spray pipe section is gradually reduced from top to bottom, and the inner diameter of the lower inner spray pipe section is gradually increased from top to bottom.

Further, the inner nozzle is made of high temperature plastic such as polyimide or stainless steel.

The utility model adopts the above technical scheme, the beneficial effect who has is: the utility model discloses a set up the upper and lower two-layer air chamber baffle of different sectional areas of ventilating, can avoid the air chamber pressure fluctuation, play the steady voltage effect, improve the coating quality. In addition, by providing a cooling system, the laval nozzle can be made from a less expensive and easier to machine material, thereby reducing the cost of the cold spray gun.

Drawings

To further illustrate the embodiments, the present invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

Fig. 1 is a perspective view of a cold spray gun according to an embodiment of the present invention;

FIG. 2 is another perspective view of the cold spray gun shown in FIG. 1 with a portion of the outer shell removed to show internal structure;

FIG. 3 is a front view of the cold spray gun shown in FIG. 2;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 4;

FIG. 5 is an exploded perspective view of the plenum structure of the cold spray gun shown in FIG. 2;

fig. 6 is a sectional view of the air cell structure shown in fig. 5.

Detailed Description

The present invention will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 1 to 6, a cold spray gun 100 for spraying an aluminum layer is described, and the cold spray gun 100 may include a gas chamber structure 1, an inlet duct 2, a powder feeding core assembly 3, and a cold spray duct assembly 4. The plenum structure 1 may include a conical cylindrical plenum housing 11, a plenum cover 12, a plenum inner 13, a number of top posts 14 (three shown), upper plenum partitions 15, and lower plenum partitions 16. The air chamber housing 11 is integrally formed and includes a cylindrical upper portion 111 and a conical lower portion 112. The gas chamber housing 11 has an upper opening 113 and a lower opening 114. The inner wall of the upper opening 113 has an internal thread and the outer wall of the lower opening 114 has an external thread. The chamber lid 12 is hermetically installed at the upper opening 113 of the chamber housing 11. An upper air chamber partition 15 and a lower air chamber partition 16 are fixedly installed in the air chamber housing 11 to divide the air chamber into three parts. The inlet pipe 2 passes through the chamber cover 12 into the portion of the chamber above the upper chamber partition 15. The powder feeding core assembly 3 passes through the central through holes of the gas chamber cover 12, the upper gas chamber partition plate 15 and the lower gas chamber partition plate 16 until it is close to the lower opening 114 to feed the aluminum powder to the lower opening 114. The cold jet assembly 4 is fixedly mounted to the lower opening 114. Therefore, the aluminum powder airflow forms high-speed particle flow through the cold spray pipe assembly 4, and the aluminum powder airflow collides with the surface to be sprayed to generate severe plastic deformation so as to deposit and form an aluminum coating. The specific structure of the chamber lid 12, upper chamber baffle 15, lower chamber baffle 16, powder feed core assembly 3 and cold spray tube assembly 4 is described below.

As shown in fig. 5 and 6, the gas chamber lid 12 includes an upper flange portion 121, an intermediate threaded connection portion 122, and a lower extension portion 123, which have gradually decreasing outer diameters. The chamber lid 12 is fixedly mounted to the upper opening 113 by the external thread of the intermediate threaded portion 122 being threadedly engaged with the internal thread of the upper opening 113. The end of the lower extension 123 passes through the upper plenum partition 15. The air chamber cover 12 is provided with a central through hole 124, an air pipe through hole 125, a temperature sensor through hole 126 and a pressure sensor through hole 127. Wherein the powder feeding core assembly 3 is inserted into the air cell structure from the central through hole 124 with its end near the lower opening 114. The air pipe through hole 125, the air pipe through hole 26, and the temperature sensor through hole 127 are located beside the central through hole 124, and are respectively used for the air inlet pipe 2, the temperature sensor 5, and the pressure sensor 6 to pass through (see fig. 2). The gas inlet tube 2 may have a spiral coil heating section 21 (see fig. 4) for heating the powder feeding gas. The powder feeding gas is usually an inert gas such as nitrogen gas. The temperature sensor 5 and the pressure sensor 6 are used to measure the temperature and the pressure, respectively, in the gas chamber (specifically, in the portion of the gas chamber above the upper chamber partition 16).

With continued reference to fig. 5 and 6, the upper and lower plenum partitions 15 and 16 are fixedly mounted within the plenum housing 11 by the plenum inner 13 and the top post 14. Wherein the upper plenum partition 15 is located at the intersection of the cylindrical upper section 111 and the conical lower section 112 and the lower plenum partition 16 is located in the conical lower section 112 (approximately mid-way). The upper end of the air chamber inner sleeve 13 abuts against the air chamber cover 12 (specifically, the middle threaded connection portion 122), and the lower end abuts against the upper air chamber partition 15; the upper end of the top pillar 14 supports an upper air chamber partition 15, and the lower end is fixed to a lower air chamber partition 16. The fixing structure is simple, and the installation and the disassembly are very convenient. Of course, the upper and lower chamber partitions 15 and 16 may be mounted in the chamber housing 11 using other fixing structures.

In the illustrated embodiment, the sides of the lower plenum partition 16 are tapered the same as the inner wall of the conical lower portion 112 so that the lower plenum partition 16 can fit snugly against the inner wall of the conical lower portion 112. This configuration of lower chamber baffle 16 facilitates installation.

As shown in fig. 5 and 6, the top post 14 has a smaller diameter upper end 141 and an externally threaded lower end 142. The upper plenum partition 15 has a through hole 152, and the upper plenum partition 15 is supported by the top pillar 14 by fitting over the upper end 141 through the through hole 152. The lower end 142 of the top post 14 is fixedly connected to the threaded hole 162 of the lower plenum partition 16 by threads. This mounting arrangement of the top pillar 14 to the upper and lower air chamber partitions 15 and 16 facilitates installation and removal.

The upper and lower chamber partitions 15, 16 each have at least one turn of air holes 151, 161 (two turns are shown in fig. 5) and the sum of the cross-sectional areas of the air holes of the upper chamber partition 15 is greater than the sum of the cross-sectional areas of the air holes of the lower chamber partition 16. When the powder feeding amount fluctuates, the generated air pressure fluctuation is buffered through the air chamber between the upper air chamber partition plate and the lower air chamber partition plate, so that the air pressure above the upper air chamber partition plate 15 is basically unchanged, and the pressure stabilizing effect is achieved. Namely, the upper air chamber is equivalent to a 'pressure stabilizing air storage tank', and after the pressure of the lower air chamber is reduced, the upper air chamber supplements the pressure in time to achieve the effect of automatic and rapid balance, so that the powder feeding pressure can be basically maintained unchanged.

In the illustrated embodiment, the air holes 151 of the upper chamber partition 15 are straight holes, and the air holes 161 of the lower chamber partition 16 are inclined holes. The inclination of the air hole 161 is the same as the taper of the conical lower portion 112, i.e., the air hole 161 is parallel to the inner wall of the conical lower portion 112. Because the air holes 161 are inclined, the air flow direction is towards the middle, which is beneficial to preventing the powder from diffusing and leading the powder to be sent into the cold spray pipe component 4 more intensively.

In the present embodiment, the number of the air holes 151 corresponds to the number of the air holes 161. In this case, the diameter of the air hole 151 is larger than the diameter of the air hole 161. In one embodiment, the diameter of the air holes 151 is 3 mm and the diameter of the air holes 161 is 2.5 mm. It should be understood that the number of air holes 151 and 161 may not be the same; the diameter and number of air holes 161 and air holes 151 per turn may also be non-uniform.

As shown in fig. 2-4, the cold spray gun of the present invention further includes a cooling system for cooling the powder feeding core assembly 3 and the cold spray pipe assembly 4, which will be described separately below. The powder feeding core assembly 3 may comprise a powder feeding core 31 and a powder feeding core sleeve 32 sleeved on the powder feeding core 31. The powder feeding core sleeve 32 is provided with a cooling water sleeve 33 at the inlet end position corresponding to the powder feeding core 31 to cool the powder feeding core 31, so as to prevent aluminum powder from being adhered to the powder feeding core 31 due to overhigh temperature, further influence the powder feeding amount and even block the powder feeding core 31. The cooling water jacket 33 is provided with diametrically opposed water inlets and outlets in the side wall for connection to a source of cooling water (not shown), for example via a water inlet tube 34. The conductivity of the cooling water is required to be below 20 mu S/cm, so that the cooling water needs to be replaced by new cooling water if the conductivity of the cooling water is more than 20 mu S/cm during the use process. The cooling water can be pure water or deionized water with the conductivity of less than 6 mu S/cm, and the like.

Cold spray pipe assembly 4 may include a spray pipe base 41, an inner spray pipe 42, an outer sleeve 43, and a cooling return pipe 44. The nozzle holder 41 has a water inlet passage 411 and a water outlet passage 412. The inner lance 42 and the outer jacket 43 form a cooling water channel therebetween. One end of the water inlet passage 411 is communicated with the water outlet (through the water pipe 45) of the cooling water jacket 33, and the other end is communicated with the cooling water passage. The cooling water return pipes 44 are arranged side by side beside the outer sleeve 43, and the lower ends thereof are communicated with the cooling water passage and the upper ends thereof are communicated with the water outlet passage. The outlet passage 412 is connected to the outlet pipe 46. Fig. 4 shows the flow direction of the cooling water by arrows.

The inner nozzle 42 is a laval nozzle and may include an upper inner nozzle segment 421 and a lower inner nozzle segment 422 that are butted together, wherein the inner diameter of the upper inner nozzle segment 421 gradually decreases from top to bottom and the inner diameter of the lower inner nozzle segment 422 gradually increases from top to bottom.

In this case, the inner nozzle 42 may be made of a low-cost material such as high-temperature plastic such as polyimide, or stainless steel.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A cold spray gun for spraying an aluminum layer is characterized by comprising an air chamber structure, an air inlet pipe, a powder feeding core assembly and a cold spray pipe assembly, wherein the air chamber structure comprises a conical air chamber shell, an air chamber cover, an upper air chamber partition plate and a lower air chamber partition plate, the air chamber shell comprises a cylindrical upper part and a conical lower part and is provided with an upper opening and a lower opening; the air chamber cover is hermetically arranged at the upper opening, and the upper air chamber partition plate and the lower air chamber partition plate are fixedly arranged in the air chamber shell and divide the air chamber into three parts, wherein the upper air chamber partition plate is positioned at the junction of the cylindrical upper part and the conical lower part, and the lower air chamber partition plate is positioned in the conical lower part; the upper air chamber partition plate and the lower air chamber partition plate are provided with at least one circle of air holes, and the sum of the sectional areas of the air holes of the upper air chamber partition plate is larger than that of the air holes of the lower air chamber partition plate; the air inlet pipe penetrates through the air chamber cover and enters the air chamber part above the upper air chamber partition plate; the powder feeding core assembly penetrates through central through holes of the air chamber cover, the upper air chamber partition plate and the lower air chamber partition plate until the powder feeding core assembly is close to the lower opening; the cold spray pipe assembly is fixedly mounted on the lower opening.

2. The cold spray gun of claim 1 wherein said lower plenum partition is tapered on the same side as the inner wall of said conical lower portion.

3. The cold spray gun of claim 1 wherein said air holes in said upper plenum partition are straight holes; the air holes in the lower air chamber partition plate are inclined holes, and the inclination of the inclined holes is the same as the taper of the inner wall of the conical lower part.

4. The cold spray gun of claim 1 wherein the number of air holes in said upper plenum partition is the same as the number of air holes in said lower plenum partition.

5. The cold spray gun of claim 1 wherein said plenum structure further comprises a plenum inner sleeve and a plurality of top posts, said upper and lower plenum partitions being fixedly mounted within said plenum housing by said plenum inner sleeve and said plurality of top posts; the upper end of the air chamber inner sleeve is abutted against the air chamber cover, and the lower end of the air chamber inner sleeve is abutted against the upper air chamber partition plate; the upper end of the top column supports the upper air chamber partition plate, and the lower end of the top column is fixed on the lower air chamber partition plate.

6. The cold spray gun of claim 5 wherein said top post has a smaller diameter upper end, said upper plenum partition having a through hole, said upper plenum partition being supported by said top post by said through hole being sleeved over said upper end; the lower end of the top column is fixedly connected with the lower air chamber partition plate through threads.

7. The cold spray gun of claim 1 wherein said plenum cover further mounts a temperature sensor and a pressure sensor for measuring the temperature and pressure, respectively, in the portion of the plenum above said upper plenum partition.

8. The cold spray gun of claim 1 wherein said powder feeding core assembly comprises a powder feeding core and a powder feeding core sleeve sleeved on said powder feeding core, said powder feeding core sleeve is provided with a cooling water sleeve at a position corresponding to an inlet end of said powder feeding core, a side wall of said cooling water sleeve is provided with a water inlet and a water outlet which are diametrically opposite, and said water inlet is used for connecting a cooling water source.

9. The cold spray gun of claim 8 wherein said cold spray tube assembly includes a nozzle tube base, an inner nozzle, an outer sleeve, and a cooling return tube, said nozzle tube base having a water inlet channel and a water outlet channel, said inner nozzle and said outer sleeve forming a cooling water channel therebetween, said water inlet channel communicating at one end with said cooling water sleeve outlet and at the other end with said cooling water channel, said cooling return tubes being arranged side-by-side adjacent to said outer sleeve with a lower end communicating with said cooling water channel and an upper end communicating with said water outlet channel.

10. The cold spray gun of claim 9 wherein said inner lance includes upper and lower inner lance sections butted together, said upper inner lance section having an inside diameter that gradually decreases from top to bottom and said lower inner lance section having an inside diameter that gradually increases from top to bottom.

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