A laval nozzle assembly for a cold spray apparatus

Abstract

The utility model provides a kind of laval nozzle assembly for cold spraying equipment, including nozzle, adapter assembly and sealing assembly, nozzle and adapter assembly are detachably connected, sealing assembly is located at the interface of nozzle and adapter assembly connection place.Nozzle is provided as hollow pipe body, nozzle is provided with powder gas mixing passage along axis, and nozzle outer periphery is provided with convex ring near butt joint end.Adapter assembly includes adapter and compression nut, adapter is provided with through hole along axis, and adapter one end is provided with flange, adapter middle section is provided with powder passage along radial direction, and powder passage and through hole are communicated.Nozzle is inserted in through hole, so that through hole and powder gas mixing passage are coaxial.Compression nut is detachably connected to the outer periphery of flange, and convex ring indirectly abuts against the inner side wall of compression nut through sealing assembly.The utility model is convenient to disassemble and maintain, reduces downtime, has good sealing property, and the stability of nozzle connection is high.

Description

Technical Field

[0001] This utility model belongs to the field of powder coating technology, specifically relating to a Laval nozzle assembly for cold spraying equipment. Background Technology

[0002] Cold spraying technology accelerates powder particles to supersonic speeds under high-pressure gas, causing them to impact the substrate surface and form a coating. This achieves molecular bonding between the powder and the metal substrate, resulting in ultra-high adhesion. In cold spraying equipment, the Laval nozzle assembly is one of the key components for achieving supersonic powder spraying. The design principle of the Laval nozzle is based on the Laval nozzle effect in gas dynamics. Through specific geometric design, powder particles are accelerated to supersonic speeds of Mach 1-2. When these high-speed sprayed powder particles collide with the substrate surface, they generate sufficient kinetic energy to achieve molecular bonding between the powder and the metal substrate, thus resulting in ultra-high coating adhesion.

[0003] However, existing Laval nozzle assemblies for cold spraying equipment still have shortcomings. The installation process of some nozzle assemblies is relatively complex, and the installation accuracy is difficult to guarantee, which can easily lead to coaxiality deviation and affect the spraying effect. On the other hand, the structural design of some nozzle assemblies is not reasonable enough, making disassembly and maintenance difficult, increasing equipment maintenance costs and downtime, and reducing equipment operating efficiency.

[0004] Therefore, the above problems urgently need to be solved. Utility Model Content

[0005] Purpose of the utility model: In order to overcome the above shortcomings, this utility model provides a Laval nozzle assembly for cold spraying equipment, which has precise connection, convenient disassembly, reduced maintenance difficulty, reduced downtime, and improved operating efficiency.

[0006] Technical Solution: To achieve the above objectives, this utility model provides a Laval nozzle assembly for cold spraying equipment, including a nozzle, an adapter assembly, and a sealing assembly. The nozzle and the adapter assembly are detachably connected, and the sealing assembly is located at the interface between the nozzle and the adapter assembly. The nozzle is a hollow tube, and a powder-air mixing channel extends along the nozzle axis. One end of the nozzle has a mating end, and a protruding ring is provided on the outer periphery of the nozzle near the mating end.

[0007] The adapter assembly includes an adapter and a clamping nut. The adapter is a hollow cylinder with a through hole extending along its axis. One end of the adapter has a flange, and the middle section of the adapter has a powder channel running radially, communicating with the through hole. The nozzle is inserted into the through hole, making the through hole and the powder-air mixing channel coaxial. The clamping nut is detachably connected to the outer circumference of the flange, and the flange indirectly abuts against the inner wall of the clamping nut through a sealing assembly. This invention features a detachable connection between the adapter and the spray gun, and a detachable connection between the nozzle and the adapter assembly, reducing disassembly and maintenance difficulty, minimizing downtime, and improving operating efficiency. Furthermore, a sealing assembly at the connection interface between the nozzle and the adapter assembly prevents high-pressure gas leakage. The nozzle is inserted into the through hole, and the clamping nut clamps the flange, preventing nozzle connection failure due to vibration and ensuring the stability of the nozzle connection.

[0008] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the powder-gas mixing channel is designed as a tapered through-hole that gradually increases in diameter away from the adapter. The inner diameter of the powder channel is smaller than that of the powder-gas mixing channel. When high-pressure gas passes through the through-hole, a negative pressure is created in the powder channel, drawing powder particles into the powder-gas mixing channel for mixing. The small inner diameter of the powder channel limits the amount of powder injected, preventing excessive powder from reducing the airflow velocity. Within the powder-gas mixing channel, the high-pressure gas and powder mix and expand, accelerating to supersonic speeds, allowing the powder particles to gain sufficient kinetic energy to impact the substrate and form a coating.

[0009] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the through-hole includes a docking section and an air inlet section. The inner diameter of the docking section is larger than that of the air inlet section, forming a step. The nozzle is inserted into the docking section, and the smaller inner diameter end of the powder-air mixing channel aligns with the air inlet section, corresponding to the inner diameter of the air inlet section. The powder channel and the air inlet section are connected. Connecting the powder channel and the air inlet section allows the powder to receive sufficient acceleration after entering the air inlet section. The docking section and the nozzle are precisely coaxially positioned to ensure accurate alignment of the powder-air mixing channel and the air inlet section, ensuring a smooth airflow transition and reducing energy loss.

[0010] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the sealing assembly includes a first seal and a second seal. The first seal is located within the mating section and between the nozzle and the step formed by the mating section and the air inlet section. The nozzle presses against the first seal, causing it to abut against the step formed by the mating section and the air inlet section. The second seal is fitted around the outer periphery of the nozzle and is located on the side of the convex ring away from the adapter. The tightening nut presses against the second seal, causing it to abut against the side of the convex ring away from the adapter. The first and second seals are respectively configured as sealing rings, made of soft copper. The first and second seals form a double-layer seal, achieving a high-pressure seal, preventing gas leakage, reducing energy loss, avoiding powder leakage, and isolating the nozzle 1 and the adapter assembly 2, preventing damage to the nozzle 1 due to pressure or friction during assembly.

[0011] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the clamping nut is a hollow cylinder with knurled outer surface. The clamping nut has a channel along its axis for the nozzle to pass through, and includes a locking end and a pressing end along this channel. The inner wall of the locking end has internal threads, and the locking end is threaded to the outer circumference of the flange. The pressing end has a through hole for the nozzle to pass through, the inner diameter of which corresponds to the outer diameter of the nozzle, and a pressing step is provided along the outer circumference of the through hole. The pressing step presses against the second seal, causing it to abut against the side of the flange away from the adapter. The through hole corresponding to the outer diameter of the nozzle provides support for the nozzle. The nozzle is made of metal or ceramic, and is a consumable part requiring frequent replacement. Replacement is simple: loosen the clamping nut, pull out the nozzle, insert the new nozzle, tighten the clamping nut, and complete the assembly. Replacement is convenient, requiring only the nozzle to be replaced, thus saving maintenance costs.

[0012] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the powder channel is provided with an internally threaded hole, and the powder channel is connected to a powder delivery pipe. The threaded connection of the powder delivery pipe provides reliable sealing, good vibration resistance, and convenient maintenance.

[0013] Furthermore, in the Laval nozzle assembly for the aforementioned cold spraying equipment, the adapter has a mating step at the end away from the flange. This mating step has external threads, and the mating step and the spray gun are detachably connected. The external threads on the mating step are preferably fine threads. The adapter and spray gun are connected by threads, facilitating disassembly, ensuring precise axial positioning, and easily controlling the connection seal, thus meeting the requirements of cold spraying.

[0014] As can be seen from the above technical solution, this utility model has the following beneficial effects: The Laval nozzle assembly for the cold spraying equipment of this utility model uses a Laval structure for the powder-gas mixing channel, allowing high-pressure gas and powder to mix and expand within the channel, accelerating to supersonic speeds. This enables powder particles to gain sufficient kinetic energy to impact the substrate and form a coating, achieving molecular bonding between the powder and the metal substrate, thus resulting in ultra-high adhesion of the coating. When the powder is a lubricating material, an ultra-thin coating can be obtained; when the powder is a soft metal, a 3D metal printing effect can be achieved for emergency repairs. Because the gas temperature is lower than the oxidation temperature and melting point of the powder, it produces lower residual stress compared to thermal spraying, achieving additive manufacturing with the same mechanical properties as the substrate. The nozzle and adapter assembly are detachably connected, reducing maintenance difficulty, downtime, and improving operating efficiency. A sealing component is provided at the connection interface between the nozzle and adapter assembly to prevent high-pressure gas leakage and reduce energy loss. The nozzle is inserted into the through hole to ensure accurate axial positioning. The tightening nut secures the convex ring, preventing nozzle connection failure due to vibration and ensuring the stability of the nozzle connection. The first and second sealing elements form a double seal, achieving high-pressure sealing, preventing gas leakage, reducing energy loss, and avoiding powder leakage. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the Laval nozzle assembly for the cold spraying equipment of this utility model;

[0016] Figure 2 This is an axial cross-sectional view of the nozzle;

[0017] Figure 3 This is a cross-sectional view of the Laval nozzle assembly for the cold spraying equipment of this utility model;

[0018] Figure 4 This is an axial sectional view of the adapter;

[0019] Figure 5 for Figure 3 A magnified view of a portion of the image;

[0020] Figure 6 This is an axial sectional view of the clamping nut.

[0021] In the diagram: 1. Nozzle; 11. Powder-air mixing channel; 12. Convex ring; 2. Adapter assembly.

[0022] 21. Adapter; 211. Through hole; 2111. Butt joint section; 2112. Air inlet section; 212. Flange; 213. Powder channel; 214. Butt joint step; 22. Compression nut; 221. Locking end; 222. Extrusion end; 2221. Through hole; 2222. Extrusion step; 31. First seal; 32. Second seal. Detailed Implementation

[0023] Example 1

[0024] like Figure 1-3 The Laval nozzle assembly for a cold spraying device shown includes a nozzle 1, an adapter 2, and a sealing assembly. The nozzle 1 and the adapter 2 are detachably connected, and the sealing assembly is located at the interface between the nozzle 1 and the adapter 2. The nozzle 1 is a hollow tube, and a powder-air mixing channel 11 extends along the axis of the nozzle 1. One end of the nozzle 1 has a mating end, and a protruding ring 12 is provided on the outer periphery of the nozzle 1 near the mating end.

[0025] The adapter assembly 2 includes an adapter 21 and a clamping nut 22. The adapter 21 is a hollow cylinder with a through hole 211 extending along its axis. One end of the adapter 21 has a flange 212, and the middle section of the adapter 21 has a powder channel 213 arranged radially, communicating with the through hole 211. The nozzle 1 is inserted into the through hole 211, making the through hole 211 and the powder-air mixing channel 11 coaxial. The clamping nut 22 is detachably connected to the outer periphery of the flange 212, and the flange 12 indirectly abuts against the inner wall of the clamping nut 22 through a sealing assembly. This invention allows for detachable connection between the adapter and the spray gun, and between the nozzle 1 and the adapter assembly 2, reducing disassembly and maintenance difficulty, reducing downtime, and improving operating efficiency. Furthermore, a sealing assembly is provided at the connection interface between the nozzle 1 and the adapter assembly 2 to prevent high-pressure gas leakage. Nozzle 1 is inserted into through hole 211, and protruding ring 12 is pressed by clamping nut 22 to prevent nozzle 1 from failing due to vibration and to ensure the stability of nozzle 1 connection.

[0026] In this embodiment, the powder-gas mixing channel 11 is configured as a tapered through-hole that gradually increases in size in the direction away from the adapter 21. The inner diameter of the powder channel 213 is smaller than that of the powder-gas mixing channel 11. When high-pressure gas passes through the through-hole 211, a negative pressure is formed in the powder channel 213, drawing powder particles into the powder-gas mixing channel 11 for mixing. The small inner diameter of the powder channel 213 limits the amount of powder injected, preventing excessive powder from reducing the airflow velocity. Inside the powder-gas mixing channel 11, the high-pressure gas and powder mix and expand, accelerating to supersonic speed, allowing the powder particles to gain sufficient kinetic energy to impact the substrate and form a coating.

[0027] like Figure 4The Laval nozzle assembly for the cold spraying equipment shown has a through-hole 211 comprising a mating section 2111 and an air inlet section 2112. The inner diameter of the mating section 2111 is larger than that of the air inlet section 2112, forming a step. The nozzle 1 is inserted into the mating section 2111. The smaller inner diameter end of the powder-air mixing channel 11 mates with the air inlet section 2112, and the smaller inner diameter end of the powder-air mixing channel 11 corresponds to the inner diameter of the air inlet section 2112. The powder channel 213 is connected to the air inlet section 2112. Connecting the powder channel 213 and the air inlet section 2112 allows the powder to be sufficiently accelerated after entering the air inlet section 2112. The mating section 2111 and the nozzle 1 are precisely coaxially positioned to ensure the alignment accuracy of the powder-air mixing channel 11 and the air inlet section 2112, ensuring a smooth airflow transition and reducing energy loss.

[0028] like Figure 5 The Laval nozzle assembly for the cold spraying equipment shown includes a sealing component comprising a first seal 31 and a second seal 32. The first seal 31 is located within the mating section 2111 and between the nozzle 1 and the step formed by the mating section 2111 and the air inlet section 2112. The nozzle 1 presses against the first seal 31, causing it to abut against the step formed by the mating section 2111 and the air inlet section 2112. The second seal 32 is fitted around the outer periphery of the nozzle 1 and is located on the side of the convex ring 12 away from the adapter 21. The clamping nut 22 presses against the second seal 32, causing it to abut against the side of the convex ring 12 away from the adapter 21. The first seal 31 and the second seal 32 are respectively configured as sealing rings, made of soft copper. The first seal 31 and the second seal 32 form a double-layer seal, achieving a high-pressure seal, preventing gas leakage, reducing energy loss, avoiding powder leakage, and isolating the nozzle 1 from the adapter assembly 2, preventing damage to the nozzle 1 due to pressure or friction during assembly.

[0029] like Figure 6The Laval nozzle assembly for the cold spraying equipment shown has a hollow cylindrical clamping nut 22 with knurled outer surface. The clamping nut 22 has a channel along its axis through which the nozzle 1 passes. Along this channel, the clamping nut 22 includes a locking end 221 and a pressing end 222. The inner wall of the locking end 221 has internal threads, and the locking end 221 is threaded to the outer periphery of the flange 212. The pressing end 222 has a through hole 2221 through which the nozzle 1 passes. The inner diameter of the through hole 2221 corresponds to the outer diameter of the nozzle 1, and a pressing step 2222 is provided along the outer periphery of the through hole 2221. The pressing step 2222 presses against the second seal 32, causing it to abut against the side of the flange 12 away from the adapter 21. The through hole 2221, corresponding to the outer diameter of the nozzle 1, provides support for the nozzle. Nozzle 1 is made of metal or ceramic and is a consumable part that needs to be replaced frequently. When replacing it, loosen the clamping nut 22, pull out nozzle 1 directly, insert the new nozzle 1, tighten the clamping nut 22, and the assembly is completed. Replacement is convenient and only nozzle 1 needs to be replaced, saving maintenance costs.

[0030] In this embodiment, the powder channel 213 is provided with an internally threaded hole, and the powder channel 213 is connected to a powder conveying pipe. The threaded connection of the powder conveying pipe provides reliable sealing, good vibration resistance, and convenient maintenance.

[0031] In this embodiment, the adapter 21 has a mating step 214 at the end away from the flange 212. The mating step 214 has external threads, and the mating step 214 and the spray gun are detachably connected. The external threads on the mating step 214 are preferably fine threads. The adapter 21 and the spray gun are connected by threads, which facilitates disassembly, ensures precise axial positioning, and allows for easy control of the connection seal, meeting the requirements of cold spraying.

[0032] The above embodiments are exemplary and are intended to illustrate the technical concept and features of this utility model, so that those skilled in the art can understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A Laval nozzle assembly for a cold spray apparatus, characterized by: It includes a nozzle (1), a connecting component (2) and a sealing component. The nozzle (1) and the connecting component (2) are detachably connected. The sealing component is located at the connection interface between the nozzle (1) and the connecting component (2). The nozzle (1) is a hollow tube. The nozzle (1) extends along the axis and has a powder-gas mixing channel (11). One end of the nozzle (1) has a docking end. The outer periphery of the nozzle (1) near the docking end has a protruding ring (12). The adapter assembly (2) includes an adapter (21) and a clamping nut (22). The adapter (21) is a hollow cylinder. The adapter (21) extends along the axis and has a through hole (211). One end of the adapter (21) has a flange (212). The middle section of the adapter (21) has a powder channel (213) along the radial direction. The powder channel (213) and the through hole (211) are connected. The nozzle (1) is inserted into the through hole (211) so that the through hole (211) and the powder-air mixing channel (11) are coaxial. The clamping nut (22) is detachably connected to the outer periphery of the flange (212). The convex ring (12) indirectly abuts against the inner wall of the clamping nut (22) through a sealing assembly.

2. The Laval nozzle assembly for cold spray equipment of claim 1, wherein: The powder-gas mixing channel (11) is configured as a tapered through hole that gradually increases in size in the direction away from the adapter (21); the inner diameter of the powder channel (213) is set to be smaller than the inner diameter of the powder-gas mixing channel (11).

3. The Laval nozzle assembly for cold spray equipment of claim 1, wherein: The through hole (211) includes a docking section (2111) and an air inlet section (2112). The inner diameter of the docking section (2111) is larger than that of the air inlet section (2112). The docking section (2111) and the air inlet section (2112) form a step. The nozzle (1) is inserted into the docking section (2111). The smaller inner diameter of the powder-gas mixing channel (11) is docked with the air inlet section (2112). The smaller inner diameter of the powder-gas mixing channel (11) is corresponding to the inner diameter of the air inlet section (2112). The powder channel (213) and the air inlet section (2112) are connected.

4. The Laval nozzle assembly for cold spraying equipment according to claim 3, characterized in that: The sealing assembly includes a first seal (31) and a second seal (32). The first seal (31) is located inside the mating section (2111) and between the nozzle (1) and the step formed by the mating section (2111) and the air intake section (2112). The nozzle (1) squeezes the first seal (31) so that it abuts against the step formed by the mating section (2111) and the air intake section (2112). The second seal (32) is sleeved on the outer periphery of the nozzle (1) and is located on the side of the convex ring (12) away from the adapter (21). The clamping nut (22) squeezes the second seal (32) so that it abuts against the side of the convex ring (12) away from the adapter (21).

5. The Laval nozzle assembly for cold spraying equipment according to claim 4, characterized in that: The clamping nut (22) is a hollow cylinder with a knurled outer surface. The clamping nut (22) has a channel along its axis through which the nozzle (1) passes. Along the channel, the clamping nut (22) includes a locking end (221) and a pressing end (222). The inner wall of the locking end (221) is provided with an internal thread, and the locking end (221) is threaded to the outer periphery of the flange (212). The pressing end (222) is provided with a through hole (2221) through which the nozzle (1) passes. The inner diameter of the through hole (2221) corresponds to the outer diameter of the nozzle (1), and a pressing step (2222) is provided along the outer periphery of the through hole (2221). The pressing step (2222) presses the second seal (32) so that it abuts against the side of the convex ring (12) away from the adapter (21).

6. The Laval nozzle assembly for cold spraying equipment according to claim 1, characterized in that: The powder channel (213) is provided with an internal thread hole, and the powder channel (213) is connected to a powder conveying pipe.

7. The Laval nozzle assembly for cold spraying equipment according to claim 1, characterized in that: The adapter (21) has a mating step (214) at the end away from the flange (212), the mating step (214) has an external thread, and the mating step (214) is detachably connected to the spray gun.

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