A small-diameter groove structure inner hole spraying process

Abstract

The application provides a small-diameter groove structure inner hole spraying process and relates to the technical field of aero-engine spraying processes.The small-diameter groove structure inner hole spraying process comprises the following steps: installing a part to be sprayed on a rotary table, controlling the rotary speed of the rotary table to be 200 rpm-500 rpm, first spraying 3-5 times from the small end of the part to the groove position of the large end of the part by using a first spraying program, then turning over the large end and the small end of the part, and spraying 2-5 times from the large end of the part to the groove position of the small end of the part by using a second spraying program.The first spraying program comprises the following steps: 10 seconds are kept between each spraying, the spraying angle is 20 DEG -30 DEG, and the spraying mode is fixed-point spraying.The second spraying program comprises the following steps: 10 seconds are kept between each spraying, the spraying angle is 60 DEG -80 DEG, the spraying mode is up-and-down movement spraying of a spray gun, and the movement speed of the spray gun is 10 mm / s-30 mm / s.The small-diameter groove structure inner hole spraying process solves the problem of coating falling off of a small-diameter groove part and improves the spraying quality.

Description

Technical Field

[0001] This invention relates to the field of aero-engine spraying technology, specifically to an internal hole spraying process for a small-diameter groove structure. Background Technology

[0002] For the process of spraying a silver-copper coating onto the inner hole of a small-diameter grooved part (the spraying area is located in the middle region of the inner ring of the part), existing technologies mainly involve the spray gun entering the inner cavity of the part perpendicularly to the spraying surface for spraying. However, for parts with a small inner diameter of the spraying surface, the spray gun generally cannot enter the interior of the part, and spraying can only be done at a small angle on the outside of the part. The processing principle is as follows: Figure 1 As shown, when spraying, the spray gun must spray from both ends of the part at a small angle. This will cause interference at both ends of the sprayed surface, resulting in defects such as no coating or poor adhesion at the bottom of the corner. At the same time, spraying from both ends will cause the coating to accumulate too thickly in the middle of the sprayed surface, which will aggravate the incomplete coating on both ends of the coating surface, making the coating easy to fall off and the spraying quality cannot be guaranteed.

[0003] Even with a properly sized internal spray gun, the following problems exist during the spraying process: the spraying distance of the internal spray gun is relatively short, which can easily lead to overheating and deformation of the parts during the spraying process; the parts rotate at high speed, and the short spraying distance poses a significant safety risk. Summary of the Invention

[0004] In view of this, embodiments of this application provide an internal hole spraying process for small-diameter groove structures to solve the problem of coating peeling off small-diameter groove parts, thereby improving the spraying quality.

[0005] This application provides the following technical solution: an internal hole spraying process for a small-diameter groove structure, including:

[0006] Mount the part to be coated on the turntable and control the turntable speed to 200 rpm to 500 rpm. First, use the first coating program to spray 3 to 5 times from the small end of the part to the groove position of the large end of the part. Then, flip the large end and the small end of the part over and use the second coating program to spray 2 to 5 times from the large end of the part to the groove position of the small end of the part.

[0007] The first spraying procedure includes: a 10-second interval between each spraying pass, a spraying angle of 20° to 30°, and a fixed-point spraying method; the second spraying procedure includes: a 10-second interval between each spraying pass, a spraying angle of 60° to 80°, and a spraying method of moving the spray gun up and down, with the spray gun moving speed controlled at 10mm / s to 30mm / s.

[0008] According to one embodiment of this application, before mounting the part to be painted on the turntable, the method further includes: pre-treating the small-diameter grooved part, the pre-treating including degreasing and sandblasting.

[0009] According to one embodiment of this application, the process further includes degreasing and cleaning the parts to be sprayed after degreasing, and performing the spraying operation within two hours after sandblasting the parts to be sprayed.

[0010] According to one embodiment of this application, the method further includes first spraying a base coat, spraying the large end and small end of the part in sequence once as a spraying cycle, and after every two spraying cycles, measuring the thickness of the base coat of the part. If the thickness of the base coat does not meet the set base coat thickness requirement, the next spraying cycle is continued until the thickness of the base coat of the part meets the set base coat thickness requirement.

[0011] According to one embodiment of this application, the method further includes: spraying the top layer coating of the part after the thickness of the bottom layer coating of the part reaches the set bottom layer coating thickness requirement; spraying the large end and the small end of the part in sequence to complete one coat is one spraying cycle; after every ten spraying cycles, the thickness of the top layer coating of the part is measured; if the thickness of the top layer coating does not reach the set top layer coating thickness requirement, the next spraying cycle is continued until the thickness of the top layer coating of the part reaches the set top layer coating thickness requirement.

[0012] According to one embodiment of this application, the method further includes: during the spraying process, cooling gas is used to cool the part, and a laser thermometer is used to monitor the temperature of the sprayed surface of the part.

[0013] According to one embodiment of this application, the method further includes: after the coating is completed, removing the protective material from the part after the part has cooled to room temperature.

[0014] According to one embodiment of this application, the inner diameter of the sprayed part is ≤50mm, the inner diameter of the small end of the part is Φ20mm~Φ30mm, and the inner diameter of the large end of the part is Φ80~Φ120mm.

[0015] Compared with the prior art, the beneficial effects achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: The spraying process for the inner hole (spraying area located in the middle region of the inner ring of the part) of a small-diameter groove structure provided by the embodiments of this invention clarifies the sandblasting requirements of the part. During the spraying process, the large end and small end of the part need to be flipped over for spraying separately, and the spraying paths of the large end and small end of the part are inconsistent. In order to control the temperature of the sprayed surface, a cooling air knife is turned on to cool the part during the spraying process, and a laser thermometer is used to monitor the temperature of the sprayed surface. Through the improvement of the spraying process, the coating is complete and uniform on both sides, with good adhesion, solving the problems of uneven coating thickness, overheating deformation of the part, and coating separation and peeling, effectively improving the spraying quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a spraying process in the prior art;

[0018] Figure 2 This is a schematic diagram of spraying paint from the small end to the large end of the part in an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of spraying paint from the large end of the part to the small end of the part in an embodiment of the present invention;

[0020] Among them, 1-spraying dead corner; 2-spray gun. Detailed Implementation

[0021] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0022] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] like Figure 1 As shown, in the existing spraying process, the spray gun 2 must spray from both ends of the part at a small angle. This will cause interference at both ends of the sprayed surface, resulting in defects such as no coating or poor adhesion at the bottom of the corner. At the same time, when spraying at both ends, the coating in the middle of the sprayed surface will be too thick, which will aggravate the incomplete coating at both ends of the coating surface. The coating is prone to peeling off, and there are many spraying dead corners 1, which makes it impossible to guarantee the spraying quality.

[0024] like Figures 2-3 As shown, this embodiment of the invention provides an internal hole spraying process for a small-diameter groove structure, including:

[0025] The part to be painted is mounted on a turntable with a rotation speed of 200 rpm to 500 rpm. First, a first painting program is used, spraying 3 to 5 times from the small end of the part to the groove at the large end. Then, the large and small ends of the part are flipped, and a second painting program is used, spraying 2 to 5 times from the large end of the part to the groove at the small end. The first painting program includes a 10-second interval between each spray, a spray angle of 20° to 30°, and a fixed-point spraying method. The second painting program includes a 10-second interval between each spray, a spray angle of 60° to 80°, and a spraying method where the spray gun 2 moves up and down, with the spray gun 2 moving at a speed of 10 mm / s to 30 mm / s.

[0026] This invention provides a spraying process for the inner hole (spraying area located in the middle region of the inner ring of the part) of a small-diameter groove structure, which solves the problems of uneven coating thickness, overheating deformation of the part, and coating separation and peeling, thus ensuring the quality of the spraying. Compared with traditional spraying processes, this invention significantly improves the coating quality. First, this invention performs fixed-point spraying from the small end of the part to the large end, solving the problem of localized loose separation of the bottom layer on the large end side. Second, this invention performs fixed-point spraying from the small end side while the spray gun 2 moves up and down to spray the large end side, avoiding the problem of coating accumulation in the middle and uneven coating thickness. Third, compressed air is used to cool the part during the spraying process, avoiding the problem of overheating deformation. Fourth, the spraying path and spraying parameters proposed in this invention have been verified through multiple process explorations and experiments. The processed parts, after dissection analysis, show that the coating on both sides is complete and uniform, with good adhesion.

[0027] In one specific embodiment, such as Figures 2-3 The diagram shows a small-diameter groove structure. The spraying area is located in the middle region of the inner ring of the part. The diameter of the spraying inner hole is ≤50mm, with the inner hole diameter at the small end being Φ20mm~Φ30mm and the inner hole diameter at the large end being Φ80~Φ120mm. A silver-copper coating is sprayed, with a base layer of nickel-aluminum powder and a spraying thickness of 0.1mm~0.3mm, and a top layer of silver-copper powder, with a total spraying thickness of 0.8mm~1.5mm.

[0028] This embodiment proposes a spraying process for the inner hole (spraying area located in the middle region of the inner ring of the part) of a small diameter groove structure, which mainly includes the following steps: preparation before spraying, degreasing of the part, sandblasting of the part, spraying of the coating, disassembly and cleaning, and inspection and acceptance.

[0029] The preparation before spraying mainly involves confirming the spraying powder, argon, hydrogen, nitrogen, sandblasting particles, and compressed air. Before spraying, the powder is dried at a temperature of 90°C for 1 to 2 hours.

[0030] Before mounting the parts to be coated on the turntable, the process includes: pre-treatment of small-diameter grooved parts, which includes degreasing and sandblasting. For degreasing, the parts are cleaned using an ultrasonic cleaner before spraying. For sandblasting, the parts are sandblasted before spraying to remove dirt from the surface to be coated, expose the sandblasted surface, and roughen the surface to increase the contact area between the coating and the substrate, thus improving the coating adhesion. After sandblasting, the sandblasted surface is visually inspected under natural light or flashlight illumination. The illuminance should be no less than 300 LX (equivalent to the light intensity of the part placed 0.5m under a 40W fluorescent lamp). If necessary, a 5-10x magnifying glass can be used for inspection. After sandblasting, the dimensions of the parts before spraying are measured using measuring tools. Spraying must be carried out within 2 hours after sandblasting. The sandblasted parts are clamped on the turntable, and the turntable is started, using the cooling air duct on the spray gun 2 to clean the surface to be coated. After cleaning, spraying is carried out according to the spraying path.

[0031] The specific spraying path in this embodiment is as follows: When spraying the part, it is necessary to flip the part so that the large end and the small end are sprayed separately. During the spraying process, the rotation speed of the part is controlled between 200 rpm and 500 rpm. First, the part is mounted on the turntable with the large end facing down (see...). Figure 2 Call the small-end spraying program and spray the groove near the large end of the part 3-5 times, with a 10-second interval between each spray, at a spraying angle of 20°-30°. Then flip the part over, mount it on the turntable with the small end facing down, and call the large-end spraying trajectory (see...). Figure 3 Spray the part surface 2 to 5 times, with a 10-second interval between each spray. During the spraying process, move the spray gun 2 up and down, with a spraying angle of 60° to 80° and a speed of 10mm / s to 30mm / s.

[0032] During spraying, first apply the base coat according to the above spraying path, spraying one coat sequentially from both the large and small ends of the part, constituting one spraying cycle. After every two spraying cycles, measure the thickness of the base coat. If the base coat thickness does not meet the set requirement, continue with the next spraying cycle until the base coat thickness reaches 0.1mm to 0.3mm. After the base coat thickness reaches the set requirement, proceed with the top coat application. Spray one coat sequentially from both the large and small ends of the part, constituting one spraying cycle. After every ten spraying cycles, measure the thickness of the top coat. If the top coat thickness does not meet the set requirement, continue with the next spraying cycle until the top coat thickness reaches 0.8mm to 1.5mm.

[0033] In this embodiment, to control the temperature of the sprayed surface, a cooling air knife is turned on during the spraying process to cool the parts, and a laser thermometer is used to monitor the temperature of the sprayed surface. Alternatively, a multi-station turntable can be used to spray in rotation to control the part temperature. Disassembly and cleaning stage: After spraying, if the coating thickness of the parts meets the requirements, the protective clamps or tape should not be removed immediately. The parts should be allowed to cool to room temperature before removing the protective materials. Excess coating at the edges should then be removed with a file and whetstone, followed by wiping clean with acetone-soaked cotton. Finally, inspection and acceptance are required. The coating color should be uniform and consistent, without overheating or discoloration. The coating should be uniform and continuous, without defects such as cracks, peeling, delamination, or edge lifting.

[0034] This invention discloses a spraying process for the inner hole (spraying area located in the middle region of the inner ring of the part) of a small-diameter groove structure. The process clarifies the sandblasting requirements for the part, requiring the part to be flipped over and sprayed separately at both ends, with different spraying paths at the two ends. To control the temperature of the sprayed surface, a cooling air knife is used to cool the part during spraying, and a laser thermometer is used to monitor the temperature of the sprayed surface. Through this improved spraying process, the coating is complete and uniform on both sides, with good adhesion, solving problems such as uneven coating thickness, overheating deformation of the part, and coating separation and peeling, thus ensuring the quality of the spraying.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A process for spraying internal holes with a small-diameter groove structure, characterized in that, include: Mount the part to be coated on the turntable and control the turntable speed to 200 rpm to 500 rpm. First, use the first coating program to spray 3 to 5 times from the small end of the part to the groove position of the large end of the part. Then, flip the large end and the small end of the part over and use the second coating program to spray 2 to 5 times from the large end of the part to the groove position of the small end of the part. The first spraying procedure includes: a 10-second interval between each spraying pass, a spraying angle of 20° to 30°, and a fixed-point spraying method; the second spraying procedure includes: a 10-second interval between each spraying pass, a spraying angle of 60° to 80°, and a spraying method of moving the spray gun up and down, with the spray gun moving speed controlled at 10mm / s to 30mm / s. It also includes first spraying a base coat, spraying the large end and small end of the part in sequence to complete one spraying cycle. After every two spraying cycles, the thickness of the base coat of the part is measured. If the thickness of the base coat does not meet the set base coat thickness requirement, the next spraying cycle is continued until the thickness of the base coat of the part meets the set base coat thickness requirement. After the thickness of the bottom layer coating of the part reaches the set bottom layer coating thickness requirement, the top layer coating of the part is sprayed. One spraying cycle is completed by spraying the large end and the small end of the part in turn. After every ten spraying cycles, the thickness of the top layer coating of the part is measured. If the thickness of the top layer coating does not reach the set top layer coating thickness requirement, the next spraying cycle is continued until the thickness of the top layer coating of the part reaches the set top layer coating thickness requirement. The inner diameter of the part to be sprayed is ≤50mm, the inner diameter of the small end of the part is Φ20mm~Φ30mm, and the inner diameter of the large end of the part is Φ80~Φ120mm.

2. The internal hole spraying process for the small-diameter groove structure according to claim 1, characterized in that, Before mounting the parts to be painted on the turntable, the process also includes: pre-treatment of small-diameter grooved parts, the pre-treatment including degreasing and sandblasting.

3. The internal hole spraying process for the small-diameter groove structure according to claim 2, characterized in that, This also includes degreasing and cleaning the parts to be painted after degreasing, and painting within two hours after sandblasting the parts to be painted.

4. The internal hole spraying process for the small-diameter groove structure according to claim 1, characterized in that, Also includes: During the spraying process, cooling air is used to cool the parts, and a laser thermometer is used to monitor the temperature of the sprayed surface of the parts.

5. The internal hole spraying process for the small-diameter groove structure according to claim 1, characterized in that, Also includes: After the coating is applied, wait for the parts to cool to room temperature before removing the protective coating.

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