A method of coating and jig for HM322 room temperature vulcanising silicone rubber coating

Abstract

The application discloses a kind of machine case shell parts HM322 room temperature vulcanized silicone rubber coating coating method, to design coating front processing, coating thickness control, clamping and demoulding mode and so on Parameter optimization, solve product quality problem, satisfy production efficiency requirement.The application designs and optimizes the stirring speed when three components of HM322 room temperature vulcanized silicone rubber are mixed, improves coating process, ensures that the color after coating is uniform in color and luster.Adjust the pressure and time of coating air hole removal, reduce the air in coating, reduce the number and size of air hole after coating.Thin coating thickness, optimize the bottom sealing structure of coating tooling, solve the problem of uneven coating in height direction and difficult processing of thick coating.Optimize demoulding mode, change from knocking demoulding to ejection demoulding, increase demoulding agent, optimize the surface roughness and demoulding angle of tooling, realize simple and stable demoulding.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of surface engineering, and particularly relates to a coating method and clamp for HM322 room temperature vulcanized silicone rubber coating. BACKGROUND

[0002] In order to meet the matching requirements with the rotor, the inner circle of the shell of an aero-engine is coated with HM322 room temperature vulcanized silicone rubber in a local position. Figure 1 HM322 room temperature vulcanized silicone rubber is a new type of wear-resistant coating. During the coating process, problems such as excessive coating pores, uneven coating color, difficult coating demolding and long machining cycle occur. SUMMARY

[0003] In order to solve the above problems, the present application aims to provide a coating method and clamp for HM322 room temperature vulcanized silicone rubber coating.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution: a coating method for HM322 room temperature vulcanized silicone rubber coating, comprising the following steps:

[0005] Step 1: configure HM322 room temperature vulcanized silicone rubber, put the required raw materials into a container, and stir them at a speed of 80 r / min to 120 r / min using a stirrer. After the color and luster are uniform, stop stirring;

[0006] Step 2: sandblast and coat the coating surface of the part;

[0007] Step 3: use the clamp to assist in coating the inner circle of the part with HM322 coating, and use pouring to form the required semi-closed cavity;

[0008] Step 4: solidify and demold, use a ejector rod to support the part and the clamp to separate them;

[0009] Step 5: trim the coating and check, trim the residual HM322 coating using a blade, check the appearance, color and luster of the part, and conduct hardness and strength checks.

[0010] Preferably, the specific steps of step 3 are as follows:

[0011] Step 31: treatment before clamping the clamp, spray the mating surface of the clamp with a demolding agent using an air spraying method, spray 3 to 5 times to ensure that the demolding agent is uniform and complete, and air dry for more than 30 minutes;

[0012] Step 32: clamp the part, use the clamp and the part to be sprayed to form a semi-closed cavity, the semi-closed cavity is composed of two sections of surfaces with different angles and thicknesses, and the lower end surface of the clamp is tightly attached to the bottom surface of the part to form a sealed structure;

[0013] Step 33: Pour the mixed HM322 into the semi-closed cavity from the pouring port on the upper end surface, and the pouring coating plane is higher than the highest point of the coating surface by more than 2mm.

[0014] Preferably, the semi-closed cavity of step 32 is a profiled cavity, the thickness of the lower part is less than that of the upper part, the angle of the lower part with the part is 3°-6°, and the angle of the upper part with the part is 30°-45°.

[0015] Preferably, the mixed raw materials of step 1 do not exceed 1 / 4 of the volume of the container.

[0016] Preferably, the mixed material of step 1 needs to be degassed, and the mixed material is placed in a vacuum or negative pressure device, the pressure is kept at 0.01kPa-0.5kPa, the pressure holding time is ≥30min, and the air in the mixed material is fully discharged.

[0017] Preferably, the curing demolding of step 4 is to place the coated part into the drying oven according to the process requirements for vulcanization, and after vulcanization, the part and the clamp are separated by the ejector rod to realize demolding.

[0018] Preferably, the ejector rod is a threaded or pneumatic ejector rod, and the two ends of the ejector rod are supported on the clamp bottom plates arranged on the upper and lower ends of the part (2).

[0019] A clamp, the clamp is a combined structure, including a bottom plate arranged on the upper and lower end surfaces of the part, a profiled support plate vertically connected to the lower end surface of the bottom plate through a bolt, and a curing plate vertically arranged on the upper end surface of the profiled support plate, the curing plate being parallel to the bolt.

[0020] Preferably, the upper and lower parts of the profiled plate are connected at an acute angle, and the end surface of the profiled plate in contact with the part to be sprayed is a smooth inclined surface.

[0021] Compared with the prior art, the coating method has the following advantages: the operation process is stable, the quality is good, and the efficiency is high, which can meet all design requirements, and has the following advantages: the coating layer has good consistency in appearance, and the coating thickness is uniform; the internal quality of the coating layer is good, and there are only small pores in the coating layer, which is much higher than the design standard requirement; the coating is thinned, the machining allowance is small, the machining cycle is short, and the tool is saved; the demolding operation is simple and efficient, and solves other hidden troubles caused by knocking demolding. And design a special clamp to ensure the smoothness and convenience of operation. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings described below only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0023] Figure 1 A schematic diagram of a casing shell part in the present application

[0024] Figure 2 A schematic diagram of part clamping and coating in the present application

[0025] In the figure, 1 is a clamp, 2 is a part, 3 is a top rod, 4 is a matching surface of the clamp, 5 is the highest point of a coating surface, 6 is a sealing point of the clamp and the bottom end of the part, 7 is a pouring port, and A is a part to be sprayed area. DETAILED DESCRIPTION

[0026] The present application will be further described below in combination with the drawings and specific embodiments, but it should not be understood that the scope of the subject matter described in the present application is limited to the following embodiments. Any modifications, substitutions and changes made according to the ordinary technical knowledge and conventional means in the art without departing from the above technical idea of the present application are included in the scope of the present application.

[0027] The coating method of the HM322 room temperature vulcanized silicone rubber coating of the aero-engine casing shell part, by designing the coating pre-treatment, coating thickness control, optimizing the coating clamping and demolding mode and other parameters, realizes the coating of the HM322 room temperature vulcanized silicone rubber coating of the casing shell part, and the coating quality is high and the operation is simple.

[0028] REFERENCE Figure 1 A casing shell part diagram, in order to meet the matching requirements with the fan rotor, the inner circle local position of the casing shell needs to be coated with HM322 room temperature vulcanized silicone rubber. The area to be sprayed is A, and reference is made to Figure 2The present application discloses a fixture for spraying parts, which comprises a fixture 1 arranged on a part 2, and the fixture 1 is a combined structure and comprises a bottom plate arranged on the upper and lower end faces of the part 2, a shaped support plate connected with the lower end face of the bottom plate through a bolt, and a solidifying plate arranged on the upper end face of the shaped support plate and parallel to the bolt.

[0029] The coating method of the HM322 room temperature vulcanized silicone rubber coating is as follows:

[0030] Step 1: HM322 room temperature vulcanized silicone rubber configuration. The required proportion is mixed, each time the mixing does not exceed 1 / 4 of the container, the uniform speed mixer is used for mixing, the mixing speed is 100 r / min, and the stirring is ended after the color is uniform.

[0031] Step 2: Degassing. The mixed material is placed into a vacuum device, the pressure is kept at 0.3 kPa, the pressure maintaining time is 30 min, and the air in the mixed material is fully discharged.

[0032] Step 3: Sand blasting. The coating surface is sand blasted according to the process parameters, and clean compressed air is used to remove the surface sand and dust after the sand blasting is finished.

[0033] Step 4: Coating the bottom layer. The bottom layer is coated according to the process requirements, and the coating time interval is controlled.

[0034] Step 5: HM322 coating coating.

[0035] Step 51: The matching surface 4 of the fixture is sprayed with a release agent by using an air spraying method, the spraying is performed 4 times, the release agent is ensured to be uniform and complete, and the release agent is dried for 40 min.

[0036] Step 52: Clamping the part 2. According to the fixture 1 shown in Figure 2 Figure 2 ​The matching surface 4 of the clamp and the part 2 to be painted form a semi-closed cavity, wherein the matching surface 4 of the clamp and the part to be painted form two surfaces with different angles and thicknesses, the lower part of the matching surface 4 of the clamp forms a 6° angle with the part, and the upper part forms a 42° angle with the part, while ensuring that the clamp and the part are tightly attached at the sealing point at the bottom end of the part.

[0037] Step 53: Pour the mixed HM322 from the pouring port 7, so that the clamp 1 and the part to be painted form a semi-closed cavity, and the pouring coating plane is higher than the highest point 5 of the coating surface by a distance of 3mm.

[0038] Step 6: Curing. After the coating is completed, the part is placed in the drying oven according to the process requirements for vulcanization.

[0039] Step 7: Demolding. After vulcanization, the part and the clamp are separated by the ejector rod 3 to realize demolding.

[0040] Step 8: Trim the coating, use a blade to trim the residual HM322 coating.

[0041] Step 9: Inspection, check the appearance and color of the part, and carry out hardness and strength inspection.

[0042] The present application has the following advantages: 1. The stirring speed of the three-component mixing of the HM322 room temperature vulcanized silicone rubber is optimized, the coating process is improved, and the color and shade after coating are uniform. 2. Adjust the pressure and time of air hole removal of the coating, reduce the air in the coating, and reduce the number and size of air holes after coating. 3. Reduce the coating thickness, optimize the bottom sealing structure of the coating tooling, solve the problem of uneven coating in the height direction. 4. Optimize the demolding method, change the knocking demolding to the ejecting demolding, and increase the demolding agent, optimize the surface roughness and demolding angle of the tooling, realize simple and stable demolding.

[0043] The coating method and clamp for the HM322 room temperature vulcanized silicone rubber coating provided by the present application are described in detail above, and specific examples are applied in this paper to describe the structure and working principle of the present application. The above examples are only used to help understand the method and core idea of the present application. It should be pointed out that for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method of coating a HM322 room temperature vulcanizing silicone rubber coating characterized by: The method comprises the following steps: Step 1: configure the HM322 room temperature vulcanized silicone rubber, put the required raw materials into a container, the mixed raw materials should not exceed 1 / 4 of the volume of the container, use a stirrer to stir at a speed of 80 r / min to 120 r / min, stop stirring after the color is uniform, and then degas the mixed materials in a vacuum or negative pressure device, keep the pressure at 0.01 kPa to 0.5 kPa for more than 30 min, and fully discharge the air in the mixed materials; Step 2: sandblast and coat a bottom layer on the coating surface of the part (2); Step 3: use the clamp (1) to assist in coating the HM322 coating on the inner circle of the part, and use pouring to form a required semi-closed cavity; Step 4: curing and demolding, use the ejector pin (3) to support and separate the part (2) and the clamp (1); Step 5: trim the coating and check, trim the residual HM322 coating using a blade, check the appearance and color of the part (2), and check the hardness and strength; The specific steps of step 3 are as follows: Step 31: processing before clamping the clamp (1), spray the release agent on the matching surface (4) of the clamp using an air spraying method, spray 3 to 5 times to ensure that the release agent is uniform and complete, and dry for more than 30 min; Step 32: clamp the part (2), use the clamp (1) to form a semi-closed cavity with the part to be sprayed (A), the semi-closed cavity is a special-shaped cavity composed of two sections of surfaces with different angles and thicknesses, the thickness of the lower section is less than that of the upper section, the angle of the lower section is 3° to 6° with the part (2), and the angle of the upper section is 30° to 45° with the part (2); at the same time, the lower end surface of the clamp (1) is tightly attached to the end point of the bottom surface of the part to form a sealed structure; Step 33: pour the mixed HM322 into the pouring port (7) at the upper end surface of the semi-closed cavity, and the pouring coating plane is higher than the highest point (5) of the coating surface by more than 2 mm; The clamp (1) is a combined structure, comprising a bottom plate arranged on the upper and lower end surfaces of the part, a special-shaped support plate vertically connected to the lower end surface of the bottom plate through a bolt, and a curing plate vertically arranged on the upper end surface of the special-shaped support plate, wherein the curing plate is parallel to the bolt, the upper and lower sections of the special-shaped support plate are connected at an acute angle, and the end surface of the special-shaped support plate in contact with the part to be sprayed (A) is a smooth inclined surface.

2. The method of coating a HM322 room temperature vulcanizing silicone rubber coating according to claim 1, characterized in that: The curing and demolding of step 4 is to place the coated part (2) into a drying oven according to the process requirements, separate the part (2) and the clamp (1) using the ejector pin (3) after vulcanization, and realize demolding.

3. The method of applying a coating of HM322 room temperature vulcanizing silicone rubber as claimed in claim 1, characterized in that: The ejector pin (3) is a threaded or pneumatic ejector pin, and the two ends of the ejector pin (3) are supported on the bottom plates of the clamps (1) arranged on the upper and lower ends of the part (2).

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