Bubble-free construction method for filling airplane surface nail head groove with high-viscosity DG-3 glue solution

Abstract

The invention discloses a bubble-free construction method for filling a nail head groove in the surface of an airplane with a high-viscosity DG-3 glue solution, and belongs to the technical field of airplane assembling.The bubble-free construction method comprises the steps that a static glue mixing device is used for mixing DG-3 component base glue and DG-3 component base glue to obtain a nail head filling glue solution; injecting type filling glue liquid from the bottom of the groove of the nail head by using a glue injection gun by adopting an injection method; performing equal-thickness scraping treatment on the just filled glue solution by using a glue scraping plate; using a strong light flashlight to check and puncture accidental bubbles possibly existing after the glue solution is filled, using a blade to remove residual glue after the glue solution is solidified for a set time, and finally using abrasive paper to file uneven glue after the glue solution is continuously solidified for a set time, so as to complete the glue solution filling work of the nail head groove. The operation method is simple, tools and materials are convenient to use, the production efficiency is effectively improved, the surface flatness of the airplane is guaranteed, and the surface quality requirement of the airplane is met.

Description

Technical Field

[0001] The present invention relates to the field of aircraft assembly, and particularly to a bubble-free construction method for filling the nail head grooves on the aircraft surface with high-viscosity DG-3 glue. Background Art

[0002] In order to meet the requirements for the surface quality of the aircraft, after the connection of the aircraft body structure is completed, it is usually necessary to perform a glue filling operation on the aircraft surface. Among them, DG-3 glue coating is a common process for filling the flatness of the aircraft surface. After the aircraft skin and the skeleton are connected by fasteners, affected by the outer surface morphology of the connectors (for example, the cross-section morphology of the blind rivets is uneven, the surface grooves of the connectors, etc.) and the connection process requirements (the nail head is usually lower than the skin surface), the flatness of the aircraft surface cannot meet the morphological requirements of the aircraft shape. In this case, a high-viscosity DG-3 glue is usually used for filling.

[0003] DG-3 glue is a multi-component glue, which is mixed and stirred by two base glues, namely, glue A and glue B. During the stirring process, it is very easy to mix air, forming a large number of bubbles in the glue. Moreover, due to the high viscosity of the glue, it is very difficult to remove the bubbles. At present, the coating process of DG-3 glue usually pours the glue on the aircraft surface and uses a scraper to scrape the glue flat so that it covers the area to be filled. With this stacking coating method, the air in the surface grooves and surface depressions of the connectors is not easy to be discharged, forming a large number of bubbles. At the same time, due to the high viscosity of the glue, the bubbles introduced during the glue mixing process are hardly discharged during the glue coating. After the glue is completely cured, it is necessary to perform grinding according to the requirements of the aircraft surface morphology. The grinding will cause the bubbles in the cured glue to leak out again, forming surface defects such as pinholes and holes. In order to meet the flatness requirements of the aircraft surface, it is necessary to repeatedly perform glue filling, curing and grinding and trimming.

[0004] Due to the above problems of glue bubbles and coating process, this process will be repeated several times, resulting in extremely low production efficiency, generating a large amount of hazardous waste, and increasing the risk of damage to the aircraft surface body caused by multiple repairs and grindings. It is very easy to cause the skin grinding to exceed the tolerance, and even cause the skin to be scrapped. Therefore, it has become an urgent need to explore a bubble-free construction method for filling high-viscosity DG-3 glue on the aircraft surface. Summary of the Invention

[0005] The present invention aims to solve the quality problems in the prior art that after the high-viscosity DG-3 is filled in the nail head grooves on the aircraft surface connected by fasteners, there are a large number of bubbles and pinholes in the colloid, and multiple rework repairs and fillings are required, resulting in extremely low production efficiency, serious waste of glue, and even damage and out-of-tolerance of the aircraft surface parts. The present invention provides a bubble-free construction method for filling the nail head grooves on the aircraft surface with high-viscosity DG-3 glue. This operation method is simple, the tools and materials are convenient to use, effectively improves the production efficiency, ensures the flatness of the aircraft surface, and meets the requirements for the surface quality of the aircraft.

[0006] To achieve the above-mentioned invention purpose, the technical solution of the present invention is as follows: A construction method for filling the nail head grooves on the aircraft surface with high-viscosity DG-3 glue solution without bubbles, which is characterized by including the following steps: using a static mixing device to mix the DG-3 component A and component B base glues to obtain a nail head filling glue solution; using a glue injection gun to inject the glue solution from the bottom of the nail head groove by injection; using a glue scraping plate to level the just-filled glue solution to an equal thickness; using a strong flashlight to check and puncture the occasional bubbles that may exist after the glue solution is filled. After the glue solution is cured for a set time, use a blade to remove the surplus of the colloid. After the glue solution continues to be cured for a set time, finally use sandpaper to file and repair the uneven colloid to complete the work of filling the nail head groove with the glue solution.

[0007] Further, in the obtained nail head filling glue solution, the mixing ratio of the DG-3 component A and component B base glues is 3:1.

[0008] Further, during the mixing process, a static mixing device is used to reduce the mixing of air bubbles in the glue solution by reducing the contact between the glue solution and air. The number of air bubbles in the mixed filling glue solution is less than 5 per 100 ml.

[0009] Further, the outer diameter of the glue injection port of the glue injection gun is smaller than the width of the nail head groove. When filling, start injecting from the bottom of each small groove of the nail head, and inject the glue amount until the glue solution overflows to the surface of the nail head.

[0010] Further, when using a blade to remove the surplus, the angle between the blade and the surface part is between 3° and 5°, and the working surface of the blade edge is closely attached to the surface of the part.

[0011] Further, the blade is a "one"-shaped blade.

[0012] Further, 180# fine sandpaper is selected.

[0013] Further, the glue scraping plate is "mouth"-shaped. The inner cavity width dimension of the "mouth"-shaped glue scraping plate is 4 mm larger than the nail head diameter, and the inner cavity height dimension is 0.2 mm.

[0014] Further, the first curing time of the glue solution is not less than 8 hours, and the second curing time of the glue solution is not less than 40 hours.

[0015] Further, the nail head groove should be cleaned before injecting the glue.

[0016] In summary, the present invention has the following advantages: 1. The method of the present invention can achieve a 100% one-time qualification rate for the filling of the nail head glue solution, while reducing the glue solution usage by 50%. At the same time, it can avoid the risk of exceeding the tolerance of the surface damage of aircraft parts. Moreover, the operation method is simple, and the tools and materials are convenient to use, effectively improving the production efficiency, ensuring the flatness of the aircraft surface, and meeting the surface quality requirements of the aircraft.

[0017] 2. In the present invention, after the glue solution is filled in the nail head groove, the height of the colloid on the nail head surface does not exceed 0.2 mm, and the diameter of the colloid does not exceed 4 mm of the nail head diameter. After the glue solution is cured, there is only a small amount of cured colloid remaining on the nail head. While saving the glue solution, a blade is used to remove the remaining glue solution after the glue solution is cured; 3. In the present invention, after the glue solution on the nail head is leveled, a strong flashlight is used to check for possible accidental bubbles and pierce the existing bubbles to avoid holes in the colloid caused by the omission of accidental and entrained bubbles after the glue solution is cured.

[0018] 4. In the present invention, after the nail head glue solution is completely cured in 48 hours, 180# sandpaper is used to file and repair the knife marks or other protrusions left by the blade when cutting the colloid, avoiding the quality risk of damaging the surface of the aircraft parts when using other polishing tools to polish the colloid. Description of the Drawings

[0019] Figure 1 is a common grooved connecting fastener for aircraft; Figure 2 is a schematic diagram of a DG-3 glue solution static mixing injection gun; Figure 3 is a schematic diagram of an injection-type filling cartridge and an injection port; Figure 4 is a schematic diagram of the structure of a "mouth"-shaped glue scraping plate; Figure 5 is a schematic diagram of the injection-type filling of the nail head groove with glue solution; Figure 6 is a schematic diagram of leveling the glue solution to an equal thickness; Figure 7 is a schematic diagram of removing the remaining colloid; Figure 8 is a schematic diagram of filing and repairing the remaining colloid; Figure 9 is a flow chart of filling the nail head groove on the aircraft surface with high-viscosity DG-3 glue solution; Figure 10 is a schematic diagram of the inner cavity size of the "mouth"-shaped glue scraping plate; In the figure: 1. Nail head groove; 2. Connecting fastener; 3. Glue mixing gun; 4. Injection port; 5. "Mouth"-shaped glue scraping plate; 6. Filling glue solution; 7. Cured colloid; 8. "One"-shaped blade; 9. Part surface; 10. 180# sandpaper. Detailed Embodiments

[0020] To more clearly illustrate the present invention, the present invention will be further described below in conjunction with preferred embodiments and the accompanying drawings. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0021] The present invention provides a construction method without air bubbles for filling the nail head grooves on the aircraft surface with high-viscosity DG-3 glue solution. The implementation process is as Figure 9 shown. In this method, a mixing gun is used to mix the base glue of components A and B of DG-3 to obtain a nail head filling glue solution with less than 5 air bubbles per 100 ml. An injection gun is used to inject the glue solution into the nail head groove from the bottom of the nail head groove by injection. A "mouth"-shaped scraping plate is used to level the just-filled glue solution to an equal thickness of 0.2 mm. A strong flashlight is used to check and puncture the occasional air bubbles that may exist after the glue solution is filled. After the glue solution is cured for 8 hours, a sharp flat-blade screwdriver is used to remove the remaining glue. After the glue solution continues to cure for 40 hours, finally, 180# sandpaper is used to file and repair the uneven glue body.

[0022] The common fastener structure with grooves on the aircraft is as Figure 1 shown. In this method, high-viscosity DG-3 glue is used to fill the nail head grooves. The specific implementation steps are as follows: S1. Glue solution mixing: Use a mixing gun with a mixing ratio of 3:1 to statically mix the DG-3 glue solution base glue containing components A and B, and load the mixed glue solution into the injection cylinder of the injection gun; as Figure 2 shown is a schematic diagram of the static mixing component gun of the DG-3 glue solution, Figure 3 and is a schematic diagram of the injection-type filling cylinder and the injection port.

[0023] In this step, the air bubbles in the glue solution are reduced by reducing the contact between the glue solution and air during the mixing process , and the number of air bubbles in the mixed filling glue solution is less than 5 per 100 ml; S2. Cleaning: Clean the nail head grooves of the fasteners.

[0024] S3. Glue solution filling: Inject the mixed DG-3 glue into the bottom of the nail head groove through the injection nozzle of the pneumatic injection gun; the outer diameter of the injection port of the injection gun is smaller than the width of the nail head groove. When injecting glue at the bottom of the nail head groove, each small groove of the nail head should be injected once. When filling, start injecting from the bottom of the groove, and inject the glue until the glue overflows to the surface of the nail head, as Figure 5 shown.

[0025] S4. Glue solution leveling: Use a "mouth"-shaped scraping plate to level the nail head glue solution to an equal thickness of 0.2 mm, and it should be scraped 2-3 times repeatedly; as Figure 4 shown is a schematic diagram of the structure of the "mouth"-shaped scraping plate,Figure 6 The figure shows a schematic diagram of leveling the adhesive liquid with equal thickness.

[0026] In this step, the inner cavity width dimension of the "mouth"-shaped rubber scraper needs to be greater than the nail head diameter by 4 mm, the total length is about 100 mm, and the total thickness is about 1.5 mm. Its material is generally a plastic product with medium hardness, such as Figure 10 The figure shows a schematic diagram of the inner cavity dimensions of the "mouth"-shaped rubber scraper. After the nail head adhesive liquid is leveled, the adhesive liquid is 0.2 mm higher than the surface of the part. This thickness can meet the better coating of the adhesive liquid, making the adhesive liquid meet the requirements of being thin and uniform in thickness, providing a prerequisite for subsequent removal of the surplus.

[0027] S5. Inspection: Use a strong flashlight to check whether there are accidental and entrained bubbles after the adhesive liquid is filled, and pierce the possible bubbles; each nail head should be inspected thoroughly.

[0028] S6. Preliminary curing: After the adhesive liquid is filled, it is cured at room temperature for 8 hours.

[0029] S7. Removal of surplus: On the premise of the thickness control in step S4, use a sharp "one"-shaped blade to cut and remove the excess colloid on the nail head; when the blade removes the surplus, the angle between the blade and the surface part is between 3° and 5°, and the working surface of the blade edge is closely attached to the surface of the part, as shown in Figure 7 the figure.

[0030] S8. Complete curing: Continue to cure at room temperature for 40 hours.

[0031] S9. Filing and grinding: Use 180# fine sandpaper to file and grind the uneven colloid after the nail head is cut until the colloid of the nail head is finally flush with the surface of the aircraft part, as shown in Figure 8 the figure.

[0032] S10. Complete the work of filling the adhesive liquid in the nail head groove.

[0033] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention falls within the protection scope of the present invention.

Claims

1. A method for filling the nail head groove on the surface of an aircraft with high viscosity DG-3 glue without bubbles, characterized in that: The steps include: using a static glue mixing device to mix the DG-3 base glue of component A and component B to obtain the nail head filling glue solution; using a glue injection gun to inject the glue solution in an injection manner from the bottom of the nail head groove; using a glue scraping plate to level the just-filled glue solution to an equal thickness; using a strong flashlight to check and puncture the occasional air bubbles that may exist after the glue solution is filled. After the set curing time of the glue solution, use a blade to remove the excess glue. After the glue solution continues to cure for the set time, finally use sandpaper to file and repair the uneven glue body to complete the glue solution filling work in the nail head groove.

2. A method for constructing a high-viscosity DG-3 glue solution to fill the nail head groove on the surface of an aircraft without bubbles as claimed in claim 1, characterized in that: In the obtained nail head filling glue solution, the mixing ratio of the DG-3 base glue of component A and component B is 3:

1.

3. The method for filling the nail head groove on the surface of an aircraft with a high viscosity DG-3 glue without bubbles as claimed in claim 1, characterized in that: During the glue mixing process, a static glue mixing device is used to reduce the mixing of air bubbles in the glue solution by reducing the contact between the glue solution and air. The number of air bubbles in the mixed filling glue solution is less than 5 per 100 ml.

4. The method for constructing a high-viscosity DG-3 glue solution to fill the nail head groove on the surface of an aircraft without bubbles as claimed in claim 1, characterized in that: The outer diameter of the glue injection port of the glue injection gun is smaller than the width of the nail head groove. During filling, start injecting from the bottom of each small groove of the nail head and inject the glue amount until the glue solution overflows to the surface of the nail head.

5. The method for filling the nail head groove on the surface of an aircraft with a high viscosity DG-3 glue without bubbles as claimed in claim 1, characterized in that: When using a blade to remove the excess, the angle between the blade and the surface part is between 3° and 5°, and the working surface of the blade edge is closely attached to the surface of the part.

6. A method for constructing a high-viscosity DG-3 glue solution to fill nail head grooves on the surface of an aircraft without bubbles as described in claim 1 or 5, characterized in that: The blade is a "one"-shaped blade.

7. The method for constructing a high-viscosity DG-3 glue solution to fill the nail head groove on the surface of an aircraft without bubbles as claimed in claim 1, characterized in that: The sandpaper selected is 180# fine sandpaper.

8. The method for filling the nail head groove on the surface of an aircraft with a high viscosity DG-3 glue without bubbles as claimed in claim 1, characterized in that: The glue scraping plate is "mouth"-shaped. The inner cavity width dimension of the "mouth"-shaped glue scraping plate is 4 mm larger than the nail head diameter, and the inner cavity height dimension is 0.2 mm.

9. The method for constructing a high-viscosity DG-3 glue solution to fill the nail head groove on the surface of an aircraft without bubbles as claimed in claim 1, characterized in that: The first curing time of the glue solution is not less than 8 hours, and the second curing time of the glue solution is not less than 40 hours.

10. The method for filling the nail head groove on the surface of an aircraft with a high viscosity DG-3 glue without bubbles as claimed in claim 1, characterized in that: Before injecting the glue, the nail head groove should be cleaned thoroughly.

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