Practical damage-based aircraft composite material protective fence replacement and repair method

Abstract

The invention relates to the field of composite material repairing, in particular to an aircraft composite material protective fence replacing and repairing method based on actual damage, which comprises the following specific steps: S1, damage detection; s2, preparing materials; s3, generating a damage removal path; s4, calculating a processing path of the filling material; s5, processing preparation; s6, material processing; s7, finishing after processing; s8, cutting the adhesive film; s9, material filling; s10, curing is conducted; s11, finishing is conducted; and S12, nondestructive testing is conducted on the repaired area, and it is ensured that the repaired area is intact. According to the two-side synchronous machining method, in other words, damage area removal and filling material machining are conducted synchronously, the machining paths of the damage area removal and the filling material machining can be monitored in real time, damage area removal and filling material machining can be conducted according to the damage condition of the composite material protective fence, and therefore precise repairing is achieved.

Description

Technical Field

[0001] The invention relates to the field of composite material repair, in particular to a method for replacing and repairing an aircraft composite material protective grid based on actual damage. Background Art

[0002] Aircraft protective grilles contain a large number of grid structures and are placed in the aircraft engine air intake to prevent various foreign objects from entering the air intake. Traditional aircraft protective grilles are usually made of high-strength alloys, but composite materials are now widely used in the production of protective grilles. Due to the one-piece molding characteristics of composite materials, after cracks and delamination, they are limited to a very small grid space. The grid structure is precise and the grid wall thickness is only 1mm. Repair methods such as patching cannot be used, and the only option is to replace the entire piece, which has a high repair cost. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a method for replacing and repairing aircraft composite material protective grilles based on actual damage.

[0004] A method for replacing and repairing an aircraft composite material protective grille based on actual damage, the specific steps of which are as follows:

[0005] S1. Damage detection: Before repairing, the damaged protection grille is inspected to obtain the outer contour of the damage and the inclination angle of the air intake protection grille;

[0006] S2. Material preparation: According to the material and shape of the damaged protection fence, select a local protection fence with the same material parameters, wall thickness and inclination angle;

[0007] S3. Damage removal path generation:

[0008] When a grid wall of the protective fence is damaged, its damage removal path needs to include the entire grid wall. If the protective fence is partially damaged irregularly, all grids with damage should be removed. The corresponding damage removal path is to remove the damaged grids in sequence along the inner wall of the outermost grid according to the shape of the grids.

[0009] After the damage is removed, a local vacancy grid is obtained;

[0010] S4, calculation of the processing path of the filling material: the filling material is processed through the local protective fence, and the shape of the processing path is the same as the shape of the material processing path described in step S3;

[0011] According to the processing path, the grid material area is obtained;

[0012] S5, processing preparation: start the controller, adjust the processing tool 1 to the same angle according to the inclination angle of the damage protection fence in step S1, the processing tool 1 is installed in the multi-degree-of-freedom robot arm 1, and the posture is adjusted according to the air inlet protection fence, and according to the processing path of step S3, the processing tool 1 is adjusted to the starting point of the processing path of step S3;

[0013] S6. Material processing:

[0014] S61, the processing tool 1 processes the damaged area of ​​the damage protection fence according to the processing path of step S3. During the processing, the actual tool trajectory is sent to the controller in real time.

[0015] S62, the second processing tool processes the local protective fence according to the processing path of step S4, and also sends the tool trajectory to the controller in real time, and the controller monitors and compares the tool processing status in real time;

[0016] S7, finishing after processing: after processing, turn off the controller, remove the protective grille after damage removal and the partial protective grille used for filling and repair, compare their shapes to see if they are consistent, and use sandpaper to remove burrs;

[0017] S8, cutting the adhesive film: cutting the adhesive film into a quadrilateral shape with the outer perimeter of the processing path described in step S3 as one side and the protective wall length of the air intake protection grille as the other side;

[0018] S9, material filling: firstly wrapping the adhesive film on the side of the partial protective grille described in step S7, and then filling the protective grille in the blank area of ​​the protective grille to be repaired according to the processed shape;

[0019] S10, curing: according to the curing temperature, time and pressure of the adhesive film, a vacuum bag system is laid in the repair area of ​​the protective fence and heated for curing;

[0020] S11, finishing: remove the vacuum bag system and remove the excess material on the laminate surface by manual sandpaper polishing;

[0021] S12: Perform non-destructive testing on the repaired area to ensure that the repair is complete.

[0022] In the step S1, the detection is performed by visual detection, X-ray or ultrasonic scanning methods.

[0023] In the step S2, the area size of the local protection grid is larger than the area size of the damaged protection grid.

[0024] The damage removal path in step S3 includes the entire grid wall except the outermost grid.

[0025] The processing size of the filling material determined according to the thickness of the adhesive film in step S4 is shorter by 1 mm on all sides than the processing path of the local protective grille 7 material in step S3.

[0026] In the step S5, according to the filling material processing path described in step S4, another processing tool 2 is adjusted to the starting point of the processing path, and the processing tool 2 is installed on the multi-degree-of-freedom robot arm 2.

[0027] The beneficial effects of the present invention are: proposing a two-side synchronous processing method, that is, the removal of the damaged area and the processing of the filling material are carried out simultaneously, the processing paths of the two can be monitored in real time, and the damaged area can be removed and the filling material can be processed according to the damage of the composite material protective grille, thereby achieving precise repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0029] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the damage protection grid structure of the present invention;

[0031] Figure 3 A schematic diagram of a local vacancy grid structure for damage removal of the present invention;

[0032] Figure 4 It is a schematic diagram of the processing path structure of the present invention;

[0033] Figure 5 It is a schematic diagram of the structure of the filling grid material of the present invention;

[0034] Figure numerals: 1. damage protection fence; 2. processing tool 1; 3. multi-degree-of-freedom robot arm 1; 4. controller; 5. processing tool 2; 6. multi-degree-of-freedom robot arm 2; 7. local protection fence. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0036] like Figures 1 to 5 As shown, a method for replacing and repairing an aircraft composite material protective grille based on actual damage, the specific steps are as follows:

[0037] S1. Damage detection: Before repairing, the damaged protection grille 1 is inspected to obtain the outer contour of the damage and the inclination angle of the air inlet protection grille;

[0038] S2. Material preparation: according to the material and shape of the damage protection fence 1, select a local protection fence 7 with the same material parameters, wall thickness and inclination angle;

[0039] S3. Damage removal path generation:

[0040] When a grid wall of the protective fence is damaged, the damage removal path should include the entire grid wall, such as Figure 2 As mentioned above, the protective grille has irregular damage locally, so all the damaged grilles should be removed, as shown by the shadow in the figure. The corresponding damage removal path is to remove the damaged grilles in sequence along the inner wall of the outermost grille according to the shape of the grille, such as Figure 2 As indicated by the arrow;

[0041] After the damage is removed, the Figure 3 The local vacancy grid shown;

[0042] S4, calculation of the processing path of the filling material: The filling material is processed through the local protective fence 7, and the shape of the processing path is the same as the shape of the material processing path described in step S3. The processing path is as follows: Figure 4 As indicated by the arrow;

[0043] According to the above processing path, the final filling grid material can be obtained as follows Figure 5 As shown;

[0044] S5, processing preparation: start the controller 4, and adjust the processing tool 2 to the same angle according to the inclination angle of the damage protection fence 1 in step S1. The processing tool 2 is installed in the multi-degree-of-freedom robot arm 3, and can adjust the posture according to the air intake protection fence. According to the processing path of step S3, the processing tool 2 is adjusted to the starting point of the processing path of step S3;

[0045] S6. Material processing:

[0046] S61, the processing tool 1 2 processes the damaged area of ​​the damage protection fence 1 according to the processing path described in step S3. The specific processing parameters, such as the rotation speed and the feed speed, are determined according to the properties of the composite material itself, as shown in the following table:

[0047] Table 1 Processing parameter reference table

[0048]

[0049] During the machining process, the actual tool trajectory is sent to the controller 4 in real time;

[0050] S62, the second processing tool 5 processes the local protective fence 7 according to the processing path of step S4, and also sends the tool trajectory to the controller 4 in real time. The controller 4 monitors and compares the tool processing status in real time. According to step S4, in principle, the geometric shapes of the two processing paths are consistent, and the overall dimensions differ by 2 mm in length and width, ensuring the accuracy of the processing;

[0051] S7, finishing after processing: after processing, turn off the controller 4, remove the protective grille after damage removal and the local protective grille 7 used for filling and repair, compare their shapes to see if they are consistent, and use sandpaper to remove burrs;

[0052] S8, cutting the adhesive film: cutting the adhesive film into a quadrilateral shape with the outer perimeter of the processing path described in step S3 as one side and the protective wall length of the air intake protection grille as the other side;

[0053] S9, material filling: firstly wrap the adhesive film on the side of the partial protective grille 7 described in step S7, and then fill the protective grille in the blank area of ​​the protective grille to be repaired according to the processed shape, and pay attention to ensure that it is pressed tightly;

[0054] S10, curing: according to the curing temperature, time and pressure of the adhesive film, a vacuum bag system is laid in the repair area of ​​the protective fence and heated for curing;

[0055] S11, finishing: remove the vacuum bag system and remove the excess material on the laminate surface by manual sandpaper polishing;

[0056] S12: Perform non-destructive testing on the repaired area to ensure that the repair is complete.

[0057] In the step S1, the inspection is performed by visual inspection, X-ray or ultrasonic scanning methods, and the damaged area can be accurately removed in combination with the damage condition and the structural characteristics of the protective grille itself.

[0058] In the step S2 , the area size of the local protection grid 7 is larger than the area size of the damage protection grid 1 .

[0059] The damage removal path in step S3 includes the entire grid wall except the outermost grid.

[0060] The processing size of the filling material determined according to the thickness of the adhesive film in step S4 is 1 mm shorter than the processing path of the local protective grille 7 material in step S3. On the one hand, it takes into account the damage situation, and on the other hand, it takes into account the thickness of the repaired adhesive film to ensure that the processed filling material can accurately fit the adhesive film and the area to be repaired.

[0061] In the step S5, according to the filling material processing path described in step S4, another processing tool 2 5 is adjusted to the starting point of the processing path, and the processing tool 2 5 is installed on the multi-degree-of-freedom robot arm 2 6.

[0062] The step S6 proposes a two-side synchronous processing method, that is, the damaged area removal and the filling material processing are performed simultaneously, and the processing paths of the two can be monitored in real time to ensure accurate and reliable processing.

[0063] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for replacing and repairing aircraft composite material protective grilles based on actual damage, characterized in that: The specific steps are as follows: S1. Damage detection: Before repairing, the damaged protection grille (1) is inspected to obtain the outer contour of the damage and the inclination angle of the air inlet protection grille; S2. Material preparation: according to the material and shape of the damage protection grid (1), a local protection grid (7) having the same material parameters, wall thickness and inclination angle as the damage protection grid (1) is selected; S3. Damage removal path generation: When a grid wall of the protective fence is damaged, its damage removal path needs to include the entire grid wall. If the protective fence is partially damaged irregularly, all grids with damage should be removed. The corresponding damage removal path is to remove the damaged grids in sequence along the inner wall of the outermost grid according to the shape of the grids. After the damage is removed, a local vacancy grid is obtained; S4, calculation of the filling material processing path: the filling material is processed through the local protection fence (7), and the shape of the processing path is the same as the shape of the material processing path described in step S3; According to the processing path, the grid material area is obtained; S5, processing preparation: start the controller (4), adjust the processing tool 1 (2) to the same angle according to the inclination angle of the damage protection fence (1) in step S1, install the processing tool 1 (2) in the multi-degree-of-freedom robot arm 1 (3), adjust the posture according to the air inlet protection fence, and adjust the processing tool 1 (2) to the starting point of the processing path in step S3 according to the processing path in step S3; S6. Material processing: S61, the processing tool 1 (2) processes the damaged area of ​​the damage protection fence (1) according to the processing path of step S3, and during the processing, the actual tool trajectory is sent to the controller (4) in real time; S62, the second processing tool (5) processes the local protective fence (7) according to the processing path of step S4, and also sends the tool trajectory to the controller (4) in real time, and the controller (4) monitors and compares the tool processing status in real time; S7, finishing after processing: after processing, turn off the controller (4), remove the protective grille after damage removal and the partial protective grille (7) used for filling and repair, compare their shapes to see if they are consistent, and use sandpaper to remove burrs; S8, cutting the adhesive film: cutting the adhesive film into a quadrilateral shape with the outer perimeter of the processing path described in step S3 as one side and the protective wall length of the air intake protection grille as the other side; S9, material filling: firstly wrapping the adhesive film on the side of the partial protective grille (7) described in step S7, and then filling the protective grille in the blank area of ​​the protective grille to be repaired according to the processed shape; S10, curing: according to the curing temperature, time and pressure of the adhesive film, a vacuum bag system is laid in the repair area of ​​the protective fence and heated for curing; S11, finishing: remove the vacuum bag system and remove the excess material on the laminate surface by manual sandpaper polishing; S12: Perform non-destructive testing on the repaired area to ensure that the repair is complete.

2. The method for replacing and repairing an aircraft composite material protective grille based on actual damage according to claim 1, characterized in that: In the step S1, the detection is performed by visual detection, X-ray or ultrasonic scanning methods.

3. The method for replacing and repairing an aircraft composite material protective grille based on actual damage according to claim 1, characterized in that: In the step S2, the area size of the local protection grid (7) is larger than the area size of the damage protection grid (1).

4. The method for replacing and repairing an aircraft composite material protective grille based on actual damage according to claim 1, characterized in that: The damage removal path in step S3 includes the entire grid wall except the outermost grid.

5. The method for replacing and repairing an aircraft composite material protective grille based on actual damage according to claim 1, characterized in that: The processing size of the filling material determined according to the thickness of the adhesive film in step S4 is shorter by 1 mm on all sides than the processing path of the local protective grille (7) material in step S3.

6. The method for replacing and repairing an aircraft composite material protective grille based on actual damage according to claim 1, characterized in that: In the step S5, according to the filling material processing path described in step S4, another processing tool 2 (5) is adjusted to the starting point of the processing path, and the processing tool 2 (5) is installed on the multi-degree-of-freedom robot arm 2 (6).

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