Aircraft skin repair method

Abstract

The present application belongs to the technical field of aircraft repair. The present application discloses an aircraft skin repair method, which includes the following steps: paint stripping operation on the original aircraft skin; checking the damaged part on the surface of the original aircraft skin to determine whether it needs to be repaired in situ or replaced; when it needs to be replaced, using a drill gun to remove the rivets fixing the original aircraft skin, and then separating the original aircraft skin; cutting materials according to the original aircraft skin, and then drilling rivet holes in the raw material to obtain a new skin; fixing the new skin on the orthopedic plate, so that the surface of the new skin and the orthopedic plate fit, and the curvature of the surface of the orthopedic plate is 1.2 to 1.7 times the curvature of the original aircraft skin; after setting the time, removing the new skin from the orthopedic plate, and then test-installing the new skin on the aircraft, and installing the new skin after the curvature of the new skin meets the process requirements. The present application solves the problem of complicated steps in the skin replacement in the prior art.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft repair, and specifically relates to an aircraft skin repair method. Background Art

[0002] The aircraft skin is a key component covering the outside of the aircraft frame. It is tightly fixed to the frame by rivets, and together they shape the aerodynamic shape of the aircraft. This skin design not only has excellent load-bearing capacity and rigidity, but is also relatively light in weight, effectively bearing and transmitting aerodynamic loads. When the skin is subjected to aerodynamic forces, it can efficiently disperse these forces to the fuselage and wing frame structures connected to it. However, as the aircraft is used for a long time, cracks may appear in the skin. According to the standard process for aircraft structural repair, once skin cracks are found, measures such as crack arrest, reinforcement, patching, cutting or replacement of new parts should be taken immediately.

[0003] The original aircraft skin is usually made of aluminum alloy plates that have been heat-treated and surface-treated. After cutting and drilling, these plates can be directly used to make new skins installed on the aircraft. However, it should be noted that the skins of some parts of the aircraft have a certain curvature or even a hyperbolic shape. Therefore, when the new skins are directly assembled with rivets, assembly stress will often be generated, which will affect the service life of the new skins.

[0004] To solve this problem, a mold that matches the curvature of the original skin is currently used to pre-process the new skin. However, since the new skin has a certain elasticity, after being corrected by the mold, it will rebound a part under the action of its own elasticity, resulting in the curvature of the processed skin being smaller than the preset value, increasing the risk of skin processing failure. The current practice is to achieve a stable curvature of the skin through multiple operations and adjustments. However, this method not only prolongs the molding time of the skin, but also makes the operation process more complicated and reduces work efficiency. Summary of the invention

[0005] The embodiment of the present application solves the problem of complicated steps in the prior art when replacing the aircraft skin by providing a method for repairing the aircraft skin.

[0006] In order to achieve the above object, an embodiment of the present invention provides an aircraft skin repair method, comprising the following steps:

[0007] Strip paint from the original aircraft skin;

[0008] Check the damaged parts on the surface of the original aircraft skin to determine whether in-situ repair or replacement is required;

[0009] When it is necessary to replace it with a new one, the rivets fixing the original machine skin are removed by using a drill gun, and then the original machine skin is separated;

[0010] Cutting the original machine skin, and then drilling rivet holes in the raw material to obtain a new skin;

[0011] Fixing the replaced skin on the orthopedic plate so that the replaced skin and the surface of the orthopedic plate are in contact with each other, and the curvature of the surface of the orthopedic plate is 1.2 to 1.7 times the curvature of the original skin;

[0012] After the time is set, the replacement skin is removed from the orthopedic plate, and then the replacement skin is trial-installed on the aircraft. After the curvature of the replacement skin meets the process requirements, the replacement skin is installed.

[0013] In a possible implementation, when in-situ repair is required, the damaged part of the original aircraft skin surface is repaired:

[0014] When the crack of the original aircraft skin is less than 3mm, drill a 1.5mm crack stop hole;

[0015] When the crack of the original aircraft skin is greater than or equal to 3mm and less than 15mm, the repair method of in-situ reinforcement or patching is adopted;

[0016] After the repair is completed, the original aircraft skin is spray-painted.

[0017] In a possible implementation, before the drill gun is used to remove the rivet, a positioning mechanism is installed on the housing of the drill gun; the positioning mechanism includes a mounting seat, a positioning cylinder, a sliding ring, a sliding rod and a positioning pin;

[0018] The mounting seat is mounted on the outer shell of the drill gun, the positioning cylinder is connected to the mounting seat through a bracket, and the drill bit on the drill gun is located at the axis of the positioning cylinder; an inner cavity with an annular structure is vertically arranged on the upper part of the side wall of the positioning cylinder, the sliding ring is slidably arranged in the inner cavity, and three grooves are arranged on the lower end surface of the sliding ring, the bottom surface of the groove is an inclined surface, and the inclined surface of the groove is arranged toward one side of the center of the positioning cylinder;

[0019] Three sliding holes are evenly distributed on the lower part of the side wall of the positioning cylinder, and the sliding holes are connected to the inner cavity. A sliding rod is slidably arranged in the sliding hole, and a positioning pin is arranged at the lower end of the sliding rod. The lower ends of the three positioning pins are adapted to the edge structure of the rivet head, and the upper end of the sliding rod is an inclined surface, and the inclined surface of the sliding rod is arranged toward a side away from the center of the positioning cylinder, and the inclined surface of the sliding rod abuts against the inclined surface of the sliding ring groove body.

[0020] In a possible implementation, when the rivet is removed using the drill gun, the lower ends of the three positioning pins are abutted against the edge of the rivet head, and then the drill gun is moved longitudinally in a direction parallel to the axis of the rivet, and the upper end of the sliding rod pushes the sliding ring to move longitudinally until the lower end of the drill bit of the drill gun abuts against the center of the rivet head, the drill gun is started, and the drill gun continues to be moved in a direction parallel to the axis of the rivet until the drill bit drills through the rivet.

[0021] In a possible implementation, when the drill gun is moved, if the moving direction is not parallel to the rivet axis, the three sliding rods apply unequal thrusts to the sliding ring, causing one side of the lower end of the sliding ring to move laterally, thereby tilting the sliding ring, so that one side outer wall of the lower end of the sliding ring and the other side outer wall of the upper end of the sliding ring are both in contact with the cavity wall of the inner cavity, thereby increasing the friction force of the longitudinal movement of the sliding ring, increasing the resistance of the sliding ring when it moves, and increasing the resistance of the drill gun when it moves. After the moving direction of the drill gun is adjusted to be parallel to the rivet axis, the sliding ring continues to move longitudinally.

[0022] In a possible implementation, the outer wall of the sliding ring and the cavity wall of the inner cavity are both covered with a rubber layer, and the friction coefficient between the rubber layer of the outer wall of the sliding ring and the rubber layer of the cavity wall of the inner cavity is 0.75-0.85.

[0023] In a possible implementation, the roughness of the inclined surface of the groove body and the inclined surface of the sliding rod is 0.3-0.8 μm.

[0024] In a possible implementation, the outer wall of the sliding ring is provided with an annular resistance bar, and the cross section of the resistance bar is a triangle;

[0025] The cavity wall of the inner cavity is provided with an annular resistance groove, the cross section of the resistance groove is triangular, the resistance strip matches the resistance groove, and the width and length of the resistance strip are 1-2 mm.

[0026] In a possible implementation, a spring sheet is provided between the inner wall of the sliding ring and the cavity wall of the inner cavity, and the spring sheet enables the sliding ring and the inner cavity to be in a coaxial state.

[0027] In a possible implementation, the angle between the two inclined surfaces of the resistance groove and the axis of the inner cavity is 45°;

[0028] The angle between the inclined surface of the resistance bar located at the lower part of the sliding ring and close to the mounting seat and the axis of the sliding ring is 38° to 43°;

[0029] The included angle between the inclined surface of the resistance bar located at the upper part of the sliding ring and close to one side of the mounting seat and the axis of the sliding ring is 47° to 52°.

[0030] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0031] The embodiment of the present invention provides an aircraft skin repair method, in which the curvature of the surface of the correction plate is set to 1.2 to 1.7 times the curvature of the original aircraft skin. After the new skin is corrected, the elastic deformation of the new skin is pre-compensated. When the new skin rebounds a part of the margin, it can also meet the preset curvature range, thereby meeting the process requirements. Such a process can shorten the skin molding time, and the operation steps are simple, which improves work efficiency.

[0032] The positioning mechanism of the present invention is a detachable installation mode, that is, it is selectively installed according to actual conditions. The positioning mechanism is used to assist repair personnel to quickly position the drill gun and the rivet, thereby improving the efficiency of rivet removal. The movement direction of the drill gun and the rivet axis are not parallel, which will increase the resistance of the drill gun when it moves, so that the repair personnel can find it in time and adjust the angle of the drill gun in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic diagram of the state of using a positioning mechanism to assist in removing rivets provided in the first embodiment of the present invention.

[0035] Figure 2 for Figure 1 Enlarged view of point A.

[0036] Figure 3 A schematic structural diagram of a sliding ring provided in an embodiment of the present invention.

[0037] Figure 4 A schematic diagram of the arrangement of the groove body of the sliding ring provided in an embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of installing a new skin and a correction plate provided in the second embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of the installation of the sliding ring provided in the fourth embodiment of the present invention.

[0040] Figure 7 for Figure 6 Enlarged view of point B.

[0041] Figure numerals: 1-original machine skin; 2-rivet; 3-new skin; 4-corrective plate; 5-mounting seat; 6-drill gun; 7-positioning cylinder; 71-inner cavity; 72-sliding hole; 8-bracket; 9-drill bit; 10-sliding ring; 101-groove body; 11-sliding rod; 12-positioning needle; 13-reset spring; 14-resistance bar; 15-resistance groove. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0044] like Figures 1 to 7 As shown, the aircraft skin repair method provided by the embodiment of the present invention comprises the following steps:

[0045] The paint removal operation is performed on the original machine skin 1.

[0046] Check the damaged parts on the surface of the original aircraft skin 1 to determine whether it needs to be repaired in situ or replaced.

[0047] When it is necessary to replace it with a new one, the rivets 2 fixing the original machine skin 1 are removed by using a drill gun 6, and then the original machine skin 1 is separated.

[0048] Cut the raw material according to the original machine skin 1, and then drill rivet holes on the raw material to obtain a new skin 3.

[0049] The new skin 3 is fixed on the orthopedic plate 4 so that the surfaces of the new skin 3 and the orthopedic plate 4 fit together, and the curvature of the surface of the orthopedic plate 4 is 1.2 to 1.7 times that of the original skin 1 .

[0050] After the time is set, the replacement skin 3 is removed from the orthopedic plate 4, and then the replacement skin 3 is trial-installed on the aircraft. After the curvature of the replacement skin 3 meets the process requirements, the replacement skin 3 is installed.

[0051] It should be noted that after the original aircraft skin 1 is stripped of paint, the damaged part of the original aircraft skin 1 can be more clearly seen. Visual inspection can be used for inspection, and color flaw detection and other inspection methods can be used for uncertain positions. The aircraft skin repair method of the present invention can be applied to aircraft overhaul or routine maintenance.

[0052] In the first embodiment, the orthopedic plate 4 includes a male mold and a female mold, and the new skin 3 is clamped between the male mold and the female mold. The orthopedic plate 4 of this embodiment clamps and fixes the new skin 3, so the new skin 3 is installed faster, but accurate positioning is required during installation to avoid the problem of misalignment of the new skin 3.

[0053] In the second embodiment, the replacement skin 3 is detachably mounted on the surface of the orthopedic plate 4 by means of aviation positioning pins. The orthopedic plate 4 has mounting holes corresponding to the rivet holes of the replacement skin 3. The aviation positioning pins are fixed through the rivet holes and the mounting holes. The replacement skin 3 of the present embodiment is fixed by means of aviation positioning pins. When the arc of the replacement skin 3 is large, the replacement skin 3 can be installed gradually at intervals of a certain time in different areas to avoid the problem of cracks on the edge of the hole caused by the large force on the rivet hole.

[0054] In the first or second embodiment, the orthopedic plate 4 can heat the replaced skin 3 in a self-heating manner to improve the orthopedic efficiency of the replaced skin 3 .

[0055] The duration of fixing the new skin 3 to the orthopedic plate 4 is adjusted according to the following two conditions: 1. the specific ratio of the curvature of the surface of the orthopedic plate 4 to the curvature of the original skin 1 . 2. the thickness and area of ​​the new skin 3 .

[0056] The present invention sets the curvature of the surface of the correction plate 4 to 1.2 to 1.7 times the curvature of the original machine skin 1. After the new skin 3 is corrected, the elastic deformation of the new skin 3 is pre-compensated. When the new skin 3 rebounds a part of the margin, it can also meet the preset curvature range, thereby meeting the process requirements. Such a process can shorten the skin molding time, simplify the operation steps, and improve work efficiency.

[0057] In the second embodiment, the curvature of the orthopedic plate 4 is adjustable, and after the new skin 3 is fixed on the orthopedic plate 4, the curvature of the orthopedic plate 4 is gradually increased as time goes by. In this way, the curvature of the new skin 3 is gradually increased, so the new skin 3 will not be damaged due to a sudden increase in force.

[0058] The structures of the orthopedic plates 4 of the first and second embodiments are easily conceivable by those skilled in the art, and thus will not be further described in detail in this embodiment.

[0059] In this embodiment, when in-situ repair is required, the damaged part on the surface of the original aircraft skin 1 is repaired:

[0060] When the crack of the original machine skin 1 is less than 3mm, drill a 1.5mm crack stop hole.

[0061] When the crack of the original machine skin 1 is greater than or equal to 3mm and less than 15mm, the repair method of in-situ reinforcement or patching is adopted.

[0062] After the repair is completed, the original aircraft skin 1 is spray-painted.

[0063] It should be noted that when there are multiple cracks or the cracks are long, they can be directly replaced. The damage on the surface of the original machine skin 1 also includes bulges, deformations, pits, etc., and the specific repair method is performed according to the existing process.

[0064] In this embodiment, before the rivet 2 is removed by the drill gun 6, a positioning mechanism is installed on the housing of the drill gun 6. The positioning mechanism includes a mounting seat 5, a positioning cylinder 7, a sliding ring 10, a sliding rod 11 and a positioning pin 12.

[0065] The mounting seat 5 is mounted on the outer shell of the drill gun 6, the positioning cylinder 7 is connected to the mounting seat 5 through the bracket 8, and the drill bit 9 on the drill gun 6 is located at the axis of the positioning cylinder 7. An inner cavity 71 of an annular structure is vertically arranged on the upper part of the side wall of the positioning cylinder 7, and a sliding ring 10 is slidably arranged in the inner cavity 71. The lower end surface of the sliding ring 10 is provided with three grooves 101, and the bottom surface of the groove 101 is an inclined surface, and the inclined surface of the groove 101 is arranged toward the side of the center of the positioning cylinder 7.

[0066] Three sliding holes 72 are evenly distributed on the lower part of the side wall of the positioning cylinder 7. The sliding holes 72 are connected to the inner cavity 71. A sliding rod 11 is slidably arranged in the sliding hole 72. A positioning pin 12 is arranged at the lower end of the sliding rod 11. The lower ends of the three positioning pins 12 are adapted to the edge structure of the rivet head. The upper end of the sliding rod 11 is an inclined surface. The inclined surface of the sliding rod 11 is arranged to face the side away from the center of the positioning cylinder 7. The inclined surface of the sliding rod 11 abuts against the inclined surface of the groove body 101 of the sliding ring 10.

[0067] It should be noted that the positioning cylinder 7 is an annular structure, and the sliding ring 10 can slide in the inner cavity 71 along the axis of the positioning cylinder 7. The lower end of the positioning pin 12 is sharp so as to press the edge of the rivet head tightly. The three positioning pins 12 adopt the three-point circle theorem to clamp the circular rivet head so that the drill bit 9 can be quickly positioned. Different rivets 2 correspond to different groups of positioning pins 12 to adapt to various types of rivets 2. The rivet head of this embodiment is a semi-circular head rivet 2. In actual use, the positioning mechanism is also suitable for oval head rivets or flat head rivets. A reset spring 13 can also be set at the rear end of the sliding ring 10 so that when the rivet 2 and the drill bit 9 are in contact, the sliding ring 10 always plays a guiding role.

[0068] In this embodiment, when the rivet 2 is removed by using the drill gun 6, the lower ends of the three positioning pins 12 are abutted against the edge of the rivet head, and then the drill gun 6 is moved longitudinally in a direction parallel to the axis of the rivet 2, and the upper end of the sliding rod 11 pushes the sliding ring 10 to move longitudinally until the lower end of the drill bit 9 of the drill gun 6 abuts against the center of the rivet head, the drill gun 6 is started, and the drill gun 6 continues to be moved in a direction parallel to the axis of the rivet 2 until the drill bit 9 drills through the rivet 2.

[0069] It should be noted that in the prior art, when disassembling the original machine skin 1, the repair personnel usually drill the rivet 2 manually and then disassemble it, so the efficiency is low, especially when the repair personnel are tired after disassembling the rivet 2 for a long time or when the repair personnel with insufficient experience disassemble the rivet 2, the drill bit 9 may be tilted, thereby causing the rivet hole to become larger or damaging the skin. The positioning mechanism of the present invention is a detachable installation method, that is, it is selectively installed according to the actual situation. The positioning mechanism is used to assist the repair personnel to quickly position the drill gun 6 and the rivet 2, thereby improving the disassembly efficiency of the rivet 2.

[0070] In this embodiment, when the drill gun 6 is moved, if the moving direction is not parallel to the axis of the rivet 2, the three sliding rods 11 apply unequal thrusts to the sliding ring 10, causing one side of the lower end of the sliding ring 10 to move laterally, thereby tilting the sliding ring 10, so that the outer wall on one side of the lower end of the sliding ring 10 and the outer wall on the other side of the upper end of the sliding ring 10 are both in contact with the cavity wall of the inner cavity 71, thereby increasing the friction force of the longitudinal movement of the sliding ring 10, increasing the resistance when the sliding ring 10 moves, and increasing the resistance when the drill gun 6 moves. After the moving direction of the drill gun 6 is adjusted to be parallel to the axis of the rivet 2, the sliding ring 10 continues to move longitudinally.

[0071] It should be noted that the movement direction of the drill gun 6 is not parallel to the axis of the rivet 2, which will increase the resistance when the drill gun 6 moves, so that the repair personnel can find it in time and adjust the angle of the drill gun 6 in time.

[0072] In the third embodiment, the outer wall of the sliding ring 10 and the wall of the inner cavity 71 are both covered with a rubber layer, and the friction coefficient between the rubber layer of the outer wall of the sliding ring 10 and the rubber layer of the wall of the inner cavity 71 is 0.75-0.85.

[0073] It should be noted that, by providing the rubber layer, when the moving direction of the drill gun 6 is not parallel to the axis of the rivet 2, it can ensure that the resistance of the drill gun 6 is greatly increased when moving, so that the repair personnel can find it in time and obviously.

[0074] In this embodiment, the roughness of the inclined surface of the groove body 101 and the inclined surface of the sliding rod 11 is 0.3-0.8 μm.

[0075] It should be noted that the inclined surface of the groove body 101 and the inclined surface of the sliding rod 11 are both made of steel. The roughness of the two inclined surfaces is set to reduce the friction between them so that the force of the sliding rod 11 can be quickly transmitted to the sliding ring 10 to tilt the sliding ring 10.

[0076] In the fourth embodiment, an annular resistance bar 14 is provided on the outer wall of the sliding ring 10 , and the cross section of the resistance bar 14 is triangular.

[0077] The cavity wall of the inner cavity 71 is provided with an annular resistance groove 15, the cross section of the resistance groove 15 is triangular, the resistance strip 14 and the resistance groove 15 are matched, and the width and length of the resistance strip 14 are 1 to 2 mm.

[0078] It should be noted that when the movement direction of the drill gun 6 is not parallel to the axis of the rivet 2, the sliding ring 10 tilts, and the resistance strip 14 on one side of the upper end of the outer wall of the sliding ring 10 and the resistance strip 14 on the other side of the lower end are respectively engaged in the resistance groove 15, thereby clamping the sliding ring 10 and making it difficult to move, thereby providing greater resistance. The resistance can be further increased when the drill gun 6 moves, so that the repair personnel can sense it in time.

[0079] In the fourth embodiment, a spring sheet is provided between the inner wall of the sliding ring 10 and the wall of the inner cavity 71 , and the spring sheet makes the sliding ring 10 and the inner cavity 71 in a coaxial state.

[0080] It should be noted that the spring sheet keeps the sliding ring 10 in its initial center state, preventing the resistance bar 14 and the resistance groove 15 from contacting each other under normal conditions. The positioning mechanism of this embodiment is suitable for the use scenario where the drill bit 9 is in a vertical state. When the drill bit 9 is in a horizontal state or an inclined state, it is necessary to consider the influence of the gravity of the sliding ring 10 on its position. When it is used specifically, by reducing the weight of the sliding ring 10 and reasonably distributing the spring sheet to offset the gravity of the sliding ring 10, when the drill bit 9 is in a horizontal state or an inclined state, the sliding ring 10 can also be in a coaxial state with the inner cavity 71 in a natural state or within an allowable error range, thereby ensuring that the positioning mechanism can be used normally.

[0081] The cross section of the spring sheet may be a V-shaped structure. The structure and installation method of the spring sheet are prior art and will not be described in detail in this embodiment.

[0082] In the fourth embodiment, the angle between the two inclined surfaces of the resistance groove 15 and the axis of the inner cavity 71 is 45°.

[0083] The angle between the inclined surface of the resistance strip 14 located at the lower part of the sliding ring 10 and close to the drill bit 9 and the axis of the sliding ring 10 is 45°, and the angle between the inclined surface of the resistance strip 14 located at the lower part of the sliding ring 10 and close to the mounting seat 5 and the axis of the sliding ring 10 is 38°~43°.

[0084] The angle between the inclined surface of the resistance strip 14 located at the upper part of the sliding ring 10 and close to the drill bit 9 and the axis of the sliding ring 10 is 45°, and the angle between the inclined surface of the resistance strip 14 located at the upper part of the sliding ring 10 and close to the mounting seat 5 and the axis of the sliding ring 10 is 47°~52°.

[0085] It should be noted that the angle between the inclined surface of the resistance bar 14 located at the lower part of the sliding ring 10 and close to the mounting seat 5 and the axis of the sliding ring 10 is 38° to 43°, that is, the angle between the cross section of the upper half of the resistance bar 14 at the lower part of the sliding ring 10 and the axis of the sliding ring 10 is 38° to 43°. The angle between the inclined surface of the resistance bar 14 located at the upper part of the sliding ring 10 and close to the mounting seat 5 and the axis of the sliding ring 10 is 47° to 52°, that is, the angle between the cross section of the upper half of the resistance bar 14 at the upper part of the sliding ring 10 and the axis of the sliding ring 10 is 47° to 52°. With such a structural arrangement, when the sliding ring 10 is tilted, the contact area between the resistance bar 14 and the resistance groove 15 becomes larger, especially when the resistance bar 14 and the resistance groove 15 are in a state of surface contact, the resistance is the largest, making it difficult for the sliding ring 10 to move.

[0086] The positioning mechanism of this embodiment can timely detect and adjust the movement angle of the drill gun 6 when the drill gun 6 deviates from the set direction, thereby maintaining the drilling effect and improving the drilling efficiency. The principle of the present invention can also be applied to other similar situations, thereby ensuring that the target part can move along the set direction.

[0087] In this embodiment, it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and therefore it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A method for repairing aircraft skin, characterized in that: The following steps are involved: Performing a paint removal operation on the original aircraft skin (1); Inspecting the damaged parts on the surface of the original machine skin (1) to determine whether it needs to be replaced; When replacement is required, a drill gun (6) is used to remove the rivets (2) fixing the original machine skin (1), and then the original machine skin (1) is separated; Cutting the original machine skin (1) and then drilling rivet holes in the raw material to obtain a new skin (3); The replacement skin (3) is fixed on the orthopedic plate (4) so ​​that the surfaces of the replacement skin (3) and the orthopedic plate (4) are in contact with each other, and the curvature of the surface of the orthopedic plate (4) is 1.2 to 1.7 times the curvature of the original skin (1); After the time is set, the replacement skin (3) is removed from the orthopedic plate (4), and then the replacement skin (3) is trial-installed on the aircraft. After the curvature of the replacement skin (3) meets the process requirements, the replacement skin (3) is installed; Before using the drill gun (6) to remove the rivet (2), a positioning mechanism is installed on the outer shell of the drill gun (6); the positioning mechanism comprises a mounting seat (5), a positioning cylinder (7), a sliding ring (10), a sliding rod (11) and a positioning pin (12); The mounting seat (5) is mounted on the outer shell of the drilling gun (6); the positioning cylinder (7) is connected to the mounting seat (5) via a bracket (8); the drill bit (9) on the drilling gun (6) is located at the axis of the positioning cylinder (7); an inner cavity (71) of an annular structure is vertically arranged at the upper part of the side wall of the positioning cylinder (7); the sliding ring (10) is slidably arranged in the inner cavity (71); three grooves (101) are arranged on the lower end surface of the sliding ring (10); the bottom surface of the groove (101) is an inclined surface; and the inclined surface of the groove (101) is arranged toward the side of the center of the positioning cylinder (7); Three sliding holes (72) are evenly distributed at the lower part of the side wall of the positioning cylinder (7), the sliding holes (72) are connected to the inner cavity (71), a sliding rod (11) is slidably arranged in the sliding hole (72), a positioning pin (12) is arranged at the lower end of the sliding rod (11), the lower ends of the three positioning pins (12) are adapted to the edge structure of the rivet head, the upper end of the sliding rod (11) is an inclined surface, the inclined surface of the sliding rod (11) is arranged toward a side away from the center of the positioning cylinder (7), and the inclined surface of the sliding rod (11) abuts against the inclined surface of the groove body (101) of the sliding ring (10); When the rivet (2) is removed by using the drill gun (6), the lower ends of the three positioning pins (12) are abutted against the edge of the rivet head, and then the drill gun (6) is moved longitudinally in a direction parallel to the axis of the rivet (2), and the upper end of the sliding rod (11) pushes the sliding ring (10) to move longitudinally until the lower end of the drill bit (9) of the drill gun (6) abuts against the center of the rivet head, the drill gun (6) is started, and the drill gun (6) is continued to be moved in a direction parallel to the axis of the rivet (2) until the drill bit (9) drills through the rivet (2); When the drill gun (6) is moved, if the moving direction is not parallel to the axis of the rivet (2), the three sliding rods (11) apply different thrusts to the sliding ring (10), causing one side of the lower end of the sliding ring (10) to move laterally, thereby causing the sliding ring (10) to tilt, so that the outer wall on one side of the lower end of the sliding ring (10) and the outer wall on the other side of the upper end of the sliding ring (10) are both in contact with the cavity wall of the inner cavity (71), thereby increasing the friction force of the longitudinal movement of the sliding ring (10), increasing the resistance when the sliding ring (10) moves, and increasing the resistance when the drill gun (6) moves. After the moving direction of the drill gun (6) is adjusted to be parallel to the axis of the rivet (2), the sliding ring (10) continues to move longitudinally.

2. The aircraft skin repair method according to claim 1, characterized in that: The outer wall of the sliding ring (10) and the wall of the inner cavity (71) are both coated with a rubber layer, and the friction coefficient between the rubber layer of the outer wall of the sliding ring (10) and the rubber layer of the wall of the inner cavity (71) is 0.75-0.

85.

3. The aircraft skin repair method according to claim 1, characterized in that: The roughness of the inclined surface of the groove body (101) and the inclined surface of the sliding rod (11) is 0.3-0.8 μm.

4. The aircraft skin repair method according to claim 1, characterized in that: The outer wall of the sliding ring (10) is provided with an annular resistance strip (14), and the cross section of the resistance strip (14) is triangular; The cavity wall of the inner cavity (71) is provided with an annular resistance groove (15), the cross section of the resistance groove (15) is triangular, the resistance strip (14) matches the resistance groove (15), and the width and length of the resistance strip (14) are 1 to 2 mm.

5. The aircraft skin repair method according to claim 4, characterized in that: A spring sheet is provided between the inner wall of the sliding ring (10) and the cavity wall of the inner cavity (71), and the spring sheet enables the sliding ring (10) and the inner cavity (71) to be in a coaxial state.

6. The aircraft skin repair method according to claim 4, characterized in that: The included angle between the two inclined surfaces of the resistance groove (15) and the axis of the inner cavity (71) is 45°; The included angle between the inclined surface of the resistance strip (14) located at the lower part of the sliding ring (10) and close to the side of the mounting seat (5) and the axis of the sliding ring (10) is 38° to 43°; The angle between the inclined surface of the resistance strip (14) located on the upper part of the sliding ring (10) and close to the mounting seat (5) and the axis of the sliding ring (10) is 47° to 52°.

Images