A metal skin pit elimination process

Abstract

The application relates to the technical field of aircraft maintenance, and particularly discloses a metal skin pit elimination process, wherein the metal skin has oppositely arranged first and second surfaces, and the process comprises the following steps: determining the positions of pits on the first and second surfaces; arranging a shrink hammer and a support body according to the positions of the pits, so that the shrink hammer abuts against the first surface, the support body abuts against the second surface, and the shrink hammer and the support body are oppositely arranged; starting the shrink hammer, so that the shrink hammer generates an action force perpendicular to the first surface and a shrink force parallel to the first surface, the shrink force is configured to be transmitted from the periphery of the pit to the center of the pit, and the support body generates a counteraction force perpendicular to the second surface. The process can effectively repair the pits of the metal skin and avoid damage to the metal skin.

Description

Technical Field

[0001] This invention relates to the field of aircraft maintenance technology, and in particular to a process for eliminating pits in metal skin. Background Technology

[0002] Aircraft metal skin can develop dents for various reasons. If the dents are within acceptable damage limits, they can be filled or reshaped. Currently, there are two reshaping methods. One is a pneumatic or manual hammering process using tools such as wooden sticks to reshape the dented area by generating a force perpendicular to the metal skin surface. This method has the disadvantage of easily causing damage to the metal skin. The other method uses an electromagnetic dent removal process, which uses electromagnetic force generated by the equipment to pull the dented area of ​​the metal skin back to its original position. This method has the disadvantage of easily causing the repaired metal skin surface to be uneven. Summary of the Invention

[0003] The purpose of this invention is to provide a process for eliminating pits in metal skin, which can effectively repair pits in metal skin while avoiding damage to the metal skin.

[0004] To achieve the above objectives, the present invention provides a process for eliminating pits in metal skin, wherein the metal skin has a first surface and a second surface disposed opposite to each other, including:

[0005] Determine the position of the pit on the first surface and the second surface;

[0006] The shrinking hammer and the support body are arranged according to the position of the recess, so that the shrinking hammer abuts against the first surface and the support body abuts against the second surface, and the shrinking hammer and the support body are kept opposite to each other.

[0007] The shrinking hammer is activated, causing it to generate an action force perpendicular to the first surface and a shrinking force parallel to the first surface. The shrinking force is configured to be transmitted from the outer periphery of the pit to the center of the pit. The support generates a reaction force perpendicular to the second surface. The pit is eliminated by the action force, the shrinking force, and the reaction force.

[0008] In some embodiments, the shrink hammer is arranged according to the position of the recess, including connecting the housing of the shrink hammer to a pneumatic riveting gun and abutting the core claw of the shrink hammer against the first surface.

[0009] In some embodiments, the core claw of the shrinking hammer abuts against the first surface, and the core claw of the shrinking hammer abuts against the first surface via a buffer pad.

[0010] In some embodiments, the shrinking hammer has eight claws arranged around the outer periphery of the recess.

[0011] In some embodiments, activating the shrink hammer includes activating the pneumatic riveting gun to generate an intermittent impact force on the housing of the shrink hammer, causing the core claw of the shrink hammer to generate the force and the shrinking force on the first surface.

[0012] In some embodiments, when the pit is eliminated by the action force, the contraction force and the reaction force, the duration of the intermittent impact force generated by the pneumatic riveting gun on the housing of the contraction hammer for the same location of the pit does not exceed 5 seconds.

[0013] In some embodiments, when the pit is eliminated by the action force, the contraction force and the reaction force, the position of the core claw on the first surface is moved according to the location of the pit at different locations, and the distance moved each time does not exceed one-third of the diameter of the core claw.

[0014] In some embodiments, the support body is a top iron, and the support body is arranged according to the position of the recess, including a pillar for holding the support body and a support platform of the support body abutting against the second surface.

[0015] In some embodiments, the support platform of the support body abuts against the second surface, and the support platform abuts against the second surface through an energy-absorbing layer.

[0016] In some embodiments, the support body is a shrinking hammer, and the support body is arranged according to the position of the recess, including a housing that holds the support body and a core claw of the support body abutting against the second surface.

[0017] This invention provides a process for eliminating pits in metal skins, which has the following advantages compared with the prior art:

[0018] Activating the shrinking hammer generates an action force perpendicular to the first surface and a shrinking force parallel to the first surface. The shrinking force is configured to be transmitted from the outer periphery of the pit to the center of the pit. The support generates a reaction force perpendicular to the second surface. The pit is eliminated by the action force, the shrinking force, and the reaction force, which can effectively repair pits in the metal skin. Compared with the prior art, the shrinking force is increased, which can prevent damage to the metal skin. Attached Figure Description

[0019] Figure 1 A schematic diagram of the process flow for eliminating pits in metal skin provided in an embodiment of the present invention.

[0020] Figure 2 A schematic diagram of a structure using a top iron as a support and a shrinking hammer.

[0021] Figure 3 A schematic diagram of a structure using a top iron with an energy-absorbing layer and a shrinking hammer.

[0022] Figure 4 A schematic diagram of a structure using a shrinking hammer as a support and combined with the shrinking hammer.

[0023] In the diagram, 100 is the contraction hammer; 1 is the housing; 11 is the connecting column; 12 is the mounting groove; 13 is the tapered hole; 14 is the first through hole; 2 is the core claw; 21 is the mounting part; 22 is the contraction part; 23 is the second through hole; 24 is the elastic sleeve; 25 is the shaft pin; 26 is the abutment part; 27 is the elastic washer; 28 is the buffer pad; 3 is the pneumatic riveting gun; 4 is the support body; 41 is the pillar; 42 is the support platform; 43 is the energy-absorbing layer; and 5 is the metal skin. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] It should be understood that in the description of this application, the terms "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. That is, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, unless otherwise stated, "a plurality of" means two or more.

[0026] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0027] The metal skin pit removal process in this embodiment is achieved through the cooperation of a shrink hammer 100 and a support body 4. The shrink hammer 100 includes a housing 1 and a claw 2.

[0028] like Figure 2-4As shown, a connecting post 11 extends from one end of the housing 1, and the connecting post 11 is configured to be drivenly connected to the pneumatic riveting gun 3. A mounting groove 12 and a tapered hole 13 are sequentially formed inside the housing 1 along a direction away from the connecting post 11. The housing 1 also has a first through hole 14 that radially connects to the mounting groove 12. To improve the repair effect of the mandrel 2 on the metal skin 5, the pneumatic riveting gun 3 is configured to generate intermittent impact force, which is transmitted axially along the housing 1.

[0029] The core claw 2 includes a mounting part 21 and a plurality of spaced-apart contraction parts 22. The mounting part 21 is correspondingly disposed in the mounting groove 12. A second through hole 23 is provided on the mounting part 21 along the radial direction of the housing 1. A shaft pin 25 is installed in the second through hole 23. An elastic sleeve 24 is provided between the shaft pin 25 and the mounting part 21. The two ends of the shaft pin 25 extend out of the second through hole 23 and are installed in the first through hole 14 of the housing 1. The outer walls of the plurality of contraction parts 22 form a cone shape and are correspondingly disposed in the cone-shaped hole 13. One end of the contraction part 22 is connected to the mounting part 21. The other end of the contraction part 22 extends outward along the radial direction of the housing 1 to form an abutment part 26. An elastic washer 27 is provided between the plurality of abutment parts 26 and the housing 1.

[0030] In this embodiment, when the connecting post 11 of the housing 1 is subjected to an impact force along the axial direction of the housing 1, the contraction part 22 and the abutment part 26 contract inward along the radial direction of the housing 1, and the abutment part 26 can eliminate the pits in the metal skin 5.

[0031] During operation, the pneumatic riveting gun 3 generates intermittent impact force, which is transmitted to the housing 1 through the connecting post 11. At this time, both the elastic sleeve 24 and the elastic washer 27 are compressed, causing the housing 1 to squeeze the outer wall of the contraction part 22. This causes the abutment part 26 to contract radially inward along the housing 1, bringing it against the pitted area of ​​the metal skin 5. This causes the pit to contract, ultimately achieving repair. The intermittent impact force generated by the pneumatic riveting gun 3 causes the contraction part 22 to switch back and forth between contraction and rebound states, allowing the abutment part 26 to cyclically repair the pit.

[0032] like Figure 2 As shown, in one embodiment, the support body 4 is a top iron, which includes a support column 41 and a support platform 42 connected to the support column 41. The support platform 42 abuts against and supports the metal skin 5. In use, the support body 4 is moved to the working position by holding the support column 41.

[0033] like Figure 3 As shown, the top iron further includes an energy-absorbing layer 43, which is disposed on the surface of the support platform 42 and abuts against the metal skin 5. The energy-absorbing layer 43 is a lead layer or a lead-tin alloy layer. The lead layer or lead-tin alloy layer has good ductility and can buffer and absorb energy, thereby further reducing the damage to the metal skin 5 during the repair process.

[0034] like Figure 4 As shown, in one embodiment, the support 4 is composed of a housing 1 and a core claw 2, and the connecting post 11 is removed from one end of the housing 1. Using this method, both sides of the metal skin 5 can be subjected to a radially inward contraction force generated by the abutment portion 26 along the housing 1, thereby improving the repair efficiency.

[0035] In one embodiment, the core claw 2 further includes a buffer pad 28, which is mounted on the bottom surface of the abutment portion 26 near the metal skin 5. The buffer pad 28 is made of rubber or plastic and is elastic, which can further reduce damage to the metal skin 5 during the repair process.

[0036] like Figure 1 As shown, the metal skin pit elimination process provided in this embodiment of the invention includes the following steps: The metal skin has a first surface and a second surface disposed opposite to each other.

[0037] S1. Determine the location of the pit on the first and second surfaces;

[0038] S2. Arrange the shrinking hammer and the support body according to the position of the pit, so that the shrinking hammer abuts against the first surface and the support body abuts against the second surface, and keep the shrinking hammer and the support body relatively opposite to each other.

[0039] S3. Activate the shrinking hammer to generate an action force perpendicular to the first surface and a shrinking force parallel to the first surface. The shrinking force is configured to be transmitted from the outer periphery of the pit to the center of the pit. The support generates a reaction force perpendicular to the second surface. The pit is eliminated through the action force, shrinking force and reaction force.

[0040] Based on the above steps, the grooves in the metal skin are repaired by the combined action of force, contraction force and reaction force. Compared with the existing technology, the contraction force is increased, which can prevent damage to the metal skin.

[0041] In one embodiment, a shrink hammer is positioned according to the location of the dent, including connecting the housing of the shrink hammer to a pneumatic riveting gun drive, and abutting the mandrel of the shrink hammer against a first surface. Repair work can then be performed by gripping and activating the riveting gun.

[0042] Furthermore, the core claw of the shrink hammer abuts against the first surface, and the core claw of the shrink hammer also abuts against the first surface via a buffer pad. The buffer pad is made of rubber or plastic, which can reduce scratches on the metal skin during the repair process.

[0043] Specifically, the shrink hammer has eight claws arranged around the outer perimeter of the recess. The claws can evenly apply shrinkage force to the metal skin.

[0044] In one embodiment, activating the shrink hammer includes activating a pneumatic riveting gun to generate intermittent impact forces on the housing of the shrink hammer, causing the mandrel of the shrink hammer to exert forces and shrinkage forces on the first surface. The intermittent impact forces ensure that the forces and shrinkage forces are also intermittent, further reducing damage to the metal skin by decreasing the amplitude of each repair action.

[0045] For example, when eliminating dents using action, contraction, and reaction forces, the pneumatic riveting gun applies intermittent impact force to the housing of the contraction hammer at the same dent location for no more than 5 seconds. This is to avoid damage to the metal skin caused by prolonged impact.

[0046] For example, when eliminating pits using action, contraction, and reaction forces, the position of the mandrel on the first surface is moved according to the location of the pit, with each movement not exceeding one-third of the mandrel's diameter. This ensures uniform repair of the metal skin surface.

[0047] In one embodiment, the support body is a top iron, and the support body is arranged according to the position of the recess, including a pillar for holding the support body and a support platform of the support body abutting against the second surface. This facilitates the movement of the support body.

[0048] In one embodiment, the support platform of the support abuts against the second surface, and the support platform is further abutted against the second surface by an energy-absorbing layer. The lead layer or lead-tin alloy layer has good ductility and can buffer and absorb energy, thereby further reducing damage to the metal skin during the repair process.

[0049] In one embodiment, the support is a contraction hammer, arranged according to the location of the pit, including a housing that holds the support and a mandrel that abuts against the second surface. The energy-absorbing layer is a lead layer or a lead-tin alloy layer. This allows both the first and second surfaces of the metal skin to be subjected to the contraction force generated by the mandrel, thereby improving the repair efficiency.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A process for eliminating pits in a metal skin, wherein the metal skin has a first surface and a second surface disposed opposite to each other, characterized in that, include: Determine the position of the pit on the first surface and the second surface; The shrinking hammer and the support body are arranged according to the position of the recess, so that the shrinking hammer abuts against the first surface and the support body abuts against the second surface, and the shrinking hammer and the support body are kept opposite to each other. The shrinking hammer is activated, causing it to generate an action force perpendicular to the first surface and a shrinking force parallel to the first surface. The shrinking force is configured to be transmitted from the outer periphery of the pit to the center of the pit. The support generates a reaction force perpendicular to the second surface. The pit is eliminated by the action force, the shrinking force, and the reaction force. The shrinking hammer includes a housing and a mandrel. One end of the housing extends to form a connecting post, which is configured to be connected to a pneumatic riveting gun. Inside the housing, a mounting groove and a tapered hole are sequentially formed along the direction away from the connecting post. The housing also has a first through hole that connects to the mounting groove in the radial direction of the housing. The mandrel includes a mounting part and a plurality of spaced shrinking parts. The mounting part is correspondingly disposed in the mounting groove. A second through hole is provided on the mounting part in the radial direction of the housing. A shaft pin is installed in the second through hole. An elastic sleeve is provided between the shaft pin and the mounting part. Both ends of the shaft pin extend out of the second through hole and are installed in the first through hole of the housing. The outer walls of the plurality of shrinking parts form a cone and are correspondingly disposed in the tapered hole. One end of the shrinking part is connected to the mounting part, and the other end of the shrinking part extends outward from the housing in the radial direction of the housing to form an abutment part.

2. The process for eliminating pits in metal skin according to claim 1, characterized in that, The shrinking hammer is arranged according to the position of the recess, including connecting the housing of the shrinking hammer to the pneumatic riveting gun and abutting the core claw of the shrinking hammer against the first surface.

3. The process for eliminating pits in metal skin according to claim 2, characterized in that, The core claw of the shrinking hammer abuts against the first surface, and the core claw of the shrinking hammer abuts against the first surface through a buffer pad.

4. The process for eliminating pits in metal skin according to claim 2, characterized in that, Activating the shrink hammer includes activating the pneumatic riveting gun to generate intermittent impact force on the housing of the shrink hammer, causing the core claw of the shrink hammer to generate the force and the shrinking force on the first surface.

5. The process for eliminating pits in metal skin according to claim 4, characterized in that, When the pit is eliminated by the action force, the contraction force and the reaction force, the duration of the intermittent impact force generated by the pneumatic riveting gun on the housing of the contraction hammer at the same location of the pit does not exceed 5 seconds.

6. The process for eliminating pits in metal skin according to claim 4, characterized in that, When the pit is eliminated by the action force, the contraction force and the reaction force, the position of the core claw on the first surface is moved according to the location of the pit at different locations, and the distance moved each time does not exceed one-third of the diameter of the core claw.

7. The process for eliminating pits in metal skin according to claim 1, characterized in that, The support body is made of top iron and is arranged according to the position of the recess. It includes a pillar for holding the support body and a support platform of the support body abutting against the second surface.

8. The process for eliminating pits in metal skin according to claim 7, characterized in that, The support platform of the support body abuts against the second surface, and the support platform abuts against the second surface through an energy-absorbing layer.

9. The process for eliminating pits in metal skin according to claim 1, characterized in that, The support body is a shrinking hammer, and the support body is arranged according to the position of the recess. It includes a shell that holds the support body and a core claw of the support body that abuts against the second surface.

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