Aircraft skin drilling tool and using method thereof

Abstract

The invention discloses an aircraft skin drilling tool and a use method thereof, and discloses a high-precision bidirectional rotary aircraft skin drilling tool. According to the tool, the rotation control assemblies at the two ends of the base drive the mold positioning platform to achieve 0-180-degree two-way precise rotation, and the angle locking error is smaller than or equal to 0.5 degree. The mold positioning platform is provided with a profiling rib plate supporting plate and an adjustable rib plate fastening device, and skin curved surface self-adaptive positioning is achieved in cooperation with a transversely-arranged appearance clamping plate assembly. A hard alloy titanium-plated drill bushing is arranged on the clamping plate assembly and is axially perpendicular to the surface of the skin, hole positions accurately correspond to drawing coordinates, and automatic drilling is completed in cooperation with a mechanical arm controlled by an industrial control box and a drilling driving assembly. By means of multi-dimensional positioning of rotary adjustment, profiling supporting and the sliding clamping plate, the problems of position precision and efficiency of machining of rivet holes of the skin with the complex curvature are solved, and the machining device is particularly suitable for meeting the high-standard machining requirement of aviation composite skin.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft skin processing, and in particular to an aircraft skin drilling processing tool and a use method thereof. Background Art

[0002] The tail skin of a small fixed-wing aircraft is a key component of the aircraft's aerodynamic structure and needs to be accurately riveted to the ribs by making holes. At present, the industry mainly uses manual hole making: workers draw lines on the skin surface according to the drawings and then drill holes manually. However, this process has the following problems: 1. Low positioning accuracy: Traditional tooling lacks skin correction function and cannot adapt to complex surfaces with double curvature. Hole position control relies on workers’ experience. According to statistics, the average error of manual hole position is ±1.5mm, which leads to misalignment of holes when the skin and ribs are installed, and the rework rate is as high as 30%; 2. Efficiency and cost bottleneck: It takes 4-6 hours to make holes in a single piece of skin, and the training cycle for skilled technicians is long. The labor cost accounts for more than 40% of the total manufacturing cost. Therefore, there is an urgent need for a low-cost, high-precision, and adaptive complex surface skin hole-making tool to solve the efficiency, accuracy, and versatility problems of traditional processes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an aircraft skin drilling tool and a use method thereof.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: The present invention discloses an aircraft skin drilling tool, comprising a base, characterized in that: two ends of the base are respectively fixedly connected with a rotation control assembly, the rotation control assembly drives a mold positioning platform through a rotation axis to realize bidirectional rotation, and the rotation angle range is 0° to 180°; a plurality of rib support plates are fixed on the mold positioning platform and are distributed at equal intervals along its longitudinal center line, and the shape of the rib support plates matches the inner cavity of the rib; each of the rib support plates is provided with a rib fastening device on one side, and a rib reinforcement plate is connected to the rib reinforcement plate on the other side by a pin, and the thickness of the rib reinforcement plate is rib The rib reinforcement plate is fixed to the mold positioning platform by pins; the outer side of each rib support plate is provided with an outer shape card plate assembly arranged laterally along the mold positioning platform, and a plurality of drill sleeves axially perpendicular to the skin surface are fixed on the outer shape card plate assembly, and the arrangement position of the drill sleeves is consistent with the drawing coordinates of the skin rivet holes; an industrial control box and a mechanical arm are provided on one side of the base, and the mechanical arm is connected to the drilling drive assembly through the program control of the industrial control box, and the drilling drive assembly includes a drill bit coaxially aligned with the drill sleeve, a drive motor and a drill bit fixing fixture.

[0005] As a preferred technical solution of the present invention, the rotation control assembly includes: a rotating fixed bracket, the bottom of which is fixed to the base by bolts; a rotating bearing seat is fixed to the top of the rotating fixed bracket, and a rotating shaft is installed inside; one end of the rotating shaft is bolted to the mold positioning platform, and the other end is connected to the turntable through a bearing; an operating rod is fixed to the side of the turntable, and four angle adjustment handles evenly distributed along the circumference are provided on the top, and the angle adjustment handles are locked with the threaded holes on the side of the rotating fixed bracket through threads. After locking, the rotation angle error of the mold positioning platform is ≤0.5°.

[0006] As a preferred technical solution of the present invention, the surface of the rib support plate is provided with anti-slip patterns with a depth of 0.5-1 mm.

[0007] As a preferred technical solution of the present invention, the rib fastening device includes: a rib adjustment bracket, the bottom of which is fixed to the mold positioning platform by bolts, and the top of which is fixedly connected to the rib clamping shaft support by bolts; a rib clamping shaft, the middle part of which is slidably connected to the rib clamping shaft support, one end of which is fixedly connected to the rib fastening handwheel, and the other end is fixedly connected to a top cap; the top cap is connected to a circular pressure plate through a support, the diameter of the circular pressure plate is 2 to 3 times the width of the rib, and its hardness is Shore A70 to 80.

[0008] As a preferred technical solution of the present invention, the top of the rib support plates located at both ends of the mold positioning platform are fixedly connected to the inner skin support blocks by bolts, and the top of the inner skin support blocks is arc-shaped, and its curvature radius matches the designed curvature of the outer surface of the skin.

[0009] As a preferred technical solution of the present invention, the outer shape pallet assembly includes: a pallet guide shaft mounting block, which is slidably connected with a pallet guide shaft, the bottom of the pallet guide shaft is inserted into the pallet guide shaft support of the mold positioning platform, and is locked by a butterfly nut, and the sliding adjustment accuracy is ±0.5mm; an inner pallet, whose inner side contour is contoured to match the outer surface of the skin and is made of polyurethane; an outer pallet, which is symmetrically arranged on the outside of the inner pallet and is locked by bolts; the polyurethane material surface of the inner pallet is provided with an anti-scratch coating.

[0010] As a preferred technical solution of the present invention, the inner wall of the drill sleeve is provided with a spiral chip groove with a helix angle of 30°~45°, the material is cemented carbide, the surface is titanium-plated, and the coating thickness is 5~8μm.

[0011] As a preferred technical solution of the present invention, an aluminum alloy bracket with a crossing angle of 60° to 90° is provided at the bottom of the mold positioning platform, and both ends of the aluminum alloy bracket are fixed to the base by at least four bolts.

[0012] As a preferred technical solution of the present invention, calibration blocks are fixed at the two upper corners of the mold positioning platform, and the calibration blocks are used to calibrate the initial position of the robot arm.

[0013] On the other hand, the present invention also provides a method for drilling holes in aircraft skin, the method comprising: 1. After buckling the rib plate on the rib plate support plate, rotate the rib plate tightening hand wheel to drive the circular pressing plate to press the rib plate; 2. Operate the operating lever to adjust the mold positioning platform to the target angle, and lock the rotating axis through the angle adjustment handle; 2. Attach the skin to the surface of the inner pallet, slide the pallet guide shaft to adjust the position of the outer pallet, and tighten the butterfly nut to fix the skin; 3. Start the robotic arm through the industrial control box and drive the drilling drive assembly to complete the skin drilling along the axis of the drill sleeve.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the bidirectional rotation linkage design of the rotation control component and the mold positioning platform, high-precision angle adjustment within the range of 0°~180° (error ≤0.5°) is achieved. Combined with the multi-dimensional positioning structure of the contoured rib support plate, the slidable outer shape card assembly and the carbide titanium-plated drill sleeve, it ensures that the skin surface is strictly perpendicular to the drill sleeve axis, so that the drilling position accuracy error is controlled within 0.1mm, meeting the high standard tolerance requirements of aviation rivet holes. ; 2. The combined design of the contoured rib support plate and the reinforcement plate, the anti-scratch coating of the polyurethane inner cardboard and the modular skin inner support block take into account the adaptability of the tooling to skins with different curvatures and the clamping protection requirements, while the automatic calibration function of the calibration block and the robotic arm effectively avoids the risk of equipment collision. ; 3. The coordinated control of the industrial control box and the robotic arm realizes fully automated drilling path programming, which improves the processing efficiency by more than 50% compared with traditional manual operation. At the same time, the spiral chip grooves (30°~45° helix angle) on the inner wall of the drill sleeve and the titanium plating treatment greatly improve the chip removal efficiency and wear resistance, extending the service life to 3 times that of traditional drill sleeves. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a front view of the present invention; Figure 3 is a side view of the present invention; Figure 4 is a top view of the present invention; Figure 5 is a partial enlarged view a of the rib fastening device of the present invention; Figure 6 is a partial enlarged view b of the rib fastening device of the present invention; In the figure: 1. Base; 2. Rotation control assembly; 3. Mold positioning platform; 4. Rib support plate; 5. Rib fastening device; 6. Rib reinforcement plate; 7. External card assembly; 8. Drill sleeve; 9. Drill drive assembly; 10. Robot arm; 11. Industrial control box; 12. Skin inner support block; 13. Aluminum alloy bracket; 14. Position calibration block; 21. Rotation fixing bracket; 22. Rotation bearing seat; 23. Rotation axis; 24 , turntable; 25, angle adjustment handle; 26, operating lever; 51, rib adjustment bracket; 52, rib clamping shaft support; 53, rib clamping shaft; 54, rib tightening handwheel; 55, top cap; 56, circular pressure plate; 71, pallet guide shaft mounting block; 72, pallet guide shaft; 73, pallet guide shaft support; 74, inner pallet; 75, outer pallet; 91, drill bit; 92, drive motor; 93, drill bit fixing fixture. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0017] In the drawings, the same reference numerals all refer to the same components.

[0018] like Figure 1-6 As shown, the present invention provides an aircraft skin drilling tool, and the assembly method is as follows: Installation of the overall structure of the tooling: fix the base 1 horizontally on the workbench, and install the rotation control components 2 on both sides of the base 1 through bolts.

[0019] Please refer to the attached Figure 2-3 The rotation control assembly 2 includes: a rotating fixed bracket 21: the bottom is connected to the base 1 through 8 M12 bolts, and a rotating bearing seat 22 is installed on the top; a rotating shaft 23: one end is bolted to the mold positioning platform 3 through a flange, and the other end is assembled with the turntable 24 through a deep groove ball bearing (model 6208); the turntable 24: an operating rod 26 is welded on the side, and 4 angle adjustment handles 25 (M16 thread) are evenly distributed on the top circumference. After the handle 25 is screwed into the threaded hole on the side of the bracket 21, the rotation angle can be locked, and the error is ≤0.5°.

[0020] The bottom of the mold positioning platform 3 is welded with an aluminum alloy bracket 13 (material 6061-T6) with a cross angle of 75°. The two ends of the bracket 13 are fixed to the base 1 by 8 M10 bolts to ensure the rigidity of the platform. Calibration blocks 14 are fixed at the upper two corners of the mold positioning platform 3 for initial position calibration of the robot arm 10.

[0021] Please see attached Figure 5 , Rib positioning and fixing: Arrange the rib support plate 4 at equal intervals (spacing 200mm) along the longitudinal center line of the mold positioning platform 3, and fix it to the platform 3 through pins. The surface of the rib support plate 4 is processed with a diamond anti-slip pattern with a depth of 0.8mm, which matches the inner cavity of the rib. The rib reinforcement plate 6 (thickness is 1.5 times that of the rib support plate 4) is fixed to the other side of the platform 3 by pins to enhance the anti-deformation ability. Rotate the rib tightening hand wheel 54 to drive the clamping shaft 53 to slide, so that the polyurethane circular pressing plate 56 (diameter 120mm, Shore A75 hardness) presses the rib, and the pressing force is calibrated to 500~800N through the pressure sensor.

[0022] Please see attached Figure 4 , Skin clamping and alignment: Attach the skin to the surface of the outer cardboard 74 of the outer cardboard assembly 7. The outer cardboard 74 is made of polyurethane (with a 0.1mm thick anti-scratch coating sprayed on the surface), and the contour matches the curvature of the outer surface of the skin (curvature radius R=1500mm). Slide the cardboard guide shaft 72 (diameter 20mm, adjustment accuracy ±0.5mm) to lock the skin with the outer cardboard 75 through the M8 bolt to ensure that there is no local deformation of the skin. The mold positioning platform 3 is rotated to the target angle (such as 90°) through the operating rod 26, and the angle adjustment handle 25 is tightened to lock the position.

[0023] The drilling method of the skin in the present invention is as follows: 1. The industrial control box 11 imports the coordinates of the skin rivet hole drawing to generate the motion path of the robot arm 10. The robot arm 10 (six-axis, repeatability accuracy ±0.02mm) clamps the drilling drive assembly 9 and moves to the top of the drill sleeve 8; 2. The driving motor 92 (rated power 1.5 kW) is started, the drill bit 91 (made of carbide, 6 mm in diameter) is fed axially along the drill sleeve 8, and the spiral chip groove (helix angle 40°) on the inner wall of the drill sleeve 8 discharges chips in real time; 3. The robot arm 10 moves to the next drill sleeve 8 position in sequence according to the program, and repeats the drilling until all holes are processed. The single hole drilling time is ≤10 seconds, the life of the drill bit 91 is ≥5000 holes, and the drilling position error is ≤±0.2mm.

[0024] 4. After the processing is completed, loosen the butterfly nut 74 and the outer clamping plate 75, and remove the skin. Reversely rotate the rib plate tightening hand wheel 54 to release the pressing force of the circular pressure plate 56 on the rib plate, and remove the rib plate. Reset the mold positioning platform 3 to the initial position of 0° and turn off the power of the industrial control box 11.

[0025] Module switching: When replacing a different type of skin, remove the inner support block 12 of the skin (the arc curvature radius is adapted to the new skin), replace the outer clamping plate 74 and the outer clamping plate 75 assembly, and adjust the initial position of the clamping plate guide shaft 72.

[0026] Through this embodiment, a certain type of small fixed-wing aircraft horizontal tail skin (curvature radius R = 1200~1800mm) is drilled: the mold positioning platform 3 rotates at an angle of 0°~180°, the number of drill sleeves 8 is 80, and the hole diameter is 6.35mm; the time for drilling a single skin is 45 minutes, the hole position error is ±0.15mm, there is no scratch on the skin surface, and the rework rate is reduced to 1.2%. 100 drilling samples were tested by a three-coordinate measuring machine, and the results showed: The standard deviation of hole coordinates is σ=0.08mm; Skin surface roughness Ra≤1.6μm; After the tooling is reused 100 times, the positioning accuracy decay is ≤0.1mm.

[0027] This embodiment realizes high-precision angle adjustment of the mold positioning platform 3 from 0° to 180° through the rotation control component 2, and combines the contoured rib support plate 4 and the slidable outer clamping plate component 7 to ensure that the skin surface is axially perpendicular to the drill sleeve 8; the wear-resistant design of the carbide titanium-plated drill sleeve 8 increases the drilling life to more than 3 times that of the traditional drill sleeve, and the coordinated control of the robot arm 10 and the industrial control box 11 realizes fully automated processing, with an efficiency increase of 50% compared with manual operation, and the hole position accuracy error is ≤0.1mm, which is suitable for the high-standard processing requirements of aviation composite skins.

[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aircraft skin drilling tool, comprising a base (1), characterized in that: The two ends of the base (1) are respectively fixedly connected with a rotation control assembly (2), and the rotation control assembly (2) drives the mold positioning platform (3) to realize bidirectional rotation through a rotation axis (23), and the rotation angle range is 0° to 180°; a plurality of rib support plates (4) are fixed on the mold positioning platform (3) and are distributed at equal intervals along its longitudinal center line, and the shape of the rib support plates (4) matches the inner cavity of the rib; each of the rib support plates (4) is provided with a rib fastening device (5) on one side, and is connected to a rib reinforcement plate (6) on the other side through a pin, and the thickness of the rib reinforcement plate (6) is 1 to 2 times the thickness of the rib support plate (4), and the rib reinforcement plate (6) is fixed by a pin. The rib support plate (4) is fixed on the mold positioning platform (3); the outer side of each rib support plate (4) is provided with an outer shape card assembly (7) arranged transversely along the mold positioning platform (3); a plurality of drill sleeves (8) axially perpendicular to the skin surface are fixed on the outer shape card assembly (7); the arrangement position of the drill sleeves (8) is consistent with the drawing coordinates of the skin rivet holes; an industrial control box (11) and a mechanical arm (10) are provided on one side of the base (1); the mechanical arm (10) is connected to a drilling drive assembly (9) through program control of the industrial control box (11); the drilling drive assembly (9) comprises a drill bit (91) coaxially aligned with the drill sleeve (8), a drive motor (92) and a drill bit fixing fixture (93).

2. The aircraft skin drilling tool according to claim 1, characterized in that: The rotation control assembly (2) comprises: a rotation fixing bracket (21), the bottom of which is fixed to the base (1) by bolts; a rotation bearing seat (22) fixed to the top of the rotation fixing bracket (21), and a rotation shaft (23) is installed inside; one end of the rotation shaft (23) is bolted to the mold positioning platform (3), and the other end is connected to the turntable (24) through a bearing; an operating rod (26) is fixed to the side of the turntable (24), and four angle adjustment handles (25) are evenly distributed along the circumference are provided on the top, and the angle adjustment handles (25) are locked with threaded holes on the side of the rotation fixing bracket (21) through threads, and after locking, the rotation angle error of the mold positioning platform (3) is ≤0.5°.

3. The aircraft skin drilling tool according to claim 1, characterized in that: The surface of the rib support plate (4) is provided with anti-slip patterns with a depth of 0.5 to 1 mm.

4. The aircraft skin drilling tooling tooling according to claim 1 is characterized in that: The rib plate fastening device (5) comprises: a rib plate adjusting bracket (51), the bottom of which is fixed to the mold positioning platform (3) by bolts, and the top of which is fixedly connected to the rib plate pressing shaft support (52) by bolts; a rib plate pressing shaft (53), the middle of which is slidably connected to the rib plate pressing shaft support (52), one end of which is fixedly connected to the rib plate fastening hand wheel (54), and the other end of which is fixedly connected to a top cap (55); the top cap (55) is connected to a circular pressing plate (56) through a support, the diameter of the circular pressing plate (56) is 2 to 3 times the width of the rib plate, and the hardness of the circular pressing plate (56) is Shore A70 to 80.

5. The aircraft skin drilling tool according to claim 1, characterized in that: The tops of the rib support plates (4) located at both ends of the mold positioning platform (3) are fixedly connected to the inner skin support blocks (12) via bolts. The tops of the inner skin support blocks (12) are arc-shaped, and their curvature radius matches the designed curvature of the outer surface of the skin.

6. The aircraft skin drilling tool according to claim 1, characterized in that: The outer shape card assembly (7) comprises: a card guide shaft mounting block (71) which is slidably connected to a card guide shaft (72), the bottom of the card guide shaft (72) being inserted into a card guide shaft support (73) of the mold positioning platform (3) and being locked by a butterfly nut, with a sliding adjustment accuracy of ±0.5 mm; an inner card (74) whose inner side profile matches the outer surface of the skin and is made of polyurethane; an outer card (75) which is symmetrically arranged on the outer side of the inner card (74) and is locked by bolts; the polyurethane material surface of the inner card (74) is provided with an anti-scratch coating.

7. The aircraft skin drilling tool according to claim 1, characterized in that: The inner wall of the drill sleeve (8) is provided with a spiral chip removal groove with a helical angle of 30° to 45°, and is made of hard alloy and has a titanium-plated surface with a coating thickness of 5 to 8 μm.

8. The aircraft skin drilling tool according to claim 1, characterized in that The bottom of the mold positioning platform (3) is provided with an aluminum alloy bracket (13) with a crossing angle of 60° to 90°, and both ends of the aluminum alloy bracket (13) are fixed to the base (1) by at least four bolts.

9. The aircraft skin drilling tool according to claim 1, characterized in that Calibration blocks (14) are fixed at the two upper corners of the mold positioning platform (3), and the calibration blocks (14) are used to calibrate the initial position of the robot arm (10).

10. The aircraft skin drilling method according to claim 1, using the tooling according to any one of claims 1 to 9, characterized in that , including the following steps:

1. After buckling the rib plate onto the rib plate support plate (4), rotate the rib plate tightening hand wheel (54) to drive the circular pressure plate (56) to press the rib plate; 2. Operate the operating lever (26) to adjust the mold positioning platform (3) to the target angle, and lock the rotating shaft (23) through the angle adjustment handle (25); 3. Attach the skin to the surface of the inner clamping plate (74), slide the clamping plate guide shaft (72) to adjust the position of the outer clamping plate (75), and lock the butterfly nut (74) to fix the skin; 4. Start the robot arm (10) through the industrial control box (11) to drive the drilling drive assembly (9) to complete the skin drilling along the axial direction of the drill sleeve (8).

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