Aircraft assembly hole drilling tilt-mill apparatus and method
By using an inclined milling device to coordinate the control of eccentricity and tilt angle, the problem of rapid tool wear in aircraft assembly hole making was solved, achieving efficient and stable multi-specification hole diameter processing, and improving hole making quality and efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
- Filing Date
- 2025-12-30
- Publication Date
- 2026-06-05
AI Technical Summary
In the process of drilling holes for aircraft assembly, traditional manual drilling is labor-intensive and has poor quality stability. Existing robotic drilling is inefficient and the tools wear out quickly. In particular, in spiral milling, the cutting edge of the tool is not fully utilized, resulting in severe local wear and short life.
By employing an inclined milling device, the tilt angle and eccentricity of the milling tool are adjusted through coordinated control of the eccentricity and tilt angle. This achieves a uniform change in the contact arc area between the milling tool and the machined hole, extending tool life and improving machining quality.
It improves the overall service life of milling tools and the stability of hole machining quality, reduces machining costs, expands the scope of application, enables the machining of various hole diameters, reduces tool change time, and improves hole making efficiency.
Smart Images
Figure CN122142384A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hole-making technology, and in particular to an inclined milling device and method for making holes in aircraft assembly. Background Technology
[0002] In the field of aerospace vehicle manufacturing, aircraft assembly holes are characterized by a large number and variety of specifications. Traditional manual hole making is labor-intensive and has poor quality stability, while existing robotic hole making is inefficient due to the bulky terminal mechanism and the need for frequent tool changes.
[0003] To improve hole-making quality and efficiency, hole-making processes have evolved from traditional drilling to spiral milling and inclined spiral milling. The latter, by changing the tool's movement and inclination angle, can effectively reduce cutting forces and heat, significantly improve hole-making quality, and overcome the efficiency bottleneck of frequent tool changes required for different hole diameters. However, in spiral milling, simply changing the inclination angle keeps the contact arc between the tool's cutting edge and the workpiece constant. If this is done for a long time for a fixed hole diameter, it can easily lead to severe local wear, incomplete utilization of the cutting edge, and short tool life. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide an inclined milling device and method for drilling holes in aircraft assembly, so as to solve the problem of rapid tool wear during the drilling process in aircraft assembly.
[0005] To achieve the above objectives, the present invention provides an inclined milling device for aircraft assembly holes, comprising a mounting platform and a PLC controller. A milling revolution device is mounted on the mounting platform, and an eccentric adjustment device is connected to the output end of the milling revolution device. The milling revolution device controls the rotation of the eccentric adjustment device. An eccentric adjustment device is connected to an angle adjustment device, which adjusts the eccentric distance between the angle adjustment device and the output axis of the milling revolution device. A milling rotation device is connected below the angle adjustment device, and a milling cutter for milling holes is mounted on the milling rotation device. An angle sensor and an eccentric distance sensor connected to the PLC controller are mounted on the milling rotation device, and the angle adjustment device adjusts the angle of the milling cutter.
[0006] Optionally, the mounting platform consists of a steel square flange with four mounting holes at its four corners. The entire milling device is rigidly connected to the CNC machine tool spindle terminal connection flange or the industrial robot terminal connection flange through the mounting holes.
[0007] Optionally, the milling hole revolution device includes a direct drive motor connected to the mounting platform. The drive motor includes a motor stator fixedly mounted on the lower surface of the mounting platform. A motor rotor is provided inside the motor stator. The motor rotor is the revolution motion output end of the entire milling hole device and is fixedly connected to a disc on the eccentricity adjustment device below.
[0008] Optionally, the eccentricity adjustment device includes a disk connected to the output end of the milling hole revolution device, a linear guide rail is provided on the disk, a slider connected to the tilt adjustment device is slidably connected in the linear guide rail, an electric actuator is installed on the disk, the telescopic end of the electric actuator is connected to the slider, and the telescopic extension of the electric actuator is used to adjust the distance between the slider and the axis of the output end of the milling hole revolution device, thereby adjusting the eccentricity.
[0009] Optionally, the tilt angle adjustment device includes a connecting bracket connected to the eccentricity adjustment device, a rotating component is provided on the connecting bracket, the rotating component is connected to a rotatable rotating shaft, the rotating shaft is connected to the milling hole rotation device, and the rotating component is used to control the rotation of the rotating shaft to adjust the tilt angle of the milling tool.
[0010] Optionally, the rotating component includes an electric worm gear mounted on the connecting bracket, the electric worm gear being meshed with a worm wheel, the worm wheel being coaxially connected to the rotating shaft, and a housing connected to the connecting bracket being provided on the outer side of the electric worm gear, the housing having an opening for meshing transmission between the worm wheel and the electric worm gear.
[0011] Optionally, the milling rotation device includes a spindle motor, the output end of which is connected to an electric spindle, and the electric spindle is equipped with a milling cutter.
[0012] A method for inclined milling holes in aircraft assembly, comprising the following steps:
[0013] Step 1: Install the milling device on the spindle end of the CNC machine tool or the terminal of the industrial robot through the mounting platform. Align the center of the milling cutter with the center of the hole to be machined. Calibrate and zero the eccentricity adjustment device and the tilt angle adjustment device so that the axis of the milling cutter is perpendicular to the cross section of the hole to be machined, and the milling cutter is eccentric relative to the revolution.
[0014] Step 2: Based on the machining hole diameter D, the milling cutter diameter d, and the effective overhang L of the milling cutter, determine the maximum milling cutter tilt angle θ for machining the hole without eccentricity. Activate the tilt angle adjustment device according to the tilt angle θ to adjust the milling cutter tilt angle θ to the required position.
[0015] Step 3: Start the milling hole revolution device and the milling hole rotation device. After the rotation speed reaches the required speed, start the PLC controller. The PLC controller receives the milling tool tilt angle θ and eccentricity e in real time based on the tilt angle sensor and the eccentricity sensor.
[0016] Step 4: Start machining the hole. The PLC controller sends control commands to the eccentricity adjustment device and the tilt angle adjustment device according to the relationship between the hole diameter D, eccentricity e, tilt angle θ, tool diameter d, and effective tool overhang L: D=2(e+Lsinθ)+d. The PLC controller coordinates the adjustment of the tilt angle θ and eccentricity e.
[0017] The tilt angle θ is at its maximum when the hole-making process begins; at this point, the tilt angle θ is... When the eccentricity e is zero, the eccentricity e at this time is As the milling process progresses, the eccentricity e begins to increase, and at this point, the eccentricity e is... The tool tilt angle decreases, and the tilt angle θ is now... Continue until the machining of the entire hole is completed;
[0018] Step 5: After completing the machining, retract the tool and adjust the tilt angle θ and eccentricity e to their initial states.
[0019] The beneficial effects of this invention are as follows: The inclined milling device and method for aircraft assembly holes provided by this invention, through coordinated control of eccentricity and tilt angle, makes the contact arc area between the milling tool and the hole to be machined change uniformly, increases the effective cutting edge length of the milling tool, reduces the possibility of rapid wear of local cutting edges of the milling tool, improves the overall service life of the milling tool and the stability of hole machining quality, reduces machining costs, and can process multiple hole diameters with only one milling tool. By connecting to the CNC machine tool spindle terminal or industrial robot terminal through the mounting platform, the applicability of aircraft assembly hole making is improved. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of the present invention;
[0022] Figure 2 This is a side view of the structure of the present invention;
[0023] Figure 3This is a schematic diagram of a partial explosion structure of the present invention;
[0024] Figure 4 This is a schematic diagram of the direct drive motor of the present invention;
[0025] Figure 5 This is a schematic diagram of the milling process of the present invention.
[0026] In the diagram: 1. Mounting platform; 2. Milling hole revolution device; 3. Eccentricity adjustment device; 4. Inclination adjustment device; 5. Milling hole rotation device; 101. Square flange; 201. Direct drive motor; 2011. Motor stator; 2012. Motor rotor; 301. Disc; 302. Slider; 303. Electric actuator; 401. Connecting bracket; 402. Housing; 403. Electric worm gear; 404. Worm wheel; 405. Rotating shaft; 406. Clamping plate; 501. Electric spindle. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this invention should have the ordinary meaning understood by those skilled in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0029] like Figures 1 to 5As shown, an inclined milling device for aircraft assembly holes includes a mounting platform 1 and a PLC controller. A milling revolution device 2 is mounted on the mounting platform 1. An eccentric adjustment device 3 is connected to the output end of the milling revolution device 2. The milling revolution device 2 controls the rotation of the eccentric adjustment device 3. An eccentric adjustment device 3 is connected to an angle adjustment device 4, which adjusts the eccentric distance between the angle adjustment device 4 and the axis of the output end of the milling revolution device 2. A milling rotation device 5 is connected below the angle adjustment device 4. A milling cutter for milling holes is mounted on the milling rotation device 5. An angle sensor and an eccentric distance sensor connected to the PLC controller are mounted on the milling rotation device 5. The angle adjustment device 4 adjusts the angle of the milling cutter.
[0030] By coordinating the control of eccentricity and tilt angle, the contact arc area between the milling cutter and the hole to be machined is uniformly varied, which increases the effective cutting edge length of the milling cutter, reduces the possibility of rapid wear of local cutting edges of the milling cutter, improves the overall service life of the milling cutter and the stability of hole machining quality, reduces machining costs, and can machine multiple hole diameters with only one milling cutter. By connecting to the CNC machine tool spindle terminal or industrial robot terminal through the mounting platform 1, the applicability of aircraft assembly hole machining is expanded.
[0031] The mounting platform 1 can be composed of a steel square flange 101. The square flange 101 has four mounting holes distributed at its four corners. The entire milling device can be rigidly connected to the CNC machine tool spindle terminal connection flange or the industrial robot terminal connection flange through the mounting holes.
[0032] The milling hole revolution device 2 includes a direct drive motor 201 connected to the mounting platform 1. The drive motor 201 includes a motor stator 2011 fixedly mounted on the lower surface of the mounting platform 1. The motor stator 201 contains a motor rotor 2012, which is the output end of the revolution motion of the entire milling hole device. It is fixedly connected to the disc 301 on the eccentricity adjustment device 3 below. When the direct drive motor 201 is powered on, it controls the motor rotor 2012 and the eccentricity adjustment device 3 to revolve.
[0033] The eccentricity adjustment device 3 includes a disc 301 connected to the output end of the milling hole revolution device 2. The disc 301 is fixed to the rotating part of the direct drive motor 201 by screws, i.e., fixed to the motor rotor 201. A linear guide rail is provided on the disc 301. A slider 302 connected to the tilt angle adjustment device 4 is slidably connected in the linear guide rail. An electric push rod 303 is installed on the disc 301. The telescopic end of the electric push rod 303 is rigidly connected to the slider 302. The telescopic extension of the electric push rod 303 is used to adjust the distance between the slider 302 and the axis of the output end of the milling hole revolution device 2, thereby adjusting the eccentricity. The eccentricity adjustment device 3 is connected to the tilt angle adjustment device 4 through the slider 302. The telescopic extension of the electric push rod 303 converts the direct motion into the linear motion of the slider 302, thereby driving the entire tilt angle adjustment device 4 and the devices below it to move radially as a whole, realizing precise adjustment of the eccentricity.
[0034] By raising the disc 301 with the built-in linear guide rail, and using the electric actuator 303 to push the slider to reciprocate within the linear guide rail, the eccentricity e can be adjusted. This not only provides high positioning accuracy and controllable speed, but also reduces the weight and structural complexity of the entire device.
[0035] The tilt angle adjustment device 4 includes a connecting bracket 401 connected to the eccentricity adjustment device 3. The connecting bracket 401 is fixedly connected to the slider 302 on the eccentricity adjustment device 3. A rotating component is provided on the connecting bracket 401. The rotating component is connected to a rotatable rotating shaft 405. The milling hole rotation device 5 is connected to the rotating shaft 405. The rotating component is used to control the rotation of the rotating shaft 405 and thereby adjust the tilt angle θ of the milling tool.
[0036] The rotating component includes an electric worm gear 403 mounted on the connecting bracket 401. The electric worm gear 403 is meshed with a worm wheel 404, which is coaxially connected to the rotating shaft 405. A housing 402 connected to the connecting bracket 401 is provided on the outer side of the electric worm gear 403. An opening is provided on the housing 402 for the meshing transmission between the worm wheel 404 and the electric worm gear 403. A rotating motor is provided on the electric worm gear 403 for rotation. The worm wheel 404 uses a portion of its teeth to form a transmission pair with the electric worm gear 402 to meet the requirements of small tilt angle adjustment and reduce structural space. The rotating motor controls the electric worm gear 403, driving a portion of the worm wheel 404 and the rotating shaft 405 to rotate, thereby adjusting the tilt angle of the milling tool. Since the electric worm gear 403 and the worm wheel 404 together have the characteristics of large transmission ratio and reverse self-locking, the tilt angle θ can be precisely controlled.
[0037] The electric worm gear 403 adjusts the tilt angle θ of the milling cutter, enabling precise adjustment of the tilt angle θ and ensuring that the milling cutter angle remains unchanged after adjustment. Simultaneously, when milling holes with the cutter tilted, the cutting force is lower than when drilling or helical milling, and heat dissipation and chip removal are easier, thus improving hole quality.
[0038] The connecting bracket 401 is provided with a clamping plate 406 connected to the rotating shaft 405. The clamping plate 406 is connected to the milling hole rotation device 5. The rotating component is used to control the rotation of the rotating shaft 405 and the clamping plate 406, thereby adjusting the tilt angle of the milling tool.
[0039] The milling rotation device 5 includes a spindle motor, the output end of which is connected to an electric spindle 501. The electric spindle is equipped with a milling cutter, which can be a large radius end mill. When the spindle motor is started, the electric spindle 501 drives the milling cutter to rotate and perform milling on the hole to be machined.
[0040] A method for inclined milling holes in aircraft assembly, comprising the following steps:
[0041] Step 1: Install the milling device on the spindle end of the CNC machine tool or the terminal of the industrial robot via the mounting platform 1. Align the center of the milling cutter with the center of the hole to be machined. Calibrate and zero the eccentricity adjustment device 3 and the tilt adjustment device 4 so that the axis of the milling cutter is perpendicular to the cross section of the hole to be machined, and so that the milling cutter is eccentric relative to the revolution.
[0042] Step 2: Based on the machining hole diameter D, the milling cutter diameter d, and the effective overhang L of the milling cutter, determine the maximum milling cutter tilt angle θ for machining the hole without eccentricity. Activate the tilt angle adjustment device 4 according to the tilt angle θ to adjust the milling cutter tilt angle θ to the required position.
[0043] Step 3: Start the milling hole revolution device 2 and the milling hole rotation device 5. After the rotation speed reaches the required speed, start the PLC controller. The PLC controller receives the milling tool tilt angle θ and eccentricity e in real time according to the tilt angle sensor and the eccentricity sensor.
[0044] Step 4: Start the CNC machine tool or industrial robot to provide the milling device with axial feed motion for the machined hole and start machining the hole. The PLC controller sends control commands to the eccentricity adjustment device 3 and the tilt angle adjustment device 4 according to the relationship between the diameter D of the hole to be machined, the eccentricity e, the tilt angle θ, the tool diameter d, and the effective overhang length L of the tool, D=2(e+Lsinθ)+d, so as to coordinate the adjustment of the tilt angle θ and the eccentricity e.
[0045] Specific processing methods include Figure 5As shown, the tilt angle θ is at its maximum when hole drilling begins, and the tilt angle θ at this time is... When the eccentricity e is zero, the eccentricity e at this time is As the milling process progresses, the eccentricity e begins to increase, and at this point, the eccentricity e is... The tilt angle θ decreases, and the tilt angle θ at this time is Continue until the machining of the entire hole is completed;
[0046] Step 5: After machining is completed, stop the milling hole revolution device 2 and the milling hole rotation device 5, and use a CNC machine tool or industrial robot to retract the tool, and adjust the tilt angle θ and eccentricity e to the initial state.
[0047] In addition, this milling device can meet the needs of machining multiple hole diameters with a single tool by adjusting only the eccentricity e, only the tilt angle θ, or both the eccentricity e and the tilt angle θ. This significantly reduces the requirements for the specifications of the drilling tool and helps to reduce tool change time and improve drilling efficiency.
[0048] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples. The invention is not limited to the above-described embodiments, that is, it does not mean that the invention must rely on the above methods and structures to be implemented. Under the concept of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.
[0049] The embodiments of this invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A tilting milling device for drilling holes in aircraft assembly, characterized in that, The device includes an installation platform and a PLC controller. A milling revolving device is mounted on the installation platform. An eccentric adjustment device is connected to the output end of the milling revolving device, which controls the rotation of the eccentric adjustment device. An eccentric adjustment device is connected to a tilt adjustment device, which adjusts the eccentric distance between the tilt adjustment device and the output axis of the milling revolving device. A milling self-rotating device is connected below the tilt adjustment device. A milling cutter for milling is mounted on the milling self-rotating device. A tilt angle sensor and an eccentric distance sensor, both connected to the PLC controller, are mounted on the milling self-rotating device. The tilt adjustment device adjusts the tilt angle of the milling cutter.
2. The inclined milling device and method for aircraft assembly holes according to claim 1, characterized in that, The mounting platform consists of a steel square flange with four mounting holes at its four corners. The entire milling device is rigidly connected to the CNC machine tool spindle terminal connection flange or the industrial robot terminal connection flange through the mounting holes.
3. The inclined milling device and method for aircraft assembly holes according to claim 1, characterized in that, The milling hole revolution device includes a direct drive motor connected to the mounting platform. The drive motor includes a motor stator fixedly mounted on the lower surface of the mounting platform. A motor rotor is provided inside the motor stator. The motor rotor is the revolution motion output end of the entire milling hole device and is fixedly connected to a disc on the eccentricity adjustment device below.
4. The inclined milling device and method for aircraft assembly holes according to claim 1, characterized in that, The eccentricity adjustment device includes a disk connected to the output end of the milling hole revolution device. A linear guide rail is provided on the disk. A slider connected to the tilt adjustment device is slidably connected inside the linear guide rail. An electric push rod is installed on the disk. The telescopic end of the electric push rod is connected to the slider. The telescopic extension of the electric push rod is used to adjust the distance between the slider and the axis of the output end of the milling hole revolution device, thereby adjusting the eccentricity.
5. The inclined milling device and method for aircraft assembly holes according to claim 4, characterized in that, The tilt angle adjustment device includes a connecting bracket connected to the eccentricity adjustment device. A rotating component is provided on the connecting bracket. The rotating component is connected to a rotatable rotating shaft. The milling hole rotation device is connected to the rotating shaft. The rotating component is used to control the rotation of the rotating shaft and thereby adjust the tilt angle of the milling tool.
6. The inclined milling device and method for aircraft assembly holes according to claim 5, characterized in that, The rotating component includes an electric worm gear mounted on the connecting bracket. The electric worm gear is meshed with a worm wheel, which is coaxially connected to the rotating shaft. A housing connected to the connecting bracket is provided on the outside of the electric worm gear, and an opening is provided on the housing for meshing and transmission between the worm wheel and the electric worm gear.
7. The inclined milling device and method for aircraft assembly holes according to claim 1, characterized in that, The milling rotation device includes a spindle motor, the output end of which is connected to an electric spindle, and the electric spindle is equipped with milling cutters.
8. A method for an inclined milling device for aircraft assembly holes according to any one of claims 1-7, characterized in that: The specific steps include: Step 1: Install the milling device on the spindle end of the CNC machine tool or the terminal of the industrial robot through the mounting platform. Align the center of the milling cutter with the center of the hole to be machined. Calibrate and zero the eccentricity adjustment device and the tilt angle adjustment device so that the axis of the milling cutter is perpendicular to the cross section of the hole to be machined, and the milling cutter is eccentric relative to the revolution. Step 2: Based on the machining hole diameter D, the milling cutter diameter d, and the effective overhang L of the milling cutter, determine the maximum milling cutter tilt angle θ for machining the hole without eccentricity. Activate the tilt angle adjustment device according to the tilt angle θ to adjust the milling cutter tilt angle θ to the required position. Step 3: Start the milling hole revolution device and the milling hole rotation device. After the rotation speed reaches the required speed, start the PLC controller. The PLC controller receives the milling tool tilt angle θ and eccentricity e in real time based on the tilt angle sensor and the eccentricity sensor. Step 4: Start machining the hole. The PLC controller sends control commands to the eccentricity adjustment device and the tilt angle adjustment device according to the relationship between the hole diameter D, eccentricity e, tilt angle θ, tool diameter d, and effective tool overhang L: D=2(e+Lsinθ)+d. The PLC controller coordinates the adjustment of the tilt angle θ and eccentricity e. The tilt angle θ is at its maximum when the hole-making process begins; at this point, the tilt angle θ is... When the eccentricity e is zero, the eccentricity e at this time is As the milling process progresses, the eccentricity e begins to increase, and at this point, the eccentricity e is... The tool tilt angle decreases, and the tilt angle θ is now... Continue until the machining of the entire hole is completed; Step 5: After completing the machining, retract the tool and adjust the tilt angle θ and eccentricity e to their initial states.