Electromagnetic driving hole method and device for aircraft blind area structure

Abstract

The present application belongs to the field of aircraft assembly and maintenance, and relates to a method and device for electromagnetic driving of a hole in a blind area structure of an aircraft. The method uses an alternating bias voltage to act on an electromagnet to generate an alternating magnetic field, so that an impact assembly containing a permanent magnet vibrates at a high frequency. The vibration energy is small and controllable, and leaves an impact mark on the outer part. The method is suitable for composite materials, aluminum alloys and the like, and realizes accurate and rapid hole guiding of a connecting hole in an inner part of a closed structure assembly. The guide sleeve and the vibration impact assembly are installed quickly and attract each other, are suitable for hole guiding in different postures, and the permanent magnet on the vibration impact assembly can be attracted to the guide piece without additional fixation to prevent falling off. The vibration impact assembly is suitable for mass arrangement and efficient hole guiding.

Description

Technical Field

[0001] This invention belongs to the field of aircraft assembly and maintenance, and relates to a method and device for electromagnetic drive pilot hole of aircraft blind zone structure. Background Technology

[0002] In aircraft assembly, composite material skin structures are increasingly used, resulting in very compact internal structures. When drilling holes in the external skin and frames, stringers, and ribs, many internal frames, stringers, and ribs are either invisible or inaccessible. The width of these structures is limited, requiring extremely high precision in hole placement and edge distance. Therefore, ensuring the accuracy of connecting holes on the frames, stringers, and ribs is quite challenging. During maintenance and parts replacement, it is also necessary to transfer holes from the structure to the new parts. Traditional punching methods are unsuitable for drilling holes in composite materials, and for areas with significant curvature, punching errors are substantial.

[0003] To address the aforementioned problems, a method based on electromagnetic effects is invented, which utilizes an electromagnet to apply a voltage of a special waveform to drive a hole-guiding device to vibrate periodically, thereby guiding the center of the guide hole on the inner layer blind zone component to the outer layer component. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method and apparatus for electromagnetic drive apertures in aircraft blind zone structures.

[0005] The technical solution of the present invention is as follows:

[0006] An electromagnetically driven drilling method for aircraft blind zone structures utilizes a biased alternating voltage to generate an alternating electromagnetic field in an electromagnet. A specially designed drilling mechanism containing a permanent magnet is installed inside the guide hole of the inner layer component. The electromagnet is placed on the outer side of the outer layer component, and the electromagnet periodically attracts and repels the permanent magnet on the inner side of the inner layer component, causing the drilling tool to create punch marks or traces on the outer layer component. The specific steps are as follows:

[0007] Step 1: Power Waveform Selection

[0008] Choose a power supply with AC / DC series connection capability and adjustable voltage and frequency; alternatively, choose a programmable power supply with customizable voltage waveform settings, where the final operating voltage waveform is a biased sine wave or square wave, such as... Figure 1 As shown, V is voltage, t is time, and Δ is DC bias voltage. The function of this bias DC voltage is that within one AC cycle, the alternating magnetic field generated by the current in the electromagnet is asymmetrical, and the maximum attractive force on the permanent magnet is greater than the maximum repulsive force. It can be simply understood that the magnetic field generated by the DC voltage has an attractive force on the permanent magnet, while the AC current generates periodic attractive and repulsive forces. The peak voltage of the AC current is higher than that of the DC voltage.

[0009] Step 2: Select an electromagnet

[0010] An alternating current electromagnet is selected, with a silicon steel core to reduce eddy current heating. The function of the electromagnet is to generate an electromagnetic field that continuously exchanges magnetic poles, causing the permanent magnet used for the pilot hole to vibrate.

[0011] Step 3: Design the pilot hole device

[0012] The hole-reaming mechanism consists of two parts: a guide and a vibration assembly. The guide is a bushing structure made of carbon steel, which can be attracted by a magnet. The outer circle of the guide is inserted into the guide hole of the inner layer part. The guide includes a shoulder, which is sandwiched between the inner and outer layer parts, thus being stably fixed. The vibration assembly is inserted into the hole of the guide and can vibrate within the guide under the action of the alternating magnetic field of the electromagnet. The vibration assembly includes a permanent magnet and a punch, which are fixedly connected. The punch is inserted into the hole of the guide and has a sharp point. During vibration, it can create a punch mark on the outer layer part, which is the center of the hole position of the inner layer part. Before the electromagnet works, the permanent magnet on the vibration assembly attracts the guide to prevent the hole-reaming device from slipping out of the hole of the guide.

[0013] Step 4: Guiding Hole

[0014] Before installing the outer layer parts, guide holes are first made on the inner layer parts. The diameter of the guide hole is smaller than the final hole diameter, and its diameter is consistent with the outer diameter of the guide component.

[0015] Step 5: Installation of guide components

[0016] A guide is installed inside the guide hole of the inner part. The outer diameter of the guide is the same as the diameter of the guide hole of the inner part, and the inner diameter is the same as the diameter of the punch of the hole-guiding device.

[0017] Step 6: Install outer components

[0018] Install the vibration assembly inside the inner layer part and in the hole of the guide component. After installation, install the outer layer part on the outside of the inner layer part.

[0019] Step 7: Determine the installation location of the electromagnet

[0020] Using a lightweight and compact powerful permanent magnet, move it on the outer layer part. Because there is a permanent magnet on the vibrating device at the guide hole position of the inner layer part, the lightweight and compact permanent magnet will be attracted to the surface of the outer layer part. This position is the position of the permanent magnet on the vibrating device, which is the approximate position of the guide hole of the inner layer part. Mark this position with a marker. The powerful permanent magnet is chosen to be ring-shaped, and the marker can be easily marked through its inner circle.

[0021] Step 8: Electromagnet in operation

[0022] Connect the electromagnet to the power source selected in step 1, wherein the magnetic field generated by the DC power source is in the same direction as the magnetic field of the permanent magnet on the vibrating mechanism, that is, within one AC cycle, the attractive force is greater than the repulsive force, and place the electromagnet at the marked position in step 7.

[0023] Step 9: Power Supply Adjustment

[0024] Adjust the AC voltage, frequency, and DC voltage of the power supply, ensuring that the DC voltage does not exceed 2 / 3 of the peak value of the AC voltage. Finally, adjust the power supply until the vibration mechanism produces stable vibration, with an intensity sufficient to create a punch mark on the outer part of the working rod. Record the adjusted AC voltage, frequency, and DC voltage for use in subsequent drilling.

[0025] Step 10: Locating the location of punch marks or traces

[0026] When removing the outer part and the resulting scratch is difficult to find, place a permanent magnet at the marked position on the outside of the outer part in step 7, and move the lightweight and compact permanent magnet on the inside of the outer part using the magnet from step 7. The magnet will attract the scratch or mark at a rough location, which will be used to confirm the scratch.

[0027] Step 11: Drilling holes

[0028] Based on the punch marks created on the outer layer part in steps 9 and 10, drill holes on the outer layer part, making the holes concentric with the holes on the inner layer part. Reinstall the outer layer part, aligning the holes drilled on the outer layer part with the guide holes on the inner layer part, and simultaneously enlarge the holes to the final size.

[0029] Based on the above method, a blind zone structure electromagnetic drive aperture device is invented. The device includes an electromagnet assembly, a guide, a vibration and impact assembly, a power supply, and a ring-shaped small magnet.

[0030] The electromagnet assembly is used to provide an alternating electromagnetic field and includes an electromagnet, handle, switch, cable, and plug. The electromagnet and handle are fixed together with bolts, and the plug is used to supply power to the electromagnet after being plugged into a power source.

[0031] This vibration and impact assembly is used to vibrate under an alternating electromagnetic field, leaving marks on the product. The assembly includes a punch, permanent magnet A5-2, permanent magnet B, and a spring. The annular permanent magnets A and B are nested on both sides of the punch head, attracting each other and holding the punch and magnet together as a single unit. The spring is fitted onto the working rod of the punch and remains attached under the magnetic attraction of permanent magnet B, thus assisting the device in generating stable vibration. The working rod of the punch is fitted inside the inner hole of a guide member, clamping the spring between the guide member and the punch head. The guide member is used to insert into the guide hole of the inner layer part of the product to be processed; the inner hole of the guide member is coaxial with the guide hole of the inner layer part.

[0032] The beneficial effects of this invention are:

[0033] The method of this invention is designed to use an alternating bias voltage to act on an electromagnet to generate an alternating magnetic field, causing the impact component containing a permanent magnet to vibrate at a high frequency. The vibration energy is small and controllable, leaving punch marks on the outer part. It is applicable to composite materials, aluminum alloys, etc., and realizes precise and rapid drilling of connection holes for inner part of closed structure assembly.

[0034] The invented guide sleeve and vibration impact assembly are quick to install, attract each other, and are suitable for drilling in different postures. The permanent magnet on the vibration impact assembly can attract the guide component, and does not need to be fixed to prevent it from falling off. It is suitable for mass deployment and efficient drilling. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a biased sine wave, where Δ is the biased DC voltage;

[0036] Figure 2 This is a schematic diagram of a biased square sinusoidal wave, where Δ is the biased DC voltage;

[0037] Figure 3 Isometric view of electromagnetic drive pilot hole device;

[0038] Figure 4 Isometric drawing of an electromagnet assembly;

[0039] Figure 5 Cross-sectional view of the guide component and vibration and shock assembly in operation.

[0040] In the diagram: 1-Inner layer parts; 2-Outer layer parts; 3-Electromagnet assembly; 4-Guide component; 5-Vibration and impact assembly; 6-Power supply; 7-Small ring magnet. 3-1 Electromagnet; 3-2 Handle; 3-3 Switch; 3-4 Cable; 3-5 Plug; 5-1 Punch; 5-2 Permanent magnet A; 5-3 Permanent magnet B; 5-4 Spring. Detailed Implementation

[0041] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0042] Step 1: Inner layer component guide hole

[0043] Before installing the outer layer part 2, several guide holes are first made on the inner layer part 1. The diameter of the guide hole is smaller than the final design diameter, and the drilled guide hole is consistent with the outer diameter of the guide part 4.

[0044] Step 2: Install guide components and vibration / shock assembly

[0045] Several guide members 4 are inserted into the guide holes made in step 1 from the front of the inner layer part 1, and then several vibration impact components 5 are inserted into the inner holes of the guide members 4 from the back of the inner layer part 1.

[0046] Step 3: Install outer components

[0047] The outer layer part 2 is installed on the outside of the inner layer part 1 and fixed in its theoretical position.

[0048] Step 4: Determine the preliminary location of the hole

[0049] Swing the small magnet 7 around the outside of the outer layer part 2 until it attracts the approximate location of the vibration impact assembly 5 containing the permanent magnet. Mark the outer layer part 2 with a marker through the central hole of the small magnet 7. Repeat this step to mark the locations of all guide holes.

[0050] Step 5: Connect the electromagnet assembly and the power supply.

[0051] Insert the plug 3-5 of the electromagnet assembly 3 into the power supply 6 and turn on the power supply 6 power switch.

[0052] Step 6: Place the electromagnet to vibrate.

[0053] Place electromagnet 3 at the position marked in step 4, turn on switch 3-3, the electromagnet starts working and generates an alternating electromagnetic field. The vibration impact component 5 vibrates under the action of the alternating electromagnetic field of the electromagnet, and the punch 5-1 produces a punch mark on the outer part 2. Adjust the AC voltage, frequency and DC voltage value of the power supply 6 to change the impact force of the punch 5-1, and finally ensure that a recognizable punch mark is produced on the part 2. Record the voltage and frequency values, which can be used directly in the future.

[0054] Step 7: Remove the outer components and vibration / shock assembly.

[0055] Remove the outer part 2, remove the vibration and impact assembly 5 from the guide 4, and then remove the guide 4 from the inner part 1.

[0056] Step 8: Locate the punch mark and guide the hole.

[0057] When the punch marks generated in step 6 on the inner side of the outer part 2 are not obvious, place the vibration impact component 5 at the marked position in step 4 on the outer side of the outer part 2. The permanent magnet 5-2 is attached to the outer part 2. A small magnet 7 is shaken on the inner side of the outer part 2. The position attracted by the permanent magnet 5-2 is the approximate location of the punch mark, which makes it easy to find the punch mark position. Drill a guide hole on the outer part 2 according to the punch mark position. Its diameter is the same as the diameter of the guide hole of the inner part.

[0058] Step 9: Drill the final hole

[0059] Repeat step 3 to reinstall the outer layer part 2 onto the outside of the inner layer part 1 and fix it in place. Expand the guide holes made in steps 1 and 8 together to the final hole diameter.

Claims

1. A method for electromagnetic drive apertures in aircraft blind zone structures, characterized in that, The steps are as follows: Step 1: Power Waveform Selection The working voltage waveform is a biased sine wave or square wave. The effect of this biased DC voltage is that within one AC cycle, the alternating magnetic field generated by the current in the electromagnet is asymmetrical, and the maximum attractive force on the permanent magnet is greater than the maximum repulsive force. Step 2: Select an electromagnet Step 3: Design the pilot hole device The hole-guiding mechanism consists of two parts: a guide (4) and a vibration assembly. The guide (4) is a bushing structure. The outer circle of the guide (4) is inserted into the guide hole of the inner layer part (1). The guide (4) includes a shoulder, which is sandwiched between the inner and outer layer parts (2) and thus is stably fixed. The vibration assembly is inserted into the hole of the guide (4) and can vibrate in the guide (4) under the action of the alternating magnetic field of the electromagnet. Step 4: Guiding Hole Before the outer layer part (2) is installed, a guide hole is first made on the inner layer part (1). The diameter of the guide hole is smaller than the final hole diameter, and its hole diameter is consistent with the outer diameter of the guide part (4). Step 5: Installation of guide component (4) A guide (4) is installed in the guide hole of the inner layer part (1). The outer diameter of the guide (4) is consistent with the diameter of the guide hole of the inner part, and the inner diameter is consistent with the diameter of the punch of the hole-guiding device. Step 6: Installation of outer component (2) A vibration assembly is installed inside the inner layer part (1) and inside the hole of the guide (4). After installation, the outer layer part (2) is installed outside the inner layer part (1). Step 7: Determine the installation location of the electromagnet Use a permanent magnet to move on the outer part (2). Because there is a permanent magnet on the vibrating device at the guide hole position of the inner part (1), the permanent magnet will be attracted to the surface of the outer part (2). This position is the position of the permanent magnet on the vibrating device, that is, the approximate position of the guide hole of the inner part (1). Mark this position with a marker. Step 8: Electromagnet in operation Connect the electromagnet to the power source selected in step 1, wherein the magnetic field generated by the DC power source is in the same direction as the magnetic field of the permanent magnet on the vibration mechanism, that is, within one AC cycle, the attractive force is greater than the repulsive force, and place the electromagnet at the marked position in step 7. Step 9: Power Supply Adjustment Adjust the AC voltage, frequency, and DC voltage of the power supply, where the DC voltage is no more than 2 / 3 of the peak value of the AC voltage, until the vibration mechanism produces stable vibration, the intensity of which is sufficient to create a punch mark on the outer part (2) of the working rod. Record the adjusted AC voltage, frequency, and DC voltage, and use this voltage and frequency directly when drilling holes later. Step 10: Find the location of the punch mark or trace. When the outer part (2) is removed and the resulting scratch is not easy to find, place a permanent magnet at the marked position on the outside of the outer part (2) in step 7, and move the lightweight and compact permanent magnet in step 7 on the inside of the outer part (2). The adsorption position is the approximate position of the scratch or mark, which is used to confirm the scratch. Step 11: Drilling Holes According to the punch marks produced on the outer layer part (2) in steps 9 and 10, make holes on the outer layer part (2) and make the holes concentric with the holes on the inner layer part (1). Reinstall the outer layer part (2), align the holes made on the outer layer part (2) with the guide holes on the inner layer part (1), and enlarge the holes to the final size.

2. The electromagnetic drive aperture method for aircraft blind zone structures as described in claim 1, characterized in that, The vibration assembly in step 3 includes a permanent magnet and a punch. The permanent magnet and the punch are fixed together. The punch is inserted into the hole of the guide (4) and has a sharp point. When vibrating, it can generate a punch mark on the outer part (2). The punch mark is the center of the hole position of the inner part (1). Before the electromagnet works, the permanent magnet on the vibration assembly attracts the guide (4) to prevent the hole-leading device from slipping out of the hole of the guide (4).

3. The electromagnetic drive aperture method for aircraft blind zone structures as described in claim 1 or 2, characterized in that, The powerful permanent magnet in step 7 is selected to be a ring shape, through which it is easy to mark with a marker pen.

4. The electromagnetic drive aperture method for aircraft blind zone structures as described in claim 1 or 2, characterized in that, In step 2, the core of the AC electromagnet is a silicon steel sheet.

5. The electromagnetic drive aperture method for aircraft blind zone structures as described in claim 3, characterized in that, In step 2, the core of the AC electromagnet is a silicon steel sheet.

6. The electromagnetic drive aperture method for aircraft blind zone structure as described in claim 1, 2, or 5, characterized in that, The guide (4) is made of carbon steel and can be attracted by a magnet.

7. The electromagnetic drive aperture method for aircraft blind zone structures as described in claim 3, characterized in that, The guide (4) is made of carbon steel and can be attracted by a magnet.

8. The electromagnetic drive aperture method for aircraft blind zone structure as described in claim 4, characterized in that, The guide (4) is made of carbon steel and can be attracted by a magnet.

9. A device for electromagnetic drive apertures in aircraft blind zone structures, characterized in that, It includes an electromagnet assembly (3), a guide (4), a vibration and impact assembly (5), a power supply (6), and a ring-shaped small magnet (7); The electromagnet assembly (3) is used to provide an alternating electromagnetic field and includes an electromagnet (3-1), a handle (3-2), a switch (3-3), a cable (3-4), and a plug (3-5). The electromagnet (3-1) and the handle (3-2) are fixed together with bolts. The plug (3-5) is plugged into the power supply (6) to supply power to the electromagnet (3-1). A vibration and impact assembly (5) is used to vibrate under the action of an alternating electromagnetic field, leaving a stamp mark on the product. The vibration and impact assembly (5) includes a punch (5-1), a permanent magnet A (5-2), a permanent magnet B (5-3), and a spring (5-4). Among them, the annular permanent magnet A (5-2) and permanent magnet B (5-3) are nested on both sides of the head of the punch (5-1). The permanent magnets A (5-2) and B (5-3) attract each other, and the permanent magnets A (5-2), B (5-3), and punch (5-4) are held together. 5-1) Adsorption into a whole; the spring (5-4) is sleeved on the working rod of the punch (5-1) and will not detach under the magnetic attraction of the permanent magnet B (5-3), thus assisting the device to generate stable vibration; the working rod of the punch (5-1) is sleeved in the inner hole of the guide (4), and the spring is clamped in the middle between the guide (4) and the head of the punch (5-1); the guide (4) is used to insert into the guide hole of the inner layer part (1) of the product to be processed, and the inner hole of the guide (4) is coaxial with the guide hole of the inner layer part (1).

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