A heating system and method for repairing honeycomb sandwich composite materials

Abstract

This invention relates to the field of composite material repair, specifically disclosing a heating system and method for repairing honeycomb sandwich composite materials. The system includes a heating device, a temperature measuring device, and a control device, both electrically connected to the control device. The heating device comprises a shell and an internally installed heating wire, the outer wall of which is covered with a polyimide insulating film. The control device includes a control console, and the temperature measuring device includes a thermocouple. The control console controls the operating state of the heating wire and receives temperature values ​​measured by the thermocouple. By evenly distributing multiple small-diameter rod-shaped heating devices into the honeycomb holes of the repair area, the traditional heating method is changed, improving heating efficiency and temperature uniformity. This allows for uniform, efficient, and rapid curing of the repair foam or adhesive, thereby improving the quality of composite material structure repair.

Description

Technical Field

[0001] This invention relates to a heating system, specifically a heating system and method for repairing honeycomb sandwich composite materials, belonging to the field of composite material repair. Background Technology

[0002] Honeycomb sandwich composite structures, with their thermal insulation and lightweight properties, are widely used in aerospace, shipbuilding, and other fields. When honeycomb sandwich composite structures are damaged, replacing the damaged honeycomb cores with new ones using adhesives such as foam is the primary repair method. However, the curing degree and uniformity of these adhesives significantly affect the repair quality. The curing process of these adhesives requires heating, and currently, the main method is to lay an electric heating blanket over the repair area, transferring heat to the structure through the honeycomb structure. However, the thin honeycomb walls result in low heat transfer and rapid heat dissipation, leading to a high degree of curing near the heating blanket and a low degree of curing further away. Furthermore, the uneven curing becomes increasingly severe with increasing honeycomb thickness. Currently, there are few patents in China related to heating for composite structure repair, and there are no reports specifically on heating for repairing honeycomb sandwich composite structures. Chinese patent application number 202310509303.5 discloses a method for repairing carbon fiber composite materials using microwave heating. However, this method can only be used to heat the surface of the composite material and is not applicable to honeycomb structures, failing to address the problem of uneven curing of the foam. Therefore, there is an urgent need to propose a new method for heating and curing the foam in the repair of honeycomb sandwich composite material structures to solve problems such as low heating efficiency and uneven curing, thereby improving the repair quality of honeycomb sandwich composite materials. Summary of the Invention

[0003] To address the problems in the prior art, the present invention provides a heating system and method for repairing honeycomb sandwich composite materials.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A heating system for repairing honeycomb sandwich composite materials includes a heating device, a temperature measuring device, and a control device, wherein the heating device and the temperature measuring device are both electrically connected to the control device;

[0006] The heating device includes a housing and an electric heating wire installed inside it, the outer wall of which is covered with a polyimide insulating film.

[0007] The control device includes a console, and the temperature measuring device includes a temperature measuring thermocouple. The console is used to control the working state of the heating wire and to receive the temperature value measured by the temperature measuring thermocouple.

[0008] Optionally, the heating wire has a spiral structure, and the gap between the heating wire and the inner wall of the outer shell is filled with thermally conductive rigid silicone, and a wire is connected to the top of the heating wire.

[0009] Optionally, the outer shell is detachably fitted with a flexible thermally conductive silicone sleeve, which is used to protect the honeycomb core during the insertion of the heating device into the honeycomb core.

[0010] Optionally, a heating tube end cap is installed at the top of the housing. The heating tube end cap is used to encapsulate the heating wire and thermally conductive rigid silicone, and to fix the wire. One end of the wire extends through the top of the heating tube end cap to the outside.

[0011] Optionally, the control device further includes a power socket and a plug for connecting to an external power source, with the heating wire connected to the power socket via a wire.

[0012] Optionally, the power socket is provided with multiple sockets for connecting multiple heating devices simultaneously.

[0013] A heating method for repairing honeycomb sandwich composite materials, the heating method utilizing the aforementioned heating system, and the heating method further comprising the following steps:

[0014] Step 1: Grind the damaged area of ​​the damaged honeycomb sandwich composite material structure to form a repair area, remove the damaged honeycomb core, and form a repair cavity in the repair area;

[0015] Step 2: Based on the size of the repair cavity in the repair area, select a new honeycomb core of the corresponding size and a preset number of heating devices and temperature measuring devices, and connect the heating devices and temperature measuring devices to the control console;

[0016] Step 3: After wrapping the outer wall of the new honeycomb core with expanding foam, insert it into the repair cavity of the repair area;

[0017] Step 4: Evenly place a predetermined number of thermocouples in the gaps between the foam and the original honeycomb core and between the foam and the new honeycomb core to monitor the temperature of the foam and the honeycomb core structure.

[0018] Step 5: Evenly insert multiple heating devices into the honeycomb holes of the original honeycomb core and the new honeycomb core on both sides of the expanding foam.

[0019] Step 6: Connect each heating device to a power outlet;

[0020] Step 7: Lay out release cloth, release film and insulation cotton in sequence over the repair area to protect it;

[0021] Step 8: Connect the control panel to an external power source via a plug, and control the heating device through the control panel to set the heating rate, holding time and cooling rate of the expanding foam curing agent;

[0022] Step 9: Start the heating program on the control panel to control the operation of the heating device and heat and cure the expanding foam;

[0023] Step 10: After the expanding foam has cured, turn off the heating program and remove the insulation cotton, release film and release cloth in sequence;

[0024] Step 11: Remove the heating device and the temperature measuring thermocouple;

[0025] Step 12: Repair any excess expanding foam in the repair area and complete the heating and curing of the expanding foam for the honeycomb sandwich structure repair.

[0026] The beneficial effects of this invention are:

[0027] This invention employs a distributed small rod-shaped heating device and control system to achieve heating and curing repair of foamed adhesive for honeycomb sandwich structures with different pore sizes and thicknesses. The method is simple and effective.

[0028] By using a rod-shaped heating device, the temperature gradient of the expanding foam is reduced, thereby improving the curing uniformity of the expanding foam and the quality of adhesive bonding repairs.

[0029] By using a distributed rod-shaped heating device and control system, the heat transfer path is shortened, the curing efficiency of the foam is improved, and the repair time of the honeycomb sandwich composite material is reduced.

[0030] The device system is small in size, easy to carry and transport, and simple and convenient to operate. It can be used for interior structure repair and battlefield damage repair.

[0031] By using heating devices of different lengths appropriately, a heating method can be provided for the repair of variable thickness honeycomb sandwich composite material structures.

[0032] The main method involves evenly distributing multiple small-diameter rod-shaped heating devices into the honeycomb holes of the repair area, thereby changing the traditional heating method, improving heating efficiency and temperature uniformity, and enabling the foam or adhesive used for repair to cure evenly, efficiently, and quickly, thus improving the repair quality of composite material structures. Attached Figure Description

[0033] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0035] Figure 2This is a schematic diagram showing the distribution of heating devices during the repair of the honeycomb sandwich composite material of the present invention.

[0036] Figure 3 This is a schematic diagram of the heating system of the present invention.

[0037] In the diagram: 1. Heating device; 2. Temperature measuring device; 3. Control device; 4. Steel outer shell; 5. Heating wire; 6. Polyimide insulating film; 7. Thermally conductive rigid silicone; 8. Flexible thermally conductive silicone sleeve; 9. Heating tube end cap; 10. Wire; 11. Temperature measuring thermocouple; 12. Control console; 13. Power socket; 14. Socket; 15. Plug; 16. Damaged honeycomb sandwich composite material structure; 17. Repair area; 18. Original honeycomb core; 19. New honeycomb core; 20. Foam; 21. Release cloth; 22. Isolation film; 23. Insulation cotton. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Please see Figure 1-3 As shown, a heating system for repairing honeycomb sandwich composite materials includes a heating device 1, a temperature measuring device 2, and a control device 3. The heating device 1 and the temperature measuring device 2 are both electrically connected to the control device 3.

[0040] The heating device 1 includes a housing 4 and an electric heating wire 5 installed inside it. The outer wall of the electric heating wire 5 is covered with a polyimide insulating film 6. The polyimide insulating film 6 tightly wraps the electric heating wire 5 to prevent the electric heating wire 5 from being short-circuited due to current breakdown during use. The housing 4 is a steel housing, which is tubular and serves as the main structure of the heating device 1, ensuring that the heating device 1 has a certain strength.

[0041] The control device 3 includes a control console 12, and the temperature measuring device 2 includes a temperature measuring thermocouple 11. The control console 12 is used to control the working state of the heating wire 5 and to receive the temperature value measured by the temperature measuring thermocouple 11. During use, the control console 12 can set the heating curve of the heating device 1 through an internally preset heating program, and based on the temperature value measured by the temperature measuring device 2, it can control the heating device 1 in real time through a proportional-integral-differential algorithm, thereby regulating the heating temperature.

[0042] Preferably, the heating wire 5 has a spiral structure and serves as the heat source for the entire heating device 1. The gap between the heating wire 5 and the inner wall of the outer casing 4 is filled with thermally conductive rigid silicone 7, which is used to fix the heating wire 5 and conduct heat outward. The top of the heating wire 5 is connected to a wire 10.

[0043] Preferably, a flexible thermally conductive silicone sleeve 8 is detachably fitted onto the exterior of the outer casing 4. The flexible thermally conductive silicone sleeve 8 is used to protect the honeycomb core during the insertion of the heating device 1 into the honeycomb core. The detachable design allows the flexible thermally conductive silicone sleeve 8 to be maintained and replaced at any time after severe wear during use. The flexible thermally conductive silicone sleeve 8 is fitted onto the exterior of the outer casing 4, providing comprehensive coverage while being easy to remove and install.

[0044] Preferably, a heating tube end cap 9 is installed at the top of the outer casing 4. The heating tube end cap 9 is used to encapsulate the heating wire 5 and the thermally conductive rigid silicone 7, and to fix the wire 10. One end of the wire 10 extends through the top of the heating tube end cap 9 to the outside.

[0045] Preferably, the control device 3 also includes a power socket 13 and a plug 15 for connecting to an external power source, and the heating wire 5 is connected to the power socket 13 via a wire 10.

[0046] Preferably, the power socket 13 is provided with multiple sockets 14 for connecting multiple heating devices 1 at the same time, which can provide heat sources for multiple areas at the same time and improve heating efficiency.

[0047] A heating method for repairing honeycomb sandwich composite materials, the heating method utilizing the aforementioned heating system, and the heating method further comprising the following steps:

[0048] Step 1: Grind the damaged area of ​​the damaged honeycomb sandwich composite material structure 16 to form a repair area 17, and remove the damaged honeycomb core to form a repair cavity in the repair area 17.

[0049] Step 2: Based on the size of the repair cavity in the repair area 17, select a new honeycomb core 19 of the corresponding size and a preset number of heating devices 1 and temperature measuring devices 2. Connect the heating devices 1 and temperature measuring devices 2 to the control console 12. The length of the heating device 1 is available in various lengths, which can be selected according to actual needs during use.

[0050] Step 3: After wrapping the outer wall of the new honeycomb core 19 with expanding foam 20, insert it into the repair cavity of the repair area 17;

[0051] Step 4: Evenly place a preset number of temperature measuring thermocouples 11 in the gaps between the foam 20 and the original honeycomb core 18 and between the foam 20 and the new honeycomb core 19 to monitor the temperature of the foam 20 and the honeycomb core structure.

[0052] Step 5: Evenly insert multiple heating devices 1 into the honeycomb holes of the original honeycomb core 18 and the new honeycomb core 19 on both sides of the expanding foam 20;

[0053] Step 6: Connect the multiple heating devices 1 to the power socket 13 respectively, and connect the power socket 13 to the control panel 12;

[0054] Step 7: Lay out the release cloth 21, the isolation film 22 and the insulation cotton 23 in sequence on the repair area 17 to protect the repair area 17 and reduce the heat dissipation of the repair area 17.

[0055] Step 8: Connect the control console 12 to an external power source via plug 15, and control the heating device 1 via the control console 12 to set the heating rate, holding time and cooling rate of the curing foam 20.

[0056] Step 9: Start the heating program of the control console 12 to control the operation of the heating device 1 and heat and cure the expanding foam 20;

[0057] Step 10: After the expanding foam 20 has cured, turn off the heating program and remove the insulation cotton 23, the release film 22 and the release cloth 21 in sequence;

[0058] Step 11: Remove the heating device 1 and the temperature measuring thermocouple 11;

[0059] Step 12: Repair the overflowing expanding foam 20 in the repair area 17 and complete the heating and curing of the expanding foam 20 for the honeycomb sandwich structure repair.

[0060] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A heating method for repairing honeycomb sandwich composite materials, characterized in that, The heating method includes the following steps: Step 1: Grind the damaged area of ​​the damaged honeycomb sandwich composite material structure (16) to form a repair area (17), and remove the damaged honeycomb core to form a repair cavity in the repair area (17); Step 2: Based on the size of the repair cavity in the repair area (17), select a new honeycomb core (19) of the corresponding size and a preset number of heating devices (1) and temperature measuring devices (2), and connect the heating devices (1) and temperature measuring devices (2) to the control console (12); Step 3: After wrapping the outer wall of the new honeycomb core (19) with expanding foam (20), insert it into the repair cavity of the repair area (17); Step 4: Place a predetermined number of thermocouples (11) evenly in the gaps between the foam (20) and the original honeycomb core (18) and between the foam (20) and the new honeycomb core (19) to monitor the temperature of the foam (20) and the honeycomb core structure. Step 5: Insert multiple heating devices (1) evenly into the honeycomb holes of the original honeycomb core (18) and the new honeycomb core (19) on both sides of the foam (20); Step 6: Connect the multiple heating devices (1) to the power socket (13) respectively; Step 7: Lay out the release cloth (21), the release film (22) and the insulation cotton (23) in sequence on the repair area (17) to protect the repair area (17). Step 8: Connect the control console (12) to an external power source via plug (15), and control the heating device (1) via the control console (12) to set the heating rate, heat preservation time and cooling rate of the curing of the foam adhesive (20); Step 9: Start the heating program of the control console (12) and control the operation of the heating device (1) to heat and cure the foam (20); Step 10: After the foam (20) has cured, turn off the heating program and remove the insulation cotton (23), release film (22) and release cloth (21) in sequence. Step 11: Remove the heating device (1) and the temperature measuring thermocouple (11); Step 12: Repair the overflowing foam (20) in the repair area (17) and complete the heating and curing of the foam (20) for the honeycomb sandwich structure repair.

2. The heating method for repairing honeycomb sandwich composite materials according to claim 1, characterized in that, The heating device (1) and the temperature measuring device (2) are both electrically connected to the control device (3); The heating device (1) includes a housing (4) and an electric heating wire (5) installed inside it. The outer wall of the electric heating wire (5) is covered with a polyimide insulating film (6). The control device (3) includes a control console (12), and the temperature measuring device (2) includes a temperature measuring thermocouple (11). The control console (12) is used to control the working state of the heating wire (5) and to receive the temperature value measured by the temperature measuring thermocouple (11).

3. The heating method for repairing honeycomb sandwich composite materials according to claim 2, characterized in that, The heating wire (5) has a spiral structure, and the gap between the heating wire (5) and the inner wall of the outer shell (4) is filled with thermally conductive hard silicone (7). The top of the heating wire (5) is connected to a wire (10).

4. The heating method for repairing honeycomb sandwich composite materials according to claim 3, characterized in that, The outer shell (4) is detachably fitted with a flexible thermally conductive silicone sleeve (8), which is used to protect the honeycomb core during the insertion of the heating device (1) into the honeycomb core.

5. The heating method for repairing honeycomb sandwich composite materials according to claim 4, characterized in that, The top of the outer shell (4) is equipped with a heating tube end cap (9), which is used to encapsulate the heating wire (5) and the thermally conductive hard silicone (7) and fix the wire (10). One end of the wire (10) extends through the top of the heating tube end cap (9) to the outside.

6. The heating method for repairing honeycomb sandwich composite materials according to claim 5, characterized in that, The control device (3) also includes a power socket (13) and a plug (15) for connecting to an external power source, with the heating wire (5) connected to the power socket (13) via a wire (10).

7. The heating method for repairing honeycomb sandwich composite materials according to claim 6, characterized in that, The power socket (13) is provided with multiple sockets (14) for connecting multiple heating devices (1) at the same time.

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