Heating system and method for repairing honeycomb sandwich composite material

Abstract

The invention relates to the field of composite material repairing, and particularly discloses a heating system and method for repairing a honeycomb sandwich composite material, the heating system comprises a heating device, a temperature measuring device and a control device, and the heating device and the temperature measuring device are both electrically connected with the control device; the heating device comprises a shell and an electric heating wire mounted in the shell, and the outer wall of the electric heating wire is coated with a polyimide insulating film; the control device comprises a control table, the temperature measuring device comprises a temperature measuring thermocouple, and the control table is used for controlling the working state of the electric heating wire and receiving the temperature value measured by the temperature measuring thermocouple. A plurality of small-diameter rod-shaped heating devices are uniformly distributed and inserted into honeycomb holes of a repair area, so that a traditional heating mode is changed, the heating efficiency and the temperature uniformity are improved, polystyrene foam or adhesive for repair is uniformly, efficiently and quickly cured, and the repair quality of a composite material structure is improved.

Description

Technical Field

[0001] The invention relates to a heating system, in particular to a heating system and method for repairing a honeycomb sandwich composite material, belonging to the field of composite material repair. Background Art

[0002] Honeycomb sandwich composite materials have the characteristics of heat insulation and light weight and are widely used in aerospace, shipbuilding and other fields. After the honeycomb sandwich composite material is damaged, the main repair method of the honeycomb sandwich composite material structure is to replace the damaged honeycomb core with a new honeycomb core by adhesives such as foam glue. Among them, the curing degree and uniformity of adhesives such as foam glue seriously affect the repair quality of the structure. The curing process of adhesives such as foam glue needs to be achieved by heating. The current main heating method is to lay an electric blanket on the repair area and transfer heat to the inside of the structure through the honeycomb structure. However, the honeycomb wall is thin, the heat transfer rate is low, and the heat dissipation is fast, resulting in a high degree of curing of the foam glue in the area close to the electric blanket and a low degree of curing in the area far away from the electric blanket. In addition, as the thickness of the honeycomb increases, the degree of non-uniform curing becomes more serious. At present, there are few domestic patents on the heating of composite structure repairs, and there are no reports on the heating of honeycomb sandwich composite materials. The Chinese patent application number 202310509303.5 discloses a method for repairing carbon fiber composite materials by microwave heating radiation. However, this method can be used to heat the surface of the composite material, but is not applicable to honeycomb structures and cannot solve the problem of non-uniform curing of foam adhesive. Therefore, it is urgent to propose a new method for heating and curing foam adhesive for repairing honeycomb sandwich composite materials to solve the problems of low heating efficiency and uneven curing, and improve the quality of honeycomb sandwich composite material repairs. Summary of the invention

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

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A heating system for repairing honeycomb sandwich composite materials, comprising 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 comprises a housing and an electric heating wire installed inside the housing, wherein the outer wall of the electric heating wire is coated with a polyimide insulating film;

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

[0008] Optionally, the heating wire is in a spiral structure, and the gap between the heating wire and the inner wall of the shell is filled with heat-conductive hard silica gel, and the top of the heating wire is connected to a wire.

[0009] Optionally, the outer detachable sleeve of the shell is provided with a flexible heat-conductive silicone sleeve, and the flexible heat-conductive silicone sleeve is used to protect the honeycomb core during the process of inserting the heating device into the honeycomb core.

[0010] Optionally, a heating tube seal is installed at the top of the shell, and the heating tube seal is used to encapsulate the heating wire and the heat-conductive hard silicone and fix the wire, and one end of the wire passes through the top of the heating tube seal and extends to the outside.

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

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

[0013] A heating method for repairing a honeycomb sandwich composite material, the heating method utilizing the above-mentioned heating system, and the heating method further comprising the following steps:

[0014] Step 1: Grind the damaged part 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: According to the size of the repair cavity in the repair area, select a new honeycomb core of 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: Wrap the outer wall of the new honeycomb core with foam glue and insert it into the repair cavity of the repair area;

[0017] Step 4: evenly placing a preset number of temperature measuring thermocouples in the gaps between the foam glue and the original honeycomb core and between the foam glue and the new honeycomb core to monitor the temperature of the foam glue and the honeycomb core structure;

[0018] Step 5: Evenly insert and install multiple heating devices in the honeycomb holes of the original honeycomb core and the new honeycomb core on both sides of the foam glue;

[0019] Step 6: Connect multiple heating devices to power sockets respectively;

[0020] Step 7: Lay release cloth, isolation film and thermal insulation cotton on the repair area in turn to protect the repair area;

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

[0022] Step 9: Start the heating program of the control console, control the operation of the heating device, and heat and cure the foam glue;

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

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

[0025] Step 12: Repair the overflowed foam glue in the repair area and complete the heating and curing work of the foam glue for repairing the honeycomb sandwich structure.

[0026] Beneficial effects of the present invention:

[0027] The invention adopts a distributed small rod-shaped heating device and a control system to achieve heating and curing repair of honeycomb sandwich structure foam adhesives with different pore diameters and thicknesses, and the method is simple and effective.

[0028] The rod-shaped heating device reduces the temperature gradient of the foam adhesive, thereby improving the uniformity of the foam adhesive curing and the quality of the adhesive repair.

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

[0030] The device system is small in size, easy to carry and transport, and the system is simple and convenient to operate. It can be used for infield structure repairs and battle damage repairs.

[0031] By using heating devices of different lengths in a reasonable manner, a heating method can be provided for repairing honeycomb sandwich composite structures with variable thickness.

[0032] The method mainly involves inserting multiple small-diameter rod-shaped heating devices evenly into the honeycomb holes in the repair area, changing the traditional heating method, improving the heating efficiency and temperature uniformity, achieving uniform, efficient and rapid curing of the foam glue or adhesive used for repair, and improving the repair quality of the composite material structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

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

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

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

[0037] In the figure: 1. Heating device; 2. Temperature measuring device; 3. Control device; 4. Steel casing; 5. Heating wire; 6. Polyimide insulating film; 7. Thermally conductive hard silicone; 8. Flexible thermally conductive silicone sleeve; 9. Heating tube head; 10. Wire; 11. Temperature measuring thermocouple; 12. Control console; 13. Power socket; 14. Jack; 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 DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1-3 As shown, a heating system for repairing honeycomb sandwich composite materials comprises a heating device 1, a temperature measuring device 2, and a control device 3, wherein 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 an outer shell 4 and an electric heating wire 5 installed inside. 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 current from breaking through the electric heating wire 5 and causing a short circuit during use. The outer shell 4 is a steel shell, which is tubular and serves as the main structure of the heating device 1 to ensure 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 electric heating wire 5 and 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 internal preset heating program, based on the temperature value measured by the temperature measuring device 2, and control the heating device 1 in real time through a proportional integral differential algorithm, thereby adjusting the heating temperature.

[0042] Preferably, the heating wire 5 has a spiral structure, and the heating wire 5 serves as the heat source of the entire heating device 1. The gap between the heating wire 5 and the inner wall of the outer shell 4 is filled with thermally conductive hard 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, the outer part of the housing 4 is detachably covered with a flexible heat-conducting silicone sleeve 8, which 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 heat-conducting silicone sleeve 8 to be maintained and replaced at any time after severe wear and tear during use. The flexible heat-conducting silicone sleeve 8 is covered on the outer part of the housing 4, which can not only cover the entire area but also be easily disassembled and installed.

[0044] Preferably, a heating tube sealing head 9 is installed at the top of the shell 4, and the heating tube sealing head 9 is used to encapsulate the electric heating wire 5 and the heat-conductive hard silicone 7, and fix the wire 10, one end of the wire 10 passes through the top of the heating tube sealing head 9 and extends to the outside.

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

[0046] Preferably, the power socket 13 is provided with a plurality of sockets 14 for connecting a plurality of heating devices 1 at the same time, so that heat sources can be provided to a plurality of areas at the same time, thereby improving the heating efficiency.

[0047] A heating method for repairing a honeycomb sandwich composite material, the heating method utilizing the above-mentioned heating system, and the heating method further comprising the following steps:

[0048] Step 1: grinding the damaged part of the damaged honeycomb sandwich composite material structure 16 to form a repair area 17, and removing the damaged honeycomb core to form a repair cavity in the repair area 17;

[0049] Step 2: According to the size of the repair cavity in the repair area 17, select a new honeycomb core 19 of corresponding size and a preset number of heating devices 1 and temperature measuring devices 2, connect the heating device 1 and the temperature measuring device 2 to the console 12, and the length of the heating device 1 has various lengths, which can be selected according to actual needs during use;

[0050] Step 3: Wrap the outer wall of the new honeycomb core 19 with the foam glue 20 and insert it into the repair cavity of the repair area 17;

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

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

[0053] Step 6: Connect the multiple heating devices 1 to the power sockets 13 respectively, and the power sockets 13 are connected to the console 12;

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

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

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

[0057] Step 10: After the foam glue 20 is completely cured, the heating process is turned off, and the insulation cotton 23, the isolation film 22 and the demoulding cloth 21 are removed in sequence;

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

[0059] Step 12: Repair the foam glue 20 overflowing from the repair area 17, and complete the heating and curing work of the foam glue 20 for repairing the honeycomb sandwich structure.

[0060] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A heating system for repairing honeycomb sandwich composite materials, comprising a heating device (1), a temperature measuring device (2), and a control device (3), 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) comprises a housing (4) and an electric heating wire (5) installed inside the housing, wherein the outer wall of the electric heating wire (5) is coated 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 receive the temperature value measured by the temperature measuring thermocouple (11).

2. A heating system for repairing honeycomb sandwich composite materials according to claim 1, characterized in that: The heating wire (5) is in a spiral structure, and the gap between the heating wire (5) and the inner wall of the housing (4) is filled with heat-conductive hard silica gel (7), and the top of the heating wire (5) is connected to a wire (10).

3. A heating system for repairing honeycomb sandwich composite materials according to claim 2, characterized in that: The outer part of the shell (4) is detachably covered with a flexible heat-conducting silicone sleeve (8), and the flexible heat-conducting silicone sleeve (8) is used to protect the honeycomb core during the process of inserting the heating device (1) into the honeycomb core.

4. A heating system for repairing honeycomb sandwich composite materials according to claim 3, characterized in that: A heating tube sealing head (9) is installed at the top end of the housing (4), and the heating tube sealing head (9) is used to encapsulate the electric heating wire (5) and the heat-conducting hard silica gel (7) and fix the wire (10), and one end of the wire (10) passes through the top end of the heating tube sealing head (9) and extends to the outside.

5. A heating system for repairing honeycomb sandwich composite materials according to claim 4, characterized in that: The control device (3) further comprises a power supply socket (13) and a plug (15) for connecting to an external power source, and the heating wire (5) is connected to the power supply socket (13) via a wire (10).

6. A heating system for repairing honeycomb sandwich composite materials according to claim 5, characterized in that: The power supply socket (13) is provided with a plurality of sockets (14) for connecting a plurality of heating devices (1) simultaneously.

7. A heating method for repairing honeycomb sandwich composite materials, characterized in that: The heating method utilizes the heating system of claim 6, and the heating method further comprises the following steps: Step 1: grinding the damaged part of the damaged honeycomb sandwich composite material structure (16) to form a repair area (17), removing the damaged honeycomb core, and forming a repair cavity in the repair area (17); Step 2: According to the size of the repair cavity in the repair area (17), a new honeycomb core (19) of corresponding size and a preset number of heating devices (1) and temperature measuring devices (2) are selected, and the heating devices (1) and the temperature measuring devices (2) are connected to the control console (12); Step 3: Wrap the outer wall of the new honeycomb core (19) with foam glue (20) and insert it into the repair cavity of the repair area (17); Step 4: evenly placing a preset number of temperature measuring thermocouples (11) in the gaps between the foam glue (20) and the original honeycomb core (18) and between the foam glue (20) and the new honeycomb core (19) to monitor the temperature of the foam glue (20) and the honeycomb core structure; Step 5: Evenly insert and install multiple heating devices (1) in the honeycomb holes of the original honeycomb core (18) and the new honeycomb core (19) on both sides of the foam glue (20); Step 6: Connect the plurality of heating devices (1) to the power sockets (13) respectively; Step 7: Lay a release cloth (21), an isolation film (22) and a heat-insulating cotton (23) on the repair area (17) in sequence to protect the repair area (17); Step 8: Connect the control console (12) to an external power source via the 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 glue (20); Step 9: starting the heating program of the control console (12), controlling the heating device (1) to operate, and heating and curing the foam glue (20); Step 10: After the foam glue (20) is completely cured, the heating process is turned off, and the heat-insulating cotton (23), the isolation film (22) and the demoulding cloth (21) are removed in sequence; Step 11: Take out the heating device (1) and the temperature measuring thermocouple (11); Step 12: Repair the foam glue (20) overflowing from the repair area (17), and complete the heating and curing work of the foam glue (20) for repairing the honeycomb sandwich structure.

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