CN112607048B - Adjustable temperature solar composite repair device - Google Patents

Abstract

The invention discloses a temperature-adjustable solar composite material repairing device, which belongs to the field of structure repairing and comprises a supporting structure, a plate-shell structure and a repairing area, wherein a vacuum bag is arranged at the upper end of the plate-shell structure, and in a space formed by the vacuum bag: a composite material repairing component is adhered to the upper end of the repairing area; the composite material repairing assembly comprises an adhesive film, a composite material patch is arranged at the upper end of the adhesive film, a plurality of thermocouples are arranged above the composite material patch, the thermocouples are connected with a temperature control system, and isolating films are arranged above the composite material patch and the thermocouples; and a solar heat absorption material film is adhered and covered on the isolating film, and a plurality of electrochromic films are adhered on the upper surface of the solar heat absorption material film. The invention utilizes the technology of combining the heating layer with the solar heat-absorbing material coating and the electrochromic film, so that the heating curing composite material and the like are coated with glue and cured, cracks are repaired or a patch is adhered to a damaged area, and the damage of equipment such as an airplane and the like is repaired more conveniently and rapidly.

Description

Adjustable temperature solar composite repair device

technical field

The invention relates to the field of structural repair, more particularly, to a heating process required in the process of using composite materials or special adhesives to repair the surface structure of aircraft and other equipment, in particular to a temperature-adjustable solar energy composite material repair device.

Background technique

Composite materials are widely used because of their excellent properties. For example, due to the good mechanical properties of composite materials, various types of aircraft, such as fighter jets and civil aircraft, have integrated more and more composite materials into structures such as skins. In addition, automobiles, ships and other machinery have also begun to use composite materials in structures such as shells.

Cracks, peels, voids, dents, corrosion and other damage are often seen in the outer surface structure of equipment such as aircraft, ships and automobiles. Most of the damage occurs in structures such as metal plates, shells, etc. With the extensive use of composite materials, such damage also occurs in structures made of composite materials. The use of composite materials as a new type of "connector" or patch to glue directly to the damaged area of the device surface (also known as the rework area) has been successful.

For small cracks and other damages, heat-cured composite material is directly used for gluing. For larger damages, the patch is typically bonded to the reworked area by means of an adhesive, wherein the adhesive is placed at the bond line between the patch and the reworked area. Typically, heat and pressure are applied to the patch, such as with heating pads and vacuum bags. A heating pad is used to raise the bond line to the proper adhesive curing temperature. Vacuum bags can be used to consolidate the compacted patch. During curing, the bond line may be kept within a relatively narrow temperature range for a predetermined period of time in order to fully cure the adhesive. Furthermore, the entire area of the bond line can be maintained within a temperature range that is substantially unchanged at the bond line.

If the patch is large, a thermal survey of the rework area is required before bonding the patch to the rework area. A thermal survey may be required to identify locations of non-uniform heating of the rework area by the heating pad. Since the rework area is mostly metallic, the thermal conductivity is significantly different from that of the patch, resulting in differential heating of the area near the bond line, which can result in non-uniform heating. In this regard, thermal surveys may provide a means for identifying hot and cold spots within the rework area, either by adding temporary insulation to the composite structure or by adjusting the heating pad temperature until the temperature is within the desired range.

The traditional thermal survey process requires the assembly of a surrogate patch, which is a replica of the patch to be permanently bonded to the composite structure. In this regard, conventional surrogate patches are formed from the same type of composite material as the final patch and have the same number of plies as the final patch. The construction of traditional replacement patches is a time-consuming and labor-intensive process that often requires hand-cutting multiple composite plies, where each composite ply has a unique size and shape. After thermal surveying, traditional replacement patches are usually discarded after one use.

In the field of aviation, the application of composite materials for repair has restored the flight performance of a large number of aircraft, extended the life, and achieved very significant economic benefits. But traditional heating methods also expose some problems. The thermal survey process takes a lot of time and wastes a patch. Such patches need to be made by hand, and the production process also consumes a lot of time. Separating thermal surveying and heating into two processes also results in repeated heating, which can easily damage the structure.

Heating pads that use electric heating require an external power supply with a large amount of electricity, so it is difficult to achieve field repair of active aircraft. It is also difficult to carry larger batteries and electric heating equipment for other equipment such as cars and ships when working outdoors.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention is based on the repairing technology of composite materials. In the vacuum bag, a heating layer coated with a solar endothermic material is used, and an electrochromic film is used for semi-active control to keep the temperature of each area within Within a reasonable range, the heat-curing composite materials can be cured by applying glue, repairing cracks or adhering the patch to the damaged area, so as to repair the damage of aircraft and other equipment more conveniently and quickly.

The present invention is realized in this way:

A temperature-adjustable solar energy composite material repair device, comprising a support structure, a plate-shell structure at the upper end of the support structure, and a damaged part existing on the plate-shell structure, that is, a repair area, characterized in that a vacuum bag is arranged at the upper end of the plate-shell structure , the vacuum bag completely covers the repair area; in the space formed by the vacuum bag: the upper end of the repair area is pasted with a composite material repair component.

The composite material repair component includes a plastic film, the upper end of the plastic film is provided with a composite material patch, and a plurality of thermocouples are arranged above the composite material patch, and the thermocouple is connected with the temperature control system. An isolation film is arranged above the composite material patch and the thermocouple; the isolation film is then pasted and covered with a solar heat-absorbing material film, and several electrochromic films are pasted on the upper surface of the solar heat-absorbing material film; in this patent In the adopted method, the size and thickness of the solar heat absorbing material film and which solar heat absorbing material and coating method to use can be determined according to the actual situation. The traditional coating can be selected such as 1. Electroplating coating, such as black chrome coating, black cobalt coating, etc. 2. Electrochemical surface conversion coating. Such as aluminum anodized coating, CuO conversion coating, steel anodized coating, etc. 3. The absorption coating is prepared by vacuum coating and magnetron sputtering technology. 4. Paint coating. Wait. Or opt for new materials such as graphene in unconventional forms. Substrates can be classified into hard materials and flexible materials. When repairing on some planes and regular curved surfaces, hard materials can be used to use metal (such as aluminum plate), glass, graphene, carbon fiber, etc. as the substrate. Flexible materials such as tin foil, rubber and other polymer flexible materials can be used for repairing more complex curved surfaces. A thin film of solar heat absorbing material is placed over the composite patch during repair work installation. If it is considered that the composite patch or other adhesive material will stick to the solar heat absorbing film when it is melted, an insulating layer can be covered between the patch and the film. The isolation layer should have good thermal conductivity.

The repairing device is placed in the sunlight, and the solar heat absorbing material film converts the solar energy into heat energy, so that the temperature of the composite material patch continues to rise; the temperature is monitored in real time by a thermocouple and fed back to the temperature control system, and then the electrochromic adjustment is adjusted. The voltage of the film in turn regulates the temperature, heating according to a preset curve, and finally the vacuum bag and components are removed to complete the repair process.

Electrochromic materials, that is, electrochromic films, can change light transmittance in response to changes in voltage. The flexible electrochromic material is cut into 50~100 square centimeters (other area sizes can be used according to the actual situation), and the positive and negative electrodes of each flexible electrochromic film are connected to the power supply and the controller. Since the power required is very small, the power supply and controller can be made very small. There is a pre-edited control program in the controller. The thermocouple attached to the surface of the composite material and each flexible electrochromic film at the corresponding position form a semi-active control system. When the temperature of the thermocouple is too high or the temperature rises too fast to cause uneven heating, the signal is transmitted to the In the controller, the controller will change the voltage on the corresponding flexible electrochromic film, making it darker in color and lower in light transmittance, thereby reducing the heat gain.

Further, a sealing rubber ring is arranged between the vacuum bag and the repair area, and the sealing rubber ring is completely sealed.

Further, the positions of the plurality of thermocouples correspond to the positions of the plurality of electrochromic films up and down, and the installation position of the thermocouples corresponds to the middle position of each electrochromic film covered.

Further, an air bag is arranged above the vacuum bag, and the air bag is used for heat preservation.

Further, an air felt may be provided on the lower surface of the solar heat absorbing material film. The air felt can be attached under the solar heat absorbing material film, or it can be eliminated.

Further, the thermocouple is connected with the temperature control system outside the structure; the temperature control system is connected with the electrochromic film by wires.

The beneficial effects of the present invention and the prior art are:

The traditional method of repairing composite materials, which is heated with resistance wires in a vacuum bag, consumes a lot of electricity, which makes this method unable to be used in the field. In many occasions, such as field areas and aircraft carriers, our aircraft may not have the conditions to quickly enter and exit the hangar, and some areas may not have maintenance hangars. In many cases, connecting the power supply from the hangar to the vicinity of the aircraft parked in the field will also cause the problem of too many ground lines, which is easy to cause safety hazards, not to mention the problem of unstable voltage or power failure in remote areas. Thin films made of solar heat-absorbing materials can perfectly solve this problem. In the oceans, deserts, the Middle East, plateaus and other regions with sufficient sunshine, abundant solar energy can make up for the shortcomings of traditional power-dependent repair methods. On July 3, 2019, American researchers recently developed a new cost-effective aerogel material for solar collectors to improve the heat collection efficiency and keep the temperature at 220 °C. This temperature far exceeds the maximum temperature of 120°C for unidirectional carbon fiber prepregs. It shows that the use of solar endothermic materials to cure composites is feasible.

In addition, when the repaired area is large, the temperature may vary from place to place. In the position where the skin and the beam are in contact, there is more heat conduction, which makes the temperature there easier to be lower. The method of heating with resistance wires is difficult to control. For different patch shapes, the resistance wire arrangement needs to be rearranged, which is easy to cause wiring. complex issues. The use of electrochromic film to adjust the light transmittance can adjust the temperature everywhere. It has good adaptability to different shapes of patches. Electrochromic films require very little electricity and voltage, and only a small power supply is needed.

In the repairing device of the present invention, solar energy is used as the direct energy source for curing the adhesive, so that the repairing process can be carried out in an external field, and there is no need to carry a huge power source or an external power source. This patent also provides a method for adjusting the temperature based on a flexible electrochromic film, so that the thermal survey step can be omitted, the requirement of uniform heating near the bonding line is met, and the problem that the temperature during the electric heating process is difficult to control during large-area repair is avoided. . The traditional electric heating has disadvantages such as complex equipment and dependence on power supply. This patent uses a solar heat-absorbing material film to convert solar energy into heat energy to heat the composite material patch, and uses an electrochromic film to adjust the temperature.

Based on the flexible plastic film material, the invention realizes the phenomenon that its optical properties (reflectivity, transmittance, absorption rate, etc.) undergo stable and reversible color depth changes under the action of an external electric field. The electricity used by this technology is very small, in addition, the solar energy absorption coating has a great influence on the technical and economic performance of solar energy utilization, and the various coatings used in the present invention can achieve good results.

Description of drawings

1 is a specific example diagram of a cross-sectional view of a temperature-adjustable solar energy composite repair device of the present invention;

Fig. 2 is the top view of electrochromic film structure and circuit system diagram;

3 is a schematic example diagram of a cross-sectional view of a temperature-adjustable solar energy composite repair device according to the present invention;

In the figure, 1-support structure, 2-plate shell structure, 3-rework area (damaged part on the skin), 4-vacuum bag, 5-sealing rubber ring, 6-adhesive film, 7-composite material patch, 8-thermocouple, 9-isolation film, 10-solar endothermic material film, 11-electrochromic film, 12-air felt, 13-composite repair component, 14-airbag, 15-temperature control system, 16-wire .

Detailed ways

In order to make the objectives, technical solutions and effects of the present invention clearer and clearer, the following examples are given to further describe the present invention in detail. It should be pointed out that the specific implementations described herein are only used to explain the present invention, but not to limit the present invention.

As shown in FIG. 1 and FIG. 3 , it is a schematic cross-sectional view of a film coated with a solar heat absorbing material and a vacuum bag assembly using a flexible electrochromic film for temperature control in the present invention. In the composite material repair component 13 of the present invention, the solar endothermic material film 10 and the electrochromic film 11 are used to replace the traditional resistance wire heating pad. The specific operations are as follows:

First find the position of the repair area 3, and select the appropriate composite material bonding method according to the damage such as fracture, corrosion and potholes. The composite material repair component 13 is glued to the repair area 3 , and the composite material repair component 13 is composed of the adhesive film 6 , the composite material patch 7 , the thermocouple 8 (the line is not marked), and the isolation film 9 . First, the composite material patch 7 is glued to the repair area 3 with the adhesive film 6, and a thermocouple 8 is glued on the composite material patch 7. The thermocouple 8 will transmit the temperature of the composite material patch 7 to the temperature controller. The installed number of thermocouples 8 is determined according to the area of the composite material patch 7 . In this embodiment, a piece of 50-100 square centimeters is installed, and the installation position of each thermocouple corresponds to the middle position of each electrochromic film 11 as much as possible. The thermocouple 8 and the composite material patch 7 are covered with an isolation film 9, and the isolation film 9 can prevent the composite material patch 7 from adhering to the solar heat absorbing material film 10 when it is melted, and can transfer heat. The solar endothermic material film 10 is covered on the isolation film 9 with ordinary glue.

The electrochromic film 11 is adhered to the surface of the solar endothermic material film 10 with ordinary colorless glue. The number and size of the electrochromic films 11 are determined according to the size of the solar heat absorbing material film 10 . The area of one electrochromic film 11 may be 50-100 square centimeters. In this embodiment, nine electrochromic films 11 of the same size are used, as shown in FIG. 2 .

The air felt 12 can be attached under the solar heat absorbing material film 10, or can be eliminated. Stick the sealing rubber ring 5 on the vacuum bag 4 around, and then use a vacuum pump to pump air to compact the whole structure. An air bag 14 is provided on the vacuum bag 4, and the air bag is blown with the mouth. The airbag 14 can play the role of heat preservation.

After the installation is completed and placed in the sun, the solar heat absorbing material film converts the solar energy into heat energy, so that the temperature of the composite material patch 7 continues to rise. The temperature is monitored in real time by thermocouple and fed back to the temperature control system 15. If the thermocouple shows a high temperature and a safe temperature standard, the voltage of the electrochromic film 11 at that place is adjusted to make it darker, reducing the light transmission of the sun. rate to make it heat according to the preset curve. The safe temperature standard can be adjusted according to the curing temperature of different materials. If the composite material patch 7 needs to be uniformly heated in actual conditions, and the temperature rise curve should be the same as possible everywhere, more heat may be conducted at the position of the support structure 1, resulting in cold spots. At this time, the controller 15 needs to adjust the light transmittance of the electrochromic film 11 so that the temperature of each part is close. In an example, according to the curing requirements of the resin in the prepreg, the curing process is to raise the temperature to 120° C., keep the temperature for a period of time, and then cool to room temperature. Finally, the vacuum bag and components are removed to complete the repair process.

If the time is urgent (such as in wartime), the solar heat absorbing material film 10 can be placed in the sun to a certain temperature in advance, and then installed in a vacuum bag when needed.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, some improvements can be made without departing from the principles of the present invention, and these improvements should also be regarded as the present invention. the scope of protection of the invention.

Claims (7)

1. A temperature-adjustable solar energy composite repair device, comprising a support structure (1), a plate-shell structure (2) at the upper end of the support structure (1), and a damaged part existing on the plate-shell structure (2), that is, a repair area ( 3), characterized in that a vacuum bag (4) is arranged on the upper end of the plate-shell structure (2), and the vacuum bag (4) completely covers the repair area (3); In the space formed by the vacuum bag (4): the composite material repair component (13) is pasted on the upper end of the repair area (3); The composite material repair assembly (13) includes a glue film (6), a composite material patch (7) is arranged on the upper end of the glue film (6), and a plurality of thermoelectrics are arranged above the composite material patch (7). Couple (8), the thermocouple (8) is connected with the temperature control system (15), and an isolation film (9) is arranged above the composite material patch (7) and the thermocouple (8); the isolation The top of the film (9) is then pasted and covered with a solar heat-absorbing material film (10), and a plurality of electrochromic films (11) are pasted on the upper surface of the solar heat-absorbing material film (10); the repairing device is placed in the sunlight Then, the solar endothermic material film (10) converts solar energy into heat energy, so that the temperature of the composite material patch (7) continues to rise; the temperature is monitored in real time by a thermocouple (8) and fed back to the temperature control system (15), and then Adjust the voltage of the electrochromic film (11) to adjust the temperature, heat according to the preset curve, and finally remove the vacuum bag and the components to complete the repair process; The adhesive film (6) glues the composite patch (7) to the rework area (3), and a thermocouple (8) is glued over the composite patch (7), which will attach the composite patch ( 7) The temperature is transmitted to the temperature controller in time; the installation number of thermocouples (8) is determined according to the area of the composite material patch (7); after installation, it is placed in the sun, and the solar heat absorbing material film converts solar energy into heat energy , so that the temperature of the composite material patch (7) continues to rise; the thermocouple is used to monitor the temperature in real time and feed it back to the temperature control system (15). If the thermocouple shows that the temperature is higher than the safe temperature standard, adjust the electrical The voltage of the color-changing film (11) makes it darker, reduces the transmittance of the sun, and makes it heat according to a preset curve. 2. A temperature-adjustable solar energy composite repair device according to claim 1, characterized in that a sealing rubber ring (5) is arranged between the vacuum bag (4) and the repair area (3), The rubber ring (5) is completely sealed. 3. A temperature-adjustable solar energy composite repair device according to claim 1, characterized in that the positions of the plurality of thermocouples (8) and the plurality of electrochromic films (11) correspond up and down, so The installation position of the thermocouple (8) corresponds to the middle position of each electrochromic film (11). 4 . The temperature-adjustable solar energy composite material repairing device according to claim 1 , wherein an air bag ( 14 ) is arranged above the vacuum bag ( 4 ), and the air bag ( 14 ) is used for heat preservation. 5 . 5 . The temperature-adjustable solar energy composite material repairing device according to claim 1 , wherein an air felt ( 12 ) is further provided on the lower surface of the solar heat absorbing material film ( 10 ). 6 . 6. A temperature-adjustable solar energy composite repair device according to claim 1, characterized in that the thermocouple (8) is connected to a temperature control system (15) outside the structure; the temperature control system (15) Connect with the electrochromic film (11) by means of wires. 7 . The temperature-adjustable solar energy composite material repair device according to claim 1 , wherein the coating of the solar heat absorbing material film ( 10 ) is selected from black chrome coating, black cobalt coating, aluminum Anodized coating, CuO conversion coating, anodized coating of steel, vacuum coating, magnetron sputtering technology to prepare absorber coating, paint-type coating or graphene.

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