Automatic repairing tool for damage of aero-engine composite material silencing plate

Abstract

The utility model discloses an aero-engine composite material silencing plate damage automatic repair tool, which comprises a main machine, a temperature control system, a vacuum degree control system and a vacuum bag, the main machine is respectively connected with the temperature control system and the vacuum degree control system, the temperature control system measures and controls the temperature in the vacuum bag, and the vacuum bag is connected with the temperature control system. And the vacuum degree control system measures the vacuum degree in the vacuum bag and controls the vacuum degree. Control parameters are input through the host, and the temperature control system and the vacuum degree control system are used for automatic control and monitoring, namely key parameters such as temperature, vacuum degree and time are automatically controlled, so that the temperature, vacuum degree and time requirements required by repair are met, the repaired silencing plate meets the airworthiness requirement, and the repair efficiency is improved. The tool has the advantages of being convenient to operate, high in efficiency, capable of guaranteeing repairing quality and the like.

Description

Technical Field

[0001] The utility model relates to an automatic repair tool for damage of a composite muffler plate of an aero-engine. Background Art

[0002] Composite muffler panels for aircraft engines generally include a backing plate layer, a honeycomb interlayer in the middle, and a microporous panel layer thereon to reduce engine noise. During the operation of aircraft engines, due to the combined effects of engine vibration, airflow impact, and foreign object strikes, the muffler panels will have surface pits, local damage, and internal honeycomb layer damage.

[0003] For the repair of composite materials, existing methods include glue injection repair and glue filling repair, wet layup repair, prepreg repair, etc. Among them, the glue injection and glue filling repair methods cannot repair the damaged honeycomb layer, so they are usually only used when the honeycomb interlayer is not damaged; although the prepreg repair method has better strength performance after repair, the prepreg has a short shelf life and high storage and transportation requirements, which makes it difficult to meet the requirements of engine maintenance; and the wet layup repair method has the advantages of convenient raw material storage, no need for low-temperature storage, and relatively low price. Therefore, the wet layup repair method is more commonly used to repair damaged mufflers.

[0004] However, the existing wet-lay repair process of aviation composite silencers is not automatically controlled and monitored, and cannot effectively monitor key parameters such as temperature, vacuum degree and time. The repair operation is inconvenient and inefficient, and the repair quality cannot be guaranteed. This may cause the repaired silencers to fail to meet airworthiness requirements and even affect aviation safety. Utility Model Content

[0005] The utility model aims to provide an automatic repair tool for damage of composite muffler plate of aircraft engine which is convenient to operate, high in efficiency and can ensure the repair quality.

[0006] The purpose of the utility model is achieved through the following technical measures: an automatic repair tool for damage to a composite muffler plate of an aircraft engine, characterized in that it includes a main engine, a temperature control system, a vacuum control system and a vacuum bag, the main engine is connected to the temperature control system and the vacuum control system respectively, the temperature control system measures the temperature in the vacuum bag and controls it, and the vacuum control system measures the vacuum degree in the vacuum bag and controls it.

[0007] The utility model inputs control parameters through a host, and the temperature control system and the vacuum control system perform automatic control and monitoring, that is, through automatic control of key parameters such as temperature, vacuum and time, the temperature, vacuum and time requirements required for repair are met, so that the repaired silencer plate meets the airworthiness requirements. The utility model has the advantages of easy operation, high efficiency, and guaranteed repair quality.

[0008] The temperature control system of the utility model comprises a controller, a heater and a temperature sensor arranged in a vacuum bag. The host is connected to the controller, and the controller is respectively connected to the heater and the temperature sensor. There are several temperature sensors arranged at temperature measuring points in the vacuum bag. The temperature of the repair area is characterized by measuring the temperature of several temperature measuring points. The controller receives the temperature data transmitted by the temperature sensor and controls the heater to adjust the heating temperature as needed.

[0009] The vacuum control system of the utility model comprises a vacuum pump, a pressure sensor and a controller. The host is connected to the controller, and the controller is respectively connected to the vacuum pump and the pressure sensor. The pressure sensor is connected to the pressure measurement interface of the vacuum bag to measure the vacuum degree in the vacuum bag. The vacuum pump is connected to the deflation interface of the vacuum bag. The controller receives the pressure data transmitted by the pressure sensor and controls the vacuum pump to adjust the vacuum degree as needed.

[0010] The vacuum bag of the utility model comprises a bag body and accessories therein, wherein the accessories comprise a demoulding cloth, a porous isolation film, a glass fiber breathable cloth, a non-porous isolation film, a pad, a silicone heating blanket and a breathable felt which are laid in sequence from bottom to top on the repair area, a temperature sensor is arranged near the repair area, an electric heating wire as a heater is evenly laid in the silicone heating blanket, the silicone heating blanket is made of silicone material, is relatively soft, can fit the curved surface of the silencer board, and has a good heat-averaging effect, and can ensure that the temperature inside the repair area is uniform.

[0011] The temperature measuring points of the utility model are greater than 4 and are located around the repair area.

[0012] Compared with the prior art, the utility model has the following significant effects:

[0013] The utility model inputs control parameters through a host, and the temperature control system and the vacuum control system perform automatic control and monitoring, that is, through automatic control of key parameters such as temperature, vacuum and time, the temperature, vacuum and time requirements required for repair are met, so that the repaired silencer plate meets the airworthiness requirements. The utility model has the advantages of easy operation, high efficiency, and guaranteed repair quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0015] Figure 1 It is a structural schematic diagram of the utility model;

[0016] Figure 2 It is a structural schematic diagram of the vacuum bag of the utility model and its internal accessories. DETAILED DESCRIPTION

[0017] like Figure 1 , 2 As shown, the utility model is an automatic repair tool for composite muffler panel damage of an aircraft engine, comprising a main engine 1, a temperature control system 2, a vacuum control system 3 and a vacuum bag 4. The main engine 1 is connected to the temperature control system 2 and the vacuum control system 3 respectively. The temperature control system 2 measures the temperature in the vacuum bag 4 and controls it, and the vacuum control system 3 measures the vacuum degree in the vacuum bag 4 and controls it.

[0018] The temperature control system includes a PID automatic controller, a heater and a temperature sensor arranged in the vacuum bag 4. The host 1 is connected to the controller, and the controller is respectively connected to the heater and the temperature sensor. The temperature sensor includes a thermocouple and a temperature 16-channel data acquisition card, and the two are connected through a thermocouple adapter 7. Among them, there are several thermocouples and they are arranged at the temperature measurement points in the vacuum bag 1. In this embodiment, there are 6 temperature measurement points. The temperature of the repair area is characterized by measuring the temperature of the 6 temperature measurement points. The controller receives the temperature data transmitted by the temperature sensor and controls the heater to adjust the heating temperature as needed. In this embodiment, a 12-24VDC DC power supply is used, and a 3m heating pad power cord is used to connect the heater and the controller.

[0019] The vacuum control system includes a vacuum pump 5, a pressure sensor 8 and a controller. The host 1 is connected to the controller, and the controller is connected to the vacuum pump 5 and the pressure sensor 8 respectively. The pressure sensor 8 is connected to the pressure measurement interface 6 of the vacuum bag 4 to measure the pressure inside the vacuum bag 4. The vacuum pump 5 is connected to the deflation interface 9 of the vacuum bag 4. The controller receives the pressure data transmitted by the pressure sensor 8 and controls the vacuum pump 5 to adjust the vacuum degree as needed. In this embodiment, the vacuum pump 5 adopts a KNF electrically controlled membrane vacuum pump with a limit pressure greater than 91.2 kPa. A 3m vacuum tube is used with a sealing joint. A single-channel pressure data acquisition card is used. The pressure sensor (range -100 kPa-0) is connected to the vacuum bag joint through a vacuum tube, and the signal of the pressure sensor is connected to the automatic controller through an adapter.

[0020] The host 1 includes a human-machine interface for inputting temperature requirements and vacuum requirements, a driver and communication interface for controlling the temperature control system and vacuum control system respectively, a monitoring system and a display. The monitoring system obtains the temperature and vacuum data of the temperature control system and vacuum control system at a sampling frequency of 2Hz, and stores and draws the temperature and vacuum curves during the repair process in real time. The display has a real-time display function, and the operator can monitor and review the temperature, vacuum and time during the repair. The host 1 has an emergency management function. When the monitoring parameters deviate from the requirements, a yellow warning pattern will be displayed on the display to give necessary warnings to the operator.

[0021] The vacuum bag 4 includes a bag body and accessories therein. The bag body is made of nylon material, has a sealable opening and sufficient space inside the bag, and the muffler to be repaired and the accessories inside the bag can be loaded and sealed. The bag body has a temperature measurement interface so that the temperature signal can be transmitted to the controller through the temperature measurement interface. The bag body has a deflation interface and a pressure measurement interface to connect a vacuum pump and a pressure sensor.

[0022] The accessories include a demoulding cloth 10, a porous isolation film 11, a glass fiber breathable cloth 12, a non-porous isolation film 13, a pad 14, a silicone heating blanket 15 (power 500W, diameter 300mm) and a breathable felt 16, which are laid in sequence from bottom to top on the repair area. A thermocouple set at a temperature measurement point 17 is arranged near the repair area, that is, six copper-constantan type thermocouples are arranged at intervals of 60 degrees around the repair area and fixed with high-temperature resistant tape. The other end of the thermocouple extends out of the vacuum bag 4 and is connected to a thermocouple data acquisition card for temperature control. Electric heating wires as heaters are evenly laid inside the silicone heating blanket 15 and are controlled by a temperature control system. Moreover, the silicone heating blanket is made of silicone material, which is relatively soft and can fit the curved surface of the muffler board. It has a good heat-averaging effect and can ensure uniform temperature inside the repair area.

[0023] The process of repairing using the utility model is as follows:

[0024] 1. Remove the surface paint film by grinding: Confirm the location and scope of the damage. Use masking tape to cover the non-repair area and use sandpaper to grind the repair area. Grind the edge of the panel to make it beveled. Use acetone to clean the repair area and make sure the repair area is clean and dry.

[0025] 2. Make a new honeycomb and install it: Apply the mixed two-component epoxy adhesive and filler to the area where the new honeycomb and the adjacent honeycombs are installed to ensure that the new honeycomb and the adjacent honeycombs are flush in height after installation.

[0026] 3. Soak the glass fiber cloth in two-component epoxy adhesive to make a wet layer. Make sure the glass fiber cloth is completely soaked in the adhesive. Take out the wet layer and lay it on the repair location. Make sure the number and direction of the wet layer are consistent with the original panel layer.

[0027] 4. Make a vacuum bag in the repair area to complete the curing process:

[0028] 1) Lay release cloth, isolation film, glass fiber breathable cloth, isolation film, pad, silicone heating blanket and breathable felt in sequence on the repair area where the wet layer has been laid. Figure 2 .

[0029] 2) Arrange six copper-constantan type thermocouples at 60 degree intervals around the repair area and fix them with high temperature resistant tape. Figure 2 The other end of the thermocouple extends out of the vacuum bag and is connected to a thermocouple data acquisition card for temperature control.

[0030] 3) Make a vacuum bag in the repair area, connect the heating blanket power cord, vacuum tube adapter, and complete the sealed bag opening.

[0031] 4) Turn on the power of the host, temperature control system, vacuum control system and vacuum pump, enter the host user interface, enter the temperature curve, first cure at room temperature for 3 hours, then cure at 87℃ ±5℃ for 1.5 hours, and finally cool naturally to room temperature. Set the vacuum degree to 80kPa.

[0032] 5) Click the start button, the system will automatically start the vacuum pump until the vacuum degree in the vacuum bag is greater than 80kPa, then stop. The temperature will also be based on the input parameters, first maintain room temperature for 3 hours, then heat to around 87℃ and maintain for 1.5 hours, and finally cool naturally.

[0033] 6) Cool at room temperature and demould to obtain a sound-absorbing board that has been completely cured.

[0034] 5. Drill small holes in the cured muffler panel, ensuring that the holes in the repair area are consistent in arrangement and diameter with those in the original microporous panel.

[0035] 6. Sand and clean the repaired area. Make sure the repaired area has a smooth transition with the original muffler.

[0036] The utility model can automatically control and monitor the repair process, especially the key parameters such as temperature, vacuum degree and time. It has the advantages of convenient operation, high efficiency and good quality. In the repair process, the key parameters affecting the repair quality such as curing effect and infiltration effect can be guaranteed.

[0037] The muffler repaired by the utility model was subjected to appearance inspection, section inspection and non-destructive testing. The inspection results showed that the repaired muffler was smooth and clean in the repaired area, without pits, protrusions, wrinkles and deformation, etc. The section and non-destructive inspection also showed that the repaired internal structure had no delamination or debonding, the porosity was well controlled, and the internal structure had no defects. The structural integrity can meet the airworthiness requirements.

[0038] The mechanical property test of the repaired muffler also showed that compared with the unrepaired structure, the recovery rate of the repaired structure's compression strength was 106.7%, and the recovery rate of the straight tensile strength was 58.7%. The mechanical properties are good and can meet the airworthiness requirements.

[0039] The implementation methods of the utility model are not limited to this. According to the above content of the utility model, in accordance with the common technical knowledge and customary means in the field, without departing from the above basic technical ideas of the utility model, the utility model can also make other various forms of modifications, replacements or changes, all of which fall within the scope of protection of the utility model.

Claims

1. An automatic repair tool for damage to composite muffler panels of aircraft engines, characterized by: It includes a main machine, a temperature control system, a vacuum control system and a vacuum bag. The main machine is connected to the temperature control system and the vacuum control system respectively. The temperature control system measures the temperature in the vacuum bag and controls it. The vacuum control system measures the vacuum degree in the vacuum bag and controls it.

2. The automatic repair tool for composite muffler panels of aircraft engines according to claim 1 is characterized by: The temperature control system includes a controller, a heater and a temperature sensor arranged in a vacuum bag. The host is connected to the controller, and the controller is respectively connected to the heater and the temperature sensor. There are several temperature sensors arranged at temperature measurement points in the vacuum bag. The temperature of the repair area is characterized by measuring the temperature of several temperature measurement points. The controller receives temperature data transmitted by the temperature sensor and controls the heater to adjust the heating temperature as needed.

3. The automatic repair tool for damage to composite muffler panels of aircraft engines according to claim 2 is characterized by: The vacuum control system includes a vacuum pump, a pressure sensor and a controller. The host is connected to the controller, and the controller is respectively connected to the vacuum pump and the pressure sensor. The pressure sensor is connected to the pressure measurement interface of the vacuum bag to measure the vacuum degree in the vacuum bag. The vacuum pump is connected to the deflation interface of the vacuum bag. The controller receives the pressure data transmitted by the pressure sensor and controls the vacuum pump to adjust the vacuum degree as needed.

4. The automatic repair tool for composite muffler panels of aircraft engines according to claim 3 is characterized by: The vacuum bag includes a bag body and accessories therein, wherein the accessories include a demoulding cloth, a porous isolation film, a glass fiber breathable cloth, a non-porous isolation film, a pad, a silicone heating blanket and a breathable felt which are laid in sequence from bottom to top on the repair area, a temperature sensor is arranged near the repair area, and electric heating wires serving as a heater are evenly laid in the silicone heating blanket.

5. The automatic repair tool for composite muffler panels of aircraft engines according to claim 4 is characterized by: The number of the temperature measurement points is greater than 4 and they are located around the repair area.

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