CN103587130B - The method of microwave curing fiber-reinforced resin matrix compound material component and device - Google Patents

Abstract

A method and device for microwave curing of fiber-reinforced resin-based composite components. The microwave source with linearly adjustable power generates microwaves, which are guided into the resonant cavity by the waveguide, penetrate and heat the composite material, and make it solidify quickly. The device adopts an advanced octagonal microwave mode resonant cavity structure to realize the uniformity of the electromagnetic field in the device. The automatic impedance matching system is used to reduce the interference of reflected waves on the microwave source and realize the optimal transmission of microwave power. Vacuum pipe joints and temperature sensors are arranged on the inner wall of the octagonal multi-mode resonant cavity of the microwave oven. A glass worktable is placed in the resonant cavity, and the forward and backward movement of the worktable is controlled by the stepping motor to control the rotation of the ball screw. The device adopts a choke groove to prevent microwave leakage. The invention solves the problems of long production time, high energy consumption and uneven heating of the fiber-reinforced composite material produced by the traditional autoclave molding method, saves curing time, and improves the quality and performance of the composite material component.

Description

Method and device for microwave curing of fiber-reinforced resin-based composite components

technical field

The invention relates to a method for curing composite materials, in particular to a method and device for final curing of composite material components using microwaves, in particular to a method for microwave-cured fiber-reinforced resin-based composite material components.

Background technique

As we all know, fiber-reinforced resin-based composite materials have the advantages of high specific strength and specific stiffness, light weight, heat resistance, corrosion resistance, fatigue resistance, and good shock absorption performance, and are widely used in aerospace, transportation, wind power, electronic power and other fields. Prepreg is a prepreg sheet product made by impregnating reinforcing fibers (carbon fiber, glass fiber, aramid fiber) in a matrix (epoxy resin, polyester resin, thermoplastic resin, etc.). intermediate material.

Due to the above-mentioned excellent properties of composite materials, different molding methods have been developed for different composite material components. Among them, the autoclave forming method is widely used in the fields of aerospace, automobile manufacturing and petrochemical industry. Especially in the field of aerospace, it has become the most important molding process. However, there are many problems and defects in the autoclave forming technology: (1) The autoclave has a long curing time, high energy consumption and low resource utilization. The autoclave process mainly heats the components from the outside to the inside in the form of convective heat transfer, and the temperature difference is the root cause of the internal heat conduction. The molding and curing time of composite materials is long, and sufficient temperature uniformity needs to be ensured. This heating method is inefficient, takes a long time, and the temperature control has hysteresis, and a large amount of energy is consumed. (2) Unacceptable temperature gradients and relatively poor compaction will occur in components of large size and thickness formed by autoclave. The molding of large-scale complex composite materials requires complex mold surfaces and supports, heat conduction and surface convection heat transfer are difficult, and the temperature uniformity of components is poor. Eventually it will lead to residual stress and deformation of the component. The temperature gradient in the curing of the thick-layer composite board will lead to anisotropy of viscosity and curing degree. The temperature peak first appears near the surface of the laminate and then diffuses to the center. Degumming has a significant effect. At the same time, there are some defects in the bonding interface of the composite material cured in the autoclave, and the mechanical properties are not ideal, which affects the quality and service life of the composite material.

Ordinary microwave ovens have the following disadvantages: (1) Linear control cannot be achieved, and the minimum heating power is too large, which is not conducive to the control of the curing temperature and process of the composite material, and is easy to burn out the composite material components. (2) Without a special vacuuming device and temperature sensor, it is impossible to vacuumize and monitor the heating temperature change in real time, and the curing process of the composite material is not easy to control. (3) The microwave source directly transmits microwaves into the furnace through the antenna, and the uncontrolled microwaves are continuously reflected in the furnace, and the distribution is uneven, resulting in uneven heating of the composite material, inconsistent curing degree in the composite material, and internal generation of components. Stress seriously affects the performance of materials. (4) Ordinary metal molds conduct electricity, will shield electromagnetic waves, and cannot be heated.

Contents of the invention

The purpose of the present invention is to solve the problem that the existing composite material autoclave curing has large energy consumption and long cycle, and ordinary microwaves cannot be directly used for composite material curing, and to invent a method that can use microwaves to cure composite material components. method, and provide a matching microwave curing device at the same time.

One of technical solutions of the present invention is:

A method for microwave curing fiber-reinforced resin-based composite components, which is characterized in that a microwave source with adjustable power is used to generate microwaves, and after being adjusted by an automatic impedance matching system, the microwaves enter the octagonal multimode uniformly and stably through waveguides and slot antennas The resonant cavity heats the fiber-reinforced resin-based composite material component placed on the glass plate in the octagonal multimode resonant cavity; The mold cloth, air felt, isolation film and vacuum bag are sealed with vacuum tape; when curing, vacuumize according to the process regulations, and a temperature sensing device is attached to the mold, and the measured temperature is fed back to the control system and compared with the process curve. Real-time adjustment of the microwave heating temperature; the uniformity of the electromagnetic field and the stability of the load in the heating area are realized through the octagonal multi-mode resonant cavity and the automatic impedance matching system to ensure uniform curing temperature distribution of the composite material components; at the same time, real-time measurement of the composite material components through the temperature sensor The curing temperature ensures the controllability of the curing process; after the composite material component is solidified and formed, the composite material component is directly taken out and cooled to room temperature externally.

The composite material mold is one of carbon fiber reinforced composite material mold, glass fiber reinforced composite material mold, ceramic material mold, quartz material mold, high temperature resistant cement material mold or high temperature resistant gypsum material mold.

The microwave frequency range of the microwave heating source with linearly adjustable power includes: 300MHz to 300GHZ, the microwave frequency is fixed or changes linearly or non-linearly in the range of 1-20MHz; the power of the microwave depends on the size of the cavity and the heating The heating process requirements of the medium can be linearly adjusted between 0 and the maximum power; the microwaves entering the octagonal multimode resonator include one or more of TEM waves, TE waves, and TM waves; the microwave source It consists of a controllable autotransformer and a magnetron, or a signal generator and a microwave amplifier.

The fiber-reinforced resin-based composite material is formed by laying prepregs layer by layer on a composite material mold, and the laying directions are different; the fiber reinforcement for fiber reinforcement includes continuous carbon fiber or glass fiber or Aramid fiber or boron fiber, or chopped carbon fiber or glass fiber or aramid fiber or a mixture of one or more; resin matrix includes: phenolic resin, epoxy resin, bismaleimide resin, polyimide One of the amine resins or its modified resin.

The surface of the octagonal microwave multimode resonant cavity is provided with a choke groove which can effectively counteract microwaves and reduce leakage of microwaves, and the depth of the choke groove is 1/4 microwave wavelength.

The automatic impedance matching system is driven by a computer-controlled stepping motor. By controlling the position of the pins in the impedance matching device, the size of the impedance is adjusted, and the microwave changes of the waveguide are controlled. Under the joint action, the microwave distribution in the furnace cavity is uniform and the load is stable, thereby ensuring uniform and stable heating of the microwave;

The temperature sensing device includes one or more of thermocouples, thermistors, infrared sensors, optical fiber fluorescence sensors and optical fiber grating sensors.

The second technical scheme of the present invention is:

A device for microwave curing of fiber-reinforced resin-based composite components, characterized in that it includes: a carrier glass plate 1, a vacuum tube interface 2, a choke slot 3, a slit antenna 4, a furnace body 5, a temperature sensor joint 6, a temperature control Panel 7, operation panel 8, furnace door 9, ball screw 10, stepping motor 11, PLC 12, cooling water inlet 13, cooling water outlet 18, microwave source 19, microwave transmission line 20, impedance matching device 21, rectangular waveguide device 22 and octagonal multimode resonant cavity 23, described octagonal multimode resonant cavity 23 is installed in the body of heater 5, and the rear portion of octagonal multimode resonant cavity 23 leaves the motion channel of ball screw 10, The rest of the rear part is sealed, and the front furnace door 9 adopts a general-purpose choke-sealed metal coil to ensure no electromagnetic leakage; the loading glass plate 1 is connected with the ball screw 10 and driven by it, the composite material component to be cured is sent into the In or taken out from the octagonal multi-mode resonant cavity; the ball screw 10 is driven by a stepping motor 11, and the stepping motor 11 is controlled by the PLC 12, and the microwave of the microwave source 19 passes through the microwave transmission line 20 And the impedance matching device 21 is transmitted to the rectangular waveguide device 22, and then the microwave is introduced into the octagonal multimode resonator 23 by the slot antenna 4; the microwave is reflected back and forth in the octagonal octagonal multimode resonator 23, and finally Absorbed by the fiber-reinforced resin-based composite material; cooling water enters from the cooling water inlet 13 to cool the microwave generating source 19 and then flows out from the cooling water outlet 18; the impedance matching device 21 is driven by a computer 27 and a stepping motor 29 and placed in a rectangular Between the waveguide device 22 and the microwave generating source 19; the temperature sensor joint 6 is connected with each temperature sensor to measure the temperature values of multiple points on the composite material component in real time, and transmit the temperature data to the PLC12 to automatically control the microwave power so that the heating temperature conforms to the process Curve; the temperature control panel 7 and the operation panel 8 control the power, heating temperature and vacuuming of the device to meet the normal operation requirements of the device.

The temperature and vacuum degree of the composite material components measured in real time during the curing process are displayed on the temperature control panel 7 and the operation panel 8 for the control system to monitor and adjust the working status of the device. The control system is divided into manual and automatic control. , the heating power, heating time and vacuuming state are manually controlled according to the data displayed on the panel; during automatic control, the temperature process curve required for curing is input at 8 on the operation panel, and the PLC control device automatically operates.

Described microwave generating source 19 is made up of microwave signal generator 14, microwave amplifier 15, controllable autotransformer 16 and magnetron 17, and the output of microwave signal generator 14 connects microwave amplifier 15, and the output of microwave amplifier connects controllable The input of the autotransformer, the output of the controllable autotransformer is connected to the magnetron, and the magnetron is sent to the impedance matching device 21 through the microwave transmission line for matching and then transferred to the rectangular waveguide device 22, and then the microwave is introduced to the eight sides by the slot antenna 4 Shaped multimode resonant cavity 23.

Beneficial effects of the present invention:

The invention solves the problems of long time for manufacturing fiber-reinforced composite materials, high energy consumption, serious component curing deformation, large internal stress and complicated mold support by the traditional autoclave molding method, saves curing time, and improves the quality of composite material components and performance. At the same time, it also solves the problems of uneven distribution of microwaves, inability to linearly regulate power, unstable load, and inability to vacuumize the interior of ordinary microwave ovens.

1. The present invention adopts microwave heating with linearly adjustable power and vacuum pressurization to solidify composite materials, which can complete the molding of fiber-reinforced resin-based composite materials in a short time, improve the quality and performance of components, and the molding time is only as long as the traditional method About 25% of that, but the strength of the component can be increased by more than 30% year-on-year.

2. The present invention can form a fiber-reinforced resin-based composite material with high performance, good dimensional stability, and small internal stress and deformation. At the same time, the production time is greatly shortened and the energy utilization rate is improved. The rapid curing molding of fiber-reinforced resin-based composites has been realized. Experiments have proved that the deformation is only about 20% of the existing method, so the internal stress can be ignored.

3. The present invention realizes the uniformity of electromagnetic field distribution by adopting an octagonal microwave multimode resonant cavity, ensures uniform heating of the cured composite material, and eliminates curing deformation and internal stress problems caused by uneven heating.

4. The present invention realizes the requirement of vacuuming in the device by arranging the vacuum tube interface inside the furnace cavity, keeps the vacuum in the vacuum bag mold during the heating process, and makes the composite material close to the surface of the mold and compacted, thereby improving the molding quality and performance.

5. The present invention solves the problem of conducting electricity and shielding electromagnetic waves in ordinary metal molds by using molds made of composite materials, and also solves the problem of matching thermal expansion coefficients existing in molds made of other materials. First, the metal is machined into the shape of the mold by machining, and then the mold is turned over to produce a composite mold with the required shape.

6. By adopting an automatic impedance matching system, the present invention solves the problem that the reflected wave in the microwave oven interferes with the microwave source, can quickly and accurately match the required impedance, ensures the stability of the load, and realizes the optimal transmission of microwave power.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the overall structure of the microwave-cured fiber-reinforced resin-based composite component device of the present invention.

Fig. 2 is a schematic diagram of the overall structure of the microwave-cured fiber-reinforced resin-based composite component device of the present invention.

Fig. 3 is a schematic diagram of the working principle of the automatic impedance matching device of the microwave-cured fiber-reinforced resin matrix composite component device of the present invention.

Fig. 4 is a schematic view of laying the fiber-reinforced resin-based composite material on the mold of the present invention.

In the figure: 1 is the carrier glass plate, 2 is the vacuum tube interface, 3 is the choke slot, 4 is the slit antenna, 5 is the furnace body, 6 is the temperature sensor connector, 7 is the temperature control panel, 8 is the operation panel, 9 is Furnace door, 10 is a ball screw, 11 is a stepping motor, 12 is a PLC, 13 is a cooling water inlet, 14 is a signal generator, 15 is a microwave amplifier, 16 is a controllable autotransformer, 17 is a magnetron, 18 is cooling water outlet, 19 is microwave generating source, 20 is microwave transmission line, 21 is impedance matching device, 22 is rectangular waveguide device, 23 is octagonal multimode resonant cavity, 24 is six-terminal interface, 25 is A/D Converter, 26 is interface, 27 is computer, 28 is drive circuit, 29 is stepper motor, 30 is pin, 31 is load, 32 is port I, 33 is port II (surface to be tested), 101 is mold, 102 103 is a release cloth, 104 is a vacuum bag, 105 is a porous isolation film, 106 is a composite material, 107 is an air felt, 108 is a vacuum valve, 109 is a quick connector, and 110 is a sealing tape.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Embodiment one.

As shown in Figure 1-4.

A method for microwave curing of fiber-reinforced resin-based composite components, which first pre-evacuates one or several layers of prepreg fiber layups used to manufacture composite components, and puts them into octagonal multi-mode Microwave heating is carried out in the resonant cavity. During the entire curing process, temperature sensors are used to monitor the temperature of multiple points on the surface of the component, and the microwave power is automatically controlled to make the heating temperature conform to the process curve. Real-time measurement and monitoring of temperature and vacuum of components during curing. After the composite material is solidified, the furnace door is opened, and the component is placed outside the device to cool down. The next batch of parts and components are then put into the device for solidification and molding according to the above method. As shown in Figure 1 and 2.

During the curing process, a microwave source with linearly adjustable power can be used to generate microwaves. After being adjusted by the automatic impedance matching system, the microwaves enter the octagonal microwave multimode resonant cavity through the waveguide and slit antenna, and are heated and placed on the glass plate in the octagonal cavity. Fiber-reinforced resin-based composite material, the adjusted microwave is uniform and stable in the oven cavity. The composite material is placed on the surface of the composite material mold coated with a release agent. The surface of the material is covered with auxiliary vacuum materials such as release cloth, air felt, isolation film and vacuum bag, and sealed with vacuum tape as shown in Figure 4. When curing, vacuumize according to the process regulations, and paste the temperature sensing device on the mold. The device adopts an advanced octagonal microwave multi-mode resonant cavity structure and an automatic impedance matching system to realize the uniformity of the electromagnetic field and the stability of the load in the device, and to ensure the uniform distribution of the curing temperature of the components. At the same time, the temperature sensor installed in the device measures the temperature of the component in real time to ensure the controllability of the curing process. The device also uses choke slots to reduce microwave leakage. After the composite component is formed, the composite material is directly removed and cooled externally to room temperature. The mold can be made of one of carbon fiber reinforced composite material, glass fiber reinforced composite material, ceramic material, quartz material, high temperature resistant cement material or high temperature resistant gypsum material. A microwave heating source with linearly adjustable power, the microwave frequency range includes: 300MHz to 300GHZ, and the microwave frequency can be fixed or changed linearly or non-linearly within the range of 1-20MHz. The power of the microwave can be linearly adjusted from 0 to the maximum power according to the size of the cavity and the heating process requirements of the heating medium. The microwave in the multi-mode resonant cavity includes at least one or more modes of TEM wave, TE wave and TM wave. The microwave source consists of a controllable autotransformer and a magnetron, or a signal generator and a microwave amplifier. Fiber-reinforced resin-based composite materials are laid by laying prepregs layer by layer on the mold, and the laying directions can be different. As shown in Figure 4, the fiber reinforcement includes continuous carbon fiber or glass fiber or aramid fiber or boron fiber; or chopped carbon fiber or glass fiber or aramid fiber, one or more of which are mixed. The resin matrix includes: one of phenolic resin, epoxy resin, bismaleimide resin, polyimide resin or a modified resin thereof. The depth of the adopted choke groove can be a quarter of the microwave wavelength, so as to effectively counteract the microwave and reduce the leakage of the microwave. The automatic impedance matching system controls the drive of the stepping motor through the computer, controls the position of the pin in the impedance matcher, as shown in Figure 3, and then adjusts the size of the impedance, controls the microwave change of the waveguide, and combines with the octagonal microwave multimode resonant cavity structure Under the joint action, the microwave distribution in the furnace cavity is uniform and the load is stable, thereby ensuring uniform and stable heating of the microwave. Temperature sensors are used to measure the temperature of multiple points on the surface of composite components in real time during microwave heating. The measured temperature is fed back to the control system of the device, compared with the process curve, and the microwave heating temperature is adjusted in real time to achieve high-precision temperature control. The temperature sensor includes one or more of thermocouple, thermistor, infrared sensor, optical fiber fluorescence sensor and optical fiber grating sensor.

Embodiment two.

As shown in Figure 1-3.

A device for microwave-curing fiber-reinforced resin-based composite components, which includes: a carrier glass plate 1, a vacuum tube interface 2, a choke groove 3, a slit antenna 4, a furnace body 5, a temperature sensor joint 6, a temperature control panel 7, Operation panel 8, as shown in Figure 1, furnace door 9, ball screw 10, stepper motor 11, PLC 12, cooling water inlet 13, cooling water outlet 18, microwave generating source 19, microwave transmission line 20, impedance matching device 21, rectangular waveguide Device 22 and octagonal multimode resonator 23, as Fig. 2, described octagonal multimode resonator 23 is installed in the furnace body 5, and the rear portion of octagonal multimode resonator 23 has ball screw 10, the rest of the rear part is sealed, and the front furnace door 9 adopts a general-purpose choke-sealed metal coil to ensure no electromagnetic leakage; The composite material components are sent into or taken out from the octagonal multimode resonant cavity; the ball screw 10 is driven by the stepping motor 11, and the stepping motor 11 is controlled by the PLC12, and the microwave generating source 19 The microwave is transmitted to the rectangular waveguide device 22 through the microwave transmission line 20 and the impedance matching device 21, and then the microwave is introduced into the octagonal multimode resonator 23 by the slot antenna 4; internally reflected back and forth, and finally absorbed by the fiber-reinforced resin-based composite material; the cooling water enters from the cooling water inlet 13 to cool the microwave generating source 19 and then flows out from the cooling water outlet 18; the impedance matching device 21 is controlled by a computer 27 and a stepping motor 29 drive, placed between the rectangular waveguide device 22 and the microwave source 19; the temperature sensor joint 6 is connected with each temperature sensor to measure the temperature values of multiple points on the composite material component in real time, and transmits the temperature data to PLC12 to automatically control the microwave power, Make the heating temperature conform to the process curve; the temperature control panel 7 and the operation panel 8 control the power, heating temperature and vacuuming of the device to meet the normal operation requirements of the device. The temperature and vacuum degree of the composite material components measured in real time during the curing process are displayed on the temperature control panel 7 and the operation panel 8 for the control system to monitor and adjust the working status of the device. The control system is divided into manual and automatic control. , the heating power, heating time and vacuuming state are manually controlled according to the data displayed on the panel; during automatic control, the temperature process curve required for curing is input at 8 on the operation panel, and the PLC control device automatically operates. Described microwave generating source 19 is made up of microwave signal generator 14, microwave amplifier 15, controllable autotransformer 16 and magnetron 17, and the output of microwave signal generator 14 connects microwave amplifier 15, and the output of microwave amplifier connects controllable The input of the autotransformer, the output of the controllable autotransformer is connected to the magnetron, and the magnetron is sent to the impedance matching device 21 through the microwave transmission line for matching and then transferred to the rectangular waveguide device 22, and then the microwave is introduced to the eight sides by the slot antenna 4 Shaped multimode resonant cavity 23. The microwave is transmitted to the rectangular waveguide 22 through the microwave transmission line 20 connected with the microwave generating source 19 and the impedance matching device 21 , and then the microwave is guided into the multimode resonant cavity 23 by the slot antenna 4 . The microwaves are reflected back and forth in the octagonal multi-mode resonant cavity 23, and are finally absorbed by the fiber-reinforced resin-based composite material. At the beginning of curing, the vacuum tube is connected to the vacuum tube interface 2, and the system is evacuated. As the temperature of the material rises, the curing reaction of the resin begins, and after a period of heating and heat preservation, the composite material is solidified and formed. The size of the octagonal resonant cavity 23 is determined by the number of resonant modes and the power. There is a movement channel for the ball screw at the rear, and the rest of the rear is sealed. The front furnace door 9 adopts a general-purpose choke-sealed metal coil to ensure no electromagnetic leakage. The octagonal multi-mode resonant cavity 23 can excite multiple electromagnetic field working modes. Cooperating with the rectangular waveguide 22 and the impedance matching device 21, a uniform and stable electromagnetic field is formed in the resonant cavity, so that the temperature uniformity of the heated material is better. The impedance matching device 21 is driven by a computer and a stepping motor, and placed between the rectangular waveguide 22 and the microwave generating source 19 . Multiple temperature sensors are installed on the top of the device and connected to the temperature sensor joint 6 to measure the temperature values of multiple points on the composite material component in real time, and transmit the temperature data to PLC12 to automatically control the microwave power to make the heating temperature conform to the process curve. The temperature control panel 7 and the operation panel 8 control the power, heating temperature and vacuuming of the device to meet the normal operation requirements of the device. The control system measures the temperature and vacuum of the components during the curing process in real time, and displays them on the temperature control panel 7 and the operation panel 8 for monitoring and adjusting the working status of the device. The control system is divided into manual and automatic control. In manual control, the heating power, heating time and vacuuming state are controlled manually according to the data displayed on the panel. During automatic control, the temperature process curve required for curing is input at the operation panel 8, and the PLC control device automatically operates. PLC12 controls the stepping motor 11, and through the transmission of the ball screw 10, pushes the glass plate 1 back and forth, and cooperates with the crane outside the furnace to facilitate loading and unloading of molds with large volume and mass.

Taking carbon fiber as a reinforcing material and taking a thermosetting resin as a matrix, the specific embodiments of curing the components of the present invention are as follows:

Fig. 4 is the layering process of the composite material of the present invention on the mold. Brush a layer of release agent 102 evenly on the molding surface of the mold 101, brush the second time after 20 minutes, and brush the third time after another 30 minutes. After the release agent 102 is dried and solidified, take 20 layers of the prepreg 106 of the thermosetting resin-based carbon fiber reinforced composite material that has been cut, and lay them on the mold made of the composite material in the order of 0°, 45°, 90°, and 135°. 101, make the layer and layer, between the material surface and the mould, be close to each other.

After the layering is completed, a release cloth 103, a porous isolation film 105, an air felt 107, and a vacuum bag 104 are sequentially laid on the surface of the composite material. Vacuum bag 104 is sealed with sealing tape 110 along the periphery of mold 101, vacuum valve 108 and quick connector 109 are placed at the edge, vacuumed, and air tightness is tested, if air leaks, continue to compact sealing tape 110 and repeat the detection steps, if air If the tightness is intact, the mold is ready to be moved into a microwave oven for curing.

Fig. 1, 2 is the process that the microwave oven of the present invention controls and solidifies the composite material. Instructions are input on the operation panel 8, and the stepper motor 11 is controlled by the PLC 12. Through the transmission of the ball screw 10, the glass plate 1 is pushed to move out of the furnace, and the composite material to be cured and the mold are placed on the glass plate 1 by a crane, and the The vacuum tube is connected with the vacuum tube joint 2, vacuumized, and then an instruction is input from the operation panel 8 to retract the glass plate 1. Close the oven door 9 and tighten the knob on the door. Set the required temperature and process curve on the operation panel 8, first set 80 degrees for a period of pre-curing, then set the curing transition temperature of 120 degrees for a period of time, set the control mode to automatic control, and start the microwave oven.

After the microwave oven is started, the PLC12 controls the starting capacitor transformer to energize the microwave source 19 to generate microwaves. At the same time, cooling water enters from the cooling water inlet 13 to cool the microwave source and flows out from the cooling water outlet 18. The microwave passes through the microwave transmission line 20 and is transmitted into the rectangular waveguide 22 through the adjustment of the impedance matching device 21 . After the microwave enters the resonant cavity 23 through the slit antenna 4, it starts to heat the fiber-reinforced resin-based composite material. The vacuum joint 2 and the temperature sensor joint 6 transmit the vacuum degree and the temperature value of the temperature sensor in real time, display them on the host computer interface, and transmit the signal to the PLC12 at the same time, adjust the output of the microwave generator 19 after signal processing, and regulate the microwave power in real time , so that the temperature curve conforms to the set process curve.

After curing is completed, turn off the microwave source, and open the oven door 9. PLC12 controls the stepper motor 11, drives the glass plate 1 to move out of the furnace through the transmission of the ball screw 10, uses a crane to take out the cured composite material and mold, and cools to room temperature under natural conditions.

Fig. 3 is the working process of the automatic impedance matching device of the present invention. In the impedance matching device, the port II33 is connected to the magnetic induction device, and the port I32 is connected to the rectangular waveguide 22 . During the microwave heating process, the microwaves generated by the microwave generator 19 enter the impedance matching device 21 . Use the six-terminal interface 24 to complete the detection of the port II33, the detected value is transformed by the A/D converter 25, and then transferred to the computer 27 through the interface 26. The computer 27 compares the data with the data in the database to obtain the required adjustment value, and then transmits the adjustment signal to the drive circuit 28 through the interface 26, drives the stepper motor 29 to rotate, and adjusts the depth of the three pins 30, thereby changing The impedance of the impedance matching device realizes high-precision and high-speed impedance matching, thereby eliminating the interference of reflected waves on the microwave source and realizing the optimal transmission of microwave power.

The above are only specific application examples of the present invention, and do not constitute any limitation to the protection scope of the present invention. All technical solutions formed by equivalent transformation or equivalent replacement fall within the protection scope of the present invention.

The parts not involved in the present invention are the same as the prior art or can be realized by adopting the prior art.

Claims (6)

1. A method for microwave curing fiber-reinforced resin-based composite components, characterized in that a microwave heating source with adjustable power is used to generate microwaves, and the microwaves enter the octagon evenly and stably through waveguides and slot antennas after being adjusted by an automatic impedance matching system Shaped multimode resonant cavity, heating the fiber reinforced resin matrix composite material component placed on the glass plate in the octagonal multimode resonant cavity; the composite material component is laid on the surface of the composite material mold coated with a release agent, and the The surface is covered with release cloth, air felt, isolation film and vacuum bag and sealed with vacuum tape; when curing, vacuumize according to the process regulations, and attach a temperature sensor device to the mold, and the measured temperature is fed back to the control system and compared with the process curve Compare and adjust the microwave heating temperature in real time; realize the uniformity of the electromagnetic field and the stability of the load in the heating area through the octagonal multi-mode resonant cavity and the automatic impedance matching system, and ensure that the curing temperature of the composite material component is evenly distributed; The curing temperature of the composite material component ensures the controllability of the curing process; after the composite material component is solidified and formed, the composite material component is directly taken out and cooled to room temperature externally; the microwave frequency range of the microwave heating source with linearly adjustable power Including: 300MHz to 300GHZ, the microwave frequency is fixed or varies linearly or nonlinearly in the range of 1-20MHz; the microwave power can be linearly adjusted from 0 to the maximum power according to the size of the cavity and the heating process requirements of the heating medium ; The microwave entering the octagonal multimode resonant cavity includes TEM wave, TE wave, one or more of TM waves; the microwave heating source with linearly adjustable power is composed of a controllable autotransformer and a magnetron Composed, or composed of a signal generator and a microwave amplifier; on the surface of the octagonal microwave multimode resonator, there is a choke groove that can effectively offset microwaves and reduce microwave leakage. The groove depth of the choke groove is 1/4 microwave wavelength; the automatic impedance matching system is driven by a computer-controlled stepping motor, and then adjusts the size of the impedance by controlling the position of the pin in the impedance matching device, controls the microwave variation of the waveguide, and resonates with the octagonal microwave multimode Under the combined effect of the cavity structure, the microwave distribution in the furnace cavity is uniform and the load is stable, thereby ensuring uniform and stable heating of the microwave. 2. The method according to claim 1, wherein the composite material mold is a carbon fiber reinforced composite material mold, a glass fiber reinforced composite material mold, a ceramic material mold, a quartz material mold, a high temperature resistant cement material mold or a high temperature resistant mold. One of the plaster material molds. 3. The method according to claim 1, characterized in that the fiber-reinforced resin-based composite material is formed by laying up layers of prepregs on the composite material mold, and the laying directions are different; The fiber reinforcement used for reinforcement includes continuous carbon fiber or glass fiber or aramid fiber or boron fiber, or one or more mixtures of chopped carbon fiber or glass fiber or aramid fiber; the resin matrix includes: phenolic resin, ring One of oxygen resin, bismaleimide resin, polyimide resin or its modified resin. 4. The method according to claim 1, wherein the temperature sensing device comprises one or more of thermocouples, thermistors, infrared sensors, optical fiber fluorescence sensors and optical fiber grating sensors. 5. A microwave-cured device for fiber-reinforced resin-based composite components, characterized in that it includes: a loading glass plate (1), a vacuum tube interface (2), a choke slot (3), a slit antenna (4), a furnace body (5), temperature sensor connector (6), temperature control panel (7), operation panel (8), furnace door (9), ball screw (10), stepper motor (11), PLC (12), Cooling water inlet (13), cooling water outlet (18), microwave generating source (19), microwave transmission line (20), impedance matching device (21), rectangular waveguide device (22) and octagonal multimode resonant cavity (23 ), the octagonal multimode resonant cavity (23) is installed in the furnace body (5), and the rear part of the octagonal multimode resonant cavity (23) has a movement channel for the ball screw (10). The rest of the part is sealed, and the front furnace door (9) adopts a general-purpose choke-sealed metal coil to ensure no electromagnetic leakage; the loading glass plate (1) is connected with the ball screw (10) and driven by it to Composite material components are sent into or taken out of the octagonal multimode resonant cavity; the ball screw (10) is driven by a stepping motor (11), and the stepping motor (11) is controlled by the PLC (12), the microwave from the microwave source (19) is transmitted to the rectangular waveguide device (22) through the microwave transmission line (20) and the impedance matcher (21), and then the microwave is introduced into the octagonal multimode by the slot antenna (4). Inside the resonant cavity (23); microwaves are reflected back and forth in the octagonal octagonal multimode resonant cavity (23), and finally absorbed by the fiber-reinforced resin-based composite material; cooling water enters from the cooling water inlet (13) to support the microwave The generating source (19) flows out from the cooling water outlet (18) after being cooled; the impedance matching device (21) is driven by the computer (27) and the stepping motor (29), and placed between the rectangular waveguide device (22) and the microwave generating source ( 19); the temperature sensor joint (6) is connected with each temperature sensor to measure the temperature values of multiple points on the composite material component in real time, and transmit the temperature data to the PLC (12), and automatically control the microwave power to make the heating temperature conform to the process curve The temperature control panel (7) and the operation panel (8) control the power, heating temperature and vacuuming of the device to meet the normal operation requirements of the device; the microwave generating source (19) is composed of a microwave signal generator (14), a microwave amplifier (15), a controllable autotransformer (16) and a magnetron (17), the output of the microwave signal generator (14) is connected to the microwave amplifier (15), and the output of the microwave amplifier is connected to the input of the controllable autotransformer, The output of the controllable autotransformer is connected to the magnetron, and the magnetron is sent to the impedance matching device (21) through the microwave transmission line for matching and then transmitted to the rectangular waveguide device (22), and then the microwave is introduced into the octagon by the slot antenna (4). Shaped multimode resonant cavity (23). 6. The device according to claim 5, characterized in that the temperature and vacuum degree of the composite material component measured in real time during the curing process are displayed on the temperature control panel (7) and the operation panel (8) for monitoring by the control system and adjust the working state of the device. The control system is divided into manual and automatic control. In manual control, the heating power, heating time and vacuuming state are controlled manually according to the data displayed on the panel; in automatic control, input the curing time at the operation panel (8). The required temperature process curve is automatically operated by the PLC control device.