Electro-ignited combustion device and method of ignition

Abstract

The application discloses an electrically excited combustion device and an ignition method. The device comprises an ignition tube shell, an ultrasonic wave emitting end and a coupling receiving end. The ultrasonic wave emitting end converts external electric energy into high-frequency ultrasonic waves. The coupling receiving end comprises a primer and an ultrasonic wave receiving terminal. The primer is provided with a concave cavity opposite to the position of the ultrasonic wave emitting end. The ultrasonic wave receiving terminal is arranged at the geometric focal point of the parabolic surface of the concave cavity. The ultrasonic wave energy is gathered through the ultrasonic wave receiver, and then the directional ultrasonic waves emitted by the emitting end are converted into alternating current signals through the piezoelectric composite transducer. The electric signals are rectified and boosted through a boosting ignition module, and then used to excite the primer. The application realizes energy isolation transmission without metal contact through ultrasonic wave variable pressure transmission, and the ultrasonic wave energy is gathered. The sealed structure integrity is maintained, and efficient and stable energy transmission can be realized in a complex environment, so that the reliability and adaptability of the ignition system are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of energetic material ignition technology, and relates to an electro-induced combustion device and ignition method. Background Technology

[0002] In the ignition applications of solid rocket motors and other energetic materials, traditional ignition methods typically rely on components such as thermal resistance wires and detonators to first ignite the sensitive agent, and then gradually ignite the main charge through heat transfer. This approach suffers from low ignition efficiency, complex structure, stringent control requirements, and significant potential safety risks. In recent years, researchers have discovered that by directly applying a high-voltage, strong electric field to the main charge, rapid energy injection and direct ignition can be achieved. This method possesses significant advantages such as high intrinsic safety, extremely short ignition delay (down to the microsecond level), and excellent consistency, thus gradually becoming a cutting-edge research area of ​​interest in academia and engineering.

[0003] The currently prevalent technical approach is to transmit high-voltage, high-field energy through metal electrodes. However, this approach often requires the metal electrodes to be in direct contact with the ignition agent or to penetrate a sealed structure to introduce energy. Although some progress has been made in certain applications, significant shortcomings remain: metal electrodes can compromise structural integrity and airtightness, and additional insulation and protective measures are required in complex environments such as low pressure or flight, limiting their adaptability and reliability.

[0004] To address these issues, explorations have emerged into wireless power transfer ignition technologies, with electromagnetic induction being the most common. This method achieves energy transfer through magnetic field coupling, avoiding some metal-to-metal contact problems. However, electromagnetic induction technology inherently relies on air gaps or magnetic materials as the propagation medium, making it unsuitable for environments requiring high-strength solid seals. Furthermore, electromagnetic interference is difficult to completely eliminate in complex electromagnetic environments. In addition, electromagnetic coils have inherent limitations in terms of miniaturization and spatial adaptability. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides an electro-ignition combustion device that achieves metal-free energy isolation transmission through ultrasonic voltage conversion. Simultaneously, it focuses ultrasonic energy to enhance energy conversion, maintaining the integrity of the sealed structure and avoiding safety hazards associated with metal electrodes. Furthermore, it enables efficient and stable energy transmission in complex environments, significantly improving the reliability and adaptability of the ignition system.

[0006] Another object of the present invention is to provide an ignition method for an electro-induced combustion device.

[0007] The technical solution adopted in this invention is an electro-induced combustion device, comprising an ignition tube housing, and further comprising: The ultrasonic transmitter is used to convert external electrical energy into high-frequency ultrasonic waves and transmit them directionally to the coupled receiver. The coupling receiving end includes a propellant and an ultrasonic receiving terminal. The ultrasonic receiving terminal includes an ultrasonic receiver and a piezoelectric composite transducer. The propellant is installed in a cavity in the middle of the ignition tube housing. A concave cavity is provided in the propellant directly opposite the ultrasonic transmitting end. The ultrasonic receiving terminal is located at the geometric focus of the parabolic surface of the concave cavity. The ultrasonic receiver focuses the ultrasonic energy, and then the piezoelectric composite transducer converts the directional ultrasonic wave emitted by the transmitting end into an alternating current signal. The voltage boosting ignition module rectifies and boosts the voltage of the electrical signal to excite the propellant.

[0008] Furthermore, the ultrasonic transmitter includes an ultrasonic transducer circuit, which converts the electrical signal into ultrasonic waves with a working frequency of 20kHz to 100kHz through the inverse piezoelectric effect. The ultrasonic waves are then transmitted to the coupled receiver through the ultrasonic transmitter terminal.

[0009] Furthermore, the ultrasonic transmitting terminal uses multiple independent transmitters connected in parallel or series to form an array to form a transmitting surface; the transmitting surface of the ultrasonic transmitting terminal is provided with a horn-shaped sound-focusing cover, and the opening diameter of the sound-focusing cover is consistent with the cavity diameter of the ignition powder.

[0010] Furthermore, the cavity on the propellant end face is a paraboloid of revolution structure, and the surface equation of the paraboloid of revolution structure satisfies ,in Let h be the focal length; the relationship between the cavity depth h and the aperture D satisfies: .

[0011] Furthermore, the coupling receiver also includes an acoustically permeable potting layer, which encapsulates the ultrasonic receiving terminal and the boost ignition module, and fills the space between the ultrasonic receiving terminal, the boost ignition module and the ignition propellant. The concave surface of the ignition propellant is in close contact with the acoustically permeable potting layer. The material of the acoustically permeable potting layer is epoxy resin or acoustically permeable ceramic.

[0012] Furthermore, the coupling receiver adopts a bidirectional receiving structure, including two back-to-back ultrasonic receivers. One ultrasonic receiver has its receiving surface facing the ultrasonic transmitter to receive direct ultrasonic waves; the other ultrasonic receiver has its receiving surface facing the concave surface of the propellant 4 to receive ultrasonic waves reflected and focused by the concave surface.

[0013] Furthermore, the boost ignition module integrates a rectifier circuit, an energy storage circuit, a boost circuit, and an ignition electrode. It converts the AC pulse signal output from the receiving end into DC power, boosts the stable DC power to the kV level, and ignites the propellant through the ignition electrode embedded in the propellant. The ignition electrode is completely enclosed inside the ignition tube shell, with no metal pins extending to the outside through the side wall of the ignition tube shell.

[0014] Furthermore, a bandpass filter is added before the rectifier circuit, the passband of which is determined by the operating frequency.

[0015] Furthermore, the propellant is an energetic material doped with metal powder, wherein the metal powder is selected from at least one of aluminum powder, magnesium powder or aluminum-magnesium alloy powder, and the mass fraction of the metal powder in the propellant is 5%-20%.

[0016] An ignition method for an electro-induced combustion device includes the following steps: An external power source drives the ultrasonic transmitter to generate high-frequency ultrasonic waves, which are then transmitted directionally to the coupled receiver. High-frequency ultrasonic waves propagate through the medium to the concave surface of the propellant, and are reflected and focused to the ultrasonic receiving terminal. The ultrasonic receiving terminal converts acoustic energy into an alternating current signal, which is then rectified and boosted by the boost ignition module to ignite the combustion of the propellant.

[0017] The beneficial effects of this invention are: (1) The pre-embedded electrode of this invention is completely enclosed inside the ignition tube shell and integrated with the boost module. No metal wires penetrate the sealed structure of the propellant throughout the process, completely avoiding the risks of leakage, short circuit and accidental ignition caused by traditional pyrotechnics. The receiving end is directional, and can only receive ultrasonic signals of a fixed direction and frequency, which are then converted into electrical energy. Energy transmission is only initiated when the transmitting end receives the trigger signal, reducing the probability of false triggering and improving safety.

[0018] (2) This invention relies on the stable propagation characteristics of ultrasound in solid media and combines piezoelectric materials to achieve bidirectional conversion of electrical energy and ultrasonic vibration. A shallow concave cavity with a rotating parabolic surface is designed on the surface of the energetic drug, and its acoustic focusing characteristics are used to concentrate the ultrasonic energy, so that the energy coupling efficiency breaks through the limitations of conventional receiving methods, significantly improving energy conversion and ignition reliability. In addition, it breaks through the propagation medium limitations of traditional electromagnetic induction, does not rely on air gaps or magnetic materials, and can be adapted to solid sealed environments. Each unit of the device adopts a high temperature and pressure resistant metal shell, and the whole has a wide temperature range (-20℃~105℃), high pressure resistance, and is not affected by electromagnetic interference. The device does not generate electromagnetic interference and has little impact on other devices, thereby greatly improving environmental adaptability.

[0019] (3) Compact structure and wide adaptability: The ultrasonic transmitter and coupling receiver of this invention have independent physical structures, which can be flexibly adjusted according to the size of the drug body and adapted to various types of energetic materials; the device is small in size, compact in structure, and widely adaptable, and can be embedded in a miniaturized ignition system, taking into account both integration and practicality. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the receiving device according to an embodiment of the present invention.

[0023] In the diagram, 1. Ignition tube housing; 2. Flange; 3. Ignition port; 4. ignition propellant; 5. Discharge needle tip; 6. Boost ignition module; 7. Ultrasonic receiving terminal; 8. Acoustic-permeable potting layer; 9. Ultrasonic transmitting terminal; 10. Sound-focusing cover; 11. Ultrasonic transducer circuit; 12. Power supply input terminal; 13. Control signal input terminal; 14. Ultrasonic signal; 15. Bandpass filter; 16. Rectifier circuit; 17. Energy storage circuit; 18. Boost circuit; 19. High voltage output terminal. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1, An electro-induced combustion device, such as Figure 1 As shown, it includes a physically independent coupled receiver and an ultrasonic transmitter.

[0026] The ultrasonic transmitter is used to convert externally input electrical energy into high-frequency ultrasonic waves and transmit them directionally to the coupling receiver, providing a stable sound source for subsequent energy focusing and conversion.

[0027] The coupling receiver includes a propellant 4 and an ultrasonic receiving terminal 7. The propellant 4 has a cavity on its end face facing the ultrasonic transmitter. The ultrasonic receiving terminal 7 is located at the geometric focus of the parabolic surface of the cavity to converge ultrasonic energy.

[0028] In this embodiment, the ultrasonic transmitter includes an ultrasonic transducer circuit 11, which employs a piezoelectric ceramic transducer. The circuit is connected to a control signal input terminal 13 and a power supply input terminal 12. The control signal input terminal 13 receives a 100ms ignition pulse from a timing controller, controlling the ultrasonic transducer circuit 11 to start. The ultrasonic transducer circuit 11 converts the electrical signal into ultrasonic waves with a working frequency of 20kHz to 100kHz (preferably 40kHz to 100kHz) through the inverse piezoelectric effect. The ultrasonic waves are transmitted to the coupled receiver terminal through the ultrasonic transmitter terminal 9. The size of the piezoelectric ceramic transducer is adapted to the cavity diameter of the propellant 4 end face. Frequency ranges below 20kHz are audible but generate noise interference; frequencies above 100kHz attenuate too quickly in solid media, limiting propagation distance; piezoelectric transducers in the 40kHz to 100kHz range have high efficiency and are easily miniaturized; this frequency range avoids common mechanical vibration and electromagnetic interference bands.

[0029] The ultrasonic transmitting terminal 9 can use multiple independent transmitters connected in parallel or series to form an array to form a transmitting surface. The transmitting surface of the ultrasonic transmitting terminal 9 is equipped with a sound-focusing cover 10, which is made of a material with high sound reflectivity (such as stainless steel 304 or aluminum alloy 6061). The sound-focusing cover 10 is horn-shaped, and the opening diameter is consistent with the cavity diameter of the end face of the propellant 4, guiding the ultrasonic waves to be transmitted directionally to the propellant block and reducing the diffusion loss of sound waves to the surrounding environment. Secondly, the parabolic structure of the propellant 4 has directional selectivity for the incident wave, and only incident waves in a specific direction can be effectively reflected to the focal point.

[0030] The ultrasonic receiving terminal 7 includes an ultrasonic receiver and a piezoelectric composite transducer. The piezoelectric composite transducer is the core component of the ultrasonic receiving terminal 7 and is also the component that realizes energy conversion. The piezoelectric composite transducer is fixed at the rear of the ultrasonic receiving terminal 7 (this front-rear layout is the standard structure of transducers). When designing the ultrasonic receiving terminal 7, a miniaturized design is adopted to facilitate fixing it at the geometric focus of the concave cavity parabolic surface, without obstructing the sound path, and avoiding occupying too much area, thus preventing energy loss of the ultrasonic waves. The piezoelectric composite transducer uses a piezoelectric composite material, or a multi-layer structure composed of a PZT piezoelectric ceramic sheet and a matching layer and a backing layer (known in the art).

[0031] In this embodiment, the cavity at the end face of the ignition powder 4 is a paraboloid of revolution, and its surface equation satisfies ,in Let h be the focal length; the relationship between the cavity depth h and the aperture D satisfies: By controlling the ratio of f to D, the piezoelectric composite transducer is positioned precisely at the geometric focal point, with a positional deviation of less than ±0.2 mm. Its specific dimensions can be calculated based on the actual dimensions of the engine compartment. The surface roughness Ra of the concave cavity should be as small as possible (less than 1.6 μm) to ensure specular reflection of acoustic waves, reduce diffuse reflection loss, ensure the convergence of ultrasonic waves within the cavity, and prevent random energy diffusion into the propellant.

[0032] The ultrasonic receiving terminal 7 is fixed at the focal point of the parabolic surface of the front cavity of the propellant 4 by the acoustically permeable potting layer 8. The ultrasonic receiving terminal 7 can be a single terminal or an array of receiving terminals forming the receiving surface. This receiving surface can face the propellant block, or it can be a bidirectional receiving surface, where two ultrasonic receivers are connected back-to-back. One faces the propellant block, receiving the sound waves reflected and converged at the focal point by the parabolic surface; the other faces the ultrasonic transmitting terminal 9, receiving the direct waves. This ensures sufficient ultrasonic energy is received. If the ultrasonic receiver only faces the ultrasonic transmitting terminal 9, it can only receive the direct ultrasonic waves and cannot receive the ultrasonic waves reflected and converged by the parabolic surface, resulting in low energy reception efficiency.

[0033] In this embodiment of the invention, ultrasonic signals 14 penetrate a solid medium (the solid medium mainly refers to the acoustically permeable potting layer 8, and also includes the bottom material of the ignition tube shell 1) to wirelessly transmit energy to a receiving end within a sealed structure. The parabolic structure design on the surface of the energetic propellant is not intended to create an ignition focal point inside or outside the propellant, but rather to efficiently focus the acoustic energy onto a specific piezoelectric composite transducer. The ultrasonic receiving terminal 7, in conjunction with the piezoelectric composite transducer, converts the directional ultrasonic signal emitted by the transmitting end into an electrical signal, outputting an AC pulse electrical signal.

[0034] The piezoelectric composite transducer is connected to the boost ignition module 6, such as... Figure 2 As shown, the boost ignition module 6 integrates a rectifier circuit 16, an energy storage circuit 17, a boost circuit 18, and a high-voltage output terminal 19. The rectifier circuit 16 uses a high-voltage rectifier bridge to convert the AC pulse signal output from the receiving end into DC power. The energy storage circuit 17 is responsible for storing the DC pulses and outputting a relatively stable DC voltage. The boost circuit 18 uses a charge pump circuit and a piezoelectric stacked structure to boost the stable DC power to the kV level. The high-voltage output terminal 19 is connected to the discharge needle tip 5 through a high-voltage wire, and the discharge needle tip 5, which is pre-embedded in the ignition propellant, ignites the propellant 4.

[0035] A bandpass filter 15 is added before the rectifier circuit 16. The electrical signal is filtered out by the bandpass filter 15 to remove non-specific frequency signals and output AC pulse electrical signals. The passband of the bandpass filter 15 can be designed according to the operating frequency to avoid accidental ignition caused by misoperation or external interference.

[0036] The ultrasonic receiving terminal 7 and the boost ignition module 6 constitute the receiving module, which is encapsulated by the acoustically transparent potting layer 8. The internal cavity of the ignition tube shell 1 is the ignition chamber. The ignition tube shell 1 is cylindrical. The encapsulated receiving module and the ignition charge 4 with a shallow concave cavity are sequentially installed on the end face of the ignition tube shell 1 near the ultrasonic transmitting end. The other end of the ignition tube shell 1 and the curved side wall are provided with multiple ignition holes 3. When ignition is successful, the flame is ejected from the ignition holes 3 and ignites the main charge.

[0037] The propellant 4 uses one or more chemical substances that enhance sound reflectivity, such as metal powder (aluminum powder (Al), magnesium powder (Mg), or aluminum-magnesium alloy powder), with a metal mass fraction of 5% to 20%, to improve the focusing ability of the parabola on sound.

[0038] The receiving module can be pre-filled with sound-permeable materials such as epoxy resin to obtain a sound-permeable filling layer 8. The shape of the sound-permeable filling layer 8 can be designed according to the ignition cavity. The direction of contact with the propellant block can be molded into a parabolic shape to facilitate the filling of the propellant and ensure a tight fit between the propellant block and the sound-permeable filling layer 8, avoiding sound energy attenuation caused by gaps. The ignition powder 4 is made by using a filling powder mixed with metal powder. The ignition powder 4 is filled into the ignition cavity, and the pre-filled resin material is placed inside as a mold to construct a parabolic shape. This process ensures that the roughness of the parabolic surface of the ignition powder 4 is small, reducing diffuse reflection of sound.

[0039] The material selection for the acoustically transparent potting layer 8 should be determined based on the operating temperature of the specific application scenario: Epoxy resin (bisphenol A type epoxy resin (such as E-51, E-44) or alicyclic epoxy resin) is suitable for normal temperature environments (long-term operating temperature -40℃ to 80℃, short-term resistance to 120℃), with simple processing, low cost, and an acoustic impedance of approximately 3 MRayleigh. Acoustically transparent ceramic materials such as alumina ceramics and silicon nitride ceramics are suitable for ultra-high temperature environments (1600℃). Due to their extremely high acoustic impedance, a quarter-wavelength matching layer must be designed to reduce interface reflection and ensure effective sound energy transmission.

[0040] The acoustic impedance matching strategy between the acoustically transparent potting layer 8, the ignition propellant 4, and the ultrasonic receiving terminal 7 is as follows: First, epoxy resin, a material with good sound transmission properties, is selected. The acoustic impedance of epoxy resin is approximately 3 MRayles, which is moderately different from the acoustic impedance of propellant 4 (approximately 3-5 MRayles) and the acoustic impedance of the piezoelectric composite transducer (approximately 10-15 MRayles). It can be used directly as a coupling medium, eliminating the need for an additional matching layer design. This simplifies the process and reduces costs.

[0041] Secondly, impedance gradient is achieved through a multi-layered composite structure; a multi-layered material with a gradual transition in acoustic impedance is set between the propellant 4 and the piezoelectric composite transducer, including epoxy resin and acoustically transparent ceramics, to reduce abrupt reflections.

[0042] Experimental data demonstrates the following energy transmission efficiencies: Using only a support structure to fix the ultrasonic receiving terminal, the acoustic energy transmittance is approximately 35% to 40%. After encapsulation with epoxy resin, the transmittance increases to 55% to 60%. Using epoxy resin encapsulation, and with a multi-layered material (multi-layered composite matching structure) providing a gradual transition in acoustic impedance between the propellant 4 and the piezoelectric composite transducer, the transmittance can reach 70% to 75%.

[0043] Using the preferred scheme of this invention (rotating parabolic cavity at the four ends of the propellant, bidirectional receiving structure, propellant doped with metal powder, potting material and multi-layer composite matching design), the overall acoustic-electric conversion efficiency is measured to be 72%, which is more than 80% higher than the conventional scheme (planar propellant surface without focusing, single-phase piezoelectric ceramic transducer, no multi-layer composite matching design, no doped propellant).

[0044] In complex electromagnetic / acoustic environments, misfires can be caused by interference signals of various frequencies. In this embodiment of the invention, the passband of the bandpass filter is strictly matched with the set transmission frequency; simultaneously, high-intensity reflected sound is received only at the focal point of the parabolic surface, while interference sound deviating from the focal point cannot effectively excite the transducer; furthermore, the bidirectional receiving surface design allows the receiving terminal to simultaneously receive both direct and reflected sound, but the receiving efficiency for non-axially propagating interference sound is low. Through the dual selection of the physical layer and the circuit layer, the probability of misfires is significantly reduced, overcoming the above-mentioned problems.

[0045] This device does not require the electrodes to be inserted through an opening in the engine compartment. If high-pressure resistant metal materials (such as 304 stainless steel) are used, it can withstand working pressure ≤20MPa, which meets the working pressure requirements of the solid rocket engine combustion chamber and ensures the strength of the device to a certain extent, thus having high pressure resistance.

[0046] Example 2, An ignition method for an electro-induced combustion device includes the following steps: During operation, the user first fixes the ignition tube housing 1 to the bracket via the flange 2 to achieve positioning and ensure that the bottom surface of the ignition tube is in close contact with the top surface of the transmitter (specifically, the bottom surface of the ignition tube housing 1 is in close contact with the bottom of the sound focusing cover 10).

[0047] After the control system is started, the ultrasonic transducer circuit 11 converts the electrical signal into ultrasonic waves of a specific frequency through the inverse piezoelectric effect. The ultrasonic waves are then transmitted through the sound-transmitting material to the parabolic surface of the propellant 4 via the transmitting terminal, and then reflected to the receiving terminal at the focal point of the parabolic surface.

[0048] The piezoelectric composite transducer converts the received ultrasonic waves into electrical signals, which are then rectified, stored, and boosted to generate a high-voltage electric field between the ignition electrodes in the pre-embedded propellant 4. This rapidly ignites the propellant and then ignites the main charge through the ignition port 3. The entire ignition response time is less than 100 nanoseconds, the ignition energy is controllable, and the process is highly precise and reliable.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. An electro-induced combustion device, comprising an ignition tube housing (1), characterized in that, Also includes: The ultrasonic transmitter is used to convert external electrical energy into high-frequency ultrasonic waves and transmit them directionally to the coupled receiver. The coupling receiving end includes a propellant (4) and an ultrasonic receiving terminal (7). The ultrasonic receiving terminal (7) includes an ultrasonic receiver and a piezoelectric composite transducer. The propellant (4) is installed in the cavity in the middle of the ignition tube shell (1). The propellant (4) has a concave cavity in front of the ultrasonic transmitting end. The ultrasonic receiving terminal (7) is located at the geometric focus of the parabolic surface of the concave cavity. The ultrasonic energy is gathered by the ultrasonic receiver, and then the directional ultrasonic wave emitted by the transmitting end is converted into an AC signal by the piezoelectric composite transducer. The AC signal is rectified and boosted by the boost ignition module (6) and used to excite the propellant (4).

2. The electro-induced combustion device according to claim 1, characterized in that, The ultrasonic transmitter includes an ultrasonic transducer circuit (11), which converts electrical signals into ultrasonic waves with a working frequency of 20kHz to 100kHz through the inverse piezoelectric effect. The ultrasonic waves are transmitted to the coupled receiver through the ultrasonic transmitter terminal (9).

3. The electro-induced combustion device according to claim 2, characterized in that, The ultrasonic transmitting terminal (9) uses multiple independent transmitters connected in parallel or series to form an array to form a transmitting surface; the transmitting surface of the ultrasonic transmitting terminal (9) is provided with a horn-shaped sound-gathering cover (10), and the opening diameter of the sound-gathering cover (10) is consistent with the cavity diameter of the ignition powder (4).

4. The electro-induced combustion device according to claim 1, characterized in that, The cavity on the end face of the ignition powder (4) is a parabolic rotating surface structure.

5. The electro-induced combustion device according to claim 1, characterized in that, The coupling receiver also includes a sound-permeable potting layer (8), which wraps the ultrasonic receiving terminal (7) and the boost ignition module (6) and fills the space between the ultrasonic receiving terminal (7), the boost ignition module (6) and the ignition charge (4). The concave surface of the ignition charge (4) is in close contact with the sound-permeable potting layer (8). The material of the sound-permeable potting layer (8) is epoxy resin or sound-permeable ceramic.

6. The electro-induced combustion device according to claim 1, characterized in that, The coupling receiver adopts a bidirectional receiving structure, including two back-to-back ultrasonic receivers, one of which has its receiving surface facing the ultrasonic transmitter; the other has its receiving surface facing the concave surface of the propellant 4.

7. The electro-induced combustion device according to claim 1, characterized in that, The boost ignition module (6) integrates a rectifier circuit (16), an energy storage circuit (17), a boost circuit (18), and an ignition electrode. It converts the AC pulse signal output from the receiving end into DC power, boosts the stable DC power to the kV level, and ignites the propellant (4) through the ignition electrode embedded in the propellant. The ignition electrode is completely enclosed inside the ignition tube shell (1), and no metal pins extend to the outside through the side wall of the ignition tube shell (1).

8. The electro-induced combustion device according to claim 7, characterized in that, A bandpass filter (15) is added before the rectifier circuit (16), and the passband of the bandpass filter (15) is based on the operating frequency.

9. The electro-induced combustion device according to claim 1, characterized in that, The ignition powder (4) is an energetic material doped with metal powder, wherein the metal powder is selected from at least one of aluminum powder, magnesium powder or aluminum-magnesium alloy powder, and the mass fraction of the metal powder in the ignition powder (4) is 5%-20%.

10. The ignition method of the electro-induced combustion device as described in claim 1, characterized in that, Includes the following steps: An external power source drives the ultrasonic transmitter to generate high-frequency ultrasonic waves, which are then transmitted directionally to the coupled receiver. High-frequency ultrasonic waves propagate through the medium to the concave surface of the propellant (4), and are reflected and focused to the ultrasonic receiving terminal (7). The ultrasonic receiving terminal (7) converts acoustic energy into an alternating current signal, and the signal is rectified and boosted by the boost ignition module (6) to ignite the propellant (4) into combustion.

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