CN202031756U - Gap coupling microwave plasma igniter for combustion engine - Google Patents

Abstract

A gap coupling microwave plasma igniter for a combustion engine belongs to the technical field of microwave application, and is formed by integrally designing and processing a quarter-wave coaxial resonant cavity, a gap coupling structure, a step coaxial matching structure and an N-typed radio frequency coaxial connector. The quarter-wave coaxial resonant cavity can realize body combustion of a combustion chamber and adequate combustion of fuel-vapor mixture under a low input power. The gap coupling structure can finish microwave energy input of the quarter-wave coaxial resonant cavity, and reduces effects on the resonant cavity of an outer circuit. The step coaxial matching structure can realize fine match of the whole circuit. The N-typed radio frequency coaxial connector serves as a microwave input terminal, and can be used by being directly matched with an existing low-cost microwave generator. The gap coupling microwave plasma igniter for the combustion engine has a similar appearance with an existing spark plug, and can be matched with a cylinder of a general combustion engine. Further, the gap coupling microwave plasma igniter for the combustion engine directly replaces the existing spark plug on the basis of not changing the cylinder structure, and has the advantages of being high in combustion efficiency, low in manufacture cost, good in processing repeatability, easy to produce massively and the like.

Description

A gap-coupled microwave plasma igniter for internal combustion engines

technical field

The utility model belongs to the field of microwave application technology and relates to an ignition device for an automobile engine. the

Background technique

At present, the ignition system of an automobile engine is usually composed of a battery, a generator, a distributor, an ignition coil, and a spark plug. In a gasoline engine, the combustible mixture in the cylinder is ignited by an electric spark. For this reason, a spark plug is installed on the cylinder head of the gasoline engine, and the head of the spark plug extends into the combustion chamber. The ignition system turns the low voltage of the power supply into a high voltage, which is then sent to each cylinder in turn according to the ignition sequence of the engine to ignite the compressed air mixture. However, a lot of potential energy has not been utilized in the above-mentioned combustion process. About 35% to 40% of the heat energy of fuel combustion is used for actual driving, and the insufficient combustion of the mixture produces a large amount of harmful substances, such as carbon monoxide, nitrogen oxides, Hydrocarbons, etc., aggravated environmental pollution. the

Recent studies have shown that microwave plasma ignition can make the combustion more rapid and complete, and greatly improve the combustion efficiency [1]. At the same time, for some current new technologies to improve the fuel economy of gasoline engines, such as lean combustion technology of gasoline engines, microwave plasma ignition has obvious advantages over spark plug ignition [2]. The current microwave plasma ignition system can be divided into two categories. One type directly inputs the microwave into the engine cylinder, but at this time it needs to input extremely high microwave power to achieve the ignition condition; the other type of more practical microwave ignition technology requires A special microwave plasma igniter is used to feed microwaves into the combustion chamber to generate plasma. At this time, only low input power is required to complete the ignition task. the

The utility model adopts the realization scheme of the second type of microwave ignition. As one of the key technologies, the microwave plasma igniter not only needs to meet and adapt to the index requirements and working conditions of the microwave plasma ignition system, but also needs to have the same shape as the existing spark plug for direct replacement or upgrade. Existing microwave plasma igniters are usually assembled from several sub-components, each component is processed separately, the consistency is poor, the design index and the actual measurement result are quite different, the stability is low, manual debugging is required, and it is difficult to mass produce . the

Contents of the invention

The utility model provides a series of gap-coupled igniters suitable for the microwave plasma automobile ignition system. There are three types in total, all of which are designed and processed by four sub-parts: a quarter-wavelength coaxial resonant cavity, a gap-coupled structure, Ladder coaxial matching structure, N-type RF coaxial connector. The appearance of this type of igniter is similar to the existing spark plug, and can be matched with the conventional automobile engine cylinder, directly replacing the existing spark plug without changing the structure of the engine cylinder. the

The technical scheme of the utility model is:

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy dismounting and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour one 31, corresponding to the inner conductor tip 5, respectively The outer conductor inner contour two 32 corresponding to the inner conductor one 41, the outer conductor inner contour three 33 corresponding to the inner conductor two 42, the outer conductor inner contour four 34 corresponding to the inner conductor three 43, and the inner conductor three 43 The corresponding outer conductor inner contour four 34, the outer conductor inner contour five 35 corresponding to the inner conductor four 44; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44, Inner conductor tip 5 is formed; inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44 are coaxial cylinder structures, inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor The tip 5 is connected to the first inner conductor 41, there is a coupling gap 6 between the first inner conductor 41 and the second inner conductor 42, the second inner conductor 42, the third inner conductor 43 and the fourth inner conductor 44 are sequentially connected, and the radii of the three gradually increase; The side of conductor one 41 close to the coupling gap 6 is directly connected to the outer conductor through the horizontal connecting conductor 7 of the cylinder, and the axis of the horizontal connecting conductor 7 of the cylinder is perpendicular to the axis of the inner conductor one 41; between the inner conductor and the outer conductor, except the inner conductor The area between the tip 5 and the outer conductor inner contour one 31 and the area between the inner conductor four 44 and the outer conductor inner contour five 35 are all filled with insulating medium 8; the outer conductor inner contour five 35 and the inner conductor four 44 A microwave input port 1 is formed, and its size is consistent with that of a standard N-type radio frequency coaxial connector. the

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy dismounting and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour-31, corresponding to the inner conductor tip 5 respectively The outer conductor inner contour two 32 corresponding to the inner conductor one 41, the outer conductor inner contour three 33 corresponding to the inner conductor two 42, the outer conductor inner contour four 34 corresponding to the inner conductor three 43, and the inner conductor three 43 The corresponding outer conductor inner contour four 34, the outer conductor inner contour five 35 corresponding to the inner conductor four 44; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44, Inner conductor tip 5 is formed; inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44 are coaxial cylinder structures, inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor The tip 5 is connected to the first inner conductor 41, there is a coupling gap 6 between the first inner conductor 41 and the second inner conductor 42, the second inner conductor 42, the third inner conductor 43 and the fourth inner conductor 44 are sequentially connected, and the radii of the three gradually increase; The side of the conductor one 41 close to the coupling gap 6 is connected to the outer conductor through a cylinder horizontal connection conductor 71 and a cylinder vertical connection conductor 72, the axis of the cylinder horizontal connection conductor 71 is perpendicular to the axis of the inner conductor one 41, and the cylinder vertical connection The axis of the conductor 72 is parallel to the axis of the inner conductor one 41; between the inner conductor and the outer conductor except the area between the inner conductor tip 5 and the outer conductor inner contour one 31 and between the inner conductor four 44 and the outer conductor inner contour five 35 Other regions except the region are filled with insulating medium 8; the outer conductor inner contour 5 35 and the inner conductor 4 44 form the microwave input port 1, and its size is consistent with the standard N-type radio frequency coaxial connector. the

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy dismounting and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour one 31, corresponding to the inner conductor tip 5, respectively Outer conductor inner contour two 32 corresponding to inner conductor one 41, outer conductor inner contour three 33 and outer conductor inner contour four 34 corresponding to inner conductor two 42, outer conductor inner contour five corresponding to inner conductor three 43 35; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, and inner conductor tip 5; inner conductor one 41, inner conductor two 42, and inner conductor three 43 are cylindrical structures, and the inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor two 42 and the inner conductor three 43 are coaxial; the inner conductor tip 5 is connected with the inner conductor one 41, and the bottom of the inner conductor one 41 is directly connected with the outer conductor; the inner conductor one 41 The side near the bottom is connected to the inner conductor two 42 successively through the coupling gap 6 and the cylindrical horizontal connecting conductor 7, the inner conductor two 42 is connected to the inner conductor three 43, and the radii of the two gradually increase; the axis of the cylindrical horizontal connecting conductor 7 Perpendicular to the axis of the inner conductor one 41; between the inner conductor and the outer conductor except the area between the inner conductor tip 5 and the outer conductor inner contour one 31 and the area between the inner conductor three 43 and the outer conductor inner contour five 35 The other areas of the other parts are filled with insulating medium 8, the inner contour five 35 of the outer conductor and the third inner conductor 43 constitute the microwave input port 1, and its size is consistent with the standard N-type radio frequency coaxial connector. the

In the design process, the quality factor of the igniter can be effectively controlled by setting the inner and outer radii of the quarter-wavelength coaxial resonator reasonably. The igniter with a high quality factor can generate a larger electric field under the same input power, and more Excite the plasma well and save energy. The slot coupling structure described in this patent is an electrical coupling method, which ensures that the quality factor of the coaxial resonator is less affected by external circuits while inputting microwave power into the quarter-wavelength coaxial resonator. In this patent, the three kinds of igniters all adopt the realization method of gap coupling, but the specific circuit forms are different. Generally speaking, the shape and spacing of the coupling gap determine the size of the coupling coefficient; the diameter and position of the connecting conductor also affect the coupling coefficient; meanwhile, these parameters also have a significant impact on the standing wave ratio of the igniter. The microwave power output by high-power microwave devices such as magnetrons is input into the igniter through microwave devices such as coaxial cables and N-type radio frequency coaxial connectors, which requires the input end of the igniter to be the same size as the standard N-type radio frequency coaxial connector. unanimous. For the integrated design, an additional transition matching structure is required inside the igniter, and multi-level coaxial cables with different inner and outer diameters can achieve good matching. For ease of use, the microwave input ports of the igniter are all designed at the bottom of the igniter. the

All three gap-coupled microwave plasma igniters include an outer conductor and an inner conductor, and the corresponding area between the outer conductor and the inner conductor is filled with ceramic materials to block direct contact between fuel oil and the ignition system and reduce corrosion. the

The working principles of these igniters are the same, and they all use the structural characteristics of the quarter-wavelength coaxial resonant cavity and the electrical characteristics of high quality factor, which can form a very high electric field intensity at the end of the inner conductor of the igniter, and the end of the inner conductor The tip structure can further enhance the electric field strength. When the input power is 500W, the average electric field intensity at the tip of the inner conductor of the igniter can be higher than 2.25*10 ⁷ V/m. At this time, it can break down the oil-gas mixture around the tip of the inner conductor at 10 standard atmospheric pressure and generate plasma. Achieve ignition. Subsequently, through the rapid movement of plasma electrons in the combustion chamber, the bulk combustion of the entire combustion chamber and the complete combustion of the oil-gas mixture are realized extremely quickly.

Beneficial effect:

The utility model has the following advantages:

1. Compared with ordinary spark plugs, this igniter can ignite a very thin mixture of oil and gas【1】【2】;

2. Compared with ordinary spark plugs, the ignition efficiency of this igniter is higher【3】;

3. The igniter has no cathode structure, which can avoid the hot spot load generated between the two electrodes of the traditional spark plug【3】;

4. The microwave is input from the bottom of the igniter, and its shape is consistent with that of the existing spark plug, which matches the cylinder of a conventional automobile engine;

5. The gap coupling structure in the igniter can reduce the influence of the external circuit on the quality factor of the igniter;

6. It can be designed and processed in an integrated manner without debugging, and is suitable for mass production;

7. It can be easily transplanted to other plasma ignition systems for use. the

Description of drawings

Fig. 1 is a cross-sectional view of the first gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Fig. 2 is a top view of the first gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Fig. 3 is a cross-sectional view of the second gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Fig. 4 is a top view of the second gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Fig. 5 is a cross-sectional view of a third gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Fig. 6 is a top view of a third gap-coupled microwave plasma igniter for an internal combustion engine provided by the present invention. the

Detailed ways

Example 1

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy dismounting and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour one 31, corresponding to the inner conductor tip 5, respectively The outer conductor inner contour two 32 corresponding to the inner conductor one 41, the outer conductor inner contour three 33 corresponding to the inner conductor two 42, the outer conductor inner contour four 34 corresponding to the inner conductor three 43, and the inner conductor three 43 The corresponding outer conductor inner contour four 34, the outer conductor inner contour five 35 corresponding to the inner conductor four 44; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44, Inner conductor tip 5 is formed; inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44 are coaxial cylinder structures, inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor The tip 5 is connected to the first inner conductor 41, there is a coupling gap 6 between the first inner conductor 41 and the second inner conductor 42, the second inner conductor 42, the third inner conductor 43 and the fourth inner conductor 44 are sequentially connected, and the radii of the three gradually increase; The side of conductor one 41 close to the coupling gap 6 is directly connected to the outer conductor through the horizontal connecting conductor 7 of the cylinder, and the axis of the horizontal connecting conductor 7 of the cylinder is perpendicular to the axis of the inner conductor one 41; between the inner conductor and the outer conductor, except the inner conductor The area between the tip 5 and the outer conductor inner contour one 31 and the area between the inner conductor four 44 and the outer conductor inner contour five 35 are all filled with insulating medium 8; the outer conductor inner contour five 35 and the inner conductor four 44 A microwave input port 1 is formed, and its size is consistent with that of a standard N-type radio frequency coaxial connector. the

In the above solution, the outer contour of the outer conductor also includes a cylindrical transition surface 22, and the cylindrical transition surface 22 is located between the external thread 21 connected to the cylinder of the automobile engine and a hexagonal prism working surface 23 that is convenient for disassembly and installation. between. the

In the above solution, the material of the tip 5 of the inner conductor is platinum, the materials of the other inner conductors and outer conductors are metals resistant to high temperature, carbonization and oxidation, and the insulating medium 8 is a ceramic medium. the

Example 2

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy dismounting and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour-31, corresponding to the inner conductor tip 5 respectively The outer conductor inner contour two 32 corresponding to the inner conductor one 41, the outer conductor inner contour three 33 corresponding to the inner conductor two 42, the outer conductor inner contour four 34 corresponding to the inner conductor three 43, and the inner conductor three 43 The corresponding outer conductor inner contour four 34, the outer conductor inner contour five 35 corresponding to the inner conductor four 44; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44, Inner conductor tip 5 is formed; inner conductor one 41, inner conductor two 42, inner conductor three 43, inner conductor four 44 are coaxial cylinder structures, inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor The tip 5 is connected to the first inner conductor 41, there is a coupling gap 6 between the first inner conductor 41 and the second inner conductor 42, the second inner conductor 42, the third inner conductor 43 and the fourth inner conductor 44 are sequentially connected, and the radii of the three gradually increase; The side of the conductor one 41 close to the coupling gap 6 is connected to the outer conductor through a cylinder horizontal connection conductor 71 and a cylinder vertical connection conductor 72, the axis of the cylinder horizontal connection conductor 71 is perpendicular to the axis of the inner conductor one 41, and the cylinder vertical connection The axis of the conductor 72 is parallel to the axis of the inner conductor one 41; between the inner conductor and the outer conductor except the area between the inner conductor tip 5 and the outer conductor inner contour one 31 and between the inner conductor four 44 and the outer conductor inner contour five 35 Other regions except the region are filled with insulating medium 8; the outer conductor inner contour 5 35 and the inner conductor 4 44 form the microwave input port 1, and its size is consistent with the standard N-type radio frequency coaxial connector. the

In the above solution, the outer contour of the outer conductor also includes a cylindrical transition surface 22, and the cylindrical transition surface 22 is located between the external thread 21 connected to the cylinder of the automobile engine and a hexagonal prism working surface 23 that is convenient for disassembly and installation. between. the

In the above solution, the material of the tip 5 of the inner conductor is platinum, the materials of the other inner conductors and outer conductors are metals resistant to high temperature, carbonization and oxidation, and the insulating medium 8 is a ceramic medium. the

Example 3

A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one Connected external thread 21 and a hexagonal prism working surface 23 for easy disassembly and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including outer conductor inner contour one 31, corresponding to the inner conductor tip 5, respectively The outer conductor inner contour two 32 corresponding to the inner conductor one 41, the outer conductor inner contour three 33 corresponding to the inner conductor two 42 and the outer conductor inner contour four 34, the outer conductor inner contour five corresponding to the inner conductor three 43 35; the inner conductor is composed of inner conductor one 41, inner conductor two 42, inner conductor three 43, and inner conductor tip 5; inner conductor one 41, inner conductor two 42, and inner conductor three 43 are cylindrical structures, and the inner conductor tip 5 is a cone, and the top of the cone is a hemisphere; the inner conductor two 42 and the inner conductor three 43 are coaxial; the inner conductor tip 5 is connected with the inner conductor one 41, and the bottom of the inner conductor one 41 is directly connected with the outer conductor; the inner conductor one 41 The side near the bottom is connected to the second inner conductor 42 through the coupling gap 6 and the horizontal connecting conductor 7 of the cylinder in turn, the second inner conductor 42 is connected to the third inner conductor 43, and the radii of the two gradually increase; the axis of the horizontal connecting conductor 7 of the cylinder Perpendicular to the axis of the inner conductor one 41; between the inner conductor and the outer conductor except the area between the inner conductor tip 5 and the outer conductor inner contour one 31 and the area between the inner conductor three 43 and the outer conductor inner contour five 35 The other areas of the other parts are filled with insulating medium 8, the inner contour five 35 of the outer conductor and the third inner conductor 43 constitute the microwave input port 1, and its size is consistent with the standard N-type radio frequency coaxial connector. the

In the above solution, the outer contour of the outer conductor also includes a cylindrical transition surface 22, and the cylindrical transition surface 22 is located between the external thread 21 connected to the cylinder of the automobile engine and a hexagonal prism working surface 23 that is convenient for disassembly and installation. between. the

In the above solution, the material of the tip 5 of the inner conductor is platinum, the materials of the other inner conductors and outer conductors are metals resistant to high temperature, carbonization and oxidation, and the insulating medium 8 is a ceramic medium. the

Any gap-coupled microwave plasma igniter described in the above embodiments is characterized in that the appearance of the igniter is consistent with the existing spark plug, which is convenient for replacement or upgrade. the

This series of igniters can be regarded as a combination of a quarter-wavelength coaxial resonant cavity, a slot coupling structure, a stepped coaxial matching structure, and an N-type radio frequency coaxial connector. Theoretically speaking, the length of the quarter-wavelength coaxial resonator should be a quarter of the wavelength of the medium-filled coaxial line, but the actual design is slightly different due to the influence of the inner conductor tip 5 and different coupling structures; combined with the actual According to application requirements and circuit design requirements, the inner and outer diameters of quarter-wavelength coaxial resonators are also different to meet the dual requirements of high quality factor and circuit realizability; according to different quarter-wavelength coaxial resonators, coupling For the structural characteristics and electrical performance of the gap, it is necessary to design a corresponding transition structure to achieve matching with the N-type RF coaxial connector; the transition structure is realized by a stepped coaxial matching structure. the

When designing, it is necessary to first test the output spectrum characteristics of high-power microwave devices such as magnetrons when driven by pulsed high voltage. The center frequency of the igniter is set according to the test results; Under the premise of body conditions, determine the quality factor and working frequency band of the igniter; when designing the igniter gap coupling structure and stepped coaxial matching structure, it is also necessary to make the reflection coefficient of the igniter in the working frequency band as small as possible; when the input When the microwave power is 500W, the average electric field intensity at the tip of the conductor inside the igniter needs to be greater than 2.25*10 ⁷ V/m to ensure that the plasma can be effectively excited in a cylinder with 10 standard atmospheric pressure.

Through the design of electromagnetic full-wave simulation software, the reflection coefficients of these three slot-coupled microwave plasma igniters at the resonant frequency are all less than -20dB, and the average electric field strength at the tip is greater than 2.25*10 ⁷ V/m.

references

【1】F A Pertl, et al, Electromagnetic design of a novel microwave internal combustion engine ignition source, the quarter wave coaxial cavity igniter, Proceeding IMechE Part D: J.Automobile Engineering, 223, 2009, 1450-1474. the

[2] K Linkenheil, et al, A novel spark-plug for improved ignition in engines with gasoline direct injection (GDI), IEEE Transactions on Plasma Science, 33, 2005, 1696-1702. the

【3】J E Smith, Integration of microwave plasma ignition into a multi-fuel engine, 2009. the

Claims (5)

1. A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one The external thread (21) connected to the engine cylinder and a hexagonal prism working surface (23) for easy disassembly and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including corresponding to the tip of the inner conductor (5) Outer conductor inner contour one (31), outer conductor inner contour two (32) corresponding to inner conductor one (41), outer conductor inner contour three (33) corresponding to inner conductor two (42), and inner conductor inner contour three (33) corresponding to inner conductor one (41) Outer conductor inner contour four (34) corresponding to conductor three (43), outer conductor inner contour four (34) corresponding to inner conductor three (43), outer conductor inner contour corresponding to inner conductor four (44) Five (35); the inner conductor is made of inner conductor one (41), inner conductor two (42), inner conductor three (43), inner conductor four (44), inner conductor tip (5); inner conductor one ( 41), inner conductor two (42), inner conductor three (43), and inner conductor four (44) are coaxial cylinder structures, and the tip of the inner conductor (5) is a cone, and the top of the cone is a hemisphere; the inner conductor The tip (5) is connected to the inner conductor one (41), there is a coupling gap (6) between the inner conductor one (41) and the inner conductor two (42), the inner conductor two (42), the inner conductor three (43) and the inner conductor The four conductors (44) are connected in sequence, and the radii of the three gradually increase; the side of the inner conductor one (41) close to the coupling gap (6) is directly connected to the outer conductor through a cylinder horizontal connection conductor (7), and the cylinder horizontal connection conductor ( 7) axis is perpendicular to the axis of the inner conductor one (41); between the inner conductor and the outer conductor except the area between the inner conductor tip (5) and the outer conductor inner contour one (31) and the inner conductor four (44) Other areas except the area between the outer conductor inner contour five (35) are filled with insulating medium (8); the outer conductor inner contour five (35) and the inner conductor four (44) form a microwave input port (1), and its size Consistent with standard N-type RF coaxial connectors. 2. A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one The external thread (21) connected to the engine cylinder and a hexagonal prism working surface (23) for easy disassembly and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including corresponding to the tip of the inner conductor (5) Outer conductor inner contour one (31), outer conductor inner contour two (32) corresponding to inner conductor one (41), outer conductor inner contour three (33) corresponding to inner conductor two (42), and inner conductor inner contour three (33) corresponding to inner conductor one (41) Outer conductor inner contour four (34) corresponding to conductor three (43), outer conductor inner contour four (34) corresponding to inner conductor three (43), outer conductor inner contour corresponding to inner conductor four (44) Five (35); the inner conductor is made of inner conductor one (41), inner conductor two (42), inner conductor three (43), inner conductor four (44), inner conductor tip (5); inner conductor one ( 41), inner conductor two (42), inner conductor three (43), and inner conductor four (44) are coaxial cylinder structures, and the tip of the inner conductor (5) is a cone, and the top of the cone is a hemisphere; the inner conductor The tip (5) is connected to the inner conductor one (41), there is a coupling gap (6) between the inner conductor one (41) and the inner conductor two (42), the inner conductor two (42), the inner conductor three (43) and the inner conductor The four conductors (44) are connected in sequence, and the radii of the three gradually increase; the side of the inner conductor one (41) close to the coupling gap (6) successively connects the conductor (71) horizontally through the cylinder and connects the conductor (72) and the outer conductor vertically through the cylinder. The conductors are connected, the axis of the cylinder horizontal connection conductor (71) is perpendicular to the axis of the inner conductor one (41), and the axis of the cylinder vertical connection conductor (72) is parallel to the axis of the inner conductor one (41); the inner conductor and the outer conductor Except for the area between the inner conductor tip (5) and the outer conductor inner contour one (31) and the area between the inner conductor four (44) and the outer conductor inner contour five (35), other areas are filled with insulating medium (8); Outer conductor inner contour five (35) and inner conductor four (44) form a microwave input port (1), and its size is consistent with a standard N-type radio frequency coaxial connector. 3. A gap-coupled microwave plasma igniter for an internal combustion engine, comprising an inner conductor and an outer conductor; the outer conductor is formed by sealing the outer contour of the outer conductor and the inner contour of the outer conductor; the outer contour of the outer conductor includes at least one The external thread (21) connected to the engine cylinder and a hexagonal prism working surface (23) for easy disassembly and installation; the inner contour of the outer conductor is a cylindrical surface structure with different radii, including corresponding to the tip of the inner conductor (5) Outer conductor inner contour one (31), outer conductor inner contour two (32) corresponding to inner conductor one (41), outer conductor inner contour three (33) corresponding to inner conductor two (42) and outer conductor Internal contour four (34), external conductor inner contour five (35) corresponding to inner conductor three (43); said inner conductor is composed of inner conductor one (41), inner conductor two (42), inner conductor three (43) ), inner conductor tip (5); inner conductor one (41), inner conductor two (42), inner conductor three (43) are cylindrical structures, inner conductor tip (5) is a cone, and the top of the cone is a hemisphere body; inner conductor two (42) and inner conductor three (43) are coaxial; inner conductor tip (5) is connected with inner conductor one (41), and the bottom of inner conductor one (41) is directly connected with outer conductor; inner conductor one (41) The side near the bottom is connected to the inner conductor two (42) successively through the coupling gap (6) and the cylindrical horizontal connecting conductor (7), and the inner conductor two (42) is connected to the inner conductor three (43). The radius gradually increases; the axis of the cylinder horizontally connecting the conductor (7) is perpendicular to the axis of the inner conductor one (41); between the inner conductor and the outer conductor except the tip of the inner conductor (5) and the inner contour of the outer conductor one (31) Insulation medium (8) is filled in other areas outside the area between the inner conductor three (43) and the outer conductor inner contour five (35), and the outer conductor inner contour five (35) and the inner conductor three (43) constitute The microwave input port (1) has the same size as the standard N-type radio frequency coaxial connector. 4. According to the gap-coupled microwave plasma igniter for any internal combustion engine described in claim 1-3, it is characterized in that the outer contour of the outer conductor also includes a cylindrical transition surface (22), and the cylindrical transition surface The surface (22) is located between the external thread (21) connected with the automobile engine cylinder and a hexagonal prism working surface (23) which is convenient for disassembly and installation. 5. According to the gap-coupled microwave plasma igniter for any internal combustion engine described in claim 1-3, it is characterized in that the material of the inner conductor tip (5) is platinum, and the materials of the remaining inner conductors and outer conductors are selected from anti- High temperature, anti-carbonization, anti-oxidation metal, the insulating medium (8) is a ceramic medium.

Images