CN217469104U - High-efficient coupled microwave-assisted integrated spark plug - Google Patents

Abstract

The utility model belongs to the combustion field of internal combustion engines, and particularly discloses a high-efficiency coupled microwave-assisted integrated spark plug, which comprises a ceramic body, a circuit component and a metal shell, wherein the whole ceramic body is in a T shape or a Y shape and comprises a main ceramic body path and a side ceramic body branch path; the tail end of the main path of the ceramic body is connected with a microwave generating device, and the front end of the main path of the ceramic body is provided with a skirt part of the ceramic body; the circuit component comprises a branch electrode and a main circuit electrode which are connected, the branch electrode is connected with an external power supply, and the front end of the main circuit electrode is provided with a central electrode; the branch electrode, the main circuit electrode and the central electrode are respectively sleeved inside the branch of the ceramic body, the main circuit of the ceramic body and the skirt part of the ceramic body; the metal shell is sleeved outside the main circuit of the ceramic body, the front end of the metal shell is provided with a grounding electrode, and the grounding electrode is opposite to the front end of the center electrode to form an ignition electrode together. The utility model discloses need not to carry out engine structure transformation to can overcome conventional spark plug fire difficulty, the unstable scheduling problem of fire core under the extreme condition.

Description

High-efficient coupled microwave-assisted integrated spark plug

Technical Field

The utility model belongs to the internal-combustion engine field of burning, more specifically relates to a microwave of high-efficient coupling assists integrated spark plug.

Background

In the technical field of internal combustion engines, lean combustion enables mixed gas to be more fully combusted by utilizing high air-fuel ratio and high compression ratio, and becomes an effective means for improving fuel economy and reducing oil consumption and emission level; in addition, some applications of low carbon and carbon-free fuels, such as ammonia fuel, can effectively reduce CO ₂ Emission, becomes an important direction of the dual carbon strategy. However, the working conditions of lean combustion, ammonia fuel application and the like have the problems of difficult ignition, unstable fire core and the like of the conventional spark plug, and the problems need to be solved urgently.

Increasing the ignition energy is one of the effective means to solve the above problems, but simply increasing the ignition energy results in spark plug ablation, thereby reducing the ignition system life. In recent years, ignition technologies and ignition devices based on microwave plasma gradually show potential, wherein the ignition of a microwave resonance torch and the ignition of a microwave resonance cavity utilize microwave to resonate at the local part of an electrode or in a combustion cavity to form a strong electric field to break down mixed gas to realize ignition, and the microwave resonance torch and the ignition device have certain application potential.

Chinese patent CN102080619B proposes an engine ignition device based on microwave plasma, which is arranged by coupling a waveguide with a cylinder, when a piston moves to a certain position, microwave resonance is formed in the cylinder, thereby exciting plasma to ignite. The method can only utilize the strong electric field generated by microwave resonance to puncture the mixed gas under the high-voltage environment, and has certain difficulty, so that the method has larger instability. It is also mentioned in this patent that spark plugs can be considered as pre-ionization devices, and the difficulty of breaking down the mixture using microwave resonance alone is further illustrated. Therefore, the microwave-assisted ignition (MAI) technology provides a beneficial solution to the ignition problem under the above-mentioned operating conditions.

In the microwave-assisted ignition technology, the mixed gas is punctured by high voltage electricity of a spark plug, and then microwave energy is fed into the punctured discharge, so that an initial discharge plasma cluster is rapidly diffused outwards, and the ignition process is enhanced. The scheme combines the advantages of the traditional spark plug ignition and the microwave plasma ignition and has strong practicability.

Chinese patent CN106762331A proposes a microwave-assisted spark plug ignition method and an integrated device, which respectively send pulse signals to a spark plug system and a microwave system to make the two systems respectively generate pulsed high-voltage and microwave pulses with specific frequency and power, the two pulses are integrated by a mixer device, and finally the mixed gas is broken down at two electrodes. However, the design has a separate mixer, and the structure of the spark plug is a conventional spark plug, so that the whole system is large in size, the installation on an engine is difficult, meanwhile, the microwave energy is difficult to focus, and the microwave auxiliary effect is low, so that the method has certain difficulty in practical application.

Chinese patent CN102797612A proposes a microwave plasma ignition coupling device for an internal combustion engine, namely a microwave ignition plug, which breaks down the mixture by microwave electrodeless discharge at the coupling end of the inner conductor to achieve the purpose of lean combustion and stable ignition. However, the pure microwave electrodeless ignition mode is difficult to successfully ignite under high environmental pressure and cannot be really applied to an internal combustion engine.

SUMMERY OF THE UTILITY MODEL

To the above defect of prior art or improve the demand, the utility model provides a microwave of high-efficient coupling assists integrated spark plug, its aim at both need not to carry out the transformation of engine structure, can satisfy the stable demand of igniting under the extreme operating mode such as engine thin combustion or carbon-free fuel engine again, overcome difficult, the unstable scheduling problem of fire that conventional spark plug leads to under the extreme operating mode.

In order to achieve the above object, the utility model provides a microwave-assisted integrated spark plug of high-efficient coupling, including ceramic body, circuit module and metal casing, wherein:

the ceramic body is integrally T-shaped or Y-shaped and comprises a ceramic body main path and a ceramic body branch path arranged on the side edge of the ceramic body main path; the tail end of the ceramic body main road is connected with a microwave generating device, and the front end of the ceramic body main road is provided with a ceramic body skirt part;

the circuit component comprises a branch electrode and a main circuit electrode which are connected, the branch electrode is connected with an external high-voltage power supply, and the front end of the main circuit electrode is provided with a central electrode; the branch electrode, the main circuit electrode and the central electrode are respectively sleeved inside the branch of the ceramic body, the main circuit of the ceramic body and the skirt of the ceramic body;

the metal shell is sleeved outside the main circuit of the ceramic body, a protruding grounding electrode is arranged at the front end of the metal shell, and the grounding electrode is opposite to the front end of the center electrode to jointly form an ignition electrode.

Preferably, the main path of the ceramic body and the metal shell are of a coaxial structure.

Further preferably, the inner side of the skirt of the ceramic body, i.e., the side in contact with the center electrode, is streamlined.

As a further preference, the ceramic body skirt is tapered in cross-section.

More preferably, a resistor is connected to the branch electrode.

Further preferably, the grounding electrode is provided with an elliptical protrusion, and the short axis of the elliptical protrusion is opposite to the central electrode; the inner part of the oval bulge is made of metal material of the grounding electrode, and the outer part of the oval bulge is plated with noble metal.

More preferably, the center electrode is in a needle point shape, the inside of the center electrode is an electric good conductor, the outside of the center electrode is wrapped by nickel, and the head part of the center electrode is plated with noble metal or alloy thereof.

More preferably, the ratio of the outer diameter of the ceramic branch to the outer diameter of the branch electrode is 1.8:1 to 3: 1.

As a further preferred, the ceramic body is an electrical insulator microwave conductor, which is made of a ceramic material or a teflon material.

Preferably, the outer side of the front part of the metal shell is provided with a front end external thread for fixing the spark plug on the cylinder; an external sealing ring is arranged at the rear part of the external thread at the front end; an inner sealing ring is arranged between the maximum diameter position of the tail end of the skirt part of the ceramic body and the metal shell.

Generally, through the utility model above technical scheme who thinks compares with prior art, mainly possesses following technical advantage:

1. the utility model realizes the coupling of high voltage electric breakdown and microwave feed-in the same spark plug through the design of the T-shaped or Y-shaped structure; therefore, the advantages of the traditional spark plug that the mixed gas is broken down by high-voltage discharge and the energy is coupled to the plasma by the microwave are combined on one spark plug, stable ignition under some extreme working conditions can be realized, and the problems of difficult ignition, unstable flame and the like caused by the current lean combustion and the carbon-free fuel combustion are solved. Meanwhile, the combustion chamber of the existing engine is not required to be changed, the spark plug can be exchanged with the conventional spark plug, and the replacement cost is low.

2. The idea of high-voltage linear propagation and microwave side circuit feed-in the traditional microwave coupling device is changed. The microwave circuit and the shell outside the spark plug form a coaxial structure, so that the effect of microwave near linear coaxial transmission is realized, and meanwhile, the on-way dissipation of the microwave is reduced and the microwave transmission efficiency is greatly improved through the streamline transmission design of the microwave circuit. Meanwhile, the loss of the high-voltage electricity is mainly related to resistance and is not related to a path, so that the high-voltage circuit is propagated from a side path without generating extra loss of the high-voltage circuit. The coupling mode can obviously improve the microwave transmission efficiency and the microwave-assisted ignition efficiency.

3. The insulator skirt portion wraps the front portion of the central electrode, so that microwave energy can be conveniently concentrated between the two electrodes, the coupling effect of the microwave and the high-voltage electricity is enhanced, and meanwhile, the insulator skirt portion plays a role in heat dissipation, and burning loss of the ignition electrode can be reduced.

4. The ceramic body skirt part at the front end of the microwave circuit adopts a mode of gradually reducing the transmission cross section area to achieve the function of gradually collecting the microwave energy, so that the microwave is conveniently and finally intensively radiated between ignition electrodes, and meanwhile, the ceramic body skirt part with shorter length can reduce the formation of a local microwave energy high-energy area, thereby reducing the excessive loss of the microwave energy.

5. Since the ignition of the spark plug several times in succession can generate microwaves of other frequencies, which, unlike the transmitted microwaves, generate a large amount of interference. The resistor body closer to the ignition electrode of the traditional spark plug is changed into the T-shaped branch at the side edge, so that on one hand, the loss of the resistor in the circuit to energy in the microwave transmission process can be eliminated, on the other hand, the normal work of other electrical appliances can be prevented from being interfered by high voltage electricity, and the erosion of the discharge current to the spark plug electrode can be reduced.

6. The grounding electrode is provided with an elliptical bulge, the elliptical bulge is also made of a composite material, the inner part of the elliptical bulge is made of a metal material of the grounding electrode, and the outer part of the elliptical bulge is plated with a noble metal; the design of the elliptical bulge can control a high-voltage breakdown path and improve ignition stability, and meanwhile, the noble metal layer is plated on the outer portion of the elliptical bulge, so that corrosion caused by electron avalanche can be reduced.

7. The central electrode is made of composite materials, conventional good electrical conductors such as copper cores are selected in the central electrode, nickel is wrapped outside, and the head of the central electrode is plated with precious metals such as platinum or iridium or alloys thereof, so that the heat dissipation capacity is improved, and the oxidation resistance can be improved to deal with the ablation problem of high-energy ignition.

8. Main tributary way junction has a small amount of microwaves to branch road loss, the utility model discloses a design ceramic body branch road external diameter and branch road electrode external diameter's ratio can adjust the microwave to the loss ability of ceramic body branch road, realizes the microwave to the minimum loss of branch road for the microwave mainly propagates in the ceramic body main road, thereby has promoted the microwave transmission efficiency on the ceramic body main road.

9. The outside parcel of integrated spark plug has metal casing, as the bad conductor of microwave, can effectual prevention microwave outward diffusion of transmission causes the loss in the microwave circuit, also can prevent simultaneously that outside electromagnetic interference is right microwave transmission system's influence.

Drawings

Fig. 1 is a schematic structural view of an efficient coupled microwave-assisted integrated spark plug according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the junction between the microwave circuit and the high voltage circuit of the microwave-assisted integrated spark plug according to the embodiment of the present invention;

fig. 3 is a schematic diagram of a partially enlarged structure at a ignition electrode in a microwave-assisted integrated spark plug according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of the microwave connector and the rf interface in the microwave-assisted integrated spark plug according to the embodiment of the present invention.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: 1-ceramic body, 11-ceramic body branch, 12-ceramic body main path, 13-ceramic body skirt, 21-main path electrode, 22-branch electrode, 23-center electrode, 24-connection point, 25-branch electrode binding post, 31-external sealing ring, 32-internal sealing ring, 41-metal shell rear half section, 42-metal shell front half section, 43-hexagon nut, 44-front end external thread, 45-grounding electrode, 46-rear end internal thread, 5-ignition electrode, 51-ignition anode, 52-ignition cathode, 6-radio frequency interface and 7-resistor body.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention. Furthermore, the technical features mentioned in the embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

The embodiment of the utility model provides a pair of microwave-assisted integrated spark plug of high-efficient coupling, it includes microwave circuit, high-voltage line, ignition electrode, high-pressure seal and fixed subassembly.

The spark plug is integrally in a T-shaped (or Y-shaped) structure, as shown in fig. 1, the microwave circuit is arranged on the main part of the T-shaped structure of the spark plug, and the path of the microwave circuit is an approximately straight line, so that the microwave transmission efficiency can be improved, the efficient input of microwaves and the efficient energy collection of the microwaves are realized, and the microwaves are radiated to an ignition area between the electrodes of the spark plug in a concentrated manner. Meanwhile, in order to meet the requirement of high-efficiency microwave transmission, a high-voltage circuit is designed to the side edge of the spark plug, the high-voltage circuit transmits high-voltage electricity to an ignition electrode with minimum energy consumption, and a strong electric field is generated between two electrodes of the spark plug and the combustible mixed gas is punctured. The microwave circuit and the high-voltage circuit are not interfered with each other, and finally, the microwave circuit and the high-voltage circuit are coupled at the ignition electrode of the spark plug, so that the ignition capability of the spark plug is enhanced, and stable ignition under extreme working conditions is realized.

Specifically, the method comprises the following steps:

in the microwave circuit, the internal material is a high-voltage electric insulator microwave conductor which is used as an excellent microwave conductor and can reduce the loss in the microwave transmission process, and meanwhile, the internal material is used as an electric insulator and can prevent the spark plug from being broken down by high voltage electricity; preferably, ceramic materials are adopted, namely, the main part of the microwave circuit is a ceramic body main path 12 and a ceramic body skirt part 13 which are connected; the ceramic body skirt 13 is arranged at the front end of the ceramic body main circuit 12, the cross section of the ceramic body skirt 13 is gradually reduced, and the transmission cross section area of the microwave circuit is gradually reduced, so that the function of gradually collecting microwave energy is achieved, and the microwave is conveniently and finally intensively radiated between the ignition electrodes. In the microwave circuit, the exterior is a metal shell, the metal shell is tightly matched with the ceramic body main path 12, the ceramic body main path 12 and the metal shell form a coaxial structure, and microwaves are fed in through a coaxial transmission line, are transmitted in the ceramic body and enter the microwave circuit; meanwhile, as the cross section of the ceramic body skirt part 13 is gradually reduced, a certain gap exists between the front end of the metal shell and the ceramic body skirt part 13.

Further, the metal shell comprises a metal shell front half section 42 and a metal shell rear half section 41; the rear internal thread 46 is provided inside the rear end of the rear section 41 of the metal shell for connecting the rear of the spark plug to the radio frequency interface 6. as shown in fig. 4, the radio frequency interface 6 is connected to a microwave transmission coaxial line, the other end of which is connected to a microwave source. The microwave enters the spark plug through the radio frequency interface 6, passes through the main path 12 of the ceramic body, and is finally fed into the ignition section between the two electrodes by air at the skirt part 13 of the ceramic body, and the skirt part 13 of the insulator plays a role of heat dissipation at the same time.

Furthermore, a direct current blocking device is arranged between the microwave source and the radio frequency interface, so that high voltage of a high-voltage circuit can be effectively prevented from being transmitted to the microwave source through the microwave circuit, the microwave source is prevented from being damaged by the high voltage, and the use safety of the spark plug is ensured.

Furthermore, the microwave circuit and the outer shell of the spark plug form a coaxial structure, and the effect of near-linear coaxial transmission of microwaves is achieved. The transmission section of the microwave circuit is streamline, and the turning part is subjected to large-curvature fillet transition, namely the contact side of the ceramic body skirt part 13 and the central electrode 23 is streamline, so that the on-way loss of the microwave can be obviously reduced.

Furthermore, the microwave circuit is connected with a microwave generating and controlling system through a microwave connector, and the system comprises a magnetron, a magnetron driving coil, a microwave transmission coaxial line and the like. Specifically, the method comprises the following steps: the magnetron generates microwaves with specific frequency and power, the frequency of the microwaves is about 2.45GHz generally, and the power can be selected to be 1000W; the magnetron driving coil generates an electric signal required for driving the magnetron; the devices can be connected by a microwave transmission coaxial line, so that the microwave is transmitted to the spark plug from a microwave source.

Furthermore, metal casing is as the bad conductor of microwave, can effectual prevention the microwave of transmission in the microwave circuit outwards diffuses and causes the loss, also can prevent simultaneously that outside electromagnetic interference is right the influence of microwave transmission system.

The high-voltage circuit is a turning circuit and is arranged on the side edge of the integral spark plug, the internal material is a metal conductor, and the metal conductor transmits high-voltage electricity to the ignition electrode; the outer side material is an electric insulator such as ceramic, and the electric insulator can effectively block high-voltage electric breakdown air to cause safety problems. Specifically, a circuit component is arranged in the high-voltage circuit, and the circuit component includes a branch electrode 22 and a main electrode 21 which are connected, wherein, as shown in fig. 2, the branch electrode 22 is arranged on a side, one side of which is connected with the high-voltage through a branch electrode binding post 25, and the other side of which is connected with the main electrode 21 through a connection point 24; the main road electrode 21 is arranged on the main road, and the front end of the main road electrode is provided with a central electrode 23; the branch electrode 22, the main circuit electrode 21 and the central electrode 23 are respectively sleeved inside the ceramic body branch 11, the ceramic body main circuit 12 and the ceramic body skirt 13. High voltage is fed from the branch electrode terminal 25, and reaches the center electrode 23 via the branch electrode 22 and the main electrode 21 in sequence, and the safety of the external ceramic body 1 is ensured.

Further, a resistor 7 is arranged in the high-voltage line, and the resistor 7 is positioned on the outer side of the high-voltage line far away from the microwave line. Because the spark plug can generate microwaves with other frequencies after continuous multiple ignition, and the microwaves have different frequencies from the transmitted microwaves (2.45GHz), and can generate great interference, a resistor body which is closer to an ignition electrode of the spark plug in the traditional spark plug is changed into a high-voltage electric transmission line, namely a T-shaped branch, so that on one hand, the loss of the resistor in the circuit to energy in the microwave transmission process can be eliminated, on the other hand, the normal work of other electric appliances can be prevented from being interfered by high voltage electricity, and the erosion of the discharge current to the spark plug electrode can be reduced.

Further, the ratio of the outer diameters of the ceramic body branch 11 and the branch electrode 22 is 1.8:1 to 3.0: 1. By adjusting the ratio of the outer diameter of the branch of the ceramic body to the outer diameter of the branch electrode, the microwave dissipated in the branch of the ceramic body can be ignored to be mainly transmitted in the main path of the ceramic body, and the transmission efficiency of the microwave in the ceramic body is improved.

The ignition electrode 5 comprises a center electrode 23 and a grounding electrode 45, as shown in fig. 3, the center electrode 23 is connected with high voltage electricity through a high voltage circuit; the grounding electrode 45 is welded at the front end of the metal shell and is L-shaped, the grounding electrode 45 is connected with the engine, and the voltage is 0; an ignition anode 51 and an ignition cathode 52 are oppositely disposed on the center electrode 23 and the ground electrode 45 to achieve ignition.

Furthermore, the center electrode 23 is in a needle point shape to control a breakdown path, the center electrode material is a composite material, a conventional good electric conductor such as a copper core is selected in the center electrode, nickel is wrapped outside the center electrode, and the head of the center electrode is plated with precious metal such as platinum or iridium or alloy thereof, so that the heat dissipation capability is improved, and the oxidation resistance can be improved to deal with the ablation problem of high-energy ignition. The grounding electrode 45 is provided with an elliptical bulge which is also made of composite material, the inner part of the elliptical bulge is made of the metal material of the grounding electrode, and the outer part of the elliptical bulge is plated with noble metal; the elliptical short axis is opposite to the central electrode, and the elliptical convex design can control a high-voltage breakdown path, improve the ignition stability and reduce the corrosion caused by electron avalanche.

The high pressure sealing and fixing assembly includes an outer packing 31, an inner packing 32, and a hexagonal nut 43. The outer side of the front half section 42 of the metal shell is provided with a front end external thread 44 for fixing the spark plug on the cylinder, and the external sealing ring 31 is arranged at the rear part of the front end external thread 44; an inner seal ring 32 is disposed between the ceramic body head and the metal shell head; the hexagonal nut 43 is disposed in the middle of the metal shell, and the hexagonal protruding structure facilitates the use of a hexagonal wrench or other tools to screw the spark plug into the cylinder.

The following are specific examples:

the ceramic body 1 is made of 95% alumina ceramic, the main road electrode 21, the branch road electrode 22 and the connection point 24 of the main road electrode and the branch road electrode are all made of copper, the outer surface adopts a nickel plating process, the inner material of the central electrode 23 is copper, the outer material is nickel alloy, the metal shell material is nickel alloy, and the ignition anode 51 and the ignition cathode 52 are made of platinum-iridium alloy.

The inner seal ring 32 is made of expanded graphite, which has high temperature resistance and corrosion resistance, and in the spark plug, the structure completely fills the gap between the sealing ceramic body and the metal shell, thereby preventing high-temperature gas and fuel stain from entering the gap to cause damage to the ignition device.

The feasibility of the embodiment was further determined by simulation. The method comprises the following steps of simulating the cylinder environment in simulation software to set the external environment, specifically as follows: the temperature is 1000K, and the pressure is 10 atm. High-voltage electricity with specified size and microwaves with the frequency of 2.45GHz and the power of 1000W are respectively input to the interfaces of the high-voltage electric transmission line and the microwave transmission line.

The results are as follows: the average value of the microwave electric field between the two electrodes can reach 5.4 multiplied by 105V/m. In addition, the high voltage does not influence the transmission effect of the microwave, and the synchronous transmission of the microwave and the high voltage cannot influence each other.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. An efficiently coupled microwave assisted integrated spark plug comprising a ceramic body (1), a circuit assembly and a metal shell, wherein:

the ceramic body (1) is integrally T-shaped or Y-shaped and comprises a ceramic body main path (12) and a ceramic body branch path (11) arranged on the side edge of the ceramic body main path (12); the tail end of the ceramic body main path (12) is connected with a microwave generating device, and the front end of the ceramic body main path (12) is provided with a ceramic body skirt part (13);

the circuit component comprises a branch electrode (22) and a main circuit electrode (21) which are connected, the branch electrode (22) is connected with an external high-voltage power supply, and the front end of the main circuit electrode (21) is provided with a central electrode (23); the branch electrode (22), the main circuit electrode (21) and the central electrode (23) are respectively sleeved in the ceramic body branch (11), the ceramic body main circuit (12) and the ceramic body skirt part (13);

the metal shell is sleeved outside the main circuit (12) of the ceramic body, a protruding grounding electrode (45) is arranged at the front end of the metal shell, and the grounding electrode (45) is opposite to the front end of the central electrode (23) to form an ignition electrode (5) together.

2. The highly efficient coupled microwave assisted integrated spark plug of claim 1 wherein the ceramic body primary path (12) and the metal shell are of a coaxial configuration.

3. A high efficiency coupled microwave assisted integrated spark plug according to claim 1 wherein the inside of the ceramic body skirt (13), on the side in contact with the center electrode (23), is streamlined.

4. A high efficiency coupled microwave assisted integrated spark plug according to claim 1 wherein the ceramic body skirt (13) is tapered in cross-section.

5. An efficiently coupled microwave-assisted integrated spark plug according to claim 1, wherein a resistor (7) is connected to the branch electrode (22).

6. The highly efficient coupled microwave assisted integrated spark plug of claim 1 wherein the ground electrode (45) is provided with an elliptical protrusion having its minor axis opposite the center electrode (23); the inner part of the oval bulge is made of metal material of the grounding electrode (45), and the outer part of the oval bulge is plated with noble metal.

7. The high-efficiency coupled microwave-assisted integrated spark plug according to claim 6, wherein the center electrode (23) is needle-point-shaped, the inside of the center electrode is an electric good conductor, the outside of the center electrode is coated with nickel, and the head of the center electrode is plated with noble metal or alloy thereof.

8. The highly efficient coupled microwave assisted integrated spark plug of claim 1 wherein the ratio of the outer diameter of the ceramic body leg (11) to the outer diameter of the leg electrode (22) is 1.8:1 to 3: 1.

9. An efficiently coupled microwave assisted integrated spark plug according to claim 1 wherein the ceramic body (1) is an electrical insulator microwave conductor made of ceramic or teflon material.

10. An efficiently coupled microwave assisted integrated spark plug according to any of claims 1-9 wherein the metal shell has a front external thread (44) on the outside of the front portion for securing the spark plug to the cylinder; an external sealing ring (31) is arranged at the rear part of the front end external thread (44); an inner sealing ring (32) is arranged between the position where the diameter of the tail end of the ceramic body skirt portion (13) is largest and the metal shell.

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