Spark plug, engine and vehicle

Abstract

The utility model discloses a spark plug, an engine and a vehicle, the spark plug comprises a central junction pole and a connecting sleeve, one end of the central junction pole is provided with a first electrode; the connecting sleeve is arranged outside the central junction pole in a sleeving manner, an insulator is arranged between the connecting sleeve and the central junction pole, a second electrode is formed at one end of the connecting sleeve, the second electrode is an annular electrode, and the second electrode is distributed around the first electrode and is separated from the first electrode. According to the spark plug provided by the utility model, the second electrode of the spark plug does not need to adopt a single-claw or multi-claw electrode structure, the annular second electrode can prevent the single-claw or multi-claw structure from being influenced by the temperature of a combustion chamber, so that the phenomenon of preignition caused by concentrated heating can be avoided, and the annular second electrode is uniformly heated and can uniformly transfer heat to the connecting sleeve; and the risk of preignition is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a spark plug, an engine and a vehicle. Background Art

[0002] Hydrogen energy is the best form of energy to achieve carbon peak and carbon neutrality, and is also known as the ultimate energy in the 21st century. In the transportation field, hydrogen internal combustion engines have significant advantages of near-zero carbon emissions, high efficiency, high reliability and low cost, and are important carriers to contribute to carbon peak and carbon neutrality.

[0003] Similar to gasoline engines, the ignition mode of hydrogen internal combustion engines is also spark ignition, that is, a high-voltage electric spark is used to ignite the hydrogen-air mixture at the end of the compression stroke. However, the fuel characteristics of hydrogen and gasoline are different. The minimum ignition energy of hydrogen is less than one-tenth of that of gasoline. The combustible volume fraction range of the mixture is wide, it is easy to catch fire, and the combustion speed is fast, reaching more than five times that of gasoline. In view of the combustion characteristics of hydrogen, especially the characteristics of easy abnormal combustion, if the ignition system of a hydrogen internal combustion engine simply uses the ignition system of a gasoline engine, problems of abnormal combustion will occur. Summary of the Utility Model

[0004] The utility model aims to at least solve one of the technical problems existing in the prior art. For this reason, an object of the utility model is to provide a spark plug. The second electrode of the spark plug does not need to adopt a single-claw or multi-claw electrode structure. The annular second electrode can avoid the phenomenon that the single-claw or multi-claw structure is affected by the combustion chamber temperature and is heated concentratedly and causes pre-ignition. The annular second electrode is heated evenly and can transfer heat evenly to the connecting sleeve, reducing the risk of pre-ignition.

[0005] The spark plug according to the embodiment of the utility model includes: a central terminal rod, one end of the central terminal rod is formed with a first electrode; a connecting sleeve, the connecting sleeve is sleeved outside the central terminal rod, and an insulator is provided between the connecting sleeve and the central terminal rod. One end of the connecting sleeve is formed with a second electrode, the second electrode is configured as an annular electrode, the second electrode surrounds the first electrode and is spaced apart from the first electrode.

[0006] The spark plug according to the embodiment of the utility model is a special spark plug for hydrogen internal combustion engines. One end of the connecting sleeve is formed with an annular second electrode, that is, the entire connecting sleeve can be used as the second electrode. Compared with the multi-claw or single-claw second electrode in the prior art, it can prevent the multi-claw or single-claw electrode from being heated concentratedly after extending into the combustion chamber and causing pre-ignition. The annular second electrode can transfer heat evenly and prevent pre-ignition caused by concentrated heating.

[0007] A spark plug according to an embodiment of the present invention, a through hole is formed in the center of the second electrode, and a spark generated between the first electrode and the second electrode is adapted to pass through the through hole into the combustion chamber.

[0008] A spark plug according to an embodiment of the present invention, the diameter of the through hole is 1 / 5 - 1 / 7 of the diameter of the second electrode; the outer diameter of the first electrode is 1 / 3 - 1 / 4 of the inner diameter of the through hole.

[0009] A spark plug according to an embodiment of the present invention, the gap between the second electrode and the first electrode is 0.35 mm - 0.45 mm.

[0010] A spark plug according to an embodiment of the present invention, the thickness of the second electrode is set to gradually increase from the position close to the through hole to the position far from the through hole to form an inclined surface, and the inclined surface is located inside the connection sleeve.

[0011] A spark plug according to an embodiment of the present invention, the bottom of the center terminal extends out of the insulator, and an ignition buffer cavity is left between the inclined surface, the bottom of the center terminal and the bottom of the insulator.

[0012] A spark plug according to an embodiment of the present invention, the connection sleeve is made of nickel-plated steel material.

[0013] A spark plug according to an embodiment of the present invention, the temperatures of both the second electrode and the first electrode are lower than the auto-ignition temperature of hydrogen.

[0014] An embodiment of the present invention discloses an engine, including a cylinder and the above-mentioned spark plug. The cylinder includes a cylinder head, the cylinder head is provided with a spark plug hole, the spark plug is installed at the spark plug hole, and the end surface of the second electrode is flush with the top surface of the combustion chamber of the cylinder.

[0015] An embodiment of the present invention discloses a vehicle, including the above-mentioned engine.

[0016] The advantages of the described vehicle compared with the prior art and the described engine compared with the prior art are the same, and will not be elaborated here.

[0017] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0019] Figure 1It is a schematic structural diagram of a spark plug according to an embodiment of the present utility model;

[0020] Figure 2 It is a schematic partial structural diagram of a spark plug according to an embodiment of the present utility model;

[0021] Figure 3 It is a schematic circuit diagram of an ignition coil according to an embodiment of the present utility model.

[0022] Reference numerals:

[0023] Spark plug 100, primary circuit 101, secondary circuit 102, ignition coil 103, switch 104, first contact point 105, second contact point 106, connection sleeve 1, second electrode 11, inclined surface 111, through hole 112, central terminal rod 2, first electrode 21, insulator 3, ignition buffer cavity 4. Detailed implementation manners

[0024] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0025] Below, refer to Figure 1 - Figure 2 Describe the spark plug 100 according to an embodiment of the present utility model. It does not need to adopt a single-claw or multi-claw electrode structure. One end of the connection sleeve 1 of the spark plug 100 forms an annular second electrode 11, that is, the whole connection sleeve 1 can be used as the conductive structure of the second electrode 11. The annular second electrode 11 can avoid the phenomenon that the single-claw or multi-claw structure is affected by the combustion chamber temperature and heat is concentrated, resulting in pre-ignition. The annular second electrode 11 is heated evenly and can transfer heat evenly to the connection sleeve 1, reducing the risk of pre-ignition, thereby increasing the service life of the engine.

[0026] As Figure 1 - Figure 2 Describe the spark plug 100 according to an embodiment of the present utility model, including: a central terminal rod 2 and a connection sleeve 1.

[0027] Among them, one end of the central terminal rod 2 forms a first electrode 21; the connection sleeve 1 is sleeved outside the central terminal rod 2, and an insulator 3 is provided between the connection sleeve 1 and the central terminal rod 2. One end of the connection sleeve 1 forms a second electrode 11, and the second electrode 11 is configured as an annular electrode. The second electrode 11 is distributed around the first electrode 21 and is spaced apart from the first electrode 21.

[0028] In practice, the connecting sleeve 1 is a housing, and the connecting sleeve 1 has external threads. The connecting sleeve 1 is installed with the cylinder so that the spark plug 100 is installed in the cylinder. The external threads are mainly used to fix the spark plug 100 and connect and support the second electrode 11. The connecting sleeve 1 also has a heat dissipation function. Specifically, the first electrode 21 is the positive electrode, and the second electrode 11 is the negative electrode. Under the action of high-voltage electricity, the air between the first electrode 21 and the second electrode 11 of the spark plug 100 will quickly ionize, forming positively charged ions and negatively charged free electrons. When the number of ions and electrons explodes and the air loses its insulation, a discharge channel is formed and a breakdown phenomenon occurs, that is, a spark. In addition, the insulator 3 is made of ceramic material to isolate the central terminal rod 2 of the spark plug 100 from the outside and ensure the safe and stable ignition of the spark plug 100.

[0029] Furthermore, the central terminal rod 2 is used to connect with the ignition coil 103. High voltage is input to the central terminal rod 2 through the ignition coil 103. The voltage of the central terminal rod 2 is relatively high, so that a spark can be generated between the second electrode 11 and the first electrode 21 at the end of the central terminal rod 2 even when there is a gap.

[0030] The embodiment of the present utility model is a spark plug 100 dedicated for a hydrogen internal combustion engine. One end of the connecting sleeve 1 forms an annular second electrode 11. The connecting sleeve 1 is made of metal material, that is, the entire connecting sleeve 1 can form the conductive structure of the second electrode 11, and the entire central terminal rod 2 serves as the conductive structure of the positive electrode. Compared with the multi-claw or single-claw second electrode 11 of the prior art, it can prevent the multi-claw or single-claw second electrode 11 from being heated concentratedly after extending into the combustion chamber and causing pre-ignition. The annular second electrode 11 can transfer heat evenly, prevent heat concentration and cause pre-ignition, thereby reducing the knocking risk of the engine and improving the service life of the engine.

[0031] In some embodiments, a through hole 112 is formed in the center of the second electrode 11. The spark generated between the first electrode 21 and the second electrode 11 is adapted to pass through the through hole 112 into the combustion chamber.

[0032] In practice, by providing the through hole 112 in the center of the second electrode 11, the spark generated between the first electrode 21 and the second electrode 11 can be transmitted to the combustion chamber through the through hole 112, thereby igniting the mixture of hydrogen and air in the combustion chamber. In addition, the through hole 112 is provided at the central position of the second electrode 11, so that the sparks between the first electrode 21 and the second electrode 11 can be transmitted more evenly towards the combustion chamber.

[0033] Moreover, the first electrode 21 is located inside the connecting sleeve 1, which also reduces the influence of the relatively high temperature on the first electrode 21, providing a basis for the temperatures of both the first electrode 21 and the second electrode 11 to be lower than the self-ignition temperature of hydrogen.

[0034] Of course, the temperatures of the first electrode 21 and the second electrode 11 are also related to the energy used by the ignition coil 103, and the ignition coil 103 includes a primary circuit 101 and a secondary circuit 102. Refer to Figure 3 As shown, when the switch 104 is closed with the first contact point 105, the primary coil is charged; when the switch 104 is closed with the second contact point 106, the primary coil is de-energized. Before the circuit is closed, the current in the inductor is zero; at the moment t = 0, the switch 104 is switched from the second contact point 106 to the first contact point 105, and the voltage U charges the primary coil. The switch 104 is switched from the first contact point 105 to the second contact point 106, indicating the end of charging. The time when the switch 104 is closed is the charging pulse width.

[0035] When current passes through the primary coil winding of the ignition coil 103, the magnet core is magnetized, and electromagnetic energy is stored therein, and there is a magnetic field around it; when the ignition coil 103 disconnects the primary circuit 101 under the action of the switch 104, the magnetic field changes, generating a self-inductance effect, and a voltage of 300 - 500V is generated on the primary coil winding. Using the voltage generated on the primary coil winding and the mutual inductance effect, a high voltage can be induced on the secondary coil winding. The high voltage breaks down the first electrode 21 and the second electrode 11 of the spark plug 100, that is, the positive and negative electrodes of the spark plug 100, generating an electric spark, thereby igniting the mixture of hydrogen and air. The ratio of the voltage of the primary coil winding to the voltage of the secondary coil winding is the ratio of the number of turns of the primary coil winding to the number of turns of the secondary coil winding.

[0036] Among them, the discharge energy of the secondary circuit 102 of the ignition coil 103 is equal to the integral of the discharge voltage and the discharge current over the entire spark duration, and can be expressed by equation (1):

[0037]

[0038] In the above formula, E is the discharge energy (mJ) of the ignition coil 103, U is the discharge voltage (V), I is the discharge current (A), t is the spark duration (ms), and the spark duration is proportional to the charging pulse width of the primary coil winding and can be characterized by the charging pulse width; the discharge voltage and the discharge current can be collected and stored by devices such as high-voltage probes. The minimum ignition energy of hydrogen is only one-tenth of that of gasoline, that is, the charging pulse width of the primary coil winding can be reduced, thereby reducing the discharge ignition energy. The ignition energy of the embodiment of the present invention ≤ 45mJ. For example, the general ignition energy can be set to 30 - 45mj, which is less than the ignition energy used by a conventional gasoline engine. The ignition energy of a conventional gasoline engine is above 90mj, thus meeting the requirements of a hydrogen internal combustion engine while improving the service life of the ignition coil 103.

[0039] In some embodiments, the diameter of the through hole 112 is 1 / 5 - 1 / 7 of the diameter of the second electrode 11; and / or, the outer diameter of the first electrode 21 is 1 / 3 - 1 / 4 of the inner diameter of the through hole 112.

[0040] In practice, the diameter of the through hole 112 is set to be smaller than the diameter of the second electrode 11. For example, the diameter of the through hole 112 is about 1 / 6 of the diameter of the second electrode 11. At this time, when a spark is generated between the first electrode 21 and the second electrode 11, the spark can be sprayed into the combustion chamber along the through hole 112, avoiding the situation when the through hole 112 is larger and preventing the overheated temperature in the combustion chamber from affecting the temperatures of the first electrode 21 and the second electrode 11.

[0041] In addition, the outer diameter of the first electrode 21 is slightly smaller than the inner diameter of the through hole 112. Since the outer diameter of the first electrode 21 is smaller, the relative area between the first electrode 21 and the second electrode 11 is smaller. The positively charged ions and negatively charged free electrons generated between the first electrode 21 and the second electrode 11 are located between the first electrode 21 and the second electrode 11, that is, at the relative position between the first electrode 21 and the second electrode 11, which can make the spark quickly spray out towards the through hole 112, avoiding the aggregation of the spark at a position far from the through hole 112 and affecting the effect of the spark entering the combustion chamber.

[0042] In some embodiments, the gap between the second electrode 11 and the first electrode 21 is 0.35 mm - 0.45 mm.

[0043] In practice, by reducing the gap between the first electrode 21 and the second electrode 11 to meet the actual situation of the hydrogen ignition energy requirement, the gap between the first electrode 21 and the second electrode 11 is smaller than the gap of 0.6 - 0.8 mm between the two electrodes of the gasoline engine spark plug 100. In the case of low hydrogen ignition energy requirement, the ignition voltage can be reduced and the service life of the spark plug 100 can be improved.

[0044] As Figure 1 shown, the gap between the first electrode 21 and the second electrode 11 in the embodiment of the present invention is the distance between the side of the second electrode 11 facing the first electrode 21 and the first electrode 21. For example, the distance between the first electrode 21 and the second electrode 11 can be 0.35 mm, 0.4 mm, etc.

[0045] In some embodiments, the thickness of the second electrode 11 is set to gradually increase from the position close to the through hole 112 to the position far from the through hole 112 to form an inclined surface 111, and the inclined surface 111 is located inside the connecting sleeve 1.

[0046] In practice, by setting the thickness of the second electrode 11 near the through hole 112 to be relatively thin, it is convenient to design the through hole 112 during manufacturing. Additionally, with a relatively thin thickness at the position near the through hole 112, the sparks generated by the first electrode 21 and the second electrode 11 can be sprayed into the combustion chamber more efficiently, reducing the path for the sparks generated by the first electrode 21 and the second electrode 11 to enter the combustion chamber. At the same time, the first electrode 21 can be arranged inside the connecting sleeve 1 to protect the first electrode 21.

[0047] In addition, the inclined surface 111 on the inner side of the second electrode 11 can play a role in guiding the sparks generated between the first electrode 21 and the second electrode 11, causing the sparks to spray out towards the through hole 112 along the inclined surface 111 and then into the combustion chamber, thereby improving the efficiency of igniting the air-fuel mixture in the combustion chamber.

[0048] In some embodiments, the bottom of the central terminal rod 2 extends out of the insulator 3, and an ignition buffer cavity 4 is left between the inclined surface 111 and the bottom of the central terminal rod 2 as well as the bottom of the insulator 3.

[0049] Among them, the bottom of the central terminal rod 2 extending out of the insulator 3 can separate the central terminal rod 2 from the connecting sleeve 1 through the insulator 3. The bottom of the central terminal rod 2 extending out of the insulator 3 facilitates the generation of sparks between the first electrode 21 at the bottom of the central terminal rod 2 and the second electrode 11. Moreover, the insulator 3 can separate the central terminal rod 2 from the external environment, transfer the ignition energy to the central terminal rod 2, enabling the generation of sparks between the first electrode 21 and the second electrode 11 without damage. Additionally, the insulator 3 also has a heat dissipation function, preventing the temperature of the first electrode 21 from being too high and avoiding problems such as pre-ignition or ablation of the first electrode 21.

[0050] In addition, the inclined surface 111 on the inner side of the second electrode 11, the extended part of the central terminal rod 2, and the insulator 3 form the ignition buffer cavity 4, that is, the end of the connecting sleeve 1 surrounds the end of the central terminal rod 2 to form the ignition buffer cavity 4. When sparks are generated between the first electrode 21 and the second electrode 11, there is a buffer for a certain ignition pressure, and it does not cause the problem of pre-ignition or knocking by completely exposing the first electrode 21 and the second electrode 11 to the combustion chamber.

[0051] In some embodiments, the connecting sleeve 1 is made of nickel-plated steel material.

[0052] In practice, the negative electrode of the gasoline engine spark plug in the prior art contains precious metal platinum. Platinum has a high melting point, about 1772°C, and strong ablation resistance. It is usually fixed on the second electrode 11 of the spark plug by sintering or laser welding. Platinum can be used as a catalyst to promote the reaction between hydrogen and oxygen, and there is a risk of abnormal ignition of the engine when used in a hydrogen internal combustion engine. The connecting sleeve 1 in the embodiment of the present invention is made of nickel-plated steel. It has been verified that its service life is equivalent to that of the gasoline engine spark plug, and it can also avoid the risk of abnormal ignition of the engine.

[0053] In some embodiments, the temperatures of the second electrode 11 and the first electrode 21 are both lower than the self-ignition temperature of hydrogen.

[0054] Specifically, when the temperatures of the second electrode 11 and the first electrode 21 are both lower than the self-ignition temperature of hydrogen, it can prevent the first electrode 21 and the second electrode 11 from prematurely igniting the hydrogen in the combustion chamber. Premature ignition is regarded as the most important limiting factor for further cylinder reduction and strengthening of the engine. In the working cycle with premature ignition, the mixture of air and hydrogen is ignited before the spark plug 100 generates a spark, resulting in a much higher pressure than normal combustion. Since the increase in pressure level and the self-ignition point usually occur at spatial positions that are not conducive to combustion, the combustion process turns into a strong detonation, seriously damaging the engine. That is to say, when the temperatures of the first electrode 21 and the second electrode 11 are lower than the self-ignition temperature of hydrogen, the risk of engine knocking can be reduced and the service life of the engine can be increased.

[0055] In practice, the self-ignition temperature of hydrogen is about 585°C. Under the premise of the structural improvement of the spark plug and the ignition energy of 45 mj in the embodiment of the present invention, through CAE comparative simulation analysis, the temperature of the second electrode 11 is about 447°C, and the temperature of the first electrode 21 is 535°C, both of which are lower than the temperature of the second electrode 11 of the conventional gasoline engine spark plug 100, which is 776°C. It can not only meet the ignition requirements of the hydrogen internal combustion engine but also suppress the possible premature ignition phenomenon of the hydrogen internal combustion engine.

[0056] The embodiment of the present invention discloses an engine, including the above-mentioned spark plug 100. The cylinder includes a cylinder head, and the cylinder head is provided with a spark plug hole. The spark plug 100 is installed at the spark plug hole, and the end face of the second electrode 11 is flush with the top surface of the combustion chamber of the cylinder.

[0057] That is to say, the single-claw or multi-claw structure of the spark plug 100 in the prior art extends into the combustion chamber. After the spark plug 100 of the embodiment of the present invention is installed in the cylinder, the end face of the second electrode 11 of the spark plug 100 is flush with the top surface of the combustion chamber of the cylinder, and the second electrode 11 does not extend into the combustion chamber; after the high-temperature mixed gas in the combustion chamber burns, a stable hot spot will be formed in the combustion chamber, and the mixed gas in the subsequent intake and compression strokes is not enough to cool the temperature of the second electrode 11 of the spark plug 100 to a low enough level. The single-claw or multi-claw structure extending into the combustion chamber has the risk of prematurely igniting the hydrogen and air mixture, causing pre-ignition in the hydrogen internal combustion engine.

[0058] When the spark plug 100 of the embodiment of the present invention is installed, there is no single-claw or multi-claw structure extending into the combustion chamber, and the end face of the second electrode 11 is flush with the top surface of the combustion chamber of the cylinder, reducing the risk of pre-ignition of the mixed gas in the combustion chamber. At the same time, in combination with the low-energy ignition situation of hydrogen, the end face of the second electrode 11 being flush with the top surface of the combustion chamber of the cylinder prevents the second electrode 11 from being too far away from the mixed gas in the combustion chamber, and also prevents the situation of non-ignition.

[0059] In addition, it should be noted that the ignition coil charging characteristic MAP of the embodiment of the present invention is shown in Table 1.

[0060] Table 1 Ignition Coil Charging MAP for Hydrogen Internal Combustion Engine

[0061]

[0062]

[0063] That is to say, the charging time of the ignition coil 103 is determined by the charging voltage and the engine speed, and the charging time is the charging pulse width. As described above, reducing the charging pulse width of the primary coil can reduce the discharge ignition energy. Therefore, by reducing the charging voltage to reduce the discharge ignition energy, the ignition coil 103 uses low-energy 30 - 45 mj ignition, which meets the requirements of the hydrogen internal combustion engine and improves the service life of the ignition coil 103 at the same time.

[0064] The embodiment of the present invention discloses a vehicle, including the above-mentioned engine. Without using a single-claw or multi-claw electrode structure, one end of the connecting sleeve 1 forms a ring-shaped second electrode 11, that is, the connecting sleeve 1 as a whole can be used as the conductive structure of the second electrode 11. The ring-shaped second electrode 11 can avoid the single-claw or multi-claw structure from being affected by the temperature of the combustion chamber and being heated concentratedly to cause pre-ignition. The ring-shaped second electrode 11 is heated evenly and can transfer heat evenly to the connecting sleeve 1, reducing the risk of pre-ignition, thereby improving the service life of the engine and the practicality of the vehicle.

[0065] 1. In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0066] 2. In the description of the present utility model, the "first feature" and "second feature" may include one or more of such features.

[0067] 3. In the description of the present utility model, the meaning of "a plurality of" is two or more.

[0068] 4. In the description of the present utility model, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween.

[0069] 5. In the description of the present utility model, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature.

[0070] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A spark plug, characterized in that, Comprising: A central connection rod, one end of the central connection rod is formed with a first electrode; A connection sleeve, the connection sleeve is sleeved outside the central connection rod, and an insulator is provided between the connection sleeve and the central connection rod. One end of the connection sleeve is formed with a second electrode, the second electrode is configured as an annular electrode, the second electrode is distributed around the first electrode and spaced apart from the first electrode; A through hole is formed in the center of the second electrode, and the spark generated between the first electrode and the second electrode is adapted to pass through the through hole into the combustion chamber; The thickness of the second electrode is set to gradually increase from a position close to the through hole to a position far from the through hole to form an inclined surface. The inclined surface is located inside the connection sleeve, and the end of the first electrode is spaced apart from the through hole in the length direction of the spark plug, and the end of the first electrode is located inside the inclined surface.

2. The spark plug according to claim 1, characterized in that, The diameter of the through hole is 1 / 5 - 1 / 7 of the diameter of the second electrode; And / or, the outer diameter of the first electrode is 1 / 3 - 1 / 4 of the inner diameter of the through hole.

3. The spark plug according to claim 1, characterized in that, The gap between the second electrode and the first electrode is 0.35mm - 0.45mm.

4. The spark plug according to claim 1, characterized in that, The bottom of the central connection rod extends out of the insulator, and an ignition buffer cavity is left between the inclined surface, the bottom of the central connection rod and the bottom of the insulator.

5. The spark plug according to claim 1, characterized in that, The connection sleeve is made of nickel-plated steel material.

6. The spark plug according to claim 1, characterized in that, The temperatures of the second electrode and the first electrode are both lower than the self-ignition temperature of hydrogen.

7. An engine, characterized in that, Comprising a cylinder and the spark plug according to any one of claims 1 - 6, the cylinder includes a cylinder head, the cylinder head is provided with a spark plug hole, the spark plug is installed at the spark plug hole, and the end face of the second electrode is flush with the top surface of the combustion chamber of the cylinder.

8. A vehicle, characterized in that, Comprising the engine according to claim 7.

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