CN115898621A

CN115898621A - Pre-combustion chamber and engine

Info

Publication number: CN115898621A
Application number: CN202110888142.6A
Authority: CN
Inventors: 纪雷
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2023-04-04

Abstract

The invention provides a precombustion chamber and an engine, wherein the precombustion chamber comprises a shell, a precombustion cavity is formed at the lower part in the shell, an insertion hole which is communicated with the precombustion cavity and is suitable for inserting a spark plug is formed at the upper part of the shell, a flame spray hole which is communicated with the precombustion cavity is also formed at the lower part of the shell, and the length H of the precombustion cavity in the vertical direction is more than or equal to the diameter D of the insertion hole and is less than or equal to 3 times of the diameter D of the insertion hole. The length H of the precombustion cavity is set in the limited range, so that the dense oil-gas mixture can be effectively concentrated in the limited space, the electric spark generated by a spark plug electrode can quickly ignite the oil-gas mixture to form flame flow with high energy, and meanwhile, the high-energy flame flow can enter the main combustion chamber through the flame jetting holes in the shortest path to quickly ignite the oil-gas mixture in the main combustion chamber, so that the ignition effect of the engine can be improved.

Description

Pre-combustion chamber and engine

Technical Field

The invention relates to the technical field of spark plugs, in particular to a precombustion chamber. The invention also relates to an engine.

Background

At present, in the domestic and foreign automobile industry, the gasoline engine special for the hybrid power system with high heat efficiency and small discharge capacity is concerned a lot. The gasoline engine ignites the oil-gas mixture in the cylinder by a spark plug, and outputs power torque outwards after full combustion. The traditional gasoline engine adopts a spark plug mounting hole arranged at the upper part of a combustion chamber of a cylinder cover, and after an electrode of the spark plug generates electric sparks, the well-mixed oil gas in the cylinder body is ignited.

The existing high thermal efficiency engine often uses a novel ignition device, adds a new precombustion chamber on the basis of the cylinder cover combustion chamber, or the precombustion chamber spark plug, and the combustion chamber of the existing gasoline engine mainly has: the combustion chamber has the advantages of simple processing, low production cost and small heating area. When the spark plug works, the oil gas in the precombustion chamber is ignited by the spark plug to form flame flow, the flame flow is sprayed out through the flame spraying holes of the precombustion chamber, and then the mixed gas in the main combustion chamber is ignited, so that the combustion speed is improved.

The arrangement of the spark plug electrode and the flame spray hole of the pre-combustion chamber in the prior pre-combustion chamber is unreasonable, so that the flame flow in the pre-combustion chamber cannot be fully and effectively utilized, and the ignition effect of an engine can be influenced. Moreover, there are three main manifestations of existing prechamber arrangements: firstly, flame flow is not fully formed and is sprayed to a main combustion chamber through a flame spraying hole, and the flame energy is low; secondly, after the flame flow is fully formed, the flame flow is sprayed to the main combustion chamber through the flame spraying holes after flowing in a section of space in the precombustion chamber, so that the utilization rate of the flame flow is low; thirdly, the flame is not transmitted, the mixed gas at the tail end is natural, the detonation is generated, and the normal flame flow cannot be formed.

Disclosure of Invention

In view of the above, the present invention is directed to a prechamber to improve the ignition effect of the engine.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the utility model provides a precombustion chamber, includes the casing, the lower part in the casing is formed with the precombustion chamber, the upper portion of casing be formed with the precombustion chamber intercommunication and be suitable for the inserted cartridge hole of spark plug, the lower part of casing still be formed with the bocca intercommunication spout fire hole, length H more than or equal to in the direction from top to bottom of precombustion chamber the diameter D of cartridge hole, and less than or equal to 3 times the diameter D of cartridge hole.

Further, the precombustion cavity comprises a first chamber, a second chamber and a third chamber which are sequentially arranged from top to bottom; the second chamber is a variable-diameter chamber which gradually reduces from the first chamber to the third chamber, the first chamber is an equal-diameter chamber which has the same diameter with the large-diameter end of the second chamber, and the third chamber at least has an equal-diameter part which has the same diameter with the small-diameter end of the second chamber; the fire spraying hole is formed in the bottom of the third chamber.

Further, the third chamber is also provided with an arc-shaped chamber part positioned at the bottom of the third chamber; the arc-shaped cavity part is connected with the equal-diameter part; the fire spraying hole is formed in the inner wall of the arc-shaped cavity portion.

Further, the height h1 of the first chamber satisfies: h1 ≦ 35 ≦ H; the height h2 of the second chamber satisfies: h 1. Ltoreq. H2. Ltoreq.50% h; the height h3 of the third chamber satisfies: 90% h 1. Ltoreq.h 3. Ltoreq.35%.

Further, a head portion of the inserted spark plug extends into the first chamber, and a ground electrode in the head portion extends into the second chamber.

Further, a distance h0 between the ground electrode and the upper end portion of the second chamber, and a distance h4 between the ground electrode and the upper end portion of the first chamber satisfy: h 0. Ltoreq.30% h4.

Further, the distance H4 between the ground electrode and the upper end of the first chamber, the height H of the prechamber, and the diameter D of the spark plug satisfy: 30% h.ltoreq.h 4.ltoreq.40% h, and 50% d.ltoreq.h 4.ltoreq.70% d.

Furthermore, the flame holes comprise a plurality of first flame holes and a plurality of second flame holes, and the communication ports of the second flame holes and the arc-shaped cavity part are lower than the communication ports of the first flame holes and the arc-shaped cavity part;

the distance h5 between the first flame-throwing hole and the communication port of the arc-shaped cavity part and the grounding electrode satisfies the following condition: 50% h.ltoreq.h 5.ltoreq.60% h; the distance H6 between the communication port of the second flame spray hole and the arc-shaped cavity part and the grounding electrode, and the height H of the pre-combustion cavity meet the following conditions: h 6. Ltoreq.70% of H.

Further, the number of the flame spraying holes is between 4 and 8, and the diameter of the flame spraying holes is between 0.8 and 2 mm.

Compared with the prior art, the invention has the following advantages:

according to the precombustion chamber, the length H of the precombustion cavity is set within the limited range, so that the concentrated oil-gas mixture can be effectively concentrated in a limited space, electric sparks generated by a spark plug electrode can quickly ignite the oil-gas mixture to form flame flow with high energy, meanwhile, the high-energy flame flow can enter the main combustion chamber through the flame holes in the shortest path, the oil-gas mixture in the main combustion chamber can be quickly ignited, and the ignition effect of an engine can be improved.

Another object of the invention is to propose an engine with a prechamber as described above, in which the housing is integrated in the cylinder head of the engine; alternatively, the housing is integrated on the spark plug.

According to the engine, the pre-combustion chamber is assembled, so that mixed gas can be rapidly ignited to form flame flow with high energy, the flame flow enters the main combustion chamber of the cylinder to introduce oil-gas mixed gas, and a good ignition effect can be formed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a cross-sectional view of a precombustor according to a first embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of a precombustor according to a first embodiment of the present invention.

Description of the reference numerals:

1. a housing; 101. a first chamber; 102. a second chamber; 103. a third chamber; 1031. a constant diameter portion; 1032. an arcuate chamber portion; 10321. a flame spray hole; 103211, a first flame spray hole; 103212, a second flame spray hole; 2. a spark plug; 201. a head portion; 2011. and (4) grounding the electrode.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it should be noted that, if terms indicating orientation or positional relationship such as "upper", "lower", "inside", "outside", etc. appear, they are based on the orientation or positional relationship shown in the drawings and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the appearances of the terms first, second, etc. in this specification are not necessarily all referring to the same order, but are to be construed as referring to the same order.

In addition, in the description of the present invention, the terms "mounted," "connected," and "connecting" are to be construed broadly unless otherwise specifically limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. To those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in conjunction with specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example one

The present embodiment relates to a prechamber, which comprises a housing 1, a prechamber formed in the lower part of the housing 1, an insertion hole formed in the upper part of the housing 1 and communicating with the prechamber and adapted to insert a spark plug 2, and a flame jet 10321 formed in the lower part of the housing 1 and communicating with the prechamber.

In the present embodiment, the length H of the prechamber in the vertical direction is equal to or greater than the diameter D of the insertion hole, and is equal to or less than 3 times the diameter D of the insertion hole.

The prechamber of this embodiment, length H through with the prechamber sets up in above-mentioned scope, can make during the effectual finite space of concentrating in the prechamber of richer air-fuel mixture, the electric spark that is favorable to spark plug 2's electrode to produce ignites air-fuel mixture fast, in order to form the flame current of higher energy, and simultaneously, high energy flame current also can pass through bocca 10321 with the shortest route and get into cylinder main combustion chamber, the air-fuel mixture in the main combustion chamber can ignite fast, thereby can improve the ignition effect of engine.

Based on the above description of the overall structure, an exemplary structure of the precombustion chamber of the present embodiment is shown in fig. 1, in this case, as a preferred embodiment, the precombustion chamber formed in the housing 1 includes a first chamber 101, a second chamber 102 and a third chamber 103 which are arranged in sequence from top to bottom, the second chamber 102 is a diameter-variable chamber which gradually reduces from the first chamber 101 to the third chamber 103, the first chamber 101 is an equal-diameter chamber which is equal to the large-diameter end of the second chamber 102, and the third chamber 103 has an equal-diameter part 1031 which is equal to the small-diameter end of the second chamber 102.

As a further preferred embodiment, in this embodiment, the third chamber 103 also has an arcuate chamber portion 1032 at its own bottom. The arcuate chamber portion 1032 is connected to the constant diameter portion 1031 to form the integral third chamber 103. Meanwhile, the present embodiment is provided with the above-described flame spray holes 10321 at the bottom of the third chamber 103, specifically, on the inner wall of the arc-shaped chamber portion 1032.

The setting of flame jet 10321 is passed through to this embodiment, the fresh gas mixture in the cylinder main combustion chamber, and specifically be the fresh gas mixture in the cylinder cap combustion chamber through flame jet 10321 get into the prechamber of precombustion chamber promptly, and is the same, and flame flow in the precombustion chamber also flows to the cylinder cap combustion chamber through flame jet 10321 to this can be in the precombustion back in the precombustion chamber, realizes igniteing to main combustion chamber.

In addition, instead of further providing the arc-shaped chamber portion 1032, it should be noted that, of course, the third chamber 103 may be formed only by the equal-diameter portion 1031, and in this case, the flame holes 10321 may be formed directly in the bottom of the third chamber 103.

In the present embodiment, the head 201 of the spark plug 2 inserted through the insertion hole extends into the first chamber 101, and the ground electrode 2011 in the head 201 also extends into the second chamber 102. Further, in the present embodiment, the number of the flame ejection holes 10321 is also set to be 4 to 8, and the specific number thereof may be determined according to the vehicle displacement, and further, the diameter of each flame ejection hole 10321 is also set to be 0.8mm to 2mm, and it is noted that the diameter of the flame ejection hole 10321 is approximately inversely proportional to the number of the flame ejection holes 10321 in the overall design of the flame ejection holes 10321.

Thus, when the number of the flame holes 10321 is large, for example, 8, the diameter of the flame holes 10321 may take a low value, for example, 0.8mm, and when the number of the flame holes 10321 is small, for example, 4, the diameter of the flame holes 10321 may increase, for example, 2mm may be used, so as to obtain a superior ignition effect.

Further, the present embodiment enables the flame flow entering the main combustion chamber of the cylinder through the flame ports 10321 to effectively maintain its high energy by limiting the diameter of the flame ports 10321 within the above range, thereby ensuring the ignition effect. If the diameter of the flame port 10321 is too small, the flame is easily extinguished, which directly affects the combustion efficiency of the mixture in the main combustion chamber.

Meanwhile, through the above limitation on the number of the flame spraying holes 10321, the embodiment can also obtain balance between the flame covering performance and the ignition performance, and further can ensure the ignition effect on the cylinder cover combustion chamber. Moreover, if the number of the flame holes 10321 is too small, the flame flow in the pre-combustion chamber is not beneficial to completely cover the whole cylinder head combustion chamber space, the uniform combustion of the mixed gas in the cylinder head combustion chamber is not beneficial, the phenomenon of spontaneous combustion of the mixed gas at the tail end around the combustion chamber is easy to occur, and the combustion efficiency is low. The excessive number of the flame ejection holes 10321 can effectively cover the combustion chamber space, but in the limited bottom space of the pre-combustion chamber, the excessive number of the flame ejection holes 10321 means that the diameter of the flame ejection holes 10321 is too small, so that the flame ejection holes are easy to extinguish when the flame flows, and the ignition of the oil-gas mixture in the cylinder head combustion chamber can be also not facilitated.

As also shown in fig. 1, in the present embodiment, the plurality of flame holes 10321 includes a plurality of first flame holes 103211 and a plurality of second flame holes 103212, and the communication openings of the second flame holes 103212 with the arc-shaped chamber portion 1032 are lower than the communication openings of the first flame holes 103211 with the arc-shaped chamber portion 1032. Because the spark plug 2 in the prechamber 1 is ignited by the grounding electrode 2011, the formed flame flow can flow out through the flame holes 10321 and then ignite the mixed gas in the main combustion chamber, the ignition of the mixed gas can be more uniform by reasonably arranging the positions of the first flame holes 103211 and the second flame holes 103212, the occurrence of the knocking phenomenon of the engine can be improved, and the working stability of the engine can be further improved.

In this embodiment, referring to fig. 2, it should be noted that h0 is a distance that the ground electrode 2011 extends into the second chamber 102, h1 is a height of the first chamber 101, h2 is a height of the second chamber 102, h3 is a height of the third chamber 103, h4 is a distance between the ground electrode 2011 and an upper end portion of the first chamber 101, h5 is a distance between the first flame ejection hole 103211 and a communication port of the arc-shaped chamber portion 1032 and the ground electrode 2011, and h6 is a distance between the second flame ejection hole 103212 and a communication port of the arc-shaped chamber portion 1032 and the ground electrode 2011. H is the overall height of the prechamber, and D is the diameter of the insertion hole, i.e. the diameter of the spark plug 2.

At this time, in order to improve the ignition effect of the ground electrode 2011 of the spark plug 2, the ground electrode 2011 in the present embodiment extends into the second chamber 102 by a distance h0, and the ground electrode 2011 is spaced from the upper end of the first chamber 101 by a distance h4, which satisfy: h 0. Ltoreq.30% h4, whereby the mixture gas in the precombustion chamber 1 can be ignited quickly and the mixture gas can be sufficiently combusted.

Meanwhile, after the relative position between the ground electrode 2011 of the spark plug 2 and the second chamber 102 is determined, the position of the center electrode of the spark plug 2 is also determined, and the initial spark center position of the spark plug 2 is determined. At this time, by making the ground electrode 2011 adopt the above arrangement range, the electric spark generated by the electrode of the spark plug 2 can be guaranteed to be effectively transmitted to the upper end portion of the first chamber 101, so that the oil-gas mixture at the upper end portion of the first chamber 101 can be effectively ignited, and the air-gas mixture flows to the bottom of the precombustion chamber under the driving of airflow movement in the precombustion chamber. Meanwhile, the arrangement can also avoid spontaneous combustion and even detonation of high-temperature oil-gas mixture generated in advance at the upper end of the first chamber 101 before the electric spark reaches due to the long electric spark transmission distance at the upper end of the first chamber 101.

The distance H4 between the ground electrode 2011 and the upper end of the first chamber 101, the height H of the prechamber, and the diameter D of the spark plug 2 satisfy: 30% H4H 40H, and 50% D4H 70D, by setting the matching relationship between the distance H4 between the ground electrode 2011 and the upper end of the first chamber 101 and the height H of the precombustion chamber, the ground electrode 2011 of the spark plug 2 can exert a good effect in the precombustion chamber 1 and can improve the ignition speed of the mixed gas, and in addition, the setting of the matching relationship between the diameter D of the spark plug 2 and the distance H4 between the ground electrode 2011 and the upper end of the first chamber 101 can ensure the ignition effect of the ground electrode 2011.

In addition, the height h1 of the first chamber 101 in the present embodiment satisfies: h1 ≦ 35%: h 1. Ltoreq. H2. Ltoreq.50%, the height h3 of the third chamber 103 satisfying: 90% h 1. Ltoreq.h 3. Ltoreq.35%. Through setting up the proportion of first cavity 101 height H1, second cavity 102 height H2 and third cavity 103 height H3 and precombustion chamber height H, can rationalize the distribution of a plurality of cavities of precombustion chamber to can guarantee the flash ignition of gas mixture, and make the burning become more even, with the combustion effect that can improve main combustion chamber.

By limiting the height of the first chamber 101 to the above range, the relatively rich air-fuel mixture can be effectively concentrated around the electrode of the spark plug 2, and the distances from the electric spark generated by the electrode of the spark plug 2 to the periphery and the upper end of the first chamber 101 are approximately the same, so that the electric spark can be simultaneously transmitted to the periphery and the upper end of the first chamber 101, the air-fuel mixture can be ignited to form high-energy flame flow, the electric spark is prevented from propagating at different distances and time, and the peripheral air-fuel mixture can be self-ignited to generate detonation.

Meanwhile, by limiting the height of the second chamber 102 within the above range, the high-energy flame flow in the precombustion chamber can be effectively gathered at the upper portion of the flame port 10321, so that the flame flow can quickly and directly enter the main combustion chamber through the flame port 10321 to ignite the oil-gas mixture in the main combustion chamber, thereby forming quick and uniform combustion, and effectively improving the combustion efficiency of the mixture.

In this embodiment, the distance H5 between the communication port of the first flame ejection hole 103211 and the arc-shaped cavity portion 1032 and the ground electrode 2011, and the height H of the prechamber satisfy: 50% h.ltoreq h 5.ltoreq.60%; the distance H6 between the communication port of the second flame port 103212 and the arc chamber portion 1032 and the ground electrode 2011, and the height H of the prechamber, satisfy: h6 ≦ 70%.

It can be understood that, after the telluric electricity field 2011 of spark plug 2 igniteed, can ignite the oil-gas mixture of precombustion chamber fast to can form the fire core fast, and then ignite the gas mixture in the precombustion chamber, form the flame current of high energy, the flame current of high energy can be quick at this moment enters into main combustion chamber through flame projecting hole 10321, can reduce the energy loss in the flame propagation, and can make the gas mixture burn fully, improve and ignite the effect.

Moreover, by the above-mentioned limitations on the distance h5 and the distance h6, in combination with the aforementioned limitation on the range of the distance h4, the present embodiment can make the electric spark generated by the electrode of the spark plug 2 effectively transmitted to the upper end portion of the first chamber 101 and the lower end of the second chamber 102, and can make the time and distance of propagation of the electric spark or flame flow approximately the same in the prechamber at the upper portion of the flame spray port 10321, so that the air-fuel mixture in the prechamber can be effectively ignited, and the occurrence of knocking due to spontaneous combustion of the peripheral mixture caused by the difference in propagation distance and time of the electric spark can be avoided.

The prechamber of this embodiment adopts whole setting as above, through arranging 2 ignition electrodes of spark plug and the relative position of flame projecting hole 10321 height, and 1 prechamber structure of rational design prechamber, can make spark plug 2 ignite the back can form the high-energy flame core fast, the flame current rethread flame projecting hole 10321 of high energy ignites the gas mixture in the main combustion chamber, the gas mixture in the main combustion chamber is ignited through flame projecting hole 10321 to the flame current of high energy that from this can make the prechamber, can make the abundant burning of gas mixture in the combustion chamber, and then can improve engine economy and emission, and there is fine practicality.

Meanwhile, the precombustion chamber of the embodiment also enables the time and the distance from the electric spark generated by the electrode of the spark plug 2 to the wall surfaces of each part of the precombustion chamber to be approximately the same, can effectively ignite the oil-gas mixture in the precombustion chamber, can avoid the peripheral mixed gas from generating spontaneous combustion due to different electric spark propagation distances and different time, and can further reduce the possibility of generating knocking.

Example two

The present embodiment relates to an engine having a prechamber according to embodiment one, and the above-described housing 1 is integrated in the cylinder head of the engine; alternatively, the housing 1 is integrated on the spark plug. When the housing 1 is integrated in the spark plug 2, the spark plug 2 is also an integrated spark plug integrated with a prechamber, and the integration of the housing 1 in the spark plug 2 and the integration of the housing 1 in the cylinder head are all as described in the related art.

The engine of this embodiment through setting up the precombustion chamber of embodiment one, can ignite the gas mixture in the precombustion chamber fast to form the higher flame current of energy and get into the cylinder, in order to form better ignition effect, and it also can reduce the possibility that takes place the detonation in the combustion chamber, can improve the stability of engine work, and has fine practicality.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.

Claims

1. A prechamber, comprising a housing (1), a prechamber being formed in the lower part of the housing (1), an insertion opening communicating with the prechamber and adapted for insertion of a spark plug (2) being formed in the upper part of the housing (1), and a flame jet (10321) communicating with the prechamber being formed in the lower part of the housing (1), characterized in that the length H in the vertical direction of the prechamber is greater than or equal to the diameter D of the insertion opening and less than or equal to 3 times the diameter D of the insertion opening.

2. The precombustor of claim 1, wherein:

the precombustion cavity comprises a first chamber (101), a second chamber (102) and a third chamber (103) which are arranged from top to bottom in sequence;

the second chamber (102) is a reducing chamber gradually reducing from the first chamber (101) to the third chamber (103), the first chamber (101) is an equal-diameter chamber with the same diameter as the large-diameter end of the second chamber (102), and the third chamber (103) at least has an equal-diameter part (1031) with the same diameter as the small-diameter end of the second chamber (102);

the flame spray holes (10321) are arranged at the bottom of the third chamber (103).

3. The precombustor of claim 2, wherein:

said third chamber (103) further having an arcuate chamber portion (1032) at the bottom thereof;

the arc-shaped chamber portion (1032) is connected with the constant diameter portion (1031);

the flame spray holes (10321) are formed in the inner wall of the arc-shaped cavity portion (1032).

4. The precombustor of claim 2, wherein:

the height h1 of the first chamber (101) satisfies: h1 ≦ 35 ≦ H;

the height h2 of the second chamber (102) satisfies: h 1. Ltoreq. H2. Ltoreq.50%;

the height h3 of the third chamber (103) satisfies: 90% h 1. Ltoreq.h 3. Ltoreq.35%.

5. The precombustor of claim 2, wherein:

the head (201) of the inserted spark plug (2) projects into the first chamber (101), and a ground electrode (2011) in the head (201) projects into the second chamber (102).

6. A prechamber according to claim 5, characterised in that:

a distance h0 between the ground electrode (2011) and an upper end of the second chamber (102), and a distance h4 between the ground electrode (2011) and an upper end of the first chamber (101), wherein: h 0. Ltoreq.30% h4.

7. A prechamber according to claim 5, characterised in that:

the distance H4 between the ground electrode (2011) and the upper end of the first chamber (101), the height H of the precombustion chamber, and the diameter D of the spark plug (2) satisfy:

30% h ≦ h4 ≦ 40%, and 50% D ≦ h4 ≦ 70% D.

8. The precombustor of claim 5, wherein:

the flame spray holes (10321) comprise a plurality of first flame spray holes (103211) and a plurality of second flame spray holes (103212), and the communication opening of the second flame spray holes (103212) and the arc-shaped cavity part (1032) is lower than the communication opening of the first flame spray holes (103211) and the arc-shaped cavity part (1032);

a distance h5 between the first flame ejection hole (103211) and the communication port of the arc-shaped chamber portion (1032) and the ground electrode (2011) satisfies: 50% h.ltoreq.h 5.ltoreq.60% h;

a distance H6 between the communication opening of the second flame spray hole (103212) and the arc-shaped chamber portion (1032) and the ground electrode (2011), and a height H of the prechamber, both of which satisfy: h 6. Ltoreq.70% H.

9. A prechamber according to any of claims 1-8, characterised in that:

the number of the flame spray holes (10321) is between 4 and 8, and the diameter of the flame spray holes (10321) is between 0.8 and 2 mm.

10. An engine, characterized in that: the engine having a prechamber according to any of claims 1-9 therein, and the housing (1) being integrated in a cylinder head of the engine; alternatively, the housing (1) is integrated on the spark plug (2).