CN217761137U - Compression ignition type pre-combustion chamber structure and engine - Google Patents

Abstract

The utility model discloses a compression formula of catching fire precombustion chamber structure and engine, compression formula of catching fire precombustion chamber structure is including precombustion main part, the engine cylinder, precombustion main part is equipped with the precombustion body hole of blind hole structure, precombustion body hole slidable mounting has the plunger body, the plunger body coupling has plunger actuating mechanism, the interior terminal surface of plunger body is equipped with precombustion inner chamber, the bottom surface and the lateral wall of precombustion body hole are injectd jointly and are formed the precombustion chamber, precombustion body hole lateral wall is equipped with the jet passage with main combustion chamber intercommunication, precombustion inner chamber lateral wall is equipped with the jet orifice that corresponds with jet passage, the plunger body is in spacing messenger jet passage direct intercommunication main combustion chamber and precombustion chamber down, the plunger body is in lower spacing messenger jet orifice with jet passage, precombustion chamber and main combustion chamber intercommunication, the compression of combustible mixture catches fire in the precombustion chamber, need not to arrange ignition on the precombustion chamber, save one set of ignition and fuel injection apparatus, moreover, the steam generator is simple structure, low cost.

Description

Compression ignition type pre-combustion chamber structure and engine

Technical Field

The utility model relates to the technical field of engines, in particular to compression ignition formula precombustion chamber structure and engine.

Background

At present, the requirement of energy conservation, emission reduction and oil consumption regulations is met, and the aim of pursuing the effective heat efficiency of an engine to be 45 percent or even higher becomes to be achieved. Aiming at the lean combustion of various fuel engines such as gasoline, natural gas, methanol, ammonia and the like, the engine can improve the adiabatic index of mixed gas, reduce the combustion temperature and inhibit knocking, and is an effective technology for realizing the thermal efficiency of more than 45 percent. For example, the fuel economy can be improved by 5% -10% for the lean combustion of a gasoline engine, and the emission of carbon monoxide (CO), hydrogen (H2), hydrocarbons (HC) and the like can be reduced. If ultra-lean combustion (lambda is more than 1.5) is adopted, the combustion temperature is relatively low because the air dilution degree is high, and the thermal efficiency of the gasoline engine can be improved without causing excessive NOx emission.

However, the existing spark plug is difficult to ignite the ultra-lean mixture, so the ultra-lean combustion needs to be matched with a high-energy ignition device to meet the use requirement. Therefore, in the research of ultra-lean combustion, the precombustion chamber technology has received extensive attention. According to the technology, mixed gas which can be easily ignited by a spark plug is formed in the precombustion chamber, high-temperature combustion mixture after the mixed gas in the precombustion chamber is combusted is sprayed into the main combustion chamber from the precombustion chamber, and lean mixed gas in the main combustion chamber is quickly ignited. The jet ignition of the pre-chamber, which generates multiple ignition sources in the jet hole jet area, can achieve very fast combustion rates.

Obviously, the ignition difficulty of lean combustion working conditions can be reduced by the precombustion chamber, the combustion rate is obviously improved, the defects of low flame propagation speed and large combustion cycle variation under super lean combustion are overcome, and in the prior art, a fuel injection device is usually adopted in the precombustion chamber, and part of fuel is injected into the precombustion chamber to form relatively rich gas mixture which is easy to be ignited by a spark plug in the precombustion chamber. However, this measure has the following disadvantages: the volume of the precombustion chamber is small, it is very difficult to arrange a fuel injection device and a spark plug reasonably, internal mixed gas organization is very difficult, the fuel concentration stability at the position of the spark plug is poor, the uncertainty of flame development is enhanced, the cycle variation of an engine is large, the fuel hits the wall seriously due to a direct injection mode, coking is easy to occur, and soot is generated; after being directly sprayed, the liquid fuel is gasified and absorbs heat in the precombustion chamber, so that cold start is more difficult.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a compression ignition formula precombustion chamber structure and engine to solve one or more technical problem that exist among the prior art, provide a profitable selection or creation condition at least.

The technical scheme adopted for solving the technical problems is as follows:

at first the utility model provides a compression formula prechamber structure that catches fire, it includes: the pre-combustion main body is provided with a pre-combustion body hole with a blind hole structure, a plunger body is slidably mounted in the pre-combustion body hole, the plunger body is connected with a plunger driving mechanism used for driving the plunger body to reciprocate along the axial direction of the pre-combustion body hole, the inner end face of the plunger body is provided with a pre-combustion inner cavity with an open cavity structure, the pre-combustion inner cavity, the bottom face and the side wall of the pre-combustion body hole are jointly limited to form the pre-combustion chamber, the inner end side wall of the pre-combustion body hole is provided with an injection channel communicated with the main combustion chamber, the side wall of the pre-combustion inner cavity is provided with an injection hole corresponding to the injection channel, the plunger body has an upper limit and a lower limit in reciprocating movement, the plunger body is located at the upper limit so that the injection channel is directly communicated with the main combustion chamber and the pre-combustion chamber, and the plunger body is located at the lower limit so that the injection channel, the injection hole and the main combustion chamber are communicated with the main combustion chamber.

The utility model provides a prechamber structure beneficial effect is: the plunger body is driven to axially reciprocate in the pre-combustion body hole by the plunger driving mechanism, so that the volume of the pre-combustion chamber is changed, the compression of fresh mixed gas in the pre-combustion chamber is realized, the spontaneous combustion of fuel in the fresh mixed gas or partial combustion reaction is promoted, when the plunger body is positioned at the upper limit of the pre-combustion body hole, the volume of the pre-combustion chamber is maximum, the injection passage at the moment is directly communicated with the main combustion chamber and the pre-combustion chamber, and the main combustion chamber and the fresh mixed gas in the pre-combustion chamber can enter the pre-combustion chamber through the injection passage; when the plunger body is positioned at the lower limit of the pre-combustion body hole, the volume of the pre-combustion chamber is minimum, the mixed gas in the pre-combustion chamber is compressed to generate spontaneous combustion or partial combustion reaction, the injection hole communicates the injection passage, the pre-combustion chamber and the main combustion chamber, and the high-temperature and high-pressure mixed gas after reaction in the pre-combustion chamber enters the main combustion chamber to ignite thin fresh mixed gas; when the plunger body is in other positions in the middle of the upper limit and the lower limit, the jet passage is blocked by the side wall of the precombustion inner cavity, and the precombustion chamber is communicated and disconnected with the main combustion chamber.

The combustible mixed gas in the precombustion chamber is compressed and ignited without arranging an ignition device on the precombustion chamber, the requirement of compression ignition on the mixed gas organization in the precombustion chamber is obviously reduced, a fuel injection device is not required to be arranged on the precombustion chamber, one set of ignition device and fuel injection device is omitted, the structure is simple, and the cost is low. To the fuel that ignition energy is high, for example ammonia fuel, it is more difficult that current ignition ignites the air mixture in the precombustion chamber, but the utility model discloses a compression is caught fire and can be made the reliable spontaneous combustion of precombustion chamber air mixture or take place partial combustion reaction, makes this type of fuel realize using on the engine possible.

As a further improvement of the technical scheme, a plurality of the jet passages are circumferentially distributed on the side wall of the inner side of the precombustion body hole, and a plurality of jet holes which are consistent with the circumferential arrangement positions of the jet passages are arranged on the side wall of the precombustion inner cavity.

The plurality of injection channels is primarily used to increase the ignition source because each injection channel injects a jet corresponding to one ignition source. The number and arrangement of the injection channels generally need to be obtained by in-cylinder combustion calculation and need to be matched with in-cylinder flow.

As a further improvement of the above technical solution, the sidewall of the precombustion body hole is provided with a first circumferential positioning part, and the plunger body is provided with a second circumferential positioning part in sliding fit with the first circumferential positioning part.

This scheme is through the sliding fit of second circumference location portion and first circumference location portion, realizes fixing a position plunger body circumference for the plunger body is at the reciprocating motion in-process, and the jet orifice can correspond the intercommunication with injection passage accurately.

As the further improvement of the technical scheme, the peripheral wall of the plunger body is provided with a plurality of annular grooves, the annular grooves are sleeved with the plunger rings, and the injection holes are formed between the two adjacent annular grooves.

The plunger body in this scheme conflicts with burning body hole lateral wall sliding seal in advance through a plurality of plunger rings, improves the plunger body and burns the leakproofness between the body hole in advance, prevents that the interior high temperature high pressure gas mixture of burning in advance from revealing.

As a further improvement of the above technical solution, the precombustion body hole is of a "T" shaped stepped structure, the precombustion body hole includes an upper end large hole and a lower end small hole, the plunger body is of a "T" shaped shaft structure, the plunger body includes a large head arranged in the upper end large hole and a small head arranged in the lower end small hole, the plunger driving mechanism includes a plunger spring, a plunger driving cam and a plunger cam shaft, the large head is flexibly connected with the stepped surface of the precombustion body hole through the plunger spring, the plunger driving cam is mounted on the plunger cam shaft, and the outer peripheral surface of the plunger driving cam is abutted against the top end of the plunger body.

The plunger driving mechanism in the scheme drives the plunger driving cam to rotate through the plunger cam shaft, the large end of the plunger body is pressed against the surface of the cam by the elastic force of the plunger spring, the plunger body is driven to do reciprocating motion in the pre-combustion body hole by the rotating plunger driving cam by overcoming the elastic force of the plunger spring, and the volume change of the pre-combustion chamber is realized.

As a further improvement of the technical scheme, the pre-combustion inner cavity is provided with a flow guide structure for guiding the mixed gas in the pre-combustion chamber to flow and a reinforcing rib structure for enhancing the structural strength.

As a further improvement of the technical scheme, the wall surface of the pre-combustion inner cavity, the flow guide and the surface of the reinforcing rib structure are coated with a heat insulation coating. The heat insulating coating can reduce heat transfer loss between high-temperature mixed gas in the pre-combustion chamber and the wall surface.

As a further improvement of the technical scheme, the engine cylinder comprises a cylinder body and a cylinder cover, and the pre-combustion main body is a part of the cylinder cover.

This scheme is direct to process out on the cylinder head and to burn partly the main part in advance, reduces engine part quantity, and this body hole of burning in advance and injection passage are direct to be processed out on the cylinder head, reduce assembly error.

The utility model also provides an engine, it includes foretell compression ignition formula precombustion chamber structure, plunger actuating mechanism includes the plunger camshaft of being connected with one of them transmission of engine crankshaft or engine camshaft, the plunger camshaft passes through plunger drive cam and drives plunger body reciprocating motion.

The plunger camshaft is driven by the engine crankshaft or the engine camshaft through a gear train or a belt, wherein the transmission ratio between the plunger camshaft and the engine crankshaft is 1; the variable valve timing technology on the existing engine camshaft is utilized, the timing of the plunger driving cam can be changed, and the time when the high-temperature and high-pressure mixture in the pre-combustion chamber is injected into the main combustion chamber can be controlled by the method, so that the purpose of controlling combustion is achieved.

The utility model also provides an operation method of engine, it adopts foretell engine, and this engine is four-stroke engine operation mode operation to external output power, concrete operation method as follows:

in the early stage of the compression stroke of the engine, the plunger body is in an upper limit position, the injection passage is communicated with the main combustion chamber and the precombustion chamber, the volume of the precombustion chamber is maximum, and the fresh mixed gas is gradually pressed into the precombustion chamber by the upward piston;

in the later stage of the compression stroke of the engine, the plunger body starts to move downwards, the injection passage is not communicated with the precombustion chamber, the plunger body which gradually moves downwards compresses the mixed gas in the precombustion chamber, so that the mixed gas in the precombustion chamber spontaneously combusts or part of combustion reaction causes the temperature and pressure in the precombustion chamber to rise, when the plunger body moves downwards to the lower limit, the injection hole is communicated with the injection passage, the high-temperature and high-pressure mixed gas in the precombustion chamber is injected into the main combustion chamber through the injection hole and the injection passage in sequence, and ignition of lean mixed gas in the main combustion chamber is realized;

in the early period of the power stroke, the exhaust stroke and the air inlet stroke of the engine, the plunger body is kept at the lower limit position, the volume of the precombustion chamber is kept to be minimum, and the residual waste gas in the precombustion chamber is minimum;

in the later stage of the intake stroke of the engine, the plunger body gradually moves upwards to the upper limit, the jet passage is communicated with the precombustion chamber, the volume of the precombustion chamber is maximum, and fresh mixed gas as much as possible enters the precombustion chamber through the jet passage;

the engine then reenters the compression stroke and the engine completes a complete cycle.

The utility model provides an engine beneficial effect is: the combustible mixed gas in the precombustion chamber is compressed and ignited, the ignition in the precombustion chamber is more stable, the cycle variation of the engine is reduced, the engine can adopt thinner mixed gas, the heat efficiency of the engine is improved, and the pollutant emission is reduced.

Drawings

The present invention will be further explained with reference to the drawings and examples;

FIG. 1 is a cross-sectional view of an embodiment of an engine according to the present invention, wherein the arrows indicate upward and downward directions, respectively;

FIG. 2 is a cross-sectional view of the plunger of an embodiment of the compression ignition precombustor structure of the present invention at the upper limit, wherein two arrows respectively show the upward direction and the downward direction;

FIG. 3 is a cross-sectional view of the plunger of an embodiment of the compression ignition precombustor structure of the present invention at a lower limit, wherein two arrows respectively indicate upward and downward directions;

fig. 4 is a schematic diagram of positions of a piston and a plunger in a cycle of an embodiment of the engine provided by the present invention.

Detailed Description

This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.

In the description of the present invention, it should be understood that the directional descriptions, such as the directions or positional relationships indicated by upper, lower, front, rear, left, right, etc., are based on the directions or positional relationships shown in the drawings, and are only for convenience of description and simplification of the description, but not for indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention.

In the description of the present invention, if words such as "a plurality" are used, the meaning is one or more, the meaning of a plurality of words is two or more, and the meaning of more than, less than, more than, etc. is understood as not including the number, and the meaning of more than, less than, more than, etc. is understood as including the number.

In the description of the present invention, unless there is an explicit limitation, the terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the terms in the present invention by combining the specific contents of the technical solution.

Referring to fig. 1 to 3, the engine of the present invention is made as follows:

the engine is a reciprocating piston internal combustion engine, and the engine of the present embodiment includes a compression ignition type pre-chamber structure including: the pre-combustion engine comprises a pre-combustion main body 900 and an engine cylinder, wherein the engine cylinder comprises a cylinder body 700 and a cylinder cover 800 covered on the top of the cylinder body 700, the cylinder cover 800 is provided with an air inlet channel 810 and an air outlet channel 820, the air inlet channel 810 is provided with an air inlet valve 830, the air outlet channel 820 is provided with an exhaust valve 840, a piston 100 is arranged in the cylinder body 700 in a sliding mode, and the piston 100, the cylinder body 700 and the cylinder cover 800 form a main combustion chamber 200 in an enclosed mode.

In order to reduce assembly errors, the pre-combustion main body 900 in the present embodiment is a part of the cylinder head 800, and when machining, the present embodiment directly machines a part of the pre-combustion main body 900 on the cylinder head 800, thereby reducing the number of engine parts.

In other embodiments, additional pre-combustion bodies 900 may be provided and then mounted to the cylinder head 800.

Wherein the precombustion main part 900 top is provided with the axial and is the precombustion body hole 300 that extends from top to bottom, and precombustion body hole 300 is blind hole structure, and the slip is provided with plunger body 400 in precombustion body hole 300, and the lower extreme of plunger body 400 conflicts with the inside wall slip density of precombustion body hole 300.

The lower end of the plunger body 400 is concavely provided with a pre-combustion inner cavity 410, the pre-combustion inner cavity 410 is of an open cavity structure, the pre-combustion inner cavity 410, the bottom surface and the side wall of the pre-combustion body hole 300 are jointly limited to form a pre-combustion chamber 600, the wall body of the pre-combustion body hole 300 is provided with an injection passage 310, one port of the injection passage 310 is communicated with the main combustion chamber 200, the other port of the injection passage 310 is arranged on the side wall of the pre-combustion body hole 300, the injection passage 310 is of a circular pipeline structure, the injection passage 310 of the embodiment is directly machined on the cylinder cover 800, and the assembly error is also reduced. The injection passage 310 may be a circular straight pipe structure, which is convenient for drilling process, or a pipe structure with other shape.

The present embodiment is provided with a plunger driving mechanism 500, the plunger driving mechanism 500 is used for driving the plunger body 400 to reciprocate up and down in the pre-combustion body hole 300, and specifically: the precombustion body hole 300 of the embodiment is a stepped blind hole structure, the shape is similar to a 'T' shape, further the precombustion body hole 300 of the embodiment comprises an upper end large hole 320 and a lower end small hole 330 which are connected up and down, a step surface is formed between the upper end large hole 320 and the lower end small hole 330, the plunger body 400 is of a 'T' -shaped shaft type structure, the plunger body 400 comprises a large head 420 and a small head 430 which are connected in sequence, wherein the lower end of the small head 430 is sleeved in the lower end small hole 330 in a vertically sliding manner, the large head 420 is positioned in the upper end large hole 320, the plunger driving mechanism 500 comprises a plunger cam shaft 530, a plunger driving cam 520 and a plunger spring 510, the plunger spring 510 is positioned between the large head 420 and the step surface in the precombustion body hole 300, the plunger spring 510 is sleeved on the outer peripheral side of the upper end of the small head 430, thus the plunger spring 510 has a limiting effect, the large head 420 is flexibly connected with the step surface through the plunger spring 510, the plunger driving cam 520 is connected with the cam shaft 530, the plunger driving cam surface of the plunger driving cam is abutted against the top end of the plunger body 520, the plunger body 400, the plunger spring 510 drives the plunger body to rotate the plunger 400, and overcomes the elastic force of the plunger body 400 to change of the plunger 400, and the plunger body 400 to drive the plunger 400 to drive cam surface to drive the plunger 400 to drive the plunger body 300 to drive the plunger 400 to rotate to change of the precombustion body to overcome the volume of the plunger body 300 to change of the plunger body to drive cam surface to change of the plunger body to rotate.

An injection hole 411 is formed in the side wall of the precombustion chamber 410, the injection hole 411 corresponds to the other port of the injection passage 310, when the plunger body 400 moves to the upper limit, the injection passage 310 directly communicates the main combustion chamber 200 with the precombustion chamber 600, when the plunger body 400 moves to the lower limit, the precombustion chamber 600 communicates with the injection passage 310 through the injection hole 411, so that the precombustion chamber 600 communicates with the main combustion chamber 200, and during the movement of the plunger body 400 between the lower limit and the upper limit, the side wall of the precombustion chamber 410 blocks the other port of the injection passage 310.

The injection hole 411 has a through hole structure, and may have a circular hole, an oval shape, a rounded rectangle shape, or the like.

In order to make the injection hole 411 accurately communicate with the injection passage 310, a first circumferential positioning portion 321 is provided on a side wall of the large hole 320 at the upper end of the pre-combustion body hole 300, a second circumferential positioning portion 421 is provided on an outer peripheral wall of the large head 420, the first circumferential positioning portion 321 is slidably engaged with the second circumferential positioning portion 421, the first circumferential positioning portion 321 of the present embodiment is a key slot, the second circumferential positioning portion 421 is a key, and the key slot are engaged with each other for circumferentially positioning the plunger body 400.

In other embodiments, the circumferential orientation between the plunger body 400 and the precombustion body bore 300 may also be other orientations, such as pin orientations.

Further, in order to increase the ignition source, the number of the injection passages 310 and the number of the injection holes 411 are both multiple, the multiple injection passages 310 are circumferentially arranged on the inner end side wall of the precombustion body hole 300, the multiple injection holes 411 are circumferentially arranged on the side wall of the precombustion inner cavity 410, 4-8 injection passages 310 are circumferentially symmetrically arranged on the inner end side wall of the precombustion body hole 300 in the embodiment, and the circumferential positions of the injection passages 310 are determined according to the flowing condition of the mixed gas in the cylinder and can also be asymmetrically arranged.

In order to prevent the high-temperature and high-pressure mixture gas in the prechamber 600 from leaking, the outer peripheral wall of the small end 430 of the plunger body 400 is provided with a plurality of ring grooves 431, each ring groove 431 is sleeved with a plunger ring, specifically, the embodiment is provided with three ring grooves 431, namely, a first ring groove 431, a second ring groove 431 and a third ring groove 431 which are sequentially arranged from top to bottom at intervals, and the injection holes 411 are located between the first ring groove 431 and the second ring groove 431. Like this plunger body 400 through a plurality of plunger rings with burn the body hole 300 lateral wall sliding seal conflict in advance, improve the leakproofness between plunger body 400 and the body hole 300 of burning in advance, prevent that high temperature high pressure gas mixture in the precombustion chamber 600 from revealing.

And, the precombustion inner chamber 410 is equipped with water conservancy diversion structure and strengthening rib structure, and water conservancy diversion structure is used for leading the air mixture in the precombustion chamber 600 to flow, and the strengthening rib structure is used for strengthening structural strength, simultaneously, all coats the thermal-insulated coating on the wall of precombustion inner chamber 410, water conservancy diversion structure and the surface of strengthening rib structure, and the thermal-insulated coating can reduce the heat transfer loss between the wall and the high temperature air mixture in precombustion chamber 600.

In addition, the structure of the guide flow or the reinforcing rib can be adjusted according to the type of fuel and the composition of the mixed gas, so that the purpose of adjusting the volume of the precombustion chamber 600 is achieved.

In other embodiments, the plunger 400 may be driven in other ways, such as hydraulically, electrically, or by a worm gear.

In this embodiment, a driving manner of the plunger driving cam 520 and the plunger spring 510 are adopted, the utility model discloses a control of pre-combustion chamber combustion is realized by controlling the timing of the plunger driving cam 520, and when in use, the plunger cam shaft 530 can be in transmission connection with one of an engine crankshaft or an engine cam shaft, the plunger cam shaft 530 is driven by the engine crankshaft or the engine cam shaft through a gear train or a belt, wherein the transmission ratio between the plunger cam shaft 530 and the engine crankshaft is 1; and the timing of the plunger driving cam 520 can be changed by using the variable valve timing technology on the existing engine camshaft, and the time when the high-temperature and high-pressure mixture in the precombustion chamber 600 is injected into the main combustion chamber 200 can be controlled by the method, so that the purpose of controlling combustion is achieved.

In the embodiment, the plunger body 400 is driven by the plunger driving mechanism 500 to axially reciprocate in the precombustion body hole 300, so that the volume of the precombustion chamber 600 is changed, the fresh mixed gas in the precombustion chamber 600 is compressed, and the spontaneous combustion or partial combustion reaction of fuel in the fresh mixed gas is promoted.

When the plunger body 400 is positioned at the upper limit of the pre-combustion body hole 300, the volume of the pre-combustion chamber 600 is the largest, the injection passage 310 at the moment is directly communicated with the main combustion chamber 200 and the pre-combustion chamber 600, and the main combustion chamber 200 and the internal fresh mixed gas can enter the pre-combustion chamber 600 through the injection passage 310;

when the plunger body 400 is positioned at the lower limit of the pre-combustion body hole 300, the volume of the pre-combustion chamber 600 is minimum, the mixed gas in the pre-combustion chamber 600 is compressed to generate spontaneous combustion or partial combustion reaction, the injection hole 411 communicates the injection passage 310 and the pre-combustion chamber 600 with the main combustion chamber 200, and the high-temperature and high-pressure mixed gas after the reaction in the pre-combustion chamber 600 enters the main combustion chamber 200 to ignite thin fresh mixed gas;

when the plunger body 400 is at other positions between the upper limit and the lower limit, the injection passage 310 is blocked by the sidewall of the pre-combustion chamber 410, and the communication between the pre-combustion chamber 600 and the main combustion chamber 200 is disconnected.

According to the technology, the plunger body 400 moves to different positions, the side wall of the pre-combustion inner cavity 410 can be used for keeping the connection and disconnection between the pre-combustion chamber 600 and the main combustion chamber 200 through the injection passage 310, so that the mixed gas in the main combustion chamber 200 can enter the pre-combustion chamber 600 through the injection passage 310, and the high-temperature mixture combusted in the pre-combustion chamber 600 can also enter the main combustion chamber 200 through the injection hole 411 and the injection passage 310.

Therefore, the combustible mixture in the pre-combustion chamber 600 is compressed and ignited without arranging an ignition device on the pre-combustion chamber 600, the requirement of compression ignition on the mixture organization in the pre-combustion chamber 600 is obviously reduced, a fuel injection device is not required to be arranged on the pre-combustion chamber 600, a set of ignition device and fuel injection device is omitted, the structure is simple, and the cost is low.

For the fuel with high ignition energy, such as ammonia fuel, it is difficult for the existing ignition device to ignite the mixture in the precombustion chamber, but the compression ignition of the present invention can make the mixture in the precombustion chamber 600 reliably self-ignite or make partial combustion reaction, making it possible to apply this kind of fuel on the engine.

The embodiment also provides an operation method of the engine, which comprises the following specific operation methods:

in the early stage of the compression stroke of the engine, the plunger body 400 is in an upper limit position, the injection passage 310 is communicated with the main combustion chamber 200 and the precombustion chamber 600, the volume of the precombustion chamber 600 is maximum, and the piston 100 which gradually ascends presses as much fresh mixed gas into the precombustion chamber 600 as possible;

in the later stage of the compression stroke of the engine, the plunger body 400 starts to move downwards under the pushing of the plunger driving cam 520, the injection passage 310 is not communicated with the precombustion chamber 600 at this time, the main combustion chamber 200 is not communicated with the precombustion chamber 600, the plunger body 400 which gradually moves downwards compresses the fresh mixed gas in the precombustion chamber 600, the pressure and the temperature of the fresh mixed gas in the precombustion chamber 600 are increased after the fresh mixed gas in the main combustion chamber 200 undergoes a compression process, the pressure and the temperature of the fresh mixed gas in the precombustion chamber 600 are increased, the fresh mixed gas in the precombustion chamber 600 can reach a spontaneous combustion or partial combustion reaction state after undergoing compression with a small compression ratio in the precombustion chamber 600 again, and the temperature and the pressure of the mixed gas in the precombustion chamber 600 are increased due to reaction;

when the plunger body 400 descends to the lower limit, the injection hole 411 is communicated with the injection passage 310, and the high-temperature and high-pressure mixed gas in the pre-combustion chamber 600 is injected into the main combustion chamber 200 through the injection hole 411 and the injection passage 310 in sequence, so that ignition of lean mixed gas in the main combustion chamber 200 is realized;

in the power stroke of the engine, the plunger body 400 is kept at the lower limit position, the volume of the pre-combustion chamber 600 is kept to be minimum, and the residual waste gas in the pre-combustion chamber 600 is minimized;

in the exhaust stroke of the engine, the plunger body 400 is kept at the lower limit, the volume of the pre-combustion chamber 600 is kept to be minimum, and the residual waste gas in the pre-combustion chamber 600 is minimized;

and in the early stage of the engine intake stroke, the plunger body 400 is kept at the lower limit, keeping the volume of the pre-combustion chamber 600 to a minimum, and minimizing the residual exhaust gas in the pre-combustion chamber 600;

in the later stage of the intake stroke of the engine, under the action of the plunger spring 510, the plunger body 400 gradually moves upwards to the upper limit, the injection passage 310 is communicated with the pre-combustion chamber 600, the volume of the pre-combustion chamber 600 is the maximum, and fresh mixed gas as much as possible enters the pre-combustion chamber 600 through the injection passage 310;

thereafter, the engine re-enters the compression stroke, the engine completes one complete cycle, and the plunger body 400 completes one complete reciprocation.

Therefore, the combustible mixed gas in the pre-combustion chamber 600 is compressed and ignited, the ignition in the pre-combustion chamber 600 is more stable, the cycle variation of the engine is reduced, the engine can adopt thinner mixed gas, the heat efficiency of the engine is improved, and the pollutant emission is reduced.

While the preferred embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that the invention is not limited to the details of the embodiments shown, but is capable of various modifications and substitutions without departing from the spirit of the invention.

Claims (9)

1. A compression ignition prechamber arrangement, characterized by: it includes: a pre-combustion main body (900), an engine cylinder, a main combustion chamber (200) formed in the inner space of the piston (100) and the engine cylinder is arranged in the engine cylinder, the pre-burning main body (900) is provided with a pre-burning main body hole (300) with a blind hole structure, a plunger body (400) is installed in the pre-burning body hole (300) in a sliding mode, a plunger driving mechanism (500) used for driving the plunger body (400) to axially move in a reciprocating mode along the pre-burning body hole (300) is connected to the plunger body (400), the inner end surface of the plunger piston body (400) is provided with a pre-combustion inner cavity (410) with an open cavity structure, the bottom surface and the side wall of the pre-combustion inner cavity (410) and the pre-combustion body hole (300) jointly define a pre-combustion chamber (600), the side wall of the inner end of the pre-burning body hole (300) is provided with an injection passage (310) communicated with the main burning chamber (200), the side wall of the pre-combustion inner cavity (410) is provided with an injection hole (411) corresponding to the injection channel (310), the plunger body (400) has an upper limit and a lower limit in the reciprocating movement, the plunger body (400) is positioned at the upper limit to enable the injection passage (310) to be directly communicated with the main combustion chamber (200) and the pre-combustion chamber (600), the plunger body (400) is located at the lower limit position, so that the injection hole (411) communicates the injection passage (310), the pre-combustion chamber (600) and the main combustion chamber (200).

2. A compression ignition prechamber arrangement as in claim 1, wherein: the inner end side wall of the precombustion body hole (300) is circumferentially provided with a plurality of injection passages (310), and the side wall of the precombustion inner cavity (410) is provided with a plurality of injection holes (411) which are circumferentially arranged and are consistent in position with the injection passages (310).

3. A compression ignition prechamber arrangement as claimed in claim 1, characterised in that: the side wall of the precombustion body hole (300) is provided with a first circumferential positioning part (321), and the plunger body (400) is provided with a second circumferential positioning part (421) which is in sliding fit with the first circumferential positioning part (321).

4. A compression ignition prechamber arrangement as in claim 1, wherein: the periphery wall of the plunger body (400) is provided with a plurality of ring grooves (431), the ring groove (431) is sleeved with a plunger ring, and the injection hole (411) is arranged between two adjacent ring grooves (431).

5. A compression ignition prechamber arrangement as in claim 1, wherein: the pre-burning body hole (300) is of a T-shaped stepped structure, the pre-burning body hole (300) comprises an upper-end large hole (320) and a lower-end small hole (330), the plunger body (400) is of a T-shaped shaft structure, the plunger body (400) comprises a large head (420) arranged in the upper-end large hole (320) and a small head (430) sleeved in the lower-end small hole (330), the plunger driving mechanism (500) comprises a plunger spring (510), a plunger driving cam (520) and a plunger cam shaft (530), the large head (420) is flexibly connected with a step surface of the pre-burning body hole (300) through the plunger spring (510), the plunger driving cam (520) is installed on the plunger cam shaft (530), and the peripheral surface of the plunger driving cam (520) is abutted to the top end of the plunger body (400).

6. A compression ignition prechamber arrangement as in claim 1, wherein: the precombustion inner cavity (410) is provided with a flow guide structure for guiding the mixed gas in the precombustion chamber (600) to flow and a reinforcing rib structure for enhancing the structural strength.

7. A compression ignition prechamber arrangement according to claim 6, characterised in that: and the wall surface of the pre-combustion inner cavity (410), the flow guide and the surface of the reinforcing rib structure are coated with a heat insulation coating.

8. A compression ignition prechamber arrangement as in claim 1, wherein: the engine cylinder comprises a cylinder body (700) and a cylinder cover (800), and the pre-combustion main body (900) is part of the cylinder cover (800).

9. An engine, characterized in that: comprising a compression ignition pre-chamber structure according to any one of claims 1 to 8, the plunger drive mechanism (500) comprising a plunger cam shaft (530) drivingly connected to one of the engine crankshaft or the engine cam shaft, the plunger cam shaft (530) being adapted to reciprocate the plunger body (400) via a plunger drive cam (520).

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