A self-ignition pre-combustion chamber system, an internal combustion engine, and its operating method.

Abstract

This invention discloses a self-ignition pre-combustion chamber system, an internal combustion engine, and an operating method. The self-ignition pre-combustion chamber system includes a pre-combustion chamber body and a valve assembly. The pre-combustion chamber body has a valve stem hole, a pre-combustion chamber, and a fuel supply passage. The side wall of the pre-combustion chamber has an injection hole, and the inner peripheral wall of the valve stem hole has a fuel supply chamber. The outer peripheral wall of the valve assembly has an inwardly recessed fuel storage space. The valve assembly is axially slidably and sealingly fitted within the valve stem hole. The valve assembly is configured to move along the valve stem hole in a direction away from the pre-combustion chamber, so that the fuel storage space and the inner peripheral wall of the valve stem hole together form a fuel storage chamber, which is connected to the fuel supply chamber but disconnected from the pre-combustion chamber. The valve assembly is also configured to move along the valve stem hole in a direction towards the pre-combustion chamber, so that the fuel storage space is connected to the pre-combustion chamber and the fuel supply chamber is blocked. This invention avoids the need for high-pressure injection and the problem of coking in the pre-combustion chamber.

Description

Technical Field

[0001] This invention relates to the technical field of internal combustion engines, and particularly to a self-ignition pre-combustion chamber system, an internal combustion engine, and a method of operation. Background Technology

[0002] In recent years, pre-combustion chamber combustion technology has received widespread attention. This technology can effectively solve combustion problems such as difficulty in ignition, slow combustion speed, and large fluctuations in combustion cycle under lean combustion conditions.

[0003] The pre-combustion chamber combustion technology first ignites the gas mixture in the pre-combustion chamber that can be easily ignited by a spark plug. Then, the gas mixture in the pre-combustion chamber is burned to form a high-temperature, high-pressure combustion mixture, which is then introduced into the main combustion chamber and ignites the lean mixture in the main combustion chamber. After that, the lean mixture in the main combustion chamber burns rapidly. The key to pre-combustion chamber combustion technology is to form a stable air-fuel mixture within the pre-combustion chamber that can be ignited by a conventional spark plug. To achieve this, a fuel injection device using liquid high-pressure injection technology is typically employed to inject a portion of the fuel into the pre-combustion chamber, creating a mixture easily ignited by a spark plug. However, existing pre-combustion chamber combustion technologies suffer from structural layout difficulties and challenges in organizing the flow of the air-fuel mixture if spark plug ignition is used. Another approach involves injecting low auto-ignition temperature fuels into the pre-combustion chamber. To ensure the ignition timing, these fuels need to be injected near the piston's top dead center. Due to the high pressure inside the pre-combustion chamber, current fuel injection devices must use liquid high-pressure injection. Low auto-ignition temperature fuels can only be injected into the pre-combustion chamber through this technology. However, because liquid low auto-ignition temperature fuels, such as diesel and biodiesel, easily form large molecular compounds like polycyclic aromatic hydrocarbons (PAHs) in the high-temperature environment of the pre-combustion chamber, these PAHs continue to grow and polymerize, ultimately forming coke and char. Gaseous fuels with low auto-ignition temperature can solve the coking problem, but current pre-combustion chamber combustion technology is not suitable for gaseous fuels with low auto-ignition temperature. Summary of the Invention

[0004] The purpose of this invention is to provide a self-ignition pre-combustion chamber system, an internal combustion engine, and an operating method to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] The technical solution adopted to solve the above-mentioned technical problems is as follows:

[0006] This invention provides a self-ignition pre-combustion chamber system, comprising:

[0007] The pre-combustion chamber body is provided with a valve stem hole, a pre-combustion chamber and a fuel supply channel. One end of the valve stem hole is connected to the pre-combustion chamber. The side wall of the pre-combustion chamber is provided with at least one injection hole. The inner peripheral wall of the valve stem hole is provided with a fuel supply cavity connected to the fuel supply channel.

[0008] The valve assembly is a rod-shaped structure. The outer peripheral wall of the valve assembly has an inwardly recessed fuel storage space. The valve assembly is axially slidably and sealingly fitted within the valve stem bore. The valve assembly is configured to move along the valve stem bore in a direction away from the pre-combustion chamber, such that the fuel storage space and the inner peripheral wall of the valve stem bore together form a fuel storage cavity, which is connected to the fuel supply cavity, while the fuel storage space is disconnected from the pre-combustion chamber. The valve assembly is also configured to move along the valve stem bore towards the pre-combustion chamber, such that the fuel storage space is connected to the pre-combustion chamber, and the fuel supply cavity is blocked.

[0009] The beneficial effects of the self-ignition pre-combustion chamber system of the present invention are:

[0010] During operation, the pre-combustion chamber is connected to the main combustion chamber of the internal combustion engine via injection holes. As the valve assembly reciprocates through the valve stem bore, when the fuel storage chamber, formed by the fuel storage space and the inner circumferential wall of the valve stem bore, connects with the fuel supply chamber, gaseous low auto-ignition temperature fuel enters the fuel storage chamber through the fuel supply channel and fuel supply chamber. When the valve assembly moves to the point where the fuel storage space connects with the pre-combustion chamber, the high-temperature, high-pressure mixture in the pre-combustion chamber first enters the fuel storage space under pressure, causing partial auto-ignition of the gaseous low auto-ignition temperature fuel in the fuel storage space. As the valve assembly continues its rapid downward movement, the mixture in the fuel storage space is completely pushed into the pre-combustion chamber, where the gaseous low auto-ignition temperature fuel and the high-temperature mixture in the pre-combustion chamber continue to ignite. The mixture continues to mix and self-ignite, thereby igniting all the mixture in the pre-combustion chamber. The combustion of the mixture in the pre-combustion chamber further forms a mixture with higher temperature and pressure. The high-temperature and high-pressure mixture is injected outward through the injection hole, further igniting the mixture in the main combustion chamber. This invention utilizes the reciprocating motion of the valve assembly to introduce gaseous low self-ignition temperature fuel into the pre-combustion chamber under high pressure. That is, it can introduce the fuel into the pre-combustion chamber near the top dead center of the compression of the internal combustion engine. Under high pressure in the pre-combustion chamber, gaseous low self-ignition temperature fuel can be introduced and self-ignited to ignite the pre-combustion chamber, avoiding the need for high-pressure injection and the problem of coking in the pre-combustion chamber. In addition, the pre-combustion chamber of this invention can introduce gaseous low self-ignition temperature fuel, which self-ignites and ignites the mixture in the pre-combustion chamber, eliminating the need to install an ignition device in the pre-combustion chamber.

[0011] As a further improvement to the above technical solution, the valve assembly includes a valve stem and a fuel-sealing valve. The fuel-sealing valve has a mushroom-shaped valve structure and includes a valve stem and a valve disc. The valve stem has two ends, a first end and a second end. The two ends of the valve stem are rigidly connected between the first end and the valve disc, respectively. The outer diameter of the valve stem is smaller than that of the valve stem and the valve disc. The valve stem is axially slidably and sealingly fitted into the valve stem hole. The outer edge of the valve disc can seal against the end of the valve stem hole that communicates with the pre-combustion chamber. The outer peripheral wall of the valve stem, the first end, and the valve disc together form the fuel storage space. The first end can extend beyond the fuel supply chamber to block the fuel supply chamber.

[0012] As a further improvement to the above technical solution, the fuel-sealed valve is filled with a phase change material.

[0013] As a further improvement to the above technical solution, the valve disc has an annular flow guide structure on the end face facing the valve stem.

[0014] As a further improvement to the above technical solution, the fuel supply channel is provided with a one-way valve, and the one-way valve is directed toward the fuel supply chamber.

[0015] As a further improvement to the above technical solution, the valve assembly is connected to a reciprocating drive mechanism, which is configured to drive the valve assembly to reciprocate along the valve stem hole.

[0016] As a further improvement to the above technical solution, the pre-combustion chamber is provided with multiple injection holes, which are spherically distributed on the side wall of the pre-combustion chamber opposite to the valve stem hole, and the side wall of the pre-combustion chamber opposite to the valve stem hole has a concave spherical structure.

[0017] The present invention also proposes an internal combustion engine, which includes the aforementioned self-ignition pre-combustion chamber system. The self-ignition pre-combustion chamber system is provided with at least one, and also includes a cylinder block and a cylinder head covering the top of the cylinder block. At least one cylinder is formed between the cylinder block and the cylinder head. The cylinder is provided with a piston, an intake valve, an exhaust valve and a fuel injector, and the space they jointly define is a main combustion chamber. The injection port communicates with the main combustion chamber.

[0018] As a further improvement to the above technical solution, the cylinder head is provided with at least one stepped pre-combustion chamber hole, the pre-combustion chamber body is a sleeve-like structure, the pre-combustion chamber body is stepped in shape, and the pre-combustion chamber body is fitted into the stepped pre-combustion chamber hole.

[0019] The present invention also proposes an operating method applicable to the aforementioned internal combustion engine, the operating method comprising:

[0020] During the compression stroke of an internal combustion engine, the piston moves upward, compressing the air-fuel mixture in the main combustion chamber. The pressure and temperature of the mixture increase, and the high-temperature, high-pressure mixture from the main combustion chamber enters the pre-combustion chamber. The valve assembly is at top dead center, connecting the fuel storage chamber to the fuel supply chamber, while disconnecting the fuel storage space from the pre-combustion chamber. Gaseous fuel with a low auto-ignition temperature from the external fuel supply system enters the fuel storage chamber. Later in the compression stroke, the valve assembly begins to move downward, connecting the fuel storage space to the pre-combustion chamber and blocking the fuel supply chamber. Under pressure, the air-fuel mixture flows into the fuel storage space. Under the influence of the high-temperature air, the gaseous fuel with a low auto-ignition temperature in the fuel storage space undergoes auto-ignition. As the valve assembly rapidly descends, the air-fuel mixture in the fuel storage space is completely pushed into the pre-combustion chamber. The auto-ignited fuel continues to mix and auto-ignite with the high-temperature air-fuel mixture in the pre-combustion chamber, thereby igniting all the air-fuel mixture in the pre-combustion chamber. The combustion of the air-fuel mixture in the pre-combustion chamber further forms an even higher temperature and pressure mixture, which is then injected into the main combustion chamber through the injection port, further igniting the air-fuel mixture in the main combustion chamber.

[0021] During the power stroke of the internal combustion engine, the piston begins to descend, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to the bottom dead center and outputting power. The valve assembly remains at the bottom dead center, the fuel storage space merges into the pre-combustion chamber, and the internal air-fuel mixture continues to burn to form exhaust gas.

[0022] During the exhaust stroke of an internal combustion engine, the piston moves from bottom dead center to top dead center, pushing out the exhaust gas after combustion in the main combustion chamber; the valve assembly remains at bottom dead center, and the exhaust gas in the pre-combustion chamber flows into the main combustion chamber through the injection port, accompanied by a pressure reduction;

[0023] During the intake stroke of an internal combustion engine, the piston moves from top dead center to bottom dead center, and external air is drawn into the main combustion chamber through the intake valve. In the early stage of the intake stroke, after the exhaust valve closes, the valve assembly begins to move upward and reaches top dead center, which connects the fuel storage chamber with the fuel supply chamber, and disconnects the fuel storage space from the pre-combustion chamber, allowing gaseous fuel with a low auto-ignition temperature to enter the fuel storage chamber. In the middle and late stages of the intake stroke, the valve assembly remains at top dead center.

[0024] After that, the internal combustion engine re-enters the compression stroke, completing a full cycle, and the valve assembly completes one full reciprocating motion.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0027] Figure 1 This is a schematic diagram of an embodiment of the self-ignition pre-combustion chamber system provided by the present invention, installed in an internal combustion engine with the valve stem at the bottom dead center.

[0028] Figure 2 yes Figure 1 A magnified view of part A in the middle;

[0029] Figure 3 This is a schematic diagram of an embodiment of the self-ignition pre-combustion chamber system provided by the present invention, in which the valve stem is at the top dead center;

[0030] Figure 4 This is a schematic diagram of an embodiment of the self-ignition pre-combustion chamber system provided by the present invention, installed in an internal combustion engine with the valve stem at the top dead center.

[0031] Figure 5 This is a schematic diagram of the piston and valve stem stroke during an internal combustion engine cycle.

[0032] Icon labels:

[0033] Pre-combustion chamber body 100; valve stem hole 110; fuel supply chamber 111; pre-combustion chamber 120; injection hole 121; fuel supply channel 130; one-way valve 131; fuel supply port 140;

[0034] Valve assembly 200; fuel storage space 210; valve stem 220; first end 221; second end 222; fuel-sealing valve 230; valve stem 231; valve disc 232; flow guide structure 233;

[0035] Fuel storage chamber 300;

[0036] Cylinder block 400;

[0037] Cylinder head 500; intake manifold 510; exhaust manifold 520; pre-combustion chamber bore 530;

[0038] Piston 600;

[0039] Intake valve 700;

[0040] Exhaust valve 800;

[0041] Fuel injector 900;

[0042] Main combustion chamber 1000. Detailed Implementation

[0043] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0045] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0046] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0048] Currently, low auto-ignition temperature fuels are injected into the pre-combustion chamber 120 using liquid high-pressure injection technology. However, liquid low auto-ignition temperature fuels, such as diesel and biodiesel, easily form large molecular compounds like polycyclic aromatic hydrocarbons (PAHs) in the high-temperature environment of the pre-combustion chamber 120. These PAHs continue to grow and polymerize, eventually forming coke. Furthermore, gaseous low auto-ignition temperature fuels, such as dimethyl ether, are not suitable for the combustion technology in this pre-combustion chamber 120. Therefore, this invention proposes a self-ignition pre-combustion chamber system to solve the key technical problem of introducing gaseous low auto-ignition temperature fuels into the pre-combustion chamber 120 under high pressure, avoiding the need for high-pressure injection and the coking problem in the pre-combustion chamber 120.

[0049] like Figures 1 to 4 As shown, the self-ignition pre-combustion chamber system of the present invention includes a pre-combustion chamber body 100 and a valve assembly 200.

[0050] For ease of installation, the pre-combustion chamber body 100 in this embodiment is a sleeve-like structure with a stepped shape, referred to as the small diameter section and the large diameter section, respectively. In some other embodiments, the pre-combustion chamber body 100 may have other shapes.

[0051] like Figure 2 and 3 As shown, the pre-combustion chamber body 100 is provided with a valve stem hole 110, a pre-combustion chamber 120 and a fuel supply channel 130. The pre-combustion chamber 120 is located in the lower part of the small diameter section of the pre-combustion chamber body 100 and has an internal cavity structure. The side wall of the pre-combustion chamber 120 is provided with at least one injection hole 121. The pre-combustion chamber 120 is connected to the main combustion chamber 1000 in the internal combustion engine through the injection hole 121. The pre-combustion chamber 120 and the injection hole 121 are used to introduce the high-temperature and high-pressure combustion gas after combustion in the pre-combustion chamber 120 into the main combustion chamber 1000, ignite the mixture in the main combustion chamber 1000, and achieve the ignition effect of the mixture in the main combustion chamber 1000.

[0052] In this embodiment, the valve stem hole 110 extends from the top of the pre-combustion chamber body 100 to the lower pre-combustion chamber 120. The lower end of the valve stem hole 110 is connected to the pre-combustion chamber 120. The inner peripheral wall of the valve stem hole 110 is provided with a fuel supply chamber 111, which is connected to the fuel supply channel 130. The top of the pre-combustion chamber body 100 is provided with a fuel supply port 140, which is connected to the fuel supply channel 130. The fuel supply port 140 is used to connect to an external fuel supply system. The fuel supply system supplies gaseous low auto-ignition temperature fuel to the fuel supply chamber 111, thereby realizing the supply of gaseous low auto-ignition temperature fuel.

[0053] In some other embodiments, the valve stem hole 110 may extend in other directions through the pre-combustion chamber 120.

[0054] like Figure 2 and 3 As shown, the valve assembly 200 of this embodiment has a rod-shaped structure. A fuel storage space 210 is provided inwardly recessed on the outer peripheral wall of the valve assembly 200. The valve assembly 200 is axially slidably and sealingly fitted into the valve stem hole 110. The valve assembly 200 of the present invention can reciprocate up and down within the valve stem hole 110. When the valve assembly 200 is configured to move upward along the valve stem hole 110 to the top dead center, the fuel storage space 210 and the inner peripheral wall of the valve stem hole 110 can jointly form a fuel storage chamber 300, and the fuel storage chamber 300 is connected to the fuel supply chamber 111, while the fuel storage space 210 is disconnected from the pre-combustion chamber 120. When the valve assembly 200 is also configured to move downward along the valve stem hole 110 to the bottom dead center, the fuel storage space 210 is connected to the pre-combustion chamber 120, and the fuel supply chamber 111 is blocked.

[0055] During operation, as the valve assembly 200 reciprocates through the valve stem bore 110, when the valve assembly 200 is at top dead center, the fuel storage chamber 300, formed by the fuel storage space 210 and the inner peripheral wall of the valve stem bore 110, connects with the fuel supply chamber 111. Gaseous low auto-ignition temperature fuel then enters the fuel storage chamber 300 through the fuel supply channel 130 and the fuel supply chamber 111. When the valve assembly 200 moves to the point where the fuel storage space 210 connects with the pre-combustion chamber 120, the high-temperature, high-pressure mixture in the pre-combustion chamber 120 first enters the fuel storage space 210 under pressure, causing some of the gaseous low auto-ignition temperature fuel in the fuel storage space 210 to auto-ignite. As the valve assembly 200 continues its rapid downward movement, i.e., when the valve assembly 200 is at bottom dead center, the mixture in the fuel storage space 210 is completely pushed into the pre-combustion chamber 120, where the gaseous low auto-ignition temperature fuel reacts with the pre-combustion chamber 120. The high-temperature mixture in the combustion chamber 120 continues to mix and spontaneously combust, thereby igniting all the mixture in the pre-combustion chamber 120. The combustion of the mixture in the pre-combustion chamber 120 further forms a mixture with even higher temperature and pressure. The high-temperature and high-pressure mixture is injected outward through the injection hole 121, further igniting the mixture in the main combustion chamber 1000. This invention utilizes the reciprocating motion of the valve assembly 200 to introduce gaseous low auto-ignition temperature fuel into the pre-combustion chamber 120 under high pressure. That is, it can introduce the pre-combustion chamber 120 near the top dead center of the compression of the internal combustion engine. Under the high pressure of the pre-combustion chamber 120, gaseous low auto-ignition temperature fuel can be introduced and spontaneously combusted to ignite the pre-combustion chamber 120, avoiding the need for high-pressure injection and the coking problem in the pre-combustion chamber 120. In addition, the pre-combustion chamber 120 of this invention can introduce gaseous low auto-ignition temperature fuel, and the introduced fuel spontaneously combusts and ignites the mixture in the pre-combustion chamber 120, without the need to install an ignition device in the pre-combustion chamber 120.

[0056] Specifically, the valve assembly 200 of this embodiment includes a valve stem 220 and a fuel-sealed valve 230, wherein the fuel-sealed valve 230 has a mushroom-shaped valve structure and includes a valve stem 231 and a valve disc 232. The lower end and upper end of the valve stem 220 are divided into a first end 221 and a second end 222. The two ends of the valve stem 231 are rigidly connected between the first end 221 and the valve disc 232, respectively. In this embodiment, the valve stem 231 is coaxially connected to the valve stem 220 and the valve disc 232, respectively, and the outer diameter of the valve stem 231 is smaller than that of the valve stem 220 and the valve disc 232, respectively. In this embodiment, the valve stem 220 is axially slidably and sealingly fitted inside the valve stem hole 110, and the outer edge of the valve disc 232 can seal against the lower edge of the lower port of the valve stem hole 110.

[0057] In this embodiment, the outer peripheral wall of the valve stem 231, the first end 221 and the valve disc 232 together form a fuel storage space 210, and the first end 221 can extend downward over the fuel supply chamber 111 to block the fuel supply chamber 111.

[0058] It is understood that in this embodiment, the valve stem 220 can drive the fuel-sealing valve 230 to reciprocate up and down. When the valve stem 220 is at top dead center, the valve disc 232 abuts against the lower edge of the valve stem hole 110 to ensure that the fuel storage space 210 is disconnected from the pre-combustion chamber 120. The lower end face of the valve stem 220 is higher than the fuel supply chamber 111 to ensure that the fuel supply chamber 111 is connected to the fuel storage chamber 300. When the valve stem 220 is at bottom dead center, the valve disc 232 moves away from the lower edge of the valve stem hole 110 to ensure that the fuel storage space 210 is disconnected from the pre-combustion chamber 120. The valve stem 220 is connected to the fuel supply chamber 111. The lower end face of the valve stem 220 is lower than the fuel supply chamber 111 to ensure that the connection between the fuel storage space 210 and the fuel supply chamber 111 is broken. Moreover, the lower end face of the valve stem 220 is close to the lower edge of the valve stem hole 110 to ensure that the fuel storage space 210 is completely integrated into the pre-combustion chamber 120. Thus, the main function of the valve stem 220 is to realize the connection and disconnection between the fuel supply chamber 111 and the fuel storage space 210. The main function of the fuel shut-off valve 230 is to realize the connection and disconnection between the fuel storage space 210 and the pre-combustion chamber 120.

[0059] Furthermore, in this embodiment, the fuel-sealed valve 230 is filled with phase change material to enhance heat transfer between the valve disc 232 and the valve stem 231. Because the upper surface of the valve disc 232 is heated by the high-temperature mixture in the fuel storage chamber 300 and the lower surface is heated by the high-temperature gas in the pre-combustion chamber 120, its heat load is relatively large. The phase change material can transfer the heat of the valve disc 232 out through the phase change process of the phase change material, similar to the sodium filling technology of the exhaust valve 800 of an internal combustion engine.

[0060] And, such as Figure 2 and 3 As shown, a ring-shaped flow guide structure 233 is provided on the upper surface of the valve disc 232. The flow guide structure 233 is used to guide the air-fuel mixture in the pre-combustion chamber 120 into the fuel storage space 210. The flow guide structure 233 is a structure used to guide the direction, speed and distribution of fluid flow and to achieve a specific flow pattern. After the valve assembly 200 starts to move downward from the top dead center, the fuel storage space 210 is connected to the main combustion chamber 1000. The air-fuel mixture in the pre-combustion chamber 120 quickly enters the fuel storage space 210 through the gap between the valve disc 232 and the lower edge of the valve stem hole 110. The rapidly flowing air-fuel mixture can drive the fuel in the fuel storage space 210 to form a certain flow pattern. Moreover, the flowing air-fuel mixture contains oxygen, and the mixing process with the fuel in the fuel storage space 210 can promote the fuel to ignite spontaneously.

[0061] Furthermore, the flow guiding mechanism can also cause the fuel storage space 210 to form a vortex around the axis of the fuel-sealed valve 230, or a tumble around the axis perpendicular to the axis, or other flow forms that promote the spontaneous combustion of fuel in the fuel storage space 210.

[0062] In this embodiment, the fuel supply channel 130 is provided with a one-way valve 131. The one-way valve 131 is directed toward the fuel supply chamber 111, allowing fuel from the external fuel supply system to enter the fuel supply chamber 111 through the fuel supply port 140 and the fuel supply channel 130, preventing the fluid in the fuel supply chamber 111 and the fuel storage chamber 300 connected to it from flowing back into the fuel supply channel 130 and the external fuel supply system.

[0063] In this embodiment, the valve assembly 200 is connected to a reciprocating drive mechanism, which is configured to drive the valve assembly 200 to reciprocate within the valve stem hole 110. The reciprocating drive mechanism can be a known cam mechanism, hydraulic mechanism, or electromagnetic drive mechanism.

[0064] Furthermore, the pre-combustion chamber 120 of the present invention is provided with a plurality of injection holes 121, which are spherically distributed on the side wall of the pre-combustion chamber 120 opposite to the valve stem hole 110. The side wall of the pre-combustion chamber 120 opposite to the valve stem hole 110 has a concave spherical structure to improve the gas mixing effect. Specifically, the pre-combustion chamber 120 of this embodiment is provided with more than four injection holes 121 because the fuel storage space 210 is small, has low pressure, and is filled with gaseous fuel, so it carries little fuel energy. The fuel in 210 can directly ignite the main combustion chamber 1000, but the ignition effect is not as good as the jet ignition effect of the pre-combustion chamber 120 and its injection hole 121. The latter uses the fuel in the fuel storage space 210 to first ignite the pre-combustion chamber 120. Then the mixture in the pre-combustion chamber 120 burns to form high-temperature and high-pressure gas, which is then injected into the main combustion chamber 1000 through the injection hole 121 to ignite the main combustion chamber 1000. The pre-combustion chamber 120 can achieve more than four jets by using more than four injection holes, realizing multi-source ignition, improving the ignition effect and accelerating the combustion process.

[0065] The present invention also proposes an internal combustion engine, which includes the aforementioned ignition and pre-combustion chamber 120 system, and further includes a cylinder block 400 and a cylinder head 500 covering the top of the cylinder block 400. At least one cylinder is formed between the cylinder block 400 and the cylinder head 500. The number of ignition and pre-combustion chambers 120 systems corresponds one-to-one with the number of cylinders. Each cylinder is provided with a piston 600, an intake valve 700, an exhaust valve 800, and a fuel injector 900, and the space they collectively define is a main combustion chamber 1000.

[0066] Specifically, the internal combustion engine in this embodiment is a reciprocating piston 600 type internal combustion engine, whose structure and form are consistent with existing conventional internal combustion engines not described herein. The cylinder head 500 is provided with an intake port 510 and an exhaust port 520. A stepped pre-combustion chamber hole 530 is directly machined at the corresponding position of the central axis of each cylinder on the cylinder head 500. The pre-combustion chamber hole 530 runs through the entire cylinder head 500 from top to bottom. The pre-combustion chamber body 100 is installed in the pre-combustion chamber hole 530, which facilitates the installation, disassembly and maintenance of the pre-combustion chamber body 100. The bottom surface of the pre-combustion chamber body 100 is slightly lower than the bottom plane of the cylinder head 500. The injection hole 121 connects the pre-combustion chamber 120 and the main combustion chamber 1000.

[0067] This invention also proposes an operating method applicable to the aforementioned internal combustion engine. In this embodiment, the internal combustion engine operates according to the conventional four-stroke internal combustion engine operating mode not described herein, and outputs power externally, such as... Figure 5 The diagram shows the movement of piston 600 and valve stem 220 during an internal combustion engine cycle, used to intuitively explain the working principle of the internal combustion engine and the self-ignition pre-combustion chamber system. The operating method of this embodiment includes:

[0068] During the compression stroke of an internal combustion engine, the crankshaft and connecting rod drive the piston 600 upward, compressing the air-fuel mixture in the main combustion chamber 1000, increasing the pressure and temperature of the mixture. Since the injection port 121 connects the main combustion chamber 1000 and the pre-combustion chamber 120, the high-temperature, high-pressure mixture from the main combustion chamber 1000 enters the pre-combustion chamber 120. For most of the compression stroke, the valve assembly 200 is at top dead center, and the valve disc 232 of the fuel-sealing valve 230 abuts against the lower edge of the valve stem hole 110, allowing fuel to pass through. The storage space 210 is disconnected from the pre-combustion chamber 120, and at the same time, the lower end face of the valve stem 220 is higher than the fuel supply chamber 111, making the fuel supply chamber 111 connected to the fuel temporary storage chamber 300; the gaseous low auto-ignition temperature fuel from the external fuel supply system enters the fuel temporary storage chamber 300 through the fuel supply port 140, fuel supply channel 130, one-way valve 131, and fuel supply chamber 111, until the pressure in the fuel temporary storage chamber 300 is the same as the pressure in the fuel supply port 140 and the one-way valve 131 closes the fuel flow. During the later stages of the compression stroke, the valve assembly 200 begins to descend, and the valve disc 232 disengages from the lower edge of the valve stem bore 110. Under pressure, the mixture in the pre-combustion chamber 120 flows into the fuel storage space 210 through the gap between the valve disc 232 and the lower edge of the valve stem bore 110, with a flow guiding mechanism directing the fluid. The high-temperature, high-pressure mixture entering the fuel storage space 210 contains a large amount of air. Under the influence of this high-temperature air, the gaseous fuel portion within the fuel storage space 210... Spontaneous combustion occurs; as the valve assembly 200 rapidly descends, the mixture in the fuel storage space 210 is completely pushed into the pre-combustion chamber 120. The spontaneously combusting fuel continues to mix with the high-temperature mixture in the pre-combustion chamber 120 and spontaneously combusts, thereby igniting all the mixture in the pre-combustion chamber 120; the combustion of the mixture in the pre-combustion chamber 120 further forms an even higher temperature and pressure mixture, which is injected into the main combustion chamber 1000 through the injection port 121, further igniting the mixture in the main combustion chamber 1000;

[0069] During the power stroke of the internal combustion engine, the crankshaft and connecting rod drive the piston 600 to continue its downward movement. After the jet from the injection port 121 of the pre-combustion chamber 120 ignites the air-fuel mixture in the main combustion chamber 1000, the flame in the main combustion chamber 1000 gradually spreads to the surroundings through propagation. The pressure and temperature of the air-fuel mixture in the main combustion chamber 1000 both rise, pushing the piston 600 to move to bottom dead center and outputting power. The valve assembly 200 remains at bottom dead center, and the fuel storage space 210 enters the pre-combustion chamber 120, where the air-fuel mixture continues to burn to form exhaust gas.

[0070] During the exhaust stroke of the internal combustion engine, the piston 600 moves from bottom dead center to top dead center, pushing the exhaust gas after combustion in the main combustion chamber 1000 out through the exhaust passage 520; the valve assembly 200 remains at bottom dead center, the fuel storage space 210 merges into the pre-combustion chamber 120, and the exhaust gas in the pre-combustion chamber 120 flows into the main combustion chamber 1000 through the injection port 121, accompanied by a pressure reduction;

[0071] During the intake stroke of an internal combustion engine, piston 600 moves from top dead center to bottom dead center, drawing air from intake manifold 510 into main combustion chamber 1000. Early in the intake stroke, after exhaust valve 800 closes, valve assembly 200 begins to rise. During this period, fuel supply chamber 111 is connected to pre-combustion chamber 120 via fuel storage space 210. The rapidly rising valve assembly 200 reduces the amount of fuel entering pre-combustion chamber 120 from fuel supply chamber 111 during this phase. After valve assembly 200 reaches top dead center, valve disc 232 of fuel-sealing valve 230 contacts valve stem hole 11. The lower edge of valve stem 220 disconnects the fuel storage space 210 from the pre-combustion chamber 120. At the same time, the lower end face of valve stem 220 is higher than the fuel supply chamber 111, making the fuel supply chamber 111 connected to the fuel storage chamber 300. The gaseous low auto-ignition temperature fuel from the external fuel supply system enters the fuel storage chamber 300 through the fuel supply port 140, fuel supply channel 130, one-way valve 131, and fuel supply chamber 111 until the pressure in the fuel storage chamber 300 is the same as the pressure in the fuel supply port 140 and the one-way valve 131 closes the fuel flow. During the middle and late stages of the intake stroke, valve assembly 200 remains at top dead center.

[0072] After that, the internal combustion engine re-enters the compression stroke, completing a full cycle, and the valve assembly 200 completes one full reciprocating motion.

[0073] This invention utilizes the reciprocating motion of the valve assembly 200 to introduce gaseous low auto-ignition temperature fuel into the pre-combustion chamber 120 near the top dead center of the compression stroke of the internal combustion engine. The low auto-ignition temperature fuel then spontaneously ignites the air-fuel mixture within the pre-combustion chamber 120. The combustion within the pre-combustion chamber 120 generates high-temperature, high-pressure combustion gas, which then ignites the main combustion chamber 1000 of the internal combustion engine through the injection port 121. This achieves ignition and combustion in the main combustion chamber 1000, enabling the engine to output power. The introduction of gaseous low auto-ignition temperature fuel into the pre-combustion chamber 120 causes spontaneous combustion and ignites the pre-combustion chamber. The air-fuel mixture in the pre-combustion chamber 120 does not require an ignition device. The gaseous low auto-ignition temperature fuel only ignites the air-fuel mixture in the pre-combustion chamber 120, and then the jet flame in the pre-combustion chamber 120 ignites the air-fuel mixture in the main combustion chamber 1000. Therefore, the demand for low auto-ignition temperature fuel is very small, and the main combustion chamber 1000 can still burn quickly. At the top dead center of the internal combustion engine compression, under the high pressure of the pre-combustion chamber 120, the gaseous low auto-ignition temperature fuel can be introduced and auto-ignited, thus avoiding the need for high-pressure injection and the coking problem in the pre-combustion chamber 120.

[0074] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0075] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A self-ignition pre-combustion chamber system, characterized in that, include: The pre-combustion chamber body is provided with a valve stem hole, a pre-combustion chamber and a fuel supply channel. One end of the valve stem hole is connected to the pre-combustion chamber. The side wall of the pre-combustion chamber is provided with at least one injection hole. The inner peripheral wall of the valve stem hole is provided with a fuel supply cavity connected to the fuel supply channel. The valve assembly is a rod-shaped structure. The outer peripheral wall of the valve assembly has an inwardly recessed fuel storage space. The valve assembly is axially slidably and sealingly fitted within the valve stem bore. The valve assembly is configured to move along the valve stem bore in a direction away from the pre-combustion chamber, such that the fuel storage space and the inner peripheral wall of the valve stem bore together form a fuel storage cavity, which is connected to the fuel supply cavity, while the fuel storage space is disconnected from the pre-combustion chamber. The valve assembly is also configured to move along the valve stem bore towards the pre-combustion chamber, such that the fuel storage space is connected to the pre-combustion chamber, and the fuel supply cavity is blocked.

2. The self-ignition pre-combustion chamber system according to claim 1, characterized in that: The valve assembly includes a valve stem and a fuel-sealing valve. The fuel-sealing valve has a mushroom-shaped structure and includes a valve stem and a valve disc. The valve stem has two ends, a first end and a second end. The two ends of the valve stem are rigidly connected between the first end and the valve disc, respectively. The outer diameter of the valve stem is smaller than that of the valve stem and the valve disc. The valve stem is axially slidably and sealingly fitted into the valve stem hole. The outer edge of the valve disc can seal against the end of the valve stem hole that communicates with the pre-combustion chamber. The outer peripheral wall of the valve stem, the first end, and the valve disc together form the fuel storage space. The first end can extend beyond the fuel supply chamber to block the fuel supply chamber.

3. The self-ignition pre-combustion chamber system according to claim 2, characterized in that: The fuel-sealed valve is filled with a phase change material.

4. The self-ignition pre-combustion chamber system according to claim 2, characterized in that: The valve disc has an annular flow guide structure on its end face facing the valve stem.

5. The self-ignition pre-combustion chamber system according to claim 1, characterized in that: The fuel supply channel is equipped with a one-way valve, and the flow direction of the one-way valve is towards the fuel supply chamber.

6. The self-ignition pre-combustion chamber system according to claim 1, characterized in that: The valve assembly is connected to a reciprocating drive mechanism, which is configured to drive the valve assembly to reciprocate along the valve stem bore.

7. The self-ignition pre-combustion chamber system according to claim 1, characterized in that: The pre-combustion chamber is provided with multiple injection holes, which are spherically distributed on the side wall of the pre-combustion chamber opposite to the valve stem hole, and the side wall of the pre-combustion chamber opposite to the valve stem hole has a concave spherical structure.

8. An internal combustion engine, characterized in that: It includes a self-ignition pre-combustion chamber system as described in any one of claims 1 to 7, the self-ignition pre-combustion chamber system having at least one, and further including a cylinder body and a cylinder head covering the top of the cylinder body, at least one cylinder being formed between the cylinder body and the cylinder head, the cylinder having a piston, an intake valve, an exhaust valve and a fuel injector, and the space jointly defined by them being a main combustion chamber, the injection port communicating with the main combustion chamber.

9. The internal combustion engine according to claim 8, characterized in that: The cylinder head is provided with at least one stepped pre-combustion chamber hole. The pre-combustion chamber body is a sleeve-like structure with a stepped shape. The pre-combustion chamber body is fitted into the stepped pre-combustion chamber hole.

10. A method of operation, characterized in that: The operating method, applicable to any one of claims 8 or 9, comprises: During the compression stroke of an internal combustion engine, the piston moves upward, compressing the air-fuel mixture in the main combustion chamber. The pressure and temperature of the mixture increase, and the high-temperature, high-pressure mixture from the main combustion chamber enters the pre-combustion chamber. The valve assembly is at top dead center, connecting the fuel storage chamber to the fuel supply chamber, while disconnecting the fuel storage space from the pre-combustion chamber. Gaseous fuel with a low auto-ignition temperature from the external fuel supply system enters the fuel storage chamber. Later in the compression stroke, the valve assembly begins to move downward, connecting the fuel storage space to the pre-combustion chamber and blocking the fuel supply chamber. Under pressure, the air-fuel mixture flows into the fuel storage space. Under the influence of the high-temperature air, the gaseous fuel with a low auto-ignition temperature in the fuel storage space undergoes auto-ignition. As the valve assembly rapidly descends, the air-fuel mixture in the fuel storage space is completely pushed into the pre-combustion chamber. The auto-ignited fuel continues to mix and auto-ignite with the high-temperature air-fuel mixture in the pre-combustion chamber, thereby igniting all the air-fuel mixture in the pre-combustion chamber. The combustion of the air-fuel mixture in the pre-combustion chamber further forms an even higher temperature and pressure mixture, which is then injected into the main combustion chamber through the injection port, further igniting the air-fuel mixture in the main combustion chamber. During the power stroke of the internal combustion engine, the piston begins to descend, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to the bottom dead center and outputting power. The valve assembly remains at the bottom dead center, the fuel storage space merges into the pre-combustion chamber, and the internal air-fuel mixture continues to burn to form exhaust gas. During the exhaust stroke of an internal combustion engine, the piston moves from bottom dead center to top dead center, pushing out the exhaust gas after combustion in the main combustion chamber; the valve assembly remains at bottom dead center, and the exhaust gas in the pre-combustion chamber flows into the main combustion chamber through the injection port, accompanied by a pressure reduction; During the intake stroke of an internal combustion engine, the piston moves from top dead center to bottom dead center, and external air is drawn into the main combustion chamber through the intake valve. In the early stage of the intake stroke, after the exhaust valve closes, the valve assembly begins to move upward and reaches top dead center, which connects the fuel storage chamber with the fuel supply chamber, and disconnects the fuel storage space from the pre-combustion chamber, allowing gaseous fuel with a low auto-ignition temperature to enter the fuel storage chamber. In the middle and late stages of the intake stroke, the valve assembly remains at top dead center. After that, the internal combustion engine re-enters the compression stroke, completing a full cycle, and the valve assembly completes one full reciprocating motion.

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