Spontaneous combustion ignition pre-combustion chamber system, internal combustion engine and operation method

Abstract

The invention discloses a spontaneous combustion ignition pre-combustion chamber system, an internal combustion engine and an operation method, the spontaneous combustion ignition pre-combustion chamber system comprises a pre-combustion chamber body and a valve assembly, the pre-combustion chamber body is provided with a valve rod hole, a pre-combustion chamber and a fuel supply channel, the side wall of the pre-combustion chamber is provided with an injection hole, and the inner circumferential wall of the valve rod hole is provided with a fuel supply cavity; the outer peripheral wall of the valve assembly is provided with a fuel temporary storage space which is sunken inwards, and the valve assembly is sleeved with the valve rod hole in a sliding and sealing mode in the axial direction; the valve assembly is configured to move in the direction, opposite to the pre-combustion chamber, of the valve rod hole, so that a fuel temporary storage cavity is defined by the fuel temporary storage space and the inner circumferential wall of the valve rod hole, the fuel temporary storage cavity communicates with the fuel supply cavity, and the fuel temporary storage space is disconnected from the pre-combustion chamber; the valve assembly is further configured to move in the direction from the valve rod hole to the pre-combustion chamber, so that the fuel temporary storage space communicates with the pre-combustion chamber, and the fuel supply cavity is blocked. The problems of high-pressure injection requirements and coking of the pre-combustion chamber are avoided.

Description

Technical Field

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

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

[0003] Pre-chamber combustion technology first ignites the mixture in the pre-chamber that is easily ignited by a spark plug, and then introduces the high-temperature and high-pressure combustion mixture formed by the combustion of the mixture in the pre-chamber into the main combustion chamber to ignite the lean mixture in the main combustion chamber. After that, the lean mixture in the main combustion chamber burns rapidly. The key to pre-chamber combustion technology is to form a stable mixture in the pre-chamber that can be ignited by a traditional spark plug. For this purpose, a fuel injection device using liquid high-pressure injection technology is usually adopted in the pre-chamber to inject part of the fuel into the pre-chamber to form a mixture in the pre-chamber that is easily ignited by the spark plug. However, the existing pre-chamber combustion technology has the disadvantages of difficult structural arrangement and difficult mixture flow organization when using a spark plug for ignition. In another case, a fuel with a low auto-ignition temperature is injected into the pre-chamber. To ensure the ignition moment in the pre-chamber, the fuel with a low auto-ignition temperature needs to be injected into the pre-chamber near the top dead center of piston compression. Since the pressure inside the pre-chamber is very high, the current fuel injection device must adopt liquid high-pressure injection, and the fuel with a low auto-ignition temperature can be injected into the pre-chamber only through liquid high-pressure injection technology. However, due to liquid fuels with low auto-ignition temperatures, such as diesel and biodiesel, etc., in the high-temperature environment of the pre-chamber, large molecular compounds such as polycyclic aromatic hydrocarbons are easily formed. The polycyclic aromatic hydrocarbons continue to grow and polymerize, and finally form coke and coking. Gaseous fuels with low auto-ignition temperatures can solve the coking problem, but the existing pre-chamber combustion technology is not applicable to gaseous fuels with low auto-ignition temperatures. Summary of the Invention The purpose of the present invention is to provide a self-ignition ignition pre-chamber system, an internal combustion engine and an operation method to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

[0004] The technical solution adopted to solve the above technical problems: The present invention provides a self-ignition ignition pre-chamber system, including: A pre-chamber body, provided with a valve stem hole, a pre-chamber and a fuel supply channel. One end of the valve stem hole is communicated with the pre-chamber. At least one injection hole is provided on the side wall of the pre-chamber. A fuel supply cavity communicated with the fuel supply channel is provided on the inner peripheral wall of the valve stem hole; The valve assembly is of a rod-like structure. An inwardly recessed fuel temporary storage space is provided on the outer peripheral wall of the valve assembly. The valve assembly is slidably and sealingly sleeved in the valve stem hole along the axial direction. The valve assembly is configured to move along the valve stem hole in a direction away from the pre-chamber, so that the fuel temporary storage space and the inner peripheral wall of the valve stem hole jointly enclose a fuel temporary storage chamber, and the fuel temporary storage chamber is communicated with the fuel supply chamber, and the fuel temporary storage space is disconnected from the pre-chamber. The valve assembly is further configured to move along the valve stem hole in a direction towards the pre-chamber, so that the fuel temporary storage space is communicated with the pre-chamber, and the fuel supply chamber is blocked.

[0005] The beneficial effects of the self-igniting pre-chamber system of the present invention are as follows: During use, the pre-chamber is communicated with the main combustion chamber in the internal combustion engine through the injection holes. During the reciprocating movement of the valve assembly in the valve stem hole, when the fuel temporary storage chamber jointly enclosed by the fuel temporary storage space and the inner peripheral wall of the valve stem hole is communicated with the fuel supply chamber, the gaseous fuel with a low self-ignition temperature enters the fuel temporary storage chamber through the fuel supply passage and the fuel supply chamber. When the valve assembly moves to the position where the fuel temporary storage space is communicated with the pre-chamber, first, the high-temperature and high-pressure mixed gas in the pre-chamber enters the fuel temporary storage space under the action of pressure, and part of the gaseous fuel with a low self-ignition temperature in the fuel temporary storage space undergoes self-ignition. Along with the continuous rapid downward movement of the valve assembly, the mixed gas in the fuel temporary storage space is completely pushed into the pre-chamber. The gaseous fuel with a low self-ignition temperature continues to mix with the high-temperature mixed gas in the pre-chamber and undergoes self-ignition, thereby igniting all the mixed gas in the pre-chamber. The combustion of the mixed gas in the pre-chamber further forms a higher-temperature and higher-pressure mixed gas, which is ejected outwards through the injection holes to further ignite the mixed gas in the main combustion chamber. The present invention uses the reciprocating movement of the valve assembly to introduce the gaseous fuel with a low self-ignition temperature into the pre-chamber under the high-pressure state of the pre-chamber, that is, it can be introduced into the pre-chamber near the compression top dead center of the internal combustion engine. Under the high-pressure condition of the pre-chamber, the gaseous fuel with a low self-ignition temperature can be introduced and self-ignited to ignite the pre-chamber, avoiding the problems of high-pressure injection requirements and pre-chamber coking. In addition, the pre-chamber of the present invention can introduce the gaseous fuel with a low self-ignition temperature, the introduced fuel undergoes self-ignition and ignites the mixed gas in the pre-chamber, and there is no need to set an ignition device in the pre-chamber.

[0006] As a further improvement of 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. The fuel-sealing valve includes a valve stem and a valve disc. The two ends of the valve stem are respectively 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. The outer diameter of the valve stem is smaller than that of the valve stem and the valve disc respectively. The valve stem is axially slidably sleeved in the valve stem hole. The outer edge of the valve disc can be in sealing contact with one end of the valve stem hole communicating with the pre-chamber. The outer peripheral wall of the valve stem, the first end and the valve disc jointly enclose the fuel temporary storage space. The first end can cross the fuel supply chamber to block the fuel supply chamber.

[0007] As a further improvement of the above technical solution, the fuel-sealing valve is filled with phase change material inside.

[0008] As a further improvement of the above technical solution, the end face of the valve disc facing the valve stem is provided with a circumferentially arranged flow guiding structure.

[0009] As a further improvement of the above technical solution, the fuel supply passage is provided with a one-way valve, and the conduction direction of the one-way valve faces the fuel supply chamber.

[0010] As a further improvement of the above technical solution, the valve assembly is drivingly connected with a reciprocating driving mechanism, and the reciprocating driving mechanism is configured to drive the valve assembly to reciprocate in the valve stem hole.

[0011] As a further improvement of the above technical solution, the pre-chamber is provided with a plurality of injection holes. The plurality of injection holes are spherically distributed on the side wall of the pre-chamber on the opposite side of the valve stem hole, and the side wall of the pre-chamber on the opposite side of the valve stem hole is a concave spherical surface structure.

[0012] The present invention also provides an internal combustion engine, which includes the self-igniting pre-chamber system described above. The self-igniting pre-chamber system is provided with at least one. The internal combustion engine further 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 jointly defined space is the main combustion chamber. The injection holes communicate with the main combustion chamber.

[0013] As a further improvement of the above technical solution, the cylinder head is provided with at least one stepped pre-chamber hole. The pre-chamber body is a sleeve-like structure. The outer shape of the pre-chamber body is stepped, and the pre-chamber body is sleeved in the stepped pre-chamber hole.

[0014] The present invention also provides an operating method, which is applicable to the internal combustion engine described above. The operating method includes: In the compression stroke of the internal combustion engine, the piston moves upward, compressing the mixture in the main combustion chamber. The pressure and temperature of the mixture increase, and the high-temperature and high-pressure mixture in the main combustion chamber enters the pre-combustion chamber. The valve assembly is at the top dead center, and the valve assembly connects the fuel storage cavity with the fuel supply cavity, and disconnects the fuel storage space from the pre-combustion chamber. The gaseous fuel with a low auto-ignition temperature from the external fuel supply system enters the fuel storage cavity. In the later stage of the compression stroke, the valve assembly begins to move downward, the fuel storage space is connected to the pre-combustion chamber, and the fuel supply cavity is blocked. The mixture in the pre-combustion chamber flows into the fuel storage space under pressure, and part of the gaseous fuel with a low auto-ignition temperature in the fuel storage space spontaneously ignites under the action of the high-temperature air. Along with the rapid downward movement of the valve assembly, the mixture in the fuel storage space is completely pushed into the pre-combustion chamber. The self-igniting fuel continues to mix and self-ignite with the high-temperature mixture in the pre-combustion chamber, thereby igniting all the mixture in the pre-combustion chamber. The mixture combustion in the pre-combustion chamber further forms a hotter and higher-pressure mixture, and the high-temperature and high-pressure mixture is injected into the main combustion chamber through the injection holes, further igniting the mixture in the main combustion chamber. In the power stroke of the internal combustion engine, the piston begins to move downward, and the pressure and temperature of the mixture in the main combustion chamber both rise, pushing the piston towards the bottom dead center and outputting work externally. The valve assembly remains at the bottom dead center, and the fuel storage space merges into the pre-combustion chamber, and the internal mixture continues to burn to form exhaust gas. In the exhaust stroke of the internal combustion engine, the piston moves from the bottom dead center to the top dead center, pushing the exhaust gas after combustion in the main combustion chamber out. The valve assembly remains at the bottom dead center, and the exhaust gas in the pre-combustion chamber flows into the main combustion chamber through the injection holes, accompanied by a pressure drop. In the intake stroke of the internal combustion engine, the piston moves from the top dead center to the bottom dead center, and external air is inhaled into the main combustion chamber through the intake valve. In the early stage of the intake stroke, after the exhaust valve is closed, the valve assembly begins to move upward and reaches the top dead center, making the fuel storage cavity communicate with the fuel supply cavity, disconnecting the fuel storage space from the pre-combustion chamber, and the gaseous fuel with a low auto-ignition temperature enters the fuel storage cavity. In the middle and later stages of the intake stroke, the valve assembly remains at the top dead center. After that, the internal combustion engine re-enters the compression stroke, the internal combustion engine completes a full cycle, and the valve assembly completes a full reciprocating motion.

[0015] Other features and advantages of the present invention will be described in the following specification, and will, in part, be obvious from the specification, or can be understood by implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following further describes the present invention in conjunction with the drawings and embodiments; Figure 1It is a schematic diagram of the self-ignition pre-chamber system provided by the present invention, showing one embodiment installed in an internal combustion engine with the valve stem at the bottom dead center; Figure 2 is Figure 1 a partial enlarged view of part A in Figure 3 It is a schematic diagram of the self-ignition pre-chamber system provided by the present invention, showing one embodiment with the valve stem at the top dead center; Figure 4 It is a schematic diagram of the self-ignition pre-chamber system provided by the present invention, showing one embodiment installed in an internal combustion engine with the valve stem at the top dead center; Figure 5 It is a schematic diagram of the piston and valve stem strokes in one internal combustion engine cycle; Reference numerals in the drawings: Pre-chamber body 100; valve stem hole 110; fuel supply chamber 111; pre-chamber 120; injection hole 121; fuel supply passage 130; check valve 131; fuel supply port 140; Valve assembly 200; fuel temporary storage space 210; valve stem 220; first end 221; second end 222; fuel-sealing valve 230; valve stem 231; valve disc 232; flow guiding structure 233; Fuel temporary storage chamber 300; Cylinder block 400; Cylinder head 500; intake passage 510; exhaust passage 520; pre-chamber hole 530; Piston 600; Intake valve 700; Exhaust valve 800; Fuel injector 900; Main combustion chamber 1000. Detailed implementation manners

[0017] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0018] In the description of the present invention, it should be understood that for the orientation description, such as up, down, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0019] In the description of the present invention, "a plurality of" refers to more than two. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0020] In the description of the present invention, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0021] Next, the technical solution of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the following described embodiments are some embodiments of the present invention, not all embodiments.

[0022] Currently, low auto-ignition temperature fuels are all injected into the pre-chamber 120 by using liquid high-pressure injection technology. However, liquid low auto-ignition temperature fuels, such as diesel, biodiesel, etc., are prone to form macromolecular compounds such as polycyclic aromatic hydrocarbons in the high-temperature environment in the pre-chamber 120. The polycyclic aromatic hydrocarbons continue to grow and polymerize, and finally form coke. Furthermore, gaseous low auto-ignition temperature fuels, such as dimethyl ether, are not suitable for the combustion technology of this pre-chamber 120. Therefore, the present invention proposes a self-igniting pre-chamber system to solve the key technical problem of introducing gaseous low auto-ignition temperature fuels into the pre-chamber 120 under high pressure, and avoid the high-pressure injection requirement and the coking problem of the pre-chamber 120.

[0023] As Figures 1 to 4 shown, the self-igniting pre-chamber system of the present invention includes a pre-chamber body 100 and a valve assembly 200.

[0024] For the convenience of installation, the pre-chamber body 100 of this embodiment is a sleeve-like structure, and its outer shape is stepped, which are respectively called a small-diameter section and a large-diameter section. In some other embodiments, the pre-chamber body 100 can be of other shapes.

[0025] As Figure 2 and 3 shown, the pre-chamber body 100 is provided with a valve stem hole 110, a pre-chamber 120, and a fuel supply channel 130. The pre-chamber 120 is arranged at the lower part of the small-diameter section of the pre-chamber body 100, and it is an internal cavity structure. At least one injection hole 121 is provided on the side wall of the pre-chamber 120. The pre-chamber 120 is communicated with the main combustion chamber 1000 in the internal combustion engine through the injection hole 121. The pre-chamber 120 and the injection hole 121 are used to introduce the high-temperature and high-pressure combustion gas after combustion in the pre-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.

[0026] The valve stem hole 110 of this embodiment penetrates from the top of the pre-chamber body 100 to the lower pre-chamber 120. The lower end of the valve stem hole 110 communicates with the pre-chamber 120. A fuel supply chamber 111 is provided on the inner peripheral wall of the valve stem hole 110. The fuel supply chamber 111 communicates with the fuel supply passage 130. A fuel supply port 140 is provided at the top of the pre-chamber body 100. The fuel supply port 140 communicates with the fuel supply passage 130. The fuel supply port 140 is used to connect with an external fuel supply system. The fuel supply system supplies gaseous fuel with a low auto-ignition temperature to the fuel supply chamber 111 to achieve the supply of gaseous fuel with a low auto-ignition temperature.

[0027] In some other embodiments, the valve stem hole 110 may extend through the pre-chamber 120 in other directions.

[0028] Such as Figure 2 and 3 As shown, the valve assembly 200 of this embodiment is a rod-shaped structure. An inwardly recessed fuel storage space 210 is provided on the outer peripheral wall of the valve assembly 200. The valve assembly 200 of the present invention is slidably and axially sleeved in the valve stem hole 110. The valve assembly 200 of the present invention can reciprocate up and down in 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 enclose a fuel storage chamber 300, and the fuel storage chamber 300 is made to communicate with the fuel supply chamber 111. At the same time, the fuel storage space 210 is disconnected from the pre-chamber 120. And when the valve assembly 200 is further configured to move downward along the valve stem hole 110 to the bottom dead center, the fuel storage space 210 can be made to communicate with the pre-chamber 120, and the fuel supply chamber 111 is blocked.

[0029] During use, when the valve assembly 200 reciprocates in the valve stem hole 110 and is at the top dead center, when the fuel temporary storage cavity 300 formed jointly by the fuel temporary storage space 210 and the inner peripheral wall of the valve stem hole 110 communicates with the fuel supply cavity 111, the gaseous low auto-ignition temperature fuel enters the fuel temporary storage cavity 300 through the fuel supply passage 130 and the fuel supply cavity 111. When the valve assembly 200 moves to a position where the fuel temporary storage space 210 communicates with the pre-chamber 120, first, the high-temperature and high-pressure mixed gas in the pre-chamber 120 enters the fuel temporary storage space 210 under pressure, causing partial auto-ignition of the gaseous low auto-ignition temperature fuel in the fuel temporary storage space 210. Along with the valve assembly 200 continuing to move rapidly downward, that is, when the valve assembly 200 is at the bottom dead center, the mixed gas in the fuel temporary storage space 210 is completely pushed into the pre-chamber 120. The gaseous low auto-ignition temperature fuel continues to mix with the high-temperature mixed gas in the pre-chamber 120 and auto-ignites, further igniting all the mixed gas in the pre-chamber 120. The combustion of the mixed gas in the pre-chamber 120 further forms a hotter and higher-pressure mixed gas, which is ejected outward through the injection holes 121 to further ignite the mixed gas in the main combustion chamber 1000. The present invention uses the reciprocating motion of the valve assembly 200 to introduce the gaseous low auto-ignition temperature fuel into the pre-chamber 120 under high pressure in the pre-chamber 120, that is, it can introduce the fuel into the pre-chamber 120 near the compression top dead center of the internal combustion engine. Under the high-pressure condition of the pre-chamber 120, the introduction and auto-ignition of the gaseous low auto-ignition temperature fuel can be realized to ignite the pre-chamber 120, avoiding the need for high-pressure injection and the problem of coking in the pre-chamber 120. In addition, the pre-chamber 120 of the present invention can introduce the gaseous low auto-ignition temperature fuel, and the introduced fuel auto-ignites and ignites the mixed gas in the pre-chamber 120, eliminating the need to set an ignition device in the pre-chamber 120.

[0030] Specifically, the valve assembly 200 of this embodiment includes a valve stem 220 and a fuel-sealing valve 230. The fuel-sealing valve 230 has a mushroom-shaped valve structure and includes a valve stem 231 and a valve disk 232. The lower end and the upper end of the valve stem 220 are respectively 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 disk 232. In this embodiment, the valve stem 231 is coaxially connected to the valve stem 220 and the valve disk 232 respectively, and the outer diameter of the valve stem 231 is smaller than that of the valve stem 220 and the valve disk 232 respectively. In this embodiment, the valve stem 220 is axially slidably sleeved in the valve stem hole 110, and the outer edge of the valve disk 232 can sealingly abut against the lower edge of the lower port of the valve stem hole 110.

[0031] The outer peripheral wall of the valve stem 231, the first end 221 and the valve disk 232 of this embodiment jointly enclose the fuel temporary storage space 210, and the first end 221 can move downward past the fuel supply cavity 111 to block the fuel supply cavity 111.

[0032] It can be understood that the valve stem 220 of this embodiment can drive the fuel closing valve 230 to reciprocate up and down. When the valve stem 220 is at the top dead center, the valve disc 232 abuts against the lower edge of the valve stem hole 110 to ensure that the fuel temporary storage space 210 is disconnected from the pre-combustion chamber 120. The lower end surface 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 temporary storage chamber 300. When the valve stem 220 is at the bottom dead center, the valve disc 232 is away from the lower edge of the valve stem hole 110 to ensure that the fuel temporary storage space 210 is connected to the pre-combustion chamber 120. The lower end surface of the valve stem 220 is lower than the fuel supply chamber 111 to ensure that the fuel temporary storage space 210 is disconnected from the fuel supply chamber 111. Moreover, the lower end surface of the valve stem 220 is close to the lower edge of the valve stem hole 110 to ensure that the fuel temporary storage space 210 is completely integrated into the pre-combustion chamber 120. Thus, the main function of the valve stem 220 is to achieve the connection and disconnection between the fuel supply chamber 111 and the fuel temporary storage space 210, and the main function of the fuel closing valve 230 is to achieve the connection and disconnection between the fuel temporary storage space 210 and the pre-combustion chamber 120.

[0033] Furthermore, the fuel closing valve 230 of this embodiment is filled with a phase change material inside to strengthen the heat transfer between the valve disc 232 and the valve stem 231. Since the upper surface of the valve disc 232 is heated by the high-temperature mixed gas in the fuel temporary 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. Filling the phase change material inside can transfer the heat of the valve disc 232 through the phase change process of the phase change material, similar to the technology of filling sodium inside the exhaust valve 800 of an internal combustion engine.

[0034] And, as Figure 2 and 3 shown, a circumferentially arranged flow guiding structure 233 is provided on the upper surface of the valve disc 232. The flow guiding structure 233 is used to guide the mixed gas in the pre-combustion chamber 120 into the fuel temporary storage space 210. The flow guiding structure 233 is a structure for guiding the flow direction, velocity, and distribution of a fluid and achieving a specific flow pattern. After the valve assembly 200 starts to move downward from the top dead center, the fuel temporary storage space 210 is connected to the main combustion chamber 1000. The mixed gas in the pre-combustion chamber 120 quickly enters the fuel temporary storage space 210 through the gap between the valve disc 232 and the lower edge of the valve stem hole 110. The quickly flowing mixed gas can drive the fuel in the fuel temporary storage space 210 to form a certain flow pattern. Moreover, the flowing mixed gas contains oxygen, and the mixing process with the fuel in the fuel temporary storage space 210 can promote the spontaneous combustion of the fuel.

[0035] And the flow guiding mechanism can also promote the formation of a vortex around the axis of the fuel closing valve 230 in the fuel temporary storage space 210, or a tumble around an axis perpendicular to the axis, or other flow forms that promote the spontaneous combustion of the fuel in the fuel temporary storage space 210.

[0036] The fuel supply passage 130 of this embodiment is provided with a check valve 131. The conduction direction of the check valve 131 faces the fuel supply chamber 111, and only allows the fuel of the external fuel supply system to enter the fuel supply chamber 111 through the fuel supply port 140 and the fuel supply passage 130, preventing the fluid in the fuel supply chamber 111 and the fuel temporary storage chamber 300 communicating therewith from flowing reversely into the fuel supply passage 130 and the external fuel supply system.

[0037] The valve assembly 200 of this embodiment is drivingly connected with a reciprocating driving mechanism, and the reciprocating driving mechanism is configured to drive the valve assembly 200 to reciprocate in the valve stem hole 110. The reciprocating driving mechanism can be a known cam mechanism, a hydraulic mechanism, and an electromagnetic driving mechanism.

[0038] Furthermore, the pre-chamber 120 of the present invention is provided with a plurality of injection holes 121. The plurality of injection holes 121 are spherically distributed on the side wall of the pre-chamber 120 opposite to the valve stem hole 110, and the side wall of the pre-chamber 120 opposite to the valve stem hole 110 is a concave spherical surface structure to improve the gas mixing effect. Specifically, the pre-chamber 120 of this embodiment is provided with more than four injection holes 121. Because the fuel temporary storage space 210 is small, the pressure is low, and the fuel filled inside is gaseous, the fuel energy carried is not much; the fuel in the fuel temporary storage space 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-chamber 120 and its injection holes 121. The latter uses the fuel in the fuel temporary storage space 210 to first ignite the pre-chamber 120, and then the mixed gas in the pre-chamber 120 burns to form high-temperature and high-pressure gas inside, and then is injected into the main combustion chamber 1000 through the injection holes 121 to ignite the main combustion chamber 1000. The pre-chamber 120 can achieve more than four jets by using more than four jet holes, realizing multi-source ignition, improving the ignition effect and accelerating the combustion process.

[0039] The present invention also provides an internal combustion engine, which includes the above-mentioned pre-chamber 120 ignition system, and also 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 the pre-chamber 120 ignition systems corresponds to the cylinders one by one. The cylinder is provided with a piston 600, an intake valve 700, an exhaust valve 800, and a fuel injector 900, and the jointly defined space is the main combustion chamber 1000.

[0040] Specifically, the internal combustion engine of this embodiment is a reciprocating piston 600 type internal combustion engine, whose structure and form are the same as those of the existing conventional internal combustion engines not described in this article. The cylinder head 500 is provided with an intake passage 510 and an exhaust passage 520. A stepped pre-chamber hole 530 is directly machined at the position corresponding to the central axis of each cylinder on the cylinder head 500. The pre-chamber hole 530 penetrates the entire cylinder head 500 from top to bottom. The pre-chamber body 100 is installed in the pre-chamber hole 530, which facilitates the installation, disassembly and maintenance of the pre-chamber body 100. And the bottom surface of the pre-chamber body 100 is slightly lower than the bottom plane of the cylinder head 500. The injection hole 121 connects the pre-chamber 120 and the main combustion chamber 1000.

[0041] The present invention also proposes an operating method, which is applicable to the above internal combustion engine. The internal combustion engine of this embodiment operates according to the operating mode of the conventional four-stroke internal combustion engine not described in this article and outputs power externally. As Figure 5 shown, a schematic diagram of the movement of the piston 600 and the valve stem 220 under an internal combustion engine cycle is listed to intuitively explain the working principle of the internal combustion engine and the self-ignition pre-chamber system. The operating method of this embodiment includes: During the compression stroke of the internal combustion engine, the crankshaft connecting rod of the internal combustion engine drives the piston 600 to move upward. The piston 600 compresses the mixture in the main combustion chamber 1000, and the pressure and temperature of the mixture increase. Since the injection hole 121 connects the main combustion chamber 1000 and the pre-combustion chamber 120, the high-temperature and high-pressure mixture in the main combustion chamber 1000 enters the pre-combustion chamber 120. During most of the compression stroke, the valve assembly 200 is at the top dead center. The valve disc 232 of the fuel shut-off valve 230 abuts against the lower edge of the valve stem hole 110 to disconnect the fuel storage space 210 from the pre-combustion chamber 120. At the same time, the lower end face of the valve stem 220 is higher than the fuel supply chamber 111 to connect the fuel supply chamber 111 with the fuel storage chamber 300. The gaseous fuel with a low auto-ignition temperature from the external fuel supply system enters the fuel storage chamber 300 through the fuel supply port 140, the fuel supply passage 130, the one-way valve 131, and the fuel supply chamber 111 until the pressure in the fuel storage chamber 300 is the same as the pressure at the fuel supply port 140 and the one-way valve 131 closes to stop the fuel flow. In the later stage of the compression stroke, the valve assembly 200 starts to move downward. The valve disc 232 disengages from the lower edge of the valve stem hole 110. 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 hole 110 under the action of pressure. During this period, the flow guiding mechanism guides the fluid. The high-temperature and high-pressure mixture entering the fuel storage space 210 contains a large amount of air. Under the action of the high-temperature air, part of the gaseous fuel in the fuel storage space 210 spontaneously ignites. Along with the rapid downward movement of the valve assembly 200, the mixture in the fuel storage space 210 is completely pushed into the pre-combustion chamber 120. The self-ignited fuel continues to mix and self-ignite with the high-temperature mixture in the pre-combustion chamber 120, thereby igniting all the mixture in the pre-combustion chamber 120. The mixture combustion in the pre-combustion chamber 120 further forms a mixture with a higher temperature and pressure, and the high-temperature and high-pressure mixture is injected into the main combustion chamber 1000 through the injection hole 121 to further ignite the mixture in the main combustion chamber 1000. During the power stroke of the internal combustion engine, the crankshaft connecting rod drives the piston 600 to continue moving downward. After the jet flow from the injection hole 121 of the pre-combustion chamber 120 ignites the mixture in the main combustion chamber 1000, the flame in the main combustion chamber 1000 gradually spreads to the surrounding by means of propagation. The pressure and temperature of the mixture in the main combustion chamber 1000 both rise, pushing the piston 600 to move towards the bottom dead center and outputting work externally. The valve assembly 200 remains at the bottom dead center. The fuel storage space 210 enters the pre-combustion chamber 120, and the internal mixture continues to burn to form exhaust gas. During the exhaust stroke of the internal combustion engine, the piston 600 moves from the bottom dead center to the 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 the 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 hole 121, accompanied by a pressure drop. During the intake stroke of the internal combustion engine, the piston 600 moves from the top dead center to the bottom dead center, sucking the air in the intake passage 510 into the main combustion chamber 1000; in the early stage of the intake stroke, after the exhaust valve 800 is closed, the valve assembly 200 starts to move upward. During this period, there is a period when the fuel supply chamber 111 communicates with the pre-chamber 120 through the fuel temporary storage space 210; the rapidly ascending valve assembly 200 can reduce the amount of fuel in the fuel supply chamber 111 entering the pre-chamber 120 during this stage; after the valve assembly 200 reaches the top dead center, the valve disc 232 of the fuel closing valve 230 abuts against the lower edge of the valve stem hole 110 to disconnect the fuel temporary storage space 210 from the pre-chamber 120. At the same time, the lower end surface of the valve stem 220 is higher than the fuel supply chamber 111 to connect the fuel supply chamber 111 with the fuel temporary storage chamber 300; the gaseous low self-ignition temperature fuel of the external fuel supply system enters the fuel temporary storage chamber 300 through the fuel supply port 140, the fuel supply passage 130, the one-way valve 131, and the fuel supply chamber 111 until the pressure in the fuel temporary storage chamber 300 is the same as the pressure at the fuel supply port 140 and the one-way valve 131 closes the fuel flow; in the middle and late stages of the intake stroke, the valve assembly 200 remains at the top dead center.

[0042] After that, the internal combustion engine re-enters the compression stroke, the internal combustion engine completes a full cycle, and the valve assembly 200 completes a full reciprocating motion.

[0043] The present invention uses the reciprocating motion of the valve assembly 200 to introduce the gaseous low self-ignition temperature fuel near the top dead center of compression of the internal combustion engine into the pre-chamber 120. The low self-ignition temperature fuel self-ignites and ignites the mixture in the pre-chamber 120. Then, the combustion in the pre-chamber 120 forms high-temperature and high-pressure gas, which jets through the injection hole 121 to ignite the main combustion chamber 1000 of the internal combustion engine, realizing the ignition and combustion of the main combustion chamber 1000 of the internal combustion engine and outputting power to the outside. The pre-chamber 120 introduces the gaseous low self-ignition temperature fuel, the introduced fuel self-ignites and ignites the mixture in the pre-chamber 120, and there is no need to set an ignition device in the pre-chamber 120. The gaseous low self-ignition temperature fuel only ignites the mixture in the pre-chamber 120, and then the jet flame of the pre-chamber 120 ignites the mixture in the main combustion chamber 1000. Therefore, the demand for the low self-ignition temperature fuel is very small, and the main combustion chamber 1000 can still burn quickly. At the top dead center of compression of the internal combustion engine, the gaseous low self-ignition temperature fuel can be introduced and self-ignited in the pre-chamber 120 under high pressure, avoiding the problems of high-pressure injection requirements and coking in the pre-chamber 120.

[0044] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0045] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art to which it pertains.

Claims

1. A self-ignition 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 communicated with the pre-combustion chamber, the side wall of the pre-combustion chamber is provided with at least one injection hole, and the inner peripheral wall of the valve stem hole is provided with a fuel supply cavity communicated with the fuel supply channel; The valve assembly is a rod-shaped structure, and the outer peripheral wall of the valve assembly is provided with a fuel temporary storage space which is recessed inwardly, and the valve assembly is axially slidingly sealed in the valve stem hole; the valve assembly is configured to move along the direction of the valve stem hole away from the pre-combustion chamber, so that the fuel temporary storage space and the inner peripheral wall of the valve stem hole together form a fuel temporary storage cavity, and the fuel temporary storage cavity is connected with the fuel supply cavity, and the fuel temporary storage space is disconnected from the pre-combustion chamber; the valve assembly is also configured to move along the direction of the valve stem hole toward the pre-combustion chamber, so that the fuel temporary storage space is connected with the pre-combustion chamber and the fuel supply cavity is blocked.

2. The self-ignition 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 is a mushroom-shaped valve structure, the fuel sealing valve includes a valve stem and a valve disc, the two ends of the valve stem are divided into 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, the outer diameter of the valve stem is smaller than the valve stem and the valve disc, the valve stem is axially slidingly sealed in the valve stem hole, the outer edge of the valve disc can be sealed and abutted with one end of the valve stem hole connected to the pre-combustion chamber, the outer peripheral wall of the valve stem, the first end and the valve disc together enclose the fuel temporary storage space, and the first end can pass over the fuel supply cavity to seal the fuel supply cavity.

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

4. The self-ignition ignition pre-combustion chamber system according to claim 2, characterized in that: The end surface of the valve disc facing the valve stem is provided with an annular flow guide structure.

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

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

7. The self-ignition ignition pre-combustion chamber system according to claim 1, characterized in that: The pre-combustion chamber is provided with a plurality of 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 is a concave spherical structure.

8. An internal combustion engine, characterized in that: It includes the self-ignition ignition pre-combustion chamber system as described in any one of claims 1 to 7, the self-ignition ignition pre-combustion chamber system is provided with at least one, and also includes a cylinder body and a cylinder head arranged on the top of the cylinder body, at least one cylinder is formed between the cylinder body and the cylinder head, the cylinder is provided with a piston, an intake valve, an exhaust valve and a fuel injector, and the space jointly defined is a main combustion chamber, and the injection hole is connected to 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-type structure. The shape of the pre-combustion chamber body is stepped. The pre-combustion chamber body is sleeved into the stepped pre-combustion chamber hole.

10. An operating method, characterized in that: Applicable to the internal combustion engine according to any one of claims 8 or 9, the operating method comprises: During the compression stroke of the internal combustion engine, the piston moves upward, compresses the mixture in the main combustion chamber, the pressure and temperature of the mixture increase, and the high-temperature and high-pressure mixture in the main combustion chamber enters the pre-combustion chamber; the valve assembly is at the top dead center, and the valve assembly connects the temporary fuel storage chamber with the fuel supply chamber, and the temporary fuel storage space is disconnected from the pre-combustion chamber; the gaseous low auto-ignition temperature fuel of the external fuel supply system enters the temporary fuel storage chamber; in the later stage of the compression stroke, the valve assembly starts to move downward, the temporary fuel storage space is connected with the pre-combustion chamber, and the fuel supply chamber is blocked, and the pre-combustion chamber The mixed gas in the chamber flows into the temporary fuel storage space under the action of pressure, and the gaseous low auto-ignition temperature fuel in the temporary fuel storage space is partially self-ignited under the action of high-temperature air; with the rapid downward movement of the valve assembly, the mixed gas in the temporary fuel storage space is completely pushed into the pre-combustion chamber, and the self-igniting fuel continues to mix and self-ignite with the high-temperature mixed gas in the pre-combustion chamber, thereby igniting all the mixed gas in the pre-combustion chamber; the mixed gas in the pre-combustion chamber burns to further form a mixed gas with a higher temperature and pressure, and the high-temperature and high-pressure mixed gas is injected into the main combustion chamber through the injection hole, thereby further igniting the mixed gas in the main combustion chamber; During the power stroke of the internal combustion engine, the piston begins to move downward, the pressure and temperature of the mixed gas in the main combustion chamber both rise, pushing the piston to move to the bottom dead center and output work externally; the valve assembly remains at the bottom dead center, the temporary fuel storage space merges into the pre-combustion chamber, and the internal mixed gas continues to burn to form exhaust gas; During the exhaust stroke of the internal combustion engine, the piston moves from the bottom dead center to the top dead center to push out the exhaust gas after combustion in the main combustion chamber; the valve assembly remains at the bottom dead center, and the exhaust gas in the pre-combustion chamber flows into the main combustion chamber through the injection hole, accompanied by a decrease in pressure; During the intake stroke of the internal combustion engine, the piston moves from the top dead center to the bottom dead center, and external air is sucked into the main combustion chamber through the intake valve; in the early stage of the intake stroke, after the exhaust valve is closed, the valve assembly starts to move upward and reaches the top dead center, so that the temporary fuel storage chamber is connected with the fuel supply chamber, the temporary fuel storage space is disconnected from the pre-combustion chamber, and the gaseous low auto-ignition temperature fuel enters the temporary fuel storage chamber; in the middle and late stages of the intake stroke, the valve assembly remains at the top dead center; Afterwards, the internal combustion engine re-enters the compression stroke, the internal combustion engine completes a complete cycle, and the valve assembly completes a complete reciprocating motion.

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