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

Abstract

The invention discloses a stable spontaneous combustion ignition pre-combustion chamber system, an internal combustion engine and an operation method.The stable spontaneous combustion ignition pre-combustion chamber system comprises a pre-combustion chamber body and an air valve assembly. Gas-state low-spontaneous-combustion-temperature fuel is introduced into a pre-combustion chamber in the high-pressure state of the pre-combustion chamber through reciprocating motion of a valve rod and a closed air valve; the pre-combustion chamber can be introduced near the compression top dead center of the internal combustion engine, gaseous low-spontaneous-ignition-temperature fuel can be introduced under the condition that the pressure of the pre-combustion chamber is high, spontaneous combustion is conducted to ignite the pre-combustion chamber, and the high-pressure injection requirement and the pre-combustion chamber coking problem are avoided. Fuel is introduced to generate spontaneous combustion and ignite mixed gas in the pre-combustion chamber, an ignition device does not need to be arranged in the pre-combustion chamber, in addition, through sequential opening and closing of the valve rod and the closed air valve, the fuel supply cavity can be communicated with the pre-combustion chamber without passing through the fuel temporary storage space, and then the fuel is prevented from directly entering the pre-combustion chamber through the fuel temporary storage space; and abnormal ignition of the pre-combustion chamber is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engines, and particularly to a stable self-ignition ignition pre-chamber system, an internal combustion engine, and an operating 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 variations under lean burn conditions, and can also solve the combustion inertness problem of low-reactivity fuels. The working principle of pre-chamber combustion technology is as follows. First, the mixture in the pre-chamber is ignited by a spark plug. Then, the mixture in the pre-chamber burns to form a high-temperature and high-pressure mixture. Then, relying on the pressure difference, the mixture is injected into the main combustion chamber through multiple pre-chamber injection holes to form a jet. Then, the mixture in the main combustion chamber is ignited by multiple high-temperature jets to form multi-source ignition. Then, the flame in the main combustion chamber spreads rapidly around to achieve rapid combustion. 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 is usually used in the pre-chamber to inject part of the fuel into the pre-chamber to form a mixture that is easily ignited by the spark plug. There are disadvantages of difficult structural arrangement and difficult mixture flow organization in this kind of spark plug-ignited pre-chamber combustion technology. The prior art uses a pre-chamber to inject fuel with a low auto-ignition temperature and relies on fuel auto-ignition to achieve ignition, which can eliminate the spark plug. In order to ensure the ignition moment in the pre-chamber, the current pre-chamber structure must use liquid high-pressure injection technology to ensure injection into the pre-chamber near the compression top dead center. Gaseous fuels with low auto-ignition temperatures are not applicable. Moreover, liquid fuels with low auto-ignition temperatures are prone to form macromolecular compounds such as polycyclic aromatic hydrocarbons in the high-temperature environment of the pre-chamber and can continue to grow and polymerize, thus forming coke and coking problems. In addition, in the existing pre-chamber structure, the fuel supply channel is connected to the pre-chamber at the same time, resulting in fuel directly entering the pre-chamber through the fuel supply channel, and then abnormal ignition occurs in the pre-chamber. Summary of the Invention The object of the present invention is to provide a stable self-ignition ignition pre-chamber system, an internal combustion engine, and an operating method to solve the key technical problem of introducing gaseous fuels with low auto-ignition temperatures into the pre-chamber under high pressure, without high-pressure injection, and avoiding abnormal ignition and pre-chamber coking problems in the pre-chamber.

[0003] The technical solutions adopted to solve the above technical problems are as follows: The present invention provides a stable self-ignition ignition pre-chamber system, including: A pre-chamber body, provided with a valve rod hole and a pre-chamber. One end of the valve rod 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 is provided on the inner peripheral wall of the valve rod hole; The valve assembly includes a valve stem, a closing valve, a first actuating mechanism, and a second actuating mechanism. The valve stem is axially slidably and sealingly sleeved in the valve stem hole to close and open the fuel supply chamber. One end of the valve stem close to the pre-chamber is provided with an axially extending closing valve hole. The closing valve includes a valve stem and a valve disc connected in sequence. One end of the valve stem away from the valve disc is axially slidably and sealingly sleeved in the closing valve hole. The first actuating mechanism is configured to apply a force in a direction away from the pre-chamber between the valve stem and the valve stem. The second actuating mechanism is configured to apply a force in a direction towards the pre-chamber between the valve stem and the valve stem. The outer edge of the valve disc is in sealing contact with the end of the valve stem hole on the pre-chamber side. The outer peripheral wall of the valve stem, the end face of the valve stem, and the back surface of the valve disc together enclose an inwardly recessed fuel temporary storage space; The valve assembly is configured such that during the movement in the direction away from the pre-chamber along the valve stem hole, first, the valve disc closes the valve stem hole, and the fuel temporary storage space and the inner peripheral wall of the valve stem hole together enclose a fuel temporary storage chamber. Then, continuing to move drives the valve stem to open the fuel supply chamber, so that the fuel temporary storage chamber communicates with the fuel supply chamber; The valve assembly is further configured such that during the movement in the direction towards the pre-chamber along the valve stem hole, first, the valve stem closes the fuel supply chamber, cutting off the communication between the fuel temporary storage chamber and the fuel supply chamber. Then, continuing to move drives the valve disc to open the valve stem hole, so that the fuel temporary storage space communicates with the pre-chamber.

[0004] The beneficial effects of the stable self-ignition ignition pre-chamber system of the present invention are: During use, the pre - combustion chamber is connected to the main combustion chamber in the internal combustion engine through the injection holes. When the valve assembly reciprocates in the valve stem hole, during the process of the valve assembly moving away from the pre - combustion chamber along the valve stem hole, first, the valve disc closes the valve stem hole, and the fuel storage space and the inner peripheral wall of the valve stem hole jointly enclose the fuel storage cavity. Then, it continues to move to drive the valve stem to open the fuel supply cavity, making the fuel storage cavity communicate with the fuel supply cavity. At this time, the gaseous fuel with a low auto - ignition temperature enters the fuel storage cavity through the fuel supply cavity. When the valve assembly moves towards the pre - combustion chamber along the valve stem hole, first, the valve stem closes the fuel supply cavity, cutting off the connection between the fuel storage cavity and the fuel supply cavity. Then, it continues to move to drive the valve disc to open the valve stem hole, making the fuel storage space communicate with the pre - combustion chamber. The high - temperature and high - pressure mixed gas in the pre - combustion chamber enters the fuel storage space under pressure, and part of the gaseous fuel with a low auto - ignition temperature in the fuel storage space undergoes auto - ignition. Along with the further downward movement of the valve stem and the closing valve, the mixed gas in the fuel storage space is completely pushed into the pre - combustion chamber. The gaseous fuel with a low auto - ignition temperature continues to mix and auto - ignite with the high - temperature mixed gas in the pre - combustion chamber, further igniting all the mixed gas in the pre - combustion chamber. The combustion of the mixed gas in the pre - combustion chamber further forms a hotter and higher - pressure mixed gas, which is sprayed into the main combustion chamber through the injection holes, further igniting the mixed gas in the main combustion chamber. The present invention uses the reciprocating movement of the valve stem and the closing valve to introduce the gaseous fuel with a low auto - ignition temperature into the pre - combustion chamber under high - pressure conditions in the pre - combustion chamber, that is, it can introduce it into the pre - combustion chamber near the compression top dead center of the internal combustion engine. Under high - pressure conditions in the pre - combustion chamber, the introduction and auto - ignition of the gaseous fuel with a low auto - ignition temperature can be achieved, avoiding the problems of high - pressure injection requirements and pre - combustion chamber coking. The pre - combustion chamber of the present invention can introduce the gaseous fuel with a low auto - ignition temperature, and the introduced fuel undergoes auto - ignition and ignites the mixed gas in the pre - combustion chamber without the need to set an ignition device in the pre - combustion chamber. In addition, the sequential opening and closing of the valve stem and the closing valve can prevent the fuel supply cavity from remaining connected to the pre - combustion chamber through the fuel storage space, thereby preventing the fuel from directly entering the pre - combustion chamber through the fuel storage space and avoiding abnormal ignition in the pre - combustion chamber.

[0005] As a further improvement of the above - mentioned technical solution, the first actuating mechanism includes an elastic member, and the elastic member is configured to provide a restoring elastic force in a direction away from the pre - combustion chamber to the valve stem.

[0006] As a further improvement of the above - mentioned technical solution, an annular limiting step is provided on the inner peripheral wall of the closing valve hole, and an installation bracket is provided on the outer peripheral wall of the valve stem. The elastic member is compressively arranged between the installation bracket and the annular limiting step.

[0007] As a further improvement of the above technical solution, one end of the closed valve hole away from the pre-chamber is closed. The inner peripheral wall of the middle part of the closed valve hole is provided with a first groove. The second actuating mechanism includes a valve stem high-pressure oil chamber arranged between the end face of the valve stem away from the valve disc and the end of the closed valve hole, a valve stem low-pressure oil chamber arranged between the outer peripheral wall of the valve stem and the first groove, and an oil drain groove arranged at one end of the valve stem away from the valve disc. The oil drain groove is provided with an oil inlet groove opening and an oil outlet groove opening. The oil inlet groove opening is arranged on the end face of the valve stem and communicated with the valve stem high-pressure oil chamber. The oil outlet groove opening is arranged on the outer peripheral wall of the valve stem and close to the end face of the valve stem. The oil outlet groove opening is configured to move along with the valve stem to connect or disconnect the valve stem high-pressure oil chamber and the valve stem low-pressure oil chamber. The valve stem high-pressure oil chamber is connected with a valve stem oil inlet passage, and the valve stem low-pressure oil chamber is connected with a valve stem low-pressure oil passage.

[0008] As a further improvement of the above technical solution, the inner peripheral wall of the valve stem hole is provided with a second groove and a third groove arranged at intervals along the axial direction. A body oil inlet chamber is formed between the outer peripheral wall of the valve stem and the second groove, and a body oil return chamber is formed between the outer peripheral wall of the valve stem and the third groove. The pre-chamber body is provided with a body oil inlet passage communicated with the body oil inlet chamber and a body oil return passage communicated with the body oil return chamber. The body oil inlet chamber is communicated with the valve stem oil inlet passage, and the valve stem low-pressure oil passage is communicated with the body oil return chamber.

[0009] As a further improvement of the above technical solution, the valve stem oil inlet passage is provided with an oil inlet check valve, and the flow direction of the oil inlet check valve is from the valve stem oil inlet passage to the valve stem high-pressure oil chamber.

[0010] As a further improvement of the above technical solution, the pre-chamber body is provided with a fuel supply passage communicated with the fuel supply chamber. The fuel supply passage is provided with a fuel check valve, and the flow direction of the fuel check valve is from the fuel supply passage to the fuel supply chamber.

[0011] As a further improvement of the above technical solution, a flow guiding mechanism is arranged on the back of the valve disc, and the closed valve is filled with a phase change material.

[0012] The present invention also provides an internal combustion engine, which includes the stable self-ignition ignition pre-chamber system described above. The stable self-ignition ignition 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 a main combustion chamber. The injection hole is communicated with the main combustion chamber.

[0013] The present invention also provides an operating method applicable to the above internal combustion engine. The operating method includes: In the early stage of the intake stroke and the compression stroke of the internal combustion engine, the valve stem and the closing valve are both at the top dead center. The fuel temporary storage cavity is separated from the pre-chamber, and the fuel temporary storage cavity is communicated with the fuel supply cavity. The gaseous fuel with a low auto-ignition temperature enters the fuel temporary storage cavity through the fuel supply cavity. In the later stage of the compression stroke of the internal combustion engine and when the piston moves upward near the top dead center, the valve assembly moves downward in the direction towards the pre-chamber. The valve stem first separates the fuel temporary storage cavity from the fuel supply cavity, and then continues to move to drive the valve disc to open the valve stem hole, so that the fuel temporary storage space is communicated with the pre-chamber. The mixture in the pre-chamber flows into the fuel temporary storage space. Part of the gaseous fuel with a low auto-ignition temperature in the fuel temporary storage space undergoes auto-ignition, and further moves downward to completely push the mixture in the fuel temporary storage space into the pre-chamber, igniting all the mixture in the pre-chamber to form a high-temperature and high-pressure mixture. The high-temperature and high-pressure mixture is injected into the main combustion chamber through the injection hole to ignite the mixture in the main combustion chamber. In the early stage of the power stroke and the exhaust stroke of the internal combustion engine, the valve stem and the closing valve remain at the bottom dead center. In the later stage of the exhaust stroke of the internal combustion engine, the valve assembly moves upward in the direction away from the pre-chamber. First, the valve disc closes the valve stem hole to enclose the fuel temporary storage cavity, and then the valve stem continues to move to open the communication between the fuel supply cavity and the fuel temporary storage cavity, so that the fuel temporary storage cavity is communicated with the fuel supply cavity. The gaseous fuel with a low auto-ignition temperature enters the fuel temporary storage cavity through the fuel supply cavity.

[0014] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will be obvious from the specification or understood by implementing the present invention. Description of the Drawings

[0015] The present invention will be further described below in conjunction with the drawings and embodiments; Figure 1 It is a schematic diagram of the valve stem and the closing valve at the top dead center in one embodiment of the stable auto-ignition ignition pre-chamber system provided by the present invention; Figure 2 is Figure 1 The partial enlarged view of part A in Figure 3 It is a schematic diagram of the valve stem and the closing valve at the intermediate position in one embodiment of the stable auto-ignition ignition pre-chamber system provided by the present invention; Figure 4 It is a schematic diagram of the valve stem and the closing valve at the bottom dead center in one embodiment of the stable auto-ignition ignition pre-chamber system provided by the present invention; Figure 5 isFigure 4 Partial enlarged view of part B; Figure 6 It is a cylinder of an internal combustion engine provided by the present invention, and a schematic diagram of a valve stem and a closed valve at top dead center in one embodiment; Figure 7 It is a cylinder of an internal combustion engine provided by the present invention, and a schematic diagram of a valve stem and a closed valve at bottom dead center in one embodiment; Figure 8 It is an operation method provided by the present invention, and a control flow chart in one embodiment; Figure 9 It is a schematic diagram of the strokes of a piston, a valve stem and a closed valve in one internal combustion engine cycle. Detailed implementation manners

[0016] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where 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 drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0017] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up and down, etc. is based on the orientation or positional relationship shown in the drawings, and 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.

[0018] In the description of the present invention, "a plurality of" means more than two. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and should not be construed 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.

[0019] In the description of the present invention, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense. 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.

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the following described embodiments are some, but not all, embodiments of the present invention.

[0021] Based on the prior art, self-igniting fuels must adopt a liquid high-pressure injection technology to ensure injection into the pre-chamber 120 near the compression top dead center. Gaseous fuels with a low auto-ignition temperature are not applicable. Moreover, liquid fuels with a low auto-ignition temperature are prone to form large molecular compounds such as polycyclic aromatic hydrocarbons in the high-temperature environment of the pre-chamber 120 and can continue to grow and polymerize, thus resulting in coke and coking problems.

[0022] Therefore, a stable self-ignition ignition pre-chamber system of the present invention is provided to solve the key technical problem of introducing gaseous fuels with a low auto-ignition temperature into the pre-chamber 120 under high pressure. High-pressure injection is not required, and abnormal ignition and coking problems in the pre-chamber 120 can be avoided.

[0023] As Figures 1 to 5 shown, the stable self-ignition ignition 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 in this embodiment is a sleeve-like structure with a stepped outer shape, which is 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 1 and Figure 2 shown, the pre-chamber body 100 of this embodiment is provided with a valve stem hole 110 and a pre-chamber 120. The pre-chamber 120 is arranged at the lower part of the small-diameter section of the pre-chamber body 100. It is an internal cavity structure. At least one injection hole 121 is provided on the side wall of the pre-chamber 120. As Figure 6 shown, the pre-chamber 120 is communicated with the main combustion chamber 900 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 900, ignite the mixture in the main combustion chamber 900, and achieve the ignition effect of the mixture in the main combustion chamber 900.

[0026] The valve stem hole 110 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 is communicated with the pre-chamber 120. A fuel supply cavity 111 is provided on the inner peripheral wall of the lower part of the valve stem hole 110. The pre-chamber body 100 is provided with a fuel supply channel 130. The fuel supply cavity 111 is communicated with the fuel supply channel 130. A fuel supply port 131 is provided at the top of the pre-chamber body 100. The fuel supply port 131 is communicated with the fuel supply channel 130. The fuel supply port 131 is used to connect with an external fuel supply system. The fuel supply system supplies gaseous fuels with a low auto-ignition temperature to the fuel supply cavity 111 to achieve the supply of gaseous fuels with a low auto-ignition temperature.

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

[0028] The valve assembly 200 of this embodiment includes a valve stem 210, a closing valve 220, a first actuating mechanism, and a second actuating mechanism. The valve stem 210 is a cylindrical rod-shaped structure. The valve stem 210 is slidably and sealingly sleeved in the valve stem hole 110 along the axial direction. The valve stem 210 can reciprocate up and down to close and open the fuel supply chamber 111. A closing valve hole 211 extending axially is provided at the lower end of the valve stem 210.

[0029] The closing valve 220 of this embodiment is a mushroom-shaped valve structure. The closing valve 220 includes a valve stem 221 and a valve disc 222 connected in sequence. The upper part of the valve stem 221 is slidably and sealingly sleeved in the closing valve hole 211 along the axial direction. The lower end of the valve stem 221 is coaxially connected to the valve disc 222. The first actuating mechanism is configured to apply a force in the direction away from the pre-chamber 120 between the valve stem 221 and the valve stem 210. The second actuating mechanism is configured to apply a force in the direction towards the pre-chamber 120 between the valve stem 221 and the valve stem 210. The valve stem 221 can move up and down in the closing valve hole 211 and can also move up and down following the valve stem 210.

[0030] As Figure 2 shown, the outer edge of the valve disc 222 of this embodiment can be in sealing contact with the lower end of the valve stem hole 110 to close the valve stem hole 110. As Figure 5 shown, an inwardly recessed fuel temporary storage space 230 is jointly formed by the outer peripheral wall of the valve stem 221, the lower end surface of the valve stem 210, and the back surface of the valve disc 222.

[0031] When the valve stem 210 reciprocates up and down, during the process of the valve stem 210 moving along the valve stem hole 110 in the direction away from the pre-chamber 120, the valve stem 210 drives the closing valve 220 to move up together through the first actuating mechanism. First, the valve disc 222 closes the valve stem hole 110. The fuel temporary storage space 230 and the inner peripheral wall of the valve stem hole 110 jointly form a fuel temporary storage chamber 240. Then the valve stem 210 continues to move up to open the fuel supply chamber 111, so that the fuel temporary storage chamber 240 communicates with the fuel supply chamber 111. During the process of the valve stem 210 moving along the valve stem hole 110 in the direction towards the pre-chamber 120, first, the valve stem 210 moves down to close the fuel supply chamber 111, so that the fuel temporary storage chamber 240 is separated from the fuel supply chamber 111. Then the valve stem 210 drives the closing valve to move down together through the second actuating mechanism, so that the valve disc 222 opens the valve stem hole 110, and the fuel temporary storage space 230 communicates with the pre-chamber 120.

[0032] It can be understood that, as Figure 2 and Figure 3As shown, when the valve stem 210 moves upward, it first drives the closing valve 220 to close the valve stem hole 110, forming a fuel temporary storage cavity 240. Then, the fuel supply cavity 111 is opened, and the fuel temporary storage cavity 240 communicates with the fuel supply cavity 111; as Figure 3 , Figure 4 and Figure 5 shown, when the valve stem 210 moves downward, first the valve stem 210 closes the fuel supply cavity 111, and the fuel temporary storage cavity 240 is cut off from the fuel supply cavity 111. Then, it drives the closing valve 220 to open the valve stem hole 110, and the fuel temporary storage space 230 communicates with the pre-chamber 120. When the valve stem 210 reciprocates up and down, it is ensured that there is no communication between the pre-chamber 120 and the fuel supply cavity 111.

[0033] During use, the pre-chamber 120 communicates with the main combustion chamber 900 in the internal combustion engine through the injection holes 121. When the valve stem 210 reciprocates in the valve stem hole 110, during the process of the valve stem 210 moving away from the pre-chamber 120 along the valve stem hole 110, first, the valve disc 222 closes the valve stem hole 110, and the fuel temporary storage space 230 and the inner peripheral wall of the valve stem hole 110 jointly enclose the fuel temporary storage chamber 240. Then, the fuel supply chamber 111 is opened, so that the fuel temporary storage chamber 240 communicates with the fuel supply chamber 111. At this time, the gaseous fuel with a low auto-ignition temperature enters the fuel temporary storage chamber 240 through the fuel supply chamber 111; when the valve stem 210 moves towards the pre-chamber 120 along the valve stem hole 110, first, the fuel supply chamber 111 is closed, so that the fuel temporary storage chamber 240 is separated from the fuel supply chamber 111. Then, the valve disc 222 opens the valve stem hole 110, and the fuel temporary storage space 230 communicates with the pre-chamber 120. The high-temperature and high-pressure mixed gas in the pre-chamber 120 enters the fuel temporary storage space 230 under the action of pressure, causing partial auto-ignition of the gaseous fuel with a low auto-ignition temperature in the fuel temporary storage space 230. Along with the continuous rapid downward movement of the valve stem 210 and the closing valve 220, the mixed gas in the fuel temporary storage space 230 is completely pushed into the pre-chamber 120. The gaseous fuel with a low auto-ignition temperature continues to mix and auto-ignite with the high-temperature mixed gas in the pre-chamber 120, thereby igniting all the mixed gas in the pre-chamber 120. The combustion of the mixed gas in the pre-chamber 120 further forms a mixed gas with a higher temperature and higher pressure, and the high-temperature and high-pressure mixed gas is sprayed out through the injection holes 121, further igniting the mixed gas in the main combustion chamber 900. The present invention uses the reciprocating movement of the valve stem 210 and the closing valve 220 to introduce the gaseous fuel with a low auto-ignition temperature into the pre-chamber 120 under high pressure in the pre-chamber 120, that is, it can be introduced into the pre-chamber 120 near the compression top dead center of the internal combustion engine. Under the condition of high pressure in the pre-chamber 120, the introduction and auto-ignition of the gaseous fuel with a low auto-ignition temperature can be realized to ignite the pre-chamber 120, avoiding the high-pressure injection requirement and the coking problem of the pre-chamber 120. The pre-chamber 120 of the present invention can introduce the gaseous fuel with a low auto-ignition temperature, and the introduced fuel auto-ignites and ignites the mixed gas in the pre-chamber 120 without the need to set an ignition device in the pre-chamber 120. In addition, the sequential opening and closing of the valve stem 210 and the closing valve 220 can prevent the fuel supply chamber 111 from communicating with the pre-chamber 120 through the fuel temporary storage space 230, thereby preventing the fuel from directly entering the pre-chamber 120 through the fuel temporary storage space 230 and avoiding abnormal ignition of the pre-chamber 120.

[0034] It can be understood that as Figure 1 and Figure 2 shown, when the valve stem 210 is at the top dead center, the lower end surface of the valve stem 210 is higher than the lower edge of the fuel supply chamber 111, and the fuel supply chamber 111 communicates with the fuel temporary storage chamber 240 to ensure that the fuel enters the fuel temporary storage chamber 240 from the fuel supply chamber 111. As Figure 5As shown, when the valve stem 210 is at the bottom dead center, the lower end surface of the valve stem 210 is lower than the lower edge of the fuel supply chamber 111 and is close to extending into the pre-chamber 120, ensuring that the fuel supply chamber 111 is separated from the fuel temporary storage space 230, and the fuel temporary storage space 230 is integrated with the pre-chamber 120. As Figure 2 shown, when the closing valve 220 is at the top dead center, the back surface of the valve disc 222 abuts against the lower edge of the closing valve hole 211, realizing the separation between the fuel temporary storage chamber 240 and the pre-chamber 120; as Figure 5 shown, when the closing valve 220 is not at the top dead center, the back surface of the valve disc 222 is separated from the lower edge of the closing valve hole 211, realizing the communication between the fuel temporary storage chamber 240 and the pre-chamber 120.

[0035] Regarding the force applied by the first actuating mechanism between the valve stem 221 and the valve stem 210, according to the closing form of the valve disc 222 to the valve stem hole 110, in some embodiments, the first actuating mechanism can apply a rigid force. There is an upward first acting step in the valve stem 210, and the valve stem 221 is provided with a downward second acting step. When the valve stem 210 moves upward, the valve stem 221 is driven to move upward by the abutment of the first acting step and the second acting step. At this time, the valve disc 222 is slidably sealed and sleeved in the valve stem hole 110, and the valve stem 221 can also follow the valve stem 210 to move upward, and successively realize the closing of the valve stem hole 110 and the opening of the fuel supply chamber 111.

[0036] In order to reduce the noise and vibration during operation in this embodiment, the first actuating mechanism of this embodiment includes an elastic member, and the elastic member is configured to apply a restoring elastic force to the valve stem 221 in the direction away from the pre-chamber 120. It can be understood that the elastic force applied between the valve stem 221 and the valve stem 210 of the first actuating mechanism. At this time, the back surface of the valve disc 222 abuts against the lower edge of the closing valve hole 211, and the valve stem 210 always gives the closing valve 220 an upward elastic force through the elastic member, prompting the closing valve 220 to move upward to realize the back surface of the valve disc 222 abutting against the lower edge of the closing valve hole 211, and also improving the sealing performance of the closing of the closing valve hole 211.

[0037] Specifically, as Figure 2 and Figure 5As shown in the figure, in this embodiment, an annular limiting step 212 is provided on the inner peripheral wall of the closed valve hole 211, and the annular limiting step 212 is arranged upward. An installation bracket 223 is provided on the outer peripheral wall of the valve stem 221. The elastic member in this embodiment is a spring 250. The upper and lower ends of the spring 250 respectively act between the installation bracket 223 and the annular limiting step 212. The spring 250 is always in a compressed state. The compressed spring 250 pulls the closed valve 220 to maintain an upward movement trend. When the closed valve 220 moves upward to the top dead center, the back surface of the valve disc 222 abuts against the lower edge of the closed valve hole 211, and the fuel temporary storage space 230 is separated from the pre-chamber 120. When the closed valve 220 is below the top dead center, the back surface of the valve disc 222 is separated from the lower edge of the closed valve hole 211, and the fuel temporary storage space 230 is communicated with the pre-chamber 120.

[0038] Regarding the force applied by the second actuating mechanism between the valve stem 221 and the valve rod 210, in some embodiments, the second actuating mechanism can apply a rigid force. The upper end of the closed valve hole 211 directly abuts against the upper end of the valve stem 221, or two acting steps are provided to abut against each other. At this time, the valve disc 222 is slidably and sealingly sleeved in the valve rod hole 110 to close the valve rod hole 110. When the valve rod 210 moves downward, it directly drives the valve stem 221 to move downward, realizing that the valve stem 221 follows the valve rod 210 to move downward, and sequentially realizing the closing of the fuel supply chamber 111 and the opening of the valve rod hole 110.

[0039] In order to reduce the noise and vibration during operation in this embodiment, the transmission of the force is realized through hydraulic oil. Specifically, as Figure 2 and Figure 5 As shown in the figure, the upper end of the closed valve hole 211 in this embodiment is closed, and a first groove 213 is provided on the inner peripheral wall of the middle part of the closed valve hole 211. The above-mentioned installation bracket 223 is slidably arranged in the first groove 213, and the annular limiting step 212 is directly set as the lower edge of the first groove 213 to make the structure compact.

[0040] As Figure 2 and Figure 5As shown in the figure, the second actuating mechanism of this embodiment includes a valve stem high-pressure oil cavity 260 disposed between the upper end surface of the valve stem 221 and the end portion closing the valve hole 211, a valve stem low-pressure oil cavity 270 disposed between the outer peripheral wall of the valve stem 221 and the first groove 213, and an oil drain groove 224 provided at the upper end of the valve stem 221. The oil drain groove 224 is provided with an oil inlet groove opening 2241 and an oil outlet groove opening 2242. The oil inlet groove opening 2241 is provided on the upper end surface of the valve stem 221 and communicates with the valve stem high-pressure oil cavity 260, while the oil outlet groove opening 2242 is provided on the outer peripheral wall of the valve stem 221 and close to the end surface of the valve stem 221. The oil outlet groove opening 2242 is configured to move with the valve stem 221 to connect or disconnect the valve stem high-pressure oil cavity 260 and the valve stem low-pressure oil cavity 270. When the oil outlet groove opening 2242 is lower than the upper edge of the valve stem low-pressure oil cavity 270, the valve stem high-pressure oil cavity 260 is connected to the valve stem low-pressure oil cavity 270; when the oil outlet groove opening 2242 is higher than the upper edge of the valve stem low-pressure oil cavity 270, the valve stem high-pressure oil cavity 260 is disconnected from the valve stem low-pressure oil cavity 270.

[0041] The valve stem high-pressure oil cavity 260 of this embodiment is connected with a valve stem oil inlet passage 261 to introduce hydraulic oil into the valve stem high-pressure oil cavity 260. The valve stem low-pressure oil cavity 270 is connected with a valve stem low-pressure oil passage 271. During normal use, the externally supplied hydraulic oil flows unidirectionally along the valve stem oil inlet passage 261, the valve stem high-pressure oil cavity 260, the oil drain groove 224, the valve stem low-pressure oil cavity 270, and the valve stem low-pressure oil passage 271 in sequence.

[0042] In the initial stage when the valve stem 210 descends from the top dead center, the closing valve 220 is under the elastic force of the spring 250, and the back surface of the valve disk 222 abuts against the lower edge of the hole. This remains the case even when the degree of compression of the spring 250 is reduced. During this period, the volume of the valve stem high-pressure oil cavity 260 decreases. When the pressure in the valve stem high-pressure oil cavity 260 is greater than the elastic force of the spring 250, the closing valve 220 begins to descend, and the back surface of the valve disk 222 separates from the lower edge of the closing valve hole 211.

[0043] Among them, as Figures 2 to 5As shown in the figure, when the valve stem 210 descends a certain distance from the top dead center until the lower end surface of the valve stem 210 is lower than the lower edge of the fuel supply chamber 111, the closing valve 220 remains stationary and the valve disc 222 abuts against the lower edge of the closing valve hole 211. On the one hand, the volume change of the fuel temporary storage chamber 240 is realized, and on the other hand, the communication between the fuel temporary storage chamber 240 and the fuel supply chamber 111 changes from connection to disconnection. After that, the valve stem 210 continues to descend, and at the same time drives the closing valve 220 to descend. The back of the valve disc 222 of the closing valve 220 disengages from the lower edge of the closing valve hole 211. The volume of the fuel temporary storage chamber 240 no longer changes and is communicated with the pre-chamber 120. Finally, the valve stem 210 and the closing valve 220 reach their respective bottom dead centers at the same time, and the fuel temporary storage space 230 is completely integrated with the pre-chamber 120; during the whole process, it is required that the fuel supply chamber 111 cannot be connected to the pre-chamber 120 through the fuel temporary storage space 230. To achieve the above process, it is required that when the valve stem 210 descends the upper half from the top dead center, the pressure in the high-pressure oil chamber 260 of the valve stem cannot be established. However, during this stage, the volume of the high-pressure oil chamber 260 of the valve stem continues to decrease. Therefore, an oil drain groove 224 that is continuously communicated with the high-pressure oil chamber 260 of the valve stem should be provided at the top of the valve stem 221, and the lower edge of the oil drain groove 224 should be lower than the upper edge of the low-pressure oil chamber 270 of the valve stem during this stage to ensure that the high-pressure oil chamber 260 of the valve stem is communicated with the low-pressure oil chamber 270 of the valve stem; when the lower end surface of the valve stem 210 is lower than the lower edge of the fuel supply chamber 111, the lower edge of the oil drain groove 224 should be higher than the upper edge of the low-pressure oil chamber 270 of the valve stem, and the high-pressure oil chamber 260 of the valve stem is separated from the low-pressure oil chamber 270 of the valve stem. The pressure in the high-pressure oil chamber 260 of the valve stem is quickly established, and the pressure of the hydraulic oil exceeds the elastic force of the spring 250. The closing valve 220 and the valve stem 210 are no longer independent of each other, and the two almost remain fixed and move downward together towards their respective bottom dead centers.

[0044] As Figure 1 , Figure 2 and Figure 5 shown, on the inner peripheral wall of the valve stem hole 110 of this embodiment, a second groove 112 and a third groove 113 are arranged at intervals along the axial direction. A body oil inlet chamber 140 is formed between the outer peripheral wall of the valve stem 210 and the second groove 112, and a body oil return chamber 150 is formed between the outer peripheral wall of the valve stem 210 and the third groove 113. The pre-chamber body 100 is provided with a body oil inlet passage 141 communicated with the body oil inlet chamber 140 and a body oil return passage 151 communicated with the body oil return chamber 150. The body oil inlet chamber 140 is communicated with the valve stem oil inlet passage 261, and the valve stem low-pressure oil passage 271 is communicated with the body oil return chamber 150.

[0045] Moreover, the valve stem oil inlet passage 261 is provided with an oil inlet check valve 2611, which only allows the hydraulic oil to enter the high-pressure oil chamber 260 of the valve stem from the body oil inlet chamber 140, preventing leakage through the valve stem oil inlet passage 261 and unable to establish a high pressure.

[0046] The first groove 213, the second groove 112, and the third groove 113 of this embodiment are all annular groove structures for convenient assembly.

[0047] As Figure 1 shown, the pre-chamber body 100 of this embodiment is also provided with an oil inlet 142 communicating with the body oil inlet passage 141 and an oil return port 152 communicating with the body oil return passage 151. The oil inlet 142 is used to introduce external hydraulic oil into the body oil inlet chamber 140, and the oil return port 152 is used to lead out the excess hydraulic oil in the body oil return chamber 150 to the outside. The hydraulic oil flows unidirectionally along the oil inlet 142, the body oil inlet passage 141, the body oil inlet chamber 140, the valve stem oil inlet passage 261, the valve stem high-pressure oil chamber 260, the oil drain groove 224, the valve stem low-pressure oil chamber 270, the valve stem low-pressure oil passage 271, the body oil return chamber 150, the body oil return passage 151, and the oil return port 152.

[0048] Moreover, the hydraulic oil in the valve stem low-pressure oil chamber 270 directly contacts the valve stem 221 of the closing valve 220, the valve stem 210, and the spring 250, enabling forced cooling thereof.

[0049] The present invention realizes the linkage between the valve stem 210 and the closing valve 220 through hydraulic oil and the spring 250, achieving a change in the volume of the fuel temporary storage chamber 240. When the fuel temporary storage chamber 240 gradually communicates with the fuel supply chamber 111, the volume of the fuel temporary storage chamber 240 increases and the internal pressure decreases, facilitating the entry of the fuel in the fuel supply chamber 111 into the fuel temporary storage chamber 240.

[0050] Furthermore, the fuel supply passage 130 is provided with a fuel check valve 132. The flow direction of the fuel check valve 132 is from the fuel supply passage 130 to the fuel supply chamber 111, and only allows fuel to flow into the fuel supply chamber 111 through the fuel check valve 132.

[0051] On the back of the valve disc 222 of this embodiment, a flow guiding mechanism 225 is provided. After the closing valve 220 starts to move downward from the top dead center, the fuel temporary storage space 230 communicates with the pre-chamber 120. The high-temperature mixed gas in the pre-chamber 120 quickly enters the fuel temporary storage space 230 through the gap between the valve disc 222 of the closing valve 220 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 230 to form a certain flow pattern, and the incoming mixed gas contains oxygen. The mixing process with the fuel in the fuel temporary storage space 230 can promote the spontaneous combustion of the fuel.

[0052] The flow guiding mechanism 225 can promote the formation of a vortex around the axis of the closing valve 220 in the fuel temporary storage space 230, or can also form 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 230.

[0053] The inside of the closed valve 220 in this embodiment is filled with a phase change material to enhance the heat transfer between the valve disc 222 and the valve stem 221. Since the upper surface of the valve disc 222 of the closed valve 220 is heated by the high-temperature mixed gas in the fuel storage cavity 240, and the lower surface is heated by the high-temperature combustion gas in the pre-chamber 120, its heat load is relatively large. Filling the inside with a phase change material can transfer the heat of the valve disc 222 through the phase change process of the phase change material, similar to the sodium filling technology in the exhaust valve 700 of an internal combustion engine.

[0054] The reciprocating movement of the valve stem 210 can be realized by known cam mechanisms, hydraulic mechanisms, and electromagnetic drive mechanisms.

[0055] 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. The fuel in the fuel storage space 230 can directly ignite the main combustion chamber 900, 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 storage space 230 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 combustion gas inside, and then is injected into the main combustion chamber 900 through the injection holes 121 to ignite the main combustion chamber 900. The pre-chamber 120 can achieve more than four jets by using more than four injection holes 121, realizing multi-source ignition, improving the ignition effect and accelerating the combustion process.

[0056] As Figure 6 and Figure 7 As shown, the present invention also proposes an internal combustion engine, which includes the above-mentioned stable self-ignition ignition pre-chamber system, and also includes a cylinder block 300 and a cylinder head 400 covering the top of the cylinder block 300. At least one cylinder is formed between the cylinder block 300 and the cylinder head 400. The number of the stable self-ignition ignition pre-chamber systems corresponds to the cylinders one by one. The cylinder is provided with a piston 500, an intake valve 600, an exhaust valve 700, and a fuel injector 800, and the jointly defined space is the main combustion chamber 900.

[0057] Specifically, the internal combustion engine in this embodiment is a reciprocating piston internal combustion engine, and its structure and form are the same as those of the existing conventional internal combustion engines not described herein. The cylinder head 400 is provided with an intake passage and an exhaust passage. A stepped pre-chamber hole is directly machined at the position corresponding to the central axis of each cylinder on the cylinder head 400. The pre-chamber hole penetrates the entire cylinder head 400 from top to bottom. The pre-chamber body 100 is installed in the pre-chamber hole, which is convenient for 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 400. The injection holes 121 communicate the pre-chamber 120 and the main combustion chamber 900.

[0058] The present invention also provides an operating method applicable to the above internal combustion engine. The internal combustion engine in this embodiment operates according to the operating mode of a conventional four-stroke internal combustion engine not described herein and outputs power, such as Figure 9 shown, a schematic diagram of the movements of the piston 500, valve stem 210, and closing valve 220 under an internal combustion engine cycle is listed to intuitively explain the working principle of the internal combustion engine and the stable self-ignition pre-chamber system, such as Figure 8 shown, the operating method of this embodiment includes: Step S100: In the early stage of the intake stroke and compression stroke of the internal combustion engine, both the valve stem 210 and the closing valve 220 are at the top dead center. The fuel temporary storage cavity 240 is separated from the pre-chamber 120, and the fuel temporary storage cavity 240 is communicated with the fuel supply cavity 111. The gaseous fuel with a low self-ignition temperature enters the fuel temporary storage cavity 240 through the fuel supply cavity 111. Step S200: In the later stage of the compression stroke of the internal combustion engine and when the piston 500 moves upward near the top dead center, the valve assembly 200 moves downward in the direction of the pre-chamber 120. The valve stem 210 first separates the fuel temporary storage cavity 240 from the fuel supply cavity 111, and then continues to move to drive the valve disc 222 to open the valve stem hole 110, so that the fuel temporary storage space 230 is communicated with the pre-chamber 120. The mixture in the pre-chamber 120 flows into the fuel temporary storage space 230. Part of the gaseous fuel with a low self-ignition temperature in the fuel temporary storage space 230 undergoes self-ignition, and further moves downward to completely push the mixture in the fuel temporary storage space 230 into the pre-chamber 120, igniting all the mixture in the pre-chamber 120 to form a high-temperature and high-pressure mixture. The high-temperature and high-pressure mixture is sprayed into the main combustion chamber 900 through the injection hole 121 to ignite the mixture in the main combustion chamber 900. Step S300: In the early stage of the power stroke and exhaust stroke of the internal combustion engine, the valve stem 210 and the closing valve 220 remain at the bottom dead center. Step S400: In the later stage of the exhaust stroke of the internal combustion engine, the valve assembly 200 moves upward in the direction away from the pre-chamber 120. First, the valve disc 222 closes the valve stem hole 110 to enclose the fuel temporary storage cavity 240, and then the valve stem 210 continues to move to open the communication between the fuel supply cavity 111 and the fuel temporary storage cavity 240. The gaseous fuel with a low self-ignition temperature enters the fuel temporary storage cavity 240 through the fuel supply cavity 111.

[0059] Specifically, such as Figure 9As shown, during the compression stroke of the internal combustion engine, the crankshaft connecting rod drives the piston 500 to move upward. The piston 500 compresses the mixture in the main combustion chamber 900, and the pressure and temperature of the mixture increase. Since the injection hole 121 connects the main combustion chamber 900 and the pre-combustion chamber 120, the high-temperature and high-pressure mixture in the main combustion chamber 900 enters the pre-combustion chamber 120. During most of the compression stroke, the valve stem 210 is at the top dead center, and the lower end surface of the valve stem 210 is higher than the lower edge of the fuel supply chamber 111, so that the fuel supply chamber 111 is communicated with the fuel temporary storage chamber 240; the fuel from the external fuel supply system enters the fuel temporary storage chamber 240 through the fuel supply port 131, the fuel supply passage 130, the fuel check valve 132, and the fuel supply chamber 111; the elastic force of the spring 250 makes the closing valve 220 also at the top dead center, and the back surface of the valve disc 222 keeps contacting with the lower edge of the valve stem hole 110, so that the fuel temporary storage chamber 240 is separated from the pre-combustion chamber 120; the oil outlet groove opening 2242 of the oil drainage groove 224 at the top of the valve stem 221 of the closing valve 220 is lower than the upper edge of the valve stem low-pressure oil chamber 270, and the valve stem high-pressure oil chamber 260 and the valve stem low-pressure oil chamber 270 are communicated. The hydraulic oil flows out through the oil inlet 142, the body oil inlet passage 141, the body oil inlet chamber 140, the valve stem oil inlet passage 261, the oil inlet check valve 2611, the valve stem high-pressure oil chamber 260, the oil drainage groove 224, the valve stem low-pressure oil chamber 270, the valve stem low-pressure oil passage 271, the body oil return chamber 150, the body oil return passage 151, and the oil return port 152.

[0060] Near the top dead center in the late stage of the compression stroke, the valve stem 210 first starts to move downward, and the degree of compression of the spring 250 decreases, but the elastic force still keeps the back surface of the valve disc 222 of the closing valve 220 in contact with the lower edge of the valve stem hole 110; during the downward movement of the valve stem 210, the fuel supply chamber 111 and the fuel temporary storage chamber 240 are gradually separated, the volume of the fuel temporary storage chamber 240 decreases, and the internal fuel is compressed but does not ignite; during the downward movement of the valve stem 210, the high-pressure oil chamber 260 and the low-pressure oil chamber 270 of the valve stem are also gradually separated, the volume of the high-pressure oil chamber 260 of the valve stem decreases, and the internal hydraulic oil is squeezed into the low-pressure oil chamber 270 of the valve stem through the oil drain groove 224; when the lower end surface of the valve stem 210 is lower than the lower edge of the fuel supply chamber 111 and the oil outlet 2242 of the oil drain groove 224 is higher than the upper edge of the low-pressure oil chamber 270 of the valve stem, the fuel supply chamber 111 and the fuel temporary storage chamber 240 are separated, and the high-pressure oil chamber 260 and the low-pressure oil chamber 270 of the valve stem are also separated, the hydraulic oil pressure in the high-pressure oil chamber 260 of the valve stem rises, and the pressure applied to the top of the valve stem 221 of the valve stem 210 overcomes the elastic force of the spring 250 to promote the closing valve 220 and the valve stem 210 to move downward together, and the fuel temporary storage space 230 and the pre-chamber 120 are gradually connected; the mixture in the pre-chamber 120 flows into the fuel temporary storage space 230 through the gap between the valve disc 222 and the lower edge of the valve stem hole 110 under the action of pressure, and during this period, the flow guiding mechanism 225 guides the fluid; the high-temperature and high-pressure mixture entering the fuel temporary storage space 230 contains a large amount of air, and part of the gaseous fuel in the fuel temporary storage space 230 spontaneously ignites under the action of the high-temperature air; as the valve stem 210 and the closing valve 220 continue to move downward, the mixture in the fuel temporary storage space 230 is completely pushed into the pre-chamber 120, and the self-ignited fuel continues to mix with the high-temperature mixture in the pre-chamber 120 and self-ignites, thereby igniting all the mixture in the pre-chamber 120; the mixture combustion in the pre-chamber 120 further forms a mixture with higher temperature and pressure, and the high-temperature and high-pressure mixture is sprayed into the main combustion chamber 900 through the injection hole 121 to further ignite the mixture in the main combustion chamber 900.

[0061] In the power stroke of the internal combustion engine, the crankshaft connecting rod drives the piston 500 to continue to move downward; after the jet flow from the injection hole 121 of the pre-chamber 120 ignites the mixture in the main combustion chamber 900, the flame in the main combustion chamber 900 gradually spreads to the surrounding by means of propagation, the pressure and temperature of the mixture in the main combustion chamber 900 both rise, push the piston 500 to move towards the bottom dead center and output work externally; in the initial stage, after the valve stem 210 and the closing valve 220 reach the bottom dead center, they continue to remain, the fuel temporary storage space 230 merges into the pre-chamber 120, and the internal mixture continues to burn to form exhaust gas.

[0062] During the exhaust stroke of the internal combustion engine, the piston 500 moves from the bottom dead center to the top dead center, pushing the exhaust gas after combustion in the main combustion chamber 900 out through the exhaust passage; in the early stage of the exhaust stroke, the valve stem 210 and the closing valve 220 remain at the bottom dead center, the fuel temporary storage space 230 merges into the pre-combustion chamber 120, and the exhaust gas in the pre-combustion chamber 120 flows into the main combustion chamber 900 through the injection holes 121, accompanied by a pressure drop; in the later stage of the exhaust stroke, the valve stem 210 and the closing valve 220 start to move upward, and the fuel temporary storage space 230 is gradually separated from the pre-combustion chamber 120; when the back of the valve disk 222 of the closing valve 220 abuts against the lower edge of the valve stem hole 110, the closing valve 220 reaches its top dead center; the valve stem 210 continues to move upward, the volumes of the fuel temporary storage cavity 240 and the valve stem high-pressure oil cavity 260 increase, and the internal pressure decreases, and the elastic force of the spring 250 causes the back of the valve disk 222 of the closing valve 220 to continuously abut against the lower edge of the valve stem hole 110; once the lower end surface of the valve stem 210 is higher than the lower edge of the fuel supply chamber 111, the fuel supply chamber 111 communicates with the fuel temporary storage cavity 240, and the fuel from the external fuel supply system enters the fuel temporary storage cavity 240 through the fuel supply port 131, the fuel supply passage 130, the fuel one-way valve 132, and the fuel supply chamber 111; once the oil outlet groove opening 2242 of the oil drain groove 224 is lower than the upper edge of the valve stem low-pressure oil cavity 270, the valve stem high-pressure oil cavity 260 and the valve stem low-pressure oil cavity 270 communicate, and the hydraulic oil flows out through the oil inlet 142, the body oil inlet passage 141, the body oil inlet cavity 140, the valve stem oil inlet passage 261, the oil inlet one-way valve 2611, the valve stem high-pressure oil cavity 260, the oil drain groove 224, the valve stem low-pressure oil cavity 270, the valve stem low-pressure oil passage 271, the body oil return cavity 150, the body oil return passage 151, and the oil return port 152.

[0063] During the intake stroke of the internal combustion engine, the piston 500 moves from the top dead center to the bottom dead center, sucking the air in the intake passage into the main combustion chamber 900; in the early stage of the intake stroke, after the valve stem 210 and the closing valve 220 reach the top dead center, they continue to remain, the fuel supply chamber 111 is continuously communicated with the fuel temporary storage cavity 240, and the fuel from the external fuel supply system enters the fuel temporary storage cavity 240 through the fuel supply port 131, the fuel supply passage 130, the fuel one-way valve 132, and the fuel supply chamber 111 until the pressure in the fuel temporary storage cavity 240 is the same as the pressure at the fuel supply port 131 and the fuel one-way valve 132 closes the fuel flow; in the later stage of the intake stroke, the valve stem 210 and the closing valve 220 remain at the top dead center.

[0064] After that, the internal combustion engine re-enters the compression stroke, the internal combustion engine completes a full cycle, and the valve stem 210 and the closing valve 220 complete a full reciprocating motion.

[0065] The pre-chamber 120 of the present invention can introduce gaseous fuel with a low auto-ignition temperature. The introduced fuel undergoes auto-ignition and ignites the mixture in the pre-chamber 120, eliminating the need for an ignition device in the pre-chamber 120. The gaseous fuel with a low auto-ignition temperature only ignites the mixture in the pre-chamber 120, and the mixture in the main combustion chamber 900 is ignited by the jet flame from the pre-chamber 120. Therefore, the demand for the fuel with a low auto-ignition temperature is very small. At the top dead center of the internal combustion engine compression, the gaseous fuel with a low auto-ignition temperature can be introduced and auto-ignited in the pre-chamber 120 under high pressure, avoiding the need for high-pressure injection and the problem of coking in the pre-chamber 120. The sequential opening and closing of the valve stem 210 and the closing valve 220 can ensure that the fuel supply chamber 111 remains connected to the pre-chamber 120 without passing through the fuel temporary storage space 230, thereby preventing the fuel from directly entering the pre-chamber 120 through the fuel temporary storage space 230 and avoiding abnormal ignition in the pre-chamber 120.

[0066] 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0067] 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. Within the scope of knowledge possessed by those of ordinary skill in the relevant art, various changes can be made without departing from the purpose of the present invention.

Claims

1. A stable self-ignition pre-chamber ignition system, characterized in that, Comprising: A pre-chamber body, provided with a valve stem hole and a pre-chamber. One end of the valve stem hole communicates with the pre-chamber. At least one injection hole is provided on the side wall of the pre-chamber. A fuel supply chamber is provided on the inner peripheral wall of the valve stem hole; A valve assembly, including a valve stem, a closing valve, a first actuating mechanism and a second actuating mechanism. The valve stem is slidably and sealingly sleeved in the valve stem hole along the axial direction to close and open the fuel supply chamber. One end of the valve stem close to the pre-chamber is provided with a closing valve hole extending axially. The closing valve includes a valve stem and a valve disc connected in sequence. One end of the valve stem away from the valve disc is slidably and sealingly sleeved in the closing valve hole along the axial direction. The first actuating mechanism is configured to apply a force in the direction away from the pre-chamber between the valve stem and the valve stem. The second actuating mechanism is configured to apply a force in the direction towards the pre-chamber between the valve stem and the valve stem. The outer edge of the valve disc is in sealing contact with the end of the valve stem hole on the pre-chamber side. The outer peripheral wall of the valve stem, the end face of the valve stem and the back of the valve disc together enclose an inwardly recessed fuel temporary storage space; The valve assembly is configured to, during the movement along the valve stem hole in the direction away from the pre-chamber, first make the valve disc close the valve stem hole. The fuel temporary storage space and the inner peripheral wall of the valve stem hole together enclose a fuel temporary storage chamber. Then continue to move to drive the valve stem to open the fuel supply chamber, so that the fuel temporary storage chamber communicates with the fuel supply chamber; The valve assembly is further configured to, during the movement along the valve stem hole in the direction towards the pre-chamber, first make the valve stem close the fuel supply chamber, cut off the communication between the fuel temporary storage chamber and the fuel supply chamber. Then continue to move to drive the valve disc to open the valve stem hole, so that the fuel temporary storage space communicates with the pre-chamber.

2. The stable self-ignition ignition pre-chamber system according to claim 1, characterized in that: The first actuating mechanism includes an elastic member, and the elastic member is configured to provide a reset elastic force in the direction away from the pre-chamber to the valve stem.

3. The stable self-ignition ignition pre-chamber system according to claim 2, characterized in that: An annular limiting step is provided on the inner peripheral wall of the closing valve hole. An installation bracket is provided on the outer peripheral wall of the valve stem. The elastic member is compressively arranged between the installation bracket and the annular limiting step.

4. The stable self-ignition ignition pre-chamber system according to claim 2, characterized in that: One end of the closed valve hole away from the pre-combustion chamber is closed. A first groove is provided on the inner peripheral wall of the middle part of the closed valve hole. The second actuating mechanism includes a valve stem high-pressure oil chamber provided between the end face of the valve stem away from the valve disc and the end of the closed valve hole, a valve stem low-pressure oil chamber provided between the outer peripheral wall of the valve stem and the first groove, and an oil drain groove provided at one end of the valve stem away from the valve disc. The oil drain groove is provided with an oil inlet groove opening and an oil outlet groove opening. The oil inlet groove opening is provided on the end face of the valve stem and communicates with the valve stem high-pressure oil chamber. The oil outlet groove opening is provided on the outer peripheral wall of the valve stem and is close to the end face of the valve stem. The oil outlet groove opening is configured to move with the valve stem to connect or disconnect the valve stem high-pressure oil chamber and the valve stem low-pressure oil chamber. The valve stem high-pressure oil chamber is connected with a valve stem oil inlet passage, and the valve stem low-pressure oil chamber is connected with a valve stem low-pressure oil passage.

5. The stable self-ignition ignition pre-combustion chamber system according to claim 4, characterized in that: Second grooves and third grooves are provided at intervals along the axial direction on the inner peripheral wall of the valve stem hole. A body oil inlet chamber is formed between the outer peripheral wall of the valve stem and the second groove, and a body oil return chamber is formed between the outer peripheral wall of the valve stem and the third groove. The pre-combustion chamber body is provided with a body oil inlet passage communicating with the body oil inlet chamber and a body oil return passage communicating with the body oil return chamber. The body oil inlet chamber communicates with the valve stem oil inlet passage, and the valve stem low-pressure oil passage communicates with the body oil return chamber.

6. The stable self-ignition ignition pre-combustion chamber system according to claim 4, characterized in that: An oil inlet check valve is provided in the valve stem oil inlet passage, and the flow direction of the oil inlet check valve is from the valve stem oil inlet passage to the valve stem high-pressure oil chamber.

7. The stable self-ignition ignition pre-combustion chamber system according to claim 1, characterized in that: The pre-combustion chamber body is provided with a fuel supply passage communicating with the fuel supply chamber. The fuel supply passage is provided with a fuel check valve, and the flow direction of the fuel check valve is from the fuel supply passage to the fuel supply chamber.

8. The stable self-ignition ignition pre-combustion chamber system according to claim 1, characterized in that: A flow guiding mechanism is provided on the back surface of the valve disc, and the closed valve is filled with a phase change material.

9. An internal combustion engine, characterized in that: It includes the stable self-ignition ignition pre-combustion chamber system according to any one of claims 1 to 8. At least one stable self-ignition ignition pre-combustion chamber system is provided. It 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 a main combustion chamber. The injection hole communicates with the main combustion chamber.

10. A running method, characterized in that: Applicable to the internal combustion engine according to claim 9, the operation method includes: In the early stage of the intake stroke and the compression stroke of the internal combustion engine, the valve stem and the closed valve are both at the top dead center. The fuel temporary storage chamber is separated from the pre-combustion chamber, and the fuel temporary storage chamber communicates with the fuel supply chamber. The gaseous low self-ignition temperature fuel enters the fuel temporary storage chamber through the fuel supply chamber. In the later stage of the compression stroke of the internal combustion engine and when the piston moves upward near the top dead center, the valve assembly moves downward in the direction towards the pre-chamber. First, the valve stem cuts off the fuel temporary storage cavity from the fuel supply cavity, and then continues to move to drive the valve disc to open the valve stem hole, so that the fuel temporary storage space communicates with the pre-chamber. The mixed gas in the pre-chamber flows into the fuel temporary storage space, and part of the gaseous fuel with a low auto-ignition temperature in the fuel temporary storage space undergoes auto-ignition. Further downward movement completely pushes the mixed gas in the fuel temporary storage space into the pre-chamber, igniting all the mixed gas in the pre-chamber to form a mixed gas with high temperature and high pressure. The mixed gas with high temperature and high pressure is injected into the main combustion chamber through the injection hole, igniting the mixed gas in the main combustion chamber; In the early stage of the power stroke and the exhaust stroke of the internal combustion engine, the valve stem and the closing valve remain at the bottom dead center; In the later stage of the exhaust stroke of the internal combustion engine, the valve assembly moves upward in the direction away from the pre-chamber. First, the valve disc closes the valve stem hole to enclose the fuel temporary storage cavity, and then the valve stem continues to move to open the connection between the fuel supply cavity and the fuel temporary storage cavity, so that the fuel temporary storage cavity communicates with the fuel supply cavity, and the gaseous fuel with a low auto-ignition temperature enters the fuel temporary storage cavity through the fuel supply cavity.

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