A compression ignition pre-combustion ignition system and its operation method

Abstract

This invention discloses a compression ignition pre-combustion ignition system and its operating method, comprising an internal combustion engine, a compression ignition pre-combustion injection device, and a hydraulic drive device. The hydraulic drive device uses a compression ignition drive cam to drive a compression ignition drive plunger to compress hydraulic oil. The incompressibility of the hydraulic oil drives the compression ignition plunger to compress the air-fuel mixture in the compression ignition pre-combustion chamber. The relationship between the axial cross-sections of the compression ignition plunger's high-pressure oil chamber and the compression ignition drive high-pressure oil chamber is rationally designed to increase the plunger's stroke, thereby achieving a high compression ratio in the compression ignition pre-combustion chamber. This invention also uses an injection drive cam of the hydraulic drive device to drive an injection drive plunger to compress hydraulic oil, thereby connecting or disconnecting the injection valve between the compression ignition pre-combustion chamber and the main combustion chamber. The hydraulic drive camshaft is driven to rotate by the piston crankshaft or valve camshaft in the internal combustion engine. The timing of the injection drive plunger reaching top dead center is variable, achieving accurate and controllable injection ignition of the main combustion chamber from the compression ignition pre-combustion chamber.

Description

Technical Field

[0001] This invention relates to the technical field of internal combustion engines, and particularly to a compression ignition pre-combustion ignition system and its operating method. Background Technology

[0002] The key to pre-combustion chamber combustion technology is forming a stable air-fuel mixture within the pre-combustion chamber that can be ignited by a conventional spark plug. To achieve this, a fuel injection device is typically used to inject a portion of highly reactive fuel into the pre-combustion chamber, creating a mixture easily ignited by a spark plug. For example, patent number ZL2024102185650 discloses a homogeneous charge compression ignition (CCAC) pre-combustion chamber structure, internal combustion engine, and operating method. However, current pre-combustion chamber combustion technology suffers from the following drawbacks: the opening and closing of the pre-combustion valve is controlled by the pressure of the air-fuel mixture and the spring force. The spring stiffness and preload determine a fixed valve opening pressure difference, making it impossible to achieve reasonable opening under different operating conditions of the internal combustion engine. This hinders accurate and controllable injection from the compression ignition pre-combustion chamber to ignite the main combustion chamber. Furthermore, existing compression ignition pre-combustion chamber technologies suffer from problems such as uncontrolled pre-combustion timing and difficulty in increasing the pre-combustion chamber compression ratio. Summary of the Invention

[0003] The purpose of this invention is to provide a compression ignition pre-combustion ignition system and its operation method, which enables the compression ignition pre-combustion chamber to achieve a high compression ratio and to achieve accurate and controllable injection ignition of the main combustion chamber from the compression ignition pre-combustion chamber, thereby solving one or more technical problems existing in the prior art and at least providing a beneficial option or creating conditions.

[0004] The technical solution adopted to solve the above-mentioned technical problems is as follows:

[0005] This invention provides a compression ignition pre-combustion ignition system, comprising:

[0006] An internal combustion engine has at least one cylinder, and a piston is provided inside the cylinder with an axially sliding sealing sleeve. The piston and the internal space of the cylinder form the main combustion chamber.

[0007] A compression ignition pre-combustion injection device is provided, comprising at least one device body, a compression ignition plunger, a compression ignition plunger spring, an injection plunger, an injection plunger spring, and an injection valve. The compression ignition pre-combustion injection device body has a compression ignition plunger cavity, an injection plunger cavity, an air inlet, and an injection hole. The compression ignition plunger is axially slidably and sealingly fitted within the compression ignition plunger cavity. The two end faces of the compression ignition plunger respectively form a high-pressure oil chamber and a compression ignition pre-combustion chamber with the compression ignition plunger cavity. The high-pressure oil chamber of the compression ignition plunger has a high-pressure oil inlet. The compression ignition plunger spring is configured to provide a restoring force for the compression ignition plunger to move toward the high-pressure oil chamber. The inner peripheral wall of the compression ignition plunger cavity has a connection to the air inlet and the compression ignition pre-combustion chamber. The air intake chamber of the chamber has an injection plunger that is axially slidably sealed within the injection plunger orifice. The two end faces of the injection plunger form a high-pressure oil chamber and an injection chamber with the injection plunger orifice, respectively. The high-pressure oil chamber is provided with a high-pressure oil inlet. The injection plunger spring is configured to provide a restoring force to the injection plunger to move toward the high-pressure oil chamber. The injection orifice is located on the extension line of the axis of the injection plunger. One end of the injection orifice passes through the injection chamber, and the other end of the injection orifice communicates with the main combustion chamber. The injection valve is connected to the end of the injection plunger away from the high-pressure oil chamber. The injection valve is configured to open and close the injection orifice. At least one pre-combustion chamber connection channel connects the injection chamber and the compression ignition pre-combustion chamber.

[0008] A hydraulic drive unit includes a hydraulic drive unit body, a compression ignition drive plunger, an injection drive plunger, a compression ignition drive plunger spring, an injection drive plunger spring, at least one hydraulic drive camshaft, a compression ignition drive cam, and an injection drive cam. The compression ignition drive cam and the injection drive cam are fixedly sleeved on the hydraulic drive camshaft, which is driven to rotate by a piston crankshaft or valve camshaft in an internal combustion engine. The hydraulic drive unit body has a compression ignition drive plunger cavity, an injection drive plunger cavity, a compression ignition drive hydraulic oil outlet, and an injection drive hydraulic oil outlet. The compression ignition drive plunger is axially slidably and sealingly sleeved within the compression ignition drive plunger cavity. One end of the compression ignition drive plunger forms a compression ignition drive high-pressure oil chamber with the compression ignition drive plunger cavity. The other end of the compression ignition drive plunger... One end of the injection drive plunger abuts against the compression ignition drive cam. The compression ignition drive high-pressure oil chamber is provided with a compression ignition drive hydraulic oil outlet, which is connected to the compression ignition plunger high-pressure oil inlet. The compression ignition drive plunger spring is configured to provide a restoring force for the compression ignition drive plunger to move toward the compression ignition drive cam. The injection drive plunger is axially slidably sealed within the injection drive plunger cavity. One end of the injection drive plunger forms the injection drive high-pressure oil chamber with the injection drive plunger cavity. The other end of the injection drive plunger abuts against the injection drive cam. The injection drive high-pressure oil chamber is provided with an injection drive hydraulic oil outlet, which is connected to the injection plunger high-pressure oil chamber. The injection drive plunger spring is configured to provide a restoring force for the injection drive plunger to move toward the injection drive cam.

[0009] The advantages of the compression ignition pre-combustion ignition system of the present invention are:

[0010] The compression ignition pre-combustion ignition system of this invention employs a compression ignition drive cam of a hydraulic drive device to drive a compression ignition drive plunger to compress hydraulic oil. The incompressibility of the hydraulic oil drives the compression ignition plunger to compress the air-fuel mixture in the compression ignition pre-combustion chamber. The relationship between the axial cross-sections of the compression ignition plunger's high-pressure oil chamber and the compression ignition drive high-pressure oil chamber is rationally designed to increase the plunger's stroke, thereby achieving a high compression ratio in the compression ignition pre-combustion chamber. This invention also employs an injection drive cam of a hydraulic drive device to drive an injection drive plunger to compress hydraulic oil. The hydraulic oil drives the injection plunger to reciprocate, thereby connecting or disconnecting the injection valve between the compression ignition pre-combustion chamber and the main combustion chamber. Furthermore, the hydraulic drive camshaft is driven to rotate by the piston crankshaft or valve camshaft in the internal combustion engine, allowing for variable control of the injection drive plunger's timing at top dead center, achieving accurate and controllable injection ignition of the main combustion chamber from the compression ignition pre-combustion chamber.

[0011] As a further improvement to the above technical solution, the axial cross-sectional area of ​​the compression ignition driven high-pressure oil chamber is larger than the axial cross-sectional area of ​​the compression ignition plunger high-pressure oil chamber.

[0012] The axial cross-sectional area of ​​the high-pressure oil chamber driven by the injection is smaller than that of the high-pressure oil chamber of the injection plunger.

[0013] As a further improvement to the above technical solution, the injection valve includes a valve disc and a valve stem connected coaxially. One end of the valve stem is connected to the injection plunger, and the other end of the valve stem is connected to the valve disc. The end face of the valve disc facing the valve stem abuts against the edge of the injection orifice away from the injection chamber.

[0014] The diameter of the injection port at the contact point with the valve disc is equal to the diameter of the small diameter section of the injection plunger;

[0015] The walls of the pre-combustion chamber connecting passage and the injection chamber are coated with heat-insulating material;

[0016] The inside of the injection valve is filled with phase change material.

[0017] As a further improvement to the above technical solution, the transmission ratio between the hydraulically driven camshaft and the piston crankshaft of the internal combustion engine is 1:2, or the transmission ratio between the hydraulically driven camshaft and the valve camshaft of the internal combustion engine is 1:1.

[0018] As a further improvement to the above technical solution, the compression ignition driven high-pressure oil chamber is provided with a compression ignition driven hydraulic oil inlet for supplying hydraulic oil to the compression ignition driven high-pressure oil chamber, and the compression ignition driven hydraulic oil inlet is provided with a first check valve for flow from the outside to the compression ignition driven high-pressure oil chamber.

[0019] The injection-driven high-pressure oil chamber is provided with an injection-driven hydraulic oil inlet for supplying hydraulic oil to the injection-driven high-pressure oil chamber, and the injection-driven hydraulic oil inlet is provided with a second check valve for flow from the outside to the injection-driven high-pressure oil chamber.

[0020] As a further improvement to the above technical solution, the compression ignition driven high-pressure oil chamber is provided with a compression ignition driven hydraulic drain port, and the compression ignition driven hydraulic drain port is provided with a first pressure relief valve.

[0021] The high-pressure oil chamber for injection drive is equipped with an injection drive hydraulic drain port, and the injection drive hydraulic drain port is equipped with a second pressure relief valve.

[0022] As a further improvement to the above technical solution, the main body of the compression ignition pre-combustion injection device is provided with an exhaust port, and the inner peripheral wall of the compression ignition plunger cavity is provided with an exhaust chamber that connects the exhaust port and the compression ignition pre-combustion chamber.

[0023] The exhaust chamber is larger than the intake chamber in the direction of the central axis of the compression ignition plunger cavity.

[0024] As a further improvement to the above technical solution, the compression ignition plunger cavity and the injection plunger cavity are both "T"-shaped stepped orifice structures, each including a large orifice section, a small orifice section, and a stepped surface. The compression ignition plunger and the injection plunger are both "T"-shaped stepped shaft structures, each including a large diameter section, a small diameter section, and a stepped surface. The compression ignition pre-combustion chamber is located in the small orifice section of the compression ignition plunger cavity, and the injection chamber is located in the small orifice section of the injection plunger cavity.

[0025] The low-pressure oil chamber of the compression ignition plunger is formed between the stepped surface of the compression ignition plunger, the stepped surface of the compression ignition plunger cavity, and the sidewall of the large orifice section of the compression ignition plunger cavity.

[0026] The low-pressure oil chamber of the injection plunger is formed between the stepped surface of the injection plunger, the stepped surface of the injection plunger cavity, and the sidewall of the large orifice section of the injection plunger cavity.

[0027] The compression ignition pre-combustion injection device body is provided with a low-pressure oil inlet channel and a low-pressure oil outlet channel. The low-pressure oil inlet channel is connected to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger respectively. The low-pressure oil inlet channel is provided with a low-pressure oil port configured to supply low-pressure oil to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger respectively. The low-pressure oil outlet channel is connected to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger respectively. The low-pressure oil outlet channel is provided with a low-pressure oil port configured to discharge the low-pressure oil in the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger.

[0028] As a further improvement to the above technical solution, a third check valve is provided at the low-pressure inlet, and a throttling device is provided between the low-pressure outlet and the low-pressure oil chamber of the compression ignition plunger.

[0029] Furthermore, this invention also proposes an operating method for use in a compression ignition pre-combustion ignition system, the operating method comprising:

[0030] The internal combustion engine is set to operate at a preset speed, and the hydraulically driven camshaft rotates at half of the preset speed;

[0031] In the early to mid-stage of the compression stroke of an internal combustion engine, the piston moves upward, compressing the air-fuel mixture in the main combustion chamber. The compression ignition drive cam drives the compression ignition drive plunger upward, and incompressible hydraulic oil flows into the high-pressure oil chamber of the compression ignition plunger, pushing the compression ignition plunger downward. The compression ignition plunger compresses the air-fuel mixture in the compression ignition pre-combustion chamber, increasing the pressure and temperature of the mixture. The volume of the low-pressure oil chamber of the compression ignition plunger decreases, and a portion of the hydraulic oil in the low-pressure oil chamber flows directly into the low-pressure oil outlet through the throttling device. Another portion of the hydraulic oil is forced into the low-pressure oil chamber of the injection plunger and flows into the low-pressure oil outlet. At this time, the injection chamber remains disconnected from the main combustion chamber. Initially, the compression ignition plunger connects the intake chamber, the compression ignition pre-combustion chamber, and the exhaust chamber for scavenging and gas exchange. Afterward, the compression ignition plunger isolates the three chambers and seals the compression ignition pre-combustion chamber.

[0032] Near the top dead center (TDC) of the later stage of the compression stroke of the internal combustion engine, the piston continues to move upward and approaches TDC; the compression ignition drive cam drives the compression ignition drive plunger to TDC, and the hydraulic oil drives the compression ignition plunger to bottom dead center; the temperature of the air-fuel mixture in the compression ignition pre-combustion chamber reaches the fuel auto-ignition temperature and achieves homogeneous compression ignition; the injection drive cam drives the injection drive plunger to begin moving upward, incompressible hydraulic oil flows into the high-pressure oil chamber of the injection plunger and pushes the injection plunger downward, the injection valve disengages from the lower edge of the injection orifice, and the injection chamber communicates with the main combustion chamber; the downward movement of the injection plunger forces the hydraulic oil in the low-pressure oil chamber of the injection plunger into the low-pressure oil outlet; the high-temperature, high-pressure air-fuel mixture in the compression ignition pre-combustion chamber is injected into the main combustion chamber, and the high-temperature jet air-fuel mixture ignites the fuel-air mixture in the main combustion chamber;

[0033] In the early stage of the power stroke of the internal combustion engine, the piston continues to descend; the compression ignition drive cam drives the compression ignition drive plunger to remain at top dead center, and the high-pressure hydraulic oil drives the compression ignition plunger to remain at bottom dead center; the injection drive cam drives the injection drive plunger to continue to rise and reach top dead center, and the injection plunger continues to descend under the drive of hydraulic oil and reaches bottom dead center; after the injection drive plunger remains at top dead center for a period of time, the injection drive plunger begins to descend under the drive of the injection drive plunger spring; after the injection plunger remains at bottom dead center for a period of time, the injection drive plunger begins to descend under the drive of the injection drive plunger spring. At this time, the flame in the main combustion chamber gradually spreads to the surroundings through propagation, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to bottom dead center and outputting power.

[0034] During the later stages of the power stroke of an internal combustion engine, the piston continues to descend and reaches bottom dead center; the compression ignition drive plunger spring drives the compression ignition drive plunger to begin descending, and the compression ignition plunger spring also drives the compression ignition plunger to begin ascending; the injection drive plunger continues to descend and reaches bottom dead center under the drive of the injection drive plunger spring, and the injection plunger continues to ascend and reaches top dead center under the drive of the injection plunger spring; the injection plunger drives the injection valve to ascend, causing the injection valve to re-engage with the lower edge of the injection orifice, and the injection chamber and the main combustion chamber are disconnected again; at this time, the flame in the main combustion chamber is transmitted to the entire main combustion chamber through propagation, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to bottom dead center and outputting power; due to the increased volume of the low-pressure oil chambers of the compression ignition plunger and the injection plunger, the hydraulic oil pressure decreases, and external hydraulic oil enters the low-pressure oil chambers of the compression ignition plunger and the injection plunger through the third check valve and the low-pressure oil inlet.

[0035] During the exhaust stroke of an internal combustion engine, the piston moves from bottom dead center to top dead center, expelling the exhaust gas from the main combustion chamber through the exhaust passage. The compression ignition drive plunger spring drives the compression ignition drive plunger to continue downward and reach bottom dead center, and the compression ignition plunger spring drives the compression ignition plunger to continue upward and reach top dead center. Near the top dead center, the compression ignition plunger first connects the exhaust chamber with the compression ignition pre-combustion chamber, and the mixture in the pre-combustion chamber rapidly enters the exhaust chamber under its own pressure to achieve free exhaust. The compression ignition plunger continues to rise until... At top dead center, the intake chamber, the exhaust chamber, and the compression ignition pre-combustion chamber are interconnected. Fresh fuel-air mixture enters the compression ignition pre-combustion chamber through the intake chamber, forcing residual exhaust gas in the compression ignition pre-combustion chamber into the exhaust chamber for continuous scavenging and gas exchange. The injection drive plunger is held at bottom dead center by the injection drive plunger spring and at top dead center by the injection plunger spring. The injection plunger drives the injection valve to contact the lower edge of the injection orifice, disconnecting the injection chamber from the main combustion chamber.

[0036] During the intake stroke of an internal combustion engine, the piston moves from top dead center to bottom dead center, drawing air from the intake manifold into the main combustion chamber. Later in the intake stroke, the compression ignition drive plunger cam drives the compression ignition drive plunger to begin moving upwards, and hydraulic oil enters the high-pressure oil chamber of the compression ignition plunger, pushing it downwards. During the intake stroke, the injection drive plunger is held at bottom dead center by the injection drive plunger spring, and the injection plunger is held at top dead center by the injection plunger spring. The injection plunger causes the injection valve to contact the lower edge of the injection orifice, disconnecting the injection chamber from the main combustion chamber. After the compression ignition plunger descends, the volume of the low-pressure oil chamber of the compression ignition plunger decreases. Part of the hydraulic oil in the low-pressure oil chamber of the compression ignition plunger is forced into the low-pressure oil outlet passage, and the other part of the hydraulic oil is forced into the low-pressure oil chamber of the injection plunger and then enters the low-pressure oil outlet passage. After the compression ignition plunger descends a certain distance, it first disconnects the intake chamber from the compression ignition pre-combustion chamber. As the compression ignition plunger continues to descend, a portion of the fresh mixture in the compression ignition pre-combustion chamber is pushed out through the exhaust chamber. Then, the compression ignition plunger disconnects the exhaust chamber from the compression ignition pre-combustion chamber, sealing the compression ignition pre-combustion chamber. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0038] Figure 1 This is a schematic diagram of an embodiment of the compression ignition pre-combustion ignition system provided by the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the compression ignition pre-combustion injection device provided by the present invention when the compression ignition plunger is at the top dead center in one embodiment.

[0040] Figure 3 This is a schematic diagram of the compression ignition pre-combustion injection device provided by the present invention when the compression ignition plunger is at the bottom dead center in one embodiment.

[0041] Figure 4 This is a schematic diagram of the low-pressure oil circuit of an embodiment of the compression ignition pre-combustion injection device provided by the present invention;

[0042] Figure 5 This is a schematic diagram of the high-pressure oil circuit of an embodiment of the compression ignition pre-combustion injection device provided by the present invention;

[0043] Figure 6 This is a partial lower schematic diagram of an embodiment of the compression ignition pre-combustion injection device provided by the present invention;

[0044] Figure 7 This is a schematic diagram of the hydraulic drive device provided by the present invention, showing the compression ignition drive plunger and the injection drive plunger in one embodiment when they are at the top dead center.

[0045] Figure 8 This is a schematic diagram of the hydraulic drive device provided by the present invention when the compression ignition drive plunger and the injection drive plunger are at the bottom dead center in one embodiment.

[0046] Figure 9 The present invention provides a compression ignition pre-ignition system with an exhaust chamber and an exhaust passage. One embodiment of the system includes a piston, a compression ignition drive plunger, an injection drive plunger, a compression ignition plunger, and an injection plunger.

[0047] Figure 10 This is a schematic diagram of the stroke of the piston, compression ignition drive plunger, injection drive plunger, compression ignition plunger, and injection plunger in one embodiment of the compression ignition pre-ignition system provided by the present invention, which eliminates the exhaust chamber and exhaust passage. Detailed Implementation

[0048] like Figures 1 to 8 As shown, a compression ignition pre-ignition system according to this embodiment includes: an internal combustion engine, at least one compression ignition pre-ignition injection device 200, and a hydraulic drive device 300.

[0049] The internal combustion engine is a reciprocating piston internal combustion engine, and it is a conventional four-stroke internal combustion engine. Its structure and form are consistent with existing conventional internal combustion engines not described in this article, such as... Figure 1 As shown, the internal combustion engine includes components such as cylinder head, cylinder block, piston, fuel injector, intake valve and exhaust valve. Its structure and form are the same as those of existing conventional internal combustion engines not described in this article, wherein the cylinder head is provided with intake and exhaust ports.

[0050] The compression ignition pre-ignition injection device 200 includes a compression ignition pre-ignition injection device body 210, a compression ignition plunger 220, a compression ignition plunger spring 230, an injection plunger 240, an injection plunger spring 250, and an injection valve 260. The cylinder head is also provided with a stepped cylindrical pre-ignition compression ignition injection device body hole, which runs through the entire cylinder head from top to bottom. The shape of the pre-ignition compression ignition injection device body hole matches the compression ignition pre-ignition injection device body 210, which facilitates the installation, disassembly, and maintenance of the pre-ignition compression ignition injection device body.

[0051] The cylinder block is equipped with at least one cylinder, and the number of cylinders corresponds one-to-one with the number of compression ignition pre-ignition injection devices 200. A piston is slidably sealed inside the cylinder along the axis, and the piston and the internal space of the cylinder form the main combustion chamber 100. The compression ignition pre-ignition injection device body 210 is a sleeve-like structure with a stepped shape. The compression ignition pre-ignition injection device body 210 is installed in the compression ignition pre-ignition injection device body hole, and its bottom surface is flush with the bottom plane of the cylinder head.

[0052] The compression ignition pre-combustion injection device 200 includes a compression ignition pre-combustion injection device body 210, a compression ignition plunger 220, a compression ignition plunger spring 230, an injection plunger 240, an injection plunger spring 250, and an injection valve 260.

[0053] The top of the compression ignition pre-ignition injection device body 210 is provided with an air inlet 211, an exhaust port 212, a low-pressure oil inlet 213, a low-pressure oil outlet 214, a compression ignition plunger high-pressure oil inlet 215, and an injection plunger high-pressure oil inlet 216. These are all conventionally known connector-type interfaces that enable fluid flow connection with the outside world. The upper center of the compression ignition pre-ignition injection device body 210 is provided with a compression ignition plunger cavity 217, which is shaped like a "T"-shaped cylindrical stepped hole, including a large hole section, a small hole section, and a stepped surface. Below the compression ignition plunger cavity 217 of the compression ignition pre-ignition injection device body 210 is an injection plunger cavity 218, which is also shaped like a "T"-shaped cylindrical stepped hole, including a large hole section, a small hole section, and a stepped surface.

[0054] The compression ignition plunger 220 has a "T"-shaped cylindrical stepped shaft structure, similar to the plunger shape commonly used in hydraulic transmission systems, including a large-diameter section, a small-diameter section, and a stepped surface. The injection plunger 240 also has a "T"-shaped cylindrical stepped shaft structure, including a large-diameter section, a small-diameter section, and a stepped surface, but its central axis is machined with a through hole.

[0055] The injection valve 260 has a mushroom-shaped valve structure, similar in shape to the intake and exhaust valve structure of an internal combustion engine. The injection valve 260 includes a valve disc 261 and a valve stem 262 connected coaxially. One end of the valve stem 262 is connected to the injection plunger 240, and the other end of the valve stem 262 is connected to the valve disc 261. The end face of the valve disc 261 facing the valve stem 262 abuts against the edge of the injection port 2421 away from the injection chamber 242. The compression ignition plunger spring 230 and the injection plunger spring 250 are common springs, such as cylindrical springs.

[0056] The compression ignition plunger 220 is axially slidably sealed within the compression ignition plunger cavity 217 of the compression ignition pre-combustion injection device body 210. The space enclosed by the large-diameter end face of the compression ignition plunger 220 and the large-hole sidewall and end face of the compression ignition plunger cavity 217 is the high-pressure oil chamber 221 of the compression ignition plunger. The space enclosed by the small-diameter end face of the compression ignition plunger 220 and the small-hole sidewall and end face of the compression ignition plunger cavity 217 is the compression ignition pre-combustion chamber 222. The space enclosed by the stepped surfaces of the compression ignition plunger 220 and the compression ignition plunger cavity 217, as well as the large-hole sidewall of the compression ignition plunger cavity 217, is the low-pressure oil chamber 223 of the compression ignition plunger. The two ends of the compression ignition plunger spring 230 abut against the stepped surfaces of the compression ignition plunger 220 and the compression ignition plunger cavity 217, respectively. During the axial sliding process of the compression ignition plunger 220, the compression ignition plunger spring 230... The compression ignition plunger cavity 217 is compressed; the side wall of the small-diameter section of the compression ignition plunger cavity 217 is provided with an intake chamber 2171 and an exhaust chamber 2172, which are connected through the compression ignition plunger cavity 217; the intake chamber 2171 is connected to the intake port 211 through the intake passage 2173, and the exhaust chamber 2172 is connected to the exhaust port 212 through the exhaust passage 2174; when the compression ignition plunger 220 is at the top dead center, the end face of the small-diameter section of the compression ignition plunger 220 is above the intake chamber 2171 and the exhaust chamber 2172, and the intake chamber 2171 and the exhaust chamber 2172 are connected through the compression ignition plunger cavity 217; when the compression ignition plunger 220 descends a certain distance, the end face of the small-diameter section of the compression ignition plunger 220 is below the intake chamber 2171 and the exhaust chamber 2172, and the intake chamber 2171 and the exhaust chamber 2172 are not connected, and the compression ignition pre-combustion chamber 222 is closed. When the compression ignition plunger 220 is at top dead center, the fresh fuel mixture from the outside enters the compression ignition pre-combustion chamber 222 through the intake port 211, intake passage 2173, and intake chamber 2171. The residual exhaust gas from the previous cycle in the compression ignition pre-combustion chamber 222 is swept out through the exhaust chamber 2172, exhaust passage 2174, and exhaust port 212 by cross-flow scavenging. When the compression ignition plunger 220 descends to the point where its small diameter end face is lower than the intake chamber 2171 and exhaust chamber 2172, the intake chamber 2171, exhaust chamber 2172, and compression ignition pre-combustion chamber 222 are no longer connected, and the scavenging ends. As the compression ignition plunger 220 continues to descend, the mixture in the compression ignition pre-combustion chamber 222 is compressed. Once the compression process reaches the auto-ignition conditions of the mixture, the mixture in the compression ignition pre-combustion chamber 222 burns rapidly to obtain a high-temperature and high-pressure mixture.

[0057] The high-pressure oil chamber 221 of the compression ignition plunger is connected to the high-pressure oil inlet 215 of the compression ignition plunger, ensuring that high-pressure hydraulic oil can enter the high-pressure oil chamber 221 of the compression ignition plunger; under high oil pressure, the hydraulic oil pushes the compression ignition plunger 220 downward; when the hydraulic oil pressure decreases, the compression ignition plunger 220 is pushed upward by the elastic force of the plunger spring. The low-pressure oil chamber 223 of the compression ignition plunger is connected to the low-pressure oil inlet 213 through the low-pressure oil inlet passage 2133, and a third check valve 2131 is provided at the low-pressure oil inlet 213; the compression ignition plunger The low-pressure oil chamber 223 is connected to the low-pressure oil outlet 214 through the low-pressure oil outlet passage 2132; during the upward movement of the compression ignition plunger 220, external hydraulic oil overcomes the pressure difference of the third check valve 2131 and enters the low-pressure oil chamber 223 of the compression ignition plunger; during the downward movement of the compression ignition plunger 220, the low-pressure oil chamber 223 of the compression ignition plunger is pressed into the low-pressure oil outlet passage 2132; a throttling device 2134 is provided on the low-pressure oil outlet passage 2132 of the low-pressure oil chamber 223 of the compression ignition plunger to prevent the low-pressure oil chamber 223 of the compression ignition plunger from flowing out.

[0058] The injection plunger 240 is axially slidably sealed within the injection plunger cavity 218. The space enclosed by the large-diameter end face of the injection plunger 240, the large-orifice sidewall and end face of the injection plunger cavity 218 together form the high-pressure oil chamber 241 of the injection plunger. The space enclosed by the small-diameter end face of the injection plunger 240, the small-orifice sidewall of the injection plunger cavity 218 together form the injection chamber 242. The stepped surfaces of the injection plunger 240 and the injection plunger cavity 218, as well as the injection... The space enclosed by the sidewall of the large orifice section of the injection plunger cavity 218 is the low-pressure oil chamber 243 of the injection plunger. The small orifice section below the injection plunger cavity 218 directly penetrates the injection chamber 242. The injection chamber 242 is connected to the compression ignition pre-combustion chamber 222 through the pre-combustion chamber connecting channel 244. An injection hole 2421 is provided below the injection chamber 242. One end of the injection hole 2421 directly penetrates the injection chamber 242, and the other end of the injection hole 2421 is connected to the main combustion chamber 100.

[0059] The two ends of the injection plunger spring 250 abut against the stepped surfaces of the injection plunger 240 and the injection plunger cavity 218, respectively. During the axial sliding process of the injection plunger 240, the injection plunger spring 250 is compressed throughout. The injection valve 260 is installed inside the injection orifice 2421, with its valve disc 261 abutting against the lower edge of the injection orifice 2421. Its valve stem 262 is inserted into the central hole of the injection plunger 240 and rigidly connected. Under the elastic force of the injection plunger spring 250, the injection plunger 240 drives the valve disc 261 of the injection valve 260 to tightly press against the lower edge of the injection orifice 2421, forming a seal. This isolates the injection chamber 242 from the main combustion chamber 100. The injection chamber 242 is connected to the compression ignition pre-combustion chamber 222 via the pre-combustion chamber connection channel 244. When the compression ignition plunger 220 continues to descend, igniting the mixture in the compression ignition pre-combustion chamber 222 and causing auto-ignition, the injection chamber 242 is also filled with a high-temperature, high-pressure mixture.

[0060] The high-pressure oil chamber 241 of the injection plunger is connected to the high-pressure oil inlet 216 of the injection plunger through the high-pressure oil passage 2161, ensuring that high-pressure hydraulic oil can enter the high-pressure oil chamber 241 of the injection plunger. Under high oil pressure, the hydraulic oil pushes the injection plunger 240 downward, and the injection plunger 240 drives the injection valve 260 downward, and the injection chamber 242 is connected to the main combustion chamber 100. When the hydraulic oil pressure decreases, the injection plunger 240 can move upward by the elastic force of the injection plunger spring 250, and the injection chamber 242 is isolated from the main combustion chamber 100. During the communication between the injection chamber 242 and the main combustion chamber 100, the high-temperature and high-pressure mixed gas in the injection chamber 242, the compression ignition pre-combustion chamber 222 and the pre-combustion chamber connecting channel 244 is injected into the main combustion chamber 100 through the injection hole 2421 and the cylindrical flow interface between the valve plate 261 of the injection valve 260 and the lower edge of the injection hole 2421, igniting the fuel-air mixture in the main combustion chamber 100; unlike the multi-hole jet of the existing conventional pre-combustion chamber, the jet of the present invention is an annular jet.

[0061] The injection plunger low-pressure oil chamber 243 is connected to the low-pressure oil inlet 213 and the compression ignition plunger low-pressure oil chamber 223 through the low-pressure oil inlet passage 2133; the injection plunger low-pressure oil chamber 243 is connected to the low-pressure oil outlet 214 through the low-pressure oil outlet passage 2132; during the upward movement of the compression ignition plunger 220 and the injection plunger 240, external hydraulic oil overcomes the pressure difference of the third check valve 2131 and enters the compression ignition plunger low-pressure oil chamber 223; during the downward movement of the compression ignition plunger 220, due to the throttling effect of the throttling device 2134 of the low-pressure oil outlet passage 2132, part of the hydraulic oil in the compression ignition plunger low-pressure oil chamber 223 is forced into the low-pressure oil inlet passage 2133 and the injection plunger low-pressure oil chamber 243, and then enters the low-pressure oil outlet passage 2132 and flows out through the low-pressure oil outlet 214. The forced flow of hydraulic oil during the downward movement of the compression ignition plunger 220 and the injection plunger 240 can achieve forced cooling of the stepped surface and small diameter section of the injection plunger 240, thereby reducing the thermal load on the injection valve 260.

[0062] The hydraulic drive device 300 of this embodiment includes a hydraulic drive device body 310, a compression ignition drive plunger 320, an injection drive plunger 330, a compression ignition drive plunger spring 340, an injection drive plunger spring 350, at least one hydraulic drive camshaft 360, a compression ignition drive cam 370, and an injection drive cam 380, wherein the compression ignition drive cam 370 and the injection drive cam 380 are fixedly sleeved on the hydraulic drive camshaft 360.

[0063] The hydraulic drive unit body 310 is a box-like structure, on which compression ignition drive plunger cavity 311 and injection drive plunger cavity 312 are arranged side by side. Both compression ignition drive plunger cavity 311 and injection drive plunger cavity 312 are "T"-shaped cylindrical stepped hole structures, including small hole section, large hole section and stepped surface. Above the compression ignition drive plunger cavity 311 of the hydraulic drive unit body 310, there are compression ignition drive hydraulic oil inlet 313, compression ignition drive hydraulic oil outlet 314 and compression ignition drive hydraulic oil drain port 315, all of which are conventionally known connector-type interfaces for fluid flow connection with the outside world. Above the injection drive plunger cavity 312 of the hydraulic drive device body 310, there are injection drive hydraulic oil inlet 316, injection drive hydraulic oil outlet 317, and injection drive hydraulic oil drain port 318. These are all conventionally known connector-type interfaces that connect to the outside world for fluid flow. The compression ignition drive plunger 320 and injection drive plunger 330 are "T"-shaped cylindrical stepped shaft structures, similar in shape to the plunger shapes commonly used in hydraulic transmission systems, including small diameter sections, large diameter sections, and stepped surfaces. The compression ignition drive plunger spring 340 and injection drive plunger spring 350 are common springs, such as cylindrical springs.

[0064] The compression ignition driven plunger 320 is axially slidably sealed within the compression ignition driven plunger cavity 311. The space enclosed by the small-diameter end face of the compression ignition driven plunger 320 and the small-hole sidewall and end face of the compression ignition driven plunger cavity 311 is the compression ignition driven high-pressure oil chamber 321. The compression ignition driven hydraulic oil inlet 313 communicates with the compression ignition driven high-pressure oil chamber 321, with a first check valve 3131 installed in between. The compression ignition driven hydraulic oil drain port 315 communicates with the compression ignition driven high-pressure oil chamber 321, with a first pressure relief valve 3151 installed in between. The compression ignition driven hydraulic oil outlet 314 is connected to the compression ignition driven high-pressure oil chamber. 321 is connected to the high-pressure inlet 215 of the compression ignition plunger via an external connecting pipe; the two ends of the compression ignition drive plunger spring 340 abut against the stepped surfaces of the compression ignition drive plunger 320 and the compression ignition drive plunger cavity 311, respectively; the compression ignition drive plunger spring 340 is compressed throughout the axial sliding process of the compression ignition drive plunger 320; the large-diameter end face of the compression ignition drive plunger 320 abuts against the compression ignition drive cam 370 on the hydraulic drive camshaft 360, and the hydraulic drive camshaft 360 is rigidly connected to the compression ignition drive cam 370, and the rotating hydraulic drive camshaft 360 can drive the compression ignition drive plunger. The piston 320 reciprocates up and down; when the compression ignition drive cam 370 drives the compression ignition drive piston 320 upward, the compression ignition drive high-pressure oil chamber 321 is compressed, and the incompressibility of the hydraulic oil causes the hydraulic oil inside to enter the compression ignition piston high-pressure oil chamber 221 through the connecting pipe, pushing the compression ignition piston 220 downward; when the compression ignition drive cam 370 and the compression ignition drive piston spring 340 work together to move the compression ignition drive piston 320 downward, the hydraulic oil pressure in the compression ignition drive high-pressure oil chamber 321 and the compression ignition piston high-pressure oil chamber 221 decreases, and the compression ignition piston 220 is subjected to the elastic force and pressure of the compression ignition piston spring 230. Under the pressure of the gas in the pre-combustion chamber 222, the hydraulic oil in the high-pressure oil chamber 221 of the compression ignition plunger is pushed back into the high-pressure oil chamber 321 of the compression ignition drive. When the pressure in the high-pressure oil chamber 321 of the compression ignition drive plunger 320 is too high during the upward movement, the hydraulic oil can be released through the first pressure relief valve 3151 and the hydraulic oil drain port 315 of the compression ignition drive. When the pressure in the high-pressure oil chamber 321 of the compression ignition drive plunger 320 is too low during the downward movement, external hydraulic oil can be introduced into the high-pressure oil chamber 321 of the compression ignition drive through the first check valve 3131 and the hydraulic oil inlet 313 of the compression ignition drive.

[0065] The injection-driven plunger 330 is axially slidably sealed within the injection-driven plunger cavity 312. The space enclosed by the small-diameter end face of the injection-driven plunger 330 and the small-hole sidewall and end face of the injection-driven plunger cavity 312 is the injection-driven high-pressure oil chamber 331. The injection-driven hydraulic oil inlet 316 communicates with the injection-driven high-pressure oil chamber 331, with a second check valve 3161 installed in between. The injection-driven hydraulic oil drain port 318 communicates with the injection-driven high-pressure oil chamber 331, with a second pressure relief valve 3181 installed in between. The injection-driven hydraulic oil outlet 317 communicates with the injection-driven high-pressure oil... The cavity 331 is connected to the high-pressure oil inlet 216 of the injection plunger via an external connecting pipe; the two ends of the injection drive plunger spring 350 abut against the stepped surfaces of the injection drive plunger 330 and the injection drive plunger cavity 312, respectively; the injection drive plunger spring 350 is compressed throughout the axial sliding process of the injection drive plunger 330; the large-diameter end face of the injection drive plunger 330 abuts against the injection drive cam 380 on the hydraulic drive camshaft 360, and the hydraulic drive camshaft 360 is rigidly connected to the injection drive cam 380, and the rotating hydraulic drive camshaft 360 can drive the injection drive... The moving plunger 330 reciprocates up and down; when the injection drive cam 380 drives the injection drive plunger 330 upward, the injection drive high-pressure oil chamber 331 is compressed, and the incompressibility of the hydraulic oil causes the hydraulic oil inside to enter the injection plunger high-pressure oil chamber 241 through the connecting pipe, pushing the injection plunger 240 and the injection valve 260 downward; when the injection drive cam 380 and the injection drive plunger spring 350 work together to move the injection drive plunger 330 downward, the hydraulic oil pressure in the injection drive high-pressure oil chamber 331 and the injection plunger high-pressure oil chamber 241 decreases, and the injection plunger 240 moves downward in the injection... Under the elastic force of the spring 250, the hydraulic oil in the high-pressure oil chamber 241 of the injection plunger is pushed back into the injection drive high-pressure oil chamber 331. When the pressure in the injection drive high-pressure oil chamber 331 is too high during the upward movement of the injection drive plunger 330, the hydraulic oil can be released through the second pressure relief valve 3181 and the injection drive hydraulic oil drain port 318. When the pressure in the injection drive high-pressure oil chamber 331 is too low during the downward movement of the injection drive plunger 330, external hydraulic oil can be introduced into the injection drive high-pressure oil chamber 331 through the second check valve 3161 and the injection drive hydraulic oil inlet 316.

[0066] The hydraulically driven camshaft 360 is driven by the piston crankshaft or valve camshaft in the internal combustion engine via a gear train or belt, ensuring that their rotational movements are coupled. The transmission ratio between the hydraulically driven camshaft 360 and the piston crankshaft of the internal combustion engine is 1:2, or the transmission ratio between the hydraulically driven camshaft 360 and the valve camshaft of the internal combustion engine is 1:1. In one cycle of a four-stroke internal combustion engine, the crankshaft rotates twice, and the hydraulically driven camshaft 360 rotates once. The injection drive cam 380 and the compression ignition drive cam 370 drive the injection drive plunger 330 and the compression ignition drive plunger 320 to reciprocate up and down once each, respectively. Utilizing the existing variable valve timing technology on the internal combustion engine camshaft, the variable timing of driving the reciprocating up and down movements of the injection drive plunger 330 and the compression ignition drive plunger 320 can also be achieved.

[0067] The low-pressure oil chamber 223 of the compression ignition plunger is located between the high-pressure oil chamber 221 and the compression ignition pre-combustion chamber 222. On the one hand, it collects the hydraulic oil leaking from the high-pressure oil chamber, and on the other hand, it prevents the high-pressure gas in the compression ignition pre-combustion chamber 222 from leaking into the high-pressure oil chamber. It also has the function of cooling the compression ignition plunger 220.

[0068] Furthermore, the exhaust chamber 2172 is larger than the intake chamber 2171 along the central axis of the compression ignition plunger cavity 217 to achieve a free exhaust stage and ensure that the amount of exhaust gas remaining in the compression ignition pre-combustion chamber 222 is minimized. During the upward movement of the compression ignition plunger 220, the small-diameter end face of the compression ignition plunger 220 first connects the exhaust chamber 2172 with the compression ignition pre-combustion chamber 222. The exhaust gas in the compression ignition pre-combustion chamber 222 is driven by the pressure of the compression ignition pre-combustion chamber 222 and enters the exhaust port 212 through the exhaust chamber 2172 and the exhaust passage 2174, forming a free exhaust stage, and the residual exhaust gas in the compression ignition pre-combustion chamber 222 is rapidly reduced. Afterward, the compression ignition plunger 220 continues to move upward, and the small-diameter end face of the compression ignition plunger 220 connects the intake chamber 2171, the exhaust chamber 2172 and the compression ignition pre-combustion chamber 222. The fresh mixture in the intake chamber 2171 enters the compression ignition pre-combustion chamber 222 under pressure, while squeezing the residual exhaust gas into the exhaust chamber 2172.

[0069] In some other embodiments, the exhaust chamber 2172, exhaust passage 2174, and exhaust port 212 are eliminated. The intake chamber 2171 is arranged along the side wall of the small hole section of the compression ignition plunger cavity 217. The injection drive cam 380 is redesigned to ensure that the injection drive plunger 330 is driven to reciprocate up and down twice in one internal combustion engine cycle. The first time is near the top dead center of compression, and the second time is during the intake phase. During the intake phase, the reciprocating up and down movement of the injection drive plunger 330 can open the injection valve 260. The fresh mixture entering the compression ignition pre-combustion chamber 222 from the intake chamber 2171 can squeeze the residual exhaust gas into the main combustion chamber 100 through the pre-combustion chamber connecting passage 244, injection chamber 242, and injection hole 2421, achieving direct scavenging and better scavenging effect.

[0070] In this embodiment, the axial cross-sectional area of ​​the compression ignition driven high-pressure oil chamber 321 is larger than that of the compression ignition plunger high-pressure oil chamber 221. It can be understood that the diameter of the small diameter section of the compression ignition driven plunger 320 should be larger than the diameter of the large diameter section of the compression ignition plunger 220. Due to structural limitations, the reciprocating stroke of the compression ignition driven cam 370 driving the compression ignition driven plunger 320 is relatively small. In order to take into account different fuel auto-ignition temperatures and ensure reliable auto-ignition of the mixture in the compression ignition pre-combustion chamber 222, it is necessary to increase the compression ratio of the compression ignition pre-combustion chamber 222, which in turn requires increasing the stroke of the compression ignition plunger 220. By utilizing the incompressibility of hydraulic oil, the stroke ratio of the compression ignition plunger 220 and the compression ignition driven plunger 320 can be proportionally amplified. The amplification ratio is the square of the ratio of the small diameter section diameter of the compression ignition driven plunger 320 to the large diameter section diameter of the compression ignition plunger 220.

[0071] The compression ignition driven plunger 320 transmits its reciprocating motion to the compression ignition plunger 220 via a hydraulic system. During this transmission, the hydraulic oil pressure in the compression ignition driven high-pressure oil chamber 321 and the compression ignition plunger high-pressure oil chamber 221 remains consistent. After the air-fuel mixture in the compression ignition pre-combustion chamber 222 undergoes compression and spontaneous combustion, the hydraulic oil pressure in the high-pressure oil chamber will increase significantly. The first pressure relief valve 3151, connected to the compression ignition driven high-pressure oil chamber 321, can control the pressure in the high-pressure oil chamber to prevent structural failure, while also controlling the pressure in the compression ignition pre-combustion chamber 222. Since leakage is inevitable in both the compression ignition driven plunger 320 and the compression ignition plunger 220, the pressure in the high-pressure oil chamber of the compression ignition driven plunger 320 may be lower than the target value when the compression ignition driven plunger 320 is at its bottom dead center. The first check valve 3131, connected to the compression ignition driven high-pressure oil chamber 321, introduces external hydraulic oil under pressure differential control to compensate for the insufficient pressure in the compression ignition driven high-pressure oil chamber 321.

[0072] Adjusting the parameters of the pressure relief valve spring for different fuels maintains the pressure range of the compression ignition pre-combustion chamber 222 at 150-350 bar. After the pressure of the first pressure relief valve 3151 is fixed, when the pressure in the compression ignition pre-combustion chamber 222 reaches the target value, even if the compression ignition drive plunger 320 continues to move upward, the compression ignition plunger 220 will no longer move downward, thus realizing the variable compression ratio of the compression ignition pre-combustion chamber 222.

[0073] In this embodiment, a flange is provided on the compression ignition drive cam 370, and the hydraulic drive camshaft 360 rotates once to realize the reciprocating motion of the compression ignition drive plunger 320 once.

[0074] This embodiment of the internal combustion engine using pre-combustion chamber ignition requires that the high-temperature and high-pressure mixture in the pre-combustion chamber near the top dead center of the compression of the internal combustion engine be injected into the main combustion chamber 100 to ignite the mixture in the main combustion chamber 100. Therefore, it is necessary to ignite the mixture in the pre-combustion chamber near the top dead center of the compression of the internal combustion engine. For this purpose, there is a certain phase synchronization relationship between the compression ignition drive cam 370 on the hydraulically driven camshaft 360 and the crankshaft.

[0075] Preferably, the phase synchronization requirement between the hydraulically driven camshaft 360 and the crankshaft should be such that the compression drive cam drives the compression drive plunger to reach the top dead center within a range of 10-50 degrees before the internal combustion engine piston reaches the top dead center of the compression stroke.

[0076] In a further preferred embodiment, the hydraulically driven camshaft 360 employs the variable valve timing technology found on existing internal combustion engine camshafts to achieve variable timing control of the compression ignition driven plunger 320 reaching top dead center.

[0077] In this embodiment, the walls of the pre-combustion chamber connecting channel 244 and the injection chamber 242 are coated with heat-insulating material to reduce the heat transfer between the gas mixture in the compression ignition pre-combustion chamber 222 and the wall surface and the wall quenching effect. The pre-combustion chamber connecting channel 244 and the injection chamber 242 significantly increase the contact area between the gas mixture in the compression ignition pre-combustion chamber 222 and the wall surface. The increased contact between the two leads to increased heat transfer and also increases the wall quenching effect.

[0078] In this embodiment, the injection valve 260 is internally filled with a phase change material to enhance heat transfer between the valve disc 261 and the valve stem 262. Because the upper surface of the valve disc 261 is heated by the high-temperature mixture in the injection chamber 242, and the lower surface is heated by the high-temperature combustion gas in the main combustion chamber 100, its heat load is relatively large. Filling it with a phase change material allows the phase change process of the material to transfer heat from the valve disc 261, similar to the sodium-filled exhaust valve technology in internal combustion engines.

[0079] Furthermore, the diameter of the contact point between the lower edge of the injection orifice 2421 and the injection valve 260 is equal to the diameter of the small-diameter section of the injection plunger 240, in order to eliminate the pressure exerted on the injection plunger 240 by the high-pressure gas in the injection chamber 242. The main forces on the assembly of the injection plunger 240 and the injection valve 260 include the hydraulic pressure of the high-pressure oil chamber 241 and the low-pressure oil chamber 243 of the injection plunger, the elastic force of the injection plunger spring 250, the contact force of the lower edge of the injection orifice 2421 on the injection valve 260, and the high-pressure gas pressure in the injection chamber 242. If the high-pressure gas pressure in the injection chamber 242 is not counteracted on the assembly of the injection plunger 240 and the injection valve 260, the pressure of the high-pressure gas will have an adverse effect on its up-and-down reciprocating motion, including abnormal opening and increased oil pressure in the high-pressure oil chamber 241 of the injection plunger.

[0080] The low-pressure oil chamber 243 of the injection plunger is located between the high-pressure oil chamber 241 and the injection chamber 242 of the injection plunger. On the one hand, it collects the hydraulic oil leaking from the high-pressure oil chamber, and on the other hand, it prevents the high-pressure gas in the injection chamber 242 from leaking into the high-pressure oil chamber. It also has the function of cooling the injection plunger 240.

[0081] A throttling device 2134 is provided on the low-pressure outlet passage 2132 of the low-pressure oil chamber 223 of the compression ignition plunger, forcing part of the hydraulic oil flowing out of the low-pressure oil chamber 223 of the compression ignition plunger to flow through the low-pressure oil chamber 243 of the injection plunger, thereby enhancing the heat exchange effect of the rod of the injection plunger 240 and the injection valve 260. The low-pressure oil chambers 223 and 243 of the injection plunger are respectively provided below the compression ignition plunger 220 and the injection plunger 240. On the one hand, they are used to collect the hydraulic oil leaking from the high-pressure oil chambers 221 and 241 of the compression ignition plunger and lead it to the outside, reducing the hydraulic pressure applied by the low-pressure oil chambers; on the other hand, they are used to cool the compression ignition plunger 220 and the injection plunger 240. The stroke of the injection plunger 240 is shorter, and the hydraulic oil flow in the low-pressure oil chamber 243 of the injection plunger is slower, while that of the compression ignition plunger 220 is the opposite.

[0082] A third check valve 2131 is installed at the low-pressure oil inlet 213 on the main body 210 of the compression ignition pre-combustion injection device. On the one hand, it introduces part of the hydraulic oil in the low-pressure oil chamber 223 of the compression ignition plunger 220 into the low-pressure oil chamber 243 of the injection plunger during the downward phase, preventing backflow through the low-pressure oil inlet 213. On the other hand, it can introduce external hydraulic oil into the low-pressure oil chambers 223 and 243 of the compression ignition plunger and the injection plunger, preventing the formation of a vacuum in the low-pressure oil chambers during the upward phase of the compression ignition plunger 220 and the injection plunger 240.

[0083] In this embodiment, the axial cross-sectional area of ​​the injection drive high-pressure oil chamber 331 is smaller than that of the injection plunger high-pressure oil chamber 241. It can be understood that the diameter of the small diameter section of the injection drive plunger 330 should be smaller than the diameter of the large diameter section of the injection plunger 240. Due to structural and jet limitations, the reciprocating stroke of the injection plunger 240 cannot be too large, and 1-3 mm is recommended. The stroke of the injection drive plunger 330 driven by the injection drive cam 380 is often greater than 1-3 mm, thus requiring a reduction in the stroke of the injection plunger 240. Utilizing the incompressibility of hydraulic oil, the stroke ratio of the injection plunger 240 and the injection drive plunger 330 can be proportionally reduced. The reduction ratio is the square of the ratio of the small diameter section diameter of the injection drive plunger 330 to the large diameter section diameter of the injection plunger 240.

[0084] The injection drive plunger 330 transmits its reciprocating motion to the injection plunger 240 via a hydraulic system. During this transmission, the hydraulic oil pressure in the injection drive high-pressure oil chamber 331 and the injection plunger high-pressure oil chamber 241 remains consistent. If plunger jamming or other malfunctions occur, the hydraulic oil pressure in the high-pressure oil chamber will increase significantly. The second pressure relief valve 3181 can release the high-pressure oil chamber pressure to prevent structural failure. Since leakage is inevitable in both the injection drive plunger 330 and the injection plunger 240, the pressure in the injection drive high-pressure oil chamber 331 may be lower than the target value when the injection drive plunger 330 is at its bottom dead center. The second check valve 3161, connected to the injection drive high-pressure oil chamber 331, introduces external hydraulic oil under pressure differential control to compensate for the insufficient pressure in the injection drive plunger 330's high-pressure oil chamber.

[0085] A flange is provided on the injection drive cam 380, and the injection plunger 240 reciprocates once during one complete cycle of the internal combustion engine, ensuring that the injection chamber 242 and the main combustion chamber 100 are kept in communication as needed. To reduce the number of parts, the injection drive cam 380 and the compression ignition drive cam 370 are rigidly connected to the same hydraulically driven camshaft 360. In some other embodiments, the injection drive cam 380 is provided with two flanges, and the injection plunger 240 reciprocates twice during one complete cycle of the internal combustion engine, which, in conjunction with eliminating the exhaust chamber 2172 and the exhaust passage 2174, enables direct scavenging of the compression ignition pre-combustion chamber 222.

[0086] Internal combustion engines employing pre-combustion chamber ignition require the high-temperature, high-pressure mixture from the pre-combustion chamber near the top dead center of the compression stroke to be injected into the main combustion chamber 100 to ignite the mixture within. Therefore, it is necessary to introduce the high-temperature, high-pressure mixture from the pre-combustion chamber into the main combustion chamber 100 near the top dead center of the compression stroke. For this purpose, the injection drive cam 380 on the hydraulically driven camshaft 360 has a certain phase synchronization relationship with the crankshaft.

[0087] In some other embodiments, the phase synchronization between the injection drive cam 380 and the crankshaft should be such that the injection drive cam 380 drives the injection drive plunger 330 to reach top dead center within a range of -10 to -20 degrees before the internal combustion engine piston reaches top dead center.

[0088] In some other embodiments, the injection-driven cam 380 and the compression-ignition-driven cam 370 employ different hydraulically driven camshafts 360, with independent phases between them. The variable valve timing technology on the intake and exhaust camshafts of existing internal combustion engines is used to achieve variable timing control of the injection-driven plunger 330 reaching top dead center.

[0089] This invention also proposes an operating method for a compression ignition pre-combustion ignition system, wherein the internal combustion engine operates in the manner not described herein as a conventional four-stroke internal combustion engine and outputs power externally. Figure 9A schematic diagram showing the stroke of the piston, compression ignition drive plunger 320, injection drive plunger 330, compression ignition plunger 220, and injection plunger 240 during an internal combustion engine cycle is provided to visually explain the working principles of the internal combustion engine, the hydraulic drive unit 300, and the compression ignition pre-combustion injection device 200. The operating methods include:

[0090] The internal combustion engine is set to operate at a preset speed, and the hydraulically driven camshaft 360 rotates at half the preset speed. Two rotations of the internal combustion engine constitute one cycle, and the hydraulically driven camshaft 360 rotates once in the same amount of time.

[0091] In the early to mid-stage of the compression stroke of an internal combustion engine, the piston moves upward, compressing the air-fuel mixture in the main combustion chamber 100. The compression ignition drive cam 370 drives the compression ignition drive plunger 320 upward. Incompressible hydraulic oil flows into the high-pressure oil chamber 221 of the compression ignition plunger and pushes the compression ignition plunger 220 downward. The compression ignition plunger 220 compresses the air-fuel mixture in the compression ignition pre-combustion chamber 222. As the pressure and temperature of the air-fuel mixture increase, the volume of the low-pressure oil chamber 223 of the compression ignition plunger decreases, and a portion of the hydraulic oil in the low-pressure oil chamber 223 of the compression ignition plunger... The hydraulic oil flows directly into the low-pressure outlet passage 2132 through the throttling device 2134. Another part of the hydraulic oil is forced into the low-pressure oil chamber 243 of the injection plunger and then flows into the low-pressure outlet passage 2132. At this time, the injection chamber 242 is kept disconnected from the main combustion chamber 100. Initially, the compression ignition plunger 220 connects the intake chamber 2171, the compression ignition pre-combustion chamber 222 and the exhaust chamber 2172 and performs scavenging and air exchange. Afterward, the compression ignition plunger 220 isolates the three from each other and seals the compression ignition pre-combustion chamber 222.

[0092] Near the top dead center (TDC) of the compression stroke of the internal combustion engine, the piston continues to move upward and approaches TDC; the compression ignition drive cam 370 drives the compression ignition drive plunger 320 to TDC, and the hydraulic oil drives the compression ignition plunger 220 to BDC; the temperature of the mixture in the compression ignition pre-combustion chamber 222 reaches the auto-ignition temperature of the fuel and achieves homogeneous compression ignition; the injection drive cam 380 drives the injection drive plunger 330 to start moving upward, and incompressible hydraulic oil flows into the high-pressure oil chamber 241 of the injection plunger and pushes the injection plunger 240 downward, the injection valve 260 disengages from the lower edge of the injection orifice 2421, and the injection chamber 242 connects with the main combustion chamber 100; the downward movement of the injection plunger 240 forces the hydraulic oil in the low-pressure oil chamber 243 of the injection plunger into the low-pressure oil outlet passage 2132; the high-temperature and high-pressure mixture in the compression ignition pre-combustion chamber 222 is injected into the main combustion chamber 100, and the high-temperature jet mixture ignites the fuel-air mixture in the main combustion chamber 100;

[0093] In the early stage of the power stroke of the internal combustion engine, the piston continues to descend; the compression ignition drive cam 370 drives the compression ignition drive plunger 320 to remain at top dead center, and the high-pressure hydraulic oil drives the compression ignition plunger 220 to remain at bottom dead center; the injection drive cam 380 drives the injection drive plunger 330 to continue moving upward and reach top dead center, and the injection plunger 240 continues to descend under the drive of hydraulic oil and reaches bottom dead center; after the injection drive plunger 330 remains at top dead center for a period of time, the injection drive plunger 330 begins to descend under the drive of the injection drive plunger spring 350; after the injection plunger 240 remains at bottom dead center for a period of time, the injection drive plunger 330 begins to descend under the drive of the injection drive plunger spring 350; at this time, the flame in the main combustion chamber 100 gradually spreads to the surroundings through propagation, and the pressure and temperature of the air-fuel mixture in the main combustion chamber 100 both rise, pushing the piston to move to bottom dead center and outputting power.

[0094] During the later stages of the power stroke of an internal combustion engine, the piston continues to descend and reaches bottom dead center; the compression ignition drive plunger spring 340 drives the compression ignition drive plunger 320 to begin descending, and the compression ignition plunger spring 230 drives the compression ignition plunger 220 to begin ascending; the injection drive plunger 330 continues to descend under the drive of the injection drive plunger spring 350 and reaches bottom dead center, and the injection plunger 240 continues to ascend under the drive of the injection plunger spring 250 and reaches top dead center; the injection plunger 240 drives the injection valve 260 to ascend, causing the injection valve 260 to re-align with the injection port 2421. When the flames collide, the injection chamber 242 and the main combustion chamber 100 are disconnected again. At this time, the flame in the main combustion chamber 100 is transmitted to the entire main combustion chamber 100 through propagation. The pressure and temperature of the mixture in the main combustion chamber 100 rise, pushing the piston to move to the downward dead center and outputting power. Due to the increase in volume, the hydraulic oil pressure in the low-pressure oil chamber 223 of the compression ignition plunger and the low-pressure oil chamber 243 of the injection plunger decreases. External hydraulic oil enters the low-pressure oil chamber 223 of the compression ignition plunger and the low-pressure oil chamber 243 of the injection plunger through the third check valve 2131 and the low-pressure oil inlet 2133.

[0095] During the exhaust stroke of an internal combustion engine, the piston moves from bottom dead center to top dead center, expelling the exhaust gas from the main combustion chamber 100 through the exhaust passage. The compression ignition drive plunger spring 340 drives the compression ignition drive plunger 320 to continue downward and reach bottom dead center. The compression ignition plunger spring 230 drives the compression ignition plunger 220 to continue upward and reach top dead center. Near top dead center, the compression ignition plunger 220 first connects the exhaust chamber 2172 with the compression ignition pre-combustion chamber 222. The mixture in the pre-combustion chamber rapidly enters the exhaust chamber 2172 under its own pressure, achieving free exhaust. The compression ignition plunger 220 continues upward until it reaches top dead center. The intake chamber 2171, exhaust chamber 2172 and compression ignition pre-combustion chamber 222 are interconnected. Fresh fuel-air mixture enters compression ignition pre-combustion chamber 222 through intake chamber 2171, squeezing residual exhaust gas in compression ignition pre-combustion chamber 222 into exhaust chamber 2172 for continuous scavenging and gas exchange. Injection drive plunger 330 is held at the lower dead center by injection drive plunger spring 350, and injection plunger 240 is held at the upper dead center by injection plunger spring 250. Injection plunger 240 drives injection valve 260 to abut the lower edge of injection orifice 2421, and injection chamber 242 is disconnected from main combustion chamber 100.

[0096] During the intake stroke of an internal combustion engine, the piston moves from top dead center to bottom dead center, drawing air from the intake manifold into the main combustion chamber 100. Later in the intake stroke, the compression ignition drive plunger 320 is driven upwards by a cam, and hydraulic oil enters the high-pressure oil chamber 221 of the compression ignition plunger, pushing it downwards. During the intake stroke, the injection drive plunger 330 is held at bottom dead center by the injection drive plunger spring 350, and the injection plunger 240 is held at top dead center by the injection plunger spring 250. The injection plunger 240 drives the injection valve 260 to contact the lower edge of the injection orifice 2421, disconnecting the injection chamber 242 from the main combustion chamber 100. After the plunger 220 descends, the volume of the low-pressure oil chamber 223 of the compression ignition plunger decreases. Part of the hydraulic oil in the low-pressure oil chamber 223 of the compression ignition plunger is forced into the low-pressure oil outlet 2132, and the other part of the hydraulic oil is forced into the low-pressure oil chamber 243 of the injection plunger and then enters the low-pressure oil outlet 2132. After the compression ignition plunger 220 descends a certain distance, the compression ignition plunger 220 first disconnects the intake chamber 2171 from the compression ignition pre-combustion chamber 222. As the compression ignition plunger 220 continues to descend, a portion of the fresh mixture in the compression ignition pre-combustion chamber 222 is pushed out through the exhaust chamber 2172. Then the compression ignition plunger 220 disconnects the exhaust chamber 2172 from the compression ignition pre-combustion chamber 222, sealing the compression ignition pre-combustion chamber 222.

[0097] Afterwards, the internal combustion engine re-enters the compression stroke, completing one full cycle. The compression ignition drive cam 370 and compression ignition drive plunger spring 340, rigidly connected to the hydraulic drive camshaft 360, jointly drive the compression ignition drive plunger 320 to complete one full reciprocating motion. Similarly, the injection drive cam 380 and injection drive plunger spring 350, also rigidly connected to the hydraulic drive camshaft 360, jointly drive the compression ignition drive plunger 320 to complete one full reciprocating motion. Likewise, the hydraulic oil and compression ignition plunger spring 230 jointly drive the compression ignition plunger 220 to complete one full reciprocating motion. Spring 250 drives injection plunger 240 to complete one full reciprocating motion; the hydraulically driven camshaft 360 adopts the variable valve timing technology on the existing internal combustion engine valve camshaft, which can adjust the timing phase of the reciprocating motion of compression ignition drive plunger 320, compression ignition plunger 220, injection drive plunger 330 and injection plunger 240 as a whole, so as to ensure that the compression ignition plunger 220 reaches the bottom dead center and the injection valve 260 disengages from the lower edge of the injection orifice 2421 at the end of the compression stroke of the internal combustion engine, thereby achieving control over the auto-ignition time of compression ignition pre-combustion chamber 222 and the injection start time of injection chamber 242.

[0098] In some other embodiments, the exhaust chamber 2172 and the exhaust passage 2174 are omitted, such as... Figure 10As shown, the injection plunger 240 is required to perform two reciprocating motions in one cycle. The first reciprocating motion occurs from the late compression stroke to the exhaust stroke of the internal combustion engine, and the second reciprocating motion is recommended to occur during the intake stroke. During the intake stroke, the injection drive plunger 330 moves upward again under the drive of the injection drive plunger 330 cam, and the injection plunger 240 moves downward again under the drive of hydraulic oil. The injection plunger 240 drives the injection valve 260 to disengage from the lower edge of the injection orifice 2421, and the injection chamber 242 and the main combustion chamber 100 are reconnected. At this time, the compression ignition plunger 220 is near top dead center, and the intake chamber 2171 and the compression ignition pre-combustion chamber 222 are connected. The air is connected; under the action of pressure difference, the fresh mixture in the intake chamber 2171 flows into the compression ignition pre-combustion chamber 222, and the residual exhaust gas in the pre-combustion chamber is squeezed into the main combustion chamber 100 through the injection chamber 242 and the injection hole 2421 to achieve more efficient direct scavenging; the injection drive plunger 330 and the injection plunger 240 achieve two reciprocating motions in one cycle, requiring the injection drive cam 380 to be provided with two flanges. The first flange is required to drive the injection drive plunger 330 to complete a complete reciprocating motion during the later stage of the compression stroke to the exhaust stroke of the internal combustion engine, and the second flange is required to drive the injection drive plunger 330 to complete a complete reciprocating motion during the intake stroke of the internal combustion engine. To prevent exhaust gas from flowing back into the intake chamber 2171 from the compression ignition pre-combustion chamber 222, the flange of the compression ignition drive cam 370 is modified so that the compression ignition drive plunger 320 does not return to bottom dead center during the later stage of the power stroke or the early stage of the exhaust stroke. At the same time, the compression ignition plunger 220 remains below top dead center and disconnects the communication between the intake chamber 2171 and the compression ignition pre-combustion chamber 222. Once the second flange of the injection drive cam 380 drives the injection drive plunger 330 to begin moving upward, the compression ignition drive plunger 320 continues to move to bottom dead center, and the compression ignition plunger 220 continues to move to top dead center, maintaining communication between the intake chamber 2171 and the compression ignition pre-combustion chamber 222.

[0099] The compression ignition pre-combustion ignition system proposed in this invention uses a cam mechanism to drive the compression ignition drive plunger 320 to compress hydraulic oil. Utilizing the incompressibility of the hydraulic oil, the compression ignition plunger 220 compresses the air-fuel mixture within the compression ignition pre-combustion chamber 222. A well-designed plunger size increases the stroke of the compression ignition plunger 220, enabling the compression ignition pre-combustion chamber 222 to achieve a high compression ratio. This invention also uses a cam mechanism to drive the injection drive plunger 330 to compress hydraulic oil. The hydraulic oil drives the injection plunger 240 to reciprocate, thereby connecting or disconnecting the injection valve 260 between the compression ignition pre-combustion chamber 222 and the main combustion chamber 100. This allows for accurate and controllable injection from the compression ignition pre-combustion chamber 222 into the main combustion chamber 100. Furthermore, the injection valve 260, injection plunger 240, and injection plunger spring 250, which control the injection from the compression ignition pre-combustion chamber 222, are cooled by hydraulic oil, completely avoiding reliability issues caused by high heat loads.

Claims

1. A compression ignition pre-combustion ignition system, characterized in that, include: An internal combustion engine is provided with at least one cylinder, and a piston is provided in the cylinder with an axially sliding sealing sleeve, and the piston and the internal space of the cylinder form the main combustion chamber. A compression ignition pre-combustion injection device is provided, comprising at least one device body, a compression ignition plunger, a compression ignition plunger spring, an injection plunger, an injection plunger spring, and an injection valve. The compression ignition pre-combustion injection device body has a compression ignition plunger cavity, an injection plunger cavity, an air inlet, and an injection hole. The compression ignition plunger is axially slidably and sealingly fitted within the compression ignition plunger cavity. The two end faces of the compression ignition plunger respectively form a high-pressure oil chamber and a compression ignition pre-combustion chamber with the compression ignition plunger cavity. The high-pressure oil chamber has a high-pressure oil inlet. The compression ignition plunger spring is configured to provide a restoring force to the compression ignition plunger to move towards the high-pressure oil chamber. The inner peripheral wall of the compression ignition plunger cavity has an air inlet communicating with the air inlet and the compression ignition pre-combustion chamber. The injection plunger is axially slidably and sealingly fitted within the injection plunger orifice cavity. The two end faces of the injection plunger form a high-pressure injection chamber and an injection chamber with the injection plunger orifice cavity, respectively. The high-pressure injection chamber has a high-pressure injection inlet. The injection plunger spring is configured to provide a restoring force to the injection plunger as it moves toward the high-pressure injection chamber. The injection orifice is located on the extended axis of the injection plunger, with one end penetrating the injection chamber and the other end communicating with the main combustion chamber. The injection valve is connected to the end of the injection plunger away from the high-pressure injection chamber and is configured to open and close the injection orifice. At least one pre-combustion chamber connection channel connects the injection chamber to the compression ignition pre-combustion chamber. A hydraulic drive device includes a hydraulic drive device body, a compression ignition drive plunger, an injection drive plunger, a compression ignition drive plunger spring, an injection drive plunger spring, at least one hydraulic drive camshaft, a compression ignition drive cam, and an injection drive cam. The compression ignition drive cam and the injection drive cam are fixedly sleeved on the hydraulic drive camshaft. The hydraulic drive camshaft is driven to rotate by a piston crankshaft or valve camshaft in the internal combustion engine. The hydraulic drive device body has a compression ignition drive plunger cavity, an injection drive plunger cavity, a compression ignition drive hydraulic oil outlet, and an injection drive hydraulic oil outlet. The compression ignition drive plunger is axially slidably and sealingly sleeved in the compression ignition drive plunger cavity. One end of the compression ignition drive plunger forms a compression ignition drive high-pressure oil chamber with the compression ignition drive plunger cavity, and the other end of the compression ignition drive plunger is connected to the compression ignition drive camshaft. The compression ignition drive high-pressure oil chamber is provided with a compression ignition drive hydraulic oil outlet, which is connected to the compression ignition plunger high-pressure oil inlet. The compression ignition drive plunger spring is configured to provide a reset force to the compression ignition drive plunger to move toward the compression ignition drive cam. The injection drive plunger is axially slidably sealed within the injection drive plunger cavity. One end of the injection drive plunger forms an injection drive high-pressure oil chamber with the injection drive plunger cavity, and the other end of the injection drive plunger abuts against the injection drive cam. The injection drive high-pressure oil chamber is provided with an injection drive hydraulic oil outlet, which is connected to the injection plunger high-pressure oil chamber. The injection drive plunger spring is configured to provide a reset force to the injection drive plunger to move toward the injection drive cam.

2. The compression ignition pre-combustion ignition system according to claim 1, characterized in that: The axial cross-sectional area of ​​the compression ignition driven high-pressure oil chamber is larger than the axial cross-sectional area of ​​the compression ignition plunger high-pressure oil chamber; The axial cross-sectional area of ​​the injection-driven high-pressure oil chamber is smaller than that of the injection plunger high-pressure oil chamber.

3. The compression ignition pre-combustion ignition system according to claim 1, characterized in that: The injection valve includes a valve disc and a valve stem coaxially connected. One end of the valve stem is connected to the injection plunger, and the other end of the valve stem is connected to the valve disc. The end face of the valve disc facing the valve stem abuts against the edge of the injection orifice away from the injection chamber. The diameter of the injection orifice at the point where it abuts the valve disc is equal to the diameter of the small-diameter section of the injection plunger; The walls of the pre-combustion chamber connecting channel and the injection chamber are coated with heat-insulating material; The inside of the injection valve is filled with phase change material.

4. The compression ignition pre-combustion ignition system according to claim 1, characterized in that: The transmission ratio between the hydraulically driven camshaft and the piston crankshaft of the internal combustion engine is 1:2, or the transmission ratio between the hydraulically driven camshaft and the valve camshaft of the internal combustion engine is 1:

1.

5. The compression ignition pre-combustion ignition system according to any one of claims 1 to 4, characterized in that: The compression ignition driven high-pressure oil chamber is provided with a compression ignition driven hydraulic oil inlet for supplying hydraulic oil to the compression ignition driven high-pressure oil chamber, and the compression ignition driven hydraulic oil inlet is provided with a first check valve for flow from the outside to the compression ignition driven high-pressure oil chamber; The injection-driven high-pressure oil chamber is provided with an injection-driven hydraulic oil inlet for supplying hydraulic oil to the injection-driven high-pressure oil chamber, and the injection-driven hydraulic oil inlet is provided with a second check valve for flow from the outside to the injection-driven high-pressure oil chamber.

6. The compression ignition pre-combustion ignition system according to claim 5, characterized in that: The compression ignition driven high-pressure oil chamber is provided with a compression ignition driven hydraulic drain port, and the compression ignition driven hydraulic drain port is provided with a first pressure relief valve; The high-pressure oil chamber for injection drive is provided with an injection drive hydraulic drain port, and the injection drive hydraulic drain port is provided with a second pressure relief valve.

7. The compression ignition pre-combustion ignition system according to claim 6, characterized in that: The main body of the compression ignition pre-combustion injection device is provided with an exhaust port, and the inner peripheral wall of the compression ignition plunger cavity is provided with an exhaust chamber that connects the exhaust port and the compression ignition pre-combustion chamber. The dimension of the exhaust chamber along the central axis of the compression ignition plunger cavity is larger than that of the intake chamber.

8. The compression ignition pre-combustion ignition system according to claim 7, characterized in that: The compression ignition plunger cavity and the injection plunger cavity are both "T"-shaped stepped orifice structures, each including a large orifice section, a small orifice section, and a stepped surface. The compression ignition plunger and the injection plunger are both "T"-shaped stepped shaft structures, each including a large diameter section, a small diameter section, and a stepped surface. The compression ignition pre-combustion chamber is located in the small orifice section of the compression ignition plunger cavity, and the injection chamber is located in the small orifice section of the injection plunger cavity. The stepped surface of the compression ignition plunger, the stepped surface of the compression ignition plunger cavity, and the sidewall of the large orifice section of the compression ignition plunger cavity form a low-pressure oil cavity for the compression ignition plunger. The stepped surface of the injection plunger, the stepped surface of the injection plunger cavity, and the sidewall of the large orifice section of the injection plunger cavity form a low-pressure oil chamber for the injection plunger. The compression ignition pre-combustion injection device body is provided with a low-pressure oil inlet and a low-pressure oil outlet. The low-pressure oil inlet is connected to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger, respectively. The low-pressure oil inlet is provided with a low-pressure inlet configured to supply low-pressure oil to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger, respectively. The low-pressure oil outlet is connected to the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger, respectively. The low-pressure oil outlet is provided with a low-pressure outlet configured to discharge the low-pressure oil in the low-pressure oil chamber of the compression ignition plunger and the low-pressure oil chamber of the injection plunger.

9. The compression ignition pre-combustion ignition system according to claim 8, characterized in that: The low-pressure inlet is equipped with a third check valve, and a throttling device is provided between the low-pressure outlet and the low-pressure oil chamber of the compression ignition plunger.

10. An operating method, characterized in that, Applied to the compression ignition pre-combustion ignition system as described in claim 9, the operating method includes: The internal combustion engine is set to operate at a preset speed, and the hydraulically driven camshaft rotates at half of the preset speed; In the early to mid-stage of the compression stroke of an internal combustion engine, the piston moves upward, compressing the air-fuel mixture in the main combustion chamber. The compression ignition drive cam drives the compression ignition drive plunger upward, and incompressible hydraulic oil flows into the high-pressure oil chamber of the compression ignition plunger, pushing the compression ignition plunger downward. The compression ignition plunger compresses the air-fuel mixture in the compression ignition pre-combustion chamber, increasing the pressure and temperature of the mixture. The volume of the low-pressure oil chamber of the compression ignition plunger decreases, and a portion of the hydraulic oil in the low-pressure oil chamber flows directly into the low-pressure oil outlet through the throttling device. Another portion of the hydraulic oil is forced into the low-pressure oil chamber of the injection plunger and flows into the low-pressure oil outlet. At this time, the injection chamber remains disconnected from the main combustion chamber. Initially, the compression ignition plunger connects the intake chamber, the compression ignition pre-combustion chamber, and the exhaust chamber for scavenging and gas exchange. Afterward, the compression ignition plunger isolates the three chambers and seals the compression ignition pre-combustion chamber. Near the top dead center (TDC) of the later stage of the compression stroke of the internal combustion engine, the piston continues to move upward and approaches TDC; the compression ignition drive cam drives the compression ignition drive plunger to TDC, and the hydraulic oil drives the compression ignition plunger to bottom dead center; the temperature of the air-fuel mixture in the compression ignition pre-combustion chamber reaches the fuel auto-ignition temperature and achieves homogeneous compression ignition; the injection drive cam drives the injection drive plunger to begin moving upward, incompressible hydraulic oil flows into the high-pressure oil chamber of the injection plunger and pushes the injection plunger downward, the injection valve disengages from the lower edge of the injection orifice, and the injection chamber communicates with the main combustion chamber; the downward movement of the injection plunger forces the hydraulic oil in the low-pressure oil chamber of the injection plunger into the low-pressure oil outlet; the high-temperature, high-pressure air-fuel mixture in the compression ignition pre-combustion chamber is injected into the main combustion chamber, and the high-temperature jet air-fuel mixture ignites the fuel-air mixture in the main combustion chamber; In the early stage of the power stroke of the internal combustion engine, the piston continues to descend; the compression ignition drive cam drives the compression ignition drive plunger to remain at top dead center, and the high-pressure hydraulic oil drives the compression ignition plunger to remain at bottom dead center; the injection drive cam drives the injection drive plunger to continue to rise and reach top dead center, and the injection plunger continues to descend under the drive of hydraulic oil and reaches bottom dead center; after the injection drive plunger remains at top dead center for a period of time, the injection drive plunger begins to descend under the drive of the injection drive plunger spring; after the injection plunger remains at bottom dead center for a period of time, the injection drive plunger begins to descend under the drive of the injection drive plunger spring. At this time, the flame in the main combustion chamber gradually spreads to the surroundings through propagation, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to bottom dead center and outputting power. During the later stages of the power stroke of an internal combustion engine, the piston continues to descend and reaches bottom dead center; the compression ignition drive plunger spring drives the compression ignition drive plunger to begin descending, and the compression ignition plunger spring also drives the compression ignition plunger to begin ascending; the injection drive plunger continues to descend and reaches bottom dead center under the drive of the injection drive plunger spring, and the injection plunger continues to ascend and reaches top dead center under the drive of the injection plunger spring; the injection plunger drives the injection valve to ascend, causing the injection valve to re-engage with the lower edge of the injection orifice, and the injection chamber and the main combustion chamber are disconnected again; at this time, the flame in the main combustion chamber is transmitted to the entire main combustion chamber through propagation, and the pressure and temperature of the air-fuel mixture in the main combustion chamber rise, pushing the piston to move to bottom dead center and outputting power; due to the increased volume of the low-pressure oil chambers of the compression ignition plunger and the injection plunger, the hydraulic oil pressure decreases, and external hydraulic oil enters the low-pressure oil chambers of the compression ignition plunger and the injection plunger through the third check valve and the low-pressure oil inlet. During the exhaust stroke of an internal combustion engine, the piston moves from bottom dead center to top dead center, expelling the exhaust gas from the main combustion chamber through the exhaust passage. The compression ignition drive plunger spring drives the compression ignition drive plunger to continue downward and reach bottom dead center, and the compression ignition plunger spring drives the compression ignition plunger to continue upward and reach top dead center. Near the top dead center, the compression ignition plunger first connects the exhaust chamber with the compression ignition pre-combustion chamber, and the mixture in the pre-combustion chamber rapidly enters the exhaust chamber under its own pressure to achieve free exhaust. The compression ignition plunger continues to rise until... At top dead center, the intake chamber, the exhaust chamber, and the compression ignition pre-combustion chamber are interconnected. Fresh fuel-air mixture enters the compression ignition pre-combustion chamber through the intake chamber, forcing residual exhaust gas in the compression ignition pre-combustion chamber into the exhaust chamber for continuous scavenging and gas exchange. The injection drive plunger is held at bottom dead center by the injection drive plunger spring and at top dead center by the injection plunger spring. The injection plunger drives the injection valve to contact the lower edge of the injection orifice, disconnecting the injection chamber from the main combustion chamber. During the intake stroke of an internal combustion engine, the piston moves from top dead center to bottom dead center, drawing air from the intake manifold into the main combustion chamber. Later in the intake stroke, the compression ignition drive plunger cam drives the compression ignition drive plunger to begin moving upwards, and hydraulic oil enters the high-pressure oil chamber of the compression ignition plunger, pushing it downwards. During the intake stroke, the injection drive plunger is held at bottom dead center by the injection drive plunger spring, and the injection plunger is held at top dead center by the injection plunger spring. The injection plunger causes the injection valve to contact the lower edge of the injection orifice, disconnecting the injection chamber from the main combustion chamber. After the compression ignition plunger descends, the volume of the low-pressure oil chamber of the compression ignition plunger decreases. Part of the hydraulic oil in the low-pressure oil chamber of the compression ignition plunger is forced into the low-pressure oil outlet passage, and the other part of the hydraulic oil is forced into the low-pressure oil chamber of the injection plunger and then enters the low-pressure oil outlet passage. After the compression ignition plunger descends a certain distance, it first disconnects the intake chamber from the compression ignition pre-combustion chamber. As the compression ignition plunger continues to descend, a portion of the fresh mixture in the compression ignition pre-combustion chamber is pushed out through the exhaust chamber. Then, the compression ignition plunger disconnects the exhaust chamber from the compression ignition pre-combustion chamber, sealing the compression ignition pre-combustion chamber.

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