Engine combustion system and mechanical device

Abstract

This application relates to the field of engine technology, providing an engine combustion system and mechanical equipment. The provided engine combustion system includes a cylinder block, piston, cylinder head, pre-combustion chamber, ignition mechanism, main injection system, pre-injection system, and fuel pump. The cylinder block contains a cylinder, and the piston is movably disposed within the cylinder. The cylinder head covers the cylinder block, and the cylinder head, the inner wall of the cylinder, and the piston together form the main combustion chamber. The pre-combustion chamber is located in the cylinder head and communicates with the main combustion chamber. The volume of the pre-combustion chamber is smaller than that of the main combustion chamber. The ignition mechanism includes a spark plug, which is located in the pre-combustion chamber with its head extending into it. The main injection system communicates with the main combustion chamber and is used to inject fuel into it. The pre-injection system communicates with the pre-combustion chamber and is used to inject fuel into it. Both the main injection system and the pre-injection system are connected to the fuel pump. This solution can solve the problems of poor ignition reliability and short service life of spark plugs in engines using lean-burn technology in the prior art.

Description

Technical Field

[0001] This application relates to the field of engine technology, specifically to an engine combustion system and mechanical equipment. Background Technology

[0002] To improve thermal efficiency, existing engines typically employ lean-burn technology. Increasing the air-fuel ratio allows for more complete combustion within the engine cylinder, thereby improving thermal efficiency. However, traditional spark plugs suffer from poor ignition reliability and short lifespan under lean-burn conditions. Summary of the Invention

[0003] In view of this, this application provides an engine combustion system and mechanical device to solve the problems of poor ignition reliability and short service life of spark plugs in engines using lean-burn technology in the prior art.

[0004] To achieve the above objectives, this application provides the following technical solution: An engine combustion system, comprising: The cylinder block is equipped with a cylinder; The piston is movably disposed within the cylinder; A cylinder head is installed on the cylinder block, and the cylinder head, the inner wall of the cylinder, and the piston together form the main combustion chamber; A pre-combustion chamber is located in the cylinder head and is connected to the main combustion chamber. The volume of the pre-combustion chamber is smaller than the volume of the main combustion chamber. An ignition mechanism, including a spark plug, wherein the spark plug is disposed in the pre-combustion chamber and its head extends into the pre-combustion chamber; The main injection system, connected to the main combustion chamber, is used to inject fuel into the main combustion chamber; A pre-injection system, connected to the pre-combustion chamber, is used to inject fuel into the pre-combustion chamber; A fuel pump is provided, and both the main injection system and the pre-injection system are connected to the fuel pump.

[0005] Optionally, the fuel injected into the pre-combustion chamber by the pre-injection system is 1% to 10% of the total fuel injection amount of the engine.

[0006] Optionally, the fuel pump is used to provide a first injection pressure to the main injection system, the first injection pressure being P1, 500≤P1≤2000bar, and the fuel pump is used to provide a second injection pressure to the pre-injection system, the second injection pressure being P2, 100≤P2≤500bar.

[0007] Optionally, the pre-combustion chamber includes an outer shell, a chamber disposed within the outer shell, and a nozzle communicating with the chamber. The outer shell is disposed on the cylinder head, the nozzle is communicating with the main combustion chamber, and the spark plug is disposed on the outer shell and used to generate an electric spark in the chamber. Both the pre-combustion chamber and the cylinder have a central axis. The central axis of the pre-combustion chamber and the central axis of the cylinder are parallel and staggered. The chamber has an asymmetrical structure relative to the central axis of the pre-combustion chamber. There are multiple nozzles, which are asymmetrically distributed relative to the central axis of the pre-combustion chamber.

[0008] Optionally, the number of nozzles is 4 to 8.

[0009] Optionally, the engine combustion system further includes a crankshaft connected to the piston for driving the piston to reciprocate within the cylinder, and the pre-injection system is configured to begin injecting fuel into the pre-combustion chamber during the engine's compression stroke, within a crankshaft angle range of 20° to 240° before top dead center.

[0010] Optionally, the cylinder head is provided with an intake passage communicating with the main combustion chamber, the intake passage being used to form a vortex in the main combustion chamber.

[0011] Optionally, the piston has an ω-shaped cross-section, which is perpendicular to the piston's axis.

[0012] Optionally, the engine includes an intake manifold, intake valves, and a timing system, wherein: The air intake manifold is located in the cylinder head; The intake valve is closable and mounted on the cylinder head. When the intake valve is in the open state, the intake passage is connected to the main combustion chamber. The timing system is located on the cylinder head and is connected to the intake valve to drive the opening and closing of the intake valve; The timing system includes a first state and a second state. In the first state, the intake valve is open for a first duration. In the second state, the intake valve is open for a second duration, and the first duration is longer than the second duration.

[0013] Optionally, the timing system includes a camshaft, a first cam, a second cam, a first rocker arm, a second rocker arm, a first shaft, and a second shaft, wherein: Both the first cam and the second cam are fixedly mounted on the camshaft, and along the axial direction of the camshaft, the projection of the first cam is located within the projection of the second cam; Both the first rocker arm and the second rocker arm are rotatably mounted on the cylinder head via the first shaft. One end of the first rocker arm is rotatably connected to the intake valve, and the other end can abut against the first cam. Both the first rocker arm and the second rocker arm are provided with through holes located on the side of the first shaft opposite to the intake valve. The second shaft can be switched between a first position and a second position. In the first position, the second shaft passes through the through holes of the first rocker arm and the second rocker arm, the second rocker arm is engaged with the second cam, the first rocker arm is separated from the first cam, and the timing system is in the first state; In the second position, the second shaft is separated from the first rocker arm and the second rocker arm, the first rocker arm abuts against the first cam, the second rocker arm is disabled, and the timing system is in the second state.

[0014] A mechanical device comprising an engine combustion system as described in any of the preceding claims. The mechanical device includes, but is not limited to, vehicles, ships, construction machinery, and generator sets.

[0015] In this embodiment, the engine combustion system includes a pre-combustion chamber. The main injection system and the pre-injection system supply fuel to the main combustion chamber and pre-combustion chamber respectively. The volume of the pre-combustion chamber is smaller than that of the main combustion chamber. Fuel combustion within a smaller space facilitates rapid energy accumulation, resulting in higher combustion temperature and pressure peaks in a shorter time. This provides the necessary ignition energy density for the spark plug. Furthermore, the air-fuel ratio inside the pre-combustion chamber can be controlled by the pre-injection system, creating excellent ignition conditions and ensuring effective ignition. This achieves stable ignition under lean-burn conditions, guaranteeing ignition reliability. The spark plug is located in the pre-combustion chamber, with its head extending into the chamber, thus avoiding direct combustion in the main combustion chamber and preventing direct impact from the high-temperature airflow during intense combustion in the main combustion chamber. This reduces spark plug wear and extends its service life. Therefore, the engine combustion system provided in this embodiment can solve the problems of poor ignition reliability and short service life of spark plugs in engines using lean-burn technology. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the engine combustion system provided in an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the pre-combustion chamber provided in an embodiment of this application.

[0019] Figure 3 The timing system provided in this application is shown in a schematic diagram of the first state (left figure) and the second state (right figure).

[0020] exist Figures 1-3 middle: 100. Cylinder block; 200. Piston; 300. Cylinder head; 400. Main combustion chamber; 500. Pre-combustion chamber; 510. Shell; 520. Cap; 521. Nozzle; 530. Double-ended stud; 600. Ignition mechanism; 610. Spark plug; 710. Main injection high-pressure common rail pipe; 720. Main injection nozzle; 810. Pre-sprayed high-pressure common rail pipe; 820. Pre-sprayed nozzle; 900. Fuel pump; 1000, Intake valve; 1100, Timing system; 1110, Camshaft; 1120, First cam; 1130, Second cam; 1140, First rocker arm; 1150, Second rocker arm; 1160, First shaft; 1170, Second shaft; 1180, Perforation; 1200, turbocharger; 1300, fuel tank; 1400, post-processor; 1500, Electrical Control Unit. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] like Figures 1-3 As shown, this application provides an engine combustion system. The engine can be a methanol engine, or it can be an engine using other fuels. This engine combustion system includes a cylinder block 100, a piston 200, a cylinder head 300, a main combustion chamber 400, a pre-combustion chamber 500, an ignition mechanism 600, a main injection system, a pre-injection system, and a fuel pump 900.

[0023] The cylinder block 100 contains a cylinder, and a piston 200 is movably disposed within the cylinder to reciprocate within it. A cylinder head 300 covers the cylinder block 100. The cylinder head 300, the inner wall of the cylinder, and the piston 200 together form the main combustion chamber 400. A pre-combustion chamber 500 is disposed within the cylinder head 300. The volume of the pre-combustion chamber 500 is smaller than that of the main combustion chamber 400, accounting for approximately 1% to 4% of the main combustion chamber volume. The pre-combustion chamber 500 is connected to the main combustion chamber 400. The ignition mechanism 600 includes a spark plug 610, which is disposed within the pre-combustion chamber 500 with its head extending into the pre-combustion chamber 500. The ignition mechanism 600 also includes an ignition coil, which can be disposed within the cylinder head 300. The ignition coil is connected to the spark plug 610 and provides the high-voltage electricity required for ignition of the spark plug 610.

[0024] The main injection system is connected to the main combustion chamber 400 and is used to inject fuel into the main combustion chamber 400. The pre-injection system is connected to the pre-combustion chamber 500 and is used to inject fuel into the pre-combustion chamber 500. Both the main injection system and the pre-injection system are connected to the fuel pump 900.

[0025] Specifically, the main injection system may include a main injection high-pressure common rail 710 and a main injection nozzle 720. The main injection nozzle 720 may be located in the cylinder head 300, and its head may extend into the main combustion chamber 400. The pre-injection system may include a pre-injection high-pressure common rail 810 and a pre-injection nozzle 820. The pre-injection nozzle 820 may be located in the pre-combustion chamber 500, and its head may extend into the pre-combustion chamber 500.

[0026] Fuel pump 900 can be connected to fuel tank 1300. Fuel pump 900 can have 3 high-pressure plungers. One plunger is connected to pre-injection high-pressure common rail pipe 810 to supply fuel to pre-injection high-pressure common rail pipe 810. Pre-injection high-pressure common rail pipe 810 is connected to pre-injection nozzle 820, which is used to inject fuel into pre-combustion chamber 500. The other 2 plungers of fuel pump 900 are connected to main injection high-pressure common rail pipe 710 to supply fuel to main injection high-pressure common rail pipe 710. Main injection high-pressure common rail pipe 710 is connected to main injection nozzle 720, which is used to inject fuel into main combustion chamber 400.

[0027] In this embodiment, the engine combustion system is equipped with a pre-combustion chamber 500, and the main injection system and the pre-injection system provide fuel to the main combustion chamber 400 and the pre-combustion chamber 500 respectively. The volume of the pre-combustion chamber 500 is smaller than that of the main combustion chamber 400. The fuel burns in a smaller space, which helps to quickly accumulate energy and form a higher combustion temperature and pressure peak in a shorter time. This provides the spark plug 610 with the required ignition energy density. Furthermore, the air-fuel ratio inside the pre-combustion chamber 500 can be controlled by the pre-injection system to create excellent ignition conditions for the pre-combustion chamber 500, ensuring the ignition effect inside the pre-combustion chamber 500 and achieving stable ignition under lean-burn conditions, thus ensuring ignition reliability. The spark plug 610 is located in the pre-combustion chamber 500, with its head extending into the pre-combustion chamber 500, thus escaping the direct combustion environment of the main combustion chamber 400. This avoids the direct impact of the high-temperature airflow during the intense combustion in the main combustion chamber 400, reduces the working wear of the spark plug 610, and extends the service life of the spark plug 610. Therefore, it can be seen that the engine combustion system provided in this application embodiment can solve the problems of poor ignition reliability and short service life of spark plugs in engines using lean-burn technology.

[0028] The fuel injected into the pre-combustion chamber 500 by the pre-injection system can be 1% to 10% of the total fuel injection amount of the engine, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. If the proportion of fuel injected into the pre-combustion chamber 500 by the pre-injection system is less than 1% of the total injection amount, the air-fuel mixture concentration inside the pre-combustion chamber 500 will be too low, making it difficult to form a combustible mixture that meets the requirements for reliable ignition, easily leading to ignition failure and unstable sparking. Since combustion inside the pre-combustion chamber 500 cannot directly perform work, if the proportion of fuel injected into the pre-combustion chamber 500 by the pre-injection system exceeds 10% of the total injection amount, it will cause fuel waste, which in turn will lead to a decrease in the overall thermal efficiency of the engine. Therefore, the proportion of fuel injected into the pre-combustion chamber 500 by the pre-injection system within the range of 1% to 10% can achieve reliable ignition while preventing fuel waste.

[0029] Appropriately increasing the fuel injection ratio of the pre-combustion chamber 500 within the range of 1% to 10% can increase the internal air-fuel mixture concentration compared to the state without increasing the injection ratio, accelerate the flame propagation speed in the pre-combustion chamber 500, and make it easier to ignite the lean mixture in the main combustion chamber 400 through multiple nozzles 521 (see below), thereby accelerating the diffusion and combustion rate of the mixture in the main combustion chamber 400 and improving the engine's combustion thermal efficiency. At the same time, it can optimize the air exchange efficiency of the pre-combustion chamber 500, effectively ensuring and improving the ignition effect of the pre-combustion chamber 500.

[0030] Fuel pump 900 is used to provide a first injection pressure to the main injection system, the first injection pressure being P1, 500≤P1≤2000bar, for example, P1 can be 500bar, 1000bar, 1500bar, or 2000bar. Fuel pump 900 is used to provide a second injection pressure to the pre-injection system, the second injection pressure being P2, 100≤P2≤500bar, for example, P2 can be 100bar, 300bar, or 500bar.

[0031] In this configuration, fuel pump 900 provides the main injection system with a first injection pressure P1 and the pre-injection system with a second injection pressure P2. Through staged high-pressure injection, fuel is directly injected into the pre-combustion chamber 500 and the main combustion chamber 400, optimizing fuel atomization. Compared to port injection, it allows for more precise control of the fuel injection quantity in each cylinder of the current cycle, reducing fuel adhesion to the cylinder walls and resolving the injection interference issues associated with port injection. Simultaneously, thorough atomization and mixing accelerate the flame propagation speed, reduce combustion knock, achieve more complete combustion, and improve thermal efficiency.

[0032] The first injection pressure P1 can be varied according to different operating loads and environmental conditions. When the engine is running at low load (below 30%), the fuel injection quantity is relatively small, and the in-cylinder compression combustion temperature is relatively low. Using a lower first injection pressure P1 can weaken the fuel evaporation heat absorption effect and prevent combustion degradation caused by excessive "cooling" in the cylinder. Therefore, when the engine is running at low load, the first injection pressure P1 can be less than 1000 bar. As the engine load gradually increases, the first injection pressure P1 can be gradually increased to shorten the injection duration, improve atomization, and optimize the in-cylinder combustion state.

[0033] The main injection system adopts a high-pressure injection design, which can achieve excellent fuel atomization effect. Even under the condition of large fuel injection volume, it can still ensure the full breakup and uniform atomization of fuel droplets, forming an ideal in-cylinder injection atomization field. This significantly promotes the spread of flame, thereby increasing the in-cylinder combustion rate, improving combustion quality, reducing the probability of combustion knock, and achieving complete combustion of fuel in the cylinder.

[0034] Compared to the main combustion chamber 400, the pre-combustion chamber 500 requires less fuel and has a shorter fuel injection duration. Therefore, the second injection pressure P2 of the pre-injection system can be lower than the first injection pressure P1. Because the pre-combustion chamber 500 has a smaller space, setting the injection pressure of the pre-injection system to the second injection pressure P2 can alleviate the problem of fuel injection hitting the wall during fuel injection and prevent structural damage to the inner wall of the pre-combustion chamber 500 caused by long-term scouring of the inner wall by the high-pressure fuel jet.

[0035] Of course, after the pre-combustion chamber 500 has been working for a period of time (e.g., the first preset time), the injection pressure of the pre-injection system can be increased to make it greater than the second injection pressure P2, so as to perform high-pressure flushing on the chamber and nozzle 521 of the pre-combustion chamber 500 (see below for details), so as to avoid the accumulation of residual products in the nozzle 521 due to long-term operation and ensure the injection and ignition effect of the pre-combustion chamber 500.

[0036] In an alternative embodiment, the pre-combustion chamber 500 may be a chamber directly disposed on the cylinder head 300.

[0037] In one optional embodiment, the pre-combustion chamber 500 may include a housing, a chamber disposed within the housing, and a nozzle 521 communicating with the chamber. The housing may include a shell 510 and a cap 520 detachably connected to the shell 510. The shell 510 may be mounted to the cylinder head 300 via a double-ended stud 530. The cap 520 may be provided with multiple nozzles 521, which communicate with the main combustion chamber 400. A spark plug 610 may be disposed in the housing, and the head of the spark plug 610 may extend into the chamber. The spark plug 610 is used to generate an electric spark in the chamber, thereby igniting the pre-combustion chamber 500.

[0038] Both the pre-combustion chamber 500 and the cylinder have a central axis. The central axis of the pre-combustion chamber 500 and the central axis of the cylinder satisfy the parallel condition and are staggered. The chamber has an asymmetrical structure relative to the central axis of the pre-combustion chamber 500. There are multiple nozzles 521, and the multiple nozzles 521 are asymmetrically distributed relative to the central axis of the pre-combustion chamber 500.

[0039] Optionally, the number of nozzles 521 can be 4 to 8, for example, 4, 6, or 8. It should be noted that the parallelism between the central axis of the pre-combustion chamber 500 and the central axis of the cylinder means that the central axis of the pre-combustion chamber 500 and the central axis of the cylinder are parallel or approximately parallel. For example, the angle between the central axis of the pre-combustion chamber 500 and the central axis of the cylinder can be in the range of 0 to 15°.

[0040] In this configuration, the pre-combustion chamber 500 is connected to the main combustion chamber 400 via multiple nozzles 521. This allows for multi-point ignition of the combustible mixture within the main combustion chamber 400 through these nozzles, significantly accelerating flame propagation and further enhancing the overall ignition stability of the engine. This promotes complete combustion of the mixture in the main combustion chamber 400, effectively improving the engine's thermal efficiency. Furthermore, the asymmetrical design of both the pre-combustion chamber 500 and the multiple nozzles 521 facilitates proper air exchange, injection, and ignition within the pre-combustion chamber 500.

[0041] The engine combustion system also includes a crankshaft connected to piston 200, which drives piston 200 to reciprocate within the cylinder. The pre-injection system is configured to begin injecting fuel into the pre-combustion chamber 500 during the engine's compression stroke, within a crankshaft angle range of 20° to 240° before top dead center. If fuel injection begins too early, excessive fuel will be discharged into the main combustion chamber 400 during the scavenging process due to airflow within the pre-combustion chamber 500, resulting in a low air-fuel ratio in the pre-combustion chamber 500 and affecting ignition and flame propagation. Conversely, if injection occurs too late, the air-fuel mixture within the pre-combustion chamber 500 will be poor, affecting scavenging and leading to excessive residual exhaust gas in the pre-combustion chamber 500, which will also affect ignition and flame propagation.

[0042] The cylinder head 300 may be provided with an intake passage that communicates with the main combustion chamber 400. The intake passage is used to form a vortex in the main combustion chamber 400. The intake passage may be a spiral intake passage or a tangential intake passage. This type of intake passage can form a stable clockwise airflow around the cylinder center axis in the main combustion chamber 400, so that the main body of the airflow in the cylinder is in a strong vortex state with a vortex ratio ≥1.2, which is conducive to the uniform mixing of fuel and air and improves the combustion efficiency of the engine.

[0043] The cross-sectional shape of piston 200 can be ω-shaped, and the cross-section of piston 200 is perpendicular to the axis of piston 200. The structure of strong vortex combined with ω-shaped piston 200 can effectively avoid problems such as local fuel accumulation, uneven air-fuel mixture concentration, unstable combustion and combustion knocking that are easily caused by traditional tumble flow, and increase the engine compression ratio to 17:1 and above, thereby improving the in-cylinder combustion thermal efficiency.

[0044] The engine also includes an intake valve 1000 and a timing system 1100. The intake valve 1000 is mounted on the cylinder head 300 in an openable and closable manner. When the intake valve 1000 is in the open state, the intake passage is connected to the main combustion chamber 400. When the intake valve 1000 is in the closed state, the intake passage is not connected to the main combustion chamber 400. The timing system 1100 may be located on the cylinder head 300. The timing system 1100 is connected to the intake valve 1000 and is used to drive the opening and closing of the intake valve 1000.

[0045] The timing system 1100 may include a first state and a second state. In the first state, the opening duration of the intake valve 1000 is a first duration. In the second state, the opening duration of the intake valve 1000 is a second duration. The first duration is longer than the second duration.

[0046] The timing system 1100 can adopt a Miller cycle timing scheme, which has a first state and a second state. The Miller degree of the first state is smaller, and the Miller degree of the second state is larger. The difference in Miller degree between the two states can be set in the range of 20°CA to 40°CA, for example, 20°CA, 30°CA, or 40°CA.

[0047] In the first state, the intake valve 1000 is open for a relatively long time, resulting in high intake efficiency and ensuring good power and torque output characteristics for the engine. This is suitable for engine operation under high load conditions above 60%. When the engine is operating under medium to low load conditions below 60%, the intake demand is smaller, and the second state can be used to control the opening and closing of the intake valve 1000. In the second state, the intake valve 1000 is open for a relatively short time, which can effectively reduce engine pumping losses, improve the overall operating efficiency of the engine, and reduce throttling losses in the idling and low load areas, improving operational control stability and thus increasing the efficiency of the engine combustion system by 1% to 2%.

[0048] Specifically, the timing system 1100 may include a camshaft 1110, a first cam 1120, a second cam 1130, a first rocker arm 1140, a second rocker arm 1150, a first shaft 1160, and a second shaft 1170.

[0049] The camshaft 1110 may be equipped with gears, and the crankshaft may be equipped with gears. The gears of the camshaft 1110 may mesh with the gears of the crankshaft so that the camshaft 1110 and the crankshaft are connected for transmission and rotate synchronously. The first cam 1120 and the second cam 1130 may be an integral structure with the camshaft 1110. The first cam 1120 and the second cam 1130 may also be fixed to the camshaft 1110 by means of sleeve, spline connection, etc., so that the first cam 1120 and the second cam 1130 rotate with the rotation of the camshaft 1110. Along the axial direction of the camshaft 1110, the projection of the first cam 1120 is located within the projection of the second cam 1130.

[0050] The first rocker arm 1140 and the second rocker arm 1150 are both rotatably mounted on the cylinder head 300 via the first shaft 1160, and the first rocker arm 1140 and the second rocker arm 1150 are rotatably connected to the same first shaft 1160. One end of the first rocker arm 1140 can be rotatably connected to the intake valve 1000, and the other end can abut against the first camshaft 1120. The first rocker arm 1140 and the second rocker arm 1150 can both be provided with a through hole 1180, which is located on the side of the first shaft 1160 away from the intake valve 1000 (i.e., the side adjacent to the camshaft 1100). The second shaft 1170 can switch between the first position and the second position.

[0051] Optionally, the timing system 1100 may include a power mechanism, which may be connected to the cylinder head 300. The power mechanism is connected to the second shaft 1170 and can drive the second shaft 1170 to switch between a first position and a second position. The power mechanism may be a linear motor or a ball screw structure.

[0052] like Figure 3 As shown in the left figure, in the first position, the second shaft 1170 passes through the through hole 1180 of the first rocker arm 1140 and the second rocker arm 1150. Under the combined action of the first shaft 1160 and the second shaft 1170, the first rocker arm 1140 and the second rocker arm 1150 move synchronously and are at the same height. Since the projection of the first cam 1120 is located within the projection of the second cam 1130, the top height of the profile of the first cam 1120 is lower than the top height of the profile of the second cam 1130. As a result, the second rocker arm 1150 overlaps the second cam 1130. There is a certain distance between the first rocker arm 1140 and the first cam 1120, and the first rocker arm 1140 is separated from the first cam 1120.

[0053] In this situation, the rotation of the second cam 1130 can drive the second rocker arm 1150 to rotate around the first shaft 1160. Under the action of the second shaft 1170, the rotation of the second rocker arm 1150 around the first shaft 1160 can drive the first rocker arm 1140 to rotate around the first shaft 1160. The rotation of the first rocker arm 1140 around the first shaft 1160 can drive the intake valve 1000 to move, thereby causing the intake valve 1000 to switch between opening and closing. In this state, the timing system 1100 is in the first state.

[0054] The power mechanism drives the second shaft 1170 to be pulled out of the through hole 1180, causing the second shaft 1170 to switch to the second position, such as... Figure 3 As shown in the right figure, in the second position, the second shaft 1170 is separated from the first rocker arm 1140 and the second rocker arm 1150. Except for the first shaft 1160, the second rocker arm 1150 has no other connection with the first rocker arm 1140. In this way, even if the second rocker arm 1150 moves, it cannot affect the movement of the first rocker arm 1140. The second rocker arm 1150 is ineffective, and the first rocker arm 1140 abuts against the first cam 1120. The rotation of the first cam 1120 can drive the first rocker arm 1140 to rotate around the first shaft 1160. The rotation of the first rocker arm 1140 around the first shaft 1160 can drive the intake valve 1000 to move, thereby switching the intake valve 1000 between opening and closing. In this state, the timing system 1100 is in the second state.

[0055] The number of intake valves 1000 can be one or more, and the number of first cams 1120 and first rocker arms 1140 is the same as that of intake valves 1000 and they are installed in a one-to-one correspondence.

[0056] The engine combustion system may also include a turbocharger 1200, an after-treatment system 1400, and an electronic control unit 1500. The turbocharger 1200 may be located on the intake manifold, which is connected to the intake duct. The turbocharger 1200 may also be located on the exhaust manifold, which is connected to the exhaust duct (located on the cylinder head 300 and connected to the main combustion chamber 400; of course, the cylinder head 300 is also equipped with an exhaust valve, which controls whether the main combustion chamber 400 is connected to the exhaust duct by opening and closing). The exhaust manifold may be connected to the after-treatment system 1400, which can treat the gas discharged from the main combustion chamber 400 to prevent pollution.

[0057] The electronic control unit 1500 can be connected to the ignition mechanism 600, fuel pump 900, timing system 1100, turbocharger 1200, after-treatment system 1400 and other mechanisms via electrical wiring harnesses, thereby controlling the engine combustion system.

[0058] Based on the aforementioned engine combustion system, this application also provides a mechanical device, including but not limited to: vehicles, ships, construction machinery, and generator sets, which includes the aforementioned engine combustion system. Since this mechanical device possesses the aforementioned engine combustion system, the beneficial effects brought about by the engine combustion system are described above and will not be repeated here.

[0059] The engine combustion system can use methanol as fuel, but it can also use other fuels such as diesel, gasoline, and biofuel. At the same time, natural gas, hydrogen, and other gases can be injected into the pre-combustion chamber for ignition.

[0060] The engine combustion system in this application involves a methanol high-pressure injection system, a high-efficiency ignition system, a Miller cycle intake system, and a high-vortex combustion chamber design. It comprehensively upgrades and optimizes the injection, atomization, mixing, ignition, and combustion processes of the methanol engine, achieving a comprehensive improvement in thermal efficiency, power density, cold start performance, and power responsiveness.

[0061] The design of the injection, intake, combustion, and ignition systems of the engine combustion system in this application embodiment can achieve efficient intake, efficient ignition, good injection evaporation atomization effect, uniform air-fuel mixture, and good jet diffusion ignition effect. With precise control, it can achieve optimal combustion organization, reduce heat loss, and significantly improve thermal efficiency.

[0062] The engine combustion system in this embodiment features direct methanol injection into the cylinder and a pre-combustion chamber jet ignition structure, ensuring effective fuel-air mixing within the pre-combustion chamber 500 and achieving low-temperature ignition. Simultaneously, due to the controlled direct injection, methanol achieves excellent in-cylinder evaporation and atomization, resulting in uniform mixing and complete combustion. Because of the characteristics of methanol fuel, there is minimal co-burning of carbon soot. Furthermore, the high-efficiency combustion system design of this invention further expands the lean-burn range, reduces the temperature of the in-cylinder mixture, and decreases the generation of NOx pollutants, thus exhibiting clean combustion characteristics.

[0063] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0064] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0065] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0066] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0067] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0068] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. An engine combustion system, characterized in that, include: The cylinder block (100) is equipped with a cylinder; The piston (200) is movably disposed within the cylinder; A cylinder head (300) is installed on the cylinder block (100). The cylinder head (300), the inner wall of the cylinder, and the piston (200) together form the main combustion chamber (400). A pre-combustion chamber (500) is provided on the cylinder head (300), the pre-combustion chamber (500) is connected to the main combustion chamber (400), and the volume of the pre-combustion chamber (500) is smaller than the volume of the main combustion chamber (400); The ignition mechanism (600) includes a spark plug (610) disposed in the pre-combustion chamber (500) with its head extending into the pre-combustion chamber (500); The main injection system is connected to the main combustion chamber (400) and is used to inject fuel into the main combustion chamber (400); A pre-injection system, connected to the pre-combustion chamber (500), is used to inject fuel into the pre-combustion chamber (500); Fuel pump (900), the main injection system and the pre-injection system are both connected to the fuel pump (900).

2. The engine combustion system according to claim 1, characterized in that, The fuel injected into the pre-combustion chamber (500) by the pre-injection system is 1% to 10% of the total fuel injection amount of the engine.

3. The engine combustion system according to claim 1 or 2, characterized in that, The fuel pump (900) is used to provide a first injection pressure to the main injection system, the first injection pressure being P1, 500≤P1≤2000bar, and the fuel pump (900) is used to provide a second injection pressure to the pre-injection system, the second injection pressure being P2, 100≤P2≤500bar.

4. The engine combustion system according to claim 1, characterized in that, The pre-combustion chamber (500) includes an outer shell, a chamber disposed within the outer shell, and a nozzle (521) communicating with the chamber. The outer shell is disposed on the cylinder head (300), and the nozzle (521) communicates with the main combustion chamber (400). The spark plug (610) is disposed on the outer shell and is used to generate an electric spark in the chamber. Both the pre-combustion chamber (500) and the cylinder have a central axis. The central axis of the pre-combustion chamber (500) and the central axis of the cylinder are parallel and staggered. The chamber is asymmetrical with respect to the central axis of the pre-combustion chamber (500). There are multiple nozzles (521), and the multiple nozzles (521) are asymmetrically distributed with respect to the central axis of the pre-combustion chamber (500).

5. The engine combustion system according to claim 4, characterized in that, The number of nozzles (521) is 4 to 8.

6. The engine combustion system according to claim 1, characterized in that, The engine combustion system also includes a crankshaft connected to the piston (200) for driving the piston (200) to reciprocate within the cylinder. The pre-injection system is configured to inject fuel into the pre-combustion chamber (500) during the engine's compression stroke, within a crankshaft angle range of 20° to 240° before top dead center.

7. The engine combustion system according to claim 1, characterized in that, The cylinder head (300) is provided with an intake passage that communicates with the main combustion chamber (400), the intake passage being used to form a vortex within the main combustion chamber (400).

8. The engine combustion system according to claim 1 or 7, characterized in that, The piston (200) has an ω-shaped cross-section, which is perpendicular to the axis of the piston (200).

9. The engine combustion system according to claim 1, characterized in that, The engine includes an intake manifold, intake valves (1000), and a timing system (1100), wherein: The air intake is located in the cylinder head (300); The intake valve (1000) is closably mounted on the cylinder head (300), and when the intake valve (1000) is in the open state, the intake passage is connected to the main combustion chamber (400); The timing system (1100) is located on the cylinder head (300) and is connected to the intake valve (1000) for driving the opening and closing of the intake valve (1000); The timing system (1100) includes a first state and a second state. In the first state, the opening duration of the intake valve (1000) is a first duration. In the second state, the opening duration of the intake valve (1000) is a second duration, and the first duration is longer than the second duration.

10. The engine combustion system according to claim 9, characterized in that, The timing system (1100) includes a camshaft (1110), a first cam (1120), a second cam (1130), a first rocker arm (1140), a second rocker arm (1150), a first shaft (1160), and a second shaft (1170), wherein: The first cam (1120) and the second cam (1130) are both fixedly mounted on the camshaft (1110). Along the axial direction of the camshaft (1110), the projection of the first cam (1120) is located within the projection of the second cam (1130). The first rocker arm (1140) and the second rocker arm (1150) are rotatably mounted on the cylinder head (300) via the first shaft (1160). One end of the first rocker arm (1140) is rotatably connected to the intake valve (1000), and the other end can abut against the first cam (1120). Both the first rocker arm (1140) and the second rocker arm (1150) are provided with a through hole (1180). The through hole (1180) is located on the side of the first shaft (1160) away from the intake valve (1000). The second shaft (1170) can switch between a first position and a second position. In the first position, the second shaft (1170) passes through the through hole (1180) of the first rocker arm (1140) and the second rocker arm (1150), the second rocker arm (1150) overlaps the second cam (1130), the first rocker arm (1140) is separated from the first cam (1120), and the timing system (1100) is in the first state; In the second position, the second shaft (1170) is separated from the first rocker arm (1140) and the second rocker arm (1150), the first rocker arm (1140) abuts against the first cam (1120), the second rocker arm (1150) is disabled, and the timing system (1100) is in the second state.

11. A mechanical device, characterized in that, Includes the engine combustion system as described in any one of claims 1-10.

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