Hydrogen internal combustion engine

Abstract

To provide a hydrogen internal combustion engine capable of achieving filling efficiency and highly uniform mixing of hydrogen and air, avoiding abnormal combustion of hydrogen, reducing pollution gas NOx in the hydrogen engine, achieving stable and high output combustion, and being operated with high efficiency.SOLUTION: A cylinder block including a combustion chamber in which hydrogen and air are combusted, a piston that slides in the cylinder block, a cylinder head including an ignition plug, an intake valve seat, an exhaust valve seat, an intake valve that opens and closes the intake valve seat, and an exhaust valve that opens and closes the exhaust valve seat, which are mounted on an upper portion of the combustion chamber, an air supply pipe that supplies air to the combustion chamber, a branch pipe connected to the air supply pipe, an introduction chamber that introduces hydrogen and air into the cylinder block immediately above the intake valve seat at an end portion of the branch pipe, and a hydrogen supply injector that supplies hydrogen into the introduction chamber; An axis of hydrogen injection from a hydrogen injection port of the hydrogen supply injector is attached to be inclined at an acute angle toward an extension direction of the introduction chamber.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a hydrogen internal combustion engine, and more particularly to a hydrogen internal combustion engine in which hydrogen is injected into intake air and burned. [Background technology]

[0002] When hydrogen is burned with air, only water (water vapor) is produced. Unlike the carbon dioxide (CO2) produced when conventional hydrocarbon fuels are burned, carbon monoxide (CO), hydrocarbons (HC), and sulfur oxides (SO x ) and other substances were hardly detected. x ) may be generated depending on the combustion method, but hydrogen internal combustion engines mainly use lean combustion, so only a very small amount of NO x Even if a large amount of NO is generated in the engine, it is not a problem. If a nitrogen oxide detoxification catalyst similar to that used in the combustion of hydrocarbons is installed in the exhaust system, NO x The production of CO₂ can be reduced to a level that can be considered almost zero. For this reason, hydrogen is attracting attention as an extremely clean fuel.

[0003] Therefore, many internal combustion engines that use hydrogen as fuel have been proposed (see Patent Document 1, etc.). For example, the fuel injection device for an internal combustion engine disclosed in Patent Document 1 includes a hydrogen gas injector that injects hydrogen gas, and an ejector body that distributes the hydrogen gas injected from the hydrogen gas injector. The ejector body has an injection port that opens at a position within the intake valve seat of the internal combustion engine, close to the head portion of the intake valve. The ejector body also includes a water injector that injects water into the ejector body.

[0004] Combustion efficiency is improved by mixing and burning fuel and air in the optimal ratio. Unlike hydrocarbon fuels, hydrogen and air have extremely different specific gravities per unit volume. Because hydrogen is extremely light, it is not easy to mix hydrogen and air homogeneously in a short time in an internal combustion engine. In Patent Document 1, water is injected along with the hydrogen to assist mixing with the air for combustion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-44553 Summary of the Invention [Problem to be solved by the invention]

[0006] Ideally, hydrogen and air supplied to the combustion chamber of an internal combustion engine, i.e., the space above the piston, should be mixed and burned instantly and uniformly. x However, as mentioned above, it is not easy to instantly mix hydrogen and combustion air uniformly due to the difference in their specific gravities. Therefore, if a uniform mixture is not achieved, NO x This increases the production of NO and reduces combustion efficiency. x If a water injection mechanism is installed to reduce the generation of ash, the equipment and its control become more complex. The increased complexity of the equipment due to the water injection mechanism may lead to deterioration or damage to the equipment structure due to the effects of heat. Additionally, depending on the performance of the ejector mechanism, there is a concern that the degree of atomization of the water may cause problems, and that the water-containing jet may collide with the combustion chamber wall, resulting in contamination of the lubricating oil.

[0007] The present invention has been made in consideration of the above points, and provides a hydrogen internal combustion engine that uses hydrogen as fuel, which has a hydrogen injection device and achieves uniform mixing of hydrogen and air while avoiding a complicated structure. [Means for solving the problem]

[0008] That is, the hydrogen internal combustion engine of the embodiment comprises a cylinder block having a combustion chamber for burning hydrogen and air, a piston that slides within the cylinder block, an ignition plug attached to the top of the combustion chamber of the cylinder block, a cylinder head having an intake valve seat, an exhaust valve seat, an intake valve that opens and closes the intake valve seat, and an exhaust valve that opens and closes the exhaust valve seat, an air supply pipe that supplies air to the combustion chamber, a branch pipe connected to the air supply pipe, an introduction chamber at the end of the branch pipe directly above the intake valve seat that introduces hydrogen and air into the cylinder block, and a hydrogen supply injector that is connected to the branch pipe and supplies hydrogen to a part of the branch pipe and into the introduction chamber, and is characterized in that the axis of hydrogen injection from the hydrogen nozzle of the hydrogen supply injector is installed so as to be inclined at an acute angle toward the extension direction of the introduction chamber.

[0009] Furthermore, in a hydrogen internal combustion engine, the hydrogen supply injector may be attached to the branch pipe at an angle of 20° to 45° relative to the extension direction of the introduction chamber, with the axis of hydrogen injection from the hydrogen outlet of the hydrogen supply injector facing in the extension direction of the introduction chamber.

[0010] Furthermore, in a hydrogen internal combustion engine, an extension of the axis of hydrogen injection from the hydrogen nozzle of the hydrogen supply injector may be positioned directly above the intake valve.

[0011] Furthermore, in a hydrogen internal combustion engine, the introduction chamber may be formed in a sideways L-shape within the cylinder block.

[0012] Furthermore, in a hydrogen internal combustion engine, a spark plug, an intake valve seat, an exhaust valve seat, an intake valve, and an exhaust valve may be provided in each cylinder in the cylinder head, and at least two intake valve seats and two intake valves may be provided in each cylinder.

[0013] Furthermore, in a hydrogen internal combustion engine, an end of a branch pipe of the air supply pipe may be connected to the cylinder head substantially perpendicular to the axis of sliding of the piston in the cylinder block. Also, a recess may be formed in the upper surface of the piston. In addition, the upper part of the combustion chamber may be flat.

[0014] Furthermore, in a hydrogen internal combustion engine, the closing timing of the hydrogen supply injector may be constant at 30°±10° crank angle before the intake valve closing timing of the intake valve seat, and the opening timing of the hydrogen supply injector may be at most 30°±10° crank angle after the intake valve opening timing of the intake valve seat. Also, an injection pressure adjusting device for adjusting the hydrogen injection pressure may be provided upstream of the hydrogen supply injector. [Effects of the Invention]

[0015] a cylinder head having an intake valve seat, an exhaust valve seat, an intake valve that opens and closes the intake valve seat, and an exhaust valve that opens and closes the exhaust valve seat; an air supply pipe that supplies air to the combustion chamber; a branch pipe connected to the air supply pipe; an introduction chamber at the end of the branch pipe directly above the intake valve seat that introduces hydrogen and air into the cylinder block; and a hydrogen supply injector that is connected to the branch pipe and supplies hydrogen to part of the branch pipe and into the introduction chamber.The hydrogen supply injector is installed so that the axis of hydrogen injection from its hydrogen nozzle is inclined at an acute angle toward the extension direction of the introduction chamber.This makes it possible to realize a hydrogen internal combustion engine that achieves uniform mixing of hydrogen and air when ignited by the spark plug while avoiding complex hydrogen injection devices and structures. In addition, because the hydrogen supply injector is designed to flow as a jet from its outlet in the direction of the extension of the introduction chamber, the air entering the combustion chamber can flow into the combustion chamber with greater filling efficiency, resulting in greater power output. Furthermore, by appropriately selecting the injection timing of the hydrogen supply injector relative to the intake valve opening, a hydrogen-air mixture is not formed upstream of the intake valve, i.e., in the introduction chamber, branch pipe, and air supply pipe, making it difficult for flames to propagate upstream of the intake valve. In other words, backfires and other problems are suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an overall perspective view of a hydrogen internal combustion engine according to an embodiment; [Figure 2] FIG. 2 is an overall plan view of the air supply pipe of the hydrogen internal combustion engine of FIG. [Figure 3] FIG. 2 is a partial plan view of the hydrogen internal combustion engine of FIG. [Figure 4] FIG. 4 is an enlarged longitudinal sectional view taken along the arrow AA in FIG. 3. [Figure 5] FIG. 2 is a first partial vertical cross-sectional view showing the movement of a piston in the hydrogen internal combustion engine of FIG. 1. [Figure 6] FIG. 2 is a second partial longitudinal sectional view showing the movement of the piston of the hydrogen internal combustion engine of FIG. [Figure 7] FIG. 3 is a first explanatory diagram showing the opening and closing timing of the intake valve and the exhaust valve. [Figure 8] FIG. 4 is a second schematic diagram showing the opening and closing timing of the intake valve and the exhaust valve. DETAILED DESCRIPTION OF THE INVENTION

[0017] The hydrogen internal combustion engine of the embodiment is an internal combustion engine that mixes gaseous hydrogen with air and utilizes the combustion of the hydrogen and oxygen in the air, and its basic structure inherits that of gasoline engines and diesel engines that use diesel fuel, etc. This is because it utilizes the stability and durability that are backed by the structure and performance of existing internal combustion engines. However, compared to hydrocarbon compounds such as gasoline and diesel, hydrogen has an extremely low specific gravity per unit volume. Due to the difference in specific gravity with the air that flows into the internal combustion engine, hydrogen does not easily mix with air. In light of this, the hydrogen internal combustion engine of the embodiment, taking into account the characteristics of using gaseous hydrogen (hydrogen gas) as fuel, attempts to achieve good mixing of hydrogen and air despite its simple structure.

[0018] FIG. 1 is an overall perspective view showing the appearance of a hydrogen internal combustion engine 1 (hydrogen engine) according to an embodiment. The hydrogen internal combustion engine 1 includes a cylinder block 10 that houses a combustion chamber 11 and a piston 12 (see FIG. 5), which will be described later, and which burns hydrogen and air. A branch pipe (intake manifold) of an air supply pipe 20 that supplies air to the combustion chamber 11 is connected to the top of the cylinder block 10. The hydrogen internal combustion engine 1 also includes an intake valve 15 and an exhaust valve 16 (see FIGS. 3 and 4), which will be described later. In a generator device, a generator 2 (see FIG. 1 in the embodiment) or, in the case of a vehicle, a gearbox with a built-in transmission is connected to the engine shaft. Various necessary devices are also provided, such as a cooling fan 3 that cools the cylinder block 10 and other components of the hydrogen internal combustion engine 1.

[0019] 2 is a plan view of an intake manifold consisting of an air supply pipe 20 and branch pipes 22 of a hydrogen internal combustion engine 1 according to an embodiment. The hydrogen internal combustion engine 1 has four cylinders and four pistons 12. Therefore, the air supply pipe 20 branches into four to form branch pipes 22. A hydrogen supply injector 30 (see FIG. 4) is connected to each branch pipe 22. An end 21 of each branch pipe 22 of the air supply pipe 20 is connected to the cylinder head 17.

[0020] 3 is a partial plan view of the cylinder head 17 side (upper side of the hydrogen internal combustion engine 1) of the hydrogen internal combustion engine 1 of the embodiment. Only two of the four cylinders are partially shown. The cylinder head 17 of the hydrogen internal combustion engine 1 (above the combustion chamber 11 described below) is provided with an ignition plug 26, an intake valve seat 13, an intake valve 15 that opens and closes the intake valve seat 13, an exhaust valve seat 14, and an exhaust valve 16 that opens and closes the exhaust valve seat 14 for each cylinder. In the hydrogen internal combustion engine 1 of the embodiment, the cylinder head 17 is provided with two intake valve seats 13 and two intake valves 15 per cylinder, and similarly, two exhaust valve seats 14 and two exhaust valves 16 per cylinder.

[0021] By providing two intake valve seats 13, the mixed gas of hydrogen and air, which serves as fuel, is quickly supplied into the cylindrical combustion chamber 11, improving the filling efficiency and combustion efficiency within the combustion chamber 11. In addition, by providing two exhaust valve seats 14, the same number as the intake valve seats 13, the exhaust efficiency of exhaust gases (water vapor, etc.) produced by combustion is improved.

[0022] Figure 4 is a partial vertical cross-sectional view taken along the arrow AA in Figure 3. It shows the internal structure of a cylinder head 17 at the top of the cylinder block 10. Branch pipes 22 (intake manifolds) branching from an air supply pipe 20 to each cylinder are connected to the cylinder head 17 at the top of the cylinder block 10, and air is supplied from the branch pipes 22 to the combustion chambers 11 (see Figure 5) of each cylinder in the cylinder block 10. A hydrogen supply injector 30 is connected to each branch pipe 22. Hydrogen (hydrogen gas) is injected from the hydrogen nozzle of the hydrogen supply injector 30 into a part of the branch pipe 22 and the introduction chamber 25, with the axis of hydrogen injection tilted at an angle of 20 to 45 degrees toward the extension direction of the introduction chamber 25. An injection pressure regulator for regulating the hydrogen injection pressure, hydrogen supply piping, and the like are provided upstream of the hydrogen supply injector 30 (all not shown).

[0023] The cylinder head 17 is formed with an intake valve seat 13 and is provided with an intake valve 15 for opening and closing the intake valve seat. In the illustration, due to the location of the cross section, the spark plug 26, other intake valve seats 13, intake valves 15, exhaust valve seats 14, and exhaust valves 16 are omitted from the illustration. A branch pipe 22 of the air supply pipe 20 is connected at its end 21 to the cylinder head 17 at the top of the cylinder block 10. Of course, although not shown, the other cylinders have a similar configuration.

[0024] An introduction chamber 25 is formed in the cylinder head 17 directly above the intake valve seat 13. Air supplied into the cylinder block 10 from the end 21 and hydrogen injected from the hydrogen supply injector 30 join together in a part of the branch pipe 22 and in the introduction chamber 25. When the intake valve 15 opens, the hydrogen and air flow into the combustion chamber 11 through the intake valve seat 13.

[0025] The introduction chamber 25 is formed in the cylinder head 17 in a sideways L-shape (J-shape). Specifically, the longitudinal direction of the introduction chamber 25 is parallel to the upper part (ceiling) of the cylinder head 17, and the lateral direction is perpendicular to the upper part (ceiling) of the cylinder head. The shape of the introduction chamber 25 is designed to fit the flat shape of the upper part of the combustion chamber 11. Furthermore, the L-shape (J-shape) of the introduction chamber 25 is bent not to promote mixing of the hydrogen and air flowing within the introduction chamber 25, but rather to utilize the injection pressure of the injected hydrogen to guide it directly to the intake valve seat 13. In other words, it helps to reduce flow resistance and improves the air filling efficiency.

[0026] Regarding the relative positions of the components near the introduction chamber 25, the axis Li of hydrogen injection from the hydrogen nozzle 31 of the hydrogen supply injector 30 is connected to the branch pipe 22 so as to be inclined at an acute angle toward the extension direction of the introduction chamber 25 (toward the upper surface of the cylinder head 17). This acute angle is the angle θ shown in the figure. More specifically, the axis Li of hydrogen injection from the hydrogen nozzle 31 of the hydrogen supply injector 30 is connected to the branch pipe 22 of the air supply pipe 20 at an inclination of 20° to 45° toward the extension direction of the introduction chamber 25 (an extension line Lj that is a line parallel to the upper part (ceiling) of the combustion chamber 11 shown in the figure). This inclination can be expressed as the angle of a ray passing from the hydrogen nozzle 31 to the cylinder head 17 in the figure. Furthermore, an extension line of the axis Li of hydrogen injection from the hydrogen nozzle 31 of the hydrogen supply injector 30 is located directly above at least one intake valve 15.

[0027] As shown in the figure, the axis Li of the hydrogen injection from the hydrogen supply injector 30 intersects the extension line Lj of the introduction chamber 25 at an acute angle θ. This allows the injected hydrogen to utilize the pressure of the hydrogen injection from the hydrogen supply injector 30 to quickly reach directly above the intake valve 15 without being obstructed along the way. The injected hydrogen then entrains surrounding air supplied from the branch pipe 22 of the air supply pipe 20 and easily flows into the combustion chamber 11 from the intake valve seat 13. As mentioned above, hydrogen as a fuel has an extremely low specific gravity compared to air. In the case of hydrogen gas fuel, a method of premixing (premixing) in a space upstream of the combustion chamber 11 (the introduction chamber 25 in the embodiment) does not easily produce a homogeneous mixture compared to gasoline, which has a high specific gravity. If the angle is not too sharp, the difference in specific gravity between hydrogen and air will promote the formation of an air-fuel mixture near the hydrogen nozzle 31 of the hydrogen supply injector 30, and depending on the injection timing of the hydrogen supply injector, the formed air-fuel mixture may stagnate in the branch pipe 22 and introduction chamber 25, causing backfire.

[0028] In this case, rather than forcibly maintaining an optimal mixture ratio of hydrogen and air in introduction chamber 25 and introducing the mixed gas from intake valve seat 13 into combustion chamber 11, it is better to inject and supply hydrogen and air without mixing them in branch pipe 22 and introduction chamber 25, and then take in hydrogen and air from intake valve seat 13 and mix and burn them in combustion chamber 11. This results in better filling efficiency and combustion efficiency, and also makes it easier to control the injection of hydrogen and the supply of air.

[0029] Therefore, if one attempts to guide the hydrogen injected from the hydrogen supply injector 30 directly above the intake valve 15, the aforementioned angle θ is a good example. If the angle θ is less than 20°, installation in the branch pipe 22 is structurally difficult, and the hydrogen will collide with the introduction chamber 25 in the cylinder head 17, making it difficult for the hydrogen to flow into the combustion chamber 11. Furthermore, if the angle θ is greater than 45°, the hydrogen injected from the hydrogen supply injector 30 will collide with the branch pipe 22, as described above, making it difficult for the hydrogen to flow into the combustion chamber 11. Taking these factors into consideration, it is desirable that the angle θ of inclination at which the axis Li of hydrogen injection from the hydrogen nozzle 31 of the hydrogen supply injector 30 intersects with the extension direction (extension line Lj) of the introduction chamber 25 converges to between 20° and 45°.

[0030] 5 and 6 are partial vertical cross-sectional views showing the movement of the piston 12 of the hydrogen internal combustion engine 1. This shows the structure of the lower part of the cylinder head 17 in FIG. 4, in which the piston 12 slides up and down within the cylinder block 10. A rod 19 is rotatably connected to the piston 12, and the up and down movement of the piston 12 is converted into rotational movement via the rod 19. As can be seen from the illustration, an end 21 of a branch pipe 22 of the air supply pipe 20 (the branch pipe 22 in the illustration) is connected to the cylinder head 17 perpendicular to the axis of sliding of the piston 12 within the cylinder block 10 (the vertical direction on the page). This arrangement is adopted to maintain the inclination angle θ described above without complicating the structure of the branch pipe 22 of the air supply pipe 20 and the hydrogen supply injector 30.

[0031] In Figure 5, the piston 12 is descending from the exhaust top dead center. At this time, the intake valve 15 descends, opening the intake valve seat 13. Hydrogen is then injected from the hydrogen supply injector 30, and simultaneously, air is supplied from the branch pipe 22 of the air supply pipe 20. Both enter the combustion chamber 11 through the intake valve seat 13 via the introduction chamber 25. In Figure 6, the piston 12 is in a raised state at the compression top dead center position. The intake valve 15 has already risen, closing the intake valve seat 13. At this point, the hydrogen-air mixture is compressed, and ignition by the spark plug 26 (see Figure 3) causes the mixture to burn, increasing the pressure in the combustion chamber 11. This pressure pushes the piston 12 downward from the position shown in Figure 6. This repeated up-and-down movement of the piston 12 generates rotational motion in the engine shaft (not shown) connected to the rod 19.

[0032] The hydrogen internal combustion engine 1 of the illustrated embodiment is an engine of a type generally referred to as a diesel engine. In other words, the hydrogen internal combustion engine 1 replaces the fuel of a diesel engine, which has excellent operational stability, with hydrogen, and is configured to address the problems unique to hydrogen as described above. Like a diesel engine, the upper part (cylinder head 17 side) of the combustion chamber 11 of the hydrogen internal combustion engine 1 of this embodiment is flat. Therefore, a recess 18 (cavity) is formed in the upper surface of the piston 12 to ensure space for combustion of hydrogen and air and improve combustion efficiency. The shape and size of the recess 18 (cavity) of the piston 12 are optimally designed taking into account various conditions, such as the size and combustion performance of the hydrogen internal combustion engine 1 itself.

[0033] 7 and 8 are explanatory diagrams showing the opening and closing timing of the intake valve and the exhaust valve. For convenience, the timing of various operations is shown by assuming that an engine shaft (not shown) connected to a rod 19 moves circularly, with the top dead center position of the piston 12 being 0° and the bottom dead center position being 180°. In the explanation, TDC stands for top dead center, and BDC stands for bottom dead center. In this embodiment, there are two intake valve seats 13 and two intake valves 15 per cylinder, and two exhaust valve seats 14 and two exhaust valves 16 per cylinder. Therefore, the positions are distinguished by adding A and B, such as ATDC (ATDC means after TDC, hence the "A" from "After") and BTDC (BTDC means before TDC, hence the "B" from "Before").

[0034] In the hydrogen internal combustion engine 1 of the embodiment, the opening timing (θ air-intake valve open ) opens when the other exhaust valve 16 is at 8° exhaust BTDC, while the closing timing of the other exhaust valve 16 is 19° exhaust ATDC. Therefore, the overlap angle between both intake valves 15 and exhaust valve 16 is 27°. The closing timing of the intake valve 15 (θ air-intake valve close ) The opening timing of one exhaust valve 16 is 31° expansion BBDC, and the exhaust ATDC is 212° (intake ABDC 32°), and the valve closes when this valve is at this timing. That is, the opening timing (θ exhaust valve open ) opens when the exhaust BTDC is 211° (expansion BBDC is 31°). The closing timing of the exhaust valve 16 (θ exhaust valve close ) closes when the exhaust is at 19° ATDC. These are shown in Figure 7.

[0035] In the hydrogen injection timing control of the hydrogen internal combustion engine 1 (engine) of the embodiment, the hydrogen injection valve of the hydrogen supply injector 30 is closed when θ injclose is constant, when the intake valve is closed (θ air-intake valve close The injector opening time Δt is set to 30° before (exhaust ATDC 182°) (intake ABDC 2°). inj increases from zero. That is, the injector opening angle period Δθ inj is increased toward the opening timing of the intake valve 15, thereby increasing the amount of hydrogen.

[0036] Although it varies slightly depending on the setting position of the hydrogen supply injector 30 in the branch pipe 22 (intake manifold) of the air supply pipe 20, the hydrogen injection valve closing timing θ inj close is the closing timing θ of the intake valve 15 air-intake valve close The injector closing time θ in the example of FIG. inj close The exhaust TDC is 182° (intake ABDC 2°).

[0037] The reason for this is that the intake valve closing timing θ air-intake valve close This is because the injection valve closing timing is set to a time between 30°±10° before this time to prevent hydrogen from accumulating upstream of the intake valve 15. This is so that when the intake air starts to be drawn into the next cycle, only air is initially introduced into the combustion chamber 11 of the cylinder block 10. The reason for this is that by initially introducing air that does not contain hydrogen gas fuel into the combustion chamber 11, even if there is an ignition source in the combustion chamber 11, ignition will not occur because there is no hydrogen present. Rather, the intake air reduces the temperature of the ignition source below the ignition temperature of the hydrogen-air mixture, preventing ignition of the mixture.

[0038] The timing to start hydrogen injection, i.e., the timing to open the hydrogen injector valve, is determined by the engine speed and the amount of hydrogen injected. inj , that is, the injection valve opening angle period Δθ inj is adjusted. injopen Even at the earliest, the opening timing θ of the intake valve 15 air-intake valve open In summary, the valve closing timing of the hydrogen supply injector 30 is constant at 30°±10° crank angle before the intake valve closing timing of the intake valve seat 13, and the valve opening timing of the hydrogen supply injector 30 is, even at the earliest, 30°±10° crank angle after the intake valve opening timing of the intake valve seat 13.

[0039] As mentioned above, the reason for this is that before hydrogen is introduced into the combustion chamber 11 of the cylinder block 10, only air is introduced into the combustion chamber 11 earlier than hydrogen. This is because only air is introduced to the high-temperature gas and high-temperature spots that could be ignition sources for the hydrogen-air mixed gas in the combustion chamber 11, and the ignition sources are cooled by the air, preventing abnormal combustion such as backfire.

[0040] Injector valve opening time Δt inj , that is, the injection valve opening angle period Δθ inj If the above condition is not satisfied, the required injector valve opening angle period Δθ is inj As explained above, the opening and closing timing of the hydrogen injector is adjusted and controlled so that it always falls within the opening and closing timing of the intake valve 15.

[0041] As explained above, by using the hydrogen internal combustion engine 1 of the embodiment, it is possible to realize a hydrogen internal combustion engine 1 that avoids the need for a complicated hydrogen injection device and structure, prevents accidental mixing of hydrogen and air on the way to the combustion chamber, quickly supplies hydrogen to the combustion chamber, and achieves uniform mixing of hydrogen and air in the combustion chamber. Therefore, in the hydrogen internal combustion engine 1, by achieving high filling efficiency and high uniform mixing of hydrogen and air in the combustion chamber 11, it is possible to avoid incomplete combustion of hydrogen and reduce the amount of NOx, the only polluting gas in a hydrogen engine. x It achieves stable and high-output combustion while reducing CO2, enabling highly efficient operation. [Explanation of symbols]

[0042] 1. Hydrogen internal combustion engine 10 Cylinder block 11 Combustion chamber 12 pistons 13 Intake valve seat 14 Exhaust valve seat 15 Intake valve 16 Exhaust valve 17 Cylinder head 18 Recess 19 Rod 20 Air pipe 21 End 22 Branch pipe 26 Spark plug 30 Hydrogen supply injector 31 Hydrogen supply injector nozzle Li Hydrogen injection axis from the nozzle of the hydrogen supply injector Lj Extension line in the extension direction of the introduction chamber θ Intersection angle between axis Li and extension line Lj

Claims

1. a cylinder block having a combustion chamber for combusting hydrogen and air; a piston that slides within the cylinder block; a cylinder head attached to an upper portion of the combustion chamber of the cylinder block, the cylinder head having an ignition plug, an intake valve seat, an exhaust valve seat, an intake valve that opens and closes the intake valve seat, and an exhaust valve that opens and closes the exhaust valve seat; an air pipe for supplying air to the combustion chamber; a branch pipe connected to the air supply pipe; an introduction chamber at an end of the branch pipe, which introduces hydrogen and air into the cylinder block immediately above the intake valve seat; a hydrogen supply injector connected to the branch pipe to supply hydrogen to a part of the branch pipe and the introduction chamber, The hydrogen supply injector is attached so that the axis of hydrogen injection from the hydrogen injection port is inclined at an acute angle toward the extension direction of the introduction chamber. A hydrogen internal combustion engine.

2. 2. A hydrogen internal combustion engine according to claim 1, wherein the hydrogen supply injector is attached to the branch pipe at an angle of 20° to 45° with respect to the extension direction of the introduction chamber, with the axis of hydrogen injection from the hydrogen outlet of the hydrogen supply injector facing in the extension direction of the introduction chamber.

3. 2. The hydrogen internal combustion engine according to claim 1, wherein an extension of an axis of hydrogen injection from the hydrogen nozzle of said hydrogen supply injector is positioned directly above said intake valve.

4. 2. A hydrogen internal combustion engine according to claim 1, wherein the introduction chamber is formed in the cylinder block in a sideways L-shape.

5. In the cylinder head, the spark plug, the intake valve seat, the exhaust valve seat, the intake valve, and the exhaust valve are provided for one cylinder, 2. The hydrogen internal combustion engine according to claim 1, wherein the cylinder head is provided with at least two intake valve seats and at least two intake valves per cylinder.

6. 2. A hydrogen internal combustion engine according to claim 1, wherein an end of a branch pipe of the air supply pipe is connected to the cylinder head perpendicular to the axis of sliding of the piston in the cylinder block.

7. 2. A hydrogen internal combustion engine according to claim 1, wherein a recess is formed in the upper surface of said piston.

8. 8. The hydrogen internal combustion engine according to claim 7, wherein the upper portion of the combustion chamber is flat.

9. 2. The hydrogen internal combustion engine according to claim 1, wherein the valve closing timing of the hydrogen supply injector is constant at 30°±10° in crank angle before the intake valve closing timing of the intake valve seat, and the valve opening timing of the hydrogen supply injector is, even at the earliest, 30°±10° in crank angle after the intake valve opening timing of the intake valve seat.

10. 10. The hydrogen internal combustion engine according to claim 9, further comprising an injection pressure adjusting device for adjusting the injection pressure of hydrogen provided upstream of the hydrogen supply injector.

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