Internal combustion engine

Abstract

A hydrogen engine (1) comprises: a crankcase (15); a cylinder (16); a blow-by gas passage (61) through which a blow-by gas discharged from the crankcase (15) circulates; an intake port (21) that is in communication with the cylinder (16); and a fuel supply part that supplies fuel to the intake port (21). The fuel supply part (70) includes an injection valve (71) for injecting fuel, and an ejector (72). The ejector (72) includes an inflow port (721) into which the fuel injected from the injection valve (71) flows, and a suction port (722) that suctions the blow-by gas flowing through the blow-by gas passage (61).

Description

Internal combustion engine

[0001] The present disclosure relates to an internal combustion engine.

[0002] Japanese Patent Application Laid-Open No. 2009-133292 (Patent Document 1) discloses a negative pressure generating device provided in an engine equipped with a supercharger in an intake passage. The negative pressure generating device includes a bypass passage provided in the intake passage between the supercharger and the engine, and an ejector that generates a negative pressure by air flowing through the bypass passage. Blow-by gas is led from the crankcase to a blow-by gas reduction passage by the negative pressure generated by the ejector.

[0003] Japanese Patent Application Laid-Open No. 2009-133292

[0004] In Patent Document 1 above, in the supercharged region, blow-by gas is refluxed (circulated) by the negative pressure generated by the ejector. On the other hand, although not described in Patent Document 1 above, in the non-supercharged region, blow-by gas is refluxed by a PCV (Positive Crankcase Ventilation) valve that utilizes the negative pressure in the intake pipe. However, when the intake pressure is near atmospheric pressure, the reflux amount of blow-by gas decreases.

[0005] An object of the present disclosure is to provide an internal combustion engine capable of suppressing a decrease in the reflux amount of blow-by gas.

[0006] An internal combustion engine according to one aspect of the present disclosure includes a crankcase, at least one cylinder, a blow-by gas passage through which blow-by gas discharged from the crankcase flows, an intake portion communicating with at least one cylinder, and at least one fuel supply portion that supplies fuel to the intake portion. The at least one fuel supply portion includes an injection valve that injects fuel and an ejector. The ejector includes an inflow port into which fuel injected from the injection valve flows and a suction port that sucks blow-by gas flowing through the blow-by gas passage.

[0007] With this configuration, the negative pressure created inside the ejector by the fuel injection from the injection valve allows blow-by gas to be easily drawn in through the suction port. Therefore, by utilizing the force of the injection from the injection valve, blow-by gas can be efficiently drawn in even without supercharging. This helps to suppress a decrease in the return flow rate of blow-by gas.

[0008] Furthermore, compared to cases where an electric pump or similar device is equipped in the internal combustion engine to recirculate blow-by gas, the internal combustion engine can be made smaller.

[0009] The internal combustion engine may further include a check valve to prevent backflow of blow-by gas from the intake port into the crankcase. Such a configuration can suppress the reduction in blow-by gas return rate caused by backflow of blow-by gas into the crankcase.

[0010] The check valve may be located near the suction port. This configuration can reduce the amount of blow-by gas that flows back from the suction port towards the check valve. Note that "near the suction port" includes both the vicinity of the suction port and the location of the suction port itself.

[0011] At least one cylinder may include multiple cylinders, the intake section may include multiple intake ports connected to each of the multiple cylinders, and at least one fuel supply section may include multiple fuel supply sections that supply fuel to each of the multiple intake ports. With this configuration, the injection valves of each of the multiple fuel supply sections inject fuel alternately, so that periods of time when fuel is not supplied from the fuel supply section to the intake section can be suppressed. As a result, the decrease in the return flow rate of blow-by gas can be further suppressed.

[0012] The injection valve may inject hydrogen. Here, since hydrogen has a relatively low energy per unit volume, the time for which hydrogen is injected to drive the engine is relatively long. This increases the time for which negative pressure is formed in the ejector, which further suppresses the decrease in the return flow rate of blow-by gas.

[0013] The internal combustion engine may further include an intake passage connected to the intake section and a supercharger positioned in the intake passage. With this configuration, the output of the internal combustion engine can be increased by the supercharger while suppressing a decrease in the return flow rate of blow-by gas by the fuel supply section.

[0014] According to this disclosure, it is possible to suppress a decrease in the return flow rate of blow-by gas.

[0015] This figure shows the schematic configuration of a hydrogen engine according to this embodiment. This is a cross-sectional view showing the schematic configuration of the fuel supply section according to this embodiment. This is a schematic diagram showing multiple cylinders of a hydrogen engine according to this embodiment. This figure shows an example of the drive process for each cylinder. This figure schematically shows the relationship between the fuel injection amount, pressure, and gas ventilation amount with respect to the load of the hydrogen engine. This is a cross-sectional view of the vicinity of the injection valve and intake port according to a comparative example. This is a cross-sectional view along the line VII-VII in Figure 6.

[0016] Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same or corresponding parts in the drawings may be denoted by the same reference numerals, and their descriptions may not be repeated.

[0017] Figure 1 shows a schematic configuration of the hydrogen engine 1 according to this embodiment. The hydrogen engine 1 may be a vehicle power source mounted on a vehicle. The hydrogen engine 1 may also be used as a power source for a hydraulic pump and a driving power source for industrial vehicles such as forklifts. Note that the hydrogen engine 1 is an example of an "internal combustion engine" as disclosed herein.

[0018] The hydrogen engine 1 comprises an engine body 10, an air cleaner 20, an intake passage 22, an intake manifold 24, an intercooler 26, and a supercharger 30. The hydrogen engine 1 also comprises an exhaust passage 52, a blow-by gas passage 61, a plurality (four in this embodiment) of fuel supply units 70, a plurality (four in this embodiment) of PCV valves 80, a tank 90, and a control device 200. The PCV valve 80 is an example of a "backflow prevention valve" as disclosed herein.

[0019] The engine body 10 includes a cylinder head 11, a cylinder block 12, a piston 13, a head cover 14, and a crankcase 15.

[0020] The engine body 10 includes cylinders 16 defined by the cylinder head 11 and the cylinder block 12. In this embodiment, the hydrogen engine 1 has four cylinders 16 (i.e., it is a four-cylinder engine), but only one cylinder 16 is shown in Figure 1. Note that the number of cylinders is not limited to four, and may be three, six, or the like.

[0021] The piston 13 is mounted to reciprocate within the cylinder 16. Inside the cylinder 16, a combustion chamber 17 is formed, surrounded by the top of the piston 13, the cylinder head 11, and the cylinder block 12. The reciprocating motion of the piston 13 is converted into rotational motion by the connecting rod 18a and the crankshaft 18b.

[0022] The crankcase 15 is formed at the lower part of the cylinder block 12. The crankcase 15 houses the crankshaft 18b. In this embodiment, the crankcase 15 is formed integrally with the cylinder block 12, but a separate crankcase may be attached to the cylinder block 12. An oil pan 19 is fastened to the crankcase 15, and engine oil (lubricating oil) EO is stored therein. The upper part of the cylinder head 11 is covered by a head cover 14.

[0023] The engine body 10 further includes an intake port 21, an intake valve 23, an exhaust port 51, and an exhaust valve 53. Each of the intake port 21, intake valve 23, exhaust port 51, and exhaust valve 53 is provided corresponding to each of the multiple cylinders 16. The intake port 21 is an example of the "intake section" in this disclosure.

[0024] One end of the intake port 21 is connected to the top of the cylinder 16. Specifically, the intake port 21 is formed in the engine body 10 (cylinder head 11) and is connected to the combustion chamber 17. The intake valve 23 is provided between the intake port 21 and the cylinder 16. When the intake valve 23 is closed, the space between the intake port 21 and the cylinder 16 is blocked. When the intake valve 23 is open, the space between the intake port 21 and the cylinder 16 is open.

[0025] One end of the exhaust port 51 is connected to the top of the cylinder 16. Specifically, the exhaust port 51 is formed in the engine body 10 (cylinder head 11) and is connected to the combustion chamber 17. The exhaust valve 53 is provided between the exhaust port 51 and the cylinder 16. When the exhaust valve 53 is closed, the space between the exhaust port 51 and the cylinder 16 is blocked. When the exhaust valve 53 is open, the space between the exhaust port 51 and the cylinder 16 is open.

[0026] Each of the multiple cylinders 16 is provided with a spark plug (not shown) at its top. The spark plug performs an ignition operation in response to a control signal from the control device 200. The control device 200 performs the ignition operation of the spark plug after the compression stroke, for example. Note that the spark plug may not be provided.

[0027] External air (atmosphere) to the hydrogen engine 1 is drawn into the intake passage 22 via the air cleaner 20. Downstream of the air cleaner 20 in the intake passage 22, a compressor 32 of a turbocharger 30 is provided. The compressor 32 supercharges the air (intake air). The supercharged air is cooled by an intercooler 26. The intercooler 26 may be water-cooled or air-cooled. The supercharger may also be a supercharger.

[0028] A throttle valve (intake throttling valve) 25 is located in the intake passage 22 downstream of the intercooler 26. The downstream end of the intake passage 22 is connected to the intake manifold 24. The intake manifold 24 is connected to the intake port 21. The air that has flowed through the intake passage 22 flows into the combustion chamber 17 via the intake manifold 24 and the intake port 21.

[0029] The combustion gases (exhaust) from combustion in the combustion chamber 17 are collected in an exhaust manifold (not shown) through the exhaust port 51. The exhaust gases (combustion gases) collected in the exhaust manifold flow into the turbine 36 of the supercharger 30 through the exhaust passage 52. An exhaust gas purification device (not shown) is provided in the exhaust passage 52 downstream of the turbine 36. The exhaust gas purification device may be, for example, a selective catalytic reduction. A silencer (exhaust muffler) may be placed in the exhaust passage 52 downstream of the selective catalytic reduction. In this case, the exhaust gases are silenced by the silencer and released into the atmosphere.

[0030] The supercharger 30 includes a compressor 32 and a turbine 36. A compressor wheel 34 is housed within the housing of the compressor 32. A turbine wheel 38 is housed within the housing of the turbine 36. The compressor wheel 34 is rotationally driven by the energy of the exhaust gas supplied to the turbine wheel 38, compressing the intake air and performing supercharging.

[0031] The fuel supply unit 70 supplies fuel (hydrogen) to the intake port 21. Hydrogen gas is supplied to the fuel supply unit 70 from a tank 90 in which hydrogen gas is stored. The hydrogen gas in the tank 90 is supplied to the fuel supply unit 70 after its pressure is adjusted by a pressure reducing valve 91. The hydrogen gas whose pressure has been adjusted by the pressure reducing valve 91 is supplied to the fuel supply unit 70 through a delivery pipe 92. Note that hydrogen is an example of "fuel" in this disclosure.

[0032] In the combustion chamber 17, a mixture of air and fuel (hydrogen) burns. Unburned gas (blow-by gas) in the combustion chamber 17 passes through the gap between the piston 13 and the cylinder block 12 and flows from the combustion chamber 17 into the crankcase 15. By returning the blow-by gas that has flowed into the crankcase 15 to the intake passage 22, ventilation of the inside of the crankcase 15 is performed.

[0033] The space S between the cylinder head 11 and the head cover 14 and the inside of the crankcase 15 are connected by a connecting passage 60 formed in the cylinder head 11 and the cylinder block 12. The space S is connected to the blow-by gas passage 61 via an oil separator 62. The blow-by gas passage 61 is connected to the PCV valve 80. Therefore, the blow-by gas discharged from the crankcase 15 flows through the blow-by gas passage 61 and flows into the fuel supply unit 70 via the PCV valve 80.

[0034] The control device 200 controls the operation of the hydrogen engine 1. The control device 200 includes a CPU (Central Processing Unit) 201 that performs various processing, a memory 202 that includes a ROM (Read Only Memory) for storing programs and data and a RAM (Random Access Memory) for storing the CPU's processing results, and input / output ports (not shown) for exchanging information with the outside. Various sensors are connected to the input ports, and the devices to be controlled (for example, the injection valve 71 (Figure 2) and throttle valve 25 described later) are connected to the output ports.

[0035] The control device 200 performs predetermined calculation processing based on signals from various sensors and devices, as well as maps and programs stored in the memory 202. Based on the results of the calculation processing, the control device 200 controls the injection valve 71 (Figure 2) and throttle valve 25, etc., as described later.

[0036] In this embodiment, the various sensors include an intake air volume sensor 210, an engine rotation speed sensor 220, an accelerator opening sensor 230, a coolant temperature sensor 240, and the like.

[0037] The intake air volume sensor 210 detects the intake air volume Ga. The engine rotation speed sensor 220 detects the rotation speed NE of the hydrogen engine 1. The accelerator pedal position sensor 230 detects the accelerator pedal position AP, which is the amount the accelerator pedal is pressed. The coolant temperature sensor 240 detects the coolant temperature THW of the hydrogen engine 1.

[0038] The control device 200 calculates the fuel injection amount Qf and the fuel injection timing based, for example, the accelerator opening AP and the rotational speed NE. When the crank angle of the hydrogen engine 1 reaches the fuel injection timing, the control device opens the injection valve 71 (Figure 2), described later, for a time corresponding to the fuel injection amount Qf, and performs fuel injection.

[0039] Figure 2 is a cross-sectional view showing the configuration of the fuel supply unit 70 and the PCV valve 80. The fuel supply unit 70 includes an injection valve 71 and an ejector 72.

[0040] The injection valve 71 injects hydrogen supplied from the tank 90 (Figure 1). Specifically, hydrogen is injected from the injection valve 71 at, for example, the speed of sound. The injection valve 71 is located upstream (towards the tank 90) of the ejector 72.

[0041] The ejector 72 has an inlet port 721 and an suction port 722. Hydrogen injected from the injection valve 71 (dashed arrow in Figure 2) flows into the inlet port 721. For example, a nozzle 711 provided on the injection valve 71 may be inserted into the ejector 72 through the inlet port 721. The injection valve 71 may be fixed (for example, fastened) to the ejector 72.

[0042] The suction port 722 is in communication with the blow-by gas passage 61 via the PCV valve 80. The PCV valve 80 has a passage 81 through which blow-by gas passes. The blow-by gas that has flowed through the blow-by gas passage 61 (dotted arrow in Figure 2) passes through the passage 81 and is drawn into the ejector 72 from the suction port 722.

[0043] Inside the ejector 72, a flow path 723 connected to the inflow port 721 and a flow path 724 connected to the suction port 722 are formed. Also, inside the ejector 72, a mixing section 725 connected to the flow path 723 and the flow path 724 is formed. The hydrogen flowing through the flow path 723 and the blow-by gas flowing through the flow path 724 are mixed in the mixing section 725.

[0044] When hydrogen is injected from the injection valve 71 at high speed, a low pressure (negative pressure) is formed in the mixing section 725. Due to this negative pressure, the blow-by gas is sucked from the suction port 722. The mixed gas of hydrogen and the blow-by gas (the two-dot chain line arrow in FIG. 2) is discharged from the discharge port 726 of the ejector 72 and sucked into the intake port 21. Hereinafter, the mixed gas is described as fuel.

[0045] The PCV valve 80 has a function as a check valve that prevents the backflow of the blow-by gas from the suction port 722 to the crankcase 15 (FIG. 1). A known mechanism may be adopted for the mechanism to prevent the backflow of the blow-by gas, and the illustration is omitted in FIG. 2.

[0046] The PCV valve 80 is disposed near the suction port 722. Specifically, the PCV valve 80 is fixed to the ejector 72 (suction port 722). In detail, an end portion 82 of the PCV valve 80 disposed on the ejector 72 side is inserted (fitted) into the inflow port 721 of the ejector 72. Note that the PCV valve 80 may be disposed at a position slightly separated from the suction port 722.

[0047] FIG. 3 is a diagram schematically showing four cylinders 16, four intake ports 21, etc. Hereinafter, the four cylinders 16 are respectively denoted as cylinder 16a, cylinder 16b, cylinder 16c, and cylinder 16d. For example, the cylinder 16a, the cylinder 16b, the cylinder 16c, and the cylinder 16d are arranged in series in this order from the left side of the paper surface in FIG. 3.

[0048] The plurality of intake ports 21 includes an intake port 21a, an intake port 21b, an intake port 21c, and an intake port 21d. The intake ports 21a, 21b, 21c, and 21d are respectively connected to the cylinders 16a, 16b, 16c, and 16d.

[0049] The plurality of fuel supply units 70 includes a fuel supply unit 70a, a fuel supply unit 70b, a fuel supply unit 70c, and a fuel supply unit 70d. The fuel supply units 70a, 70b, 70c, and 70d supply fuel to the intake ports 21a, 21b, 21c, and 21d respectively. Hydrogen is supplied to each injection valve 71 of the fuel supply units 70a to 70d from a tank 90 (FIG. 1) via a delivery pipe not shown. Each injection valve 71 of the fuel supply units 70a to 70d injects hydrogen in response to a control signal from the control device 200.

[0050] The plurality of PCV valves 80 includes a PCV valve 80a, a PCV valve 80b, a PCV valve 80c, and a PCV valve 80d. The PCV valves 80a, 80b, 80c, and 80d are respectively connected to the fuel supply units 70a, 70b, 70c, and 70d.

[0051] The blow-by gas passage 61 includes a branch passage 61a, a branch passage 61b, a branch passage 61c, a branch passage 61d, and a pre-branch passage 61e. One end of each of the branch passages 61a, 61b, 61c, and 6ld is connected to the pre-branch passage 61e. The other end of each of the branch passages 61a, 61b, 61c, and 61d is connected to the PCV valves 80a, 80b, 80c, and 80d respectively. Note that instead of the PCV valves 80a, 80b, 80c, and 80d, one PCV valve may be provided in the pre-branch passage 61e. Also, the PCV valves 80a, 80b, 80c, and 80d may be respectively arranged in the branch passages 61a, 61b, 61c, and 61d.

[0052] The intake manifold 24 includes branch passages 24a, 24b, 24c, and 24d, and a surge tank 24e. One end of each of the branch passages 24a, 24b, 24c, and 24d is connected to the surge tank 24e. The other end of each of the branch passages 24a, 24b, 24c, and 24d is connected to the intake ports 21a, 21b, 21c, and 21d, respectively. One end of the intake passage 22 is connected to the surge tank 24e.

[0053] Figure 4 illustrates an example of the drive process for each cylinder 16. The drive process consists of an intake process, a compression process, a combustion (expansion) process, and an exhaust process, forming one cycle. Note that the drive process for each cylinder 16 is not limited to the example shown in Figure 4.

[0054] In each of the cylinders 16a to 16d, the above four processes are executed in sequence. As shown in Figure 4, the control device 200 (Figure 1) controls each cylinder 16 so that different processes are executed. Since the crank angle corresponding to one cycle is 720 degrees, the crank angle corresponding to each process is 180 degrees.

[0055] Each of the injection valves 71 (Figure 3) in the fuel supply units 70a to 70d injects hydrogen during the intake process. Therefore, the timing of hydrogen injection by each injection valve 71 is staggered. The injection valves 71 begin injecting hydrogen at the same time as the intake process begins.

[0056] Each injection valve 71 injects hydrogen for a time T corresponding to a predetermined crank angle during the intake stroke. For example, time T may have a length corresponding to a crank angle of 110 degrees or more and 150 degrees or less. As a result, since time T is relatively long, the time during which hydrogen is injected can be made relatively long. Also, since the crank angle is less than 180 degrees, there is a period during the intake stroke in which no hydrogen is injected. Note that the time T during which hydrogen is injected may have a length corresponding to a crank angle of 180 degrees.

[0057] By increasing the time hydrogen is injected, the time that blow-by gas is drawn in by the ejector 72 is extended. As a result, the amount of blow-by gas drawn in by the ejector 72 increases, which helps to suppress the decrease in the return flow rate of blow-by gas.

[0058] Figure 5 is a schematic diagram showing the relationship between the fuel injection amount, pressure, and blow-by gas recirculation rate (hereinafter referred to as gas recirculation rate) of the hydrogen engine 1 with respect to the load.

[0059] As shown in Figure 5, the greater the load on the hydrogen engine 1, the greater the amount of fuel (hydrogen) injected by the injection valve 71. Specifically, across the entire range from the non-supercharged to the supercharged range, the greater the load on the hydrogen engine 1, the greater the amount of hydrogen injected by the injection valve 71. Also, the greater the load on the hydrogen engine 1, the higher the pressure (internal pressure) at the intake port 21.

[0060] Specifically, as the required load on the hydrogen engine 1 increases, the fuel injection amount increases, and the opening of the throttle valve 25 also increases. When the opening of the throttle valve 25 increases, the amount of air drawn into the intake port 21 increases, so the pressure in the intake port 21 increases. As a result, when the fuel injection amount increases and the pressure in the intake port 21 increases, the load on the hydrogen engine 1 increases.

[0061] Furthermore, due to the increased fuel injection amount, the negative pressure formed by the ejector 72 increases (the pressure decreases). This increases the difference between the negative pressure and the internal pressure of the crankcase 15. As a result, the gas return flow rate by the ejector 72 (dotted line in Figure 5) increases as the load on the hydrogen engine 1 increases. Note that if the PCV valve 80 is not provided in the hydrogen engine 1 (see dotted line), the negative pressure of the ejector 72 is affected by the pressure of the intake port and increases in the supercharging region.

[0062] Figure 5 shows the gas return flow rate (dashed line in Figure 5) when a PCV valve is provided between the crankcase 15 and the intake passage 22 (comparative example). As shown in Figure 5, the gas return flow rate is suppressed from dropping (becoming close to zero) at the boundary between the non-supercharged and supercharged regions. If the PCV valve 80 is not provided in the hydrogen engine 1 (see dashed line), the gas return flow rate by the ejector 72 will decrease due to the increase in negative pressure at the ejector 72.

[0063] (Simulation Results) Under the condition that the time T for which hydrogen gas is injected from each injection valve 71 corresponds to a crank angle of 180 degrees, the simulation results showed that a certain amount or more of blow-by gas is constantly being recirculated. In other words, the results showed that the recirculation of blow-by gas is occurring without interruption.

[0064] As described above, according to this embodiment, the fuel supply unit 70 includes an injection valve 71 for injecting fuel (hydrogen) and an ejector 72. The ejector 72 includes an inlet port 721 into which the fuel injected from the injection valve 71 flows, and a suction port 722 for drawing in blow-by gas flowing through the blow-by gas passage 61. This allows blow-by gas to be easily drawn in from the suction port 722 by utilizing the negative pressure created by the injection of fuel from the injection valve 71. Therefore, it is possible to suppress a decrease in the return flow rate of blow-by gas throughout the entire range from the non-supercharged region to the supercharged region.

[0065] Furthermore, according to this embodiment, the hydrogen engine 1 is equipped with a PCV valve 80 that prevents backflow of blow-by gas from the suction port 722 of the ejector 72 to the crankcase 15. This makes it possible to suppress backflow of blow-by gas from the ejector 72 to the crankcase 15 while hydrogen is not being injected and no negative pressure is being formed in the ejector 72.

[0066] (Comparative Example) Figure 6 is a diagram of a comparative example showing a conventional configuration. In the example shown in Figure 6, the ejector 72 (Figure 2) is not provided, and the injection valve 71 is directly inserted into the intake port 21. Figure 7 is a cross-sectional view along the line VII-VII in Figure 6.

[0067] (Modification) In the above embodiment, an example was shown in which the hydrogen engine 1 has a plurality of cylinders 16, but the present disclosure is not limited thereto. The number of cylinders may be one. In this case, the number of fuel supply units 70 is also one.

[0068] In the above embodiment, an example was shown in which the hydrogen engine 1 is equipped with a PCV valve 80, but the disclosure is not limited thereto. The PCV valve 80 may not be provided.

[0069] In the above embodiment, a hydrogen engine in which the injection valve 71 injects hydrogen has been described, but the disclosure is not limited thereto. For example, the injection valve may inject LPG (Liquefied Petroleum Gas) or ammonia.

[0070] In the above embodiment, an example was shown in which the fuel supply unit 70 supplies fuel to the intake port 21, but the disclosure is not limited thereto. For example, the fuel supply unit 70 may supply fuel to each of the branch passages 24a to 24d.

[0071] In the above embodiment, an example was shown in which the hydrogen engine 1 is equipped with a supercharger 30, but the disclosure is not limited thereto. The engine may not be equipped with a supercharger.

[0072] The configurations of each of the above embodiments and each of the modified examples may be combined with each other.

[0073] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended.

[0074] 1 Hydrogen engine (internal combustion engine) 15 Crankcase 16 Cylinders 21 Intake port (intake section) 22 Intake passage 30 Supercharger 61 Blow-by gas passage 70 Fuel supply section 71 Injector 72 Ejector 80 PCV valve (check valve) 721 Inlet port 722 Suction port

Claims

1. An internal combustion engine comprising: a crankcase; at least one cylinder; a blow-by gas passage through which blow-by gas discharged from the crankcase flows; an intake section communicating with the at least one cylinder; and at least one fuel supply section for supplying fuel to the intake section, wherein the at least one fuel supply section includes an injection valve for injecting fuel and an ejector, and the ejector includes an inlet port into which fuel injected from the injection valve flows and an intake port for drawing in the blow-by gas flowing through the blow-by gas passage.

2. The internal combustion engine according to claim 1, further comprising a backflow prevention valve for preventing the backflow of blow-by gas from the suction port to the crankcase.

3. The internal combustion engine according to claim 2, wherein the backflow prevention valve is located near the suction port.

4. The internal combustion engine according to any one of claims 1 to 3, wherein the at least one cylinder comprises a plurality of cylinders, the intake unit comprises a plurality of intake ports connected to each of the plurality of cylinders, and the at least one fuel supply unit comprises a plurality of fuel supply units that supply fuel to each of the plurality of intake ports.

5. The injection valve injects hydrogen, as described in any one of claims 1 to 3.

6. An internal combustion engine according to any one of claims 1 to 3, further comprising: an intake passage connected to the intake section; and a supercharger disposed in the intake passage.

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