Hydrogen engine

Abstract

In a hydrogen engine, if the blow-by gas is configured to be discharged from the crankcase, it reduces engine oil consumption. [Solution] A discharge passage 40 connected to the crankcase 10 is provided. A separation device 4 connected to the discharge passage 40 is provided to separate engine oil E1 from the blow-by gas discharged from the crankcase 10 through the discharge passage 40 and return the separated engine oil E1 to the crankcase 10. The separation device 4 is attached to the outer surface of the cylinder 11 or the outer surface of the crankcase 10.

Description

Technical Field

[0001] The present invention relates to a hydrogen engine supplied with hydrogen as fuel.

Background Art

[0002] In a hydrogen engine, when unburned gas or a mixture (hereinafter referred to as blow-by gas) leaks from the cylinder to the crankcase, the blow-by gas due to hydrogen is more likely to ignite than the blow-by gas due to gasoline or light oil. For this reason, as disclosed in Patent Document 1, there is a device provided with a ventilation passage and a ventilation fan for discharging the blow-by gas in the crankcase.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a hydrogen engine, when blow-by gas is discharged from the crankcase, engine oil in a mist state in the crankcase may be discharged together with the blow-by gas, so there is room for improvement in suppressing the consumption of engine oil.

[0005] An object of the present invention is to suppress the consumption of engine oil when a hydrogen engine is configured such that blow-by gas is discharged from the crankcase.

Means for Solving the Problems

[0006] The present invention relates to a hydrogen engine supplied with hydrogen as fuel, comprising: a crankcase for storing engine oil and housing a crankshaft; a cylinder; a piston housed in the cylinder; and a connecting rod connected between the crankshaft and the piston; a discharge passage connected to the crankcase; and a separation device connected to the discharge passage, which separates the engine oil from the blow-by gas discharged from the crankcase through the discharge passage and returns the separated engine oil to the crankcase, wherein the separation device is attached to the outer surface of the cylinder or the outer surface of the crankcase.

[0007] According to the present invention, if blow-by gas leaks from the cylinder into the crankcase, the blow-by gas is discharged from the crankcase through a discharge passage to a separation device. Even if the engine oil, now in mist form, is discharged from the crankcase along with the blow-by gas, the separation device separates the engine oil from the blow-by gas, and the separated engine oil is returned to the crankcase.

[0008] In hydrogen engines, water is discharged as a combustion product, resulting in a high concentration of moisture in the blow-by gas. This raises concerns that in cold conditions such as winter, the moisture in the blow-by gas may mix with the engine oil and emulsify in the separation system, potentially leading to the freezing of the moisture in the blow-by gas.

[0009] According to the present invention, since the separation device is attached to the outer surface of the cylinder or the outer surface of the crankcase, the separation device is heated by the heat generated by the hydrogen engine. This heating of the separation device prevents emulsification of the moisture in the blow-by gas with the engine oil, and prevents the moisture in the blow-by gas from freezing.

[0010] According to the present invention, since the engine oil separated from the blow-by gas is returned to the crankcase, emulsification by the moisture in the blow-by gas and the engine oil is prevented, and the freezing of the moisture in the blow-by gas is prevented, the consumption of engine oil is suppressed, and the separation device operates properly, thereby improving the performance of the hydrogen engine.

[0011] In the present invention, it is preferable that the separation device has a pump function for drawing the blow-by gas from the crankcase through the discharge passage.

[0012] According to the present invention, the separation device has a pump function, and the separation device promotes the discharge of blow-by gas from the crankcase, which is advantageous in terms of improving the performance of the hydrogen engine.

[0013] In the present invention, the separation device is equipped with a pressure sensor for detecting the pressure of the blow-by gas drawn into it, and it is preferable that the separation device changes the amount of blow-by gas drawn in so that the detected value of the pressure sensor falls within a preset range.

[0014] According to the present invention, the amount of blow-by gas drawn in by the separation device is changed based on the value detected by the pressure sensor. This prevents excessive or insufficient drawing of blow-by gas when the separation device draws blow-by gas from the crankcase, stabilizing the internal state of the crankcase, which is advantageous in terms of improving the performance of the hydrogen engine.

[0015] In the present invention, it is preferable that an intake passage for supplying combustion air to the cylinder is provided, and a recirculation passage for supplying the blow-by gas discharged from the separation device to the intake passage.

[0016] According to the present invention, blow-by gas from which engine oil has been separated by the separation device is supplied to the intake passage via the recirculation passage, where it is combined with combustion air and supplied back to the cylinder. This allows blow-by gases to be re-burned in the cylinder, saving hydrogen fuel, which is advantageous in terms of improving the performance of hydrogen engines.

[0017] In the present invention, it is preferable that a supercharging device is provided which has a turbine that is rotationally driven by the exhaust gas supplied from the cylinder, compresses the air in the intake passage with the turbine to supercharge the cylinder, and the recirculation passage is connected to the portion of the intake passage upstream of the supercharging device.

[0018] Hydrogen engines are sometimes equipped with a supercharger that has a turbine driven by the exhaust gas supplied from the cylinders. According to the present invention, when a supercharger is provided, the recirculation passage is connected to the portion of the intake passage upstream of the supercharger. Therefore, when blow-by gas is supplied to the intake passage via the recirculation passage, the combustion air and blow-by gas are compressed together by the supercharger and supercharged into the cylinder. This allows the combustion air and blow-by gas to be smoothly compressed by the supercharger and supplied to the cylinder, which is advantageous in terms of improving the performance of the hydrogen engine.

[0019] In the present invention, it is preferable that the device is equipped with a switching unit that can switch between a reduction state in which the blow-by gas discharged from the separation device is guided to the reduction passage and a discharge state in which the blow-by gas discharged from the separation device is discharged.

[0020] According to the present invention, by switching the switching unit between a reduction state and a discharge state, a state is obtained in which blow-by gas, from which engine oil has been separated by the separation device, is supplied to the intake passage via the reduction passage, and a state in which it is discharged from the separation device. In a hydrogen engine, water is discharged as a combustion product, so even if blow-by gas is discharged into the atmosphere, the environmental burden is small. This allows the switching mechanism to switch between the recirculation state and the exhaust state depending on conditions such as the load on the hydrogen engine, which is advantageous in terms of improving the performance of the hydrogen engine.

[0021] In the present invention, it is preferable that a hydrogen concentration sensor for detecting the hydrogen concentration of the blow-by gas discharged from the separation device is provided, and the switching unit is operated based on the detection value of the hydrogen concentration sensor.

[0022] According to the present invention, the hydrogen concentration sensor detects the hydrogen concentration of the blow-by gas from which engine oil has been separated by the separation device, and the switching unit is automatically operated based on the detection value of the hydrogen concentration sensor. Therefore, it is advantageous in terms of improving the performance of the hydrogen engine.

[0023] In the present invention, a first air cleaner for supplying outside air as clean combustion air to the intake passage, and a first supply passage connected across a portion on the side of the first air cleaner with respect to a portion of the intake passage to which the reduction passage is connected and the crankcase are provided, and it is preferable that the air in the intake passage is supplied to the crankcase through the first supply passage.

[0024] In a hydrogen engine, an air cleaner for supplying outside air as clean combustion air to the intake passage is provided. In the case of a configuration in which blow-by gas is discharged from the crankcase, it is preferable to have a configuration in which air is supplied to the crankcase.

[0025] According to the present invention, the first air cleaner is provided, and the first supply passage is connected across a portion on the side of the first air cleaner with respect to a portion of the intake passage to which the reduction passage is connected and the crankcase. In this case, in the intake passage, since the air flow from the first air cleaner to the cylinder occurs, by connecting the first supply passage to a portion on the side of the first air cleaner rather than to a portion of the intake passage to which the reduction passage is connected, the blow-by gas supplied from the reduction passage to the intake passage does not flow backward through the intake passage and enter the first supply passage.

[0026] According to the present invention, the combustion air that has passed through the first air cleaner is divided at the point where the first supply passage is connected in the intake passage into air flowing into the intake passage and air flowing into the first supply passage. The air flowing into the intake passage merges with blow-by gas supplied from the recirculation passage and is supplied to the cylinder. The air flowing into the first supply passage flows to the crankcase via the first supply passage. As a result, the first air cleaner is used for both the intake passage and the first supply passage, which simplifies the structure of the hydrogen engine.

[0027] In the present invention, it is preferable that a second supply passage connected to the crankcase and a second air cleaner connected to the second supply passage are provided, and outside air is supplied to the second supply passage through the second air cleaner and then supplied to the crankcase via the second supply passage.

[0028] According to the present invention, in addition to air being supplied to the crankcase via the first supply passage, outside air is also supplied to the crankcase via the second supply passage through the second air cleaner, so that a large amount of air is supplied to the crankcase. This promotes the discharge of blow-by gases from the crankcase, which is advantageous in terms of improving the performance of hydrogen engines. [Brief explanation of the drawing]

[0029] [Figure 1] This diagram shows the overall configuration of the power unit. [Figure 2] This diagram shows the operating status of the power unit. [Figure 3] This diagram shows the overall configuration of the power unit in a first alternative embodiment of the invention. [Figure 4] This diagram shows the overall configuration of the power unit in a second alternative embodiment of the invention. [Modes for carrying out the invention]

[0030] (Overall configuration of the power unit) Figures 1 to 4 show a power unit having a hydrogen engine 1 supplied with hydrogen as fuel. In addition to the hydrogen engine 1, the power unit includes a motor generator 2, an E-turbo 3, and a separation device 4, etc. The power from the power unit drives the generator, pumps, etc.

[0031] (Configuration of hydrogen engine 1) As shown in Figure 1, the hydrogen engine 1 has a crankcase 10, cylinders 11, cylinder head 12, etc., and is configured as an inline four-cylinder type.

[0032] A crankshaft 13 is rotatably housed in a crankcase 10, and engine oil E1 is stored in the crankcase 10. Four cylinders 11 are located at the top of the crankcase 10, and connecting rods 15 are connected to pistons 14 located inside the cylinders 11 and to the crankshaft 13.

[0033] Intake ports 16 and exhaust ports 17, intake valves 18 and exhaust valves 19, and spark plugs 20 are provided in the cylinder head 12, corresponding to each of the cylinders 11. An intake manifold 24 is provided in the cylinder head 12 so as to connect across the four intake ports 16. An exhaust manifold 25 is provided in the cylinder head 12 so as to connect across the four exhaust ports 17.

[0034] (Configuration related to motor generator 2) As shown in Figure 1, the first inverter 21 is provided for the motor generator 2, and a battery 23 is provided.

[0035] A motor generator 2 is provided in the crankcase 10 of the hydrogen engine 1. In the hydrogen engine 1, a flywheel (not shown) is connected to the crankshaft 13, and a transmission gear (not shown) of the motor generator 2 meshes with the gear portion on the outer circumference of the flywheel. The flywheel is capable of storing rotational energy and releasing the stored rotational energy.

[0036] When the motor generator 2 operates as a motor, the DC power from the battery 23 is converted to AC power by the first inverter 21 and supplied to the motor generator 2, causing the motor generator 2 to operate as a motor. The power from the motor generator 2 is transmitted to the crankshaft 13 of the hydrogen engine 1 via the flywheel, and the power from the hydrogen engine 1 and the power from the motor generator 2 are combined and output from the crankshaft 13 of the hydrogen engine 1. The above state is the state in which the combining operation by the first inverter 21 has been performed.

[0037] When the motor generator 2 is operating as a generator, power from the hydrogen engine 1 is transmitted to the motor generator 2 via the flywheel, driving the motor generator 2. The AC power generated by the motor generator 2 is converted to DC power by the first inverter 21 and charged into the battery 23. The above state represents the state in which the charging operation by the first inverter 21 has been performed.

[0038] (Configuration of E-Turbo3) As shown in Figure 1, the E-turbo 3 has a turbine 31 and a turbine motor 32. The turbine 31 has a compressor wheel 31a and a turbine wheel 31b, and the compressor wheel 31a and the turbine wheel 31b are connected so as to rotate together as a single unit.

[0039] A first air cleaner 33 is provided. An intake passage 34 extends from the first air cleaner 33 and is connected to the compressor wheel 31a of the E-turbo 3. An intake passage 35 extends from the compressor wheel 31a of the E-turbo 3 and is connected to the intake manifold 24 of the hydrogen engine 1. A throttle 36 is provided in the intake passage 35.

[0040] An exhaust passage 37 extends from the exhaust manifold 25 of the hydrogen engine 1 and is connected to the turbine wheel 31b of the E-turbo 3. An exhaust passage 38 extends from the turbine wheel 31b of the E-turbo 3.

[0041] The turbine motor 32 is capable of rotating the turbine 31. A second inverter 22 is provided for the turbine motor 32, and the DC power from the battery 23 is converted into AC power by the second inverter 22 and supplied to the turbine motor 32, causing the turbine motor 32 to operate. The above state is the state in which supercharging operation by the second inverter 22 is performed.

[0042] The turbine wheel 31b (turbine 31) of the E Turbo 3 is rotationally driven by the exhaust from the exhaust manifold 25 and exhaust passage 37 of the hydrogen engine 1, and is also rotationally driven by the turbine motor 32.

[0043] A hydrogen tank 26 for storing hydrogen is provided, and an injection device 27 is installed on the intake manifold 24 of the hydrogen engine 1. Hydrogen from the hydrogen tank 26 is supplied to the injection device 27 through the fuel passage 28, and from the injection device 27 to the intake manifold 24 of the hydrogen engine 1.

[0044] With the above configuration, outside air passes through the first air cleaner 33 as clean combustion air, is supplied to the compressor wheel 31a of the E turbo 3 via the intake passage 34, is compressed, and then supplied (supercharged) to the intake manifold 24 of the hydrogen engine 1 via the intake passage 35 and throttle 36. The air supplied to the intake manifold 24 of the hydrogen engine 1 is regulated by the throttle 36.

[0045] Hydrogen is supplied to the intake manifold 24 of the hydrogen engine 1 via the injection device 27, and a mixture of hydrogen and air is supplied (supercharged) to the cylinder 11 via the intake manifold 24, intake port 16, and intake valve 18 of the hydrogen engine 1 for combustion.

[0046] The combustion gas from the combustion in the cylinder 11 of the hydrogen engine 1 is supplied as exhaust to the turbine wheel 31b of the E-turbo 3 via the exhaust port 17 and exhaust valve 19, exhaust manifold 25, and exhaust passage 37 of the hydrogen engine 1, thereby rotating the turbine 31 (turbine wheel 31b) of the E-turbo 3. The exhaust gas that has rotated the turbine 31 of the E-turbo 3 is discharged from the turbine wheel 31b of the E-turbo 3 via the exhaust passage 38.

[0047] (Configuration of separation device 4) As shown in Figure 1, the separation device 4 is directly attached to the outer surface of the cylinder 11 of the hydrogen engine 1, and the heat generated by combustion in the cylinder 11 of the hydrogen engine 1 is easily transferred to the separation device 4. A specific mounting location for the separation device 4 is, for example, the area where the fuel supply pump is attached in a diesel engine.

[0048] The discharge passage 40 is connected to the crankcase 10 of the hydrogen engine 1 and the separation device 4. The return passage 41 is also connected to the crankcase 10 of the hydrogen engine 1 and the separation device 4. A pressure sensor 48 is provided in the discharge passage 40.

[0049] The recirculation passage 42 extends from the separation device 4 and is connected to the portion of the intake passage 34 that is on the side of the first air cleaner 33 (upstream side) from the E turbo 3. A switching valve 43 is provided in the recirculation passage 42, and a hydrogen concentration sensor 44 is provided in the portion of the recirculation passage 42 between the separation device 4 and the switching valve 43.

[0050] The supply passage 45 extends from the portion of the intake passage 34 that is connected to the recirculation passage 42, on the side of the first air cleaner 33, and is connected to the crankcase 10 of the hydrogen engine 1. A second air cleaner 47 is provided, and the supply passage 46 extends from the second air cleaner 47 and is connected to the supply passage 45.

[0051] (Operating status of separation device 4) - 1 As shown in Figure 1, in the hydrogen engine 1, unburned gases and the fuel-air mixture (hereinafter referred to as blow-by gas) may leak from the cylinder 11 into the crankcase 10. The separation device 4 functions in response to this situation as described below.

[0052] The separation device 4 has a pump function that draws blow-by gas from the crankcase 10 of the hydrogen engine 1 through the discharge passage 40, and is configured so that the amount of blow-by gas drawn in can be changed. When the separation device 4 draws in blow-by gas from the crankcase 10 of the hydrogen engine 1, the engine oil E1 that has turned into a mist in the crankcase 10 of the hydrogen engine 1 is drawn into the separation device 4 together with the blow-by gas.

[0053] The separation device 4 separates the engine oil E1 from the inhaled blow-by gas and returns the separated engine oil E1 to the crankcase 10 of the hydrogen engine 1 via the return passage 41. The blow-by gas from which the engine oil E1 has been separated is supplied from the separation device 4 to the switching valve 43 via the recirculation passage 42.

[0054] The pressure of the blow-by gas drawn into the separation device 4 is detected by the pressure sensor 48. A setting device (not shown) sets a setting range for the blow-by gas pressure. The setting device allows the width of the setting range to be changed, and the setting range can be changed overall to the high-pressure or low-pressure side.

[0055] The separation device 4 changes the amount of blow-by gas drawn in so that the value detected by the pressure sensor 48 falls within the set range pre-set by the setting device. If the pressure sensor 48 detects a value higher than the set range, it is determined that this could lead to a blockage in the exhaust passage 40 and potentially stall the hydrogen engine 1. As a result, the amount of blow-by gas drawn in by the separation device 4 is changed to a higher level until the pressure sensor 48 detects a value within the set range. If the pressure sensor 48 detects a value lower than the set range, it is determined that the separator 4 is excessively drawing in blow-by gas. As a result, the amount of blow-by gas drawn in by the separator 4 is changed to a lower level until the pressure sensor 48 detects a value within the set range.

[0056] (Operating status of separation device 4) - 2 As shown in Figure 1, the switching valve 43 can be operated to a recirculation position in which blow-by gas from the separation device 4 is supplied to the recirculation passage 42 and then to the intake passage 34, and to a discharge position in which blow-by gas from the separation device 4 is released into the atmosphere.

[0057] The hydrogen concentration sensor 44 detects the hydrogen concentration of the blow-by gas from which the engine oil E1 has been separated by the separation device 4. If the hydrogen concentration detected by the hydrogen concentration sensor 44 is higher than a preset value, the switching valve 43 is automatically operated to the reduction position. The blow-by gas from which the engine oil E1 has been separated by the separation device 4 is supplied to the intake passage 34 via the reduction passage 42, merges with the air that has passed through the first air cleaner 33, and is supplied to the compressor wheel 31a of the E turbo 3, where it is compressed as described above and supplied to the cylinder 11 of the hydrogen engine 1.

[0058] If the hydrogen concentration detected by the hydrogen concentration sensor 44 is lower than the aforementioned set value, the switching valve 43 is automatically operated to the discharge position, and the blow-by gas from which the engine oil E1 has been separated by the separation device 4 is released into the atmosphere.

[0059] As described above, when the blow-by gas from the crankcase 10 of the hydrogen engine 1 is drawn in by the separation device 4, a portion of the air that enters the intake passage 34 through the first air cleaner 33 enters the supply passage 45 from the intake passage 34 and is supplied to the crankcase 10 of the hydrogen engine 1 via the supply passage 45. Outside air enters the supply passage 45 from the supply passage 46 as clean air after passing through the second air cleaner 47 and is supplied to the crankcase 10 of the hydrogen engine 1.

[0060] As a result, the following processes are continuously performed: intake of blow-by gas from the crankcase 10 of the hydrogen engine 1, supply or discharge of blow-by gas to the cylinder 11 of the hydrogen engine 1, and supply of air that has passed through the first air cleaner 33 and the second air cleaner 47 to the crankcase 10 of the hydrogen engine 1.

[0061] (Operating status of the power unit) - 1 As shown in Figure 1, under normal conditions, exhaust gas from the exhaust manifold 25 and exhaust passage 37 of the hydrogen engine 1 is supplied to the turbine wheel 31b (turbine 31) of the E-turbo 3, causing the turbine wheel 31b (turbine 31) of the E-turbo 3 to rotate, and the turbine motor 32 is not operating.

[0062] Air passing through the first air cleaner 33 is supplied to the compressor wheel 31a of the E turbo 3 via the intake passage 34, compressed, and then supplied (supercharged) to the intake manifold 24 of the hydrogen engine 1 via the intake passage 35 and throttle 36.

[0063] As described above, the hydrogen engine 1 operates at a constant rotational speed. The aforementioned intake of blow-by gas from the crankcase 10 of the hydrogen engine 1, supply or discharge of blow-by gas to the cylinder 11 of the hydrogen engine 1, and supply of air that has passed through the first air cleaner 33 and the second air cleaner 47 to the crankcase 10 of the hydrogen engine 1 are performed continuously.

[0064] Under normal conditions, the motor generator 2 operates as a generator. Power from the hydrogen engine 1 is transmitted to the motor generator 2 via the flywheel, driving the motor generator 2. The AC power generated by the motor generator 2 is converted to DC power by the first inverter 21 and charged into the battery 23.

[0065] (Operating status of the power unit) - 2 In the aforementioned normal state, if the load on the power unit increases and the rotational speed of the crankshaft 13 of the hydrogen engine 1 decreases, the following operations are performed in order to restore (increase) the rotational speed of the crankshaft 13 of the hydrogen engine 1.

[0066] As shown in Figures 1 and 2, assume that air volume AV1 is supplied to the cylinder 11 of the hydrogen engine 1 (supercharging), and the hydrogen engine 1 (crankshaft 13) is outputting power with torque NM1. In this state, if the load on the power unit increases and the rotational speed of the crankshaft 13 of the hydrogen engine 1 decreases, the throttle 36 is opened (time T1).

[0067] When the throttle 36 is opened and operated (time T1), the amount of air supplied (supercharged) to the cylinder 11 of the hydrogen engine 1 increases from air volume AV1 to air volume AV2 (time T2).

[0068] Simultaneously, the motor generator 2 operates as a motor (time T1), and the power of the hydrogen engine 1 and the power of the motor generator 2 are combined, causing the torque NM1 of the crankshaft 13 of the hydrogen engine 1 to increase to torque NM2 (time T2), and the rotational speed of the crankshaft 13 of the hydrogen engine 1 begins to recover (increase) rapidly.

[0069] As mentioned above, once the rotational speed of the crankshaft 13 of the hydrogen engine 1 begins to recover (increase) rapidly, the increased exhaust from the hydrogen engine 1 causes the rotational speed of the turbine wheel 31b (turbine 31) of the E turbo 3 to begin to increase.

[0070] In this case, in the E-turbo 3, the turbine motor 32 starts operating (time T2), the rotational speed of the turbine wheel 31b (turbine 31) of the E-turbo 3 increases rapidly, and the amount of air supplied (supercharged) to the cylinder 11 of the hydrogen engine 1 rapidly increases from air volume AV2 (time T2) to air volume AV3 (time T3). As a result, the torque NM2 of the crankshaft 13 of the hydrogen engine 1 increases to torque NM3 (at time T3), and the rotational speed of the crankshaft 13 of the hydrogen engine 1 quickly recovers (increases) to its normal state.

[0071] Subsequently, as the load on the power unit decreases, the rotational speed of the crankshaft 13 of the hydrogen engine 1 increases further from its normal state, indicating that the load on the power unit has decreased.

[0072] When it is determined that the load on the power unit has decreased (time T4), the motor generator 2 returns to operating as a generator. In the E-turbo 3, the turbine motor 32 stops, and the turbine wheel 31b (turbine 31) of the E-turbo 3 returns to a state where it is rotated solely by the exhaust from the hydrogen engine 1.

[0073] As a result, the hydrogen engine 1 returns to a state where air volume AV1 is supplied to cylinder 11 (supercharging) (time T5), and the hydrogen engine 1 (crankshaft 13) returns to a normal state where it outputs power of torque NM1 (time T5).

[0074] (First alternative embodiment of the invention) Instead of the configuration shown in Figure 1, the configuration shown in Figure 3 may be used. In Figure 3, the switching valve 43, hydrogen concentration sensor 44, second air cleaner 47, and supply passage 46 from Figure 1 have been eliminated.

[0075] As a result, the blow-by gas from which the engine oil E1 has been separated by the separation device 4 is constantly supplied to the intake passage 34 via the recirculation passage 42. Only a portion of the air that has passed through the first air cleaner 33 and entered the intake passage 34 is supplied to the crankcase 10 of the hydrogen engine 1 via the supply passage 45.

[0076] (Second alternative embodiment of the invention) Instead of the configuration shown in Figure 1, the configuration shown in Figure 4 may be used. In Figure 4, the switching valve 43, hydrogen concentration sensor 44, reduction passage 42, and supply passage 45 from Figure 1 have been eliminated, and the supply passage 46 is connected to the crankcase 10 of the hydrogen engine 1.

[0077] As a result, the blow-by gas from which the engine oil E1 has been separated by the separation device 4 is continuously released into the atmosphere from the separation device 4. Only the air that has passed through the second air cleaner 47 is supplied to the crankcase 10 of the hydrogen engine 1 via the supply passage 46.

[0078] (Third alternative form of the invention) The number and arrangement of the cylinders 11 of the hydrogen engine 1 may be configured as an inline 3-cylinder type, an inline 6-cylinder type, a V6 type, a V8 type, etc. The system may be configured so that liquefied hydrogen is stored in the hydrogen tank 26.

[0079] (Fourth alternative embodiment of the invention) The motor generator 2 may be located inside a flywheel housing (not shown) that accommodates the flywheel. The motor generator 2 may be provided inside or outside the flywheel housing, and the case (not shown) housing the motor generator 2 and the flywheel housing may be integrally configured.

[0080] The input / output shaft (not shown) of the motor generator 2 and the flywheel may be arranged coaxially, and the input / output shaft of the motor generator 2 and the flywheel may be connected so that the motor generator 2 and the flywheel rotate as a single unit.

[0081] (Fifth alternative embodiment of the invention) The motor generator 2 and the first inverter 21 may be omitted.

[0082] (Sixth alternative embodiment of the invention) The second inverter 22 and the turbine motor 32 may be eliminated, and a turbocharger (not shown) without a turbine motor 32 may be provided in place of the E-turbo 3.

[0083] (Seventh alternative embodiment of the invention) The motor generator 2, the first inverter 21, the second inverter 22, and the turbine motor 32 may be eliminated, and a turbocharger (not shown) without a turbine motor 32 may be provided in place of the E-turbo 3.

[0084] (Eighth alternative form of the invention) The motor generator 2, the first inverter 21, the second inverter 22, the E-turbo 3, and the battery 23 may be eliminated to form a naturally aspirated hydrogen engine 1. In this configuration, the reduction passage 42 may be connected to the intake manifold 24.

[0085] (Ninth alternative embodiment of the invention) The separation device 4 may be attached to the outer surface of the crankcase 10. The discharge passage 40 may be composed of a pipe (not shown) that connects the separation device 4 and the crankcase 10 of the hydrogen engine 1 outside the crankcase 10 and cylinder 11 of the hydrogen engine 1. The discharge passage 40 may be composed of an internal passage (not shown) formed inside the wall of the cylinder block (not shown) of the hydrogen engine 1, spanning between the separation device 4 and the crankcase 10 of the hydrogen engine 1.

[0086] (Tenth alternative embodiment of the invention) The setting values ​​for operating the switching valve 43 to the recirculation position and the discharge position may be configured to be manually changed to the high and low sides. The hydrogen concentration sensor 44 may be eliminated, and the switching valve 43 may be configured to be manually operated to the reduction position and the discharge position.

[0087] (Eleventh alternative embodiment of the invention) In Figure 1, a supply switching valve (not shown) having the following functions may be provided at the point where the supply passage 46 is connected to the supply passage 45.

[0088] When the supply switching valve is operated to the first position, the air from the first air cleaner 33 and the air from the second air cleaner 47 merge and are supplied to the crankcase 10 of the hydrogen engine 1. When the supply switching valve is operated to the second position, air from the first air cleaner 33 is supplied to the crankcase 10 of the hydrogen engine 1, and air from the second air cleaner 47 is not supplied to the crankcase 10 of the hydrogen engine 1. When the supply switching valve is operated to the third position, air from the second air cleaner 47 is supplied to the crankcase 10 of the hydrogen engine 1, and air from the first air cleaner 33 is not supplied to the crankcase 10 of the hydrogen engine 1.

[0089] (Correspondence with claims) - 1 E Turbo 3 corresponds to the supercharger. Switching valve 43 corresponds to the switching section. The return position of switching valve 43 corresponds to the return state of the switching section, and the discharge position of switching valve 43 corresponds to the discharge state of the switching section. Supply passage 45 corresponds to the first supply passage. Supply passage 46 corresponds to the second supply passage.

[0090] (Correspondence with claims) - 2 In a hydrogen engine 1 supplied with hydrogen as fuel, the engine is equipped with a crankcase 10 in which engine oil E1 is stored and which houses a crankshaft 13, a cylinder 11, a piston 14 housed in the cylinder 11, and a connecting rod 15 connected across the crankshaft 13 and the piston 14.

[0091] A discharge passage 40 is provided, which is connected to the crankcase 10. A separation device 4 is provided, which is connected to the discharge passage 40 and separates engine oil E1 from the blow-by gas discharged from the crankcase 10 through the discharge passage 40, and returns the separated engine oil E1 to the crankcase 10.

[0092] The separation device 4 is attached to the outer surface of the cylinder 11 or the outer surface of the crankcase 10. The separation device 4 has a pump function that draws blow-by gas from the crankcase 10 through the discharge passage 40.

[0093] The separation device 4 is equipped with a pressure sensor 48 that detects the pressure of the blow-by gas being drawn into it. The separation device 4 changes the amount of blow-by gas drawn in so that the value detected by the pressure sensor 48 falls within a preset range.

[0094] (Correspondence with claims) - 3 Intake passages 34 and 35 are provided to supply combustion air to the cylinder 11. A recirculation passage 42 is provided to supply blow-by gas from the separation device 4 to the intake passage 34.

[0095] The vehicle is equipped with a turbocharger (E-turbo 3) that has a turbine 31 which is rotated by the exhaust gas supplied from the cylinder 11, and compresses the air in the intake passage 35 with the turbine 31 to supercharge the cylinder 11. The recirculation passage 42 is connected to the portion of the intake passage 34 upstream of the turbocharger (E-turbo 3).

[0096] (Correspondence with claims) - 4 A switching unit (switching valve 43) is provided that can switch between a reduction state, in which the blow-by gas from the separation device 4 is guided to the reduction passage 42, and a discharge state, in which the blow-by gas from the separation device 4 is discharged.

[0097] A hydrogen concentration sensor 44 is provided to detect the hydrogen concentration of the blow-by gas discharged from the separation device 4. The switching unit (switching valve 43) is operated based on the value detected by the hydrogen concentration sensor 44.

[0098] (Correspondence with claims) - 5 A first air cleaner 33 is provided to supply outside air to the intake passage 34 as clean combustion air. A first supply passage (supply passage 45) is provided, which extends from the portion of the intake passage 34 that is connected to the reduction passage 42, to the portion on the side of the first air cleaner 33, and to the crankcase 10. Air from the intake passage 34 is supplied to the crankcase 10 via the first supply passage (supply passage 45).

[0099] A second supply passage (supply passage 46) is provided connected to the crankcase 10. A second air cleaner 47 is provided connected to the second supply passage (supply passage 46). Outside air is supplied through the second air cleaner 47 to the second supply passage (supply passage 46), and then supplied to the crankcase 10 via the second supply passage (supply passage 46). [Industrial applicability]

[0100] This invention can be applied to hydrogen engines. [Explanation of symbols]

[0101] 3 E-Turbo (Supercharger) 4 Separation device 10 Crankcase 11 cylinders 13 Crank Axle 14 pistons 15 Connecting Rod 40 Discharge passage 31 Turbine 33. First air cleaner 34 Intake passage 35 Intake passage 42 Reduction passage 43. Switching valve (switching section) 44 Hydrogen concentration sensor 45 Supply passage (1st supply passage) 46 Supply passage (2nd supply passage) 47. Second air cleaner 48 Pressure Sensor E1 Engine Oil

Claims

1. A hydrogen engine that is supplied with hydrogen as fuel, The engine comprises a crankcase that stores engine oil and houses the crankshaft, a cylinder, a piston housed in the cylinder, and a connecting rod that connects the crankshaft and the piston. A discharge passage connected to the aforementioned crankcase, The system is equipped with a separation device connected to the aforementioned discharge passage, which separates the engine oil from the blow-by gas discharged from the crankcase through the aforementioned discharge passage and returns the separated engine oil to the crankcase. A hydrogen engine in which the separation device is attached to the outer surface of the cylinder or the outer surface of the crankcase.

2. The hydrogen engine according to claim 1, wherein the separation device has a pump function for drawing the blow-by gas from the crankcase through the discharge passage.

3. The separation device is equipped with a pressure sensor for detecting the pressure of the blow-by gas drawn into it. The hydrogen engine according to claim 2, wherein the separation device changes the amount of blow-by gas drawn in so that the detected value of the pressure sensor falls within a preset range.

4. An intake passage is provided for supplying combustion air to the cylinder, The hydrogen engine according to claim 1, further comprising a recirculation passage for supplying the blow-by gas discharged from the separation device to the intake passage.

5. The system includes a turbine that is driven to rotate by the exhaust gas supplied from the cylinder, and a supercharger that compresses the air in the intake passage with the turbine to supercharge the cylinder. The hydrogen engine according to claim 4, wherein the reduction passage is connected to a portion of the intake passage upstream of the supercharger.

6. The hydrogen engine according to claim 4, further comprising a switching unit that can switch between a reduction state in which the blow-by gas discharged from the separation device is guided to the reduction passage, and a discharge state in which the blow-by gas discharged from the separation device is discharged.

7. The separation device is equipped with a hydrogen concentration sensor for detecting the hydrogen concentration of the blow-by gas discharged from the separation device. The hydrogen engine according to claim 6, wherein the switching unit is operated based on the detected value of the hydrogen concentration sensor.

8. A first air cleaner supplies outside air to the intake passage as clean combustion air, A first supply passage is provided, which extends from the portion of the intake passage closer to the first air cleaner than the portion to which the recirculation passage is connected, to the crankcase. The hydrogen engine according to claim 4, wherein the air from the intake passage is supplied to the crankcase via the first supply passage.

9. A second supply passage connected to the crankcase, The system is equipped with a second air cleaner connected to the second supply passage, The hydrogen engine according to claim 8, wherein outside air is supplied through the second air cleaner to the second supply passage and supplied to the crankcase via the second supply passage.

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