vehicle

Abstract

To put an internal combustion engine into a completion state of warming up with improved promptness.SOLUTION: A vehicle VC comprises an internal combustion engine 10 using hydrogen as fuel and a cooling mechanism 80. A radiator 85 is arranged in the middle of a main flow passage 82. A bypass flow passage 83 is extended from a point downstream of the internal combustion engine 10 and upstream of the radiator 85 in the main flow passage 82 and connected to a point downstream of the radiator 85 in the main flow passage 82. A valve 84 is installed on the bypass flow passage 83. A control device 100 performs a warm-up completion determination process on the basis of an engine temperature of the internal combustion engine 10. The control device 100 performs a valve closing process to close the valve 84 under a condition that the internal combustion engine 10 is determined to be in a completion state of warming up. The control device 100 also performs a valve opening process to open the valve 84 under a condition that the internal combustion engine 10 is determined not to be in the completion state of warming up.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] Patent Document 1 describes a vehicle including an internal combustion engine and a cooling mechanism. The internal combustion engine has a fuel tank, a fuel pipe, a regulator, and an injector. The fuel tank stores high-pressure gaseous fuel. The fuel pipe constitutes a gaseous fuel passage connecting the fuel tank and the injector. The regulator reduces the pressure of the gaseous fuel flowing through the fuel pipe. The injector is attached to the fuel pipe downstream of the regulator. Meanwhile, the cooling mechanism has a flow path through which cooling water flows. The regulator is located on the flow path of the cooling mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-131947 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an internal combustion engine such as that described in Patent Document 1, when the temperature of the internal combustion engine is low, for example, water adhering to the vicinity of the nozzle of the injector may freeze. If water freezes near the nozzle of the injector, there is a risk that the injector will not be able to inject an appropriate amount of gaseous fuel. Therefore, it is desirable to complete the warm-up of the internal combustion engine as quickly as possible. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention provides an internal combustion engine that uses hydrogen as fuel, a cooling mechanism having a flow path for cooling the internal combustion engine, and a control device that controls the cooling mechanism, wherein the internal combustion engine has a fuel pipe that is connected to a hydrogen tank and that constitutes a passage for the hydrogen, a regulator that is attached midway along the fuel pipe and that reduces the pressure of the hydrogen, and an injector that is attached to the fuel pipe downstream of the regulator, and the cooling mechanism includes a pump that pressurizes the cooling water, a main flow path through which the cooling water pressurized from the pump flows and through which the cooling water returns to the pump, a radiator that is arranged midway along the main flow path, and a control device that controls the cooling mechanism, wherein the internal combustion engine has a fuel pipe that is connected to a hydrogen tank and that constitutes a passage for the hydrogen, a regulator that is attached midway along the fuel pipe and that reduces the pressure of the hydrogen, and an injector that is attached to the fuel pipe downstream of the regulator, and the cooling mechanism includes a pump that pressurizes the cooling water, a main flow path through which the cooling water pressurized from the pump flows and through which the cooling water returns to the pump, The vehicle has a bypass flow path that connects from a location upstream of the radiator to a location of the main flow path downstream of the radiator, and a valve attached to the bypass flow path, wherein the regulator is disposed in the bypass flow path downstream of the valve, and the control device executes a warm-up completion determination process that determines whether the internal combustion engine is in a warm-up completion state based on an engine temperature of the internal combustion engine, a valve closing process that closes the valve on condition that it is determined by the warm-up completion determination process that the internal combustion engine is in a warm-up completion state, and a valve opening process that opens the valve on condition that it is determined by the warm-up completion determination process that the internal combustion engine is not in a warm-up completion state.

[0006] According to the above configuration, when the internal combustion engine has finished warming up, the cooling water does not flow through the bypass flow path but flows through the main flow path. On the other hand, when the internal combustion engine has not finished warming up, the cooling water does not flow through the main flow path but flows through the bypass flow path. Therefore, when the internal combustion engine has not finished warming up, heat is exchanged between the cooling water and the regulator. When the internal combustion engine has not finished warming up, the temperature of the cooling water is low, so that the cooling water can be warmed in the regulator by heat generated by the expansion of hydrogen.

[0007] In the vehicle, in the warm-up completion determination process, the control device may calculate the engine temperature based on the temperature of the hydrogen. According to the above configuration, it is determined whether the internal combustion engine has finished warming up based on the temperature of hydrogen. The temperature of hydrogen is easily affected by heat caused by combustion in the internal combustion engine. Furthermore, if the temperature of hydrogen is known, it is easy to determine whether hydrogen can be burned in the internal combustion engine as designed. Therefore, it is possible to detect with high sensitivity whether the internal combustion engine has finished warming up, i.e., whether the temperature condition allows the internal combustion engine to operate as designed.

[0008] In the vehicle, in the warm-up completion determination process, the control device may calculate the engine temperature based on a temperature of the regulator. According to the above configuration, it is determined whether the internal combustion engine has completed warming up based on the temperature of the regulator. The temperature of the regulator can be obtained by attaching a sensor that detects the temperature to the regulator. In other words, the temperature of the regulator is a parameter that is relatively easy to detect, and therefore this is easy to implement.

[0009] In the above vehicle, the internal combustion engine may further have a temperature sensor that detects the temperature of the cooling water flowing out from the internal combustion engine, and the control device may calculate the engine temperature based on the temperature of the cooling water in the warm-up completion determination process.

[0010] According to the above-mentioned configuration, it is determined whether the internal combustion engine has completed warming up based on the temperature of the coolant. The coolant is an object that exchanges heat with the regulator. Therefore, the temperature of the regulator and, ultimately, the temperature of the hydrogen can be detected based on the temperature of the coolant flowing out from the internal combustion engine.

[0011] The vehicle may further include a motor generator as a drive source, and the control device may control the internal combustion engine and the motor generator, and in the warm-up completion determination process, the control device may determine that the internal combustion engine is in a warm-up completion state on condition that at least the engine temperature is equal to or higher than a predetermined first temperature, and when the engine temperature is lower than a second temperature defined as a temperature lower than the first temperature, the control device may execute an EV driving process to stop the internal combustion engine and drive the motor generator as a drive source.

[0012] According to the above configuration, when the internal combustion engine has not finished warming up, the motor generator is driven as a drive source. On the other hand, the internal combustion engine is not driven as a drive source. Therefore, by not driving the internal combustion engine when it is cold, it is possible to suppress the occurrence of problems that would occur if the internal combustion engine were driven when it is cold. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a vehicle. [Diagram 2] FIG. 2 is a schematic diagram showing the overall configuration of an internal combustion engine. [Diagram 3] FIG. 3 is a schematic diagram showing the cooling mechanism. [Figure 4] FIG. 4 is a flowchart showing a series of processes according to the control program. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (One embodiment) Hereinafter, an embodiment of a vehicle will be described with reference to the drawings. <Vehicle Overview> As shown in Fig. 1, the vehicle VC is equipped with a spark ignition type internal combustion engine 10. The vehicle VC also includes a first motor generator 71 and a second motor generator 72 that function as both an electric motor and a generator. Therefore, the vehicle VC is a so-called hybrid vehicle. In other words, the vehicle VC includes the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 as drive sources.

[0015] <Configuration of an internal combustion engine> First, the overall configuration of the internal combustion engine 10 will be described. As shown in FIG. 2, the internal combustion engine 10 includes a cylinder block 11, a cylinder head 12, a piston 13, and a cylinder 14. The cylinder 14 is a cylindrical space defined inside the cylinder block 11. Both axial ends of the cylinder 14 are open to the outside of the cylinder block 11. The piston 13 is disposed in the cylinder 14. The top surface of the piston 13 faces a first axial end of the cylinder 14. The cylinder head 12 is connected to the cylinder block 11. The outer surface of the cylinder head 12 has a recess 15. The recess 15 faces the cylinder 14 in the axial direction of the cylinder 14. The wall surface of the cylinder block 11 that defines the cylinder 14, the wall surface of the recess 15, and the top surface of the piston 13 define a combustion chamber R. The cylinder head 12 has a water jacket WJ therein. The water jacket WJ is a passage through which cooling water of a cooling mechanism 80 described later flows.

[0016] The internal combustion engine 10 includes a connecting rod 16 and a crankshaft 17. The connecting rod 16 is connected to the piston 13. The connecting rod 16 extends in the opposite direction to the cylinder head 12, sandwiching the piston 13 therebetween. The crankshaft 17 is connected to the connecting rod 16. The crankshaft 17 and the connecting rod 16 convert the reciprocating motion of the piston 13 into rotational motion.

[0017] The cylinder head 12 has an intake port 18. The intake port 18 is a space defined inside the cylinder head 12. A first end of the intake port 18 opens toward the recess 15. A second end of the intake port 18 opens toward the outside of the cylinder head 12.

[0018] The cylinder head 12 has an exhaust port 19. The exhaust port 19 is a space defined inside the cylinder head 12. A first end of the exhaust port 19 opens toward the recess 15. A second end of the exhaust port 19 opens toward the outside of the cylinder head 12.

[0019] The internal combustion engine 10 includes an intake valve 20 and an exhaust valve 21. The intake valve 20 is a valve that opens and closes a first end of the intake port 18. The exhaust valve 21 is a valve that opens and closes a first end of the exhaust port 19.

[0020] In addition, although Figure 1 shows only one set of the combustion chamber R and the intake port 18 and exhaust port 19 connected to the combustion chamber R, the internal combustion engine 10 has multiple sets of the combustion chamber R and the intake port 18 and exhaust port 19 connected to the combustion chamber R, etc.

[0021] The internal combustion engine 10 has an intake passage 22 for drawing in outside air. The intake passage 22 is connected to a second end of the intake port 18. The intake passage 22 houses a throttle valve 23. The throttle valve 23 adjusts the intake air amount, which is the flow rate of air flowing through the intake passage 22, by changing the valve opening degree. The air drawn in from the intake passage 22 flows into the combustion chamber R via the intake port 18.

[0022] The internal combustion engine 10 is equipped with a port injector 24. The port injector 24 is attached to the cylinder head 12. Therefore, the port injector 24 is located downstream of the throttle valve 23 in the intake passage 22. The port injector 24 injects fuel into the intake port 18.

[0023] The internal combustion engine 10 is equipped with an in-cylinder injector 25. The in-cylinder injector 25 is attached to the cylinder head 12. The in-cylinder injector 25 injects fuel directly into the combustion chamber R.

[0024] The internal combustion engine 10 is equipped with an ignition plug 26. The ignition plug 26 is attached to the cylinder head 12. The ignition plug 26 is located between the intake port 18 and the exhaust port 19. The ignition plug 26 ignites the mixture introduced into the combustion chamber R by means of a spark.

[0025] The internal combustion engine 10 is equipped with an exhaust passage 27 which is a discharge path for exhaust gas generated by combustion in the combustion chamber R. The exhaust passage 27 is connected to a second end of the exhaust port 19. The exhaust passage 27 accommodates an exhaust purification catalyst 28. The exhaust purification catalyst 28 purifies, for example, nitrogen oxides in the exhaust gas.

[0026] The internal combustion engine 10 also includes a fuel supply device 30. The fuel supply device 30 includes a hydrogen tank 31, a fuel pipe 32, and a regulator 35. The hydrogen tank 31 is a tank that stores hydrogen, which is a fuel, under high pressure. The fuel pipe 32 constitutes a passage for hydrogen. The fuel pipe 32 is made up of a first fuel pipe 33 and a second fuel pipe 34. A first end of the first fuel pipe 33 is connected to the hydrogen tank 31. Furthermore, a second end of the first fuel pipe 33 is connected to the in-cylinder injector 25. The regulator 35 is located midway through the first fuel pipe 33. The regulator 35 reduces the pressure of the hydrogen.

[0027] A first end of the second fuel pipe 34 is connected to a portion of the first fuel pipe 33 closer to the port injector 24 than the regulator 35. A second end of the second fuel pipe 34 is connected to the in-cylinder injector 25.

[0028] <Vehicle configuration> As shown in FIG. 1, the vehicle VC includes a first planetary gear mechanism 40, a ring gear shaft 45, a second planetary gear mechanism 50, a reduction mechanism 62, a differential mechanism 63, and a plurality of drive wheels 64.

[0029] The first planetary gear mechanism 40 includes a sun gear 41, a ring gear 42, a plurality of pinion gears 43, and a carrier 44. The sun gear 41 is an external gear. The sun gear 41 is connected to the first motor generator 71. The ring gear 42 is an internal gear, and is located coaxially with the sun gear 41. Each pinion gear 43 is located between the sun gear 41 and the ring gear 42. Each pinion gear 43 meshes with both the sun gear 41 and the ring gear 42. The carrier 44 supports the pinion gear 43. The pinion gear 43 is rotatable on its own axis, and is revolved by rotating together with the carrier 44. The carrier 44 is connected to the crankshaft 17.

[0030] The ring gear shaft 45 is connected to the ring gear 42. The ring gear shaft 45 is also connected to drive wheels 64 via a reduction mechanism 62 and a differential mechanism 63. The reduction mechanism 62 reduces the rotation speed of the ring gear shaft 45 and outputs it. The differential mechanism 63 allows a difference in rotation speed to occur between the left and right drive wheels 64.

[0031] The second planetary gear mechanism 50 includes a sun gear 51, a ring gear 52, a plurality of pinion gears 53, a carrier 54, and a case 55. The sun gear 51 is an external gear. The sun gear 51 is connected to the second motor generator 72. The ring gear 52 is an internal gear and is located coaxially with the sun gear 51. The ring gear 52 is connected to the ring gear shaft 45. Each pinion gear 53 is located between the sun gear 51 and the ring gear 52. Each pinion gear 53 meshes with both the sun gear 51 and the ring gear 52. The carrier 54 supports the pinion gear 53. The pinion gear 53 is rotatable. The carrier 54 is fixed to the case 55. Therefore, the pinion gear 53 is not capable of revolving.

[0032] The vehicle VC includes a battery 75, a first inverter 76, and a second inverter 77. The battery 75 is a secondary battery. The first inverter 76 performs AC-DC power conversion between the first motor generator 71 and the battery 75. The first inverter 76 also adjusts the amount of power exchanged between the first motor generator 71 and the battery 75. The second inverter 77 performs AC-DC power conversion between the second motor generator 72 and the battery 75. The second inverter 77 adjusts the amount of power exchanged between the second motor generator 72 and the battery 75.

[0033] 3, the vehicle VC includes a cooling mechanism 80. The cooling mechanism 80 cools the internal combustion engine 10, which is a device to be cooled. The cooling mechanism 80 includes a pump 81, a main flow path 82, a bypass flow path 83, a valve 84, and a radiator 85.

[0034] The pump 81 is an electric pump that pumps cooling water as a refrigerant. The main flow path 82 is a flow path through which the cooling water pumped from the pump 81 flows and through which the cooling water returns to the pump 81. The upstream end of the main flow path 82 is connected to the discharge port of the pump 81. The downstream end of the main flow path 82 is connected to the suction port of the pump 81. A water jacket WJ of the internal combustion engine 10, which is an apparatus to be cooled, is located on the main flow path 82. The water jacket WJ constitutes a part of the main flow path 82. The water jacket WJ is located downstream of the pump 81 in the main flow path 82.

[0035] Furthermore, a radiator 85 is located at a location on the main flow passage 82 downstream of the internal combustion engine 10. The radiator 85 exchanges heat between the cooling water flowing inside the radiator 85 and the air outside the radiator 85.

[0036] The bypass passage 83 connects a portion of the main passage 82 that is downstream of the internal combustion engine 10 and upstream of the radiator 85 to a portion of the main passage 82 that is downstream of the radiator 85. The regulator 35 is disposed in the bypass passage 83 at a portion downstream of the valve 84. The regulator 35 exchanges heat with the cooling water flowing through the bypass passage 83.

[0037] The valve 84 is attached to the bypass flow path 83. When the valve 84 is open, the cooling water flows through the bypass flow path 83. When the valve 84 is closed, the cooling water does not flow through the bypass flow path 83. In Fig. 3, the flow of the cooling water is indicated by a two-dot chain line arrow.

[0038] As shown in FIG. 1, the vehicle VC is equipped with an accelerator operation amount sensor 95, a vehicle speed sensor 96, a cooling water temperature sensor 97, and a power switch 98. The accelerator operation amount sensor 95 detects the accelerator operation amount ACC, which is the amount of operation of the accelerator pedal operated by the driver. The vehicle speed sensor 96 detects the vehicle speed V, which is the speed of the vehicle VC. The coolant temperature sensor 97 detects the coolant temperature WT, which is the temperature of the coolant that is the refrigerant of the cooling mechanism 80. Specifically, the coolant temperature sensor 97 detects the outlet temperature of the water jacket WJ as the coolant temperature WT. Thus, the coolant temperature sensor 97 detects the temperature of the coolant flowing out from the internal combustion engine 10. The power switch 98 transmits a start request R1 when it is turned on while the power of the vehicle VC is in an off state. The power switch 98 transmits a stop request R2 when it is turned off while the power of the vehicle VC is in an on state.

[0039] <Control device> As shown in FIG. 1, the vehicle VC is equipped with a control device 100. The control device 100 controls the internal combustion engine 10, the first motor generator 71, the second motor generator 72, and the cooling mechanism 80. The control device 100 obtains a signal indicating an accelerator operation amount ACC from an accelerator operation amount sensor 95. The control device 100 obtains a signal indicating a vehicle speed V from a vehicle speed sensor 96. The control device 100 obtains signals indicating a current IB and a battery temperature TB of the battery 75 from the battery 75. The control device 100 obtains a signal indicating a coolant temperature WT from a coolant temperature sensor 97. The control device 100 obtains a signal indicating a start request R1 and a signal indicating a stop request R2 from a power switch 98.

[0040] The control device 100 includes a CPU 101, a peripheral circuit 102, a ROM 103, a storage device 104, and a bus 105. The bus 105 connects the CPU 101, the peripheral circuit 102, the ROM 103, and the storage device 104 so that they can communicate with each other. The peripheral circuit 102 includes a circuit that generates a clock signal that regulates internal operations, a power supply circuit, a reset circuit, and the like. The ROM 103 stores various programs in advance for the CPU 101 to execute various controls. The CPU 101 controls the internal combustion engine 10, the first motor generator 71, the second motor generator 72, and the cooling mechanism 80 by executing the various programs stored in the ROM 103.

[0041] <Control by driving program> The ROM 103 stores a drive program for driving the internal combustion engine 10, the first motor generator 71, and the second motor generator 72. When the CPU 101 acquires a start request R1, the CPU 101 repeatedly executes the drive program.

[0042] The CPU 101 calculates a vehicle required driving force, which is a required value of driving force necessary for the vehicle VC to travel, based on the accelerator operation amount ACC and the vehicle speed V. The CPU 101 determines the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72, based on the vehicle required driving force. The CPU 101 controls the output of the internal combustion engine 10 and the power running and regeneration of the first motor generator 71 and the second motor generator 72, based on the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72.

[0043] The CPU 101 calculates a target value of the output of the internal combustion engine 10 based on the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72. The CPU 101 outputs a control signal to the internal combustion engine 10 based on the target value of the output of the internal combustion engine 10. As a result, the CPU 101 controls the opening of the throttle valve 23, the fuel injection amount from the in-cylinder injector 25, the fuel injection amount from the port injector 24, the ignition timing of the spark plug 26, and the like. The CPU 101 also controls the first motor generator 71 via the first inverter 76 by outputting a control signal to the first inverter 76. Furthermore, the CPU 101 controls the second motor generator 72 via the second inverter 77 by outputting a control signal to the second inverter 77.

[0044] In determining the torque distribution, the CPU 101 calculates the charge rate of the battery 75 and an input upper limit value. The CPU 101 calculates the charge rate based on an integrated value of the current IB. The CPU 101 also calculates an input upper limit value, which is the maximum allowable power that may be charged to the battery 75, based on the calculated charge rate and the battery temperature TB. The input upper limit value is expressed as zero or a positive value, and the larger the absolute value, the larger the power that is allowed to be charged to the battery 75. The CPU 101 determines the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 so that the charge rate of the battery 75 is maintained within a certain control range.

[0045] <Control by control program> The ROM 103 stores a control program for controlling the internal combustion engine 10, the first motor generator 71, the second motor generator 72, and the cooling mechanism 80 based on the coolant temperature WT. When the CPU 101 acquires a start request R1, the CPU 101 repeatedly executes the control program.

[0046] 4, when the control program is started, the CPU 101 first performs the process of step S11. In step S11, the CPU 101 performs a warm-up completion determination process for determining whether or not the internal combustion engine 10 has completed warm-up based on the engine temperature ET of the internal combustion engine 10.

[0047] Specifically, the CPU 101 compares the engine temperature ET with a predetermined first temperature T1 to determine whether the internal combustion engine 10 has completed warming up. The first temperature T1 is set in advance through testing or simulation as the temperature at which the internal combustion engine 10 has completed warming up. For example, the first temperature T1 is set within a range of 60 degrees or more and less than 95 degrees.

[0048] In step S11, the CPU 101 estimates the engine temperature ET. In this embodiment, the CPU 101 calculates the engine temperature ET based on the coolant temperature WT detected by the coolant temperature sensor 97. As the coolant flows through the water jacket WJ of the internal combustion engine 10, it is affected by heat generated in, for example, the combustion chamber R of the internal combustion engine 10. Therefore, the higher the engine temperature ET, the higher the coolant temperature WT becomes. In this embodiment, the coolant temperature WT is directly used as the engine temperature ET.

[0049] Next, the CPU 101 compares the engine temperature ET with the first temperature T1. If the engine temperature ET is lower than the first temperature T1, the CPU 101 determines that the internal combustion engine 10 has not completed warming up. If the CPU 101 determines that the internal combustion engine 10 has not completed warming up (S11: YES), the CPU 101 advances the process to step S12.

[0050] In step S12, the CPU 101 performs a process for opening the valve 84. That is, the CPU 101 performs the process for opening the valve 84 on the condition that the internal combustion engine 10 has not yet completed warming up. After that, the CPU 101 advances the process to step S13.

[0051] In step S13, the CPU 101 determines whether the engine temperature ET is lower than a predetermined second temperature T2. The second temperature T2 is predetermined as a temperature lower than the first temperature T1. The second temperature T2 is set in advance by a test or a simulation as a temperature at which the port injector 24 and the in-cylinder injector 25 of the internal combustion engine 10 may freeze. Furthermore, the second temperature T2 is set as a temperature at which the engine temperature ET becomes higher than the second temperature T2 by driving the first motor generator 71 and the second motor generator 72 in a state in which the engine temperature ET is equal to or lower than the second temperature. For example, the second temperature T2 is set as a temperature less than 10 degrees. If the engine temperature ET is lower than the second temperature T2 (S13: YES), the CPU 101 advances the process to step S14.

[0052] In step S14, the CPU 101 performs EV driving processing. In the EV driving processing, the CPU 101 sets the torque distribution of the internal combustion engine 10 to 0%, and sets the sum of the torque distributions of the first motor generator 71 and the second motor generator 72 to 100%. As a result, the CPU 101 forcibly sets the torque distribution of the internal combustion engine 10 to 0% and drives the first motor generator 71 and the second motor generator 72, regardless of the torque distribution calculated by the above-mentioned drive program. That is, in the EV driving processing, the CPU 101 stops the internal combustion engine 10 and drives the first motor generator 71 and the second motor generator 72 as drive sources. After that, the CPU 101 ends the series of processes.

[0053] Incidentally, in step S11, when the engine temperature ET is equal to or higher than the first temperature T1, the CPU 101 determines that the internal combustion engine 10 has completed warming up. When the CPU 101 determines that the internal combustion engine 10 has completed warming up (S11: NO), the CPU 101 advances the process to step S15.

[0054] In step S15, the CPU 101 performs a process to close the valve 84. That is, the CPU 101 performs the process to close the valve 84 on the condition that the internal combustion engine 10 has completed warming up. After that, the CPU 101 advances the process to step S16.

[0055] In step S16, the CPU 101 performs normal driving processing. In the normal driving processing, the CPU 101 drives the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 with the torque distribution calculated by the drive program described above. That is, in step S16, the CPU 101 cancels the EV driving processing in step S14 described above. After that, the CPU 101 ends the series of processes.

[0056] Furthermore, in step S13, if the engine temperature ET is equal to or higher than the second temperature T2 (S13: NO), the CPU 101 also advances the process to step S16. In other words, if the engine temperature ET is equal to or higher than the second temperature T2, the internal combustion engine 10 is not forcibly stopped.

[0057] <Operation of the embodiment> According to the embodiment described above, in the valve opening process of step S12, the CPU 101 opens the valve 84. As a result, the cooling water flows into the bypass flow path 83. Therefore, the cooling water flowing through the bypass flow path 83 exchanges heat with the regulator 35 located on the bypass flow path 83.

[0058] On the other hand, in the valve closing process in step S15, the CPU 101 closes the valve 84. This causes the cooling water to stop flowing through the bypass passage 83. Therefore, the cooling water stops exchanging heat with the regulator 35.

[0059] <Effects of the embodiment> (1) According to the above embodiment, the CPU 101 performs the valve closing process on the condition that the internal combustion engine 10 is in a warm-up completion state. Therefore, when the internal combustion engine 10 is in a warm-up completion state, the valve 84 is in a valve closing state, so that the cooling water does not flow into the bypass flow path 83. On the other hand, the CPU 101 performs the valve opening process on the condition that the internal combustion engine 10 is not in a warm-up completion state. Therefore, when the internal combustion engine 10 is not in a warm-up completion state, the valve 84 is in an open state, so that the cooling water flows into the bypass flow path 83. Therefore, when the internal combustion engine 10 is not in a warm-up completion state, heat exchange is performed between the cooling water and the regulator 35. Here, hydrogen generates heat as it is decompressed and expanded in the regulator 35. On the other hand, when the internal combustion engine 10 is not in a warm-up completion state, the temperature of the cooling water is low. As a result, even the heat caused by the expansion of hydrogen in the regulator 35 can sufficiently warm the cooling water.

[0060] (2) According to the above embodiment, it is determined whether the internal combustion engine 10 has completed warming up, based on the coolant temperature WT. The coolant is an object that exchanges heat with the regulator 35. Therefore, the temperature of the regulator 35 and, ultimately, the temperature of the hydrogen can be detected based on the coolant temperature WT, which is the temperature of the coolant flowing out from the internal combustion engine 10.

[0061] (3) According to the above embodiment, when the engine temperature ET is lower than the second temperature T2, the CPU 101 performs EV driving processing. In the EV driving processing, the CPU 101 stops the internal combustion engine 10 and drives the first motor generator 71 and the second motor generator 72 as drive sources. This makes it possible to suppress the occurrence of problems that may occur when the internal combustion engine 10 is driven when the engine temperature ET is equal to or lower than the second temperature T2.

[0062] The first motor generator 71 and the second motor generator 72 generate heat as they are driven. When this heat is transmitted to the internal combustion engine 10, the temperature of the coolant flowing out of the water jacket WJ of the internal combustion engine 10 increases. Therefore, as the EV driving process continues, the situation where the engine temperature ET is the second temperature T2 is resolved. If the engine temperature ET is equal to or higher than the second temperature T2, there is a high probability that adverse effects caused by the low engine temperature ET, such as freezing of water around the nozzles of the injectors, have been resolved. Therefore, even if the internal combustion engine 10 is permitted to be driven, malfunctions are unlikely to occur. Furthermore, if the internal combustion engine 10 is driven as the engine temperature ET becomes equal to or higher than the second temperature T2, the engine temperature ET of the internal combustion engine 10 will rise quickly due to the combustion of hydrogen.

[0063] (Other embodiments) The above embodiment can be modified as follows: The embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0064] The vehicle VC may have a single motor generator as a drive source. The vehicle VC does not necessarily have to have the first motor generator 71 and the second motor generator 72 as a drive source. In this case, the vehicle VC has the internal combustion engine 10 as a drive source, and the CPU 101 may omit the processes of steps S13, S14, and S16.

[0065] The internal combustion engine 10 may omit the port injector 24 or the in-cylinder injector 25. In this case, the configuration of the fuel pipe 32 of the fuel supply device 30 may also be changed as appropriate. In the above embodiment, other valves may be located on the main flow path 82 and the bypass flow path 83. An example of this type of valve is a thermostat valve attached to the upstream end of the bypass flow path 83.

[0066] The valve 84 in the above embodiment may be any valve as long as it can open and close the bypass flow passage 83. For example, it may be an electromagnetic three-way valve attached to the upstream end of the bypass flow passage 83. When closing the bypass flow passage 83, the electromagnetic three-way valve of this modified example opens the passage on the radiator 85 side in the main flow passage 82. Therefore, in this state, the cooling water does not flow through the bypass flow passage 83, but flows through the flow passage on the radiator 85 side in the main flow passage 82. On the other hand, when opening the bypass flow passage 83, the passage on the radiator 85 side in the main flow passage 82 is closed. Therefore, in this state, the cooling water flows through the bypass flow passage 83, but does not flow through the flow passage on the radiator 85 side in the main flow passage 82.

[0067] The engine temperature ET is not limited to being calculated based on the coolant temperature WT. For example, if a sensor for detecting the temperature of hydrogen flowing through the fuel pipe 32 of the vehicle VC is provided, the CPU 101 may calculate the engine temperature ET based on the temperature of the hydrogen. The temperature of hydrogen is approximately the same as the temperature of the fuel pipe 32. Since the fuel pipe 32 is located near the internal combustion engine 10, it is affected by heat from the internal combustion engine 10. Therefore, the temperature of the fuel pipe 32, i.e., the temperature of the hydrogen, is strongly correlated with the engine temperature ET, which is the temperature of the internal combustion engine 10. In this case, the temperature of hydrogen can be obtained by a sensor that detects the temperature of hydrogen. According to this modification, it is not necessary to use a sensor that detects the temperature of the coolant in order to detect the engine temperature ET.

[0068] In the above modified example, the temperature of the hydrogen may be the temperature of the hydrogen before the pressure is reduced by the regulator 35, or the temperature of the hydrogen after the pressure is reduced by the regulator 35. However, when detecting the temperature of the hydrogen after the pressure is reduced by the regulator 35, it is necessary to estimate the engine temperature ET by taking into account that this temperature is the temperature after heat generation associated with the expansion of the hydrogen.

[0069] Furthermore, for example, if the vehicle VC is equipped with a sensor that detects the temperature of the regulator 35, the CPU 101 may estimate the engine temperature ET based on the temperature of the regulator 35. In this case, the temperature of the regulator 35 can be acquired by the sensor that detects the temperature of the regulator 35. According to this modification, it is not necessary to use a sensor that detects the temperature of the coolant in order to detect the engine temperature ET, i.e., the temperature of the hydrogen.

[0070] Even when a motor generator is provided as in the above embodiment, the processes of steps S13, S14, and S16 may be omitted. That is, the normal driving process may be performed regardless of whether the engine temperature ET is lower than the second temperature T2. Also, the EV driving process may be performed according to other conditions regardless of whether the engine temperature ET is lower than the second temperature T2.

[0071] The CPU 101 may perform the EV driving process on the condition that the vehicle VC is stopped. In this case, it is possible to prevent the internal combustion engine 10 from stopping while the vehicle VC is traveling. Therefore, it is possible to prevent the passengers of the vehicle VC from feeling uncomfortable due to the internal combustion engine 10 suddenly stopping while the vehicle VC is traveling. [Explanation of symbols]

[0072] 10. Internal combustion engine 24…Port injector 25…In-cylinder injector 30…Fuel supply device 31...Hydrogen tank 32…Fuel piping 35…Regulator 71…First motor generator 72…Second motor generator 80…Cooling mechanism 81…Pump 82…Main flow path 83...Bypass flow path 84…Valve 85…Radiator 97...Coolant temperature sensor 100...Control device ET…Engine temperature T1…1st temperature T2…Second temperature VC…Vehicle WJ…Water jacket WT…Cooling water temperature

Claims

1. An internal combustion engine that uses hydrogen as fuel, a cooling mechanism having a flow path of cooling water for cooling the internal combustion engine, and a control device that controls the cooling mechanism, The internal combustion engine includes: a fuel pipe connected to a hydrogen tank and constituting a passage for the hydrogen; a regulator attached midway through the fuel pipe to reduce the pressure of the hydrogen; an injector attached to the fuel pipe downstream of the regulator, The cooling mechanism includes: A pump for pumping the cooling water; a main flow path through which the cooling water pumped from the pump flows and through which the cooling water returns to the pump; A radiator disposed midway through the main flow path; a bypass flow passage that is connected from a portion of the main flow passage that is downstream of the internal combustion engine and upstream of the radiator to a portion of the main flow passage that is downstream of the radiator; a valve attached to the bypass flow path; having The regulator is disposed in the bypass flow path at a location downstream of the valve, The control device includes: a warm-up completion determination process for determining whether or not the internal combustion engine has completed warm-up based on an engine temperature of the internal combustion engine; a valve closing process for closing the valve on condition that it is determined that the internal combustion engine is in a warm-up completion state by the warm-up completion determination process; a valve opening process for opening the valve on condition that it is determined that the internal combustion engine is not in a warm-up completion state by the warm-up completion determination process; Run vehicle.

2. In the warm-up completion determination process, the control device calculates the engine temperature based on the temperature of the hydrogen.

2. The vehicle of claim 1.

3. In the warm-up completion determination process, the control device calculates the engine temperature based on the temperature of the regulator.

2. The vehicle of claim 1.

4. The internal combustion engine further includes a temperature sensor that detects a temperature of the cooling water flowing out from the internal combustion engine, In the warm-up completion determination process, the control device calculates the engine temperature based on the temperature of the cooling water.

2. The vehicle of claim 1.

5. Further comprising a motor generator as a drive source; the control device controls the internal combustion engine and the motor generator, The control device determines that the internal combustion engine is in a warm-up completion state when the engine temperature is equal to or higher than a predetermined first temperature in the warm-up completion determination process, When the engine temperature is lower than a second temperature defined as a temperature lower than the first temperature, the control device stops the internal combustion engine and executes an EV driving process in which the motor generator is driven as a driving source. A vehicle according to any one of claims 1 to 4.

Images