Hybrid vehicle, control device, and operating method

Abstract

The present invention provides a hybrid vehicle, a control device for the hybrid vehicle, and a method for operating the hybrid vehicle, which facilitate engine starting by a motor at low temperatures. [Solution] The motor (6) of the hybrid vehicle (100) cranks the engine (1). The engine (1) is connected to a plurality of pipes that allow air to circulate inside. The hybrid vehicle (100) is equipped with a plurality of valves, a first temperature sensor (27), and a control device (8). The plurality of valves open and close the air circulation paths in the plurality of pipes and the inside of the engine (1). The first temperature sensor (27) is for obtaining the temperature of the engine (1). Before starting the engine (1), the control device (8) opens the plurality of valves if the temperature obtained by the first temperature sensor (27) is less than a first threshold temperature, and after a first time has elapsed since the plurality of valves were opened, it causes the motor (6) to start operating.

Description

Technical Field

[0001] The present invention relates to a hybrid vehicle including a motor and an engine, a control device for the hybrid vehicle, and an operation method for the hybrid vehicle.

Background Art

[0002] Conventionally, a hybrid vehicle including an engine and a motor and traveling by the outputs of the engine and the motor has been known (see, for example, Patent Document 1). In some hybrid vehicles, a motor is connected to the crankshaft of the engine via a belt, and the crankshaft is rotated by the rotational force of the motor via the belt to start the engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when the outside air temperature is low, the friction in the engine increases, and the force required to rotate the crankshaft may increase. When the motor rotates in such a case, due to belt slip, the rotational force may not be transmitted to the crankshaft, and it may be difficult to start the engine.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a hybrid vehicle, a control device for the hybrid vehicle, and an operation method for the hybrid vehicle that facilitate starting of the engine by the motor at low temperatures.

Means for Solving the Problems

[0006] A hybrid vehicle (100) according to one aspect of the present invention is a hybrid vehicle (100) that runs on power from a motor (6) and an engine (1), and comprises a plurality of pipes connected to the engine (1) for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), a plurality of valves for opening and closing the air circulation paths in the plurality of pipes and the inside of the engine (1), and a first temperature sensor (27) for obtaining the temperature of the engine (1), wherein the motor (6) cranks the engine (1), the plurality of valves open before the engine (1) is started if the temperature obtained by the first temperature sensor (27) is less than a predetermined first threshold temperature, and the motor (6) starts operation after a predetermined first time has elapsed since the plurality of valves opened if the temperature is less than the first threshold temperature before the engine (1) is started.

[0007] A control device (8) according to one aspect of the present invention is a control device (8) for a hybrid vehicle (100) that runs on power from a motor (6) and an engine (1), wherein the hybrid vehicle (100) is connected to the engine (1) and comprises a plurality of pipes for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), a plurality of valves for opening and closing the air circulation paths in the plurality of pipes and the inside of the engine (1), and a first temperature sensor (27) for obtaining the temperature of the engine (1), wherein the motor (6) cranks the engine (1), and the control device (8), before starting the engine (1), opens the plurality of valves if the temperature obtained by the first temperature sensor (27) is less than a predetermined first threshold temperature, and starts the motor (6) after a predetermined first time has elapsed since the plurality of valves were opened.

[0008] An operating method according to one aspect of the present invention is an operating method for a hybrid vehicle (100) that is driven by power from a motor (6) and an engine (1), wherein the hybrid vehicle (100) comprises a plurality of pipes connected to the engine (1) for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), a plurality of valves for opening and closing the air circulation paths in the plurality of pipes and the inside of the engine (1), and a first temperature sensor (27) for obtaining the temperature of the engine (1), the motor (6) cranks the engine (1), and the operating method includes the steps of opening the plurality of valves if the temperature obtained by the first temperature sensor (27) is less than a predetermined first threshold temperature before the engine (1) is started, and the motor (6) starts operating after a predetermined first time has elapsed since the plurality of valves were opened. [Effects of the Invention]

[0009] According to the hybrid vehicle, control device, and operating direction of the present invention, before the engine is started, if the engine temperature obtained by the first temperature sensor is below a first threshold temperature, multiple valves are opened. Then, after a first hour has elapsed since the multiple valves were opened, the motor starts operating. As a result, air flows into the engine from the outside before the motor starts, causing the air pressure inside the engine to rise. Therefore, the negative pressure inside the engine relative to the outside is suppressed, thus reducing pumping losses. Consequently, friction in the engine is reduced. For this reason, it becomes easier to start the engine with the motor, even at low temperatures. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the components included in a hybrid vehicle according to an embodiment. [Figure 2] This is a schematic diagram illustrating the configuration of the engine in the embodiment. [Figure 3] This is a time chart illustrating the timing of the engine and motor operations in the embodiment. [Figure 4] This is a block diagram showing an example of the hardware configuration of a control device according to an embodiment. [Figure 5] This is a flowchart illustrating the process flow for starting the engine of a hybrid vehicle according to the embodiment. [Modes for carrying out the invention]

[0011] The following describes a hybrid vehicle, a control device for the hybrid vehicle, and an operating method for the hybrid vehicle according to the embodiments, with reference to the drawings. Note that the present invention is not limited to the following embodiments, and can be modified in various ways without departing from the spirit of the invention. Furthermore, the present invention includes all possible combinations of the configurations shown in the following embodiments. Also, the configurations included in the hybrid vehicle and control device, as well as the various processes included in the operating method for the hybrid vehicle, in the drawings are illustrative examples, and the present invention is not limited by the drawings. In each figure, components denoted by the same reference numerals are either identical or corresponding to each other, and this is true throughout the entire specification.

[0012] Figure 1 is a schematic diagram illustrating the components included in a hybrid vehicle 100 according to an embodiment. The hybrid vehicle 100 comprises an engine 1, a transmission 3, an axle 4, wheels 5, a motor 6, a belt 7, and a control device 8.

[0013] Engine 1 is an internal combustion engine that uses gasoline or diesel fuel. Engine 1 includes a crankshaft 10, which burns fuel to generate combustion gases, and the crankshaft 10 rotates due to the thermal energy of the combustion gases.

[0014] The crankshaft 10 is connected to the transmission 3 and the axle 4. The transmission 3 changes the speed of the rotational force transmitted from the crankshaft 10 and transmits the changed rotational force to the axle 4. The axle 4 transmits the rotational force from the transmission 3 to the wheels 5. As a result, the wheels 5 rotate and the hybrid vehicle 100 moves.

[0015] Motor 6 is a device that converts electrical energy into rotational energy and vice versa. Motor 6 is connected to a battery (not shown) via an inverter (not shown). Motor 6 then exchanges electrical energy with the battery via the inverter.

[0016] The motor 6 has an output shaft 60, which is connected to the crankshaft 10 of the engine 1 via a belt 7. The motor 6 cranks the engine 1. That is, the motor 6 starts rotating due to electrical energy from the battery, and the rotational force of the motor 6 is transmitted to the crankshaft 10 via the output shaft 60 and the belt 7, causing the crankshaft 10 to start rotating. The crankshaft 10 starts rotating due to the rotation of the motor 6 before the combustion gases are generated.

[0017] During regenerative braking, such as when the hybrid vehicle 100 is decelerating, the motor 6 is driven by the rotational force transmitted from the wheels 5 via the axle 4 and crankshaft 10, etc., to generate electrical energy. The motor 6 then supplies the generated electrical energy to the battery via an inverter.

[0018] The inverter is a device that converts electrical energy exchanged between the battery and the motor 6. Specifically, when the motor 6 drives the wheels 5 via the crankshaft 10 etc. during power running, the inverter converts the frequency and voltage of the alternating current from the battery and outputs the converted alternating current power to the motor 6. Also, during regeneration, the inverter converts the frequency and voltage of the alternating current from the motor 6 and outputs the converted alternating current power to the battery. Alternatively, during power running, the inverter converts the direct current from the battery into alternating current and outputs the converted power to the motor 6, and during regeneration, it converts the alternating current from the motor 6 into direct current and outputs the converted power to the battery.

[0019] The control device 8 is connected to one or more actuators and one or more sensors etc. provided in the engine 1 etc. by, for example, a wire harness. And as will be described later, the control device 8 controls the engine 1 by adjusting the ignition timing and fuel injection amount in the engine 1, as well as the opening degree etc. of various valves provided in the engine 1 based on the signals from the one or more sensors. Also, the control device 8 is connected to the inverter provided in the motor 6 via CAN (Controller Area Network) etc. The control device 8 outputs a command signal to the inverter based on the signals from a rotation sensor etc. provided in the motor 6 and controls the motor 6 via the inverter. The rotation sensor is a sensor that detects a quantity related to the rotation of the motor 6, and is, for example, an angular velocity sensor or a torque sensor etc.

[0020] Figure 2 is a schematic diagram illustrating the configuration of the engine 1 in the embodiment. The engine 1 has a cylinder block 11 in which a cylinder 11A and a crankcase 11B are integrated. A combustion chamber 12 is formed in the cylinder 11A. The combustion chamber 12 is a space for accommodating an air-fuel mixture which is air with added fuel, and is a space for burning the fuel.

[0021] A cylinder head 13 is provided on the upper part of the cylinder block 11. An injector 14 and a spark plug 15 are provided on the cylinder head 13. The injector 14 injects fuel into the combustion chamber 12 in which air is contained. The injector 14 is connected to the control device 8 by a wire harness or the like and performs injection based on an instruction from the control device 8. Note that the injector 14 may inject fuel into an intake port 18 through which air flows, which will be described later, instead of the combustion chamber 12. The spark plug 15 is connected to the control device 8 by a wire harness or the like and ignites the air-fuel mixture in the combustion chamber 12 based on an instruction from the control device 8.

[0022] A piston 16 is disposed in the combustion chamber 12. The piston 16 is interlocked with the crankshaft 10 via a connecting rod 17 and moves up and down in the combustion chamber 12. Specifically, the crankshaft 10 rotates by the drive of the motor 6, and the rotational force of the crankshaft 10 is transmitted to the piston 16 via the connecting rod 17, causing the piston 16 to move up and down. Further, the piston 16 is pushed down by the burned fuel, and the downward movement of the piston 16 is transmitted to the crankshaft 10 via the connecting rod 17, causing the crankshaft 10 to rotate.

[0023] An intake port 18 and an exhaust port 19 are formed in the cylinder head 13. The engine 1 is connected to an intake pipe 20 and a return pipe 21 by the intake port 18. Further, the engine 1 is connected to an exhaust pipe 22 by the exhaust port 19.

[0024] Air flows through the intake pipe 20, the return pipe 21, and the exhaust pipe 22, respectively. Hereinafter, the path through which air flows in the intake pipe 20 may be described as an intake path 20A, the path through which air flows in the return pipe 21 may be described as a return path 21A, and the path through which air flows in the exhaust pipe 22 may be described as an exhaust path 22A. The combustion chamber 12 communicates with the intake path 20A and the return path 21A via the intake port 18 and communicates with the exhaust path 22A via the exhaust port 19.

[0025] The intake path 20A and the exhaust path 22A are each connected to the space outside the hybrid vehicle 100. The return pipe 21, although not shown, is connected to the exhaust pipe 22, and the return path 21A is connected to the exhaust path 22A. Air from the space outside the hybrid vehicle 100 flows into the combustion chamber 12 through the intake path 20A. Air from the combustion chamber 12 flows through the exhaust path 22A, and a portion of it flows into the space outside the hybrid vehicle 100. The remaining air circulating in the exhaust path 22A flows into the return path 21A and flows back into the combustion chamber 12 from the intake port 18.

[0026] Hereafter, when referring to multiple pipes, it shall refer to the intake pipe 20, the return pipe 21, and the exhaust pipe 22. Note that the hybrid vehicle 100 does not need to have a return pipe 21; in this case, the multiple pipes shall refer to the intake pipe 20 and the exhaust pipe 22.

[0027] The cylinder head 13 is provided with an intake valve 23 and an exhaust valve 24. The intake valve 23 opens and closes the space between the intake port 18 and the combustion chamber 12. More specifically, the opening degree of the intake valve 23 is adjusted by an actuator (not shown), allowing air from the intake port 18 to flow into the combustion chamber 12 when open, and blocking the flow of air from the intake port 18 to the combustion chamber 12 when closed. The exhaust valve 24 opens and closes the space between the exhaust port 19 and the combustion chamber 12. More specifically, the opening degree of the exhaust valve 24 is adjusted by an actuator (not shown), allowing air from the combustion chamber 12 to flow into the exhaust port 19 when open, and blocking the flow of air from the combustion chamber 12 to the exhaust port 19 when closed.

[0028] In this embodiment, the intake valve 23 and the exhaust valve 24 are each electrically operated valves. However, the intake valve 23 and the exhaust valve 24 may each be hydraulic valves whose opening degree is adjusted by hydraulic pressure from an oil pump driven by the engine 1. The actuator that adjusts the opening degree of the intake valve 23 and the actuator that adjusts the opening degree of the exhaust valve 24 operate based on instructions from the control device 8.

[0029] A throttle valve 25 is provided in the intake passage 20A. The opening degree of the throttle valve 25 is adjusted by an actuator (not shown). When open, it allows air flowing through the intake passage 20A to flow into the combustion chamber 12, and when closed, it blocks the flow of air from the intake passage 20A to the combustion chamber 12.

[0030] An EGR (Exhaust Gas Recirculation) valve 26 is provided in the return path 21A. The opening degree of the EGR valve 26 is adjusted by an actuator (not shown). When open, it allows air flowing through the return path 21A to circulate to the combustion chamber 12, and when closed, it blocks the flow of air from the return path 21A to the combustion chamber 12. Note that if the hybrid vehicle 100 does not have a return pipe 21, it does not need to have an EGR valve 26.

[0031] The throttle valve 25 and the EGR valve 26 are both electrically operated valves. The actuator that adjusts the opening degree of the throttle valve 25 and the actuator that adjusts the opening degree of the EGR valve 26 operate based on instructions from the control device 8.

[0032] Hereafter, when "multiple valves" is mentioned, it refers to the intake valve 23, exhaust valve 24, throttle valve 25, and EGR valve 26. However, if the hybrid vehicle 100 does not have an EGR valve 26, "multiple valves" refers to the intake valve 23, exhaust valve 24, and throttle valve 25.

[0033] Engine 1 is further equipped with a first temperature sensor 27. The first temperature sensor 27 is for obtaining the temperature of engine 1. Specifically, the first temperature sensor 27 measures the temperature of the cooling water for engine 1. The temperature of engine 1 is estimated from the temperature of the cooling water for engine 1. Alternatively, the first temperature sensor 27 may measure the temperature of the air flowing into the combustion chamber 12, the temperature of the air flowing out of the combustion chamber 12, or the temperature of cylinder 11A. If the first temperature sensor 27 measures the temperature of the air flowing into the combustion chamber 12, it may be installed in the intake port 18 or intake pipe 20. If the first temperature sensor 27 measures the temperature of the air flowing out of the combustion chamber 12, it may be installed in the exhaust port 19 or exhaust pipe 22. The first temperature sensor 27 is connected to the control device 8 via a wire harness or the like. The control device 8 obtains the measurement results from the first temperature sensor 27.

[0034] Furthermore, the engine 1 is also equipped with a crank angle sensor 28. The crank angle sensor 28 is a sensor that measures physical quantities related to the rotation of the crankshaft 10, namely the angle, angular velocity, or rotational speed of the crankshaft 10, and is installed in the crankcase 11B.

[0035] As described above, the engine 1 starts operating due to the rotation of the motor 6. However, in low-temperature environments, the friction of the engine 1, that is, the friction loss between the parts of the engine 1, increases. Therefore, in order to start the engine 1 in a low-temperature environment, that is, to start the crankshaft 10 to rotate in a low-temperature environment, the driving force of the motor 6 required increases. Consequently, when the motor 6 is operated to start the engine 1 in a low-temperature environment, the driving force of the motor 6 may not be sufficient to rotate the crankshaft 10, and slippage of the output shaft 60 may occur in the belt 7. This can make it difficult to start the engine 1 and impair user convenience. The hybrid vehicle 100 according to this embodiment facilitates the starting of the engine 1 even in low-temperature environments, thereby improving user convenience.

[0036] In the embodiment, when an operation to start the engine 1 is performed, such as by the user operating an ignition switch (not shown), the control device 8 determines whether the temperature obtained by the first temperature sensor 27 is equal to or greater than a predetermined first threshold temperature. If the temperature obtained by the first temperature sensor 27 is less than the first threshold temperature, the control device 8 controls the multiple valves to an open state. Specifically, the control device 8 controls each of the multiple valves to be fully open.

[0037] The first threshold temperature is the upper limit temperature at which slippage of the output shaft 60 occurs in the belt 7, such as the temperature of the engine 1, the temperature of the air flowing into the combustion chamber 12, the temperature of the air flowing out of the combustion chamber 12, or the temperature of the coolant of the engine 1, and is obtained from experiments, etc.

[0038] The control device 8 controls the motor 6 to start driving after a predetermined first time has elapsed since controlling each of the multiple valves to the open state. The first time is the time it takes for the air pressure in the combustion chamber 12 to become equal to atmospheric pressure as each of the multiple valves opens, and this time has been determined in advance through experiments, etc. After the first time has elapsed, the air pressure acting on the upper surface of the piston 16 balances the atmospheric pressure acting on the lower surface of the piston 16. This makes it possible to reduce the pumping loss caused by negative pressure inside the cylinder 11A. In other words, it becomes possible to reduce the resistance when the piston 16 descends. Therefore, it becomes possible to reduce the torque of the motor 6 required to rotate the crankshaft 10 in a low-temperature environment compared to conventional methods. As a result, the motor 6 can start driving the crankshaft 10 without slipping.

[0039] The control device 8 sets the torque value of the motor 6 to 0 when the rotational speed of the crankshaft 10 reaches a predetermined first rotational speed or higher. The control device 8 allows the motor 6 to continue rotating until the rotational speed of the crankshaft 10 reaches the first rotational speed or higher. The rotational speed of the crankshaft 10 is obtained by the crank angle sensor 28. After the torque value of the motor 6 becomes 0, the rotational speed of the crankshaft 10 decreases. When the rotational speed of the crankshaft 10 falls to the second rotational speed or lower, the control device 8 controls the injector 14 to inject fuel and controls the spark plug 15 to ignite the fuel mixture. Here, the second rotational speed is a rotational speed lower than the first rotational speed, for example, the idling speed of the engine 1. The control device 8 does not allow the injector 14 to inject fuel or the spark plug 15 to ignite before the rotational speed of the crankshaft 10 reaches the first rotational speed.

[0040] Prior to the crankshaft 10 reaching a first rotational speed, the control device 8 instructs the actuators of the multiple valves to optimize the opening of each of the multiple valves. Here, the opening of each of the multiple valves is optimized according to, for example, the operation of the engine 1 at idle or the current operation of the engine 1.

[0041] In the following, the time from when the control device 8 controls the multiple valves to an open state when the temperature obtained by the first temperature sensor 27 is below the first threshold temperature, until the control device 8 instructs each of the multiple valve actuators to optimize the opening degree of each valve, may be referred to as the second time. Also, in the following, the time from when the control device 8 controls the multiple valves to an open state when the temperature obtained by the first temperature sensor 27 is below the first threshold temperature, until the rotational speed of the crankshaft 10 reaches the first rotational speed, may be referred to as the third time. The second time is, for example, the time spent adjusting the opening degrees of the multiple valves, subtracted from the third time. The difference between the third time and the second time is, for example, 1 second. The control device 8 keeps each of the multiple valves open, for example, fully open, until the second time has elapsed. Between the elapsed time of the second time and the elapsed time of the third time, each of the multiple valves moves from, for example, fully open to an opening degree suitable for the operation of the engine 1.

[0042] The operation of engine 1 and motor 6 at each timing will be described in more detail below with reference to Figure 3. Figure 3 is a time chart illustrating the timing of the operation of engine 1 and motor 6 in the embodiment. The horizontal axis in Figure 3 represents time. The vertical axis indicated by RS represents the rotational speed of the crankshaft 10, and the vertical axis indicated by TM represents the torque value of motor 6. The torque value of motor 6 is obtained from the rotation sensor described above. Specifically, if the rotation sensor is a torque sensor, the rotation sensor detects the torque value of motor 6, and if the rotation sensor detects the rotational speed, the torque value of motor 6 may be obtained from the power consumption and rotational speed of motor 6. In addition, the torque value of motor 6 in Figure 3 may be the torque value instructed by the control device 8 to motor 6.

[0043] At time T0 in Figure 3, the temperature obtained by the first temperature sensor 27 is below the first threshold temperature, and the control device 8 controls the multiple valves to be in the open state. At time T1, one hour after time T0, the control device 8 starts driving the motor 6. As a result, at time T1, the torque value of the motor 6 becomes greater than 0. In Figure 3, the torque value at time T1 is shown as TM1. In Figure 3, the torque value from time T1 onward and up to time T3, which will be described later, is shown as a constant TM1, but the torque value does not have to be constant; for example, it may increase.

[0044] At time T1, the air pressure in the combustion chamber 12 is equal to atmospheric pressure, and the friction of the engine 1 is reduced. Therefore, as the motor 6 rotates at time T1, the crankshaft 10 also begins to rotate.

[0045] At time T2, the control device 8 instructs each of the multiple valve actuators to optimize the opening degree of the multiple valves. Here, time T2 is two hours after time T0, and at time T2, the rotational speed of the crankshaft 10 has not yet reached the first rotational speed.

[0046] At time T3, the crankshaft 10 reaches its first rotational speed, and the control device 8 sets the torque value of the motor 6 to 0. In Figure 3, the first rotational speed is indicated by RS1. The elapsed time from time T0 to time T3 is the third hour. Here, both or either the third hour and the first rotational speed are set so that the engine 1 does not stop even after the torque value of the motor 6 is set to 0, and so that the power consumption of the motor 6 does not become excessive.

[0047] By setting the torque value of motor 6 to 0 at time T3, the rotational speed of crankshaft 10 decreases over time from time T3 onward. At time T4, the rotational speed of crankshaft 10 becomes less than or equal to the second rotational speed mentioned above. Here, in Figure 3, the second rotational speed is shown as RS2. As the rotational speed of crankshaft 10 falls below the second rotational speed, the control device 8 controls the injector 14 and spark plug 15 to ignite engine 1. As a result, the rotational speed of crankshaft 10 rises above the second rotational speed again. However, because motor 6 is no longer driving, the rotational speed of crankshaft 10 decreases again over time. From then on, engine 1 is ignited each time the rotational speed of crankshaft 10 falls below the second rotational speed.

[0048] The hardware configuration of the control device 8 in the embodiment will be described below with reference to Figure 4. Figure 4 is a block diagram showing an example of the hardware configuration of the control device 8 according to the embodiment. The control device 8 includes a CPU (Central Processing Unit) 81 connected to a bus 80, a memory 82, a communication interface circuit 83, and an input / output interface circuit 84. The memory 82 is, for example, ROM (Read Only Memory), RAM (Random Access Memory), or a combination of ROM and RAM.

[0049] The function of the control device 8 to communicate with the operating unit, etc., can be realized by the communication interface circuit 83. Here, the operating unit refers to a shift lever, accelerator pedal, brake pedal, etc. (not shown), which receive operations from the user. The function of the control device 8 to obtain measurement results from various sensors can be realized by the input / output interface circuit 84. The function of the control device 8 to control the motor 6, injector 14, spark plug 15, and various actuators, etc., can be realized by the CPU 81 reading and executing various programs stored in memory 82 to generate control signals, and outputting these control signals to the inverter of the motor 6, injector 14, spark plug 15, and various actuators, etc., via the input / output interface circuit 84.

[0050] All or part of the control device 8 may be dedicated hardware such as a CPLD (Complex Programmable Logic Device) or an FPGA (Field Programmable Gate Array).

[0051] Figure 5 is a flowchart illustrating the process flow for starting the engine 1 of a hybrid vehicle 100 according to an embodiment. Prior to step S1, the user performs operations to start the engine 1, such as operating the ignition switch. In step S1, the control device 8 determines whether the temperature measured by the first temperature sensor 27 is below the first threshold temperature. If the temperature measured by the first temperature sensor 27 is above the first threshold temperature (step S1: NO), in step S2, the control device 8 controls the motor 6 and engine 1 as conventionally. That is, the control device 8 starts the motor 6 and controls the ignition of the engine 1. As a result, the engine 1 starts operating as conventionally. After the processing in step S2, the process for starting the engine 1 is completed.

[0052] If the temperature measured by the first temperature sensor 27 is equal to or greater than the first threshold temperature (step S1: YES), in step S3, the control device 8 controls the multiple valves to be in the open state. In step S4, the control device 8 determines whether or not the first time has elapsed. If the first time has not elapsed (step S4: NO), the control device 8 returns to step S4. If the first time has elapsed (step S4: YES), in step S5, the control device 8 causes the motor 6 to start driving the engine 1. In step S6, the control device 8 determines whether or not the second time has elapsed. Alternatively, in step S6, the control device 8 may determine whether or not the rotational speed of the crankshaft 10 is equal to or greater than a predetermined indicator rotational speed. The indicator rotational speed is a rotational speed determined such that the time it takes for the rotational speed of the crankshaft 10 to change from the indicator rotational speed to the first rotational speed is the difference between the second time and the third time.

[0053] If two hours have not elapsed since the multiple valves were controlled to be in the open state, or if the rotational speed of the crankshaft 10 is less than the instruction rotational speed (step S6: NO), the control device 8 returns to step S6. If two hours have elapsed since the multiple valves were controlled to be in the open state, or if the rotational speed of the crankshaft 10 is equal to or greater than the instruction rotational speed (step S6: YES), in step S7, the control device 8 controls the actuators that adjust the opening degree of each of the multiple valves to optimize each opening degree. In step S8, the control device 8 determines whether the rotational speed of the crankshaft 10 is equal to or greater than the first rotational speed. If the rotational speed of the crankshaft 10 is less than the first rotational speed (step S8: NO), the control device 8 returns to step S8. If the rotational speed of the crankshaft 10 is equal to or greater than the first rotational speed (step S8: YES), in step S9, the control device 8 sets the torque value of the motor 6 to 0.

[0054] In step S10, the control device 8 determines whether the rotational speed of the crankshaft 10 is less than or equal to the second rotational speed. If the rotational speed of the crankshaft 10 is greater than the second rotational speed (step S10: NO), the control device 8 returns to step S10. If the rotational speed of the crankshaft 10 is less than or equal to the second rotational speed (step S10: YES), in step S11, the control device 8 controls the injector 14 and spark plug 15 to ignite the engine 1. After the processing in step S11, the process for starting the engine 1 is completed.

[0055] The following describes the effects of the hybrid vehicle 100 according to the embodiment, the control device 8 for the hybrid vehicle 100, and the operating method of the hybrid vehicle 100. The hybrid vehicle 100 according to the embodiment is driven by power from a motor 6 and an engine 1. In addition to the motor 6 and engine 1, the hybrid vehicle 100 includes a plurality of pipes, a plurality of valves, a first temperature sensor 27, and a control device 8. The plurality of pipes are connected to the engine 1 and circulate air between the space outside the hybrid vehicle 100 and the inside of the engine 1. The inside of the engine 1 refers to the combustion chamber 12. The plurality of valves open and close the air circulation paths in the plurality of pipes and the inside of the engine 1. The first temperature sensor 27 is for obtaining the temperature of the engine 1. The motor 6 cranks the engine 1. Before starting the engine 1, the control device 8 opens multiple valves if the temperature obtained by the first temperature sensor 27 is below a predetermined first threshold temperature, and then starts the motor 6 after a predetermined first time has elapsed since the multiple valves were opened.

[0056] According to the above configuration, when multiple valves are opened, air flows into the engine 1 from outside the hybrid vehicle 100. Then, when the motor 6 starts operating after the first time has elapsed, negative pressure is suppressed inside the engine 1 relative to the outside, that is, the combustion chamber 12 above the piston 16 relative to the space below the piston 16. Therefore, pumping losses are reduced and friction in the engine 1 is reduced. Thus, it becomes possible to reduce the torque of the motor 6 required to rotate the crankshaft 10 at low temperatures. Consequently, slippage in the belt 7 on the output shaft 60 of the motor 6 is suppressed, and the driving of the crankshaft 10 by the motor 6 at low temperatures is facilitated.

[0057] In this embodiment, the first time is the time required for the air pressure inside the engine 1 to reach or exceed atmospheric pressure. This further suppresses negative pressure in the combustion chamber 12, and further reduces friction in the engine 1. As a result, the torque of the motor 6 required to start the rotation of the crankshaft 10 at low temperatures is further reduced, making it easier to drive the crankshaft 10 by the motor 6.

[0058] The hybrid vehicle 100 according to this embodiment further includes an injector 14 and a spark plug 15. The injector 14 injects fuel to be supplied into the engine 1, and the spark plug 15 ignites the fuel in the engine 1. The control device 8 starts the motor 6 after the first time has elapsed and continues the motor 6 to operate until the rotational speed of the crankshaft 10 of the engine 1 reaches a first rotational speed. The control device 8 also maintains the multiple valves in an open state for a second time after the multiple valves have opened. The second time is longer than the first time and is less than or equal to the third time, which is the time from when the multiple valves are open until the rotational speed of the crankshaft 10 reaches a first rotational speed. The injector 14 injects fuel after the third time has elapsed. The spark plug 15 ignites the fuel injected into the engine 1. Before ignition of engine 1 and while motor 6 is operating, for a period of two hours, multiple valves are kept open, thereby suppressing negative pressure inside engine 1. This suppresses slippage on the belt 7 of the output shaft 60 while motor 6 is operating. Consequently, power can be transmitted more reliably from motor 6 to engine 1. [Explanation of Symbols]

[0059] 1 Engine, 3 Transmission, 4 Axle, 5 Wheel, 6 Motor, 7 Belt, 8 Control device, 10 Crankshaft, 11 Cylinder block, 11A Cylinder, 11B Crankcase, 12 Combustion chamber, 13 Cylinder head, 14 Injector, 15 Spark plug, 16 Piston, 17 Connecting rod, 18 Intake port, 19 Exhaust port, 20 Intake piping, 20A Intake path, 21 Return piping, 21A Return path, 22 Exhaust piping, 22A Exhaust path, 23 Intake valve, 24 Exhaust valve, 25 Throttle valve, 26 EGR valve, 27 First temperature sensor, 28 Crank angle sensor, 60 Output shaft, 80 Bus, 81 CPU, 82 Memory, 83 Communication interface circuit, 84 Input / Output interface circuit, 100 Hybrid vehicle.

Claims

1. A hybrid vehicle (100) that is driven by power from a motor (6) and an engine (1), Multiple pipes connected to the engine (1) for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), Multiple valves that open and close the air circulation path in the multiple pipes and the inside of the engine (1), A first temperature sensor (27) for obtaining the temperature of the engine (1), Equipped with, The motor (6) cranks the engine (1), The aforementioned plurality of valves Before starting the engine (1), if the temperature obtained by the first temperature sensor (27) is less than a predetermined first threshold temperature, the device will open. The motor (6) is A hybrid vehicle (100) in which, if the temperature is below the first threshold temperature before the engine (1) is started, the vehicle starts operating after a predetermined first time has elapsed since the plurality of valves were opened.

2. The hybrid vehicle (100) according to claim 1, wherein the first time is the time required for the air pressure inside the engine (1) to become equal to or greater than atmospheric pressure.

3. An injector (14) for injecting fuel to be supplied into the engine (1), A spark plug (15) that ignites the fuel in the engine (1), Furthermore, The motor (6) is After the first hour has elapsed, the engine (1) starts operating until the rotational speed of the crankshaft (10) reaches a predetermined first rotational speed. The aforementioned plurality of valves If the temperature obtained by the first temperature sensor (27) is less than the first threshold temperature, the open state is maintained until a second time has elapsed since the state was opened. The aforementioned second hour, A time that is longer than the first time, and is less than or equal to the third time, which is the time from when the plurality of valves are in the open state until the rotational speed of the crankshaft (10) reaches the first rotational speed. The injector (14) is After the third time has elapsed, the fuel is injected. The spark plug (15) is A hybrid vehicle (100) according to claim 1 or 2, wherein the fuel in the engine 1 that has been injected is ignited.

4. A control device (8) for a hybrid vehicle (100) that runs on power from a motor (6) and an engine (1), The aforementioned hybrid vehicle (100) Multiple pipes connected to the engine (1) for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), Multiple valves that open and close the air circulation path in the multiple pipes and the inside of the engine (1), A first temperature sensor (27) for obtaining the temperature of the engine (1), Equipped with, The motor (6) cranks the engine (1), The control device (8) is A control device (8) that, before starting the engine (1), opens the plurality of valves if the temperature obtained by the first temperature sensor (27) is below a predetermined first threshold temperature, and starts the motor (6) after a predetermined first time has elapsed since the plurality of valves were opened.

5. The control device (8) according to claim 4, wherein the first time is the time required for the air pressure inside the engine (1) to become equal to or greater than atmospheric pressure.

6. The aforementioned hybrid vehicle (100) An injector (14) for injecting fuel to be supplied into the engine (1), A spark plug (15) that ignites the fuel in the engine (1), Furthermore, The control device (8) is After the first time has elapsed, the motor (6) is started to operate, and the motor (6) is allowed to continue operating until the rotational speed of the crankshaft (10) of the engine (1) reaches a predetermined first rotational speed. The plurality of valves are kept in the open state for a period of time from the time the plurality of valves are in the open state until a second time has elapsed. The aforementioned second hour, A time that is longer than the first time, and is less than or equal to the third time, which is the time from when the plurality of valves are in the open state until the rotational speed of the crankshaft (10) reaches the first rotational speed. The control device (8) is The control device (8) according to claim 4 or 5, which controls the injector (14) to inject the fuel after the third time has elapsed, and controls the spark plug (15) to ignite the fuel injected into the engine (1).

7. A method for operating a hybrid vehicle (100) that is driven by power from a motor (6) and an engine (1), The aforementioned hybrid vehicle (100) Multiple pipes connected to the engine (1) for circulating air between the space outside the hybrid vehicle (100) and the inside of the engine (1), Multiple valves that open and close the air circulation path in the multiple pipes and the inside of the engine (1), A first temperature sensor (27) for obtaining the temperature of the engine (1), Equipped with, The motor (6) cranks the engine (1), The aforementioned operation method is, Before starting the engine (1), if the temperature obtained by the first temperature sensor (27) is below a predetermined first threshold temperature, the plurality of valves are opened. The motor (6) starts operating after a predetermined first time has elapsed since the plurality of valves were opened. The method of operation, including the operation method.

8. The operating method according to claim 7, wherein the first time is the time required for the air pressure inside the engine (1) to become equal to or greater than atmospheric pressure.

9. The aforementioned hybrid vehicle (100) An injector (14) for injecting fuel to be supplied into the engine (1), A spark plug (15) that ignites the fuel in the engine (1), Furthermore, The aforementioned operation method is, The motor (6) starts operating after the first time has elapsed, and continues to operate until the rotational speed of the crankshaft (10) of the engine (1) reaches a predetermined first rotational speed. The steps include: maintaining the open state of the plurality of valves for a period of time from when the plurality of valves are in the open state until a second time has elapsed; It further includes, The aforementioned second hour, A time that is longer than the first time, and is less than or equal to the third time, which is the time from when the plurality of valves are in the open state until the rotational speed of the crankshaft (10) reaches the first rotational speed. The aforementioned operation method is, The injector (14) injects the fuel after the third time has elapsed, The spark plug (15) ignites the fuel injected into the engine (1), The operating method according to claim 7 or 8, further comprising:

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