JP7230700B2 - hybrid vehicle - Google Patents

Description

The present disclosure relates to hybrid vehicles, and more particularly to engine control in hybrid vehicles.

Japanese Patent Application Laid-Open No. 2013-230794 (Patent Document 1) discloses a hybrid vehicle that further includes an electric motor that generates driving force for driving in addition to an engine that generates driving force for driving.

JP 2013-230794 A

In the hybrid vehicle described in Patent Document 1, the power source is switched according to the vehicle speed and the degree of opening of the accelerator. be By switching the power source in this way, the fuel consumption of the engine is suppressed, and the fuel consumption rate of the vehicle (the amount of fuel consumed per unit traveled distance) can be improved. However, in such a hybrid vehicle, the power source automatically switches to the electric motor when the vehicle is stopped, so the driver cannot perform racing by operating the accelerator. Racing is the process of activating the engine while the vehicle is stationary and rotating the output shaft (eg, crankshaft) of the engine while the vehicle is stationary.

Also, if the engine speed increases too much during racing, the rotational speed of the parts that transmit the rotational power of the engine (e.g., gears) may exceed the allowable range (i.e., the range in which normal operation is guaranteed). The subject that there exists was newly discovered by this inventor.

The present disclosure has been made to solve the above problems, and its object is to provide a hybrid vehicle in which the driver can perform racing by operating the accelerator and can appropriately adjust the engine rotation speed during racing. It is to be.

A hybrid vehicle according to the present disclosure includes an engine that generates driving force, an electric motor that generates driving force, an accelerator sensor that detects an accelerator operation amount by a driver, and a control device that controls the engine and the electric motor. . The control device is configured to limit an increase in the rotation speed of the engine, and when the driver operates the accelerator such that the amount of accelerator operation becomes equal to or greater than a first threshold when the shift range is in the parking range. , racing (hereinafter also referred to as “first racing”) is executed with the above restrictions relaxed.

In the above hybrid vehicle, when the driver performs a predetermined accelerator operation (that is, an accelerator operation amount equal to or greater than the first threshold value) while the shift range is in the parking range, racing is performed. Therefore, the driver can perform racing by operating the accelerator during parking. Note that the first threshold can be set arbitrarily.

In the above hybrid vehicle, the control device limits the increase in the engine rotation speed (hereinafter also referred to as "Ne increase limit"). Any method can be used to limit the increase in Ne. For example, the degree of increase (acceleration) of the engine rotation speed may be limited, or an upper limit value may be set for the engine rotation speed. By restricting the increase in Ne, it is possible to prevent the rotation speed of a part that transmits the rotational force of the engine (hereinafter also referred to as a "rotation transmission part") from exceeding an allowable range. On the other hand, if the increase in the engine rotation speed during racing is restricted, it may impair the user's convenience. For example, the engine body can be used as a heat source for on-vehicle devices. Hereinafter, an in-vehicle device that uses the engine body as a heat source is also referred to as an "ENG heat device." Since part of the heat of the engine body is taken by the engine cooling water, the ENG heat device can also utilize the heat of the engine body via the engine cooling water. Racing can increase the temperature of the engine body (and thus the temperature of the cooling water of the engine). The faster the engine rotation speed during racing, the faster the temperature rise of the engine during racing. By increasing the warm-up speed of the engine during racing, the ENG heat device can be activated earlier. An example of an ENG thermal system is an air conditioner that uses engine coolant as a heat source for heating and/or defrostering. By activating such an air conditioner during racing, it is possible to heat the vehicle interior and eliminate fogging of the vehicle windows.

Therefore, the control device described above executes the first racing when the shift range is the parking range, and relaxes the Ne increase restriction during the first racing. When the shift range is in the parking range, the engine does not drive the vehicle (i.e., it does not rotate the vehicle's drive wheels), so the engine is more powerful than when the shift range is in the driving range (i.e., when the engine drives the vehicle). Torque becomes smaller. Rotation transmission components (eg, gears) can normally operate up to high rotational speeds if the driving torque is small. Therefore, in the parking range, the allowable upper limit of the rotation speed of the rotation transmission components is larger than in the driving range. Therefore, even if the Ne increase restriction is relaxed during execution of the first racing, the rotation transmission component can be operated within the rotational speed range that the rotation transmission component allows. Since the restriction on the increase in Ne is relaxed during the first racing, it becomes possible to quickly start the vehicle-mounted device (for example, the air conditioner described above) that uses engine cooling water as a heat source. Thus, according to the control device described above, the engine rotation speed during racing is appropriately adjusted.

The above control device controls the engine so that the rotation speed of the engine does not exceed an upper limit value (hereinafter also referred to as "Ne upper limit value"), and during the execution of the first racing, the shift range is set to the driving range. It may be configured to relax the Ne increase limit by increasing the Ne upper limit value.

According to the above configuration, it is possible to protect the rotation transmission component by limiting the engine rotation speed to the Ne upper limit value or less. Also, during the execution of the first racing, it is possible to increase the engine rotation speed above the Ne upper limit value in the running range and start the ENG heating device early.

The above-described control device may be configured to increase the Ne upper limit value and match the engine rotational speed with the Ne upper limit value when the accelerator operation amount increases during execution of the first racing.

According to the above configuration, it is possible for the driver to adjust the engine rotation speed during racing according to the accelerator operation amount.

When the accelerator operation amount is greater than or equal to the first threshold when the shift range is in the parking range, the above control device determines the Ne upper limit value (hereinafter referred to as The first racing may be configured to be executed at an engine rotation speed exceeding the "normal Ne upper limit"). When the accelerator operation amount is greater than or equal to the second threshold value and less than the first threshold value when the shift range is in the parking range, the above-described control device normally operates at the engine rotation speed equal to or lower than the Ne upper limit value. It may be configured to run two races. The above control device may be configured not to execute racing when the accelerator operation amount is less than the second threshold when the shift range is in the parking range. The second threshold is less than the first threshold.

The above configuration also allows the driver to adjust the engine rotation speed during racing by adjusting the amount of accelerator operation.

The hybrid vehicle described above may further include a motor generator (hereinafter also referred to as a "first motor generator"). The electric motor that generates the traveling driving force described above may be a motor generator (hereinafter also referred to as a "second motor generator"). Each of the engine and the first motor generator may be mechanically coupled to driving wheels of the hybrid vehicle via planetary gears. The planetary gear and the second motor generator may be configured such that the power output from the planetary gear and the power output from the second motor generator are combined and transmitted to the driving wheels. The above control device may be configured to lock the output shaft of the planetary gear when the shift range is the parking range.

In the above configuration, the planetary gear corresponds to the rotation transmission component, and the rotation speed and torque of the driving wheels can be adjusted by the first motor generator and the second motor generator. In addition, the first motor generator and the second motor generator can generate reaction torque and generate power. Furthermore, in the parking range, the output shaft of the planetary gear is locked, so that the rotational force of the engine is not transmitted to the drive wheels, making it possible to properly execute the first racing described above. On the other hand, since the engine and the first motor generator are each connected to the planetary gears, the planetary gears and the first motor generator are susceptible to damage when the rotational speed of the engine excessively increases. Further, during the first racing, the rotation speed of the first motor generator also increases as the rotation speed of the engine increases while the output shaft of the planetary gear is locked. Therefore, when the rotational speed of the engine excessively increases, the first motor generator tends to over-rotate. In this regard, since the hybrid vehicle is provided with the above-described control device, the engine rotation speed is appropriately adjusted by the above-described Ne increase limit, and the planetary gears and the first motor generator can be appropriately protected.

When a compression check request is input from a first external tool for checking whether or not the compression operation of the engine is normally performed (hereinafter also referred to as "compression check"), the control device performs compression check. It may be configured to be able to shift to a check mode (hereinafter also referred to as "C check mode"). The above-described control device is configured to perform motoring of the engine by the first motor generator in the C check mode when the first external tool performs the compression check while the fuel of the engine is cut.

In the C check mode, the motoring rotates the output shaft of the engine, so the first external tool can check whether the compression operation of the engine is performed normally. In the C check mode, motoring is performed in a fuel cut state, so the output shaft of the engine can be rotated without consuming fuel in the engine. The above control device may be configured to rotate the output shaft of the engine at a constant speed (eg, 250 rpm), or configured to adjust the engine rotation speed in response to a request from the first external tool. may

The control device may be configured to shift to the C check mode when a compression check request is input from the first external tool and a predetermined first permission condition is satisfied. The first permission condition may include that the shift range is the parking range. In the parking range, the output shaft of the planetary gear is locked, so the compression check is performed when the shift range is in the parking range, thereby preventing the vehicle from moving during the compression check.

The hybrid vehicle described above may include a power storage device configured to be chargeable with electric power generated using power output from the engine. The control device described above may be configured to determine the output power of the engine using the accelerator operation amount, the power storage amount of the power storage device, and the cooling water temperature of the engine. The above control device may be configured to limit the power output from the engine so that the temperature of cooling water for the engine does not exceed a predetermined temperature.

As a method for suppressing overheating of the engine, it is known to provide a lamp near the driver's seat (that is, a position visible to the driver) that lights when the temperature of the engine cooling water is equal to or higher than a predetermined temperature. The driver can lower the temperature of the engine by driving the vehicle so as to reduce the running load while the lamp is on.

On the other hand, in a hybrid vehicle, the power storage device may be charged by the power output from the engine. In a typical hybrid vehicle, when the amount of electricity stored in the power storage device decreases, the output power of the engine is increased, and the power storage device is forcibly charged by the output power of the engine.

If the forced charging described above is executed when the temperature of the engine cooling water rises, there is a possibility that the output power of the engine will not be reduced sufficiently even if the user reduces the running load of the vehicle. Therefore, in the hybrid vehicle described above, the control device is configured to limit the power output from the engine when the temperature of the engine cooling water reaches or exceeds a predetermined temperature. With such a configuration, when the temperature of the engine cooling water reaches or exceeds a predetermined temperature, the output power of the engine is limited, so that the temperature of the engine can be quickly lowered.

The control device for the hybrid vehicle is configured such that when the shift range is the driving range and the hybrid vehicle is stopped with the brake operation performed by the driver, the amount of accelerator operation by the driver is equal to or greater than a third threshold. The stall start control may be configured to be executed when the accelerator operation is performed. The above control device may be configured to maintain the engine in an operating state and increase the power output from the engine as the accelerator operation amount increases in the stall start control. Note that the third threshold may be the same as or different from the first threshold.

2. Description of the Related Art Stall starting is known as a method for starting an automobile (generally referred to as a “conveyor car”) that uses only an engine as a power source for running. Stall start is a method of starting the vehicle by releasing only the brake pedal (brake release) from a state in which both the brake pedal and the accelerator pedal are depressed (hereinafter also referred to as "both depressed state"). In a conveyor vehicle, even when the brake pedal is stepped on, the output power of the engine increases as the accelerator operation amount increases. In a stall start, the brakes are released while the engine speed is high, so the car can start suddenly. However, in general hybrid vehicles, the engine is controlled in consideration of the fuel consumption rate (hereinafter simply referred to as "fuel consumption"). Become. When the engine stops, stall start as described above cannot be performed.

Therefore, the control device described above is configured to execute stall start control when a predetermined stall start condition is satisfied. In the stall start control, the engine is maintained in an operating state, and the output power of the engine increases as the accelerator operation amount increases, so the above-described stall start can be performed. The stall start condition is that when the hybrid vehicle is stopped with the shift range in the driving range and the driver performing a brake operation, the driver does not operate the accelerator to a predetermined amount or more. established if done. This stall start condition is met in the same situation as when a conveyor vehicle stalls. Therefore, the driver can cause the hybrid vehicle to stall by performing the same operation as when stalling the conveyor vehicle.

The hybrid vehicle described above may include a power storage device configured to be chargeable with electric power generated using power output from the engine. The control device may be configured to charge the power storage device with the output power of the engine when the power storage amount of the power storage device falls below a predetermined amount. The above control device is configured to be able to shift to a pressure inspection mode when a pressure inspection request is input from a second external tool that inspects the intake pressure of the engine (hereinafter also referred to as "pressure inspection"). good too. In the pressure inspection mode, the control device controls the engine while the inspection is being performed by the second external tool, and the power storage device is charged at a constant charging rate by the power output from the engine. may be configured to maintain

For example, in inspection of an EGR (Exhaust Gas Recirculation) device, it is known to inspect whether or not the intake pressure during engine operation is normal. If the above charging is performed while the pressure inspection is being performed, the load on the engine increases and the intake pressure fluctuates, making it difficult to properly perform the pressure inspection.

In this regard, the control device described above is configured to be able to shift to the pressure inspection mode. In the pressure inspection mode, charging of the power storage device at a constant charging rate (hereinafter also referred to as "inspection charging") is performed, so fluctuations in the engine load during the pressure inspection are suppressed. According to the control device described above, it becomes easier to perform a proper pressure inspection.

The control device may be configured to shift to the pressure inspection mode when a pressure inspection request is input from the second external tool and a predetermined second permission condition is satisfied. The second permission condition may include that the power storage amount of the power storage device is less than a predetermined threshold. Overcharging of the power storage device can be suppressed by failing to satisfy the second permission condition (thus, test charging is not performed) when the power storage amount of the power storage device is equal to or greater than a predetermined threshold.

In addition, the first external tool and the second external tool may be two divided tools, or a common tool (that is, a single tool that performs both the compression check and the pressure test). good too.

The above hybrid vehicle further includes a variable valve timing mechanism (hereinafter also referred to as "VVT mechanism") configured to be able to change at least one of the engine intake timing and exhaust timing (hereinafter also referred to as "intake and exhaust timing"). You may prepare. The above control device is configured to obtain the target power of the engine using the accelerator operation amount, and is configured to limit the increase in the rotation speed of the engine so that the rotation speed of the engine does not exceed the upper limit value. may be The control device determines whether or not the target power can be output from the engine without exceeding the upper limit of the rotational speed of the engine, and if it is determined that the target power cannot be output from the engine, the variable valve timing mechanism may be configured to change the intake/exhaust timing so as to increase the torque of the engine.

For example, the fuel efficiency of the hybrid vehicle is improved by controlling the engine mounted on the hybrid vehicle according to the optimum fuel efficiency line. The fuel efficiency of the hybrid vehicle is also improved by determining the intake and exhaust timings of the engine with priority given to fuel efficiency. However, if the engine is always controlled with priority given to fuel efficiency, it may not be possible to cope with situations requiring strong acceleration (for example, when overtaking or merging on a highway). Therefore, when the target power cannot be output from the engine without the engine rotation speed exceeding the upper limit value, the above control device changes the intake/exhaust timing so as to increase the torque of the engine by means of the variable valve timing mechanism. configured to Such a change in the intake/exhaust timing makes the engine torque at the same engine rotation speed larger than during normal operation (for example, during steady running). According to the above control device, when the accelerator operation amount becomes large (that is, in a situation where it is required to increase the output power of the engine), the engine output power is It becomes possible to bring the power closer to the target power.

In the Otto cycle engine, the intake valve is closed at the bottom dead center of the intake stroke to improve the charging efficiency, but in the high expansion ratio cycle engine such as the Atkinson cycle, the intake valve is slowed down (for example, the compression stroke) to make the expansion ratio greater than the compression ratio. Such a high expansion ratio cycle (that is, intake valve late closing cycle) has better fuel efficiency than the Otto cycle, but the torque is small. In an engine that normally improves fuel efficiency by the above intake valve late closing cycle, the VVT mechanism advances the intake timing so that the intake valve closes earlier and the engine torque increases.

The hybrid vehicle described above may include a power storage device configured to be chargeable with electric power generated using power output from the engine. The above control device may be configured to determine the output power of the engine using the amount of accelerator operation and the amount of power stored in the power storage device. The control device may be configured to charge the power storage device with the output power of the engine when the power storage amount of the power storage device falls below a predetermined amount (hereinafter also referred to as "threshold value Th1"). When the vehicle speed of the hybrid vehicle is below a predetermined speed (hereinafter also referred to as "threshold value Th2"), the control device increases the amount of charge in the charging process more than when the vehicle speed of the hybrid vehicle exceeds the threshold value Th2. may be configured to limit The vehicle speed is the lowest (vehicle speed=0 km/h) when the vehicle is stopped.

When the amount of electricity stored in the power storage device falls below the threshold value Th1 and the above charging is performed, NV (noise and vibration) characteristics deteriorate due to an increase in engine load. If the NV characteristic is deteriorated due to the above-described charging when the vehicle is stopped with little background noise and when the vehicle is running at low speed, the driver may feel uncomfortable. Therefore, the control device described above strengthens the limit on the charging amount when the vehicle speed is lower than the threshold value Th2. As a result, when the vehicle is traveling at low speed (and/or when the vehicle is stopped), an increase in the engine load due to charging is suppressed, and the driver is less likely to feel discomfort.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a hybrid vehicle in which the driver can perform racing by operating the accelerator and can appropriately adjust the engine rotation speed during racing.

1 is a diagram showing a hybrid vehicle drive system according to an embodiment of the present disclosure; FIG. 1 is a diagram showing an engine of a hybrid vehicle according to an embodiment of the present disclosure; FIG. 1 is a block diagram showing a hybrid vehicle control system according to an embodiment of the present disclosure; FIG. 1 is a diagram for explaining a device arranged near a driver's seat of a hybrid vehicle according to an embodiment of the present disclosure; FIG. 4 is a flow chart showing a procedure for determining a control amount for a hybrid vehicle drive system according to an embodiment of the present disclosure; FIG. 6 is a flowchart showing an example of a procedure for determining execution of forced charging shown in FIG. 5; FIG. FIG. 7 is a diagram showing an example of a charge upper limit map used in the forced charge execution determination shown in FIG. 6; FIG. FIG. 6 is a flowchart showing an example of a processing procedure for engine output adjustment shown in FIG. 5; FIG. FIG. 9 is a diagram showing an example of vehicle operation when VVT control is executed in the process of FIG. 8; FIG. FIG. 10 is a diagram for explaining how the engine operating point changes in the operation of the vehicle shown in FIG. 9; FIG. 4 is a flowchart showing processing executed while the hybrid vehicle is stopped according to the embodiment of the present disclosure; FIG. 12 is a flow chart showing a process of setting an R flag used in the process of FIG. 11; FIG. FIG. 4 is a nomographic diagram showing an example of the relationship between rotational speeds of rotating elements (sun gear, carrier, ring gear) of planetary gears during racing in the hybrid vehicle according to the embodiment of the present disclosure; FIG. 12 is a diagram showing the relationship between the engine rotation speed and the accelerator operation amount in the racing control executed in the process of FIG. 11; FIG. 15 is a diagram showing a modified example of the racing control shown in FIG. 14; FIG. 12 is a flow chart showing a process of setting an S flag used in the process of FIG. 11; FIG. FIG. 12 is a flow chart showing a series of processes executed in the C check mode shown in FIG. 11; FIG. FIG. 4 is a nomographic chart showing an example of the relationship between rotational speeds of rotating elements (sun gear, carrier, ring gear) of planetary gears during motoring in C-check mode in the hybrid vehicle according to the embodiment of the present disclosure; FIG. 12 is a flow chart showing a series of processes executed in the pressure inspection mode shown in FIG. 11; FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated. Hereinafter, the electronic control unit is also referred to as "ECU". Moreover, a hybrid vehicle (Hybrid Vehicle) is also called "HV" and an electric vehicle (Electric Vehicle) is also called "EV."

FIG. 1 is a diagram showing a drive system for a hybrid vehicle according to this embodiment. In this embodiment, a front-wheel-drive four-wheeled vehicle (more specifically, a hybrid vehicle) is assumed, but the number of wheels and drive system can be changed as appropriate. For example, the drive system may be four-wheel drive.

Referring to FIG. 1, a vehicle drive device 10 includes an engine 13 and MGs (Motor Generators) 14 and 15 as power sources for running. Each of the MGs 14 and 15 is a motor generator that has both a function as a motor that outputs torque when supplied with drive power and a function as a generator that generates generated power when torque is applied. . AC motors (for example, permanent magnet synchronous motors or induction motors) are used as each of MGs 14 and 15 . Each of MG14 and MG15 is electrically connected to battery 18 via PCU (Power Control Unit) 19 . MG14 and MG15 have rotor shafts 23 and 30, respectively. The rotor shafts 23 and 30 correspond to the rotation shafts of MG14 and MG15, respectively. MG14 and MG15 according to this embodiment correspond to examples of a "first motor generator (MG1)" and a "second motor generator (MG2)" according to the present disclosure, respectively.

The battery 18 is configured to be chargeable with electric power generated using the power output from the engine 13 . The MG 14 is configured to be driven by the engine 13 to generate power and supply the generated power to the battery 18 . Battery 18 includes, for example, a secondary battery. A lithium ion battery, for example, can be used as the secondary battery. The battery 18 may include an assembled battery composed of a plurality of electrically connected secondary batteries (for example, lithium ion batteries). In addition, the secondary battery that constitutes the battery 18 is not limited to the lithium ion battery, and may be another secondary battery (for example, a nickel metal hydride battery). As the battery 18, an electrolyte secondary battery may be adopted, or an all-solid secondary battery may be adopted. Any storage device can be used as the battery 18, and a large-capacity capacitor or the like can also be used. The battery 18 according to this embodiment corresponds to an example of the "power storage device" according to the present disclosure.

Drive device 10 includes a planetary gear mechanism 20 . Engine 13 and MG 14 are connected to planetary gear mechanism 20 . The MG 14 can forcibly rotate the output shaft 22 of the engine 13 . The output shaft 22 of the engine 13 is connected via a torsional damper 22a to a crankshaft 131 shown in FIG. 2, which will be described later. Thus, the MG 14 is configured to be able to motor the engine 13 . The torsional damper 22 a is configured to absorb torque fluctuations of the engine 13 . The planetary gear mechanism 20 is a single pinion type planetary gear, and is arranged on the same axis line Cnt as the output shaft 22 of the engine 13 .

The planetary gear mechanism 20 has a sun gear S, a ring gear R arranged coaxially with the sun gear S, a pinion gear P meshing with the sun gear S and the ring gear R, and a carrier C holding the pinion gear P so that it can rotate and revolve. Each of the engine 13 and MG 14 is mechanically connected to drive wheels 24 via a planetary gear mechanism 20 . An output shaft 22 of the engine 13 is connected to the carrier C. As shown in FIG. A rotor shaft 23 of the MG 14 is connected to the sun gear S. Ring gear R is connected to output gear 21 .

The planetary gear mechanism 20 has three rotating elements, namely an input element, an output element and a reaction force element. In the planetary gear mechanism 20, the carrier C is an input element, the ring gear R is an output element, and the sun gear S is a reaction force element. Torque output from the engine 13 is input to the carrier C. As shown in FIG. The planetary gear mechanism 20 is configured to divide and transmit the torque output from the engine 13 to the output shaft 22 to the sun gear S (and thus the MG 14) and the ring gear R (and thus the output gear 21). The ring gear R outputs torque to the output gear 21, and the sun gear S receives reaction torque from the MG14. The power output from the planetary gear mechanism 20 (planetary gear) (that is, the power output to the output gear 21) is driven by a driven gear 26, a counter shaft 25, a drive gear 27, a differential gear 28, and a drive shaft 32, which will be described below. 33 to drive wheels 24 .

The drive device 10 further comprises a countershaft 25, a driven gear 26, a drive gear 27, a differential gear 28, a drive gear 31 and drive shafts 32,33. The differential gear 28 corresponds to a final reduction gear and includes a ring gear 29 .

The planetary gear mechanism 20 and the MG 15 are configured such that the power output from the planetary gear mechanism 20 and the power output from the MG 15 are combined and transmitted to the drive wheels 24 . Specifically, the output gear 21 connected to the ring gear R of the planetary gear mechanism 20 meshes with the driven gear 26 . A drive gear 31 attached to the rotor shaft 30 of the MG 15 also meshes with the driven gear 26 . The countershaft 25 is attached to the driven gear 26 and arranged parallel to the axis Cnt. The drive gear 27 is attached to the countershaft 25 and meshes with the ring gear 29 of the differential gear 28 . Driven gear 26 acts to combine torque output from MG 15 to rotor shaft 30 and torque output from ring gear R to output gear 21 . The drive torque thus synthesized is transmitted to the drive wheels 24 via drive shafts 32 and 33 extending left and right from the differential gear 28 .

The drive device 10 further comprises a parking device 35 . The parking device 35 has a mechanism that mechanically prevents the ring gear R from rotating. Specifically, the parking device 35 includes a parking gear 35a and a parking pole (P pole) 35b. The parking gear 35a is provided coaxially and integrally with the ring gear R of the planetary gear mechanism 20, and is configured to rotate integrally with the ring gear R. As shown in FIG. The P pole 35b is configured to be driven by an electric actuator (for example, a motor) (not shown) and engage with the parking gear 35a. The engagement of the P pole 35b with the parking gear 35a locks the ring gear R of the planetary gear mechanism 20 (that is, the output shaft of the planetary gear). The state (locked state/unlocked state) of the P pole 35b is controlled by the HVECU 62 (see FIG. 3), which will be described later. In the locked state, the P pole 35b engages with the parking gear 35a to restrict the rotation of the ring gear R. In the unlocked state, the P pole 35b does not engage with the parking gear 35a, and the P pole 35b does not hinder the rotation of the ring gear R. The HVECU 62 can move the P-pole 35b to the desired state by sending a command to the actuator of the P-pole 35b. When the shift range is the parking range (P range), the HVECU 62 locks the P pole 35b, and when the shift range is not the P range, the HVECU 62 unlocks the P pole 35b. Thus, the HVECU 62 is configured to lock the ring gear R of the planetary gear mechanism 20 (that is, the output shaft of the planetary gear) when the shift range is the P range.

The drive device 10 further comprises a mechanical oil pump 36 and an electric oil pump 38 . The oil pump 36 is provided coaxially with the output shaft 22 . Oil pump 36 is driven by engine 13 . Oil pump 36 delivers lubricating oil to planetary gear mechanism 20, MG14, MG15, and differential gear 28 when engine 13 is operating. The electric oil pump 38 is driven by power supplied from the battery 18 or another vehicle-mounted battery (for example, an auxiliary battery) (not shown), and controlled by an HVECU 62 (see FIG. 3), which will be described later. The electric oil pump 38 sends lubricating oil to the planetary gear mechanism 20, MG14, MG15, and the differential gear 28 when the engine 13 is stopped. Lubricating oil delivered by each of oil pump 36 and electric oil pump 38 has a cooling function.

FIG. 2 is a diagram showing the configuration of the engine 13. As shown in FIG. Although FIG. 2 shows only one cylinder 40, engine 13 includes multiple cylinders (eg, four cylinders). In this embodiment, all cylinders provided in the engine 13 have the same structure, so only the structure of the cylinder 40 shown in FIG. 2 will be described.

Referring to FIG. 2, engine 13 is a spark ignition internal combustion engine. The engine 13 includes an intake passage 41 and an exhaust passage 42 connected to all cylinders, and a crankshaft 131, an intake camshaft 432, and an exhaust camshaft 442 common to all cylinders. When the intake camshaft 432 rotates, the intake cam of each cylinder (including the intake cam 433 of the cylinder 40) rotates. When the exhaust camshaft 442 rotates, the exhaust cams of each cylinder (including the exhaust cam 443 of the cylinder 40) rotate. Intake camshaft 432, exhaust camshaft 442, and crankshaft 131 are configured to rotate synchronously by being connected by, for example, a timing chain.

Engine 13 further includes a crank angle sensor 70 , a cam angle sensor 71 and an engine cooling water temperature sensor 79 . A first timing rotor (not shown) is attached to the crankshaft 131, and a crank angle sensor 70 is arranged near the first timing rotor. As the crankshaft 131 rotates, the crank angle sensor 70 outputs a crank signal corresponding to the unevenness of the first timing rotor. As crank angle sensor 70, for example, an electromagnetic pickup can be employed. A second timing rotor (not shown) is attached to the intake camshaft 432, and the cam angle sensor 71 is arranged near the second timing rotor. As the intake camshaft 432 rotates, the cam angle sensor 71 outputs a cam signal (cylinder discrimination signal) corresponding to the unevenness of the second timing rotor. As the cam angle sensor 71, for example, a sensor using a magnetoresistive element (MRE) can be employed. The engine coolant temperature sensor 79 is configured to detect the temperature of the engine coolant (that is, the water that cools the engine 13). Engine cooling water flows through a water jacket formed in the engine body (eg, cylinder block).

The intake passage 41 is provided with a throttle valve 49 (intake throttle valve), an air flow meter 50 and a pressure sensor 72 . The throttle valve 49 is configured to be able to adjust the flow rate of intake air flowing through the intake passage 41 . The degree of opening of the throttle valve 49 is controlled by an HVECU 62 (see FIG. 3), which will be described later. The airflow meter 50 is configured to detect the flow rate of air flowing through the intake passage 41 . The pressure sensor 72 is configured to detect the pressure within the intake manifold of the intake passage 41 . On the other hand, the exhaust passage 42 is provided with a start catalytic converter 56 and an aftertreatment device 57 . Exhaust gas emitted from each cylinder of the engine 13 is released into the atmosphere after harmful substances are removed by the starter catalytic converter 56 and the aftertreatment device 57 . Aftertreatment device 57 includes, for example, a three-way catalyst.

The engine 13 further includes an EGR (Exhaust Gas Recirculation) device 58 . The EGR device 58 includes an EGR passage 59 and an EGR valve 60 . The EGR passage 59 is configured to extract part of the exhaust gas from the exhaust passage 42 as EGR gas and guide it to the intake passage 41 . The EGR valve 60 is configured to be able to adjust the flow rate of EGR gas flowing through the EGR passage 59 .

An intake port 43 and an exhaust port 44 of the cylinder 40 are connected to an intake passage 41 and an exhaust passage 42, respectively. Cylinder 40 includes combustion chamber 401 , piston 402 , connecting rod 403 , intake valve 431 , intake cam 433 , exhaust valve 441 , exhaust cam 443 , ignition device 45 , and injector 46 . Ignition device 45 includes a spark plug and a boost circuit (not shown), and is configured to ignite the air-fuel mixture in combustion chamber 401 . Injector 46 is configured to perform in-cylinder fuel injection into cylinder 40 (that is, direct fuel injection into cylinder 40).

As the intake camshaft 432 rotates, the intake valve 431 is driven to open and close by the intake cam 433 . As the exhaust camshaft 442 rotates, the exhaust valve 441 is driven to open and close by the exhaust cam 443 . The intake port 43 is opened and closed by an intake valve 431 , and the exhaust port 44 is opened and closed by an exhaust valve 441 . A mixture of air and fuel is produced by adding fuel (eg, gasoline) to the air supplied into cylinder 40 through intake port 43 . Fuel is injected into cylinder 40 by injector 46 and an air-fuel mixture is generated within cylinder 40 . A voltage is applied to the ignition plug of the ignition device 45 to ignite the air-fuel mixture in the cylinder 40 . As a result, combustion and explosion occur in the combustion chamber 401, and the high-temperature, high-pressure combustion gas expands and pushes the piston 402 downward. The power of the piston 402 thus generated is transmitted to the crankshaft 131 via the connecting rod 403 . Power generated in each cylinder of the engine 13 is output to the crankshaft 131 .

When the engine 13 is operating, each cylinder repeats four strokes consisting of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke (hereinafter also referred to as "one combustion cycle"). In the intake stroke, the piston 402 descends, the intake valve 431 opens, and air is sucked into the cylinder 40 from the intake port 43 . In the compression stroke, piston 402 rises to compress the air in cylinder 40 . During the expansion stroke, combustion and explosion occur in combustion chamber 401 and combustion gases push piston 402 downward. In the exhaust stroke, the piston 402 rises, the exhaust valve 441 opens, and the combustion gas in the cylinder 40 is discharged from the exhaust port 44 .

Cylinder 40 further includes a variable valve timing (VVT) mechanism 400 . VVT mechanism 400 is configured to be able to change the rotational phase of intake cam 433 . In this embodiment, the VVT mechanism 400 operates to change the opening/closing timing of the intake valve 431 (and thus the intake timing) while keeping the open period of the intake valve 431 constant. As the VVT mechanism 400, for example, a VVT-i (Variable Valve Timing-intelligent system) can be adopted.

In this embodiment, the engine 13 is operated in a high expansion ratio cycle (more specifically, an intake valve late closing cycle) during normal times (for example, during steady HV running). In the intake valve late closing cycle, by closing the intake valve 431 late (for example, after the piston 402 rises to some extent in the compression stroke), the expansion ratio becomes larger than the compression ratio, and the fuel efficiency of the engine 13 is improved.

Note that the VVT mechanism 400 may be of an electric type or of a hydraulic type. The VVT mechanism 400 may be configured to be able to change the valve opening period of the intake valve 431 , or may be configured to be able to change the valve opening period and opening/closing timing of the exhaust valve 441 . Further, the VVT mechanism 400 may be configured to be able to change the valve lift amount in addition to the valve opening/closing timing.

FIG. 3 is a block diagram showing a hybrid vehicle control system according to this embodiment. 3 together with FIGS. 1 and 2, the vehicle control system includes an HVECU 62, an MGECU 63, and an engine ECU 64. As shown in FIG. The HVECU 62 includes an airflow meter 50, an accelerator sensor 66, a vehicle speed sensor 67, an MG1 rotation speed sensor 68, an MG2 rotation speed sensor 69, a crank angle sensor 70, a cam angle sensor 71, a pressure sensor 72, an SOC sensor 73, and an MG1 temperature sensor 74. , MG2 temperature sensor 75, INV1 temperature sensor 76, INV2 temperature sensor 77, catalyst temperature sensor 78, and engine cooling water temperature sensor 79 are connected.

The airflow meter 50 is configured to output to the HVECU 62 a signal corresponding to the intake air amount of the engine 13 . Accelerator sensor 66 outputs a signal to HVECU 62 according to the amount of accelerator operation (for example, the amount of depression of an accelerator pedal (not shown)). The accelerator operation amount is a parameter that indicates the amount of acceleration that the driver requests of the vehicle (hereinafter also referred to as "requested acceleration amount"). The greater the amount of accelerator operation, the greater the amount of acceleration requested by the driver. The vehicle speed sensor 67 outputs to the HVECU 62 a signal corresponding to the vehicle speed (that is, the running speed of the vehicle). MG1 rotation speed sensor 68 outputs a signal corresponding to the rotation speed of MG14 to HVECU 62 . The MG2 rotation speed sensor 69 outputs a signal corresponding to the rotation speed of the MG15 to the HVECU 62 .

Crank angle sensor 70 outputs a crank signal to HVECU 62 . Cam angle sensor 71 outputs a cam signal to HVECU 62 . The HVECU 62 has a crank counter (not shown) indicating the crank angle (that is, the rotational position of the crankshaft 131 shown in FIG. 2) in the storage device 62c, and updates the crank counter using the crank signal and the cam signal. configured to The HVECU 62 is also configured to calculate the rotation speed of the engine 13 using the crank signal.

Pressure sensor 72 outputs to HVECU 62 a signal corresponding to the intake pressure (for example, the pressure in the intake manifold). The SOC sensor 73 outputs to the HVECU 62 a signal corresponding to the SOC (State of Charge), which is the ratio of the remaining charge amount to the full charge amount (that is, storage capacity) of the battery 18 . MG1 temperature sensor 74 outputs a signal corresponding to the temperature of MG 14 to HVECU 62 . MG2 temperature sensor 75 outputs a signal corresponding to the temperature of MG15 to HVECU 62 . The INV1 temperature sensor 76 outputs a signal corresponding to the temperature of the first inverter 16 to the HVECU 62 . The INV2 temperature sensor 77 outputs a signal corresponding to the temperature of the second inverter 17 to the HVECU 62 . Catalyst temperature sensor 78 outputs a signal corresponding to the temperature of aftertreatment device 57 to HVECU 62 . The engine cooling water temperature sensor 79 outputs a signal to the HVECU 62 according to the temperature of the engine cooling water.

The HVECU 62 includes a processor 62a, a RAM (Random Access Memory) 62b, a storage device 62c, an input/output port and a timer (not shown). A CPU (Central Processing Unit), for example, can be employed as the processor 62a. The RAM 62b functions as a working memory that temporarily stores data processed by the processor 62a. The storage device 62c is configured to be able to save the stored information. The storage device 62c includes, for example, ROM (Read Only Memory) and rewritable nonvolatile memory. The storage device 62c stores programs as well as information used in the programs (for example, maps, formulas, and various parameters). Various controls of the vehicle are executed by the processor 62a executing programs stored in the storage device 62c. However, the control is not limited to this, and various controls may be executed by dedicated hardware (electronic circuit). The HVECU 62 according to this embodiment corresponds to an example of the "control device" according to the present disclosure. Other ECUs (for example, the MGECU 63 and the engine ECU 64) also have the same hardware configuration as the HVECU 62. Although the HVECU 62, the MGECU 63, and the engine ECU 64 are separate in this embodiment, one ECU may have these functions.

HVECU 62 is configured to output a command for controlling engine 13 (for example, an engine operating state command) to engine ECU 64 . Engine ECU 64 is configured to control throttle valve 49 , ignition device 45 , injector 46 , VVT mechanism 400 , and EGR valve 60 according to commands from HVECU 62 . The HVECU 62 can perform engine control through the engine ECU 64 .

HVECU 62 is configured to output commands for controlling each of MG 14 and MG 15 (for example, a first MG torque command and a second MG torque command) to MGECU 63 . MGECU 63 is configured to control MG 14 and MG 15 through PCU 19 . The MGECU 63 generates a current signal (for example, a signal indicating the magnitude and frequency of the current) corresponding to the target torque of each of the MG 14 and the MG 15 according to a command from the HVECU 62 and outputs the generated current signal to the PCU 19. Configured. The HVECU 62 can perform motor control through the MGECU 63 .

PCU 19 includes first inverter 16 , second inverter 17 , and converter 65 . Each of MG14 and MG15 is electrically connected to PCU19. First inverter 16 and converter 65 are configured to perform power conversion between battery 18 and MG 14 . Second inverter 17 and converter 65 are configured to perform power conversion between battery 18 and MG 15 . PCU 19 is configured to supply power accumulated in battery 18 to each of MG 14 and MG 15 and to supply power generated by each of MG 14 and MG 15 to battery 18 . The PCU 19 is configured to be able to control the states of the MGs 14 and 15 separately. For example, the MG 15 can be brought into the power running state while the MG 14 is brought into the regenerative state (that is, the power generation state). PCU 19 is configured to be able to supply electric power generated by one of MG 14 and MG 15 to the other. MG14 and MG15 are configured to be able to exchange power with each other.

The vehicle is configured to perform HV running and EV running. HV travel is travel performed by the engine 13 and the MG 15 while the engine 13 is generating travel driving force. EV travel is travel performed by MG 15 with engine 13 stopped. When the engine 13 is stopped, combustion is not performed in each cylinder. When the combustion in each cylinder stops, the engine 13 no longer generates combustion energy (and thus driving force for driving the vehicle). The HVECU 62 is configured to switch between EV running and HV running depending on the situation.

The planetary gear mechanism 20 shown in FIG. 1 can function as a continuously variable transmission mechanism. The planetary gear mechanism 20 is configured to be able to continuously change the ratio of the rotation speed of the input element (carrier C) to the rotation speed of the output element (ring gear R). The rotation speed of the engine 13 can be adjusted by the HVECU 62 controlling the rotation speed of the MG 14 . The HVECU 62 can arbitrarily control the rotation speed of the MG 14 according to the magnitude and frequency of the current that flows through the MG 14 .

FIG. 4 is a diagram for explaining various devices arranged near a driver's seat (not shown) of a vehicle. Referring to FIG. 4, the vehicle further includes an input device 101, a notification device 102, a brake device 103, a shift lever 104, a P position switch 105, and an air conditioner 106.

Input device 101 is configured to accept input from a user. The input device 101 is operated by a user and outputs a signal corresponding to the user's operation to the HVECU 62 . For example, the user can input a predetermined instruction or request to the HVECU 62 or set a parameter value to the HVECU 62 through the input device 101 . The communication method may be wired or wireless. As the input device 101, for example, various switches (eg, push button switches or slide switches) provided around the driver's seat (eg, steering wheel or instrument panel) can be employed. However, the input device 101 is not limited to this, and various pointing devices (for example, a mouse or a touch pad), keyboards, and touch panels can be employed as the input device 101 . The input device 101 may be an operation unit of a mobile device (for example, a smart phone) or an operation unit of a car navigation system.

Notification device 102 is configured to perform predetermined notification processing to a user (for example, a driver) when requested by HVECU 62 . Examples of notification device 102 include a display device (for example, a meter panel or head-up display), a speaker, and a lamp. Notification device 102 may include a lamp that lights when the temperature of the engine cooling water is equal to or higher than a predetermined temperature. The notification device 102 may be a display unit of a mobile device (for example, a smart phone) or a display unit of a car navigation system.

The brake device 103 includes a hydraulic brake device 103a and a P (parking) brake device 103b. The hydraulic brake device 103a is actuated by the driver depressing a first brake pedal (not shown) to apply braking force to the wheels (for example, the drive wheels 24 shown in FIG. 1 and the driven wheels not shown). configured as The P brake device 103b operates when the driver depresses the first brake pedal and depresses the second brake pedal (not shown) to lock the wheels (for example, the rear wheels of the vehicle) (i.e., the braking force is granted state). Hereinafter, application of the braking force by the P brake device 103b is also referred to as "parking brake". When the driver again depresses the second brake pedal in the vehicle with the parking brake applied, the P brake device 103b is deactivated and the parking brake (that is, application of braking force to the wheels) is released. Note that the brake operation for operating each of the hydraulic brake device 103a and the P brake device 103b is not limited to the above and can be arbitrarily changed. Also, the brake release operation can be arbitrarily changed. Hereinafter, the first brake pedal will be simply referred to as "brake pedal" and the second brake pedal will be referred to as "parking brake pedal".

The hydraulic brake device 103a includes a master cylinder that is pressurized by the driver's brake operation (and thus the force applied to the brake pedal), a brake mechanism provided for each wheel, and a brake actuator (all not shown). consists of The brake mechanism has a caliper and a brake rotor fixed to the wheel. The brake mechanism is configured to use hydraulic pressure supplied from the master cylinder to press the brake pads of the caliper against the brake rotor to generate frictional braking force. The brake actuator is provided between the master cylinder and the brake mechanism and configured to be able to adjust the hydraulic pressure applied to the brake mechanism. By controlling the brake actuator, the HVECU 62 can perform anti-slip control (TCS function) when starting and accelerating, vehicle stability control (VSC) when turning, and anti-lock brake control (ABS function) when braking hard. configured to The configuration of the hydraulic brake device 103a is not limited to the above, and any configuration can be selected from among various known hydraulic brake device configurations.

The P brake device 103b includes a piston, an electric actuator (for example, a motor) that moves the piston, a brake pad, and a disk rotor. The disc rotor is fixed to the wheel. When the parking brake pedal is operated by the driver to activate the P brake device 103b, the HVECU 62 controls the electric actuator to advance the piston. This forward movement of the piston presses the brake pad against the disk rotor, generating a frictional braking force on the wheel. While the P brake device 103b is operating, the piston is prohibited from retracting, and the wheels are locked. After that, when the parking brake pedal is operated again by the driver and the P brake device 103b is put into a non-operating state, the HVECU 62 controls the electric actuator to retract the piston. As a result, the parking brake is released, and braking force is no longer applied to the wheels from the P brake device 103b. The configuration of the P brake device 103b is not limited to the above, and any configuration can be selected from among various known parking brake device configurations.

Each of the shift lever 104 and the P position switch 105 is operated by the driver when switching the shift range, and outputs a signal indicating the shift range selected by the driver (hereinafter also referred to as "shift range signal") to the HVECU 62. do. The HVECU 62 can recognize the shift range from the shift range signal. The shift range includes an N (neutral) range, an R (reverse) range, a D (drive) range, a B (brake) range, and a P (parking) range. Of these, only the D range and B range correspond to the running range. Engine braking is more likely to be applied while the vehicle is running in the B range than in the D range. The driver can select any of the N range, R range, D range, and B range by moving the shift lever 104 to a predetermined position (see FIG. 4). Also, the driver can select the P range by stopping the vehicle, applying the parking brake, and pressing the P position switch 105 . When the driver selects the P range, the HVECU 62 controls the parking device 35 shown in FIG. 1 (for example, the actuator of the P pole 35b) to lock the ring gear R. Note that the shift change method is not limited to the lever method and the push button method described above, and may be arbitrarily selected.

The air conditioner 106 includes a suction port, a filter, an air conditioning fan, an evaporator, an air mix door, a heater core, and an air outlet (all not shown). The number and installation location of the outlets are arbitrary, and may be provided near each seat in the passenger compartment, for example. Air taken into the air conditioner 106 from the suction port passes through a filter, and the filter removes foreign substances in the air. The air conditioning fan is controlled by the HVECU 62 and configured to blow filtered air toward each outlet. The air sent out by the air-conditioning fan is air-conditioned by the evaporator and the heater core, and then blown into the passenger compartment through the air outlet.

An evaporator is a heat exchanger for cooling and is configured to cool and dehumidify the air supplied. The heater core is a heat exchanger for heating the engine cooling water as a heat source, and is configured to heat the supplied air. The air mix door is a movable door provided in front of the heater core and controlled by the HVECU 62 . The air mix door is configured to be able to change the air distribution ratio to the heater core (that is, the ratio of air passing through the heater core).

The air outlets provided in the air conditioner 106 include, for example, a first air outlet for blowing air toward the upper body of the occupant, a second air outlet for blowing air toward the feet of the occupant, and a windshield (not shown) of the vehicle. ), and a third outlet for blowing air toward the inner surface. The air conditioner 106 has a door that adjusts the opening of each air outlet, and each door is controlled by the HVECU 62 to adjust the amount of air blown out from each air outlet. The HVECU 62 is configured to switch the operating modes of the air conditioner 106 (eg, cooling mode, heating mode, and defroster mode) automatically depending on the situation or by user's instruction. In the defroster mode, the degree of opening of the third outlet is increased, and the air warmed by the heater core is blown out from the third outlet. As a result, dry air is supplied from the third outlet to the inner surface of the windshield, and fogging of the windshield is suppressed.

The HVECU 62 further includes an interface 62 d for a DLC (Data Link Connector) 91 . The DLC 91 is a connector that can be connected to each of the connector 92a of the first external tool 92 and the connector 93a of the second external tool 93, and is arranged around the driver's seat of the vehicle, for example. Each of the first external tool 92 and the second external tool 93 is, for example, an external diagnostic device used by a mechanic in a maintenance shop to ascertain the state of the vehicle. The first external tool 92 is configured to perform a check (compression check) as to whether or not the compression operation of the connected vehicle engine (for example, the engine 13 shown in FIG. 2) is normally performed. The second external tool 93 is configured to perform an intake pressure test (pressure test) of a connected vehicle engine (eg, engine 13 shown in FIG. 2). Hereinafter, each of the first external tool 92 and the second external tool 93 will simply be referred to as an "external tool", unless otherwise specified.

By connecting the connector of the external tool to the DLC 91, the diagnostic data accumulated in the storage device 62c can be transferred to the external tool, and the engine 13 can be inspected by processing the external tool (for example, executing a program in the external tool). It becomes possible to The diagnostic data includes, for example, DTC (Diagnostic Trouble Code), freeze frame data, and readiness code.

Details of the compression check and pressure inspection will be described later. In this embodiment, the compression check and pressure test are performed by different external tools (first external tool 92 and second external tool 93), but the compression check and pressure test are performed by a common external tool. good too.

FIG. 5 is a flow chart showing the procedure for determining the control amount of the hybrid vehicle drive system 10 according to this embodiment. The processing shown in this flowchart is called from a main routine (not shown) at predetermined intervals and repeatedly executed.

Referring to FIG. 5 together with FIG. 3, HVECU 62, in step (hereinafter simply referred to as "S") 101, outputs information indicating the state of the vehicle (for example, accelerator operation amount, currently selected shift range, and vehicle speed). to get Subsequently, in S102, the HVECU 62 acquires the required driving force corresponding to the state of the vehicle. When acquiring the required driving force, the HVECU 62 may refer to information indicating the relationship between the vehicle state and the required driving force (hereinafter also referred to as "driving force acquisition information"). The driving force acquisition information may be a map indicating the relationship between the accelerator operation amount and the vehicle speed, which is prepared in advance for each shift range.

In S103, the HVECU 62 multiplies the required driving force obtained in S102 by the vehicle speed, and further adds a predetermined power loss to calculate the running power of the vehicle. In S104, the HVECU 62 executes a series of processes for determining whether to execute forced charging (hereinafter also referred to as "forced charging execution determination"). Forced charging is charging of battery 18 that is forcibly performed when the amount of charge (for example, SOC) of battery 18 falls below a predetermined amount. In forced charging, the engine 13 is put into an operating state, and electric power generated by the MG 14 using the power of the engine 13 is supplied to the battery 18 .

FIG. 6 is a flow chart showing an example of forced charging execution determination. Referring to FIG. 6 together with FIG. 3, in S11, the HVECU 62 determines whether the SOC of the battery 18 is equal to or less than a predetermined threshold value Th1. The threshold Th1 can be set arbitrarily, and may be an SOC value selected from 50% to 65%, for example.

When the SOC of battery 18 exceeds threshold Th1 (NO in S11), HVECU 62 determines that forced charging is not to be executed. The HVECU 62 then determines the discharge amount of the battery 18 in S13. For example, the HVECU 62 increases the amount of discharge as the SOC of the battery 18 increases.

When the SOC of battery 18 is equal to or lower than threshold Th1 (YES in S11), HVECU 62 determines that forced charging is to be executed. Then, in S121, the HVECU 62 determines the upper limit value of the charge amount (hereinafter also referred to as "charge upper limit value") with reference to the charge upper limit map described below.

FIG. 7 is a diagram showing an example of a charge upper limit map. In FIG. 7, line L1 indicates the minimum guaranteed charging amount for completing forced charging. A line L2 indicates a charge upper limit map employed in the hybrid vehicle according to this embodiment. The charge upper limit map is information indicating the relationship between the vehicle speed and the charge upper limit value of the battery 18, and is stored in advance in the storage device 62c (FIG. 4), for example.

Referring to FIG. 7 together with FIG. 6, HVECU 62, in S121 of FIG. 6, determines the charge upper limit according to the charge upper limit map indicated by line L2 in FIG. Specifically, when the vehicle speed exceeds the predetermined threshold value Th2, the HVECU 62 determines the unrestricted charge amount Pchg as the charge upper limit value. On the other hand, when the vehicle speed is equal to or lower than the threshold Th2, the HVECU 62 determines the charge amount indicated by the line L2 (that is, the charge amount smaller than the charge amount Pchg) as the charge upper limit value. As described above, when the vehicle speed is equal to or lower than the threshold Th2, the forced charging amount is limited by the limit amount ΔPchg shown in FIG. 7 compared to when the vehicle speed exceeds the threshold Th2. Note that the threshold Th2 can be arbitrarily set, and may be a speed selected from, for example, 10 km/h to 40 km/h.

Referring to FIG. 6 again, in S122, the HVECU 62 determines the charge amount of the battery 18 so as not to exceed the charge upper limit value determined in S121. For example, the HVECU 62 increases the amount of charge as the SOC of the battery 18 decreases, within a range not exceeding the charge upper limit.

As described above, in the hybrid vehicle according to this embodiment, HVECU 62 is configured to forcibly charge battery 18 with the output power of engine 13 when the SOC of battery 18 falls below threshold Th1. Further, the HVECU 62 is configured to limit the amount of charge in forced charging when the vehicle speed is below the threshold Th2 more than when the vehicle speed exceeds the threshold Th2. The HVECU 62 is configured to limit the amount of charge using the charge upper limit. The HVECU 62 is configured to set the charging upper limit when the vehicle speed is below the threshold Th2 to be smaller than the charging upper limit when the vehicle speed exceeds the threshold Th2 (see line L2 in FIG. 7). The HVECU 62 is configured to decrease the charge upper limit as the vehicle speed decreases.

With the above configuration, when the vehicle is traveling at low speed (and/or when the vehicle is stopped), the engine load is reduced, and the NV characteristics of the vehicle are improved. Specifically, vehicle muffled noise, floor vibration, and steering vibration are suppressed. Deterioration of NV characteristics tends to make the driver feel uncomfortable, especially when the vehicle is stopped, so by setting the threshold Th2 to 0 km/h, forced charging may be performed only when the vehicle is stopped. If forced charging is executed during quiet EV travel, the driver is particularly likely to feel uncomfortable, so the charge upper limit during EV travel may be made smaller than the charge upper limit during HV travel.

In this embodiment, when the SOC of the battery 18 matches the threshold value Th1 in S11 of FIG. ) can be changed to In this embodiment, when the vehicle speed matches the threshold Th2, the forced charge amount is limited (that is, the forced charge amount is smaller than the charge amount Pchg). It may be changed so that the forced charge amount is limited when the vehicle speed is less than the threshold value Th2 without limiting the charge amount.

The charge amount or discharge amount required for the battery 18 (hereinafter also referred to as "required charge/discharge amount") is determined by performing either one of the processes of S13 and S122 of FIG. After that, the process proceeds to S105 in FIG. Referring to FIG. 5 again, in S105, the HVECU 62 adds the required charging/discharging amount (positive value on the charging side) to the running power calculated in S103 to calculate the system power of the vehicle.

In S106, the HVECU 62 determines whether the engine 13 is activated/stopped. For example, when the running power is greater than a predetermined threshold value, the HVECU 62 determines to operate the engine 13 . The HVECU 62 also determines that the engine 13 is to be operated when the required charge/discharge amount is a positive value (that is, when forced charging is to be performed). The HVECU 62 also determines that the engine 13 should be operated when either the R flag or the S flag (see FIG. 11), which will be described later, is ON. On the other hand, the HVECU 62 stops the engine 13 when the running power is equal to or less than the threshold and when various controls involving the operation of the engine 13 (for example, forced charging control, racing control, and stall start control) are not executed. make a judgment. The HVECU 62 also determines that the engine 13 should be stopped when both the brake pedal and the accelerator pedal (not shown) are depressed when the shift range is the driving range.

When the HVECU 62 determines that the engine 13 should be operated, the vehicle travels to HV travel. In HV running, the processes from S107 onward are executed, and the engine 13 is put into an operating state. On the other hand, when the HVECU 62 determines that the engine 13 should be stopped, the vehicle travels to EV travel. In EV running, a motor torque calculation process (not shown) is executed to calculate the torque of the MG 15 based on the required driving force.

In S107, the HVECU 62 calculates the required engine power (hereinafter also referred to as "request Pe") from the system power calculated in S105. The demand Pe corresponds to the power required of the engine 13 to achieve the system power required for the vehicle. The HVECU 62 can obtain the demand Pe by performing predetermined arithmetic processing on the system power.

In S108, the HVECU 62 executes a series of processes for adjusting the output of the engine 13 (hereinafter also referred to as "engine output adjustment").

FIG. 8 is a flowchart showing an example of engine output adjustment. Referring to FIG. 8 together with FIG. 3, in S21, the HVECU 62 determines whether or not the engine cooling water temperature (that is, the cooling water temperature of the engine 13) is equal to or higher than a predetermined threshold Th3. The engine coolant temperature is detected by an engine coolant temperature sensor 79, for example.

If it is determined in S21 that the engine coolant temperature is less than the threshold Th3 (NO), the process proceeds to S222 without going through S221. In this case, in S222, the HVECU 62 directly determines the requested Pe (S107 in FIG. 5) as the target engine power (hereinafter also referred to as "target Pe").

On the other hand, when it is determined in S21 that the engine coolant temperature is equal to or higher than the threshold Th3 (YES), the HVECU 62 determines the upper limit value of the target Pe (hereinafter also referred to as "Pe upper limit value") in S221. The output of the engine 13 is restricted by the Pe upper limit. The Pe upper limit value is calculated, for example, based on the engine cooling water temperature and the degree of increase in the engine cooling water temperature (that is, the amount of increase in the engine cooling water temperature per unit time). The HVECU 62 decreases the Pe upper limit as the engine cooling water temperature increases. Further, when the degree of increase in the engine coolant temperature is greater than the predetermined value, the HVECU 62 determines the Pe upper limit so as to limit the degree of increase in the engine coolant temperature. Then, in S222, the HVECU 62 compares the Pe upper limit and the demand Pe (S107 in FIG. 5), and if the demand Pe is equal to or less than the Pe upper limit, the HVECU 62 determines the demand Pe as the target Pe. If the Pe upper limit is exceeded, the Pe upper limit is determined as the target Pe.

As described above, the HVECU 62 according to this embodiment is configured to limit the power output from the engine 13 when the cooling water temperature of the engine 13 reaches or exceeds the threshold Th3 (YES in S21). In such a configuration, when the engine cooling water temperature becomes equal to or higher than the threshold Th3, the output power of the engine 13 is restricted, so that the temperature of the engine 13 can be quickly lowered, which in turn prevents overheating of the engine 13. can be suppressed.

The HVECU 62 is configured to limit the engine output as described above, and the engine ECU 64 is configured to perform ignition retardation control of the engine 13 based on the output of at least one of the engine cooling water temperature sensor 79 and the knock sensor. good too. With such a configuration, overheating of the engine 13 can be suppressed more reliably.

In S23, the HVECU 62 obtains an engine operating point (hereinafter also referred to as "recommended operating point") following the recommended operating line based on the target Pe determined in S222. The recommended operating point corresponds to the intersection of the target Pe and the recommended operating line on the coordinate plane of the engine rotation speed and the engine torque (hereinafter also referred to as "Te-Ne coordinate plane"). In this embodiment, the optimum fuel consumption line is adopted as the recommended operation line. The optimal fuel consumption line is a line connecting engine operating points at which fuel consumption is optimal on the Te-Ne coordinate plane.

In S24, the HVECU 62 determines whether or not the Ne increase restriction is relaxed. In the hybrid vehicle according to this embodiment, the HVECU 62 limits the increase in Ne (that is, limits the increase in the rotational speed of the engine 13). More specifically, the HVECU 62 controls the engine 13 so that the engine rotation speed does not exceed the Ne upper limit. However, the HVECU 62 is configured to relax the Ne increase limit when a predetermined condition is satisfied. A restriction relaxation flag indicating whether or not the Ne increase restriction is relaxed is prepared in advance in the storage device 62c (FIG. 4). In this embodiment, the restriction relaxation flag (initial value is OFF) is set to ON (relaxed) in S441 of FIG. 12, which will be described later. The Ne upper limit is set in S241 and S242 described below and stored in the storage device 62c (FIG. 4).

When the restriction relaxation flag is OFF (no relaxation) (NO in S24), the HVECU 62 sets the Ne upper limit value to NE1 in S241. On the other hand, if the restriction relaxation flag is ON (relaxed) (YES in S24), the HVECU 62 sets the Ne upper limit value to NE2, which is larger than NE1, in S242. NE1 and NE2 can be arbitrarily set within a range in which NE2 is greater than NE1.

In S25, when the HVECU 62 sets the engine rotation speed (S23) of the recommended operating point to the target engine rotation speed (hereinafter also referred to as "target Ne"), the engine rotation speed exceeds the Ne upper limit (S241, S242). or not. Whether or not the engine rotation speed exceeds the Ne upper limit is determined based on the engine rotation speed and the degree of increase in the engine rotation speed (that is, the acceleration of the engine 13). Overshoot in engine control is also considered in this determination. The greater the acceleration of the engine 13, the more likely it is that overshoot (that is, exceeding the target Ne) will occur. The rotational speed and acceleration of engine 13 are detected by crank angle sensor 70, for example.

If it is determined in S25 that the engine speed does not exceed the Ne upper limit (NO), the process proceeds to S262 without going through S261. In this case, the HVECU 62 determines the engine rotation speed at the recommended operating point (hereinafter also referred to as "recommended Ne") as the target Ne in S262.

On the other hand, if it is determined in S25 that the engine rotation speed exceeds the Ne upper limit value (YES), the HVECU 62, in S261, sets a correction coefficient for limiting the increase in the engine rotation speed (hereinafter referred to as "Ne correction coefficient"). ) is determined. The Ne correction coefficient is a correction coefficient that reduces the correction target (recommended Ne here). Calculated based on acceleration. The smaller the Ne margin and the higher the acceleration of the engine 13, the more likely the engine rotation speed exceeds the Ne upper limit. The degree of correction of the Ne correction coefficient (that is, the degree of reducing the correction target) is determined so as not to exceed the value. Then, in S262, the HVECU 62 determines the engine rotation speed obtained by correcting the recommended Ne using the Ne correction coefficient (hereinafter also referred to as "limit Ne") as the target Ne. The limit Ne corresponds to a target Ne corrected so that the rotation speed of the engine 13 does not exceed the Ne upper limit, and is an engine rotation speed lower than the recommended Ne.

The smaller the Ne upper limit value, the more likely it will be determined as YES in S25, and the more likely it will be that the engine rotation speed will be limited in S261. That is, setting a large value (NE2) as the Ne upper limit value in S242 relaxes the limit on the increase in Ne as compared to the case where a small value (NE1) is set as the Ne upper limit value in S241.

In S27, the HVECU 62 determines whether or not it is possible to control the output power of the engine 13 to the target Pe determined in S222 without the engine rotation speed exceeding the Ne upper limit. The target Pe according to this embodiment corresponds to an example of the "target power" according to the present disclosure.

If it is determined that the target Pe can be output from the engine 13 without the engine rotation speed exceeding the Ne upper limit (YES in S27), the process proceeds to S109 in FIG. 5 without going through S28.

On the other hand, if it is determined that the target Pe cannot be output from the engine 13 without the engine rotation speed exceeding the Ne upper limit value (NO in S27), the HVECU 62 adjusts the intake timing by the VVT mechanism 400 in S28. advances the angle. As a result, the intake valve of each cylinder (including the intake valve 431 of the cylinder 40 shown in FIG. 2) in the engine 13 closes early (for example, at a timing close to the Otto cycle), and the torque output from the engine 13 increases. growing. That is, in S28, the intake timing of the engine 13 is changed so that the torque of the engine 13 increases. The degree of advance in S28 may be a fixed value, or may be variable according to the target Ne and target Pe. After the process of S28, the process proceeds to S109 of FIG.

The intake/exhaust timing change control (hereinafter also referred to as "VVT control") executed in S28 of FIG. 8 will be described below with reference to FIGS. 9 and 10. FIG. VVT control is control that changes at least one of the intake timing and the exhaust timing of the engine 13 so that the torque of the engine 13 increases.

FIG. 9 is a diagram showing an example of the operation of the vehicle when VVT control is executed. Referring to FIG. 9, in this example, at timing t1, the accelerator pedal (not shown) is depressed by the driver and the accelerator operation amount (Ac) becomes a large value (for example, accelerator opening 70%). After that, the driver continues to depress the accelerator pedal (that is, the accelerator operation amount is maintained at a large value), so that each of the engine rotation speed (Ne) and the target Pe increases.

When both the engine rotation speed and the target Pe increase and the target Pe reaches the threshold value Th41 at timing t2, it is determined NO in S27 of FIG. More specifically, in S27 of FIG. 8, the target Pe is output from the engine 13 under normal engine control (in this embodiment, engine control based on a high expansion ratio cycle) without the engine rotation speed exceeding the Ne upper limit. It is judged that it cannot be done. Then, in S28 of FIG. 8, VVT control (in this embodiment, control for advancing the intake timing) is executed. There is a time lag between when the VVT control is executed and when the torque output from the engine 13 increases. In the example of FIG. 9, the torque output from the engine 13 increases at timing t3. The threshold Th41 is desirably set in consideration of such a time lag. The threshold Th41 may be a fixed value, or may be variable according to the engine speed. In the example of FIG. 9, VVT control is executed before the engine speed reaches the Ne upper limit.

FIG. 10 is a diagram for explaining how the engine operating point changes in the example of FIG. In FIG. 10, line L11 indicates the optimum fuel efficiency line. A line L12 indicates the relationship between the engine rotation speed (Ne) and the engine torque (Te) when the VVT control is being executed. A line Lt2 indicates an equal power line corresponding to the target Pe at timing t2 in FIG. 9, and a line Lt3 indicates an equal power line corresponding to the target Pe at timing t3 in FIG.

9 and 10, the rotation speed of engine 13 increases to the Ne upper limit value during period t1 to t4 in FIG. At this time, the operating point of the engine 13 changes as indicated by an arrow L10 in FIG.

Referring to FIG. 9 again, in this example, the accelerator is turned off by the driver at timing t5, and the accelerator operation amount becomes zero. As a result, each of the engine rotation speed (Ne) and the target Pe decreases.

When the target Pe falls below the threshold Th42 at timing t6, it is determined YES in S27 of FIG. As a result, the VVT control (S28 in FIG. 8) is no longer executed. The threshold Th42 is a value smaller than the threshold Th41. In order to suppress repetition (hunting) of ON (execution)/OFF (non-execution) of VVT control, threshold values Th41 and Th42 are provided with hysteresis.

As described above, in the hybrid vehicle according to this embodiment, the HVECU 62 determines whether or not the target Pe can be output from the engine 13 without the engine speed exceeding the Ne upper limit (S27 in FIG. 8), When it is determined that the target Pe cannot be output from the engine 13 (NO in S27 of FIG. 8), the VVT mechanism 400 (variable valve timing mechanism) controls the intake and exhaust of the engine 13 so that the torque of the engine 13 increases. Configured to change timing. Such a change in the intake/exhaust timing (that is, the VVT control described above) makes the engine torque at the same engine rotation speed larger than in normal times (for example, during steady HV running). According to the HVECU 62, in a situation where strong acceleration is required (for example, when overtaking or when merging on a highway), the output power of the engine 13 is adjusted to the target Pe while maintaining the engine speed below the Ne upper limit. can be brought closer. Note that the HVECU 62 may be configured to increase the torque of the engine 13 by changing the exhaust timing of the engine 13 in addition to or instead of the intake timing of the engine 13 in the VVT control.

In this embodiment, the target Pe is set to a threshold value (i.e., threshold value Th41) that determines the timing for executing VVT control. engine torque).

As described above, in this embodiment, the demand Pe is calculated in S107 of FIG. 5, and the target Ne and target Pe are determined by the process of FIG. Further, in this embodiment, the HVECU 62 is configured to determine the output power of the engine 13 using the accelerator operation amount, the SOC of the battery 18, and the cooling water temperature of the engine 13 (S101 to S105 in FIG. 5). , S107, and S21, S221, and S222 in FIG. 8).

The target Ne and the target Pe correspond to engine operating state commands for the engine 13, and are transmitted from the HVECU 62 to the engine ECU 64 (FIG. 3). The engine ECU 64 controls the engine 13 so that the rotational speed and output power of the engine 13 approach the target Ne and the target Pe, respectively. The engine ECU 64 may be configured to cut fuel from the injector 46 when it is determined that the engine speed exceeds the Ne upper limit value. According to such a configuration, it becomes possible to more reliably prevent the engine rotation speed from exceeding the Ne upper limit.

Again referring to FIG. 5 together with FIG. 3, in S109, the HVECU 62 calculates the torque of the MG 14 (hereinafter also referred to as "Tg") using the target Ne. The torque (that is, Tg) generated by the MG 14 is calculated so that the rotational speed of the engine 13 becomes the target Ne. The HVECU 62 can obtain Tg from the target Ne, for example, according to a mathematical formula including the planetary gear ratio ρ of the planetary gear mechanism 20 (FIG. 1). Tg corresponds to a torque command for the MG 14 and is transmitted from the HVECU 62 to the MGECU 63 .

In S110, the HVECU 62 calculates engine direct torque (hereinafter also referred to as "Tep") using Tg. Tep corresponds to torque output from the planetary gear mechanism 20 (FIG. 1). When the engine torque is input to the carrier C of the planetary gear mechanism 20, the ring gear R of the planetary gear mechanism 20 outputs engine direct torque (Tep). The HVECU 62 can obtain Tep from Tg, for example, according to a mathematical formula including the planetary gear ratio ρ of the planetary gear mechanism 20 .

At S111, the HVECU 62 calculates the torque of the MG 15 (hereinafter also referred to as "Tm") using the required driving force obtained at S102 and Tep calculated at S110. The torque (that is, Tm) generated by the MG 15 is calculated so that the required driving force is output to the drive wheels 24 (FIG. 1). The HVECU 62 calculates Tm, for example, by subtracting Tep from the required driving force. Tm corresponds to a torque command for the MG 15 and is transmitted from the HVECU 62 to the MGECU 63 .

FIG. 11 is a flow chart showing processing executed while the hybrid vehicle according to this embodiment is stopped. The processing shown in this flowchart is called from a main routine (not shown) at predetermined intervals and repeatedly executed. The R flag and S flag used in the processing of FIG. 11 are prepared in advance in the storage device 62c. The R flag indicates execution (ON)/non-execution (OFF) of racing control, and the S flag indicates execution (ON)/non-execution (OFF) of stall start control.

Referring to FIG. 11, in S31, HVECU 62 determines whether or not the R flag is ON. If the R flag is ON (YES in S31), the HVECU 62 executes racing control in S32. While the R flag is ON, the racing control (S32) is continuously executed. The details of the R flag setting and racing control processing will be described below with reference to FIGS. 12 to 14. FIG.

FIG. 12 is a flow chart showing a series of processes related to determination of whether or not to execute racing control (racing determination). The processing in FIG. 12 is repeatedly executed in parallel with the processing in FIG.

Referring to FIG. 12, in S41, HVECU 62 determines whether the shift range is the P range (parking range). HVECU 62 can determine whether the shift range is the P range, for example, based on a shift range signal transmitted from P position switch 105 (FIG. 4). If the shift range is the P range (YES in S41), the HVECU 62 sets the first threshold value and the second threshold value in S42, S421 and S422 described below.

At S42, the HVECU 62 determines whether or not the R flag is ON. If the R flag is ON (YES in S42), the HVECU 62 sets y3 and y1 as the first and second threshold values, respectively, in S421. On the other hand, if the R flag is OFF (NO in S42), the HVECU 62 sets y4 and y2 as the first and second threshold values, respectively, in S422. Note that y1, y2, y3, and y4 are numerical values indicating the amount of accelerator operation, and have a magnitude relationship in the order of y1, y2, y3, and y4 (for example, see FIG. 14 described later).

Through the processes of S42, S421, and S422, different values are set to the first threshold value and the second threshold value depending on whether the R flag is ON or OFF. By providing hysteresis to each of the first threshold and the second threshold in this way, repetition (hunting) of ON (execution)/OFF (non-execution) of the racing control is suppressed.

In S43, the HVECU 62 determines whether or not the amount of accelerator operation by the driver is greater than or equal to the first threshold. The accelerator operation amount by the driver is detected by an accelerator sensor 66 (FIG. 3). If the accelerator operation amount is greater than or equal to the first threshold value (YES in S43), the HVECU 62 sets the aforementioned restriction relaxation flag to ON in S441. As a result, YES (relaxed) is determined in S24 of FIG. 8, and the Ne increase limit is relaxed by the process of S242 of FIG. After the process of S441, the HVECU 62 sets the R flag to ON in S45. As a result, the racing control (S32 in FIG. 11) is executed with the Ne increase limit relaxed.

If the accelerator operation amount is less than the first threshold value (NO in S43), the HVECU 62 sets the restriction relaxation flag to OFF in S442. As a result, NO (no relief) is determined in S24 of FIG. 8, and normal Ne increase limitation is performed by the processing of S241 of FIG. After the processing of S442, the HVECU 62 determines in S46 whether or not the amount of accelerator operation by the driver is equal to or greater than the second threshold. If the accelerator operation amount is greater than or equal to the second threshold (YES in S46), the HVECU 62 sets the R flag to ON in S45. As a result, the racing control (S32 in FIG. 11) is executed while the normal Ne increase is restricted. On the other hand, if the accelerator operation amount is less than the second threshold (NO in S46), the HVECU 62 sets the R flag to OFF in S47. As a result, racing control is no longer executed.

When it is determined that the shift range is not the P range (NO) in S41, the HVECU 62 sets the restriction relaxation flag to OFF in S443, and then sets the R flag to OFF in S47. As a result, racing control is no longer executed.

If the R flag is set in either S45 or S47 of FIG. 12, the process returns to the main routine.

During the execution of the racing control, racing of the engine 13 is permitted, and racing of the engine 13 is executed by the driver's accelerator operation. FIG. 13 is a nomographic chart showing an example of the relationship between the rotational speeds of the sun gear S, carrier C, and ring gear R of the planetary gear mechanism 20 during racing. Referring to FIG. 13 together with FIG. 1, since the racing control is performed in the P range, the P pole 35b (FIG. 1) is locked and the rotational speed of the ring gear R becomes zero during racing. In racing control, the HVECU 62 adjusts the rotation speed of the engine 13 by activating the engine 13 and increasing or decreasing the output of the engine 13 according to the amount of accelerator operation. In racing control, the HVECU 62 increases the rotation speed of the engine 13 (and thus the rotation speed of the carrier C) within a range not exceeding the Ne upper limit when the accelerator operation amount increases. During racing, the rotation speed of the engine 13 becomes a value corresponding to the amount of accelerator operation. The driver can perform racing by operating the accelerator during parking. Since the engine 13 and the MG 14 are connected via the planetary gear mechanism 20 (FIG. 1), as the rotational speed of the engine 13 increases, the rotational speed of the MG 14 (and thus the rotational speed of the sun gear S) also increases.

FIG. 14 is a diagram showing the relationship between the engine rotation speed and the accelerator operation amount in racing control. Referring to FIG. 14, when the accelerator operation amount is small and racing control is not being executed (R flag=OFF), the engine rotation speed is 0 (engine stopped). When the accelerator operation amount becomes equal to or greater than y2 (for example, accelerator opening of 15%) and less than y4 (for example, accelerator opening of 50%) while racing control is not being executed, the R flag is turned ON and racing is executed. be. As a result, the rotational speed of the engine 13 increases to NE3 (for example, 1500 rpm), which is lower than NE1 (S241 in FIG. 8). NE1 is, for example, 2500 rpm. When the accelerator operation amount becomes y4 or more while the racing control is not executed, the restriction relaxation flag and the R flag are turned ON, and the racing is executed with the Ne increase restriction relaxed. As a result, the rotation speed of the engine 13 increases to NE2 (S242 in FIG. 8), which is higher than NE1. NE2 is, for example, 3500 rpm.

When the accelerator operation amount becomes less than y3 (for example, accelerator opening 45%) from the state where the accelerator operation amount is y4 or more, the restriction relaxation flag is turned OFF, and the accelerator operation amount becomes y1 (for example, accelerator opening 10%). ), the R flag is further turned OFF.

As described above, in the hybrid vehicle according to this embodiment, the HVECU 62 is configured to limit the increase in the rotation speed of the engine 13 by executing the above-described Ne increase limit. By restricting the increase in Ne, it is possible to protect the planetary gear mechanism 20 (FIG. 1) and prevent the MG 14 from over-rotating. The planetary gear mechanism 20 according to this embodiment corresponds to an example of a "rotation transmission component".

Further, when the shift range is in the P range, the HVECU 62 performs racing in a state in which the Ne increase limit is relaxed when the driver performs an accelerator operation that causes the accelerator operation amount to be equal to or greater than the first threshold value. Configured. Hereinafter, racing that is performed with the Ne increase limit relaxed is also referred to as "relaxed racing", and racing that is performed with the Ne increase limit not relaxed is also referred to as "non-mitigation racing". Racing with relief according to this embodiment is racing performed at engine rotation speed NE2 shown in FIG. 14, and corresponds to an example of "first racing" according to the present disclosure. The non-mitigation racing according to this embodiment is racing performed at the engine rotation speed NE3 shown in FIG. 14, and corresponds to an example of the "second racing" according to the present disclosure.

Relaxation of the Ne increase limit during racing makes it possible to early start up an in-vehicle device (for example, the air conditioner 106 shown in FIG. 4) that uses engine cooling water as a heat source. By activating the air conditioner 106 during racing, it is possible to heat the vehicle interior and eliminate fogging of the vehicle glass. The air conditioner 106 according to this embodiment corresponds to an example of an "ENG heat device".

When the shift range is the P range, the engine 13 does not drive the vehicle (that is, does not rotate the drive wheels 24 of the vehicle), so the engine torque is smaller than when the shift range is the drive range. Therefore, in the P range, the allowable upper limit value of the rotational speed of the planetary gear mechanism 20 is larger than in the travel range. Even if the Ne increase restriction is relaxed during racing in the P range, the planetary gear mechanism 20 can be operated within the rotational speed range that the planetary gear mechanism 20 allows.

The HVECU 62 is configured to relax the Ne increase limit by making the Ne upper limit value larger than when the shift range is the running range during execution of racing with relief. In this embodiment, the Ne upper limit value during racing with relief is NE2, and the Ne upper limit value (normal Ne upper limit value) when the shift range is the driving range is NE1 (see FIGS. 8 and 14). .

During execution of racing with relief, the HVECU 62 increases the Ne upper limit (for example, changes from NE1 to NE2) when the accelerator operation amount increases, and increases the rotational speed of the engine 13 to the Ne upper limit (NE2). (see FIG. 14). More specifically, when the shift range is in the P range and the accelerator operation amount is greater than or equal to the first threshold value (YES in S43 of FIG. 12), the HVECU 62 performs NE1 (normal Ne upper limit) is configured to execute racing with relief at an engine speed NE2 (see FIG. 14). When the accelerator operation amount is greater than or equal to the second threshold and less than the first threshold when the shift range is in the P range (NO in S43 and YES in S46 in FIG. 12), the HVECU 62 It is configured to execute racing without mitigation at an engine speed NE3 that is equal to or lower than NE1 (see FIG. 14). The HVECU 62 is configured not to execute racing when the accelerator operation amount is less than the second threshold when the shift range is in the P range (NO in S46 of FIG. 12). (See FIG. 14). Note that the second threshold is smaller than the first threshold.

According to the above configuration, it is possible for the driver to adjust the engine rotation speed during racing according to the accelerator operation amount. As the engine rotation speed during racing increases, the warm-up speed of the engine 13 increases, but the fuel consumption of the vehicle tends to deteriorate. In this embodiment, non-mitigation racing is performed with NE3 smaller than NE1, but is not so limited. No-mitigation racing may be performed at the upper Ne limit (NE1).

The engine rotation speed during racing may change continuously according to the amount of accelerator operation. FIG. 15 is a diagram showing a modified example of the racing control shown in FIG. 14. In FIG. Referring to FIG. 15, in this modification, when the accelerator operation amount becomes y11 or more, the R flag is turned ON and racing is performed. When the accelerator operation amount becomes less than y11, the R flag is turned OFF and racing is not executed. When the accelerator operation amount is y12 or less, the restriction relaxation flag is turned OFF, and the Ne upper limit becomes NE1 (normal Ne upper limit) (S241 in FIG. 8). When the accelerator operation amount exceeds y12, the restriction relaxation flag is turned ON, and the rotation speed of the engine 13 is controlled so as to match the Ne upper limit value. That is, in this modification, NE2 (S242 in FIG. 8) changes as indicated by line L20. When the accelerator operation amount is greater than y12 and equal to or less than y13, NE2 (and thus the engine rotation speed during racing) continuously changes according to the accelerator operation amount, as indicated by line L20. When the accelerator operation amount exceeds y13, NE2 (and thus the engine rotation speed during racing) becomes constant. Each of y11 to y13 can be set arbitrarily.

Referring to FIG. 11 again, when the R flag is OFF (NO in S31), HVECU 62 determines in S33 whether or not the S flag is ON. If the S flag is ON (YES in S33), the HVECU 62 executes stall start control in S34. While the S flag is ON, the stall start control (S34) is continuously executed. The processing contents of the S flag setting and the stall start control will be described below with reference to FIG. 16 .

FIG. 16 is a flow chart showing a series of processes for determining whether or not to execute stall start control (stall start determination). The processing in FIG. 16 is repeatedly executed in parallel with the processing in FIG.

Referring to FIG. 16, at S51, HVECU 62 determines whether the vehicle is stopped. HVECU 62 can determine whether or not the vehicle is stopped based on the vehicle speed detected by vehicle speed sensor 67 (FIG. 3), for example. At S52, HVECU 62 determines whether or not the driver is performing a braking operation. HVECU 62 can determine whether or not the driver is performing a braking operation based on whether or not the amount of depression of a brake pedal (not shown) is equal to or greater than a predetermined amount. At S53, the HVECU 62 determines whether the shift range is the driving range (for example, either the D range or the B range). HVECU 62 can determine whether the shift range is the driving range based on, for example, a shift range signal transmitted from shift lever 104 (FIG. 4).

If NO is determined in any of the above S51 to S53, the process is returned to the main routine. On the other hand, when all of the above S51 to S53 are determined to be YES, the HVECU 62 sets the third threshold value in S54, S541 and S542 described below.

In S54, the HVECU 62 determines whether the S flag is ON. If the S flag is OFF (NO in S54), the HVECU 62 sets y21 as the third threshold value in S541. On the other hand, if the S flag is ON (YES at S54), the HVECU 62 sets the third threshold value to y22 at S542. y21 and y22 are numerical values indicating the amount of accelerator operation, and y22 is smaller than y21.

Through the processes of S54, S541, and S542, different values are set to the third threshold depending on whether the S flag is ON or OFF. By providing hysteresis to the third threshold in this way, repetition (hunting) of ON (execution)/OFF (non-execution) of the stall start control is suppressed.

In S55, the HVECU 62 determines whether or not the accelerator operation amount by the driver is equal to or greater than the third threshold. The accelerator operation amount by the driver is detected by an accelerator sensor 66 (FIG. 3). If the accelerator operation amount is greater than or equal to the third threshold (YES in S55), the HVECU 62 sets the S flag to ON in S551. As a result, the stall start control (S34 in FIG. 11) is executed. On the other hand, if the accelerator operation amount is less than the third threshold (NO in S55), the HVECU 62 sets the S flag to OFF in S552. As a result, the stall start control is no longer executed.

If the S flag is set in either S551 or S552 of FIG. 16, the process is returned to the main routine.

In the stall start control, the HVECU 62 maintains the engine 13 in an operating state, and increases the power output from the engine 13 as the accelerator operation amount increases. This enables stall start. Stall start is a method of starting the vehicle by releasing only the brake pedal (brake release) from a state where both the brake pedal and the accelerator pedal (not shown) are depressed.

As described above, in the hybrid vehicle according to this embodiment, when the HVECU 62 is in the driving range in the shift range and the hybrid vehicle is stopped with the brake operation performed by the driver (Fig. 16 (YES in all of S51 to S53 of FIG. 16), the above-described stall start control is executed when the driver operates the accelerator so that the accelerator operation amount becomes equal to or greater than the third threshold value (YES in S55 of FIG. 16). configured as In such a hybrid vehicle, stall start control is executed in the same situation as when stall start is performed in a conveyor vehicle. Therefore, the driver can stall start the hybrid vehicle by the same operation as when stalling the conveyor vehicle.

Referring to FIG. 11 again, when the S flag is OFF (NO in S33), the HVECU 62 determines in S35 whether or not the compression check is requested. For example, when the connector 92a of the first external tool 92 is connected to the DLC 91 shown in FIG. The HVECU 62 determines YES (there is a request) in S35. If it is determined YES (request exists) in S35, the HVECU 62 shifts to the C check mode (compression check mode) in S36. The C check mode will be described below with reference to FIG.

FIG. 17 is a flow chart showing a series of processes executed by the HVECU 62 in the C check mode. When the normal mode shifts to the C check mode, the HVECU 62 stops the processes of FIG. 5 and FIG. 11 that have been executed in the normal mode, and executes the process of FIG. 17 instead.

Referring to FIG. 17, in S61, HVECU 62 determines a target value (target Ne) of the rotational speed of engine 13 and a target value of the rotational speed of MG 14 (hereinafter also referred to as "target Ng"). The target Ne can be arbitrarily set, but in this embodiment, it is determined to be about the same (eg, 250 rpm) as when the engine is started (that is, during cranking). The target Ng is uniquely determined by the planetary gear ratio ρ of the planetary gear mechanism 20 (FIG. 1) and the target Ne.

In S62, the HVECU 62 determines whether or not a predetermined prohibited item applies. Prohibited items include, for example, (A) to (F) shown below.
(A) The shift range is not P range.
(B) Either the engine 13 or the MG 14 is over-rotating.
(C) The engine 13 is rotating in reverse.
(D) It is determined that resonance occurs in the resonance determination of the torsional damper 22a (FIG. 1).
(E) The load factor of either MG14 or MG15 is higher than the allowable range.
(F) Either the voltage, current, power, or SOC of the battery 18 is lower than the allowable range.

The determination of resonance of the torsional damper 22a in (D) above is determination of whether or not resonance of the torsional damper 22a occurs. Any method can be used for determining resonance. It may be determined.

The prohibited item (F) may be enabled after a predetermined time has passed since motoring is started in S63, which will be described later.

Prohibited items are not limited to the above and can be set arbitrarily. For example, any item may be removed from (A) to (F) above. Further, in a vehicle in which the reduction gear is a transmission, the prohibition item may include a state in which the oil pump cannot operate.

If none of the prohibited items apply (NO in S62), the HVECU 62 motors the engine 13 by controlling the MG 14 in S63. HVECU 62 starts the motoring after the voltage of MG 14 is stabilized (for example, after a predetermined time has elapsed since the start of power supply from battery 18 to MG 14). If the prohibited items in S62 do not apply, the motoring continues until it is determined in S64 that the compression check has been completed. During motoring, the engine 13 is kept in a fuel cut state.

FIG. 18 is a nomographic chart showing an example of the relationship between the rotational speeds of the sun gear S, the carrier C, and the ring gear R of the planetary gear mechanism 20 during motoring in the C check mode. Referring to FIG. 18 together with FIG. 1, since motoring is performed in the P range, the rotational speed of ring gear R is 0 during motoring. The HVECU 62 keeps the opening of the throttle valve 49 (FIG. 2) constant (for example, fully open) and feedback-controls the MG 14 so that the rotation speed of the engine 13 approaches the target Ne. This feedback control controls the rotational speed of the MG 14 to the target Ng. Since the engine 13 and the MG 14 are connected via the planetary gear mechanism 20 (FIG. 1), as the rotation speed of the MG 14 (and thus the rotation speed of the sun gear S) increases, the rotation speed of the engine 13 (and thus the carrier speed) increases. C) also increases. The HVECU 62, for example, performs PI control of the MG 14, sets the P term (proportional gain) to a large value at the start of motoring, and increases the rotation speed of the MG 14 so as to quickly pass through the resonance band. When the rotation speed reaches the target Ng, the I term (integral gain) is increased to keep the rotation speed of the MG 14 at the target Ng. The HVECU 62 may be configured to cancel the torque generated in the ring gear R during motoring with the reaction torque of the MG 15 .

Referring to FIG. 17 again, the first external tool 92 (FIG. 4) performs a compression check (that is, checks whether the compression operation of the engine 13 is normally performed) during the motoring. The compression check is performed, for example, with a pressure gauge for detecting the pressure in each cylinder of the engine 13 attached. A spark plug for each cylinder may be replaced with a pressure gauge (pressure gauge for checking). The first external tool 92 detects the pressure (eg, compression pressure) in each cylinder when the output shaft 22 (FIG. 1) of the engine 13 is rotating (more specifically, during motoring). is configured to perform a compression check based on In S64, the HVECU 62 determines whether or not the compression check by the first external tool 92 has ended. When the compression check ends, the first external tool 92 transmits a signal indicating that the compression check has ended (hereinafter also referred to as “C check end signal”) to the HVECU 62 . During a period in which the HVECU 62 does not receive the C-check end signal, a determination of NO is made in S64, and the process returns to S61. When the HVECU 62 receives the C-check end signal from the first external tool 92, it determines that the compression check has ended (YES in S64), and ends the C-check mode.

If it is determined in S62 that any prohibited item applies (YES), the HVECU 62 sets the C-check prohibition flag (initial value is OFF) to ON, and then terminates the C-check mode. The C-check prohibition flag is prepared in advance in the storage device 62c (FIG. 4).

When the C check mode ends, the mode returns to the normal mode, and the processing in FIG. 5 and the processing in FIG. 11 are resumed. However, the HVECU 62 does not accept the C check request from the first external tool 92 when the C check prohibition flag is ON. That is, when the C check prohibition flag is ON, it is determined as NO (no request) in S35 of FIG. The C-check prohibition flag is kept ON (C-check prohibited) until the activation switch of the vehicle system is turned off, and is turned OFF (C-check permitted) when the vehicle system is restarted. The activation switch is a switch for activating a vehicle system, and is generally called a "power switch" or an "ignition switch."

As described above, in the hybrid vehicle according to this embodiment, the HVECU 62 is configured to be able to shift to the C check mode when the C check request is input from the first external tool 92 (FIG. 4). In the C check mode (see FIG. 17), when the first external tool 92 performs a compression check, the HVECU 62 performs motoring of the engine 13 by the MG 14 while the engine 13 is cut off fuel (see FIG. 17). S63) is configured as follows. In the C check mode, motoring rotates the output shaft 22 (FIG. 1) of the engine 13, so that the first external tool 92 can check whether the compression operation of the engine 13 is normally performed. The HVECU 62 is configured to shift to the compression check mode when a C-check request is input from the first external tool 92 and a predetermined first permission condition is satisfied. The first permission condition is satisfied when the prohibited item does not apply (NO in S62).

Referring to FIG. 11 again, if it is determined NO (no request) in S35, the HVECU 62 determines in S37 whether or not the pressure test is requested. For example, when the connector 93a of the second external tool 93 is connected to the DLC 91 shown in FIG. 4 and the pressure inspection request is input from the second external tool 93 to the HVECU 62, the HVECU 62 answers YES (requested) in S37. to decide. When the HVECU 62 does not receive the pressure inspection request, it determines NO (no request) in S37. If NO is determined in S37, the process is returned to the main routine.

If it is determined YES (required) in S37, the HVECU 62 shifts to the pressure inspection mode in S38. The pressure inspection mode will be described below with reference to FIG.

FIG. 19 is a flow chart showing a series of processes executed by the HVECU 62 in the pressure inspection mode. When the normal mode is shifted to the pressure inspection mode, the HVECU 62 stops the processes of FIG. 5 and FIG. 11 that have been executed in the normal mode, and executes the process of FIG. 19 instead.

Referring to FIG. 19, at S71, the HVECU 62 determines whether or not a predetermined cancellation condition is satisfied. The cancellation condition is met, for example, when the vehicle is not ready for inspection. The HVECU 62 determines that the vehicle state is engine cranking, engine blow-up request, evacuation running, N range selection, engine extremely low temperature (eg -10°C or below), and engine control abnormality (eg engine output command). If the value and the actual engine output do not match), it may be determined that the vehicle is not ready for inspection. The cancellation condition is also satisfied when the battery 18 cannot be forcedly charged. Examples of states in which forced charging cannot be performed include a state in which the SOC of the battery 18 is high and execution of forced charging results in overcharging, and a state in which forced charging cannot be executed due to input limitation (Win) for protecting the battery 18. be done. Note that the cancellation condition is not limited to the above and can be arbitrarily set.

If the cancellation condition is not satisfied (NO in S71), the HVECU 62 puts the engine 13 into an operating state in S72 and executes forced charging (that is, test charging). During test charging, power generated by the MG 14 using the power of the engine 13 is supplied to the battery 18 . If the cancellation condition of S71 is not satisfied, the test charging is continued until it is determined that the pressure test is finished in S73, which will be described later. During test charging, the HVECU 62 controls the engine 13 so that the power output from the engine 13 keeps the battery 18 charged at a constant charging rate. During test charging, the required charging/discharging amount of the battery 18 becomes constant, and fluctuations in the load of the engine 13 (and thus fluctuations in the intake pressure) are suppressed.

A second external tool 93 (FIG. 4) performs a pressure test (that is, whether the intake pressure is normal during engine operation) during the test charge. Such a pressure test is performed, for example, during factory inspection of the EGR system 58 (FIG. 2). The second external tool 93 detects the pressure (for example, the pressure sensor 72) in the intake manifold of the intake passage 41 (FIG. 2) detected when the engine 13 is running (more specifically, during the test charging described above). is configured to perform pressure inspection based on the detected value of In S73, the HVECU 62 determines whether or not the pressure inspection by the second external tool 93 has ended. When the pressure inspection ends, the second external tool 93 transmits a signal indicating that the pressure inspection has ended (hereinafter also referred to as a “pressure inspection end signal”) to the HVECU 62 . During a period in which the HVECU 62 does not receive the pressure inspection end signal, a determination of NO is made in S73, and the process returns to S71. When the HVECU 62 receives the pressure inspection end signal from the second external tool 93, the HVECU 62 determines that the pressure inspection has ended (YES in S73), and ends the pressure inspection mode.

If it is determined in S71 that the cancellation condition is satisfied (YES), the HVECU 62 notifies the second external tool 93 of the reason for stopping the pressure inspection in S74, and then terminates the pressure inspection mode. This aborts the pressure test. The second external tool 93 informs the user of the reason why the pressure test was stopped, for example, by display or voice.

As described above, in the hybrid vehicle according to this embodiment, the HVECU 62 is configured to be able to shift to the pressure inspection mode when the pressure inspection request is input from the second external tool 93 . In the pressure inspection mode (see FIG. 19), the HVECU 62 controls the engine 13 while the inspection is being performed by the second external tool 93 so that the power output from the engine 13 charges the battery 18 at a constant charging rate. configured to remain charged. In the pressure inspection mode, since inspection charging is performed at a constant charging rate, load fluctuations of the engine 13 are suppressed, making it easier to perform a proper pressure inspection in the second external tool 93 . The HVECU 62 is configured to shift to a pressure inspection mode when a pressure inspection request is input from the second external tool 93 and a predetermined second permission condition is satisfied. The second permission condition is met when the cancellation condition is not met (NO in S71).

Note that the contents of the various controls described above are not limited to the contents of the flowcharts. For example, in the above-described racing control, stall start control, and VVT control, it is not essential to provide the threshold with hysteresis.

The configuration of the vehicle drive device is not limited to the configuration shown in FIG. Also, the configuration of the engine is not limited to the configuration shown in FIG. 2, and can be changed as appropriate. For example, each cylinder of the engine has a fuel injection valve for in-cylinder injection (e.g., injector 46) and a fuel injection valve for injecting fuel into an intake port (i.e., fuel injection valve for port injection). You may prepare. Also, the number of cylinders and the number of valves can be changed arbitrarily.

The embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

10 drive device, 13 engine, 14, 15 MG, 16 first inverter, 17 second inverter, 18 battery, 19 PCU, 20 planetary gear mechanism, 21 output gear, 22 output shaft, 22a torsional damper, 23, 30 rotor shaft, 24 drive wheel, 25 countershaft, 26 driven gear, 27, 31 drive gear, 28 differential gear, 29 ring gear, 32, 33 drive shaft, 35 parking device, 35a parking gear, 35b P pole, 36 oil pump, 38 electric Oil pump, 40 cylinder, 41 intake passage, 42 exhaust passage, 43 intake port, 44 exhaust port, 45 ignition device, 46 injector, 49 throttle valve, 50 air flow meter, 56 start catalytic converter, 57 aftertreatment device, 58 EGR device , 59 EGR passage, 60 EGR valve, 62 HVECU, 62a processor, 62b RAM, 62c storage device, 62d interface, 63 MGECU, 64 engine ECU, 65 converter, 66 accelerator sensor, 67 vehicle speed sensor, 68 MG1 rotational speed sensor, 69 MG2 rotational speed sensor, 70 crank angle sensor, 71 cam angle sensor, 72 pressure sensor, 73 SOC sensor, 74 MG1 temperature sensor, 75 MG2 temperature sensor, 76 INV1 temperature sensor, 77 INV2 temperature sensor, 78 catalyst temperature sensor, 79 engine cooling water temperature sensor 92 first external tool 92a connector 93 second external tool 93a connector 101 input device 102 notification device 103 brake device 103a hydraulic brake device 103b P brake device 104 shift lever 105 P position switch, 106 air conditioner, 131 crankshaft, 400 VVT mechanism, 401 combustion chamber, 402 piston, 403 connecting rod, 431 intake valve, 432 intake camshaft, 433 intake cam, 441 exhaust valve, 442 exhaust camshaft, 443 Exhaust cam, C carrier, P pinion gear, R ring gear, S sun gear.

Claims (10)

an engine that generates driving force;
an electric motor that generates a running driving force;
an accelerator sensor that detects the amount of accelerator operation by the driver;
A control device that controls the engine and the electric motor,
The control device is configured to control the engine so that the rotation speed of the engine does not exceed an upper limit value , and when the shift range is in the parking range, the accelerator operation amount by the driver reaches a first threshold value. A hybrid vehicle configured to execute a first racing with the upper limit value set larger than when the shift range is in the driving range when an accelerator operation exceeding the above is performed. The control device is configured to increase the upper limit value and match the rotation speed of the engine to the upper limit value when the accelerator operation amount increases during the execution of the first racing. A hybrid vehicle according to claim 1 . The control device exceeds the upper limit value when the shift range is the driving range when the accelerator operation amount is greater than or equal to the first threshold when the shift range is the parking range. configured to perform the first racing at an engine speed;
When the accelerator operation amount is greater than or equal to the second threshold value and less than the first threshold value when the shift range is the parking range, the control device determines that the accelerator operation amount is equal to or greater than the second threshold value and less than the first threshold value. configured to execute the second racing at an engine speed equal to or lower than the upper limit;
The control device is configured not to execute racing when the accelerator operation amount is less than the second threshold when the shift range is the parking range, and
The hybrid vehicle according to claim 1 or 2 , wherein said second threshold is smaller than said first threshold. further comprising a first motor generator,
the electric motor is a second motor generator,
each of the engine and the first motor generator is mechanically coupled to drive wheels of the hybrid vehicle via planetary gears;
The planetary gear and the second motor generator are configured such that power output from the planetary gear and power output from the second motor generator are combined and transmitted to the drive wheels,
The hybrid vehicle according to any one of claims 1 to 3 , wherein the control device is configured to lock the output shaft of the planetary gear when the shift range is the parking range. The control device is configured to be able to shift to a compression check mode when a compression check request is input from a first external tool that performs a compression check to check whether the compression operation of the engine is normally performed. is,
In the compression check mode, when the first external tool performs the compression check, the control device performs motoring of the engine with the first motor generator in a state in which the fuel of the engine is cut. 5. The hybrid vehicle according to claim 4 , wherein: A power storage device configured to be chargeable with power generated using the power output from the engine,
The control device is configured to determine the output power of the engine using the accelerator operation amount, the power storage amount of the power storage device, and the cooling water temperature of the engine,
6. The hybrid vehicle according to any one of claims 1 to 5 , wherein said control device is configured to limit power output from said engine when a coolant temperature of said engine reaches or exceeds a predetermined temperature. When the hybrid vehicle is stopped in a state where the shift range is the driving range and the brake operation is performed by the driver, the accelerator operation amount by the driver becomes equal to or greater than a third threshold. configured to execute stall start control when an accelerator operation is performed;
7. The control device according to any one of claims 1 to 6 , wherein in the stall start control, the control device is configured to maintain the engine in an operating state and increase the power output from the engine as the accelerator operation amount increases. or the hybrid vehicle according to item 1. A power storage device configured to be chargeable with power generated using the power output from the engine,
The control device is configured to charge the power storage device with the output power of the engine when the power storage amount of the power storage device falls below a predetermined amount,
The control device is configured to be able to shift to a pressure inspection mode when a pressure inspection request is input from a second external tool that inspects the intake pressure of the engine,
In the pressure inspection mode, the control device controls the engine while the inspection is being performed by the second external tool, and the power output from the engine causes the power storage device to charge at a constant charging rate. A hybrid vehicle according to any one of claims 1 to 7 , configured to maintain a charged state. further comprising a variable valve timing mechanism configured to change at least one of intake timing and exhaust timing of the engine;
The control device is configured to obtain a target power of the engine using the accelerator operation amount, and limits an increase in the rotation speed of the engine so that the rotation speed of the engine does not exceed a limit value. configured as
The control device determines whether or not the target power can be output from the engine without the rotation speed of the engine exceeding the limit value, and if it is determined that the target power cannot be output from the engine, 9. The variable valve timing mechanism according to any one of claims 1 to 8 , wherein at least one of intake timing and exhaust timing of the engine is changed so as to increase torque of the engine. hybrid vehicle. A power storage device configured to be chargeable with power generated using the power output from the engine,
The control device is configured to determine the output power of the engine using the accelerator operation amount and the power storage amount of the power storage device,
The control device is configured to charge the power storage device with the output power of the engine when the power storage amount of the power storage device falls below a predetermined amount,
The control device is configured to limit the charge amount in the charging when the vehicle speed of the hybrid vehicle is less than a predetermined speed than when the vehicle speed of the hybrid vehicle exceeds the predetermined speed. 10. The hybrid vehicle according to any one of 1 to 9 .

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