Hybrid vehicle

Abstract

To suppress inconvenience such as vibration that may occur during high-speed traveling.SOLUTION: A hybrid vehicle includes: an engine in which an exhaust system is attached with a purification device having a catalyst that purifies exhaust gas; a first motor; a planetary gear mechanism in which a rotation shaft of the first motor, an output shaft of the engine, and a drive shaft coupled to a drive wheel are connected to three shafts arranged in order in an alignment chart in this order; and a second motor in which a rotation shaft is coupled to the drive shaft. A control device of the hybrid vehicle performs catalyst warming-up control of warming the catalyst of the purification device by setting a rotation speed of the engine to a predetermined engine rotation speed and retarding an ignition timing of the engine. When a vehicle speed is equal to or higher than a predetermined vehicle speed, the control device prohibits the catalyst warming-up control.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle provided with a planetary gear mechanism in which a rotating shaft of a first electric motor, an output shaft of an engine, a drive wheel, and a drive shaft connected to a second electric motor are connected in this order to three axes arranged in order on a collinear diagram.

Background Art

[0002] Conventionally, as a technology for an engine mounted on this type of hybrid vehicle, when warming up the catalyst of a purification device attached to the exhaust system of the engine, ignition is performed by an ignition plug in the expansion stroke, and fuel is injected from an in-cylinder injection valve in synchronization with the ignition in this expansion stroke. Expansion stroke injection warm-up has been proposed (see, for example, Patent Document 1). When performing such expansion stroke injection warm-up, the intake air amount and the ignition timing are adjusted so that the engine speed becomes a predetermined speed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a hybrid vehicle provided with a planetary gear mechanism in which a rotating shaft of a first electric motor, an output shaft of an engine, a drive wheel, and a drive shaft connected to a second electric motor are connected in this order to three axes arranged in order on a collinear diagram, when performing expansion stroke injection warm-up while driving at a high vehicle speed, the first electric motor may over-rotate. In response to such a problem, it is conceivable to increase the engine speed in order to reduce the rotational speed of the first electric motor. However, since the ignition is significantly retarded in the expansion stroke injection warm-up, when the engine speed is increased, the output torque from the engine may fluctuate and vibrate.

[0005] The hybrid vehicle of the present invention mainly aims to suppress inconveniences such as vibrations that may occur when driving at high vehicle speeds.

Means for Solving the Problems

[0006] The hybrid vehicle of the present invention has adopted the following means to achieve the above main object.

[0007] The hybrid vehicle of the present invention an engine with a purification device having a catalyst for purifying exhaust gas attached to an exhaust system, a first electric motor, a planetary gear mechanism in which the rotation shaft of the first electric motor, the output shaft of the engine, and a drive shaft connected to drive wheels are connected in this order to three axes arranged in order on a collinearity diagram, a second electric motor having a rotation shaft connected to the drive shaft, a power storage device capable of power exchange with the first electric motor and the second electric motor, a control device for controlling the engine, the first electric motor, and the second electric motor, A hybrid vehicle comprising: The control device executes catalyst warm-up control to set the engine speed to a predetermined engine speed and retard the ignition timing of the engine to warm up the catalyst of the purification device. The control device prohibits the catalyst warm-up control when the vehicle speed is equal to or higher than a predetermined vehicle speed. It is characterized by this.

[0008] In the hybrid vehicle of the present invention, catalyst warm-up control is executed to warm up the catalyst of the purification device by setting the engine speed to a predetermined engine speed and retarding the ignition timing of the engine. However, when the vehicle speed is equal to or higher than a predetermined vehicle speed, the catalyst warm-up control is prohibited. As a result, even if the engine speed is increased to suppress the over-rotation of the first electric motor when the vehicle speed is equal to or higher than the predetermined vehicle speed, since the catalyst warm-up control is prohibited, the vibration associated with the output torque variation caused by increasing the engine speed while the ignition timing is significantly retarded can be suppressed. That is, it is possible to suppress inconveniences such as vibrations that may occur when driving at a high vehicle speed.

[0009] In such a hybrid vehicle of the present invention, the control device may be configured to control the absolute value of the rotational speed of the first electric motor to be equal to or lower than a predetermined electric motor rotational speed when the vehicle speed is equal to or higher than the predetermined vehicle speed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0011] Next, modes for carrying out the present invention will be described using examples.

Examples

[0012] FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of the engine 22. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as HVECU) 70.

[0013] The engine 22 is configured as a six-cylinder internal combustion engine that outputs power through four strokes of intake, compression, expansion (explosive combustion), and exhaust using fuel such as gasoline or diesel fuel. As shown in FIG. 2, the engine 22 includes a port injection valve 126 that injects fuel supplied from a fuel supply device 150 through a low-pressure supply pipe 153 into an intake port, and an in-cylinder injection valve 127 that injects fuel supplied from the fuel supply device 150 through a high-pressure supply pipe 158 into the cylinder. The in-cylinder injection valve 127 is disposed substantially at the center of the top of the combustion chamber 129 and injects fuel in a spray pattern. The ignition plug 130 is disposed in the vicinity of the in-cylinder injection valve 127 so as to be able to ignite the fuel sprayed in a spray pattern from the in-cylinder injection valve 127. By having the port injection valve 126 and the in-cylinder injection valve 127, the engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode. In the port injection mode, air cleaned by the air cleaner 122 is inhaled into the intake pipe 123, passed through the throttle valve 124 and the surge tank 125, and fuel is injected from the port injection valve 126 on the downstream side of the surge tank 125 in the intake pipe 123 to mix the air and fuel. Then, this air-fuel mixture is inhaled into the combustion chamber 129 through the intake valve 128 and explosively combusted by an electric spark from the ignition plug 130 to convert the reciprocating motion of the piston 132 pushed down by the energy in the cylinder bore into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is inhaled into the combustion chamber 129 in the same manner as in the port injection mode, fuel is injected from the in-cylinder injection valve 127 during the intake stroke and the compression stroke, and explosively combusted by an electric spark from the ignition plug 130 to obtain the rotational motion of the crankshaft 23. In the common injection mode, fuel is injected from the port injection valve 126 when air is inhaled into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and the compression stroke, and explosively combusted by an electric spark from the ignition plug 130 to obtain the rotational motion of the crankshaft 23. These injection modes are switched based on the operating state of the engine 22. Exhaust discharged from the combustion chamber 129 to the exhaust pipe 134 through the exhaust valve 133 is discharged to the outside air through the purification device 135.The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust gas.

[0014] The fuel supply device 150 is configured as a device that supplies the fuel in the fuel tank 151 to the port injection valve 126 and the in-cylinder injection valve 127 of the engine 22. The fuel supply device 150 includes a fuel tank 151, a feed pump 152, a low-pressure supply pipe 153, a check valve 154, a relief pipe 155, a relief valve 156, a high-pressure pump 157, and a high-pressure supply pipe 158.

[0015] The feed pump 152 is configured as an electric pump that operates by receiving power from a battery (not shown) and is disposed in the fuel tank 151. This feed pump 152 supplies the fuel in the fuel tank 151 to the low-pressure supply pipe 153. The low-pressure supply pipe 153 is connected to the port injection valve 126. The check valve 154 is provided in the low-pressure supply pipe 153 and allows the flow of fuel in the direction from the feed pump 152 side to the port injection valve 126 side while restricting the flow of fuel in the reverse direction.

[0016] The relief pipe 155 is connected to the low-pressure supply pipe 153 and the fuel tank 151. The relief valve 156 is provided in the relief pipe 155 and closes when the fuel pressure in the low-pressure supply pipe 153 is less than the threshold value Pflolim and opens when the fuel pressure in the low-pressure supply pipe 153 is equal to or greater than the threshold value Pflolim. When the relief valve 156 opens, a part of the fuel in the low-pressure supply pipe 153 is returned to the fuel tank 151 via the relief pipe 155. In this way, an excessive increase in the fuel pressure in the low-pressure supply pipe 153 is suppressed.

[0017] The high-pressure pump 157 is configured as a pump that is driven by the power from the engine 22 (in the embodiment, the rotation of the intake camshaft that opens and closes the intake valve 128) and pressurizes the fuel in the low-pressure supply pipe 153 to supply it to the high-pressure supply pipe 158. The high-pressure pump 157 includes an electromagnetic valve 157a that is connected to its suction port and opens and closes when pressurizing the fuel, a check valve 157b that is connected to its discharge port to regulate the backflow of the fuel and maintain the fuel pressure in the high-pressure supply pipe 158, and a plunger 157c that operates (moves in the vertical direction in FIG. 1) by the rotation of the engine 22 (the rotation of the intake camshaft). During the operation of the engine 22, when the electromagnetic valve 157a is opened, the high-pressure pump 157 sucks the fuel in the low-pressure supply pipe 153, and when the electromagnetic valve 157a is closed, the fuel compressed by the plunger 157c is intermittently sent into the high-pressure supply pipe 158 through the check valve 157b, thereby pressurizing the fuel supplied to the high-pressure supply pipe 158.

[0018] The engine 22 is under operation control by the engine ECU 24. Although not shown, the engine ECU 24 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, input / output ports, and communication ports.

[0019] Various signals from various sensors necessary for controlling the operation of the engine 22 are input into the engine ECU 24 via the input ports. Examples of the signals input into the engine ECU 24 include the crank angle θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and the coolant temperature Tw from the water temperature sensor 142 that detects the temperature of the coolant of the engine 22. Also included are the cam angles θci and θco from the cam position sensor 144 that detects the rotational position of the intake camshaft that opens and closes the intake valve 128 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve 133. Further examples are the throttle opening TH from the throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air quantity Qa from the air flow meter 123a attached upstream of the throttle valve 124 in the intake pipe 123, the intake air temperature Ta from the temperature sensor 123t attached upstream of the throttle valve 124 in the intake pipe 123, and the surge pressure Ps from the pressure sensor 125a attached to the surge tank 125. Also included are the front air-fuel ratio AF1 from the front air-fuel ratio sensor 137 attached upstream of the purification device 135 in the exhaust pipe 134, and the rear air-fuel ratio AF2 from the rear air-fuel ratio sensor 138 attached between the purification device 135 and the PM filter 136 in the exhaust pipe 134. Additionally, the fuel temperature Tftnk from the fuel temperature sensor 151t attached to the fuel tank 151, the rotational speed Np of the feed pump 152 from the rotational speed sensor 152a attached to the feed pump 152, the low-pressure fuel pressure (the pressure of the fuel supplied to the port injection valve 126) PL from the fuel pressure sensor 153p attached near the port injection valve 126 in the low-pressure supply pipe 153 (for example, the low-pressure delivery pipe), and the high-pressure fuel pressure (the pressure of the fuel supplied to the in-cylinder injection valve 127) PH from the fuel pressure sensor 158p attached near the in-cylinder injection valve 127 in the high-pressure supply pipe 158 (for example, the high-pressure delivery pipe) can be mentioned.

[0020] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via the output ports. Examples of the signals output from the engine ECU 24 include a control signal to the throttle valve 124, a control signal to the port injection valve 126, a control signal to the in-cylinder injection valve 127, and a control signal to the spark plug 130. Also included are a control signal to the feed pump 152 of the fuel supply device 150 and a control signal to the electromagnetic valve 157a of the high-pressure pump 157.

[0021] The engine ECU 24 is connected to the HV ECU 70 via a communication port. The engine ECU 24 calculates the engine speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. Further, the engine ECU 24 calculates the load factor KL (the ratio of the volume of air actually inhaled in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 123a and the engine speed Ne of the engine 22.

[0022] As shown in FIG. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The drive shaft 36, which is connected to the drive wheels 39a, 39b via the differential gear 38, is connected to the ring gear of the planetary gear 30. The crankshaft 23 of the engine 22 is connected to the carrier of the planetary gear 30.

[0023] The motor MG1 is configured as a synchronous generator motor, for example. As described above, the rotor is connected to the sun gear of the planetary gear 30. The motor MG2 is configured as a synchronous generator motor, for example, and the rotor is connected to the drive shaft 36. The inverters 41 and 42 are used to drive the motors MG1 and MG2 and are connected to the battery 50 via the power line 54. The motors MG1 and MG2 are rotationally driven by the motor electronic control unit (hereinafter referred to as "motor ECU") 40 by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42.

[0024] The motor ECU 40 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port, although not shown. Signals from various sensors necessary for driving and controlling the motors MG1 and MG2 are input to the motor ECU 40 via the input port. Examples of the signals input to the motor ECU 40 include the rotational positions θm1 and θm2 from a rotational position sensor (not shown) that detects the rotational positions of the rotors of the motors MG1 and MG2, and the phase currents Iu1, Iv1, Iu2, and Iv2 from a current sensor (not shown) that detects the phase currents flowing through each phase of the motors MG1 and MG2. Switching control signals and the like to a plurality of switching elements (not shown) of the inverters 41 and 42 are output from the motor ECU 40 via the output port. The motor ECU 40 is connected to the HV ECU 70 via the communication port. The motor ECU 40 calculates the electrical angles θe1 and θe2 and the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position sensor.

[0025] The battery 50 is configured as a lithium-ion secondary battery or a nickel-metal hydride secondary battery, for example, and is connected to the inverters 41 and 42 via the power line 54 as described above. This battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52.

[0026] The battery ECU 52 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input ports. Examples of the signals input to the battery ECU 52 include the voltage Vb of the battery 50 from a voltage sensor (not shown) attached between the terminals of the battery 50, the current Ib of the battery 50 from a current sensor (not shown) attached to the output terminal of the battery 50, and the temperature Tb of the battery 50 from a temperature sensor (not shown) attached to the battery 50. The battery ECU 52 is connected to the HV ECU 70 via the communication port. The battery ECU 52 calculates the state of charge SOC of the battery 50 based on the integrated value of the current Ib of the battery 50 from the current sensor. The state of charge SOC is the ratio of the amount of electric power that can be discharged from the battery 50 to the total capacity of the battery 50.

[0027] The HV ECU 70 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Signals from various sensors are input to the HV ECU 70 via the input ports. Examples of the signals input to the HV ECU 70 include the ignition signal from the ignition switch 80 and the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Also, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed V from the vehicle speed sensor 87 can be mentioned. As described above, the HV ECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

[0028] In the hybrid vehicle 20 of the embodiment configured in this way, through the cooperative control of the HVECU 70, the engine ECU 24, and the motor ECU 40, basically, there are a hybrid driving mode (HV driving mode) in which driving is accompanied by the operation of the engine 22 and an electric driving mode (EV driving mode) in which driving is performed without the operation of the engine 22. The engine 22 is intermittently operated while switching between these modes to perform driving.

[0029] In the HV driving mode, basically, the HVECU 70 first sets the driving torque Td* required for driving (required for the drive shaft 36) based on the accelerator opening Acc and the vehicle speed V, and multiplies the set driving torque Td* by the rotational speed Nd of the drive shaft 36 (the rotational speed Nm2 of the motor MG2) to calculate the driving power Pd* required for driving. Subsequently, based on the driving power Pd* and the state of charge SOC of the battery 50, the target power Pe* of the engine 22 is set, and the target rotational speed Ne* and target torque Te* of the engine 22, and the torque commands Tm1*, Tm2* of the motors MG1, MG2 are set so that the target power Pe* is output from the engine 22 and the driving torque Td* is output to the drive shaft 36. The set target rotational speed Ne* and target torque Te* are transmitted to the engine ECU 24, and the torque commands Tm1*, Tm2* are transmitted to the motor ECU 40.

[0030] The engine ECU 24 performs driving control of the engine 22, such as intake air amount control, fuel injection control, ignition control, and opening / closing timing control, so that the engine 22 is operated based on the target rotational speed Ne* and target torque Te*. The intake air amount control is performed by controlling the opening of the throttle valve 124. The fuel injection control is performed by controlling the fuel injection amount from the port injection valve 126 and the in-cylinder injection valve 127 in the port injection mode, in-cylinder injection mode, or common injection mode. The ignition control is performed by controlling the ignition timing of the spark plug 130. The motor ECU 40 performs switching control of a plurality of switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

[0031] In the EV driving mode, the HV ECU 70 sets the driving torque Td* in the same manner as in the HV driving mode, sets the value 0 for the torque command Tm1* of the motor MG1, and sets the torque command Tm2* of the motor MG2 so that the driving torque Td* is output to the drive shaft 36, and transmits the set torque commands Tm1* and Tm2* to the motor ECU 40. The control of the inverters 41 and 42 by the motor ECU 40 has been described above.

[0032] In the HV driving mode, when the target power Pe* reaches less than the power threshold value Peref, etc., it is determined that the stop condition of the engine 22 is satisfied, the engine 22 is stopped, and the vehicle shifts to the EV driving mode. In the EV driving mode, when the target power Pe* calculated in the same manner as in the HV driving mode reaches the power threshold value (Peref + α) or more, etc., it is determined that the start condition of the engine 22 is satisfied, the engine 22 is started, and the vehicle shifts to the HV driving mode.

[0033] In the hybrid vehicle 20 of the embodiment, rapid catalyst warming is performed on the purification catalyst (three-way catalyst) 135a of the purification device 135 attached to the exhaust pipe 134 of the engine 22. The rapid catalyst warming of the purification device 135 is performed when conditions such as the catalyst temperature Tc being below a predetermined temperature lower than the activation temperature and the accelerator-off condition are satisfied. The rapid catalyst warming is performed by performing fuel injection one to three times during the intake stroke and the compression stroke, performing the final fuel injection during the expansion stroke, and igniting in synchronization with the fuel injection during this expansion stroke by expansion stroke injection.

[0034] In such rapid catalyst warm-up, the engine speed Ne of the engine 22 is set to a predetermined speed (e.g., 1300 rpm, etc.) Neset, and the ignition timing Tp is controlled to retard as much as possible. When the ignition timing Tp is retarded, the combustion efficiency decreases, so the intake air amount is increased to maintain the engine speed Ne of the engine 22. As a result, the amount of combustion gas increases, and the absolute amount of emission components also increases, but the catalyst warm-up is promoted. Note that the engine speed Ne is controlled to be the predetermined speed Neset by correcting the ignition timing and the intake air amount with a correction value based on feedback control based on the engine speed Ne of the engine 22.

[0035] In the hybrid vehicle 20 of the embodiment, when traveling at a high vehicle speed, the motor MG1 may over-rotate on the negative rotation side. In this case, in the hybrid vehicle 20 of the embodiment, control is performed to increase the rotational speed Ne of the engine 22 so that the rotational speed Nm1 of the motor MG1 does not fall below the lower limit rotational speed Nm1lim. FIG. 3 shows an example of a collinear diagram of the planetary gear 30 when traveling at a high vehicle speed. In the figure, the S axis indicates the rotational speed Ns of the sun gear of the planetary gear 30, which is the rotational speed Nm1 of the motor MG1, the C axis indicates the rotational speed Nc of the carrier 34, which is the rotational speed Ne of the engine 22, and the 32 axis indicates the rotational speed Nr of the ring gear (drive shaft 36) of the planetary gear 30, which is the rotational speed Nm2 of the motor MG2. Now, consider a state where the vehicle speed V is at a value V1 and the engine 22 is operating so that the rotational speed Ne is at the rotational speed Ne1 (the state of the solid line in FIG. 3). At this time, the rotational speed Nm1 of the motor MG1 becomes the value Ns1. If the rotational speed Ne of the engine 22 is maintained at the value Ne1 when accelerating from this state until the vehicle speed V changes from the value V1 to the value V2, as shown by the dashed-dotted line in FIG. 3, the rotational speed Nm1 of the motor MG1 falls below the lower limit rotational speed Nm1lim and becomes the value Ne2, and over-rotation occurs. For this reason, in the hybrid vehicle 20 of the embodiment, the rotational speed Ne of the engine 22 is increased to the value Ne2 so that the rotational speed Nm1 of the motor MG1 becomes the lower limit rotational speed Nm1lim, and the state shown by the broken line in FIG. 3 is set. In this way, when traveling at a high vehicle speed, by increasing the rotational speed Ne of the engine 22 so that the rotational speed Nm1 of the motor MG1 does not fall below the lower limit rotational speed Nm1lim, inconveniences (such as damage) due to over-rotation of the motor MG1 are suppressed. In the embodiment, the control to increase the rotational speed Ne of the engine 22 when traveling at such a high vehicle speed is referred to as high vehicle speed rotational speed control.

[0036] Next, the operation of permitting or not permitting rapid catalyst warm-up by the hybrid vehicle 20 of the embodiment will be described. FIG. 4 is a flowchart showing an example of a rapid catalyst warm-up permission determination process executed by the HVECU 70. This rapid catalyst warm-up permission determination process is repeatedly executed every predetermined time (for example, every several tens of msec).

[0037] When the rapid catalyst warm-up permission determination process is executed, the HVECU 70 first inputs the vehicle speed V from the vehicle speed sensor 87 (step S100), and executes a process of determining whether the input vehicle speed V is less than the threshold value Vref (step S110). When it is determined that the vehicle speed V is less than the threshold value Vref, rapid catalyst warm-up is permitted (step S120). When it is determined that the vehicle speed V is greater than or equal to the threshold value Vref, rapid catalyst warm-up is prohibited (step S130), and this process ends. FIG. 5 shows an example of a collinearity diagram of the planetary gear 30 when driving at a high vehicle speed. As the threshold value Vref, the vehicle speed (the vehicle speed Vref of the rotational speed Nrref in the state of the broken line in FIG. 5) at which the rotational speed Nm1 of the motor MG1 becomes the lower limit rotational speed Nm1lim when the rotational speed Ne of the engine 22 is set to the predetermined rotational speed Neset during rapid catalyst warm-up can be used.

[0038] Now, consider a state where the vehicle speed V is a value V3 greater than the threshold value Vref, the rotational speed Ne of the engine 22 is a value Ne3 greater than the predetermined rotational speed Neset, and the rotational speed Nm1 of the motor MG1 is the lower limit rotational speed Nm1lim (the state of the solid line in FIG. 5). When rapid catalyst warm-up is performed in this state, since the rotational speed Ne of the engine 22 is set to the predetermined rotational speed Neset smaller than the value Ne3, the state shown by the dashed-dotted line in FIG. 5 is obtained, and the rotational speed Nm1 of the motor MG1 becomes a value Ns3 smaller than the lower limit rotational speed Nm1lim (larger in absolute value), and the motor MG1 is in an over-rotation state. In the embodiment, by prohibiting rapid catalyst warm-up when the vehicle speed V is greater than or equal to the threshold value Vref, such a state of the dashed-dotted line in FIG. 5 (a state where the motor MG1 over-rotates on the negative rotation side) can be avoided.

[0039] In the hybrid vehicle 20 of the embodiment described above, when the vehicle speed V is equal to or higher than the vehicle speed (threshold value Vref) at which the rotational speed Nm1 of the motor MG1 becomes the lower limit rotational speed Nm1lim when the rotational speed Ne of the engine 22 is set to the predetermined rotational speed Neset during rapid catalyst warming-up, rapid catalyst warming-up is prohibited. As a result, it is possible to prevent the motor MG1 from over-rotating on the negative rotation side when rapid catalyst warming-up is performed when the vehicle speed V is equal to or higher than the threshold value Vref. Further, in order to avoid over-rotation of the motor MG1 due to rapid catalyst warming-up when the vehicle speed V is equal to or higher than the threshold value Vref, it is possible to avoid control (high vehicle speed rotational speed control) for increasing the rotational speed Ne of the engine 22 during rapid catalyst warming-up from the predetermined rotational speed Neset. As a result, it is possible to suppress vibrations associated with fluctuations in output torque caused by increasing the rotational speed of the engine while significantly retarding the ignition timing during rapid catalyst warming-up. That is, it is possible to suppress inconveniences such as vibrations that may occur when driving at a high vehicle speed.

[0040] In the hybrid vehicle 20 of the embodiment, as rapid catalyst warming-up, the rotational speed Ne of the engine 22 is set to the predetermined rotational speed Neset, fuel injection is performed one to three times during the intake stroke and the compression stroke, the final fuel injection is performed during the expansion stroke, and ignition is performed in synchronization with the fuel injection during this expansion stroke by expansion stroke injection. However, as rapid catalyst warming-up, as long as the catalyst 135a is warmed up by retarding the ignition timing with the rotational speed Ne of the engine 22 set to the predetermined rotational speed Neset, the fuel injection timing for combustion injection may be set to any timing.

[0041] In the hybrid vehicle 20 of the embodiment, the in-cylinder injection valve 127 is arranged substantially at the center of the top of the combustion chamber 129, and the spark plug 130 is arranged in the vicinity of the in-cylinder injection valve 127. However, the in-cylinder injection valve 127 may be arranged on the side of the combustion chamber 129, and the spark plug 130 may be arranged at the center of the top of the combustion chamber 129.

[0042] In the hybrid vehicle 20 of the embodiment, the rotating shaft of the motor MG2 is directly connected to the drive shaft 36. However, the rotating shaft of the motor MG2 may be connected to the drive shaft 36 via a reduction gear.

[0043] In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, the battery ECU 52, and the HV ECU 70 are provided. However, at least two of these may be integrally configured.

[0044] The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the "engine", the purification device 135 corresponds to the "purification device", the motor MG1 corresponds to the "first electric motor", the planetary gear 30 corresponds to the "planetary gear mechanism", the motor MG2 corresponds to the "second electric motor", the battery 50 corresponds to the "power storage device", and the engine ECU 24, the motor ECU 40, the battery ECU 52, and the HV ECU 70 correspond to the "control device".

[0045] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the form for implementing the invention described in the column of means for solving the problems in the embodiment. Therefore, it does not limit the elements of the invention described in the column of means for solving the problems. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the column of means for solving the problems.

[0046] As described above, the embodiments for implementing the present invention have been described using examples. However, the present invention is not limited to such examples, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Industrial Applicability

[0047] The present invention can be used in the manufacturing industry of hybrid vehicles and the like.

Explanation of Signs

[0048] 20 Hybrid vehicle, 22 Engine, 23 Crankshaft, 24 Engine ECU, 30 Planetary gear, 36 Drive shaft, 38 Differential gear, 39a, 39b Drive wheels, 40 Motor ECU, 41, 42 Inverter, 50 Battery, 52 Battery ECU, 54 Power line, 70 HVECU, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 Vehicle speed sensor, 122 Air cleaner, 123 Intake pipe, 123a Airflow meter, 123t Temperature sensor, 124 Throttle valve, 124a Throttle valve position sensor, 125 Surge tank, 125a Pressure sensor, 126 Port injection valve, 127 In-cylinder injection valve, 128 Intake valve, 129 Combustion chamber, 130 Spark plug, 132 Piston, 133 Exhaust valve, 134 Exhaust pipe, 135 Purification device, 135a Purification catalyst, 136 PM filter, 136a Differential pressure sensor, 137 Front air-fuel ratio sensor, 138 Rear air-fuel ratio sensor, 140 Crank position sensor, 142 Water temperature sensor, 144 Cam position sensor, 150 Fuel supply device, 151 Fuel tank, 151t Fuel temperature sensor, 152 Feed pump, 152a Rotation speed sensor, 153 Low-pressure supply pipe, 153p Fuel pressure sensor, 154 Check valve, 155 Relief pipe, 156 Relief valve, 157 High-pressure pump, 157a Electromagnetic valve, 157b Check valve, 157c Plunger, 158 High-pressure supply pipe, 158p Fuel pressure sensor, MG1, MG2 Motors.

Claims

1. An engine with a purification device having a catalyst for purifying exhaust gas attached to an exhaust system, A first electric motor, A planetary gear mechanism in which the rotation shaft of the first electric motor, the output shaft of the engine, and the drive shaft connected to the drive wheels are connected in this order to three axes arranged in order on a collinearity diagram, A second electric motor having a rotation shaft connected to the drive shaft, A power storage device capable of power exchange with the first electric motor and the second electric motor, A control device for controlling the engine, the first electric motor, and the second electric motor, A hybrid vehicle comprising: The control device executes catalyst warm-up control to set the engine speed to a predetermined engine speed and retard the ignition timing of the engine to warm up the catalyst of the purification device. The control device prohibits the catalyst warm-up control when the vehicle speed is equal to or higher than a predetermined vehicle speed. A hybrid vehicle characterized by this.

2. The hybrid vehicle according to Claim 1, The control device controls such that the absolute value of the rotation speed of the first electric motor is equal to or lower than a predetermined electric motor rotation speed when the vehicle speed is equal to or higher than the predetermined vehicle speed. A hybrid vehicle.

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