Hybrid vehicles

Abstract

To suppress reduction of an intake air quantity at startup of an engine.SOLUTION: At startup of an engine during intermittent stop, a clutch is half engaged, and fuel injection and ignition are re-started while cranking the engine by a motor in a state of opening a throttle valve to a target opening degree. The clutch is released while reducing a difference between an engine rotation number as the rotation number of the engine, and a motor rotation number as the rotation number of the motor, and when an engagement condition of the clutch is established, the engine, the motor and the clutch are controlled so as to engage the clutch. The target opening degree is an opening degree based on an in-manifold pressure as a pressure of intake manifold of the engine, the engine rotation number and the motor rotation number.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle including an engine and a motor connected to an output shaft of the engine via a clutch. [Background technology]

[0002] Conventionally, as this type of hybrid vehicle, one that includes an engine that outputs power for running and a motor that outputs power for running has been proposed (for example, see Patent Document 1). In this hybrid vehicle, when the pressure in the engine in-manifold (intake pipe) is low, the amount of intake air at the time of starting the engine is increased compared to when the pressure is high. This allows the engine to start quickly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-339781 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned hybrid vehicle, when starting the engine, the amount of intake air of the engine decreases depending on the engine speed and the motor speed. When the amount of intake air of the engine decreases, the torque output from the engine decreases, and it becomes difficult to increase the engine speed quickly.

[0005] The main object of the hybrid vehicle of the present invention is to suppress a decrease in the amount of intake air when starting the engine. [Means for solving the problem]

[0006] The hybrid vehicle of the present invention employs the following means to achieve the above-mentioned main object.

[0007] The hybrid vehicle of the present invention is A hybrid vehicle including an engine, a motor connected to an output shaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch, The control device includes: When starting the engine that has been intermittently stopped, with a throttle valve set to a target opening, the engine, the motor, and the clutch are controlled so as to half-engage the clutch and restart fuel injection and ignition while cranking the engine by the motor, release the clutch while reducing the difference between the engine rotation speed as the rotation speed of the engine and the motor rotation speed as the rotation speed of the motor, and engage the clutch when an engagement condition for the clutch is established; The target opening degree is set based on an intake manifold pressure as a pressure of the engine's intake manifold, the engine speed, and the motor speed. The gist of the present invention is as follows.

[0008] In the hybrid vehicle of the present invention, when starting the intermittently stopped engine, the throttle valve is set to a target opening, the clutch is half-engaged and the engine is cranked by the motor while fuel injection and ignition are resumed, the clutch is released while reducing the difference between the engine speed as the engine speed and the motor speed as the motor speed, and the engine, motor, and clutch are controlled so that the clutch is engaged when the clutch engagement condition is satisfied. Here, as the "clutch engagement condition", a condition that the difference between the engine speed and the motor speed is less than a predetermined speed difference as a speed difference between the engine speed and the motor speed that can be determined to be synchronized can be used. The target opening is set to an opening based on the intake manifold pressure as the pressure of the engine intake manifold, the engine speed, and the motor speed. This allows the intake air volume to be an air volume according to the intake manifold pressure, the engine speed, and the motor speed. As a result, it is possible to suppress a decrease in the intake air volume when starting the engine.

[0009] In such a hybrid vehicle of the present invention, when starting the engine that has been intermittently stopped, if there is no throttle opening history in which the throttle valve was temporarily opened before the intermittent stop, the control device may set the target opening to the larger of a first opening predetermined as an opening when starting the engine and a second opening based on the intake manifold pressure, the engine speed, and the motor speed, and may set the target opening to the first opening when there is a throttle opening history. If the throttle valve is set to an opening based on the intake manifold pressure, the engine speed, and the motor speed when there is a throttle opening history, the pressure in the cylinder may become too high when fuel injection and ignition are resumed, which may cause pre-ignition in the engine. Therefore, by setting the throttle valve to the first opening predetermined as an opening when starting the engine when there is a throttle opening history, the occurrence of pre-ignition can be suppressed.

[0010] In the hybrid vehicle of the present invention, when starting the engine that is intermittently stopped, the control device may open the throttle valve to a larger degree when the intake manifold pressure is low compared to when it is high, to a larger degree when the engine speed is high compared to when it is low, and to a larger degree when the motor speed is high compared to when it is low. In this way, a decrease in the amount of intake air into the engine can be suppressed when starting the engine that is intermittently stopped. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device as an embodiment of the present invention. [Diagram 2] 1 is a diagram showing an outline of the configuration of an engine 22 mounted on a hybrid vehicle 20. FIG. [Diagram 3] 13 is a flowchart showing an example of a target opening setting process executed by an HVECU 24. [Figure 4]11 is an explanatory diagram for illustrating an example of time changes in rotation speed (rotation speed Ne of the engine 22, rotation speed Nm of the motor 30), opening degree of the throttle valve 124 (throttle opening degree), intake manifold pressure Pin, and the presence or absence of a throttle opening history. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, an embodiment of the present invention will be described with reference to the accompanying drawings. EXAMPLES

[0013] Fig. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an engine device according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing the configuration of an engine 22 equipped in the hybrid vehicle 20. As shown in Fig. 1, the hybrid vehicle 20 of the embodiment includes the engine 22, a motor 30, an inverter 32, a clutch K0, an automatic transmission 40, a high-voltage battery 60, a low-voltage battery 62, a DC / DC converter 64, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0014] The engine 22 is configured as a six-cylinder internal combustion engine that uses fuel such as gasoline or diesel to output power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel into an intake port, and an in-cylinder injection valve 127 that injects fuel into a cylinder. The engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode by having the port injection valve 126 and the in-cylinder injection valve 127. In the port injection mode, air purified by the air cleaner 122 is sucked into the intake pipe 123 and passes through the throttle valve 124 and the surge tank 125, and fuel is injected from the port injection valve 126 downstream of the surge tank 125 of the intake pipe 123, and the air and fuel are mixed. This mixture is then drawn into the combustion chamber 129 via the intake valve 128, where it is explosively combusted by an electric spark from the spark plug 130, and the reciprocating motion of the piston 132, which is pushed down in the cylinder bore by the energy of the mixture, is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is drawn into the combustion chamber 129 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark plug 130, to obtain the rotational motion of the crankshaft 23. In the shared injection mode, fuel is injected from the port injection valve 126 when air is drawn into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark 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 an exhaust pipe 134 via an exhaust valve 133 is discharged into the outside air via a purification device 135 and a PM filter 136. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The PM filter 136 is formed as a porous filter from ceramics, stainless steel, or the like, and collects particulate matter (PM) such as soot in the exhaust.In place of the PM filter 136, a four-way catalyst may be used that combines the purification function of a three-way catalyst with the function of trapping particulate matter.

[0015] The operation of the engine 22 is controlled by the engine ECU 24. The engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via input ports. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and a cooling water temperature Tw from a water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. Other examples of signals input to the engine ECU 24 include cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133. Other examples of the above include the throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 of the intake pipe 123, the intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and the surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples of the above include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 of the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached between the purification device 135 of the exhaust pipe 134 and the PM filter 136, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure before and after the PM filter 136 (a differential pressure between the upstream side and the downstream side).

[0016] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via an output port. Examples of signals output from the engine ECU 24 include a control signal to a throttle valve 124, a control signal to a port injection valve 126, a control signal to an in-cylinder injection valve 127, and a control signal to an ignition plug 130.

[0017] The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed (engine speed) Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a load factor (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) KL based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates a PM accumulation amount Qpm as the accumulation amount of particulate matter accumulated on the PM filter 136 based on a differential pressure ΔP from the differential pressure sensor 136a, and calculates a filter temperature Tf as the temperature of the PM filter 136 based on the rotation speed Ne of the engine 22 and the load factor KL.

[0018] 1, a starter motor 25 for cranking the engine 22 and an alternator 26 for generating power using power from the engine 22 are connected to the crankshaft 23 of the engine 22. The starter motor 25 and the alternator 26 are connected to a low-voltage power line 63 together with a low-voltage battery 62, and are controlled by the HVECU 70.

[0019] The motor 30 is configured as a synchronous generator motor, and has a rotor in which a permanent magnet is embedded in a rotor core, and a stator in which a three-phase coil is wound around a stator core. A rotating shaft 31 to which the rotor of the motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via a clutch K0, and is also connected to an input shaft 41 of an automatic transmission 45. The inverter 32 is used to drive the motor 30, and is connected to a high-voltage power line 61. The motor 30 is rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 34 controlling the switching of multiple switching elements of the inverter 32.

[0020] The motor ECU 34 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. Signals from various sensors are input to the motor ECU 34 via the input ports. Examples of signals input to the motor ECU 34 include a rotational position θm from a rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and phase currents Iu and Iv from current sensors that detect the phase currents of the respective phases of the motor 30. A control signal to the inverter 32 and the like are output from the motor ECU 34 via the output port. The motor ECU 34 is connected to the HVECU 70 via a communication port. The motor ECU 34 calculates the rotational speed (motor rotational speed) Nm of the motor 30 based on the rotational position θm of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

[0021] The clutch K0 is configured as, for example, a hydraulically driven friction clutch, and is controlled by the HVECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotating shaft 31 of the motor 30.

[0022] The automatic transmission 40 has a torque converter 43 and an automatic transmission 45 with, for example, six speeds. The torque converter 43 is configured as a general fluid transmission device, and transmits the power of an input shaft 41 connected to a rotating shaft 31 of the motor 30 to a transmission input shaft 44 which is an input shaft of the automatic transmission 45 with amplified torque, or transmits the torque as is without amplifying it. The automatic transmission 45 has the transmission input shaft 44, an output shaft 42 connected to driving wheels 49 via a differential gear 48, a plurality of planetary gears, and a plurality of hydraulically driven friction engagement elements (clutches, brakes). Each of the plurality of friction engagement elements has a hydraulic servo configured of a piston, a plurality of friction engagement plates (friction plates and separator plates), an oil chamber to which hydraulic oil is supplied, and the like. The automatic transmission 45 forms forward gears from 1st gear to 6th gear and reverse gears by engaging and disengaging a plurality of friction engagement elements, and transmits power between the transmission input shaft 44 and the output shaft 42. The hydraulic pressure of hydraulic oil from a mechanical oil pump or an electric oil pump is adjusted and supplied to the clutch K0 and the automatic transmission 45 by a hydraulic control device (not shown). The hydraulic control device has a valve body with a plurality of oil passages formed therein, a plurality of regulator valves, a plurality of linear solenoid valves, etc. This hydraulic control device is controlled by the HVECU 70.

[0023] High-voltage battery 60 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery with a rated voltage of several hundred volts, and is connected to high-voltage power line 61 together with inverter 32. Low-voltage battery 62 is configured as, for example, a lead-acid battery with a rated voltage of about 12 V or 14 V, and is connected to low-voltage power line 63 together with starter motor 25 and alternator 26. DC / DC converter 64 is connected to high-voltage power line 61 and low-voltage power line 63. This DC / DC converter 64 supplies power from high-voltage power line 61 to low-voltage power line 63 with a voltage step-down.

[0024] Although not shown, the HVECU 70 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include the rotation speed Nin from the rotation speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotation speed Nmi from the rotation speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotation speed Nout from the rotation speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. Examples of signals input to the HVECU 70 include the voltage Vbh of the high-voltage battery 60 from a voltage sensor attached between the terminals of the high-voltage battery 60, the current Ibh of the high-voltage battery 60 from a current sensor attached to the output terminal of the high-voltage battery 60, and the voltage Vbl from a voltage sensor attached between the terminals of the low-voltage battery 62. Other examples of such signals include an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 87.

[0025] Various control signals are output from the HVECU 70 via an output port. Examples of signals output from the HVECU 70 include a control signal to the starter motor 25 and a control signal to the alternator 26. Examples of signals output from the HVECU 70 include a control signal to the clutch K0 and the automatic transmission 40 (hydraulic control device), and a control signal to the DC / DC converter 64. The HVECU 70 is connected to the engine ECU 24 and the motor ECU 34 via a communication port. The HVECU 70 calculates a rotation speed ratio Gt of the automatic transmission 40 by dividing the rotation speed Nin of the input shaft 41 of the automatic transmission 40 from the rotation speed sensor 41a by the rotation speed Nout of the output shaft 42 of the automatic transmission 40 from the rotation speed sensor 42a.

[0026] In the hybrid vehicle 20 of the embodiment thus configured, the engine 22, the clutch K0, the motor 30, and the automatic transmission 40 are controlled by cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 34 so as to travel in a hybrid driving mode (HV driving mode) or an electric driving mode (EV driving mode). Here, the HV driving mode is a mode in which the clutch K0 is in an engaged state and the vehicle travels using the power of the engine 22, and the EV driving mode is a mode in which the clutch K0 is in a released state and the vehicle travels without using the power of the engine 22.

[0027] In controlling the automatic transmission 40 in the HV driving mode or the EV driving mode, the HVECU 70 first sets a target gear M* of the automatic transmission 45 based on the accelerator opening Acc and the vehicle speed V. Then, when the gear M of the automatic transmission 45 matches the target gear M*, the HVECU 70 controls the automatic transmission 45 so that the gear M is maintained. On the other hand, when the gear M and the target gear M* differ, the HVECU 70 controls the automatic transmission 45 so that the gear M matches the target gear M*.

[0028] In controlling the engine 22 and the motor 30 in the HV driving mode, the HVECU 70 first sets a required torque Tout* required for driving (required of the output shaft 42 of the automatic transmission 40) based on the accelerator opening Acc and the vehicle speed V. Next, the required torque Tout* of the output shaft 42 is divided by the rotation speed ratio Gt of the automatic transmission 40, and the value is set as the required torque Tin* of the input shaft 41. After setting the required torque Tin* of the input shaft 41 in this manner, the HVECU 70 sets a target torque Te* of the engine 22 and a torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the target torque Te* of the engine 22 to the engine ECU 24 and transmits the torque command Tm* of the motor 30 to the motor ECU 34. Upon receiving the target torque Te*, the engine ECU 24 performs operation control of the engine 22 (intake air amount control, fuel injection control, ignition control, etc.) so that the engine 22 is operated at the target torque Te*. When the motor ECU 34 receives the torque command Tm*, it performs switching control of a plurality of switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0029] In controlling the motor 30 in the EV driving mode, the HVECU 70 sets a required torque Tin* of the input shaft 41 in the same manner as in the HV driving mode, sets a torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the torque command Tm* to the motor ECU 34. Upon receiving the torque command Tm*, the motor ECU 34 performs switching control of a plurality of switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0030] In the hybrid vehicle 20 of the embodiment, when a stop (intermittent stop) condition in the HV driving mode is established by cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 34, the torque from the engine 22 is replaced with the torque from the motor 30, and then the fuel supply to the engine 22 is cut and the throttle valve 124 is closed, and the clutch K0 is released when the rotation speed Ne of the engine 22 is less than a threshold value Neref1 (for example, about 600 rpm to 800 rpm). As the stop (intermittent stop) condition, for example, a condition that the required torque Tin* of the input shaft 41 is less than a threshold value Tinref while the engine 22 is operating can be used.

[0031] In the embodiment, when the stop (intermittent stop) condition in the HV driving mode is satisfied and the vehicle speed V is equal to or higher than a predetermined vehicle speed Vref (for example, about several km / h), the throttle valve 124 is temporarily opened immediately before the engine 22 is stopped (intermittent stop). The reason for temporarily opening the throttle valve 124 immediately before the engine 22 is stopped (intermittent stop) is to increase the amount of air in the cylinder that is stopped during the compression stroke. If the throttle valve 124 is temporarily opened immediately before the engine 22 is stopped (intermittent stop), the manner in which the number of revolutions of the engine 22 changes changes, and noise and vibration may occur. When the vehicle speed V is less than the predetermined vehicle speed Vref, the user is likely to recognize the noise and vibration, so the throttle valve 124 is closed to prevent the user from feeling uncomfortable.

[0032] Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when starting the engine 22 intermittently stopped in the HV driving mode, will be described. When starting the engine 22 intermittently stopped in the HV driving mode, the clutch K0 is half-engaged (slip-engaged) to crank the engine 22 using the cranking torque from the motor 30 with the throttle valve 124 at the target opening TH*, the clutch K0 is released while controlling the engine 22 so that the differential speed ΔN between the rotation speed Ne of the engine 22 and the rotation speed Nm of the motor 30 becomes small, and the clutch K0 is engaged when the engagement condition of the clutch K0 is satisfied. As the engagement condition of the clutch K0, a condition that the differential speed ΔN is less than a threshold value ΔNref (for example, about 50 rpm to 150 rpm) can be used. The fuel injection control when starting the engine 22 is performed in the in-cylinder injection mode.

[0033] Here, the setting of the target opening TH* when restarting fuel injection and ignition of the engine 22 will be described. Fig. 3 is a flowchart showing an example of a target opening setting process executed by the HVECU 24. This routine is repeatedly executed at predetermined time intervals (e.g., every few msec) from when a start condition for the engine 22 is satisfied. As the start condition, a condition that the required torque Tin* is equal to or greater than a threshold value Tinref while the engine 22 is intermittently stopped, etc., can be used.

[0034] When this routine is executed, the CPU of the HVECU 24 inputs the rotation speed Ne of the engine 22, the rotation speed Nm of the motor 30, and the intake manifold pressure Pin (step S100). The rotation speed Ne is calculated by the engine ECU 24 and input via communication. The rotation speed Nm is calculated by the motor ECU 34 and input via communication. The intake manifold pressure Pin is the pressure inside the intake manifold of the engine 22, and in this embodiment, the surge pressure Ps from the pressure sensor 125a attached to the surge tank 125 of the engine 22 is input as the intake manifold pressure Pin via communication via the engine ECU 24.

[0035] Next, it is determined whether or not there is a throttle opening history in which the throttle valve 124 was temporarily opened before the engine 22 was stopped (intermittently stopped) (step S110). If there is no throttle opening history, the target opening TH* is set to the larger of a first opening TH1 based on the rotation speed Nm of the motor 30 and a second opening TH2 based on the intake manifold pressure Pin and the rotation speeds Ne and Nm, and the set target opening TH* is sent to the engine ECU 24 (step S120), and this routine ends. The engine ECU 24, which has received the target opening TH*, controls the throttle valve 124 so that the opening becomes the target opening TH*.

[0036] In step S120, the first opening TH1 is a predetermined opening as a basic value of the opening of the throttle valve 124 when starting the engine 22, and is a predetermined opening (e.g., 20%, 30%, 40%, etc.) that is determined in consideration of the startability of the engine 22 and suppression of the shock of the initial explosion at the time of starting. The second opening TH2 is set to be larger when the intake manifold pressure Pin is low compared to when it is high, larger when the rotation speed Ne is high compared to when it is low, and larger when the rotation speed Nm is high compared to when it is low. This is based on the fact that, when the opening of the throttle valve 124 is constant, the intake air amount is smaller when the intake manifold pressure Pin is low compared to when it is high, and smaller when the rotation speeds Ne and Nm are high compared to when they are low.

[0037] If there is a throttle opening history in step S110, the target opening TH* is set to the first opening TH1 in step S120, the set target opening TH* is sent to the engine ECU 24 (step S130), and this routine ends. The engine ECU 24, which has received the target opening TH*, controls the throttle valve 124 so that the opening becomes the target opening TH*.

[0038] 4 is an explanatory diagram for illustrating an example of time changes in rotation speed (rotation speed Ne of engine 22, rotation speed Nm of motor 30), opening of throttle valve 124 (throttle opening), intake manifold pressure Pin, and the presence or absence of a throttle opening history. In the diagram, with regard to the time changes in rotation speed, the solid line shows an example of time changes in rotation speed Ne of engine 22, and the dashed line shows an example of time changes in rotation speed Nm of motor 30. With regard to the time changes in throttle opening, intake manifold pressure Pin, and throttle opening history, the solid line shows an example of time changes in throttle opening TH, intake manifold pressure Pin, and throttle opening history when there is no throttle opening history, and the dashed line shows an example of time changes in throttle opening TH, intake manifold pressure Pin, and throttle opening history when there is a throttle opening history.

[0039] If there is no throttle opening history, when the start condition of the engine 22 is satisfied (time t1), the target throttle opening TH* is set to the larger of the first throttle opening TH1 and the second throttle opening TH2, so that the throttle opening increases and the intake manifold pressure Pin increases, as shown by the solid line. This makes it possible to suppress a decrease in the intake air amount when starting the engine 22.

[0040] When the throttle valve 124 is temporarily opened before the intermittent stop of the engine 22 and there is a throttle opening history (time t0), the intake manifold pressure Pin rises, and the intake manifold pressure Pin may become high when the start condition of the engine 22 is satisfied. At this time, if the target opening TH* is set to the larger of the first opening TH1 and the second opening TH2, the pressure inside the cylinder may become too high when fuel injection and ignition are resumed, and pre-ignition may occur in the engine 22. In the embodiment, as shown by the dashed line, the target opening TH* is set to the first opening TH1, so that the pressure inside the cylinder is prevented from becoming too high, and pre-ignition of the engine 22 can be suppressed.

[0041] According to the hybrid vehicle 20 of the embodiment described above, when starting the engine 22 that has been intermittently stopped, with the throttle valve 124 set to the target opening degree TH*, the clutch K0 is half-engaged and the engine 22 is cranked by the motor 30 while fuel injection and ignition are resumed, the clutch K0 is released while reducing the difference between the rotation speed Ne of the engine 22 and the rotation speed Nm of the motor 30, and the engine 22, the motor 30 and the clutch K0 are controlled so that the clutch K0 is engaged when the engagement condition for the clutch K0 is satisfied, and when there is no history of the throttle valve 124 being temporarily opened before the engine 22 is stopped (intermittently stopped), the target opening degree TH* is set to an opening degree based on the intake manifold pressure Pin and the rotation speeds Ne, Nm of the engine 22, thereby suppressing a decrease in the amount of intake air when the engine 22 is started.

[0042] Furthermore, when there is a throttle opening history, the occurrence of pre-ignition of the engine 22 can be suppressed by setting the target opening TH* to the first opening TH1.

[0043] In the hybrid vehicle 20 of the embodiment, in the target opening setting process illustrated in Fig. 3, it is determined in step S110 whether or not there is a throttle opening history, and the target opening TH* is set in steps S120 and S130 depending on whether or not there is a throttle opening history. However, in a hybrid vehicle in which the throttle valve 124 is temporarily maintained in a closed state rather than opened before the engine 22 is stopped (intermittently stopped), step S120 may be executed after step S100 without executing the determination in step S110.

[0044] The hybrid vehicle 20 of the embodiment is provided with a six-speed automatic transmission 45. However, it may be provided with a four-speed, five-speed, eight-speed, or other automatic transmission.

[0045] The hybrid vehicle 20 of the embodiment includes the engine ECU 24, the motor ECU 34, and the HVECU 70. However, at least two of these may be integrated into one unit.

[0046] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be described below. In the embodiment, the engine 22 corresponds to the "engine", the motor 30 corresponds to the "motor", and the engine ECU 24, the motor ECU 34, and the HVECU 70 correspond to the "control device".

[0047] The correspondence between the main elements of the Examples and the main elements of the invention described in the Summary of the Problem column does not limit the elements of the invention described in the Summary of the Problem column, since the Examples are examples for specifically explaining the mode for implementing the invention described in the Summary of the Problem column. In other words, the interpretation of the invention described in the Summary of the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Summary of the Problem column.

[0048] Although the form for carrying out the present invention has been described above using examples, the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the gist of the present invention. [Industrial Applicability]

[0049] The present invention can be used in the hybrid vehicle manufacturing industry and the like. [Explanation of symbols]

[0050] 20 hybrid vehicle, 22 engine, 23 crankshaft, 24 engine ECU, 25 starter motor, 26 alternator, 30 motor, 30a rotational position sensor, 31 rotating shaft, 32 inverter, 34 motor ECU, 40 automatic transmission, 41 input shaft, 41a rotational speed sensor, 42 output shaft, 42a rotational speed sensor, 43 torque converter, 44 transmission input shaft, 44a rotational speed sensor, 45 automatic transmission, 48 differential gear, 49 drive wheel, 60 high voltage battery, 61 high voltage side power line, 62 low voltage battery, 63 low voltage side power line, 64 DC / DC converter, 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 air flow 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.

Claims

1. A hybrid vehicle including an engine, a motor connected to an output shaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch, The control device includes: When starting the engine that has been intermittently stopped, with a throttle valve set to a target opening, the engine, the motor, and the clutch are controlled so as to half-engage the clutch and restart fuel injection and ignition while cranking the engine by the motor, release the clutch while reducing the difference between the engine rotation speed as the rotation speed of the engine and the motor rotation speed as the rotation speed of the motor, and engage the clutch when an engagement condition for the clutch is established; The target opening degree is set based on an intake manifold pressure as a pressure of the engine's intake manifold, the engine speed, and the motor speed. Hybrid car.

2. 2. The hybrid vehicle according to claim 1, The control device includes: When starting the engine that has been intermittently stopped, if there is no history of the throttle valve being temporarily opened before the intermittent stop, the target opening is set to the larger of a first opening that is predetermined as the opening when starting the engine and a second opening based on the intake manifold pressure, the engine speed, and the motor speed, and if there is a throttle opening history, the first opening is set. Hybrid car.

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