Engine device

Abstract

To properly select whether opening delay control is to be executed or not.SOLUTION: In a case when calculated injection control for controlling a fuel injection valve by using a target injection amount based on a predicted in-cylinder air amount is executed from initial fuel injection as fuel injection control in executing start control with start request of an engine, opening delay control for controlling a throttle valve by using a target opening obtained by providing request opening with delay is executed from the start of start request as the control of air amount. At this time, when the calculated injection control is executed after execution of speculative injection control for controlling the fuel injection valve by using a target injection amount not based on the predicted in-cylinder air amount as the fuel injection control, opening delay cut control for controlling the throttle valve by using the request opening as the target opening is executed from start of the start request to termination of the speculative injection control as the air amount control, and then opening delay control is executed when the calculated injection control is started.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] Conventionally, as this type of engine device, a hybrid vehicle equipped with an engine, a motor connected to an output shaft of the engine via a clutch, and an automatic transmission connected to a rotating shaft of the motor and an axle has been proposed (see, for example, Patent Document 1). In this engine device, when the vehicle is being driven by the motor with the clutch disengaged, the engine is started while controlling the clutch toward engagement.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such an engine device, for the engine, in order to accurately predict (forecast) the in-cylinder air amount, throttle valve control is performed using a target opening with a delay in the required opening, that is, opening delay control is executed, and the predicted in-cylinder air amount is calculated based on the required opening. However, there are cases where it is required to realize the required opening more quickly. For this reason, how to select whether to execute the opening delay control or not has been an issue.

[0005] The main object of the engine device of the present invention is to more appropriately select whether to execute the opening delay control or not.

Means for Solving the Problems

[0006] The engine device of the present invention has adopted the following means to achieve the above-mentioned main object.

[0007] The engine device of the present invention is summarized as follows.

[0008] In the engine device of the present invention, an engine having a throttle valve and a fuel injection valve, a motor connected to the output shaft of the engine via a clutch, a control device that controls the engine, the motor, and the clutch, and performs air amount control for controlling the throttle valve using a target opening degree based on a required opening degree and fuel injection control for controlling the fuel injection valve using a target injection amount for the engine, and calculates a predicted in-cylinder air amount based on the required opening degree, is an engine device comprising: the control device when executing start control in accordance with a start request for the engine, as the fuel injection control, when executing calculation injection control for controlling the fuel injection valve using a target injection amount based on the predicted in-cylinder air amount from the first fuel injection, as the air amount control, opening delay control for controlling the throttle valve using a target opening degree with a delay in the required opening degree from the start of the start request is executed, as the fuel injection control, when shifting to the calculation injection control after executing expected injection control for controlling the fuel injection valve using the target injection amount not based on the predicted in-cylinder air amount, as the air amount control, opening delay cut control for controlling the throttle valve using the required opening degree as the target opening degree from the start of the start request to the end of the expected injection control is executed, and when starting the calculation injection control, a shift is made to the opening delay control. is summarized as follows.

[0009] In the engine device of the present invention, for the engine, air amount control for controlling the throttle valve using a target opening based on a required opening and fuel injection control for controlling the fuel injection valve using a target injection amount are performed, and the predicted in-cylinder air amount is calculated based on the required opening. Then, when starting control is executed in response to a starting request of the engine, as fuel injection control, when performing calculation injection control for controlling the fuel injection valve using the target injection amount based on the predicted in-cylinder air amount from the first fuel injection, as air amount control, opening delay control for controlling the throttle valve using a target opening with a delay in the required opening is executed from the start of the starting request. By executing the opening delay control, the actual in-cylinder air amount can be accurately predicted (predicted in advance) by the predicted in-cylinder air amount. Therefore, in the calculation injection control, the target injection amount can be set more appropriately. Further, when starting control is executed in response to a starting request of the engine, as fuel injection control, when performing expected injection control for controlling the fuel injection valve using a target injection amount not based on the predicted in-cylinder air amount and then shifting to the calculation injection control, as air amount control, opening delay cut control for controlling the throttle valve using the required opening as the target opening from the start of the starting request to the end of the expected injection control is executed, and when the calculation injection control is started, the control shifts to the opening delay control. By executing the opening delay cut control from the start of the starting request to the end of the expected injection control, the required opening can be realized more quickly, and the actual in-cylinder air amount can be made to approach more quickly the air amount corresponding to the required opening. Note that in the case of the expected injection control, since the fuel injection valve is controlled using a target injection amount not based on the predicted in-cylinder air amount, it is considered that there is a low possibility of a problem even if the prediction accuracy of the predicted in-cylinder air amount decreases. As a result, it is possible to more appropriately select whether to execute the opening delay control or the opening delay cut control.

[0010] In the engine device of the present invention, when the control device executes the stop control of the engine, when the rotational speed of the engine reaches less than a predetermined rotational speed, the throttle valve is temporarily opened. Further, when the control device executes the stop control, before temporarily opening the throttle valve, the opening delay control is executed, and after temporarily opening the throttle valve, the opening delay cut control may be executed. By doing so, before temporarily opening the throttle valve, the in-cylinder air amount can be accurately predicted (read ahead) based on the predicted cylinder air amount, and when the throttle valve is temporarily opened, the required opening can be realized more quickly, and the in-cylinder air amount can be more quickly approximated to the air amount corresponding to the required opening.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0012] Next, embodiments for carrying out the present invention will be described using examples.

Example

[0013] FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device as an embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of the configuration of an engine 22 mounted on the hybrid vehicle 20. As shown in FIG. 1, the hybrid vehicle 20 of the embodiment includes an 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 outputs power through four strokes of intake, compression, expansion (explosive combustion), and exhaust using fuel such as gasoline or diesel oil. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel into the intake port and an in-cylinder injection valve 127 that injects fuel into the cylinder. By having the port injection valve 126 and the in-cylinder injection valve 127, the engine 22 can be operated in either a port injection mode, an in-cylinder injection mode, or a common injection mode. In the port injection mode, air cleaned by the air cleaner 122 is inhaled into the intake pipe 123, passes 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 spark plug 130, converting 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 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 spark 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 also 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 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. The 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 and the PM filter 136. 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. The PM filter 136 is formed as a porous filter made of ceramics, stainless steel, etc., and collects particulate matter (PM) such as soot in the exhaust.Note that instead of the PM filter 136, a four-way catalyst that combines the purification function of a three-way catalyst and the collection function for particulate matter may be used.

[0015] The engine 22 is under operation control by the engine ECU 24. The engine ECU 24 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, input / output ports, and communication ports, although not shown. Signals from various sensors necessary for operation control of the engine 22 are input to the engine ECU 24 via the input ports. Examples of the signals input to 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 include the throttle opening TH from the throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air amount 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. Additionally, 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, 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, and the differential pressure ΔP from the differential pressure sensor 136a that detects the differential pressure (the differential pressure between the upstream side and the downstream side) across the PM filter 136 can be mentioned.

[0016] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via the output ports. Examples of 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 ignition plug 130.

[0017] The engine ECU 24 is connected to the HV ECU 70 via a communication port. The engine ECU 24 calculates the rotational 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 volume Qa from the air flow meter 123a and the rotational speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates the PM deposition amount Qpm as the deposition amount of particulate matter deposited on the PM filter 136 based on the differential pressure ΔP from the differential pressure sensor 136a, or calculates the filter temperature tf as the temperature of the PM filter 136 based on the rotational speed Ne and the load factor KL of the engine 22.

[0018] As shown in FIG. 1, a starter motor 25 for cranking the engine 22 and an alternator 26 for generating power using the 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 the low-voltage side power line 63 together with the low-voltage battery 62 and are controlled by the HV ECU 70.

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

[0020] Although not shown, the motor ECU 34 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 motor ECU 34 via the input port. Examples of the signals input to the motor ECU 34 include the rotational position θmg from a rotational position sensor 30a that detects the rotational position of the rotor (rotary shaft 31) of the motor 30, and the phase currents Iu and Iv from a current sensor that detects the phase current of each phase of the motor 30. Control signals 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 HV ECU 70 via the communication port. The motor ECU 34 calculates the rotational speed Nmg of the motor 30 based on the rotational position θmg of the rotor (rotary 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 HV ECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotary shaft 31 of the motor 30.

[0022] The automatic transmission 40 includes a torque converter 43 and an automatic transmission 45 with, for example, six forward speeds. The torque converter 43 is configured as a general fluid transmission device and transmits the power of the input shaft 41 connected to the rotating shaft 31 of the motor 30 to the transmission input shaft 44, which is the input shaft of the automatic transmission 45, either by amplifying the torque or transmitting it as it is without torque amplification. The automatic transmission 45 includes a transmission input shaft 44, an output shaft 42 connected to the drive wheels 49 via a differential gear 48, a plurality of planetary gears, and a plurality of hydraulically actuated friction engagement elements (clutches, brakes). Each of the plurality of friction engagement elements has a hydraulic servo composed 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 and reverse gears from the first speed to the sixth speed by engaging and disengaging the plurality of friction engagement elements, and transmits power between the transmission input shaft 44 and the output shaft 42. The clutch K0 and the automatic transmission 45 are supplied with hydraulic oil pressure regulated from a mechanical oil pump or an electric oil pump by a hydraulic control device (not shown). The hydraulic control device includes a valve body in which a plurality of oil passages are formed, a plurality of regulator valves, a plurality of linear solenoid valves, and the like. This hydraulic control device is controlled by the HVECU 70.

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

[0024] The HVECU 70 includes, although not shown, a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Signals from various sensors are input to the HVECU 70 via the input ports. Examples of signals input to the HVECU 70 include the rotational speed Nin from the rotational speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotational speed Nmi from the rotational speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotational speed Nout from the rotational speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. Also included are 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. Further examples are the ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operating position of the shift lever 81, 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.

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

[0026] In the embodiment, as the engine device, an engine 22, a clutch K0, a motor 30, an HVECU 70, an engine ECU 24, and a motor ECU 34 correspond to each other.

[0027] In the hybrid vehicle 20 of the embodiment configured in this way, the engine 22, the clutch K0, the motor 30, and the automatic transmission 40 are controlled so as to travel in a hybrid driving mode (HV driving mode) or an electric driving mode (EV driving mode) by the cooperative control of the HVECU 70, the engine ECU 24, and the motor ECU 34. Here, the HV driving mode is a mode in which the vehicle travels using the power of the engine 22 with the clutch K0 engaged, and the EV driving mode is a mode in which the vehicle travels without using the power of the engine 22 with the clutch K0 disengaged.

[0028] In the control of the automatic transmission 40 in the HV driving mode and the EV driving mode, the HVECU 70 first sets a target gear position M* of the automatic transmission 45 based on the accelerator opening Acc and the vehicle speed V. Then, when the gear position M of the automatic transmission 45 coincides with the target gear position M*, the automatic transmission 45 is controlled so that the gear position M is maintained. On the other hand, when the gear position M and the target gear position M* are different, the automatic transmission 45 is controlled so that the gear position M coincides with the target gear position M*.

[0029] In the control of the engine 22 and the motor 30 in the HV running mode, the HVECU 70 first sets a required torque Tout* required for running (required for the output shaft 42 of the automatic transmission 40) based on the accelerator opening Acc and the vehicle speed V. Subsequently, a value obtained by dividing the required torque Tout* of the output shaft 42 by the gear ratio Gt of the automatic transmission 40 is set as the required torque Tin* of the input shaft 41. When the required torque Tin* of the input shaft 41 is set in this way, the target torque Te* of the engine 22 and the torque command Tm* of the motor 30 are set so that the required torque Tin* is output to the input shaft 41. The target torque Te* of the engine 22 is transmitted to the engine ECU 24, and the torque command Tm* of the motor 30 is transmitted to the motor ECU 34. When receiving the target torque Te*, the engine ECU 24 performs operation control of the engine 22 (such as air volume control for controlling the throttle valve 124, fuel injection control for controlling the port injection valve 126 and the in-cylinder injection valve 127, and ignition control for controlling the ignition plug 130) so that the engine 22 is operated at the target torque Te*. When 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 control of the motor 30 in the EV running mode, the HVECU 70 sets the required torque Tin* of the input shaft 41 in the same manner as in the HV running mode, sets the torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits it to the motor ECU 34. When 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*.

[0031] Also, in the hybrid vehicle 20 of the embodiment, when a stop request for the engine 22 is made while the engine 22 is being operated by the cooperative control of the HVECU 70, the engine ECU 24, and the motor ECU 34, stop control of the engine 22 is executed. The stop request is made, for example, when a condition that the required torque Tin* of the input shaft 41 is less than the threshold value Tinref is satisfied. In the stop control, basically, fuel injection and ignition are stopped, the throttle valve 124 is closed, and when the rotational speed Ne of the engine 22 reaches less than the threshold value Neref1 (for example, about 600 rpm to 800 rpm), the clutch K0 is disengaged. Further, when the rotational speed Ne of the engine 22 reaches less than the threshold value Neref2 (for example, lower by about several hundred rpm) that is lower than the threshold value Neref1, the throttle valve 124 is temporarily opened. The reason for temporarily opening the throttle valve 124 will be described later.

[0032] Then, when a start request for the engine 22 is made while the fuel injection and ignition of the engine 22 are stopped, start control of the engine 22 is executed. The start request is made, for example, when a condition that the required torque Tin* is equal to or greater than the threshold value Tinref is satisfied. Examples of the start control of the engine 22 include FC (Fuel Cut) return start control, self-sufficient COM (Change Of Mind) start control, COM start control, TDC (Top Dead Center) start control, PUSH start control, and the like. The selection of the start control method is made, for example, based on the rotational speed Ne of the engine 22 and the rotational speed Nmg of the motor 30 when the start request is made (started). Note that the fuel injection control during the start control is performed in the in-cylinder injection mode.

[0033] The FC return start control is basically performed when the rotational speed Ne of the engine 22 is equal to or greater than the threshold value Neref1 (with the clutch K0 engaged) and the rotational speed Nmg of the motor 30 is equal to or greater than the threshold value Nmgref (for example, the same value as the threshold value Neref1) when the start request is made. In the FC return start control, basically, fuel injection and ignition of the engine 22 are started while continuing the engagement of the clutch K0.

[0034] The self-sustaining COM start control is basically performed when a start request is made, provided that the engine speed Ne of the engine 22 is less than the threshold value Neref1 (the clutch K0 is disengaged) and is equal to or higher than a lower threshold value Neref3 (for example, several hundred rpm lower), and the motor speed Nmg of the motor 30 is equal to or higher than the threshold value Nmgref. In the self-sustaining COM start control, basically, while continuing to disengage the clutch K0, fuel injection and ignition of the engine 22 are started, the engine 22 is controlled so that the differential speed ΔN between the motor speed Nmg of the motor 30 and the engine speed Ne of the engine 22 becomes smaller, and when the engagement condition of the clutch K0 is satisfied, the clutch K0 is engaged. As the engagement condition of the clutch K0, for example, 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.

[0035] The COM start control is basically performed when a start request is made, provided that the engine speed Ne of the engine 22 is less than the threshold value Neref3 and is greater than 0, and the motor speed Nmg of the motor 30 is equal to or higher than the threshold value Nmgref. In the COM start control, basically, the clutch K0 is semi-engaged (slip engaged), and while cranking the engine 22 using the cranking torque from the motor 30, fuel injection and ignition are started, the clutch K0 is disengaged while controlling the engine 22 so that the differential speed ΔN becomes smaller, and when the above-described engagement condition of the clutch K0 is satisfied, the clutch K0 is engaged.

[0036] TDC start control is basically performed when a start request is made, provided that the engine speed Ne of the engine 22 is 0 (the engine 22 is stopped), and the motor speed Nmg of the motor 30 is equal to or higher than the threshold value Nmgref. In TDC start control, basically, the clutch K0 is semi-engaged (slip engaged), and the engine 22 is cranked using the cranking torque from the motor 30. The first fuel injection and ignition are performed in the cylinder that first reaches top dead center of compression (the first target cylinder) or the cylinder that secondarily reaches top dead center of compression (the second target cylinder). While controlling the engine 22 so that the differential speed ΔN becomes small, the clutch K0 is released, and when the above-described engagement condition of the clutch K0 is satisfied, the clutch K0 is engaged. The selection of whether to perform the first fuel injection and ignition in the first target cylinder or the second target cylinder is basically determined by whether the crank angle (stop crank angle) θcrsp when the engine 22 is intermittently stopped (stopped rotating) is within a predetermined crank angle range (for example, BTDC40 to 80 (Before TDC 40 to 80 degrees)) where first explosion can occur in the first target cylinder. Therefore, when the stop crank angle θcrsp is within the predetermined crank range, the first fuel injection and ignition are performed in the first target cylinder, and when the stop crank angle θcrsp is not within the predetermined crank range, the first fuel injection and ignition are performed in the second target cylinder. In the embodiment, as described above, when the engine speed Ne of the engine 22 reaches less than the threshold value Neref2 during stop control, the throttle valve 124 is temporarily opened. This is to increase the amount of in-cylinder air in the first target cylinder in preparation for performing the first fuel injection and ignition in the first target cylinder.

[0037] PUSH start control is basically performed when a start request is made, provided that the motor speed Nmg of the motor 30 is less than the threshold value Nmgref. In PUSH start control, basically, the clutch K0 is semi-engaged (slip engaged), and the engine 22 is cranked using the cranking torque from the motor 30. When the above-described clutch K0 engagement condition is satisfied, the clutch K0 is engaged, and thereafter, fuel injection and ignition of the engine 22 are started.

[0038] In the embodiment, during the FC return start control, as fuel injection control for controlling the in-cylinder injection valve 127 using the target injection amount Qf*, calculation injection control is executed starting from the first fuel injection. In the calculation injection control, basically, the target injection amount Qf* is set so that the front air-fuel ratio AF1 becomes the target air-fuel ratio AF1* (for example, the stoichiometric air-fuel ratio) based on the predicted in-cylinder air amount Qcypr which is the predicted value of the in-cylinder air amount, and the in-cylinder injection valve 127 is controlled using the set target injection amount Qf*. The calculation method of the predicted in-cylinder air amount Qcypr will be described later.

[0039] Also, during the self-sustaining COM start control, COM start control, TDC start control, and PUSH start control, as fuel injection control, prediction injection control is executed until the transition condition is satisfied starting from the first fuel injection, and when the transition condition is satisfied, it shifts to the calculation injection control. In the prediction injection control, basically, the target injection amount Qf* is set without depending on the predicted in-cylinder air amount Qcypr, the front air-fuel ratio AF1, and the target air-fuel ratio AF1*, and the in-cylinder injection valve 127 is controlled using the set target injection amount Qf*. As the target injection amount Qf* in the prediction injection control in the self-sustaining COM start control and COM start control, for example, a fixed amount can be used, or a value based on at least one of the engine 22 rotation speed Ne and the intake manifold pressure Pin (surge pressure Ps) at the time when the intake valve 128 of the target cylinder is closed, i.e., the closed intake manifold pressure Pinc, can be used. As the target injection amount Qf* in the prediction injection control in the TDC start control, for example, a fixed amount can be used, or a value based on at least one of the stop crank angle θcrsp and the elapsed time since the engine 22 stopped rotating can be used. As the target injection amount Qf* in the prediction injection control in the PUSH start control, for example, a value similar to the target injection amount Qf* in the prediction injection control in the self-sustaining COM start control and COM start control can be used, or a value similar to the target injection amount Qf* in the prediction injection control in the TDC start control can be used. As the transition condition for shifting from the prediction injection control to the calculation injection control, for example, a condition where the number of fuel injections (number of fuel injection cylinders) is equal to or more than a predetermined number (for example, about 6 to 9 times) and the engine 22 rotation speed Ne is a predetermined rotation speed (for example, about 300 to 500 rpm) can be used.

[0040] Next, the operation of the hybrid vehicle 20 of the embodiment, particularly, the air amount control of the engine 22 (control of the throttle valve 124) and the process of calculating the predicted in-cylinder air amount Qcypr will be described. FIG. 3 is a flowchart showing an example of an air amount control routine executed by the engine ECU 24. This routine is repeatedly executed.

[0041] In the air amount control routine of FIG. 3, the engine ECU 24 first inputs the required opening degree THtg of the throttle valve 124 (step S100). Here, the required opening degree THtg of the throttle valve 124 is basically set using a well-known inverse air model based on the target in-cylinder air amount Qcy* based on the target torque Te* of the engine 22 from the end of the start control to the start of the stop control. Also, during the stop control, as a stop value, a relatively large value is set when the throttle valve 124 is temporarily opened, and a substantially value 0 is set otherwise. Further, during the FC return start control in the start control, it is set using the inverse air model based on the target in-cylinder air amount Qcy*, and during the self-sustaining COM start control, COM start control, TDC start control, and PUSH start control in the start control, start values are set. As the start values in the self-sustaining COM start control and COM start control, for example, a constant value can be used, or a value based on at least one of the engine speed Ne of the engine 22 and the intake manifold pressure Pinc at the time of closing can be used. As the start value in the TDC start control, for example, a constant amount can be used, or a value based on at least one of the stop crank angle θcrsp and the elapsed time since the engine 22 stopped rotating can be used. As the start value in the PUSH start control, for example, a value similar to the start value in the self-sustaining COM start control and COM start control can be used, or a value similar to the start value in the TDC start control can be used.

[0042] Next, the opening delay control permission flag Fd is input (step S102), and the value of the input delay process permission flag Fd is examined (step S110). Here, the opening delay control permission flag Fd is a flag for which a value of 1 is set when opening delay control is permitted, and a value of 0 is set when opening delay control is prohibited, and it is set by an opening delay control permission flag setting process described later.

[0043] When the opening delay control permission flag Fd has a value of 1 in step S110, that is, when opening delay control is permitted, as opening delay control, a delay is given to the required opening THtg of the throttle valve 124 to set the target opening TH* (step S120), and the throttle valve 124 is controlled using the set target opening TH* (step S140). Here, the delay time is preset by experiments, analysis, machine learning, or the like.

[0044] When the opening delay control permission flag Fd has a value of 0 in step S110, that is, when opening delay control is prohibited, as opening delay cut control, the required opening THtg of the throttle valve 124 is set to the target opening TH* (step S130). The throttle valve 124 is controlled using the set target opening TH* (step S140).

[0045] Subsequently, the in-cylinder air quantity Qcypr is calculated using a well-known air model based on the required opening THtg of the throttle valve 124 or the like (step S150), and this routine is terminated. FIG. 4 is a time chart showing the required opening THtg, the target opening TH*, the predicted in-cylinder air quantity Qcypr, and the actual in-cylinder air quantity Qcyac of the throttle valve 124 when the opening delay control is executed. As can be seen from FIG. 4, when the opening delay control is executed, the predicted in-cylinder air quantity Qcypr is a value that anticipates the actual in-cylinder air quantity Qcyac. In this way, the actual in-cylinder air quantity Qcyac can be accurately predicted (anticipated) by the predicted in-cylinder air quantity Qcypr. The predicted in-cylinder air quantity Qcy thus obtained is used for setting the target injection quantity Qf* when performing the calculation injection control as described above. Therefore, by accurately predicting the actual in-cylinder air quantity Qcyac, the target injection quantity Qf* can be set more appropriately when performing the calculation injection control.

[0046] Next, the process of setting the opening delay control permission flag Fd used in the air quantity control routine of FIG. 3 will be described using the opening delay control permission flag setting process of FIG. 5. This process is repeatedly executed in parallel with the routine of FIG. 3 or the like by the engine ECU 24 from when the stop request starts until the value 1 is set in the opening delay control permission flag Fd during the start control. In the embodiment, it is assumed that the opening delay control permission flag Fd is held at the value 1 until the stop request starts after the repeated execution of this process is completed.

[0047] In this process, the engine ECU 24 first checks the value of the current opening delay control permission flag Fd (step S200). When the opening delay control permission flag Fd has the value 1, that is, when the opening delay control is permitted, it is determined whether the start request has been made before or is being made (step S210).

[0048] When it is determined that it is before the start request is made in step S210, it is determined whether it is before or at the time of temporarily opening the throttle valve 124 in the air amount control (temporarily increasing the required opening degree THtg from the value 0) (step S220). When it is determined that it is before the throttle valve 124 is temporarily opened, the opening degree delay control permission flag Fd is held at the value 1, and this process ends. On the other hand, when it is determined that it is the time when the throttle valve 124 is temporarily opened, the opening degree delay control permission flag Fd is switched to the value 0 (step S240), and this process ends.

[0049] When it is determined that the start request is being made in step S210, it is determined whether it is during the FC return start control or during any of the independent COM start control, COM start control, TDC start control, and PUSH start control (step S230). When it is determined that it is during the FC return start control, the opening degree delay control permission flag Fd is held at the value 1, and the execution of this process is ended. In this case, the delay control permission flag Fd is held at the value 1 until the start of the next stop request. On the other hand, when it is determined that it is during any of the independent COM start control, COM start control, TDC start control, and PUSH start control, the opening degree delay control permission flag Fd is switched to the value 0 (step S240), and this process ends.

[0050] When the current opening degree delay control permission flag Fd has the value 0 in step S200, that is, when the opening degree delay control is prohibited, it is determined whether the start request is before or during the start request (step S250). When it is determined that the start request is before, the opening degree delay control permission flag Fd is held at the value 0, and this process ends.

[0051] When it is determined that a start request is being made in step S250, it is determined whether it is before or at the time of shifting the fuel injection control from the expected injection control to the calculated injection control (step S260). When it is determined that it is before shifting the fuel injection control from the expected injection control to the calculated injection control, the opening delay control permission flag Fd is held with the value 0, and this process ends. On the other hand, when it is determined that it is at the time of shifting the fuel injection control from the expected injection control to the calculated injection control, the opening delay control permission flag Fd is switched to the value 1 (step S270), and the execution of the repetition of this process ends. In this case, the delay control permission flag Fd is held with the value 1 until the start of the next stop request.

[0052] FIG. 6 is a time chart showing an example of the state when performing stop control or FC return start control. FIG. 7 is a time chart showing an example of the state when performing stop control or COM start control. In FIGS. 6 and 7, the type of the required opening THtg of the throttle valve 124 (any one of the value based on the reverse air model, the value for stop, and the value for start), the fuel injection control (either the expected injection control or the calculated injection control), the opening delay control permission flag Fd, the required opening THtg and the target opening TH* of the throttle valve 124, the rotational speed Nmg of the motor 30 and the rotational speed Ne of the engine 22, and the predicted in-cylinder air amount Qcypr and the actual in-cylinder air amount Qcyac are shown.

[0053] In the example of FIG. 6, when a stop request is made during the operation of the engine 22 (at time t11), the required opening THtg of the throttle valve 124 is shifted from the value based on the reverse air model to the value for stopping. At this time, since the opening delay control permission flag Fd has a value of 1, opening delay control is executed, and the target opening TH* follows the required opening THtg with a delay. Then, when a start request is made and the FC return start control is started (at time t12), the required opening THtg is shifted from the value for stopping to the value based on the reverse air model. Also at this time, since the opening delay control permission flag Fd has a value of 1, opening delay control is executed, and the target opening TH* follows the required opening THtg with a delay. By doing so, when the opening delay control is being executed, the actual in-cylinder air amount Qcyac can be accurately predicted (predicted in advance) by the predicted in-cylinder air amount Qcypr. Therefore, in the calculated injection control during the FC return start control, the target injection amount Qf* can be set more appropriately.

[0054] In the example of FIG. 7, when a stop request is made during the operation of the engine 22 (at time t11), the required opening THtg of the throttle valve 124 is shifted from the value based on the reverse air model to the value for stopping. At this time, since the opening delay control permission flag Fd has a value of 1, the opening delay control is executed, and the target opening TH* follows the required opening THtg with a delay. As a result, the actual in-cylinder air amount Qcyac can be accurately predicted (forecasted) by the predicted in-cylinder air amount Qcypr. Thereafter, when the required opening THtg is temporarily increased (when the throttle valve 124 is temporarily opened) (at time t22), the opening delay control permission flag Fd is switched to a value of 0. When the opening delay control permission flag Fd has a value of 0, the opening delay cut control is executed, and the target opening TH* is made the same as the required opening THtg. Thereby, the required opening THtg can be realized more quickly, and the in-cylinder air amount Qcy can be made to approach more quickly the air amount corresponding to the required opening THtg. Note that during the stop control, since fuel injection is not performed, it is considered that there is little possibility of a problem even if the prediction accuracy of the actual in-cylinder air amount Qcyac by the predicted in-cylinder air amount Qcypr decreases. And when a start request is made and the COM start control is started (at time t23), the required opening THtg is shifted from the value for stopping to the value for starting. Also at this time, since the opening delay control permission flag Fd has a value of 0, the opening delay cut control is executed, and the target opening TH* is made the same as the required opening THtg. Thereby, the required opening THtg can be realized more quickly, and the in-cylinder air amount Qcy can be made to approach more quickly the air amount corresponding to the required opening THtg. Note that at this time, it is the estimated injection control, and the target injection amount Qf* is set without depending on the predicted in-cylinder air amount Qcypr, so it is considered that there is little possibility of a problem even if the prediction accuracy of the actual in-cylinder air amount Qcyac by the predicted in-cylinder air amount Qcypr decreases. Thereafter, when the fuel injection control is shifted to the calculated injection control (at time t24), the opening delay control permission flag Fd is switched to a value of 1. When the opening delay control permission flag Fd has a value of 1, the opening delay control is executed, and the target opening TH* follows the required opening THtg with a delay.As a result, the in-cylinder air quantity Qcyac can be accurately predicted (forecasted) based on the predicted in-cylinder air quantity Qcypr.

[0055] In the engine device included in the hybrid vehicle 20 of the embodiment described above, for the engine 22, air quantity control is performed to control the throttle valve 124 using the target opening TH* based on the required opening THtg, and the predicted in-cylinder air quantity Qcypr is calculated using an air model based on the required opening THtg. Then, in the case of FC return start control (when performing calculation injection control from the first fuel injection), as air quantity control, opening delay control is executed from the start of the start request. By executing the opening delay control, the in-cylinder air quantity Qcyac can be accurately predicted (forecasted) based on the predicted in-cylinder air quantity Qcypr. Therefore, in the calculation injection control, the target injection quantity Qf* can be set more appropriately. Also, in the case of self-sustaining COM start control, COM start control, TDC start control, and PUSH start control (when shifting from predicted injection control to calculation injection control), as air quantity control, opening delay cut control is executed from the start of the start request until the end of the predicted injection control, and when shifting to the calculation injection control, it shifts to the opening delay control. By executing the opening delay cut control from the start of the start request until the end of the predicted injection control, the required opening THtg can be realized more quickly, and the in-cylinder air quantity Qcyac can be made to approach more quickly the air quantity corresponding to the required opening THtg. Note that during the predicted injection control, since the in-cylinder injection valve 127 is controlled using the target injection quantity Qf* not based on the predicted in-cylinder air quantity Qcypr, it is considered that there is a low possibility of a problem even if the prediction accuracy of the predicted in-cylinder air quantity Qcypr decreases. As a result, it is possible to more appropriately select whether to execute the opening delay control or the opening delay cut control.

[0056] In addition, in the engine device included in the hybrid vehicle 20 of the embodiment, during stop control, before temporarily opening the throttle valve 124, opening delay control is executed, and after temporarily opening the throttle valve 124, opening delay cut control is executed. As a result, before temporarily opening the throttle valve 124, the in-cylinder air amount Qcyac can be accurately predicted (pre-read) based on the air amount Qcypr. Further, when temporarily opening the throttle valve 124, the required opening THtg can be realized more quickly, and the in-cylinder air amount Qcyac can be made to approach more quickly the air amount corresponding to the required opening THtg.

[0057] In the engine device included in the hybrid vehicle 20 of the embodiment, during stop control, it was assumed that opening delay control is executed before temporarily opening the throttle valve 124, and opening delay cut control is executed after temporarily opening the throttle valve 124. However, during stop control, delay control may be executed regardless of whether or not the throttle valve 124 is temporarily opened.

[0058] In the engine device included in the hybrid vehicle 20 of the embodiment, the opening delay control permission flag setting process of FIG. 5 is repeatedly executed from the start of the stop request until the value 1 is set to the opening delay control permission flag Fd during the start control. After the execution of the repetition of the opening delay control permission flag setting process is terminated and until the stop request is started, the opening delay control permission flag Fd is maintained with the value 1. However, during the period from the termination of the repetition of the opening delay control permission flag setting process until the stop request is started, while the rotational speed Ne of the engine 22 is lower than the threshold value Neref4, the value 0 may be set to the delay control permission flag Fd. As the threshold value Neref4, the upper limit of the rotational speed range where engine stall may occur can be used, for example. By doing so, when the rotational speed Ne of the engine 22 decreases, the required opening THtg can be realized more quickly, and the in-cylinder air amount Qcyac can be made to approach more quickly the air amount corresponding to the required opening THtg. Therefore, when the rotational speed Ne of the engine 22 reaches less than the threshold value Neref4 and the required opening THtg is increased, the in-cylinder air amount Qcyac can be increased more quickly.

[0059] In the hybrid vehicle 20 of the embodiment, an automatic transmission 45 with six-speed shifting is provided. However, an automatic transmission with four-speed shifting, five-speed shifting, eight-speed shifting, or the like may be provided.

[0060] In the hybrid vehicle 20 of the embodiment, an engine ECU 24, a motor ECU 34, and an HV ECU 70 are provided. However, at least two of these may be integrally configured.

[0061] In the engine device of the embodiment, it is mounted on the hybrid vehicle 20, but it may be mounted on a moving body other than a vehicle or incorporated into equipment that does not move.

[0062] A description will be given of 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. In the embodiment, the engine 22 corresponds to the "engine", the clutch K0 corresponds to the "clutch", the motor 30 corresponds to the "motor", and the HVECU 70, the engine ECU 24, and the motor ECU 34 correspond to the "control device".

[0063] 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.

[0064] As described above, the embodiments have been used to explain the forms for implementing the present invention. However, the present invention is not limited to such embodiments, 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

[0065] The present invention can be used in the manufacturing industry of engine devices and the like.

Explanation of Reference Numerals

[0066] 20 Hybrid vehicle, 22 Engine, 23 Crankshaft, 24 Engine ECU, 25 Starter motor, 26 Alternator, 30 Motor, 30a Rotation position sensor, 31 Rotation 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 unit, 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 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, K0 Clutch.

Claims

【Claim 1】 An engine having a throttle valve and a fuel injection valve, a motor connected to an output shaft of the engine via a clutch, a control device that controls the engine, the motor, and the clutch, and performs air amount control for controlling the throttle valve using a target opening based on a required opening and fuel injection control for controlling the fuel injection valve using a target injection amount, and calculates a predicted in-cylinder air amount based on the required opening, An engine device comprising: The control device is When executing start control in accordance with a start request for the engine, As the fuel injection control, when executing calculation injection control for controlling the fuel injection valve using a target injection amount based on the predicted in-cylinder air amount from the first fuel injection, as the air amount control, opening delay control for controlling the throttle valve using a target opening with a delay in the required opening from the start of the start request is executed. As the fuel injection control, when executing estimated injection control for controlling the fuel injection valve using the target injection amount not based on the predicted in-cylinder air amount and then shifting to the calculation injection control, as the air amount control, opening delay cut control for controlling the throttle valve using the required opening as the target opening from the start of the start request to the end of the estimated injection control is executed, and when starting the calculation injection control, the opening delay control is shifted to. Engine device.

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