JP7697376B2 - Engine equipment - Google Patents

Description

The present invention relates to an engine device, and more specifically, to an engine device that includes an engine and a motor connected to the output shaft of the engine via a clutch.

Conventionally, an engine device of this type has been proposed for installation in a hybrid vehicle that includes an engine, a motor connected to the engine's output shaft via a clutch, and an automatic transmission connected to the motor's rotating shaft and the axle (see, for example, Patent Document 1). In this engine device, when the vehicle is driven by the motor with the clutch released, the engine is started while controlling the clutch toward engagement.

JP 2020-111276 A

In such engine systems, in order to accurately predict (look ahead) the actual in-cylinder air volume for the engine, an opening delay control is performed to control the throttle valve using a target opening with a delay from the required opening, and the predicted in-cylinder air volume is calculated based on the required opening. However, there are cases where it is required to achieve the required opening more quickly. For this reason, how to select whether or not to execute opening delay control is an issue.

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

The engine device of the present invention employs the following means to achieve the above-mentioned main objective.

The engine device of the present invention comprises:
The gist of the present invention is as follows.

In the engine device of the present invention,
an engine having a throttle valve and a fuel injector;
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 an air amount control for controlling the throttle valve using a target opening based on a required opening of the engine, and a fuel injection control for controlling a 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 includes:
When executing a start control in response to a request to start the engine,
When a calculated injection control is executed as the fuel injection control, which controls the fuel injection valve using a target injection amount based on the predicted in-cylinder air amount from the first fuel injection, an opening delay control is executed as the air amount control, which controls the throttle valve using a target opening amount obtained by delaying a requested opening amount from the start of the start request,
In the case where a prospective injection control is executed as the fuel injection control, in which the fuel injection valve is controlled using the target injection amount not based on the predicted in-cylinder air amount, and then a transition is made to the calculated injection control, a delay cut control is executed as the air amount control, in which the throttle valve is controlled using the requested opening as the target opening from the start of the start request to the end of the prospective injection control, and when the calculated injection control is started, a transition is made to the delay cut control.
The gist of the present invention is as follows.

In the engine device of the present invention, air volume control is performed for the engine, in which the throttle valve is controlled using a target opening based on the requested opening, and fuel injection control is performed for the engine, in which the fuel injection valve is controlled using a target injection amount based on the predicted cylinder air volume, and a predicted cylinder air volume is calculated based on the requested opening. When starting control is performed in response to an engine start request, calculated injection control is performed as fuel injection control, in which the fuel injection valve is controlled from the first fuel injection using a target injection amount based on the predicted cylinder air volume, and opening delay control is performed as air volume control, in which the throttle valve is controlled using a target opening with a delay from the requested opening from the start of the start request. By performing opening delay control, the actual cylinder air volume can be accurately predicted (read ahead) using the predicted cylinder air volume. Therefore, the target injection volume can be set more appropriately in calculated injection control. In addition, when starting control is performed in response to an engine start request, if the fuel injection control is performed as a prospective injection control in which the fuel injection valve is controlled using a target injection amount not based on a predicted in-cylinder air amount, and then the control is switched to a calculated injection control, the air amount control is performed as an opening delay cut control in which the throttle valve is controlled using the requested opening as a target opening from the start of the start request to the end of the prospective injection control, and when the calculated injection control is started, the control is switched to an opening delay control. By performing the opening delay cut control from the start of the start request to the end of the prospective injection control, the requested opening can be realized more quickly, and the actual in-cylinder air amount can be made to approach the air amount corresponding to the requested opening more quickly. Note that, during the prospective injection control, the fuel injection valve is controlled using a target injection amount not based on a predicted in-cylinder air amount, so it is considered that even if the prediction accuracy of the predicted in-cylinder air amount decreases, it is unlikely to be a problem. As a result, it is possible to more appropriately select whether to perform the opening delay control or the opening delay cut control.

In the engine device of the present invention, when executing the stop control of the engine, the control device temporarily opens the throttle valve when the engine speed falls below a predetermined speed, and further, when executing the stop control, the control device may execute the opening delay control before temporarily opening the throttle valve, and execute the opening delay cut control after temporarily opening the throttle valve. In this way, before temporarily opening the throttle valve, the actual in-cylinder air volume can be accurately predicted (pre-read) based on the predicted in-cylinder air volume, and when temporarily opening the throttle valve, the required opening can be realized more quickly, and the actual in-cylinder air volume can be made to more quickly approach the air volume corresponding to the required opening.

1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device according to an embodiment of the present invention; 2 is a diagram showing an outline of the configuration of an engine 22 mounted on a hybrid vehicle 20. FIG. 4 is a flowchart showing an example of an air amount control routine executed by an engine ECU 24. 11 is a time chart showing the required opening THtg, the target opening TH*, the predicted in-cylinder air amount Qcypr, and the actual in-cylinder air amount Qcyac of the throttle valve 124 when the opening delay control is executed. 4 is a flowchart showing an example of an opening delay control permission/prohibition flag setting process executed by an engine ECU 24. 5 is a time chart showing an example of a state in which stop control and FC recovery start control are performed. 5 is a time chart showing an example of a state in which stop control and COM start control are performed.

Next, we will explain how to implement the present invention using examples.

Figure 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an engine device according to one embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of an engine 22 equipped in the hybrid vehicle 20. As shown in Figure 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.

The engine 22 is configured as a six-cylinder internal combustion engine that uses fuel such as gasoline or diesel and outputs 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 the intake port and an in-cylinder injection valve 127 that injects fuel into the cylinder. The engine 22 can be operated in any of the port injection mode, the in-cylinder injection mode, and the shared injection mode by having the port injection valve 126 and the in-cylinder injection valve 127. In the port injection mode, air cleaned 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 to mix the air and fuel. 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. The exhaust gas discharged from the combustion chamber 129 to the exhaust pipe 134 through the exhaust valve 133 is discharged to the outside air through 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 such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust gas. The PM filter 136 is formed as a porous filter using ceramics, stainless steel, or the like, and collects particulate matter (PM) such as soot in the exhaust gas. Note that instead of the PM filter 136, a four-way catalyst that combines the purification function of the three-way catalyst with the function of collecting particulate matter may be used.

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 the input ports. Examples of 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 cooling water temperature Tw from the water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. 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 can also be mentioned. Other 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 of the intake pipe 123, the intake air temperature Ta from the temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and the surge pressure Ps from the pressure sensor 125a attached to the surge tank 125. Other examples include the front air-fuel ratio AF1 from the front air-fuel ratio sensor 137 attached upstream of the purifier 135 of the exhaust pipe 134, the rear air-fuel ratio AF2 from the rear air-fuel ratio sensor 138 attached between the purifier 135 of the exhaust pipe 134 and the PM filter 136, 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) of the PM filter 136.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. 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 spark plug 130.

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

As shown in FIG. 1, a starter motor 25 for cranking the engine 22 and an alternator 26 for generating electricity 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.

The motor 30 is configured as a synchronous generator motor, and has a rotor with a permanent magnet embedded in the rotor core, and a stator with a three-phase coil wound around the stator core. The rotating shaft 31 to which the rotor of the motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via the 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 power line 61. The motor 30 is driven to rotate by the motor electronic control unit (hereinafter referred to as the "motor ECU") 34 controlling the switching of multiple switching elements of the inverter 32.

Although not shown, the motor ECU 34 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the motor ECU 34 via the input port. Examples of signals input to the motor ECU 34 include the rotational position θmg from the rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and the phase currents Iu and Iv from the current sensors that detect the phase currents of each phase of the motor 30. The motor ECU 34 outputs control signals to the inverter 32 and the like via the output port. The motor ECU 34 is connected to the HVECU 70 via a communication port. The motor ECU 34 calculates the rotation speed Nmg of the motor 30 based on the rotational position θmg of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

The clutch K0 is configured, for example, as 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.

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 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, with the torque amplified, 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 the drive wheels 49 via a differential gear 48, multiple planetary gears, and multiple hydraulically driven friction engagement elements (clutches, brakes). Each of the multiple friction engagement elements has a hydraulic servo consisting of a piston, multiple friction engagement plates (friction plates and separator plates), an oil chamber to which hydraulic oil is supplied, etc. The automatic transmission 45 forms forward gears from 1st to 6th gears and reverse gears by engaging and disengaging multiple friction engagement elements, and transmits power between the transmission input shaft 44 and the output shaft 42. The hydraulic pressure of the 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 multiple oil passages, multiple regulator valves, multiple linear solenoid valves, etc. This hydraulic control device is controlled by the HVECU 70.

The 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 the high-voltage 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 12 or 14 volts, and is connected to the low-voltage power line 63 together with the starter motor 25 and the alternator 26. The DC/DC converter 64 is connected to the high-voltage power line 61 and the low-voltage power line 63. This DC/DC converter 64 supplies power from the high-voltage power line 61 to the low-voltage power line 63 with a voltage step-down.

Although not shown, the HVECU 70 is equipped with 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 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. 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 can also be mentioned. Other examples 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.

Various control signals are output from the HVECU 70 via output ports. 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. Other examples include control signals 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 communication ports. The HVECU 70 calculates the 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.

In this embodiment, the engine device corresponds to the engine 22, the clutch K0, the motor 30, the HVECU 70, the engine ECU 24, and the motor ECU 34.

In the hybrid vehicle 20 of the embodiment thus configured, the engine 22, clutch K0, motor 30, and automatic transmission 40 are controlled by cooperative control between the HVECU 70, engine ECU 24, and motor ECU 34 so that the vehicle runs 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 engaged and the vehicle runs using the power of the engine 22, and the EV driving mode is a mode in which the clutch K0 is released and the vehicle runs without using the power of the engine 22.

When controlling the automatic transmission 40 in the HV driving mode or the EV driving mode, the HVECU 70 first sets the 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*.

In controlling the engine 22 and the motor 30 in the HV driving mode, the HVECU 70 first sets the required torque Tout* required for driving (required for 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 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, and the target torque Te* of the engine 22 is sent to the engine ECU 24 and the torque command Tm* of the motor 30 is sent to the motor ECU 34. When the engine ECU 24 receives the target torque Te*, it performs operation control of the engine 22 (air amount control to control the throttle valve 124, fuel injection control to control the port injection valve 126 and the in-cylinder injection valve 127, ignition control to control the spark plug 130, etc.) so that the engine 22 operates at the target torque Te*. When the motor ECU 34 receives the torque command Tm*, it performs switching control of multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

In controlling the motor 30 in the EV driving mode, the HVECU 70 sets the required torque Tin* of the input shaft 41 in the same manner as in the HV driving 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 the set torque command Tm* to the motor ECU 34. Upon receiving the torque command Tm*, the motor ECU 34 controls the switching of multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

In addition, in the hybrid vehicle 20 of the embodiment, when a request to stop the engine 22 is made while the engine 22 is in operation, the engine ECU 70, the engine ECU 24, and the motor ECU 34 perform cooperative control to stop the engine 22. The request to stop is made, for example, when the 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 and the throttle valve 124 is closed, and when the rotation speed Ne of the engine 22 falls below the threshold value Neref1 (for example, about 600 rpm to 800 rpm), the clutch K0 is released, and further, when the rotation speed Ne of the engine 22 falls below the threshold value Neref2 that is lower than the threshold value Neref1 (for example, about several hundred rpm lower), the throttle valve 124 is temporarily opened. The reason for temporarily opening the throttle valve 124 will be described later.

When a request to start the engine 22 is made while fuel injection and ignition of the engine 22 are stopped, the engine 22 start control is executed. The start request is made, for example, when a condition is met in which the required torque Tin* is equal to or greater than a threshold value Tinref. Examples of the start control of the engine 22 include FC (Fuel Cut) recovery start control, independent COM (Change Of Mind) start control, COM start control, TDC (Top Dead Center) start control, and PUSH start control. The method of start control is selected, for example, based on the rotation speed Ne of the engine 22 and the rotation 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.

FC recovery start control is basically performed when a start request is made and the engine 22 rotation speed Ne is equal to or greater than the threshold value Neref1 (the clutch K0 is engaged) and the motor 30 rotation speed Nmg is equal to or greater than the threshold value Nmgref (e.g., the same value as the threshold value Neref1). In FC recovery start control, fuel injection and ignition of the engine 22 are basically started while the clutch K0 continues to be engaged.

Independent COM start control is basically performed when a start request is made, the engine 22 rotation speed Ne is less than the threshold Neref1 (the clutch K0 is released) and is equal to or greater than the lower threshold Neref3 (e.g., several hundred rpm lower), and the motor 30 rotation speed Nmg is equal to or greater than the threshold Nmgref. In independent COM start control, the engine 22 fuel injection and ignition are started while the clutch K0 is continued to be released, the engine 22 is controlled so that the differential rotation speed ΔN between the motor 30 rotation speed Nmg and the engine 22 rotation speed Ne is small, and the clutch K0 is engaged when the clutch K0 engagement condition is met. The clutch K0 engagement condition can be, for example, a condition in which the differential rotation speed ΔN is less than the threshold ΔNref (e.g., about 50 rpm to 150 rpm).

COM start control is basically performed when a start request is made, the engine 22 rotation speed Ne is less than the threshold value Neref3 and greater than 0, and the motor 30 rotation speed Nmg is equal to or greater than the threshold value Nmgref. In COM start control, the clutch K0 is basically half-engaged (slip-engaged) to crank the engine 22 using the cranking torque from the motor 30 while starting fuel injection and ignition, the clutch K0 is released while controlling the engine 22 so that the differential rotation speed ΔN becomes small, and the clutch K0 is engaged when the above-mentioned clutch K0 engagement condition is met.

TDC start control is basically performed when the engine 22 rotation speed Ne is 0 (the engine 22 is stopped) and the motor 30 rotation speed Nmg is equal to or greater than the threshold value Nmgref when a start request is made. In TDC start control, the clutch K0 is half-engaged (slip-engaged) to crank the engine 22 using the cranking torque from the motor 30, and the first fuel injection and ignition are performed in the cylinder that reaches the compression top dead center first (target cylinder No. 1) or the cylinder that reaches the compression top dead center second (target cylinder No. 2). The clutch K0 is released while controlling the engine 22 so that the differential rotation speed ΔN is small, and the clutch K0 is engaged when the above-mentioned clutch K0 engagement condition is met. The selection of which of the first target cylinder and the second target cylinder is to perform the initial fuel injection and ignition is basically made based on whether the crank angle (stop crank angle) θcrsp when the engine 22 is stopped intermittently (stopped rotating) is within a predetermined crank angle range (e.g., BTDC 40 to 80 (before TDC 40 to 80 degrees)) in which the first explosion can be performed 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 rotation speed Ne of the engine 22 becomes less than the threshold value Neref2 during the stop control, the throttle valve 124 is temporarily opened. This is to ensure that there is a large amount of air in the first target cylinder in preparation for when the first fuel injection and ignition will be performed in the first target cylinder.

PUSH start control is basically performed when the rotation speed Nmg of the motor 30 is less than the threshold value Nmgref when a start request is made. In PUSH start control, the clutch K0 is basically half-engaged (slip-engaged) to crank the engine 22 using the cranking torque from the motor 30, and when the above-mentioned clutch K0 engagement condition is met, the clutch K0 is engaged, and then fuel injection and ignition of the engine 22 are started.

In the embodiment, during FC recovery start control, calculated injection control is executed from the first fuel injection as fuel injection control that controls the in-cylinder injection valve 127 using the target injection amount Qf*. In calculated injection control, the target injection amount Qf* is basically set so that the front air-fuel ratio AF1 becomes the target air-fuel ratio AF1* (e.g., theoretical air-fuel ratio) based on the predicted in-cylinder air amount Qcypr, which is a 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 method of calculating the predicted in-cylinder air amount Qcypr will be described later.

In addition, in the case of independent COM start control, COM start control, TDC start control, and PUSH start control, as fuel injection control, prospective injection control is executed from the first fuel injection until the transition condition is satisfied, and when the transition condition is satisfied, the fuel injection control is switched to calculated injection control. In prospective injection control, the target injection amount Qf* is basically set without being based on the predicted in-cylinder air amount Qcypr, the front air-fuel ratio AF1, or 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 prospective injection control in independent COM start control or COM start control, for example, a fixed amount can be used, or a value based on at least one of the rotation speed Ne of the engine 22 and the intake manifold pressure Pin (surge pressure Ps) when the intake valve 128 of the target cylinder is closed can be used. The target injection amount Qf* in the prospective injection control in the TDC start control can be, for example, a fixed amount, or a value based on at least one of the stop crank angle θcrsp and the time elapsed since the engine 22 stopped rotating. The target injection amount Qf* in the prospective injection control in the PUSH start control can be, for example, a value similar to the target injection amount Qf* in the prospective injection control in the independent COM start control or the COM start control, or a value similar to the target injection amount Qf* in the prospective injection control in the TDC start control. The transition condition for transitioning from the prospective injection control to the calculated injection control can be, for example, a condition in which the number of fuel injections (number of fuel injection cylinders) is a predetermined number (for example, about 6 to 9 times) or more, and the rotation speed Ne of the engine 22 is a predetermined rotation speed (for example, about 300 to 500 rpm).

Next, the operation of the hybrid vehicle 20 of the embodiment will be described, in particular 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. FIG. 3 is a flowchart showing an example of an air amount control routine executed by the engine ECU 24. This routine is executed repeatedly.

In the air amount control routine of FIG. 3, the engine ECU 24 first inputs the required opening THtg of the throttle valve 124 (step S100). Here, the required opening THtg of the throttle valve 124 is basically set using a 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. In addition, during the stop control, a somewhat large value is set as a stop value when the throttle valve 124 is temporarily opened, and an approximate value of 0 is set otherwise. Furthermore, during the FC recovery start control among the start controls, the inverse air model is used based on the target in-cylinder air amount Qcy*, and during the independent COM start control, COM start control, TDC start control, and PUSH start control among the start controls, a start value is set. The starting value in the independent COM start control or COM start control may be, for example, a constant value or a value based on at least one of the engine 22 rotation speed Ne or the closed intake manifold pressure Pinc. The starting value in the TDC start control may be, for example, a constant amount or a value based on at least one of the stop crank angle θcrsp or the elapsed time since the engine 22 stopped rotating. The starting value in the PUSH start control may be, for example, a value similar to the starting value in the independent COM start control or COM start control or a value similar to the starting value in the TDC start control.

Then, the opening delay control permission flag Fd is input (step S102), and the value of the input delay processing permission flag Fd is checked (step S110). Here, the opening delay control permission flag Fd is a flag that is set to a value of 1 when the opening delay control is permitted, and is set to a value of 0 when the opening delay control is prohibited, and is set by the opening delay control permission flag setting process described later.

When the opening delay control permission flag Fd is set to 1 in step S110, i.e., when the opening delay control is permitted, the target opening TH* is set by adding a delay to the required opening THtg of the throttle valve 124 as the opening delay control (step S120), and the throttle valve 124 is controlled using the set target opening TH* (step S140). Here, the delay time is set in advance by experiment, analysis, machine learning, etc.

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

Next, the predicted in-cylinder air amount Qcypr is calculated using a known air model based on the required opening THtg of the throttle valve 124, etc. (step S150), and this routine is terminated. FIG. 4 is a time chart showing the required opening THtg of the throttle valve 124, the target opening TH*, the predicted in-cylinder air amount Qcypr, and the actual in-cylinder air amount Qcyac 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 amount Qcypr becomes a value obtained by reading the actual in-cylinder air amount Qcyac in advance. In this way, the actual in-cylinder air amount Qcyac can be accurately predicted (read ahead) by the predicted in-cylinder air amount Qcypr. The predicted in-cylinder air amount Qcy thus obtained is used to set the target injection amount Qf* when the calculation injection control is executed, as described above. Therefore, by accurately predicting the actual in-cylinder air volume Qcyac, the target injection volume Qf* can be set more appropriately when performing calculated injection control.

Next, the process for setting the opening delay control permission flag Fd used in the air volume control routine in FIG. 3 will be explained using the opening delay control permission flag setting process in FIG. 5. This process is repeatedly executed by the engine ECU 24 in parallel with the routine in FIG. 3 and the like from the start of a stop request until the opening delay control permission flag Fd is set to a value of 1 during start control. In this embodiment, the opening delay control permission flag Fd is held at a value of 1 from the end of the repeated execution of this process until the start of a stop request.

In this process, the engine ECU 24 first checks the current value of the opening delay control permission flag Fd (step S200), and when the opening delay control permission flag Fd is set to a value of 1, i.e., when opening delay control is permitted, it determines whether a start request has not yet been made or has been made (step S210).

If it is determined in step S210 that a start request has not yet been made, it is determined whether the throttle valve 124 is about to be temporarily opened in the air flow control (the requested opening THtg is temporarily increased from the value 0) (step S220). If it is determined that the throttle valve 124 is about to be temporarily opened, the opening delay control permission flag Fd is held at a value of 1, and the process ends. On the other hand, if it is determined that the throttle valve 124 is about to be temporarily opened, the opening delay control permission flag Fd is switched to a value of 0 (step S240), and the process ends.

When it is determined in step S210 that a start request is being made, it is determined whether the current control is FC recovery start control, independent COM start control, COM start control, TDC start control, or PUSH start control (step S230). If it is determined that the current control is FC recovery start control, the opening delay control permission flag Fd is held at a value of 1, and the repeated execution of this process is terminated. In this case, the delay control permission flag Fd is held at a value of 1 until the start of the next stop request. On the other hand, if it is determined that the current control is independent COM start control, COM start control, TDC start control, or PUSH start control, the opening delay control permission flag Fd is switched to a value of 0 (step S240), and this process is terminated.

When the current opening delay control permission flag Fd is 0 in step S200, i.e., when the opening delay control is prohibited, it is determined whether a start request has been made before or since (step S250). If it is determined that a start request has not been made before, the opening delay control permission flag Fd is maintained at 0, and this process is terminated.

When it is determined in step S250 that a start request is being made, it is determined whether it is before or at the time of transition of fuel injection control from predictive injection control to calculated injection control (step S260). Then, when it is determined that the fuel injection control is before transition from predictive injection control to calculated injection control, the opening delay control permission flag Fd is held at a value of 0, and this process is terminated. On the other hand, when it is determined that the fuel injection control is about to transition from predictive injection control to calculated injection control, the opening delay control permission flag Fd is switched to a value of 1 (step S270), and the repeated execution of this process is terminated. In this case, the delay control permission flag Fd is held at a value of 1 until the start of the next stop request.

Figure 6 is a time chart showing an example of the state when stop control and FC recovery start control are performed. Figure 7 is a time chart showing an example of the state when stop control and COM start control are performed. Figures 6 and 7 show the type of required opening THtg of the throttle valve 124 (either a value based on the inverse air model, a value for stop, or a value for start), fuel injection control (either prospective injection control or calculated injection control), opening delay control permission flag Fd, the required opening THtg and target opening TH* of the throttle valve 124, the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22, the predicted in-cylinder air amount Qcypr, and the actual in-cylinder air amount Qcyac.

In the example of FIG. 6, when a stop request is made during operation of the engine 22 (time t11), the requested opening THtg of the throttle valve 124 is shifted from a value based on the inverse air model to a value for stopping. At this time, the opening delay control permission flag Fd is set to a value of 1, so opening delay control is executed, and the target opening TH* is made to follow the requested opening THtg with a delay. Then, when a start request is made and the FC recovery start control is started (time t12), the requested opening THtg is shifted from a value for stopping to a value based on the inverse air model. At this time, the opening delay control permission flag Fd is also set to a value of 1, so opening delay control is executed, and the target opening TH* is made to follow the requested opening THtg with a delay. In this way, when the opening delay control is being executed, the actual in-cylinder air amount Qcyac can be accurately predicted (pre-read) by the predicted in-cylinder air amount Qcypr. Therefore, the target injection amount Qf* can be set more appropriately in the calculated injection control during FC recovery start control.

In the example of FIG. 7, when a stop request is made during operation of the engine 22 (time t11), the requested opening THtg of the throttle valve 124 is shifted from a value based on the inverse air model to a value for stopping. At this time, since the opening delay control permission flag Fd is a value of 1, the opening delay control is executed, and the target opening TH* is made to follow the requested opening THtg with a delay. This allows the actual in-cylinder air amount Qcyac to be predicted (pre-read) with high accuracy by the predicted in-cylinder air amount Qcypr. Thereafter, when the requested opening THtg is temporarily increased (the throttle valve 124 is temporarily opened) (time t22), the opening delay control permission flag Fd is switched to a value of 0. When the opening delay control permission flag Fd is a value of 0, the opening delay cut control is executed, and the target opening TH* is made the same as the requested opening THtg. This allows the required opening THtg to be realized more quickly, and the in-cylinder air amount Qcy to approach the air amount corresponding to the required opening THtg more quickly. Since fuel injection is not performed during the stop control, it is considered that even if the prediction accuracy of the actual in-cylinder air amount Qcyac by the predicted in-cylinder air amount Qcypr decreases, it is unlikely to cause a problem. Then, when a start request is made and the COM start control is started (time t23), the required opening THtg is shifted from the stop value to the start value. At this time, since the opening delay control permission flag Fd is also set to the value 0, the opening delay cut control is executed, and the target opening TH* is made the same as the required opening THtg. This allows the required opening THtg to be realized more quickly, and the in-cylinder air amount Qcy to approach the air amount corresponding to the required opening THtg more quickly. At this time, since the fuel injection control is prospective and the target injection amount Qf* is set without being based on the predicted in-cylinder air amount Qcypr, it is considered that even if the prediction accuracy of the actual in-cylinder air amount Qcyac by the predicted in-cylinder air amount Qcypr decreases, it is unlikely to cause a problem. After that, when the fuel injection control is shifted to the calculated injection control (time t24), the opening delay control permission flag Fd is switched to a value of 1. When the opening delay control permission flag Fd is a value of 1, the opening delay control is executed, and the target opening TH* is made to follow the required opening THtg with a delay. This allows the actual in-cylinder air amount Qcyac to be predicted (read ahead) with high accuracy by the predicted in-cylinder air amount Qcypr.

In the engine device provided in the hybrid vehicle 20 of the embodiment described above, air volume control is performed for the engine 22 to control the throttle valve 124 using a target opening TH* based on the required opening THtg, and a predicted in-cylinder air volume Qcypr is calculated using an air model based on the required opening THtg. In the case of FC recovery start control (when calculation injection control is performed from the first fuel injection), opening delay control is performed from the start of the start request as air volume control. By performing opening delay control, the actual in-cylinder air volume Qcyac can be accurately predicted (read ahead) using the predicted in-cylinder air volume Qcypr. Therefore, the target injection volume Qf* can be set more appropriately in the calculation injection control. In addition, in the case of independent COM start control, COM start control, TDC start control, and PUSH start control (when performing prospective injection control and then transitioning to calculated injection control), the opening delay cut control is executed as the air amount control from the start of the start request to the end of prospective injection control, and when transitioning to calculated injection control, the opening delay control is executed. By executing the opening delay cut control from the start of the start request to the end of prospective injection control, the requested opening THtg can be realized more quickly, and the actual in-cylinder air amount Qcyac can be made to approach the air amount corresponding to the requested opening THtg more quickly. In addition, in the case of prospective injection control, the in-cylinder injection valve 127 is controlled using the target injection amount Qf* that is not based on the predicted in-cylinder air amount Qcypr, so it is considered that even if the prediction accuracy of the predicted in-cylinder air amount Qcypr decreases, it is unlikely to become a problem. As a result, it is possible to more appropriately select whether to execute the opening delay control or the opening delay cut control.

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

In the engine device of the hybrid vehicle 20 of the embodiment, during stop control, opening delay control is executed before the throttle valve 124 is temporarily opened, and opening delay cut control is executed after the throttle valve 124 is temporarily opened. However, during stop control, delay control may be executed regardless of whether the throttle valve 124 is temporarily opened or not.

In the engine device of 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 opening delay control permission flag Fd is set to a value of 1 during start control, and the opening delay control permission flag Fd is held at a value of 1 from the end of the repeated execution of the opening delay control permission flag setting process until the start of the stop request. However, the delay control permission flag Fd may be set to a value of 0 throughout the period during which the rotation speed Ne of the engine 22 falls below the threshold value Neref4 from the end of the repeated execution of the opening delay control permission flag setting process until the start of the stop request. As the threshold value Neref4, the upper limit of the rotation speed range in which the engine stall may occur can be used. In this way, when the rotation speed Ne of the engine 22 falls, the required opening THtg can be realized more quickly, and the actual in-cylinder air amount Qcyac can be more quickly approached to the air amount corresponding to the required opening THtg. Therefore, when the engine 22 speed Ne falls below the threshold Neref4 and the required opening THtg is increased, the actual in-cylinder air amount Qcyac can be increased more quickly.

In the embodiment, the hybrid vehicle 20 is equipped with a six-speed automatic transmission 45. However, it may be equipped with a four-speed, five-speed, eight-speed, or other automatic transmission.

In the embodiment, the hybrid vehicle 20 is equipped with an engine ECU 24, a motor ECU 34, and an HVECU 70. However, at least two of these may be integrated into one unit.

The engine device in the embodiment is mounted on a hybrid vehicle 20, but it may be mounted on a moving object other than a vehicle or incorporated into stationary equipment.

The following describes 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. 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".

The correspondence between the main elements of the Examples and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the Examples are examples for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving 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 Means for Solving the Problem column.

The above describes the form for carrying out the present invention using examples, but 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 invention.

The present invention can be used in the engine equipment manufacturing industry, etc.

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 Revolution speed sensor, 42 Output shaft, 42a Revolution speed sensor, 43 Torque converter, 44 Transmission input shaft, 44a Revolution speed sensor, 45 Automatic transmission, 48 Differential gear, 49 Drive wheels, 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, K0 clutch.

Claims (1)

an engine having a throttle valve and a fuel injector;
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 an air amount control for controlling the throttle valve using a target opening based on a required opening of the engine, and a fuel injection control for controlling a 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 includes:
When executing a start control in response to a request to start the engine,
When a calculated injection control is executed as the fuel injection control, which controls the fuel injection valve using a target injection amount based on the predicted in-cylinder air amount from the first fuel injection, an opening delay control is executed as the air amount control, which controls the throttle valve using a target opening amount obtained by delaying a requested opening amount from the start of the start request,
In the case where a prospective injection control is executed as the fuel injection control, in which the fuel injection valve is controlled using the target injection amount not based on the predicted in-cylinder air amount, and then a transition is made to the calculated injection control, a delay cut control is executed as the air amount control, in which the throttle valve is controlled using the requested opening as the target opening from the start of the start request to the end of the prospective injection control, and when the calculated injection control is started, a transition is made to the delay cut control.
Engine equipment.

Images