JP7707897B2 - Engine equipment - Google Patents

Description

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

Conventionally, this type of engine device has been proposed to be installed in a hybrid vehicle equipped with 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 hybrid vehicle, 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

However, in the engine device mounted on the hybrid vehicle described above, it may take time to extract power for driving from the started engine. In order to extract power for driving from the started engine, the clutch must be fully engaged, and in order to suppress the shock that occurs when the clutch is engaged, the engine speed must be matched to the motor speed. Therefore, it is necessary to quickly match the engine speed to the motor speed, but because the engine torque required to reach the motor speed differs depending on the engine speed, it takes time to match the engine speed to the motor speed.

The main purpose of the engine device of the present invention is to more quickly bring the engine speed after starting up to approximately match the motor speed.

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:
An engine device including an engine having an in-cylinder injection valve, a motor connected to an output shaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch,
The control device includes:
controlling the engine, the motor, and the clutch so as to half-engage the clutch to crank the engine using the motor and to start the engine by injecting fuel and igniting into a cylinder that reaches a compression top dead center first or second in the engine;
releasing the half-engagement of the clutch when a condition for releasing the clutch is satisfied during the cranking;
During the release of the half-engagement of the clutch, an ignition timing of the target cylinder that is to be the next target for ignition is set based on the rotation speed of the motor, the rotation speed of the engine, and an intake manifold pressure that is the pressure of the intake manifold when the intake valve of the target cylinder that is to be the next target for ignition is closed.
It is characterized by:

The engine device of the present invention includes an engine having an in-cylinder injection valve, a motor connected to the output shaft of the engine via a clutch, and a control device that controls the engine, motor, and clutch. The control device first half-engages the clutch to crank the engine using the motor, and controls the engine, motor, and clutch to start the engine by injecting fuel and igniting the cylinder that will reach the first or second compression top dead center in the engine. The control device releases the half-engagement of the clutch when a condition for releasing the clutch is met during cranking, and while the clutch is half-engaged, sets the ignition timing of the target cylinder based on the motor rotation speed, the engine rotation speed, and the intake manifold pressure, which is the pressure of the intake manifold when the intake valve of the target cylinder that is to be ignited next, is closed. In this way, while the clutch is half-engaged, the ignition timing of the target cylinder is set based on the motor rotation speed, the engine rotation speed, and the intake manifold pressure, so that the engine rotation speed can be more quickly made to match the motor rotation speed.

The reason for setting the ignition timing based on the motor RPM is that the higher the motor RPM, the greater the engine torque, which encourages an increase in engine RPM. The reason for setting the ignition timing based on the engine RPM is that the ignition timing is correlated with the engine RPM. The reason for setting the ignition timing based on the intake manifold pressure is that the higher the intake manifold pressure Pin, the greater the amount of air in the cylinder, which in turn increases the output torque from the engine.

In the engine device of the present invention, the control device may set the ignition timing of the target cylinder using a predefined map so that the higher the rotation speed of the motor, the more advanced the ignition timing is, the higher the rotation speed of the engine, and the higher the intake manifold pressure, the more retarded the ignition timing is. In this way, the ignition timing can be quickly set so that the engine rotation speed quickly matches the motor rotation speed.

In the engine device of the present invention, the control device may correct the ignition timing of the target cylinder based on the differential speed when the number of ignitions since starting the engine is equal to or greater than a predetermined number while the clutch is being released from the half-engagement state and the differential speed between the motor speed and the engine speed is equal to or greater than a predetermined speed. In this way, the engine speed can be quickly brought to approximately match the motor speed. In this case, the control device may correct the ignition timing of the target cylinder so that the differential speed becomes smaller.

1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention; FIG. 2 is a diagram showing an outline of the configuration of an engine 22. 4 is a flowchart showing an example of a starting ignition timing setting process executed by the HVECU 70, the engine ECU 24, etc.

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 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.

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 engine 22 rotation speed Ne 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 engine 22 rotation speed Ne. The engine ECU 24 also 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 engine 22 rotation speed Ne 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 θm 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 the communication port. The motor ECU 34 calculates the rotation speed Nm of the motor 30 based on the rotational position θm of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

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 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 controls the operation of the engine 22 (intake air amount control, fuel injection control, ignition control, etc.) so that the engine 22 operates at the target torque Te*. When the motor ECU 34 receives the torque command Tm*, it controls the switching of multiple switching elements of the inverter 32 so that the motor 30 is driven at 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 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.

Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the starting of the engine 22 when the engine 22 is intermittently operated, will be described. In the embodiment, the starting of the engine 22 when the engine 22 is intermittently operated is basically performed by half-engaging (slipping) the clutch K0 to output the target cranking torque Tcr* from the motor 30 to crank the engine 22, and performing the first fuel injection and ignition (initial explosion) in the cylinder that first reaches the compression top dead center (TDC) or the cylinder that second reaches the compression top dead center. The choice of whether to perform the initial fuel injection and ignition in the cylinder that reaches the compression top dead center first or the cylinder that reaches the compression top dead center second is basically made based on whether the crank angle (stop crank angle) θstop when the engine 22 is stopped is within a predetermined crank angle range (e.g., BTDC 40 to 80 (Before TDC 40 to 80 degrees)) that allows the initial explosion in the cylinder that reaches the compression top dead center first. In other words, when the stop crank angle θstop is within the predetermined crank angle range, the initial fuel injection and ignition is performed in the cylinder that reaches the compression top dead center first, and when the stop crank angle θstop is not within the predetermined crank angle range, the initial fuel injection and ignition is performed in the cylinder that reaches the compression top dead center second.

In the embodiment, in order to start the cylinder that reaches the compression top dead center first, the throttle valve 124 is temporarily opened just before the engine 22 is stopped and stopped within a predetermined crank angle range. The throttle valve 124 is temporarily opened just before the engine 22 is stopped in order to increase the amount of air in the cylinder that stops during the compression stroke. The fuel injection in the cylinder that reaches the compression top dead center first and the cylinder that reaches the compression top dead center second is performed by injecting the fuel injection amount set based on the stop crank angle θstop and the elapsed time since the engine 22 was stopped before the compression top dead center is reached. The reason why the fuel injection amount is based on the elapsed time since the engine 22 was stopped is that the pressure in the cylinder that is stopped during the compression stroke decreases over time, and the amount of air in the cylinder decreases. The throttle opening TH at the start of the engine 22 is basically a predetermined opening (for example, 5%). Ignition is performed by setting the ignition timing by the start-time ignition timing setting process illustrated in FIG. 3. In this start-time ignition timing setting process, the control of the clutch K0 is performed by the HVECU 70, and the setting of the ignition timing Ti is performed by the engine ECU 24.

When the start-time ignition timing setting process is executed, first, the clutch K0 is half-engaged (slip engaged) to output the target cranking torque Tcr* from the motor 30 to start cranking the engine 22 (step S100). This process is performed by sending a control signal from the HVECU 70 to a hydraulic control device (not shown) so that the clutch K0 is half-engaged (slip engaged), and sending the sum of the required torque Tin* required for the input shaft 41 and the target cranking torque Tcr* to the motor ECU 34 as the torque command Tm* for the motor 30. The hydraulic control device that receives the control signal adjusts the hydraulic pressure to a predetermined level so that the clutch K0 can transmit the target cranking torque Tcr* while slipping. The motor ECU 34 that receives the torque command Tm* controls the switching of the switching element (not shown) of the inverter 32 so that the torque command Tm* is output from the motor 30. In the embodiment, the target crank torque Tcr* is a torque sufficient to cause the cylinder stopped during the compression stroke to exceed the compression top dead center, and is set based on the stop crank angle θstop and the time elapsed since the engine 22 was stopped. It is based on the stop crank angle θstop in order to take into account the pressure in the cylinder stopped during the compression stroke, and it is based on the time elapsed since the engine 22 was stopped in order to take into account the fact that the pressure in the cylinder stopped during the compression stroke decreases over time.

Next, it is determined whether the cylinder is the first to reach the compression top dead center (step S110). When it is determined that the cylinder is the first to reach the compression top dead center, the ignition timing Ti is set based on the stop crank angle θstop, the target crank torque Tcr*, and the rotation speed Nmg of the motor 30 (step S120). In the cylinder that first performs fuel injection and ignition, the further the stop crank angle θstop is from the compression top dead center (larger as BTDC), the greater the amount of air in the cylinder. If the amount of air in the cylinder is large, the shock at the time of the initial explosion becomes large, so it is preferable to retard the ignition timing to reduce the shock. Therefore, in the embodiment, the ignition timing Ti is set to be retarded as the stop crank angle θstop is further from the compression top dead center (larger as BTDC) within the range of the retard limit at which ignition is possible. As described above, the target crank torque Tcr* is set to be larger as the amount of air in the cylinder that first reaches the compression top dead center increases. Therefore, in the embodiment, the ignition timing Ti is set to be retarded as the target cranking torque Tcr* is larger within the retard limit range where ignition is possible. In order to start the engine 22 quickly and run using the power from the engine 22 via the clutch K0, it is necessary to control the rotation speed Ne of the engine 22 to be approximately equal to the rotation speed Nmg of the motor 30 quickly and engage the clutch K0. If the rotation speed Nmg of the motor 30 is large, it takes time to make the rotation speed Ne immediately after the start of the engine 22 approximately equal to the rotation speed Nmg of the motor 30, so it is preferable to increase the torque of the engine 22 even at the first explosion to increase the rotation speed Ne of the engine 22. Therefore, in the embodiment, the ignition timing Ti is set to be advanced as the rotation speed Nmg of the motor 30 is larger. For these reasons, in the embodiment, the relationship between the stop crank angle θstop, the target crank torque Tcr*, the rotation speed Nmg of the motor 30, and the ignition timing Ti is determined in advance through experiments, analysis, machine learning, etc., and stored as a first ignition timing setting map, and when the stop crank angle θstop, the target crank torque Tcr*, and the rotation speed Nmg of the motor 30 are given, the corresponding ignition timing Ti is derived from the first ignition timing setting map and set.

When it is determined in step S110 that the cylinder is not the first to reach the compression top dead center (the cylinder is the second or later to reach the compression top dead center), the ignition timing Ti is set based on the target cranking torque Tcr*, the rotation speed Nmg of the motor 30, and the rotation speed Ne of the engine 22 (step S130). If the target cranking torque Tcr* is large, the rotation speed Ne of the engine 22 increases quickly and the engine 22 is more likely to rev up. For this reason, in the embodiment, the ignition timing Ti is set to be more retarded as the target cranking torque Tcr* is larger within the range of the retard limit at which ignition is possible. Since it is necessary to control the rotation speed Ne of the engine 22 to approximately match the rotation speed Nmg of the motor 30 quickly, in the embodiment, the ignition timing Ti is set to be more advanced as the rotation speed Nmg of the motor 30 is larger. Since the ignition timing Ti is correlated with the rotation speed Ne of the engine 22, in the embodiment, the ignition timing Ti is set according to the rotation speed Ne of the engine 22. For these reasons, in the embodiment, the relationship between the target cranking torque Tcr*, the rotation speed Nmg of the motor 30, the rotation speed Ne of the engine 22, and the ignition timing Ti is determined in advance through experiments, analysis, machine learning, etc., and stored as a second ignition timing setting map, and when the target cranking torque Tcr*, the rotation speed Nmg of the motor 30, and the rotation speed Ne of the engine 22 are given, the corresponding ignition timing Ti is derived from the second ignition timing setting map and set.

When the ignition timing Ti is set in this way, it is determined whether the condition for releasing the clutch K0 is satisfied (step S140). The condition for releasing the clutch K0 can be a condition that the number of times the compression top dead center has been passed is equal to or greater than a predetermined number (for example, two or three times), a condition that the rotation speed Ne of the engine 22 is increasing, and a condition that the rotation speed Ne of the engine 22 is equal to or greater than a threshold value based on the rotation speed Nmg of the motor 30. In the embodiment, it is determined that the condition for releasing the clutch K0 is satisfied when all of the above three conditions are satisfied. When it is determined that the condition for releasing the clutch K0 is not satisfied, the process returns to step S110, which determines whether the ignition in the cylinder that will next reach the compression top dead center is the first ignition (initial ignition). Therefore, the processes of steps S110 to S140 are repeated until the condition for releasing the clutch K0 is satisfied.

When it is determined in step S140 that the conditions for releasing the clutch K0 are met, the clutch K0 is released by controlling the hydraulic control device to wait at a hydraulic pressure that does not cause the clutch K0 to slip (step S150). The constant pressure wait is used in this way to quickly engage the next clutch K0.

When the clutch K0 is released, the process of setting the ignition timing Ti so that the rotation speed Ne of the engine 22 approximately matches the rotation speed Nmg of the motor 30 is repeated until the condition for engaging the clutch K0 is met (steps S160 to S200). The condition for engaging the clutch K0 can be, for example, that the differential rotation speed ΔN between the rotation speed Ne of the engine 22 and the rotation speed Nmg of the motor 30 is less than a threshold value (e.g., 50 rpm, 100 rpm, 150 rpm, etc.) and the number of ignitions is a predetermined number or more (e.g., 5 times, 6 times, 8 times, etc.). Note that the intake air amount and fuel injection amount during this repeated process are basically set so that the engine 22 approaches the rotation speed Nmg of the motor 30.

The repeated process until the condition for engaging the clutch K0 is satisfied is first performed by setting the ignition timing Ti based on the rotation speed Nmg of the motor 30, the rotation speed Ne of the engine 22, and the intake manifold pressure (intake manifold pressure) Pin at the timing of closing the intake valve 128 (step S160). In the embodiment, the surge pressure Ps from the pressure sensor 125a is used as the intake manifold pressure Pin. As described above, in order to quickly make the rotation speed Ne of the engine 22 approximately match the rotation speed Nmg of the motor 30, the ignition timing Ti is set to be more advanced as the rotation speed Nmg of the motor 30 is larger. In addition, since the ignition timing Ti is correlated with the rotation speed Ne of the engine 22, the ignition timing Ti is set according to the rotation speed Ne of the engine 22. The amount of air in the cylinder increases as the intake manifold pressure Pin at the timing when the intake valve 128 is closed increases, and the greater the amount of air in the cylinder, the greater the output torque from the engine 22. Therefore, in the embodiment, the ignition timing Ti is set to be retarded as the intake manifold pressure Pin at the timing when the intake valve 128 is closed increases. For these reasons, in the embodiment, the relationship between the rotation speed Nmg of the motor 30, the rotation speed Ne of the engine 22, the intake manifold pressure Pin, and the ignition timing Ti is determined in advance by experiments, analysis, machine learning, etc., and stored as a third ignition timing setting map, and when the rotation speed Nmg of the motor 30, the rotation speed Ne of the engine 22, and the intake manifold pressure Pin are given, the corresponding ignition timing Ti is derived from the third ignition timing setting map and set.

Next, it is determined whether the number of ignitions is a predetermined number (for example, 5 times or 6 times) or more (step S170), and whether the absolute value of the difference in rotation between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is equal to or more than the threshold value Nref (step S180). When it is determined that the number of ignitions is equal to or more than the predetermined number and the absolute value of the difference in rotation between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is equal to or more than the threshold value Nref, the ignition timing Ti is corrected in a direction in which the rotation speed Ne of the engine 22 approaches the rotation speed Nmg of the motor 30. Specifically, when Nmg>Ne, the ignition timing Ti is advanced by an angle obtained by multiplying the proportional constant k by the difference between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22. When Nmg<Ne, the ignition timing Ti is retarded. On the other hand, when it is determined that the number of ignitions is less than the predetermined number, or when it is determined that the absolute value of the difference in rotation speed between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is less than the threshold value Nref even if the number of ignitions is equal to or greater than the predetermined number, the above correction of the ignition timing Ti is not performed.

If it is determined in step S200 that the conditions for engaging the clutch K0 are met, the clutch K0 is engaged (step S210) and the process ends.

In the engine device mounted on the hybrid vehicle 20 of the embodiment described above, the clutch K0 is half-engaged (slip engaged) to output the target cranking torque Tcr* from the motor 30 to start cranking the engine 22 and start the engine 22, and the clutch K0 is released by controlling the clutch K0 to wait at a hydraulic pressure that does not slip when the condition for releasing the clutch K0 is met. Then, while the clutch K0 is being released, the process of setting the ignition timing Ti is repeated so that the rotation speed Ne of the engine 22 approximately matches the rotation speed Nmg of the motor 30 until the condition for engaging the clutch K0 is met. At this time, the ignition timing Ti is set based on the rotation speed Nmg of the motor 30, the rotation speed Ne of the engine 22, and the intake manifold pressure (intake manifold pressure) Pin at the timing for closing the intake valve 128. That is, the ignition timing Ti is set so that the higher the rotation speed Nmg of the motor 30, the more advanced the ignition timing Ti is, so that the ignition timing Ti corresponds to the rotation speed Ne of the engine 22, and so that the higher the intake manifold pressure Pin, the more retarded the ignition timing Ti is. This allows the rotation speed Ne of the engine 22 to be quickly brought to approximately the same value as the rotation speed Nmg of the motor 30.

Moreover, when the number of ignitions is equal to or greater than a predetermined number, and the absolute value of the difference in rotation speed between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is equal to or greater than the threshold value Nref, the ignition timing Ti is corrected in a direction such that the rotation speed Ne of the engine 22 approaches the rotation speed Nmg of the motor 30. That is, when Nmg>Ne, the ignition timing Ti is corrected to be advanced by an angle obtained by multiplying the proportional constant k by the difference between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22. When Nmg<Ne, the ignition timing Ti is corrected to be retarded. This allows the rotation speed Ne of the engine 22 to quickly match the rotation speed Nmg of the motor 30.

In the engine device mounted on the hybrid vehicle 20 of the embodiment, when the number of ignitions is equal to or greater than a predetermined number and the absolute value of the difference in rotation speed between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is equal to or greater than a threshold value Nref, the ignition timing Ti is corrected in a direction in which the rotation speed Ne of the engine 22 approaches the rotation speed Nmg of the motor 30. However, even if the number of ignitions is less than a predetermined number or the absolute value of the difference in rotation speed between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 is less than the threshold value Nref, the ignition timing Ti may be corrected in a direction in which the rotation speed Ne of the engine 22 approaches the rotation speed Nmg of the motor 30. In addition, the correction of the ignition timing Ti based on the number of ignitions or the difference in rotation speed between the rotation speed Nmg of the motor 30 and the rotation speed Ne of the engine 22 may not be performed.

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 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 (3)

An engine device including an engine having an in-cylinder injection valve, a motor connected to an output shaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch,
The control device includes:
controlling the engine, the motor, and the clutch so as to half-engage the clutch to crank the engine using the motor and to start the engine by injecting fuel and igniting into a cylinder that reaches a compression top dead center first or second in the engine;
releasing the half-engagement of the clutch when a condition for releasing the clutch is satisfied during the cranking;
while the clutch is being released from the half-engagement state, an ignition timing for the target cylinder is set based on a rotation speed of the motor, a rotation speed of the engine, and an intake manifold pressure that is a pressure in an intake manifold when an intake valve of the target cylinder that is to be the next target for ignition is closed ;
The ignition timing of the target cylinder is set using a preset map so that the ignition timing is advanced as the rotation speed of the motor increases, the ignition timing is advanced as the rotation speed of the engine increases, and the ignition timing is retarded as the intake manifold pressure increases.
An engine device characterized by: 2. The engine device according to claim 1 ,
When the number of ignitions since the start of the engine is equal to or greater than a predetermined number and the differential speed between the rotation speed of the motor and the rotation speed of the engine is equal to or greater than a predetermined rotation speed while the clutch is released from the half-engagement state, the control device corrects the ignition timing of the target cylinder based on the differential speed.
Engine equipment. 3. The engine device according to claim 2 ,
The control device corrects the ignition timing of the target cylinder so that the differential rotation speed becomes smaller.
Engine equipment.