JP7647604B2 - 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, as an engine device of this type, one that takes into consideration the position of the missing tooth, which is the reference position of the timing rotor, when stopping the operation of the engine has been proposed (see, for example, Patent Document 1). In this device, the sum of the angle at which the crankshaft is expected to rotate within the preparation time consisting of the mask time and control delay time required to detect the missing tooth of the timing rotor when starting the engine and the angle required to detect the reference position of the timing rotor is subtracted from 360 degrees crank angle, and the reference position of the timing rotor is controlled so that the reference position of the timing rotor stops as the crankshaft stops rotating within a target stopping range from the stopping position to a position a predetermined angle before that.

JP 2009-275635 A

However, in the above engine device, when the engine stops with the electromagnetic pickup at the missing tooth position, the crank angle cannot be detected accurately, and the startability of the engine is reduced. In particular, when starting the engine by injecting fuel and igniting in the cylinder that first reaches top dead center of compression, the fuel injection amount and ignition timing are set for the air amount that differs depending on the stop crank angle, so when the engine stops with the electromagnetic pickup at the missing tooth position, inconveniences arise such as unstable combustion at the initial explosion and a large shock at the initial explosion.

The main purpose of the engine device of the present invention is to ensure good engine startability even when the engine stops with the electromagnetic pickup at the position of the missing tooth.

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 a crankshaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch,
a crank angle sensor including a timing rotor attached to the crankshaft and having a plurality of protrusions formed on its outer periphery at equal angular intervals except for some missing teeth, and an electromagnetic pickup that detects the passage of the protrusions in response to rotation of the timing rotor,
the control device, when controlling the engine, the motor, and the clutch so as to half-engage the clutch to crank the engine by the motor and to start the engine by injecting fuel and igniting into a cylinder which first reaches a compression top dead center in the engine, sets an ignition timing for the cylinder which first reaches a compression top dead center based on a stop crank angle when the engine is stopped, a target crank torque when cranking by the motor, and a rotation speed of the motor;
When the electromagnetic pickup is located at the missing tooth position when the engine is stopped, the control device performs at least one of a fuel injection amount correction for correcting a fuel injection amount so that combustion by ignition becomes stable, or an ignition timing correction for correcting an ignition timing so that a shock of an initial explosion is suppressed.
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 engine output shaft via a clutch, a control device for controlling the engine, the motor, and the clutch, a timing rotor attached to the crankshaft with a plurality of protrusions formed on its outer periphery at equal angular intervals except for some missing teeth, and a crank angle sensor having an electromagnetic pickup for detecting the passage of the protrusions in response to the rotation of the timing rotor. When controlling the engine, the motor, and the clutch to crank the engine by half-engaging the clutch and to start the engine by injecting fuel and igniting the cylinder that first reaches compression top dead center in the engine, the control device sets the fuel injection amount for the cylinder that first reaches compression top dead center based on the elapsed time since the engine was stopped and sets the ignition timing based on the stop crank angle when the engine was stopped.

The stop crank angle of the cylinder that first reaches the compression top dead center is within 180 degrees before the compression top dead center (TDC) in a four-cylinder engine, and within 120 degrees before the compression top dead center in a six-cylinder engine. Therefore, in order to perform fuel injection and ignition (initial explosion) in the cylinder that first reaches the compression top dead center, fuel is injected during the compression stroke from the stop crank angle to the compression top dead center, and ignition is performed near the compression top dead center. The reason for setting the fuel injection amount based on the elapsed time since the engine was stopped when starting the engine is that the amount of air in the cylinder that first reaches the compression top dead center decreases the longer the elapsed time since the engine was stopped. The fuel injection amount for the cylinder that first reaches the compression top dead center when starting the engine may be set based not only on the elapsed time since the engine was stopped, but also on the stop crank angle (piston position) and the intake manifold pressure (intake manifold pressure) at the timing when the intake valve is closed. The reason why the fuel injection amount is set based on the stop crank angle (piston position) is because the closer the piston position is to the compression top dead center, the higher the pressure inside the cylinder, making it easier for air to escape from the piston rings. The reason why the fuel injection amount is set based on the intake manifold pressure is because the amount of air inside the cylinder increases as the intake manifold pressure increases. Thus, in order to obtain good startability at the first explosion, the fuel injection amount for the cylinder that first reaches the compression top dead center can be set to be smaller the longer the elapsed time since the engine was stopped, to be smaller the closer the stop crank angle (piston position) is to the compression top dead center, and to be larger the higher the intake manifold pressure.

In addition, the further the stop crank angle is from the compression top dead center (the larger the BTDC), the more air there is in the cylinder, and the greater the shock at the time of the initial explosion, so it is preferable to retard the ignition timing to reduce the shock. The ignition timing for the cylinder that first reaches the compression top dead center when starting the engine may be set not only based on the stop crank angle, but also based on the target cranking torque when cranking by the motor and the motor speed. The reason for setting the ignition timing based on the target cranking torque is that the target cranking torque is set to be larger the greater the amount of air in the cylinder that first reaches the compression top dead center, and the greater the amount of air in the cylinder, the greater the shock, so it is preferable to retard the ignition timing to reduce the shock. The reason for setting the ignition timing based on the motor speed is that the greater the motor speed, the longer it takes to make the engine speed approximately equal to the motor speed immediately after starting the engine, so it is preferable to increase the engine torque even at the initial explosion to increase the engine speed. As a result, in order to suppress the shock caused by the initial explosion, the ignition timing of the cylinder that reaches the compression top dead center first can be set to be more retarded the further the stop crank angle is from the compression top dead center of the target cylinder, more retarded the larger the target crank torque is, and more advanced the higher the motor speed is.

In the engine device of the present invention, when the electromagnetic pickup of the crank angle sensor is located at the missing tooth of the timing rotor when the engine is stopped, the control device performs at least one of the following: fuel injection amount correction, which corrects the fuel injection amount so that combustion due to ignition is stabilized, or ignition timing correction, which corrects the ignition timing so that the shock of the initial explosion is suppressed. The fuel injection amount correction corresponds to a correction to the fuel injection amount when the amount of air in the cylinder is the greatest in the crank angle range of the missing tooth. The ignition timing correction corresponds to a correction to the ignition timing when the amount of air in the cylinder is the greatest in the crank angle range of the missing tooth. This allows the engine to have good startability even when the engine is stopped with the electromagnetic pickup located at the missing tooth.

In the engine device of the present invention, when the electromagnetic pickup is at the position of the missing tooth when the engine is stopped, the control device may use the crank angle farthest from the compression top dead center of the cylinder that first reaches the compression top dead center within the crank angle range due to the missing tooth as the stop crank angle. By setting the stop crank angle to the crank angle farthest from the compression top dead center within the crank angle range due to the missing tooth, it is possible to assume the case where the amount of air in the cylinder that first reaches the compression top dead center within the crank angle range due to the missing tooth is the largest, and start the engine using a fuel injection amount and ignition timing appropriate for this assumption.

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 startup initial explosion process executed by an engine ECU 24 and an HVECU 70.

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 the 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. 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 of the pressure sensor include a throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 of the intake pipe 123, an intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and a surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples of the pressure sensor include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purifying device 135 of the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached between the purifying device 135 of the exhaust pipe 134 and the PM filter 136, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure (a pressure difference between the upstream side and the downstream side) before and after the PM filter 136. As is well known, the crank position sensor 140 is composed of a timing rotor with 34 protrusions, which are made by removing two consecutive protrusions as missing teeth from the 36 protrusions every 10 degrees on the outer circumference, and an electromagnetic pickup that detects the passage of the protrusions as the timing rotor rotates.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via the 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 a 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. After setting the required torque Tin* of the input shaft 41 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 the 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 operation for the initial explosion at the start of the engine 22 when the engine 22 is operating intermittently, will be described. In the embodiment, the engine 22 is started when the engine 22 is operating intermittently by basically half-engaging (slipping) the clutch K0 to output the target cranking torque Tcr* from the motor 30 to crank the engine 22, and the first fuel injection and ignition (initial explosion) are performed in the cylinder that first reaches the compression top dead center (TDC).

In addition, in this embodiment, in order to start the engine in the cylinder that first reaches the compression top dead center, 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 is stopped during the compression stroke. Figure 3 is a flowchart showing an example of the initial explosion process at start executed by the engine ECU 24 and the HVECU 70.

When the initial explosion process is executed at the start, first, a process is executed to input the crank angle (stop crank angle) θstop when the engine 22 is stopped (step S100). Then, it is determined whether the electromagnetic pickup of the crank angle sensor 140 is stopped at the position of the missing tooth (step S110). Whether the electromagnetic pickup of the crank angle sensor 140 is stopped at the position of the missing tooth can be determined by the stop crank angle θstop. When it is determined that the electromagnetic pickup of the crank angle sensor 140 is stopped at the position of the missing tooth, the crank angle θcr farthest from the compression top dead center of the cylinder that first reaches the compression top dead center within the range of the crank angle θcr of the missing tooth is set as the stop crank angle θstop (step S120). As described above, the timing rotor of the crank angle sensor 140 has 34 protrusions at 10 degree intervals, and two protrusions are formed consecutively as missing teeth. When the electromagnetic pickup stops at a position where there is a missing tooth, the stop crank angle θstop is uncertain by the maximum missing tooth (20 degrees). For example, even if the stop crank angle θstop is BTDC 40 (before TDC 40 degrees), when the electromagnetic pickup stops at a position where there is a missing tooth, it is unclear which position between BTDC 40 and BTDC 60 it is. In this case, in the process of step S120, BTDC 60, which is the farthest from the compression top dead center within the range of BTDC 40 to BTDC 60, is set as the stop crank angle θstop. In this way, the crank angle θcr farthest from the compression top dead center of the cylinder that first reaches the compression top dead center within the range of the crank angle θcr of the missing tooth is set as the stop crank angle θstop in order to improve the startability of the engine 22 and suppress the shock of the initial explosion by assuming the case where the amount of air in the cylinder that first reaches the compression top dead center within the range of the crank angle θcr of the missing tooth is the largest, and by setting the fuel injection amount Fi and ignition timing Ti appropriate for this assumption. Note that, if it is determined in step S110 that the electromagnetic pickup of the crank angle sensor 140 is not stopped at the position of the missing tooth, the stop crank angle θstop continues to be the one input in step S100.

Next, 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 S110). 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* of 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 a 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.

Then, the fuel injection amount Fi for the cylinder that first reaches the compression top dead center is set based on the elapsed time Tstop after the engine 22 is stopped, the stop crank angle θstop (position of the piston 132), and the intake manifold pressure (intake manifold pressure) Pin at the timing of closing the intake valve 128 (step S140). The reason for setting the fuel injection amount Fi based on the elapsed time Tstop after the engine 22 is stopped is that the amount of air in the cylinder that first reaches the compression top dead center decreases as the elapsed time Tstop after the engine 22 is stopped increases. The reason for setting the fuel injection amount Fi based on the stop crank angle θstop (position of the piston 132) is that the closer the position of the piston 132 is to the compression top dead center, the higher the pressure in the cylinder becomes, and the easier it is for air to escape from the piston ring. The reason for setting the fuel injection amount Fi based on the intake manifold pressure Pin is that the larger the intake manifold pressure Pin, the greater the amount of air in the cylinder. In order to obtain good startability at the initial explosion, it is preferable to set the fuel injection amount Fi for the cylinder that first reaches the compression top dead center so that it decreases as the elapsed time Tstop after the engine 22 is stopped is longer, decreases as the stop crank angle θstop (position of the piston 132) is closer to the compression top dead center, and increases as the intake manifold pressure Pin is larger. In the embodiment, the fuel injection amount Fi is set by determining in advance the relationship between the elapsed time Tstop after the engine 22 is stopped, the stop crank angle θstop (position of the piston 132), the intake manifold pressure Pin, and the fuel injection amount Fi through experiments, analysis, machine learning, etc., and storing it as a map for setting the fuel injection amount for the initial explosion, and setting it by deriving the corresponding fuel injection amount Fi from the map when the elapsed time Tstop, the stop crank angle θstop, and the intake manifold pressure Pin are given.

In addition to the above-mentioned setting of the fuel injection amount Fi, 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 S150). In the cylinder in which fuel injection and ignition are performed first, the amount of air in the cylinder increases as the stop crank angle θstop is farther from the compression top dead center (larger as BTDC). If the amount of air in the cylinder is large, the shock at the time of the first explosion increases, 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 farther 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 crank torque Tcr* is larger within the range of the retard limit at which 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 so as to quickly coincide with the rotation speed Nmg of the motor 30 and engage the clutch K0. If the rotation speed Nmg of the motor 30 is large, it takes time for the rotation speed Ne immediately after starting the engine 22 to coincide with the rotation speed Nmg of the motor 30. Therefore, it is preferable to increase the torque of the engine 22 even at the initial explosion to increase the rotation speed Ne of the engine 22. Therefore, in this embodiment, the ignition timing Ti is set to be more advanced as the rotation speed Nmg of the motor 30 increases. 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 by experiments, analysis, machine learning, etc., and stored as a map for setting the ignition timing for initial combustion. 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 map and set. Note that the ignition timing may be set by advancing or retarding the stop crank angle θstop, the target crank torque Tcr*, and the rotation speed Nmg of the motor 30 with respect to the timing near the compression top dead center, for example, ATDC5 (after TDC 5 degrees), as the basic ignition timing.

After the fuel injection amount Fi and the ignition timing Ti are set in this way, the set fuel injection amount Fi is injected from the in-cylinder injection valve 127 at a timing before the compression top dead center is reached, and ignition is performed at the set ignition timing Ti (step S160), and this process is terminated. After that, for the cylinder that reaches the compression top dead center from the second time onwards, the fuel injection amount Fi and the ignition timing Ti are set and performed so that the rotation speed Ne of the engine 22 approaches the rotation speed Nmg of the motor 30, and the engine 22 is controlled so that the rotation speed Ne of the engine 22 is synchronized with the rotation speed Nmg of the motor 30 while the clutch K0 is kept half-engaged (slip engagement) or while the clutch K0 is released from the half-engagement (slip engagement), and when the rotation speed Ne of the engine 22 is synchronized with the rotation speed Nmg of the motor 30, the clutch K0 is fully engaged and the start process of the engine 22 is terminated.

In the engine device mounted on the hybrid vehicle 20 of the embodiment described above, when 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, when fuel injection and ignition (initial explosion) are performed in the cylinder that first reaches the compression top dead center, the fuel injection amount Fi is set so that it decreases the longer the elapsed time Tstop after the engine 22 is stopped, the smaller the stop crank angle θstop (position of the piston 132) is closer to the compression top dead center, and the larger the intake manifold pressure Pin is. This makes it possible to more appropriately inject fuel into the cylinder that first reaches the compression top dead center, and to improve the startability of the engine 22. In addition, when starting the engine 22, when fuel injection and ignition (initial explosion) are performed in the cylinder that first reaches the compression top dead center, the ignition timing Ti is set so that the further the stop crank angle θstop is from the compression top dead center (larger as BTDC), the greater the target crank torque Tcr* is, the greater the advance is, and the greater the rotation speed Nmg of the motor 30 is. This allows the engine 22 to start quickly and suppresses the shock of the initial explosion. As a result, it is possible to achieve both good startability of the engine 22 and suppression of shock that may occur when the engine 22 is started.

In the engine device mounted on the hybrid vehicle 20 of the embodiment, when starting the engine 22, if the electromagnetic pickup of the crank angle sensor 140 is stopped at the position of the missing tooth, the crank angle θcr farthest from the compression top dead center of the cylinder that first reaches the compression top dead center within the range of the crank angle θcr of the missing tooth is set as the stop crank angle θstop, and the fuel injection amount Fi and ignition timing Ti of the cylinder that first reaches the compression top dead center are set using the set stop crank angle θstop. By setting the stop crank angle θstop in this way, it is possible to assume the case where the amount of air in the cylinder that first reaches the compression top dead center within the range of the crank angle θcr of the missing tooth is the largest, and it is possible to set the fuel injection amount Fi and ignition timing Ti appropriate for this assumption. As a result, even when the electromagnetic pickup of the crank angle sensor 140 is stopped at the position of the missing tooth, the startability of the engine 22 can be improved and the shock of the initial explosion can be suppressed.

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 spirit of the present 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 (2)

An engine device including an engine having an in-cylinder injection valve, a motor connected to a crankshaft of the engine via a clutch, and a control device that controls the engine, the motor, and the clutch,
a crank angle sensor including a timing rotor attached to the crankshaft and having a plurality of protrusions formed on its outer periphery at equal angular intervals except for some missing teeth, and an electromagnetic pickup that detects the passage of the protrusions in response to rotation of the timing rotor,
the control device, when controlling the engine, the motor, and the clutch so as to half-engage the clutch to crank the engine by the motor and to perform fuel injection and ignition for a cylinder that first reaches a compression top dead center in the engine to start the engine, sets a fuel injection amount for the cylinder that first reaches a compression top dead center based on the elapsed time since the engine was stopped and sets an ignition timing for the cylinder based on a stop crank angle when the engine was stopped,
When the electromagnetic pickup is located at the missing tooth position when the engine is stopped, the control device performs at least one of a fuel injection amount correction for correcting a fuel injection amount so that combustion by ignition becomes stable, or an ignition timing correction for correcting an ignition timing so that a shock of an initial explosion is suppressed.
An engine device characterized by: 2. The engine device according to claim 1,
when the electromagnetic pickup is at the position of the missing tooth when the engine is stopped, the control device uses, as the stop crank angle, the crank angle farthest from the compression top dead center of the cylinder that first reaches the compression top dead center within the crank angle range caused by the missing tooth.
Engine equipment.

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