Engine equipment

Abstract

To suppress shock caused when nearly matching a rotation speed of an engine with a rotation speed of a motor.SOLUTION: An engine device comprises an engine having an injection valve in a cylinder, a motor connected to an output shaft of the engine through a clutch, and a control device that controls the engine, the motor and the clutch. The control device brings the clutch into a half-engagement state to make the motor crank the engine and controls the engine, the motor and the clutch so that the engine is started by injecting fuel to a cylinder reaching a compression top dead center first or second in the engine and performing ignition. In the middle of the cranking, when all of three conditions of a condition that the number of times by which the cylinder has reached the compression top dead center is equal to predetermined number of times or more, a condition that the rotation speed of the engine is on the rise and a condition that the rotation speed of the engine is above a predetermined rotation speed are satisfied, the half-engagement state of the clutch is released.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] Conventionally, as this type of engine device, a hybrid vehicle equipped with an engine, a motor connected to the output shaft of the engine via a clutch, and an automatic transmission connected to the rotating shaft of the motor and an axle has been proposed (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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-111276 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the engine device mounted on the above-mentioned hybrid vehicle, when the engine speed is increased by slipping the clutch to match the motor speed, the engine speed overshoots, and the torque caused by the increase in engine speed is transmitted to the drive wheels, which may cause a shock that is uncomfortable for the driver and passengers.

[0005] The main object of the engine device of the present invention is to suppress shocks that occur when the engine speed is made to substantially match the motor speed. [Means for solving the problem]

[0006] In order to achieve the above-mentioned main object, the engine device of the present invention employs the following means.

[0007] 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; The half-engagement of the clutch is released when all of the following three conditions are met: the number of times the compression top dead center has passed a predetermined number or more during the cranking, the engine speed is increasing, and the engine speed is a predetermined speed or more. It is characterized by:

[0008] The engine device of the present invention includes 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 controls the engine, the motor, and the clutch so that the clutch is partially engaged to crank the engine by the motor, and fuel injection and ignition are performed on the cylinder that reaches the compression top dead center first or second in the engine to start the engine. During cranking, the control device releases the clutch from half-engagement when all three conditions are met: the number of times the compression top dead center has been passed is equal to or greater than a predetermined number, the engine speed is increasing, and the engine speed is equal to or greater than a predetermined speed. This allows the engine speed to be approximately equal to the motor speed with the clutch partially engaged, and suppresses shock that may occur when the engine speed is approximately equal to the motor speed with the clutch partially engaged.

[0009] Here, the predetermined rotation speed may be a rotation speed based on the rotation speed of the motor. The higher the rotation speed of the motor, the higher the predetermined rotation speed may be. In this way, the engine rotation speed can be made to substantially match the motor rotation speed more quickly. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of an engine 22. [Diagram 3] 5 is a flowchart showing an example of a starting ignition timing setting process executed by the HVECU 70, the engine ECU 24, etc. [Figure 4] 4 is a flowchart showing an example of a clutch release condition satisfaction determination process executed by an HVECU 70. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be described with reference to the accompanying drawings. EXAMPLES

[0012] Fig. 1 is a schematic diagram showing the configuration of a hybrid vehicle 20 equipped with an engine device according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing the configuration of an engine 22 equipped in the hybrid vehicle 20. As shown in Fig. 1, the hybrid vehicle 20 of the embodiment includes the engine 22, a motor 30, an inverter 32, a clutch K0, an automatic transmission 40, a high-voltage battery 60, a low-voltage battery 62, a DC / DC converter 64, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70.

[0013] The engine 22 is configured as a six-cylinder internal combustion engine that uses fuel such as gasoline or diesel to output power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. As shown in FIG. 2, the engine 22 has a port injection valve 126 that injects fuel into an intake port, and an in-cylinder injection valve 127 that injects fuel into a cylinder. The engine 22 can be operated in any one of a port injection mode, an in-cylinder injection mode, and a common injection mode by having the port injection valve 126 and the in-cylinder injection valve 127. In the port injection mode, air purified by the air cleaner 122 is sucked into the intake pipe 123 and passes through the throttle valve 124 and the surge tank 125, and fuel is injected from the port injection valve 126 downstream of the surge tank 125 of the intake pipe 123, and the air and fuel are mixed. This mixture is then drawn into the combustion chamber 129 via the intake valve 128, where it is explosively combusted by an electric spark from the spark plug 130, and the reciprocating motion of the piston 132, which is pushed down in the cylinder bore by the energy of the mixture, is converted into the rotational motion of the crankshaft 23. In the in-cylinder injection mode, air is drawn into the combustion chamber 129 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark plug 130, to obtain the rotational motion of the crankshaft 23. In the shared injection mode, fuel is injected from the port injection valve 126 when air is drawn into the combustion chamber 129, and fuel is injected from the in-cylinder injection valve 127 during the intake stroke and compression stroke, and is explosively combusted by an electric spark from the spark plug 130, to obtain the rotational motion of the crankshaft 23. These injection modes are switched based on the operating state of the engine 22. Exhaust discharged from the combustion chamber 129 to an exhaust pipe 134 via an exhaust valve 133 is discharged into the outside air via a purification device 135 and a PM filter 136. The purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The PM filter 136 is formed as a porous filter from ceramics, stainless steel, or the like, and collects particulate matter (PM) such as soot in the exhaust.In place of the PM filter 136, a four-way catalyst that combines the purification function of a three-way catalyst with the function of trapping particulate matter may be used.

[0014] The operation of the engine 22 is controlled by the engine ECU 24. The engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. Signals from various sensors required for controlling the operation of the engine 22 are input to the engine ECU 24 via input ports. Examples of signals input to the engine ECU 24 include a crank angle θcr from a crank position sensor 140 that detects the rotational position of the crankshaft 23 of the engine 22, and a cooling water temperature Tw from a water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. Other examples of signals input to the engine ECU 24 include cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 133. Other examples of the above include the throttle opening TH from a throttle valve position sensor 124a that detects the position of the throttle valve 124, the intake air amount Qa from an air flow meter 123a attached upstream of the throttle valve 124 of the intake pipe 123, the intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 of the intake pipe 123, and the surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples of the above include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 of the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached between the purification device 135 of the exhaust pipe 134 and the PM filter 136, and a differential pressure ΔP from a differential pressure sensor 136a that detects a differential pressure before and after the PM filter 136 (a differential pressure between the upstream side and the downstream side).

[0015] From the engine ECU 24, various control signals for controlling the operation of the engine 22 are output via an output port. Examples of signals output from the engine ECU 24 include a control signal to a throttle valve 124, a control signal to a port injection valve 126, a control signal to an in-cylinder injection valve 127, and a control signal to an ignition plug 130.

[0016] The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 140. The engine ECU 24 also calculates a load factor KL (the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter 123a and the rotation speed Ne of the engine 22. Furthermore, the engine ECU 24 calculates a PM accumulation amount Qpm as the accumulation amount of particulate matter accumulated on the PM filter 136 based on a differential pressure ΔP from the differential pressure sensor 136a, and calculates a filter temperature Tf as the temperature of the PM filter 136 based on the rotation speed Ne of the engine 22 and the load factor KL.

[0017] 1, a starter motor 25 for cranking the engine 22 and an alternator 26 for generating power using power from the engine 22 are connected to the crankshaft 23 of the engine 22. The starter motor 25 and the alternator 26 are connected to a low-voltage power line 63 together with a low-voltage battery 62, and are controlled by the HVECU 70.

[0018] The motor 30 is configured as a synchronous generator motor, and has a rotor in which a permanent magnet is embedded in a rotor core, and a stator in which a three-phase coil is wound around a stator core. A rotating shaft 31 to which the rotor of the motor 30 is fixed is connected to the crankshaft 23 of the engine 22 via a clutch K0, and is also connected to an input shaft 41 of an automatic transmission 45. The inverter 32 is used to drive the motor 30, and is connected to a high-voltage power line 61. The motor 30 is rotationally driven by a motor electronic control unit (hereinafter referred to as "motor ECU") 34 controlling the switching of multiple switching elements of the inverter 32.

[0019] The motor ECU 34 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, not shown. Signals from various sensors are input to the motor ECU 34 via the input ports. Examples of signals input to the motor ECU 34 include a rotational position θm from a rotational position sensor 30a that detects the rotational position of the rotor (rotating shaft 31) of the motor 30, and phase currents Iu and Iv from current sensors that detect the phase currents of the respective phases of the motor 30. A control signal to the inverter 32 and the like are output from the motor ECU 34 via the output port. The motor ECU 34 is connected to the HVECU 70 via a communication port. The motor ECU 34 calculates the rotational speed 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.

[0020] The clutch K0 is configured as, for example, a hydraulically driven friction clutch, and is controlled by the HVECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotating shaft 31 of the motor 30.

[0021] The automatic transmission 40 has a torque converter 43 and an automatic transmission 45 with, for example, six speeds. The torque converter 43 is configured as a general fluid transmission device, and transmits the power of an input shaft 41 connected to a rotating shaft 31 of the motor 30 to a transmission input shaft 44 which is an input shaft of the automatic transmission 45 with amplified torque, or transmits the torque as is without amplifying it. The automatic transmission 45 has the transmission input shaft 44, an output shaft 42 connected to driving wheels 49 via a differential gear 48, a plurality of planetary gears, and a plurality of hydraulically driven friction engagement elements (clutches, brakes). Each of the plurality of friction engagement elements has a hydraulic servo configured of a piston, a plurality of friction engagement plates (friction plates and separator plates), an oil chamber to which hydraulic oil is supplied, and the like. The automatic transmission 45 forms forward gears from 1st gear to 6th gear and reverse gears by engaging and disengaging a plurality of friction engagement elements, and transmits power between the transmission input shaft 44 and the output shaft 42. The hydraulic pressure of hydraulic oil from a mechanical oil pump or an electric oil pump is adjusted and supplied to the clutch K0 and the automatic transmission 45 by a hydraulic control device (not shown). The hydraulic control device has a valve body with a plurality of oil passages formed therein, a plurality of regulator valves, a plurality of linear solenoid valves, etc. This hydraulic control device is controlled by the HVECU 70.

[0022] High-voltage battery 60 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery with a rated voltage of several hundred volts, and is connected to high-voltage power line 61 together with inverter 32. Low-voltage battery 62 is configured as, for example, a lead-acid battery with a rated voltage of about 12 V or 14 V, and is connected to low-voltage power line 63 together with starter motor 25 and alternator 26. DC / DC converter 64 is connected to high-voltage power line 61 and low-voltage power line 63. This DC / DC converter 64 supplies power from high-voltage power line 61 to low-voltage power line 63 with a voltage step-down.

[0023] Although not shown, the HVECU 70 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. Examples of signals input to the HVECU 70 include the rotation speed Nin from the rotation speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotation speed Nmi from the rotation speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotation speed Nout from the rotation speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. Examples of signals input to the HVECU 70 include the voltage Vbh of the high-voltage battery 60 from a voltage sensor attached between the terminals of the high-voltage battery 60, the current Ibh of the high-voltage battery 60 from a current sensor attached to the output terminal of the high-voltage battery 60, and the voltage Vbl from a voltage sensor attached between the terminals of the low-voltage battery 62. Other examples of such signals include an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 87.

[0024] Various control signals are output from the HVECU 70 via an output port. Examples of signals output from the HVECU 70 include a control signal to the starter motor 25 and a control signal to the alternator 26. Examples of signals output from the HVECU 70 include a control signal to the clutch K0 and the automatic transmission 40 (hydraulic control device), and a control signal to the DC / DC converter 64. The HVECU 70 is connected to the engine ECU 24 and the motor ECU 34 via a communication port. The HVECU 70 calculates a rotation speed ratio Gt of the automatic transmission 40 by dividing the rotation speed Nin of the input shaft 41 of the automatic transmission 40 from the rotation speed sensor 41a by the rotation speed Nout of the output shaft 42 of the automatic transmission 40 from the rotation speed sensor 42a.

[0025] In the hybrid vehicle 20 of the embodiment thus configured, the engine 22, the clutch K0, the motor 30, and the automatic transmission 40 are controlled by cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 34 so as to travel in a hybrid driving mode (HV driving mode) or an electric driving mode (EV driving mode). Here, the HV driving mode is a mode in which the clutch K0 is in an engaged state and the vehicle travels using the power of the engine 22, and the EV driving mode is a mode in which the clutch K0 is in a released state and the vehicle travels without using the power of the engine 22.

[0026] In controlling the automatic transmission 40 in the HV driving mode or the EV driving mode, the HVECU 70 first sets a target gear M* of the automatic transmission 45 based on the accelerator opening Acc and the vehicle speed V. Then, when the gear M of the automatic transmission 45 matches the target gear M*, the HVECU 70 controls the automatic transmission 45 so that the gear M is maintained. On the other hand, when the gear M and the target gear M* differ, the HVECU 70 controls the automatic transmission 45 so that the gear M matches the target gear M*.

[0027] In controlling the engine 22 and the motor 30 in the HV driving mode, the HVECU 70 first sets a required torque Tout* required for driving (required of the output shaft 42 of the automatic transmission 40) based on the accelerator opening Acc and the vehicle speed V. Next, the required torque Tout* of the output shaft 42 is divided by the rotation speed ratio Gt of the automatic transmission 40, and the value is set as the required torque Tin* of the input shaft 41. After setting the required torque Tin* of the input shaft 41 in this manner, the HVECU 70 sets a target torque Te* of the engine 22 and a torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the target torque Te* of the engine 22 to the engine ECU 24 and transmits the torque command Tm* of the motor 30 to the motor ECU 34. Upon receiving the target torque Te*, the engine ECU 24 performs operation control of the engine 22 (intake air amount control, fuel injection control, ignition control, etc.) so that the engine 22 is operated at the target torque Te*. When the motor ECU 34 receives the torque command Tm*, it performs switching control of a plurality of switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0028] In controlling the motor 30 in the EV driving mode, the HVECU 70 sets a required torque Tin* of the input shaft 41 in the same manner as in the HV driving mode, sets a torque command Tm* of the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the torque command Tm* to the motor ECU 34. Upon receiving the torque command Tm*, the motor ECU 34 performs switching control of a plurality of switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0029] 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 .

[0030] 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 reaches the compression top dead center (TDC) first or the cylinder that reaches the compression top dead center second. The selection 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 depending on whether the crank angle (stop crank angle) θstop when the engine 22 is stopped is within a predetermined crank angle range (for example, BTDC 40 to 80 (before TDC 40 to 80 degrees)) in which the initial explosion can be performed in the cylinder that reaches the compression top dead center first. That is, 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.

[0031] In the embodiment, in order to start the cylinder that reaches the compression top dead center first, the throttle valve 124 is temporarily opened immediately before the engine 22 is stopped and stopped within a predetermined crank angle range. The throttle valve 124 is temporarily opened immediately 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 based on the fact that the pressure in the cylinder that stops 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 starting ignition timing setting process, the control of the clutch K0 is executed by the HVECU 70, and the setting of the ignition timing Ti is executed by the engine ECU 24.

[0032] 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 transmitting 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 transmitting 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 a torque command Tm* for the motor 30. The hydraulic control device that has received 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 has received 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 this embodiment, the target crank torque Tcr* is a torque sufficient to cause a cylinder stopped in the compression stroke to exceed the compression top dead center, and is set based on the stop crank angle θstop and the elapsed time since the engine 22 was stopped. The reason it is based on the stop crank angle θstop is to take into account the pressure in the cylinder stopped in the compression stroke, and the reason it is based on the elapsed time since the engine 22 was stopped is to take into account the fact that the pressure in the cylinder stopped in the compression stroke decreases over time.

[0033] 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 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 initial 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 retard limit range where 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 reaches the compression top dead center first 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 quickly approximately match 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 to make the rotation speed Ne immediately after the start of the engine 22 approximately match the rotation speed Nmg of the motor 30, so 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 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.

[0034] When it is determined in step S110 that the cylinder is not the first cylinder to reach the compression top dead center (the cylinder is the second or later cylinder 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 likely to rev up. For this reason, in the embodiment, the ignition timing Ti is set to be retarded as the target cranking torque Tcr* increases within the retard limit range where 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 advanced as the rotation speed Nmg of the motor 30 increases. 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.

[0035] When the ignition timing Ti is set in this way, it is determined whether or not the condition for releasing the clutch K0 is satisfied (step S140). The determination of whether or not the condition for releasing the clutch K0 is satisfied is performed by a clutch release condition satisfaction determination process executed by the HVECU 70 illustrated in FIG. 4. This clutch release condition satisfaction determination process is repeatedly executed at predetermined time intervals. When the clutch release condition satisfaction determination process is executed, the HVECU 70 determines whether or not the condition that the number of times the compression top dead center has passed is a predetermined number of times (for example, two or three times) or more is satisfied (step S300), and determines whether or not the condition that the rotation speed Ne of the engine 22 is increasing is satisfied (step S310), and further determines whether or not the condition that the rotation speed Ne of the engine 22 is equal to or higher than a threshold value Nref based on the rotation speed Nmg of the motor 30 is satisfied (step S320). Here, the threshold value Nref can be set to a larger rotation speed as the rotation speed Nmg of the motor 30 is larger. This allows the rotation speed Ne of the engine 22 to be approximately equal to the rotation speed Nmg of the motor 30 more quickly. When all of the above three conditions are met, it is determined that the conditions for releasing the clutch K0 are met (step S330), and when any of the above three conditions are not met, it is determined that the conditions for releasing the clutch K0 are not met (step S340), and this process ends. When it is determined in step S140 that the conditions for releasing the clutch K0 are not met, the process returns to step S110, which determines whether or not 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 conditions for releasing the clutch K0 are met.

[0036] When it is determined in step S140 that the condition for releasing the clutch K0 is satisfied, 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 reason for waiting at a constant pressure in this manner is to quickly engage the next clutch K0.

[0037] When the clutch K0 is released, a process of setting the ignition timing Ti so that the rotation speed Ne of the engine 22 substantially coincides with the rotation speed Nmg of the motor 30 is repeated until a condition for engaging the clutch K0 is satisfied (steps S160 to S200). The condition for engaging the clutch K0 may 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 that the number of ignitions is equal to or greater than a predetermined number (e.g., 5 times, 6 times, 8 times, etc.). Note that the intake air amount and the fuel injection amount during this repeated process are basically set so that the engine 22 approaches the rotation speed Nmg of the motor 30.

[0038] The repeated process until the condition for engaging the clutch K0 is satisfied starts with a process of 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 this 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 substantially coincide with 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. Since the amount of air in the cylinder increases as the intake manifold pressure Pin at the timing at which 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, in this embodiment, the ignition timing Ti is set to be retarded as the intake manifold pressure Pin at the timing at which the intake valve 128 is closed increases. For these reasons, in this 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 experiment, analysis, machine learning, or the like, 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.

[0039] Subsequently, it is determined whether the number of ignition times is equal to or greater than a predetermined number of times (for example, 5 times, 6 times, etc.) (step S170), and it is determined whether the absolute value of the differential rotation between the rotational speed Nmg of the motor 30 and the rotational speed Ne of the engine 22 is equal to or greater than a threshold value Nref (step S180). When it is determined that the number of ignition times is equal to or greater than the predetermined number of times and the absolute value of the differential rotational speed between the rotational speed Nmg of the motor 30 and the rotational 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 in which the rotational speed Ne of the engine 22 approaches the rotational speed Nmg of the motor 30. Specifically, when Nmg > Ne, the ignition timing Ti is advanced by an angle obtained by multiplying the difference between the rotational speed Nmg of the motor 30 and the rotational speed Ne of the engine 22 by a proportionality constant k, and when Nmg < Ne, the ignition timing Ti is retarded. On the other hand, when it is determined that the number of ignition times is less than the predetermined number of times, or when it is determined that the absolute value of the differential rotational speed between the rotational speed Nmg of the motor 30 and the rotational speed Ne of the engine 22 is less than the threshold value Nref even though the number of ignition times is equal to or greater than the predetermined number of times, the above correction of the ignition timing Ti is not performed.

[0040] When it is determined that the condition for engaging the clutch K0 is satisfied in step S200, the clutch K0 is engaged (step S210), and this process is terminated.

[0041] In the engine device mounted on the hybrid vehicle 20 of the embodiment described above, the clutch K0 is half-engaged (slip-engaged), the target cranking torque Tcr* is output from the motor 30, cranking of the engine 22 is started, and the clutch K0 is released by controlling the clutch K0 to wait at a hydraulic pressure that does not slip-engage until the condition for releasing the clutch K0 is satisfied. The condition for releasing the clutch K0 is that the number of times the compression top dead center has passed is equal to or greater than a predetermined number of times, the number of revolutions Ne of the engine 22 is increasing, and the number of revolutions Ne of the engine 22 is equal to or greater than a threshold value Nref based on the number of revolutions Nmg of the motor 30. This allows the number of revolutions Ne of the engine 22 to be approximately equal to the number of revolutions Nmg of the motor 30 with the clutch K0 released from the slip engagement, and suppresses shock that may occur when the number of revolutions Ne of the engine 22 is approximately equal to the number of revolutions Nmg of the motor 30 with the clutch K0 in the slip engagement.

[0042] In the engine device mounted on the hybrid vehicle 20 of the embodiment, one of the conditions for releasing the clutch K0 is that the rotation speed Ne of the engine 22 is equal to or greater than the threshold value Nref based on the rotation speed Nmg of the motor 30. However, the condition that the rotation speed Ne of the engine 22 is equal to or greater than the threshold value Nref regardless of the rotation speed Nmg of the motor 30 may be used.

[0043] The hybrid vehicle 20 of the embodiment 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.

[0044] The hybrid vehicle 20 of the embodiment includes the engine ECU 24, the motor ECU 34, and the HVECU 70. However, at least two of these may be integrated into one unit.

[0045] Although the engine device of the embodiment is mounted on the hybrid vehicle 20, it may be mounted on a moving body other than a vehicle, or may be incorporated into equipment.

[0046] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be described below. In the embodiment, the engine 22 corresponds to the "engine", the 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".

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

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

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

[0050] 20 hybrid vehicle, 22 engine, 23 crankshaft, 24 engine ECU, 25 starter motor, 26 alternator, 30 motor, 30a rotational position sensor, 31 rotating shaft, 32 inverter, 34 motor ECU, 40 automatic transmission, 41 input shaft, 41a rotational speed sensor, 42 output shaft, 42a rotational speed sensor, 43 torque converter, 44 transmission input shaft, 44a rotational speed sensor, 45 automatic transmission, 48 differential gear, 49 drive wheel, 60 high voltage battery, 61 high voltage side power line, 62 low voltage battery, 63 low voltage side power line, 64 DC / DC converter, 70 HVECU, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 Brake pedal position sensor, 87 vehicle speed sensor, 122 air cleaner, 123 intake pipe, 123a air flow meter, 123t temperature sensor, 124 throttle valve, 124a throttle valve position sensor, 125 surge tank, 125a pressure sensor, 126 port injection valve, 127 in-cylinder injection valve, 128 intake valve, 129 combustion chamber, 130 spark plug, 132 piston, 133 exhaust valve, 134 exhaust pipe, 135 purification device, 135a purification catalyst, 136 PM filter, 136a differential pressure sensor, 137 front air-fuel ratio sensor, 138 rear air-fuel ratio sensor, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, K0 clutch.

Claims

[Claim 1] 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; The half-engagement of the clutch is released when all of the following three conditions are met: the number of times the compression top dead center has passed a predetermined number or more during the cranking, the engine speed is increasing, and the engine speed is a predetermined speed or more. An engine device characterized by:

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