Engine equipment

Abstract

To prevent a calculated gap air amount from becoming excessive compared to an actual gap air amount.SOLUTION: An amount of air in a cylinder is one obtained by adding a gap air amount, which is an amount of air introduced into a gap in the cylinder of an engine, to an amount of intake air suctioned in from a throttle valve. The gap air amount is set so that it increases when a cranking time, which is a time it takes to crank the engine by a motor, is long compared to when it is short. An increase rate of the gap air amount is set based on an intake manifold pressure, which is a pressure of an intake manifold in the engine when the cranking of the engine starts.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an engine device, and more particularly to an engine device including an engine and a motor that cranks the engine. [Background technology]

[0002] Conventionally, as this type of engine device, one that includes an engine and a motor (rotating electric machine) that cranks the engine has been proposed (see, for example, Patent Document 1). In this device, the motor increases the engine rotation speed, and when the difference between the motor rotation speed and the engine rotation speed is within a predetermined range, fuel injection and ignition in the engine are initiated to start the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-113051 Summary of the Invention [Problem to be solved by the invention]

[0004] In the engine system described above, fuel is injected at a fuel injection amount based on the in-cylinder air volume, which is the amount of air in the cylinder. Therefore, accurately calculating the in-cylinder air volume is recognized as an important issue. One possible method for calculating the in-cylinder air volume is to assume that the intake manifold pressure has returned to near atmospheric pressure and all of the gaps in the cylinder have been scavenged and filled with fresh air. The gap volume is then used to calculate the in-cylinder air volume, which is calculated by correcting the intake air volume from the throttle valve. However, when an engine start request is made immediately before the engine is stopped, the start occurs under low intake manifold pressure, which slows scavenging of the in-cylinder gaps. This may result in the entire gap volume not being filled with fresh air. Therefore, if the entire gap volume is used as the gap air volume, the calculated gap air volume may be excessively large compared to the actual gap air volume.

[0005] The main object of the engine device of the present invention is to prevent the calculated gap air volume from becoming excessively large compared to the actual gap air volume. [Means for solving the problem]

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

[0007] The engine device of the present invention comprises: The engine and a motor for cranking the engine; a control device for the engine and the motor; An engine device comprising: The control device when a request to start the engine is made when the engine speed is less than a predetermined speed and greater than 0, cranking the engine with the motor, and executing predetermined start control to start fuel injection and ignition at a fuel injection amount based on an in-cylinder air amount after the difference between the engine speed and the motor speed falls within a predetermined range; The in-cylinder air amount is defined as the amount of intake air taken in through a throttle valve plus a gap air amount as the amount of air introduced into a gap in the cylinder of the engine, the gap air amount is set to be larger when the cranking time of the engine by the motor is long than when it is short, The rate of increase of the gap air amount is set based on an intake manifold pressure as the pressure in the intake manifold of the engine during a predetermined period from when the start request is made until when cranking of the engine by the motor is started. The gist of this is as follows.

[0008] In the engine system of the present invention, the control device may increase the rate of increase of the gap air amount when the intake manifold pressure is high compared to when it is low when cranking of the engine is started, or may increase the rate of increase when the maximum value of the intake manifold pressure during the predetermined period is high compared to when it is low. In this way, the gap air amount can be calculated more appropriately.

[0009] In this case, the gap air amount may be set using an smoothing process so that it increases from a value of 0 toward the clearance volume within the cylinder when the cranking time is long compared to when it is short, and the smoothing number of times as a time constant for the smoothing process may be set so that it is smaller when the intake manifold pressure is high compared to when it is low when the cranking of the engine is started, or smaller when the maximum value of the intake manifold pressure during the predetermined period is high compared to when it is low. In this way, the gap air amount can be calculated using a more appropriate smoothing number of times.

[0010] In addition, in the engine device of the present invention, a clutch may be provided between the engine and the motor, and the control device may partially engage the clutch when cranking the engine with the motor during the predetermined start control, and fully engage the clutch when the difference between the engine speed and the motor speed falls within a predetermined range. This makes it possible to prevent the calculated gap air volume from becoming excessively large compared to the actual gap air volume in an engine device of the type that has a clutch between the engine and the motor. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device as an embodiment of the present invention. [Figure 2] 1 is a diagram showing the outline of the configuration of an engine 22 mounted on a hybrid vehicle 20. FIG. [Figure 3] 4 is a flowchart showing an example of a startup air amount calculation process executed by a CPU of an engine ECU 24. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a change over time in intake manifold pressure Pin. DETAILED DESCRIPTION OF THE INVENTION

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

[0013] Fig. 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. 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.

[0014] 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 an intake port and an in-cylinder injection valve 127 that injects fuel into a cylinder. By having the port injection valve 126 and the in-cylinder injection valve 127, the engine 22 can operate in any of a port injection mode, an in-cylinder injection mode, and a combined injection mode. In the port injection mode, air purified by an air cleaner 122 is drawn into an intake pipe 123 and passes through a throttle valve 124 and a surge tank 125, and fuel is injected from a port injection valve 126 downstream of the surge tank 125 in the intake pipe 123 to mix the air and fuel. This air-fuel mixture is then drawn into combustion chamber 129 via intake valve 128, where it is explosively combusted by an electric spark from spark plug 130. The reciprocating motion of piston 132, which is pushed down in the cylinder bore by the energy of the mixture, is converted into rotational motion of crankshaft 23. In in-cylinder injection mode, air is drawn into combustion chamber 129 as in port injection mode, and fuel is injected from in-cylinder injection valve 127 during the intake stroke or compression stroke, where it is explosively combusted by an electric spark from spark plug 130, thereby generating rotational motion of crankshaft 23. In dual injection mode, fuel is injected from port injection valve 126 when air is drawn into combustion chamber 129, and fuel is also injected from in-cylinder injection valve 127 during the intake stroke or compression stroke, where it is explosively combusted by an electric spark from spark plug 130, thereby generating rotational motion of crankshaft 23. These injection modes are switched based on the operating state of engine 22. Exhaust gas discharged from combustion chamber 129 into exhaust pipe 134 via exhaust valve 133 is then discharged into the outside air via purification device 135 and PM filter 136. Purification device 135 has a purification catalyst (three-way catalyst) 135a that purifies harmful components in the exhaust gas, such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). PM filter 136 is formed as a porous filter using ceramics, stainless steel, or the like, and captures particulate matter (PM) such as soot in the exhaust gas.Instead of the PM filter 136, a four-way catalyst may be used that combines the purification function of a three-way catalyst with the function of trapping particulate matter.

[0015] The operation of the engine 22 is controlled by an engine ECU 24. Although not shown, the engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. 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 a crankshaft 23 of the engine 22, and a coolant temperature Tw from a water temperature sensor 142 that detects the temperature of the coolant for the engine 22. Other examples of signals 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 intake valves 128 and an exhaust camshaft that opens and closes exhaust valves 133. Other examples 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 in the intake pipe 123, an intake air temperature Ta from a temperature sensor 123t attached upstream of the throttle valve 124 in the intake pipe 123, and a surge pressure Ps from a pressure sensor 125a attached to the surge tank 125. Other examples include a front air-fuel ratio AF1 from a front air-fuel ratio sensor 137 attached upstream of the purification device 135 in the exhaust pipe 134, a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 138 attached between the purification device 135 and the PM filter 136 in the exhaust pipe 134, 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).

[0016] The engine ECU 24 outputs various control signals via an output port to control the operation of the engine 22. 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.

[0017] 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 per 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. The engine ECU 24 also calculates a PM accumulation amount Qpm as the accumulation amount of particulate matter accumulated on the PM filter 136 based on the 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.

[0018] 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.

[0019] 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. 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 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.

[0020] 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 port. Examples of signals input to the motor ECU 34 include a rotational position θmg 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 each phase of the motor 30. The motor ECU 34 outputs control signals to the inverter 32 via the output port. The motor ECU 34 is connected to the HVECU 70 via the communication port. The motor ECU 34 calculates the rotational speed Nmg of the motor 30 based on the rotational position θmg of the rotor (rotating shaft 31) of the motor 30 from the rotational position sensor 30a.

[0021] The clutch K0 is configured as, for example, a hydraulically driven friction clutch, and is controlled by the HVECU 70 to connect and disconnect the crankshaft 23 of the engine 22 and the rotary shaft 31 of the motor 30.

[0022] The automatic transmission 40 includes a torque converter 43 and, for example, a six-speed automatic transmission 45. The torque converter 43 is configured as a typical fluid power transmission device and amplifies the torque of the power of an input shaft 41 connected to the rotating shaft 31 of the motor 30 and transmits it to a transmission input shaft 44, which is the input shaft of the automatic transmission 45, or transmits the torque directly without amplifying it. The automatic transmission 45 includes the transmission input shaft 44, an output shaft 42 connected to 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 configured with 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 establishes forward gears from first to sixth 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 clutch K0 and the automatic transmission 45 are supplied with hydraulic oil from a mechanical oil pump or an electric oil pump at a regulated pressure by a hydraulic control device (not shown). The hydraulic control device includes a valve body with multiple oil passages, multiple regulator valves, multiple linear solenoid valves, and the like. This hydraulic control device is controlled by the HVECU 70.

[0023] High-voltage battery 60 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery with a rated voltage of 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. DC / DC converter 64 supplies power from high-voltage power line 61 to low-voltage power line 63 while stepping down the voltage.

[0024] The HVECU 70 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 HVECU 70 via the input ports. Examples of signals input to the HVECU 70 include the rotation speed Nin from a rotation speed sensor 41a attached to the input shaft 41 of the automatic transmission 40, the rotation speed Nmi from a rotation speed sensor 44a attached to the transmission input shaft 44 of the automatic transmission 40, and the rotation speed Nout from a rotation speed sensor 42a attached to the output shaft 42 of the automatic transmission 40. Other 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 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.

[0025] 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. 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.

[0026] In this embodiment, the engine device corresponds to the engine 22, the motor 30, the HVECU 70, the engine ECU 24, and the motor ECU 34.

[0027] In the hybrid vehicle 20 of this embodiment configured as described above, 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 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 engaged 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 disengaged and the vehicle travels without using the power of the engine 22.

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

[0029] In controlling the engine 22 and motor 30 in the HV driving mode, the HVECU 70 first sets a required torque Tout* required for driving (required from the output shaft 42 of the automatic transmission 40) based on the accelerator opening Acc and the vehicle speed V. Next, the HVECU 70 sets a required torque Tin* for the input shaft 41 by dividing the required torque Tout* for the output shaft 42 by the rotation speed ratio Gt of the automatic transmission 40. After setting the required torque Tin* for the input shaft 41 in this manner, the HVECU 70 sets a target torque Te* for the engine 22 and a torque command Tm* for the motor 30 so that the required torque Tin* is output to the input shaft 41, and transmits the target torque Te* for the engine 22 to the engine ECU 24 and the torque command Tm* for the motor 30 to the motor ECU 34. Upon receiving the target torque Te*, the engine ECU 24 performs operation control (air amount control, fuel injection control, ignition control, etc.) for the engine 22 so that the engine 22 is operated at the target torque Te*. When the motor ECU 34 receives the torque command Tm*, it controls the switching of the multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0030] 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 a torque command Tm* for 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 the multiple switching elements of the inverter 32 so that the motor 30 is driven by the torque command Tm*.

[0031] Furthermore, in the hybrid vehicle 20 of the embodiment, when a stop request for the engine 22 is made while the engine 22 is running, stop control for the engine 22 is executed through cooperative control between the HVECU 70, the engine ECU 24, and the motor ECU 34. The stop request is made, for example, when a condition is met in which the required torque Tin* of the input shaft 41 is less than a threshold value Tinref. In the stop control, the torque of the engine 22 is basically replaced with the torque of the motor 30, and then fuel injection and ignition are stopped and the throttle valve 124 is closed. When the rotation speed Ne of the engine 22 falls below a threshold value Neref1 (for example, approximately 600 rpm to 800 rpm), the clutch K0 is released. Furthermore, when the rotation speed Ne of the engine 22 falls below a threshold value Neref2 that is lower than the threshold value Neref1 (for example, approximately several hundred rpm lower), the throttle valve 124 is temporarily opened.

[0032] If a start request for the engine 22 is made while fuel injection and ignition of the engine 22 are stopped, start control for the engine 22 is executed. The start request is made, for example, when a condition is met in which the required torque Tin* is equal to or greater than a threshold value Tinref. Examples of types of start control for the engine 22 include TDC (Top Dead Center) start control and PUSH start control. Note that fuel injection control during start control is performed in a direct injection mode. TDC start control is basically performed when a start request is made and the engine 22 rotation speed Ne is 0 (the engine 22 is stopped) and the motor 30 rotation speed Nmg is equal to or greater than a threshold value Nmgref; however, since this is not central to the present invention, detailed description thereof will be omitted.

[0033] PUSH start control is basically performed when a start request is made and the rotation speed Nmg of the motor 30 is less than a threshold value Nmgref. In PUSH start control, the clutch K0 is basically half-engaged (slip engaged) and the engine 22 is cranked using the cranking torque from the motor 30, and when an engagement condition for the clutch K0 is met, the clutch K0 is engaged and fuel injection and ignition for the engine 22 are initiated. An example of an engagement condition for the clutch K0 is that the differential rotation speed ΔN is less (within a predetermined range) than a threshold value ΔNref (for example, approximately 50 rpm to 150 rpm).

[0034] Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, in particular the start control of the engine 22 when a start request is made immediately before the engine 22 stops rotating, will be described.

[0035] When a start request is made immediately before the engine 22 is stopped, that is, when the engine 22 rotation speed Ne is less than a threshold value (predetermined rotation speed) Neref1 and greater than 0, and the motor 30 rotation speed Nmg is less than the threshold value Nmgref, the above-described push start control is executed (predetermined start control). In this push start control, when fuel injection into the engine 22 is started, fuel injection into the engine 22 is started with a fuel injection amount based on the calculated in-cylinder air amount Qc.

[0036] The calculation of the in-cylinder air amount Qc is executed by the engine ECU 24. Figure 3 is a flowchart showing an example of a start-time air amount calculation process executed by the CPU of the engine ECU 24. This routine is executed when fuel injection into the engine 22 is started under PUSH start control.

[0037] When this routine is executed, the CPU of the engine ECU 24 executes a process to input the pressure of the intake manifold of the engine 22 (intake manifold pressure Pin) (step S100). The maximum value Pmax of the surge pressure Ps during the period from when a start request for the engine 22 is made to when fuel injection and ignition start is used as the intake manifold pressure Pin in step S100. FIG. 4 is an explanatory diagram showing an example of the change in intake manifold pressure Pin over time. For reference, the diagram also shows an example of the change in the engine speed Ne of the engine 22, the motor speed Nmg (broken line), and the throttle opening TH over time. In the diagram, time t1 is the timing when a start request for the engine 22 is made. Time t2 is the timing when cranking of the engine 22 by the motor 30 is started. Time t3 is the timing when fuel injection and ignition start. When a start request is made immediately before the engine 22 is stopped, the intake manifold pressure Pin is a negative pressure lower than the atmospheric pressure Patm, as shown in the diagram. When the engine 22 is cranked by the motor 30, air flows from the intake manifold through the cylinders to the exhaust manifold, scavenging the cylinders and introducing fresh air. The amount of fresh air introduced at this time varies depending on the extent to which the intake manifold pressure Pin has recovered before cranking of the engine 22 begins. In this embodiment, the maximum value Pmax of the surge pressure Ps during the period from when a start request for the engine 22 is made to when fuel injection and ignition begin is used as the intake manifold pressure Pin, as an indicator of the recovery of the intake manifold pressure Pin. Note that the surge pressure Ps during the period from when a start request for the engine 22 is made to when cranking of the engine 22 begins may be used as the intake manifold pressure Pin, as long as it is the surge pressure Ps during the period from when a start request for the engine 22 is made to when cranking of the engine 22 begins. Alternatively, the surge pressure Ps at the time when cranking of the engine 22 begins may be used.

[0038] Next, an average smoothing count N is set as a time constant when the gap air amount Qcgap, which will be described later, is smoothed using the intake manifold pressure Pin (step S110), and the gap air amount Qcgap is calculated as the amount of air introduced into the gaps in the cylinder when fuel injection of the engine 22 is started (step S120). In step S120, the gap air amount Qcgap is calculated using the intra-cylinder gap volume Qgap, the average smoothing count N, and the cranking time tcr from when cranking of the engine 22 is started by the motor 30 to when fuel injection of the engine 22 is started, using an average smoothing process that increases from a value of 0 to the gap volume Qgap when the cranking time tcr is long compared to when the cranking time tcr is short. The intra-cylinder gap volume Qgap is the volume of the part above the head of the piston 132 when the piston 132 is positioned at top dead center (TDC), and is a volume determined by the specifications of the engine 22. The smoothing number N corresponds to the reciprocal of the scavenging speed when fresh air is introduced into the cylinders during cranking of the engine 22 by the motor 30. When the intake manifold pressure Pin is low, the amount of air flowing from the intake manifold through the cylinders to the exhaust manifold decreases, resulting in a slower scavenging speed. In other words, the scavenging speed in the cylinders is slower when the intake manifold pressure Pin is low than when it is high. Because the smoothing number N corresponds to the reciprocal of the scavenging speed, in step S110, the smoothing number N is set to be larger when the intake manifold pressure Pin is low than when it is high. This allows the gap air amount Qcgap to be closer to the actual gap air amount in step S120. This prevents the calculated gap air amount Qcgap from being excessively large compared to the actual gap air amount, compared to an estimate that the entire gap volume Qgap is filled with fresh air during fuel injection of the engine 22, regardless of the intake manifold pressure Pin.

[0039] Once the gap air amount Qcgap has been calculated in this way, the startup air amount setting process calculates the amount of air by adding the gap air amount Qcgap to the intake air amount Qa (the amount of air flowing into the cylinder via the throttle valve 124) detected by the air flow meter 123a (step S130), and then ends this process. By performing fuel injection control using the in-cylinder air amount Qc in this way, more appropriate fuel injection control can be performed compared to fuel injection control that uses the intake air amount Qa as the in-cylinder air amount Qc, or fuel injection control that assumes that all of the gap volume Qgap is filled with fresh air and uses the intake air amount Qa plus the gap air amount Qcgap as the in-cylinder air amount Qc.

[0040] In the hybrid vehicle 20 equipped with the engine device of the embodiment described above, the in-cylinder air amount Qc is calculated by adding the intake air amount Qa drawn in from the throttle valve 124 to the gap air amount Qcgap, which is the amount of air introduced into the gaps in the cylinders of the engine 22. The gap air amount Qcgap is set so that it increases when the cranking time tcr, which is the time it takes for the motor 30 to crank the engine 22, is long compared to when it is short. The rate of increase of the gap air amount Qcgap (the reciprocal of the smoothing number N) is set based on the intake manifold pressure Pin, which is the pressure in the intake manifold of the engine 22 during a predetermined period from when a start request is made to when the motor 30 starts cranking the engine 22, thereby preventing the calculated gap air amount Qcgap from becoming excessively large compared to the actual gap air amount.

[0041] In addition, the intake manifold pressure Pin is set to the surge pressure Ps when a start request is made or the maximum value Pmax of the surge pressure Ps over a predetermined period, and the rate of increase of the gap air volume Qcgap is set to be larger when the intake manifold pressure Pin is large than when it is small (the number of times of smoothing N is set to be smaller when the intake manifold pressure Pin is large than when it is small), thereby making it possible to calculate the gap air volume Qcgap more appropriately.

[0042] In the hybrid vehicle 20 of the embodiment, the engine 22 has a port injection valve 126 and an in-cylinder injection valve 127. However, the hybrid vehicle 20 may have only the in-cylinder injection valve 127 without the port injection valve 126. The hybrid vehicle 20 of the embodiment is equipped with a six-speed automatic transmission 45. However, the hybrid vehicle 20 may have a four-speed, five-speed, eight-speed, or other automatic transmission. The hybrid vehicle 20 of the embodiment is equipped with an engine ECU 24, a motor ECU 34, and an HVECU 70. However, at least two of these may be integrated. While the engine device of the embodiment is mounted on the hybrid vehicle 20, it may be mounted on a moving object other than a vehicle or incorporated into stationary equipment. The embodiment illustrates an example in which the present invention is applied to a hybrid vehicle 20 equipped with an engine 22 and a motor 30 connected to a crankshaft 23 of the engine 22 via a clutch K0. However, the present invention may also be applied to an engine device in which the motor is connected to the crankshaft of the engine without a clutch.

[0043] 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 within the scope that does not deviate from the gist of the present invention. [Industrial Applicability]

[0044] The present invention is applicable to the engine device manufacturing industry. [Explanation of symbols]

[0045] 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 Speed ​​sensor, 42 Output shaft, 42a Speed ​​sensor, 43 Torque converter, 44 Transmission input shaft, 44a Speed ​​sensor, 45 Automatic transmission, 48 Differential gear, 49 Drive wheels, 60 High-voltage battery, 61 High-voltage power line, 62 Low-voltage battery, 63 Low-voltage power line, 64 DC / DC converter, 70 HVECU, 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 vehicle speed sensor, 122 air cleaner, 123 intake pipe, 123a air flow meter, 123t temperature sensor, 124 throttle valve, 124a throttle valve position sensor, 125 surge tank, 125a pressure sensor, 126 port injection valve, 127 in-cylinder injection valve, 128 intake valve, 129 combustion chamber, 130 spark plug, 132 piston, 133 exhaust valve, 134 exhaust pipe, 135 purification device, 135a purification catalyst, 136 PM filter, 136a differential pressure sensor, 137 front air-fuel ratio sensor, 138 rear air-fuel ratio sensor, 140 crank position sensor, 142 water temperature sensor, 144 cam position sensor, K0 clutch.

Claims

1. The engine and a motor for cranking the engine; a control device for the engine and the motor; An engine device comprising: The control device when a request to start the engine is made when the engine speed is less than a predetermined speed and greater than zero, cranking the engine with the motor, and executing predetermined start control to start fuel injection and ignition at a fuel injection amount based on an in-cylinder air amount after the difference between the engine speed and the motor speed falls within a predetermined range; The in-cylinder air amount is defined as the amount of intake air taken in through a throttle valve plus a gap air amount as the amount of air introduced into a gap in the cylinder of the engine, the gap air amount is set to be larger when the cranking time of the engine by the motor is long than when it is short, The rate of increase of the gap air amount is set based on an intake manifold pressure as the pressure in the intake manifold of the engine during a predetermined period from when the start request is made until when cranking of the engine by the motor is started. Engine equipment.

2. 2. The engine device according to claim 1, The control device The increasing rate of the gap air amount is made larger when the intake manifold pressure is large compared to when it is small when cranking of the engine is started, or is made larger when the maximum value of the intake manifold pressure during the predetermined period is large compared to when it is small. Engine equipment.

3. 3. The engine device according to claim 2, The gap air amount is set using a smoothing process so that it increases from a value of 0 toward the gap volume in the cylinder when the cranking time is long compared to when the cranking time is short, The number of times of smoothing as a time constant of the smoothing process is set to be smaller when the intake manifold pressure is large compared to when it is small when cranking of the engine is started, or to be smaller when the maximum value of the intake manifold pressure during the predetermined period is large compared to when it is small. Engine equipment.

Images