CN111720226B

CN111720226B - Engine control device and control method thereof

Info

Publication number: CN111720226B
Application number: CN201910841506.8A
Authority: CN
Inventors: 芦志锐
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2022-03-18
Anticipated expiration: 2039-09-06
Also published as: CN111720226A

Abstract

An engine control device and a control method thereof are applied to a vehicle having an engine, a motor generator, a storage battery, a crank position sensor, an engine temperature sensor and an intake pressure sensor, the engine control device having an automatic power-off function, and includes: a first determination unit that determines whether the engine has stopped based on a detection result of the crank position sensor; a fuel initial adhesion amount calculation unit that calculates an initial adhesion amount of fuel at the time of stop based on at least one or more of an engine speed, an engine temperature, and an intake pipe pressure at the time of stop of the engine; a second determination unit that determines whether or not the vehicle power switch is turned off; and an auto power-off time calculation unit that calculates an auto power-off time based on the initial fuel adhesion amount at the time of stop and the engine temperature when the second determination unit determines that the vehicle power switch has been turned off. The automatic power-off time and the fuel injection amount during restarting can be adjusted, and the storage battery can be ensured not to be lack of power.

Description

Engine control device and control method thereof

Technical Field

The present invention relates to an engine control device and a control method thereof, and more particularly, to an engine control device and a control method thereof capable of adjusting an auto-power-off time and adjusting a fuel injection amount at the time of restart.

Background

Conventionally, there is known a technology for improving restarting performance by detecting whether or not there is a restart mainly after an engine is stopped, and correcting a fuel injection amount at the time of restart in accordance with an engine cooling water temperature and a stop time.

However, in the above-described technique, the engine ECU needs to be constantly in a power supply state (the main power switch remains on). In the case of a small-capacity battery used for a motorcycle, a problem such as a power shortage is likely to occur. If the engine ECU is powered off and then powered on, when the engine ECU is restarted, the engine ECU cannot judge that the engine ECU is restarted, and the fuel injection quantity correction is invalid.

Documents of the prior art

Patent document

Patent document 1: japanese patent every open No. 1-8330

Disclosure of Invention

The present invention has been made to solve the above-described problems of the conventional art, and an object of the present invention is to provide an engine control device and a control method thereof, which can determine an initial fuel adhesion amount and an auto-power-off time based on vehicle parameters such as an engine speed, an intake pipe pressure, an engine temperature, an intake air temperature, and the like when an engine is stopped, maintain power supply during the auto-power-off time, calculate a real-time adhesion amount based on the initial fuel adhesion amount and an elapsed time after the engine is stopped when it is determined that the engine is restarted during the auto-power-off time, and determine an injection amount of an injector for each stroke cycle within a plurality of stroke cycles after the restart is started, thereby ensuring that a battery is not short of power.

A first aspect of the present invention relates to an engine control device 2 applied to a vehicle 100, the vehicle 100 including an engine 4 and a motor generator 5 as power sources, and a battery 20 as a power source, the vehicle 100 further including: a crank position sensor 13, provided in the cylinder block of the engine 4, for detecting a rotational position of a crankshaft of the engine 4 and an engine rotation speed Ne; an engine temperature sensor 12 provided in the cylinder block of the engine 4, the engine temperature sensor 12 detecting an engine temperature Thw; and an intake pressure sensor 17 provided in the intake pipe 6, the intake pressure sensor 17 detecting an intake pipe pressure Pm, the engine control device 2 having an auto-power-off function and being capable of maintaining power supply for a predetermined auto-power-off time after the vehicle power switch 11 is turned off, the engine control device 2 comprising: a first determination unit that determines whether or not the engine 4 has stopped based on a detection result of the crank position sensor 13; a fuel initial deposit amount calculation unit that calculates a fuel initial deposit amount MFstable at the time of stop of the engine 4 based on at least one or more of an engine speed Ne, an engine temperature Thw, and an intake pipe pressure Pm at the time of stop of the engine 4; a second determination unit that determines whether or not the vehicle power switch 11 is turned off; and an auto power-off time calculation unit that calculates the auto power-off time t1 based on the initial fuel adhesion amount MFstable at the time of stop and the engine temperature Thw when the vehicle power switch 11 is determined to be off by the second determination unit, and the engine control device 2 executes the auto power-off control based on the calculated auto power-off time t 1.

According to the engine control device 2 having the above configuration, the instantaneous state before the engine stop is regarded as the steady operation state, the engine speed, the engine temperature, and the intake pipe pressure at the moment before the engine stop are read, the initial fuel adhesion amount and the auto-power-off time can be calculated from the engine speed, the engine temperature, and the intake pipe pressure at the time of the stop (the moment before the stop), and the auto-power-off control can be executed based on the calculated auto-power-off time. When the initial fuel adhesion amount at the time of stopping is large, the auto-power-off time is appropriately lengthened, and when the initial fuel adhesion amount at the time of stopping is small, the auto-power-off time is appropriately shortened. When the engine temperature at the time of stop is high, the auto-power-off time is appropriately shortened, and when the engine temperature at the time of stop is low, the auto-power-off time is appropriately lengthened. In this way, the operating time of the auto-power-off module of the engine control device 2 can be appropriately set, and the battery 20 can be used appropriately.

Preferably, the vehicle 100 further includes an intake air temperature sensor 15, the intake air temperature sensor 15 being provided in an intake pipe 6 at a position close to a throttle valve 16 and detecting an intake air temperature Tha, the initial fuel adhesion amount calculation unit calculates an initial fuel adhesion amount MFstable at the time of stop of the engine 4 based on at least one of an engine speed Ne, an engine temperature Thw, an intake air temperature Tha, and an intake pipe pressure Pm at the time of stop of the engine 4, and the auto power off time calculation unit calculates the auto power off time t1 based on the initial fuel adhesion amount MFstable at the time of stop, the engine temperature Thw, and the intake air temperature Tha, when the second determination unit determines that the vehicle power switch 11 is turned off.

According to the engine control device 2 having the above configuration, the auto-power-off time is calculated based on the initial fuel adhesion amount at the time of stop, the engine temperature, and/or the intake air temperature, and the auto-power-off time can be calculated more accurately.

Preferably, the engine control device 2 further includes: a timer unit that counts an elapsed time t2 after the engine 4 is stopped; a third determination unit that determines that the restart is performed within the auto power-off time t1 when the elapsed time t2 is within the auto power-off time t1 and a signal is present from the crank position sensor 13; and a real-time adhesion amount initial value calculation unit that calculates a real-time adhesion amount initial value Fwet1 of the fuel based on the fuel initial adhesion amount MFstable at the time of stop and the elapsed time t 2.

According to the engine control device 2 having the above configuration, when it is determined that the restart is within the auto-power-off time, the initial value of the amount of fuel deposited in real time is calculated based on the initial amount of fuel deposited at the time of the stop and the elapsed time. Thus, the initial value of the real-time adhesion amount can be calculated reasonably according to the state of the vehicle at the time of stop, and the fuel injection amount at the time of restart can be calculated reasonably.

Preferably, the engine control device 2 further includes a current value calculation unit for a real-time adhesion amount, which calculates a current value Fwet of a real-time adhesion amount of the fuel at predetermined intervals tc.

According to the engine control device 2 having the above configuration, the current value of the real-time adhesion amount of the fuel can be constantly calculated, the proper fuel injection amount at the time of restart is ensured, and the problems such as difficult start due to insufficient fuel injection and start hunting due to excessive fuel injection do not occur.

Preferably, the engine control device 2 further includes a power supply voltage detection unit that detects a voltage of the battery 20 and automatically turns off the power supply after a predetermined time elapses when the voltage is equal to or lower than a predetermined voltage value.

According to the engine control device 2 having the above configuration, the battery can be kept from being short-circuited. The control of the engine can be ensured under the condition that the storage battery is ensured not to be lack of power.

Preferably, the engine control device 2 is configured to automatically turn off the power supply directly when the initial fuel adhesion MFstable is smaller than a predetermined value.

Preferably, the engine control device 2 automatically turns off the power supply as it is when the real-time adhesion amount initial value Fwet1 or the real-time adhesion amount current value Fwet is smaller than a predetermined value.

A second aspect of the present invention relates to an engine control method executed by an engine control device 2, the engine control device 2 being applied to a vehicle 100, the vehicle 100 having an engine 4 and a motor generator 5 as power sources, and a battery 20 as a power source, the vehicle 100 further including: a crank position sensor 13, provided in the cylinder block of the engine 4, for detecting a rotational position of a crankshaft of the engine 4 and an engine rotation speed Ne; an engine temperature sensor 12 provided in the cylinder block of the engine 4, the engine temperature sensor 12 detecting an engine temperature Thw; and an intake pressure sensor 17 provided in the intake pipe 6 for detecting an intake pipe pressure Pm, wherein the engine control device 2 has an auto-power-off function for maintaining power supply for a predetermined auto-power-off time after the vehicle power switch 11 is turned off, and wherein the engine control method comprises: a first determination step of determining whether or not the engine 4 has stopped based on a detection result of the crank position sensor 13; a fuel initial deposit amount calculation step of calculating a fuel initial deposit amount MFstable at the time of stopping the engine 4 based on at least one or more of an engine speed Ne, an engine temperature Thw, and an intake pipe pressure Pm at the time of stopping the engine 4; a second determination step of determining whether or not the vehicle power switch 11 is turned off; and an auto power-off time calculation step of calculating the auto power-off time t1 based on the initial fuel adhesion amount MFstable at the time of stop and the engine temperature Thw when it is determined by the second determination step that the vehicle power switch 11 is turned off, and the engine control device 2 executes the auto power-off control based on the calculated auto power-off time t 1.

Preferably, the vehicle 100 further includes an intake air temperature sensor 15, the intake air temperature sensor 15 being provided in a position in the intake pipe 6 near the throttle valve 16 for detecting an intake air temperature Tha, the initial fuel adhesion amount calculating step calculates an initial fuel adhesion amount MFstable at the time of stopping the engine 4 based on at least one of an engine speed Ne, an engine temperature Thw, an intake air temperature Tha, and an intake pipe pressure Pm at the time of stopping the engine 4, and the auto shutoff time calculating step calculates the auto shutoff time t1 based on the initial fuel adhesion amount MFstable at the time of stopping, the engine temperature Thw, and the intake air temperature Tha, when the vehicle power switch 11 is determined to be turned off by the second determining step.

Preferably, the engine control method further includes: a timing step of, in the timing step, timing an elapsed time t2 after the engine 4 is stopped by a timing unit included in the engine control device 2; a third determination step of determining that the restart is performed within the automatic power-off time t1 when the elapsed time t2 is within the automatic power-off time t1 and a signal is present from the crank position sensor 13; and a real-time deposit amount initial value calculation step of calculating a real-time deposit amount initial value Fwet1 of the fuel based on the initial fuel deposit amount MFstable at the time of stop and the elapsed time t 2.

Preferably, the engine control method further includes a real-time adhesion amount current value calculation step of calculating a real-time adhesion amount current value Fwet of the fuel at every predetermined period tc.

Preferably, the engine control method further includes a power supply voltage detection step of detecting a voltage of the battery 20 and automatically turning off the power supply after a predetermined time elapses when the voltage is equal to or lower than a predetermined voltage value.

Preferably, the automatic power-off is performed directly when the initial fuel adhesion MFstable is less than a predetermined value.

Preferably, the automatic power-off is performed directly when the initial value Fwet1 of the real-time adhesion amount or the current value Fwet of the real-time adhesion amount is smaller than a predetermined value.

Drawings

The above objects, other objects, features and advantages of the present invention will become more apparent with reference to the accompanying drawings and the following detailed description. The drawings are as follows.

Fig. 1 is a block diagram showing a vehicle to which an engine control device according to an embodiment of the present invention is applied.

Fig. 2 is a schematic configuration diagram showing a vehicle to which an engine control device according to an embodiment of the present invention is applied.

Fig. 3 is a schematic diagram showing the automatic power-off principle of the engine control device.

Fig. 4 is a flowchart showing automatic power-off control and restart determination of the engine control device according to the embodiment of the present invention.

Fig. 5 is a diagram showing a method of calculating the initial fuel adhesion amount, the initial value of the real-time adhesion amount, and the current value of the real-time adhesion amount in the engine control device according to the embodiment of the present invention.

Fig. 6 is a flowchart showing restart fuel injection control of the engine control device according to the embodiment of the present invention.

(symbol description)

100 vehicle

1 input part

2 Engine ECU

3 output part

4 engines

5 Motor generator

6 air inlet pipe

8 fuel pump

11 vehicle power switch

12 engine temperature sensor

13 crankshaft position sensor

14 throttle position sensor

15 air inlet temperature sensor

16 air throttle

17 air inlet pressure sensor

20 accumulator

41 oil sprayer

44 crankshaft

Detailed Description

Hereinafter, an engine control device and a control method thereof according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a block diagram showing a vehicle to which an engine control device according to an embodiment of the present invention is applied, and fig. 2 is a schematic configuration diagram showing a vehicle to which an engine control device according to an embodiment of the present invention is applied. In the present embodiment, a motorcycle will be described as an example of the vehicle 100. In the vehicle 100, the engine 4 and the motor generator 5 are provided as power sources, the battery 20 is provided as a power source, and the supply voltage of the battery 20 is, for example, 14V.

As shown in fig. 1 and 2, the vehicle 100 includes an input unit 1, an engine control device (hereinafter simply referred to as "engine ECU") 2, and an output unit 3.

The input unit 1 includes: a vehicle power switch 11 that energizes and de-energizes a battery 20 (power source) of the vehicle in accordance with an operation (on/off) by a driver, and outputs a signal for turning on or off the motor generator 5 to an engine ECU 2; an engine temperature sensor 12 provided in a cylinder block of the engine 4, for detecting a temperature of the engine 4, that is, an engine temperature Thw, and outputting the detection result to the engine ECU 2; a crank position sensor 13 provided in the cylinder block of the engine 4, the crank position sensor 13 detecting a rotational position of a crankshaft of the engine 4 and an engine rotation speed Ne, and outputting the detection result to the engine ECU 2; a throttle position sensor 14, the throttle position sensor 14 being provided on a throttle valve 16 in the intake pipe 6, for detecting an opening degree of the throttle valve 16; and an intake pressure sensor 17 (hereinafter, simply referred to as "MAP sensor") provided in the intake pipe 6, the MAP sensor 17 detecting the intake pipe pressure Pm and outputting the detection result to the engine ECU 2.

The engine ECU2 is a so-called microcomputer including a CPU, ROM, RAM, interfaces, and the like. The engine ECU2 is electrically connected to the battery 20, the vehicle power switch 11 operated by the driver, various sensors including the engine temperature sensor 12 and the crank position sensor 13, the motor generator 5, the fuel pump 8, the injector 41, and the like via interfaces, respectively, and CAN receive and transmit information via a communication network such as a CAN. The engine ECU2 reads a program stored in a semiconductor memory, for example, and the CPU executes processing defined by the program code. The ECU performs signal transmission with external devices through the I/O. The ECU executes predetermined processing based on the signal input via the I/O and outputs a signal of the execution result. Thus, the engine ECU2 provides a predetermined control function. In addition, the method of providing the function is not limited to the above-described method by software. As another providing method, for example, a method using hardware using a circuit such as an IC or a logic circuit may be used.

The engine ECU2 has an automatic power-off function. Fig. 3 is a schematic diagram showing the automatic power-off principle of the engine ECU. As shown in fig. 3, when the normal vehicle power switch is turned on, the engine ECU is in a normal operating state. When the vehicle power switch is turned from on to off, the engine ECU can also maintain the power supply through its own auto-power-off module. After the engine ECU detects that the switching signal is changed, the power-off time of the automatic power-off module is controlled according to the preset automatic power-off time, and when the preset control time is reached, the automatic power-off module disconnects the circuit, so that the power supply is cut off.

The engine ECU2 controls the operations of the motor generator 5, the fuel pump 8, the injector 41, and other parts based on the outputs of various sensors including the engine temperature sensor 12, the crank position sensor 13, and the like, and the state of the vehicle power switch 11.

The engine ECU2 described above includes: a first determination unit that determines whether or not the engine 4 has stopped based on a detection result of the crank position sensor 13; a fuel initial deposit amount calculation unit that calculates a fuel initial deposit amount MFstable at the time of stop of the engine 4 based on at least one or more of an engine speed Ne, an engine temperature Thw, and an intake pipe pressure Pm at the time of stop of the engine 4; a second determination unit that determines whether or not the vehicle power switch 11 is off, the engine ECU2 being electrically connected to the battery 20 when the vehicle power switch 11 is on, the diode of the engine ECU2 connected to the vehicle power switch 11 outputting a high level, the diode of the engine ECU2 connected to the vehicle power switch 11 being grounded and outputting a low level when the vehicle power switch 11 is off, the second determination unit determining that the vehicle power switch 11 is on when the high level is detected and determining that the vehicle power switch 11 is off when the low level is detected; and an auto power-off time calculation unit that calculates the auto power-off time t1 based on the initial fuel adhesion amount MFstable at the time of stop and the engine temperature Thw when the vehicle power switch 11 is determined to be off by the second determination unit, and the engine control device 2 executes the auto power-off control based on the calculated auto power-off time t 1.

As described above, the initial fuel adhered amount MFstable is the amount of fuel adhered to the engine when the engine is stopped. Since the fuel injected when the engine is stopped is not completely combusted, the fuel may adhere to the inside of the engine even though the engine is stopped.

According to the present invention configured as described above, the influence of the amount of fuel adhering to the engine when the engine is stopped on the engine restart ability is taken into consideration. The automatic power-off time t1 can be calculated from the initial fuel adhesion amount MFstable at the time of stop and the engine temperature Thw, and the automatic power-off control can be executed based on the calculated automatic power-off time t 1. The automatic power-off time t1 is appropriately lengthened when the initial fuel deposit amount MFstable at the time of stopping is high, and the automatic power-off time t1 is appropriately shortened when the initial fuel deposit amount MFstable at the time of stopping is low. The auto-power-off time t1 is appropriately shortened when the engine temperature Thw at the time of stop is high, and the auto-power-off time t1 is appropriately lengthened when the engine temperature Thw at the time of stop is low. In this way, the operating time of the auto power-off module of the engine ECU2 can be appropriately set, and the battery 20 can be used appropriately.

The engine ECU2 described above further includes: a timer unit that counts an elapsed time t2 after the engine 4 is stopped; a third determination unit that determines that the engine is restarted within the auto-power-off time t1 when the elapsed time is within the auto-power-off time t1 and a signal from the crank position sensor 13 is present; and a real-time adhesion amount initial value calculation unit that calculates a real-time adhesion amount initial value Fwet1 of the fuel based on the fuel initial adhesion amount MFstable at the time of stop and the elapsed time t 2.

As described above, the initial value Fwet1 of the amount of fuel deposited in real time is the amount of fuel deposited in real time at the time t2 after the engine 4 is stopped in the auto-power-off time t 1.

According to the present invention configured as described above, when it is determined that the restart is performed within the auto-power-off time t1, the real-time adhesion amount initial value Fwet1 of the fuel can be calculated based on the initial fuel adhesion amount MFstable at the time of the stop and the elapsed time t 2. Therefore, the restart time injection amount Tau can be set appropriately according to the condition of the vehicle at the time of stop. When the initial value Fwet1 of the real-time adhesion amount is high, the injection amount Tau at the time of restart is appropriately set low, and when the initial value Fwet1 of the real-time adhesion amount is low, the injection amount Tau at the time of restart is appropriately set high. Thus, the proper fuel injection amount during restarting can be ensured, and adverse conditions such as difficult starting caused by insufficient fuel injection and starting jitter caused by excessive fuel injection can be avoided.

The engine ECU2 further includes a real-time adhesion amount current value calculation unit that calculates a real-time adhesion amount current value Fwet of the fuel oil at every predetermined period tc. The predetermined period tc is a time that is set in advance as needed, and may be, for example, a time required for the crankshaft 44 to rotate at a phase angle of 720 ° at different rotational speeds, and is, for example, a value within 0 to 40 ms. Further, when the real-time adhesion amount Fwet is "0" or the detected value of the amount of change of the throttle position sensor 14 is equal to or greater than a predetermined threshold value, the real-time adhesion amount current value calculation unit fixes the real-time adhesion amount current value Fwet to 0.

As described above, the current value Fwet of the real-time adhesion amount of fuel is a value obtained by attenuating the initial value Fwet1 of the real-time adhesion amount of fuel every predetermined period tc.

According to the invention with the structure, the current value Fwet of the real-time adhesion amount of the fuel can be calculated every a specified period tc, so that the proper fuel injection amount can be ensured in a plurality of stroke periods of the engine after the restart in the automatic power-off time is started.

The engine ECU2 further includes a power supply voltage detection unit that detects the voltage from the battery 20, and automatically turns off the power supply after a predetermined time Tfix has elapsed when the voltage from the battery 20 is equal to or lower than a predetermined voltage value, for example, 11V. The prescribed time Tfix is an arbitrary value of 0 to 5 minutes.

Thus, the battery 20 can be kept without a shortage of electricity. Various controls of the engine can be ensured without a shortage of the battery 20.

The engine ECU2 also includes a fuel injection control unit that operates the fuel pump 8 and the injector 41, which will be described later, based on the calculated restart time injection amount Tau.

The output section 3 includes: a motor generator 5 described later; a fuel pump 8, the fuel pump 8 supplying fuel of a fuel tank to the injector 41; and an injector 41 provided in the intake pipe 6 at a position close to the cylinder of the engine 4, for injecting fuel supplied by the fuel pump 8 into the cylinder of the engine 4 in accordance with a command from the engine ECU2 to perform combustion.

The motor generator 5 is a so-called ACG starter that serves as both a starter motor and an AC generator (alternator). The motor generator 5 is coupled to the crankshaft 44 of the engine 4 so as not to interrupt transmission of the rotational driving force. That is, a rotor (not shown) of motor generator 5 is directly coupled to crankshaft 44 (fixed to one end of crankshaft 44) so that rotational driving force is constantly transmitted between motor generator 5 and crankshaft 44. The motor generator 5 is configured to: after the engine 4 is started, the crankshaft 44 functions as a generator by the rotational driving force generated by the crankshaft 44, and when the engine 4 is started, the crankshaft 44 is rotationally driven in the same direction as that after the engine 4 is started by the electric power from the battery 20, and functions as a starter motor.

Next, a control flow of the engine control device according to the embodiment of the present invention will be described with reference to fig. 4 to 6.

Fig. 4 is a flowchart showing automatic power-off control and restart determination of the engine control device according to the embodiment of the present invention. Fig. 5 is a diagram showing a method of calculating the initial fuel adhesion amount, the initial value of the real-time adhesion amount, and the current value of the real-time adhesion amount in the engine control device according to the embodiment of the present invention. Fig. 6 is a flowchart showing restart fuel injection control of the engine control device according to the embodiment of the present invention.

First, referring to fig. 4, the automatic power-off control and restart determination of the engine control device according to the embodiment of the present invention will be described.

Initially, the user turns on the vehicle power switch 11, and the battery 20 supplies power to the engine ECU2 and various sensors including the engine temperature sensor 12 and the crank position sensor 13, and outputs a signal to turn on the motor generator 5 to the engine ECU2, and the engine ECU2 starts executing the control flow.

Then, in step S1, the engine ECU2 determines whether the engine 4 has stopped based on the signal from the crank position sensor 13. If the signal from the crank position sensor 13 is not received, it is determined that the engine 4 is stopped (S1: YES), and the process proceeds to step S2. When the signal from the crank position sensor 13 is present, it is determined that the engine 4 is not stopped (no in S1), and the control proceeds to the restart fuel injection control.

Next, in step S2, engine ECU2 calculates an initial fuel adhesion amount MFstable at the time of stop. Fig. 5 shows a method for calculating the initial fuel adhesion MFstable at the time of stop. In the calculation, the engine ECU2 regards the state immediately before the engine stop as the steady operation state, reads the engine speed Ne, the engine temperature Thw, and the intake pipe pressure Pm immediately before the engine stop, calculates the initial fuel adhesion MFstable at the time of the stop by the following equation using the parameters of the engine speed Ne, the engine temperature Thw, and the intake pipe pressure Pm, and using the tables 11, 12, 21, and 22.

Table 11 is a table relating the fuel adhesion rate X, the engine speed Ne, and the intake pipe pressure Pm, and is hereinafter referred to as "map 11(Ne, Pm)". Table 12 is a table relating to the fuel adhesion rate X, the engine rotation speed Ne, and the engine temperature Thw, and is hereinafter referred to as "map 12(Ne, Thw)". The table 21 is a table relating the fuel evaporation coefficient a, the engine speed Ne, and the intake pipe pressure Pm, and is hereinafter referred to as "map 21(Ne, Pm)". Table 22 is a table relating to the fuel evaporation coefficient a, the engine rotation speed Ne, and the engine temperature Thw, and is hereinafter referred to as "map 22(Ne, Thw)".

MFstable ═ X/(1-a). GFET (formula 1)

(wherein GFET: basic injection quantity, X: fuel adhesion rate, a: fuel evaporation coefficient)

X ═ map11(Ne, Pm) × map12(Ne, Thw) (formula 2)

a ═ map21(Ne, Pm) × map22(Ne, Thw) (formula 3)

Then, in step S3, engine ECU2 determines whether vehicle power switch 11 has been turned off. When the output of the diode connected to the vehicle power switch 11 is at the low level, it is determined that the vehicle power switch 11 is off (yes in S3), and the process proceeds to step S6. When the output of the diode connected to the vehicle power switch 11 is at the high level, it is determined that the vehicle power switch 11 is not turned off (no in S3), and the process proceeds to step S4.

In step S4, engine ECU2 determines whether or not it is a restart. When the signal from the crank position sensor 13 is present, it is determined that the engine is restarted (yes in S4), and the process proceeds to step S11, where the restart flag is set to "1". If the signal from the crank position sensor 13 is not present, it is determined that the engine is not restarted (no in S4), and the process proceeds to step S3.

In step S6, engine ECU2 determines whether or not the voltage of battery 20 is equal to or lower than a predetermined voltage value, for example, 11V, based on the detection result of the power supply voltage detection unit. When the detection result of the power supply voltage detection unit is equal to or less than the predetermined voltage value (S6: YES), the process proceeds to step S5, and the power is turned off automatically after a predetermined time Tfix elapses, and the process is ended, where the predetermined time Tfix is an arbitrary value from 0 to 5 minutes. If the detection result of the power supply voltage detector is higher than the predetermined voltage value (no in S6), the process proceeds to step S7.

In step S7, the auto power-off time t1 is calculated from the table 31 based on the initial fuel adhesion amount MFstable and the engine temperature Thw. Table 31 is a table relating to the relationship between the auto-power-off time t1, the initial fuel adhesion amount MFstable, and the engine temperature Thw, and is hereinafter referred to as "map 31(MFstable, Thw)".

Next, in step S9, engine ECU2 determines whether or not an auto power-off time t1 has elapsed since the vehicle power switch 11 was turned off, based on a timer time t2 of the timer unit, that is, an elapsed time after the engine was stopped. When the auto-power-off time t1 has elapsed since the vehicle power switch 11 was turned off (S9: yes), the process proceeds to step S8, auto-power-off is performed, and the process ends. If the auto power-off time t1 has not elapsed since the vehicle power switch 11 was turned off (S9: no), the process proceeds to step S10.

Then, in step S10, engine ECU2 determines whether or not the restart is within the auto power-off time. When the signal from the crank position sensor 13 is present, it is determined that the restart is within the auto-power-off time (yes in S10), and the process proceeds to step S11. If there is no signal from the crank position sensor 13, it is determined that there is no restart (no in S10), and the process proceeds to step S9.

In step S11, engine ECU2 sets the restart flag to "1". Then, the routine shifts to restart fuel injection control and returns to the process.

Next, the restart fuel injection control of the engine control device according to the embodiment of the present invention will be described with reference to fig. 6.

In step S12, engine ECU2 determines whether or not the restart flag is "1". If the restart flag is determined to be "1", that is, if the restart is performed within the auto power-off time (yes in S12), the process proceeds to step S13. If it is determined that the restart flag is not "1", that is, the restart is performed outside the auto-power-off time (no in S12), the routine proceeds to step S18, and the normal injection control is performed so that the injector 41 is driven to inject the fuel of the normal injection amount tauunormalal.

In step S13, engine ECU2 calculates a real-time adhesion amount initial value Fwet1 from table 41 based on the initial fuel adhesion amount MFstable at the time of stop calculated in step S2 and the time t2 counted by the timer unit. The table 41 is a table relating to the relationship between the initial value of the real-time adhesion amount Fwet1, the initial fuel adhesion amount MFstable, and the timer time t2, and is hereinafter referred to as "map 41(MFstable, t 2)".

Then, in step S14, engine ECU2 calculates the restart time injection amount based on equation 4.

The restart-time injection amount Tau is equal to the normal injection amount taulormal — the initial value of the real-time adhesion amount Fwet1 (equation 4).

Next, in step S15, since the real-time adhesion amount initial value Fwet1 is attenuated every predetermined period tc, the real-time adhesion amount current value Fwet is calculated based on equation 5 every predetermined period tc.

The current value Fwet of the real-time adhesion amount is equal to the initial value Fwet 1-X × n (equation 5)

Where n is the number of decaying times, and X is a constant value obtained through experiments according to different vehicle models.

The predetermined period tc is a time that is preset as needed, and may be, for example, a time required for the crankshaft to rotate at a phase angle of 720 ° at different rotational speeds, and may be, for example, a value within 0 to 40 ms. And further calculating the injection amount Tau during restarting according to the calculated current value Fwet of the real-time adhesion amount.

Restart time injection amount Tau equal to normal injection amount taulormal — current real-time adhesion amount value Fwet

Then, in step S16, the engine ECU2 determines whether the current value Fwet of the real-time adhesion amount has become "0", or whether there is an acceleration request. When the real-time adhesion amount current value Fwet has become "0" or the detected value of the amount of change in the throttle position sensor 14 is equal to or greater than the predetermined threshold value, the process proceeds to step S17. If the real-time adhesion amount current value Fwet is not "0" or the detected value of the amount of change in the throttle position sensor 14 is smaller than the predetermined threshold value, the process proceeds to step S15.

In step S17, engine ECU2 resets the restart flag to "0" and fixes current real-time adhesion amount value Fwet to "0" until the start of the next restart determination.

Then, in step S18, engine ECU2 performs normal injection control to cause injector 41 to inject fuel of a normal injection amount tauunormal and drive the engine.

In the present embodiment, step S1 corresponds to a first determination step, step S2 corresponds to a fuel initial adhesion amount calculation step, step S3 corresponds to a second determination step, step S7 corresponds to an auto power off time calculation step, step S9 corresponds to a time counting step, step S10 corresponds to a third determination step, step S13 corresponds to a real-time adhesion amount initial value calculation step, step S15 corresponds to a real-time adhesion amount current value calculation step, and steps S6 and S5 correspond to a power supply voltage detection step.

According to the present embodiment described above, the following effects can be obtained.

1) The engine ECU has an automatic power-off function, can keep power supply through the automatic power-off module when a vehicle power switch is switched off, and can adjust automatic power-off time according to the initial fuel oil adhesion amount when the engine stops.

2) In the auto-power-off time of the vehicle, if the restart is detected, the real-time adhesion amount can be determined from the initial adhesion amount of the fuel and the engine stop time, and the injection amount at the time of the restart can be determined. If the vehicle is not restarted within the automatic power-off time, the power supply is cut off according to the preset automatic power-off time.

3) When the voltage of the storage battery is detected to be lower than the specified voltage value, the power is automatically cut off after the specified time, so that the power shortage of the storage battery can be avoided.

Although the present invention has been described in terms of embodiments, it should be understood that the present invention is not limited to the embodiments and configurations described above. The present invention also includes various modifications and modifications within an equivalent range. In addition, various combinations and modes, and other combinations and modes including only one element, one or more elements, and one or less elements also belong to the scope and the idea of the present invention.

For example, in the above embodiment, in step S2, engine ECU2 calculates the initial fuel deposit amount MFstable at the time of stop based on the engine speed Ne, the engine temperature Thw, and the intake pipe pressure Pm at the moment before the engine stop.

However, the present invention is not limited to this, and for example, the input unit 1 may further include an intake air temperature sensor 15, the intake air temperature sensor 15 being provided in the intake pipe 6 at a position close to the throttle valve 16 for detecting an intake air temperature Tha, and the engine ECU2 may calculate an initial fuel adhesion amount MFstable at the time of stop based on the engine speed Ne immediately before the engine stop, the intake air temperature Tha, and the intake pipe pressure Pm, instead of the parameters engine temperature Thw, at step S2.

Further, in step S2, engine ECU2 may calculate an initial fuel deposit amount MFstable at the time of stop based on engine speed Ne, intake air temperature Tha, engine temperature Thw, and intake pipe pressure Pm at the moment before the engine stop.

Thus, the calculation accuracy of the auto-power-off time and the initial fuel adhesion amount can be further improved.

In the calculation of step S2, the calculation may be performed using at least one of the engine speed Ne, the intake air temperature Tha, the engine temperature Thw, and the intake pipe pressure Pm.

For example, in the above embodiment, in step S6, when the detection result of the power supply voltage detection unit is equal to or less than the predetermined voltage value, the power supply is automatically turned off after the predetermined time Tfix has elapsed.

However, the present invention is not limited to this, and for example, in any step, if the fuel initial adhesion amount MFstable, the real-time adhesion amount initial value Fwet1, or the real-time adhesion amount current value Fwet is smaller than a predetermined value, the automatic power off may be performed directly. In any step, when abnormality occurs in the parameters of the engine speed Ne, the engine temperature Thw, the intake air temperature Tha, and the intake pipe pressure Pm at the time of engine stop, the automatic power cut may be performed as it is.

It should be noted that the execution order of the operations, the sequence, the steps, the stages, and the like in the apparatus, the system, the program, and the method shown in the claims, the description, and the drawings is not particularly explicitly expressed as "before", and the like, and the output of the previous process can be realized in an arbitrary order as long as it is not used in the subsequent process. Even if the operational flow in the claims, the specification, and the drawings is described using "first", "next", and the like for convenience of description, it does not mean that the operational flow must be executed in this order.

Claims

1. An engine control device (2) applied to a vehicle (100), the vehicle (100) having an engine (4) and a motor generator (5) as power sources, and a battery (20) as a power source, the vehicle (100) further comprising: a crankshaft position sensor (13), the crankshaft position sensor (13) being provided to a cylinder block of the engine (4) and detecting a rotational position of a crankshaft of the engine (4) and an engine speed; an engine temperature sensor (12), the engine temperature sensor (12) being provided in a cylinder block of the engine (4) and detecting an engine temperature; and an intake pressure sensor (17), the intake pressure sensor (17) is provided in the intake pipe (6) and detects the intake pipe pressure, the engine control device (2) has an automatic power-off function, and can maintain the supply of power for a predetermined automatic power-off time after the vehicle power switch (11) is turned off,

the engine control apparatus is characterized in that,

the engine control device (2) includes:

a first determination unit that determines whether the engine (4) has stopped based on a detection result of the crank position sensor (13);

a fuel initial adhesion amount calculation unit that calculates an initial adhesion amount of fuel at the time of stop of the engine (4) based on at least one or more of the engine speed, the engine temperature, and the intake pipe pressure at the time of stop of the engine (4);

a second determination unit that determines whether or not the vehicle power switch (11) has been turned off; and

an auto power-off time calculation unit that calculates the auto power-off time based on the initial fuel adhesion amount at the time of stop and the engine temperature when the vehicle power switch (11) is determined to be turned off by the second determination unit,

the engine control device (2) executes automatic power-off control based on the calculated automatic power-off time.

2. The engine control apparatus (2) according to claim 1,

the vehicle (100) further includes an intake air temperature sensor (15), the intake air temperature sensor (15) being provided in the intake pipe (6) at a position near the throttle valve (16) for detecting an intake air temperature,

the fuel initial adhesion amount calculation unit calculates an initial adhesion amount of fuel at the time of stopping the engine (4) based on at least one of the engine speed, the engine temperature and/or the intake air temperature, and the intake pipe pressure at the time of stopping the engine (4),

the auto power-off time calculation unit calculates the auto power-off time based on the initial fuel adhesion amount at the time of stop, the engine temperature, and/or the intake air temperature when the vehicle power switch (11) is determined to be turned off by the second determination unit.

3. The engine control apparatus (2) according to claim 2,

the engine control device (2) further includes:

a timing unit that counts an elapsed time after the engine (4) is stopped;

a third determination unit that determines that the engine is restarted within the automatic power-off time when the elapsed time is within the automatic power-off time and a signal from the crank position sensor (13) is present; and

and a real-time adhesion amount initial value calculation unit that calculates a real-time adhesion amount initial value of the fuel based on the initial adhesion amount of the fuel at the time of engine stop and the elapsed time.

4. The engine control apparatus (2) according to claim 3,

the engine control device (2) further includes a real-time adhesion amount current value calculation unit that calculates a real-time adhesion amount current value of the fuel at every predetermined cycle.

5. The engine control apparatus (2) according to any one of claims 1 to 4,

the engine control device (2) further comprises a power supply voltage detection unit that detects the voltage of the battery (20) and automatically cuts off the power supply after a predetermined time has elapsed when the voltage is equal to or lower than a predetermined voltage value.

6. The engine control apparatus (2) according to claim 1 or 2,

and if the initial fuel oil adhesion amount is smaller than a specified value, the engine control device (2) directly performs automatic power-off.

7. The engine control apparatus (2) according to claim 3 or 4,

and if the initial value of the real-time adhesion amount or the current value of the real-time adhesion amount is smaller than a specified value, the engine control device (2) directly performs automatic power-off.

8. An engine control method that an engine control device (2) executes, the engine control device (2) being applied to a vehicle (100), the vehicle (100) having an engine (4) and a motor generator (5) as power sources, and a battery (20) as a power source, the vehicle (100) further comprising: a crankshaft position sensor (13), the crankshaft position sensor (13) being provided to a cylinder block of the engine (4) and detecting a rotational position of a crankshaft of the engine (4) and an engine speed; an engine temperature sensor (12), the engine temperature sensor (12) being provided in a cylinder block of the engine (4) and detecting an engine temperature; and an intake pressure sensor (17), the intake pressure sensor (17) is provided in the intake pipe (6) and detects the intake pipe pressure, the engine control device (2) has an automatic power-off function, and can maintain the supply of power for a predetermined automatic power-off time after the vehicle power switch (11) is turned off,

the engine control method is characterized in that,

the engine control method includes:

a first determination step of determining whether or not the engine (4) has stopped, based on a detection result of the crank position sensor (13);

a fuel initial adhesion amount calculation step of calculating a fuel initial adhesion amount at the time of stop of the engine (4) based on at least one or more of an engine speed, an engine temperature, and an intake pipe pressure at the time of stop of the engine (4);

a second determination step of determining whether or not the vehicle power switch (11) is turned off; and

an auto power-off time calculation step of calculating the auto power-off time based on the initial fuel adhesion amount at the time of stop and the engine temperature when it is determined by the second determination step that the vehicle power switch (11) is turned off,

9. The engine control method according to claim 8,

in the fuel initial adhesion amount calculation step, an initial adhesion amount of fuel at the time of stop of the engine (4) is calculated based on at least one or more of an engine speed, an engine temperature and/or an intake air temperature, and an intake pipe pressure at the time of stop of the engine (4),

in the auto power-off time calculation step, when it is determined by the second determination step that the vehicle power switch (11) is turned off, the auto power-off time is calculated based on the initial fuel adhesion amount at the time of stop, the engine temperature, and/or the intake air temperature.

10. The engine control method according to claim 9,

the engine control method further includes:

a timing step of timing an elapsed time after the engine (4) is stopped by a timing unit provided in the engine control device (2);

a third determination step of determining that the restart is performed within the automatic power-off time when the elapsed time is within the automatic power-off time and a signal from the crank position sensor (13) is present; and

and a real-time adhesion amount initial value calculation step of calculating a real-time adhesion amount initial value of the fuel based on the initial adhesion amount of the fuel at the time of engine stop and the elapsed time.

11. The engine control method according to claim 10,

the engine control method further comprises a real-time adhesion amount current value calculation step, wherein in the real-time adhesion amount current value calculation step, the real-time adhesion amount current value of the fuel oil is calculated every other specified period.

12. The engine control method according to any one of claims 8 to 11,

the engine control method further includes a power supply voltage detection step of detecting a voltage of the battery (20) and automatically cutting off the power supply after a predetermined time elapses if the voltage is equal to or lower than a predetermined voltage value.

13. The engine control method according to claim 8 or 9,

14. The engine control method according to claim 10 or 11,