JP2004251220A - Engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem such as reduction of the negative pressure and reduction of stored electricity to be generated by continuation of the automatic engine stop condition, while reducing a risk such as being caught by an engine rotary unit. <P>SOLUTION: During the automatic engine stop, in the case where engagement of a part to be engaged in the normal travelling condition is released and shift position of a transmission is a non-drive position, the engine is started again. Furthermore, during the operation of the engine, in the case where the part to be engaged in the normal travelling condition is not engaged and shift position of the transmission is in the non-drive position, automatic engine stop is inhibited. On the other hand, during the automatic engine stop, in the case where engagement of the part to be engaged in the normal travelling condition is released and shift position of the transmission is a driving position, the engine is transferred to the stall condition. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic stop / start control technique for an engine that saves fuel and reduces exhaust emissions by executing automatic stop and restart of the engine under predetermined conditions.
[0002]
[Prior art]
Conventionally, while automatically stopping the engine under predetermined stop conditions, for example, when an automobile stops at an intersection, etc., the engine is restarted under predetermined restart conditions, for example, when an accelerator pedal is depressed. There is known an automatic stop / start control device capable of saving fuel consumption and reducing exhaust emissions.
[0003]
In the automatic stop / start control device described in Patent Document 1, when the hood (hood covering the engine) of the vehicle is open during the automatic stop of the engine, the operation of the starter is prohibited. By prohibiting restarting, it is possible to prevent the engine from suddenly restarting during an inspection or the like and being caught in the engine rotating portion (such as an accessory drive belt).
[0004]
[Patent Document 1]
JP-A-58-202368
[Problems to be solved by the invention]
As described above, in the related art, when the hood or the like is open, the restart of the engine is prohibited, thereby preventing the entrainment by the engine rotating unit.
[0006]
However, since the brake booster called master back uses the negative pressure generated by the rotation of the engine to increase the braking force, the automatic stop of the engine is maintained as long as the hood is open as described above. In a configuration in which the engine does not rotate, the negative pressure may decrease and a necessary and sufficient braking force may not be obtained. In addition, since the battery is not charged as long as the hood or the like is open, the amount of stored power may be reduced and the function as the battery may be reduced.
[0007]
Here, even with the configuration of the related art, it is possible to improve the state in which the negative pressure is reduced and the amount of stored power is reduced by starting the engine using the ignition key. However, in this case, it is necessary for the driver or the like to check the state of the vehicle, such as the negative pressure or the amount of stored power, to determine the necessary timing and manually start the engine, so that the burden imposed on the driver or the like is not necessarily small. Absent.
[0008]
Therefore, an object of the present invention is to reduce the risk of entanglement or the like by the engine rotating unit and to avoid the problem that occurs when the engine automatic stop state continues.
[0009]
[Means for Solving the Problems]
An engine control device or an engine control method according to the present invention is an engine control device or a method for automatically stopping or restarting an engine based on a predetermined condition. When the engagement is released and the shift position of the transmission is in the non-drive position, the engine is restarted. According to this configuration, it is possible to reduce the risk of entanglement or the like by the engine rotating unit, and to avoid problems such as a decrease in negative pressure and a decrease in the amount of stored power caused by the continuation of the automatic engine stop state.
[0010]
Preferably, during the operation of the engine, when the portion that is in the engaged state during normal running is in the disengaged state and the shift position of the transmission is in the non-drive position, the automatic stop of the engine is prohibited. According to such a configuration, the automatic stop / restart does not occur as long as the part is in the disengaged state, so that the above effect can be further enhanced.
[0011]
An engine control device or an engine control method according to the present invention is an engine control device or a method for automatically stopping or restarting an engine based on a predetermined condition. Is disengaged, and when the shift position of the transmission is in the drive position, the engine is shifted to a stall state. According to such a configuration, it is possible to effectively prevent the vehicle from starting while the engagement of the parts is released, and to stall the engine so that the vehicle is in a startable drive position. Regardless, it is possible to inform the driver or the like of the irregular state in which the engagement of the above-mentioned portions is released.
[0012]
In the engine control device and the engine control method according to the present invention, preferably, the portion that is in the engaged state during normal traveling is a hood and / or a door that covers the engine.
[0013]
An engine control device or an engine control method according to the present invention is an engine control device or a method for automatically stopping or restarting an engine based on a predetermined condition. Is restarted. Preferably, the engine is restarted when the shift position of the transmission is in the non-drive state. According to this configuration, it is possible to reduce the risk of entanglement or the like by the engine rotating unit, and to avoid problems such as a decrease in negative pressure and a decrease in the amount of stored power caused by the continuation of the automatic engine stop state.
[0014]
The engine control method of the present invention can be implemented by a computer, and a computer program for that can be installed or loaded on the computer through various media such as a CD-ROM, a magnetic disk, a semiconductor memory, and a communication network. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram of a vehicle internal combustion engine to which the above-described invention is applied and a control device thereof. Here, a gasoline engine (hereinafter, referred to as "engine") 2 is used as an internal combustion engine.
[0016]
The output of the engine 2 is output from a crankshaft (corresponding to a drive shaft) 2a of the engine 2 via a torque converter 4 and an automatic transmission (automatic transmission: hereinafter referred to as "A / T") 6 on the output shaft 6a side. And finally transmitted to the wheels. Further, separately from such a driving force transmission system from the engine 2 to the wheels, the output of the engine 2 is transmitted to the belt 14 via the pulley 10 connected to the crankshaft 2a. The other pulleys 16 and 18 are rotated by the output transmitted by the belt 14. The pulley 10 is provided with an electromagnetic clutch 10a, which is turned on (connected) and turned off (disconnected) as necessary, so that transmission and non-transmission of output can be switched between the pulley 10 and the crankshaft 2a. Things.
[0017]
Of the pulleys 16 and 18, the pulley 16 is connected to a rotating shaft of accessories 22 and can be driven by the rotational force transmitted from the belt 14. Examples of the accessories 22 include a compressor for an air conditioner, a power steering pump, a water pump for cooling an engine, and the like. Although one accessory 22 is shown in FIG. 1, one or more of an air conditioner compressor, a power steering pump, an engine cooling water pump, and the like are actually present, and the belt is provided with pulleys. 14 to rotate. In the present embodiment, it is assumed that an air conditioner compressor, a power steering pump, and an engine cooling water pump are provided as the auxiliary devices 22.
[0018]
A motor generator (hereinafter, referred to as “M / G”) 26 is linked to the belt 14 by the pulley 18. The M / G 26 functions as a generator as required (hereinafter referred to as a “power generation mode”), thereby converting the torque transmitted from the engine 2 via the pulley 18 to electric energy. Further, the M / G 26 rotates one or both of the engine 2 and the accessories 22 by the belt 14 via the pulley 18 by functioning as a motor (hereinafter referred to as “drive mode”) as necessary.
[0019]
Here, the M / G 26 is electrically connected to the inverter 28. When the M / G 26 is set to the power generation mode, the inverter 28 performs switching so that the M / G 26 is connected to the battery 30 for the high-voltage power supply (here, 36 V) and to the low-voltage power supply (here, the DC / DC converter 32). The battery 34 is switched to charge electric energy to the 12V) battery 34, and to be a power source for the ignition system, meters, ECUs and others.
[0020]
When the M / G 26 is set to the “drive mode”, the inverter 28 drives the M / G 26 by supplying power from the high-voltage power supply battery 30 which is a power source to the M / G 26, and drives the pulley 18 and the belt. 14, when the engine is stopped, the accessory 22 is rotated, and in some cases, the crankshaft 2 a is rotated at the time of automatic start, automatic stop, or vehicle start. The inverter 28 can adjust the number of rotations of the M / G 26 by adjusting the supply of electric energy from the high-voltage power supply battery 30.
[0021]
Note that a starter 36 is provided for starting the engine during cold start. The starter 36 is supplied with electric power from the low-voltage power supply battery 34 and rotates the ring gear to start the engine 2.
[0022]
The A / T 6 is provided with an electric hydraulic pump 38 that is supplied with power from the low-voltage power supply battery 34, and supplies hydraulic oil to a hydraulic control unit inside the A / T 6. This hydraulic oil adjusts the operating states of the clutch, brake and one-way clutch in the A / T 6 by a control valve in the hydraulic control unit, and switches the shift state as necessary.
[0023]
The above-described on / off switching of the electromagnetic clutch 10a, the mode control of the M / G 26, the inverter 28, the control of the starter 36, and the control of the charged amount of the batteries 30 and 34 (not shown) are executed by the eco-run ECU 40. Also, the drive on / off of the auxiliary equipments 22 except the water pump, the drive control of the electric hydraulic pump 38, the shift control of the A / T 6, the fuel injection control by the fuel injection valve (intake port injection type or the in-cylinder injection type) 42, the electric motor The control of the opening of the throttle valve 46 by the control 44 and other engine controls are executed by the engine ECU 48. In addition, since the brake ECU 50 is provided, automatic control of the brake of each wheel is also performed.
[0024]
The eco-run ECU 40 determines the number of revolutions of the rotating shaft of the M / G 26 from a revolution number sensor built into the M / G 26, whether or not the driver has activated the eco-run system from the eco-run switch, the open / close state of the hood covering the engine room from the hood sensor, The door sensor detects the open / closed state of the door and other data. Further, the engine ECU 48 is provided with an engine cooling water temperature from a water temperature sensor, an accelerator pedal depression state from an idle switch, an accelerator opening degree from an accelerator opening sensor, a steering angle from a steering angle sensor, a vehicle speed from a vehicle speed sensor, and a throttle opening sensor. , The throttle position from the shift position sensor, the engine speed from the engine speed sensor, the presence / absence of on / off operation from the air conditioner switch, and other data for engine control and the like. The brake ECU 50 also detects the presence or absence of depression of a brake pedal from a brake switch and other data for braking control and the like.
[0025]
Each electronic control unit such as the eco-run ECU 40 includes a CPU (processor), a ROM, a RAM (which may include a backup RAM for storing data to be stored when the engine 2 is stopped), an input interface, an output interface, and the like. Be composed. The CPU is capable of accessing a ROM or the like via an internal bus, executes various control processes based on predetermined data stored in the ROM, a control algorithm, or the like, and executes a calculation result or an input result via an input interface. A process for storing data and the like input from the sensor in the RAM is executed. The ECU 40, 48, 50, and the like can exchange data with each other on these calculation results, data, and the like, and exchange data as necessary to execute control in conjunction with each other. Is possible.
[0026]
Here, similarly to the conventional case, the eco-run ECU 40 instructs the engine ECU 48 to cut off the fuel supply when the vehicle is under a predetermined condition, for example, when the vehicle is temporarily stopped at a traffic light or the like. Automatically stop the engine 2 and, under a predetermined condition such as when the vehicle starts again, drive the M / G 26 and instruct the engine ECU 48 to restart the fuel supply to restart the engine 2. It is configured to execute control processing.
[0027]
However, in the automatic stop control process of the present embodiment, as described later, the mode in which the engine 2 is restarted during the automatic engine stop is a portion (for example, a hood or a door) that is engaged with the vehicle body during normal traveling. Is different from the conventional configuration in that it includes a mode in which the engine 2 is restarted when the engagement of the A / T 6 is released and the shift position of the A / T 6 is at the non-drive position.
[0028]
The automatic stop / start control process executed by the eco-run ECU 40 will be described with reference to the flowchart shown in FIG. The automatic stop / start control includes a D eco-run for performing automatic stop / start control of the engine 2 in the D or NP range, and an automatic stop / start control for the engine 2 only in the NP range. There are two types known as N eco-run, which does not perform the automatic stop / start control. However, in the present embodiment, description will be given for D eco-run.
[0029]
When the eco-run switch is turned on, the eco-run ECU 40 repeatedly executes the following process, for example, at predetermined time intervals under the control of the CPU, based on the control algorithm recorded in the ROM. However, each step (including a partial step without a reference numeral) can be executed in an arbitrary order or in parallel without changing the processing contents.
[0030]
First, the eco-run ECU 40 determines whether or not the engine 2 is automatically stopped (S100).
[0031]
If it is determined that the automatic stop is not being performed, the eco-run ECU 40 determines the open / closed state of the hood based on a signal from the hood sensor (S101).
[0032]
If it is determined that the hood is open (the engagement between the hood and the engine room has been released), the eco-run ECU 40 ends the automatic stop / start control process without automatically stopping the engine 2.
[0033]
On the other hand, if it is determined that the hood is not open, the eco-run ECU 40 determines whether the automatic stop condition is satisfied (S102).
[0034]
The automatic stop conditions include, for example, 1) when the brake pedal is depressed, the brake master pressure exceeds a predetermined threshold value due to the depression force, and a predetermined time has elapsed in that state; 2) Various conditions are considered according to the design, such as an operation of changing the shift position from the driving position to the non-driving position, or an operation of putting the parking brake into an operating state and a predetermined time set in that state has elapsed. be able to.
[0035]
If it is determined that the automatic stop condition is not satisfied, the eco-run ECU 40 ends the automatic stop / start control process.
[0036]
On the other hand, if it is determined that the automatic stop condition is satisfied, the eco-run ECU 40 outputs a control signal to another ECU or the like to automatically stop the engine 2 (S103), and thereafter ends the automatic stop and start control processing. . In this case, for example, an indicator (for example, a lamp) provided in the driver's seat may be turned on to indicate to the driver that the engine 2 is automatically stopped.
[0037]
If it is determined in S100 that the vehicle is being automatically stopped, the eco-run ECU 40 determines the open / closed state of the hood based on a signal from the hood sensor (S104).
[0038]
If it is determined that the hood is open, the eco-run ECU 40 determines whether the shift position of the A / T 6 is in the non-drive position (P or N range) (S105).
[0039]
If it is determined that the vehicle is in the non-drive position, the eco-run ECU 40 outputs a control signal to another ECU or the like to restart the engine 2 (S106), and thereafter ends the automatic stop / start control process.
[0040]
On the other hand, when it is determined that the vehicle is not in the non-drive position, that is, in the drive position (D range), the eco-run ECU 40 outputs a control signal to another ECU or the like to shift the engine 2 to a stall state (S107). Then, the automatic stop / start control process ends. In this case, the condition for starting the engine is that the driver or the like changes the shift position of the transmission to the non-drive position and then performs a start operation using the ignition key.
[0041]
If it is determined in S104 that the hood is not open, the ECU 40 determines whether a restart condition is satisfied (S108).
[0042]
The restart conditions include, for example, 1) that the shift position is in the non-drive position and that there is a start request by key operation, 2) that the shift position is in the drive position (D eco-run is being executed), and that the brake is started. The request flag is ON, 3) the shift position is in the drive position (D eco-run is being performed), and 200 ms has elapsed with the idle switch flag indicating OFF, depending on the design. Various conditions can be considered.
[0043]
The brake start request flag indicates that the brake switch indicates that the brake pedal is not depressed, or that the brake master pressure is smaller than a predetermined threshold value (for example, 0.4 MPa), or that the decreasing change width of the brake master pressure is a predetermined threshold value ( For example, a flag indicating the ON state when either of the conditions is equal to or greater than 0.06 MPa), and indicating the OFF state otherwise. The idle switch flag indicates an ON state when the idle switch indicates that the accelerator pedal is fully closed (when an output request is not issued to the engine 2), and indicates an OFF state otherwise.
[0044]
If it is determined that the restart condition is satisfied, the eco-run ECU 40 outputs a control signal to another ECU or the like to restart the engine 2 (S106), and thereafter ends the automatic stop / start control process.
[0045]
On the other hand, if it is determined that the restart condition is not satisfied, the eco-run ECU 40 ends the automatic stop / start control process without restarting the engine 2.
[0046]
Normally, it is considered that the entrainment by the engine rotating section occurs when the engine 2 restarts from the automatic stop state while performing work or the like with the hood opened. However, in the present embodiment, when the hood is opened during the automatic stop of the engine, the engine 2 restarts or enters a stall state. Therefore, the engine 2 is in the automatic stop state at the time of starting work or the like. Therefore, naturally, a situation in which the engine 2 restarts from the automatic stop state while performing work or the like with the hood opened cannot occur. Therefore, the risk of entrainment by the engine rotating section can be greatly reduced.
[0047]
Note that, strictly speaking, from when the hood is disengaged to when the engine 2 is restarted, the hood is open and the engine 2 is automatically stopped. It is extremely short, and it is considered that the engine 2 has restarted by the time the hood is lifted and the engine room is sufficiently opened to start work or the like. There is no stop state.
[0048]
Further, in the present embodiment, when the hood is opened during the automatic stop of the engine, switching between restarting the engine 2 or shifting to the stall state is performed according to the state of the shift position of the A / T 6. By adopting such a configuration, when the shift position of the A / T 6 is in the non-drive position and there is no possibility that the vehicle starts, unlike the related art, the rotation of the engine 2 is ensured even when the hood is open. Therefore, problems such as a decrease in negative pressure and a decrease in the amount of stored electricity can be avoided.
[0049]
On the other hand, if the shift position of the A / T 6 is in the drive position and the vehicle may start by, for example, releasing the brake, the engine 2 shifts to a stalled state when the hood is opened. It is possible to effectively prevent the vehicle from starting. Further, by stalling the engine 2, it is possible to inform a driver or the like of an irregular state in which the hood is open in spite of the drive position where the engine 2 can start. Note that the processing may be configured to prohibit restarting instead of stalling the engine 2, but in this case, the driver or the like is notified of the irregular state by turning on a lamp or the like. It is desirable to do.
[0050]
(Other)
The present invention is not limited to the above embodiment, but can be applied in various modifications.
[0051]
For example, in the above embodiment, the hood has been described as an example of the portion that is brought into the engaged state during the normal running, but such a portion is not limited to the hood, and may be, for example, a door. That is, instead of / in addition to the hood, based on other parts, for example, the engagement state of the door (when the door is open; when the engagement between the door and the vehicle body is released), the A / The automatic stop / start control process may be configured to restart or stall the engine according to the state of the shift position at T6.
[0052]
Further, for example, the presence or absence of the restart may be directly determined based on whether or not the hood is opened. That is, when it is determined in S104 that the hood is open, the eco-run ECU 40 may output a control signal to another ECU or the like to restart the engine 2.
[0053]
Further, for example, in the above embodiment, the case where the transmission is an AT (automatic transmission) has been described, but the present invention can be applied to the case of a manual transmission.
[0054]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, while reducing the risk of the entanglement etc. by an engine rotating part, it can avoid the problem that the negative pressure which arises by the engine automatic stop state continuing, and the reduction of the amount of electric power storage.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a system configuration of a vehicle internal combustion engine and a control device thereof in a vehicle according to a first embodiment.
FIG. 2 is a flowchart illustrating a flow of an automatic stop / start control process according to the first embodiment.
[Explanation of symbols]
2 Engine 2a Crankshaft 4 Torque Converter 6 Automatic Transmission 6a Output Shaft 10 Pulley 10a Electromagnetic Clutch 14 Belt 16, 18 Pulley 22 Accessories 26 Motor Generator 28 Inverter 30 Battery for High Voltage Power Supply 32 DC / DC Converter 34 Battery for Low Voltage Power Supply 36 Starter 38 Electric hydraulic pump 40 Eco-run ECU
42 fuel injection valve 44 electric motor 46 throttle valve 48 engine ECU
50 brake ECU

Claims (9)

An engine control device for automatically stopping or restarting the engine based on predetermined conditions,
An engine control device for restarting an engine when a portion which is in an engaged state during normal running is released and an automatic transmission is in a non-drive position during an automatic stop of the engine. While the engine is running, the automatic stop of the engine is prohibited when the part that is engaged during normal running is in the disengaged state and the shift position of the transmission is in the non-drive position. The engine control device according to claim 1. An engine control device for automatically stopping or restarting the engine based on predetermined conditions,
An engine control device for shifting the engine to a stalled state when a portion that is brought into an engaged state during normal running is disengaged and the shift position of the transmission is at a drive position during automatic engine stop; . The engine control device according to any one of claims 1 to 3, wherein the portion that is in the engaged state during normal traveling is a hood that covers the engine. An engine control device for automatically stopping or restarting the engine based on predetermined conditions,
An engine control device for restarting an engine when an engine hood is opened during an automatic engine stop. The engine control device according to claim 5, wherein the engine is restarted when the shift position of the transmission is in a non-drive state. An engine control method for automatically stopping or restarting an engine based on predetermined conditions,
An engine control method comprising: restarting an engine when a portion that is in an engaged state during normal running is disengaged and a shift position of a transmission is at a non-drive position during automatic engine stop. An engine control method for automatically stopping or restarting an engine based on predetermined conditions,
An engine control method comprising: shifting an engine to a stall state when a portion that is in an engaged state during normal running is disengaged and a shift position of a transmission is in a drive position during automatic engine stop. . A program for causing a computer to execute the engine control method according to claim 7.

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