JP2004218606A - Automatic stopping starter device of internal- combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic stopping starter device for an internal-combustion engine to make automatic stop/start control of the engine under the specified conditions capable of precluding giving a sense of incompatibleness to a driver/passenger such as a sense of the vehicle hopping out in case the automatic starting condition of the engine are met after the automatic stop control and when the restarting of the engine is completed and of preventing the vehicle from hopping out. <P>SOLUTION: The automatic stopping starter device of the internal-combustion engine is equipped with a limiting means. If the automatic starting conditions are met after the automatic stopping conditions are met and the engine is stopped by an automatic stop/start means, the engine is to be restarted by the automatic stop/start means, and in this case, the limiting means limits the fuel supply to the engine so as to suppress a steep increase of the engine torque. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an automatic stop / start technique for an internal combustion engine that automatically stops and starts an internal combustion engine mounted on an automobile or the like when a predetermined condition is satisfied.
[0002]
[Prior art]
In recent years, for the purpose of reducing fuel consumption, exhaust emissions, or noise of an internal combustion engine mounted on an automobile or the like, when the vehicle stops at an intersection or the like, the operation of the internal combustion engine is automatically stopped, An automatic stop / start device that automatically restarts the internal combustion engine when the vehicle starts moving is under development.
[0003]
In addition, a technique has been proposed that prevents sudden torque generation at the time of restarting the internal combustion engine and eliminates shock to the vehicle body and the occupant (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-20787 A
[Patent Document 2]
JP 2000-313253 A
[Patent Document 3]
JP 2001-14067 A
[0005]
[Problems to be solved by the invention]
By the way, the internal combustion engine is restarted when the automatic start condition is satisfied. However, when it takes time from the establishment of the automatic start condition to the restart of the internal combustion engine, the driver is required to restart the internal combustion engine before the completion of the internal combustion engine restart. It is assumed that the accelerator pedal is continuously depressed in order to start the vehicle early, or the accelerator pedal is depressed more strongly.
[0006]
When the restart of the internal combustion engine is completed with the driver depressing the accelerator pedal, the engine torque sharply increases in accordance with the depression amount of the accelerator pedal (accelerator opening), and the operation is stopped. The driver feels a sense of discomfort, such as the feeling of the vehicle jumping out, and if the accelerator pedal is further depressed, the vehicle may jump out at the completion of starting.
[0007]
The present invention has been made in view of such circumstances, and in an apparatus for performing automatic stop control and automatic start control of an internal combustion engine under predetermined conditions, a case where the automatic start condition of the internal combustion engine is satisfied after the automatic stop control. It is another object of the present invention to prevent a passenger from feeling uncomfortable when the restart of the internal combustion engine is completed, and to prevent the vehicle from jumping out.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to a case where the automatic start condition is satisfied and the internal combustion engine is restarted by the automatic stop and start means after the automatic stop condition is satisfied and the internal combustion engine is stopped by the automatic stop and start means. In addition, the gist of the present invention is to limit the supply of fuel to the internal combustion engine.
[0009]
According to the above configuration, when the automatic start condition is satisfied and the restart of the internal combustion engine is completed, the supply of fuel to the internal combustion engine can be restricted by the restricting means. Does not occur. Therefore, the occupant does not feel discomfort, such as a feeling of popping out, and the vehicle does not jump out. The limiting means can limit the fuel supply to the internal combustion engine, and may limit the fuel supply amount to the internal combustion engine determined based on, for example, the depression amount of an accelerator pedal operated by the driver.
[0010]
Here, as the automatic stop condition for automatically stopping the internal combustion engine, for example, the vehicle speed is zero, the brake switch is on (the brake pedal is depressed, or the parking brake is operated). That the accelerator pedal is not depressed; that the water temperature of the internal combustion engine is within a predetermined range (the internal combustion engine is in a warm-up state); that the shift position is in the drive position or the neutral position; (For example, there is no need to operate a compressor or alternator for an air conditioner). Note that, in place of the vehicle speed being zero, one of the vehicle speed being zero and the vehicle being in a decelerating state to stop may be one of the automatic stop conditions.
[0011]
The automatic start condition is a case where the above-mentioned automatic stop condition is not satisfied.For example, a brake pedal is released or an accelerator pedal is depressed for restart of the vehicle, or After the automatic stop, there is a case where the battery charge falls below a predetermined value due to the operation of the air conditioner.
[0012]
Further, the limiting means is configured to, when the automatic start condition is satisfied within a predetermined time after the automatic stop condition is satisfied and the internal combustion engine is stopped by the automatic stop start means, the fuel supply to the internal combustion engine when the internal combustion engine is restarted. It is also preferred to limit the supply.
[0013]
The above configuration is effective, for example, when the driver wants to start the vehicle quickly. The driver may recognize that the establishment of the automatic start condition and the restart of the internal combustion engine are at substantially the same timing. Actually, a required time (predetermined time) is required (for example, a time lag) from the establishment of the automatic start condition to the completion of the restart of the internal combustion engine. Thinks that the vehicle is restarting, or wants to start the vehicle quickly (by restarting the internal combustion engine quickly), it is possible to keep pressing the accelerator pedal until the vehicle starts, or to depress the accelerator pedal strongly There is.
[0014]
If the internal combustion engine is started with the accelerator pedal depressed, fuel is supplied to the internal combustion engine according to the amount of depression of the accelerator pedal when the start is completed, and the engine torque sharply increases. If the driver feels a sense of incongruity, such as a feeling of jumping out, and the accelerator pedal is further depressed, the vehicle may jump out upon completion of the start.
[0015]
Therefore, by providing the limiting means, even if the accelerator pedal is depressed when the automatic starting condition is satisfied and the restart of the internal combustion engine is completed, a sudden rise in torque of the engine does not occur, and the occupant jumps out. There is no discomfort such as a feeling, and the vehicle does not jump out.
[0016]
The automatic stop / start means stops the supply of fuel to the internal combustion engine when the automatic stop condition is satisfied, thereby stopping the internal combustion engine, and the limiting means stops the supply of fuel to the internal combustion engine by the automatic stop / start means. It is also preferable to limit the supply of fuel to the internal combustion engine when the automatic start condition is satisfied before the rotation detection unit detects the stop of the rotation of the internal combustion engine.
[0017]
In the above-described configuration, for example, immediately after the vehicle stops at a traffic light at an intersection or in a traffic jam, the automatic stop condition of the internal combustion engine is satisfied, and immediately after the operation of the internal combustion engine is automatically stopped, the signal turns blue. This is effective when the driver releases the brake pedal or depresses the accelerator pedal due to the start of the vehicle that has been stopped during traffic congestion. When the automatic stop condition of the internal combustion engine is satisfied, the internal combustion engine is stopped by cutting off the fuel supply to the internal combustion engine, but when the fuel supply to the internal combustion engine is cut off, the rotation speed gradually increases. Falling.
[0018]
When a starter is used as a starting device for cranking the internal combustion engine when starting the internal combustion engine, the internal combustion engine is started by operating the starter while the internal combustion engine is stopped to prevent damage to the starter. Let me. In particular, when starting the internal combustion engine by engaging the pinion gear of the starter with the ring gear of the flywheel of the internal combustion engine, if the internal combustion engine is not stopped, the pinion gear cannot be engaged with the flywheel, The internal combustion engine cannot be started.
[0019]
Therefore, if the automatic stop condition of the internal combustion engine is satisfied and the supply of fuel to the internal combustion engine is stopped, and the automatic start condition is satisfied while the engine speed is decreasing, the stop of the internal combustion engine must be waited. In addition, the internal combustion engine cannot be started immediately.
[0020]
In such a case, the driver may depress the accelerator pedal more strongly in order to start the vehicle sooner. If the internal combustion engine is started with the accelerator pedal strongly depressed, when the start is completed, the occupant feels discomfort such as a feeling of popping out of the vehicle, and when the accelerator pedal is further depressed, when the start is completed, The vehicle may jump out.
[0021]
Even in such a case, with the above-described configuration, a sudden rise in torque of the engine does not occur, the vehicle is prevented from jumping out, and an uncomfortable feeling such as a jumping out feeling given to the occupant can be eliminated.
[0022]
In addition, the above-described configuration is also applicable to a hybrid vehicle having an internal combustion engine and an electric motor as power sources, when the internal combustion engine cannot be started by the electric motor (for example, a torque sufficient for starting the internal combustion engine due to a shortage of charge amount is obtained). This is effective when the internal combustion engine is started using the starter.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific embodiments of an automatic stop and start device for an internal combustion engine according to an embodiment of the present invention will be described with reference to the drawings.
[0024]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which an automatic stop / start device according to an embodiment of the present invention is applied, and is an embodiment applied to a vehicle diesel engine as the internal combustion engine.
[0025]
As shown in FIG. 1, the internal combustion engine 1 according to the present embodiment injects fuel into four cylinders (combustion chambers) 5a, 5b, 5c, and 5d (hereinafter, collectively referred to as cylinders 5) arranged in series. The fuel injection system 600, the intake system 700, the exhaust system 800, an electronic control unit (Electronic Control Unit: hereinafter referred to as ECU) 30, and the like are configured as main components.
[0026]
Further, a transmission (T / M) 200 is connected to the internal combustion engine 1 according to the present embodiment via a torque converter (or clutch mechanism) 100. The transmission (T / M) 200 is connected to a propeller shaft (not shown). And a differential gear or the like, and is connected to wheels as driving wheels.
[0027]
In the power transmission system configured as described above, when the torque converter 100 is in the engaged state, the torque of the output shaft (crankshaft) (not shown) of the internal combustion engine 1 is transmitted via the torque converter 100 to the transmission (T / M ) 200, decelerated or accelerated by a transmission (T / M) 200, and then transmitted from the transmission (T / M) 200 to drive wheels via a propeller shaft, a differential gear, and the like.
[0028]
An intake branch pipe 2 is connected to the internal combustion engine 1, and each branch pipe of the intake branch pipe 2 communicates with a combustion chamber of each cylinder 5 via an intake port. The intake branch pipe 2 is connected to a surge tank 4, and the surge tank 4 communicates with an air cleaner box via an intake pipe 6.
[0029]
In the intake system 700 configured as described above, fresh air taken into the air cleaner box is supplied to the surge tank 4 via the intake pipe 6 and then distributed from the surge tank 4 to each branch pipe of the intake branch pipe 2, The fuel is supplied from the branch pipe to the combustion chamber of each cylinder 5 through the intake port.
[0030]
Fuel injection valves 3a, 3b, 3c, 3d (hereinafter collectively referred to as fuel injection valves 3) are attached to the respective branch pipes of the intake branch pipe 2 such that the injection holes face the intake ports. A fuel distribution pipe 7 is connected to these fuel injection valves 3, and the fuel distribution pipe 7 is connected to a fuel pump (not shown). Each fuel injection valve 3 is electrically connected to the ECU 30, and the fuel injection valve 3 is driven to open by the ECU 30.
[0031]
In the fuel injection system 600 configured as described above, the fuel discharged from the fuel pump is supplied to the fuel distribution pipe 7 and then distributed from the fuel distribution pipe 7 to each fuel injection valve 3. Then, the fuel supplied from the fuel distribution pipe 7 is injected into the combustion chamber of the cylinder 5 by opening the fuel injection valve 3 controlled by the ECU 30.
[0032]
On the other hand, an exhaust branch pipe 9 is connected to the internal combustion engine 1, and each branch pipe of the exhaust branch pipe 9 communicates with a combustion chamber of the cylinder 5 via an exhaust port (not shown). The exhaust branch pipe 9 is connected to the exhaust pipe 8. An exhaust purification catalyst (not shown) for purifying harmful gas components contained in exhaust gas discharged from the internal combustion engine 1 is provided in the exhaust pipe 8. The exhaust pipe 8 is connected to a muffler (not shown) downstream of the exhaust purification catalyst.
[0033]
In the exhaust system 800 configured as described above, the exhaust gas discharged from the internal combustion engine 1 is guided to the exhaust pipe 8 through the exhaust branch pipe 9, and is included in the exhaust gas by the exhaust purification catalyst in the exhaust pipe 8. After purifying harmful gas components, they are released into the atmosphere via a muffler.
[0034]
Next, the ECU 30 provided in the internal combustion engine 1 will be described.
[0035]
The ECU 30 includes a drive circuit for opening and closing the fuel injection valve 3, a crank position sensor 21, a water temperature sensor 22, an accelerator position sensor 23, a shift position sensor 24, a brake switch 25, a vehicle speed sensor 26, an SOC controller 27, a starter 300, and power generation. The mechanism 400 and the like are connected via electric wiring so that an output signal is input or a control signal is output. Further, an on / off signal of a starter switch (ST.SW) 28 and an on / off signal of an ignition switch (IG.SW) 29 are input to the ECU 30.
[0036]
The ECU 30 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a backup RAM, a timer counter, an external input circuit including an A / D converter, an external output circuit, and the like. . The CPU, the ROM, the RAM, the backup RAM, the timer counter, and the like, and the external input circuit, the external output circuit, and the like are mutually connected by a bidirectional bus, and constitute a logical operation circuit as a whole.
[0037]
Further, the ECU 30 is provided with an engine ECU 31 for executing control of the internal combustion engine, and an eco-run (automatic run / start control for executing automatic stop / start control for automatically stopping the internal combustion engine under predetermined automatic stop conditions and restarting the internal combustion engine under predetermined automatic return conditions). (Economy running) ECU 32.
[0038]
Here, the crank position sensor 21 outputs a pulse signal each time the crankshaft rotates a predetermined angle (for example, 10 degrees). The accelerator position sensor 23 is attached to an accelerator lever, It outputs an electric signal corresponding to the amount of rotation of the lever (electric signal corresponding to the amount of depression of the accelerator pedal).
[0039]
The shift position sensor 24 detects the position of a shift lever installed in the vehicle compartment, the brake switch 25 detects operation / non-operation of a brake pedal, and the vehicle speed sensor 26 detects the traveling speed of the vehicle. Is what you do. The SOC controller 27 calculates the state of charge (State Of Charge) of the battery 500 from the integrated value of the amount of discharge current and the amount of charge current of the battery 500.
[0040]
The power generation mechanism 400 is connected to a crank pulley (not shown) attached to the base end of the crankshaft 10 of the internal combustion engine 1 via a belt, and is mounted on the internal combustion engine 1. The power generation mechanism 400 includes, for example, an alternator, a regulator, a controller, and the like.
[0041]
The starter 300 includes a pinion gear 303 that meshes with a ring gear provided on the circumference of a flywheel (or drive wheel) 11 attached to the tip of the crankshaft 10 of the internal combustion engine 1.
[0042]
When the internal combustion engine 1 is started, the starter 300 operates using the battery 500 as a drive source. At that time, the rotational force of the starter 300 is transmitted to the crankshaft 10 via the pinion gear 303 and the flywheel 11, and Cranking is performed.
[0043]
Here, the starter 300 will be described with reference to FIGS. 2 and 3 are diagrams for explaining the operation of the starter in the internal combustion engine according to the present embodiment. FIG. 2A is a diagram illustrating the start of the internal combustion engine 1, FIG. 2B is a diagram illustrating the operation of the internal combustion engine 1, and FIG. 3A is a diagram illustrating a state in which the pinion gear 303 of the starter 300 has retreated. FIG. 3B is a diagram showing a state where the pinion gear 303 has advanced.
[0044]
As shown in FIG. 3, the starter 300 includes a DC motor 301, a pinion gear 303 spline-coupled to a motor shaft 302 of the DC motor 301, a magnet switch 304 for driving the pinion gear 303 forward and backward in the axial direction of the motor shaft 302, It is provided with.
[0045]
When the drive current is not applied (when it is off), the magnet switch 304 keeps the pinion gear 303 in a retreat state as shown in FIG. On the other hand, when the drive current is applied (when it is on), the magnet switch 304 advances the pinion gear 303 as shown in FIG. 3B.
[0046]
The starter 300 thus configured is provided in the internal combustion engine 1 such that when the pinion gear 303 advances, the pinion gear 303 and the ring gear of the flywheel 11 mesh with each other, as shown in FIG. .
[0047]
When the internal combustion engine 1 is started, the magnet switch 304 is first turned on, the pinion gear 303 advances, and the pinion gear 303 meshes with the ring gear of the flywheel 11. Subsequently, a drive current is applied to the DC motor 301 to rotate the motor shaft 302, and the rotational torque of the motor shaft 302 is transmitted to the crankshaft 10 via the pinion gear 303 and the ring gear (flywheel 11).
[0048]
When the internal combustion engine 1 is operating, the magnet switch 304 is turned off to bring the pinion gear 303 into the retreat state as shown in FIG. 3A, and the pinion gear 303 and the flywheel 11 are turned off as shown in FIG. It does not mesh with the ring gear.
[0049]
If the pinion gear 303 and the ring gear of the flywheel 11 are always in mesh with each other, a large load is applied to the starter 300. Therefore, as described above, the pinion gear 303 and the ring gear of the flywheel 11 Are engaged with each other.
[0050]
Next, an automatic stop / start device provided in the internal combustion engine 1 will be described.
[0051]
An automatic stop / start device for the internal combustion engine 1 that automatically stops the internal combustion engine under predetermined stop conditions and restarts the internal combustion engine under predetermined return conditions is implemented on the ECU 30 according to a control program stored in the ROM.
[0052]
The eco-run ECU 32 determines the execution condition of the automatic stop of the internal combustion engine 1 (automatic stop determination), and issues a command to cut off the fuel supply to the internal combustion engine 1 when it is determined that the automatic stop condition is satisfied (fuel A cut command) means, a condition for determining an execution condition for restarting the internal combustion engine 1 (automatic return determination), and a means for restarting the internal combustion engine 1 when it is determined that the internal combustion engine 1 should be restarted. Means for issuing a command to drive the starter 300 and for giving a command to restart fuel supply to the internal combustion engine 1 (return command).
[0053]
The ECU 30 receives a vehicle speed sensor signal, a shift position signal, an accelerator position sensor signal, a brake switch signal, and the like for the automatic stop determination and the automatic return determination in the eco-run ECU 32.
[0054]
The eco-run ECU 32 determines, for example, (1) that the vehicle speed is zero (the output signal value of the vehicle speed sensor 26 is zero), (2) that the brake pedal is depressed (the output signal value of the brake switch 25 is “ (3) that the accelerator pedal is not depressed (the output signal value of the accelerator position sensor 23 indicates that the accelerator pedal depression amount is zero). (4) The water temperature of the internal combustion engine and the operating oil temperature of the A / T are within a predetermined range (the temperature calculated based on the output signal value of the water temperature sensor 22 is within a predetermined range). (5) The shift position is in the drive (D) position or the neutral (N) position (the output signal value of the shift position sensor 24 is "D position position Or (N) position signal), and (6) that the SOC (battery charge) is not lower than a predetermined value (the output signal value of the SOC controller 27 is within a predetermined range). It is determined that the internal combustion engine 1 should be stopped (automatic stop determination). In (1), instead of the vehicle speed being zero, the vehicle speed may be either zero or the vehicle may be in a decelerating state of stopping.
[0055]
Here, when the transmission is a manual transmission, the condition of the above (5) is that the shift position is at the N position and the clutch pedal is depressed (the clutch is disengaged).
[0056]
Performing the automatic stop / start control when the shift position is at the D or N position is referred to as D eco-run. The automatic stop / start control is performed only at the N position, and the automatic stop / start control is not performed at other positions. It is called N eco-run. It is also possible to select and control whether to use D eco-run or N eco-run.
[0057]
On the other hand, the eco-run ECU 32 determines whether a predetermined restart condition is satisfied (automatic return determination). This is because when any one of the conditions for determining that the internal combustion engine should be stopped when the above-described automatic stop determination is performed is not satisfied, for example, when the accelerator pedal is depressed or the brake pedal is released. Then, it is determined that the internal combustion engine should be restarted.
[0058]
When the eco-run ECU 32 determines that the automatic stop conditions have been met, the automatic stop start device turns on a control execution indicator, for example, a lamp, provided on the driver's seat, and informs the driver that the internal combustion engine is being automatically stopped. It is preferable to provide an automatic stop display means as shown.
[0059]
Hereinafter, the automatic stop / start control according to the present embodiment will be described. In the automatic stop / start control, the ECU 30 executes an automatic stop / start control routine as shown in FIG.
[0060]
For example, when the traffic light turns red at the intersection and the brake is depressed and the vehicle stops, the eco-run ECU 32 determines the execution condition of the automatic stop of the internal combustion engine 1.
[0061]
In step S101, the eco-run ECU 32 determines that the vehicle speed is zero, the brake pedal is depressed, the accelerator pedal is not depressed, the water temperature of the internal combustion engine and the operating oil temperature of the A / T are within predetermined ranges, for example. If it is determined that the internal combustion engine should be stopped on the condition that the shift position is at D or N, or that the SOC (battery charge) is not less than a predetermined value, the engine ECU 31 is sent to the internal combustion engine 1 Command to cut off the fuel supply (→ Eco-run request).
[0062]
In step S102, the amount of intake air is reduced in order to suppress the vibration accompanying the stop of the internal combustion engine 1.
[0063]
In step S103, it is confirmed whether or not a command to cut fuel supply to the internal combustion engine 1 (eco-run request) by the eco-run ECU 32 is continued. If the determination in step S103 is affirmative, the process proceeds to step S105. If the determination is negative, the process exits this routine (step S104).
[0064]
In step S105, the engine ECU 31 stops supplying fuel to the internal combustion engine by stopping supplying drive power to the fuel injection valve 3, for example. When the fuel supply to the internal combustion engine 1 is stopped, the engine speed NE gradually decreases, and eventually the engine stops.
[0065]
In step S106, the ECU 30 checks whether or not the command (eco-run request) for cutting off the fuel supply to the internal combustion engine 1 by the eco-run ECU 32 is continued. If the determination in step S106 is affirmative, the process proceeds to step S107. If the determination is negative, the process proceeds to step S109.
[0066]
In step S107, the stop state of the internal combustion engine 1 is continued. In step S108, the ECU 30 checks whether or not the command (eco-run request) for cutting off the fuel supply to the internal combustion engine 1 by the eco-run ECU 32 is continued. When the determination in step S108 is affirmative, the determination is continued, and when the determination is negative, the process proceeds to step S109.
[0067]
Hereinafter, a case where the determinations in steps S106 and S108 are negative will be described.
[0068]
If the determinations in steps S106 and S108 are negative, for example, the vehicle is in a stopped state waiting for a traffic light at an intersection and the internal combustion engine 1 is stopped by the automatic stop / start device, and the traffic light turns green. This is the case where the driver releases the brake pedal or depresses the accelerator pedal. In this case, the eco-run ECU 32 determines that the internal combustion engine 1 should be restarted (performs automatic return determination), and issues a command to restart fuel supply to the internal combustion engine 1 (return command). 1 is restarted, and the internal combustion engine 1 is restarted.
[0069]
Here, a predetermined time is required from when the driver releases the brake pedal or depresses the accelerator pedal until the fuel supply to the internal combustion engine 1 is restarted and the internal combustion engine 1 is restarted. This is because, after the eco-run ECU 32 determines that the internal combustion engine 1 should be restarted, a command to drive the starter 300 and a command to restart fuel supply to the internal combustion engine 1 are issued. The engine ECU 31 that has received the command of (1) confirms that the internal combustion engine 1 has stopped, and then drives the starter 300 and restarts fuel supply to the internal combustion engine 1.
[0070]
As described above, the restart of the internal combustion engine 1 is performed by the pinion gear 303 of the starter 300 being engaged with the ring gear of the flywheel 11, so that the internal combustion engine 1 is stopped. Therefore, the engine ECU 31 must operate the starter 300 after it is confirmed that the rotation of the internal combustion engine 1 is stopped (engine speed NE ≒ 0).
[0071]
In particular, the fuel supply to the internal combustion engine 1 is cut off when the automatic stop condition is satisfied, and while the engine speed NE is gradually decreasing, the automatic start condition is satisfied and the eco-run ECU 32 restarts the internal combustion engine 1. When a command (restart of the internal combustion engine) is issued to the engine ECU 31 to start the engine, the time until it is confirmed that the rotation of the internal combustion engine 1 has stopped becomes relatively long.
[0072]
This is because, for example, the vehicle stops when waiting for a traffic light at an intersection or in a traffic jam, and the eco-run ECU 32 determines that the automatic stop condition has been satisfied, and issues a command to cut off the fuel supply to the internal combustion engine 1. When the driver releases the brake pedal or restarts the accelerator pedal to restart the internal combustion engine 1 due to the timing at which the fuel supply to the internal combustion engine 1 is cut off and the preceding vehicle starting when the signal turns green or during a traffic jam. Occurs when the timing of stepping on is substantially the same.
[0073]
The state of the engine speed NE from when the command to cut off the fuel supply to the internal combustion engine 1 is issued until the starter 300 is driven to restart the internal combustion engine 1 will be described with reference to FIG.
[0074]
FIG. 5 shows that the engine speed NE at time t1 is at the idling speed. At time t1, the eco-run ECU 32 issues a command to cut off the fuel supply to the internal combustion engine 1 (→ eco-run request: step S101). Then, at time t2 after a predetermined time (period A: time lag) elapses after the fuel supply cut command is issued from the eco-run ECU 32 at time t1, fuel supply to the internal combustion engine 1 is performed by the engine ECU 31 based on the command from the eco-run ECU 32. It is cut (step S105). When the fuel supply to the internal combustion engine 1 is cut, the engine speed NE of the internal combustion engine 1 gradually decreases (period B).
[0075]
t3 indicates the time when the rotation of the internal combustion engine 1 is no longer detected by the crank position sensor 21. When the rotation of the internal combustion engine 1 is not detected even at a time t4 when a predetermined time (period C) has elapsed from the time t3. It is determined that the rotation of the internal combustion engine 1 has stopped (step S110). This is because the stop of the rotation of the internal combustion engine 1 is confirmed by the crank position sensor 21 that outputs a pulse signal each time the crankshaft rotates by a predetermined angle.
[0076]
The time t4 also indicates the time when the starter 300 started operating (step S110). At time t4, the pinion gear 303 of the starter 300 starts to advance and a predetermined time (period D) elapses. The motor shaft 302 is rotated by the application, and the rotational torque of the motor shaft 302 is transmitted to the crankshaft 10 via the pinion gear 303 and the ring gear (flywheel 11), and the internal combustion engine 1 is restarted.
[0077]
As described above, when the internal combustion engine 1 is restarted immediately after the command to cut off the fuel supply to the internal combustion engine 1 is issued by the eco-run ECU 32, the stop of the rotation of the internal combustion engine 1 (vehicle stopped state) is confirmed. Since the starter 300 must be actuated after that, as shown in FIG. 5, the time (period (period (t)) from the fuel cut command by the eco-run ECU 32 until the starter 300 cranks the internal combustion engine 1. A + B + C + D)) is required.
[0078]
Therefore, immediately after the eco-run ECU 32 determines that the automatic stop condition is satisfied and the command to cut off the fuel supply to the internal combustion engine 1 is issued, that is, in the period A or the period B shown in FIG. Is released or the accelerator pedal is depressed to satisfy the automatic start condition of the internal combustion engine 1, it takes time from the time to the time t5 until the internal combustion engine is restarted.
[0079]
On the other hand, if sufficient time has passed since the stop of the rotation of the internal combustion engine 1 (the stop of the rotation of the internal combustion engine 1 (vehicle stop state) is confirmed), the automatic operation of the internal combustion engine 1 is stopped. Until the internal combustion engine 1 is restarted when the start condition is satisfied, the time required for the starter 300 to operate (the time from when the pinion gear 303 starts to advance until it meshes with the ring gear of the flywheel 11: period D) If there is.
[0080]
Usually, the driver is not particularly conscious of the timing from when the brake pedal is released or the accelerator pedal is depressed to establish the automatic start condition of the internal combustion engine 1 until the internal combustion engine is restarted. Even after the automatic start condition of the internal combustion engine 1 is satisfied, it is recognized that the internal combustion engine is restarted within the time period D shown in FIG. Therefore, when it takes more time to restart the internal combustion engine than the driver recognizes (when the internal combustion engine does not restart immediately after releasing the brake pedal or depressing the accelerator pedal to establish the automatic start condition of the internal combustion engine 1) ) Or in a situation where it is desired to start the vehicle anyway soon, the driver may continue to depress the accelerator pedal in an attempt to start the internal combustion engine 1 quickly, and may further depress the accelerator pedal. There is.
[0081]
When the internal combustion engine 1 is restarted with the driver depressing the accelerator pedal, the engine torque increases rapidly according to the amount of depression of the accelerator pedal (accelerator opening). The driver may feel a sense of discomfort such as a feeling of popping out, and if the accelerator pedal is further depressed, the vehicle may fly out.
[0082]
Therefore, in the present embodiment, a limiting means for limiting the amount of depression of the accelerator pedal (accelerator opening) is provided. Then, in step S109, the depression amount of the accelerator pedal is set to the upper limit value ACCPmax by the limiting means constituting the ECU 30.
[0083]
Here, the torque control of the diesel engine is performed by adjusting the fuel injection amount, and in the diesel engine, the fuel injection amount is adjusted according to the depression amount (operation amount) of the accelerator pedal.
[0084]
Therefore, regarding the setting of the upper limit value ACCPmax, fuel injection is performed such that the vehicle does not jump out (do not suddenly start) when the restart of the internal combustion engine 1 is completed, and the occupant does not feel uncomfortable, such as a feeling of jumping out of the vehicle. It only has to be quantity.
[0085]
In this way, by providing the limiting means, even if the restart of the internal combustion engine 1 is completed in a state where the driver depresses the accelerator pedal, the engine torque of the internal combustion engine 1 sharply increases according to the depression amount of the accelerator pedal. The rise of the engine torque is not increased and the occupant does not feel discomfort such as the feeling of the vehicle jumping out, and the vehicle jumps out even if the driver depresses the accelerator pedal more strongly. Not even.
[0086]
Returning to the automatic stop / start control routine shown in FIG. 4, the description will be continued. In step S110, after confirming that the internal combustion engine 1 has stopped, the starter 300 is operated. Then, in step S111, the internal combustion engine 1 is restarted.
[0087]
In step S112, it is checked whether the engine speed or the vehicle speed is equal to or higher than a specified value. According to this determination, the accelerator pedal is depressed when the restart of the internal combustion engine 1 is completed due to the situation (engine speed, vehicle speed, etc.) of the vehicle that started with the amount of depression of the accelerator pedal being restricted by the restricting means. To check whether the vehicle may fly out. If the determination in step S112 is negative, the determination is continued, and if the determination is positive, the process proceeds to step S113.
[0088]
In step S113, since the possibility that the vehicle jumps out is small, the restriction on the depression amount of the accelerator pedal by the restriction means is released. After the processing in step S113, the ECU 30 once exits this routine.
[0089]
Here, step S102 and step S103 may be omitted, and the process may shift from step S101 to step S105. Further, in the automatic stop / start control routine shown in FIG. 4, it is repeatedly confirmed whether or not the command (eco-run request) for cutting off the fuel supply to the internal combustion engine 1 by the eco-run ECU 32 is continued. In addition, the control characteristics (especially responsiveness) of the automatic stop / start control are improved, and further the drivability can be improved.
[0090]
As described above, according to the present embodiment, when the vehicle does not start immediately when the automatic start condition is satisfied, for example, when the driver releases the brake pedal or depresses the accelerator pedal, the vehicle starts early. The driver who wants to be operated may continue to depress the accelerator pedal until the vehicle starts, but the provision of the limiting means limits the fuel supplied to the internal combustion engine when the internal combustion engine is restarted. The engine torque does not suddenly increase, the occupant does not feel discomfort such as the feeling of jumping out of the vehicle, and the vehicle does not jump out (start suddenly) even if the accelerator pedal is depressed by a large amount. .
[0091]
As described above, the torque control of the diesel engine is performed by adjusting the fuel injection amount, and in the diesel engine, the fuel injection amount is adjusted according to the depression amount of the accelerator pedal.
[0092]
Therefore, as the restricting means, for example, when the accelerator pedal is depressed without following the depression amount of the accelerator pedal, the fuel injection amount may be controlled to be a predetermined amount. Further, by defining an upper limit value of the fuel injection amount, the fuel injection amount may be adjusted according to the depression amount of the accelerator pedal up to the upper limit value. Further, a mechanical configuration may be employed in which the accelerator pedal cannot be depressed beyond a predetermined amount.
[0093]
In the present embodiment, a diesel engine is described as an example of the internal combustion engine. However, the present invention is not limited to this, and may be applied to, for example, a gasoline engine. The torque control of the gasoline engine is performed by adjusting the intake air amount. For this reason, in a diesel engine, the fuel injection amount is adjusted according to the depression amount of the accelerator pedal, whereas in the gasoline engine, the intake air amount is adjusted according to the depression amount of the accelerator pedal.
[0094]
Even if the accelerator pedal is depressed when starting the gasoline engine, the torque of the engine may increase sharply immediately after the start is completed.However, by providing the limiting means, when the internal combustion engine is restarted, By limiting the fuel supplied to the internal combustion engine, it is possible to prevent a sudden increase in engine torque.
[0095]
As a limiting means, in the case of a gasoline engine, the intake air amount may be a predetermined amount. Further, by defining an upper limit value of the intake air amount, the intake air amount may be adjusted according to the depression amount of the accelerator pedal until the upper limit value is reached. Further, a mechanical configuration may be employed in which the accelerator pedal cannot be depressed beyond a predetermined amount. The stop of the internal combustion engine in the case of the diesel engine is performed by cutting off the fuel supply, but the stop of the internal combustion engine in the case of the gasoline engine is not limited to this, and the ignition may be cut.
[0096]
Further, the automatic stop and start device for an internal combustion engine according to the present embodiment includes an internal combustion engine and an electric motor as power sources, and can be suitably applied to a hybrid vehicle including a starter for starting the internal combustion engine. .
[0097]
In some of such hybrid vehicles, the internal combustion engine is started by using an electric motor. However, when the internal combustion engine cannot be started by the electric motor, for example, the electric motor is used due to insufficient power storage (for example, in a cold region). If the engine cannot be used, or if sufficient torque cannot be obtained for starting the internal combustion engine even if it can be used, or if the electric motor or the like breaks down, the internal combustion engine is started by the starter. Even in such a case, the effects described above can be obtained by performing control by the automatic stop and start device for the internal combustion engine according to the present embodiment.
[0098]
Further, the automatic stop and start device for an internal combustion engine according to the present embodiment may include means for maintaining a braking force of the vehicle. With this means, it is possible to suppress a sense of discomfort (for example, due to engagement of the transmission) felt when the internal combustion engine 1 is started by being cranked by the starter 300. As means for maintaining the braking force, for example, a brake signal is sent to a normal braking system or an ABS system to stop the wheel with the braking force of the brake, or the wheel is stopped by mechanically locking a rotating shaft connected to the wheel. Good.
[0099]
Although the means for holding the vehicle's braking force alone can reduce the sense of popping out of the vehicle, it is difficult to maintain the braking force when the brake negative pressure is insufficient, and the amount of depression of the accelerator pedal is large. When the engine torque becomes large, it is difficult to suppress the feeling of popping out. Therefore, by providing the means for maintaining the braking force of the vehicle in the above-described automatic stop and start apparatus for an internal combustion engine according to the present embodiment, it is possible to reliably eliminate a sense of discomfort such as a feeling of popping out of the vehicle.
[0100]
【The invention's effect】
As described above, according to the present invention, since the engine torque does not suddenly increase, it is possible to prevent the occupant from feeling uncomfortable, such as a feeling of popping out of the vehicle, and to prevent the vehicle from popping out. Become.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which an automatic stop and start device according to an embodiment of the present invention is applied.
FIGS. 2A and 2B are diagrams illustrating the operation of a starter. FIG. 2A is a diagram illustrating a start of the internal combustion engine, and FIG. 2B is a diagram illustrating a run of the internal combustion engine.
3A and 3B are diagrams illustrating an operation of a starter, in which FIG. 3A illustrates a state in which a pinion gear 303 retreats, and FIG. 3B illustrates a state in which the pinion gear 303 advances.
FIG. 4 is a flowchart illustrating an automatic stop / start control routine;
FIG. 5 is a diagram illustrating a state of an engine speed NE of the internal combustion engine.
[Explanation of symbols]
1 Internal combustion engine
2 Intake branch pipe
3 Fuel injection valve
4 surge tank
5 cylinders
6 Intake pipe
7 Fuel distribution pipe
8 Exhaust pipe
9 Exhaust branch pipe
10 Crankshaft
11 Flywheel
21 Crank position sensor
22 Water temperature sensor
23 Accelerator position sensor
24 shift position sensor
25 Brake switch
26 Vehicle speed sensor
27 SOC controller
28 Starter switch (ST.SW)
29 Ignition switch (IG.SW)
30 ECU
31 Engine ECU
32 Eco-run ECU
100 torque converter (or clutch mechanism)
200 Transmission (T / M)
300 Starter
301 motor
302 motor shaft
303 pinion gear
400 power generation mechanism
500 battery
600 Fuel injection system
700 intake system
800 Exhaust system

Claims (5)

Automatic stop and start means for automatically stopping the internal combustion engine when the automatic stop condition is satisfied, and automatically restarting the internal combustion engine when the automatic start condition is satisfied,
After the automatic stop condition is satisfied and the internal combustion engine is stopped by the automatic stop and start means, if the automatic start condition is satisfied and the internal combustion engine is restarted by the automatic stop and start means, Limiting means for limiting the supply of fuel;
An automatic stop and start device for an internal combustion engine, comprising: The limiting means, when the automatic start condition is satisfied within a predetermined time after the automatic stop condition is satisfied and the internal combustion engine is stopped by the automatic stop start means, the internal combustion engine The automatic stop / start apparatus for an internal combustion engine according to claim 1, wherein the supply of fuel is restricted. The automatic stop start means stops the supply of fuel to the internal combustion engine when the automatic stop condition is satisfied, to stop the internal combustion engine,
The limiting means may be configured such that the automatic start condition is satisfied during a period from when the supply of fuel to the internal combustion engine is stopped by the automatic stop and start means to when the rotation detection means detects the stop of the rotation of the internal combustion engine. 3. The automatic stop / start device for an internal combustion engine according to claim 1, wherein the supply of fuel to the internal combustion engine is restricted in such a case. 4. The fuel supply system according to claim 1, wherein the restricting unit restricts a fuel supply amount to the internal combustion engine that is determined based on a depression amount of an accelerator pedal operated by a driver. 5. Automatic stop and start device for internal combustion engines. The automatic stop / start device for an internal combustion engine according to any one of claims 1 to 4, further comprising a starter that starts the internal combustion engine when the automatic start condition is satisfied.

Images