JPH1077937A - Automatic stopping starter of engine and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate operation of a driver, be superior in safety, and smoothly perform stop, start and backward operations. SOLUTION: At a state where an engine 1 automatically stops, it is detected from an output of reverse switch 9b that a shift lever 8 of an automatic transmission 3 is positioned at a reverse range. A control ECU 4 discriminates whether or not a predetermined time has passed. If a predetermined time has passed, the engine 1 is started. While the shift lever 8 is at the reverse range, the engine 1 does not stop automatically in order to perform a smooth back operation. Only in the state where a brake 13 is operated, a smooth back operation is performed by changing the shift lever 8 to the reverse range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for automatically stopping and starting an engine which automatically stops the engine at an intersection or the like and starts the engine automatically to save fuel and reduce exhaust gas. In particular, the present invention relates to a device and method for automatically stopping and starting an engine used in a vehicle having an automatic transmission.

[0002]

2. Description of the Related Art When a vehicle stops at an intersection or the like while traveling in a city, the engine is stopped under predetermined stop conditions, and then the engine is started under predetermined start conditions, thereby saving fuel and reducing exhaust gas. Automatic stop and start devices for reducing gas are known. As a conventional technology of this type of device,
For example, there is one disclosed in JP-A-57-186063.

The technique disclosed in Japanese Patent Application Laid-Open No. 57-186063 discloses that when an automatic stop / start device and an automatic transmission are used, the vehicle speed is 0, the automatic transmission is set to a neutral range, and When a stop condition such as a brake being applied is satisfied, the engine is stopped, and the engine is started by releasing the side brake.

[0004]

Problems to be Solved by the Invention
In the automatic stop and start device disclosed in No. 63, the operation of the shift lever and the side brake is required for the automatic stop and start processing, and the operation may be troublesome. For this reason, the number of engine stops may be reduced, and the contribution to fuel efficiency may be reduced.

Therefore, even when the automatic transmission is set to the drive range or the reverse range, if the vehicle speed satisfies a predetermined condition such as 0, the engine may be stopped. In this case, the engine may be restarted by depressing the accelerator pedal.

However, when the engine is stopped,
Since the oil pump (hydraulic pump) that generates hydraulic pressure by the driving force of the engine also stops, the operating hydraulic pressure of the automatic transmission is also reduced, and the clutch is released. After the restart, the operating oil pressure of the automatic transmission also increases with an increase in the engine speed. When a sufficient operating oil pressure is obtained, the clutch is engaged, and, for example, the first speed is entered. At this time, since the engine is restarted by depressing the accelerator pedal, the engine speed is high, so when the clutch is engaged, the engine torque is suddenly transmitted to the tires as driving force and a shock is generated, causing a smooth There is a problem that can not start. In particular, when the vehicle moves backward, a smooth start is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to enable a vehicle equipped with an automatic engine stop / start system to start smoothly. It is another object of the present invention to provide an automatic stop / start apparatus and method for an engine having excellent driver operability.

[0008]

According to the present invention, there is provided a means for detecting that the shift lever is in the reverse range and starting the engine when the engine is automatically stopped. . Therefore, when the engine is automatically stopped, the engine is started (restarted) only by setting the shift lever to the reverse range.

According to the second aspect, the shift lever measures the duration set in the reverse range, and starts the engine only when the selection of the reverse range has continued for a predetermined time or more. After the engine is stopped, the shift lever may pass through the reverse range and enter the parking range. According to this configuration, the operation of starting the engine in such a case can be prevented.

According to the third aspect, the automatic stop of the engine is prohibited while the shift lever is in the reverse range. Therefore, smooth operation at the time of retreat is possible.

According to the present invention, the shift lever can be switched to the reverse range only when the brake is depressed. Therefore, it is possible to prevent the vehicle from starting rearward simultaneously with the selection of the reverse range.

According to the fifth aspect, at least one of the rotation speed and the vehicle speed of the engine after the start is continuously detected, and when the detected value is only equal to or less than the reference value, the automatic stop / start device stops the engine. Means for prohibiting the operation. According to this configuration, after running the engine, if the vehicle is running only at the reference rotation speed or vehicle speed, the engine does not stop automatically. Therefore, it is possible to drive at a very low speed such as utilizing the creeping phenomenon, or to smoothly drive the vehicle in a garage.

According to the sixth aspect, after the engine is stopped, if it is determined that the shift speed is set to reverse, the engine is started. Therefore, in a state where the engine is automatically stopped, the engine is started (restarted) only by setting the gear position to reverse.

According to the seventh aspect, the continuation time when the gear is set to reverse is measured, and when the continuation of the predetermined time has elapsed, the engine is started. Therefore, erroneous start due to temporary selection of the reverse gear can be prevented.

According to the present invention, the automatic stop of the engine is prohibited while the gear position is set to reverse. Therefore, smooth operation at low speed when the vehicle retreats can be performed.

According to the ninth aspect, it is possible to switch the shift speed to the reverse only when the brake is depressed. Therefore, it is possible to prevent the vehicle from starting backward at the same time as switching to reverse.

According to the tenth aspect, at least one of the rotation speed and the vehicle speed of the engine after the start is continuously detected,
If the detected value is only equal to or less than the reference value, stopping the engine is prohibited. According to this configuration, it is possible to drive at a very low speed such as utilizing the creeping phenomenon, or to smoothly drive in a garage or the like.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an automatic stop / start system for an engine according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an automatic stop / start device for an engine according to this embodiment. As shown in the figure, the engine 1 is provided with a fuel injector 7 for injecting fuel, a starter 2 for starting the engine 1, an igniter 15 for igniting fuel, and the like. A fluid coupling (fluid clutch) (not shown) is provided on the output shaft (rotating shaft) of the engine 1.
The automatic transmission 3 is connected via the transmission, and the output of the automatic transmission 3 is transmitted to the tire.

The automatic transmission 3 is provided with a plurality of gears and a clutch for appropriately connecting the gears to each other in accordance with switching of the shift speed. Each clutch is driven by a hydraulic pressure generated by a hydraulic pump. Therefore, when the engine 1 is stopped, the clutch is not engaged because the hydraulic pressure is low even when the shift lever 8 is in the range of the drive or the like, and the engine 1 is substantially in a neutral state. When the engine 1 starts and a sufficient number of revolutions is obtained, the hydraulic pressure increases and the clutch is engaged.

In the automatic transmission 3, a shift range (parking, reverse, neutral, drive, second, low) is selected by a shift lever 8, and when each range is selected, a shift range switch for outputting a signal indicating the range is selected. Group 9 (parking switch 9a, reverse switch 9b, neutral switch 9c, drive switch 9d, second switch 9e, low switch 9f)
And a vehicle speed sensor 11 for detecting the vehicle speed.

The setting of the gear position (gear position) of the automatic transmission 3 is determined by the range of the shift lever 8 and a control signal from a control ECU (electronic control unit) 4 described later. For example, when the shift lever 8 is set to the reverse range, the gear position of the automatic transmission 3 is set to reverse (reverse gear).

The automatic transmission 3 is provided with a lock mechanism for releasing the lock when the brake pedal 13 is depressed, for example, so that the shift lever 8 can be put into the reverse range. By using this lock mechanism, as will be described later, by setting the shift lever 8 to the reverse range, even when the engine 1 is automatically started, it is possible to prevent a sudden start backward.

In the intake manifold portion of the engine 1, the throttle valve 5 which operates in conjunction with the accelerator pedal 23, a throttle position sensor 5a for detecting the opening of the throttle valve 5, and the throttle valve 5 are fully closed. And an idle switch 6 for detecting the situation.

The operation of the entire vehicle including the engine 1,
The engine automatic stop / start control specific to this embodiment is executed by the control ECU 4. That is, the control ECU 4
Based on detection signals from various sensors disposed in the vehicle, a throttle valve 5, a fuel injector 7
And the like, and an engine stop monitor 19 for notifying that the engine 1 is stopped. In addition, the starter relay 12 controls driving and stopping of the starter 2. As the various sensors, the aforementioned throttle position sensor 5a,
In addition to the idle switch 6, the shift range switch group 9, the vehicle speed sensor 11, and the like, a brake switch 14 for detecting the state of the brake pedal 13 is operated by a driver to determine whether to automatically stop and start (restart) the engine 1. An idle stop permission switch 20 for instructing the engine 1, a temperature sensor 21 for measuring the temperature of the engine cooling water, a rotation speed sensor 22 for detecting the rotation speed of the engine 1, and the like are included.

The control ECU 4, as shown in FIG.
U (microprocessor unit) 41 and memory 42
And an input / output interface 43 and the like. MPU41
Receives various detection signals from the sensor group 44 via the input / output interface 43, stores the detection signals in the memory 42, processes the stored detection signals in accordance with a program stored in the memory 42, Outputs various control signals.

Next, the control operation of the entire vehicle, which is executed by the control ECU 4, will be described with reference to the flowcharts of FIGS.

FIG. 3 shows a main routine of control processing executed by the control ECU 4. This main routine is started, for example, by turning on an ignition key. In step S1, control of the engine 1 and shift control during normal running are executed. That is, the control ECU 4 supplies a fuel injection signal to the fuel injector 7 from each state of the engine 1 indicated by the detection signal input from the sensor group 44, supplies an ignition signal to the igniter 15,
To control the rotation of Further, a control signal is supplied to the automatic transmission 3 based on the vehicle speed information supplied from the vehicle speed sensor 11 and the throttle opening information supplied from the throttle position sensor 5a and the idle switch 6, and the speed of the automatic transmission 3 is changed. Perform control.

Next, the flow proceeds to step S11,
Based on the detection signal from the rotation speed sensor 22, the rotation speed of the engine 1 is changed to a reference value A rpm (for example, 1500 rpm).
Is determined, and if so, the idle stop permission flag IS is set to “1” (ON) (step S12). The rotation speed of the engine 1 is the reference value Arp
If not, the process jumps to step S2.
If the engine speed exceeds the reference value A rpm even once, the idle stop permission flag IS
Remains at "1" until is stopped. In the next step S2, engine automatic stop / start control is executed.

FIG. 4 is a flowchart showing details of the engine automatic stop / start control S2. First, step S2
In step 1, it is determined from the state of the idle stop permission switch 20 whether or not the driver permits the stop of the engine 1 during idling. If the idle stop permission switch 20 is off, that is, if the driver does not permit the automatic stop of the engine 1, the process exits from this routine and returns to the main routine, and does not perform the automatic stop / start operation of the engine 1.

When the idle stop permission switch 20 is turned on, that is, when the driver is idling the engine 1
If the stop of is permitted, the process proceeds to step S22,
It is determined whether or not the idle stop permission flag IS is “1”.

The idle stop permission flag IS is "0"
(Off), that is, after the engine 1 is started, the rotation speed of the engine 1 is reduced to a reference value Arpm (for example, 1
If the vehicle is traveling only at 500 rpm or less, the process exits from this routine. As a result, at the time of low-speed operation, the engine 1 does not stop automatically, and running at a very low speed utilizing the creeping phenomenon, and smooth operation in a garage or the like can be performed. In step S11, the same control is possible even if the speed of the vehicle detected by the vehicle speed sensor 11 is used as the determination condition instead of the rotation speed of the engine 1.

If it is determined in step S22 that the idle stop permission flag IS is "1" (ON),
That is, when the rotation speed of the engine 1 exceeds the reference value Arpm, the process proceeds to step S23, and it is determined whether the reverse switch 9b is off, that is, whether the shift lever 8 is not in the reverse range. If it is determined that the reverse switch 9b is turned on (it is in the reverse range), the process exits from this routine. This allows
The automatic stop of the engine 1 during the retreat of the vehicle is canceled.

In step S23, the reverse switch 9b
Is determined to be off (not in the reverse range), in order to determine the engine stop condition, it is determined in step S24 whether or not the vehicle is in a stopped state from the output signal of the vehicle speed sensor 11, and in step S25. It is determined from the detection signal of the idle switch 6 whether the throttle valve 5 is fully closed.

If it is determined in steps S24 and S25 that the vehicle speed is not 0 and / or that the throttle valve 5 is not fully closed (idle switch 6 is off), the routine exits from this routine.

If it is determined in steps S24 and S25 that the vehicle speed is 0 and the throttle valve 5 is fully closed,
The flow proceeds to step S26. In step S26, it is determined whether the brake signal supplied from the brake switch 14 is on (the brake pedal 13 is depressed), whether the temperature of the engine cooling water is equal to or higher than the reference temperature, Other engine stop conditions, such as signal usage, are determined, and if all are affirmatively determined, the process proceeds to step S27. On the other hand, if at least one condition is not satisfied, the process exits this routine.

In step S27, steps S23 to S23
It is determined by using a software timer or the like whether or not the state determined to be affirmative in 26 has continued for a reference time (for example, 2 seconds).
If not, the process exits this routine. On the other hand, if it is determined that the operation has been continued, the engine 1 is stopped.
Move to step S28.

In step S28, in order to stop the engine 1, a fuel cut signal is supplied to the fuel injector 7, an ignition cut signal is supplied to the igniter 15, and an idle speed control valve (ISCV) for adjusting an idle speed is fully closed. Send a signal to In addition, a display on the engine stop monitor 19 is executed to notify the driver of the engine stop. Then, in step S29, the idle stop permission flag IS is set to "0" (off).

Next, in step S30, the state of the idle switch 6 is determined. If it is on, the process proceeds to step S31 described later, and if it is off, the process proceeds to step S32.

When the driver depresses the accelerator pedal 23 to start, the throttle valve 5 opens in conjunction with the movement of the accelerator pedal 23 and the idle switch 6
Turns off. When the idle switch 6 is turned off, step S
The determination is made at 30 and the flow proceeds to step S32. In order to prevent malfunction, an additional condition may be that the opening of the throttle valve 5 obtained by the throttle position sensor 5a is equal to or greater than a certain opening.

In step S32, the control ECU 4
Drives the starter 2 via the starter relay 12,
A fuel injection signal is supplied to the fuel injector 7 to inject fuel, an ignition signal is supplied to the igniter 15 to ignite, the engine 1 is started (restarted), and an ISCV signal for setting an idling speed is supplied. Also,
The display of the engine stop monitor 19 is turned off.

Since the on / off state of the reverse switch 9b is determined in step S23, the flow proceeds from step S30 to step S32 only when the reverse switch 9b is off, that is, when the shift lever 8 is in a position other than the reverse range. This is when the range is set. Therefore,
With the shift lever 8 set to the reverse range,
When the accelerator pedal 23 is depressed, the engine 1 starts and the vehicle does not start backward.

On the other hand, if it is determined in step S30 that the idle switch 6 remains on, it is determined whether or not the shift lever 8 is in the reverse range from the on / off state of the reverse switch 9b (step S31). ). If it is determined that the reverse switch 9b is off, that is, if the shift lever 8 is not in the reverse range, the process proceeds to step S28, and the state in which the engine 1 is stopped is maintained.

On the other hand, if it is determined that the reverse switch 9b is ON, that is, if the shift lever 8 is in the reverse range, the process proceeds to step S32, and the engine 1 is started.

In step S23, the reverse switch 9b
Is determined to be on in step S31 when the shift lever 8 is moved from another range to the reverse range. In order to put the shift lever 8 into the reverse range, the brake pedal 13 must be depressed by the lock mechanism. The flow proceeds from step S30 to step S31 when the idle switch 6 is off, that is, when the accelerator pedal 23 is not depressed.

Therefore, when the shift lever 8 is put into the reverse range and the engine 1 is started automatically, the brake pedal 13 is depressed and the accelerator pedal 23
Is not depressed. Therefore, even when the engine 1 is automatically started, the hydraulic pressure of the hydraulic pump is increased, and the clutch of the automatic transmission 3 is engaged, the brakes hold down the tires, so that the vehicle maintains a stopped state, and the engine 1 is stopped. The output is rapidly transmitted to the tires, and the vehicle does not start moving significantly. Thereafter, when the brake pedal 13 is released and the accelerator 23 is depressed, the output of the engine 1 is transmitted to the tires, and the vehicle starts smoothly backward.

After the engine 1 is started in step S32, the rotation speed of the engine 1 is determined from the detection signal of the rotation speed sensor 22, and the reference rotation speed B rpm (for example, 400 rpm)
It is determined whether or not the engine 1 has completely exploded based on whether or not it is as described above (step S33). If the engine 1 has not completely exploded, the flow returns to step S30, and the above processing is repeated. On the other hand, if the engine 1 has completely exploded, the flow proceeds to step S34, and the starter relay 1
Then, the starter 2 is turned off.

After the above processing is completed, the process exits the automatic stop / start routine and returns to step S1 in FIG.

With the above configuration, according to the apparatus and method for automatically stopping and starting the engine 1 of this embodiment, the shift lever 8 can be operated while the engine 1 is automatically stopped.
The engine 1 can be started simply by putting the in the reverse range (steps S31 and S32). Therefore,
Driving becomes very easy. In addition, the vehicle can be smoothly started backward. When the shift lever 8 is in the drive range or the like, the engine 1 can be started only by depressing the accelerator pedal 23.

Also, in the determination step of step S23,
While the automatic transmission 3 is in the reverse range,
Since the automatic stop of the engine 1 is prohibited, the engine 1 does not stop even if the speed is temporarily reduced or stopped when retreating, so that a smooth operation can be performed.

The shift mechanism 8 can be switched to the reverse range only when the brake pedal 13 is depressed by the lock mechanism. Only when the accelerator pedal 23 is not depressed, the engine 1 is automatically started by selecting the reverse range. Therefore, even if the hydraulic pressure of the hydraulic pump increases and the clutch of the automatic transmission 3 is engaged, the tire is pressed by the brake, and the vehicle is substantially stopped. Thereafter, when the brake pedal 13 is released and the accelerator pedal 23 is depressed, the tire is driven. Therefore, when the clutch of the automatic transmission 3 is engaged, the engine torque is rapidly transmitted to the tires as a driving force, and the occurrence of a shock at the time of starting is prevented, so that a smooth reversing is possible.

Since the fluid coupling (fluid clutch) is used, the output torque of the engine 1 is transmitted to the automatic transmission 3 to some extent. For this reason, a creep phenomenon occurs similarly to a vehicle equipped with a normal hydraulic automatic transmission, and traveling at a very low speed when the vehicle retreats, for example, garage can be smoothly performed. Also, according to the determination in step S23, even if the vehicle temporarily stops when
Does not stop and the creep phenomenon can be maintained even in the case of garage parking.

As shown by the broken line in FIG. 4, if the reverse range continues for a certain period of time (for example, 0.5 seconds) between the ON determination in step S31 and step S32, the engine 1 is turned on in step S32. If the engine has started and does not continue, a determination step of returning to step S31 may be inserted (step S40). This can prevent the engine 1 from starting when the shift lever 8 enters the parking range or the like after passing through the reverse range.

For example, "off of the brake switch 14" may be adopted as the start condition of the engine 1 in step S30. Further, both the “idle switch 6 off” and the “brake switch 14 off” may be set as the starting conditions.

In the above-described example, the condition for shifting the shift lever 8 to the reverse range is "depressing the brake pedal 13". However, if the vehicle can start backward simultaneously with the selection of the reverse range, The structure of the lock mechanism is arbitrary. For example, a condition that a button is arranged at the upper end of the shift lever 8 and the shift lever 8 is operated while pressing the button may be set as a condition for entering the reverse range. In this case, for example, the control ECU 4 controls to automatically apply a brake to the drive wheels in response to the operation of the operation button. Further, as a condition for entering the reverse range, “the rotational speed of the engine 1 is equal to or less than a certain value” may be added.

[Brief description of the drawings]

FIG. 1 is a block diagram of an automatic stop / start device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control ECU shown in FIG.

FIG. 3 is a main routine flowchart showing a control operation of the automatic stop / start device of FIG. 1;

FIG. 4 is a flowchart showing automatic stop / start control in the main routine of FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 engine 2 starter 3 automatic transmission 4 control ECU 5 throttle valve 5a throttle position sensor 6 idle switch 7 fuel injector 8 shift lever 9 shift range switch group 11 vehicle speed sensor 12 starter relay 13 brake pedal 14 brake switch 15 igniter 19 engine stop monitor Reference Signs List 20 idle stop permission switch 21 temperature sensor 22 speed sensor 23 accelerator pedal 41 MPU (microprocessor unit) 42 memory 43 input / output interface

Claims (10)

[Claims] 1. An automatic stop / start apparatus for automatically stopping or starting an engine according to predetermined conditions, wherein a shift lever for changing a gear position of a transmission connected to the engine is detected, and a position of the shift lever is detected. Shift lever position detecting means, and starting means for starting the engine in response to the shift lever position detecting means detecting that the shift lever is located in the reverse range when the engine is stopped. Automatic stop / start system for engines. 2. The timer according to claim 1, wherein the starting means measures a duration of time when the shift lever is set to a reverse range from an output of the shift lever position detecting means, and the shift lever is set to a reverse range. 2. The automatic stop / start device for an engine according to claim 1, further comprising: means for starting the engine when the timer measures that the state has continued for a predetermined time. 3. The apparatus according to claim 1, further comprising means for inhibiting automatic stop of the engine while the shift lever is in the reverse range in accordance with the detection of the shift lever position detecting means. An automatic stop / start device for an engine as described in the above. 4. A brake for limiting movement of a vehicle equipped with the engine, and only when the brake is applied,
The automatic stop / start device for an engine according to any one of claims 1 to 3, further comprising: a unit configured to switch the shift lever to a reverse range. 5. A detecting means for continuously detecting at least one of a rotational speed of the engine after starting and a speed of a vehicle on which the engine is mounted, and wherein the detected value of the detecting means is only a reference value or less. 5. The automatic stop and start device for an engine according to claim 1, further comprising means for prohibiting the automatic stop and start device from stopping the engine. 6. A stopping step for stopping the engine in accordance with a predetermined stopping condition; a range determining step for determining whether or not a shift speed of a transmission connected to the engine is set to reverse; and the range determining step. A start step of starting the engine when it is determined that the shift speed is set to reverse. 7. The starting step includes: a measuring step of measuring a duration in which the speed is set to reverse; and a state in which the speed is set to reverse is continued for a predetermined time by the measuring step. If it is determined that
The method for automatically stopping and starting an engine according to claim 6, further comprising a step of starting the engine. 8. The method according to claim 6, further comprising a step of prohibiting the automatic stop of the engine while the shift speed is set to reverse according to the detection of the range determination step. How to stop and start the engine automatically. 9. A shift restricting step for restricting the movement of a vehicle equipped with the engine, and the shift stage can be switched to reverse only when the movement of the vehicle is restricted by the shift restricting step. The method according to claim 6, 7, or 8, further comprising the steps of: 10. A detecting step for continuously detecting at least one of a rotation speed of the engine after starting and a speed of a vehicle on which the engine is mounted, and a case where a detected value of the detecting step is only a reference value or less. The method according to any one of claims 6 to 9, further comprising: prohibiting stopping of the engine by the stopping step.