JPH07247881A - Automatic engine stopping and starting device - Google Patents

Abstract

PURPOSE:To automatically start an engine, even when the automobile is started by inertia during the automatic stop of the engine, in an automatic engine stopping and starting device which automatically stops the engine when the automobile is brought into an idle operation state and automatically starts the engine when a given condition (the condition of a block A) for starting running is set during its automatic stop. CONSTITUTION:In a case an engine is at an automatic stop, when a gear is neutral and a condition (the condition of a block B) that a car speed exceeds a given car speed indicating that running is started is satisfied, an engine is brought into an automatic starting. In which case, even when an engine is automatically stopped on a downward slope and running is started owing to a brake being loosen, an engine is automatically started and a hydraulic mechanism, such as power steering, wherein an engine is a power source, is rendered operable. Thereby, for example, running in a state that power steering is rendered ineffective is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic engine stop / start device for automatically starting or stopping an engine in accordance with the driving condition of an automobile.

[0002]

2. Description of the Related Art Since automobile exhaust gas is an important factor of environmental pollution, it is necessary to reduce harmful components (NOx etc.) contained in the exhaust gas or reduce the amount of exhaust gas itself. However, it is socially demanded as an urgent issue.

The automatic engine stop / start device is one of the devices that meets such a request, and is intended to reduce the amount of exhaust gas. That is, automatic engine stop
The starting device is a device that automatically stops the engine when the engine is in an idle operation so that exhaust gas is not emitted, and automatically starts the engine when a predetermined starting condition is satisfied during the automatic stop.

FIG. 4 is a block diagram of such an engine automatic stop / start device. In FIG. 4, 1 is an engine rotation sensor, 2 is a neutral switch, 3 is a clutch switch, 4 is a vehicle speed sensor, 5 is a control unit, 6 is an automatic stop display flag, 7 is an engine stopper, and 8 is a starter.

The neutral switch 2 is a switch for informing whether or not the gear is in the neutral position.
For example, it is on when in neutral. The clutch switch 3 is a switch that informs whether the clutch is disengaged. Since the clutch is disengaged when the clutch pedal is depressed, for example, the clutch switch 3 is turned on when the clutch pedal is depressed.

The control unit 5 is composed of a microcomputer including a CPU (Central Processing Unit), and controls the whole. The engine stopper 7 is, for example, a magnetic valve that controls an on-off valve inserted in an intake passage to the engine in the case of stopping the engine by a method of cutting intake air. In that case, when the engine stopper 7 is operated, the on-off valve is closed, the intake air is shut off, and the engine stops.

The control unit 5 synthesizes signals from various sensors, and when it judges that the engine is in an idle operation state, sends a signal for operating the engine stopper 7 to automatically stop the engine. At the same time, the automatic stop display flag 6 is set (for example, the value of the flag is "1"),
Indicates that the automatic stop state has been entered.

FIG. 5 is a diagram showing conditions of automatic engine stop of the automatic engine stop / start device. The engine is automatically stopped when the following four conditions are met. The gear is in neutral. The clutch is engaged. The vehicle speed is almost zero. The engine speed is below the idle speed (this is slightly different depending on the engine, for example, 800 rpm). Since it is satisfied when the vehicle is in the driving state, it is automatically stopped when the vehicle is driven and the vehicle is in the idle driving state.

When the control unit 5 combines signals from various sensors and determines that the engine should be started, the control unit 5 sends a signal for operating the starter 8 to automatically start the engine. At the same time, the automatic stop display flag 6 is lowered (for example, the value of the flag is set to "0") to indicate that the automatic stop state is not set.

FIG. 6 is a diagram showing conditions for automatic engine start in a conventional automatic engine stop / start device. The engine is automatically started when the following three conditions are met. The engine is automatically stopped (that is, the value of the automatic stop display flag 6 is "1") The gear is in neutral The clutch is disengaged

These conditions are satisfied when the driver depresses the clutch pedal in order to drive the automobile that has stopped automatically. Therefore, even if the driver does not operate the starter 8 by turning the key, the starter 8 is automatically operated only by depressing the clutch pedal, and the traveling can be resumed without imposing a troublesome operation on the driver. . Even if the engine is not equipped with an automatic engine stop / start device, the operation to depress the clutch pedal is a natural operation to restart the vehicle from the stopped state while in idle operation. It does not impose operations. FIG. 2 is a flow chart for explaining an engine automatic start operation in the conventional engine automatic stop / start device as described above. In steps 1-3, the starter 8 is activated in step 4 when all of the above conditions are met.

Prior art documents relating to automatic engine stop / start devices include, for example, Japanese Utility Model Publication No. 63-65831 and Japanese Utility Model Publication No. 60-188833.

[0013]

[Problems to be Solved by the Invention]

(Problem) However, in the above-described conventional engine automatic stop / start device, when the engine is automatically stopped on the downhill and the traveling is started because the brake is loosened,
Since the vehicle travels without operating the hydraulic mechanism powered by the engine, there is a problem in that the operation is inadequate.

(Explanation of Problems) An automobile may be equipped with a hydraulic mechanism that uses an engine as a power source. An example of such a hydraulic mechanism is a power steering. Since this hydraulic mechanism does not operate unless the engine is started, the power steering also does not operate. Needless to say, if the vehicle starts traveling with the hydraulic mechanism not operating, various deficiencies will result. However, the use of the conventional automatic engine stop / start device may cause such defects as described below.

That is, the engine is automatically stopped on the downhill.
When the brake is released while the engine is automatically stopped by the starter, the vehicle starts running by inertia. In that case, since the vehicle has already started running, the driver unconsciously feels like the engine is starting, and tries to operate the hydraulic mechanism such as the power steering as usual. However, since the engine is not running, it requires much more force than usual to operate. An object of the present invention is to solve the above problems.

[0016]

In order to solve the above-mentioned problems, according to the present invention, an engine speed sensor, a neutral switch, a clutch switch, a vehicle speed sensor, and signals input from these sensors and switches are used as a basis. It has an engine stopper and a control unit that sends an operation signal to the starter, and automatically stops the engine when the vehicle is in an idle state. An automatic engine stop / start device that automatically starts the engine when it is in neutral and the clutch is disengaged. When the engine is automatically stopped, the gear is in neutral and the vehicle speed is equal to or higher than a predetermined vehicle speed. It was decided to automatically start the engine even when.

[0017]

[Operation] Automatically start the engine with the engine automatic stop / start device even when the engine is in the automatic stop state and the gear is in neutral and the vehicle speed exceeds the predetermined speed that indicates that the vehicle has started traveling. I chose
As a result, the engine is automatically stopped on the downhill,
The engine is automatically started even if the vehicle starts running because the brakes have been released. Therefore, it is possible to prevent a hydraulic mechanism (eg, power steering) powered by the engine from traveling without operating.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. The block diagram of the automatic engine stop / start system of the present invention is the same as that of FIG. The conditions for automatically stopping the engine are the same as in the conventional case (see FIG. 5). The difference from the conventional example is that in the present invention, when the engine is automatically started from the state where it is automatically stopped, it is automatically started not only when the conventional conditions are satisfied but also when the separately defined conditions are satisfied. It is a thing.

FIG. 1 is a diagram showing conditions for automatic engine start in the automatic engine stop / start system of the present invention.
The condition of block A is the same starting condition as the conventional one (FIG. 6).
reference). The condition of block B is the starting condition newly defined in the present invention. In the present invention, automatic start is performed regardless of which condition is satisfied.

The condition of block B is satisfied when the following three conditions are satisfied. The engine is automatically stopped (that is, the value of the automatic stop display flag 6 is "1") The gear is in neutral The vehicle speed is equal to or higher than the predetermined vehicle speed

The value of the predetermined vehicle speed may be set to a value indicating that the vehicle has started to move instead of being stopped. However, if the value is too small, malfunction may occur due to noise contained in the vehicle speed detection signal. There is a risk that Therefore, it is large enough to be distinguished from such noise (eg, 4K).
m / h).

When the engine is automatically stopped on a downhill and the vehicle is started to coast due to the brake being released, the condition of block B is satisfied when the vehicle speed becomes equal to or higher than a predetermined vehicle speed. Therefore, even in such a case, the engine is automatically started, and the hydraulic mechanism powered by the engine can operate normally. For example, when the power steering is operated, it can be operated with a light force as normal. Therefore, the operability is not impaired.

FIG. 3 is a flow chart for explaining the engine automatic start operation in the automatic engine stop / start apparatus of the present invention. The difference from the conventional flowchart of FIG. 2 is that between the determination process "step 3" of "disengaged clutch" and the operation process "step 5" of "actuating the starter", "the vehicle speed is equal to or higher than a predetermined vehicle speed". That is, the starter 8 is operated even if any of the steps 3 and 4 is YES.

[0024]

As described above, according to the automatic engine stop / start system of the present invention, when the engine is automatically stopped, the gear is in neutral and the vehicle speed is a predetermined vehicle speed indicating that the vehicle has started traveling. When the above is over,
Since the engine is automatically started by the automatic engine stop / start device, the engine is automatically started even when the engine is automatically stopped on a downhill and the vehicle is started because the brake is released. Therefore, it is possible to prevent traveling without operating a hydraulic mechanism (eg, power steering) powered by the engine.

[Brief description of drawings]

FIG. 1 is a diagram showing conditions for automatic engine start in an automatic engine stop / start device of the present invention.

FIG. 2 is a flowchart illustrating an engine automatic start operation in a conventional engine automatic stop / start device.

FIG. 3 is a flowchart illustrating an engine automatic start operation in the automatic engine stop / start device of the present invention.

FIG. 4 is a block diagram of an engine automatic stop / start device.

FIG. 5 is a diagram showing conditions of automatic engine stop of an automatic engine stop / start device.

FIG. 6 is a diagram showing conditions for automatic engine start in a conventional automatic engine stop / start device.

[Explanation of symbols]

1 ... Engine rotation sensor, 2 ... Neutral switch,
3 ... Clutch switch, 4 ... Vehicle speed sensor, 5 ... Control unit, 6 ... Automatic stop display flag, 7 ... Engine stopper, 8 ... Starter

Claims (1)

[Claims] 1. An engine rotation sensor, a neutral switch, a clutch switch, a vehicle speed sensor, and a signal input from these sensors and switches to determine the operating state of the vehicle and actuate an engine stopper and a starter. A control unit that sends a signal, automatically stops the engine when the vehicle is in an idle state, and automatically starts the engine when the engine is in the automatic stop when the gear is in neutral and the clutch is disengaged. The automatic engine stop / start device is characterized in that when the engine is automatically stopped, the gear is in neutral and the engine is automatically started even when the vehicle speed exceeds a predetermined vehicle speed indicating that the vehicle has started traveling. Automatic engine stop / start device.