JPH0319367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an automobile engine (mainly an internal combustion engine), and more particularly to a device for automatically controlling engine stop and start.

In recent years, in order to reduce fuel consumption by idling when the vehicle is stopped, such as waiting at a traffic light or in traffic jams, devices have been developed that stop the engine when the vehicle stops and start the engine when the vehicle starts moving.

For example, the device described in Japanese Patent Publication No. 51-9085 automatically starts the engine by operating the accelerator pedal when starting the car.
When the vehicle is stopped, the engine is stopped by manually turning off the ignition circuit.

However, the above device was designed to stop the engine using a manual switch that was separate from normal driving operations, so the driver had to operate the manual switch as a separate operation from normal driving operations. First, it is extremely complicated, and as a result, there is a problem that it is difficult to make full use of this device.

Furthermore, when a manual switch is operated, the engine is stopped even when the car is running, and the method of stopping the engine is to cut off the power to the ignition circuit. Therefore, if you accidentally operate the manual switch while driving, the ignition system will stop but the fuel supply will continue, causing unburned fuel to be sent to the heated exhaust purification catalyst device, causing the catalyst device to deteriorate. There was also a risk of a fire occurring.

In addition, the device described in Automotive Engineering (Published by Railway Japan Co., Ltd.), November 1981 issue, pages 72 to 78, stops the engine when the car stops, and when the driver depresses the clutch pedal when the car starts. Configured to automatically start the engine.

However, in the above-mentioned devices, the engine is automatically stopped when the car stops, so the engine frequently stops even during extremely short stops such as stopping at an intersection or waiting at a traffic light. Since the engine has to be started, fuel consumption due to power consumption at the time of starting increases, and there is a possibility that effective reduction in fuel consumption cannot be achieved.

Furthermore, since the engine is started by depressing the clutch pedal, there is also the problem that it cannot be applied to vehicles equipped with automatic transmissions that do not have a clutch.

Furthermore, if the car is stopped on a slope with the engine stopped and the parking brake is released before the clutch pedal is pressed to start the engine, the car will start moving with the engine still stopped. Especially in modern cars, there are many devices such as power steering devices and power brake devices that provide auxiliary power from the engine power, so if you start the car with the engine stopped, the above auxiliary power will not be provided. The steering wheel suddenly became heavy and the brakes became less effective, which could pose a safety problem.

The present invention has been made in order to solve the various problems of the prior art as described above, and provides engine control that automatically stops and starts the engine only by normal driving operations and that does not pose any safety problems. The purpose is to provide equipment.

In order to achieve the above object, in the present invention,
The system is configured to stop the engine when the parking brake is applied, and to start the engine when the parking brake release button is pressed.

With the above configuration, the engine does not stop during extremely short stops where there is no need to apply the parking brake, eliminating deterioration in fuel efficiency due to power consumption caused by frequent starts, and even when stopping on a slope, the engine does not stop. If you return it, the engine will start without fail, so there is no risk of problems with the power brakes, etc. Furthermore, since the operation of the parking brake is a completely normal driving operation, there is no fear that the operation will become complicated, and it can also be applied to vehicles equipped with automatic transmissions, so that many excellent effects can be obtained.

The present invention will be explained in detail below based on the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a signal waveform diagram of the circuit of FIG.

In Figure 1, S ₁ is the parking brake signal,
“1” when the parking brake is applied as detailed later; “0” when it is not applied.
become.

Further, _S2 is an ignition switch signal, which becomes "1" when the ignition switch is on.

Further, _S3 is a release signal, which becomes "1" while the parking brake release button, which will be described in detail later, is pressed.

Further, _S4 is a starter signal, which is "1" while the starter switch for operating the starter motor is on.

Further, _S5 is a rotational speed signal, which is a voltage signal proportional to the engine rotational speed. This rotation speed signal S ₅
For example, the neutral point voltage of the alternator may be used, or if the engine has a crank angle sensor that outputs a pulse every time the engine crank angle rotates by a predetermined angle, the frequency of the pulse may be converted into a voltage. You may also use the

Further, _S14 is a starter drive signal, and while this signal is "1", the starter motor operates. Further, _S15 is a fuel cut signal, and while this signal is "1", fuel supply to the engine is cut off.

Next, 1, 2, 3 and 4 are one-shot multivibrators, respectively, which output narrow trigger signals S ₆ , S ₇ , S ₈ and S ₁₀ , respectively, when the input signal rises.

Further, 5, 6 and 7 are OR circuits, 8 is an AND circuit, and 9 and 10 are flip-flops.

Further, 11 is a comparator, which is set to "1" when the value of the rotation speed signal _S5 is less than a predetermined reference voltage V _S ;
In the above case, a signal _S9 which becomes "0" is output. The value of the reference voltage V _S is set to the lowest value when the engine rotates independently, for example, a value corresponding to 400 rpm. Therefore, when the signal _S9 is "1", it indicates that the engine is stopped or cranking, and when it is "0"
When , it indicates that the engine is running (starting has been completed and is running independently).

Further, 12 is an inverter that inverts and outputs the signal _S9 .

Then the parking brake signal S ₁ and release signal as mentioned above
A device that outputs _S3 will be explained.

FIG. 3 is an example of a parking brake operating device for operating the parking brake.

In FIG. 3, 13 is a floor panel of the vehicle body, and a parking brake bracket 14 is bolted to the floor panel 13. 15 is a tooth provided on the parking brake bracket 14; 16 is a parking brake lever; 17 is a release button for unlocking the parking brake lever 16;
6 is a claw that locks it in an arbitrary position; 19 is a rod that connects the release button 17 and the claw 18; 20 is a return spring;
7. Always push the rod 19 and pawl 18 to the left in the drawing. Reference numeral 21 denotes a stopper for the return spring 20, which is fixed to the parking brake lever 16. 22 also connects the pawl 18 to the parking brake lever 16.
23 is a pin that connects the rod 19 and the pawl 18, 24 is a pin that rotatably supports the parking brake lever 16, 25 is a parking brake cable, 26 is a switch fixed to the parking brake lever 16, Reference numeral 27 is a switch fixed to the floor panel 13, and 28 is a part of the parking brake lever 16, which is a pressing part for pressing the button of the switch 27.

Next, the action will be explained.

The state shown in FIG. 3 is a state in which the parking brake is not applied at all.

From this state, the driver should press the parking brake lever 16.
When pulled upward in the drawing, the parking brake cable 25 is pulled to the left in the drawing, and a parking brake (not shown) is applied. Since the pawl 18 engages with the teeth 15, the parking brake lever 16 is held in the raised position. Also, at this time, since the pressing part 28 is in a state of pressing the button of the switch 27,
The switch 27 is turned on, and the parking brake signal _S1 shown in FIG. 1 becomes "1".

On the other hand, when the release button 17 is pushed to the right in the drawing by the driver, the pawl 18 and the teeth 15 are disengaged, so that the parking brake lever 16 can be pulled down. If you pull down the parking brake lever 16 in this state, the parking brake cable 25
returns to the right side of the drawing, the parking brake (not shown) is released, and the switch 27 is turned off, so the parking brake signal _S1 becomes "0".

Also, while the release button 17 is pressed to the right in the drawing, the upper part of the claw 18 is pressing the switch 26 button, so the switch 26 is turned on.
The release signal _S3 in FIG. 1 becomes "1".

When the driver stops pressing the release button 17, the claw 18 returns to its previous position by the force of the return spring 20, so the switch 26 is turned off and the release signal _S3 becomes "0".

While the parking brake is applied as described above, the parking brake signal _S1 becomes "1", and while the release button 17 is pressed, the release signal _S3 becomes "1". As can be seen from the above explanation, when releasing the parking brake once applied, it is necessary to press the release button 17. Therefore, when releasing the parking brake, the release signal S ₃ is always "1". "become.

Although the example in Fig. 3 shows a case where a so-called handbrake is used as the parking brake, there are other types of parking brakes, such as those installed in front of the driver's seat, which the driver can pull toward to stop the vehicle. The present invention can be applied in exactly the same way to a brake system.

The operation of the circuit shown in FIG. 1 will be explained in detail below with reference to FIG.

First, when the ignition switch is turned on at time t1 in FIG. ₂ when the engine is completely stopped, the ignition switch signal _S2 becomes "1". Therefore, the one-shot multivibrator 2 outputs the trigger signal _S7 , and this signal is sent to the OR circuits 6 and 7 as trigger signals respectively.
S ₁₁ and S ₁₂ become flip-flops 9 and 9, respectively.
10 reset terminal R. Therefore, flip-flops 9 and 10 are both reset and Q
The outputs (the Q output of 9 is S ₁₅ and the Q output of 10 is S ₁₃ ) both become "0". In this state, both the starter drive signal _S14 and the fuel cut signal _S15 are "0", and the engine is ready to start.

Then at time t ₂ the starter switch is turned on and
When the starter signal _S4 becomes "1", this signal is applied to the one-shot multivibrator 3 via the OR circuit 5, and the one-shot multivibrator 3 outputs a trigger signal _S8 .

This trigger signal _S8 is applied to the set terminal S of the flip-flop 10, so that the signal at the Q output
_S13 becomes "1". Note that this trigger signal _S8 is
The reset signal _S11 for the flip-flop 9 is passed through the OR circuit 6, so when the trigger signal _S8 is output, the fuel cut signal _S15 is always "0".
and becomes ready for fuel supply.

On the other hand, at time _t2 , since the engine is stopped, the rotational speed signal _S5 is at a low level, and therefore the signal _S9 of the comparator 11 is "1".

As above, both signal S ₁₃ and signal S ₉ are “1”
Therefore, the starter drive signal _S14 output from the AND circuit 8 becomes "1".

When the starter drive signal _S14 becomes "1", a starter motor drive device (not shown) is activated to rotate the starter motor and start the engine. At this time, since the fuel cut signal _S15 is "0" as described above, the fuel injection device (not shown) is operating normally and is supplying fuel.

Next, the engine speed gradually increases until the point
When the rotational speed signal S ₅ becomes equal to or higher than the reference voltage V _S at t ₃ , that is, when the engine starts to operate independently after completion of starting, the signal S ₉ becomes “0”. Therefore, the starter drive signal S ₁₄ output from the AND circuit 8
also becomes "0" and the starter motor stops.

Note that when the signal _S9 becomes “0”, the inverter 12
The output becomes "1", so the one-shot multivibrator 4 outputs the trigger signal _S10 .

This trigger signal _S10 is sent as a signal via the OR circuit 7.
Since the signal _S12 is applied to the reset terminal R of the flip-flop 10, the flip-flop 10 is reset and the signal _S13 also becomes "0".

Next, when starting the car, the release button is pressed at time _t4 to release the parking brake, and the release signal _S3 becomes "1". This signal is applied to the one-shot multivibrator 3 via the OR circuit 5, and as a result, the trigger signal _S8 becomes "1", so the flip-flop 10 is set and the signal _S13 becomes "1". However, at this time, the engine is already operating and the signal _S9 is "0", so the starter drive signal _S14 output from the AND circuit 8 remains at "0". Therefore, the starter motor does not operate.

Next, at time _t5 , when the parking brake is released, the parking brake signal _S1 becomes "0".

In this state, the first engine start is completed and the vehicle is ready to run.

In the above explanation, the case where the initial start is performed by the starter signal S ₄ (turning on the starter switch) was illustrated, but as can be seen from Fig. 1, the starter signal S ₄ and the release signal S ₃ are different from each other. OR circuit 5
The release signal S ₃ (pressing the parking brake release button) is used identically through
The first start can also be performed by

Next, a case will be described in which the engine is stopped using the parking brake.

First, when the parking brake is applied at time _t6 , the parking brake signal _S1 becomes "1" and the one-shot multivibrator 1 outputs the trigger signal _S6 . Therefore, the flip-flop 9 is set and its Q output, that is, the fuel cut signal _S15 becomes "1".

When the fuel cut signal _S15 becomes "1", a fuel injection device (not shown) cuts off the fuel supply, so the engine stops.

Note that the trigger signal S6 is applied to the flip-flop 10 as the signal _S12 via the OR circuit 7, so the flip-flop 10 is reset and the signal _S13 becomes "0".

Next, the engine stops and the rotation speed gradually decreases, and when the rotation speed signal S ₅ becomes less than the reference voltage V _S at time t ₇ , the signal S ₉ becomes “1”.

Next, the case where the engine is started using the release button will be explained.

First, at time _t8 , when the driver presses the parking brake release button, the release signal _S3 becomes "1".

When the release signal _S3 becomes "1", the trigger signal _S8 outputted from the one-shot multivibrator 3 becomes "1" as described above.

This trigger signal _S8 is sent as a signal via the OR circuit 6.
Reset terminal R of flip-flop 9 as _S11
given to. Therefore, the flip-flop 9 is reset and the fuel cut signal _S15 becomes "0", making it possible to inject fuel.

Further, since the trigger signal _S8 sets the flip-flop 10 in the same way as described above, the signal _S13 becomes "1", and at this time, the engine is stopped and the signal _S9
Since is "1", the starter drive signal _S14 output from the AND circuit 8 becomes "1", and the starter motor operates and the engine starts in the same manner as described above.

When starting is completed and the rotation speed signal _S5 becomes equal to or higher than the reference voltage V _S , the signals _S9 and _S13 become "0", the starter drive signal _S14 becomes "0", and the starter motor stops. This is the same as above.

Although not shown in FIG. 1, when the ignition switch is turned off, the power to the ignition device is cut off and the engine is stopped, as in a normal automobile engine.

As mentioned above, in the circuit shown in Fig. 1, in addition to the conventional start/stop control function using the ignition switch and starter switch, the engine automatically stops when the parking brake is applied while the engine is running. It has a function that automatically starts when the parking brake release button is pressed.

Therefore, when the parking brake is applied when the vehicle is stopped, the engine automatically stops, and when the parking brake is released when the vehicle is started, the engine is automatically started, thereby eliminating wasteful fuel consumption due to idling while the vehicle is stopped.

In addition, the engine does not stop during extremely short stops that do not require applying the parking brake (such as stopping at an intersection or waiting for a short traffic light), resulting in frequent engine stops and resulting fuel consumption due to power consumption during frequent engine starts. Since there is no increase in fuel consumption, fuel efficiency can be further improved.

Furthermore, since the operation of the parking brake is a completely normal operation when stopping and starting a car, the driver does not have any sense of complication and can drive the car in the same way as a normal car.

In addition, even when starting from parking on a slope, the engine will always start as soon as the parking brake is released to start, so there is no effect on the auxiliary power of power steering, power brakes, etc.
It's safe.

Additionally, when the parking brake is applied to automatically stop the engine, the fuel cut signal is used to cut off the fuel supply, so there is no risk of unburned fuel having an adverse effect on the catalyst device, etc. .

Furthermore, since the parking brake is provided in all automobiles, it has the advantage that it can be applied to all vehicle types regardless of the type of transmission, etc.

Although the embodiment shown in FIG. 1 illustrates the case where the present invention is constructed using ordinary hardware, it is of course possible to perform similar control using a microcomputer. When applied to an automobile equipped with a central engine control device, the present invention can be implemented simply by changing the program of the microcomputer.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a signal waveform diagram of the circuit of FIG. 1, and FIG. 3 is a diagram of an example of a parking brake operating device. Explanation of symbols, 1 to 4...One-shot multivibrator, 5 to 7...OR circuit, 8...AND circuit, 9, 10...flip-flop, 11...
Comparator, 12... Inverter, S ₁ ... Parking brake signal, S ₂ ... Ignition switch signal, S ₃ ...
...release signal, _S4 ...starter signal, S5 ...rotation speed signal, _{S14 ...} starter drive signal, _S15 ...fuel cut signal.

Claims (1)

[Claims] 1. A first means for stopping the engine when the parking brake is applied while the engine is running, and a second means for starting the engine when the parking brake release button is pressed while the engine is stopped. An engine control device characterized by: