JPH048625B2 - - 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 traffic lights 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.

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

As mentioned above, in conventional devices, when the starting condition of pressing the accelerator pedal or clutch pedal is satisfied, the starter motor is driven, and when starting is completed and the engine enters self-sustaining operation, the engine speed is increased. The system was configured to automatically stop the starter motor upon detection.

Therefore, when the engine is malfunctioning and the engine does not start easily even if the starter motor is driven, the starter motor remains driven for a long time, causing the battery to run out of power and cause a so-called battery failure. This may cause the engine to fail to start.

Also, when starting the engine when starting,
It is necessary to perform some kind of operation to start the engine, and this device, in which the engine automatically stops every time the vehicle stops, has a problem in that even a simple operation is troublesome for the driver.

The present invention has been made in order to solve the problems of the prior art as described above, and provides engine control that eliminates the risk of battery build-up even in the event of engine malfunction, and that makes it extremely easy to start the engine at the time of starting. The purpose is to provide equipment.

In order to achieve the above object, the present invention includes a circuit that stops the engine when the parking brake is applied, and a circuit that is linked to the release button of the parking brake, and when the release button is operated while the engine is stopped, the starter motor is activated. Start the drive,
A circuit that stops the starter motor when engine starting is completed, a means for limiting the time during which the starter motor is continuously driven within a predetermined time, and a circuit that sets the predetermined time to a long value when the temperature is low and a short value when the temperature is high. and a means for doing so.

As mentioned above, in the present invention, when the parking brake is applied, the engine is automatically stopped;
Further, the parking brake release button is used to start driving the starter motor. Therefore, when the vehicle stops while driving,
When the engine is automatically stopped, the parking brake is always applied, and the release button must be operated to release the parking brake when starting the vehicle. Therefore, the driver can start the engine simply by performing a normal parking brake release operation, without having to be aware of any special operations for starting the engine.

In addition, by setting the time during which the starter motor is continuously driven to a long value at low temperatures and a short value at high temperatures, it is possible to start reliably even at low temperatures, and the engine may malfunction at high temperatures. In this case, it is possible to prevent battery power from being wasted due to continuous starting for a long time.

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 FIG. 1, _S1 is a parking brake signal, which is "1" when the parking brake is applied as will be described in detail later, and "0" when it is not applied.

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, 4 and 5 are one-shot multivibrators, respectively, and when the input signal rises, narrow trigger signals S ₆ , S ₇ , S ₈ , S _{10 are} generated.
and S ₁₃ (details regarding S ₁₃ will be described later).

Further, 6, 7 and 8 are OR circuits, 9 and 10 are flip-flops, and 11 is an AND circuit.

Further, 12 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, 13 is an inverter that inverts and outputs the signal _S9 , and ₁₄ is a timer, which is a starter drive signal that becomes "1" for a predetermined time set by the variable resistor _R0 from the time the signal S12 rises. Output S ₁₄ . Note that the timer 14 sends a signal to the reset terminal R.
When _S10 is applied, it is reset and the signal _S14 becomes "0" immediately.

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, 20 is a floor panel of the vehicle body, and a parking brake bracket 21 is bolted to the floor panel 20. Further, 22 is a tooth provided on the parking brake bracket 21, 23 is a parking brake lever, 24 is a release button for releasing the lock of the parking brake lever 23, and 25 is a tooth that engages with the above teeth 22, and a parking brake lever 2
3, a claw that locks in any position; 26, a rod that connects the release button 24 and the claw 25; 27, a return spring;
4. Always push the rod 26 and pawl 25 to the left in the drawing. 28 is a stopper for the return spring 27, which is fixed to the parking brake lever 23. 29 also connects the pawl 25 to the parking brake lever 23.
30 is a pin that connects the rod 26 and the claw 25, 31 is a pin that rotatably supports the parking brake lever 23, 32 is a parking brake cable, 33 is a switch fixed to the parking brake 23, 34 is a switch fixed to the floor panel 20; 35 is a part of the parking brake lever 23, and is a pressing part for pressing the button of the switch 34;

Next, the effect 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 23.
When pulled upward in the drawing, the parking brake cable 32 is pulled to the left in the drawing, and a parking brake (not shown) is applied. Since the pawl 25 engages with the teeth 22, the parking brake lever 23 is held in the raised position. Also, at this time, since the pressing part 35 is in a state of pressing the button of the switch 34,
The switch 34 is turned on, and the parking brake signal _S1 shown in FIG. 1 becomes "1".

On the other hand, when the release button 24 is pushed to the right in the drawing by the driver, the pawl 25 and teeth 22 are disengaged, so that the parking brake lever 23 can be pulled down. If you pull down the parking brake lever 23 in this state, the parking brake cable 32
returns to the right side of the drawing, the parking brake (not shown) is released, and the switch 34 is turned off, so the parking brake signal _S1 becomes "0".

Also, while the release button 24 is pressed to the right in the drawing, the upper part of the claw 25 is pressing the button of the switch 33, so the switch 33 is turned on.
The release signal _S3 in FIG. 1 becomes "1".

When the driver stops pressing the release button 24, the claw 25 returns to its previous position by the force of the return spring 27, so the switch 33 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 24 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 24. Therefore, when releasing the parking brake, the release signal _S3 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 with the engine completely stopped, the ignition switch signal _S2
becomes “1”. Therefore, the one-shot multivibrator 2 outputs a trigger signal _S7 , which is applied to the reset terminals R of flip-flops 9 and 10 via OR circuits 6 and 7, respectively.
Therefore, flip-flops 9 and 10 are both reset, and the Q outputs (the Q output of flip-flop 9 is S ₁₅ and the Q output of flip-flop 10 is S ₁₁ ) 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 8, 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
_S11 becomes "1". Note that this trigger signal _S8 is
Since it is also applied to the reset terminal R of the flip-flop 9 via the OR circuit 6, when the trigger signal _S8 is output, the fuel cut signal _S15 is always "0", and the fuel cut signal S15 becomes ready for fuel supply.

On the other hand, at time _t2 , the engine is stopped, so the rotational speed signal _S5 is at a low level, so the signal _S9 of the comparator 12 is "1".

As above, both signal S ₁₁ and signal S ₉ are “1”
Therefore, the signal _S12 of the AND circuit 11 is “1”
Therefore, the timer 14 is set and the starter drive signal _S14 becomes "1" for a predetermined time _τ1 .

While the starter drive signal _S14 is "1", a starter motor drive device (not shown) operates to rotate the starter motor and start the engine. At this time, as mentioned above, the fuel cut signal _S15 is "0".
Therefore, the fuel injection device (not shown) operates normally and supplies fuel.

Also, when the starter drive signal _S14 becomes “1”,
After a slight delay from that point, the one-shot multivibrator 5 outputs the trigger signal _S13 . The flip-flop 10 is reset by this trigger signal _S13 , and the signals _S11 and _S12 return to "0". As mentioned above, in order to output the signal _S13 with a slight delay from the time when the signal _S14 rises, for example, the one-shot multivibrator 5 is a combination of two one-shot multivibrators connected in series, and the signal S14 is outputted with a slight delay. The configuration may be such that the first one-shot multivibrator is triggered when the signal ₁₄ rises, and the next one-shot multivibrator is triggered when the output of that one-shot multivibrator falls.

Next, if the start is completed within the predetermined time τ ₁ and the engine starts self-sustaining operation, the engine speed gradually increases, and at time t ₃ the engine speed signal S ₅
becomes higher than the reference voltage _VS. Therefore, comparator 12
Since the signal _S9 becomes "0" and the output of the inverter 13 becomes "1", the one-shot multivibrator 4 outputs the trigger signal _S10 .

This trigger signal _S10 is applied to the reset terminal of the timer 14, and the timer 14 is reset even if it is within the predetermined time _τ1 , and the starter drive signal
_S14 returns to "0".

Incidentally, since the trigger signal _S10 is also applied to the reset terminal R of the flip-flop 10 via the OR circuit 7, the flip-flop 10 is also reset.

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 8, and as a result, the trigger signal _S8 becomes "1", so the flip-flop 10 is set and the signal _S11 becomes "1". However, at this time, the engine is already operating and the signal _S9 has become "0", so the signal _S12 output from the AND circuit 11 remains at "0". Therefore, the timer 14 is not set, so the starter drive signal _S14 is "0", and therefore the starter motor is not driven.

Then the parking brake is released (parking brake signal
_S1 becomes "0"), the release button is returned at time _t5 , and the release signal _S3 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 (starter switch turned on) was illustrated, but as can be seen from FIG. 1, the starter signal S ₄ and the release signal S ₃ are Since they are used in exactly the same way via the OR circuit 8, a first start can also be effected by means of the release signal _S3 (pressing the release button).

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

First, at time _t6 , when the parking brake is applied, the parking brake signal _S1 becomes "1" and the 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 since the trigger signal _S6 is applied to the flip-flop 10 via the OR circuit 7, the flip-flop 10 is reset and the signal _S11 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, a case will be described in which the engine is started using the release button.

First, at time _t8 , when the driver presses the release button to release the parking brake, 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 applied to the reset terminal R of the flip-flop 9 via the OR circuit 6. Therefore, the flip-flop 9 is reset and the fuel cut signal _S15 becomes "0", making it possible to inject fuel.

Furthermore, since the trigger signal _S8 sets the flip-flop 10 in the same manner as described above, the signal _S11 becomes "1", and since the signal _S9 is "1" while the engine is stopped, the AND circuit 11 becomes "1". The signal _S12 becomes "1", so the timer 14 is set and the starter drive signal _S14 becomes "1", and the starter motor operates and the engine starts in the same manner as described above.

Similarly to the above, if the starting is completed within the predetermined time _τ1 set by the timer 14 and the rotational speed signal _S5 becomes equal to or higher than the reference voltage _Vs , the signal _S9 becomes "0" and the starter is driven. The signal _S14 becomes "0" and the starter motor stops.

Next, a case will be described in which the engine is malfunctioning and does not start within the predetermined time _τ1 .

First, at time _t9 , when the release button is pressed and the release signal _S3 becomes "1", the timer 14 is set by the same action as described above, and the starter drive signal _S14 becomes " ₁ " for a predetermined time τ1. 1” and the starter motor is driven.

However, if the engine does not start within the predetermined time τ ₁ , the starter drive signal S ₁₄ returns to “0” at time t ₁₀ when the predetermined time τ ₁ has elapsed, and the starter motor stops.

Then, when the release button is pressed again and the release signal S ₃ (or starter signal S ₄ ) becomes “1”,
Similarly to the above, the starter motor is driven for a predetermined time τ ₁ .

Note that the value of the above-mentioned predetermined time τ ₁ is set to a value that takes into account the time required for the engine to be started in a normal state with some margin, for example, from several seconds to more than ten seconds.

With the above configuration, even if the engine is out of order and does not start easily, there is no fear that the starter motor will remain driven and the battery will overheat.

Next, FIG. 4 is a circuit diagram of another embodiment of the present invention.

The circuit of FIG. 4 uses a thermistor 15 as a resistor for setting the predetermined time τ ₁ of the timer 14,
The configuration is such that the value of the predetermined time τ ₁ is automatically changed according to the temperature. The configuration and operation other than those described above are similar to the circuit shown in FIG.

As is well known, the time required to start an engine varies considerably depending on temperature, and is longer at lower temperatures.

Therefore, as shown in Figure 4, if the value of the predetermined time τ ₁ is set to a value that corresponds to the temperature, that is, to a long value at low temperatures and a short value at high temperatures, it is possible to start reliably even at low temperatures, and also to a value that is short at high temperatures. This can prevent wasteful consumption of battery power due to continuous starting for a long period of time.

It is ideal if the temperature of the combustion chamber of the engine itself can be detected, but the temperature of the cooling water of the engine or the temperature of the outside air is also sufficiently effective. The thermistor 15 (or other temperature sensing element) described above is installed, for example, in the water jacket of the engine, depending on where the temperature is to be detected.

In the embodiments shown in FIGS. 1 and 4, the present invention is constructed using ordinary hardware, but it goes without saying that similar control can be performed using a microcomputer, for example. When applied to an automobile equipped with a centralized engine control device using a microcomputer, the present invention can be implemented simply by changing the program of the microcomputer. As explained above, in the present invention, when the parking brake is applied, the engine is stopped, and the parking brake release button is used to start driving the starter motor. The engine can be started simply by performing a normal parking brake release operation without having to be conscious of any special starting operation. In addition, by setting the time during which the starter motor is continuously driven to a long value at low temperatures and a short value at high temperatures, it is possible to start reliably even at low temperatures, and the engine may malfunction at high temperatures. In this case, it is possible to prevent wasteful consumption of battery power due to continuous starting for a long time.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is a signal waveform diagram of the circuit of FIG. 1, FIG. 3 is a diagram of an example of a parking brake operating device, and FIG. 4 is another embodiment of the present invention. This is an example diagram. Explanation of symbols, 1 to 5...One-shot multivibrator, 6 to 8...OR circuit, 9 to 10...
Flip-flop, 11...AND circuit, 12...
... Comparator, 13 ... Inverter, 14 ... Timer, 15 ... Thermistor, S ₁ ... Parking brake signal, S ₂ ... Ignition switch signal, S ₃ ... Release signal, S ₄ ... Starter signal, _S5 ...Rotation speed signal, _S14 ...Starter drive signal, _S15 ...Fuel cut signal.

Claims (1)

[Claims] 1. A circuit that stops the engine when the parking brake is applied, and a circuit that is linked to a release button of the parking brake, and starts driving the starter motor when the release button is operated while the engine is stopped. a circuit for stopping the starter motor upon completion of starting; a means for limiting the time during which the starter motor is continuously driven within a predetermined time; and a circuit for setting the above predetermined time to a long value when the temperature is low and a short value when the temperature is high. An engine control device comprising: means;