JPS58140434A - Engine controller - Google Patents

Abstract

PURPOSE:To prevent an engine from being incapable of starting running, by a method wherein, in an automobile stop-start controller, if a battery voltage decreases to lower than a given value, an integration is made for a given time to compare it with a reference value, and if it is decided that a battery is short of a charging quantity, an antomatic-stop is prohibitted. CONSTITUTION:If a starting motor drive signal S12 brought to ''H'' to run a starting motor, a battery voltage VB drops, and if a partial pressure VE thereof reduces to lower than a reference value V2, an AND circuit 48 outputs a signal S17 for a given time set in a timer 40 to turn ON a switch 43. Meanwhile, the signal S17 produces signals S18 and S19 which delay by a minute time in delay circuit 41 and 42, an integrating circuit 44 set by the S19 integrates a partial pressure VC of the voltage VB, an output VD thereof is compared with a reference voltage V1 by a comparator 45, and in the case of VD<V1, it is decided that a battery is short of a charging quantity to store an ''L'' signal in a memory circuit 46 at each signal S18. In case the battery deciding signal S0 is ''L'', even if a parking brake signal is brought to ''H'', the output of the AND circuit is brought to ''L'', an engine is prevented from stopping automatically.

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 while waiting at a traffic light or in a traffic jam, devices have been developed that stop the engine when the vehicle stops and start the engine when the vehicle starts.

For example, 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.

Further, the above-mentioned device is configured to cancel the functions of the entire device if even one of several safety conditions is not satisfied for safety reasons.

For example, from the time the starter switch is turned on,
If the battery voltage after seconds is 8.5V or less,
The device is configured to deactivate the entire device.

The above-mentioned release mechanism stops the automatic stop and start functions when the electric power charged in the battery is low, thereby preventing the engine from being able to start due to over-discharging of the battery, so-called dead battery. This is an effective method for improving safety.

However, in reality, when the engine is started, that is, during cranking when the starter motor is operating, in the NIA, the battery voltage pulsates considerably in response to fluctuations in the current flowing through the starter motor.

Therefore, as mentioned above, the battery voltage at a certain point in time after the starter switch was turned on was used as the criterion for determination.

It is difficult to accurately determine the state of charge of a battery.

As a result, the device may become deactivated even though there is still sufficient battery power.

The release mechanism did not operate even though the battery power was low, and there was a risk that the battery would die and the engine would become unable to start.

The present invention was made to solve the problems of the prior art as described above, and it accurately determines the state of charge of the battery and ensures automatic engine shutdown function only when the battery power is truly low. An object of the present invention is to provide an engine control device that can release the

In order to achieve the above object, the present invention has the following features.

The starter drive signal that activates the starter motor is output, and the battery voltage is integrated for a predetermined period of time from the time when the battery voltage drops below a predetermined value.If the integrated value is below a predetermined value, the battery voltage is The system is configured to determine that there is a power shortage and cancel the automatic shutdown function.

By configuring as above, after the starter drive signal is output, the starter motor actually starts rotating and a large current flows, which causes the battery voltage to drop, and then the value is integrated. Ω, the state of charge can be accurately determined.

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

FIG. 1 is a circuit diagram of one embodiment showing the entire apparatus of the present invention, and FIG. 2 is a signal waveform diagram of the circuit of FIG. 1.

In FIG. 1, So is a battery determination signal.

The output from the judgment circuit 5, which will be described in detail later, is ``1'' when the battery power is normal, and ``O'' when it is insufficient.
"become.

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

Also, S2 is an ignition switch signal;
When Yongsui Inochi is on, it becomes "Pa1".

Further, S3 is an IJ lease signal, which becomes 1'' while the IJ lease button of the parking brake is pressed as will be described in detail later.

Further, S4 is a starter signal, which becomes "1" when 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 rotational speed signal S5 is 1
For example, the neutral point voltage of the alternator may be used, or in an engine equipped with a crank angle sensor that outputs a pulse every time the engine crank angle rotates by a predetermined angle, the frequency of the pulse is converted into voltage. may also be used.

Also, S12 is a starter drive signal, and this signal is 1"
The starter motor operates during this time.

Also, S15 is a fuel signal, and this signal is
The fuel supply to the engine is cut off during "1".Next, 1.2.!l and 4 are one-shot multivibrators, respectively, and when the input signal rises, a narrow trigger signal S6. Output S, , S8 and S, respectively.

Further, 5 is a determination circuit which will be described in detail later.

The gist of the present invention relates to a novel configuration of this determination circuit 5.

Further, 6, 7 and 8 are OR circuits, 9 and 10 are flip-flops, and 11 and 12 are AND circuits.

Further, 13 is a comparator which outputs 1'' when the value of the 1 rotation speed signal S5 is less than a predetermined reference voltage 78.

In the above case, a signal S9 which becomes "0" is output. The reference voltage VsO value is the lowest value 1 when the engine rotates independently
For example, it is set to 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', it indicates that the engine is operating (starting has been completed and the engine is running independently).

Further, 14 is an inverter that inverts and outputs the signal S9.

Next, the device for outputting the parking brake signal S1 and the release signal S5 will be explained.

FIG. 6 is an example of a parking brake operating device for operating the parking brake.

In FIG. 6, 20 is a floor panel of the vehicle body, and a parking brake placket 21 is bolted to the floor panel 20. Also, 22 is parking brake bracket 2
1 is the tooth provided, 26 is the parking brake lever, 24 is the release button to release the lock of the parking brake lever 230, 25+'! A pawl that engages with the teeth 22 and locks the parking brake Leno<-25 in any position; 26 is an I
I11-rod connecting button 24 and pawl 25;
27 is a return spring, and release button 24
゜The rod 26 and claw 25 are always pushed to the left in the drawing.

28 is a stopper for the return spring 27, which is fixed to the parking brake lever 23.

Further, 29 is a pin that supports the pawl 25 in the parking play angle, <-25, 60 is a pin that connects the rod 26 and the pawl 25, 31 is a pin that rotatably supports the parking brake lever 23, and 32 is a parking brake cable. , 36 is a switch fixed to the parking brake lever 25, 34 is a switch fixed to the floor panel 20, 35 is a parking brake lever,
(The part of -23 is a suppressor that presses the button of 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.

When the driver pulls up the parking brake knee 25 upward in the drawing from this state, the parking brake cable 62 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 2
6 is held in the raised position. Also, at this time, the suppressor 35 is in a state of pressing the button of the switch 64.

The switch 54 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 26 can be pulled down. If the parking brake lever 23 is pulled down in this state, the parking brake cable 32 returns to the right side of the drawing.1 The parking brake (not shown) is released, and the switch 34 is turned off, so the parking brake signal S1 becomes °'0''. Become.

Also, while the button 24 is pushed to the right in the drawing, the upper part of the claw 25 is pushing the button of the switch 63, so the switch 33 is turned on.

The IJ14 signal S5 in FIG. 1 becomes "1".

When the driver stops pressing the IJ17 button 24, the claw 25 returns to its previous position by the force of the return spring 27, so the switch 63 is turned off and the release signal S5 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 you can see, when releasing the parking brake once applied, be sure to press the release button 24.
You must therefore press when releasing the parking brake.

Be sure to set the IJ signal S6 to "1".

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 and pulled toward the driver by the driver to stop the car. The present invention can be applied in exactly the same way to a brake system.

Next, FIG. 4 is a circuit diagram of one embodiment of the determination circuit 5 that determines the amount of charge (remaining power amount) of the battery.

In FIG. 4, a comparator 47 compares a voltage VE obtained by dividing the battery voltage VB with resistors R5 and R4 and a predetermined reference voltage EE.
V2 is compared, and when vE falls below v2, a 1'' signal is output.

Further, the AND circuit 48 outputs a signal of "1" when both the output of the comparator 47 and the starter drive signal 812 are "1".

Therefore, when the starter drive signal 812 becomes 1'' and the starter motor starts driving, a large current actually flows through the starter motor, and the battery voltage drops significantly as a result, the signal from the AND circuit 48 is It becomes 1″.

Next, the timer 40 is set to "1" for a predetermined period of time (for example, 05 seconds) from the time when the signal of the AND circuit 48 rises to 1#, that is, from the time when the starter motor is actually driven and the battery voltage has decreased. '' is outputted as a signal S17.

Next, the delay circuit 41- outputs the signal 818 with a slight delay from the time when the signal S17 falls to "0", and the delay circuit 42 outputs the signal 818 with an even slight delay from the signal 818, while the analog switch 43 The signal S17 is turned on while it is "1", and the voltage vc obtained by dividing the battery voltage VB by the resistors R1 and R2 is sent to the integrator 44.

The integrator integrates and outputs the voltage VC while the analog switch 46 is on, that is, for the predetermined time period from when the starter motor is actually driven and the battery voltage drops.

The output voltage VD of this integrator 44 is detected by a comparator 45.

Compare with a predetermined reference voltage ■1.

The comparator 45 detects that when VD≧V1, that is, when the integral value of the battery voltage is greater than or equal to a predetermined value, the amount of charge of the battery is within the safe limit.
If Vl)<Vl, that is, if the battery charge is insufficient, a signal of "0" is output.

Next, every time the signal 81B is applied, the storage circuit 46 reads and stores the signal of the comparator 45, and outputs the signal as the battery determination signal So.

Further, the value of the integrator 44 is reset every time the signal S19 is applied.

As described above, according to the determination circuit shown in FIG. 4, the battery voltage is integrated for a predetermined period of time from the time when the starter motor is actually driven and the battery voltage drops, and when the integrated value is smaller than the predetermined value, It is configured to determine that the battery is insufficiently charged.

Even when the battery voltage pulsates as when the starter motor is activated, the state of charge of the battery can be accurately determined.

Note that when the battery is on the verge of dying, the internal resistance of the battery increases, and therefore, when a large current flows, such as when a starter motor is activated, the voltage drop increases, making it easier to determine the state of charge.

Therefore, the above-mentioned predetermined time may be set to a value shorter than 1 the time during which the starter motor normally continues to operate, 2 for example 0.5 seconds.

Also, at the moment when the starter drive signal is output.

In reality, the starter motor is still not operating.

Therefore, the battery voltage is at a high value when there is no load.

Therefore, if the battery voltage is integrated immediately from the time point 20 when the starter drive signal is output, there is a risk that the above-mentioned high value at the time of no load will be mixed in and the 9 judgment will be incorrect.

However, in the case of the present invention, the battery voltage is integrated from the time when the starter motor is actually driven and the battery voltage drops as described above, so the above-mentioned problem does not occur. , it is possible to accurately determine the battery charge amount.

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 t 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 output (9's Q output is S, , 1o's Q output is 511
) are both '0'. In this state, the 11 stator drive signal 812 and the tool cut signal 815 are both '0', indicating that the engine is ready to start.

Next, at time t2, the starter switch is turned on.

When the starter signal S4 becomes 1'', this signal is given to the one-shot multivibrator RO via the OR circuit 8, and the one-shot multivibrator 6 receives the trigger signal S.
Outputs 8.

This trigger signal S8 is applied to the set terminal S of the flip-flop 10, so that the Q output signal SN becomes 1''.This trigger signal S8 is.

Since it is also applied to the reset terminal R of the flip 70 knob 9 via the OR circuit '#FI6, when the trigger signal S8 is output, the two-nil cut signal S15 is always 0'', and the fuel can be supplied.

On the other hand, at the second time point t2, the engine is stopped, so the rotational speed signal S5 is at a low level, so the signal S9 of the comparator 16 is ``1''. As described above, the signal SN and the signal S9 are Since both are 1'', the starter drive signal 842 output from the AND circuit 11 is also 1''.

While the starter drive signal 812 is "1", a starter motor drive device (not shown) operates to rotate the starter motor and start the engine. Furthermore, at this time.

As mentioned above, since the unit cut signal SL5 is "0", the fuel injection device (not shown) operates normally.

It supplies fuel.

Next, when the engine speed gradually increases and the engine speed signal S5 becomes equal to or higher than the reference voltage Vs at one point in time t5, that is, when the engine starts to operate autonomously after starting, the signal S9 becomes "0". Therefore, the starter drive signal 812 output from the AND circuit 11 also becomes "0", and the starter motor stops.

Note that when the signal S9 becomes "0", the output of the inverter 14 becomes "1", and therefore the one-shot multivibrator 4 outputs the trigger signal 810.

This trigger signal 810 is applied to the reset terminal R of the flip-flop 10 via the OR circuit 7, so the flip-flop 10 is reset and the signal 811 becomes °'0''.
become.

Next, when starting the car, the IJ-button is pressed at time t4 to release the parking brake, and the release signal S3 becomes "1". This signal is given to the one-shot multivibrator 6 via the OR circuit 8, and as a result, the trigger signal S8 becomes °'1'', so the flip-flop 1o is set and the signal S,1 becomes Bi. sometimes.

Since the engine is already operating and the signal S is 0'', the starter drive signal S+z output from the AND circuit 11 remains at D''.

Therefore, the starter motor does not operate.

Next, the parking brake is released (parking brake signal S1 is 0
''), the release button is returned at one point in time t5, and the release signal S5 becomes os.

In this state, the first engine start is completed and the nine cars are ready to run.

In the above explanation, the first start is performed using the starter signal S4 (
1, the starter signal S4 and the release signal S5 are used identically via the OR circuit 8, so the release signal S3 ( The first start can also be performed by 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 S becomes 1". At this time, if the battery determination signal So is "1".

The output of the AND circuit 12 becomes "1", and therefore the one-shot multivibrator 1 outputs the trigger signal S6.

Therefore, the flip-flop 9 is set, and its Q output signal, that is, the two-nil cut signal S15 becomes "1".

When the tool cut signal 815 becomes "1", the fuel injection device (not shown) cuts off the fuel supply.

The engine will stop.

Note that the trigger signal S6 is applied to the flip-flop 10 via the OR circuit 7, so the flip-flop 10 is reset and the signal S11 becomes "0".

Then the engine stops and the rpm gradually decreases.

When the rotational speed signal S5 becomes less than the reference voltage 78 at time t7, the signal S9 becomes "1".

Next, a case in which the engine is started using the release button will be explained.

First, at time t8, when the driver presses the button 14 to release the parking brake, the release signal S becomes 1''.

When the +11J-base signal S5 becomes ``1'', the trigger signal S8 outputted from the one-way multi-pipe lake 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.

Flip-flops for that? is reset and the tool cut signal S13 becomes 0'', making it possible to inject fuel.

Further, the trigger signal S8 sets the flip-flop 10 in the same manner as described above, so the signal S11 becomes "1", and since the engine is stopped and the bite S is "1" at this time, the output is output from the AND circuit 11. Starter drive signal S
12 becomes 1'', and the starter motor operates to start the engine in the same way as above.

When the starting is completed and the rotation speed signal S5 becomes equal to or higher than the reference voltage 78, the signal S9 becomes "0", and the starter drive signal 8
12 becomes "0" and the starter motor stops, as described above.

Next, a case where the amount of charge of the battery is decreasing will be explained.

As explained in FIG. 4 above, if the charge amount of the battery is low, at time t, a predetermined time (0.5 seconds) after time t8 when starter drive signal 812 becomes "1". , battery determination signal S. becomes “0”.

In this state, one time point t. When the parking brake is applied, even if the parking brake signal S1 becomes 1'', the battery determination signal 80 is 0, so the output of the AND circuit 12 remains 0. Since the one-shot multivibrator 1 is not triggered and the flip-flop 9 is not set, the fuel cap signal 815 is 10.
“It remains as it is.

The engine does not stop.

As mentioned above, the engine is configured not to automatically stop when the battery charge level is low.
There is no fear that the battery will run down due to power consumption during restart due to automatic stop, making it impossible to start.

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.

Further, in the embodiment shown in FIG. 1, the present invention is applied to a device that stops the engine when the stopping condition of applying the parking brake is satisfied, but other methods, such as stopping the car or driving Of course, the present invention can also be applied to devices that have a stop condition of a switch operation by a person.

As explained above, according to the present invention, if the value obtained by integrating the battery voltage for a predetermined period of time from the time when the battery voltage drops after the starter drive signal is output is less than or equal to the predetermined value, the amount of battery charge is reduced. Since the configuration is configured so that the engine is not automatically stopped when it is determined that the voltage has dropped, the high voltage during no-load conditions will not be mixed into the integral value.

Moreover, since it is not affected by pulsations in the battery voltage, it is possible to accurately determine the state of charge of the battery.

Therefore, it is possible to make full use of the engine's automatic stop and start functions, and there is an effect that it is possible to eliminate the inability to start due to a dead battery.

In the embodiment shown in FIG. 1, the present invention is constructed using ordinary hardware, but it goes without saying that similar control can be performed using a microco/peater. When applied to an automobile equipped with a central engine control device using a microcombinator, the present invention can be implemented simply by changing the program of the microcombinator.

[Brief explanation of drawings]

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, FIG. 6 is an example of a parking brake operating device, and FIG. 4 is a diagram of a determination circuit of the present invention. FIG. 2 is a circuit diagram of one embodiment. Explanation of symbols 1 to 4...One-shot multivibrator 5...
Judgment circuit 6-8...OR circuit 9-10...
・Flip-flop 11.12...AND circuit 13...Comparator 14...Inverter 4
0...Timer 41.42...Delay circuit 4
3...Analog switch 44...Integrator 45...Comparator 46...
- Memory circuit 47... Comparator 48... AND circuit So... Battery judgment signal S1... Parking brake signal S2... Ignition switch signal S3... Release signal S4... Starter signal S5. ...Rotation speed signal 812...Starter drive signal 81B...Tunicanto signal Attorney Junnosuke Nakamura

Claims (1)

[Claims] A starter drive signal that drives a starter motor in an engine control device that automatically stops an engine when a predetermined stop condition is satisfied, and automatically starts a machine when a predetermined start condition is satisfied. is output,
and means for determining the amount of charge of the battery by integrating the battery voltage for a predetermined period of time from the time when the battery voltage has decreased to a predetermined value or less, and comparing the integral value with a predetermined reference period, the means comprising: An engine control device configured to not automatically stop the engine if it is determined that the amount of charge is insufficient, even if other stop conditions are satisfied.