JPS58202342A - Fuel control device for car engine - Google Patents

Abstract

PURPOSE:To aim at the promotion of fuel-saving with a fuel control device, by the way of forbidding a fuel cut furing warming up, automatically stopping an engine by cutting the fuel feed after warming up is over, then forbidding the fuel cut again in time of key starting after the warm-up, and releasing the forbiddance once running takes place. CONSTITUTION:In this fuel control device bearing the above caption, there is provided with a warm-up state detecting device consisting of comparators 30 and 31, an inverter I6 and an AND gate G11, and that whether an engine is in a state of warming up or not is detected on the basis of a cooling water temperature signal S9. A fuel cut (*F.C) for biddance-release device consisting of an AND gate G4 forbids the *F.C when the warm-up state detecting device does not detect the warm-up state and releases the forbiddance when the detecting device defects it. The *F.C forbidding device consisting of a one-shot multivibrator (OS) 23, and AND gate G10, a flip-flop (FF) 27 and the AND gate G4 forbids the *F.C by a key start signal in time of warming up. In addition, the forbiddance release device is made up of an inverter I1, an AND gate G1, an OS 22, an OR gate G9, an FF 27 and the AND gate G4.

Description

[Detailed description of the invention] The present invention relates to a fuel control device for a vehicle engine.

2. Description of the Related Art Conventionally, as a fuel control device for a vehicle engine of this type, there is one shown in FIG. 1, for example.

The details of this device are described, for example, on pages 72 to 77 of the November 1981 issue of "Automotive Engineering" published by Railway Japan.
After starting the engine using an ignition key (not shown), when a manual main switch 1 is pressed, a computer 2 that controls the system is activated.

At this time, the ER8 operation indicator lamp 3 in the meter panel lights up, and a buzzer (not shown) sounds to notify the driver that the system has activated.

However, when main switch 1 is pressed, igniter 4
A signal from the regulator indicates that the engine speed is 1100 rpm or more, and terminal 10 is high, which indicates that charging is in progress, and the driver's door switch is turned off, indicating that the engine is charging. The system will not operate unless computer 2 detects whether the door is closed or not.

Then, when the vehicle is stopped by depressing the brake pedal while the vehicle is running, and then the clutch pedal is released, the computer 2 outputs an engine stop signal ST after 0.5 to 2 seconds to normally close the ERS relay 17. Contact NC is opened, thereby cutting off power to the fuel cut solenoid and igniter, and automatically stopping the L-C-r-engine.

However, since automatic stopping of the engine is dangerous, certain conditions are set for safety, and if even one of the 11 conditions shown in Table 1 is met, the engine will not be stopped automatically.

Let me know that.

Next, when the clutch pedal is fully depressed while the engine is automatically stopped, the clutch lower switch 16 is turned on, so the computer 2 outputs the engine start signal Ss to switch the ER8!J relay 17 normally open. 1 Close the front point No., thereby energizing the starter motor and automatically restarting the engine.

When the engine speed rises to 450 rpm, the engine start signal Ss is no longer output and the starter motor is automatically stopped.

In addition, if even one of the conditions shown in Table 2 applies,
For safety reasons, the operation of this entire system is canceled.

Table 2 After that, with the engine running, turn on the main switch 1.
When turned on, the system will start working again.

However, in such conventional fuel control devices for vehicle engines, after the engine is started with the ignition key, the system does not work indefinitely unless the main switch 1 is pressed9, so that the purpose of the system is to save fuel. Not only is this not possible, but if you need to warm up the engine, such as on a winter morning, even if you start the engine with the ignition key and then turn on main switch 1, it will not work until the vehicle is driven once. , the engine does not stop even after it has been warmed up, so if you warm up the vehicle while it is stopped, the engine cannot automatically stop when warm-up is complete, resulting in fuel savings. The problem was that it was not possible to do so.
- This invention was made by focusing on such conventional problems, and when starting the engine with the ignition key,
When the engine is not warmed up, the fuel cut is prohibited, and when the engine is warmed up, the engine is automatically stopped by the fuel cut, and when the engine is started with the ignition key after the engine is warmed up, for example, the heater The above-mentioned problem is solved by providing a fuel control device for a vehicle engine that prohibits fuel cut in order to keep the engine running for use, and cancels the prohibition of fuel cut once the vehicle is driven. It is.

Hereinafter, embodiments of the present invention will be described with reference to FIG.

First, to explain each input signal 81 to S9 of this embodiment, Sl is a throttle close signal that makes a "1" roar only when the throttle valve is closed, and S2 is a clutch engagement signal that makes a "1" roar only when the clutch is connected. , Sa only when the transmission gear is in neutral.
1 "Neutral signal roars, S4 becomes "1" only when the transmission gear is in 4th or 5th gear 4
, 5th speed signal, S5 is “1” only when the clutch is disengaged.
S6 is an ignition on signal that roars "1" only when the ignition switch is turned on, and S7 is a key start signal that roars "1" only when the ignition key is turned to the start position.

Further, Ss is a rotation speed signal with a voltage proportional to the engine rotation speed, and as this rotation speed signal S8, for example, the neutral point voltage of the alternator may be used, or the engine crank angle may be rotated by a predetermined angle. In an engine having a crank angle sensor that outputs a pulse every time, the frequency of this pulse may be converted into a voltage.

Furthermore, S9 is a cooling water temperature signal, and a water temperature sensor, such as a thermistor, attached to the water jacket of the engine and a fixed resistor are connected in series between the power supply and the ground so that the fixed resistor is on the ground side. It is designed to output from the connection point between the two.

Therefore, in this cooling water temperature signal S9, the sum signal level increases as the temperature of the engine cooling water increases.

810 to S21 indicate signals in the middle of the circuit, and S22, 82
3 is the output signal of this device.

The output signal S22 is a fuel cut signal, and the fuel supply to the engine is cut off during this signal "X1".

The output signal S23 is a starter drive signal, and the starter motor operates while this signal is "1".

Next, to explain the circuit configuration of this embodiment, Gl to Gs
, Glo, G11 is an and gate, G6 to G9
is an OR gate, and b-I6 is an inverter.

20 is a comparator which outputs a signal S21 which becomes "1" when the value of the rotation speed signal S8 is less than a predetermined reference voltage Vs, and becomes "0" when the value is 78 or more.

The reference voltage VsO value is set to the lowest value when the engine is in self-sustaining operation, for example, a value corresponding to 400 rpm.

Therefore, when the signal S21 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 is in autonomous operation). .

21 is a continuation judgment circuit, and when the output of AND gate G2 remains in the state of "1" for 11 seconds (for example, 1 second),
When the output of G2 becomes X'0'', it immediately outputs a signal S12 which becomes 10''.

22 to 26 are one-shot multivibrators (hereinafter "
When the human input signal rises, a predetermined narrow pulse width (trigger signal Slo, 8) is activated.
11 and outputs S13 to S15, respectively.

27 to 29 are set/reset type flip-flop circuits (hereinafter abbreviated as rFFJ).

Reference numeral 30 and 31 are comparators, and a reference voltage VTU has a predetermined signal level of the cooling water temperature signal S9.

When VTL is less than (7), signals S24 and S25 are outputted, which are Kv"l", VTU, and when VTL or more, N'X□", respectively.

The reference voltages VTU and VT are values corresponding to the upper and lower limits of the warm-up state of
VTL is set to a value corresponding to 60°C.

Since the AND gate G11 is manually inputted with a signal obtained by inverting the signals S24 and No. 18 S25 by the inverter I6, the output signal S26 of the AND gate Gll indicates that the engine cooling water temperature is above 60°C and below 100°C. It becomes “1” only when .

That is, when the signal S26 is "1", it indicates that the engine is warmed up, and when it is "0", it indicates that the engine is not warmed up or is overheated.

Note that these comparators 30, 31 . The inverter Is and the AND gate G11 constitute a warm-up state detection means.

Further, the fuel cut prohibition/cancellation means is set to 0823. by the AND gate G4. ANDGATE GIQ, F
F27 and the fuel cut inhibiting means by AND gate G4, inverter II, and gate G1
,0822. Orgate G9. FF27 and anime games
) G4 constitutes a prohibition release means.

Further, the engine stop/start means is constituted by each part other than the elements constituting each of the means described above.

Next, the operation of this embodiment will be explained.

(I) When starting the vehicle (:) When the engine is not warmed up Since the cooling water temperature is less than 60°C, the output signals 824 and 825 of the comparators 30 and 31 are both "l" and the inverter
Since the output of the AND gate Gll is "0", the output signal S26 of the AND gate Gll is 'XO'.

In this state, when the ignition key is inserted into the vehicle and the ignition switch is turned on, the ignition on signal S6 changes from ゝゝ0'' to ゝゝ1'', and the 082
5 outputs a trigger signal S14.

This trigger signal S14 is passed through the OR gate G8 to the signal S
17 to the reset terminal R of FF29.
F29 is reset and signal 820 becomes 10''.

At the same time, the trigger signal S14 passes through the OR gate G9 to F
To set F27, 13.3,, is ゝゝ1''
becomes.

Now turn the ignition key to the start position)
Since the key start signal S7 changes from "0// to "1", the trigger signal Sll is output from 0823.

At this time, since the signal S26 is X'0'', the trigger signal Sll cannot pass through the AND gate G10, so the FF
27 is not reset and signal 818 remains at 91''.

On the other hand, since the signal 826 is 'X□', the fuel cut signal S22 which is the output signal of the ant gate G4 is 9
0'' and prohibits fuel cut, so if the starter is driven by the ignition key, fuel will be supplied and the engine will start.

After this, when the engine is warmed up and the engine cooling water temperature reaches, for example, 60°C, the output signal S25 of the comparator 31 becomes
``0'' and the output of inverter ■6 becomes 11''.

At this time, since the output signal S24 of the comparator 30 is "1", the output signal 826 of the AND gate G11 becomes "1".

In this state, if the driver is not operating the accelerator pedal, clutch pedal, or transmission gear, the throttle close signal S1 and the clutch engagement signal S2 are both ゝゝ1〃, and the neutral signal S
3 is also "1", and the output of AND gate G2 is "1".

In this state, the output of the AND gate G2 has been ``1'' for more than T seconds, so the output signal S12 of the two sustain judgment circuits has also become ``1'' and set the FF28, so the output signal S19 is yelling “1”.

Therefore, the signals Sls, S19, S26 are
Therefore, the fuel cut signal S22, which is the output of G4, becomes "1", thereby cutting off the fuel supply to the engine and automatically stopping the engine.

(!When the engine is being warmed up, the signal S26 is "1" in this state, so the key start signal S7 changes from "0" to "l" and changes to 0823.
When the trigger signal Sll is output from the AND gate Glo, this trigger signal S11 passes through the AND gate Glo and resets the FF27, so the signal 818 becomes "0" and the fuel cut which is the output of the AND gate G4 is output. Signal S2
Set 2 to 50" (fuel cut prohibited).

Therefore, when the starter is driven by the ignition key, fuel is supplied and the engine starts.

Next, when the clutch is disengaged and the transmission gear is put into 1st, 2nd, or reverse in order to start the vehicle, the neutral signal S3 changes from "1//" to "0", so the output of the inverter 11 changes to It goes from ゝ0“ to ゝゝ1“.

On the other hand, when an attempt is made to start the vehicle by connecting the clutch while depressing the accelerator pedal, the clutch engagement signal S2 changes from "0" to "'1".

Therefore, the output of the game) Gl becomes ``1'' and the trigger signal Slo is output from 0822, so FF27 is set via the OR gate G9 and the signal 81 is output.
8 becomes 11″.

In other words, when the engine is warmed up, if you start the engine with the ignition key, the signal 818 will be "0" until the engine is running, and the fuel cut signal S22 will also be "0" as will be described later. Do not shut off the fuel even if the following conditions are met (fuel cut prohibited).

In addition, once the vehicle is running steadily, the signal S will be turned on until the next key start.
1s is held at “1” (fuel cut prohibition canceled).

Gl) When the vehicle is decelerating A (decelerating in 4th or 5th gear) When the vehicle starts decelerating and you release the accelerator pedal, the throttle closes and p
, the throttle close signal Sl changes from "0" to "1".

If the clutch is connected at this time, the clutch engagement signal S2 is "1", and if the transmission gear is in 4th or 5th gear, the 4th and 5th speed signals S4 are "1", so the OR gate G6 is The output is also ゝゝ1'', and it is an anime game) G
The output of 2 becomes ゝゝ1''.

When this state continues for Tr seconds, the output signal S12 of the continuation determining circuit 21 becomes "1".

Then, FF2B is set by this signal S12, and the signal S19 becomes 21'', and as mentioned above, the signal S18 is %% 1 // N while the vehicle is running.

Fuel cut signal S which is the output of AND gate G4
22 becomes "1", and the fuel supply to the engine is cut off.

At this point, if you press the accelerator pedal again, the throttle signal will close 9.
Since St becomes "O", the output of inverter I2 becomes "1".

Therefore, the signal S16 which is the output of (or game) G7 becomes 91", and in order to reset the FF28, the signal S16 becomes 91".
19 is "0" 9, fuel cut signal 2 S22
also becomes "0".

Therefore, fuel is supplied again and the vehicle is accelerated.

Furthermore, if the clutch is disengaged in a fuel cut state, the engine will stop because no driving force is transmitted from the tires, and if the clutch is connected again, the engine will be driven by the driving force from the tires.

(111 when vehicle decelerates B (deceleration in R, 1st, 2nd, 3rd gear)
When the vehicle starts to decelerate and the accelerator pedal is released, the throttle close signal S1 becomes "1" as described above, and if the clutch is connected, the clutch engagement signal S2 also becomes ((1//).Transmission When the gear is R, 1st, 2nd, or 3rd speed, the neutral signal S3 and the 4th and 5th stray signals S4 are both pr' The output of AND gate G2 is also 50''.

Therefore, the FF28 remains reset and the fuel is not cut off by the fuel cut signal S22 mode 0''.

After that, when the clutch is disengaged and the transmission gear is set to neutral to coast, the neutral signal S3 becomes ``1'', and the output of G6 becomes ``1''.

Here, when the clutch is connected, the clutch engagement signal S2 is XX1'', and the output of the AND gate G2 is 11''.
When this state continues for T1 seconds, the output signal S12 of the continuation judgment circuit 21 becomes 11", and the FF 28
Cut the fuel to set.

At this time, the transmission gear is in neutral, so the engine stops.

When restarting the engine, the engine is stopped when the clutch is disengaged from 4.5th gear, or when the engine is stopped in neutral (vehicle is coasting or stopped), the transmission is disabled when the clutch is disengaged. Gear R, 1, 2, 3
If the clutch is engaged in any of the speeds, the clutch disengagement signal S5 is set to 01".
bawl.

Further, since the neutral signal S3 and the 4,5 stray signal S4 are both "0", the output of the or game G6 is "X□", and the output of the inverter I3 is "1".

Therefore, the output of AND gate G3 becomes 91'' and O824 outputs trigger signal S13. Since FF 29 is set by this trigger signal S13,
The signal S20 becomes 91'l.

At this time, since the rotation speed signal S8 is at a low voltage, the comparator 20 sets the signal S21 to "1". Therefore, the starter drive signal S23, which is the output of the AND gate G5, becomes 'X1//.

On the other hand, the signal S13 is simultaneously sent to the FF via G7.
Fuel cut signal 822 to reset 2B.
is SJ". Therefore, the starter is activated by the starter drive signal S23.

The engine is started.

When the engine rotation speed becomes self-sustaining, the rotation speed signal S8
becomes a high voltage, the comparator 20 sets the signal S21 to "O", and the output of the inverter I5 becomes "1". Therefore, 0826 outputs the trigger signal Sts, and the FF 29 is reset by the signal S17 outputted via the OR gate G8, so the starter drive signal S23 becomes "0" and the starter stops.

The continuation determination circuit 21 is provided to prevent the fuel from being cut even if the output of the engine G2 instantaneously becomes 1 during a gear shift up or the like.

In addition, since the clutch disengagement signal S5 becomes "0" every time the clutch is disengaged, the inverter ■4 and the OR gate G
FF29 is reset via 8.

As explained above, according to this Flll, the configuration is such that when the engine is started with the ignition key, fuel cut is prohibited when the engine is not warmed up, and when the engine is warmed up, the engine is automatically cut off by fuel cut. When the vehicle is stopped and started using the ignition key after the engine has warmed up, fuel cut is prohibited, and once the vehicle is running, the fuel cut prohibition is canceled, resulting in the following effects.

First of all, the gear and clutch are automatically activated without having to operate the main switch after starting the engine, unlike conventional methods.

When the throttle conditions are met, a fuel cut is made, which eliminates wasted fuel supply to the engine while the vehicle is running.

Furthermore, even if the fuel cut conditions are met, if you want to start the vehicle using the ignition key, you can start the vehicle at any time without the fuel being cut off.

Furthermore, even if the vehicle is warmed up while the vehicle is stopped, the engine will automatically stop when warm-up is complete, resulting in fuel savings.

Note that when the engine is started with the ignition key after it has been warmed up, fuel cut is prohibited until the vehicle is running, so it is not recommended to continue running the engine for the purpose of heating the interior of the vehicle, such as in winter. You can also do it.

Furthermore, by setting the conditions for canceling the fuel cut and hyphenyl cut by the engine stop/start means and for starter operation as in the above-mentioned embodiment, it is possible to improve the efficiency without compromising safety and operability. You can measure fuel consumption savings.

Although the above-mentioned embodiment shows an example in which the present invention is implemented using a wired logic circuit, it can also be implemented using a microcomputer as in the conventional example shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional fuel control device for a vehicle engine, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. Sl...Throttle close signal S2...Clutch engagement signal S3...Neutral signal S4...4,5 stray signal S5...Clutch disengagement signal S6...Ignition e-on signal S7...Key start Signal S8...Cooling water temperature signal S22...Fuel cut signal S23...Starter drive signal G1-G5. GIO, Gll...-77toket06~G9...ORAgame) h-I6...Inverter 20.30.31...Comparator 21...Continuation judgment circuit 22-26...One shot multi vibrator 27
~29...Set/reset type flip-flop circuit

Claims (1)

[Scope of Claims] 1. An engine stop/start means for cutting fuel and restarting the engine under conditions determined by a combination of a throttle signal, a clutch signal, and a transmission gear position signal, and for warming up the engine based on an engine cooling water temperature signal. A warm-up state detection means detects whether the engine is warmed up, and the warm-up state detection means prohibits fuel cut when the warm-up state of the engine is not detected, and cuts off the fuel when the warm-up state of the engine is detected. Key star 1-fg occurs when the ignition key is turned to the start position only when the fuel cut prohibition/release means for canceling the cut prohibition and the warm-up state detection means detect the warm-up state of the engine. Fuel control for a vehicle engine characterized by comprising: a fuel cut prohibition means for prohibiting a fuel cut; and an inhibition canceling means for canceling the fuel cut prohibition when a clutch is connected and a transmission gear is in a position other than neutral. Device. 2. The engine stop/start means maintains a state in which both the throttle close signal and the clutch engagement signal, and either the 4th or 5th gear signal or the neutral signal of the transmission transmission gear are input for a predetermined period of time. A means for cutting the fuel when connected, and a throttle open signal or clutch disengage signal. Transmission gear reverse signal, speed signal, 2
A means for canceling the fuel cut when either one of the speed signal or the third speed signal is input, and the means for canceling the fuel cut when the engine is stopped, the clutch disengage signal, the transmission gear reverse signal, the first speed signal, the second speed signal, or the third speed signal. 2. The fuel control system for a vehicle engine according to claim 1, further comprising means for operating a starter to start the engine when any one of the signals is input.