JPS5825550A - Automatic start and stop device for engine - Google Patents

Abstract

PURPOSE:To enhance restarting characteristic of an engine by performing shutoff of power to the fuel cut solenoid and ignition circuit at one time and by resuming power supply to the power supply circuit, after a certain while, prior to the power supply to the solenoid. CONSTITUTION:When the engine stop condition is met, control signals IGC, FLG are, in the case for example of awaiting signal, outputted for the output transistors Q1 and Q2 respectively, of a control circuit 1, to energized relay coils 40B, 45B, and contacts 40A, 45A are opened to shut off power supply to the fuel cut solenoid LFC and ignition circuit 14. On the other hand, the control signal IGG is restituted after a certain period of time and the power supply to the ignition circuit 14 is restrored, so that the ignition signal is taken in the control circuit 1 from the terminal T3. The control signal FLG is, by contrast, released at the point of time when the engine is restarted for the next cycle, and the fuel cut relay 40 is deenergized for resumption of fuel supply. Thereby the restarting characteristic can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic engine stop/start device for automatically stopping or restarting an engine.

Generally, when we are driving on a road and encounter road congestion due to an accident with another vehicle or waiting at a traffic light, and are forced to stop for a long time, we stop the engine and then restart it when the congestion clears. conduct.

This is to avoid wasteful fuel consumption due to long periods of idling.

On the other hand, if the engine is stopped when the vehicle is stopped at a traffic light at an intersection in the city, the engine must be restarted each time the vehicle starts, which is not only troublesome but also lacks the speed of starting.

However, the stop time during city driving accounts for a small proportion of the total driving time, and the amount of exhaust gas emitted and the amount of fuel consumed during idling cannot be ignored.

Therefore, when the car stops at an intersection etc. when driving in the city, the engine is automatically stopped under certain conditions such as 9 o'clock, and the engine is automatically started when the normal start operation (depressing the clutch pedal) is performed. A device has now been developed.

In the conventional device for this purpose, when the engine is automatically stopped, the power supply to the ignition circuit that sends the ignition signal to the engine is cut off, and when the engine is restarted, the power supply to the ignition circuit is restored.

On the other hand, multiple ignition signals output from the ignition circuit are also used as engine speed data. This engine rotation speed data serves as basic data for various engine controls, and in particular, serves as a basic judgment condition for control operations in automatic engine stop/start control. As mentioned above, in the conventional device, the power supply from the ignition circuit is restored when the engine is restarted, so when the engine is restarted, the acquisition of engine speed data is started, and various data including this engine speed data are collected. Starting control was performed when the engine starting conditions were satisfied.

For this reason, there was a drawback that restartability of the engine deteriorated.

An object of the present invention is to provide an automatic engine stop/start device that improves engine restartability.

A feature of the present invention is an automatic engine stop/start system that captures the detection outputs of various sensors or circuits that detect the operating status of each part of the vehicle, and automatically stops or starts the engine under predetermined conditions based on these detection outputs. In the device, a first switch means for controlling power supply to a fuel cut solenoid provided in the fuel supply system and for blocking fuel supply to the engine, and a power supply th+Im to an ignition circuit for outputting an ignition signal.
a second switch means for simultaneously cutting off the power supply to the fuel cut solenoid and the ignition circuit, and restoring the power supply to the ignition circuit with priority over the fuel cut solenoid after a predetermined period of time has elapsed from the time of the cutoff operation. The present invention is configured to include a control circuit that outputs control signals to the two switch means.

Embodiments of the present invention will be specifically described below based on the drawings. FIG. 1 shows the overall configuration of an automatic engine stop/start device according to the present invention. In the figure, 1 is a control circuit, and the control circuit 1 receives detection outputs from various sensors or circuit sections. is input. , 10 is a main switch for setting or canceling a function to automatically stop or start the engine (hereinafter referred to as BH3). When switch 10 is pressed, BH3 is set. Also, after setting gR8, if you press the main switch 10 again, I! R8 is released. The setting of 1iiR8 is automatically canceled under other predetermined conditions, which will be described later.

Further, 12 is a vehicle speed sensor, and the nuclear vehicle speed sensor 12 detects whether the vehicle is running or stopped, and the detection output of the sensor 12 is used to determine whether the engine should automatically stop. Will be killed. 14 is an ignition circuit, t1
The control circuit 1 processes the ignition pulse signal output from the ignition circuit 14 as an engine rotation speed signal. This engine rotational speed signal is used to determine conditions such as F8gB setting, automatic engine stop, automatic engine start, and l1R8 setting cancellation, as will be described later. 16 is the clutch pedal, 18
A and 18B are Claracia horns and switches that operate on and off in response to the clutch pedal 16, respectively.

It is the clutch lower switch. Each of these switches detects the amount by which the clutch pedal foot 6 is depressed, and the clutch seven-pass switch 18A is turned on when the clutch pedal 16 is depressed by a certain percentage of the full stroke (for example, 30 degrees or more). A signal is sent to the control circuit 1, and the fFtijlj circuit 1 controls the engine so as not to stop. Further, the clutch lower switch 18B is turned on when the clutch pedal 16 is fully depressed, and sends the signal (No. 16 permitting automatic engine start) to the control circuit 1.

Water temperature sensor 22 that detects the cooling water temperature of the Maku Engine 20KFi engine. An oil pressure switch 24 is provided to detect the oil pressure of the engine oil, and when the oil pressure switch 24 is turned off, these detection outputs are input to the control circuit 1. 26 is a changeover switch for displaying the power generation status of the alternator, and tA switch 2
6 is in an off state when the alternator is generating power. 2
8 is a voltage input; 30 is a magnetic switch that controls the operation of the near conditioner; it is turned on when the p1 air conditioner is operated.

Furthermore, 32 is a headlamp switch that switches the headlamp on and off, and 34 is a wiper switch that detects the operating state of the wiper.These switches 30, 32
．． Reference numeral 34 detects whether or not the electrical load is high. Also, 36 is a turn signal switch that detects the right turn state of the vehicle, and 38 is a door switch that detects the open/close state of the driver's side door. Of these detection outputs, the former is the engine automatic stop condition, and the latter is the BH3's automatic stop condition. Used as input for setting conditions and setting cancellation conditions.

Furthermore, 50 is a slope sensor that detects whether or not the gradient of the slope on which the vehicle is stopped is at least a predetermined value (for example, 2 degrees), and turns ON when the slope is at least the predetermined value; and 52 is a slope sensor that detects whether the engine is in an idle state. An idle switch 54 detects whether the defogger is being used (turned ON in the idle state), and a defogger switch 54 detects whether the defogger is being used.

Now, the predetermined conditions are met, and BH8 is set to main switch 10.
Automatic stopping and automatic starting of the engine 2o, which has been set as appropriate, is performed as follows. That is, when the condition for stopping the engine 20 is satisfied, the control circuit 1 switches the fuel cut relay 402.
Control signals 44 and 47 are output to the ignition cut relay 45, respectively, and as a result, the fuel cut relay 40 and the engine 2
A fuel cut signal 51 is sent to a fuel cut-off renoid (not shown) of the fuel supply system in the ignition cant relay 45.
An ignition cut signal 6o is output to the reverse ignition circuit 14, and the engine is stopped. However, in order to achieve the engine automatic stop function, it may be configured to only cut the ignition without cutting the fuel, but in this case, the engine runs on (run 0fl), which may affect the driving feeling. There are drawbacks that worsen.

On the other hand, when ER8 is in the setting state and the clutch pedal 16 is fully depressed while the engine is stopped, the clutch lower main f18B is turned on, and when other conditions are met (described later), the control circuit 1 An engine start signal 46 is output to the sister starter relay 41, and as a result, the starter 4
2 is energized and the engine 20 is started.

Next, lR8 of the engine automatic stop/start device shown in Figure 1.
For each operation mode of engine stop and engine start after setting, FtR8 setting, M
I will clarify. FIG. 2 shows the operation mode of ER&setting, and as shown in the figure, when the following five conditions are ANDed, BH8 can be set.

(1) E RS (D setting must be canceled.

(2) The main switch for B RS setting is in the on state.

(3) The engine is rotating (for example, the engine speed is 40
0±50 rpm or more).

(4) The alternator is generating power.

(5) The driver's side door is closed (door switch detected).

Here, (1) cancellation of the OER8i2 constant may be performed manually (by suppressing the main switch) or automatically; this will be described later.

Also, to detect whether the engine is rotating or not (3
) The determination is made based on the engine rotation speed (4) and the power generation state of the alternator (4). This is to accurately detect whether or not the engine is rotating.

Next, FIG. 3 shows the operation mode of automatic engine stop by BH3. As shown in the figure, the engine is automatically stopped when the AND of the following conditions (1) to α is satisfied.

(11E R8 must be set.

(2) When the engine speed is at a predetermined speed (e.g. 850r)
pm) or less.

(3) The clutch upper and lower switches 18A and 18B are both in the KOFF state, that is, the clutch pedal 16 is not depressed.

(4) The turn signal switch 36 is in the OFF state, that is, no right turn signal is output.

(5) The headlamp switch 32 is in the OFF state.

(6) The wiper switch 34 is in the OFF state.

(7) Water temperature? 22 is in the OFF state, that is, the engine cooling water temperature is within a specific temperature range (for example, 75°C to 105°C).

(8) The air conditioner magnet switch 30 is in the OFF state.

(9) ] A predetermined period of time (for example, 4 seconds) has elapsed since the engine was started by 3R8.

The vehicle must be stopped.

The aυ slope sensor 50 is in the OFF state.

0 idle switch 52 is in the OFF state.

0 The defogger switch 54 is in the OFF state.

As mentioned above, (2) of the above conditions requires that the engine speed be 85 Orpm or less, and condition (9) takes into consideration that the engine will not automatically stop during racing. The reason for using 4) as the judgment condition is that when the vehicle turns right, the driver must be careful to check for oncoming vehicles, and it is not desirable to stop the engine in such a situation. Furthermore, condition (5), (
6), (8), a:1 is used to determine whether to stop the engine in order to avoid over-discharging of the battery by stopping the engine under a high electrical load.

Condition (7) is such that the engine is difficult to start when the engine cooling water temperature is low or high, so the engine is not stopped in these temperature ranges.

Regarding condition (9), this is because the engine is automatically stopped only after the engine is started by El(8).

Furthermore, the condition Qt1 that "the vehicle is in a stopped state" is determined based on the presence or absence of a change in the level of the detection output (pulse train signal) of the vehicle speed sensor 12. Condition (3) was established because the clutch pedal cannot be depressed except when starting the engine or changing gears, and in this device, the engine is started by depressing the two-legged pedal. This is because it is configured.

As explained above, the engine rotational speed signal and the clutch signal interlocked with the clutch pedal are used as criteria for automatically stopping the engine.

Next, FIG. 4 shows the operating mode of automatic engine start by gR8. As shown in the figure, the engine is automatically started when the following conditions tl) to (4) are ANDed.

(1) B R8 must be set.

(2) The engine rotation speed is the set rotation speed (for example, 50 rp
ln) or less.

(3) Jin whose alternator has stopped generating power.

(4) The clutch lower switch is in the ON state, that is, the clutch pedal is fully depressed.

Among the above conditions, <2) and <3) are used to determine whether the engine is in a stopped state, but the reason why both the engine rotation speed signal and the alternator power generation state signal are used for this determination is because both of them are used. This is to enable reliable determination even when one of the signals is not input to the control circuit 1.

On the other hand, to cancel this after setting lR8, proceed as follows.

A) When manually canceling the setting, press the main switch 10' once and then again to cancel the setting of gR8.

B) When it is automatically released (1) When the ignition switch is manually operated and the engine is restarted (2) When the driver's side door is opened (3) When the power supply voltage drops (4) When restarting, the engine speed remains above a certain number of revolutions (for example, 550 rpm) for a certain period of time (for example, 2
If it takes more than 1 second), the ER8 setting will be automatically canceled.

Among the above conditions, (1) is because the driver may forget that the engine was automatically stopped by ER8 and restart it with the key switch out of habit, and (2) is due to the driver taking a turn. This is to avoid confusion among people who are unfamiliar with BR8. In addition, (31, (41)) If the ER8 is operated with the battery capacity reduced, it will be difficult to restart it, so the ER8 will be started only that time, and the E-S setting will be set at the same time as the start. I'm trying to cancel it.

Next, FIG. 5 shows part 1 of the automatic engine stop/start device according to the present invention. Figure 6 shows the structure of the capital and its operation details.

゛ In the #I5 diagram, the anode of node #1 is the ignition switch 81. Contact 40 of fuel cut relay 4o
The fuel cut-off solenoid LrC (iD) is connected to one end of the fuel solenoid LrC (iD) through the solenoid, and the other end of the nuclear solenoid LFC is grounded.

Further, the connection point between the ignition switch 81 and the contact 40A is connected to the ignition circuit 14 via the contact 45 of the ignition cut relay 45. Note that the relays 40 and 45 are both normally closed type relays.

Further, the connection point is a fuel cut relay 40. Each relay coil 40B of the ignition cut relay 45.

45B to the output terminal T1 r T l of the control circuit.
It is connected to the.

On the other hand, output transistors Qs and Qs are connected to the output terminal "l" pTl of the control circuit 1.
The base of 1 is a control signal P for making a fuel cut.
LO is also a transistor. The snow pace is configured to receive a control signal IGO for cutting the ignition.

In the above configuration, when the ignition switch S1 is closed when starting the engine and power is supplied to each part, the starter is driven and the engine is started. Thereafter, when the engine stop condition described above is satisfied, control signals IGO and P are applied to the output transistors Q1 and Q3 in the control circuit 1, respectively.
LO (Fig. 6 (A) ? (0)) is output at time t1, and as a result, relay coils 40B and 45B are energized, so contacts 40 and 45 are in the open state. Fuel cant solenoid LFC, The power supply to the ignition circuit 14 is cut off, (
(B), (D)) The engine stops.

The reason why the ignition cut and the fuel cut are performed simultaneously when the engine is stopped is to prevent so-called run-off (ruff Qfi) and to smoothly stop the engine.

On the other hand, the control signal IGO for cutting the ignition is output from the time when the power supply to the fuel cut solenoid LFC and the ignition circuit 14 is simultaneously cut off (time t1) until the time when the predetermined time T has elapsed (time ts), and from time t3 to the time when the ignition circuit 14 is cut off. 14 is restored, the ignition signal (engine speed signal) is input into the control circuit 1 via the long terminal T3.

On the other hand, the control signal PLO that performs fuel cut is generated at the next engine restart time, that is, at the time when the starter is driven (time t3).
), and the fuel cut solenoid L is output at time tl.
Since the power supply to the relay coil 40B of the fuel cut relay 40 that controls the power supply of the FC is cut off, the contact 40A is closed and the fuel supply to the engine is started5. Although the power supply to the fuel cut solenoid is restored at time t3), it may be configured to be restored at an earlier time (however, after time t2).

Further, in this embodiment, the ignition is cut by cutting off the ignition power supply, but the ignition may be cut by other methods such as cutting off the signal that controls the ignition timing.

As explained above, in the present invention, the ignition cut and the fuel cut are performed at the same time, and the ignition signal (engine speed signal) is input to the control circuit after a predetermined period of time has elapsed from that point. It is possible to realize an automatic engine stop/start device that improves startability. Furthermore, since the engine rotational speed signal is input before restarting the engine, controllability in other engine controls can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an automatic engine stop/start device according to the present invention, and FIGS. 2 to 4 show a control circuit 1.
Fig. 2 shows the operating mode when ER8 is set, Fig. 3 shows the operating mode when the engine is automatically stopped, and Fig. 4 is an explanatory diagram showing the operating mode when the engine is automatically started. FIG. 5 is a block diagram showing the configuration of the main parts of the automatic engine stop/start device according to the present invention, and FIG. 6 is a time chart showing its operation details. 1... control circuit, 10...: main switch, 14・
...Ignition circuit, 18A, 18B...Clutch switch, 40...Fuel cut relay, 41...Starter relay, 42...Starter, 45...Ignition cut relay.

Claims (1)

[Claims] (1) Automatic engine stop/start that takes in the detection outputs of various sensors or circuits that detect the operating status of each part of the vehicle, and automatically stops or starts the engine under predetermined conditions based on these detection outputs. In the device, a first switch means for controlling power supply to a fuel cut-off renoid provided in the fuel supply system and blocking fuel supply to the engine, and a first switch means for controlling power supply to an ignition circuit for outputting an ignition signal; a second switch means that simultaneously cuts off the power supply to the fuel cut solenoid and the ignition circuit, and restores the power supply to the ignition circuit with priority over the fuel cut solenoid after a predetermined period of time has elapsed from the time of the cutoff operation. and a control circuit that outputs a control signal to the two switch means.