JPS5823251A - Automatic stop/restart device of engine - Google Patents

Abstract

PURPOSE:To ensure the safety during driving of a car by intercepting a control operation attributed to an automatic stop/restart function during an appropriate period if a sensor detects unreasonable variation in car speed during the drive. CONSTITUTION:An automatic engine stop/restart function ERS of a control circuit 1 is executed in such a manner that if a car is stopped due to some reasons, a traffic signal, for example, the engine is automatically stopped under a certain condition and then restarted by the normal starting operation. If a car speed V is temporarily changed to an unreasonable speed on account of a defect of a car speed sensor 12 during constant speed driving with the ERS operative, an ERS control command is outputted into I/O while an engine stop signal 44 and a starting signal 46 are not generated during an interval from a point after a lapse of a certain period from the variation to a point at which the car speed is returned to a damanded value. Since the malfunction of ERS attributed to the defective car speed sensor is prevented during driving of the vehicle, the safety may be ensured.

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 car or waiting at a traffic light, and are forced to stop for a long time, we shut off the engine and (1)
^ [Perform the operation to restart the engine when the traffic jam is cleared.

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

On the other hand, if you stop at a traffic light at an intersection in the city, 1
If the engine is stopped, 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 in city driving accounts for a small proportion of the total driving time. We cannot ignore the amount of exhaust gas emitted and the amount of fuel consumed during vehicle operation.

Therefore, recently, automatic engine stop/start has been developed that automatically stops the engine under certain conditions, such as when the car stops at an intersection etc. while driving in the city, and automatically starts the engine when the normal start operation (depressing the clutch pedal) is performed. A device has now been developed.

In a conventional engine automatic stop/start device, after setting the engine automatic stop/start function, the engine is automatically stopped or started when a predetermined condition is met.

(2) Therefore, if there is a change in vehicle speed that cannot actually occur due to a malfunction of the vehicle speed sensor while the vehicle is running (for example, a sudden change from 50 KffI/h to 0 KffI/h). ), the engine will be automatically stopped if other stop conditions are also met. When the engine is stopped, there is no negative pressure source for the brake booster, so if the negative pressure stored in the booster is used up, the brakes may become less effective.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic engine stop/start device that ensures safety when a vehicle is running.

A feature of the present invention is an engine automatic system 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 stop/start device, after setting the function to automatically stop or start the engine, if the sensor detects a change in vehicle speed that cannot actually occur while the vehicle is running, during the period in which the change in vehicle speed occurs,
(3) It is configured to prohibit control operations based on the above functions.

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 which 1 is a control circuit, a central processing unit (OPU), and a random access memory (RAM).

It consists of a microcomputer consisting of read-only memory (aOM), input/output interface (Ilo), etc. Detection outputs from various sensors are input to the control circuit 1.

10 is a main switch for setting or canceling a function to automatically stop or start the engine (hereinafter referred to as ER8); after starting the engine by normal operation,
When the main switch 10 is pressed, ER8 is set.

Further, after setting ER8, if the main switch 10 is pressed again, ER8 is canceled. The setting of ER8 is automatically canceled under other predetermined conditions, which will be described later.

Furthermore, 12 is a vehicle speed sensor, and this vehicle speed sensor 12 detects whether the vehicle is in a running state or a stopped state (4), and the detection output of this sensor 12 is used to automatically stop the engine. Used for judgment. Reference numeral 14 denotes an ignition circuit, and the ignition pulse signal outputted from the ignition circuit 14 is processed by the control circuit 1 as an engine revolution number 1.

This engine rotation speed signal is used to determine the conditions of gR8 setting, automatic engine stop, automatic start, and ER8 setting cancellation, as will be described later. 16 is a clutch pedal, 18A and 18B are A clutch upper switch that operates on and off in conjunction with the clutch pedal 16.

It is the clutch lower switch. Each of these switches detects the amount of depression of the clutch pedal 16, and the clutch upper switch 18 turns on when the clutch pedal 16 is depressed by a certain percentage of the full stroke (for example, 30% or more), and the control is activated. A signal is sent to circuit 1, and control circuit 1 controls f to prevent the engine from stopping.
Roar.

Also, the clutch lower switch 18B is the clutch pedal 16
When the switch is fully depressed, it is turned on and a signal (a signal that permits automatic engine start) is sent to the control circuit 1.

The engine 20 also includes a water temperature sensor 22 that detects the engine cooling water temperature. An oil pressure switch 24 is provided to detect the entire oil pressure of the engine oil, and these detection outputs are input to the control circuit 1. This switch is used to charge the battery with the output of the 26-volt alternator, and the switch 26 is turned on when the alternator is generating electricity.

28 is a voltage input, and 30 is a magnetic switch for controlling the operation of the near conditioner, which is turned on when the near 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 windshield.These switches 30, 3
2.34 is for detecting whether or not the electrical load is high. Further, 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 FOBS. It is used as a judgment 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 the gas is switched to the main switch 10.
The automatically stopped and started of the engine 20 is performed as follows. That is, when the condition for stopping the engine 20 is satisfied, an engine stop signal (low level) 44 is output from the control circuit 1 to the fuel cut relay 40, and as a result, the fuel cut relay 40 disables the fuel in the fuel supply system in the engine 20. A fuel cut signal 50 is applied to a cut-tonlenoid (not shown), and an ignition cut signal 6 is applied to the ignition circuit 14.
0 is output and the engine stops. However, in order to achieve the automatic engine stop function, the configuration may be such that only the ignition cut is performed without the fuel cut (7), but in this case, when the engine is running
This has the disadvantage that the driving feeling deteriorates.

On the other hand, when BR8 is in the set state and the clutch pedal 16 is fully depressed while the engine is stopped, the clutch lower switch 18B 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 relay 41, and as a result, a restart signal 70 is output from the starter relay 41 to the starter 42, and the engine 20 is started.

Next, ER8 of the engine automatic stop/start device shown in Figure 1.
Each operation mode of setting, engine stop after ER8 setting, and engine start will be explained based on FIGS. 2 to 4. FIG. 2 shows an operation mode for setting ER8, and as shown in the figure, setting of ER8 becomes possible when the following five conditions A and N'D are satisfied.

(1) E If the R8 setting is canceled (8) (2) 1? , It 8 The main switch of the setting is in the ON state.

(3) The engine is rotating (for example, the engine speed is 40
(4) The alternator is generating power.

(5) The driver's seat IIIP is in the closed state (detected by the door switch).

Here, the cancellation of the ER and S settings in (1) may be performed manually or automatically by suppressing the main switch, but this will be explained later when the ITC engine is running. The presence or absence of the engine is determined based on the engine rotation speed (d) (3) 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 ER8. As shown in the figure, the engine is automatically stopped when the AND of the following conditions (1) to OJ is established. 7. (1) E-S is set.

(2) When the engine speed is set to a predetermined speed (for example, 850r)
pm) or less.

(3) 18 clutch upper and lower switches.

18B are both in the OFF 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 signal ξ switch 34 is in the OFF state.

(The power water lagoon sensor 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) After the engine is started by E TLS, a predetermined period of time (
For example, 4 seconds) have elapsed.

θ0) The vehicle is in a stopped state.

(11) The slope sensor 50 is in the OFF state.

02 idle switch 52 is in the OFF state.

03) The defogger switch 54 is in the OFF state.

As mentioned above, among the above conditions (2), the condition that the engine speed be 85 Orpm or less is to take into consideration the engine stoppage due to engine stalling, and (
4) was selected as the judgment condition because when a vehicle turns right, the driver needs to focus on checking whether there is an oncoming vehicle, and it is not desirable to stop the engine in such a situation. . Furthermore, conditions (5), (6), (8
) and Q~ are used to determine whether or not to stop the engine in order to avoid over-discharge of the engine due to stopping the engine in a state where the electrical load is high.

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.

This is because condition (9) is such that the engine is automatically stopped only after the engine is started by E-S.

In addition, the condition (In "the vehicle is in a stopped state") is a car (
11) Determination is made based on the presence or absence of a level change in the detection output (pulse train signal) of the speed sensor 12. Condition (3) was established because the clutch pedal cannot be depressed except when starting the engine or changing gears, and this device is configured to start the engine by depressing the clutch pedal. This is because it has been done.

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 P of automatic engine starting using E R,S. As shown in the figure, the engine is automatically started when the following conditions (1) to (4) are ANDed.

(1) E R8 must be set.

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

(3) The alternator is in a state where power generation is stopped.

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

(12) Among the above conditions, (2) and (3) are for determining whether the engine is in a stopped state, but it is not possible to use both the engine rotation speed signal and the alternator power generation state signal for this determination. This is to ensure that the determination can be made reliably even when one of the two signals is not input to the control circuit 1.

On the other hand, to cancel the B-S setting after setting it, proceed as follows.

A) In the case of manual release: If the main switch 10 is pressed once and then pressed again, the setting of ER8 will be released.

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 patch IJ% pressure decreases (4) ) When restarting, the engine speed is at a certain speed (for example, 550 rpm)
If it takes more than a certain time (for example, FF, 2 seconds) to reach the above value, the ER8 setting is automatically canceled.

Among the above conditions, (1) is because the driver may forget that the engine was automatically stopped by ER8 and restart it by using the key switch out of habit, and IC1 (2) is due to the driver changing the engine. This should be taken into consideration to avoid confusion for people who are unfamiliar with ER8. In addition, in (3) and (4), restarting the engine will be difficult if the ER8 is operated with the battery capacity low, so the ER8 will be used to start the engine only that time, and the E-S setting will be canceled at the same time as the engine starts. That's what I do.

Next, an embodiment of the present invention will be described based on FIGS. 5 to 7. FIG. 5 shows the turns of the vehicle. In the figure, the vehicle is in an accelerating state in section AB, and in a constant speed state in section BE. For example, FIG. 6 shows how the vehicle speed pulse signal changes when the vehicle speed ■ temporarily changes to a speed that cannot actually occur due to a failure of the vehicle speed sensor 12 in the section OD where the vehicle is traveling at a constant speed. Shown in (A). In the figure, the vehicle speed is Vl (>VREF
), and thereafter vehicle speed pulse No. 218 is not detected until time T2, and at time T, the vehicle speed is higher than the set vehicle speed vR□■
Suppose that it returns to 1. However, the time Δt (=T2-TI) during which the vehicle speed pulse is not detected is longer than the time Δ1 (, which is preset in the control circuit 1).

During this time, the CPU in the control circuit 1 sends a "Ti; R, 8 control prohibited" command to Ilo during the period of T2≦t≦T3.
Engine stop signal 44. Engine start signal 46 is not output.

Next, FIG. 7 shows the processing contents of the control circuit 1 when the above-mentioned gradual change in vehicle speed is abnormal.

In the figure, when a task is activated in step 100,
If the certain conditions already mentioned in step 102 are met, E
Settings for R8 are performed. Further, the next step 104
It is determined whether the conditions for starting the engine by the engine S are satisfied or not, and if it is determined in step 104 that the conditions for starting the engine are not satisfied, the same determination is repeated.

On the other hand, if it is determined in step 104 that the engine starting condition has been met (15), the engine is started in the next step 106, and the vehicle enters a running state. Furthermore, in the next step 108, the vehicle speed ■ is set to the set vehicle speed VREF (for example, VRg
It is determined whether or not p=32.8Kn+/h) or more, and if it is determined in step 108 that the vehicle speed ■ is less than or equal to the set vehicle speed VREF, the same determination is repeated. On the other hand, if it is determined in step 108 that the vehicle speed ■ is equal to or higher than the set vehicle speed VREF, it is determined in step 110 whether the vehicle speed ■ has suddenly changed, that is, whether there has been a change in vehicle speed that is actually impossible. is determined. Here, as shown in FIG. 6, after the vehicle speed ■ becomes equal to or higher than VREF, the next time the vehicle speed ■ becomes Vjt
The time it takes to return to vehicle speed above Ev is the set time △
If Δt≧Δt6 with respect to to, there has been a change in vehicle speed that is actually impossible.

If Δt is less than Δto, it is determined that there has been no such change in vehicle speed.

Now, if it is determined in step 110 that 1N o '', the process jumps to step 118, and the execution of task (16) ends.

On the other hand, if it is determined as "Y(!8") in step 110, the process moves to step 112, and in step 112, the control operation by E11.S is prohibited.In other words, the CPU in the control circuit 1, 9ER8 A control prohibition command is issued.Then, in the next step 114, the vehicle speed is set to VREF.
In other words, after the vehicle speed pulse signal is no longer detected, the vehicle speed corresponding to the vehicle speed equal to or higher than VREF) ξ
It is determined whether a pulse signal is detected.

If it is determined in step 114 that the vehicle speed ■ is less than or equal to VRE'F, the same determination is repeated. On the other hand, step 1
If it is determined in step 14 that the vehicle speed (2) is greater than or equal to Vytr,p, the process moves to the next step 116, and the prohibition of the control operation by the E-controller 8 is canceled. That is, the sending of the ER8 control prohibition command from the CPU to Ilo is stopped, and the execution of the task ends at step 118.

As explained above, in the present invention, after setting El'L8, if an improbable change in vehicle speed is detected while the vehicle is running, the control operation based on ER8 is performed during the period when the change in vehicle speed occurs. Since the vehicle is configured to be prohibited and controlled by normal operations, the present invention can ensure safety when the vehicle is running.

[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 shows the operating mode when the engine is automatically started. 5 is a diagram showing the vehicle running pattern, FIG. 6 is a timing chart showing the relationship between the vehicle speed pulse signal and the EBS control prohibition command, and FIG. 7 is a diagram showing the control circuit 1 when the vehicle speed change is abnormal. It is a flowchart which shows the processing content. 1... Control circuit, 10... Main switch, 12.
...Vehicle speed sensor, 14...Ignition circuit, 18A, 18B
...Clutch switch, 28...Nonotsuteri voltage sensor, 40...Fuel cut relay, 41...Starter relay, 42...Starter. Agent Tatsuyuki Unuma (and 2 others) (19) Figure 1 n Figure 4 Figure 5] 6th Leh TI T2
T3 Hao. Figure 7 311-

Claims (1)

[Claims] (1) An automatic engine stop/start device 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. If, after setting the function to automatically stop or start the engine, a change in vehicle speed that cannot actually occur while the vehicle is running is detected by the sensor height, during the period in which the change in vehicle speed occurs,
An automatic engine stop/start device L characterized in that when a control operation based on the function is prohibited,