JPH036840Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic engine stop/start device applied to a vehicle with an automatic transmission.

An automatic engine stop/start device automatically stops the engine under predetermined stopping conditions when the vehicle is stopped at an intersection etc. while driving in the city, and then restarts the engine under predetermined starting conditions. This saves energy and improves exhaust emissions.

Conventional engine automatic stop/start devices applied to vehicles with automatic transmissions, for example, Japanese Patent Application Laid-open No. 50-148731
In the device described in the publication, no matter what range the shift lever is in, pressing the accelerator pedal will restart the engine. The gear position in the automatic transmission at the time of restart is selected to be first gear. Therefore, when the shift lever is in the D range, no problem will occur if the accelerator pedal is slightly depressed to restart the vehicle, but if the amount of pedal depression is large, there is a risk that the vehicle will suddenly start at the same time as the restart. Therefore,
As described in Japanese Patent Application Laid-open No. 52-8241,
It is possible to include the activation of the parking brake or foot brake as a condition for automatically stopping or restarting the engine, but (1) the engine will not automatically stop unless the parking brake is activated after the vehicle has stopped; (2) The engine will not automatically stop if the foot brake is not depressed even after the vehicle has stopped; (3) The engine will not stop automatically if the foot brake is not depressed or the parking brake is not activated when restarting the vehicle. There are problems such as the engine not restarting, etc., and the automatic engine stop/start device cannot be used effectively, and there is a risk that improvements in fuel efficiency and exhaust emissions based on such a device may not be substantially achieved.

The purpose of the present invention is to provide an automatic engine stop/start device that can prevent sudden starts when restarting a vehicle equipped with an automatic transmission, without requiring brake operation to be a condition for automatically stopping or starting the engine. It is to be.

The present invention is an automatic engine start/stop device used in a vehicle that has a braking device that brakes the vehicle and an automatic transmission. It includes an idle switch that sometimes outputs an idle signal, a group of sensors that detect the status of the engine and various parts of the vehicle, and outputs an engine stop signal when it is determined that engine stop conditions are satisfied based on the detection signals from the sensor group. stop signal generating means to generate a stop signal, and an idle signal is not generated;
and restart signal generating means for outputting an engine restart signal when it is determined that an engine restart condition is satisfied based on the detection signals from the sensor group;
An engine stop means that stops the engine in response to an engine stop signal, an engine restart means that restarts the engine in response to an engine restart signal, and when it is determined that the vehicle speed is zero based on the vehicle speed signal. vehicle speed determination means that outputs a vehicle speed zero signal when the vehicle speed is zero; engine restart confirmation means that outputs an engine restart confirmation signal after the engine restart; and engine restart confirmation means that outputs a control hold signal when the vehicle speed zero signal is output, A brake hold release signal generating means that outputs a brake release signal when a start confirmation signal is output and the engine speed after restarting the engine exceeds a predetermined value, and actuates a braking device in response to the brake hold signal. The present invention is characterized by comprising a brake holding means for holding the brake device in the activated state and releasing the operation of the activated brake device in response to a brake release signal.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. An engine 1 is provided with an injector 3, a starter 5, and an igniter 7, and an automatic transmission 9 is connected to the output shaft of the engine 1.

An intake manifold 11 and an exhaust manifold 13 are connected to each cylinder of the engine 1, and the intake manifold 11 is provided with a throttle valve 15 that is interlocked with an accelerator pedal. Further, 17 is a parking brake, and 19 is a display panel for the driver's seat.

The throttle valve 15 is provided with a throttle position sensor 15a that detects its opening degree, and an idle switch 15b that detects its fully closed state. The automatic transmission 9 is provided with a range switch group 21 that outputs a neutral range signal, a drive range signal, etc. according to each range, and also outputs a vehicle speed signal according to the rotation speed of the automatic transmission output shaft. A vehicle speed sensor 23 is provided.

A brake switch 24 that outputs a brake pedal signal when the brake pedal (not shown) is depressed is provided near the brake pedal, and a brake holding device 26 is provided near the brake pedal (not shown).
It is designed to work together with. This brake holding device 26 is configured to hold an input rod (not shown) of a master cylinder cylinder (not shown) controlled by a brake pedal in a predetermined position by energizing an electromagnet of the holding device 26, for example. If the electromagnet is excited while the brake pedal is being depressed, the braking device can be held even when the brake pedal is released. Furthermore, it goes without saying that other known techniques may be used; for example, the techniques described in Japanese Patent Publication No. 44-22247, Japanese Patent Application Laid-Open No. 48-45332, and Japanese Patent Application Laid-Open No. 51-43526 may be used. can.

The parking brake 17 is provided with a parking brake switch 25 that outputs a parking brake signal when activated, and a stop lamp 27 is provided on the display panel 19 to indicate that the engine is stopped.
is provided.

The injector 3 is connected to a control circuit 37 through a fuel relay 31, the starter 5 through a starter relay 33, and the igniter 7 through an ignition relay 35. Also, solenoid 10
a, 10b and the stop lamp 27 are the control circuit 37
It is connected to the.

The control circuit 37 includes the ignition primary coil 7a of the igniter 7, the throttle position sensor 15a, the idle switch 15b, the range switch group 21, the brake switch 24, the parking brake switch 25, the door switch 39a, and the light switch 39.
b, air conditioner switch 39c, hydraulic switch 39
d, turn switch 39e, ignition 39
f, a water temperature sensor 39g, an intake air temperature sensor 39h, and an intake air amount sensor 39i are connected, and a brake holding device 26 is also connected.

FIG. 2 shows a detailed configuration example of the control circuit 37 shown in FIG. 1. The control circuit 37 includes a central processing unit (CPU) 37a that controls various devices, a read-only memory (ROM) 37b in which various numerical values and programs are written in advance, and numerical values and flags of calculation processes are written in predetermined areas. Random access memory (RAM) 37c, A/D converter (ADC) 37d that converts analog input signals into digital signals, and input/output interface (I/O) 37e that receives various digital signals and outputs various digital signals. , and path lines 37f to which these devices are respectively connected. The program described below is in ROM37b.
is written in advance.

The I/O 37e receives an idle signal from the idle switch 15b, an engine speed signal from the ignition primary coil 7a, various range signals from the range switch group 21, and a parking brake switch 2.
Parking brake signal from 5, vehicle speed sensor 2
3, a door signal from the door switch 39a, a light signal from the light switch 39b, an air conditioner signal from the air conditioner switch 39c, an oil pressure signal from the oil pressure switch 39d, a turn signal from the turn switch 39e, a turn signal from the ignition switch 39f. The ignition signal is input to the ADC 37d, and the ADC 37d receives a water temperature signal from the water temperature sensor 39g, an intake air temperature signal from the intake air temperature sensor 39h, an intake air amount signal from the intake air amount sensor 39i, and a position signal from the throttle position sensor 15a. is input. Then, the CPU 37a executes various calculations based on these various signals, and the I/O 37a
An ignition cut and ignition signal, a fuel cut and fuel injection signal, a starter drive signal, a stop lamp on and off signal, a brake hold signal and a brake release signal are output from e.

Next, the operation of the automatic engine stop/start device configured as described above will be explained. FIG. 3 shows the main routine executed by the control circuit 37,
In step S1, the basic injection time is determined based on the intake air amount signal and the engine speed signal, and the basic injection time is corrected based on the water temperature signal, intake air temperature signal, throttle position signal, ignition signal, etc. Next, in step S2, an automatic engine stop/start process is executed.

FIG. 4 shows one procedure of the engine automatic stop/start process. When the program shown in FIG. 4 is started, in step S21 it is determined based on the vehicle speed signal whether the vehicle speed is zero, or more precisely, whether the vehicle speed is below a predetermined value.In step S22, it is determined whether the vehicle speed is below a predetermined value. Based on the idle signal, it is determined whether the throttle valve 15 is fully closed, and in step S23, it is determined whether a certain set time, for example 1.5 seconds, has elapsed since the vehicle speed became zero. In step S24, it is determined whether the brake pedal is being depressed based on the presence or absence of a brake pedal signal. Here, the judgment in step S23 is made because if the brake pedal is continued to be depressed even after the vehicle has stopped,
This is because it is determined that the driver intends to stop the vehicle.

Furthermore, in step S25, other stop conditions for automatically stopping the engine are determined, such as no turn signal being issued, headlights not being lit, air conditioner not operating, and water temperature being at a predetermined level. The above is determined based on the turn signal, light signal, air conditioner signal, water temperature signal, etc.

If all of these steps S21 to S25 are answered in the affirmative, it means that the engine automatic stop condition is satisfied, but in order to maintain the operating state of the braking device, in step S26, the I/O 37
A brake holding signal is output from e to the brake holding device 26. Next, the process advances to step S27.

In step S27, an engine stop signal is generated from the I/O 37e. A fuel cut signal and an ignition cut signal are outputted to the fuel relay 31 and the ignition relay 35, respectively, thereby deactivating the igniter 7 to prevent high voltage from being supplied to the spark plug, and deactivating the injector 3. The engine 1 is stopped by not injecting fuel. Further, in step S27, the I/O 37e
A lighting signal is output from the stop lamp 27 to the stop lamp 27, and the stop lamp 27 is turned on.

In step S28, it is determined that the throttle valve 15 is not fully closed due to the presence or absence of an idle signal;
In other words, it is determined whether the accelerator pedal is depressed by a predetermined amount, and in step S29,
Other restart conditions for automatically restarting the engine, such as that the engine is not rotating, are determined. If these steps S28 and S29 are affirmatively determined, it means that the engine restart condition is satisfied, so in step S30, the I/O
37e outputs a starter drive signal, a fuel injection signal, and an ignition signal, which constitute an engine restart signal, to the starter relay 33, fuel relay 31, and ignition relay 35, respectively.
At the same time, the igniter 7 and the injector 3 are energized, a high voltage is supplied to the spark plug at a predetermined timing, and fuel is injected from the injector 3, thereby restarting the engine 1.
In this step S30, the display panel 19
The stop lamp 27 is turned off.

In step S31, it is determined whether the engine has started restarting based on the engine rotational speed signal, which is an engine restart confirmation means, that is, whether the engine rotational speed has reached a predetermined value or higher (for example, 450 rpm). , if an affirmative determination is made, step S32
Then, the brake hold signal from the I/O 37e is turned off and a brake release signal is output to the brake hold device 26. This releases the braking state.

In this way, the procedure shown in Figure 4 automatically keeps the braking device in operation when all automatic engine stop conditions are satisfied and the brake pedal is depressed, and the engine is restarted. , the operating state of the braking device is released when the rotational speed exceeds a predetermined number.

In the above embodiment, the condition for restarting the engine includes the fact that the accelerator pedal is depressed, but instead of this, the condition for restarting the engine is that the starter switch dedicated to this device is turned on, or that the shift lever is turned to N.
Moving from the range to the D range may be used as a condition for restarting the engine.

As explained above, according to the present invention, the operating state of the braking device is maintained when the engine is automatically stopped, and the braking device is activated when the engine speed exceeds a predetermined value after restarting the engine. Since the condition is released, the braking is not immediately released even when the vehicle is restarted, and even if the shift lever is in the D range, the vehicle can be prevented from suddenly starting at the same time as the restart.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention;
FIG. 3 is a detailed diagram of the control circuit, FIG. 3 is a flowchart showing an example of a main routine for controlling the engine shown in FIG. 1, and FIG. 4 is a flowchart showing an embodiment of engine automatic stop/start processing. 1...Engine, 3...Injector, 5...
Starter, 7...Igniter, 15...Throttle valve, 15a...Throttle position sensor, 1
5b... Idle switch, 21... Range switch group, 23... Vehicle speed sensor, 24... Brake switch, 26... Brake holding device, 31... Fuel relay, 33... Starter relay, 35... Ignition relay, 37...Control circuit.

Claims (1)

[Scope of utility model registration request] In an automatic engine start/stop device used in a vehicle that has a braking device and an automatic transmission, an idle signal is generated when a vehicle speed sensor outputs a vehicle speed signal according to the vehicle speed and a throttle valve is almost fully closed. a sensor group that detects the state of the engine and each part of the vehicle, including an idle switch that outputs a generating means; and restart signal generating means for outputting an engine restart signal when the idle signal is not generated and it is determined that an engine restart condition is satisfied based on the detection signals from the sensor group. and an engine stop means for stopping the engine in response to the engine stop signal, an engine restart means for restarting the engine in response to the engine restart signal, and a vehicle speed is zero based on the vehicle speed signal. vehicle speed determination means that outputs a vehicle speed zero signal when it is determined that the vehicle speed is zero; engine restart confirmation means that outputs an engine restart confirmation signal after the engine is restarted; and a brake hold signal when the vehicle speed zero signal is output. a brake hold release signal generating means that outputs a brake release signal when the engine restart confirmation signal is output and the engine rotational speed after the engine restart reaches a predetermined value or more; An automatic engine stop/start device comprising: a brake holding means that responds to hold the brake device in an activated state, and responds to the brake release signal to release the activated brake device. .