JPS58162748A - Stopping and starting device for automotive engine - Google Patents

Abstract

PURPOSE:To contrive to prolong the service life of a battery while protecting it, by a method wherein a detecting means for the temperature of a battery is provided, and the engine can be stopped only when the temperature of the battery is within a predetermined range. CONSTITUTION:A controller 9 outputs a fuel cutoff signal 10 for stopping the engine or a starter-driving signal 11 for starting the engine. When it is detected that the temperature of the battery is within a set point range, and output of a battery temperature signal 8 is turned ON, whereby the fuel cutoff signal 10 is turned ON through a flip-flop 14. As a result, a fuel cutoff valve 16 is closed, and the engine is speedily stopped. Accordingly, it can be contrived to enhance the rate of fuel consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an engine stop/start device that is provided in an automobile engine to improve fuel efficiency and stops the engine when the vehicle is stopped.

In recent years, as part of measures to improve the fuel efficiency of automobile engines,
When the vehicle is stopped, the engine is automatically stopped to prevent fuel wastage by automatically stopping the engine when preset conditions are met in consideration of safety, etc., and when restarting, the engine is started and the vehicle is started simply by the normal starting operation. Some models are equipped with an engine stop/start device that allows the engine to stop and start.

Conventionally, as this type of engine stop/start device, for example,
There is something like the one shown in Automotive Engineering, (Edited by Railway Japan, Published by May 9, 1981, P72-P78), and after turning on the main switch of the device, it falls under the predetermined deactivation condition. If the activation device does not operate, the engine is activated, and if all of the engine stop conditions consisting of a plurality of items are satisfied when the vehicle is stopped using the activation device, the engine is then stopped.

In such conventional engine stop/start devices, each electrical component such as a headlight, wiper, or air conditioner is equipped with a detection switch that detects the usage status, and the signal from this detection switch is used to detect whether the load power of the electrical component is excessive or not. In some cases, by not stopping the engine and maintaining the alternator's power generation, and by stopping the operation of the starter, which consumes the largest amount of power when restarting, the battery capacity can rapidly decrease and this can be prevented. The aim was to suppress the accompanying decrease in battery life.

By the way, the discharge capacity of a battery changes depending on the temperature.
As shown in Figure 1, it has been experimentally confirmed that the lifespan is the longest when used at around 306C, and that the lifespan decreases at lower or higher temperatures.

However, in the conventional device, if the load power of the electrical components is steady, the engine is stopped even if the temperature condition of the battery is not good, increasing the power consumption of the battery, which shortens the life of the battery. Something happened.

The present invention has been made in order to solve the conventional problems by focusing on the relationship between battery temperature and battery life. To provide an engine stop/start device that protects a battery by reducing power consumption of the battery without stopping the engine when the battery temperature is low or high.

Hereinafter, the present invention will be explained based on an embodiment shown in FIG. 2 while referring to FIG. In order to simplify the explanation, each component will be explained only when it outputs an ON signal.
It is assumed that it is OFF at other times.

The engine and various parts of the vehicle body (not shown) are equipped with a system for determining when it is okay to stop the engine for reasons such as safety when stopped and when there is a problem with stopping the engine, and for restarting the engine after it has stopped. Various sensors are provided, and various signals, which will be described later, are output from these sensors.

The throttle close signal 1 is output from a sensor that detects the opening degree of the throttle valve in conjunction with accelerator operation, and turns ON when the throttle valve is fully closed (when the accelerator pedal is not depressed). The vehicle speed signal 2 is output from a sensor that detects the vehicle speed, and turns ON when the vehicle speed is O or below a constant speed close to stopping. Gear neutral signal 3Fi,
It is output from a sensor that detects the gear position (shift position) of the transmission, and turns ON when the gear position is in neutral. The clutch disengagement signal 4 is output from a sensor that detects engagement and engagement of the clutch, and becomes KON when the clutch is disengaged (when the clutch pedal is depressed). The engine start completion signal 5 is output from a sensor that detects the engine rotational speed or alternator L terminal voltage, and outputs a high voltage when the engine reaches a rotational speed higher than that obtained by starting the engine with the starter 6. The set value signal 7 outputs a voltage set slightly lower than the high voltage output from the engine start completion signal 5. The battery temperature signal 8 is
The battery temperature T is within the setting range suitable for the usage conditions, for example T in Fig. 1.
When 1≦T≦Tt K, it becomes KON.

Various signals from these sensors are then sent to the controller 9.
When the engine stop conditions are satisfied based on these input signals, the controller 9
Signal to stop the engine (phenyl cut signal 10)
It also outputs a signal (starter drive signal 11) that starts the engine by restarting the car after the engine has stopped.
) is output.

The operation of each unit of the controller 9 will be explained.

The first AND gate 12 includes a throttle close signal 1, a vehicle speed signal 2, a battery temperature signal 8, and a gear neutral signal 3.
All signals from the continuation determination circuit 13 that outputs are input, and when all of these signals are ON, the output becomes ON. When the vehicle speed of the vehicle speed signal 2 is set to a certain level (for example, 5 to l OKs/h), the continuation determination circuit 13 determines whether the vehicle speed is changed from 2nd gear to l OKs/h.
Gear neutral signal 3 turns ON instantaneously when downshifting to 1st gear or shifting up from 1st gear to 2nd gear, and at the same time, the throttle close signal 1 turns ON to release the accelerator pedal. This is provided to prevent the engine from stopping due to the output of the AND gate 12 being turned ON, and the output is turned ON when the gear neutral signal 3 continues to be ON for a predetermined period of time.

The flip-flop 14 inputs signals from the first AND gate 12◆ and the second AND gate 15, which will be described later.
The output remains ON for a period of time from the moment the output of the first AND gate 12 turns ON until the output of the second AND gate 15 turns ON. The fuel cut signal 10 is turned ON when the output of the prepprop 14 is turned ON, and for example, closes the electromagnetic fuel cut valve 16t installed in the fuel supply passage of the engine to stop the fuel supply. Alternatively, the fuel supply may be stopped by cutting off the energization of the electromagnetic fuel injection valve.

The inverter 17 inputs the signal from the continuation determination circuit 13, and when this input signal is OFF, the output is turned ON. The comparator 18 receives the engine start completion signal 5 and the set value signal T.
When the signal voltage of the latter exceeds that of the former, the output turns ON. 2nd AND gate 1S
inputs the clutch disengagement signal 4, the signals from the inverter 1T, and the comparator 18, and the output is ON while all these signals are ON. The starter drive signal 11 is the second
When the output of the AND gate 15 is ON, this signal drives the starter 6 to start the engine.

Next, a specific case in which the engine stop/start device having such a configuration is used during automatic operation will be described.

When the accelerator pedal is released to stop the vehicle from running, the throttle close signal 1 is turned ON, and when the vehicle speed becomes O or a speed close to stopping, the vehicle speed signal 2 is turned ON. Also, when the gear position of the transmission is set to neutral, the gear neutral signal 3 turns ON, and if this signal continues for a certain period of time, it is determined that the vehicle is stopped or is about to be stopped, and the continuation judgment circuit 13 is activated. is O
It becomes N.

These three signals and the battery temperature signal 8 are input to the first AND gate 12. At this time, the battery temperature T is outside the set temperature range (
When the sensor detects that T<'r,, T>T,), the output of the battery temperature signal 8 is turned OFF.
Since the output of the AND gate 12 is turned off, the phenyl cut pulp 16 does not operate. Furthermore, for example, T, = 2
Therefore, if the battery temperature is outside the setting range (low St or high temperature), the engine will not stop, allowing the alternator to maintain power generation and also allowing the starter, which consumes the most power, to be set. There is no need to drive the battery, reducing battery power consumption and increasing battery life.

Conversely, if the battery temperature T is within the set value range (T, ≦T≦T,
), the output of the battery temperature signal 8 is turned ON, the output of the first AND gate 12 is also turned ON, and this signal is input to the 7 lip-flop 14. At this time, the output of the inverter 17 inputting the ON signal of the sustain judgment circuit 13 is held OFF, so the output of the 717 prop 14 is turned ON by the ON signal of the first AND gate 12. Then, the unit cut signal 10 is turned ON. For this reason, the fuel cut valve 16 is closed and the fuel supply to the engine is interrupted.
Engine stops immediately.

In addition, when restarting the car after the engine has stopped, first depress the clutch pedal and the clutch disengage signal 4
becomes ON. Further, when the gear position of the transmission is changed from neutral to l-speed or reverse, the gear neutral signal 3 is turned off, the output of the sustain judgment circuit 13 is turned off, and the output of the inverter IT is turned on. Moreover, in this state, since the engine is stopped, the signal voltage of the engine start completion signal 5 is lower than the signal voltage of the set value signal T, so the output of the second comparator 18 is ON, and therefore the second AND gate 15
The output of is turned ON.

When the ON signal of the second AND gate 15 is input to the flip-flop 14, the flip-flop 14
The output of the phenyl cut pulp 16 is switched from ON to OFF, and the fuel supply to the engine is restarted, while the output of the sister starter drive signal 11 is turned ON by the ON signal of the second AND gate 15. Then, the controller S1 is driven.

Therefore, the fuel supply is restarted and the starter 6 is driven, so that the engine is restarted.

When the engine starts and reaches a rotation speed higher than the set value, the signal voltage of the engine start completion signal 5 exceeds the signal voltage of the set value signal 7, so the output of the comparator 18 turns OFF.
When F is reached, the output of the second AND gate 15 is also turned off. Therefore, the output of the starter drive signal 11 is also turned off, and the drive of the starter 6 is stopped. In addition, in this state, the output of the gear neutral signal 3 is OFF, so the first AND gate 12 is turned OFF, and the output of the flip-flop 14 and the twin cut signal 10 are also turned off, and the twin cut pulp 16 is held at the valve open position. The engine does not stop, so after the engine has started, the car can be started by engaging the clutch and pressing the accelerator pedal.

In the present invention, it is preferable to directly detect the temperature of the battery fluid as the temperature of the battery W. However, as explained above, the present invention is also capable of measuring the temperature of the outer wall of the case of the battery i. The starter K includes a battery temperature detection means, and uses a detection signal from the detection means to stop the engine only when the battery temperature is within a set range suitable for the battery usage conditions, thereby improving fuel efficiency. , when excessive battery power consumption is outside the undesirable setting range, the engine is not stopped and the battery power consumption is reduced, thereby protecting the battery and extending its lifespan.

[Brief explanation of the drawing]

Figure 1 is a diagram of the relationship between battery temperature and battery life, Figure 2
The figure is a circuit diagram showing one embodiment of the present invention. 1... Throttle close signal, 2... Vehicle speed signal, 3
...Gear neutral signal, 4.Clutch disengagement signal, 5.Engine start completion signal, 6.
- Starter, 7... Set value signal, 8... Battery temperature signal, 9... Controller, 10
... Tsuyunil cut signal, 11... Starter drive signal, 16... Tsuyunil cut pulp. Patent Applicant Nissan Motor Co., Ltd. Agent Patent Attorney Fujio Sasashima (20°C) (50'C) Ba Nteri Cliff Charcoal (0C)

Claims (1)

[Claims] When a predetermined condition for stopping the engine when stopped is detected, the engine is stopped after the detection, and after the engine is stopped, the engine is restarted by a normal starting operation to start the vehicle. An engine stop/start device for an automobile, characterized in that a detecting means for detecting battery temperature is provided, and the engine can be stopped only when the battery temperature is within a predetermined range based on a detection signal from the detecting means. Starting device.