JPH0634592Y2 - Internal combustion engine start control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a start control device for an internal combustion engine.

<Prior Art> In cold regions or during cold weather, the fuel vaporization performance deteriorates and the startability of the engine deteriorates. Therefore, the fuel injection amount at the start is often increased as compared to the normal case.

Further, if the engine fails to start in the state where the air-fuel ratio is set rich by increasing the amount of fuel supplied in this way, the fuel may be supplied as a liquid to the combustion chamber, making it impossible to start the engine.

Therefore, in the prior art, for example, as shown in FIG. 4, when the start switch is closed, the initial value of the fuel injection amount is set according to the temperature of the engine and the start switch is closed for a predetermined time, for example, The fuel injection amount was gradually reduced and corrected starting from the point when 10 seconds had elapsed to avoid starting failure due to the supply of the rich mixture.

<Problems to be solved by the device> However, when the start switch closing time (cranking time) becomes long, a normal driver habitually opens and returns the start switch to rest the battery, and then starts the start switch again. Although there are many cases where the engine is closed and cranking is started, in the past, even when such a restart was performed, a new initial value was set according to the engine temperature at that time. If such restarting is repeated, there is a possibility that the air-fuel ratio becomes excessively rich and it may be impossible to start.

The present invention has been made in view of such a situation,
When the engine restarts, it fails to start. The fuel injection amount is calculated in consideration of the amount of fuel injected at the previous start (close time of the start switch) to prevent the supply of the rich mixture. The purpose is to improve the startability of the engine.

<Means for Solving Problems> Therefore, in the present invention, as shown in FIG. 1, for example, a timer that operates when the start switch 1 for controlling the starter for cranking the engine is closed. Two
And the start switch 1 detected by the timer 2.
Of the closing time, the first resetting means 4A for resetting the elapsed time integrating means 3 when the engine speed becomes higher than a predetermined value, and the next crank Second reset means for resetting the elapsed time integrating means when a predetermined time elapses irrespective of the OFF operation of the ignition switch before the ranking is started, and a fuel injection amount at the start according to the temperature of the engine Memory 5 in which the initial value of is stored in advance, initial value setting means 6 for reading the initial value according to the temperature of the engine from the memory 5 at the start of engine start by closing the start switch 1, and the initial value. An injection amount calculation means 7 for calculating the fuel injection amount at the time of starting the engine according to the initial value output from the setting means 6 and the integration time output from the elapsed time integration means 3 is provided. It has a configuration. 8 is a water temperature sensor that detects the engine temperature via the temperature of the engine cooling water, and 9 is an output that outputs an injection signal in response to the calculated injection amount to a fuel supply means (not shown) represented by a fuel injection valve or the like. After the completion of the start of the engine is detected by the signal from the first resetting means 4A, the fuel injection amount is calculated in accordance with the engine speed and the load as in the conventional case. ing.

<Operation> With this, when the engine is restarted, the fuel injection amount is calculated in consideration of the cumulative time of the starting operation up to that time, thereby avoiding that the engine cannot start due to the supply of the rich mixture. I have to.

<Example> An example of the present invention will be described below. Regarding the hardware, the timer 2, the elapsed time accumulating unit 3, the initial value setting unit 6, the injection amount calculating unit 7 and the like are configured by a microcomputer, and the initial value is set in a state where the start switch 1 is closed. Since the injection amount calculation unit 7 calculates the fuel injection amount according to the outputs of the setting unit 6, the elapsed time integration unit 3, etc., the description thereof will be omitted.

That is, when the start switch 1 is closed to start the engine, the initial value setting means 6 causes the memory 5 to set an initial value corresponding to the output (engine temperature) of the water temperature sensor 8 at the time when the switch 1 is closed. And outputs it to the injection amount calculation means 7. While the start switch 1 is being closed, the timer 2 operates, and the elapsed time integrating means 3 integrates the operating time of the timer 2 and outputs it to the injection amount calculating means 7.

The injection amount calculation means 7 calculates the fuel injection amount based on the initial value output from the initial value setting means 6 and the integrated time output from the elapsed time integration means 3. Further, in this calculation, as shown in FIG. 2, for example, the initial value setting means 6 outputs from the start of the start by closing the start switch 1 until a predetermined time, for example, 10 seconds has elapsed. The injection signal corresponding to the determined initial value is output to the fuel injection valve or the like via the output means 9.

After that, an injection signal corresponding to the injection injection amount obtained by gradually subtracting the initial value with time is output,
When the start of the engine fails and the start switch 1 is opened and restored, the output of the injection signal is stopped in synchronization with this.

On the other hand, when the start switch 1 is opened and returned as described above, the timer 2 is stopped, and thus the elapsed time integration by the elapsed time integration means 3 is interrupted. However, the integrated time up to this point is the elapsed time integration. It is temporarily stored in the memory of the means 3. Then, when the start switch 1 is closed again to restart the engine and the operation of the timer 2 is started, the integrated time temporarily stored in the memory or the like is output to the injection amount calculation means 7, The injection amount at restart is calculated based on the integrated time and the initial value output from the initial value setting means 6. It goes without saying that the initial value output from the initial value setting means 6 is a value according to the engine temperature at the time of restart.

Further, as the restart time elapses, the integrated time output from the elapsed time accumulating means 3 increases accordingly. Therefore, as shown in FIG. Since the fuel supply amount is calculated on the basis of the fuel injection amount and the injection amount is gradually reduced, the fuel injection amount at the time of restart is reduced as compared with the conventional one shown by the broken line in FIG. Therefore, it is possible to avoid the situation of being unable to start due to excessive fuel (supply of an excessively rich air-fuel mixture) as in the conventional case.

When the engine starts, the start switch 1 is opened and returned, so that the injection amount calculation means 7 stops and the timer 2 also stops. Further, when the engine speed becomes higher than a predetermined value, for example, 500 rpm by the start, the first reset means 4A
Since the elapsed time integrating means 3 is reset by the signal from, the integrated time from the starting point of the starting is output at the next starting. After the start is completed in this way, a transition is made to the conventionally known fuel control based on the engine speed, the intake air flow rate, etc., and the time from the initial start failure to the restart start is predetermined. When the time exceeds, for example, 10 minutes, the second reset means 4B considers that the previously supplied fuel has already evaporated, and stops the accumulation of the elapsed time to integrate the elapsed time. The accumulated time so far stored in the memory of the means 3 is cleared.
If the time from the start failure to the restart is long, the ignition switch is often turned off during that time, but even in that case, the ignition switch is turned off.
Regardless of the operation, the accumulated time is maintained without being cleared until the predetermined time has elapsed. In other words, if it is within the predetermined time, the ignition switch
Even if the engine is restarted after the fuel injection is performed, the fuel injection amount control based on the integrated time is performed. In FIG. 2, the alternate long and short dash line indicates the fuel injection amount during normal idle operation.

On the other hand, the initial value stored in the memory 5 is, for example, the third value.
As shown in the figure, it changes depending on the temperature of the engine (the temperature of the engine cooling water), the initial value is increased in the cold state, and the initial value is gradually decreased as the temperature rises. Then, in the warm-up state of the engine, it is set to take a value close to the fuel injection amount during normal idle operation, but it is not limited to the embodiment, and this initial value is rewritten by learning and started. The sex can be higher.

<Effect of Device> As described above, according to the present invention, the initial value corresponding to the temperature of the engine is subtracted over time and is supplied to the combustion chamber in the same manner as in the conventional case at the time of first starting. Since the air-fuel ratio of air is enriched according to the engine temperature at that time, the startability of the engine is enhanced. Further, even if the first start fails, the integration of the start operation time is only temporarily interrupted, and the interrupted integration is restarted at the subsequent restart, and the fuel injection amount is calculated based on this integrated value. With such a configuration, it is possible to avoid the situation of being unable to start due to excessive fuel supply as in the conventional case.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a characteristic diagram of fuel injection amount at the time of starting and restarting according to the present invention, and FIG. 3 is a characteristic diagram of initial values stored in a memory,
FIG. 4 is a characteristic diagram of the fuel injection amount at the time of conventional starting and restarting. 1 ... Start switch, 2 ... Timer, 3 ... Elapsed time integrating means, 4A ... First resetting means, 4B ... Second resetting means, 5 ... Memory, 6 ... Initial value setting means, 7 ...
... Injection amount calculation means, 8 ... Water temperature sensor

Claims (1)

[Scope of utility model registration request] 1. A timer which operates when a start switch for controlling a starter for cranking an engine is being closed, and an elapsed time integrating means for integrating the closing time of the start switch detected by the timer. The first reset means for resetting the elapsed time integrating means when the engine speed becomes higher than a predetermined value and the ignition switch OFF operation between the end of cranking and the start of the next cranking Second reset means for resetting the elapsed time integrating means when a predetermined time has passed irrespectively, a memory for storing in advance an initial value of the fuel injection amount at startup according to the temperature of the engine, and closing of the start switch. Initial value setting means for reading out an initial value corresponding to the temperature of the engine from the memory at the start of the engine start by the operation of generating the engine; A start of an internal combustion engine, comprising: an injection amount calculation means for calculating a starting fuel injection amount of the engine in accordance with an initial value output from the means and an integrated time output from the elapsed time setting means. Control device.