JPS62126274A - Relaxing device for deceleration shock in internal combustion engine - Google Patents

Abstract

PURPOSE:To suppress a rapid decrease of torque so as to enable a deceleration shock to be relaxed, by correcting the basic ignition timing to an advance side for a predetermined time if deceleration operation of an engine is detected. CONSTITUTION:A control unit 30, which inputs an engine speed by a signal of a crank angle sensor 14 and a flow of intake air by an air flow meter 6, sets the basic ignition timing through map reference by the calculated basic fuel injection quantity and the engine speed. And the control unit, if it detects a deceleration condition that an idle switch 8 is turned on further a neutral switch 20 is turned off, corrects the basic ignition timing to an advance timing side for a predetermined time from the point of time said condition is detected. In this way, a deceleration shock is relaxed by suppressing a rapid decrease of torque. Further driving comfortableness of a vehicle, when it is decelerated, can be improved because of no engine acceleration by an advance timing control with a small supply amount of fuel.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a deceleration shock mitigation device for an internal combustion engine.

<Prior art> Conventionally, as an ignition timing control device, a control value for ignition timing corresponding to the operating state of the engine, specifically, the engine rotation speed and the amount of fuel supplied, is stored in advance in the memory in the control unit. Then, using the signal from the crank angle sensor and the basic fuel injection amount calculated from the intake air amount, the ignition timing control value corresponding to the engine speed and basic fuel injection amount at that time is searched from the stored data. The ignition timing was controlled from that value.

Also, during idling or deceleration (when the idle contact of the throttle valve switch is ON), the ignition timing control value based on the above basic fuel injection amount and engine speed is not used, but the settings are stored in accordance with the engine speed. The ignition timing control value is searched to control the ignition timing to ensure idle stability.

<Problems to be solved by the invention> However, with this type of vehicle, there is a problem in that during deceleration, a deceleration shock occurs due to sudden torque fluctuations, causing the vehicle to vibrate greatly and making the ride uncomfortable. .

That is, when the idle contact turns ON during deceleration, the ignition timing control value for idling and deceleration is retrieved as described above, and the ignition timing is controlled from this control value. As a result of sudden angle retard control, engine torque suddenly decreases and vehicle vibration increases.

The present invention has been made in view of these conventional problems, and an object of the present invention is to improve the riding comfort of a vehicle by alleviating shock during deceleration.

<Means for Solving the Problems> For this reason, the present invention, as shown in FIG. deceleration driving state detection means; ignition timing correction means for correcting the basic ignition timing to an advanced side for a predetermined period of time after deceleration driving is detected; and ignition timing control for controlling ignition to the basic ignition timing or its corrected ignition timing. A deceleration shock mitigation device is comprised of the device and.

<Operation> That is, during deceleration, the ignition timing is advanced by a predetermined period of time to prevent a sudden drop in torque and to alleviate deceleration shock. Note that during deceleration, since the amount of fuel supplied is small, engine acceleration due to advance angle control can be avoided.

<Example> An embodiment of the present invention will be described below.

In FIG. 2, an engine 1 includes an air cleaner 2° intake duct 3. Air is drawn in via the throttle chamber 4 and the intake manifold 5.

An air flow meter 6 is provided in the intake duct 3 and outputs a voltage signal corresponding to the intake air amount Q. The throttle chamber 4 is provided with a throttle valve 7 that operates in conjunction with an accelerator pedal (not shown), and controls the intake air flow 4.
Controls 1Q. An idle switch 8 is attached to the throttle valve 7 to detect its fully closed position. The intake manifold 5 is provided with a fuel injection valve 9 for each cylinder, which is opened by a drive pulse signal from a control unit 30 containing a microcomputer (described later), and is fed under pressure from a fuel pump (not shown) by a pressure regulator. Fuel controlled to a predetermined pressure is injected and supplied into the intake manifold 5.

Each cylinder of the engine 1 is provided with an ignition plug 10, to which a high voltage generated by an ignition coil 11 is sequentially applied via a distributor 12, thereby igniting a spark to ignite the air-fuel mixture. Ignite and burn. The timing of high voltage generation in the ignition coil 11 is controlled via a transistor 13 attached thereto. Therefore, the ignition timing is controlled by controlling the ON/OFF timing of the power transistor 13 using an ignition timing control signal from the control unit 30.

Here, the ignition plug 101 ignition coil 11. The distributor 12, the control unit 30, and the like constitute an ignition timing control device.

A photoelectric crank angle sensor 14 is built into the distributor 12 . The photoelectric crank angle sensor 14 includes a signal disk plate 16 that rotates together with the distributor shaft 15 and a detection section 17. The signal disc plate 16 is formed with 360 slits 18 for position signals (1"signal") and 4 slits 19 for reference signals (180' signal) in the case of 4 cylinders. One of the reference signal slits 19 is also used to identify the first cylinder.

The detection unit 17 detects these slits 18 and 19,
A reference signal including a position signal and a cylinder discrimination signal is output. Here, it is possible to calculate the engine rotation speed N by measuring the period of the reference signal. Therefore, the crank angle sensor 14 detects not only the crank angle but also the engine rotation speed N.

In addition, a neutral switch 20 is attached to the transmission 21, and the neutral switch 20 detects the nico-tral state of the gear position.

Next, ignition timing control according to the present invention will be explained based on the flowchart shown in FIG.

At Sl, the engine rotational speed N calculated from the reference signal output from the crank angle sensor I4 and the intake air flow rate Q detected by the air flow meter 6 are input.

In S2, it is determined whether the idle switch 8 is 0N-OFF, and if the idle switch 8 is OFF, the process proceeds to 84 as a basic ignition timing setting means (III normal operation setting means), and the basic fuel injection amount and engine rotation are set. The map value of the ignition timing (basic ignition timing) during normal operation is searched based on the speed N. On the other hand, in S2, the idle switch 8
When it is determined that is ON, the routine proceeds to 83, which serves as a basic ignition timing setting means (idling setting means), and searches for an ignition timing map (basic ignition timing) at idling based on the engine rotational speed N.

In S5, it is determined whether the vehicle is in a neutral state. Specifically, when the neutral switch 20 is OFF, the process proceeds to 86, and when it is ON, it is assumed that the neutral state is established, and the process proceeds to Sl.1. In other words, in the neutral state, in other words, in a state where the engine driving force is not transmitted to the drive wheels, even if the engine torque suddenly decreases, it will not appear as vibration in the vehicle. Therefore, in the neutral state, the ignition timing is advanced. Avoid controlling it. and,
If the idle switch 8 is ON and not in the neutral state, a predetermined time (ΔT) S after deceleration state is detected.
This is to perform advance angle correction control in step 9. Therefore, in this embodiment, the deceleration operation state detection means is constituted by the idle switch 8 and the neutral switch 20.

At Sll, the ignition timing map value retrieved at S3 or S4 is set as the final ignition timing ADV. Then, in S12, the count value C for measuring the lead angle correction control time is cleared, and in S13, the Sll
Ignition processing is performed based on the ignition timing ADV set in .

In S6, it is determined whether a count value C for measuring the time for controlling the advance angle of the ignition timing is greater than or equal to a predetermined value. If so, proceed to Sll and set the map value as the ignition timing ADV, and clear the current value C in S12.

When the count C is less than the predetermined value, it is determined in S7 whether the count C is zero. This is to determine whether or not the ignition timing is being advanced. If it is determined in S7 that the count C is not zero, that is, that the advance angle is being corrected but the predetermined time (ΔT) has not elapsed, then the advance angle correction of the ignition timing shown in S9 (map value + predetermined value) is determined. Perform α). This S9 corresponds to ignition timing correction means.

On the other hand, if the count C is determined to be zero in S7, this indicates that the advance correction of the ignition timing was not performed in the previous time, so it is determined in S8 whether the engine is in a deceleration state. Specifically, the deceleration state of the engine is determined based on whether the idle switch 8 was turned off last time and turned on this time.
If a deceleration state is detected, advance angle correction shown in S9 is performed.

In S10, the count value C for measuring the advance angle control time is incremented by 1, and if the state is not neutral and the handle switch 8 continues to be ON, the count value C is increased by 1 until the count value C reaches a predetermined value or more. That is, the predetermined time (ΔT
) The advance angle control shown in S9 is performed.

If any of the three conditions are broken: idle switch 8 is ON (S2), neutral switch 20 is OFF (S5), and count value C is less than a predetermined value (S6),
At the same time as clearing the count value C, the advance angle correction in S9 is stopped, and ignition timing control is performed using the normal map value (basic ignition timing) retrieved in S3 or S4.

It should be noted that the advance angle correction control time is sufficient as long as it can reduce the first valley (point A in the figure) of vehicle longitudinal G shown in Fig. 5 to an allowable level, and making it longer than necessary may affect idling drivability or deceleration. It will spoil the feeling.

As described above, the ignition timing is adjusted to the specified time during deceleration.
The shock during deceleration can be alleviated by controlling the advance angle correction. That is, even if the throttle valve 7 is fully closed and the amount of fuel supplied decreases, sudden retard control is not performed as in the conventional case, but advance angle correction control is performed for a predetermined period of time, as shown in FIG. A sudden drop in torque (
A sudden change in vehicle longitudinal G is suppressed, and unpleasant vehicle vibrations can be avoided. Further, when the idle switch 8 is ON, the amount of fuel supplied is small, so even if advance angle control is performed during deceleration, acceleration of the engine can be avoided.

In this embodiment, the advance angle correction was performed by adding a constant value α to the map value (basic ignition timing).
The value to be added may be gradually decreased as time passes.

<Effects of the Invention> As explained above, according to the present invention, by advancing the ignition timing for a predetermined period of time after deceleration is detected, a sudden drop in torque during deceleration can be suppressed.
Large vibrations of the vehicle are avoided.

Therefore, the shock at the time of deceleration is alleviated, and the riding comfort of the vehicle can be improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is an overall block diagram of an embodiment of the present invention, Fig. 3 is a flowchart showing ignition timing control in this embodiment, and Fig. 4 is a control in the above. Diagram showing characteristics. FIG. 5 is a diagram showing conventional control characteristics. 1... Engine 6... Air flow meter 7...
・Throttle valve 8...Idle switch 9・
...Fuel injection valve 10...Ignition plug 11...Ignition coil 12...Distributor 14...
Crank angle sensor 20... Neutral switch 30... Control unit

Claims (2)

[Claims] (1) A basic ignition timing setting means for setting the basic ignition timing based on the operating state of the engine; a deceleration operation state detection means for detecting deceleration operation of the engine; and a deceleration operation state detection means for detecting deceleration operation of the engine; A deceleration shock mitigation device for an internal combustion engine, comprising: ignition timing correcting means for correcting to the advance side; and an ignition timing control device for controlling ignition to the basic ignition timing or its corrected ignition timing. (2) The basic ignition timing setting means includes idle operation setting means for setting the ignition timing according to the engine rotation speed when the throttle valve is fully closed, and the fuel supply amount and engine rotation speed when the throttle valve is open. 2. The deceleration shock mitigation device for an internal combustion engine according to claim 1, further comprising: normal operation setting means for setting the ignition timing in accordance with the ignition timing.