JPH0763150A - Ignition timing control method - Google Patents

Abstract

PURPOSE:To suppress an acceleration shock by relaxing changing ignition timing when switched from idle on time to idle off time, in the ignition timing control method for controlling the ignition timing by an ignition timing map set to be based on an engine speed and an intake pipe pressure respectively corresponding to the idle on time and idle off time. CONSTITUTION:Ignition timing, obtained from an ignition timing map based on an engine speed and intake pipe pressure in the point of time for a fixed period just after switching from idle on time to idle off time, and ingnition timing in the preceding time of increasing weight are averaged to obtain a weighted mean value set to the ignition timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control method, and more particularly to an ignition timing control method for controlling the ignition timing based on an ignition timing map which is set in correspondence with idle-on and idle-off. .

[0002]

2. Description of the Related Art In recent years, as a method for controlling the ignition timing, in order to secure a stable operating state at the time of idling, the ignition timing is set based on an ignition timing map set to a retard side from the optimum ignition timing at the time of idling However, at the time of idling off, a method of setting the ignition timing based on the ignition timing map set to the optimum ignition timing is implemented. In the ignition timing map, the ignition timing is set based on the engine speed and the intake pipe pressure.

Explaining in detail with reference to FIG. 3, first, the engine speed and the intake pipe pressure are detected in steps # 21 and # 22, then it is determined in step # 23 whether or not the idle is on, and the step is performed when the idle is on. Based on the engine speed and intake pipe pressure detected by shifting to # 24, the idle-on table (TABSIDL) is searched, and when idle off, the process shifts to step # 25 to detect the engine speed and intake pipe pressure. Search the idle time off table (TABSIDLOFF), and step #
In step 26, the search result is detected as the ignition timing base (ABSE), and in step # 27, the previous ignition timing (AE) is detected.
The final ignition timing (AESA) is calculated from the average value of the ignition timing base (ABSE) detected as SA0). Then, ignition is performed based on the final ignition timing (AESA).

It should be noted that Japanese Patent Laid-Open No. 190945/1990 ensures the stability in a steady rotation state during idling and promptly responds when the target rotation speed is increased while driving a cooler compressor. In order to be able to do so, the ignition timing is set according to the difference between the reference rotation speed and the engine rotation speed at that time so that the engine rotation speed matches the reference rotation speed, and the reference rotation speed is When the engine is in a steady rotation state, the past engine speed is weighted, and for a predetermined period after the target speed changes, the engine speed at that time is weighted and the past engine speed and the time It is disclosed that the engine speed is calculated by weighted averaging.

[0005]

However, as described above, the ignition timing is set based on the respective ignition timing maps at the time of idling on and at the time of idling off, and the ignition timing obtained from the ignition timing map and the previous ignition timing are set. If the ignition timing is set to the average value of, the ignition torque changes suddenly from the retard side to the optimum ignition timing when switching from idle-on to idle-off, causing a sudden change in engine torque and acceleration shock. However, in the case of an automobile engine, there is a problem that it is uncomfortable to ride due to acceleration shock or start shock.

The method disclosed in the above publication accelerates quickly when the target rotation speed rises, and does not prevent the acceleration shock at the time of switching from idle on to idle off.

In view of the above-mentioned conventional problems, the present invention aims to provide an ignition timing control method capable of suppressing an acceleration shock by moderately changing the ignition timing at the time of switching from idle on to idle off. And

[0008]

SUMMARY OF THE INVENTION The present invention is an ignition timing control for controlling an ignition timing by an ignition timing map set based on an engine speed and an intake pipe pressure in correspondence with idle-on and idle-off, respectively. In the method
A weighted average value of the ignition timing obtained from the ignition timing map based on the engine speed and the intake pipe pressure at that time and the previous ignition timing with a larger weight for a certain period immediately after switching from idle on to idle off Is set as the ignition timing.

[0009]

According to the present invention, during a certain period immediately after switching from idle on to idle off, the ignition timing and weight obtained from the ignition timing map based on the engine speed and the intake pipe pressure at that time are increased. Since the weighted average value with respect to the previous ignition timing is calculated as the ignition timing, it is possible to suppress the acceleration shock by gradually changing the ignition timing at the time of switching from idle on to idle off.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, 1 is a cylinder head, 2 is a cylinder block, 3 is a piston, and 4 is a combustion chamber formed on a piston 3 below the cylinder head 1. A spark plug 5 is provided on the top of the combustion chamber 4, and an intake port 6 and an exhaust port 7 are provided on both sides of the combustion chamber 4. Reference numeral 8 denotes a distributor that is driven in conjunction with a crankshaft (not shown), and is provided with a rotation speed sensor 9 that detects the engine rotation speed. The distributor 8 has an input terminal connected to an ignition coil 11 having an ignition timing control unit 10 and an output terminal connected to the ignition plug 5.

A throttle valve 13 is provided in the intake port 6 midway.
Is connected to the intake pipe 12. This intake pipe 1
The upstream position and the downstream position of the throttle valve 13 in 2 are
The throttle valve 13 is communicated through a bypass passage 14 provided with a flow rate adjusting valve 15, the throttle valve 13 is fully closed during idle operation, the intake amount is adjusted by opening and closing the flow rate adjusting valve 15, and the idle speed is controlled to a predetermined value. There is. Reference numeral 16 is an intake pipe pressure sensor for detecting the intake pressure. Reference numeral 17 denotes a throttle valve opening sensor that detects the opening of the throttle valve 13.

Reference numeral 18 denotes a control unit having a built-in ignition timing control means, which receives detection signals from the rotation speed sensor 9, the intake pipe pressure sensor 16 and the throttle valve opening sensor 17, and sends the control signals to the ignition timing control unit 10. It is configured to output. The detection signal from the throttle valve opening sensor 17 is used to detect idle-on and idle-off.

Next, the ignition timing control operation with the above configuration will be described with reference to FIG.

First, the engine speed and the intake pipe pressure are detected in steps # 1 and # 2, and then it is determined in step # 3 whether or not the idle is on.
After turning off the built-in timer, the process goes to step # 5 to search the idle ON time table (TABSIDL) based on the detected engine speed and intake pipe pressure. Table 1 shows this idle time table (T
An example of (ABS IDL) is shown.

[0016]

[Table 1]

On the other hand, when the idle is off, step # 6,
If you go to # 7 and the timer is off, turn it on,
If it is on, the process proceeds to step # 8, and the idle off time table (TABSIDLOFF) is searched based on the detected engine speed and intake pipe pressure. Table 2 shows this idle-off table (TABSI
An example of DLOFF) is shown.

[0018]

[Table 2]

In Tables 1 and 2, the ignition timing is
It is set at BTDC (angle from top dead center to the rear).

Next, after the search result is detected as the ignition timing base ABSE in step # 9, whether the timer is on and ≤T is satisfied in step # 10, that is, for example, several seconds after the idle is switched from idle on to idle off. It is determined whether or not a predetermined time has passed.

As a result of the determination, if it is within T seconds after switching from idle-on to idle-off, step #
11, the final ignition timing AESA is calculated by the following equation. However, in the following equation, AESA0 is the previous ignition timing, and N is an arbitrarily set smoothing coefficient.

[0022]

[Equation 1]

That is, if the smoothing coefficient N is set to 32, for example, the weight of the previous ignition timing AESA0 is set to 31,
The weight of the ignition timing base ABSE is set to 1, and the final ignition timing AESA is calculated with the weighted average value. As a result, the change in ignition timing becomes gradual.

On the other hand, if the determination is negative, the routine proceeds to step # 12, where the final ignition timing AES is the same as in the conventional case.
A is calculated by the following equation, and the average value of the ignition timing base ABSE detected as the previous ignition timing AESA0 is set as the final ignition timing AESA.

[0025]

[Equation 2]

Thereafter, at the next calculation in step # 13, the final ignition timing AESA is the last ignition timing AES.
It is set to be A0. Then, ignition is performed based on the final ignition timing AESA of this time.

[0027]

As described above, according to the ignition timing control method of the present invention, during the fixed period immediately after switching from idle on to idle off, the ignition timing is based on the engine speed and the intake pipe pressure at that time. Since the ignition timing is obtained by calculating the weighted average value of the ignition timing obtained from the map and the previous ignition timing with a larger weight, the change in the ignition timing at the time of switching from idle on to idle off is made gentle. Accelerating shock can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an ignition timing control device according to an embodiment of the present invention.

FIG. 2 is a flowchart of an ignition timing control operation of the same embodiment.

FIG. 3 is a flowchart of an ignition timing control operation of a conventional example.

[Explanation of Codes] 5 Spark Plug 8 Distributor 9 Rotation Speed Sensor 10 Ignition Timing Control Unit 11 Ignition Coil 16 Intake Pipe Pressure Sensor 17 Throttle Valve Opening Sensor 18 Control Unit

Claims (1)

[Claims] 1. An ignition timing control method for controlling an ignition timing according to an ignition timing map set on the basis of an engine speed and an intake pipe pressure in correspondence with idle-on and idle-off, respectively. For a certain period immediately after switching to the ignition timing, the ignition timing is obtained by calculating the weighted average value of the ignition timing obtained from the ignition timing map based on the engine speed and the intake pipe pressure at that time and the previous ignition timing with a larger weight. An ignition timing control method comprising: