JP2537422B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ignition timing control device for an internal combustion engine.

<Prior Art> A conventional ignition timing control device for an internal combustion engine has been disclosed in
There is one disclosed in Japanese Patent Publication No. 62-251473.

This is because when it is detected that the internal combustion engine is in the cranking state when the internal combustion engine is started, the first ignition timing is set, and when it is detected that the internal combustion engine is in the complete combustion state, the first ignition timing is set. The ignition timing of 2 is set. Further, when the exposure of the internal combustion engine is detected, the first ignition timing is changed to the third ignition timing advanced from the second ignition timing. Then, the ignition device operates at the first, second and third ignition timings set in this way.

With such a configuration, the ignitability of the internal combustion engine is improved during the period after the initial explosion until it reaches the complete explosion state, so that the internal combustion engine can quickly and surely transition to the complete explosion state and the startability is improved.

<Problems to be Solved by the Invention> Generally, in an internal combustion engine, a basic fuel injection amount is calculated from an engine intake air flow rate and an engine speed, and an ignition timing is set based on the basic fuel injection amount and the engine speed. It has become.

However, if the read value of the intake air flow rate fluctuates due to erroneous detection of the intake air flow rate detection device due to intake air pulsation of the internal combustion engine, etc., the ignition timing set by the intake air flow rate at this time also fluctuates. As a result, engine rotation fluctuations occur.

Therefore, it is necessary to limit the amount of change in ignition timing per ignition from a previous time to a predetermined value so as not to be excessively large.

For example, when the internal combustion engine is started, the ignition timing is set to the first ignition timing from the cranking state to the complete explosion after the initial explosion.
The ignition timing is greatly switched to the third ignition timing, and further to the second ignition timing. At this time, if a certain limit value is set for the amount of change in the ignition advance value, as shown in FIG. 4, when the output of the cranking detection switch changes from the cranking state to the complete explosion state, the advance amount is increased. While the demand for the ignition advance value changes greatly (illustrated by the solid line in FIG. 4), the actual ignition advance value changes gradually with time due to the constant limit value as shown by the broken line. As a result, the ignition timing is not switched promptly, which may cause deterioration of engine startability.

In view of the above situation, the present invention suppresses fluctuations in engine rotation during operation of the internal combustion engine, and can quickly switch the ignition timing when switching from the cranking state to the complete explosion state when starting the internal combustion engine. It is an object of the present invention to provide an ignition timing control device.

<Means for Solving the Problems> Therefore, in the present invention, as shown in FIG. 1, the operating state detecting means for detecting the operating state of the internal combustion engine, and the internal combustion engine in the cranking state by the operating state detecting means. When it is detected that the first ignition timing is set, the first ignition timing is set, and when it is detected that the internal combustion engine is in the complete explosion state, the second ignition timing set ahead of the first ignition timing is set. Ignition timing change amount limiting means for comparing the ignition timing set by the ignition timing setting means with the ignition timing previously fired and limiting the ignition timing change amount so that the difference is within a predetermined value. And an ignition control means for igniting according to the ignition timing limited by the ignition timing change amount limiting means, the ignition timing control device for an internal combustion engine comprising: The ignition timing change amount for changing the predetermined value of the ignition timing change amount limiting means to a larger value for a predetermined period after it is detected that the operating state of the internal combustion engine is switched from the cranking state to the complete explosion state. The limit value changing means is provided.

<Operation> When the operating state detecting means detects that the internal combustion engine is in the cranking state, the ignition timing setting means sets the first ignition timing, and the operating state detecting means determines that the internal combustion engine is in the complete explosion state. When it is detected that the second ignition timing is set ahead of the first ignition timing by the ignition timing setting means. Further, when the internal combustion engine is operating, the amount of change in the ignition timing for each ignition is suppressed within a predetermined value by the ignition timing change amount limiting means.

Here, when the operating state detecting means detects that the operating state of the internal combustion engine has switched from the cranking state to the complete explosion state, the ignition timing setting means changes the ignition timing from the first ignition timing to the second ignition timing. The ignition timing can be switched quickly at this time.
During the predetermined period, the ignition timing change amount limit value changing means changes the predetermined value to a large value. When the switching of the ignition timing is completed after the lapse of a predetermined period, the limit value of the ignition timing change amount is returned to the predetermined value again to suppress the rotation fluctuation in the complete explosion state.

<Example> An example of the present invention will be described below with reference to the drawings.

FIG. 2 shows the configuration of the ignition timing control device for the internal combustion engine according to this embodiment.

In FIG. 2, an intake passage 2 of an engine 1 is provided with an air flow meter 3 for detecting an intake air flow rate and a throttle sensor 5 for detecting an opening degree of an intake throttle valve 4, and these detection signals are input to a control device 6. Has been done. Further, the engine 1 is provided with a fuel injection valve 7 for each cylinder, and these fuel injection valves 7 are opened by an injection pulse signal corresponding to the fuel injection amount from the control device 6, and fuel is supplied to the engine 1. Supply by injection. Further, the engine 1 is provided with a knock sensor 18, which detects knocking of the engine 1 and outputs a detection signal to the control device 6.

An ignition plug 8 is provided in each cylinder of the engine 1,
The high voltage generated in the ignition coil 9 is sequentially applied to the spark plug 8 through the distributor 10, whereby spark discharge is performed and the air-fuel mixture is ignited and burned. here,
The ignition coil 9 has a power transistor 11 attached to it.
The generation timing of the high voltage is controlled via the control device, and the ignition timing is controlled by controlling the on / off timing of the power transistor 11
It is carried out by controlling with an ignition signal from.

The distributor 10 has a built-in optical crank angle sensor 12. The crank angle sensor 12 includes a signal disk plate 14 that rotates integrally with the distributor shaft 13, and a detection unit 15. The signal disc plate 14 is provided with 360 position signal (1 ° signal) slits 16 and four reference crank angle signal slits 17 in the case of four cylinders. One of them is also used for identifying the first cylinder. The detection unit 15 detects the slits 16 and 17 and outputs a position signal and a reference crank angle signal including a cylinder discrimination signal to the control device 6. The control device 6 calculates the rotational speed of the internal combustion engine 1 based on the signal from the crank angle sensor 12.

Reference numeral 21 is a water temperature sensor that detects the temperature of the cooling water of the engine 1, and reference numeral 22 is a cranking detection switch that is turned on when the ignition key is placed at the start position and the starter is activated.

With this configuration, the control device 6 calculates the injection amount at the fuel injection valve 7 based on the signals from the air flow meter 3, the throttle sensor 5, the knock sensor 18, the water temperature sensor 21, and the crank angle sensor 12, and also performs cranking. Detection switch
The signal of 22 is also used to calculate the ignition timing of the spark plug 8, and the power transistor 11 of the ignition coil 9 is controlled.

Next, the operation of the control device 6 will be described with reference to the flowchart of FIG.

First, in step (denoted as S in the figure. The same applies hereinafter) 1,
Engine speed N, intake air flow rate Q, cooling water temperature Tw, intake throttle valve opening α, knock sensor output and cranking detection switch output are read.

That is, the various sensors and the function of step 1 correspond to the driving state detecting means.

In step 2, the ignition timing is calculated based on the operating state read in step 1. That is, when the operating state is the cranking state, the ignition timing having a large retard amount suitable for the cranking which is the first ignition timing is calculated. Further, in the complete explosion state, the knocking state of the engine 1 is detected by the output from the knock sensor 18, and the ignition timing is feedback-controlled to each cylinder, so that the first ignition timing
The second ignition timing suitable for the complete explosion state advanced by 10 to 15 ° is calculated.

That is, the function of step 2 corresponds to the ignition timing setting means.

In step 3, it is judged from the output of the cranking detection switch whether the engine 1 is under cranking. If cranking is in progress, the process proceeds to step 9, and ignition is performed at the first ignition timing. If cranking is not in progress, the process proceeds to step 4.

In step 4, it is determined whether or not a predetermined period has elapsed since the end of cranking, and if the predetermined time has not elapsed, the process proceeds to step 6, in which the ignition timing per ignition is different from the previous time. After changing the predetermined value (that is, the limit value of the ignition timing change amount limiting means) that is restricted so that the change amount at the time of ignition does not become excessively large, the process proceeds to step 7. When it is determined in step 4 that the predetermined period has elapsed, the process proceeds to step 5, and the process proceeds to step 7 with the predetermined value as the limit value of the ignition timing change amount.

That is, the functions of steps 4 and 6 correspond to the ignition timing change amount limit value changing means.

In step 7, the ignition timing set this time is compared with the ignition timing at the time of the previous ignition, and the amount of change in the ignition timing is calculated.

In step 8, the ignition timing change amount is limited by the limit value set in step 5 or step 6, and the process proceeds to step 9 to ignite.

That is, the functions of steps 7 and 8 correspond to the ignition timing change amount limiting means, and step 9 performs the function of the ignition control means.

Therefore, as described above, according to the present embodiment, the ignition timing change amount limit value is changed to a value larger than the predetermined value only within the predetermined period after the end of the cranking in the period 1, as shown in FIG. The number of stages at which the ignition timing is switched is reduced, and the ignition timing can be switched quickly.
Therefore, the startability at the time of starting the internal combustion engine is improved, and the fluctuation of the engine speed is suppressed during the operation of the internal combustion engine.

Here, by setting the limit value of the ignition timing change amount to a value larger than the difference between the first ignition timing and the second ignition timing or a value increased to infinity, the ignition timing change amount limit value The ignition timing may be changed over only once by canceling the restriction due to.

Further, although the crank angle sensor 12 of the angle control system is used in the present embodiment, it may be of another system, for example, a time control system. Step 4
In the case of the angle control method, the predetermined period is a period for several ignitions, and in the case of the time control method, the predetermined period is the time corresponding to the predetermined period.

<Effects of the Invention> As described above, according to the present invention, when the ignition timing is switched when the operating state of the internal combustion engine shifts from the cranking state to the complete explosion state, the control value of the ignition timing change amount is set to a greater value. Since the ignition timing is switched to a large value, the ignition timing can be switched quickly, the ignition timing can be obtained as requested by the engine, and the startability can be improved.

Further, since the amount of change in the ignition timing is limited except when the combustion state is changed, it is possible to suppress the rotation fluctuation in the complete explosion state.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing the configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, FIG. 3 is a flow chart showing an ignition timing control of an internal combustion engine in the same embodiment, and FIG. The drawings are diagrams for explaining the operation of the present invention and the prior art. 1 ... Internal combustion engine, 6 ... Control device, 8 ... Spark plug, 9 ...
Ignition coil, 10 Distributor, 11 Power transistor, 12 Crank angle sensor, 14 Signal disc plate, 18 Knock sensor, 21 Water temperature sensor, 22 Cranking switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Kume 16-1171, Kasukawa-cho, Isesaki-shi, Gunma Japan Electronic Equipment Co., Ltd. (56) Reference JP-A-1-237358 (JP, A) JP-A-62- 251473 (JP, A)

Claims (1)

(57) [Claims] 1. An operating state detecting means for detecting an operating state of an internal combustion engine, and a first ignition timing is set when the operating state detecting means detects that the internal combustion engine is in a cranking state. Ignition timing setting means for setting a second ignition timing advanced from the first ignition timing when it is detected that the ignition timing is a complete explosion state, and the ignition timing and the previous ignition set by the ignition timing setting means. The ignition timing change amount limiting means for limiting the ignition timing change amount so that the difference is within a predetermined value, and the ignition timing limited by the ignition timing change amount limiting means. In an ignition timing control device for an internal combustion engine, comprising: ignition control means for performing ignition, the operating state detecting means switches the operating state of the internal combustion engine from a cranking state to a complete explosion state. An ignition timing change amount limit value changing means for changing the predetermined value of the ignition timing change amount limiting means to a larger value for a predetermined period after the change is detected is provided for the internal combustion engine. Ignition timing control device.