JP2598278B2 - Engine ignition timing control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to an ignition timing control method for always determining and optimally controlling an ignition timing in a vehicle engine, and more particularly, to a return determination of a method of learning and determining an optimum ignition timing value by performing overall correction and partial correction.

[Prior art]

The optimal value of the ignition timing of the vehicle engine is set in a multidimensional manner on a map of the relationship between the engine speed and the basic fuel injection amount. By the way, since the knocking occurrence state greatly varies depending on the quality of the gasoline used, it is necessary to change the ignition timing accordingly. Therefore, a method has been performed in which the presence or absence of knocking is detected in an actual engine operating state, and a map of an optimum ignition timing advanced in a range where knocking does not occur is learned and determined. Therefore, conventionally, there is a prior art in Japanese Patent Application Laid-Open No. Sho 60-26172 regarding learning control of the ignition timing. Here, it is shown that when the correction retardation amount is equal to or more than a predetermined value, learning control is performed only when knocking occurs, thereby preventing the learning correction amount from becoming larger than necessary. As another prior art, there is Japanese Patent Application Laid-Open No. Sho 61-155771. Here, a basic map of the ignition timing is learned by the overall correction, and the operating range is compared with the value of the basic map by the partial correction of the next stage. Calculate advance and retard correction values in response
When this correction value exceeds a predetermined value, it returns to the overall correction and learns the basic map again.It is possible to immediately learn the ignition timing in response to the change in the quality of gasoline and improve the output of the engine. It is shown.

[Problems to be solved by the invention]

By the way, in the former of the prior art, since it is assumed that the learning control is stopped when the correction amount of the ignition timing becomes equal to or more than a predetermined value, it is difficult to optimally determine the ignition timing under such conditions. Also, if the return condition for the re-learning of the ignition timing is fixedly determined as in the latter case, it may not be preferable. That is, the knocking limit greatly changes due to a change in the engine cooling water temperature, and the knocking limit increases in the advance direction when the water temperature is low as in the early stage of engine start, and the knocking limit increases when the water temperature is likely to overheat. Increases in the retard direction. Therefore, in any of these cases, the correction amount of the ignition timing with respect to the basic map by the partial correction becomes large, and may exceed the predetermined value to return to the whole correction. And
Since the basic map is formed in a temporary low or high temperature state of the engine, the overall correction must be performed again when the engine temperature changes to a steady state temperature.
Then, it is necessary to frequently re-learn and re-create the ignition timing map upon return, so that the ignition timing control is delayed during the re-learning, and the control accuracy is reduced. In view of such a problem, the present invention provides a control method for re-learning by returning to the overall correction when the ignition timing is advanced or retarded by a predetermined value or more. Alternatively, it is another object of the present invention to provide an ignition timing control method for an engine in which the return to the overall correction in a high temperature state is limited to stabilize the ignition timing.

[Means for solving the problems]

In order to achieve the above object, the present invention provides an overall correction that corrects the actual ignition timing by defining a basic map between the advance upper limit and the retard lower limit of the ignition timing by knocking feedback, and each part of the basic map. In the ignition timing control method in which the partial correction value is advanced or retarded by a predetermined determination amount or more by a predetermined correction amount to return to the overall correction and learn the basic map, the ignition timing control method comprises: A return reference value for determining whether or not to return to the overall correction according to the cooling water temperature is calculated, and the return reference value is compared with the partial correction value. The feature is to return to.

[Action]

According to the above-described ignition timing control method, the ignition timing is controlled by creating an optimum ignition timing map by learning control of the whole correction and the partial correction within a predetermined determination amount, and at this time, the cooling water temperature of the engine is temporarily low or Even if the temperature becomes high, the return and re-learning are restricted by the value of the return determination amount or the like, and the original ignition timing control state is continued. Thus, according to the present invention, it is possible to prevent the disturbance of the ignition timing due to the temporary low or high temperature of the cooling water temperature of the engine and to stabilize it.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the overall outline of the ignition timing control will be described. The control unit 1 has an ignition timing map learning control unit 2 for an optimal ignition timing and an ignition timing setting unit 3. The ignition timing setting unit 3 receives the angle signal of the crank angle sensor 4 and the basic ignition timing signal based on the map of the ignition timing map learning control unit 2 and outputs signals of the ignition timing and the energization time to the ignition coil 5. At the crank angle position corresponding to the timing, the temporary coil side is cut off, and a high secondary voltage is supplied to the ignition plug 7 via the distributor 6 to ignite. The ignition timing map learning control unit 2 receives the engine speed signal of the crank angle sensor 4, the intake air amount signal of the air flow meter 8 and the signal of the knock sensor 9 attached to the engine body, and determines whether knocking has occurred. An optimum ignition timing map is created by learning the relationship between the engine speed N and the basic injection amount Tp (K · Q / N) based on the detected knocking feedback. Referring to the map learning control system in FIG.
The advance angle upper limit map section 11, which stores the advance angle upper limit M _H of the ignition timing,
Has a retard limit map unit 12 which stores a delay lower limit M _L of the ignition timing, these advance limit map unit 11, the retard limit map unit 1
The signal of the engine speed N and the intake air amount Q is input to 2,
Predetermined engine rotational speed N, the basic fuel injection amount Tp advance limit map in condition (k · Q / N) M H, retard limit map M _L ignition timing of T _H, T _L the retrieved basic map M _B Basic Map Creation Part 1
Enter 3 Knock sensor 9
And the signal of the presence or absence of knocking is input from the difference ΔT between the ignition timing T _H and T _L, by selecting the largest coefficient K in a state which does not cause knocking, as follows the basic ignition timing T _B Is calculated. _{T B = T L + △ T} · K (0 ≦ K ≦ 1) the correction is a correction whole applied to the entire area of the control area, basic map M _B is the third diagram the basic ignition timing T _B in this case ( As shown in a), it is determined by the engine speed N and the basic injection amount TP. A partial correction map unit 14 for storing a partial correction map.
Has, this partial correction map unit 14 in the same a predetermined engine speed N, it is searched partial correction value t in the basic injection amount Tp, the optimum ignition timing map via the return judgment unit which will be described later in conjunction with the basic map M _B Input to the creation unit 15. The map generator the optimum ignition timing 15 is define the partial correction value t for each condition to the basic map M _B, thus each part of the partial correction value
ta, tb, ··· is the set with final optimal ignition timing map M _T as in the third view (b) is determined. On the other hand, as a return (re-learning) control to the overall correction when the ignition timing map is inappropriate, a water temperature sensor 20 exposed to a water jacket or the like of the engine is provided, and this water temperature signal is input to the determination amount setting unit 21. I do. The determination amount setting unit 21 determines the determination amount L according to the engine cooling water temperature, and is a small value at a predetermined water temperature (for example, 50 to 90 ° C.) as shown in FIG. The value of the determination amount L is changed so as to increase according to the decrease or the increase. Further, on the output side of the partial correction map unit 14, a return determination unit 22 is provided,
Determination amount L, the advance limit map M _H, the value T _H of the retard limit map M _L, T _L
Is input, and the return reference value R is calculated as follows. _{R = (T H -T L)} × L and the reference value R and each partial correction value ta, tb, · · · and compared to the partial correction value ta a, tb, ... return and is equal to or higher than the reference value R The determination is made, and the basic map creation unit 13 is instructed to re-learn. Next, the operation of the ignition timing learning control will be described. First, the ignition timing advance upper limit map _MH and the retard lower limit map
Meanwhile using M _L, determine the basic map M _B by total correction in base map creation unit 13. The best the ignition timing map creation unit 15, basic map M _B each portion of the base correction value t
a, tb, and of creating an optimal ignition timing map M _T By ... addition, each partial correction value ta in this case, tb, ...
Is updated by feedback control based on the presence or absence of knocking. On the other hand, at this time, each partial correction value ta, tb,... Has been checked, and this will be described with reference to the flowchart of FIG. That is, the determination amount L is set according to the cooling water temperature of the water temperature sensor 20, and a reference value R based on the determination amount L is input to the return determination unit 22 and compared with the partial correction values ta, tb,. When the reference value R is at a relatively low level at a predetermined water temperature, the knocking limit changes due to a change in the quality of gasoline, etc., and the partial correction values ta, tb,. It is determined that the return exceeds the value R, and the basic map creation unit 13 re-determines the basic map suitable for the quality of the gasoline.
M _B is created. Next, when the water temperature is low in the cold state, the determination amount L
At the same time, the reference value R is set to a high level. Therefore, even if the knocking limit increases in the advance direction due to the decrease in the water temperature and the partial correction values ta, tb,... Increase in the advance direction, it is difficult to return. Further, even when the cooling water temperature is high, the reference value R is set to be large together with the determination amount L, and the knocking limit increases in the retard direction due to the rise in the water temperature, and the partial correction values ta, tb,
... is difficult to recover even if it increases in the retard direction. In this way, re-learning for a temporary low or high temperature of the water temperature is limited. In the control for the water temperature, a return determination area may be determined as shown in FIG. 6, and the determination may be canceled if the water temperature is outside this area.

【The invention's effect】

As described above, according to the present invention, when returning to the overall correction by the partial correction value in the ignition timing learning control, the return to the overall correction when the water temperature is temporarily low or high is performed. Because of the restriction, the ignition timing control can be stabilized, and delay can be avoided. Since the determination amount or the determination area is determined according to the water temperature, the return determination is clarified.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an embodiment of an ignition timing control method according to the present invention, FIG. 2 is a block diagram of an ignition timing learning control system, and FIGS. 3 (a) and 3 (b) show overall correction and partial correction. FIG. 4 is a characteristic diagram of the determination amount with respect to the water temperature, FIG. 5 is a flowchart of the operation, and FIG. 6 is a flowchart of the operation of another embodiment. 2: ignition timing map learning control unit, 11: advanced angle upper limit map unit, 12: retarded lower limit map unit, 13: basic map creation unit, 14: partial correction map unit, 15: optimal ignition timing Map creation unit, 20: Water temperature sensor, 21: Determination amount setting unit, 22
...... Return judgment unit

Claims (4)

(57) [Claims] 1. An overall ignition system for correcting an actual ignition timing by defining a basic map between an upper limit of an advance and a lower limit of a retard of an ignition timing by knocking feedback, and an optimum ignition by partially correcting each part of the basic map. When the partial correction value is advanced or retarded by a predetermined amount or more, the ignition timing control method returns to the overall correction and learns the basic map. A return reference value for determining whether to return to the whole correction is calculated, and the return reference value is compared with the partial correction value. When the partial correction value is equal to or more than the return reference value, it is determined that the return to the whole correction is performed. Characteristic engine ignition timing control method. 2. The method according to claim 1, wherein the return reference value is calculated based on a return determination amount set in advance based on a cooling water temperature of the engine and a difference between an advance upper limit value and a retard lower limit value. 2. The method for controlling ignition timing of an engine according to claim 1. 3. The engine ignition timing control according to claim 2, wherein the return determination amount is changed and set to a value that is difficult to return to the overall correction outside a predetermined water temperature range. Method. 4. The ignition timing control method for an engine according to claim 2, wherein the return determination amount is determined only within a predetermined water temperature range, and does not return to the overall correction outside the range.