JPS6232223A - Engine ignition timing control device - Google Patents

Abstract

PURPOSE:To eliminate misalignment of ignition timing due to a delay in the response of a change-over means for changing the strength of swirl created in intake-air flowing into a combustion chamber, by changing the ignition timing after a predetermined time period elapses from the change-over timing of the above-mentioned means. CONSTITUTION:During an engine 1 being operated, a control unit 30 calculates at first a basic injection pulse width TP in accordance with output signals from an air- flow sensor 20 and a rotational speed sensor 24, and searches the ignition timing on a map in accordance with the pulse width TP and the engine rotational speed NE. If a high volume intake-air operating range is determined in accordance with the basic fuel injection pulse TP and the engine rotational speed NE at this time, an actuator 15 is operated to open a shut-off valve 14 for feeding intake-air into a combustion chamber 3 from a main intake-air passage 4. Further, upon change-over of the shut-off valve 4 into the opening position, an compensating value for the spark retardation of the ignition timing with respect to a delay in the response of the opening operation of the shut-off valve 14 is calculated after a predetermined time period elapses, to compensate the spark retardation of the above-mentioned ignition timing, thereby a delay in the response of the opening operation of the shut-off valve 14 is compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field') The present invention relates to an ignition timing control device for an engine. In an engine equipped with a switching means for changing the substantial flow area of the intake passage, the switching means is switched and controlled according to the operating condition of the engine. This is related to consistency measures.

(Prior Art) Conventionally, as one of the intake systems of this type of engine, as disclosed in Japanese Utility Model Application Publication No. 57-186624, for example, the intensity of the swirl generated by the intake air flowing into the combustion chamber has been changed. In order to open and close the first intake passage of the first and second intake passages that communicate with the combustion chamber independently of each other, the switching means changes the substantial flow area of the intake passage near the intake port. A valve is provided, and the opening and closing of the on-off valve is controlled according to the operating state of the engine. For example, during low-load operation, intake air is drawn only from the second intake passage through the on-off valve, thereby increasing the intake flow rate and creating a C swirl. This increases the combustion speed in the combustion chamber, thereby enabling lean combustion even at low loads where combustion stability is poor.At the same time, during load operation, the on-off valve is opened and intake air is combusted from both intake passages. It is known that air is supplied to a chamber to increase the filling efficiency of intake air and improve output. Such intake systems include swirl control valve systems, dual induction condensation systems, and the like.

(Problems to be Solved by the Invention) By the way, in an engine equipped with such an intake system, a switching means (
Although the ignition timing is immediately changed in response to changes in operating conditions when the switching means (open/close valve) is switched, the switching means has a response delay in its operation. Intake air flow rate) and ignition timing do not match,
This will worsen the combustion condition. For example, when switching between an on-off valve and a closed valve, the ignition timing is advanced even though the flow rate of intake air into the combustion chamber is high due to the response delay, which may cause a misfire. Conversely, when the on-off valve is switched to close, the ignition timing is retarded even though the flow rate of intake air into the combustion chamber is slow, resulting in deterioration of combustibility.

The present invention has been made in view of this point, and its purpose is to focus on the delay in the operational response of the switching means when the switching means is in the negative state, and to change the ignition timing afterwards without changing the ignition timing during that time. By making this change, it is possible to eliminate the mismatch in ignition timing due to the response delay of the l;7J conversion means and improve the combustibility.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention is as follows:
As shown in the figure, in order to change the strength of the swirl generated by the intake air flowing into the combustion chamber 3, a switching means 14 is provided for changing the substantial flow area of the intake passage near the intake port (force). The switching means 14 is controlled according to the operating condition of the engine.
It is assumed that the engine is designed to do n. And ignition timing U to adjust the ignition timing! J adjustment means 17 is provided, and a switching timing determining means 31 for determining the switching timing of the switching means 14, and receiving the output of the switching timing determining means 31, determines the ignition timing after a predetermined period has elapsed from the switching timing of the switching means 14. The control means 32 controls the ignition timing adjustment means 17 so as to change the ignition timing to an optimum value according to the engine operating state at that time.

(Function) With the above configuration, in the present invention, when the switching means 14 is switched, the ignition timing is not changed for a predetermined period corresponding to the operational response delay of the switching means 14 from this switching timing, and after the predetermined period has elapsed. Since the ignition timing is changed to the optimum value according to the engine operating condition at that time, the switching means 14
Inconsistency in ignition timing due to delayed response is eliminated, and the intake flow state (for example, intake flow velocity state) of the combustion chamber and the ignition timing are adjusted, so that a good combustion state can be maintained at all times.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall schematic structure of an embodiment in which the present invention is applied to an ignition timing control device for an engine equipped with a swirl control valve system. In the same figure, 1 is the piston 2
The combustion chamber 3 of the engine 1 has one end that opens to the atmosphere through an air cleaner 5 and the other end that opens into the combustion chamber 3 through an intake port 4a. A main intake passage 6 for supplying intake air to the engine 1 is an exhaust passage whose one end opens into the combustion chamber 3 and the other end opens into the atmosphere for discharging exhaust gas from the combustion chamber 3 of the engine 1.

Further, 7 is an intake valve disposed at the front end of the combustion chamber 3 of the main intake passage 4 (intake port 4a), and 8 is an intake valve disposed in the combustion chamber 3 of the exhaust passage 6.
This is an exhaust valve located at the frontage.

A throttle valve 9 for controlling the amount of intake air is disposed in the main intake passage 4, a surge tank 10 for expanding intake air is provided downstream of the throttle valve 9, and a fuel injection valve 11 for injecting fuel is further downstream thereof. is installed. The main intake passage 4 also has an auxiliary air passage that communicates upstream and downstream of the throttle valve 9 by bypassing the throttle valve 9, and supplies auxiliary air to the combustion chamber 3 of the engine 1 by bypassing the throttle valve 9. 12 is provided, the auxiliary air passage 12
An auxiliary air control valve 13 that opens and closes the auxiliary air passage 12 is disposed in the middle.

Further, an on-off valve (swirl control valve) 14 as a switching means for opening and closing the main intake passage 4 is disposed immediately upstream of the fuel injection valve 11 in the main intake passage 4. An actuator 15 for opening and closing the valve 14 is connected. Further, downstream of the throttle valve 9 of the main intake passage 4, the on-off valve 14 and the intake port 4a are connected to each other, bypassing the on-off valve 14 and communicating with each other.
A bypass passage 16 that communicates with the combustion chamber 3 is provided independently of the main intake passage 4 . The bypass passage 16 is set to have a passage cross-sectional area smaller than that of the main intake passage 4, and preferably has its downstream end opening 16a open toward the circumferential direction of the combustion chamber 3, so that the intake air is passed through the bypass passage 16. By drawing the air into the combustion chamber 3 through the intake air, an intake swirl that swirls in the circumferential direction is generated within the combustion chamber 3.

Further, 17 is a distributor as an adjustment means for adjusting the ignition timing, and 18 is a valve train that opens and closes the intake/exhaust valves 7.8 by 5% at a predetermined timing (cam shirts 1 to 1 in various configurations). .

On the other hand, 20 is an air flow sensor that is disposed upstream of the throttle valve 9 in the main intake passage 4 and detects the intake air amount Qa;
Reference numeral 21 indicates an intake crystal sensor 2 which is disposed upstream of the throttle valve 9 in the main intake passage 4 and is capable of detecting the temperature of intake air (intake air temperature).
2 is a throttle opening sensor built into the idle switch that detects the opening degree of the throttle valve 9 and also detects idling when the throttle valve 9 is fully closed; 23 is the rotation angle of the camshaft 18; J: detects the reflux angle; A crank angle sensor 24 is a rotational speed sensor disposed in the distributor 17 and detects the engine rotational speed NE. The output of each of these sensors 20 to 24 is the fuel injection port→
The information can be input to a control unit 30 including a CPU that controls the operation of the valve 11, the auxiliary air control valve 13, the actuator 15 of the on-off valve 14, and the distributor 17, respectively. Accordingly, the control unit 30 controls the fuel injection valve 1 according to the engine operating state.
1 to adjust the fuel injection m from the fuel injection valve 11, and also control the duty of the auxiliary air control valve 13 according to the engine operating state to adjust the auxiliary air flow rate through the auxiliary air passage 12. ing. Furthermore, the actuator 15 is actuated and controlled according to the engine operating state, and the on-off valve 14 is closed when the load is low or the rotation speed is low, and the intake air is drawn into the combustion chamber 3 only through the bypass passage 16, thereby increasing the intake flow velocity. A swirl of intake air is generated in the combustion chamber 3 to increase the combustion speed, thereby enabling combustion near the lean limit of the air-fuel ratio.At the same time, during high load and high rotation, the on-off valve 14 is opened to transfer the intake air to the main intake. aisle 4
By supplying the intake air from the combustion chamber 3 to the combustion chamber 3, the charging efficiency of intake air is increased.

Further, the ignition timing by the distributor 17 is controlled in accordance with the engine operating state and the opening/closing switching of the on-off valve 14 accompanying changes in the engine operating state.

Next, the ignition timing control by the control unit 30 will be explained in detail with reference to the flowchart shown in FIG.
1Qa and engine speed NE are read, and in the next step S2, based on these Qa and Nε, the main injection pulse width Tp corresponding to the intake negative pressure signal is set to Tp = -Qa /
Calculated using the formula NE (K: constant). Then, the engine speed Nε and the basic blower pulse width Tp (intake negative pressure)
The ignition timing is determined from the relationship map and the distributor 17 is controlled.

At that time, in step S3, it is determined whether or not the r% main injection pulse width Tp (intake negative pressure) is larger than the predetermined 1 mA.
It is determined whether the engine speed NE is greater than a predetermined 1st shift B or not, and if any of these determinations is NO, it is determined that the engine is in a low load or low rotation low intake air amount operation range, and the
In step S5, a closing signal is output to the actuator 15 to close the on-off valve 14. On the other hand, step S3
, S4 are both YES, it is determined that the operation is in a high-load, high-speed, high-intake-amount operating region, and an open signal is output to the actuator 15 to open the on-off valve 14 in step S6.

Next, when opening the on-off valve 14, it is determined in step S7 whether or not the on-off valve 14 was closed last time, and if the answer is No, which indicates that the on-off valve 14 was open last time, the process continues;
If the answer is YES, indicating that the valve was in the closed state last time, it is determined that the on-off valve 14 is now open for the first time, and the timer is set to count down in step S8, and the next step S is performed.・Proceed to ). Then, in step S3, it is determined whether the timer is at the high value H, and in step S10, it is determined whether or not the timer has counted down from the high value H to low f11[L.
In the case of ES, the count number i is set to zero in step SII, while if both of the above determinations are No, that is, when the timer transitions from the high value w1 day to the low value, step S1 is performed.
2, the count number i is incremented by 1°, and the process proceeds to the next step S13.

Then, in step S13, the opening/closing button? The ignition timing retardation correction amount θTIS for the response delay of the opening operation of No. 14 is calculated using the formula θv+5=c−D−i (C: jF2 large retardation correction value, D: constant). As a result, the retard angle correction amount θTI'S becomes as shown in FIG. 4(d).
When the timer is at the high value H, the maximum retardation correction amount C is maintained, and thereafter it gradually decreases. After that, in order to prevent the timer from counting down (and not performing advance angle correction), it is determined in step S14 whether θT[S is greater than or equal to zero, and if θTIS≧O (YES), step S14 is performed. At +s, this θTIS is used as the advance angle correction amount, but when θTIS<O, θT is set at step S16 as well as when the on-off valve 14 is closed at step S5.
Set 1s to zero and proceed to the next step S +y.

Subsequently, in step S+y, the ignition advance value θIG is calculated from the equation θrc=f(Qa, NE)−θTIS. Here, f(Qa, NE) is the ignition advance amount set from the map based on the intake air ff1Qa and the engine speed NE, and is The ignition timing is delayed due to lean combustion due to swirl generation, while the ignition timing is delayed when the on-off valve 14 is opened (
ii! (at intake amount), the ignition timing is set to be advanced. Therefore, during a predetermined period from the switching timing of the on-off valve 14, the ignition advance value θI(, is the ignition advance angle mf() set by the opening of the on-off valve 14 as shown in FIG. 4(C). Qa
.

The retarded angle is corrected by subtracting the retard angle correction amount θTIS from NE>, and the response delay of the opening operation of the on-off valve 14 shown in FIG. It will be advanced to. Shikuru 1 Hen, Step S
At +a, the ignition operation of the spark plug is delayed at this ignition advance angle of 1 straight θIG. Thereafter, the process returns to step S1 and the above operation is repeated to control the ignition timing.

In the above flow, through steps S6 and S7,
It constitutes a switching timing determination means 31 that determines the switching timing of the on-off valve 14 (switching means). Also, steps 88 to S
113, the ignition timing is changed to the engine operating condition at that time after a predetermined period has elapsed from the switching timing of the on-off valve 14 (switching means). υ control means 32 that controls the distributor 17 to change the optimum value f (Qa, NE) according to the male
It consists of

Therefore, when the on-off valve 14 is switched due to a change in the operating state of the engine from a low load or low rotation range (at low intake air amount) to a high load and high rotation range (at high intake m), the switching timing is determined during this period. Switching timing determination means 31 (control unit 3
0), an open signal is immediately output to the actuator 15 of the on-off valve 14 as shown in Fig. 4(a). ), it gradually opens after a predetermined period of time has elapsed.

Therefore, during this response delay, the intake flow velocity is maintained high due to the open state of the on-off valve 14, and a swirl of intake air is generated in the combustion chamber 3.

On the other hand, the ignition timing is controlled according to the operating state at that time, and is controlled so that it is controlled in the closed region of the on-off valve 14 and advanced in the open region.
During a predetermined period corresponding to the above-mentioned response delay period from the opening switching timing, the retard angle correction amount θTIS as shown in FIG.
As a result, the retardation angle is corrected, resulting in the optimum retardation amount for the swirl, as shown in FIG. That is, for a predetermined period from the switching timing, the ignition timing is not changed in response to the opening signal to the on-off valve 14 and is maintained at the same retard amount as when the on-off valve 14 is closed. As a result, the on-off valve 14
There is no mismatch in ignition timing due to response delay, and the ignition timing is matched to the intake airflow condition (swirl generation condition) in the combustion chamber 3, which prevents occurrences of misfires and provides good combustibility. can be secured. After the predetermined period has elapsed, the ignition timing is not retarded and is advanced to an optimum value according to the opening range of the on-off valve 14.

Incidentally, in the flowchart of FIG.
4, the ignition timing may be controlled so as to change the ignition timing to the optimal value according to the operating condition at that time after a predetermined period has elapsed from the close switching timing. This eliminates misalignment of ignition timing due to response delay in the closing operation of L, and ensures good combustibility.

In addition, although the above embodiment describes a case where the application is applied to an engine equipped with a swirl control valve system, the present invention is also applicable to other systems such as a dual induction control system, which change the strength of swirl generated by intake air flowing into a combustion chamber. The present invention can be widely applied to engines equipped with an intake system in which a switching means for changing the major flow area of an intake passage near an intake port is controlled in accordance with engine operating conditions.

(Effects of the Invention) As explained above, according to the engine ignition timing control device of the present invention, in order to change the strength of the swirl generated by the intake air flowing into the combustion chamber, the intake passage at one corner near the intake port In an engine equipped with an intake system in which a switching means for changing the effective flow path area of the engine is controlled according to the operating state of the engine, when the switching means is switched, the ignition timing is changed after a predetermined period has elapsed from the switching timing. Since Modification 4 is adopted, it is possible to eliminate mismatching of ignition timing due to response delay of the switching means, and to maintain a good combustion state at all times, thereby improving combustibility.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of the present invention. 2 to 4 show an embodiment of the present invention, FIG. 2 is a schematic diagram of its overall structure, FIG. 3 is a flowchart showing the operation of the ignition timing control of the control unit, and FIG. )～(d
) are characteristic diagrams of the output signal to the on-off valve, the opening degree of the on-off valve, the optimum retard amount for swirl, and the retard angle correction amount when switching between the on-off valves. DESCRIPTION OF SYMBOLS 1... Engine, 3... Combustion chamber, 4... Main intake passage, 14... Opening/closing valve, 16... Bypass passage, 17
. . . distributor, 30 . . . control unit, 31 . . . switching timing determination means, 32 . . . control means. Figure 1 (Combustion chamber) Figure 4 Procedural correction type (method)

Claims (1)

[Claims] (1) A switching means is provided for changing the substantial flow area of the intake passage near the intake port in order to change the strength of the swirl generated by the intake air flowing into the combustion chamber, and the switching means is controlled according to the operating state of the engine. In the engine, the engine is controlled by: an ignition timing adjusting means for adjusting the ignition timing; a switching timing determining means for determining the switching timing of the switching means; and control means for controlling the ignition timing adjusting means to change the ignition timing to an optimal value according to the engine operating state at that time after a predetermined period has passed.