JPS631759A - Ignition timing control device for number of cylinders control engine - Google Patents

Abstract

PURPOSE:To enable rapid working of a rest cylinder and to prevent slow shifting of an engine from reduced number of cylinders operation to total cylinder operation, by a method wherein, during shifting of an engine from reduced number of cylinders operation to total cylinder operation, control is effected so that the ignition timing of a rest cylinder is delayed given time than that of a working cylinder. CONSTITUTION:A number of cylinder control engine has a number of cylinders reducing means 102 inputting an output signal from a running state detecting means 101 detecting the running state of an engine, and when low load running of the engine is detected by the number of cylinders reducing means 102, operation of a part of cylinders is stopped. In this case, an ignition timing correcting means 103 is provided for inputting an output signal from the number of cylinders reducing means 102 and delaying the ignition timing of a rest cylinder a given time than that of a working cylinder during shifting of the engine from reduced number of cylinders running to total cylinder running. An ignition means 105 is controlled according to an ignition timing corrected by an ignition timing setting means 104. This constitution enables rapid shifting of a rest cylinder during shifting of the engine from reduced number of cylinders running to total cylinder running, and prevents the occurrence of slow shifting during shifting.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides a method for reducing the number of 8! The present invention relates to an ignition timing control device for a cylinder number controlled engine that suspends lJ.

(Prior art) In general, fuel efficiency tends to improve when the engine throttle valve is opened more widely, so when the engine is under light load, the fuel supply to some cylinders is cut to stop their operation. , a cylinder number control engine is known that relatively increases the load on the remaining operating cylinders by this amount and improves fuel efficiency in the light load range as a whole.

In such an engine with cylinder number control, when switching from cylinder reduction operation to full cylinder operation, the torque suddenly increases, causing a so-called torque shock. It is known that the sudden increase in torque can be suppressed by
(See Publication No. 67).

(Problem to be Solved by the Invention) However, when switching from cylinder reduction operation to full cylinder operation, even if fuel is supplied to the idle cylinder, it does not ignite immediately due to reasons such as low combustion chamber temperature. It is normal for the engine to misfire for 2 to 3 cycles. Therefore, as described above, when the ignition timing of all cylinders is retarded, there is a phenomenon in which the torque decreases.

SUMMARY OF THE INVENTION Therefore, the present invention provides an ignition timing control device for an engine with cylinder number control, which makes it easier to burn the idle cylinders when switching from full cylinder operation to reduced cylinder operation, activates the idle cylinders early, and prevents the sluggishness at the time of switching. The purpose is to provide

(Means for Solving the Problems) The configuration of the present invention for achieving the above object is as shown in FIGS. The ignition timing control device for a cylinder number control engine is assumed to be an ignition timing control device for a cylinder number control engine, which has a means 101 and a cylinder reduction means 102 which receives the output of the operating state detection means 101 and suspends operation of some cylinders when the engine is lightly loaded. The present invention is characterized in that it includes an ignition timing correction means 103 which receives the output of 102 and retards the ignition timing of the inactive cylinders by a predetermined period of time compared to the ignition timing of the operating cylinders when switching from cylinder reduction operation to full cylinder operation.

(Function) When switching from cylinder reduction operation to full cylinder operation, the ignition timing of the idle cylinder set by the ignition timing setting means 104 is corrected by the ignition timing correction means 103, and the ignition timing of the deactivated cylinder is adjusted to be shorter than that of the operating cylinder by a predetermined time (for example, a complete explosion). ), the idle cylinders are more likely to burn, and the ignition means 105 ignites them early. At this time, the operating cylinders are maintained at the normal ignition timing, so the torque obtained during cylinder reduction operation is maintained. As a result, the idle cylinders are brought into operation early and sluggishness at the time of switching is prevented.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

In Figure 1, ■ is a 6-cylinder engine with controlled number of cylinders,
An intake passage 2 and an exhaust passage 3 are connected.

In the intake passage 2, from the upstream side, an air flow meter 4, a throttle valve 5. A throttle sensor 6, a surge tank 7, and a boost sensor 8 are arranged in this order to detect the opening degree of the throttle sensor 6, and the downstream side of the surge tank 7 is branched into branch passages 2a and 2b, which communicate with each cylinder. A shutter valve 9 is provided on each branch road 2a leading to the first to third cylinders.
It is designed to be opened and closed integrally at O.

11 is an O2 sensor as an air-fuel ratio detection means disposed in the exhaust passage 3; 12 is a rotational speed sensor provided on the engine body for detecting the engine rotational speed; 13 is a knocking sensor provided on the engine body for detecting knocking; 14a
, 14b, 14c are acupressure sensors installed in the combustion chambers of the first to third cylinders to detect complete explosion, l5a''l5
f is an ignition coil provided for each cylinder, and is connected to each spark plug 16a to 16f.

20 is an engine control unit, which includes a throttle sensor 6;
An ignition timing setting means 104 receives the output of the driving state detection means 101 such as the boost sensor 8, the rotation speed sensor 12, and the knocking sensor 13, and sets the ignition timing, and the engine rotation speed signal and boost are received from the rotation speed sensor 12 and the boost sensor 8. A cylinder reduction means 102 receives a pressure signal and suspends operation of some cylinders when the engine is lightly loaded based on FIG. It has an ignition timing correction means 103 that retards the ignition timing of the deactivated cylinder set by the means 104 to retard the ignition timing of the activated cylinder by a predetermined time.

Next, the control contents of the engine control unit 20 will be explained with reference to FIG. 2.

When starting, first check the engine speed, boost pressure,
Various signals such as throttle opening and knock strength are read (step S+), and it is determined based on FIG. 4 whether or not the cylinder reduction operation zone is in progress (step 32).

If it is not the cylinder reduction operation zone, it is determined whether or not it is the moment of switching (step S3); if it is the instant of switching, the switching determination flag F is set to 1 (step S4), and the shutter valve 9 (S/V Step S5).

It is determined whether the cylinder determination flag I is 1, that is, whether or not the cylinder is ignited at rest (step 3). In addition,
The cylinder determination flag I is 2 when the cylinder to be ignited is a constantly operating cylinder, and is 1 when the cylinder is a dormant cylinder.

If the cylinder to be ignited is a dormant cylinder (1=1), it is determined whether the switching determination flag F is 1, that is, whether it is the switching moment (step S7), and if it is the switching moment,
In order to facilitate combustion, the ignition timing Trg(x
) to IgC (step S a ) i
+Note that this setting does not have to be performed at this point, but may be set during cylinder reduction operation.

Then, the acupressure sensor signal is input (step S9).
, it is determined whether the shiatsu sensors 14 a, 14 b, and 14 c are ON or not (step 51 o), and if they are ON, it means a complete explosion, so the switching determination flag F is set to 0 (step 5 tt), and the ignition timing is set. T1g(1) to Tlg(1
)+ΔT1g and advances by ΔT1g(f) (step 512).

Therefore, it is determined whether or not Tlg(1) calculated in step S12 is larger than the optimum ignition timing TMAP (map value) set according to the operating state of the engine. When the optimum ignition timing TMAP is greater than the optimum ignition timing TM, the ignition timing TIg+1) is set as the optimum ignition timing TM.
AP step 514).

Thereafter, ignition control of the cylinder to be ignited is performed based on the ignition timing T1g(I) (step 515), and when it is smaller than the optimum ignition timing TMAP, step S
The process directly proceeds to step S15 without passing through step 14, and returns to step St.

Thereafter, the same control is repeated until the optimum ignition timing TMAP is reached, and the optimum ignition timing TMAP is gradually increased by ΔTrg.
AP is approached, and torque shock is reduced.

Further, if it is determined in step S3 that it is not the switching moment, step S4? Step S6 without going through step S35.
To, step S6+S? If the determination is that I≠1°F#l, the process advances to step S12, and if the acupressure sensor is OFF in the determination of step SIG, the process advances to step S15. On the other hand, if it is determined in step S2 that it is not the cylinder reduction operation zone, then it is the all-operation zone, so a closing signal for the shutter valve 9 is output to the opening/closing means 10, step 51a).
Set the ignition timing Trg(z) to TM A P+T and step SL? ), the process moves to step SI5. Note that T is a correction term for preventing knocking.

(Effects of the Invention) As described above, the present invention retards the ignition timing of the deactivated cylinder by a predetermined period of time compared to the operating cylinder when switching from reduced cylinder operation to full cylinder operation. This prevents delays in transitioning to full operation.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is an overall configuration diagram of an ignition timing control device for an engine with a controlled number of cylinders, FIG. 2 is a block diagram of an engine control unit, and FIG. 3 shows the control contents of the unit. The flowchart, FIG. 4 is an explanatory diagram of the cylinder reduction operation zone, and FIG. 5 is a diagram showing the relationship between the operating state and the ignition timing Txg (2>+ Ttgt 1 >of the constantly operating cylinder and the idle cylinder. 1. ... Cylinder number control engine, 2 ... Intake passage, 6 ... Throttle sensor, 8 ...
... Boost sensor, 9 ... Shutter valve, 12 ... Rotation speed sensor, 14 a, 14
b, 14 c--Shiatsu sensor, 16a-16f・
... Spark plug, 20 ... Engine control unit, 101 ... Operating state detection means, 10
2... cylinder reduction means, 103... ignition timing correction means, 104... ignition timing setting means, 10
5...Ignition means.

Claims (1)

[Claims] (1) An engine comprising an operating state detecting means for detecting the operating state of the engine, and a cylinder reducing means for suspending operation of some cylinders when the engine is under light load in response to the output of the operating state detecting means, the cylinder reducing means as described above. Ignition timing control for a cylinder number controlled engine, characterized in that it is provided with an ignition timing correction means that retards the ignition timing of the inactive cylinders by a predetermined period of time compared to the ignition timing of the operating cylinders when switching from reduced-cylinder operation to full-cylinder operation in response to the output of Device.