JPH01104972A - Ignition timing controller for engine - Google Patents

Abstract

PURPOSE:To prevent the generation of knock in the transient reduction of revolution speed on lock-up by instantly retarding the ignition timing by a prescribed quantity in correspondence, when the lock-up operation on an automatic transmission side is detected during acceleration. CONSTITUTION:An ignition timing control means controls the ignition timing of an engine according to the detected engine revolution speed on the basis of the prescribed ignition timing characteristic, and when the engine acceleration state is detected by an acceleration state detecting means, the annealing correction for the ignition timing characteristic is executed by an ignition timing characteristic correcting means. In this case, if the lock-up operation on the automatic transmission side is detected by a detecting means in the course of acceleration, the ignition timing control means instantly retards the ignition timing by a prescribed quantity in correspondence. Thus, even if the annealing correction for the ignition timing control value in consideration of the responsiveness of an ignitor in acceleration exists, for the transient reduction of revolution speed in lock, the excessive advance of the ignition timing is corrected, and generation of knocking can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ignition timing control device for an engine.

(Prior art) In general, the ignition timing of an engine is controlled by using the crank angle according to the engine speed as a reference, and correcting the basic characteristics according to the engine operating condition such as intake negative pressure. is being carried out.

Therefore, for example, when the vehicle is accelerated and the engine speed NE (FIG. 5C) increases in accordance with the vehicle speed as shown in FIG. 5(a), the ignition timing should be 1 gt
(Fig. 5b) is also subjected to advance angle control.

However, the igniter on the engine side that actually controls the advance angle value has a limited response performance.
(asec), the response performance is within 10°. Therefore, if an attempt is made to advance the ignition timing at a transient high speed of 1° as during acceleration, the driving feeling will deteriorate.

Therefore, in the past, the actual control characteristics of the ignition timing during acceleration as described above have generally been changed as shown by the solid line in FIG. 5(b) with respect to the original control characteristics on the map shown by the broken line. A type of insensitivity correction (smoothing correction) called smoothing correction is applied. (For example, Special Public Service No. 60-60025
(see publication).

Specifically, this smoothing correction is performed by changing the current ignition timing Igt+ in the relevant operating state to the next value (from the map @Ngt* to be read) that is varied in response to changes in boost pressure and rotational speed due to acceleration, etc. Subtraction (■Nt −I gtυ
and the subtracted value (I gtt I gt+=ΔI gt
) is added to the above current ignition timing 1gt+ (Igt++Δ
Igt) to determine the actual ignition timing. Therefore, in the end, the control gain for the actual ignition timing can be changed to approximately 1/2 of the original control width, making it possible to control the ignition timing appropriately in accordance with the response performance of the igniter, especially during acceleration. Improves driving feeling.

(Problems to be Solved by the Invention) However, when the ignition timing is corrected as described above, as shown in FIG. 5(d), for example, in a vehicle equipped with an automatic transmission with a lock-up mechanism, When a lock-up operation (lock-up signal SL: ON) is performed during the above-mentioned acceleration, the engine speed NE (C
) suddenly decreases, but on the other hand, the ignition timing 1st (b in the same figure) cannot follow this due to the above-mentioned rounding correction, and ends up being over-advanced, and in some cases, the throttle must be fully closed. Knocking will occur near the point.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above problems, and includes controlling the ignition timing of the engine based on predetermined ignition timing characteristics depending on the engine speed. ignition timing control means; acceleration state detection means for detecting an acceleration state of the engine; and smoothing correction of ignition timing characteristics controlled by the ignition timing control means when an acceleration state is detected by the acceleration state detection means. In the engine ignition timing control device, which is applied to a vehicle having an automatic transmission with a lock-up mechanism, the engine ignition timing control device is provided with a lock-up state detection means for detecting a lock-up state of the lock-up mechanism. When the lockup state detection means detects a lockup operation in the acceleration state, the ignition timing controlled by the ignition timing control means is immediately retarded by a predetermined amount.

(Function) According to the above means, the ignition timing control means controls the ignition timing of the engine based on a predetermined ignition timing characteristic according to the engine speed, the acceleration state detection means detects the acceleration state of the engine, A vehicle having an automatic transmission with a lock-up mechanism, comprising ignition timing characteristic correction means for smoothing and correcting the ignition timing characteristics controlled by the ignition timing control means when an acceleration state is detected by the acceleration state detection means. When a lock-up operation on the automatic transmission side is detected during acceleration in an engine applied to
Correspondingly, the ignition timing is immediately retarded by a predetermined amount.

As a result, even if the ignition timing control value is rounded and corrected in consideration of the responsive performance of the igniter during acceleration, the ignition timing does not advance due to the above-mentioned transient decrease in rotational speed during lock-up. Corrected by the retard correction,
This prevents the occurrence of bumping.

(Example) First, FIGS. 2 and 3 show an ignition timing control device for an automobile gasoline engine in which the present invention is applied to the engine, and FIG. FIG. 3, which is a schematic diagram of the control system of the apparatus, is a flowchart showing the ignition timing control operation of the engine control unit in the control system.

First, the outline of the control system according to the embodiment of the present invention will be explained with reference to FIG. 2, and then the control operation of the main parts will be explained.

In FIG. 2, reference numeral 1 is the engine body, and intake air is taken in from the outside via an air cleaner 30.
Thereafter, the air is supplied to the cylinder via an air flow meter 2 and a throttle chamber 3. Further, fuel is supplied from the fuel tank 12 to the engine side by the fuel pump 13 and injected by the fuel injector 5.

The amount of air taken into the cylinder during running is controlled by a throttle valve 6 provided in the throttle chamber 3. The throttle valve 6 is operated in conjunction with the accelerator pedal.

Note that the throttle chamber 3 is provided with a bypass intake passage 7 that bypasses the throttle valve 6, and the bypass intake passage 7 includes an intake air amount adjusting means for controlling the engine speed during idling. A current controlled solenoid valve (IsC valve) 8 is provided.

Further, the reference numeral IO indicates an exhaust pipe equipped with a three-way catalytic converter 11.

On the other hand, reference numeral 14 denotes an ignition plug provided in the cylinder head portion of the engine main body l, and the ignition plug 14
A predetermined ignition voltage is applied to the EC via the distributor 17 and the igniter 18, and the application timing of this ignition voltage, that is, the ignition timing is determined by the above-mentioned EC.
It is controlled by the ignition timing control signal Igt supplied from U9 to the igniter 18. Also, code 1
Reference numeral 9 denotes a knock sensor provided in the cylinder block portion of the engine main body I, which outputs a voltage output V0 corresponding to the intensity of occurrence of knocking in the engine, and inputs it to the ECU 9. Furthermore, reference numeral 20 denotes a boost pressure sensor 20, which detects an engine boost pressure B corresponding to the engine load and inputs it to the ECU 9.

The ECU 9 is configured to include, for example, a microcomputer (CPU) which is a calculation unit, a control circuit for intake air amount, ignition timing, etc., memory (ROM and RAM), an interface ([10] circuit, etc.). In addition to the above-mentioned detection signals, the interface circuit of the ECU 9 receives, for example, an engine start signal (ECU trigger) from a starter switch (not shown), an engine rotation speed detection signal from an engine rotation speed sensor 15, and a water temperature thermistor 16. A detection signal Tw of the detected engine cooling water temperature, for example, a throttle opening detection signal TvO detected by the throttle opening sensor 4, an intake air amount detection signal Q detected by the air flow meter 2, etc. are necessary for normal engine control. Various detection signals are also input.

On the other hand, the code 21 is the engine itself! The figure shows a lock-up torque converter type automatic transmission with overdrive connected to the output shaft of the engine. The automatic transmission 2I includes a lock-up clutch 22, a lock-up control valve 23,
A lock-up mechanism consisting of a lock-up solenoid 24, a lock-up control unit 30, etc., an overdriving gear 27, and an overdriving valve 28.
, an overdriving mechanism consisting of an oniva driving solenoid 34, an overdriving switch 35, etc., a gear train section 26 of the transmission itself, and a rotation speed detection device provided on the transmission output shaft side via the gear train section 26. Centrifugal governor 29 and the lock-up control valve 2
3. A control valve 31 that controls the overdriving gear 27, overdriving valve 28, gear train section 26, etc., and a kickdown solenoid 32.
It also includes a kickdown switch 33 and the like.

Then, the lock-up control unit 3°'0 determines whether overdrive or lock-up is OK based on input signals from various sensors, and if each condition is OK, the kick-down solenoid is 32, the lock-up control valve 23, overdriving gear 27, overdriving valve 28, gear train section 26, etc. are operably controlled via the control valve 31, and the lock-up solenoid 24
A lock-up signal SL is supplied to the lock-up clutch 22 of the lock-up mechanism, thereby locking up the torque converter.

The lock-up signal SL is also input to the ECU 9.

Next, the control operation of the ignition timing by the engine control unit 9 during vehicle acceleration will be explained in detail with reference to the flowchart of FIG. 3.

First, in step SI, the opening degree TVO of the throttle valve 6 is determined.
are sequentially input, and the process proceeds to the next step S, where it is determined from the rate of change of the throttle opening degree TVO in the opening direction whether or not the running state of the vehicle is in an acceleration state. As a result of this determination, YE
If S (acceleration state r14) is recognized, further step S3
The ignition timing during acceleration is 1g as described above.
Perform "smoothing correction" of t. As explained earlier, the smoothing correction is an insensitive correction that takes into account the response performance of the igniter 18, and its correction characteristics are shown in FIGS. 5(a) and 5(a).
As shown in b), the vehicle speed V(k
IIl/h).

Then, the process further advances to step S4, where the lock-up signal S of the lock-up clutch 22 of the automatic transmission 21 described above is
L is input, and in the next step S, the ON state of the lock-up signal SL, that is, the lock-up state of the lock-up clutch 22 is determined.

As a result, if YES (lock-up signal SLh<ON signal state) (see FIG. 4C), the next step S8
Proceed to perform the above lock-up correction of the ignition timing of 1gt. The lock-up correction is performed when the lock-up clutch 22 is locked up in the above acceleration state, as shown in FIG. 4(b), the engine rotational speed NE drops rapidly. In view of the fact that the timing control lacks followability and the ignition timing 1gt becomes over-advanced (see Figure 5), leading to knocking, the timing control should be constant from the time the lock-up signal is turned on, as shown in Figure 4(e), for example. A lock-up correction signal (retard signal) is supplied to retard the ignition timing by t (the time corresponds to the over-advance period when the rotation speed decreases due to lock-up) to specifically over-advance the ignition timing. This is done by performing minute retard control. As a result, the set ignition timing tgt after the lock-up correction becomes an appropriate value according to the fluctuation of the engine speed NE (Fig. 4 (b)), as shown in Fig. 4 (f), and this value In the next step S7, the ignition timing is actually controlled. Therefore, the fear of knocking is eliminated and the combustion performance becomes stable.

Note that when the lockup is not performed (NO in step S), the ignition timing control (step S) is performed at a normal value without performing the lockup correction (step S8).

Incidentally, the adjustment of the ignition timing at lock-up during acceleration as described above is not limited to the case where specific retard control is performed as in the above embodiment. For example, as shown in FIG. 4(g), The retarding function may be substantially realized by changing the amount of smoothing itself in response to changes in the rotational speed.

(Effects of the Invention) As described above, the present invention includes an ignition timing control means for controlling the ignition timing of the engine based on a predetermined ignition timing characteristic according to the engine speed, and a means for detecting the acceleration state of the engine. The present invention includes an acceleration state detection means, and an ignition timing characteristic correction means for smoothing and correcting the ignition timing characteristic controlled by the ignition timing control means when an acceleration state is detected by the acceleration state detection means, and is equipped with a lock-up mechanism. In an engine ignition timing control device applied to a vehicle having an automatic transmission, lockup state detection means is provided for detecting a lockup state of the lockup mechanism, and the lockup state detection means detects a lockup operation in the acceleration state. In this case, the ignition timing controlled by the ignition timing control means is immediately retarded by a predetermined amount.

That is, according to the present invention, the ignition timing control means controls the ignition timing of the engine based on a predetermined ignition timing characteristic according to the engine speed, the acceleration state detection means detects the acceleration state of the engine, and the acceleration state and an ignition timing characteristic correction means that performs smoothing correction of the ignition timing characteristic controlled by the ignition timing control means when an acceleration state is detected by the detection means, and is applied to a vehicle that uses an automatic transmission with a lock-up mechanism. When a lock-up operation on the automatic transmission side is detected in the engine during acceleration, the ignition timing is immediately retarded by a predetermined amount in response.

As a result, in response to the transient drop in rotational speed during lock-up, the ignition timing control value is rounded and corrected in consideration of the responsive performance of the igniter during acceleration. The correction corrects this and prevents knocking from occurring.

Therefore, in the present invention, while ensuring a good driving feeling by smoothing the ignition timing during acceleration, at the same time properly correcting the over-advance angle due to the smoothing correction of the ignition timing, it also prevents the occurrence of knocking. It is possible to provide an ignition timing control device for an engine that can perform the following steps.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to claims of the present invention, FIG. 2 is a control system diagram of an engine ignition timing control device according to an embodiment of the present invention, and FIG. 3 is a flowchart showing the control operation of the device. FIG. 4 is a time chart of signals of each part to explain the operation of the device, and FIG. 5 is a time chart showing the operation of a conventional ignition timing control device. 1... ψψφ Engine body 2... Air flow meter 5... Fuel injector 9... Engine control unit 14...
- Spark plug 17... Distributor 18... Igniter 20... Boost pressure sensor 21... Automatic transmission 22... Lock-up clutch 23... Lock-up control valve 24 ...Lock-up solenoid

Claims (1)

[Claims] 1. ignition timing control means for controlling the ignition timing of the engine based on a predetermined ignition timing characteristic according to the engine speed; acceleration state detection means for detecting the acceleration state of the engine;
and ignition timing characteristic correction means for smoothing and correcting the ignition timing characteristics controlled by the ignition timing control means when an acceleration state is detected by the acceleration state detection means, and an automatic transmission with a lock-up mechanism. In an engine ignition timing control device applied to a vehicle, a lockup state detection means for detecting a lockup state of the lockup mechanism is provided, and the lockup state detection means detects a lockup operation in the acceleration state. An ignition timing control device for an engine, wherein the ignition timing controlled by the ignition timing control means is immediately retarded by a predetermined amount.