JPS59213947A - Engine ignition timing control method - Google Patents

Abstract

PURPOSE:To increase an engine output by delaying ingition timing of only a cylinder in which knocking is produced, in a method where the ignition timing is fed back for control in response to knocking intensity. CONSTITUTION:A knocking sensor 5 is provided on one part of the wall surface 6 of an engine 1 for detecting engine knocking. This signal is connected to a band pass filter (BPF) 7 of a microcomputer unit (MCU) 2, and when some knocking is produced, only a cylinder with said knocking produced is delayed in its ignition timing. Hereby, the engine output is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The misfire ψ relates to a method for controlling the ignition timing of an engine, and particularly relates to a method for controlling the ignition timing of an engine, which modifies the ignition timing to suppress the occurrence of knocking.

[Background of the invention]

Hitherto, as a measure to improve the fuel economy of automobiles or increase the output per unit volume, lean mixed combustion, 11° supplementation of intake air, etc. have been put into practical use.

However, under these conditions, the engine is susceptible to non-king, and in some cases, this can have adverse effects such as a reduction in driving performance and a reduction in engine output due to the generation of reverse torque, which can even lead to engine failure. Therefore, as a method to prevent these problems [Patent Application No. 57-273]
As shown in Fig. 25J, engine knocking is detected and the ignition timing is corrected to maintain the knocking' (i=1
4y, output efficiency of the removal engine? It is known that the nails are drawn out to make the eyes look thicker. The example shown in these prior art is a method of correcting the ignition timing after knocking has occurred.
It does not reflect the effects of variations in /l (', variations in cylinder internal pressure, variations in cylinder temperature, etc.) (cylinder variations in the occurrence of knocking), and does not lead to 1, which brings out the maximum engine output. It harbored the drawback of inefficiency.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine ignition timing control method that eliminates the drawbacks of the prior art described above and improves engine output and fuel efficiency due to a lean mixture.

[Summary of the invention]

The present invention provides a method for suppressing ignition timing that detects knocking occurring in an engine and corrects the ignition timing to suppress the occurrence of non-king, in which the ignition timing is corrected only in the cylinder where knocking occurs. It is something to do.

[Embodiments of the invention]

Hereinafter, the speed of an embodiment of the present invention will be measured according to the drawings.

FIG. 1 shows the overall configuration of an ignition timing control method 6 to which the present invention is applied. coil 3
Each cylinder is ignited by receiving the intraocular pressure generated from the cylinder. 2 is a control fA1 device,
Built-in microcomputer units) (MCU 9, bandpass filter I BPF) 7, amplifier 8,
The temperature sensor 10 attached to the engine and the operating state of the engine are shown. For example, in response to a signal from an engine state detector 11 such as an intake air amount sensor including a rotation angle sensor, or a throttle position sensor, an ignition timing signal is sent to the ignition coil I to guide the engine to an appropriate operating state.
K and the engine is operated.

Further, a knock sensor 5 for detecting engine knocking is provided on a part of the wall surface 6 of the engine 1, and this signal is connected to the BPF 7 of the MCIJ 2. The ignition timing signal is corrected to perform control to suppress knocking.

Taking a four-cylinder engine as an example, the relationship between the ignition timing and each stroke of the engine is as shown in FIG. 2, and ignition is performed cyclically every cylinder tcYL1 to tcY4) with respect to the engine crank angle. In other words, the actual example is CYL1+
Ignition is carried out in a cycle of CYL3+CYL4-+CYL2→CYL1, and the ignition 111LI order is turned around again for the fourth time after ignition in the relevant cylinder.

Next, the operation of the knock control will be explained in Fig. 3.

Rotation angle I'' occurs at a predetermined timing with respect to the cylinder top dead center of the engine, and ignition is performed in each cylinder using this signal as the base point for all cylinders. For the engine operated in this state, the signal of @jJ mt knock sensor 5 is E CLJ 2 with both German and German alternating current waves as shown in Figure tC).
The output is shown in B I) Ii' 7. 13 P F
7 is the frequency of the non-king signal generated in the engine. For example, 7 KHz fil is the Sallen-Key type filter that basses your frequency sound p -+7)-'a1"'c;h'),B
P li' 717) The output signal is output as a waveform SIG in which the non-king signal is enhanced, as shown in +D) of the figure. This signal enters the amplifier 8 and is compared with a predetermined signal BGL inside the amplifier 8. When the relationship SIG>BGL is established, the pulse-like output signal from the amplifier 8 is '< raw L I same. u (E) ), M CTJ 9
VC entering Kasare b. The NIcU9 is configured to count the signal pulse signal with a built-in knock counter, read the knock detection value nx at the interruption of the rotation angle signal, and immediately reset the counter. That is, this knock detection value nx corresponds to the knocking intensity generated in the engine.

As shown in the same figure (Gl), the ignition timing during engine operation is determined by the engine operating conditions (rotational speed, load).

θIN,L) is determined by the temperature. In this condition, knocking occurred in the first cylinder (CYLI): lj! Next, when the first cylinder (CYLl) is ignited, the final ignition timing (θ(
Output as N, L) 10knp). That is, the knock correction ignition angle θknp'ir is reflected in the ignition timing four times after the occurrence of knocking in the four-cylinder engine, and control is then performed so as to return to the desired integral slope θKNI.

FIG. 4 shows a knock suppression cape proportional characteristic showing the correction amount for the knock detection Fb value explained in FIG. 3, and weights are given to the correction amount corresponding to the knock intensity.

FIG. 5 is a flowchart of the above-described ignition timing control program.

As a result, the next knocking information for the same cylinder is removed from the previously imported knocking information. Therefore, ignition timing correction is performed only on the cylinders where non-king occurs, and the variation in the occurrence of non-king in cylinder 1 can be completely absorbed, making it possible to maximize the output efficiency of the engine and having a large effect on improving fuel efficiency by using a lean mixture. can get.

In this example, a 4-cylinder engine was described, but can engines with other numbers of cylinders also be used? Of course, by changing $ and Nk, the same function and effect can be obtained.

〔Effect of the invention〕

According to the present invention, it is possible to improve engine output and improve fuel efficiency due to a lean mixture.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the ignition timing correction -4+a of a four-cylinder spark ignition engine to which the present invention is applied, and FIG. 2 is an explanatory diagram showing the relationship between the ignition timing of the four-cylinder engine and each stroke of the engine. 3 is a waveform diagram showing the operating state of each part of the ignition timing control device shown in FIG. 1, FIG. 4 is a knock control dual proportional component characteristic, and FIG. It is a flowchart showing the contents of the program. l... Engine, 2... Control device, 3... Ignition coil, 4... Ignition bladder, 5... Knock sensor, 7
...Bandpass filter, 8...Amplifier, 9...
Micro Combi $4 Hard No/7 Ship Wandering t Mi I Straight 1 and 7χ No. 50

Claims (1)

[Claims] 1. (1,1 In an ignition timing opening method that detects non-king occurring in an engine and corrects the ignition timing so as to completely suppress the occurrence of non-king, the ignition timing is corrected only in the cylinder in which non-king occurs. (2) When knocking occurs in the engine, the ignition timing is corrected for cylinder ignition after the number of ignitions corresponding to the number of engine cylinders N. A method for adjusting the ignition timing of an engine according to claim 1.