JPS5859334A - Knocking suppressing device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the response in knocking control and to simplify a control device, by delaying the angle of ignition timing when knocking occurs, releasing an air fuel ratio return control by an exhaust gas sensor, and performing rich correction. CONSTITUTION:A control cirlcuit 27 controls the returning of an actuator 23 which opens and closes auxiliary air bleeds 21 and 22 of a carburetor 4, based on the detected value of an exhaust gas sensor 26 provided in an exhaust manifold 8. The internal combustion engine 1 is provided with the control circuit 27, a contact breaker 13 of a distributor 9, and an ignition timing delaying circuit 17 which is provided in ignition coils 10. A knocking sensor 16, which is attached to the engine 1, is connected to a knocking judging circuit 15. The knocking judging circuit 15 sends a knocking signal to the control circuit 27 and the ignition timing delaying circuit 17 when the knocking occurs. Then the air fuel ratio return control is released, the air fuel ratio is appropriately made to rich, and the ignition timing in controlled so that the angle is suitably delayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The zero engine 8A relates to a system flK for suppressing and controlling the internal combustion engine of a spark ignition type internal combustion engine.

In order to obtain high output and low fuel consumption in a spark-ignition internal engine, it is desirable to always control the ignition timing by f & appropriate ignition timing (MBT) 4C over the entire operating range of the engine. In high-load, low-speed engines, the ignition timing may be on the advanced side of the 90-degree limit, so in this region, the ignition timing may be advanced. - When knocking occurs, it becomes 7. In particular, when the compression ratio of the engine is increased, the area where knocking occurs increases.

Therefore, some of the recent internal combustion engines are equipped with a fuel pump sensor, and when fuel leakage occurs, the ignition timing is retarded appropriately to eliminate fuel leakage. Knocking has been suppressed by controlling the ignition timing using a so-called knock feedback system, which returns the ignition timing to the original ignition timing. However, in order to retard the actual ignition timing in these nine engines to the point where knocking is reduced by 55%, the ignition timing must be retarded considerably. 1+, when the engine is suppressed, the engine's output drops suddenly.

On the other hand, as a prior art, Japanese Patent Application Laid-open No. 55-43206 discloses 5. There is a certain correlation between the air-fuel ratio of the intake air-fuel mixture and the air-fuel ratio of the intake air-fuel mixture, and considering the fact that the richer the air-fuel ratio, the less likely it is that the air-fuel ratio will occur. Accordingly, it is proposed to temporarily increase the air-fuel ratio to suppress the engine's engine output loss, without causing the engine's output to decrease. Not only is there a problem in that the response to engine failure is slow, but the air-fuel ratio must be significantly enriched depending on the degree of engine failure, which may cause fogging of the ignition plug or worsen fuel efficiency. There was a problem.

Therefore, the present inventors previously proposed in Japanese Patent Application No. 55-41007 that in addition to retarding the ignition timing according to the ignition timing by knock-feed control of the ignition timing, at the same time Alternatively, if additional fuel is supplied to the intake system in succession, the amount of retardation of the ignition timing is reduced by the effect of the increased amount of fuel supply, while the engine is based on retardation of the ignition timing by increasing the amount of fuel supply. Compensates for the decrease in output and eliminates output town and response delay.
We have proposed suppressing the fuel flow, but this method requires a separate means for increasing the amount of fuel by adding pressure to the fuel supply system to the intake system, so its structure is complicated. It was to become.

The present invention aims to reduce the amount of NO in exhaust gas in modern internal combustion engines.
In order to simultaneously purify the ternary harmful components of It is important to note that it is equipped with a so-called air-fuel ratio feedback system that performs feedback control so that the air-fuel ratio becomes approximately the stoichiometric air-fuel ratio, and by combining this air-fuel ratio feedback system and the above-mentioned knock feed barak system.・If the ignition timing is detected, the ignition timing is retarded, and at the same time or around the same time, the air-fuel ratio feedback system is prioritized over the exhaust sensor to increase the intake system's normal fuel ratio. By using an air-fuel ratio feed pump system to pre-register the air-fuel ratio, the inventors believe that the problem of complicating the structure described above can be solved. It becomes possible to set the system air-fuel ratio to the stoichiometric air-fuel ratio and increase the compression ratio, thereby reducing fuel consumption.

Hereinafter, an embodiment in which the present invention is applied to a carburetor internal combustion engine will be described. In the figure, (1) is a multi-cylinder internal combustion engine that has a spark plug (2) in each cylinder, and an air cleaner (2) is installed on the side of the engine. The intake manifold (5) has an exhaust gas purification device 1 (7) with a built-in three-way catalyst (61) on the other side.
are installed on each. (9) is a die repeater which is an example of an ignition timing control device +rt, Oυ is an ignition-fire coil,
(L indicates the battery, and the figure indicates the ignition system. Karanashi, also DistriF
: L-tor (9) 1. This is equipped with a conventionally known vacuum type advance mechanism (not shown) and a reciprocating center advance mechanism (not shown), which adjusts the ignition timing to a predetermined advance characteristic with respect to the engine load and rotation speed. Based on -
It is configured to be controlled.

00 is a circuit that determines the presence or absence of the switch based on the number from the switch installed on the engine (1).
If the knock determination lND$061 is determined to be in the middle, the interrupter 0 in the die repeater (9)
The ignition timing delay circuit (171) provided in the circuit connecting the ignition coil ω to the next side emits a signal. When the ignition timing retardation MO switch receives a notch signal, the ignition timing by the distributor (9) is appropriately retarded by an angle of 0, and when the noisy signal disappears, the ignition timing is returned to the original ignition timing. It has become.

Either or both of the main system fuel supply passage and the slow fuel supply passage in the above-mentioned ignition device,
An auxiliary air bleed 1IT1221 for air-fuel ratio feed/shift control for air communication points such as the air cleaner (3) is connected through passages, and both auxiliary air bleed leads 12
11! 22 Fi, the needle valve e141 in the evening of Actuary I-K will be opened on the market.

The percentage is 02, C01COhl (C or NOx) in the exhaust gas.
The exhaust sensor that detects the concentration of This function compares the value with When the stoichiometric air-fuel ratio exceeds 0 concentration, the air-fuel ratio is leaner than the stoichiometric air-fuel ratio, so the actuator (c) reduces the opening area of both auxiliary air lead hoards e2+112A and improves the intake system. The air-fuel ratio was enriched, and the detected O! When the O2 concentration has not reached the stoichiometric air-fuel ratio, the air-fuel ratio is stoichiometric! Since it is richer than the P fuel ratio, both auxiliary air bleed boat @
By increasing the opening area of t+(22) and reducing the air-fuel ratio of the intake system, the air-fuel ratio at the exhaust processor is controlled to be approximately at the stoichiometric air-fuel ratio.

The air-fuel ratio feedback control circuit f) inputs the signal from the shift discrimination circuit a@, and if a jig occurs in the engine, the air-fuel ratio feedback control circuit f) outputs a signal from the exhaust selector based on the signal. Regardless of the above, the actuator (c) reduces the opening area of both auxiliary air bleeds by an appropriate amount compared to the downward movement before the jig occurs, thereby adjusting the air-fuel ratio of the intake system by an appropriate value. K is set to make it darker.

In other words, when nozzle jig occurs in the engine, the ignition timing is retarded by an appropriate angle θ, and the air-fuel ratio in the intake system is increased by an appropriate value, so that nozzle jig is suppressed. Compared to the conventional case of controlling the ignition timing jig only by retarding the ignition timing, the amount of retardation of the ignition timing can be reduced by the effect of enriching the air-fuel ratio, while retarding the ignition timing. The increase in output due to K can be compensated for by enriching the air-fuel ratio. Therefore, it is possible to suppress the jig in the middle without causing the appearance town, and also, as a prior art,
As in Publication No. 3206, no.
When controlling a saw jig (by comparison, the unification value of the air-fuel ratio can be reduced by 1 ton due to the effect of retarding the ignition timing, so the fogging of the ignition plug and the responsiveness as well as fuel efficiency can be improved).

In this case, the l-stratification process of the intake system air-fuel ratio for knocking may be performed at the same time as the ignition timing retardation process for the nozzle jig, or may be performed before or after the ignition timing retardation process. First, the air-fuel ratio is enriched, and when the sparking disappears, the air-fuel ratio is returned to the original one, and if the knocking still does not disappear, the ignition timing is retarded, and if the sparking disappears, the reverse order is performed. Or, you can first retard the ignition timing to prevent knocking, and if the knocking disappears, the ignition timing will return to its original value.
If the air-fuel ratio still does not go away, the air-fuel ratio may be enriched, and if the air-fuel ratio disappears, the air-fuel ratio may be restored in the reverse order. In relation to this, it is possible to first retard the ignition timing in the high load range, and only retard the ignition timing in other load ranges, or to combine both. Appropriately, the amount of retardation per crank angle is 2 to 4 in terms of crank angle, and the enrichment value of the air-fuel ratio is several percent to 20% with respect to the stoichiometric air-fuel ratio.

Although the above embodiment has been described using a conventionally known istry repeater to control the ignition timing, the present invention is not limited to this; a pond ignition timing control means may also be used, and the intake system air-fuel ratio may be controlled using auxiliary air. It goes without saying that the present invention is not limited to the opening and closing of the valve, and may also be used as an air-fuel ratio control means for the pond, and is applicable not only to the zero-engine 94 Ifi carburetor type internal combustion engine but also to a fuel injection type internal combustion engine.

As described above, the present invention solves the knocking by retarding the ignition timing and by retarding the ignition timing and the intake system 22! When performing suppression control by combining fuel enrichment processing, the intake system air-fuel ratio enrichment processing was performed using an air-fuel ratio feedback system.
As shown in the inventors' prior patent - ○, there is no need to provide a separate fuel increase means in the intake system, and the structure of the device can be simplified.Moreover, the air-fuel ratio feedback system is used. Kotok Yoshi, Fu + 4 nge without any delay in response 'K11llilt, 6e &#f,d'! !
d, 61□. fee.

The set value of the air-fuel ratio in the backup system can be set to the stoichiometric air-fuel ratio, and the high pressure ratio becomes 0,
It has the effect of reducing engine fuel consumption.

[Brief explanation of drawings]

The drawings are diagrams showing embodiments of the invention. (1)・°°engine, (5)・°°intake manifold, (
8)...υF air manifold, (2)...ignition plug,
(9)... Distributor, 0 (g... Ignition coil, 161... Note+yta sensor ~ (1'n... Ignition timing delay circuit, 1211ff12''... Auxiliary air lead, (wa)... Actuator, °° exhaust sensor, and control circuit. Patent applicant: Taihatsu Kogyo Co., Ltd. Representative, Patent attorney: Akio Ishii

Claims (1)

[Claims] (1) A knock feedback system that retards the ignition timing in response to knocking detected by a knocking sensor, and an exhaust t-scissor installed in the exhaust system that adjusts the air-fuel ratio in the exhaust system to approximately the stoichiometric air-fuel ratio. In an internal combustion engine equipped with an air-fuel ratio feed shift system that controls the air-fuel ratio of the intake system as described above, when the knocking sensor detects knocking when the feed barrack system is set to the 1rf air-fuel ratio feedback system. ,
The air-fuel ratio of the intake system fJ poor 1 takes priority over the exhaust sensor signal.
+(A knocking suppression device for an internal combustion engine, characterized in that it is associated with a busy state so as to become darker by f).