JPH0323373A - Ignition timing controller of spark ignition type internal combustion engine - Google Patents

Abstract

PURPOSE:To effectively prevent malfunction of back fire and the like by controlling ignition timing so as to compensate it to an advanced angle with a compensation means for a specified time after start-up of an internal combustion engine even if air-fuel ratio is in a lean condition. CONSTITUTION:In an ECU 13 which inputs output signals of an air flow sensor 10, an engine speed sensor 11 or a water temperature sensor 12, a basic ignition angle setting means 131 which determines a basic ignition timing by engine load information and engine speed information are provided. There are provided a first compensation means which sets a compensation ignition angle in conformity with the temperature of cooling water and an ignition angle compensation means 132 which has a second compensation means which sets a compensation ignition angle after start-up of an engine. An adding means 133 which adds the output of the respective setting means 131, 132 are also provided, and ignition timing in response to the conditions of engine operation. By adding a basic ignition angle and an ignition timing compensation quantity, the ignition timing according to the conditions of engine operation is set, and then an igniter 14 is controlled in its driving.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to spark ignition internal combustion engines (such as gasoline engines).
The following relates to an ignition timing control device for an "internal combustion engine" (sometimes referred to simply as an "engine"). [Prior Art] Conventionally, for example, ignition timing control for a gasoline engine has been performed as follows. , detects the operating state of the engine from a flow rate sensor that detects the intake air amount of the engine (a pressure sensor that detects the intake passage pressure may be used instead of this flow rate sensor) and an engine rotation speed sensor that detects the engine rotation speed. Based on the detection results from these sensors, the volumetric efficiency Ev (A/N) obtained by dividing the intake air amount A by the engine speed N, or the advance angle value determined by the intake passage pressure and the engine speed N. Basic ignition timing information is obtained from a two-dimensional map with (ignition timing information), appropriate correction is made to this basic ignition timing information, and based on the ignition timing information obtained in this way, The engine's ignition timing is controlled by operating the engine (coil, etc.).

Note that the above correction of the ignition timing includes, for example, correcting the ignition timing to the advanced side when the engine coolant temperature is low. When the cooling water temperature is low, the knock point moves to the advanced side, so if the ignition timing is corrected to the advanced side as described above, knocking will be less likely to occur, thereby improving output during warm-up. It can be measured.

[Problems to be Solved by the Invention] By the way, in an engine immediately after a cold start, the combustion chamber temperature is not stable and combustion is also unstable. Therefore, in this case, increase the amount of fuel supplied. Although efforts are being made to stabilize combustion, this alone is not sufficient. In other words, immediately after such a cold start, the combustion speed is slow, so if the air-fuel ratio becomes lean due to sudden acceleration, etc., there is a risk of causing a backfire phenomenon. The present invention aims to solve these problems by making it possible to correct the ignition timing to the advanced side for a predetermined period after startup, thereby preventing the air-fuel ratio in the combustion chamber from decreasing. Even if the
The purpose of this project is to provide an ignition timing control device for a spark-ignition internal combustion engine. [Means for Solving the Problems] Therefore, the ignition timing control device for a spark-ignition internal combustion engine of the present invention includes an ignition timing setting means for setting the ignition timing according to the operating state of the spark-ignition internal combustion engine; and an ignition device operating means for operating an ignition device based on the ignition timing information set by the ignition timing setting means, the ignition timing setting means advancing the ignition timing for a predetermined period after starting the internal combustion engine. It is characterized in that it is configured to include a correction means for correction.

[Function] In the above-described ignition timing control device for a spark ignition internal combustion engine of the present invention, the ignition device is operated based on the ignition timing information set by the ignition timing setting means. , the ignition timing is corrected to the advanced side by the correction means. [Embodiment] Hereinafter, an ignition timing control device for a spark ignition internal combustion engine as an embodiment of the present invention will be explained with reference to the drawings.
Figure 1(b) is a block diagram showing the ignition timing control system, Figure 2 is a flowchart for determining the ignition timing, and Figure 1(b) is a block diagram showing the ignition timing control system. Figures 3 to 6 are characteristic diagrams for explaining the effects. Now, the in-vehicle gasoline engine system (spark ignition internal combustion engine system) controlled by this device is as shown in Fig. 1 (a), and in this Fig. 1 (a), gasoline engine E (hereinafter referred to as The engine (simply referred to as engine E) has an intake passage 2 and an exhaust passage 3 that communicate with its combustion chamber 1. The intake passage 2 and the combustion chamber 1 are controlled to communicate with each other by an intake valve 4, and the exhaust passage 3 and the combustion chamber 1 are connected to each other. 1 and is controlled to communicate with it by an exhaust valve 5.

In addition, an air cleaner 6 is installed in the intake passage 2 in order from the upstream side.
, a throttle valve 7 and an electromagnetic fuel injection valve (injector) 8. In the exhaust passage 3, starting from the upstream side, there is a catalytic converter (not shown) for purifying exhaust gas (
A three-way catalyst) and a muffler (7I four-tone) are provided.

Note that injectors 8 are provided in the intake manifold for the same number of cylinders. Now, the engine E of this embodiment is an inline 4
Assuming that it is a cylinder engine, four injectors 8 are provided.

That is, it can be said to be a so-called multi-point fuel injection (MPI) type engine.

Further, the throttle valve 7 is connected to the accelerator pedal via a wire cable, so that the opening degree changes depending on the amount of depression of the accelerator pedal. Furthermore, each spark plug i6 is provided with a spark plug 16 facing the combustion chamber 1, and each spark plug i6 is connected via a distributor 15 to an igniter device 14 having an ignition coil, a switching transistor, etc. . By turning off the power transistor of the igniter device 14, a high voltage is generated in the large coil, causing one of the spark plugs 16 connected to the distributor 15 to spark (ignite). Note that the ignition coil starts charging by turning on the power transistor. Then, these spark plugs 16, distributor 15, and igniter equipment [14
Keep the ignition system in check.

With such a structure, air taken in through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed with fuel from the injector 8 in the intake manifold part to an appropriate air-fuel ratio, and ignition occurs in the combustion chamber 1. By igniting the plug 16 at an appropriate timing, the mixture is combusted and generates engine torque, and then is discharged to the exhaust passage 3 as exhaust gas, where the catalytic converter converts Co, HC, and NOX in the exhaust gas. After the three harmful components have been purified, the sound is muffled by a muffler and released into the atmosphere. Furthermore, in order to control this engine E, various sensors are provided. First, on the intake passage 2 side, an air flow sensor 10 as a volume flow meter that detects the amount of intake air from Karman vortex information, an intake air temperature sensor that detects the intake air temperature, and an air flow sensor 10 that detects the atmospheric pressure are installed on the side of the intake passage 2. A barometric pressure sensor is provided, and a potentiometer-type throttle sensor 9 for detecting the opening of the throttle valve 7 and an idle switch for detecting the idling state are provided in the throttle valve area. In addition, on the exhaust passage 3 side, the oxygen concentration (02 concentration) in the exhaust gas is displayed at the upstream side of the catalytic converter and close to the combustion chamber 1.
An oxygen concentration sensor (02 sensor) is installed to detect the Furthermore, in addition to a water temperature sensor 12 that detects the engine cooling water temperature, a crank angle sensor 11 that detects the crank angle (this crank angle sensor 11 also serves as an engine rotation speed sensor that detects the engine rotation speed N) is provided. A TDC sensor for detecting the top dead center of the first cylinder (reference cylinder) is provided in the distributor l5. By the way, detection signals from each of the above-mentioned sensors are input to an electronic control unit (ECU) 13. In addition, when looking at the hardware configuration of the ECU 13, the CPU, RAM (including backup RAM)
, ROM, and appropriate input/output interface circuits, and signals from each sensor are input to the CPU through the input interface circuit or directly, and ignition timing control signals from the CPU are input to the igniter device 14 through the output interface circuit. Further, each spark plug 16 is sequentially sparked from the igniter device 14 via the distributor 15.

Note that the CPU outputs an injection fuel control signal to the injector 8 through the output interface circuit, so that fuel is injected from the injector 8 for a time determined by this injection fuel control signal, and the desired air-fuel ratio is achieved. It is controlled so that Now, focusing on ignition timing control, the ECU 13 is shown using functional blocks for ignition timing control.
The result will be as shown in Figure (b). That is, this ignition timing control device includes a basic ignition angle setting means 13l as a basic ignition timing setting means, an ignition angle correction means 132 as an ignition timing correction amount setting means, an addition means 133, and an ignition signal generation means 1.
It has 34. Here, the basic ignition angle setting means 131 is configured according to the operating state of the engine E (this operating state is determined from the engine load information A from the air flow sensor 10 and the engine speed information N from the engine speed sensor 11). This is used to set the basic ignition timing, such as A/N (volume efficiency), N
It has a basic ignition timing map that stores two-dimensional basic ignition timing data (advance angle data) θB determined from . The ignition angle correction means 132 corrects the ignition angle (
The lth correction means sets the advance angle data) θWT, and the corrected ignition angle (m angle data) θ^s(t
). Here, the corrected ignition angle θII set by the first correction means
The characteristics of T are shown in Figure 3. In addition, the corrected ignition angle (immediately after start-up advance angle correction value) θAs(t) set by the second correction means is (θAss−Δθ・t)xKAN≧O
It is expressed as . Here, θAgo is the initial value of the advance angle amount, and this θAss is set as a function of the cooling water temperature as shown in FIG. Further, Δθ is the amount by which the advance angle is subtracted, and this Δθ is also set as a function of the cooling water temperature as shown in Fig. 6. This Δθ may be set to a constant value. moreover. KAN is a gain (coefficient) that changes depending on the volumetric efficiency A/N (engine load) as shown in Figure 5. The reason why the gain and therefore the ignition angle are changed according to the engine load is because in the light load range, the in-cylinder airflow is weak and the compression pressure does not increase, so if the engine is advanced in the light load range, there is a risk that ignition will not occur. Therefore, the amount of advance angle is changed depending on the load. Note that t is time. Further, the adding means 133 adds the main ignition angle θB from the basic ignition angle setting means 131 and the ignition timing correction amount OwT108s(t) from the ignition timing correction amount setting means 132. Therefore, the basic ignition angle setting means l31, the ignition angle correction means l32, and the addition means 133 constitute an ignition timing setting means for setting the ignition timing according to the operating state of the engine E.

Further, the ignition signal generation means 134 generates an ignition signal for operating the igniter device [14] based on the ignition angle information θB0oVT10As(t) from the addition means 133. Ignition signal generating means 134
constitutes an ignition device operating means that operates an ignition device such as the igniter device 114 based on ignition timing information determined according to the operating state of the engine. Next, the procedure for setting the ignition timing will be explained using the flowchart of the second rM. First, in step A1, various information such as the intake air amount, engine speed, and cooling water temperature are read. Next, in step A2, it is determined whether or not the engine has started. This is determined by, for example, whether the cranking switch is turned off. If cranking is still in progress, set the ignition timing θ to the cranking timing θS (step A3). And the cranking is over? Then, in step A2. Taking the YES route, in step A4, the basic ignition timing OB is calculated, in step A5, the water temperature correction value θWT is calculated, in step A6, the immediately after start correction value θAS(t) is calculated, and in step A7, Ignition timing θ
Find θ80θVT10AS(t). Here, the correction value θAs(t) immediately after startup is O when the engine load is small or the cooling water temperature is sufficiently high, but otherwise it gradually decreases (tailing) with the passage of time. As a result, the immediately after startup correction value θAs(t) is effective in controlling the ignition timing only for a predetermined period of time after startup.

As a result, the ignition timing can be advanced during the slow combustion period immediately after a cold start, so even if the air-fuel ratio becomes lean, problems such as packfire can be sufficiently prevented. be. The present invention is applicable to spark-ignition internal combustion engines that use the L-Jetro method using an airflow sensor, as well as spark-ignition internal combustion engines that use the D-Jetro method (speed density method) that uses an intake passage pressure sensor. It is also applicable.

Furthermore, the present invention can be applied not only to gasoline engines but also to general spark ignition internal combustion engines such as alcohol engines that use alcohol fuel. [Effects of the Invention] As detailed above, according to the ignition timing control device for a spark-ignition internal combustion engine of the present invention, the correction means corrects the ignition timing to the advanced side for a predetermined period after starting the internal combustion engine. Therefore, even if a situation where the air-fuel ratio becomes lean occurs, there is an advantage that problems such as backfire can be sufficiently prevented.

[Brief explanation of the drawing]

1 to 6 show an ignition timing control device for a spark-ignition internal combustion engine as an embodiment of the present invention, and FIG. Fig. 1 (b) is a block diagram showing the ignition timing control system, Fig. 2 is a flowchart for determining the ignition timing, and Figs. 3 to 6 are characteristic diagrams for explaining the operation. 1--Combustion chamber, 2-Intake passage, 3-Exhaust passage, 4-Intake valve, 5-Exhaust valve, 6-Air cleaner, 7--Throttle valve, 8-Solenoid valve (injector), 9-- Throttle sensor. 10-Air flow sensor (volume flow meter)
, 11-...Crank angle sensor (engine speed sensor). 12-Water temperature sensor, 13-・Electronic control unit (ECU). 14. - igniter equipment IW, 15 - distributor, 16 - one spark plug constituting an ignition device, 131 - basic ignition angle setting means, 132 one point large angle correction means, 133 - addition means, 134 - one ignition signal generation means (ignition device operating means), E-engine.

Claims (1)

[Claims] comprising an ignition timing setting means for setting the ignition timing according to the operating state of the spark ignition internal combustion engine, and an ignition device operating means for operating the ignition device based on the ignition timing information set by the ignition timing setting means, The ignition timing setting means is characterized in that it includes a correction means for correcting the ignition timing to an advanced side for a predetermined period after the internal combustion engine is started.
Ignition timing control device for spark ignition internal combustion engines.