JP2861043B2 - Ignition timing control device for spark ignition type internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition timing control device for a spark ignition type internal combustion engine such as a gasoline engine (hereinafter, “internal combustion engine” may be simply referred to as “engine”). .

[Related Art] Conventionally, for example, ignition timing control of a gasoline engine has been performed as follows. That is, the operating state of the engine is detected from a flow sensor for detecting the amount of engine intake air (a pressure sensor for detecting the intake passage pressure may be used instead of the flow sensor) and an engine speed sensor for detecting the engine speed. Then, based on the detection results from these sensors, a volume efficiency Ev (A / N) obtained by dividing the intake air amount A by the engine speed N or an 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 having (ignition timing information), and the basic ignition timing information is appropriately corrected.
The ignition timing of the engine is controlled by operating an ignition device (ignition plug, ignition coil, etc.) based on the ignition timing information obtained in this manner.

[Problems to be Solved by the Invention] The appropriate correction to be performed on the basic ignition timing information described above includes a correction based on an engine cooling water temperature and a correction based on an intake air temperature. Since knocking (knocking) occurs, some correction must be made to the ignition timing information even when the engine is accelerating.

Here, knocking is a vibration phenomenon in the combustion chamber induced by self-ignition, and such knocking may not only generate an unpleasant sound but also adversely affect the engine.

Therefore, conventionally, control for delaying the ignition timing is generally performed in order to prevent the occurrence of the knock.However, in this case, it is difficult to detect an engine phenomenon that leads to the occurrence of the knock. Adopts a control method that delays to a safe side so that knock does not occur even in the worst condition.

As shown in FIG. 4, the ignition angle at which knock occurs is related to the temperature of the combustion chamber wall (combustion chamber wall temperature). Since the chamber wall temperature is lower than the steady state due to a delay in the temperature rise (see FIG. 5), knock occurs even if the ignition angle is advanced during several tens of cycles when the combustion chamber wall temperature rises to the steady state. Absent.

The present invention has been made based on such knowledge, and by making it possible to obtain ignition timing information from combustion energy amount information, it is possible to prevent the ignition timing from being unnecessarily retarded while maintaining the engine output. Further, it is an object of the present invention to provide an ignition timing control device for a spark ignition type internal combustion engine capable of improving engine efficiency and improving acceleration performance.

[Means for Solving the Problems] For this reason, an ignition timing control apparatus for a spark ignition type internal combustion engine according to the present invention comprises: an ignition timing setting means for setting an ignition timing according to an operation state of the spark ignition type internal combustion engine; Igniter operating means for operating an igniter based on the ignition timing information set by the ignition timing setting means, wherein the ignition timing setting means updates the latest measured value with respect to the measured value of the variable indicating the amount of combustion energy. Correction means for correcting data with past data of the measured value; and ignition timing correction means for correcting the ignition timing to an advanced side based on correction data on the amount of combustion energy obtained by the correction means. It is characterized by comprising.

[Operation] In the ignition timing control device for a spark ignition type internal combustion engine of the present invention described above, the ignition device is operated based on the ignition timing information set by the ignition timing setting means. At this time, the ignition timing is as follows. Is required. That is, first, the correction unit corrects the latest data of the measured value with respect to the measured value of the variable indicating the amount of combustion energy with the past data of the measured value, and then obtained by the ignition timing correction unit and the corrected unit. The ignition timing is corrected to the advanced side based on the correction data on the combustion energy amount.

[Embodiment] Hereinafter, an ignition timing control device for a spark ignition type internal combustion engine as one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram showing a control system and an engine schematic system. FIG. 3 is a flowchart for obtaining the ignition timing, and FIG. 3 is a diagram for explaining the relationship between the combustion chamber wall temperature and the amount of combustion energy.

The vehicle-mounted gasoline engine system (spark ignition type internal combustion engine system) controlled by this device is the first type.
As shown in FIG. 1, in FIG. 1, a gasoline engine E (hereinafter simply referred to as engine E) has a combustion chamber 1 thereof.
The intake passage 2 and the exhaust passage 3 communicate with each other. The communication between the intake passage 2 and the combustion chamber 1 is controlled by an intake valve 4, and the communication between the exhaust passage 3 and the combustion chamber 1 is controlled by an exhaust valve 5. It has become so.

In addition, an air cleaner is provided in the intake passage 2 in order from the upstream side.
6, a throttle valve 7 and an electromagnetic fuel injection valve (injector) 8 are provided. In the exhaust passage 3, a catalytic converter (three-way catalyst) for purifying exhaust gas and a muffler (muffler) Device) is provided.

Note that the injectors 8 are provided in the intake manifold portion by the number of cylinders. Now, assuming that the engine E of the present embodiment is an in-line four-cylinder engine, four injectors 8 are provided. That is, it can be said that the engine is a so-called multipoint 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 according to the amount of depression of the accelerator pedal.

Further, each cylinder is provided with an ignition plug 9 toward the combustion chamber 1, and each ignition plug 9 is connected to an ignition coil 10 via a distributor (not shown). And a power transistor with an ignition coil 10
A high voltage is generated in the ignition coil 9 by the OFF operation of the ignition coil 9 and the ignition plug 9 connected to the distributor
Is sparked (ignited).
The ignition coil 10 is started to be charged by the battery 12 when the power transistor 11 is turned on. And
These spark plug 9, distributor, ignition coil
10, the power transistor 11 forms an ignition device.

With such a configuration, the air sucked through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed with the fuel from the injector 8 at the intake manifold portion so as to have an appropriate air-fuel ratio. 9 is ignited at an appropriate timing to be burned to generate engine torque, and then the air-fuel mixture is discharged to the exhaust passage 3 as exhaust gas, and the catalytic converter converts CO, HC, and NO _{X in} the exhaust gas. After purifying the three harmful components,
The sound is muted by the muffler and released to the atmosphere.

Further, various sensors are provided to control the engine E. First, on the side of the intake passage 2, an air flow sensor 13 as a volume flow meter for detecting the amount of intake air from Karman vortex information, an intake air temperature sensor for detecting the intake air temperature, and a large air pressure sensor for detecting the atmospheric pressure are provided in the air cleaner portion. An air pressure sensor is provided, and a potentiometer type throttle sensor for detecting an opening degree of the throttle valve 7 and an idle switch for detecting an idling state are provided in a portion where the throttle valve is provided.

Further, on the exhaust passage 3 side, the oxygen concentration (O ₂ concentration) in the exhaust gas is located in a portion near the combustion chamber 1 on the upstream side of the catalytic converter.
Is provided with an oxygen concentration sensor (O ₂ sensor) for detecting the pressure.

Further, in addition to a water temperature sensor for detecting an engine cooling water temperature, a crank angle sensor 14 for detecting a crank angle (the crank angle sensor 14 also serves as an engine speed sensor for detecting the engine speed N, If necessary, the crank angle sensor 14 may be referred to as an engine speed sensor) and a TDC sensor for detecting the top dead center of the first cylinder (reference cylinder) is provided in each distributor.

By the way, the detection signals from the above-mentioned sensors are input to an electronic control unit (ECU) 15.

In terms of hardware, the ECU 15 has a CPU, a RAM (including a backup RAM), a ROM, and an appropriate input / output interface circuit, and receives signals from each sensor through the input interface circuit or directly. A signal is input to the CPU, an ignition timing control signal from the CPU is output to the power transistor 11 through the output interface circuit, and further, each spark plug 9 is sequentially sparked from the ignition coil 10 via the distributor. Has become.

A fuel injection control signal is output from the CPU to the injector 8 through an output interface circuit, whereby fuel is injected from the injector 8 for a time determined by the fuel injection control signal to obtain a desired air-fuel ratio. Is controlled so that

Now, focusing on the ignition timing control, the ECU 15 is shown by using a functional block for such ignition timing control, as shown in FIG. That is, the ignition timing control device includes a basic ignition angle setting means as a basic ignition timing setting means.
An ignition timing correction amount setting means 31, an adding means 34, and an ignition signal generating means 35 are provided.

Here, the basic ignition angle setting means 30 sets the basic ignition angle in accordance with the operating state of the engine E (this operating state is determined from the engine load information from the air flow sensor 13 and the engine speed information from the engine speed sensor 14). used to set the timing, for example, have a basic ignition timing Matsupu for storing a / N, 2-dimensional basic ignition timing data determined from the N (advance data) theta _0.

The ignition timing correction amount setting means 31 performs a moving average process or a primary filter process on a variable indicating the combustion energy amount (for example, the intake air amount A or the fuel injection amount u) to calculate a combustion energy index CI. Means 32
And an ignition angle correction means 33 as an ignition timing correction amount calculation means for obtaining an ignition timing correction amount ΔA from the combustion energy index CI obtained by the combustion energy index calculation means 32.

Here, moving average processing is performed to obtain the combustion energy index CI.
Is calculated using the following equations (1) and (2).

(1-1) When the intake air amount A is used as a variable indicating the combustion energy amount (1-2) When the supplied fuel amount u is used as a variable indicating the combustion energy amount Here, n is the number of moving average targets (2 to 3), A / _Nik is the amount of intake air per engine revolution in the ( _ik ) cycle, and _Nik is the engine revolution in the ( _ik ) cycle. Number, u
_ik is the supplied fuel amount in the ( _ik ) cycle.

In addition, the primary filter processing is performed to determine the combustion energy index.
When calculating the CI, the following equations (3) and (4) are used.

(2-1) When the intake air amount A is used as a variable indicating the combustion energy amount CI = K (A / Ni) Ni + (1-K) (A / N _i-1 ) N _i-1 (3) ( 2-2) When the supplied fuel amount u is used as a variable indicating the combustion energy amount CI = Kui + (1−K) u _i−1 (4) where K is a filter constant (0 or more and 1 or less), A / Ni is the intake air amount per engine speed in the i-th cycle, Ni is the engine speed in the i-th cycle, and ui is the fuel supply amount in the i-th cycle.

Therefore, the combustion energy index calculating means 32 corrects the latest data of the measured values obtained from time to time for the variables (intake air amount A and fuel injection amount u) indicating the amount of combustion energy with the past measured data. In addition to constituting the correction means, the ignition angle correction means 33 constitutes an ignition timing calculation means for obtaining an ignition timing from the correction data relating to the measurement value obtained by the combustion energy index calculation means 32.

The addition means 34 adds the basic ignition angle _{０ 0} from the basic ignition angle setting means 30 and the ignition timing correction amount ΔA from the ignition timing correction amount setting means 31.

Therefore, the basic ignition angle setting means 30, the ignition timing correction amount setting means 31, and the adding means 34 constitute ignition timing setting means for setting the ignition timing according to the operating state of the engine E.

Furthermore, the ignition signal generation means 35 is for generating an ignition signal for actuating the power transistor 11 based on the plus ignition timing correction amount ΔA to the basic ignition angle theta ₀ from the adding means 34, thereby , This ignition signal generating means
35 constitutes an ignition device operating means for operating an ignition device such as the power transistor 11 based on ignition information obtained according to the operating state of the engine.

Next, the relationship between the combustion chamber wall temperature and the amount of combustion energy will be described. Now, as shown in FIG. 3, the heat flowing into and out of the combustion chamber wall at the combustion chamber wall is Qi, Qo (Qo is the amount of heat transmitted to the cooling water side), and the heat capacity of the combustion chamber wall is C,
Assuming that the cooling water temperature is θc, the temperature rise rate of the combustion chamber wall (combustion chamber wall temperature) θw is θw = (Qi−Qo) / C (5), and Qo is α Assuming that the heat transmission coefficient is, Qo = α (θw−θc) (6)

 Here, since α is a constant and θc is constant, Qo∝θw (7)

Therefore, a similar result can be obtained by using the amount of combustion energy passing through the wall instead of the temperature of the combustion chamber wall. It can be approximated by the processed one.

Next, a method of calculating the ignition angle correction amount (ignition timing correction amount) ΔA from the combustion chamber wall temperature will be described.

That is, the relationship between the knock ignition timing and the combustion energy index CI for all steady-state operating conditions (for example, this relationship is such that the ignition advance is advanced while the amount of combustion energy during acceleration is lower than steady state). Is obtained by an experiment, and this is set in the engine control microcomputer. Thus, the ignition timing is obtained from the combustion energy index CI during a certain operation.

It should be noted that the actual setting of the ignition angle has some allowance for the value obtained in the experiment.

Next, the ignition timing calculation procedure will be described with reference to the flowchart of FIG.

First, in step a1, variable information (A / N, N or u) indicating the amount of combustion energy in the i cycle is fetched, and in step a2, a moving average or a primary filter process is performed on the amount of combustion energy, and the aforementioned ( The combustion energy index CI is calculated from the equations (1) and (2) or the equations (3) and (4).

After that, in step a3, the calculated combustion energy index
Ignition correction amount Δ based on data previously measured from CI
Determining the A, at step a4, after determining a basic ignition angle theta _0, at step a5, the ignition correction amount to the basic ignition timing theta ₀ delta
Add A.

When the ignition angle is determined as described above, an ignition signal is output from the ignition signal generating means 35 to the power transistor 11 based on this information, and the ignition plug 9 is ignited at a timing corresponding to the ignition signal.

Although the measurement of the amount of combustion energy is performed continuously,
The correction of the ignition amount may be limited only at the time of rapid acceleration (at the time of transition).

As described above, since the ignition correction amount is obtained from the combustion energy index CI, while the combustion chamber wall temperature is low during the transition from low load to high load during acceleration (between the initial number of accelerations + cycle), Since the combustion energy amount is lower than the steady state, the ignition advance angle is set on the leading side during that period. After the middle period of acceleration, if the combustion chamber wall temperature becomes higher, the combustion energy amount approaches the steady state. The angle can also be corrected to the lag side, so that during acceleration, the optimal ignition angle that does not cause knocking can be always set without delaying the ignition timing more than necessary, so that rapid acceleration is not hindered as much as possible. However, knock during acceleration can be reliably prevented. As a result, the engine output can be increased, the engine efficiency can be increased, and the acceleration performance can be significantly improved.

Note that, in the steady state, the correction based on the combustion energy index CI is not performed.

Further, in controlling the ignition timing, in addition to the correction at the time of acceleration, the correction may be performed according to the water temperature or the intake air temperature.

Further, the ignition timing calculating means may be replaced with a basic ignition timing setting means.
30 and an ignition timing correction amount setting means 31 and an addition means 34 for adding information obtained by these means, instead of a steady-state ignition timing map and a plurality of transient ignition timing maps. You may have it.

Further, the present invention provides a spark ignition type internal combustion engine employing an L jetro system using an air flow sensor, and a spark ignition type internal combustion engine employing a D jetro system (speed density system) using an intake passage pressure sensor. Is also applicable.

In addition, the present invention can be similarly applied to a spark ignition type internal combustion engine such as an alcohol engine using an alcohol fuel, in addition to a gasoline engine.

[Effects of the Invention] As described above in detail, according to the ignition timing control apparatus for a spark ignition type internal combustion engine of the present invention, the correction means uses the latest data of the measurement value for the variable indicating the combustion energy amount. Is corrected with the past data of the measured value, and then the ignition timing is corrected by the ignition timing calculation means to the advanced side based on the correction data on the combustion energy amount obtained by the correction means. There is an advantage that the engine output and the engine efficiency can be improved and the acceleration performance can be improved while preventing the ignition timing from being unnecessarily retarded.

[Brief description of the drawings]

1 to 3 show an ignition control device for a spark ignition type internal combustion engine as one embodiment of the present invention, FIG. 1 is an overall configuration diagram showing a control system and an engine schematic system, and FIG. FIG. 3 is a diagram for explaining the relationship between the combustion chamber wall temperature and the amount of combustion energy, and FIG. 4 is a flowchart showing the cylinder block ignition surface temperature (combustion chamber wall temperature) when the throttle valve is fully opened. FIG. 5 is a characteristic diagram for explaining a response state of the combustion chamber wall temperature when the engine speed changes suddenly. 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 ...
Spark plug constituting ignition device, 10 Ignition coil, 11
… Power transistor, 12… Battery, 13… Air flow sensor (volume flow meter), 14… Crank angle sensor (engine speed sensor), 15… ECU, 16… Water temperature sensor, 30… Basic ignition Angle setting means, 31: ignition timing correction amount setting means, 32: combustion energy index calculation means (correction means), 33: ignition angle correction means (ignition timing calculation means),
34 ... addition means, 35 ... ignition signal generation means (ignition device operating means), E ... engine.

Continued on the front page (72) Inventor Hiromitsu Ando 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Jun Takemura 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Inside Industrial Co., Ltd. (72) Inventor Eiichi Shinji 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (56) References JP-A-62-214270 (JP, A) JP-A Sho 63-280856 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02P 5/15

Claims (1)

(57) [Claims] An ignition device for activating an ignition device based on the ignition timing information set by the ignition timing setting device, the ignition timing setting means for setting an ignition timing according to an operation state of a spark ignition type internal combustion engine. Means for correcting the latest data of the measured value with respect to the measured value of the variable indicating the amount of combustion energy based on the past data of the measured value. An ignition timing correction means for correcting the ignition timing to an advanced side based on the correction data on the combustion energy amount. An ignition timing control apparatus for a spark ignition type internal combustion engine.