JPH05272394A - Fuel injection control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To control a fuel injection quantity of an injector on an increased quantity side based on a control pattern of a control part to conduct early warming up of a catalyst and prevent degradation of drivability in a low speed region in the case where ignition timing of an ignition plug in a fuel injection device of a multi-injection system is retarded by a predetermined value or more. CONSTITUTION:In an ECU 16, a start of an engine 2 is confirmed 100, water temperature is judged 102 being at a specified value or lower, engine speed is judged 106 being within a specified range, car speed is Judged 108 being within a specified range, and whether or not an idling switch S/W is in an OFF state is judged 110. When the judgement 110 is YES, control is performed 112. With this control, a control part 16 is controlled, having a control pattern for controlling a fuel injection quantity on an increased quantity side, in the case where ignition timing is retarded by a predetermined value or more. Degradation of drivability in a low speed region is thereby prevented without decreasing early warming up effect of a catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection control device for an internal combustion engine, and more particularly, to a single ignition operation of a spark plug by setting a fuel injection amount from a multi-injection type injector and an ignition timing of a spark plug during operation in a cold state. The present invention relates to a fuel injection control device for an internal combustion engine, which is changed every time and is controlled to perform early warm-up of a catalyst.

[0002]

2. Description of the Related Art In some internal combustion engines, an injector is provided for each cylinder, and a multi-injection system is adopted to inject and supply fuel to each cylinder by these injectors. The control unit controls the fuel injection amount from each injector.

Further, in a fuel injection control device for an internal combustion engine which employs a multi-injection system, an electronic ignition timing control (ESA) for controlling the ignition timing of an ignition plug.
Some have adopted. The electronic ignition timing control is performed to change the ignition timing when the engine is operating in the cold state and to warm up the catalyst early.

As a fuel injection control device for the internal combustion engine, there is one disclosed in Japanese Patent Application Laid-Open No. 61-76741. An engine idle speed control device disclosed in this publication includes an idle speed control valve for controlling the amount of air flowing in a bypass that bypasses a throttle valve and a catalyst that purifies exhaust gas, and is equipped with an engine load and an engine speed. The ignition timing is controlled by an ignition advance based on the number, and when the vehicle is in a steady running state, the ignition timing is controlled by an ignition advance retarded from the ignition advance and the idle speed control valve is set to a predetermined value. Open the opening,
It prevents the catalyst temperature from dropping below the activation temperature when the steady running state continues, maintains the steady running state without requiring the operation of the accelerator pedal, and controls the exhaust gas purification in the steady running state. Is improving.

Further, there is one disclosed in Japanese Patent Laid-Open No. 2-259279. The internal combustion engine ignition timing and idle speed control valve control method disclosed in this publication include an engine temperature detecting means, an engine speed detecting means, and a basic ignition for setting a basic ignition timing to a retard side as the engine temperature is lower. Output of the timing setting means, a rotation speed feedback correction means for correcting the basic ignition timing to the advance side when the idling engine speed is lower than the target value, and to the retard side when the engine speed is higher than the target value. In response to this, an ignition drive means for driving the ignition device of the engine and a control center value changing means for changing the control center value of the rotation speed feedback by the rotation speed feedback correction means to the retard side when the engine temperature is low are provided. In the engine idle speed control device by adjusting the timing,
The stability of idle rotation during cold is ensured and the engine stalling resistance against external load is improved.

[0006]

By the way, in the conventional fuel injection control device for an internal combustion engine, in order to warm up the catalyst early, from the time of start-up until a predetermined time elapses, or There is a measure to retard the ignition timing by a fixed angle, for example, 4 degrees, from the time of starting to the time when the prescribed water temperature is reached.

This measure has the effect of raising the temperature of the catalyst early, but has the disadvantage that this effect is very small and a great effect cannot be expected.

In recent years, the exhaust gas regulations of the United States are in a severe situation where the HC value is being reduced year by year, and it is earnestly desired to realize a device which can expect a great effect to satisfy the exhaust gas regulations. Has been done.

In order to solve the above-mentioned inconvenience, in an internal combustion engine having four cylinders, as shown in FIG. 4, the fuel injection amount and the ignition timing are changed for each ignition operation when the engine is operating in the cold state, so that the catalyst is activated early. There are things that control to warm up.

That is, in each of the ignition cylinders (# 1 to # 4), the fuel injection amount is changed from + 10% to -10% with respect to the basic injection amount, and the fuel injection amount is changed to -5 degrees or with respect to the basic ignition timing. The ignition timing is changed by delaying by -10 degrees.

Then, the temperature of the exhaust gas is raised to accelerate the rise of the catalyst so that the exhaust gas purification function of the catalyst can be sufficiently exerted.

However, in the above control, by intermittently changing the fuel injection amount and the ignition timing, the drivability is deteriorated during the control, especially in the low speed range, which is disadvantageous in practical use. There is.

Further, if the control for reducing the amount of injected fuel and the control for retarding the ignition timing overlap, hesitation and the like are likely to occur, and there is a disadvantage that the usability is poor.

[0014]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention determines the fuel injection amount from the injector and the ignition timing of the spark plug for each ignition operation of the spark plug during operation in a cold state. In a fuel injection control device for an internal combustion engine of a multi-injection system, which controls to perform early warm-up of the catalyst by changing it, control the fuel injection amount of the injector when retarding the ignition timing of the spark plug by a predetermined value or more. It is characterized in that a control unit having a control pattern set to be performed on the increasing side is provided.

[0015]

According to the invention as described above, when retarding the ignition timing of the spark plug by a predetermined value or more, the control of the fuel injection amount of the injector is controlled by the control pattern of the control unit on the increasing side, and the catalyst is advanced at an early stage. The warm-up can be performed, the deterioration of the effect during the warm-up control is prevented, and the drivability is prevented from being deteriorated in the low speed range.

[0016]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 3 show an embodiment of the present invention. In FIG. 2, 2 is an internal combustion engine, 4 is an air cleaner, 6 is an intake manifold, 8-1, 8-2, 8-3, 8
Reference numeral -4 denotes a multi-injection injector 10-1, 1 for injecting fuel into a plurality of, for example, four combustion chambers (not shown) of cylinders (not shown) of the internal combustion engine 2, respectively.
Reference numerals 0-2, 10-3, and 10-4 are spark plugs respectively arranged in four cylinders (not shown).

In the internal combustion engine 2, each spark plug 10-
A distributor 12 that distributes a high-voltage current is provided to each of 1, 10-2, 10-3, and 10-4, and an ignition coil 14 is connected to the distributor 12.

Further, the injectors 8-1, 8-2,
8-3, 8-4, the distributor 12, and the ignition coil 14 are connected to the control unit 16, and the control unit 16 includes an idling switch (S
W) ON / OFF signal, vehicle speed signal that detects the vehicle speed,
Detects crank angle signal, engine speed signal, engine speed signal, throttle opening signal or other load signal, cooling water temperature signal, cooling water temperature signal, and intake air temperature to internal combustion engine 2. Various signals such as the intake air temperature signal, the ignition pulse detection signal, and a catalyst temperature signal (not shown) for detecting the temperature of the catalyst are input.

The control unit 16 controls the spark plug 10-
When retarding the ignition timing of 1, 10-2, 10-3, 10-4 by a predetermined value or more, the injectors 8-1, 8-
The control pattern is set so as to control the fuel injection amounts of 2, 8-3, and 8-4 on the increasing side.

More specifically, the control operation start condition of the control unit 16 is that, when the engine is operating in the cold state, for example, the temperature of the cooling water is a predetermined temperature T1 ° C. or lower and the engine speed Ne is within a predetermined range, that is, N1 (rpm) ≦ Ne <N2
(Rpm) is satisfied and the vehicle speed is within a predetermined range, that is, V
1 (〓 / h) ≦ vehicle speed <V2 (〓 / h) is satisfied, and an idling switch (not shown) is in an OFF state.

The first item for determining the water temperature is for determining the cold state, and the second item for determining the engine speed Ne is in consideration of drivability in the low rotation range and the high rotation range. The third item for determining the vehicle speed considers the low speed range and the racing, and the last item for determining the OFF state of the fourth idling switch considers the drivability without performing the control in the idling state. It is a thing.

The control operation of the control section 16 is started when the control operation start condition consisting of these four items is satisfied.

Further, as a condition for ending the control unit 16, when it can be determined that the water temperature or the catalyst temperature has risen and is in a warm-up state, for example, when the water temperature exceeds a predetermined temperature T1 ° C.,
It is determined that the engine is warmed up, and the control of the control unit 16 is stopped.

Further, the general control operation by the controller 16 is as follows: spark plugs 10-1, 10-2, 10-3, 1
The injectors 8-1, 8-2, 8-- so that the total fuel injection amount becomes the basic injection amount for each ignition operation of 0-4.
The fuel injection amount from 3 and 8-4 is increased or decreased by a predetermined ratio, and at the same time as the fuel injection control, the spark plug 10-
For each ignition operation of 1, 10-2, 10-3, 10-4,
The ignition timing of the spark plugs 10-1, 10-2, 10-3, 10-4 is retarded.

Further, during the above-mentioned fuel injection control and ignition timing control, the spark plugs 10-1, 10-2, 10- are used.
The control is performed for each ignition operation of 3 and 10-4, but in the internal combustion engine 2 having four cylinders (not shown), as shown in FIG. 3, so that a specific condition is not concentrated on a specific cylinder. , A control pattern having a change of 3 beats, for example.

At this time, the control pattern in the control unit 16 is set to the spark plugs 10-1, 10-2, 10-.
When retarding the ignition timings of 3 and 10-4 by a predetermined value, for example, 5.1 degrees or more, the injectors 8-1, 8-2,
8-3 and 8-4 control the fuel injection amount on the increasing side,
That is, it is set to control the increase of the fuel injection amount.

Next, the operation will be described with reference to the control flow chart of the fuel injection control device for the internal combustion engine 2.

When the engine start (100) is confirmed by the starting operation of the internal combustion engine 2, the control program of the fuel injection control device is started.

Then, one of the control operation start conditions by the control section 16 is judged (102) whether the water temperature is equal to or lower than a predetermined temperature T1 ° C. If the judgment (102) is NO, When the termination condition of the control unit 16 is satisfied and the control is stopped (104), the determination (102) is YE.
In the case of S, the engine speed Ne is N1 (rpm)
It is judged (106) whether or not it is within the range of ≦ Ne <N2 (rpm).

When this judgment (106) is NO, it is judged whether the water temperature is the predetermined temperature T1 ° C. or lower (102).
Returning to, and if the determination (106) is YES,
It is judged whether the vehicle speed is within the range of V1 (〓 / h) ≦ vehicle speed <V2 (〓 / h) (108).

If the judgment (108) is NO, it is judged whether the water temperature is below the predetermined temperature T1 ° C. (1
When the determination (108) is YES while returning to 02), it is determined (110) whether the idling switch (not shown) is in the OFF state.

If the above judgment (110) is NO,
Determining whether the water temperature is below a predetermined temperature T1 ° C (10
Returning to 2), if the judgment (110) is YES, it is judged that all four items of the control operation start condition by the control unit 16 are satisfied, and the control is executed (112).

After this control execution processing operation (112),
Determining whether the water temperature is below a predetermined temperature T1 ° C (10
It returns to 2).

As a result, the spark plugs 10-1 and 1
When retarding the ignition timing of 0-2, 10-3, 10-4 by 5.1 degrees or more, the control unit 16 injects fuel from the injectors 8-1, 8-2, 8-3, 8-4. It is possible to control the increase of the amount, there is no fear of lowering the early warm-up effect of the catalyst (not shown), it is practically advantageous, and it is possible to prevent deterioration of drivability in the low speed range, The drivability can be improved.

Further, since the problem can be dealt with only by changing the control program for changing the setting of the control pattern in the control unit 16, there is no fear that the configuration will become complicated, the production is easy, and the cost is low. Can be maintained at low cost, which is economically advantageous.

The present invention is not limited to the above-mentioned embodiment, but various application modifications are possible.

For example, in the embodiment of the present invention, 4
Although the internal combustion engine having the number of cylinders is configured to be controlled by the control pattern having the change of three beats, the internal combustion engine having the number of cylinders other than four can be used.
In the case of an internal combustion engine having a plurality of cylinders other than four, it is possible to cope with it by changing the setting to a control pattern having a predetermined beat so that the specific condition is not concentrated on the specific cylinder.

[0039]

As described above in detail, according to the present invention, the amount of fuel injected from the injector and the ignition timing of the spark plug are changed for each ignition operation of the spark plug during the operation in the cold state to early warm the catalyst. In a fuel injection control device for a multi-injection type internal combustion engine for controlling the engine to control the engine, a control set to control the fuel injection amount of the injector on the increasing side when retarding the ignition timing of a spark plug by a predetermined value or more. Since we have a control unit with a pattern,
When retarding the ignition timing of the spark plug by a predetermined value or more,
The control unit can control the increase of the fuel injection amount of the injector, and there is no possibility of reducing the early warm-up effect of the catalyst, and it is possible to surely prevent the drivability in the low speed range from being deteriorated. , Can improve drivability. Further, since it is possible to deal with it only by changing the control program for changing the setting of the control pattern in the control unit, there is no fear that the configuration will become complicated, the manufacturing is easy, and the cost is kept low. It is possible and economically advantageous.

[Brief description of drawings]

FIG. 1 is a control flowchart of a fuel injection control device for an internal combustion engine showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a fuel injection control device for an internal combustion engine.

FIG. 3 is a diagram showing control of fuel injection amount and ignition timing in a four-cylinder internal combustion engine.

FIG. 4 is a diagram showing control of fuel injection amount and ignition timing in a four-cylinder internal combustion engine showing a conventional technique of the present invention.

[Explanation of symbols]

 2 Internal Combustion Engine 4 Air Cleaner 6 Intake Manifold 8-1, 8-2, 8-3, 8-4 Injector 10-1, 10-2, 10-3, 10-4 Spark Plug 12 Distributor 14 Ignition Coil 16 Control Section

Claims (1)

[Claims] 1. A multi-injection internal combustion engine which controls the amount of fuel injected from an injector and the ignition timing of a spark plug for each ignition operation of the spark plug to perform early warm-up of the catalyst during cold engine operation. In the fuel injection control device, the control unit having a control pattern set to control the fuel injection amount of the injector on the increasing side when retarding the ignition timing of the spark plug by a predetermined value or more is provided. A fuel injection control device for an internal combustion engine.