JPS61145332A - Electronic control device in internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent an engine from surging, by restraining variations in the amount of fuel fed to an internal combustion chamber upon low rotational speed operation during running of a vehicle. CONSTITUTION:A rotational speed detecting means M3 detects the rotational speed of an internal combustion engine M1. When a vehicle speed detecting means M4 detects such that the vehicle is in its running condition and the rotational speed detecting means M3 detects the engine low speed operating condition, a fuel amount variation restrains means M5 restrains variations in the amount of fuel. With this arrangement it is possible to prevent the phenomenon of surging.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic control device for controlling an internal combustion engine for a vehicle, and particularly to prevention of surging during low speed driving.

[Prior Art] Conventionally, the operating state of an internal combustion engine for a vehicle is optimized based on the outputs of various sensors that detect the operating state of the internal combustion engine, such as a rotation speed sensor, an intake air amount sensor, an oxygen sensor, etc. The ignition timing, fuel amount, etc. are controlled in this way.

The electronic control unit executes this control, which calculates the outputs of the various sensors mentioned above, determines the optimal control weight according to the characteristics of the internal combustion engine, and controls various devices, such as fuel, based on the calculation results. It operates the injection valves, igniters, etc. As a result, current vehicles have excellent driving performance with low fuel consumption and improved drivability.

[Problems to be Solved by the Invention] However, the above-mentioned electronic control device for an internal combustion engine also has the following problems, and is still not perfect.

That is, in a low-speed running state (hereinafter referred to as a creep running state) where the vehicle is in a large gear ratio, for example, 1st or 2nd gear, and the throttle valve is almost fully open,
This causes a surging phenomenon in which the vehicle shakes back and forth. This is due to the time delay between receiving the detection output from various sensors such as the intake sensor that detects the intake air level in the electronic υ1 sin device as described above, executing arithmetic processing, and actually supplying fuel to the internal combustion engine. This is due to the fact that the air-fuel ratio of the internal combustion engine is disturbed. Once such a disturbance occurs, the rotational speed of the internal combustion engine fluctuates, and the time delay increases further, causing a similar vicious cycle to cause surging in the vehicle.

The present invention is an excellent electronic control device for an internal combustion engine that can greatly improve drivability by operating a vehicle internal combustion engine more stably without causing the surging phenomenon even during creep driving. Its purpose is to provide.

Means for Solving Problem E] The means constructed by the present invention to solve the above problem are as follows.

First, as shown in the basic configuration diagram of FIG. 1(A), the means configured in the invention of Mizuo 1 detects the operating state of the vehicle internal combustion engine M1 according to the detection result of the operating state detection means M2. , an electronic control device MM for an internal combustion engine that controls the output of the internal combustion engine M1 by controlling at least the amount of fuel of the internal combustion engine M1, comprising: a rotational speed detection means M3 that detects the rotational speed of the internal combustion engine 110MI; and a rotational speed detection means M3 that detects the vehicle speed of the vehicle. The vehicle speed detecting means M4 detects that the vehicle is in a running state,
The internal combustion engine M1 is characterized in that it is provided with a fuel amount fluctuation control means M5 that suppresses fluctuations in the amount of fuel supplied to the internal combustion engine M1 when a low rotational speed state is detected by the rotational speed detection means M3. Its gist is electronic control equipment.

Next, as shown in the basic configuration diagram of FIG. 1(B), the means configured in the invention of Mizui 2 is based on the detection result of the operating state detection means M12 for detecting the operating state of the vehicle internal combustion engine M11. Accordingly, at least the ignition timing of the internal combustion engine M11 is controlled! An electronic control device MM' for an internal combustion engine that controls its output by controlling the internal combustion engine M11 includes: rotational speed detection means M13 for detecting the rotational speed of the internal combustion engine M11; vehicle speed detection means M14 for detecting the vehicle speed of the vehicle; Ignition timing retardation for changing the ignition timing of the internal combustion engine M11 to the retard side when the vehicle speed detection means M14 detects that the vehicle is in a running state and the rotation speed detection means M13 detects a low rotation speed state. The gist of the present invention is an electronic control device for an internal combustion engine M11 characterized in that it includes a changing means M15.

[Function] Internal combustion engines M1 and M in the invention of Sui-Tei 1 and the second invention
In the first invention, the output of ll is at least controlled by an electronic control device MM that changes the fuel amount of the internal combustion engine M1.
Further, in the second invention, at least the internal combustion engine M1
It is controlled by an electronic control device MM= which changes the ignition timing of the engine.

The operating state detection means M2 and M12 refer to the internal combustion engine M1.
, Mll's various operating states.

Here, the various operating states include at least the internal combustion engine M1,
It refers to the information necessary to optimally control the output of Mll for the vehicle driver, and therefore
Refers to the conditions of the internal combustion engine M1, M11, such as its rotational speed and intake air amount, and the state of the ignition timing, etc., necessary to determine the basic fuel injection amount of L1.

As mentioned above, the electronic control devices MM and MM- have the function of controlling the output of the internal combustion engines M1 and Mll, and the electronic control device 1MM of the invention of Mizui 1 has the function of controlling the output of the internal combustion engines M1 and Mll. According to the detection result of at least the internal combustion I
The output control is executed by controlling the fuel amount of IJen M1 by IIJ m, and the electronic control device MM in the second invention
- means that output control is performed by controlling at least the ignition timing of the internal combustion engine M11 based on the detection result of the operating state detection means M12.

The rotational speed detection means M3, Ml3 refer to the internal combustion engine Ml,
Detect the rotation speed of Mll. Normal internal combustion engine Ml, M11
is equipped with a rotation angle sensor and a cylinder discrimination sensor to synchronize the fuel injection timing etc. with the crank angle.
If this is used, no new configuration is required.

Further, the vehicle speed detection means M4 and Ml4 detect at what speed the vehicle is currently traveling. That is, it is realized by detecting the rotational speed of the driving wheel or the driven wheel. The outputs of the vehicle speed detection means M4 and M14 are provided to the fuel amount fluctuation control means M5 of the first invention or the ignition timing retardation changing means M15 of the second invention, which will be described later.

The fuel amount fluctuation suppressing means M5 and the ignition timing retardation changing means M, which are unique constituent elements in the first invention and the second invention.
15 are activated only when the following conditions are met. When the vehicle speed detection means M4 and M14 indicate that the vehicle is running at a low speed (for example, 8 kl/h or less), and the next rotation speed detection means M3 and Ml3 indicate that the current rotation speed of the internal combustion engines M1 and Mll is low. It's time to judge. That is, the operation is started only when the vehicle is in a creep running state. First, the fuel amount fluctuation suppressing means M5 of the invention of Mizuhiro 1, which operates in the above-mentioned state, suppresses fluctuations in the amount of fuel given to the internal combustion engine M1. That is, internal combustion engine M
The output of No. 1 is optimally controlled by changing at least the amount of fuel by the electronic control device MM,
Although the amount of fuel changes from moment to moment, this change in the amount of fuel is suppressed. For example, it is possible to keep the fuel amount constant and set the fluctuation to 0, or to set upper and lower limits for the change in fuel amount and only allow fluctuations within that range, or even to change the amount of fuel over time. So-called smoothing control may be used to provide a delay. Similarly, the ignition timing retardation changing means M15 of the invention of Mizuhiro 2, which operates only in the above-mentioned conditions, changes the ignition timing of the internal combustion engine M11 to the retard side. That is, the output of the internal combustion engine M11 is optimally controlled by the electronic control device MM- by changing at least its ignition timing. Therefore, although this ignition timing changes from moment to moment like the above-mentioned fuel amount, the ignition timing is retarded by a predetermined amount away from the control of this electronic control unit MM'.

Hereinafter, in order to explain the first and second inventions more specifically, the inventions will be described in detail using examples.

[Embodiment] FIG. 2 is a schematic diagram of an engine and a control device equipped with an electronic control device according to a first embodiment of the first invention.

In the figure, 1 is an engine, 2 is a piston, 3 is a cylinder, and 4 is a cylinder head. An exhaust manifold 6 is attached to the exhaust boat 5 of each cylinder of the cylinder head 4, and an intake port 7 of each cylinder of the cylinder head 4 is attached to an exhaust manifold 6. Intake manifolds 8 are connected to each other. The intake manifold 8 is also provided with a surge tank 9 for preventing pulsation of intake air, and the surge tank 9 is equipped with an intake pressure sensor 10 that detects the pressure inside the intake manifold 8, that is, the intake pipe pressure Pm. There is.

Next, 11 is a throttle valve that controls the amount of intake air sent to each cylinder via the surge tank 9, and 12 is an idle speed control valve (ISCV) that controls the amount of intake air that flows through the bypass passage 12A that bypasses the throttle valve 11. , 13 is an intake air temperature sensor that detects the intake air temperature, and the throttle valve 11 includes a throttle valve opening sensor that outputs a signal corresponding to the opening of the throttle valve 11 and a throttle valve opening sensor that is turned on when the engine 1 is idle. A throttle position sensor 14 having an idle switch and an idle switch is directly connected to the throttle position sensor 14.

Further, 15 is an oxygen concentration sensor attached to the exhaust manifold 6 and detects the oxygen concentration in the exhaust gas, 16 is a water temperature sensor that detects the cooling water temperature of the engine 1, and 17 is an oxygen concentration sensor for detecting the oxygen concentration in the exhaust gas.
a distributor that applies a high voltage output from the igniter 19 to the spark plug 18 at a predetermined timing;
0 is a rotation speed sensor attached to the distributor 17 and generates a pulse signal corresponding to the rotation speed Ne of the engine 1, 21 is a starter sensor that detects the operating state of a starter motor (not shown) that starts the engine, and 22 is an air conditioner compressor. The air conditioner switch 23, which detects the operating state of the vehicle, is a vehicle speed sensor that is provided on the driven wheel to detect the running state of the vehicle and detects its rotation speed.

The above-mentioned intake pressure sensor 10. Various detection signals from the intake temperature sensor 13, throttle position sensor 14, oxygen concentration sensor 15, water temperature sensor 16, and rotational speed sensor 20 are output to the control circuit 25, and the control circuit 25 controls the fuel injection valve based on each of the detection signals. A number of I control processes such as fuel injection amount control of 26 and ignition timing control of spark plug 18 are executed.

Next, FIG. 3 shows a block diagram showing the configuration of the control circuit 25 mentioned above. In the figure, 25 is an electronic engine control circuit, 27a is an input interface circuit, and intake pressure sensor 10. Intake temperature sensor 13, oxygen IIrt1. Ir-like 1
5, Water temperature sensor 16, Throttle position sensor 14
Input analog signals such as A/D to the A/D converter 28,
/D converter 28 converts the analog signal into a digital signal, and central processing unit (hereinafter referred to as CPU) 29
Enter. The CPU 29 uses these signals as parameters to perform well-known calculations such as fuel injection secondary leg control, ignition timing control, and valve opening of the bypass passage 12A. 21, air conditioner switch 22, vehicle speed sensor 23, and other digital signals are input through the input interface circuit 27b and used as parameters.

The CPU 29 stores the above-mentioned parameters in a built-in memory 30, reads them out as appropriate in accordance with the flow of the program, and processes them.

Next, 31 is a power supply for the CPU 29, and 32 is an output interface circuit for appropriately outputting a control signal from the CPU 29 to other units described later. 26a, which inputs the output from this output interface circuit, is a fuel injection valve (hereinafter referred to as an injector) that supplies fuel to the first cylinder, 26b is an injector for the second cylinder, 26c is an injector for the third cylinder, and 26d is the injector of the fourth cylinder.

Further, the spark plug 18 is ignited when a control signal from the output interface circuit 32 is input to the igniter 19. Further, l5CVI 2 is a servo motor type actuator that controls the valve opening according to a control signal from the output interface circuit 32 when the engine is idling or decelerating. CPU is output interface circuit 32
Through this, the above-mentioned control object is controlled according to the program.

FIG. 4 shows a flowchart of a condition determination routine, which is one of the programs according to this embodiment. This routine is executed by the CPU 29 at every predetermined rotation speed of the engine 1 or at every predetermined time. In the figure, step 101 determines whether or not control is being executed during fuel cut.
Step 2 determines whether the throttle valve is fully open or not. Step 103 determines whether the engine speed Ne is a predetermined value (1000 [rp
IT+]) or less is determined in step 104.
determine whether the vehicle is running at low speed using the throttle position sensor 14 and rotation speed sensor 20 . The determination is made from the output of the vehicle speed sensor 23.

Then, fuel injection is in progress, the throttle valve is fully open, the rotational speed Ne<1000 [rpm, and the vehicle is 2.
When the vehicle is running at a low speed of 51 v/h to 8 kra/h or less, the above-mentioned determination conditions are satisfied and the process moves to step 105.

In this step, flag X is set to ``1'' assuming that the condition is met.
”. On the other hand, if even one of the above judgment conditions is not satisfied, the process moves to step 106 and the flag
is reset to [0].

FIG. 5 is a flowchart of a program for a fuel injection amount determination routine of the electronic control unit, which is executed in response to determination by the condition determination routine. This routine is for engine 1.
C before fuel injection is executed from the hein injector 26.
Processed by PU29. First, in step 111, processing for determining the normal fuel injection amount is executed using the intake pipe pressure Pm1, the engine rotation speed Ne, the water temperature sensor signal 16, etc. as parameters, and the injection pulse width T of the injector 26 is executed.
Then, in step 112, the flag The following calculation is performed.

TR-(T+ (7xTO)) /8...(1)
Here, TO is the actual injection pulse width TR obtained the last time this routine was executed, and therefore this time (
The TR calculated using equation 1) becomes the next TO value. Thereafter, the process moves to step 114, in which this information TR is set in a counter in order to drive the injector 26 with the injection pulse width TR determined in this way.

As a result, the fuel injection execution routine, which is executed in synchronization with the crank angle of the engine 1 (not shown), controls the fuel amount by driving the injector 26 for a time corresponding to the content of the counter.

On the other hand, if the flag X is "0", the process moves to step 115. In this step 115, the value of T calculated in step 111 is stored as is in the TR, and the process proceeds to step 114 in the same manner as in step 113 described above.

As described above, the electronic control device, which is an embodiment of the invention of Mizui 1, which controls the fuel injection amount, accurately detects creep running by the condition determination routine, and when this detection is made, the injection is supplied to the engine 1. This is to execute control that smoothes the change in fuel amount to 1/8.

As a result, the surging phenomenon that was caused by the time delay until the injection pulse width T calculated in step 111 in FIG. ''), the fuel injection amount is smoothed, thereby smoothing the torque fluctuations of the engine 1 and completely preventing the above-mentioned surging phenomenon.

Next, a second embodiment of the electronic control device of the first invention will be described. This embodiment differs only in the processing within the CPU 29 as described below, and the other configurations are the same as in the first embodiment. FIG. 6 is a flowchart of the condition determination routine of this embodiment, which performs almost the same processing as the condition determination routine described above (FIG. 4), and is a flowchart of the condition determination routine of the first embodiment.
~Step 106 corresponds to Step 201~Step 206 of this program. In this program, after the flag X setting process (step 205) is executed, another 7-lag Y setting process (steps 207 to 209) is performed. That is, step 20
In step 5, 7 lag In this step 208, "1" is stored in flag Y. Conversely, if the air conditioner is not operating, the process moves to step 209 and the flag Y
is set to "0".

In this embodiment, the fuel injection tI4m determination routine shown in FIG. 7 is executed using the flags x1 and Y thus created. In this program, the injection pulse width T is calculated in step 211, and the flag
The determination of 7 lag
If it is "1", the process moves to step 213, and the contents of flag Y are determined. If the flag Y is "1", the process moves to step 214, and step 11 of the first embodiment
Similarly to 3, the injection pulse width T is rounded to 1/8, and if the flag Y is "0", the process moves to step 215 and the injection pulse width T calculated at step 211 is rounded by 1/2. Calculate the following equation to add .

TR-(T+TO)/2...(2) In other words, the operating status of the air conditioner fl! This means that the rounding of the injection pulse width T is changed depending on the setting state of Y. That is, when the air conditioner is operating, the electronically controlled fuel injection device normally increases the amount of air that bypasses the throttle valve to prevent the rotation from decreasing due to the load on the air conditioner.

Therefore, even if the engine is rotating at the same speed as when the air conditioner is not operating, the generated torque is large when the air conditioner is operating, and therefore, if there is a delay in fuel injection, the surging phenomenon will be more pronounced. Therefore, a large rounding process is performed only at this time.

According to this embodiment, it is possible to prevent the surging phenomenon during creep driving without reducing the responsiveness of the engine 1.

Next, an electronic control device that is an embodiment of the invention of the water bottle 2 will be described. The configuration and part of the control program of this embodiment are the same as the first embodiment of the first invention described above, and have the configuration shown in FIG. 2, and the creep running condition is set as shown in FIG. It is detected by a determination routine, and the detection result is set in flag X.

In this embodiment, the ignition timing determination routine shown in FIG. 8 is executed based on the contents of this flag X.

This routine is executed by the CPU 29 before issuing a control output to the igniter 19 and causing the spark plug 18 to fire. When the CPU 29 moves to this routine, first step 301 is executed, and based on the outputs of various sensors shown in FIG. 2, the ignition timing θ, which is estimated to be suitable for R for the engine 1, is calculated by controlling the normal ignition timing $1J. be done.

In the following step 302, the 7 lag
DC). As a result, the signal output to the igniter 19 is controlled by the ignition execution routine (not shown) executed by the CPU 29 at a predetermined crank angle so as to be equal to the content θR. On the other hand, flag X is rOJ
In this case, the process moves to step 305, and the ignition timing θ using parameters such as the intake pipe pressure Pm and engine rotational speed Ne calculated in the above-mentioned step 301 is stored as is in θR.

In this way, in this embodiment, when the flag X is "1", the ignition timing is set at
Fixed to TDC.

That is, according to this embodiment, since the ignition timing is fixed regardless of the detection result of the operating state of the engine 1, there is no factor that causes a detection delay, and furthermore, the fixed ignition timing is retarded from the normal ignition timing. (10'BTDC>), the torque generated by the engine 1 is reduced, and fluctuations in the engine speed are suppressed, thereby making it possible to prevent the surging phenomenon.

Next, other embodiments of the present invention will be described.

A part of the configuration and control program of this embodiment is as described above.
This embodiment is the same as the embodiment shown in FIG. 2, and has the configuration shown in FIG. 2. As shown in FIG.

In this embodiment, the idle speed control routine shown in FIG. 9 is executed based on the contents of this flag X.

When the CPU 29 moves to this routine, first step 401 is executed, and the flag X is determined. If it is "1", the process moves to step 402, and control is performed to close 15CV12 to a predetermined pulp opening degree V. This Vg is set to such an extent that the engine will not stall even if the transmission is set to neutral during creep driving.

On the other hand, if flag X is "0", step 403
, and normal idle speed control is performed. In other words, fsc is adjusted so that the idle speed becomes the target value.
The amount of bypass air is controlled by adjusting the opening degree of V12.

The first and second embodiments of the first invention and the second embodiment described above
This embodiment of the invention has a common part with other embodiments (condition determination routine), and then a different fuel injection tJJ
Although the amount of change v1 or the ignition timing is changed, or the intake air amount is suppressed, these changes are not contradictory, and two or more embodiments may be installed at the same time. This has the effect of further suppressing torque fluctuations and reliably prevents the surging phenomenon during creep running.

Furthermore, if a function for detecting the gear ratio state of the transmission of the internal combustion engine is added to the condition determination routine of the above embodiment, and a process is performed to determine that there is no creep running state when the gear ratio is small, control efficiency can be improved. -II becomes higher. Furthermore, the amount of change in the operating state of the engine 1, for example, the amount of change ΔQ in the intake air IQ, is included in the series of determinations in the condition determination routine.
The amount of change ΔTR in the actual injection pulse width TR, etc. is observed, and the point at which the so-called surging phenomenon occurs, where the amount of change exceeds a predetermined value, is determined, and only at this time, changes in fuel injection amount, ignition timing, and intake air are controlled. The amount may be changed.

In this way, unnecessary suppression of changes in the fuel injection amount or changes in the ignition timing will not be made when it is unnecessary for the engine 1, and control with good responsiveness will be possible.

[Effects of the Invention] As described above in detail with reference to embodiments, the electronic control device for an internal combustion engine according to the invention of Mizui 1 has the following features: An electronic control device for an internal combustion engine that controls the output of the internal combustion engine by controlling at least the amount of fuel of the internal combustion engine, comprising: rotational speed detection means for detecting the rotational speed of the internal combustion engine; and a vehicle speed detecting means for detecting the vehicle speed of the vehicle. a detection means; and a fuel amount for suppressing fluctuations in the amount of fuel supplied to the internal combustion engine when the vehicle speed detection means detects that the vehicle is in a running state and the rotation speed detection means detects a low rotation speed state. The invention is characterized by comprising a variable supination means.

Therefore, when the internal combustion engine is running in a creep state and the condition is such that the surging phenomenon occurs, sudden fluctuations in the fuel injection amount are suppressed by smoothing control, so the torque generated by the internal combustion engine does not change suddenly and the surging phenomenon is reliably prevented. It can be prevented.

Further, the electronic control device according to the invention of Suiden 2 controls the output of the internal combustion engine by controlling at least the ignition timing of the internal combustion engine according to the detection result of the operating state detection means for detecting the operating state of the internal combustion engine for a vehicle. An electronic 11JIII device for an internal combustion engine, comprising: rotational speed detection means for detecting the rotational speed of the internal combustion engine; vehicle speed detection means for detecting the vehicle speed of the vehicle; and a vehicle speed detection means that detects that the vehicle is in a running state. and ignition timing retardation changing means for changing the ignition timing of the internal combustion engine to a retarded side when a low rotational speed state is detected by the rotational speed detecting means.

Therefore, when the internal combustion engine is running in a creep state and the condition is such that a surging phenomenon occurs, the torque generated by the internal combustion engine can be suppressed to a low level by controlling the ignition timing retardation. Therefore, the above-mentioned surging phenomenon in which the rotational speed of the internal combustion engine suddenly changes can be reliably prevented.

[Brief explanation of drawings]

Figure 1 (A) is a basic configuration diagram of Suiden 1's invention;
B) is a basic configuration diagram of the invention of Sui-Tei 2, FIG. 2 is a schematic diagram of the configuration of the embodiments of the first and second inventions, FIG. 3 is a block diagram of its control system, and FIG. 4 is a diagram of the first embodiment of the invention. Flowchart of processing in the first embodiment of the invention and the second embodiment of the invention, No. 5
The figure is a flowchart of processing in the first embodiment of the first invention, FIGS. 6 and 7 are flowcharts of processing in the second embodiment of the first invention, and FIG. 8 is a flowchart of processing in the second embodiment of the invention. Flowchart of Processing FIG. 9 shows a flowchart of processing in another embodiment of the present invention. 10... Intake pressure sensor 14... Throttle position sensor 20... Rotation speed sensor 22... Air conditioner switch 25... Control circuit

Claims (1)

[Scope of Claims] 1. An electronic device for an internal combustion engine that controls the output of the internal combustion engine by controlling at least the amount of fuel in the internal combustion engine according to the detection result of an operating state detection means that detects the operating state of the internal combustion engine for a vehicle. The control device includes: a rotation speed detection means for detecting the rotation speed of the internal combustion engine; a vehicle speed detection means for detecting the vehicle speed of the vehicle; and when the vehicle speed detection means detects that the vehicle is in a running state, 1. An electronic control device for an internal combustion engine, comprising fuel amount fluctuation control means for suppressing fluctuations in the amount of fuel supplied to the internal combustion engine when a low rotational speed state is detected by the means. 2. In an electronic control device for an internal combustion engine that controls the output of the internal combustion engine by controlling at least the ignition timing of the internal combustion engine according to the detection result of the operating state detection means that detects the operating state of the internal combustion engine for a vehicle, a rotation speed detection means for detecting the rotation speed of the engine; a vehicle speed detection means for detecting the vehicle speed of the vehicle; the vehicle speed detection means detects that the vehicle is in a running state, and the rotation speed detection means detects that the vehicle is in a low rotation speed state. 1. An electronic control device for an internal combustion engine, comprising: ignition timing retardation changing means for changing the ignition timing of the internal combustion engine to a retarded side when ignition timing is detected.