JPS61104146A - Control device for engine - Google Patents

Abstract

PURPOSE:To produce the output of an engine in a stable state, by providing a fluctuation control means which controls at least either an ignition timing or EGR in a direction in which a change in the output of an engine is controlled. CONSTITUTION:A settling means 12 determines a desired intake air amount and a fuel feed amount according to the opening of an accel. A throttle control means 15 performs feedback control so as to converge the opening of a throttle to the desired intake air amount depending upon the output of an exhaust gas sensor 14. A fluctuation control means 18 is provided for controlling at least either an ignition timing control means 16 or an EGR processing means 17 in a direction in which a change in an output produced due to a change in a throttle along with said feedback. This causes control of a fluctuation in an output, and enables the output of an engine to be produced in a stable condition.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention connects an actuator that opens and closes the throttle valve to the throttle valve, and drives the actuator in response to the depression of the accelerator pedal. The present invention relates to an engine control device that controls opening and closing of valves.

(Prior Art) As described above, there has been a conventional throttle control means that drives a throttle valve with an actuator, such as a forward/reverse motor, in accordance with the amount of depression of an accelerator pedal (for example,
(Japanese Patent Application Laid-Open No. 138235/1983).

The conventional device described above converts the depression period of the accelerator pedal, that is, the accelerator opening degree, into an intake air amount, and opens and closes the throttle valve in response to this.

By the way, the above-mentioned opening/closing operation of the throttle valve can be performed by, for example,
When driven by a forward/reverse motor 1. [Determine the throttle opening corresponding to the above intake air amount as the target value,
Even if the throttle valve is moved, an error occurs between the actual intake air amount and the above-mentioned target intake air amount.

To absorb this error, it is necessary to detect the oxygen concentration of the exhaust gas with an exhaust sensor and perform feedback control to converge the throttle opening to the target value according to this output. However, in order to converge the throttle valve to the target intake air amount, the opening degree of the throttle valve is controlled to be large or small, which causes fluctuations in the output of the engine.

(Object of the Invention) An object of the present invention is to control at least one of ignition timing or EGR in a direction that suppresses output changes that occur in response to throttle changes that occur due to feedback, so that the engine An object of the present invention is to provide an engine control device that can suppress output fluctuations in the engine.

(Structure of the Invention) The present invention improves ignition timing and
The present invention is characterized in that the engine control device is provided with a fluctuation control means for suppressing at least one of R.

That is, as shown in FIG. 1, the engine 10 includes a setting means 12 that determines a target intake air amount and a fuel supply amount according to the accelerator opening of an accelerator opening sensor 11, and a setting means 12 that determines a target intake air amount and a fuel supply amount according to the accelerator opening of an accelerator opening sensor 11. , controls the throttle opening of the throttle valve 13 and according to the output of the exhaust sensor 14,
It has a throttle control means 15 that performs feedback control to converge the throttle opening degree to the target intake air ■, and an ignition timing control means 16 or EGR processing that suppresses output changes caused by throttle changes accompanying the feedback. The engine control device is characterized in that it is provided with a variation control means 18 for controlling at least one of the means 17.

(Effects of the Invention) According to the present invention, when performing feedback control to converge the accelerator opening to the target intake air 1 in response to the depression of the accelerator pedal, the engine Since the output change is suppressed by the fluctuation control means, the output change is suppressed and the engine output can be obtained in a stable state.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows a control device for an engine. In FIG. 2, an engine 10 has a cylinder 19 and a piston 20, an intake passage 22 and an exhaust passage 23 are connected to a combustion chamber 21, and each passage 22, 23 is connected to a combustion chamber 21. An intake valve 24 and an exhaust valve 25 are provided at the connection portion of the combustion chamber 21, and a spark plug 26 is installed in the combustion chamber 21.

A throttle valve 13 is provided upstream of the intake passage 22, and a fuel injection valve 27 is provided downstream thereof, and an exhaust sensor (02 sensor) 14 is provided in the exhaust passage 23. , the intake passage 22 and the exhaust passage 23 are
It is connected for exhaust gas recirculation by a bypass passage 28, in which an EGR valve 29 constituted by a solenoid valve is arranged.

An actuator 30 consisting of a forward/reverse motor is connected to the aforementioned throttle valve 13, and this actuator 3
The throttle valve 13 is driven to open and close by the forward and reverse rotation of zero.

Further, the throttle valve 13 is provided with a throttle opening sensor 31 that detects the opening of the valve 13.

The engine 10 configured as described above is controlled by an engine control unit 32, and this unit 3
2, a signal indicating the oxygen concentration of the aforementioned exhaust sensor 14;
A signal indicating the accelerator opening according to the depression M of the accelerator pedal of the accelerator opening sensor 11, a signal indicating the throttle opening of the throttle opening sensor 31, and a crank angle sensor 3
3 TDC signals are input, and based on these input signals, the spark plug 26, fuel injection valve 27, EGR valve 29
, controls the actuator 30 to drive the engine 10.

FIG. 3 shows the above-mentioned engine control unit 32, in which a CPU 34 controls each circuit device according to a program stored in a ROM 35, and an RΔM 36 stores and reads data.

The actuator drive circuit 37 is controlled by the CPLI 34 to drive the actuator 30 that rotates the throttle valve 13 in forward and reverse directions.

The EGR valve drive circuit 38 is controlled by the CPU 34,
The EGR valve 29, which controls the amount of circulation of exhaust gas, is opened and closed.

Further, the spark plug drive circuit 39 is controlled by the CPU 34 to drive the spark plug 26 at a predetermined ignition timing.

Furthermore, signals from the various sensors 11.14, 31.33 are input to the CPU 34 via the input interface 40.

In the engine control device configured as described above, when the target intake air amount is set according to the accelerator opening, the throttle opening is controlled according to this air amount, and the exhaust sensor 14 is also controlled. Feedback control is performed to converge the throttle opening to a target intake air amount according to the output, and at least one of ignition timing and EGR is controlled in a direction to suppress output changes caused by throttle changes due to feedback.

This processing operation will be explained with reference to FIG.

In the first step 41, a signal of the accelerator opening α corresponding to the depression level of the accelerator opening is read from the accelerator opening sensor 11, and in the second step 42, based on the accelerator lR [α, From the target intake air n map shown, the target intake air ff
1Qa is determined, and at the same time, based on the target intake air ff1Qa, the fuel supply amount is determined from a map (not shown) in which the fuel supply amount is set in advance in correspondence with this target intake air amount.

In a third step 43, the engine speed is read.

That is, the output cycle of the TDC signal output by the crank angle sensor 33 is calculated, and based on this cycle, the engine rotation speed is calculated from a map (not shown) in which the engine rotation speed is preset corresponding to this output cycle. Ne
Read out.

In a fourth step 44, a target throttle opening degree Tθ is determined from a target throttle opening degree map shown in FIG. 6, based on the above-mentioned target intake air 11tQa and engine speed Ne.

In a fifth step 45, the output of the exhaust sensor 14 is read, and at the same time, it is read whether the output indicates a lean or rich air-fuel ratio, and in a sixth step 46, it is compared with the air-fuel ratio read last time.
Determine whether there has been a change from lean to rich or from rich to lean.

If it is determined that there is no change in this determination, in a seventh step 47, it is determined whether the current air-fuel ratio is lean or rich.

When it is determined that the air-fuel ratio is rich, since FIG. 7 does not show the upward slope control, in this case, the control is in the direction of opening the throttle valve 13, so the throttle correction value CFB is corrected with a + side slope. The total throttle correction value CFB is determined by adding the value +IK (eighth step 48).

In addition, when it is determined that the air-fuel ratio is lean, the downward slope control shown in FIG. 7 is not shown, so in this case, the throttle valve 1
Since the control is in the direction of closing 3, the throttle correction value C
The total throttle correction value CFB is determined by adding one side inclination correction value -IK to FB (ninth step 49).

If it is determined in the aforementioned sixth step 46 that there has been a change, then in a tenth step 50 it is determined whether the current air-fuel ratio has changed to ridge or lean.

When it is determined that the change is rich, the upward vertical control shown in FIG.
Since the control is in the opening direction, the throttle correction value CFB
A total throttle correction value is determined by adding the + side vertical correction value PK to the total throttle correction value (eleventh step 41).

In addition, when a change to lean is determined, the downward vertical control shown in FIG. Vertical correction value -PK is added to determine full throttle correction ICFB (twelfth step 52).

When the total throttle correction tiiCFB of the throttle valve 13 in the ten directions and one direction is determined in this way, in a thirteenth step 53, the target throttle opening degree Tθ determined in the fourth step 44 is adjusted to the above-mentioned total throttle angle. The actual throttle opening degree p is obtained by adding the throttle correction ICFB, and this opening degree is further converted into an angle value, and a signal indicating this angle m is output to the actuator drive circuit 37.

The above-mentioned actuator drive circuit 37 drives the actuator 30 based on the input signal, and rotates the throttle valve 13 by a specified angle.

When the opening 1111J control of the throttle valve 13 described above is repeatedly executed, the target intake air is converged to the maximum, but at the same time, fluctuations occur in the output of the engine 10, so this fluctuation is suppressed.
, II, the following processing is performed.

At the fourteenth step 54, each of the aforementioned steps 48, 49.
The entire throttle correction value CF8 determined in step 51.52 is multiplied by the ignition advance influence coefficient a to determine the ignition timing correction value a-CF8, and the reference ignition advance is corrected with this.

That is, the above-mentioned ignition advance influence coefficient a is
The above-mentioned full throttle correction III! is set to suppress output fluctuations. If CF B is on the + side, a negative coefficient -a is given, and if the correction value CFB is on one side, a positive coefficient +a is given.

When the standard ignition advance angle is corrected with these values, when the throttle valve 13 is controlled in a direction that increases the output of the engine 10, the ignition advance angle becomes slower and the output of the engine 10 decreases. When the throttle valve 13 is controlled in such a way that the output of the engine 10 decreases, the ignition advance becomes earlier and the output of the engine 10 is controlled in the direction that increases, and these are canceled out. engine 10
output fluctuations are suppressed and stabilized.

The above-mentioned ignition process is then performed using the corrected ignition advance.
- angle signal is input to the spark plug drive circuit 39, and this circuit 39 drives the spark plug 26, thereby executing the process.

In the above example, the output fluctuation of the engine 10 is suppressed by the ignition advance angle, but it can be controlled by the exhaust gas circulation amount of EGR control. This control is performed by controlling the opening and closing of the lift amount of the EGR valve 29.

J, at the 15th step 55, the lift amount correction value b-CFB is determined by multiplying the total throttle correction [CFB determined in each step 48, 49, 51, 52 by the EGRffl Shōki coefficient s]. Then, the target lift of the EGR valve 29 is corrected.

In other words, the above-mentioned EGRffi influence coefficient is set in a direction to suppress output fluctuations of the engine 10, and if the above-mentioned total throttle correction value CFB is on the + side, the coefficient on the + side is also If the correction value CFB is on one side, a coefficient on the negative side is given.

When the lift M of the EG'R valve 29 is corrected with these values, when the throttle valve 13 is controlled in a direction that increases the output of the engine 10, the lift ω increases,
Exhaust circulation ■ also increases and the output of the engine 10 is controlled to decrease, and when the throttle valve 13 is controlled in the direction of decreasing the output of the engine 10, the lift amount decreases and the exhaust circulation amount decreases. engine 1
The output of 0 is controlled in the direction of increasing and rising, and these cancel each other out, suppressing fluctuations in the output of the engine 10 and stabilizing it.

The above-mentioned E G Rf, lI 0B is determined by inputting a signal indicating the corrected lift amount to the EGR valve drive circuit 38, and this circuit 38 based on the input signal.
This is executed by driving the GR valve 29.

Note that the output fluctuation of the engine 10 may be suppressed by performing either the ignition advance control or the EGR control as described above, or by performing both.

Regarding the correspondence between the configurations of this invention and the embodiments described above, the setting means 12 of the invention corresponds to the processing of the second step 42 of the CPtJ 34 of the embodiment, and the throttle control means 15 corresponds to the processing of the second step 42 of the CPtJ 34 of the embodiment. The ignition timing control means 16 corresponds to the processing of the 14th step 54 of the CPU 34, and the EGR control means 17 corresponds to the processing of the 15th step 5 of the CPU 34.
The variation control means 18 corresponds to the processing in step s4.55 of the CPU 34, and the other parts correspond to the same component names in the embodiment.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, Fig. 1 is a block diagram of the invention, Fig. 2 is a block diagram of an engine, Fig. 3 is a control circuit block diagram, Fig. 4 is a flowchart, and Fig. 5 is a target diagram. An explanatory diagram of the intake air amount map, Fig. 6 is an explanatory diagram of the target throttle opening map, and Fig. 7 is an explanatory diagram of the target throttle opening map.
It is an explanatory diagram of n-close control. 10... Engine 11... Accelerator opening sensor 12... Setting means 13... Throttle valve 1
4...Exhaust sensor 15...Throttle control means 1
6... Ignition timing control means 17... EGR control means 18... Fluctuation control means 2
6... Spark plug 29... EGR pulp 30
...Actuator 32...Engine control unit 34...C
PU Figure 1 Figure 3 q Figure 5 77, Nine Pavilions, lcL Figure 4 Figure 6 Figure 7

Claims (1)

[Claims] 1. A setting means for determining a target intake air amount and a fuel supply amount according to the accelerator opening, and controlling the throttle opening according to the target intake air amount, and controlling the throttle opening according to the output of the exhaust sensor. This engine control device has a throttle control means that performs feedback control to converge the throttle opening to a target intake air amount according to the feedback, and the ignition timing and An engine control device comprising a fluctuation control means for controlling at least one of EGR.