JPS59185840A - engine control device - Google Patents

Abstract

PURPOSE:To stably control the number of revolution of an engine with high response performance by setting the aimed value of an intake amount according to the engine operation state and feedback-controlling the number of revolution of the engine according to the deviation from the signal output from an intake amount detector. CONSTITUTION:An actuator 4 driven by a motor 5 is connected to a throttle valve 2 installed in the intake passage 1 of an engine E, and a fule injector 20 and an air flow sensor (Karman vortex flow meter) 30 are installed on the upstream side of the throttle valve 20. A controller 15 inputs the intake amount signal supplied from the air flow sensor 30, together with a variety of operation parameters such as engine revolution number, and sets the aimed value of the amount of intake air according to the operation state in idling, and feedback- controls the throttle valve 2 according to the deviation from the detected value. Thus, since the intake amount is directly detected and is controlled so as to accord with an aimed value, the idle revolution number can be controlled stably and with high response performance.

Description

[Detailed description of the invention] The present invention relates to an engine control device.

BACKGROUND OF THE INVENTION In the past, many engines for automobiles and the like have been proposed that automatically control their output according to their operating conditions.

An example of this is to control the idling speed of the engine to an appropriate value depending on the warm-up state of the engine and the load state caused by driving auxiliary equipment such as a cooler compressor. For this purpose, the engine speed is usually detected. Then, the detection result is compared with a target rotation speed set according to the warm-up state or load state of the engine, and based on this comparison result, a bypass is performed to bypass the throttle valve or throttle valve, which is an intake flow rate adjustment means. So-called feedback control of the engine speed is performed in which the engine speed is controlled to the target engine speed by controlling the opening degree of a throttle bypass valve provided in the intake passage. however.

Feedback control of rotation speed requires a feedbank because there is a considerable delay between changing the opening of the throttle valve (throttle bypass valve) and the time when the change is actually reflected in the rotation speed. There is a drawback that the gain cannot be set too thick, and therefore, when a transient change occurs in the load condition of the engine, sufficient rotational speed control cannot be performed.

Therefore, position sensors are installed on the throttle valve and throttle bypass valve, and the throttle valve opening and throttle bypass valve opening are set as target values to provide the amount of intake air that generates the idle speed according to the warm-up state and load state of the engine. Set.

The output of the position sensor is compared with the valve opening target value, and according to the comparison result, so-called position feed bank control is performed to control the opening of the throttle valve and throttle bypass valve to the target value. There have also been proposals to try to control this. JP-A-55-57638 is equipped with a position sensor that detects the position of an actuator that drives a throttle valve, and drives the actuator by comparing the output of this sensor with a target opening set according to the warm-up state. What controls the opening of the throttle valve is shown.

However, when performing position feedback control of the throttle valve in this way, although the response of the control is quick, it does not directly measure the amount of intake air that increases the target rotation speed. When mass-producing, manufacturing errors can cause variations in the intake air flow rate depending on the throttle opening, and depending on the engine, it may not always be possible to obtain the expected idle speed, resulting in engine stalling. It may also cause the vehicle to run out of control or increase noise.

The present invention has been proposed in view of the above.

An intake flow rate detection means for detecting the flow rate of intake air supplied to the combustion chamber of the engine through the intake passage, and an intake flow rate adjustment means for adjusting the flow rate of the intake air passing through the intake passage. and an intake air flow rate adjusting means that compares target intake air flow rate information set according to the operating state of the engine with detection information of the intake air flow rate detection means and controls the intake air flow rate adjustment means according to the comparison result. An engine control device comprising a flow rate control means and configured to control the flow rate of intake air supplied to the combustion chamber to the target intake air flow rate; An intake flow rate detection means for detecting the flow rate of intake air supplied to the combustion chamber of the engine through the intake passage, and an intake flow rate adjustment means for adjusting the flow rate of the intake air passing through the intake passage are provided. The target intake air flow rate information set according to the operating state is compared with the detection information of the intake flow rate detection means, and the intake air flow rate supplied to the combustion chamber is adjusted to the target intake air flow rate according to the comparison result. a first intake flow rate control means for controlling the intake flow rate adjustment means so that the intake flow rate adjuster approaches the rotation speed; a rotation speed detection means for detecting the rotation speed of the engine; and target rotation speed information set according to the operating state of the engine and the rotation speed. a second intake flow rate control means for controlling the intake flow rate adjusting means so that the rotation speed of the ennon approaches the target rotation speed according to the comparison result by comparing the detection information of the engine speed detection means; Idle detection means for detecting that the engine is in an idle state; stable state detection means for detecting that the engine is in a stable rotation speed state; based on the detection results of the idle detection means and the detection results of the stable state detection means. A switching control means for selectively operating the first intake flow rate control means or the second intake flow rate control means, wherein the switching control means is configured to selectively operate the first intake flow rate control means or the second intake flow rate control means, and when the engine is in an idle state and in a stable rotation speed state, the switching control means The control means is the second
Activate the intake flow rate control means.

The subject matter is an engine control device, characterized in that the switching control means is configured to operate the first intake flow rate control means when the engine is in an idle state and is not in a stable rotational speed state. It is something to do.

Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

As shown in FIG. 1, the downstream end communicates with a combustion chamber (not shown) of engine E. A throttle valve 2 is disposed in the intake passage 1, and a shaft 2a of the throttle valve 2 is connected to a slot (-6) outside the intake passage 1.

Furthermore, when the accelerator pedal (not shown) is depressed at the end 6a of the throttle valve ζ-6, the throttle valve 2 is rotated in the clockwise direction (opening direction) in FIG. 1 via the throttle lever. A wire (not shown) for moving the throttle valve 2 is connected to the throttle valve 2, and a return spring (not shown) is attached to the throttle valve 2 to bias it in the closing direction. When weakening, throttle valve 2
is starting to close.

Further, in the intake passage upstream of the throttle valve 2 interposed position, a fuel injection device 2o and an F-FLOW↓-sensor (Karman eddy current metering) 30 are interposed on the upstream side thereof.

The wall and the upstream side of the intake passage 1 communicate with the outside air via an air cleaner 40.

At this time, the air flow sensor 30 is composed of a Karman vortex flow meter, which uses ultrasonic waves to measure the number of Karman vortices in the intake air generated on the downstream side of the vortex generating column 32 disposed in the measurement passage 31. The absolute flow rate of intake air is measured by measuring the absolute flow rate of intake air, and this measurement information is input to a control unit 15, which will be described later. Also.

The fuel injection device 20 includes a solenoid valve 21 interposed in a fuel passage to which low-pressure fuel is supplied from a fuel pump, and the amount of fuel injected into the intake passage 1 corresponds to the opening time of the solenoid valve 21. It is now configured as follows.

An actuator 4 is provided, and this actuator 4 has a DC motor (hereinafter simply referred to as "motor") 56a having a worm 6a on seven rotational axes, and an annular worm wheel 6bKIW.

This worm wheel 6b is integrally provided with a pipe shaft 6C having a female threaded portion 6d.
A rod 7 having a male thread 7a that is screwed into the female thread 6d of the rod 7 extends through the worm wheel 6b and the pipe shaft 6C.

The tip of the rod 7 is connected to the end 3a of the throttle lever via the idle switch 9 as an idle detection means in the engine E engine operating state (in which the accelerator pedal is not depressed by the driver). )
It is designed so that it comes into contact when it is in the position.

Here, the idle switch 9 is a switch that is turned on (closed) when the engine is idling and turned off (open) at other times.

Note that the rod 7 has an elongated hole 7b formed therein.

A pin (not shown) on the actuator main body side is guided through the elongated hole 7b, thereby preventing the rod 7 from rotating.

In this way, the tip of the O-rod 7 is in contact with the end rotor a of the throttle lever rotor when the engine E is in the idle operating state, so by rotating the motor 5 in a predetermined direction, the worm gear can be rotated. When the intermediate pipe shaft 6c is rotated to cause the rod 7 to protrude (advance) from the actuator 4, the throttle valve 2 is controlled to open, and the motor 5 is rotated in the opposite direction to cause the rod 7 to protrude from the actuator 4. When retracted inward (backward), the throttle valve 2 is controlled to close by the action of the return spring.

Further, a water temperature sensor 11 is provided to detect a cooling water temperature as a warm-up temperature of the engine E.

Rotation speed sensor 1 that detects engine rotation speed using ignition pulses
2 is provided.

Further, a vehicle speed sensor 13 is provided which detects the vehicle speed using a pulse signal having a frequency comparable to the vehicle speed, and a known reed switch is used as the vehicle speed sensor 1.

Further, a cooler sensor 14 is provided to detect whether a cooler compressor (not shown) driven by the engine E is activated or not.

Then, it receives the detection signals from each of the sensors 9, 11 to 14.30, and outputs a motor forward rotation drive signal or a motor reverse rotation drive signal, which is an intake flow rate control signal, to the motor 5 of the 7-actuator 4 based on these signals. A control unit (microcomputer) 15 is provided that outputs a fuel flow control signal to the solenoid valve 21, and when outputting an intake flow control signal to the motor 5, the control unit 15 controls the idle operation state by the idle switch 9. Under the set condition I (described later) at the time of detection (when the idle switch 90 is on), the engine rotation speed is controlled by the feed bank control (
Idle speed control), while other set conditions If (described later) are carried out when detecting the above idle state.
Under these conditions, feedback control of the intake air flow rate supplied to the combustion chamber of the engine is performed based on a signal from the air flow sensor 30. That is, this control unit 15 cooperates with the actuator 4 to
and a second intake flow rate control means, and is provided with a switching control means for selectively operating the first intake flow rate control means or the second intake flow rate control means during idling.

Here, the above-mentioned condition (2) refers to a case where at least the following items are satisfied, and refers to a condition in which Nisidine is relatively stable.

(1) A predetermined period of time has elapsed after the idle switch 9 changed from off to on.

(2) Vehicle speed is extremely low (e.g. 3 km/h or less)
To be.

(3) The deviation of the actual engine speed (actual speed) from the target speed is within a predetermined range.

(7I) A predetermined period of time has elapsed after the cooler compressor was switched between operation and non-operation.

Furthermore, the above condition (■) does not satisfy the above condition (2).

This is a condition when the engine is relatively unstable and quick feedback control is desired.

The control of the amount of intake air during idling by the control unit 15 will be described below with reference to the graph I:I-chart of FIG.

As shown in Fig. 2, this control program initializes the registers of the microcomputer and computer in A-100, and then processes and makes judgments between A-101 and A-117 every set time. Executed by timer interrupt. And first of all, A-ioi.

Operating state information from each sensor 9, 11 to 14.30, i.e., idle information I sw from the idle switch 9, cooling water temperature information Tw from the water temperature sensor 11, rotation speed sensor 1
The actual rotational speed information Nr from 2 and the intake air amount information Qr of the vehicle speed sensor are stored in the RAM of the microcomputer, respectively.
A-1 is read into the address and then A-1 in A-102.
Based on the cooling water temperature information image and the compressor operation information Csw read in step 01, the target rotational speed data Ns and the target intake air amount data Qs are respectively input to each address of the RAM from the data map of the ROM of the microcomputer. Here, the target rotational speed data Ns and the target intake air amount data Qs are mapped to the cooling water temperature information and the compressor operation information Csw, respectively, as shown in FIGS. 6 and 4. Note that the target intake air amount data Qs shown in FIG. 4 is data that provides an intake air amount at which the engine idling speed is approximately equal to the target rotation speed according to the cooling water temperature information image. This is determined by experiment. Now, in the next A, -1a3, it is determined whether the idle switch 9 is on or off, and if it is off, that is, if the accelerator pedal is depressed, the current program ends there and the second timer interrupt is started. Therefore, when the idle switch 9 is in the idle state, the process reaches A-104, and in this A-104, the time from when the idle switch 9 is switched from off to on is the first set time Tz ( For example, it is determined whether or not more than 1 second has elapsed. In A-105, it is determined whether the vehicle speed is extremely low (for example, 3 Jan/h or less).

In A-106, the second set time T2 (for example, 1 second) after the cooler pump presser is switched between activation and deactivation.
It is determined whether or not the above period has elapsed, and further, in A-107, the deviation ΔN between the target rotation speed data NS and the actual rotation speed information Nr is determined, and then in A-108, the amount of deviation from the target rotation speed is within a predetermined range. It is determined whether or not it is within α (for example, 30 degrees), and these A-104, A=105. A
-106 and A-108 all stable state discrimination results.

If it is determined that the engine is in a stable state, that is, more than T1 hours have passed since the idle switch 9 was turned on, and the vehicle speed is extremely low (low speed), and the Tala compressor is not activated.
If 12 hours or more have passed since the switch to non-operation was performed and the rotation speed deviation ΔN is within a predetermined range α with respect to the target rotation speed, the program executes A- to perform feedback control of the engine rotation speed. 109, otherwise immediately A-104, A-10!5. A-106,A
If any one of -108 is determined to be NO, the program reaches A-'113 in order to perform feedbank control of the intake air flow rate. A
At -109, it is determined whether a third set time T3 (for example, 1 second) or more has elapsed since the output counter (down counter) for outputting the drive pulse to the motor 5 reached D. That is, here the output counter becomes 0 and motor 5
A prohibition time for driving the motor 5 after the motor 5 is stopped is set, and if 13 hours or more have not elapsed since the previous driving of the motor 5 ended, the program ends immediately.

On the other hand, if T3 time or more has elapsed, A-110 is reached and the output pulse 1 code data Dn corresponding to the rotational speed deviation ΔN is RO.
It is read from M and input into a predetermined register. This output pulse width data Dn is manipulated with respect to the rotational speed deviation ΔN as shown in FIG. 5 and is stored in the ROM. Then, in A-111, set this pulse width data Dn in the output counter for driving the motor 5, and
-112 triggers this output counter. As a result, the motor 5 is driven to open from when the output counter is triggered until the counter reaches zero. At this time, if the deviation ΔN found in A-107 is positive, that is, if the actual rotation speed is smaller than the target rotation speed, the control unit controls the rod 7 to move forward and the throttle valve 2 to be controlled to the open side. 15 supplies a forward rotation drive signal to the motor 5, and when the deviation ΔN is negative, that is, when the actual rotation speed is larger than the target rotation speed, the rod 7 is moved back and the throttle valve 2 is controlled to the closed side. Be(2 control unit 1
5 supplies a reverse rotation drive signal to the motor 5. On the other hand A-104, A-105, A-106, A-
1'08, and if the program reaches A113, the fourth set time T4 (for example, 02 seconds) is output while the above-mentioned output cursor becomes 0. ) or more has elapsed. In this case, the reason why the motor 5 drive prohibition time T4 in the case of feedback control of the intake air flow rate is set shorter than the motor 5 drive prohibition time T1 in the case of the foot hack control of the engine speed mentioned above is because the latter feedback control Based on the fact that the delay in the feedback system is smaller and the system is more stable in the case of If it is determined, the program ends as is, and if 14 hours or more have passed, the program reaches A-114 and the deviation △Q between the target intake air amount take Qs and the actual intake air amount information Qr is calculated. As shown in Yaso pink RO
This is what is stored in M. And in A-116 (
The pulse width cheetah of (Mako)) is set in the output counter for driving the motor 5 mentioned above, and this output counter is triggered in A-117. As a result, the motor 5 (outer counter) is driven to open from when the output counter is triggered until the output counter reaches 0. Note that at this time.

If the deviation △Q found in A-114 is positive, that is, if the actual intake air amount is less than the target intake air amount, the control unit 15 drives the motor 5 to rotate in the forward direction in order to control the throttle valve 2 to the open side. On the other hand, when the deviation △Q is negative, that is, when the actual intake air amount is greater than the target intake air amount, the control unit 15 supplies a motor tilt reverse drive signal to control the throttle valve 2 to the closed side. It's starting to look like this.

”: The mode-specific flow rate control signal output from the syntrol unit 15 is a basic signal based on the intake air amount information detected by the F70-sensor 3o. The correction value added is supplied to the electromagnetic valve 21.

According to the above configuration, immediately after the driver takes off his/her foot from the accelerator pedal (mainly after revving the accelerator pedal), immediately after switching between activation and deactivation of the Tala compressor during idling operation, or When the driver has taken his foot off the accelerator pedal and the vehicle speed is high, that is, when normal engine braking is being performed and there is a high possibility that the engine crankshaft is connected to the wheels via the power transmission system, etc. If the engine speed becomes unstable or deviates significantly from the target speed even during idling, or if there is a high possibility that this will occur, feedback control of the intake air amount will adjust the intake air amount to the target. The idle speed is quickly stabilized and approaches the target speed.

After that, through feedback control of the engine speed,
The target idle speed can be achieved reliably.

Therefore, it is possible to prevent the engine from stalling at idle, or from causing discomfort to the occupants due to a temporary increase in the idle speed when the compressor switches from operating to non-operating. This is something that gives you flexibility.

In addition, since the configuration is configured to perform feedback control on the actual intake air amount detected by the air flow sensor 30, when producing large quantities of engines with the same specifications, each engine is operated in the same idling state. Get the number of revolutions.

Each cone engine is capable of stable idling operation without stalling or the like.

Furthermore, since the above embodiment is configured to measure the absolute flow rate of the intake air using a Karman vortex flow meter, the intake air amount information Qr based on this measurement result can be obtained by zero point correction when obtaining the intake flow rate control signal. It is possible to compare the intake air amount with the target intake air amount (take) without having to perform the following, and the configuration of the entire device can be simplified.

Furthermore, in the above embodiment, the intake flow rate adjusting means 4.
Although the throttle valve 2 which is connected to the accelerator pedal is used, the intake flow rate adjusting means is disclosed in Japanese Patent Application Laid-open No. 54
It may be configured with an air control valve (idle control valve) provided in a bypass passage that conducts intake air to the combustion chamber by bypassing the suit valve as shown in Japanese Patent Application Publication No. 27624 and Japanese Patent Application Laid-open No. 54-76723. It is.

Furthermore, in the above embodiment, the water temperature sensor 11 that detects the cooling water temperature as the warm-up temperature of the engine E is provided. It may be provided.

Further, in the above embodiment, feedback control of the intake air amount and feedback control of the engine speed are switched during engine idling operation, but this is because only feedback control of the intake air amount is performed during idling operation. It is also possible that the

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, and FIG. 2 is a flow diagram of one yard for explaining its operation. FIGS. 3 to 6 are graphs for explaining the effect. 1... Intake passage, 2... Throttle valve. 4... Actuator, 9... Idle operation state. 11... Water temperature sensor, 12... Rotation speed sensor. 13... Vehicle speed sensor, 14... Cooler sensor. 15...Control unit. 30...-Airf p-sensor Figure 3% 4 figure

Claims (1)

[Scope of Claims] (]) An intake flow rate detection means for detecting the flow rate of intake air supplied to the combustion chamber of the engine through the intake passage, and a flow rate of the intake air passing through the intake passage. and an intake flow rate adjustment means for adjusting the intake air flow rate, and compares target intake air flow rate information set according to the operating state of the engine with the detection information of the intake air flow rate detection means, and determines the intake air flow rate according to the comparison result. An engine control device, comprising an intake flow rate control means for controlling the intake flow rate adjustment means, and configured such that the flow rate of intake air supplied to the combustion chamber is controlled to the target intake air flow rate. (2): An intake flow rate detection means for detecting the flow rate of intake air supplied to the combustion chamber of the engine through the intake passage of the engine; and an intake flow rate detection means for adjusting the flow rate of the intake air passing through the intake passage. The intake air flow rate adjusting means is provided to compare the target intake air flow rate information set according to the operating state of the engine with the detection information of the intake air flow rate detection means, and adjust the combustion rate according to the comparison result. first intake flow rate control means for controlling the intake flow rate adjustment means such that the intake air flow rate supplied to the chamber approaches the target intake air flow rate;
A rotation speed detection means for detecting the rotation speed of the engine, which compares target rotation speed information set according to the operating state of the engine with detection information of the rotation speed detection means, and detects the rotation speed of the engine according to the comparison result. second intake flow rate control means for controlling the intake flow rate adjusting means so that the rotation speed of the engine approaches the target rotation speed; idle detection means for detecting that the engine is in an idle state; and a rotation speed at which the engine is stable. a stable state detection means for detecting that the idle state is in the state; a switching control means for selectively operating the first intake air flow based on the detection result of the idle detection means and the detection result of the stable state detection means; When the engine is in an idle state and in a stable rotational speed state, the switching control means activates the second intake flow rate control means. An engine control device characterized in that the switching control means is configured to operate the first intake flow rate control means when the engine is in an idle state and is not in a stable rotational speed state.