JPS62276230A - Number of idling revolutions control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent abnormal increase of the number of revolutions even during control of an open loop, by a method wherein, when a power steering is in state in that a load exceeding a specified value, learning of a microcomputer is prohibited. CONSTITUTION:In a control device 9 which performs feedback control on the number of idling revolutions of an engine 1 which is adjusted to a target value by changing the area of the opening of a bypass passage 6 by means of a valve 41, a correction valve on a fundamental control amount during feedback is stored as a learning valve in a microcomputer 93. In which case, in a state in that a power steering switch is turned ON, i.e. when the load state of a power steering exceeds a given value, the memory content of a learning valve is not varied, and is held in a state in that, on and before a preceding value, the values are left unvaried. This constitution prevents control of the number of idling revolutions by means of a valve available during high load running, the occurrence of overshoot during control of an open loop, and enables subsequent convergence to a target value to be rapidly effected through feedback of the number of revolutions.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to the idling speed of an internal combustion engine that controls the engine speed during idling to a target value by changing the opening area of the intake passage. This relates to a numerical control device.

[Conventional technology]

Figure 1 shows the configuration of a general idling speed control device. In the figure, 1 is an engine, 2 is an air flow sensor that detects the amount of intake air in the intake pipe 3, and 4 is a sensor installed in the intake pipe 3. An ISO actuator such as a stepper motor or a near solenoid that controls the amount of air flowing through a bypass passage 6 that bypasses the throttle valve 5; 41 is a valve driven by this actuator 4; 7 is a fuel injection valve that injects fuel into the intake pipe 3; , 8 is a rotation sensor for detecting the rotation speed of the engine l, and 9 is a control device composed of an electronic circuit mainly including a microcomputer for controlling fuel injection and idling rotation speed. Further, 91 is an input circuit that receives water temperature signals, air conditioner switch, and on/off input signals of the air steering switch, and 92 is an AD that converts an analog value corresponding to the intake air amount obtained from air 70 - sensor 2 into a digital value. Converter 93 is a microcomputer that calculates the control amount of the IK dynamic signal actuator 4 of the fuel injection valve 7 from the output signals of the air flow sensor 2 and the rotation sensor 8 and the engine operation parameters such as the cooling water temperature of the engine 1, 94. 95 is an output circuit for signal amplification.

Next, the operation of the control device having the above configuration will be explained. Third
The figure is a flowchart showing a method of rotation speed feedback control. First, in step 11, the fibrocomputer 93 reads the cooling water temperature and load condition of the engine 1, that is, the operating condition of the air conditioner compressor and the operating condition of the power steering. This) 9-power steering is operated by a hydraulic pump driven by the engine 1, and is operated by the hydraulic pressure, and together with the air conditioner, it accounts for a large load on the engine. Next, in step 12, a target rotation speed is set based on the input signal.

Figures 4 and 5 show the values of the target rotation speed N3 and target opening degree with respect to the cooling water temperature, respectively.The target value of the idling rotation speed generally varies depending on whether the air conditioner is on or off, and when the cooling water temperature of engine 1 is low. is set to a high value, and this target rotation speed is stored in the ROM in the microcomputer 93 in advance as a value corresponding to various conditions.
is stored in Then, in step 13, the rotation sensor 8
The actual rotational speed Na obtained from the actual rotational speed Na is read, and in step 14, the rotational speed deviation ΔN from the target rotational speed Ns is calculated. Next, the control amount ΔS is set from the relationship between the rotational speed deviation ΔN and the control amount ΔS as shown in FIG. 6 (step L5).

In addition, the basic opening degree SO of the actuator 4 is read (step 16), and the previously learned value S1, which is the previous learned value, is also read (step 17), and the value of the control opening degree S is calculated based on these values. (Step 18). Further, after the drive control of the shift actuator 3 is performed by the timer in step 19, the next control is prohibited for, for example, one second until the engine rotation is stabilized.

FIG. 7 is a flowchart showing the procedure for learning idling rotation speed control. First, in step 21, set the target rotation speed N.
Controlled amount Σ based on the rotational speed deviation ΔN between 8 and the actual rotational speed Na
ΔS is read, and in step 22, this control amount ΣΔS is added to the previous learned value to obtain the current learned value, and in step 23, the memory contents of the learned value S are updated, and these steps are repeated.

In this way, the mechanical loss of the engine, the variation and change over time of the square 41, and the load fluctuation of the engine (electrical load, etc.)
etc., the valve 41 adjusts to a predetermined target rotation speed.
A discrepancy occurs between the opening degree and the actual rotation speed. Due to this deviation, when open loop control is performed transiently using feedforward control, such as when turning on and off the air conditioner, the difference between the actual rotation speed and the target rotation speed becomes temporarily large, and as a result, the rotation speed increases. There is a problem in that it takes time to converge to the target rotational speed due to undershoot or overshoot. To solve this problem, conventionally, during rotation speed foot-degree back control, a correction value for the basic side aft (opening degree) is stored as a learned value, and the bypass path 6 is adjusted based on this learned value and the basic control amount. The amount of auxiliary air was controlled. In addition, in the above device, the amount of auxiliary air is also controlled by the operation of the steering wheel, which, together with the air conditioner, occupies a large load on the engine 1. This non-power steering is driven by an engine-driven hydraulic pump, and the on/off of the power steering is detected by a hydraulic switch (power steering switch).
This was done regardless of whether the program was on or off.

[Problem that the invention seeks to solve]

As described above, in the conventional device, learning is performed based on the control amount of the rotational speed flap even when the arm steering is operated, that is, when the load on the engine 1 is large. For this reason, it learns when the load is heavy, and after learning, the open route mj control (idle increase when the air conditioner is running, etc.) 2a-
If control is performed based on this learned value during normal times when e-power steering is not operating, the opening degree of the valve 41 will be larger than necessary and the idling speed will fluctuate to the high side. There was a problem.

This invention was made in order to solve the above problems, and is an internal combustion engine that does not cause an abnormal increase in rotational speed even during open route control in a normal load state where power steering is not activated. The purpose of the present invention is to obtain an idling speed control device for the following.

[Means for solving problems]

The fitting rotation speed control device for an internal combustion engine according to the present invention is configured to prohibit learning of the microcomputer when the power steering driven by the internal combustion engine is under a load condition of a predetermined value or more.

[Effect]

In this invention, when the load state is below a predetermined value such as when the power steering is not operating, the microcomputer stores the learned value in the memory, and when the power steering is in a state where the power is 7 and the load state is above the predetermined value, the microcomputer stores the learned value in the memory. The learned value is not calculated and the previous value is retained.

〔Example〕

Hereinafter, an idling speed control device for an internal combustion engine according to an embodiment of the present invention will be described. The configuration of this invention in the drawings is the same as that in FIG. 1, but the arithmetic processing regarding the learning control of the microcomputer 93 is different. FIG. 2 is a flowchart showing this arithmetic processing), which is different from the conventional method in that it includes a step of determining the on/off state of the waste switch after calculating the learned value. That is, the control amount Σ based on the rotation speed deviation in Stella 7'lOL, 102
Reading ΔS and calculating the learned value SJI is the same as in the conventional method. In addition, the calculation of this learning value is not done instantaneously, so as not to respond to an increase in the rotation speed feedback control amount (ΣΔS) due to a temporary misfire of the engine or an inrush current of the electrical load. If lJ, the control amount (ΣΔS) every second
is reflected as a learning value in units of K. Then, in step 103, it is determined whether the power steering switch is on or off. If the power steering switch is not turned on, that is, the load is below a predetermined value, step 1
04, the microcomputer 93 stores the learning value in the memory and updates the memory contents of the learning value Sλ as in the conventional case. -A, If the waste switch is on, that is, the load condition is above the specified value, step 1.
The process advances to step 05 and the memory contents of the learning value Sλ are not updated and are held as they were until the previous time.

In this way, the value when the A4 power steering is activated and the engine load is large is not stored as a learned value, so the idle link speed is not controlled using the value when the load is % heavy, and overshoot occurs during open loop control. This does not occur, and the subsequent rotational speed feedback can quickly converge to the target value.

〔Effect of the invention〕

As described above, according to the present invention, when the I-sound power steering is in a load state exceeding a predetermined value, the learned value based on the control amount at the time of rotation speed feedback is not calculated and reflected. Even during open-loop control under normal load conditions, such as during open-loop control, there is no increase in the rotational speed due to an abnormal increase in the amount of air, and the subsequent rotational speed feedback can quickly converge to the target value.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an idling speed control device for an internal combustion engine according to the present invention, FIG. 2 is a flowchart showing the learning operation of an embodiment of the idling speed control device for an internal combustion engine, and FIG. A flowchart showing the operation of the rotation speed feedback control of the idling rotation speed control device for an internal combustion engine according to the invention, FIG. 4 and FIG. Figure 6 shows the control amount Δ relative to the rotational speed deviation ΔN.
FIG. 7 is a flow chart showing the learning operation of a conventional idling speed control device for an internal combustion engine. 101. Engine, 3...Intake 9.4...Stepper motor, 41...Valve, 6...Pi/gusu path, 9...
- Control device, 91... Input circuit, 93... Microcomputer. 94.95...Output circuit.

Claims (1)

[Claims] The idling speed of the internal combustion engine is feedback-controlled to the target value by changing the opening area of the intake pipe, and the correction value for the basic control amount during this feedback is stored as a learning value, and this learning is performed during open-loop control or feedback control. In the idling speed control device for an internal combustion engine, which controls the opening area of the intake pipe based on a value and a basic control amount, the power steering driven by the internal combustion engine is in a load state of a predetermined value or more. An idling rotation speed control device for an internal combustion engine, characterized in that said learning is prohibited at certain times.