JPS6149147A - Control method of idle speed - Google Patents

Abstract

PURPOSE:To improve restartability of an engine on the high ground, by continuously controlling a speed of the engine by a correction control value after the engine is started thereafter returning control of the speed to the feedback control at a point of time where the speed of the engine decreases less than a predetermined value. CONSTITUTION:Immediately after an engine finishes its starting, the initial value of a feeback control quantity sufficient for continuing a speed is added to a basic characteristic control quantity and a correction control quantity of each kind. Under a condition that feedback control is temporarily stopped, the speed of the engine is continuously controlled. Thereafter, the initial value is gradually decreased with the lapse of time, and control of the speed is returned to the feedback control at a point of time the speed of the engine decreases less than a predetermined idle speed. In this way, an engine stop can be surely further completely prevented.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for controlling the idle speed of an internal combustion engine in a vehicle, and more specifically to the startability of a vehicle internal combustion engine, particularly when restarting at high altitudes with low atmospheric pressure. The present invention relates to an idle speed control method for improving startability.

(Prior art 1) A conventional idle speed control system in a general vehicle internal combustion system uses an idle speed control device built into the intake system of the engine to control the ti as shown in FIG. The process is executed as shown in the figure.The idle speed control device is controlled by ensuring the air flow m necessary for the internal combustion engine during a good start, using a predetermined start control interval 1. , then after starting, the basic characteristics control 1lj1
2, various corrections are made by distorting and controlling the control value 3 and the feedback control amount 4 of the deviation from the 1 standard rotation. The idle speed is maintained at all times (see Japanese Patent Laid-Open No. 56-38540).

Problems to be Solved by the Invention) However, when using the conventional control means, for example, when the atmospheric pressure is low, 1aJl! If the internal combustion (starting between stages) is performed at 1, and the engine speed at this time is to be maintained due to the idling speed at the low altitude of normal atmospheric pressure mentioned above, in the case of this high altitude, the air pressure difference Due to the difference,
Since the engine requires a larger air flow rate than at low altitudes, the control 31I setting based on low altitudes as shown in section 11a is used to start the engine, as shown in the ffi control diagram in section 5. Immediately afterward, the rotation of the internal combustion engine itself is unstable, the aforementioned control amount is insufficient, and in addition to this control amount, basic characteristic control however, 2. Feedbacks from various parts of the correction side υIII m3 have a poor start-up, resulting in inconveniences such as intermittent stoppages, so-called engine stalls.

Therefore, in order to deal with this situation, a method has been proposed that uses a high-altitude sensor and adds high-altitude correction control m to the correction side ill @ 3, but it is not necessarily effective)
``Not only was it of no use, but it also had the disadvantages of increasing the cost of the high-altitude sensor section.

[Object of the invention] Does the present invention solve the above-mentioned conventional problems? This has been proposed extensively, and its purpose is different from that of the internal combustion engine's internal combustion engine. An object of the present invention is to provide an improved idle speed control method to prevent l5Il stoppage.

[Structure of the Invention] In order to achieve the above object, the present invention secures and controls the airflow m necessary for the gate by a predetermined starting control il]m at the start 114, and after the start j 8 for each characteristic control amount
Feedback control 1211 based on i correction control Q 715 and engine rotation fault d
), and immediately after the start (11r1.), the feedback system sufficient for continuity is applied to the base material characteristic control foot and various correction controls, and correction is made after the start. While calculating the control value, (with the feedback control based on the inter-stage rotational speed temporarily stopped, the engine rotation is continued by controlling with this post-start correction control value, and then As time passes, the initial value is gradually reduced until the engine speed falls below a predetermined idle speed.
At this point, the control is returned to feedback control based on the engine speed.

[Embodiment] Hereinafter, an embodiment of the idle speed control method according to the present invention will be described in detail with reference to FIGS. 1 and 3.

FIG. 1 is a block diagram showing an outline of the application of the method of this embodiment. In this FIG. 1, the embodiment method is one in which an idle rotation speed control device 13 interposed in a bypass passage 12 that bypasses between the upstream and downstream of the throttle valve 11 is applied to the right-handed l16 IA. The device 13 is adapted to control the bypass air passing through the bypass passage 12 by means of a control 611 signal 8 from the control unit 14.

1J, the control unit 14 has yo<1JJ
As shown, the input interface 1401,
Output ink face 1402. A central processing unit 1403 and a read-on-chip memory 1404. A random access memory 1405 and the like are provided, and these are interconnected by an address bus 140G and a data bus 1407, forming a so-called stored database programming system. The input interface 1401 of the control unit 14 includes an idle switch 15. Air conditioner switch 1G, Niko 1~Ral switch 17. In addition to inputting various signals such as the starter switch 18, the A/A of the wood tone sensor 19 is converted by Δ/[ by the A/D converter 1409, and the engine rotation fault sensor 20. Waveform shaping devices 1410 and 1411 waveform shape the respective parts δ of the ton speed hinge +) 21 and input them to each part, and each of these inputs 1a is
iX buried 11Aiiff1403 smell-(', kl
t% pulse generator 61408 supplies the box jll;
By the clock pulse, the read Δ only memory 14
Based on the program stored in 04, the second
As shown in the flowchart shown in the figure, after the program is executed and processed every predetermined cycle, it is outputted from the output interface 1402, and the operation of the idle number control device 13 is controlled by this output signal. Ze, as mentioned above! By controlling the bypass air m passing through the bypass passage 12 according to ζ, the desired idle speed control is achieved.

However, the method of this embodiment is applied to such a '3A configuration to control the idle speed as shown in the control diagram shown in FIG. Figure 3 shows the temporal changes in the control m applied to the idle speed control device 13, where time A is the start point, time B is the start point of the end of start/first power correction σl, Time point C is the end point of the post-startup correction.

In the above purchasing configuration, this embodiment method performs the following control operations.

First, as in the conventional method, the internal combustion engine starts at time A, and this start point A is detected by the above-mentioned signal inputs to the control unit 14. Then, when the start is terminated at time B, this start is terminated and the at
! Detected by the I URL unit 14, and based on this start end detection, the control alI unit 14:
In addition, this internal combustion (feedback control initial jllt value 5, which is sufficient to continue the rotational drive between the bases) is added to the basic characteristic control Hm 2 and various correction AI control values 3 that have been set in advance, and the calculated bean paste is When the idle rotation speed - 1 is outputted to the vise 13 as the post-start correction control value 6,
At this point B is +, L! The feedback control that matches the number of ozeki times is temporarily stopped and J5 <.

Then, based on the output small start correction control value 6, ti
This starts by controlling the control device 13 to increase the amount of bypass air so as to correspond to the control MI1 direct 6. The control mark at the fIIl end point B, that is, the start-up point of the idle rotation speed control, is reliably maintained LTr, and the rotational drive of the internal combustion engine 12I can be continued with the desired sufficient air R, and this state is not recorded in the na record. Similarly, each signal input to the control unit 14 is constantly monitored.

Subsequently, while the internal combustion engine continues to be driven to rotate without performing feedback control based on the engine speed, if the initial lVJ value 5 is gradually decreased as time passes, the time point C is reached. The engine speed drops below the predetermined idle speed, and the control unit 14 detects this and determines that the post-start correction end point [r! ! From this point C, the feedback control is returned to based on the engine speed, and from then on, as in the conventional method, iI (control force is calculated from the difference between the engine speed and a predetermined target idle speed, and The feedback control of the period is natural.

That is, in this way, the poor start-up of the feedback control 1 m, which was a drawback in the conventional method, is improved, and effective idle speed control of the internal combustion engine is achieved.
It is.

In the above embodiments, the method of the present invention is applied to a structure having an idle speed control device interposed in the bypass passage of a throttle valve.
It goes without saying that it can be similarly applied to Mizonari, which has an idle rotation speed control device for that song.

[Effects of the Invention] As detailed above, according to the method of the present invention, the internal combustion engine 8 for vehicles
3II3! In the idle speed control of 'I, immediately after the start of the engine is finished, the 'feedback control initial rIJJ' is controlled by the basic characteristic control claw d5 and various compensations.
fli! By adding to J Q9 ffj and calculating the post-start correction system '4+1' in this way, the engine rotation is controlled by m-ring while the feedback 1ilJ group based on the engine rotation speed is temporarily avoided, and then, As time passes, the initial value is gradually reduced, and when the engine speed falls below the predetermined idle speed, feedback based on the engine speed is given again II! Since the engine is controlled by returning to the I control, it is possible to reliably and completely prevent engine stalling, which is caused by external conditions immediately after starting due to differences in air temperature, etc., and to effectively prevent the engine from stalling. Eliminate idle speed control! In addition, Senna, 65 J, for detecting external conditions such as the difference in air pressure, etc.
Since this method does not require the use of a processing method or the like, it has unique features such as the fact that there is no need to worry about complicating the cultivation process, and it can be implemented at an extremely low cost.

[Brief explanation of drawings]

FIG. 1 shows an example 1 in which the control force dζ according to the present invention is applied.
Figure 2 is a block configuration diagram showing the steps of (1) of the A position, Figure 2 is a flowchart 1~-1 to explain the operation of the same device, Figure 3 is a control diagram to explain the same control method, Figure 4 and Fig. 5 is a control diagram for explaining the control 2IlyI method according to the conventional example. 1... Starting control ■1.2... Basic characteristic control ■, 3
...For correction control, 4...Feedback control claw, 5
...Feedback control I'#: L initial count, 6...
Post-start correction control 1n, 11... Throttle valve, 13.
...Idle rotation speed control device, 14...Control" knit, 15. IG, 17.18... Idle, air conditioner, neutral, starter switches, 19, 20.
21...Water temperature 1 engine speed, vehicle speed sensors, A...
Starting point, B...starting end/beginning! I! Correction start point after II, C...start! e Post-correction end point.

Claims (1)

[Claims] At the time of starting, the air flow rate required for the engine is secured and controlled using a predetermined starting control amount, and after starting, control is performed by superimposing various correction control amounts and feedback control amounts based on the engine speed on the basic characteristic control amount. In the method for controlling the idle speed of an internal combustion engine for a vehicle, an initial value of the feedback control amount sufficient to continue the rotation of the engine immediately after the start is added to the basic characteristic control amount and various correction control amounts, and A correction control value is calculated, and with the feedback control based on the engine rotational speed temporarily stopped, the engine rotation is continued by controlling with the correction control value after startup, and then, as time passes, the engine rotation is continued. An idle speed control method, characterized in that the value is gradually reduced, and when the engine speed falls below a predetermined idle speed, control is returned to feedback control based on the engine speed.