JPS61279751A - Engine idle rotational speed control device - Google Patents

Abstract

PURPOSE:To prevent the rotational speed from excessively racing, by controlling the idle rotational speed of an engine when a shift lever switch detects the shift of a shift lever from the nondrive position to the drive position so that the volume of intake-air is compensated to be increased stepwise. CONSTITUTION:A bypass valve 10 disposed in a bypass passage 9 which is provided in the intermediate section of an intake-air passage 2 bypassing a throttle valve 3, is subjected to a duty control so that the idle rotational speed is set to a desired rotational speed under feedback control. In the above- mentioned arrangement, there is provided a shift lever switch 14 for detecting the displacement of a shift lever of an automatic speed change gear from its nondrive position to its drive position. Further, during idle operation, when it is detected that the shift lever 15 is shifted into the drive range, a CPU 18 performs such a compensation that the volume of intake-air is adjusted by the duty control of the bypass valve 10 to be increased stepwise up to an intake- air volume which is obtained when the above-mentioned drive range is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine idle speed control device.

[Prior art]

Recently, various efforts have been made to improve engine drivability and fuel efficiency in vehicle engines.One example is feedback control of the idle speed by adjusting the intake air amount when the engine is idling. There is something I did. With this idle speed control device, if there are individual differences in engine characteristics due to engine manufacturing errors or assembly errors, the engine speed can be controlled from 6 degrees to 79 degrees to the target rotation speed. However, when loads such as cooler loads are applied to the engine, the engine speed drops temporarily and the condition
Since feedback control of the rotation speed is performed from the 11th state, there is a concern that engine stall may occur due to a drop in rotation.
[l Therefore, in the conventional idle rotation speed control device, as shown in, for example, Japanese Patent Application Laid-Open No. 54-98413, 1.1 idle rotation speed is feedback-controlled to the target rotation speed )') :,' On the other hand, when a load is applied to the engine,
:... Tsuiyu□□, □Yu□Oh, Iwayu, □
:1) Correction is being carried out.

In addition, in a vehicle equipped with an automatic transmission, when the automatic transmission is operated from the N range or P range, that is, the non-drive range, to the D or N range, that is, the drive range during idling, a load is applied to the engine. In this case as well, it is necessary to perform the above-mentioned load correction in order to prevent engine stalling.

However, with conventional idle speed control devices, there has been a problem in that when load correction is performed when the automatic transmission is operated from N range or P range to D range or N range, the engine speed jumps. .

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide an engine idle speed control device that can prevent engine speed from rising during an automatic gear shift operation during idle operation.

[Structure of the invention]

In order to prevent the rotational speed up, the inventor of the present invention has conducted extensive research into the mechanism by which it occurs, and has discovered that the cause is as follows. That is, when the automatic transmission is operated from the N range or P range to the D range or N range, the switching is determined by a shift lever switch activated by operating the shift lever of the automatic transmission. On the other hand, in automatic transmissions, gear changes are generally controlled by hydraulic pressure, and there is a time delay between when a shift lever is operated and when a gear change is actually performed. On the other hand, the intake amount of the engine can also be adjusted using the shift lever switch f″(t′)′″, h.
v*us-ahih<・111"11゜The signal from this switch immediately activates and corrects the intake air amount to increase. Therefore, due to the response delay of the automatic transmission, the timing of the load correction to increase the intake air amount and the engine There is a lag between the timing at which a load is actually applied, and the amount of intake air is increased before the load is applied, which causes the engine to rev up.

Therefore, one way to prevent the engine from speeding up is to detect that a load is actually applied to the engine and make load corrections based on this. The technology has not yet been established, and attempting to do so would result in a significant increase in cost.Therefore, it is necessary to deal with this through a software method that does not actually incur a cost increase.

Therefore, the present invention uses a shift lever switch that operates when the shift lever of an automatic transmission shifts from a non-driving position to a driving position in an engine idle speed control device, and when the shift lever switch is activated, the amount of intake air increases. The amount is corrected in stages.

That is, the present invention, as shown in the functional block diagram of FIG. A shift lever switch 22 is provided, which performs feedback control of the engine speed during idling operation, and is activated when the shift lever position of the one-way transmission shifts from the non-driving position to the driving position.
When the switch 22 is actuated, the load correction means 23 controls the idle speed control means 21 to gradually increase the intake air amount by the intake air amount adjustment means 20 to the intake air amount in the drive completion state 1.
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[〔Example〕
1 Below, embodiments of the present invention will be described with reference to the drawings.

□ FIGS. 2 and 3 show an engine idle speed control device according to an embodiment of the present invention. In the figure, 1 is an engine, and a throttle valve 3 is disposed in the middle of an intake passage 12 of the engine 1.
: A vane type air flow meter 4 is provided upstream of the sotol valve 3. In addition, a fuel injection valve 5 is installed near the downstream end of the intake passage 2.
′□、・ .

A spark plug 7 is arranged in the engine 1 facing the combustion chamber 6.
1: □ is established.
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iElcayoa9,7. . 1. Mechanism 8 is provided. This control mechanism 8 door, Tsue 3M11S2 Yuyoyu. 2), p3, 2, i2, y, [;The bypass passage 9 is branched, and in the middle of the bypass passage 9 there is a solenoid-type bypass valve]0 that adjusts the amount of air flowing into the passage 9. It is arranged.

In the figure, 11 is an ignition coil, 12 is a throttle opening sensor that detects the opening of the throttle valve 3, 13 is a rotational speed sensor that detects the engine rotational speed, and 14 is a shift lever 15 of the automatic transmission that is in the N range or The shift lever switch 16 is operated when shifting from the P range, that is, the non-driving range, to the D range or the R range, that is, the driving range. The control unit is composed of a CPU 18 and a memory 19, and the memory 19 stores programs for arithmetic processing of the CPU 8 (see FIG. 3), and the like.

When the engine is idling, the CPU 18 duty-controls the bypass valve 10 of the idle speed control mechanism 8 to adjust the amount of intake air, feedback-controls the idle speed to the target speed, and adjusts the ignition timing of the engine. The ignition timing is controlled to be retarded by a predetermined amount from the ignition timing (MBT) at which maximum output is obtained, while bypass is performed when the shift lever 15 of the automatic transmission is operated from the N range or P range to the D range or R range. The duty ratio of the valve 10 is set to 2 towards the target duty ratio when a load is applied.
Control at idle is performed by increasing the amount of intake air in two steps and advancing the engine's ignition timing in two steps toward the target ignition timing under load (see Figure 4). . In addition, the CPU 1B creates a fuel injection pulse according to the engine speed and intake air amount,
This is added to the fuel injection valve 5 to control the fuel injection amount by injecting and supplying fuel to the engine, and also to control the ignition timing by controlling the ignition timing according to the rotation of the engine during normal operation of the engine.

In the above configuration, the idle speed control mechanism 8 serves as the intake air amount adjusting means 20 shown in FIG. 1, and the CPU 8 functions as the idle speed control means 21 and load correction means shown in FIG. The function of the means 23 is realized.

Next, the operation will be explained using FIGS. 3 and 4.

Here, Fig. 3 is a flowchart of the idle control of the CPUI8, and Fig. 1 is a flowchart of the ON/OFF control of the shift lever switch.
A timing chart of F state, actual engine load timing, load correction timing, change in rotational speed, and ignition advance angle is shown.

When the engine engine operates, the CPU 18 in the control unit 16 reads the signals from the various sensors 4, 12 to 14, first calculates and creates a fuel injection pulse according to the intake air amount and engine speed, and then adjusts the fuel injection pulse as necessary. Various corrections such as water temperature correction are performed, and this fuel injection pulse is applied to the fuel injection valve 5 to supply the engine with an amount of fuel according to the operating state. Also, an ignition signal is created according to the engine operating state, and this is added to the ignition coil 11 to cause the engine to ignite at a timing according to the operating condition.

While controlling the engine in this way, at a predetermined timing, the CPU 8 executes the interwoven routine shown in FIG. 3, and first determines the engine speed and throttle opening; ; 775
"7-()'/L = Determine force/rejection force during operation" (8 [Step 30), shift if operating at idle
iLy′< −X4 y+ 147! l“ON7!
"No" (i.e., automatic gear shifting) It is determined whether the shift lever 15 of one machine is in the N range or the P range (Step 31), except when the shift lever switch 14 is ON (see part E of Figure 4). , the basic duty ratio of the bypass valve 10 is set to the first set value DQ, and a correction duty is set according to the deviation between the engine speed and the target rotation speed;

Find the ratio and calculate the actual duty ratio from these,
Also, set the engine's ignition timing to the optimum value for maximum output.
11j' Set to A (step 32), which makes the idle
The bypass valve 10 of the rotation speed control mechanism 8 is as described above.

The duty is controlled by the duty ratio, and the
1: The amount of air flowing into the bus passage 9 is adjusted and the engine rotation speed is feedback-controlled to the target rotation speed,
:”;Also, the engine will be ignited [1'] at the first target ignition timing.

Also, during idling, the shift lever 15 of the automatic transmission is operated from the N range or P range to the D range or R range, and the shift lever switch 14 changes from ON to O.
When the FF becomes FF (see part F in FIG. 4), the CPU 1B sets the basic duty ratio of the bypass valve 10 to a second basic duty ratio D1 that is larger than the first basic duty ratio DO, and sets the ignition timing T of the engine to the second basic duty ratio D1. Step 34), the bypass valve 10 is duty-controlled based on the second basic duty ratio D1, and the bypass valve 10 is set to a second target ignition timing B that is advanced from the first target ignition timing A. The amount of flowing air is increased and the ignition timing of the engine is advanced, thereby performing the first stage load correction of the intake air amount and ignition timing.

In this way, the first stage load correction is performed and the engine speed increases, and when the load actually begins to act on the engine and the engine speed changes from a state above the set value α to a state below the set value α. (See part G in Figure 4), the CPU 18 sets the basic duty ratio of the bypass valve 10 to the third basic duty ratio at the time of actual load, which corresponds to the duty ratio when the automatic transmission is in a fully driven state. Duty ratio D2
(>Dl) and the engine ignition timing T
is set to a second target ignition timing B which is further advanced.As a result, the amount of air flowing into the bypass passage 9 is further increased, or the ignition timing of the engine is further advanced, and thus the second target ignition timing B is further advanced. The load correction is performed, and the engine speed is quickly controlled to the target speed.

In the device of this embodiment as described above, the idle connection
:□ When a load is applied during rotation, reduce the amount of intake air.
Since the correction is made in 12 steps, the engine speed will not increase unnecessarily due to the delay in the actual load action, and the engine speed can be suppressed from rising.

In addition, with this device, the ignition timing is also advanced in accordance with the load correction of the intake air amount, which improves combustibility and suppresses drop in rotation. Since the advance angle is corrected, it is possible to suppress the rotational speed up.

In the above embodiment, a bypass type idle speed control device has been described, but the present invention naturally controls the throttle valve opening to adjust the amount of intake air, thereby feedback controlling the engine speed during idling operation. It can also be applied to devices using this method.

Further, the load correction may be performed in two or more stages (and the load correction of the ignition timing does not necessarily need to be performed).

〔Effect of the invention〕

As described above, the engine idle speed control device according to the present invention uses a shift lever switch that operates when the shift lever of an automatic transmission shifts from a non-driving position to a driving position. - The amount of intake air is corrected to increase in stages when the switch is activated, so the engine speed will not rise when the shift lever is operated from N or P range to D or R range during idling. It has a suppressive effect.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a functional block diagram showing the configuration of the present invention, Fig. 2 is a schematic configuration diagram of an engine idle speed control device according to an embodiment of the present invention, and Fig. 3 is a functional block diagram showing the configuration of the invention. CPU1 in
FIG. 4, which is a flowchart of the arithmetic processing in step 8, explains the operation of the above device! 20 is a diagram showing the ON/OFF '''1°F state of the shift lever switch 14, the actual load timing of the engine, the load correction: timing 2 change in rotation speed, and the timing chart of the ignition advance angle. ... Intake amount adjustment means, 21 ... Idle rotation speed) Control means, 22 ... Shift lever switch, 23 ... Load correction means, 1 ... Engine, 8
...Idle rotation i number control mechanism, 14.
...Shift lever switch, 18...CPU. 1゛- Patent applicant: Tsuda Co., Ltd.
1: Agent Patent Attorney Ken Hayase - Figure 1 Figure 3

Claims (1)

[Claims] (1) An intake air amount adjusting means that adjusts the intake air amount of the engine, and an idle speed control means that performs feedback control to drive the intake air amount adjusting means so that the engine speed during idling becomes a target speed. a shift lever switch that operates when the shift lever position of the automatic transmission shifts from a non-driving position to a driving position; and when the shift lever switch is activated, the idle rotation speed control means is controlled by the intake air amount adjusting means. An idle speed control device for an engine, comprising: load correction means for increasing the amount of intake air stepwise to the amount of intake air in a state in which the drive is completed.