JPH0255850A - Idling speed controller for engine - Google Patents

Abstract

PURPOSE:To prevent an engine from stalling by making an intake air compensating value larger when engine speed is high on the occasion of a changeover from an N or D range to a running range. CONSTITUTION:A control unit 19 controls a solenoid valve 18 for feedback at the time of idling, and also it performs one-shot compensation as intake air quantity compensation with this solenoid valve 18 at the time of a changeover from an N range to a D range. At this control unit 19, an initial value of the one-shot compensation is varied according to a state of engine speed at the time of changing the N range over to the D range. In brief, in case of high engine speed, the initial value of the one-shot compensation is yet more increased than in case of low engine speed, and it is subjected to tailing at the same grade with the case of the low engine speed, so that one-shot compensation time is made longer. With this constitution, any engine stall can be prevented.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine idle control device.

(Prior art) Engine idle control devices are
As shown in Publication No. 33, an intake air amount adjustment means such as a proportional solenoid valve is provided in the bypass passage that bypasses the throttle valve, and the intake air amount adjustment means is feedback-controlled in the idle region, while driving from the N or P range. When switching to the range, the intake air amount adjustment means is generally controlled to temporarily increase the intake air amount (for example, one-shot correction) in order to prevent the engine speed from dropping. It is known that the initial value of the correction is constant regardless of other operating conditions.

(Problem to be solved by the invention) However, for example, when the accelerator pedal is depressed while the vehicle is stopped and then released, the engine speed increases. In such a case, when switching from the N or P range to the drive range, the engine speed will drop sharply, and even with the above correction, it will not be possible to overcome the problem. However, there is a risk that so-called engine stalling may occur.

As a means of preventing this engine stall, it is conceivable to increase the amount of the correction described above to further increase the amount of intake air.

However, if it is decided to increase the correction amount of the above correction, if the engine speed is switched from the N or P range to the driving range when the engine speed is in the idle region, the speed will increase. .

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to stabilize feedback control during idling when switching from N or P range to driving range, and to improve engine rotational speed at the time of switching. The purpose is to prevent the engine from stalling due to the switching when the rotation speed is high.

(Means and effects for solving the problem) In order to achieve the above object, the present invention provides an idling system that detects whether or not the engine is in an idling state, in a vehicle equipped with an automatic transmission. a detection means; and a rotation speed detection means for detecting the rotation speed of the engine.

an intake air amount adjusting means for adjusting the intake air amount of the engine; a feedback control means for controlling the intake air amount adjusting means during idling to feedback control the engine speed to a target value; and an N or P range. a range change detection means for detecting a change from the N range to a driving range; and an intake air amount adjusting means for controlling the intake air amount adjusting means to temporarily increase the intake air amount when switching from the N or P range to the driving range. It is characterized by comprising an air amount correction means, and a correction amount changing means for changing the correction amount of the intake air ht correction means to be larger when the engine speed at the time of switching is high than when it is low. This is an idle control device for an engine.

With the above configuration, when switching from N or P range to driving range, if the engine speed is low,
As before, the intake air amount is temporarily increased by the intake air amount correction means and returned to the idle speed, but when the engine speed is high, the correction amount of the intake air amount correction means is further increased. As a result, the amount of intake air is increased compared to when the engine speed is low. Therefore, when idle, N or P
Even when switching from the range to the driving range, the speed does not rise, and the stability of feedback control can be ensured.On the other hand, when switching from the N or P range to the driving range at high speeds, Also, the required amount of intake air is supplied, and engine stall can be prevented.

(Example) Embodiments of the present invention will be described below based on the drawings.

In Fig. 2, 1 is the engine body, and the intake air amount is
Air cleaner 2, air flow chamber 3, throttle valve body 4, surge tank 5, intake manifold 6, intake boat 8 opened and closed by intake valve 7, then combustion chamber 9.
The path from the air cleaner 2 to the intake boat 8 constitutes an intake passage 10. The amount of intake air flowing through this intake passage 10 is controlled by a throttle valve 11 and measured by an air flow meter 12, and this intake air is mixed with fuel injected from a fuel injection valve 13. It has become.

On the other hand, exhaust gas from the combustion chamber 9 passes through an exhaust boat 15 opened and closed by an exhaust valve 14, an exhaust manifold 16, etc., and is discharged to the atmosphere.

A bypass air passage 17 is attached to the intake passage 10, and its upstream end 17a is located upstream of the throttle valve II, and its downstream end 17b is located downstream of the throttle valve 11. Each is connected to the intake passage 10. A solenoid valve 18, which is a proportional solenoid valve, is connected to the bypass air passage 17 as a component of the intake air amount adjusting means.

Reference numeral 19 in FIG. 2 is a control unit consisting of a microcomputer, and for this control unit +9, the cooling water temperature as the engine temperature from the water temperature sensor 20, the engine speed from the rotation speed sensor 21, and the engine speed from the idle switch 22. 0N-OFF signal indicating whether the throttle valve 11 is fully open, vehicle speed from the vehicle speed sensor 23, N range and D range from the N-D range switching sensor 24.
Switching signals to and from the range are respectively input, while the control unit 19 outputs signals to the solenoid valve 18.

During idling, this control unit 19 performs feedback control of the solenoid valve 18 as is known, and when switching from N range to D range, performs one-shot correction as intake air amount correction using the solenoid valve 18. It becomes. In this case, the intake air amount is adjusted by adjusting the opening degree of the solenoid valve I8, and the opening degree of the solenoid valve 18 is determined by the duty ratio of the pulse output from the control unit IO or one It is adjusted according to the shot correction value (in either case, the larger the value, the larger the opening degree of the solenoid valve 18).

The outline of the one-shot correction by the control unit 19 will be explained with reference to FIGS. 3 and 4. In this control unit 19, the initial value of the one-shot correction is set at the engine speed when switching from the N range to the D range. It can be changed depending on the state of the number.

That is, in the case of low rotation speed (for example, 125 or.

p, m,), one-shot correction is performed using conventional correction values as shown in FIG. Therefore, when the engine is idling, the engine does not rev up as before.

On the other hand, in the case of high rotation speed (for example, 125 Or, p, m).

(above), the initial value of the one-shot correction is increased compared to the case of low rotation speeds as shown in Figure 3, and the one-shot correction time is increased with the same slope as in the case of low rotation speeds, and the one-shot correction time is longer than in the case of numbers. this is,
Even if one-shot correction similar to the conventional one is performed at high rotational speeds, that is, one-shot correction for low rotational speeds in Fig. 3, the rotational speed returns to the idle speed as shown by the dashed line in Fig. 4. This is because, in this case, the engine speed drops suddenly, which may cause the engine to stall.

For this reason, in the case of high rotation speeds, the initial value of the one-shot correction is increased compared to the case of low rotation speeds, increasing the amount of intake air, and as shown by the solid line in Fig. 4, the idle rotation speed is reduced. This is to prevent the engine from stalling when returning.

In particular, in this embodiment, the one-shot correction value is increased on the following conditions: the engine speed is high, the N range is switched to the D range, and the vehicle speed is kept at a constant value. The conditions are that the cooling water temperature is below a certain value (for example, 45° C.) or higher (for example, 45° C.).

This means that when the vehicle speed is high, N
This is because even if the range is changed to the D range, the engine will not stall due to the inertia of the vehicle.

Regarding the cooling water temperature, when the water temperature is low, there is no problem with engine stalling because the base rotation speed of the engine is high, and there is no problem with a low one-shot correction value. This is because there is a risk that defects may occur.

The content of the one-shot correction by the control unit 19 described above will be explained in detail with reference to the flowchart shown in FIG. Note that in the following explanation, S indicates a step.

First, in S+, initialization is performed, and in S2, the engine speed, vehicle speed, cooling water temperature, switching signal between N-D sink 9, and ON/OFF signal of idle switch 22 are read. Next, in S3, it is determined whether the engine rotation speed is equal to or higher than a predetermined rotation speed Nsw (125 Or, p, m,), and when the engine rotation speed is less than the predetermined rotation speed Nsw, the rotation speed is low, and when the predetermined rotation speed Nsw or more, the engine rotation speed is high rotation speed. It is determined that If S3 is YES, then in S4,
It is determined whether the vehicle speed is below a certain value (4 km/h), and S
When 4 is YES, it is determined in S5 whether the cooling water temperature is equal to or higher than a certain value (45° C.). When S5 is YES, it is determined in S6 whether or not the N range is switched to the D range, and when S6 is YES, one-shot correction should be performed based on the characteristics at high rotation speed. , the one-shot value is set to GLSDR,ll in S7, and 16.1 in S8.
Tailing is done every 4m5eC. In this case, the tailing amount is DGLSDR, )l.

In the next step 39, it is determined whether or not the D range has been switched to the N range. If S9 is No, 5 switching has not been performed, so in SIO it is determined whether the one-shot correction value is 0 or not. Then, it is determined whether one-shot correction still needs to be performed. Sl
If O is YES, the one-shot correction has been completed, so the process returns.

When S9 is YES, there is no need to switch from the D range to the N range and perform one-shot correction, and therefore, it is reset at Sll.

When the SIO is No, the one-shot correction has not yet been completed, and it is determined in SI2 whether or not it has been determined that the N range has been switched to the D range at high rotation.

When SI2 is YES, the process returns to S8, and S8 to S
12 is repeated.

When mJ S6 is No, it means that the one-shot correction based on the characteristics in the case of a high rotational speed has already been started, and in this case, the process directly proceeds to the above-mentioned StO.

When at least one of the above-mentioned 83 to S5 is NO, it is determined that one-shot correction should be performed based on the characteristics in the case of low rotation speed, and it is determined in S13 whether or not it is the time to switch from the N range to the D range. . S13 is YES
At S+4, the one-shot correction value is set to GLSDR,L, and at S+5, tailing is performed every 16.4 m5ec, assuming that one-shot correction should be performed based on the characteristics for a low rotational speed. In this case, the tailing amount is DGLSDR,L.

After this S+5, the process proceeds to S9, and the flow is similar to that in the case of the high rotation speed. When S12 is No, the process returns to S15, and tailing is continued under the characteristics for low rotational speed.

When S13 is No, tailing has already started under the characteristics of the low rotational speed, and the process proceeds to SIO.

Although the implementation device has been described above, the present invention includes the following devices.

■In addition to the D range, the driving ranges include 1.2. Includes R range.

■The initial value of the one-shot correction value is set according to the engine speed when switching from N or P range to driving range.
Divided into 3 or more parts or continuously variable.

(Effects of the Invention) As described above, the present invention makes it possible to stabilize the feedback control during idling when switching from the N or P range to the driving range, and to maintain the stability of the feedback control when switching from the N or P range to the driving range. When the rotation speed is high, this switching can prevent the engine from stalling.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the present invention, FIG. 2 is an overall system diagram showing an embodiment of the present invention, FIG. 3 is a graph schematically showing a control example of the present invention, and FIG. FIG. 5 is a characteristic diagram showing the relationship between engine speed and time based on the control example of the present invention, and FIG. 5 is a flowchart showing the control example of the present invention. : Solenoid valve: Control unit 2 rotation speed sensor: Idle switch: N-D range switching detection sensor diagram

Claims (1)

[Claims] (1) A vehicle equipped with an automatic transmission, comprising an idle detection means for detecting whether the engine is in an idling state, a rotation speed detection means for detecting the engine rotation speed, and a rotation speed detection means for detecting the engine rotation speed. an intake air amount adjusting means for adjusting the intake air amount; a feedback control means for controlling the intake air amount adjusting means to feedback control the engine speed to a target value during idling; and detecting switching from the N or P range to the driving range. range switching detection means for detecting range switching; intake air amount correction means for controlling the intake air amount adjusting means to temporarily increase the intake air amount when switching from the N or P range to the driving range; 1. A correction amount changing means for changing the correction amount of the intake air amount correction means to be larger when the engine speed is high than when it is low.