JPH0227129A - Device for controlling air intake quantity of engine - Google Patents

Abstract

PURPOSE:To carry out proper deceleration control whether at the time of cold engine or warm engine by setting the controlled variable of an intake air quantity which is increased by a decelerating-time correcting means, to be smaller as an engine temperature is lower. CONSTITUTION:In a controller 4, the control map of a decelerating-time correcting quantity by means of an idling engine-speed control valve 3 is formed with the two of an engine speed and an engine cooling water temperature at the point of time when a throttle valve is totally closed as parameters. In this case, the correcting quantity is set to be smaller as the cooling water temperature is lower. Thereby, a control for gradually reducing an intake air quantity at the time of deceleration can be always properly carried out irrespective of engine temperature, enabling favorable engine behavior without a shock while giving a proper decelerating feeling can be achieved irrespective of engine temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine intake air amount control device, and particularly to a technique for improving engine behavior during deceleration.

(Prior Art) As is well known, in recent electronically controlled engines, the idle speed is controlled in the following manner.

As shown in FIG. 1, a solenoid valve called an idle speed control valve 3 is provided in a bypass intake passage 2 that bypasses a throttle valve 1. When the throttle valve 1 is fully open,
The controller 4 determines the target idle rotation speed based on various engine status information, and adjusts the opening degree of the control valve 3 (effective flow path of the bypass intake passage) so that the actual rotation speed matches the target rotation speed. do. This is called an idle rotation speed fitback control means.

Immediately after the throttle valve 1 changes to the fully open state, the deceleration correction means (dashpot correction means) operates as follows. When the engine speed Ne is the set value NADP (for example, 1
If the intake air amount is immediately controlled only by the feedback control means when the throttle valve 1 is fully opened in a state where the intake air amount is higher than 000 ppm, the deceleration shock will be extremely large.

Therefore, immediately after the throttle valve 1 is fully opened, the opening degree of the control valve 3 (
Increase the opening degree from time to time (basic control amount). This increased amount is referred to as the deceleration correction amount GDP.

In the conventional technology, the correction amount GDP during deceleration is determined by the engine rotation speed Ne at the time when the throttle valve 1 is fully opened, and as shown in the graph of FIG. 3, the correction amount GDP becomes larger as the rotation speed Ne becomes higher. A control map has been created. When the throttle valve 1 is fully opened, draw the control map, find the GDP corresponding to Ne at that time (this is the GDP initial value), add it to the basic control amount, and drive the control valve 3. . After this, the correction amount GDP
decreases over time and eventually reaches zero. The above control procedure is summarized and shown in the flowchart of FIG.

In this way, by reducing the amount of intake air immediately after deceleration slowly by the deceleration correction means, deceleration shock is reduced (see Japanese Patent Laid-Open No. 5560636). Note that if the deceleration correction amount GDP is larger than the appropriate value,
Immediately after deceleration, the amount of intake air becomes excessive, making it impossible to obtain a sufficient feeling of deceleration and engine cooling water temperature.The appropriate value of GDP is determined from these points.

By the way, the above-mentioned idle speed feedback control means sets the target idle speed higher as the engine cooling water temperature is lower, in order to stabilize idling when the engine is cold. Therefore, this feedback control means:
It includes a cold-time correction means that increases the effective flow path of the bypass intake passage 2 as the engine temperature decreases.

Furthermore, as shown in FIG. 1, a thermowax air valve 5 is provided in the bypass intake passage 2 in parallel with the control valve 3, which is a technology that has been in practical use for a long time. This air valve 5 is opened and closed by wax that expands upon receiving heat from the engine coolant, and closes as the coolant temperature increases. In other words, this air valve 5 is also one of cold-time correction means that increases the effective flow path of the bypass intake passage 2 as the engine temperature decreases. Note that heater bimetallic air valves are also used for the same purpose.

(Problem to be Solved by the Invention) The conventional deceleration correction means described above has a control map for the deceleration correction amount GDP so that an appropriate feeling of deceleration without shock can be obtained in an operating state where the engine is warmed up to a certain level. is being created. Therefore, when the engine is cold or semi-warmed up, the deceleration correction amount GDP is too large, causing a problem in that a sufficient sense of deceleration cannot be obtained.

When the vehicle is cold, the basic amount of intake air is increased by the cold time correction means described above, so adding the same deceleration correction amount GDP as when it is warm will result in an excessive amount of intake air.
Not slowing down enough. In addition, on the contrary, GD according to the cold time
If a control map for P is created, it will be impossible to eliminate deceleration shock during warm conditions.

This invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an engine intake air amount control device that can perform appropriate deceleration control in both cold and warm conditions. It is in.

(Means for Solving the Problems) Therefore, the present invention provides a cold time correction means that increases the amount of intake air supplied to the engine as the engine temperature decreases, and a cold time correction means that increases the amount of intake air supplied to the engine when a deceleration state of the engine is detected. In this engine intake air amount control device, the control amount of the intake air amount, which is increased by the deceleration correction means, is set to be smaller as the engine temperature becomes lower.

(Function) In the configuration of the present invention, the control M of the effective flow path of the bypass intake passage by the deceleration correction means (corresponding to the deceleration correction amount GDP described above) is warmer in the cold state. smaller than time. Therefore, as a result of combining the characteristics of the cold-time correction means, the amount of intake air immediately after deceleration does not become excessive even when the engine is cold.

(Example of implementation) In the conventional technology, as shown in Fig. 3, a control module for the correction amount GDP during deceleration is created using the engine rotational speed Ne at the time when the throttle sotol valve 1 is fully closed as a parameter. Ta.

On the other hand, in the case of the device according to the embodiment of the present invention, as shown in FIG. A control map for time-corrected fiGDP is being created. Here, the lower the cooling water temperature Te, the lower the correction amount GDP.
The relationship is set such that .

The configuration of the engine control system shown in FIG. 1 and the control procedure by the deceleration correction means shown in FIG. 2 are basically the same as in the prior art. Further, the operation of the cold time correction means described in detail above is exactly the same in this embodiment, and will not be explained again.

In FIG. 2, various engine status information is read into the controller 4 in step 201. The idle switch ID5w, which is turned on when the throttle valve 1 is fully closed, is on, and the engine speed Ne is NIDP (for example, 1
000 rpm) or more, step 202→2
Proceed as 03 → 204. In the first processing when the idle switch ID5w is reversed from off to on, the flag FIDP is reset to "0" and steps 204→205 (
Set FIDP) → Proceed to 206. In this step 206, the control map shown in FIG. 4 is drawn. That is step 2
The deceleration correction amount GDP corresponding to the engine speed Ne and cooling water temperature Te obtained in step 01 is extracted. This GI)P becomes the initial value, and thereafter, a constant value △GDP is subtracted from GDP at regular intervals (step 208), and G
The deceleration correction ends when DP reaches zero.

(Effects of the Invention) As explained in detail above, in the device of the present invention, the increase in intake air amount by the deceleration correction means is smaller when the engine is cold than when the engine is warm. The characteristics are well mixed with the time correction means, and the control to gradually reduce the amount of intake air during deceleration is always performed appropriately regardless of the engine temperature, resulting in good engine behavior with an appropriate deceleration feeling without shock. will be realized regardless of.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an engine control system common to the embodiment of the present invention and the prior art, FIG. 2 is a flowchart of the deceleration control means common to the embodiment of the present invention and the prior art, and FIG. 3 is a prior art FIG. 4 is a conceptual diagram of a control map for the correction amount during deceleration in an embodiment of the present invention. 1... Throttle valve 2... Bypass intake passage 3... Idle speed control valve 4...
controller

Claims (1)

[Claims] (1) Cold-time correction means for increasing the amount of intake air supplied to the engine as the engine temperature is lower; and deceleration-time correction means for temporarily increasing the amount of intake air when a deceleration state of the engine is detected. An intake air amount control device for an engine, characterized in that the control amount of the intake air amount that is increased by the deceleration correction means is set to be smaller as the engine temperature becomes lower.