JPH0337339A - Idle revolution speed controller for engine - Google Patents

Abstract

PURPOSE:To prevent the sharp reduction of the engine revolution speed by installing a means for prohibiting the control for the bypass air quantity up to the final time point during the time obtained from the engine revolution speed in off idling, in the transition from the off-idling to the idle state. CONSTITUTION:In the subject device, in a control part 12 which receives each signal of an idle switch 4, intake quantity sensor 9, revolution speed sensor 10, and a car speed sensor 11, an air quantity control valve 5 is controlled through an actuator 6 so that a desired engine revolution speed is obtained in idle operation, and each injector 2a - 2f is controlled according to the engine load. In the transition from the off-idling to idle state, the control for the bypass air quantity is suspended for a certain time, and the sharp reduction of the bypass air quantity is prevented, and in this case, the control for the bypass air quantity is prohibited up to the final time point during the time which is obtained from the engine revolution speed in off idling.

Description

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

[Conventional technology]

FIG. 1 shows the configuration of engine idle speed control devices according to the conventional technology and the present invention, l is the engine, 2a to 2r
3 is an injector provided for each cylinder, 3 is a throttle valve provided in the intake pipe 8, 4 is an idle switch that detects that the throttle valve 3 is in the idle position, and 5 is a pipe path that bypasses the throttle valve 3. air amount control valve provided at 7;
9 is an actuator that drives the air amount control valve 5; 9 is an intake air amount sensor provided at the entrance of the intake pipe 8 to detect the intake air amount of the engine 1; 10 is a rotational speed that detects the rotational speed of the engine 1; A sensor 11 is a vehicle speed sensor that detects the speed of a wheel connected to the engine 1 via a ξ cylinder 13. 12 is a control unit consisting of an input interface 100, a microprocessor 101S101SRO, a RAM 103, and an output interface 104.

In the above configuration, the control section 12 includes an idle switch 4
, intake air amount sensor 9, rotation speed sensor 10, and vehicle speed sensor 1
Based on this information, the control unit 12 controls the air amount control valve 5 via the actuator 6 so that the amount of bypass air corresponds to the desired engine rotation speed in the idle state. Each injector 2a to 2f is controlled so that the fuel amount corresponds to the engine load.

By the way, in conventional devices, the amount of air is rapidly reduced when transitioning from an off-idle state to an idling state, but this rapid drop in air amount can prevent a sudden drop in engine rotation or engine stoppage. In order to do this, control of the amount of bypass air was stopped for a certain period of time. This will be explained using the flowchart shown in FIG. In step 101, it is determined from the output of the idle switch 4 whether or not it is in the idle state, and when it is detected that it is in the off-idle state, in step 105, control of the amount of bypass air is prohibited according to the engine speed based on the relationship shown in FIG. The time T is calculated and stored in the timer ↑ of the RAM 103 in step 106. This calculation is always performed, and immediately before transitioning to the idle state, a prohibition time T corresponding to the engine speed at that time is stored in the RAM 103.Next, when the transition to the idle state occurs, the process proceeds to step 102.
It is determined whether the countdown timer is 0 or not, and if it is 0, control of the engine rotation speed, that is, control of the amount of bypass air is started in step 104.

If it is not 0, the prohibited state continues in step 103.

[Problem to be solved by the invention]

In the conventional device described above, the control prohibition time is calculated from the relationship shown in Figure 4 according to the engine speed immediately before the transition to the idle state, but when the engine speed gradually changes from the high engine speed to the idle state, In the case where the engine immediately shifts from the engine rotation state to the idle state, the control inhibition time should be different even if the previous engine rotation speed is the same. That is, in the latter case, the prohibition time can be short, while in the former, it must be long.However, in the conventional case, if the previous engine speed is the same, the prohibition time is also the same, and if the prohibition time is too short, the engine rotation Since the number does not decrease sufficiently, the amount of bypass air will be significantly lowered, and the engine will not be able to maintain an idle state and will stop.

This invention is like the above! The object of the present invention is to obtain an engine idle speed control device that can prevent the engine from stopping when transitioning from an off-idle state to an idle state.

[Means to solve the problem]

The engine idle speed control device according to the present invention prohibits control of bypass air amount until the end of the time determined by the engine speed during off-idle when transitioning from an off-idle state to an idle state. This means that a means has been established.

[For production]

In this invention, when transitioning to an idle state, bypass control is prohibited until the final point in time determined from the engine speed during off-idle, and if the idle state gradually changes from a high engine speed state, the prohibited time is longer. Become,
No sudden drop in engine speed occurs.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The configuration of the idle speed control device according to this embodiment is the same as that shown in FIG. FIG. 2 is a flowchart showing the control prohibition operation at the time of idle transition, and shows steps 101 to 105.
is the same as before.

In step 106, the currently calculated prohibition time T is compared with the prohibition time ↑ stored in the timer and counted down.
If TNT', store T in the timer instead of 1 in step 107, and if T≦1, step 10B
Continue the countdown above. Eventually, when the engine shifts to an idle state and becomes ↑-〇, the control prohibition is canceled and the amount of bypass air is controlled so that the engine speed becomes a predetermined number of revolutions.

In the above embodiment, bypass control is prohibited until the final point of the control prohibition time that is repeatedly calculated during off-idling, and even if the rotation speed immediately before transition to idle is the same, the rotation speed before that is If it is high, the prohibition time will be long and the bypass air amount will not be rapidly reduced.

[Effects of the Invention] As described above, according to the present invention, the prohibition time of bypass control at the time of idle transition is determined not only by the engine speed immediately before that but also by the engine speed before that, and it is determined based on the engine speed before that. The optimum prohibition time can be obtained accordingly. Therefore, it is possible to prevent the engine from stopping due to a sudden decrease in the amount of bypass air, and to continue the idling operation in a good manner.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the conventional device and the present invention device, Fig. 2 is a flowchart showing the operation of the present invention device, Fig. 3 is a flowchart showing the operation of the conventional device, and Fig. 4 is the engine rotation speed according to the conventional device and the present invention. FIG. 4 is a diagram showing the relationship between the control prohibition time and the control prohibition time. DESCRIPTION OF SYMBOLS 1... Engine, 3... Throttle valve, 4... Idle switch, 5... Air amount control valve, 6... Actuator, 7... Bypass path, 10... Rotation speed sensor,
12...Control unit.

Claims (1)

[Claims] A rotation speed detection means for detecting the engine rotation speed, an idle state detection means for detecting that the throttle valve is in the idle position, and a control for controlling the bypass air amount of the throttle valve according to the engine rotation speed during the idle state. In an engine idle speed control device equipped with a means for controlling bypass air volume when transitioning from an off-idle state to an idle state, control of the amount of bypass air is prohibited until the final point in time determined from the engine speed during off-idle. An engine idle speed control device characterized by comprising means.