JPS63113151A - Idling speed control device for automobile engine - Google Patents

Abstract

PURPOSE:To prevent fuel consumption from getting worse unnecessarily, by installing a compensation device so as to set an engine speed lower as much as the specified value than at time of clutch engagement when a clutch-off state is detected by a clutch-off state detecting device. CONSTITUTION:An engine control unit 9 recognizes that a target speedup for tooth clattering noise prevention of gears at a transmission part in the case where an idle switch SW1 is on and a clutch switch SW2 is off, and it sets minimum speed N1 to be determined by both conditions of combustion stability and fuel economy as the target speed. And, when the clutch switch SW2 is not off, it sets the target speed N2 higher as much as the specified speed than the target speed N1 in order to the tooth clattering noise prevention. Next, it compares the actual engine speed N with the N1 or the N2, and performs feedback control according to the result, whereby it converges this actual engine speed on the setting target speed N1 or N2. Therefore, at time of clutch disengagement, it is controlled to the lower speed than at time of clutch engagement, thus fuel consumption also is prevented from getting worse unnecessarily.

Description

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

(Prior art) In general, an idle speed control device for an automobile engine is
For example, a bypass passage for intake air is formed to bypass the throttle valve of the engine, and the throttle valve is placed in the minimum opening state (idle state) in this bypass passage.
An intake air m adjustment means (electromagnetic valve) is provided to adjust the amount of intake air in the engine, and the intake air m adjustment means is adjusted so that the actual rotation speed of the engine becomes a predetermined target rotation speed set by the target rotation speed setting means. It is configured to operate at a constant target idle speed by controlling the engine.

In the above case, more specifically, an engine controller composed of a microprocessor is used to control the intake air filter according to a predetermined basic control amount set corresponding to the target rotation speed. However, if the actual rotation speed obtained by the predetermined basic control amount does not match the target rotation speed, the actual rotation speed is adjusted by correcting the predetermined basic control amount according to the load amount or deviation amount at that time. A configuration is adopted that allows the number of rotations to converge to the target number of rotations.

In other words, the idle speed of an engine is normally set as the lowest speed that satisfies both the conditions of rotational stability and fuel economy. When the rotation speed starts to decrease, the amount of intake air is increased in accordance with the load amount to return to the original target rotation speed.
(see publication).

However, in reality, due to the circumstances described below, the target rotation speed is set to be a predetermined number of rotations higher than the original target rotation speed, which is determined from both the combustion stability and fuel saving conditions.

That is, for example, when the car is stopped in the above-mentioned idle region, if the clutch is not disengaged and a part of the differential gear on the transmission side and the output shaft on the engine side are directly connected, the gear shift in the transmission section will be affected. Since the meshing occurs under no load and in a low rotation range, a rattling sound is generated, which is unpleasant to the ears. Therefore, in order to prevent the occurrence of tooth rattling noise, the target revolution speed during idling is set higher than the original target revolution number by a predetermined number of revolutions to prevent the occurrence of tooth rattle noise. The reality is that there are. this is,
Not limited to feedback control as described above,
The same holds true for open-loop rotational speed control.

(Problem to be solved by the invention) However, as mentioned above, setting the target rotation speed fixedly high regardless of the actual state of the clutch and its disengaged state is completely meaningless and reduces fuel consumption when the clutch is disengaged. This is not desirable as it makes the person look like a bad person.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and provides an automobile engine comprising an engine speed control means for controlling the engine speed during idling. In this idle speed control device, an unlatch disengaged state detection means for detecting a disengaged state of the clutch is provided, and when the disengaged state of the clutch is detected by the clutch disengaged state detecting means, the engine speed is set to a predetermined level compared to when the clutch is engaged. A correction means is provided for correcting the engine rotation speed control means so as to set the engine rotation speed lower by the same value.

(Function) According to the above means, the clutch disengagement state detection means is provided, and when the clutch is disengaged, which eliminates the problem of rattling noise, the rotational speed is controlled to be lower than when the clutch is engaged, which unnecessarily worsens fuel efficiency. You can prevent this from happening.

(Example) First, FIGS. 2 and 3 show an engine idle speed control device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a control system of the above embodiment device, FIG. 3 is a flowchart illustrating the operation of the apparatus of the above embodiment.

First, the outline of the control system according to the embodiment of the present invention will be explained with reference to FIG. 2, and then the control of the main parts will be explained.

In FIG. 2, reference numeral 1 denotes the engine body, where intake air is taken in from the outside via an air cleaner, and then supplied to each cylinder via an air flow meter 2 and a throttle chamber 3, and fuel is supplied to an engine control unit 9, which will be described later. The fuel is injected by a fuel injector 5 controlled by the following. The amount of intake air into the cylinder is controlled by a throttle valve 6 provided in the throttle chamber 3, and the amount is detected by an air flow meter 2. The throttle valve 6 is operated in conjunction with the accelerator pedal, and is maintained at the minimum opening state in the idling state.

On the other hand, the throttle chamber 3 is provided with a bypass passage 7 that bypasses the throttle valve 6.
In this bypass passage 7, a solenoid valve (throttle valve) 8 serves as a means for regulating the intake air ta for controlling the engine speed during idling.
is provided. Therefore, in an idling state, the intake air that has passed through the air flow meter 2 is supplied to each cylinder via the bypass passage 7, and the amount of intake air is regulated by the solenoid valve 8. The opening/closing state of this electromagnetic valve 8 is controlled by the duty ratio of a control pulse signal (hereinafter simply referred to as a control signal) G supplied from an engine control unit (hereinafter simply referred to as ECU) 9.

The ECU 9 is configured to include, for example, a microprocessor (CPU) at its center, a memory (ROM and RAM), and an inter 2ACE CI 10) circuit. The interface circuit of this ECU 9 includes, for example, an engine start signal S1 and an engine rotation speed detection signal N1.
A detection signal Tw of the cooling water temperature of the engine body 1 detected by a thermistor, an opening signal TVO of the throttle valve 6 detected by a potentiometer, an intake air amount detection signal Q1 detected by the air flow meter 2, and an oN of the idle switch SW1. , aiF signal, clutch switch SW, ON and OFF signals, and other various detection signals are inputted.

Further, reference numeral 10 indicates an exhaust pipe provided with a three-way catalytic converter 11.

Next, the control operation of the above control device will be explained in detail with reference to the flowchart of FIG.

When the control operation is first started, the various input information mentioned above is input at predetermined time intervals, such as the actual engine speed (N), the opening degree of the throttle valve 6 (TVO), and the ON/OFF state of the idle switch SWI. 'Signals, clutch switch SW, ON/OFF signals, etc. are read, and based on that information, first in step S1, the current operating state is in the feedback control (F/B) region in the idling operating state. Idle switch S whether or not
It is determined that W + is ON. That is, when the idle switch SWl is ON, it is determined to be in the idle feedback control region, and the other switch SW, h<OF
When F', it is determined that the area is in a non-feedback control area.

And if it is in the idle feedback control region (
If YES), the process then proceeds to step St, where it is determined whether the clutch switch SW is OFF.

On the other hand, if it is determined that it is in the non-feedback control region (NO), it is recognized that the control from step S2 onwards is unnecessary, and the FFr constant standby amount is set to the final output and the control is shifted to open loop control. The control operation based on the cycle flow ends.

Then, in step S above, if it is determined that the clutch switch SWt is OFF'F (YES)
In this case, step S is performed after recognizing that the target rotation speed increase to prevent rattling noise is not necessary.

The process proceeds to Step S, where the lowest engine speed NI determined by both combustion stability and fuel saving conditions is set as the target engine speed, and then the process proceeds to step S, where it is compared with the actual engine speed N.

On the other hand, the clutch switch SW is turned OFF in step S.
If it is determined that it is not (NO), the process moves to step S4 where the target rotation speed is set to a rotation speed N higher than the target rotation speed N set in step S by a predetermined number of rotations in order to prevent rattling noise. After setting this, proceed to step S.

In step S, the actual rotation speed N of the engine is compared with each target rotation speed NI or N2 set in steps S s and S-, and according to the result, step 88
Duty ratio DI-D of the control signal G that controls the solenoid valve 8 as the intake air amount adjusting means at ~Sll
, (%), and the calculated duty ratio is -
At step D, the solenoid valve 8, which is the intake air mR leveling means, is controlled.

That is, as a result of the comparison in step S, if the actual engine rotation speed N is equal to the target rotation speed N or N, and the engine rotation speed N is controlled according to the target rotation speed, step S is performed. , the control duty ratio D for correction is
I = O (%) is calculated, and in step S, the actual engine speed N is determined as the target speed N set above.
1 or lower than N2, the correction control duty ratio D ! = + Step S1 is performed by calculating the control duty ratio Ds=y (%).
1, and performs feedback control to change the actual engine speed N to the set target rotation speed N or N.
, converge to .

In the above-mentioned embodiment, the engine speed control is performed using feedback control, but it goes without saying that the present invention is equally applicable to open-loop control.

(Effects of the Invention) As described above, the present invention provides an idle speed control device for an automobile engine that includes an engine speed control means for controlling the engine speed during idling. The engine rotation speed control means is provided with a clutch disengagement state detection means for detecting the clutch disengagement state, and when the clutch disengagement state detection means detects the clutch disengagement state, the engine rotation speed is set to be lower by a predetermined value than when the clutch is engaged. The invention is characterized in that it is provided with a correction means for operating the initial pressure.

Therefore, according to the present invention, the clutch disengagement state detection means is provided, and when the clutch is disengaged so that rattling noise does not become a problem, the rotation speed is controlled to be lower than when the clutch is engaged, so that unnecessary deterioration of fuel efficiency is avoided. It can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to claims of the present invention, Fig. 2 is a control system diagram of an idle speed control device for an automobile engine according to an embodiment of the present invention, and Fig. 3 is a diagram of the embodiment of the device shown in Fig. 2 above. 3 is a flowchart for explaining control operations in FIG. l... Engine body 2... Air flow meter 6... Throttle valve 7... Bypass port 8... Solenoid valve 9... Engine control unit SW ,...
・Idle switch SW chamber...Clutch switch

Claims (1)

[Claims] 1. An idle speed control device for an automobile engine comprising an engine speed control means for controlling the engine speed during idling, including a clutch disengagement state detection means for detecting a disengaged state of the clutch, and detecting the clutch disengaged state. The present invention is characterized in that a correction means is provided for correcting the engine rotation speed control means so that when the detection means detects a disengaged state of the clutch, the engine rotation speed is set lower by a predetermined value than when the clutch is engaged. Automotive engine idle speed control device.