JPH0243912B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides a method for controlling the idle speed to increase the idle speed when an engine load is applied while the engine of an automobile is idling. This invention relates to an engine idle control device that stabilizes the engine.

(Prior Art) Conventionally, when the engine is idling, there is a means to increase the idling speed when the cooler operates (for example, Japanese Patent Laid-Open No. 54-62419
Publication No.).

However, this conventional means has the problem that the engine may rev up when the cooler stops operating, and no consideration has been given to this problem.

For example, if an idle up device that increases the idle rotation speed is configured to open the throttle valve by a predetermined amount, even if the idle up device stops operating at the same time as the cooler operation stops, that is, the throttle valve will not open. Even if the throttle valve is returned to its original basic idle position, the amount of air-fuel mixture that exists between the throttle valve and the engine's intake valve is sufficient to support the operation of the cooler. The rotation speed increases. It is also possible that the engine speed rises due to a delay in the control system that controls the throttle valve.

Once the engine is revved up, it takes time to return to the original target idle speed, resulting in problems such as not being able to achieve stable idling, and in addition, the product value may decrease. .

(Object of the Invention) An object of the present invention is to provide an engine idle control system that has a function of preventing engine revving when execution of idle control for engine load is stopped in synchronization with a decrease in engine load. The purpose is to provide equipment.

(Structure of the Invention) This invention controls the ignition timing of the engine in the direction of decreasing the engine output for a predetermined period of time from the time of cancellation in synchronization with the cancellation of the air-fuel mixture increase correction due to the stoppage of engine load operation, and The present invention is characterized in that it is an engine idle control device that controls ignition so as to return to normal ignition timing after a certain period of time has elapsed.

(Effects of the Invention) According to the present invention, when the idle up control performed in response to the engine load is canceled at the same time as the engine load stops operating, the ignition control means changes the ignition timing of the engine in the direction of lowering the engine output. Since the ignition is controlled for a predetermined period of time and the engine returns to normal, the engine output is reduced by this ignition control.
As a result, even if a large amount of the air-fuel mixture that has already been supplied to the engine is combusted when the engine load stops, the blow-up phenomenon will not occur.
The target idle speed is quickly reached and stable idle operation can be achieved.

(Example) An example of the present invention will be described in detail below based on the drawings.

The figure shows an engine idle control device, and in FIG. A throttle valve 6 for controlling the amount of air-fuel mixture to the engine 1 is provided.

The idle up device 7 is a device that opens the throttle valve 6 by a predetermined opening degree from the set reference idle opening degree, and is composed of, for example, a solenoid that is electrically turned off and turned on, and is controlled by the aforementioned CPU 4, and The opening amount is set to an opening amount that allows stable idling of the engine 1 when an engine load is applied.

The throttle switch 8 detects whether or not the throttle valve 6 is in the idle operation position by the opening amount of the throttle valve 6, and this idle detection signal is sent to the CPU 4.
is input.

Rotation detector 1 on crank pulley 9 of engine 1
0 is provided, and this rotation detector 10 is connected to the engine 1.
outputs a signal indicating the rotational speed to the CPU 4.

The compressor 11 of the cooler is shown as an example of engine load, and is turned ON from the cooler switch 12.
By inputting the signal to CPU4, this
The drive is controlled by the CPU 4, for example, by turning on an electromagnetic clutch.

The ignition timing adjustment device 13 adjusts the ignition timing of the engine 1 from the reference position to the set retard position, and from the retard position to the reference position, and this adjustment is performed by the CPU 4.
controlled by.

The above-mentioned CPU 4 controls each device according to a set program, and has a memory inside, and this memory stores an initial retard value C1 and a retard correction amount GC shown in FIG. The retard value C1 is a retard value that retards the ignition timing of the engine 1 to the utmost when the engine load, that is, the compressor 11 of the cooler is turned off, and the retard correction amount GC is set sequentially from the above-mentioned initial retard value C1 to the reference ignition timing. This is a one-time correction amount to return to the original position.

The operation of the idle control device configured in this manner will be explained with reference to FIG. 3.

In the first step 21, in order to determine whether the engine 1 is in idle operation, the CPU 4 determines whether the throttle switch 8 is detecting the idle opening position based on its output signal. The determination is repeated until a detection signal is output.

If the answer is YES in the first step 21, the CPU 4 reads the signal indicating the engine rotation speed from the rotation detector 10 in the second step 22, and determines whether the engine 1 is below the set rotation speed α based on this signal. is determined, and when the engine speed is high, the determination is NO, the process returns to the first step 21, and idle control is not performed.

Then, in the first step 21 and the second step 22, the throttle switch 8 detects the idle opening degree and the rotation detector 10 detects the idle rotation speed, so that the engine 1 is started in idle operation. It is determined that

When it is determined that the engine 1 is in idle operation, in a third step 23, the CPU 4 determines whether the cooler switch 12 is ON.

When the ON signal of the cooler switch 12 is input to the CPU 4, the electromagnetic clutch of the compressor 11 is turned on.
When the compressor 11 is turned on and driven, the cooler is driven, and when the compressor 11 is driven, this drive becomes an engine load, so the fourth step 2
4, the CPU 4 turns on the solenoid of the idle up device 7, opens the throttle valve 6 to the set opening degree, supplies fuel corresponding to the engine load, and idles the engine 1 under this load. Perform idle control to stabilize
Returning to the first step 21, and while there is an engine load, the above-mentioned first to fourth steps 21 to
The process of 24 is repeated.

When the cooler switch 12 of the cooler is turned OFF in the third step 23 mentioned above, the CPU 4 determines this OFF and in the fifth step 25 controls the solenoid of the idle up device 7 to be OFF to stop the idle control. The throttle valve 6 is returned to the standard idle opening. Immediately after this, engine 1 starts to blow up, so the following process is performed to prevent this.

That is, in the sixth step 26, the CPU 4 determines whether the idle up device 7 was ON last time, and if the processing is to be performed immediately after the idle up device 7 is turned off, the determination is YES, and the process proceeds to the seventh step 27. In step 28, the initial correction value C1 is stored as the retardation correction amount C, and in the eighth step 28, the product of the above-mentioned correction value C and the one-time correction amount GC is calculated to obtain the retardation amount Rn.
, and the ignition timing adjustment device 13 uses this retard amount Rn.
is controlled in the retarded direction.

This control delays the ignition timing of the engine 1, and this delay reduces the output of the engine 1, thereby preventing engine 1 from revving up. When the process of the eighth step 28 is completed, the process returns to the first step 21.

Subsequently, in the second process, since the determination at the sixth step 26 is NO, the process moves to the ninth step 29, where the CPU 4 subtracts the one-time correction from the previous correction value C, and uses the value C-1 as the new correction value. Let the value be C, and then
10 In step 30, it is determined whether this new correction value C is greater than zero, that is, whether it is in the correction stage again, and if YES, the process moves to the eighth step 28.
A new retard amount Rn is calculated, and this new retard amount
The ignition timing of the engine 1 is controlled in the advance direction by Rn.

By sequentially repeating such processing, the ignition timing of the engine 1 is gradually decreased from the initially applied retard amount until it is finally returned to the reference ignition position.

That is, in the tenth step 30 described above, the correction value C
When it is determined that C has become zero, in an eleventh step 31, the CPU 4 sets the correction value C to zero. Based on this zero value, the correction amount is determined in the eighth step 28.
Since Rn also becomes zero, even if the subsequent processing is repeated, the ignition timing of the engine 1 will not be controlled in the retarded direction.

As is clear from the above processing, when the engine load is cut off, the ignition timing of engine 1 is controlled in the retarded direction, and while the retardation amount is gradually reduced and returned to the reference ignition position, engine 1 does not start up. This can be prevented by reducing the output, and stable idling can be achieved.

4 and 5 show a second embodiment of the idle control device. In FIG. 4, the throttle valve 6 is idle-controlled by an idle up device 7 as in the first embodiment, and the engine load is This is the compressor 11 of the cooler.

A branch passage 41 passes through the intake passage 2 on the negative pressure side of the throttle valve 6, and this branch passage 41 is connected to a diaphragm device 43 via a three-way solenoid 42. The above-mentioned three-way solenoid 42 normally causes the negative pressure of the branch passage 41 to act on the diaphragm device 43, and is energized to connect the atmospheric passage 44 to the diaphragm device 43. Connecting.

The diaphragm device 43 described above drives a vacuum advance device (not shown), and the diaphragm device 4
When negative pressure is acting on 3, the vacuum advance device operates the engine ignition timing at the reference ignition position,
Further, when atmospheric pressure is applied to the diaphragm 43, the diaphragm 43 is configured to operate at a predetermined retard position.

In FIG. 5, the cooler switch 12 of the cooler is
When ON, an idle up signal is generated based on this ON, and this signal operates the idle up device to control the idle operation corresponding to the engine load.

At the same time, when the cooler switch 12 is turned on, the first relay 45 is turned on, and the capacitor 46 is thereby turned on.
is charged.

When the aforementioned cooler switch 12 is turned OFF and the engine load is cut off, the idle up signal is also turned off.
Since it is turned OFF, the idle up device stops operating and returns to standard idle operation.

At the same time, the first relay 45 is turned off, and this
When the capacitor 46 is turned OFF, the charge stored in the capacitor 46 is applied to the second relay 48 via the diode 47, turning it ON.

When the second relay 48 is turned on, the three-way solenoid 42 is energized, so the three-way solenoid 42 is turned on.
switches the passage to connect the atmospheric passage 44 to the diaphragm device 43, and as a result, the vacuum advance device controls the engine ignition timing to be retarded by a set amount.

This control reduces the output of the engine, so even if the engine load is cut off, it is prevented from revving up, and stable idling operation is achieved.

This control in the retard direction is continued until the capacitor 46 finishes discharging and the second relay 48 turns OFF. When this relay 48 turns OFF, the three-way solenoid 42 returns to its original state and the diaphragm device 4
3 is acted upon by the negative pressure of the intake passage 2, and the vacuum advance device is returned to its original reference ignition position. 49 in the diagram
is a diode.

In both the first and second embodiments, the throttle valve 6 is provided to perform idle control using an idle up device, but a bypass passage that bypasses the throttle valve 6 is provided, and idle control is performed by opening and closing this passage. You can do it.

Also, the engine load was explained as a cooler, but
The same applies to the load on the power steering oil pump and alternator.

In the configuration of this invention, the idle detection means corresponds to the throttle switch 8 and the rotation detector 10, the load detection means corresponds to the ON determination process of the cooler switch 12 by the CPU 4 and the first relay 45, and the idle up means corresponds to the idle The ignition timing adjustment means corresponds to the ignition timing adjustment device 13, the diaphragm device 43, and the vacuum advance device, and the ignition retard means corresponds to the retard control processing of the CPU 4 and the capacitor 46, the second relay 4
8, corresponds to the three-way solenoid 42.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, and FIG. 1 is a block diagram of an idle control device. Figure 2 is a time chart showing the relationship between engine load and retard angle. Figure 3 is a flowchart. FIG. 4 is a configuration diagram of main parts of an idle control device according to a second embodiment. FIG. 5 is its electrical circuit diagram. 1... Engine, 4... CPU, 6... Throttle valve, 7... Idle up device, 8... Throttle switch, 10... Rotation detector, 12...
Cooler switch, 13...Ignition timing adjustment device, 4
2... Three-way solenoid, 43... Diaphragm device, 45, 48... Relay, 46... Capacitor.

Claims (1)

[Scope of Claims] 1. Idle detection means for detecting engine idling operation; Load detection means for detecting engine load operation state during idling operation; When the load detection means detects engine load operation, Idle-up means for increasing the amount of air-fuel mixture supplied to the engine by a predetermined amount while detecting engine load stoppage and canceling the correction for increasing the amount of air-fuel mixture; and ignition timing adjustment for adjusting the ignition timing of the engine. and controlling the ignition timing adjusting means in a direction to lower the engine output for a predetermined period of time from the time of cancellation, in synchronization with the cancellation of the increase correction of the air-fuel mixture amount due to the stoppage of operation of the engine load, in response to the output of the load detection means. , and ignition control means for returning to normal ignition timing after a predetermined period of time has elapsed.