JPH0226050B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine idle control device for controlling load fluctuations during idle.

(Prior art) Conventionally, when an external load is applied to the engine during idling operation, for example, due to the operation of a power steering oil pump, a cooler compressor, etc., the idle speed An idle control device is known in which a correction function operates to increase the intake air amount by a predetermined amount (for example, Japanese Patent Application Laid-Open No. 57-59038
(see issue).

However, even in the case where idle control is performed according to the operation of an external load as described above,
When the external load starts operating, there is a slight drop in the idle rotation speed due to an intake delay or the like, and a predetermined time is required to recover from this drop in rotation.
However, if another external load is operated within this time and the load increases further, the drop in the idle speed will increase, the engine speed will become unstable, and the engine will stop. There is a fear that

(Object of the Invention) In view of the above circumstances, an object of the present invention is to provide an engine idle control device that controls large idle speed fluctuations caused by overlapping external load operations during a short period of time during idle. That is.

(Structure of the Invention) The idle control device of the present invention detects the operation of an external load such as a power steering oil pump or a compressor for a cooler during idle, and prohibits the operation of other external loads for a predetermined period of time after the load is activated. The present invention is characterized in that it is provided with a control means for controlling.

(Effects of the Invention) According to the present invention, by prohibiting the operation of other external loads for a predetermined period of time after one external load operates, the number of idle revolutions due to the operation of one external load is reduced. By activating the next external load after the slump has recovered, it is possible to suppress large fluctuations in idle rotation caused by overlapping external load operations within a short period of time, and ensure stability in idle operation. It is something.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
FIG. 1 shows the overall schematic configuration.

The idle control device 1 controls the combustion chamber 3 of the engine 2.
The idle speed is controlled by adjusting the amount of bypass air that bypasses the throttle valve 5 installed in the intake passage 4 that supplies intake air to the engine, and by adjusting the amount of fuel injection from the injector 6.

That is, a bypass air passage 7 that bypasses the throttle valve 5 is provided, a bypass valve 8 is provided that opens and closes this bypass air passage 7 to adjust the amount of bypass air, and the opening degree of this bypass valve 8 is controlled by a linear actuator 9. It is operated by. Furthermore, the amount of fuel injected from the injector 6 installed in the intake passage 4 is adjusted to change the supplied air-fuel ratio.

The crankshaft 11 of the engine 1 has
As an external load driven by the rotational force,
Power steering oil pump 12, cooler compressor 13, power generation alternator 1
4, a torque converter 15 etc. are installed.

The amount of intake air and the amount of fuel supplied by the injector 6 are controlled by the control signal from the control unit 16 by adjusting the opening and closing of the bypass valve 8 in conjunction with the operation of the linear actuator 9. The control unit 16 receives a signal from the idle switch 17 to detect the idle operating state, a signal from the air conditioner switch 18 that instructs the user to operate the cooler, a signal indicating the operating state of the power steering oil pump 12, A signal indicating the power generation state of the alternator 14, a signal indicating the operating state of the torque converter 15, and the like are input, respectively. Further, the operation (drive/stop) of the cooler compressor 13 is controlled by the control unit 16.

That is, the control unit 16
In other words, these external loads are activated according to the operating state of the power steering oil pump 12, the operating state of the torque converter 15, the power generation state of the alternator 14, and the operating state of the cooler compressor 13 caused by the operation of the air conditioner switch 18. By controlling the intake air amount and fuel supply amount during idling in accordance with the increase or decrease in the load acting on the crankshaft 11 of the engine 1 due to the increase or decrease, and increasing the intake air amount and fuel supply amount when the external load increases, This control increases the output in response to an increase in load and maintains the idle speed constant. Further, the control unit 16 operates the cooler compressor 13 when the air conditioner switch 18 is turned on. The system prohibits the operation of the controller and controls the controller to operate after a predetermined period of time has elapsed.

The basic operation is shown in FIG. 2, where A shows the change in the engine speed (idle speed), B shows the change in the intake air amount, and C shows the change in the fuel injection amount. First, the power steering oil pump 12 operates at point a in the idle state, increasing the load and increasing the intake air amount and fuel injection amount, but there is a time delay until the engine output actually increases. As a result, the engine speed decreases. When the air conditioner switch 18 is turned on at point b in the process of lowering the engine speed, if the cooler compressor 13 is activated immediately, the engine speed will further decrease as shown by the broken line due to the increased load. I end up. However, the control unit 16 prohibits the operation of the compressor 13 for a predetermined time T after the operation a of the power steering oil pump 12, and by the time T elapses, the engine The rotation speed will recover. Then, as the predetermined time T elapses, the compressor 1 at point c
3, the intake air amount and fuel injection amount increase accordingly, and the engine speed decreases to 1.
3, the idle speed decreases at the initial stage of operation, but quickly recovers and increases further, and is controlled to a high idle speed in order to increase the cooling capacity of the cooler.

The operation of the control unit 16 will be explained based on the flowchart of FIG. This flowchart shows only the main parts. step
S1 determines whether or not it is idling based on the operation of the idle switch 17, and when YES during idling,
In step S2, it is determined whether an external load other than the cooler compressor 13, such as the power steering oil pump 12, is in operation.
When the external load is ON and is in operation, step S3 is performed to check whether the load is in the state immediately after operation.
It is determined whether or not there has been an increase in the external load other than the cooler compressor 13, and when the load has changed (YES), a timer t for prohibiting the operation of the compressor 13 is set to a predetermined time T.

Once the timer t is set, the next step S3 will be NO and the process will proceed to step S5.
It is determined whether this timer t has reached 0 or not. If timer t has not reached 0, step
After the timer t is decremented in S7, the permission flag F is reset to 0 in step S8.
On the other hand, when the timer t reaches 0 and the determination in step S5 becomes YES, the permission flag F is determined in step S6.
Set to 1. Also, when the operating state is other than idle and the judgment in step S1 is NO, or in step S2, the cooler compressor 13
When the other loads are OFF, the permission flag F is similarly set to 1 in step S9.

When the permission flag F is reset to 0, driving of the compressor 13 is prohibited even if the air conditioner switch 18 is turned on.
That is, step S10 determines the previous state of the air conditioner switch 18, and when it is OFF, step S10 is executed.
In S13, the current state of the air conditioner switch 18 is determined. When the air conditioner switch 18 is turned on for the first time, the process proceeds to step S14 based on the ON determination in step S13, where the permission flag F is set to 1.
Determine whether it is set to . When the timer t is decrementing and the permission flag F is reset to 0, the determination in step S14 is YES.
Wait until . When the predetermined time T set in the timer t has elapsed and the timer t becomes 0 and the permission flag F is set to 1, the step
If the determination in S14 is YES, the compressor 13 is driven in step S15, and in response to this cooler operation, anticipatory control is performed to increase the intake air amount, and fuel correction is performed to increase the fuel injection amount.

Further, if the previous air conditioner switch 18 was ON and the process advances from step S10 to step S11, the current state of the air conditioner switch 18 is determined, and if the current air conditioner switch 18 is turned OFF, the process proceeds to step S12.
At the same time as stopping the driving of the compressor 13,
Estimated correction is performed to reduce the amount of intake air.

On the other hand, when the previous air conditioner switch 18 was ON and the current air conditioner switch 18 is also ON, and
When the previous air conditioner switch 18 was OFF and the current air conditioner switch 18 is also OFF, that is, when the state of the air conditioner switch 18 has not changed, the control state is maintained without changing.

According to the embodiment described above, even if the air conditioner switch 18 is operated, the cooler compressor 13 is not driven for a predetermined period of time after the operation of other external loads, as shown by the broken line in FIG. It is possible to prevent a drop in the idle speed and maintain stable idle operation.

In the above embodiment, the cooler compressor 13 is an example of the external load whose operation is prohibited, but the operation of other external loads that have little effect even if the operation timing is slightly shifted may be similarly prohibited. Good too.

[Brief explanation of drawings]

FIG. 1 is an overall schematic configuration diagram of an engine equipped with an idle control device according to an embodiment of the present invention, and FIG.
Figures A, B, and C are characteristic diagrams showing the control of the intake air amount and fuel injection amount when an external load is applied, and the changes in engine speed associated with this, and Figure 3 is a flowchart diagram for explaining the operation of the control unit. It is. 1... Idle control device, 2... Engine, 4
... Intake passage, 5 ... Throttle valve, 7 ... Bypass air passage, 8 ... Bypass valve, 9 ... Linear actuator, 12 ... Oil pump for power steering, 13 ... Compressor for cooler, 14 ... ...Alternator, 15...Torque converter, 16...Control unit, 17...
...Idle switch, 18...Air conditioner switch.

Claims (1)

[Claims] 1. In an engine idle control device that increases the amount of intake air at idle by a predetermined amount when an external load is applied during idle due to the operation of a power steering oil pump, cooler compressor, etc., the operation of the external load is An engine idle control device comprising a control means for detecting the load and prohibiting the operation of other external loads for a predetermined period of time after the load is activated.