JPS6375330A - Idle rotation control device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an engine stop, by providing a means, changing over a means, controlling the opening of an idle control valve by feedback, to and from a means, controlling the opening of the idle control valve by open loop. CONSTITUTION:An idle control valve 26 is provided for controlling idle rotation of an engine by changing the flow passage area of a bypass passage 25 connected to the upper stream side and the downstream side of a throttle valve 24. A means D is provided for changing over a feedback control means A from and to an open feedback control means B. When an engine load is below a given value, the number of idle revolutions is controlled by means of a feedback control means A. When an engine load exceeds a given value, the number of idle revolutions is controlled by means of an open loop control means B. This constitution, when actuation of a device, increasing an engine load, is completed, prevents decrease of the number of idle revolutions to prevent the occurrence of an engine stop.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for controlling idle rotation by opening a bypass passage connecting an upstream side and a downstream side of a throttle valve.

[Conventional technology and problems]

The idle speed control device controls the idle speed so that it approaches the target value by adjusting the opening degree of the idle control valve installed in the bypass passage, and uses feedback control or open loop control depending on the engine operating state. Control takes place.

Feedback control is when a predetermined condition is met,
Open loop control changes the opening degree of the idle control valve so that the idle speed reaches the target value.
The opening degree of the idle control valve is set to a learned value stored during feedback control to bring the idle rotation speed within a predetermined range.

Now, conventionally, when the power steering device starts operating,
The discharge pressure of the power steering pump increases, and secondary air is introduced into the intake passage to increase engine output accordingly, increasing the idle speed (idle up). At this time, the amount of secondary air introduced is set to be large considering the maximum output of the power steering device, so the idle speed will rise too much, and as a result, the idle control valve will adjust the idle speed in feedback control. control in the direction of occlusion to reduce the Therefore, if the power steering device returns to the non-operating state, the introduction of secondary air as described above is stopped and the idle control valve is closed, so the amount of intake air is insufficient and the idle speed decreases. There is a problem in that the engine speed decreases, idling vibration increases, and there is a risk that the engine will stop.

The present invention aims to prevent the risk of engine stoppage due to increased idle vibration when not only a power steering device but also other devices that increase engine load, such as an air conditioner, complete their operation. .

Note that Japanese Patent Application Laid-Open No. 59-134348 discloses a configuration in which the learning control is stopped when the power steering device is in operation, that is, the learned value is determined when the power steering device is not in operation.

[Means for solving problems]

The idle rotation control device according to the present invention has a configuration shown in the configuration diagram of the invention in FIG. That is, the present invention provides a bypass passage 2 that connects the upstream side and the downstream side of the throttle valve 24.
an idle control valve 26 for controlling the idle rotation of the engine by changing the flow path area of the engine; means B for open-loop control of the opening degree of the idle control valve so that the opening degree is within a predetermined range; means C for detecting the engine load during idle rotation; The feedback control means A and the open loop control means B control the rotation speed, and when the engine load is larger than a predetermined value, the open loop control means B controls the idle rotation speed.
It is characterized by comprising a means for switching.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

FIG. 2 shows an engine having an idle speed control device according to an embodiment of the present invention. A piston 13 is slidably housed in a cylinder bore 12 formed in an engine body 11, and a combustion chamber 14 is formed. It is formed. Intake boat 15
by the intake valve 16, and the exhaust boat 17 by the exhaust valve 18.
They are opened and opened respectively. A fuel injection valve 19 is arranged near the intake boat 15. An air filter 22 and an air flow meter 23 are provided on the most upstream side of the intake passage 21 communicating with the intake boat 15, and a throttle valve 24 is provided on the downstream side thereof. The upstream and downstream sides of the throttle valve 24 are connected by a bypass passage 25, and the flow area of the bypass passage 25 can be changed by an idle control valve 26. The idle control valve 26 is a beam solenoid valve in this embodiment, and its opening degree is adjusted by the control circuit 31 during idle operation, thereby controlling the idle rotation speed. The opening degree of the idle control valve 26 is adjusted depending on the duty ratio of the energization time of the solenoid 27, and is fully closed when the duty ratio is 0% and fully open when the duty ratio is 100%.

The control circuit 31 determines the duty ratio of the energization time of the solenoid 27 of the idle control valve 26, and is composed of a microcomputer. That is, the control circuit 31 includes a microprocessing unit (MPU) 32, a memory 33, an input port 34, an output port 35, and a bus 36 connecting these. Various engine operating condition signals, which will be described later, are input to the input port 34. Output boat 35 is connected to solenoid 27 of idle control valve 26 . The MPU 32 determines the duty ratio of the energization time to the solenoid 27 according to the program stored in the memory 33.

The starter switch 41 rotates the starter when starting the engine, and the 0 rotation speed sensor 42 outputs an ON signal when the starter is driven, and outputs a signal corresponding to the engine rotation speed. Idle operation/Sochi 43 outputs an ON signal when the opening degree of the throttle valve 24 is below a predetermined value, and the vehicle speed sensor 4 outputs an ON signal.
4 outputs a signal according to the vehicle speed. Shift lever sensor 45 is automatic shift 3 of automatic car! ! It is attached to the machine and outputs an ON signal when the shift lever is in the neutral range (N range) or parking range (P range). The air conditioner switch 46 is for driving the air conditioner, and outputs an ON signal while the air conditioner is in operation.

The pump switch 47 outputs an ON signal when the discharge pressure of the pump of the power steering device is above a predetermined value. Water temperature sensor 48 outputs a signal according to the cooling water temperature.

FIG. 3 shows the structure of the pump switch 47. shell 47
A has a diaphragm 47b that connects the pressure change chamber 4F and the atmospheric chamber 4.
7d, the variable pressure chamber 47c is connected to the discharge boat of the pump of the power steering device, and the atmospheric chamber 47d communicates with the atmosphere. A switch member 47e grounded via a lead wire 51 is attached to the diaphragm 47b. A terminal 55 branching from a lead wire 54 connected to the control circuit 31 via a power source 52 and a resistor 53 extends into the atmospheric chamber 47d and connects to the switch member 47.
Opposite e. The spring 47f is provided in the atmospheric chamber 47d,
The switch member 47e is urged in a direction away from the terminal 55. When the discharge pressure of the pump is below a predetermined value, the switch member 47e is disconnected from the terminal 55, so that a 12V voltage signal is input to the control circuit 31.

Conversely, when the steering wheel is turned and the power steering device is activated and the pump discharge pressure exceeds a predetermined value, the diaphragm 47b compresses the spring 47f and is displaced, so the switch member 47e passes through the terminal 55 and the control circuit OV on 31
voltage signal is input. Figure 4 shows pump switch 47
It is understood that a signal of 0 is output when the pump discharge pressure increases as the handle angle increases and exceeds a predetermined value α.

FIG. 5 shows an idle rotation control routine.

This routine is interrupted at predetermined time intervals.

In step 101, it is determined whether f&2 seconds have elapsed since the engine was started. The engine is said to have started when the starter switch 41 changes from the ON state to the OFF state and the engine speed reaches a predetermined value or higher. If 2 seconds have elapsed since starting, the process proceeds to step 102; otherwise, the process proceeds to step 108; in step 102,
It is determined whether two seconds have passed since the idle switch 42 was turned on, that is, whether the throttle valve 24 is closed. If the throttle valve 24 is in the closed state, the process proceeds to step 103; if it is not in the closed state, the process proceeds to step 108.
Proceed to. In step 103, it is determined whether the vehicle speed is 2 Km/h or less, that is, whether the vehicle is substantially stopped. If the vehicle speed is 2 Km/b or less, the process proceeds to Step 104, and if it is greater than 2 Km/Il. Step 1
Proceed to 08. In step 104, it is determined whether two seconds have elapsed since the shift lever of the automatic transmission was set to the N range or the P range.If the determination is affirmative, the process proceeds to step 105, and if the determination is negative, the process proceeds to step 108. In step 105, it is determined whether 2 seconds have elapsed since the air conditioner was turned off. If the determination is affirmative, the process proceeds to step 106; if the determination is negative, step 1
Proceed to 08. In step 106, it is determined whether the power steering system π is substantially moving fP, that is, whether the pump switch 47 is outputting an ON signal.

Step 10 if the power steering device is ON
The process proceeds to step 7, and in the case of an OFF-like layer, the process proceeds to step 108.

That is, the engine is running at idle, set to N or P range in the case of an automatic car, and empty
If the engine is stopped and the power steering device is not operating, the idle rotation is feedback controlled in step 107, and if even one of these conditions is not satisfied, the idle rotation is controlled in open loop in step 108.

The feedback control executed in step 107 is conventionally known and is to duty-control the opening degree of the idle control valve 26 so that the idle rotation speed is maintained at a predetermined value. Here, the duty ratio DtlTY in feedback control is DUTY=DI+DP+DTHIH
-DE+DB ... is given by (1), where DI is an integral term and is determined by the difference between the actual engine speed and the drifting speed, and DP is a proportional term, which is the difference between the actual engine speed and the drifting speed. DTHW is a correction term related to the cooling water temperature, DE is a correction term related to setting to the D range, and DB is a correction term related to the electrical load. On the other hand, the open loop control executed in step 108 is also conventionally known, and is a duty control of the opening degree of the idle control valve 26 so that the idle rotation speed is within a predetermined range. Here, the duty ratio DUTY in open loop control is 0UTY = DC + DTHW + DE + DO・
... is given by (2). Here DG is the learning value,
As is conventionally known, during feedback control, the idle rotation speed is determined to be within a predetermined range.

As mentioned above, feedback control of the idle rotation during operation of the power steering device has conventionally been performed, and in order to reduce the rotation speed that has increased too much due to increased idle, the integral term in equation (1) is D
I and the proportional term DP are controlled to be small, and when the power steering device is stopped, the idle up function ceases to work, causing the problem that the idle speed drops too much. However, in this embodiment, open loop control is performed during operation of the power steering device, and equation (2) is applied to determine the duty ratio DUTY based on the learned value DG. In other words, the duty ratio DIITY does not become small, and the integral term DI and the proportional term DP also do not become small. Therefore, when the power steering device stops operating, the idle speed drops too much and the engine's fir#J becomes large. There is no risk of the engine stopping.

In the above embodiment, open-loop control is performed when the load on the power steering device becomes large, but open-loop control is performed not only on the power steering device but also when the engine load becomes large. Good too.

The above embodiment has a configuration in which idle rotation is controlled in open loop while the power steering device is operating. Therefore, if the set value of the secondary air amount at idle up is too large, the idle speed will increase before entering open loop control I when the power steering device starts operating, resulting in worsening of idle vibration and reduced fuel consumption. It could get worse. In such a case, the control shown in FIGS. 6 and 7 prevents the idle speed from increasing too much while the power steering device is in operation, and also prevents the idle speed from decreasing when the power steering device is stopped. This is to prevent it from becoming too much.

FIG. 6 shows a routine for determining the learned value DG, and this routine is interrupted at predetermined time intervals.

In step 111, it is determined whether the cooling water temperature is 85° C. or higher. If the determination is affirmative, the process proceeds to step 112, and if the determination is negative, this routine is ended.

In step 112, it is determined whether or not feedback control is currently being performed. If feedback control is currently being performed, step 113 is performed.
If open loop control is in progress, this routine ends. In step 113, it is determined whether the discharge pressure of the pump of the power steering device is equal to or higher than a predetermined value.If the determination is negative, the routine proceeds to step 114, and if the determination is affirmative, this routine is ended. In step 114, conventionally known learning control is performed. However, when the power steering device is not substantially operating during feedback control, the learning value DG in the above equation (2) is determined in step 114 so that the idle rotation speed falls within a predetermined range. . That is, at this time, unlike when the power steering device is in operation, the idle is not increased, so the seedling term DI does not become small, and therefore the learning value DG calculated based on the M bone top DI does not become small either.

FIG. 7 shows an idle rotation control routine similar to FIG. 5. This routine is different from the control routine in Figure 5,
If an affirmative determination is made in step 105, step 116 is executed, and the pump switch 4 of the power steering device
Open loop control is performed in step 108 for 2 seconds after 7 is switched from the ON state to the OFF state.
Otherwise, feedback control is performed in step 107. Other processing is the same as the routine shown in FIG.

The control shown in FIGS. 6 and 7 will be explained with reference to FIG. 8. During operation of the power steering system, feedback control is performed, so the duty ratio is reduced by the amount of secondary air supplied by the idle-up action (symbol P).
). Therefore, the idle speed N increases once (symbol Q) due to the effect of idle up, but thereafter it is maintained at the target value (symbol R) and does not increase the idle significantly (symbol S). Also, the learning value D (3
is maintained at the value when the power steering device is stopped by the action of step 113 in FIG. 6 (symbol T).
, never gets smaller. When the power steering device is stopped here, open-loop control is carried out using the learning value DG determined as described above for 2 seconds immediately thereafter (symbol U), so the duty ratio does not become small and the Similar to the control shown in FIG. 5, the rotation speed is prevented from decreasing.

Now, when the power steering device is operating and feedback control of idle rotation is being performed, the above (1)
) The integral term DI in the equation is set small. Therefore, according to only the control shown in FIGS. 6 and 7,
When the open-loop control shifts to the feedback control two seconds after the power steering device stops, the duty ratio DtlTY may be too small and the idle rotation speed may drop. Therefore, by using an integral term correction routine as shown in FIG. 9, the integral term DI can be increased to the learned value DG, thereby preventing the duty ratio DIJTY from decreasing.

This modification routine is interrupted by a predetermined blank number. In step 121, it is determined whether open loop control is currently being performed. During open loop control, that is, within 2 seconds after the power steering device is stopped, the process proceeds to step 122 and subsequent steps to correct the integral term DI.
On the other hand, if feedback control is in progress, this routine ends as is. If the integral term DI is less than or equal to the learned value DG in step 122, this integral term DI is replaced with the learned value DG in step 123. However,
The integral term DI is corrected to the learning value DG or more during about 2 seconds under open loop control. Therefore, when shifting from open loop control to feedback control, there is no possibility that the idle rotation speed will decrease because the integral term DI is small.

In step 113 of FIG. 6, it is determined whether the engine load is equal to or greater than a predetermined value, and in step 116 of FIG. 7, it is determined whether a predetermined time has elapsed since the engine load became smaller than the predetermined value. You can.

〔Effect of the invention〕

As described above, according to the present invention, when the operation of the power steering device or the like that increases the engine load is completed, the idling speed is prevented from decreasing, and there is no possibility that the engine will stop.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the invention, Fig. 2 is a sectional view showing an engine to which an embodiment of the invention is applied, Fig. 3 is a sectional view showing a pump switch, and Fig. 4 is a pump discharge of a power steering device. Graph showing pressure changes and pump switch output signals, Figure 5 is a flowchart showing the idle rotation control routine, Figure 6 is a flowchart showing the learning routine, and Figure 7 is another example of the idle rotation control routine. FIG. 8 is a time chart showing the dynamic ftE under the control shown in FIGS. 6 and 7. FIG. 9 is a flow chart showing the integral term correction routine. 24... Throttle valve, 25... Bypass passage, 26... Idle control valve, 31... Control circuit.

Claims (1)

[Claims] 1. An idle control valve that controls the idle rotation of the engine by changing the flow area of a bypass passage connecting the upstream and downstream sides of the throttle valve, and an idle control valve that controls engine idle rotation to maintain the idle rotation speed at a predetermined value. means for feedback controlling the engine speed, means for open-loop control of the opening degree of the idle control valve so that the idle speed is within a predetermined range, and means for detecting engine load during idle speed;
The above-mentioned feedback control means and an open loop are configured such that the idle speed is controlled by the feedback control means when the engine load is smaller than a predetermined value, and the idle speed is controlled by the open-loop control means when the engine load is larger than the predetermined value. An idle rotation control device comprising: means for switching the control means.