JPH03182663A - Number of idle revolutions control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve operability by performing open control of a control valve by means of a duty value stored as a learning value forming a fixed value when one of given number of idle revolutions control conditions is not established. CONSTITUTION:When all of a condition wherein a given number of idle revolutions control condition is established, a condition wherein the number of revolutions of an engine is in a given number of revolutions area between the numbers of revolutions on the slight increase side and decrease side with the target number of idle revolutions therebetween set according to a cooling water temperature, and a given duty value learning condition are established, a control part 16 stores a duty value responding to a cooling water temperature as a learning value when feedback control is effected on a control valve 14. When one of given number of revolutions control conditions is not established, open control is made on the control valve 14 by means of a duty value stored as the learning value forming a fixed value. This constitution controls the number of revolutions of an engine to a value proper to a cooling water temperature, prevents production of a fluctuation useless to the number of revolution, and stabilizes the number of revolutions of an engine.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an idle speed control device for an internal combustion engine,
In particular, an internal combustion engine that can control the engine speed to an appropriate engine speed with respect to the cooling water temperature when the control valve installed in the bypass passage that bypasses the intake throttle valve in the intake passage of the internal combustion engine is controlled to open using a fixed duty value. The present invention relates to an idle rotation speed control device.

[Conventional technology]

Some internal combustion engines are equipped with an idle speed control device to control the idle speed. The idle speed control device is provided with a bypass passage that bypasses an intake throttle valve in an intake passage of an internal combustion engine, and a control valve that is controlled by a duty value is provided in this bypass passage, and when a predetermined idle speed control condition is satisfied. Then, the control valve is feedback-controlled by the duty value so that the engine speed becomes a target idle speed set according to the cooling water temperature. This increases or decreases the amount of air passing through the control valve,
Controls the engine speed to the target idle speed.

An example of such an idle speed control device for an internal combustion engine is disclosed in Japanese Unexamined Patent Publication No. 64-69753.

The idle speed control device disclosed in this publication detects the load of the variable displacement compressor in an internal combustion engine equipped with an air conditioner system having a variable displacement compressor, and adjusts the amount of intake air during idling operation according to this load. At the same time as setting the correction amount, the target value for feedback control of the idle speed is lowered by a predetermined amount, thereby correcting the idle speed according to the load on the variable capacity compressor and improving the fuel consumption rate. It is something that

[Problem that the invention seeks to solve]

By the way, as described above, the conventional idle speed control device performs feedback control of the control valve based on the duty value when a predetermined idle speed control condition is satisfied. Further, if any one of the predetermined idle speed control conditions is not satisfied, the control valve is controlled to open using a fixed duty value. In other words, if any one of the predetermined idle speed control conditions is not satisfied, for example, if the coolant temperature is lower than the set temperature and exceeds the vehicle speed or control start vehicle speed, the clutch is disengaged (idle switch (0FF), the control valve is controlled to open using a fixed duty value.

However, when the control valve is controlled to open using a fixed duty value, the amount of air that passes through the control valve that is controlled to open is equal to the amount of air that passes through the air regulator that bypasses the intake throttle valve in the intake passage of the internal combustion engine. Due to the addition, a problem occurred in which the engine speed increased unnecessarily from the target idle speed. In addition, since the duty value for controlling the control valve to open is a fixed value, the problem of the engine speed dropping unnecessarily from the target idle speed due to compressor load addition or electrical load addition when the air conditioner system is activated after warm-up is avoided. occured. Furthermore, there is a problem in that the engine speed is greatly affected due to variations in the control valves and the like.

For this reason, it is difficult to control the engine speed to an appropriate level in relation to the cooling water temperature, and unnecessary fluctuations in the engine speed may make the driver feel uncomfortable. Vehicles equipped with a transmission have the inconvenience of running even when the accelerator pedal is not depressed, and the drop in engine speed may cause the engine to stall or stop. There is a problem in that the engine speed is greatly affected by variations in the control valves, etc., resulting in poor drivability.

[Purpose of the invention]

Therefore, an object of the present invention is to maintain an appropriate engine speed for the cooling water temperature when performing open control using a duty value with a fixed value for a control 9n valve provided in a bypass passage that bypasses an intake throttle valve in an intake passage of an internal combustion engine. This prevents unnecessary fluctuations in the engine speed, stabilizes the engine speed, eliminates the inconvenience that makes the driver feel uncomfortable, and improves the driving feeling. Therefore, it is possible to prevent the inconvenience of a vehicle equipped with an automatic transmission driving even though the accelerator pedal is not depressed, and also to prevent the occurrence of engine stall or engine stop. An object of the present invention is to realize an idle speed control device for an internal combustion engine that can reduce the influence on the engine speed caused by variations in valves, etc., and improve driveability.

[Means for solving problems]

In order to achieve this object, the present invention aims to throttle the intake passage of an internal combustion engine so that when a predetermined idle speed control condition is met, the engine speed reaches a target idle speed set according to the cooling water temperature. Cooling during feedback control of the control valve when a predetermined duty value learning control condition is satisfied in an idle rotation speed control device for an internal combustion engine that performs feedback control of a control valve provided in a bypass passage that bypasses the valve based on a duty value. The duty value corresponding to the water temperature is stored as a learned value, and when any one of the predetermined idle rotation speed control conditions is not satisfied, the control valve is determined by the duty value with the stored learned value as a fixed value. According to the structure of the present invention, the control means provides feedback control of the control valve when a predetermined duty value learning control condition is satisfied. A duty value corresponding to the cooling water temperature is stored as a learned value, and when one of the predetermined idle rotation speed control conditions is not satisfied, the control valve is activated using the duty value with the stored learned value as a fixed value. By controlling the engine speed, the engine speed can be controlled to be appropriate for the cooling water temperature.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

1 to 9 show embodiments of this invention.

In FIG. 1, 2 is an internal combustion engine, and 4 is an idle speed control device. The idle speed control device 4 bypasses the intake throttle valve 8 provided in the intake passage 6 of the internal combustion engine 2, and controls the intake passage 6-1 on the upstream side and the intake passage 6-1 on the downstream side of the intake throttle valve 8.
A bypass passage 12 is provided which communicates with the second surge tank IO.

This bypass passage 12 is provided with a control valve 14 for bypass air amount control controlled by a duty value.

The control valve 14 increases or decreases the amount of bypass air passing through the bypass passage 12, and feedback control is performed using the duty value so that the engine speed reaches the target idle speed set according to the cooling water temperature as shown in FIG. do.

This control valve 14 is connected to a control section 16 that is a control means. The control unit 16 includes a temperature sensor 18 that detects the temperature of the cooling water of the internal combustion engine 2, a rotation speed sensor 20 that detects the engine speed, and a sensor that turns on when the opening of the intake throttle valve 8 is at the idle opening. An idle switch 22 that turns off when the opening is equal to or higher than the idle opening is connected to a vehicle speed sensor 24 that detects the vehicle speed. As a result, the control section 16
As shown in FIG. 3, the control valve 14 is feedback-controlled by the duty value so that the engine speed becomes the target idle speed set according to the cooling water temperature below the control start speed.

This idle speed control device W4 includes an idle switch 2
The opening degree of the intake throttle valve 8 detected by No. 2, the vehicle speed detected by the vehicle speed sensor 24, and the engine rotation speed detected by the rotation speed sensor 20,
When all of the predetermined idle speed control conditions are satisfied, the control valve 14 is feedback-controlled by the duty value so that the engine speed becomes the target idle speed.

That is, as shown in FIG. 4, the control unit 16 determines the conditions under which the idle switch 22 is turned on, the opening of the intake throttle valve 8 becomes the idle opening, and the re-delay time has elapsed (idle switch ON+delay time), and the vehicle speed. A condition in which the vehicle speed detected by the sensor 24 is less than the control start vehicle speed (vehicle fast, control start vehicle speed), and a condition in which the engine speed detected by the rotation speed sensor 20 is less than the control start speed (engine speed <control start speed). When both of the predetermined idle speed control conditions IJ? Do n.

In addition, as shown in FIG. 4, this control unit 16 operates under the condition that the opening of the intake throttle valve 8 is at the idle opening (idle switch ON) and that the engine speed is slightly higher than the target idle speed. Even if both the condition for descending to the rising target idle speed (engine speed <target idle speed + α) and the predetermined idle speed control condition are satisfied, each of the vehicle speed and engine speed Regardless of whether or not the idle speed control conditions ((vehicle speed, vehicle speed, control start speed), (engine speed - control start speed)) are not met, the control valve 14 is controlled by the duty value so that the engine speed becomes the target idle speed. Feedback control.

Furthermore, if any one of the idle speed control conditions is not satisfied, for example, if the vehicle speed is equal to or higher than the control start vehicle speed, the control unit 16 controls the control valve 14 with a fixed duty value. Oven control.

That is, as shown in FIG. 5, the control unit 16 controls the condition under which the predetermined idle speed control condition is met (idle speed control is in progress) and the target idle condition in which the engine speed is set according to the cooling water temperature. Both of the condition that the rotation speed is within a predetermined rotation speed range between the rotation speed on the small allowable rising side and the rotation speed on the small allowable machining side with the rotation speed in between (engine speed ≦ target idle rotation speed ±χ), and the predetermined duty value learning control condition. is satisfied, the duty value corresponding to the cooling water temperature when performing feedback control of the control valve 14 is stored as a learned value, and if any one of the predetermined idle rotation speed control conditions is not satisfied. The control valve 14 is controlled to open using a duty value with the stored learning value as a fixed value.

The learning value is stored as shown in FIG. 6.7. That is, each storage area of the learning value a is provided for each cooling water temperature and is stored therein. If the existing cooling water temperature falls between the divided cooling water temperatures in the storage area of learning value a, as shown in Figure 9, the existing cooling water temperature is determined from the already stored learning value. The learning value to be calculated is obtained by interpolation, and the difference between that value and the duty value of the existing learning value storage area is stored and updated in the learning value storage area located before and after the learning value storage area.

Further, in FIG. 1, reference numeral 26 is an air regulator. The air regulator 26 opens and closes an air passage 30, which is provided bypassing the intake throttle valve 8, according to the temperature of the cooling water, using an air valve 28 that operates using the displacement of a temperature-sensitive displacement body such as thermowax. This corrects the amount of air flowing into the intake passage 6-2 on the downstream side of the intake throttle valve 8. Further, reference numeral 32 is a combustion chamber, 34 is an exhaust passage, and 36 is a buff outlet.

Next, the operation will be explained according to Fig. 8.9.

As shown in FIG. 8, the idle speed control device 4 is controlled by the control unit 6 when the control is started (100), the internal combustion engine 2 is started (101) L, and the idle switch 22 is turned O.
Determine (103) whether or not it is N (102). Then, idle switch 22 is turned on (103: YES
), it is determined (105) whether the idle speed control condition is satisfied (104).

If this determination (105) is YES, that is, the condition that the intake throttle valve 8 degrees becomes the idle opening due to the idle switch 22 being turned on and the delay time has elapsed (idle switch ON+delay time) and the vehicle speed detected by the vehicle speed sensor 24. The predetermined condition is that the engine speed is less than the control start vehicle speed (vehicle speed is faster than the control start speed) and the condition that the engine speed detected by the speed sensor 20 is less than the control start speed (engine speed (control start speed)). When all of the idle speed control conditions are satisfied, the control valve 14 is feedback-controlled according to the duty value so that the engine speed becomes the target idle speed (106).

Also, the condition that the opening degree of the intake throttle valve 8 is the idle opening degree (
Idle speed (idle switch ON) and the condition that the engine speed falls to the rising target idle speed that is slightly higher than the target idle speed (engine speed (target idle speed 10 α)). Even if all of the idle speed control conditions are satisfied, each of the idle speed control conditions for the vehicle speed and engine speed ((vehicle speed at which vehicle speed starts to be controlled quickly) and (starting speed when control starts at engine speed))) is not satisfied. regardless of,
Control valve 1 so that the engine speed reaches the target idle speed.
4 is feedback controlled by the duty value 1l (10
6) Do.

Then, it is determined (107) whether the duty value learning control condition is satisfied (10B).

If No in this determination (108), step 1
Return to 07. On the other hand, in judgment (108)
ES, that is, the condition where the idle speed control condition is satisfied (during idle speed control), and the engine speed is a slightly increasing speed and a slightly decreasing speed between the target idle speed set according to the cooling water temperature. The control valve 14 is feedback-controlled when both the condition (engine speed ≦ target idle speed χ) within a predetermined rotation speed range between the above and the predetermined duty value learning wI control condition are satisfied. The duty value corresponding to the actual cooling water temperature is set as a learning value,
As shown in FIG. 6.7, the information is stored and stored in each storage area for each cooling water temperature, and the process returns to step 102.

At this time, if the cooling water temperature is between -30°C and -20°C, which are divided into 25°C, for example, the control is started (200) as shown in Figure 9. Then, the cooling water temperature is determined (201), and the already stored learning values a and a are calculated.

Find the learned value corresponding to the current cooling water temperature of -25°C by interpolation (202), and find the difference from the previous learned value (202).
203), the difference between the value obtained by the interpolation and the existing learning value is stored in the learning areas ao and al located around -25° C. and updated (204).

In step 103, the idle switch 22 is turned to O.
In the case of FF (1037No), also step 105
If any one of the idle rotation speed control conditions is not satisfied (105: No), step 109 is executed.

In step 109, if any one of the idle speed control conditions is not satisfied, the control valve 14 is controlled to open based on a duty value with the stored learned value corresponding to the cooling water temperature as a fixed value.

In this way, the control unit 16 stores the duty value corresponding to the cooling water temperature when feedback-controlling the control valve 14 when a predetermined duty value learning control condition is satisfied as a learned value, and adjusts the duty value to a predetermined idle rotation speed. When any one of the control conditions is not satisfied, the control valve 14 is controlled to open using a duty value with the memorized learning value as a fixed value, thereby controlling the engine speed to be appropriate for the cooling water temperature. be able to.

Therefore, it is possible to prevent unnecessary fluctuations in the engine speed when controlling the control valve 14 to open using the fixed duty value, and it is possible to stabilize the engine speed. This can eliminate inconveniences that make the driver feel uncomfortable and improve the driving feeling. Furthermore, by being able to absorb variations in control valves, etc., it is possible to reduce the influence on engine speed caused by variations. Drivability can be improved.

〔Effect of the invention〕

As described above, according to the present invention, when a predetermined duty value learning control condition is satisfied, the control means stores the duty value corresponding to the cooling water temperature when performing feedback control of the control valve as a learned value, and If any one of the idle speed control conditions fails, the control valve is controlled to open according to the duty value with the stored learned value as a fixed value, so that the engine speed is adjusted to an appropriate engine speed for the cooling water temperature. can be controlled.

Therefore, it is possible to prevent unnecessary fluctuations in the engine speed when controlling the control valve to open using the fixed duty value, and to stabilize the engine speed.

This can eliminate inconveniences that make the driver feel uncomfortable and improve the driving feeling. Furthermore, by absorbing variations in control valves, etc., the influence on engine speed caused by variations can be reduced. drivability can be improved.

[Brief explanation of drawings]

1 to 9 show embodiments of the present invention, FIG. 1 is a schematic configuration diagram of an idle speed control device, FIG. 2 is a diagram showing the relationship between cooling water temperature and target idle speed, and FIG. 3 is a diagram showing the relationship between cooling water temperature and target idle speed. FIG. 4 is a logic circuit diagram showing the idle speed control conditions, and FIG. 5 is a logic circuit diagram showing the duty value learning control conditions. , FIG. 6 is a diagram showing the relationship between the learned value and the cooling water temperature and the duty value, FIG. 7 is a diagram showing the relationship between the cooling water temperature and the learned value, FIG. 8 is a flowchart of idle rotation speed control, and FIG. FIG. 9 is a flowchart of learning control. In the figure, 2 is an internal combustion engine, 4 is an idle speed control device, 6 is an intake passage, 8 is an intake throttle valve, 10 is a surge tank, 12 is a bypass passage, 14 is a control valve, 16 is a control unit, and 18 is a temperature The sensors include a rotation speed sensor 20, an idle switch 22, and a vehicle speed sensor 24.

Claims (1)

[Claims] 1. Provided in a bypass passage that bypasses the intake throttle valve in the intake passage of the internal combustion engine so that when a predetermined idle rotation speed control condition is met, the engine rotation speed becomes the target idle rotation speed set according to the cooling water temperature. In an idle rotation speed control device for an internal combustion engine that performs feedback control of a control valve using a duty value, the duty value is set according to a cooling water temperature when the control valve is feedback-controlled when a predetermined duty value learning control condition is satisfied. A control means is provided that stores the learned value as a learned value and controls the control valve to open according to a duty value with the stored learned value as a fixed value when any one of the predetermined idle rotation speed control conditions is not satisfied. An idle speed control device for an internal combustion engine, characterized in that: