JPS61272443A - Idle revolution speed controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To stabilize an idle revolution speed and prevent the engine stall by installing a load-state detecting means which detects the operation state of the engine load and an engine-state detecting means which detects the state of an internal-combustion engine. CONSTITUTION:A load-state detecting means 28 detects the operation state of the engine load operated in idling operation of an internal-combustion engine. An engine-state detecting means 30 detects the parameter for obtaining the state of the internal-combustion engine. A control circuit 31 varies an aimed idle-revolution speed according to the load state and the engine state. In the engine state after the lapse of a certain time from engine stop, the aimed idle revolution speed is increased. Therefore, the idle revolution speed can be stabilized, and the engine stall can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an idle speed control device for an internal combustion engine used in an automobile or the like.

[Conventional technology]

Generally, in a car, the engine speed at idle is compared with the target idle speed, and the throttle valve opening is changed according to the deviation to control the engine speed to the target speed. Some models are equipped with an idle speed control device to ensure stability.

However, conventional idle speed control devices uniquely set the target idle speed according to the engine load of the near conditioner, power steering, etc., regardless of parameters indicating the engine condition, such as cooling water temperature, and The engine speed was controlled to reach the target speed.

[Problem that the invention seeks to solve]

However, the conventional idle speed control device described above,
When the internal combustion engine is not completely warmed up, or when the engine is started after being completely warmed up and stopped for a certain period of time, or when the engine is in the state for a certain period of time after starting, the idle target rotation speed is controlled according to the engine load. In this case, the actual idle speed becomes unstable or the engine rotation stops.

The present invention has been made in order to solve the conventional problems as described above, and provides an idle speed control device that is stable regardless of engine load or engine condition and does not cause engine rotation to stop. The purpose is to obtain.

[Means for solving problems]

The idle speed control device according to the present invention includes an operating state detection means for detecting the operating state of the engine load that is operated during idling, and a parameter that detects the state of the internal combustion engine, such as the temperature of the cooling water of the internal combustion engine. A timer means that operates (counts up or counts down) when the internal combustion engine starts, or a timer means that operates (counts up or counts down) when the internal combustion engine starts, or a timer means that operates (counts up or counts down) when the cooling water temperature changes from 50 degrees Celsius or lower to 50 degrees Celsius.
It is equipped with a timer means that detects and operates (counts up or down) a change in a parameter that determines the state of the internal combustion engine, such as the above change, and temporarily sets the idle target rotation speed according to the output of this engine state detection means. The number is changed.

[For production]

The system detects the engine condition and changes the target idle speed according to the detected value.If the engine is not warmed up, the target idle speed is increased to stabilize the idle speed, and the engine speed is stabilized. Prevent outage. - [Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In Fig. 1, there is a lid piston, 2 a cylinder, 3 an intake valve, 4 an exhaust valve, 5 an exhaust pipe, 6 a three-way catalytic converter, 7 an intake pipe, 8 a throttle valve, and a throttle valve 8. Venturi 9 and air cleaner 1 are installed on the upstream side of
0 is provided, and the fuel in the 70-tooth chamber 11 is sucked through the main fuel passage 12 and atomized when the intake air taken in through the air cleaner 10 passes through the venturi 9, and is mixed with the intake air. The air becomes air and is guided into the cylinder 2 via the throttle valve 8 and the intake pipe 7. In this case, a main air bleed 13 is provided in the middle of the main fuel passage 12, and the fuel in the float chamber 11 is atomized in advance by intake air from the main air bleed passage 14 provided upstream of the venturi 9, and is atomized into mist. be converted into On the other hand, an idle boat 15 is provided downstream of the throttle valve 8, and a slow air bleed passage 1 is provided upstream of the venturi 9.
6 is provided, and the fuel in the main fuel passage 12 is atomized in the slow air bleed 17 (by the intake air from this slow air bleed passage 16), and the fuel in the main fuel passage 12 is atomized in the slow air bleed 17.
It is discharged from. This ensures that fuel is available during idling when the throttle valve 8 is fully closed. In this case, the amount of fuel discharged from the idle boat 15 is adjusted by the slow adjustment screw 18.

Here, the throttle valve 8 is an accelerator pedal (not shown)
While driving, the opening degree corresponds to the depression of the accelerator pedal tK, and when the accelerator pedal is released and the engine is idling, the opening degree is required to maintain the idling state (almost fully closed). becomes. Also, this throttle valve 8
is provided with a lever 19 on its rotating shaft, and this lever 1
By rotating 9 with the actuator 20, the opening degree at idle can be varied. .

Next, the configuration of the idle rotation speed control system will be explained.

The actuator 20 is composed of a DC motor 21 and a gear mechanism 22. The gear mechanism 22 converts the rotational movement of the DC motor 21 into a linear movement of a plunger 23, and this linear movement drives the lever 19 to open the throttle valve 8. Variable opening. A forward rotation control pulse U and a reverse rotation control pulse D having a predetermined pulse width are applied to the DC motor 21 from a control circuit 30. In this case, the actuator 20 is turned on (closed) when the tip of the plunger 23 is in contact with the lever 19, that is, when the accelerator pedal is released and the accelerator pedal is released.
An idle switch 24 is provided. Also, 25
is a rotational speed detector l) that detects the engine rotational speed, and here a rotational pulse signal having a period corresponding to the engine rotational speed N is extracted from the connection point between the ignition coil 26 and the interrupter 27. 2
Reference numeral 8 indicates an operation start switch for an air conditioner (hereinafter abbreviated as A/C-8W), which is one of the engine loads, and 29 indicates that a transmission (not shown) is in the neutral position or a clutch (not shown). a gear shift switch 30 that detects that the engine and the wheels are disconnected from each other;
31 is a temperature detector that detects the temperature of the engine cooling water, which is one parameter for knowing the engine state; 31 is an idle switch 24 that detects the idle state; and a rotation speed detector 25.
/C・5W28, speed change switch 29 and temperature detector 3
This is a control circuit that controls the throttle valve opening degree during idling based on an output signal of 0, and performs control to converge the engine speed to the target rotation speed No. As shown in FIG. 2, the control circuit 31 includes an arithmetic processing unit (hereinafter abbreviated as CPU) 300.
and memory for storing programs, constants, etc. for idle speed control (hereinafter abbreviated as ROM)
301, a random access memory (hereinafter abbreviated as RAM) 302 for storing intermediate results of calculations, etc., and an interface circuit (hereinafter abbreviated as IFC) 303 for transmitting and receiving signals between the various switches described above and the seven circuit units 20. be done.

Next, the operation of the above configuration will be explained using FIGS. 3 and 4. First, when the engine is started, the CPU 300
Processing as shown in FIG. 3 is executed according to the program stored in the OM 301. That is, the CPU 300 receives the output signal from the rotation detector 25 and measures the period of the signal to detect the current engine rotation speed N.
00), then calculate the target rotation speed No. at idle from the output of AC-8W28 and temperature detector 30 (step 1
01).

This target rotational speed No. is determined by different values depending on the state of the water temperature, which is a parameter indicating the engine state, and when the air conditioner is in the operating state and in the non-operating state, for example, as shown in the table below.

And this idle target rotation speed Not'iROM2O
3 is stored in advance as a constant. Therefore, the calculation is realized by reading this constant from the ROM 301. Next, the CPU 300 determines that the engine rotation speed N is 40 ORPM.
It is determined in step 102 whether or not it is within the control target range of ~1500 RPM, and if it is not within the control target range, the drive mode of the actuator 20 is set to hold mode in step 114, and idle rotation speed control for the actuator 20 is similarly executed. do not. However, N is 40 ORP
If it is within the controlled range of M to 1500 RPM, the output of the speed change switch 29 is determined in step 104 to determine whether the speed change switch 29 is on or not, that is, whether the transmission is in the neutral position or whether the clutch is on. signal), and in step 105 the idle switch 24 is
Determine whether or not is on.

As a result, if the gear shift switch 29 is off, it is assumed that the vehicle is running and the drive mode is set to hold mode in step 114, and even if the gear shift switch 29 is on, the idle switch 24 is turned off. When the accelerator pedal is in the hold mode, the drive mode is set to the hold mode in step 114, assuming that the driver is operating the accelerator pedal.
Idle rotation speed control for 0 is not executed.

However, if the speed change switch 29 is on (in the neutral state or the clutch on state) and the idle switch 24 is on, it is assumed that the main fuel for the engine is being supplied from the idle boat 15, that is, the engine is in an idle state, and the engine is in an idle state. Idle target rotation speed No. at o8
The deviation (absolute value) between the current engine speed N and the current engine speed N is determined, and it is detected whether this deviation is larger than a predetermined value ΔND. If it is smaller, the drive mode of the actuator 20 is set to the hold mode in step 114. However, the deviation is a predetermined value ΔND
If the engine speed is larger than the target speed, an idle speed control process is performed in steps 109 to 113 to converge the engine speed N to the target speed No. That is, in step 109, the current engine rotation speed N is compared with the target rotation speed, No. If NO>N, it is necessary to control the opening degree of the throttle valve 8 to the opening side, so the drive mode of the actuator 20 is set to the opening side. On the other hand, if No<N, it is necessary to control the opening of the throttle valve 8 to the closing side, so the drive mode of the actuator 20 is set to the closing mode (Step 111). ). After this, step 112
The drive time data Pw'l of the actuator 20 corresponding to the deviation No-N is read out from the ROM 301. The relationship between Pw and No N is, for example, as shown in Figure 4, as No N or N No increases, pw
It is determined that the relationship increases almost proportionally. In this way, drive time data Pw of the actuator 20 corresponding to the deviation between the idle target rotation speed No. and the current engine rotation speed N.
When obtained, in step 113, the CPU 300 causes the IFC 303 to generate a forward rotation control pulse U or fc or a reverse rotation control pulse D for driving the actuator 20 in the direction corresponding to the drive mode for a time corresponding to Pw. In this case, when the drive mode is on the open side, a forward rotation control pulse U is generated, and on the contrary, when the drive mode is on the close side, a reverse rotation control pulse D is generated. As a result, the throttle valve 8 is set to an opening degree corresponding to the target engine speed No during idling, and the engine speed N converges to the target engine speed No. After this, the CPU 300 again performs step 100.
The subsequent processing is repeatedly executed, and after a certain hold time TH has elapsed, nine control pulses are generated in response to the change in the rotational speed at that time.

As described above, the engine rotation speed N is maintained at the target rotation speed No by controlling the opening of the throttle valve 8 corresponding to the deviation between the target rotation speed No. and the engine rotation speed N, that is, by using the feedback control button. However, in the above operation, the idle target rotation speed K
As shown in FIG. 5, the maintained engine speed is determined by the state of the coolant temperature because the coolant temperature, which is a parameter that determines the state of the internal combustion engine and the warm-up state of the special button, is input to the control circuit 31. Even though no change in load is detected, the idle target rotation speed No. is processed and changed in step 101. In other words, as shown in the previous table, when the near conditioner is off and the water temperature is below 50°C, the engine speed is maintained at the target idle speed of 900 rpm, but when the near conditioner is off and the water temperature is above 5°C, the engine speed changes to the idle target speed. When the rotational speed changes to 70 Orpm, the reverse rotation control pulse D is output as a result of the processing in steps 102 to 113, so that the rotational speed converges to the changed target idle rotational speed.

In this grafted embodiment, by inputting the cooling water temperature, which is a parameter indicating the state of the internal combustion engine, particularly the warm-up state, to the control circuit 31, the idle target rotation speed is increased independently of the engine load, and the engine is completely warmed up. It is possible to stabilize the engine rotation speed at the time of starting the engine when the engine is not warmed up, or after leaving it for a certain period of time after being completely warmed up, or for a certain period of time after starting, and to prevent the engine rotation from stopping.

In the above embodiment, the state of the internal combustion engine, particularly the warm-up state, is known based on the cooling water temperature, but the engine state may also be known based on the piston temperature of the internal combustion engine. Also, when changing the target idle rotation speed, for example, if the cooling water temperature is 5.
Calculate in advance the time required for the temperature to rise from below 0°C to over 50°C, and use 100N after starting! A parameter such as c that can be substituted for the engine state may be set by a timer means. Of course, a timer means that operates according to changes in the machine open state may be used.

〔Effect of the invention〕

As described above, in the present invention, a means for detecting a parameter that indicates the state of the internal combustion engine is provided, and the target idle rotation speed is temporarily changed based on the value of this parameter. Therefore, the target idle speed can be increased in an engine state that has not been completely warmed up or after the engine has been completely warmed up, stopped and left for a certain period of time, and the idle speed can be stabilized. This can prevent engine rotation from stopping.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the device of the present invention, and FIGS. 2 and 3 are the F! FIG. 4 is a block diagram and flowchart of the control circuit related to AK, FIG. 4 is a drive time characteristic diagram of the actuator according to the present invention, and FIG. 5 is a time chart showing the operation of each part of the device of the present invention. 20... Actuator, 24... Idle switch, 25... Rotation speed detector, 28... Operation start switch (load state detection means), 30... Temperature detector (engine state detection means), 31...control circuit. Note that the same reference numerals in the drawings indicate the same or similar parts. Agent Masuo Oiwa Figure 2 Figure 4 Figure 5 = (d) Pulse U (e) Ha Lus O Procedural amendment (voluntary)

Claims (4)

[Claims] (1) a rotation speed detection means for detecting the engine rotation speed; an idle rotation speed setting means for setting a target idle rotation speed;
Equipped with an idle state detection means for detecting the idle state of the engine, the engine speed is compared with the target idle speed when the engine is idling, and the engine operating parameters are changed according to the deviation to set the engine speed to the target idle speed. In the idle speed control device for an internal combustion engine that controls the number of revolutions, the system includes a load state detection means for detecting the operating state of an engine load that is activated when the engine is idling, and an engine state detection means for detecting a parameter that determines the state of the internal combustion engine. An idle speed control device for an internal combustion engine, characterized in that the target idle speed is changed according to the load condition and the target idle speed is changed according to the value of a parameter that determines the engine condition. . (2) The idle speed control device for an internal combustion engine according to claim 1, wherein the engine state detection means detects the engine cooling water temperature or the engine internal temperature. (3) The idle speed control device for an internal combustion engine according to claim 1, wherein the engine state detection means is constituted by a timer means that is activated when the internal combustion engine is started. (4) The idle speed of the internal combustion engine according to claim 1, characterized in that the engine state detection means is constituted by a timer means that operates when a parameter for determining the engine state reaches a predetermined value. Control device.