JPS61152938A - Idling speed controlling device of engine - Google Patents

Abstract

PURPOSE:To reduce changes in idling speed of an engine by installing a driving time adjustment device to shorten the pulse width of pulse voltage supplied from an idling speed controlling device to a throttle valve opening adjusting device at the given time. CONSTITUTION:An opening adjusting device 5 adjusts the closing position of a throttle valve 2. An idling speed controlling device 8 moves the closing position of the throttle valve 2 so that a detected engine speed may become closer to a targeted engine speed. A driving time adjusting device 9 is installed to gradually shorten pulse width of pulse voltage supplied to the opening adjusting device 5 from the idling speed controlling device 8 in the case that hunting occurs due to the operation of the idling speed controlling device 8 at the time of idling. The possibility of hunting can thus be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to an idle speed control device mainly applied to an automobile engine.

[Prior Art] Modern automobile engines are equipped with various systems to improve fuel economy, one of which is an idle speed control device. Not a few.

However, prior art related to this type of control device is disclosed in, for example, the previously filed Japanese Patent Application No. 135522/1983. That is, this device receives a pulse voltage supply and adjusts the closing and position of the throttle valve during idling.
), a rotation speed detection means for detecting the rotation speed of the engine, and a rotation speed detection means for driving the opening adjustment means based on a comparison between a detected value by the rotation speed detection means and a target rotation speed to detect the rotation speed of the engine. The idle rotation speed control means moves the closing position of the throttle valve in a direction in which the value approaches the 14 standard rotation speed.

For something like this, idol [! The control of the ld turning pot is performed, for example, as follows.

As shown in FIG. 7, first, in step 51, the idle switch is turned ON-OFF, the engine speed ME, the vehicle speed,
Based on detected values such as throttle opening, it is determined whether the engine is in an idling state, that is, whether conditions for F/B control (idle rotation speed control) are satisfied. If it is determined that it is in the idling state, the control cycle counter CCDL (a counter that measures the elapsed time from the previous F/B control) is set to the drive cycle TDNF in step 52.
It is determined whether or not the time is longer than Z (for example, 1 second). Then, the control cycle counter C00L indicates the drive cycle TDNFZ.
If the above is the case, proceed to step 53 and turn on the engine rotation.
E,! -The difference from the target rotation speed NEGET is the dead zone Nt (
For example, it is determined whether the speed is greater than 2° rpm.

If the difference is greater than the dead zone N, step 5
4, the ISO driving time Kl(I
Select the pulse width of the pulse voltage supplied to the SO.

Then, in step 55, the ISO is driven for a KI time to drive the closing position of the throttle valve in a desired direction. Further, in step 56, the control periodic force wanta GG
Clear the DL and then return to step 51. In addition, F
/8 control condition is not satisfied (step 51), control cycle counter CCDL is less than drive cycle TDNFZ (step 52)
), or engine speed MK and target speed NEGE
If the difference in T is greater than the dead zone Ml "F" (step 53), step 5 is performed without driving the Isc.
Return to 1. Then repeat the above steps.

However, with just this, a periodic external load acts on the engine during idling, and the period of the action matches the ISC drive period in the idle speed control, and the KI is relatively long. In this case, the stability of the control may be impaired and hunting may occur.

That is, during idling, for example, the alternator may periodically repeat activation and deactivation, and in this case, while the alternator is in operation, an external load is applied to the engine, causing the engine speed to drop slightly. As a result, the idle rotation speed control means detects this rotation speed drop and drives the opening adjustment means to move the closed position of the throttle valve in the opening direction so as to return to the target rotation speed. However, in order to ensure reliability of control, the opening adjustment means is driven periodically at fixed time intervals called a drive period TDNFZ, so that the opening adjustment means is driven by changes in engine rotational speed. The throttle valve does not respond immediately, and the movement of the throttle valve in the opening direction is performed after a certain amount of time has elapsed after the engine speed has decreased. Therefore, when the engine speed has recovered to near the target speed, the alternator stops operating, the external load is lightened, and the engine speed may rise beyond the target speed. At this time, the idle rotation speed control means detects the increase in the rotation speed and drives the opening adjustment means to move the closing position of the throttle valve in the closing direction so as to return to the target rotation speed, thereby lowering the engine rotation speed. . However, if the drive cycle of the opening adjustment means matches the operating cycle of the alternator and the drive time is long, the alternator will start operating again when the engine speed drops to near the target speed. As an external load is applied to the engine, the throttle valve moves significantly, so the external load causes the engine speed to drop significantly below the target speed, and even after that, the engine speed remains stable. So-called hunting, which repeats rising and falling, occurs, and this hunting occurs when the alternator is turned on and off during idling.
Both the OFF cycle and the drive cycle of the idle rotation speed control device maintain the above-described constant synchronization relationship with the IS.
This will continue as long as the O drive time is relatively long.

[Problems to be solved by the invention] The present invention has been made with attention to these circumstances, and
It is an object of the present invention to provide an engine idle speed control device that can effectively eliminate the hunting described above.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention adjusts the closing position of the throttle valve (2) by controlling the idle speed control device of the engine in response to the supply of pulse pressure. An opening adjustment means (5) and a rotation speed detection means (5) for detecting the engine rotation speed.
26) and a direction in which the detected value approaches the target rotational speed by periodically driving the opening a node means (5) based on a comparison between the detected value by the rotational speed detection means (26) and the target rotational speed. The idle speed control means (8) moves the closing position of the throttle valve (2), and hunting occurs in the operation of the opening degree control means (5) due to the control of the idle speed control means (8). In this case, the idle speed control means (
8) to the opening adjustment means (5), the driving time Iul adjustment means (9) gradually shortens the pulse width of the pulse voltage supplied to the opening adjustment means (5).

[Function J If the structure is as described above,) If the opening occurs, the driving time adjusting means (9) will operate and the opening degree adjusting means ( Since the pulse width of the pulse voltage supplied to 5) is gradually shortened, the amount of movement of the throttle valve (2) decreases as the opening is adjusted, so that the engine speed changes due to idle speed control. The amount decreases and the above-mentioned I\inching is eliminated.

[Examples] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In the figure, 1 is a carburetor of an automobile engine, 2 is a throttle valve, 3 is a rotating part of the throttle valve 2, and 4 is a spring that biases the throttle valve 2 in the closing direction. 5 is an opening degree m that locks the rotating part 3 of the throttle valve and adjusts the closed position of the throttle valve 2.
The Ii means 6 is an idle switch provided in connection with the opening adjustment means 5. The rotation part 3 is lever-shaped and rotates together with a support shaft 2b that supports the throttle valve body 2a. It looks like this. Also.

The opening degree adjusting means 5 includes a feed screw fi13 provided on the output shaft 12 of the DC motor 11, and a cap nut-shaped actuator 14 screwed into the feed screw portion 13.
By operating the actuator 14 in response to a signal from the idle speed control means 8, the actuator 14, whose rotation is prohibited by a guide member (not shown), is screwed back and forth in the axial direction. Further, the idle switch 6 has a movable contact 15 that is provided so as to be movable back and forth together with the actuator 14 of the opening adjustment means 5, and the movable contact 15 is connected to a stationary contact 16.
This is an O/OFF switch that can be switched between ON and OFF by connecting and separating the switch. Here, the DC motor 11 is intermittently driven by being supplied with a pulse voltage. The output shaft 12t*IM is held so that it can move forward and backward a certain distance in the axial direction with respect to the frame 1B, and a spring (not shown) that is much weaker than the spring 4 is attached to the front. (downward in the figure). Also, the actuator 1 screwed onto this output shaft 12
4 is adapted to lock the rotating portion 3 at its tip 14a. Further, numeral 21 is a system for controlling the opening degree adjusting means 5, and serves as the idle speed adjusting means 8 and the drive time adjusting means 9. This microcomputer system 21 includes a central processing unit (CPU) 22 and a memory 2.
3 and interfaces 24 and 25.

The interface 24 receives at least the signal a from the idle switch 6 and the rotation speed detection means 26.
signal b from the transmission state detection means 27, signal d from the water temperature sensor 28, signal e from the vehicle speed sensor 29, and signal f from the throttle opening sensor 31. wA toward the opening adjustment means 5! tl+＠g is output.゛The rotation speed detection means 26 is
It is used to detect the engine speed, and uses, for example, ignition pulses. Also.

The transmission state detection means 2'/ is for detecting whether or not the transmission state between the engine and the driving wheels is disconnected. This corresponds to a neutral switch, etc. that is switched when the motor is shifted to the neutral position.

The water temperature sensor 28 is for detecting the engine cooling water temperature, and includes, for example, a thermistor that converts the water temperature into an analog electrical signal, and an A/D converter that converts the output of this thermistor into a digital signal. S (not shown). Further, the throttle opening sensor 31 includes a potentiometer that converts the opening of the throttle valve 2 into an analog electrical signal, and an A/D converter (not shown) that converts the output of this potentiometer into a digital signal. .

And, the microcomputer system 21 is @
It is programmed to operate according to the procedures schematically shown in FIGS. 3 and 4.

In the main routine shown in FIG. 3, in step lO1, signals a and b from at least the idle switch 6, the rotation speed detection means 26, the transmission state detection means 27, the water temperature sensor z8, the vehicle speed sensor 29, and the throttle opening sensor 31 are detected. , c, d, e, f, then step 1
In 02, the power '77ri (licLLIsG(a・r
It is determined whether the elapsed time since the idle switch 6 is turned ON (if the idle switch 6 is OFF, it remains zero and does not increase) is less than 5 seconds, and in step 103, the vehicle speed sensor 29 detects the elapsed time. It is determined whether the vehicle speed is, for example, 2.8 min/hr or more, and in step 104 it is determined whether the transmission system is in the transmitting state. Then, the conditions in each of these steps 102 to 104 are all NO.
If so, the process moves to step 105. On the other hand, if any of the conditions is YES, step 101
Return to In step 105, a subroutine for driving time change processing shown in FIG. 4 is executed, and the process moves to step 108. In step 106, it is determined whether the control cycle counter C00L is equal to or greater than the drive cycle TDNFZ (the time from the previous drive of the opening adjustment means 5 to the start of the next !% movement, for example 1 second). Then, the control period counter C00
If L is greater than or equal to the drive period TDNFZ, step 107
The difference between the detected engine speed ME and the target idle speed (8GO rpm) is incorrect! ! ! Emperor (20
rp layer). Note that the memory 23 stores the difference between the engine speed NK and the target idle speed (
I is mapped and stored in advance at the time when the ISO is to be driven in relation to the size of the rotational speed deviation (ME). If the difference between the detected engine speed HE and the target idle speed (800 rpm+) is greater than 2 Orpm, then in step 10B.

Based on the map, select a time Kl for driving l5C5 according to the magnitude of the difference, and wipe this selected value,
In step 109, the DC motor 11 of the ISC 5 is driven. The actual driving time S (pulse width) at this time is the value obtained by correcting the time Kl for driving the ISC 5 using the variable NX (initial value is 0) for changing the driving time.
1÷NX). Therefore, if the variable NX is O, the actual driving time S is Kl. And step 1
After clearing the control period counter GGOL in step 10, the process returns to step 101.

Further, sub-processing of the drive time changing process shown in FIG. 4 is performed.

First, in step 151, the F/8 condition is met (the judgment results of the staves 102, 103, and 104 are all NO).
It is determined whether 10 seconds or more have elapsed since If 10 seconds or more have elapsed, it is determined that the F/B control is being performed stably and the process moves to step 152, where it is determined whether the sampling counter value CSAMPL is greater than or equal to the sampling time TSAMPL (for example, 10 seconds). to judge. If the counter value C5tAMPL is less than the sampling time TSAMPL, step 1
53, the engine speed NE is the minimum value NEWIN(
The initial value is 8 GO rpm) or more.

If the detected engine speed NE is smaller than the already stored minimum value (fiNEMIN), in step 154, the engine speed is set to the minimum value NEMIN.

Input the value of the detected engine rotation speed MH. Also,
In step 155, it is determined whether the engine rotational speed HE is equal to or higher than the set value ME)IAX (increase by 800 rpm) within the engine rotational speed sampling time TjJAMPL. If the detected engine speed NE is equal to or higher than the already stored maximum value NEMAX, step 156-1' returns to the maximum (gNENA).
X D. Input the detected engine speed ME. On the other hand, if the value C9AMPL of the sampling counter is equal to or greater than the sampling time TSAMPL, the process proceeds to step 157, where it is determined whether the difference between the maximum value NEMAX and the minimum 1 mNEMIN is the hunting judgment rotation speed NEHUNT (20 Orp layer), and whether or not it is For example, the process moves to step 158 and 1 is added to the variable NX. On the other hand, the difference between the maximum value NEMAX and the minimum value NEMIN is the hunting judgment rotation speed NEJ (U
If it is not greater than or equal to NT, proceed to step 159 and set the variable NX.
Subtract 1 from.

Also, in step 151, after the F/8 condition is satisfied, lO
If it is less than seconds, the process moves to step 180 and the variable NX is set to zero. and step 158.159 or 1
After processing in 60, move to Stella 7'161, clear sampling counter C8AMPL,
In step 162, the minimum value NEMIN and the maximum value N■A
X is set to 800 rpm, respectively, and the process returns to the main routine.

If hunting occurs because the operation/stop cycle of the opening adjustment means 5 matches the drive cycle of the opening degree adjusting means 5 and the drive time is long (K1 time), the central processing unit 22 controls the operation during the sampling time TSA) IPL. The minimum value NEWIN and maximum value NEIIIAX of the engine rotation speed are determined (steps 152 to 156), and the difference between the maximum value NEMAX and the minimum value NEWIN is the hunting judgment rotation speed NEHUN.
If T (200 rpmJ or more), it is determined that hunting is occurring (step 157), and 1 is added to the variable NX for changing the above-mentioned peak drive time S, that is, the pulse width of the pulse voltage supplied to the ISC 5 (step 157). 158), therefore, the actual driving time tIIIS varies from KI to Kl.
/2, the amount of change in throttle opening is halved, and the amount of change in engine speed due to the change in throttle opening is correspondingly reduced. If the hunting still does not subside, set the variable NX for each sampling time TSANPC.
By adding 1 to The difference is 20O
(below r-91), the drive time is lengthened by shortening the variable NXt-1 (step 159). In this way, when the variable X returns to 0, the actual drive time S is
Return to the time Kl when ISO should be driven.

As described above, according to the present invention, when hunting occurs because the alternator or the like operates during idling, and its operating cycle matches the drive cycle of the opening adjustment means 5 and the drive time is long, the drive time adjustment means 9 operates to gradually shorten the driving time of the opening adjustment means 5, so that the amount of change in the throttle opening decreases, and as a result, the amount of change in the engine speed due to the change in the throttle opening decreases. Hunting is reduced.

It should be noted that the present invention is of course not limited to the above-mentioned embodiments, and also includes the following modifications.

In other words, eye e! The engine speed may be changed depending on whether the air conditioner is turned on or off, etc. Hunting can also be detected by determining the difference between the maximum and minimum engine speeds during a predetermined period of time. For example, it may be determined that hunting is occurring if the difference between the maximum value and the minimum value of the throttle opening during a predetermined period of time exceeds 1. Hunting may be determined when the opening adjustment means operates in the same direction a predetermined number of times in succession in response to a command from the control means.

In addition, various modifications can be made without departing from the spirit of the present invention.

Effects of the Invention Since the present invention has the configuration as described below, it is possible to provide an engine idle speed control device that can effectively eliminate hunting caused by the operation of the idle speed control means during idling. It is something.

[Brief explanation of drawings]

Figures 1 to WJ6 show one embodiment of the present invention, Figure 1 is a diagram of the unused embroidery floor to clarify the present invention, Figure 2 is a schematic explanatory diagram of the structure, and Figures 3 and 4 are An explanatory diagram for explaining the control procedure, Figure 1 p. 15 is a diagram showing the waveform of the pulse voltage applied to the opening adjustment means, and Figure 6 is a diagram showing the time KI to drive the mechanical SC.
A diagram showing the relationship between the rotation speed deviation port ME and the 7th Li4 is,
FIG. 3 is a diagram corresponding to FIG. 3 showing a conventional example. 1...Carburetor 2...Throttle valve 5--Opening degree adjusting means 8...Idle rotation speed controlling means 9...Driving time adjusting means 21...Microcomputer system 26--Rotation number detection means

Claims (1)

[Claims] Based on the opening adjustment means that adjusts the closing position of the throttle valve in response to the supply of pulse voltage, the rotation speed detection means that detects the engine rotation speed, and the comparison between the detected value by the rotation speed detection means and the target rotation speed. Idle rotation speed control means for driving the opening adjustment means to move the closing position of the throttle valve in a direction in which the detected value approaches the target rotation speed;
A driving time for gradually shortening the pulse width of the pulse voltage supplied from the idle rotation speed control means to the opening adjustment means when hunting occurs in the operation of the opening adjustment means due to control of the idle rotation speed control means. 1. An engine idle speed control device, comprising: an adjustment means.