JPS635136A - Number of idle revolutions control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To hold the number of idle revolutions at a desired value, by a method wherein averaging processing is made on a deviation between the actualposition of an actuator and a target position to correct a target position and control an actuator, and when the actual number of revolutions of an engine is decreased over the target number of revolutions, feedback control of the number of revolutions is effected. CONSTITUTION:Where the actual position of an actuator 4 is different from a target position when the number of revolutions is converged to a target value by means of a number of revolutions feedback control part 120, averaging processing of the deviation is effected by an average deviation computing part 145 to compute an average position deviation. Further, a short time position deviation, reflecting a fluctuation in the number of revolutions due to the temporary change in load of an engine produced during a stop of a vehicle is computed thereby. The two position deviations are added to a target position, and by means of the result value, the actuator 4 is controlled to hold the number of idle revolutions at a given value. When an engine load is increased and the actual number of revolutions under an idle running state is decreased over the target number of revolutions, a selecting circuit 130 selects an output from a control part 120, and controls the number of idle revolutions to a given value through feedback control of the number of revolutions.

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 that controls an actuator that displaces the closing side stopper position of a throttle valve to control the idle speed to a desired idle speed. .

[Conventional technology]

In general, an idle speed control device that controls the idle speed to a desired value by changing the opening degree of a throttle valve installed in the intake pipe of an engine detects the engine speed, and detects the detected actual speed. The actual rotation speed is compared with a preset target rotation speed, and feedback control is performed so that the actual rotation speed converges to the target rotation speed. In addition, at low rotation speeds such as when idling, there is a large time delay until the rotation speed changes even if the throttle opening is changed, so if the engine load changes suddenly, such as when the air conditioner is operating, the rotation speed feedback control will cause the rotation speed to change. Because it is difficult to obtain excellent followability in numbers,
Taking advantage of the characteristic that the engine speed corresponds to the throttle opening,
A device is used that is equipped with a detection panel that detects the throttle valve opening and performs opening feedback control to maintain a preset target throttle opening.

[Problem that the invention seeks to solve]

However, conventional idle speed control devices do not maintain the desired idle speed, especially when engine load changes occur that are not taken into account by the control device while the vehicle is running, such as load changes due to electrical loads such as headlights, brake lamps, radiator fan motors, etc. If it is difficult to maintain the rotational speed and the rotational speed increases or decreases abnormally, especially if there is a decrease in the rotational speed,
Even when the vehicle is running, there is a problem that the engine stalls when the accelerator is turned off when changing gears, or when the vehicle is pulled out of gear when stopping.

This invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an idle speed control device for an internal combustion engine that can maintain the idle speed at a desired value even when a load is applied to the engine while the vehicle is running. With the goal.

[Means for solving problems]

Idle speed control device for an internal combustion engine according to this invention! (
, a rotation speed feedback control section that compares the target rotation speed and the actual rotation speed and controls the actuator so that the actuator converges to the target rotation speed; a position deviation calculation unit that averages the deviation from the target position and adds the average W1 pot difference and the short-time position individual difference to the first target position to set a second target position; 2. A position feedback control section that controls the actuator based on the target position, and a rotation speed feedback control section that controls the output of the rotation speed feedback control section when the vehicle is in an idling state and stopped, or when the actual engine rotation speed is lower than the target rotation speed. and a selection circuit for making a selection.

[For production]

In this invention, the rotation speed is 7. If the actual position of one cutter machine differs from the target position when the feedback control unit converges to the target rotation speed, the average individual difference calculation unit averages the deviation and calculates the average position deviation. Calculate the short-time position deviation that reflects the rotation speed fluctuation due to temporary load changes of the engine when the engine is stopped, and calculate this I! ! The deviation is added to the target position, and one cutuator is controlled using this value to maintain a predetermined idle rotation speed. In addition, when the load on the engine increases while the vehicle is running and the actual engine speed in the idling state falls below the target engine speed, the selection circuit selects the output of the engine speed feedback control section and controls the decreased engine speed through the engine speed feedback control. The idle speed is controlled to a predetermined idle speed.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of an idle speed control device according to an embodiment of the present invention. 1 is a carburetor of the engine, 2 is a throttle valve provided on the carburetor, 3 is a lever provided on the throttle valve shaft, 4 is an actuator using a DC Ti motor, 5 is a rod of the actuator 4,
This actuator 4 converts the rotational motion of the electric motor into linear motion via a gear (not shown) to extend and contract the rod 5.
In addition to controlling the idle rotation speed, when the driver does not press an accelerator pedal (not shown), the rod 5 comes into contact with the lever 3 of the throttle valve, and also serves as an idle switch that is set to ground potential. 6 is an actuator position detection word for detecting the rod extension/contraction position of the actuator 4; 7 is a rotation speed detection means for detecting the engine speed; 8 is a water temperature detector for detecting the engine cooling water temperature; 9 is a water temperature detector for detecting whether the vehicle is running or not. This is a vehicle speed switch that detects whether the

Reference numeral 100 denotes an idle speed control device, which includes circuit blocks described below. 110 is a position feedback control section, which includes a target actuator position map storage section 111, target position and actuator position detection! ! Comparator 112 and comparison l5 for comparing the actual actuator position transmitted from s6
112 includes a position deviation ΔP-drive time T conversion map storage unit 113 that determines the drive time of the actuator 4 with respect to the position deviation obtained. Further, 120 is given by a rotation speed feedback control section, which includes a target rotation speed map storage section 121, a comparator 122 for comparing the target rotation speed and the actual rotation speed transmitted from the rotation speed detection means, and a comparison@ 12
A rotation speed deviation Δ to I movement time T conversion map storage unit 123 for determining the drive time T of the actuator 4 with respect to the rotation speed deviation ΔN obtained in step 2 is included. 130 is a selection circuit that selects either the output signal of the position feedback control section 110 or the output signal of the rotation speed feedback control section 120, and this selection circuit includes a changeover switch 131 and an operating condition determination section 132. There is. Reference numeral 140 denotes a position deviation calculation section, which includes a comparator 141 that compares the output of the target actiniator position map storage section 111 and the actual position signal of the actuator 4 detected by the actuator position detection M6; The output is input via a switch 142 that is controlled by the operating condition determination circuit 132 and is turned on when rotation speed feedback control is being performed, and is output for a short period of time [of a value approximately equal to the positional deviation that is the output of the comparator 141]. ! A short-time deviation calculation unit 143 that calculates the difference, a nonvolatile memory element 144 that stores the calculated value, and an average deviation calculation unit 145 that averages the output of the short-time deviation calculation unit 143 with a predetermined time constant that will be described later. , a non-volatile memory element 146 that stores the calculated value, and a short-time position I! of the average position deviation value which is the output of the average deviation calculation unit 145 and the output of the short-time deviation calculation unit 143. addition-147 for adding the deviation to the target position; second rotation speed determination means 1 to be described later;
60, the actual rotation speed of the engine is 1100 Orp.
A switch 148 that stops inputting the output of the short-time deviation calculation section 143 to addition @ 147 when the above occurs, adds the output of the average deviation calculation section 145 and the output of the target actuator position map storage section 111, and compares the output. It consists of an addition signal 149 which is sent to a device 141. Further, 124 compares the actual engine speed detected by the engine speed detection means 7 with the target engine speed in the target engine speed map storage section 121, and outputs the output when the actual engine speed is below the target engine speed. The first occurrence
132a is an AND circuit that inputs the signal of the idle switch to the first input terminal and the signal of the vehicle speed switch 9 to the second input terminal; 132b is the AND circuit that inputs the signal of the first rotation speed discrimination means 124 to the first input terminal; Signal, AND circuit 13 at the second input terminal
2a, and when the output is "H", the selector switch 131 is switched to the feedback control section 120 side (rotation speed).

Further, 150 is a drive circuit that receives the output of the selection circuit 130 and sends out a drive voltage for the actuator 4, and 160 inputs the output of the rotation speed detection means 7, and the actual rotation speed is 1100O.
This is second rotation speed determining means that turns off the switch 148 when the rotation speed is higher than rp.

Next, the idle speed side v! of the above configuration! The operation of the apparatus a will be explained using the time charts of FIGS. 2 and 3.

Now, time t2. If the vehicle is previously in a stopped state and the idle switch is on, the driving condition determining section 132 determines that the engine is in a so-called idle state, and selects the changeover switch 131 to the rotation speed feed pack control section 120 side. On the other hand, in the target rotation speed map storage section 121 in the rotation speed feedback measuring section 120, a target idle rotation speed corresponding to the water temperature information output from the water temperature detection N8 is set and stored in advance. This target rotation speed is determined by the comparator 12.
In comparison N122, the rotational speed deviation is calculated by comparing it with the actual rotational speed detected by the rotational speed detection means 7, and the result is sent to the rotational speed deviation-driving time conversion matsub storage section 123. The drive direction and drive time of the actuator 4 that can compensate for the rotation speed deviation in one drive are stored in the rotation number difference-drive time conversion map storage unit 123. A corresponding voltage signal is sent to selection circuit 130. Selection switch $130 1
31 is the rotation speed feedback control section 12 as described above.
Since the voltage signal is connected to 0, the voltage signal is transmitted to the actuator 4 through the adjusting time of $150, and is driven for a corresponding time. As a result, the rod 5 moves, displacing the throttle valve 2 via the lever 3, and bringing it closer to the target rotation speed.

Furthermore, when the engine is idling, even if the throttle opening is changed, it takes about one second for the rotational speed to follow the same. For this reason, the next rotational speed comparison is performed after a predetermined period of time, for example, 1 second, has elapsed since - times of driving has been completed and the throttle opening degree has changed, and if there is further deviation, correction operations are sequentially performed.

On the other hand, the above-mentioned rotation speed feedback system v! B (hereinafter referred to as NFB)
), the switch 142 of the position deviation calculation unit 140 is on, and the deviation between the target position and the actual position of the actuator 4 compared by the comparator 141 is calculated by the short-time deviation calculation unit 1.
43. Note that the target actuator position map storage section 111 that outputs the first target actuator position signal stores contents basically corresponding to the target rotation speed map storage section 121. The short-time deviation calculation unit 143 calculates a short-time position deviation that is substantially equal to the output value of the comparator 141, stores this value in the storage element 144, and outputs it to the average difference calculation unit 145. The average deviation calculation unit 145 averages the deviations with a time constant of about 30 seconds to 30 minutes, as shown in (a) of FIG.
The average deviation value is converged so that it becomes zero. The calculated average deviation value is stored in the storage element 146 and added to the target position in the adder 147.

The purpose of performing the above average position calculation is that there is a deviation between the actuator position detection WJ6 and the actual intake air amount, and when position feedback control (hereinafter referred to as PFB) is performed, a rotation speed deviation occurs, and the deviation is It is a means of absorbing the error since it differs from vehicle to vehicle, and it does not mean finding this deviation based on seasonal load changes, but rather averaging engine load fluctuations that occur due to engine warm-up, electrical load fluctuations, half-clutch operation, etc. It is necessary to do so. For this reason, the averaging time constant is set to a value of about 30 seconds to 30 minutes.

Furthermore, the non-volatile memory elements 144 and 146 are connected to the engine battery, so that they can continue to hold the previous position deviation value even if the key switch is turned off.

Furthermore, in the case of a new car where the engine has not been broken in, the friction loss is generally large, and as a result, even if the actuator 4 is set to the target position, the actual idle speed is low and the engine is likely to stall. Gender memory element 14
When power is first supplied to the engine 6, it is determined that the engine is in a new car state before being broken in, and a predetermined initial position deviation value is initially set in the memory element 146. This initial position deviation value corresponds to the friction loss before break-in, and is -
This corresponds to a value that increases the idle rotation speed by 100 to 150 rpm during boat fishing.

Next, at time t21, when the accelerator pedal is depressed and the idle switch is turned off as shown in FIG.
PFB is performed.

At this time, the switch 142 is turned off by the operating condition determination circuit 132, the learning operation of the average position deviation is stopped, the average position deviation value is added to the target position by the adder 147, and this value is used as the second target actuator position signal. So comparator 11
2.

The comparator 112 uses this signal to detect the position of one machine tool N6.
The actual position signals are compared, and the deviation thereof is output to the position deviation-driving time conversion map storage section 113. This amount M deviation-driving time conversion matsub storage section 113 contains a position IHI corresponding to the rotation speed deviation-driving time conversion matsub storage section 123.
The drive direction and drive time of the actuator 4 with respect to the difference are stored, and this signal is given to the drive circuit 150 via the selection circuit 130 to control the actuator 4.

Further, when a load such as an electric load is applied to the engine at time t22, the actiniator position does not change because the engine is performing PFB, and the engine speed depends on the throttle opening. Then, if the accelerator pedal is released and the idle switch is turned on at time t23 and the so-called gearless driving mode → in which the connection between the engine and the drive wheels is severed is carried out until the time ``2%'' when the vehicle stops, then at time t24 When the rotational speed falls below the target rotational speed as shown in FIG. Regardless of the idle switch and the vehicle running state, it is connected to the rotation speed feedback control unit 120 side, and the actuator position is added to the load increase and the engine rotation speed is immediately controlled to the target rotation speed. For comparison, the chain 1s (:l:) is the first chain shown above.
This is a case where the rotation speed determining means 124 is not provided. That is, in this case, since the vehicle is in a running state at time 24, the PFB continues, and therefore the actiniator position remains the same as before the load was applied, and the rotational speed decreases by the amount equivalent to the load applied. The time t when stops
It will continue until as.

Then, at time t28, since NFB is performed to remove the load, the rotational speed increases slightly and then is maintained at a predetermined idle rotational speed.

FIG. 3 is a time chart regarding half-clutch operation when starting the vehicle. Now, if the accelerator pedal is depressed at time 37 and the idle switch is turned off, and then the clutch is operated at time t3, the engine speed will fall below the target speed (for example, 700 rpm), as described above. The selection circuit 130 selects the rotation speed feedback control section 120. Therefore, the actuator position is immediately controlled to the open side, the rotation speed increases, and when the target rotation speed is reached at time t33, the engine is switched to PFB.

i, the actuator position at time t33 becomes the sum of the average position deviation (a) and the short-time position deviation (b). However, in this case, the short-time position deviation (b) is different from the original correction amount for the increase in load on the engine, so the sum of this short-time position deviation (b) is the value of one machine position. If correction is performed, the idle speed will increase abnormally. Therefore, the rotation speed is 110 at time t34.
When the rotation speed exceeds 0 Orp, the switch 148 is turned off by the second rotation speed determining means 160, and the position deviation (b) is detected for a short time.
is reset to prevent an abnormal increase in engine speed.

FIG. 4 shows another embodiment in which NFB is prohibited when the sum of the average position deviation and the short-time position deviation of the position a difference calculating section 140 is greater than a predetermined value. In the figure, 170 is an addition j! that adds the outputs of the short-time deviation calculation section 143 and the average deviation calculation section 145. This is an opening degree discriminator that determines whether the output of the 147a is below a predetermined value.
132c. Further, the output of the first rotation speed determining means 124 is connected to the second input terminal of this AND circuit 9132c, and the output terminal is connected to the OR circuit 1.
32b. 147b is an addition '1!' which adds the output of the adder 147a in the addition M147 and the output of the target actuator position map storage section 111 (not shown). Since the other components of this device are the same as those shown in FIG. 1, corresponding parts are given the same reference numerals and their explanation will be omitted. In other words, the condition for performing NFB is to turn on the idle switch.

In addition to when the vehicle is stopped, there are cases where the actual rotation speed is lower than the target rotation speed. The degree discriminator 170 outputs "H" when the learned value is below a predetermined value, and outputs rLJ when it is above the predetermined value. Therefore, when the learned value is above the predetermined value, the output of the AND circuit 132c becomes "L", and the OR time $
132b prohibits NFB except when the idle switch is on or the vehicle is stopped. The reason why such control is performed is that if the learned value exceeds a predetermined value, there may be some abnormality in the engine, so NFB is not performed to prevent danger.

〔Effect of the invention〕

As described above, according to the present invention, the target position is corrected using the average position deviation obtained by averaging the deviation between the actual position of the actuator and the target position and the short-time position deviation, and the actuator is controlled. Since engine speed feedback control is performed when the actual engine speed falls below the target speed, even if a load is applied to the engine while the vehicle is running, the idle speed will not drop and the specified idle speed will be maintained. There is an effect that can be maintained in numbers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an idle speed control device for an internal combustion engine according to an embodiment of the present invention, and FIGS. 2 and 3 are time charts showing the operation of the idle speed frIJ control device in each state, respectively. FIG. 4 is a block diagram of the main parts of another embodiment of the idle speed control device. 2... Throttle valve, 4... Actuator, 5...
...Rod, 6...Actuator position detector, 7.
... Rotation speed detection means, 8 ... Water temperature detection word, 9 ... Vehicle speed switch, 100 ... Idle rotation speed control device, 1
10...Position feedback fIJJ control, 111...
-Target actuator position map storage section, 113...
Position W difference-driving time conversion map storage section, 120... Rotation speed feedback control section, 121... Target rotation speed map storage section, 123... Rotation speed deviation-driving time conversion map storage section, 124 ...first rotation speed determining means, 13
0... Selection circuit, 140... Position deviation calculation section, 14
2゜148...Switch, 143...Short time deviation calculation unit, 145...Average deviation calculation unit, 147...Adder, 150...Drive circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 3 Figure 4 32a Procedural amendment (voluntary) 1. Indication of the case Patent application No. 150406/1982 2.
Name of the invention Internal combustion engine idle speed control device 3, person making the correction Representative: Moriya Shiki 4, agent (contact information: 03 (213) 3421, License Department) ・“′
, Ding. i Column 6 of the scope of claims and detailed description of the invention in the specification to be amended Contents of the amendment (1) The scope of claims in the description will be corrected as shown in the attached sheet. (21, p. 3, lines 7 to 8, "throttle valve...displaces" is corrected to "controls the amount of intake air of the engine at idle." (3) p. 4, lines 8 and 9. Add the following between the lines: The conventional idle speed control device is configured as described above, but when the vehicle is running and the gear is connected and the accelerator is released during deceleration operation, the engine is driven by the vehicle. Therefore, even if the throttle valve is in the idle position, it is different from the so-called idle state.In addition, in devices that have introduced the 7 Ast Idle function, the actuator that controls the amount of intake air must be driven to the closed side as the water temperature rises, and actuator position information is used as the target value for control in this case.However, due to variations in the actuator detection position and idle intake air amount characteristics or due to idle load Due to the variation K between engines, there is a difference between the two target values, and during deceleration operation the value differs from the amount of air required for idling, which may cause the driver to feel uneasy due to insufficient deceleration feeling, or cause the engine to stall. Particularly in the condition of a new car before the engine has been broken in, the frictional resistance of each part of the engine is large, making the engine susceptible to stalling even with the same amount of idle air. (4) ) Correct "However" in line 9 of page 4 to "also". 7. Amendment of list of attached documents Claims 1 copy 2. Claims (1) Rotational speed for detecting the rotational speed of an internal combustion engine a detecting means, an idle detector for detecting a state in which the throttle valve of the engine is depressed (not depressed), an actuator for controlling the intake air amount of the engine during idling, an actuator position detecting means for detecting the drive position of the actuator, at least The idle speed control device for an internal combustion engine receives information from the speed detection means, the idle detector, and the actuator position detection means and controls the drive of the actuator. A rotation speed feedback control section that controls the actuator to converge to the target rotation speed by comparing the actual rotation speed obtained by the rotation speed detection means, and when the rotation speed has converged to the target rotation speed by this rotation speed foot check control section. calculating an average position deviation by averaging the deviation between the actual position of the actuator and the preset first target position with a predetermined time constant;
A short-time positional deviation of the positional deviation is calculated, and the average position deviation and short-time positional deviation are added to the target position and the second position deviation is calculated.
a position deviation calculation unit that sets a target position of the actuator, a position feedback control unit that drives the actuator so that the actual position of the actuator converges to the second target position, and an output of the rotation speed feedback control unit and the position feedback control unit. a selection circuit that selects the output of the rotation speed feedback control section when the throttle valve is in an idle state and the vehicle is stopped, or when the actual rotation speed of the engine is lower than the target rotation speed; An idling speed control device for an internal combustion engine, comprising a drive section that drives the actuator based on the output of the selection circuit. (2) The idle speed control device for an internal combustion engine according to item 1 of the scope of Patent M, characterized in that the addition of the short-time position deviation to the target position is stopped when the engine speed is 1000 rPm or more. (3) When the vehicle is running and the sum of the average positional deviation and the short-time positional deviation of the positional deviation calculating section is equal to or greater than a predetermined value, the rotational speed feedback control in the direction of increasing the rotational speed is prohibited. An idle speed control device for an internal combustion engine according to claim 1 or 2.

Claims (3)

[Claims] (1) A rotation speed detection means for detecting the rotation speed of the internal combustion engine, an idle detector for detecting a state in which the engine's throttle valve is not depressed, an actuator for controlling the intake air amount of the engine during idling, and driving of this actuator. An idle rotation speed control device for an internal combustion engine that receives information from an actuator position detection means for detecting a position, at least the rotation speed detection means, an idle detector, and an actuator position detection means to control the drive of the actuator. A rotation speed feedback control section that compares the target rotation speed with the actual rotation speed obtained by the rotation speed detection means and controls the actuator so that the rotation speed converges to the target rotation speed; The deviation between the actual position of the actuator upon convergence and the first target position set in advance is averaged with a predetermined time constant to calculate an average position deviation, and a short-time position deviation of the position deviation is calculated. a position deviation calculation section that calculates and adds these average position deviation and short-time position deviation to the target position to set a second target position; Out of the position feedback control unit that drives the actuator, the output of the rotation speed feedback control unit, and the output of the position feedback control unit, when the throttle valve is in an idle state and the vehicle is stopped, or when the actual rotation speed of the engine is An idle rotation speed control device for an internal combustion engine, comprising: a selection circuit that selects an output of the rotation speed feedback control section when the rotation speed is lower than a target rotation speed; and a drive section that drives the actuator based on the output of the selection circuit. (2) The idle speed control device for an internal combustion engine according to claim 1, wherein the addition of the short-time position deviation to the target position is stopped when the engine speed is 1000 rpm or more. (3) If the sum of the average positional deviation and the short-time positional deviation of the positional deviation calculating section is greater than or equal to a predetermined value, the rotational speed feedback control is prohibited.
The idle speed control device for an internal combustion engine according to item 1 or 2.