JPS61116046A - Control system for throttle opening of engine - Google Patents

Abstract

PURPOSE:To prevent a control matching from failing caused by a so-called play of an idle switch by inputting the target throttle opening to an opening memory under idling drive and preserving it as a memory throttle opening. CONSTITUTION:A decision means I, in which an expected optimum throttle opening corresponding to engine-driving conditions at each point of time is selected to decide a target throttle opening TAGET, is prepared and the newest TAGET is memorized as a memory throttle opening MTA in an opening memory II. When an idle switch 8 is on, the same value as TAGET is inputted to the opening memory II through a renewing means III. Then the system is constituted so that the opening of a throttle valve 2 is regulated by operating an opening control mechanism 7, by which the difference between throttle openings MTA and TAGET is put within an assigned range by a prospect control means IV, under operation range when the idle switch 8 is off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a throttle opening control system mainly applied to an automobile engine.

[Prior Art] Modern automobile engines are equipped with various systems to improve fuel economy, but one of them is that few of them employ an idle speed control system. do not have.

As a prior art related to this type of control system, for example, there is one disclosed in Japanese Patent Application No. 135522/1982. That is, this idle speed control system includes a speed detection means for detecting the speed of the engine;
It has an actuator that locks the rotating part of the throttle valve that returns automatically in the opening direction, and moves the actuator forward and backward to set the throttle valve to the closed position of 21Ir! opening degree tAr
! J mechanism and this opening degree J! It has a movable contact that elastically retreats in response to the contact pushing force when the rotating part comes into contact with the actuator of the ItM mechanism, and the retreated movable contact is brought into elastic contact with the stationary contact to be in a conductive state. In an operating range where the idle switch is switched and the idle switch is maintained in a conductive state, the opening adjustment mechanism is controlled and the engine rotation speed detected by the rotation speed detection means converges to the target rotation speed. A feeder control means is provided for controlling the forward and backward positions of the actuator. Then, the target rotation speed is updated according to the engine cooling water temperature, the 0LOFF state of the air conditioner, etc., so that the idle rotation speed can be stably maintained at the lowest possible value without causing engine stall. It has become.

By the way, in something like this, when the idle switch is in a non-conducting state, that is.

Turn the air conditioner on and off during racing or normal driving.
Even if the operating state of the engine changes due to FF +) J conversion, etc., the idle speed control system described above will not operate.
Therefore, immediately after returning to idling operation, the throttle opening is not appropriate, which may cause temporary engine malfunction or unnecessary engine racing.

Therefore, in order to eliminate such problems, in addition to the above-mentioned idle speed control system, the following throttle opening control system is installed, and even during normal driving, when the engine operating condition changes, the following throttle opening control system is installed. Therefore, it is being considered to change the closing position of the throttle valve depending on the forecast. In other words, this throttle opening control system selects the predicted optimal throttle opening corresponding to the engine operating state at each point in time based on a predetermined procedure, and sets the selected value as the target throttle opening. and means of decision.

The opening memory stores the latest input value as the throttle opening, and stores the same value as the actual throttle valve opening in the operating range where the above-mentioned idle switch is in a conductive state. A memory throttle opening update means that sequentially inputs data into the opening memory, and the opening adjustment mechanism described above are controlled and controlled in an operating range where the idle switch is in a non-conducting state, and the memory throttle opening and the target throttle opening are updated. and anticipatory control means for operating the opening adjustment !tIa structure so that the difference between the opening and closing angles falls within a certain range.

However, with such a configuration, there may arise a problem that the consistency of control is impaired due to so-called play of the idle switch.

FIG. 4 is an explanatory diagram for specifically explaining this problem. In the figure, 1 is a carburetor of an automobile gasoline engine, 2 is a throttle valve of this carburetor 1, and 3 is a rotation of this throttle valve 2. 4 is a spring that biases the throttle valve 2 in the closing direction, and 5 is an accelerator pedal that biases the throttle valve in the opening direction via a wire 6. Reference numeral 7 denotes an opening adjustment mechanism that locks the rotary portion 3 of the throttle valve 2 to set the closing position of the throttle valve 2 at node yA, and 8 refers to the opening adjustment mechanism 7.
This is an idle switch installed in series A.

The opening adjustment mm mechanism 7 includes a feed screw portion 13 provided on the output shaft 12 of the DC motor 11, and a bag-like actuator 14 screwed into the feed screw portion 13. 1
1 by a signal from the feedback control means, the actuator 14, whose rotation is prohibited by a guide member (not shown), is screwed back and forth in the axial direction. And the idle switch 8
is the opening adjustment I! It has a movable contact 15 that elastically retreats in response to the contact pushing force when the rotating part 3 comes into contact with the actuator 14 of the I mechanism 7. The conductive state can be switched by bringing the two in contact with each other. Specifically, the output shaft 12 of the DC motor 11
is supported so that it can freely move in the axial direction within a certain range, and is elastically biased in the +iij n direction with a weak force,
The movable contact 15 is held on the output shaft 3 via an insulating member 17, and the stationary contact 16 is supported on the fixed housing 18. Therefore, this switch 8 is connected to the rotating part 3 of the throttle valve 2 of the carburetor l.
is away from the actuator 14, the output shaft L2 is held in the forward position N (a) and the movable contact 1
5 is away from the stationary contact 16, so it is maintained in a non-conducting state (see FIG. 5C), but the rotary part 3 comes into contact with the actuator 14, and the contact pushing force causes the output shaft to close. 12 is pushed back to the rearward WLC port).
By the way, the first contact 15 contacts the stationary contact 16 and switches to the conductive state (see FIG. 5C).
In such a configuration, in order to ensure contact pressure between the movable contact 15 and the stationary contact 16 and maintain reliable conduction, the output shaft 12 is moved from the forward position (a). On the way back to the above-mentioned retreat position (b) (c)
The movable contact 15 and the stationary contact 16 are set to start contacting each other, and after the contact, there is further play. Contact pressure can be ensured. However, if this is the case, for example, the idling state (see Figure 5C)
An inconvenience occurs when the engine is raced by pressing the 7xel pedal 5 and then returning to idling. That is, in the idling state, the idling speed control system operates and performs feedback control so that the idling speed becomes the optimal value according to the engine operating condition, and the throttle 1514 degrees is adjusted to the required value corresponding to the idling speed. It will be a 4WI. and,
This actual throttle opening is the throttle [1JIl
[The memory slow 2-torque opening updating means of the ill system sequentially inputs the opening into the opening memory. From this state,
When the accelerator pedal is depressed and the throttle valve is opened, the idle switch changes from a conductive state to a non-conductive state, and the idle speed control is stopped and the throttle opening control system's predictive control means is activated. Control begins. However, such a system L
・Then, the throttle opening degree θ in the state shown in FIG. 5C
is stored in the opening memory as the memory throttle opening,
It is desirable to perform prospective control based on this throttle opening degree θ, but in the configuration as described above, the idle switch 8 is brought into a non-conducting state after passing through the state shown in FIG. .

Therefore, while the throttle valve 2 is opening within the idle range of the idle switch 8, the desired throttle opening is sequentially written and updated in the opening memory, so that the idle switch 8 is not At the time of switching to the conductive state, the opening memory stores the throttle opening θ + Δθ with an extra opening Δθ corresponding to the free play.
is left in the opening degree memory, and the opening degree adjusting means is prospectively controlled so that the difference between this memory throttle opening degree θ+Δθ and the target throttle opening degree falls within a certain range. Therefore, the throttle valve closing position by the opening adjustment means is set closer to the closing side than the desired value by Δθ.

Therefore, when the accelerator pedal 5 is released and the throttle valve 2 is returned to the closed position δ, the throttle valve 2 is momentarily closed too much, causing the engine to temporarily malfunction or stop. This causes an inconvenience.

[Problems to be solved by the invention] The present invention has been made by focusing on such a situation.
It is an object of the present invention to reliably solve the problem that control consistency is impaired due to the so-called shading of the idle switch.

[Means for solving problems]

The present invention aims to achieve such an objective.

As shown in Fig. 1, a target throttle opening determining means selects the predicted optimal throttle opening corresponding to the engine operating state at each point in time and determines the selected value as the target throttle opening, and the accepted throttle opening value. It has an opening memory that stores the latest one as the memory throttle opening, and an actuator (14) that locks the rotating part (3) of the throttle valve (2) that returns automatically in the opening direction. Child(
14) to the closing position of the throttle valve (2) to g41! + opening WAmm structure (7) and this opening 7I4f! When the actuator (14) of the Y mechanism (7) comes into contact with the actuator (14), the movable contact (15) moves elastically in response to the pushing force of the contact. An idle switch (8) that makes contact (15) elastically contact a stationary contact (16) to switch to a conductive state, and when this idle switch (8) becomes conductive, the opening degree is the same as the target throttle opening degree (7). memory throttle opening update means for inputting a value into the opening memory; and the idle switch (
8) is in a non-conducting state, the opening adjustment f! II
a prospective control means that puts the a mechanism (7) under control and operates the opening W cylinder mechanism (7) so that the difference between the memory throttle opening and the target throttle opening falls within a certain range. It is characterized by having been made to be

[Operation] According to this means, during idling operation, the target throttle opening is manually input to the opening memory and stored as the memory throttle opening, and the throttle valve (
2) moves in the opening direction and the idle switch (8) shifts to the state shown in Fig. 5 Ca, no new value is input to the opening memory. 8) is switched to a non-conducting state.

Unless the target throttle opening is changed by switching the air conditioner from ON to OFF, the target throttle opening and the memory throttle opening are the same value, so the opening is 11ff.
The i means (7) is not actuated, therefore, when the accelerator pedal is released, the slow/torque valve (2)
will return to the correct closed position corresponding to the target throttle opening.

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 2 and 3.

Note that parts that are the same as or correspond to those shown in FIG. 4 are given the same symbols, and explanations thereof will be omitted.

This system, similar to the one shown in Fig. 4, is applied to an automobile engine, where 1 is a carburetor, 2 is a throttle valve, and 3 is a rotating part of the throttle valve 2. One of the zero rotation parts 3 is a lever-like member, so that it rotates together with a support shaft 2b that supports the throttle valve body 2a. Further, 7 is an opening degree adjustment mechanism yJ4, and the DC motor 11 of this opening degree adjustment mechanism 7 is driven by applying a DC voltage in a pulsed manner.

The output shaft 12 is held so that it can move forward and backward by a certain distance in the axial direction with respect to the fixed frame 18 (distance corresponding to the forward position and the backward position), and is far more advanced than the spring 4. Weak spring (not shown)
is urged forward (downward in the figure). The actuator 14 screwed onto the output shaft 12 has a cylindrical main body 14a that is threaded onto the 12 threaded parts 13 of the output shaft, and a pressure receiving part 14b press-fitted into the tip of the main body 14a. The rotating portion 3 is locked at the tip of the pressure receiving portion 14b. And the main body fI114
A protrusion 14C protruding from the outer periphery of the fixed frame 18
A slide 6 (not shown) is fitted in the axial direction n (not shown) provided on the cover attached to the front surface of the cover and is prohibited from rotating. A microcomputer system that selects the predicted optimal throttle opening corresponding to the operating state of the engine at each point in time and sets the selected value as the target throttle opening, and the latest one of the accepted values. an opening memory for storing the target throttle opening as a memory throttle opening; a memory throttle opening updating means for inputting the same value as the target throttle opening into the opening memory when the idle switch 8 becomes conductive; and the idle switch. 8 is in a non-conducting state, the two opening mechanisms 7 are brought under control, and the opening iri mechanism is controlled so that the difference between the memory throttle opening and the target throttle opening falls within a certain range. This microcomputer system 21 has a central processing unit 21 (CPU) 22 and a main unit 23.
and interfaces 24 and 25. Then, a signal a from the idle switch 8, a signal a from the rotation speed detection means 26 are sent to the interface 24,
Signal C from transmission state detection means 27 Signal d from water temperature sensor 28, Signal e from vehicle speed sensor 29, Signal f from throttle opening sensor 31, and Air conditioner switch 3
The signals g from 2 are inputted manually, and a drive signal is output from the interface 25 to the opening II adjustment means 7. The idle switch 8 includes a movable contact 15 held by an insulating member 17 fixed to the output shaft 12 and a stationary contact 16 supported by a fixed frame 18.

The configuration is exactly the same as that shown in FIGS. 4 and 5. Further, the rotation speed detection means 26 is for detecting the rotation speed of the engine, and uses, for example, an ignition pulse. Further, the transmission state detection means 27 is for detecting whether or not the transmission state between the engine and the NA drive wheels is disconnected, and the clutch switch and transmission, which are switched depending on the engagement and disengagement of the clutch, are in the neutral position. This corresponds to a neutral switch, etc. that is switched when the gear is shifted. Also.

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 electrical signal. Become. The throttle opening sensor 31 also includes a potentiometer that converts the opening of the throttle valve 2 into an analog electrical signal, and an A/C converter that converts the output of this potentiometer into a digital signal.
It is equipped with a D converter. In addition, the air conditioner switch 32
is a switch for starting or stopping the air conditioner.

The microcomputer system 21 is programmed to operate according to the procedure schematically shown in FIG. 1. In step 51,
Input each initial value of target throttle opening ↑AGET, variable fiTAGET+ related to engine water temperature and air conditioner ON/OFF, and memory throttle opening MTA. In addition,
The target throttle opening TAGET It, n+iW variable TACET! The variable TAGETl is the sum of the water temperature map value set in advance and stored in the memory 23, and the f number TAAC that changes due to the air conditioner being turned off to 0L. be. The water temperature map value is an optimum value selected so that the target throttle opening is higher when the engine water temperature is low than when it is high, and the selected value is converted into a -I map in relation to the temperature. . Further, the variable AAG is zero when the air conditioner is OFF, and when the air conditioner is ON, it is set to an appropriate value corresponding to the engine water temperature.For example, the idling speed can be increased to about 1200 rpm. Next, in step 52, the idle switch 8, rotational speed detection means 26, transmission state +g detection means 27, water temperature sensor 28, and vehicle speed sensor z at a specific point in time are determined.
9. Signals a, b, c, and d from the throttle opening sensor 31 and the air conditioner switch 32.

Enter e, f9g. Then, in step 53, the engine coolant temperature and the air conditioner are adjusted.
Accordingly, the target idle rotation speed N is retrieved from the memory and the variable TACETI is updated.

Moreover, with this, the target throttle opening degree TAGE
T is also updated to 0 Next, in step 54, it is determined whether the idle switch 8 is ON or not, and if it is ON,
The process moves to step 55, but if it is OFF, the process moves to step 61. In step 55, it is determined whether the idle rotation speed control starting conditions other than the idle switch 8 being on are satisfied. In other words, it is determined whether the vehicle speed is equal to or higher than fixed A1 and the transmission system interposed between the engine and the driving wheels is in a non-transmission state. If the idle speed control conditions are not satisfied, step 6
3, the memory throttle opening degree is updated, and the process returns to step 5z. The update operation in step 63 allows the target slot at that point to be updated.
The same value as ET is adopted as r^ for the memory throttle opening. On the other hand, in step 56, the rotation speed detection means 2
It is determined whether the difference between the engine rotation speed N2 detected in step 6 and the target idle rotation speed N1 is within a tolerance value 1, for example, 20 rpm. If it is determined that the difference exceeds the allowable value, step 57
On the other hand, if it is determined that the difference is within the allowable value, the process moves to step 58. In step 57, the DC motor 11 of the opening m adjusting mechanism 7 is used.

By applying only one pulse of DC voltage, the closed position of the throttle valve 2 is moved by a certain amount in the direction in which the difference between N and N2 becomes smaller. After that, the process returns to step 7 52 via step 63 in m1. On the other hand, if the process proceeds to step 58, in addition to the condition that the difference between N1 and N2 is within the tolerance value ±20 rpm,
For example, if the target idle rotation speed is the reference value (600 rpm
It is determined whether or not the J&? l! If it is determined that the actual throttle opening controlled by the idle rotation speed control is set to the above value, the process proceeds to step 59, where a throttle opening learning process is performed. If the target throttle opening is larger than the target throttle opening by a certain value or more, the learned value TAIOG is updated to a value larger by one unit, and conversely, the actual throttle opening is set to be a predetermined value larger than the target throttle opening by a predetermined value. If the learning value TAIDG is smaller than that, the learned value TAIDG is updated to a value smaller by one unit.

In other words, the target throttle opening τA is adjusted so that the target throttle opening TAGE approaches the actual throttle opening.
Update GIET. After that, step 6 of 1.i.
3, and return to the stay 52. - When the power and idle switch 54 is turned OFF and the process proceeds from step 54 to step 61, the difference between the memory throttle opening MTA and the target throttle opening TACET is a tolerance value ±Δ (for example, o, 45 degree) or not. If it is determined that the difference is within the tolerance value ±Δ, the process directly returns to step 52. On the other hand, if it is determined that the difference exceeds the allowable value ±Δ, the process proceeds to step 62 and prospective control is started. That is, in step 62, the memory throttle opening MTA is set to the target slow and torque opening TAGET.
If it is larger than , the DC motor 1 of the opening adjustment mechanism 7
1, one pulse of DC voltage in the closing direction is applied, and TA is reduced to the memory throttle opening by an amount corresponding to the operating amount of the opening adjustment mechanism 7. Also,@
When the memory slow/h throttle opening MTA is smaller than the target throttle opening TAGET, only one pulse of DC voltage in the opening direction is applied to the DC motor 11 of the opening 3I adjustment mechanism 7, and the memory Throttle opening M
is increased by an amount corresponding to the operating amount of the opening adjustment mechanism 7. Then, the procedures of STEP 1 and step 62 are repeated until the difference between the memory throttle opening XTA and the target throttle opening TAGET becomes within Δ above the tolerance value, and the procedure of STEP 1 and step 62 is repeated until the difference between the memory throttle opening XTA and the target throttle opening TAGET becomes within Δ above the tolerance value. When the value is within Δ, the process returns from step 61 to step 52. As a result of this anticipatory control, the actual closing position of the throttle/help 2 is quickly adjusted to be close to the target throttle opening degree 〒AGET changed in step 53.

With such a configuration, the target idle speed N1 is determined according to the water temperature of the engine and the ON/OFF state of the air conditioner. If the idle switch is ON, step 5? ,53.54
．． The actual throttle opening is adjusted by the idle speed control operation via steps 55, 56, and 57. Also,
In parallel, a target throttle opening degree TAGET for prospective operation is selected in step 53 according to the water temperature and the ON-OFF state of the air conditioner. The same value (1) as this target throttle opening ↑AGεT is input to the opening memory in step 63, and the memory throttle opening is updated.
ET occurs when the engine water temperature changes or when the air conditioner's O
Not only is it updated in step 53 when the N/OFF state changes, but it is also updated to an appropriate value of 1 m by the throttle opening learning process that goes through steps 58 and 59 when the idle speed control described above is stabilized. Ru. On the other hand, when the idle switch 8 is turned off, the feedback control for converging the actual idle speed N1 to the target idle speed N1 is stopped. Then, in step 53, the target throttle opening TAGεT is updated to a different value, and as a result, this target throttle opening TAG
I! When the difference between T and the memory throttle opening (ITA) exceeds the allowable value ±Δ, prospective control is performed in which steps 61 and 62 are repeatedly executed, and the closing position of the throttle/shorter valve 2 is adjusted to the above-mentioned position. It is shifted to a position that matches or is close to the target throttle opening GET.

Therefore, when the accelerator pedal 5 is released, the throttle valve 2 adjusts to the target throttle opening degree TACE.
It will immediately return to the position corresponding to T.

The above operation is obtained, but this is based on the memory throttle opening MTA, which is the standard for predictive control.
Since the target throttle opening TACET is input instead of the actual throttle opening, even if there is play in the idle switch 8, the inconvenience explained based on FIGS. 4 and 5 will not occur. In other words, when the slow 2 torque pulp 2 is completely closed, the operator 14 of the opening adjustment mechanism 7 is urged upward in the figure by the urging force of the spring 4, and the idle switch 8 is in the ON state. . At this time, the memory throttle opening MTA
is updated and the same value as the target throttle opening TAGET is entered. From this state, when the accelerator pedal 5 is depressed, the idle switch 8 remains ON for a while and the slow 7 torque valve 2 opens, but in this system, this throttle valve 2 The memory throttle opening degree (ITA) is not updated with the opening operation. Therefore, even if the idle switch 8 is turned OFF after passing through the state shown in FIG. 5, the memory throttle opening degree MTA maintains the same value as the target throttle opening TAGET.

Therefore, immediately after depressing the accelerator pedal 6 and turning off the idle switch, the target throttle opening TAG
ET M & The memory throttle opening NTA and the target slow and torque opening TAG even though they have not been changed.
Therefore, when the engine is returned to the idling state after racing, the throttle valve The closing position is prospectively controlled to an inappropriate position, and there is no problem such as engine malfunction.

In addition, in the above embodiment, the case where predictive control is performed only when the idle switch is OFF has been explained. It is also possible to apply this method to devices designed to perform the following steps.

[Effects of Development II] As detailed above, in the present invention, the target throttle opening is set in the memory throttle opening, which is a reference for prospective control, instead of the actual throttle opening when the idle switch is 08. Therefore, it is possible to provide an engine throttle opening control system that can reliably eliminate the problem of loss of control consistency due to so-called play in the idle switch.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram for clearly explaining the present invention, FIG. 2 is a schematic configuration explanatory diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart diagram for explaining the control procedure of the embodiment. g
tj Figure 4 is a schematic configuration explanatory diagram showing a conventional example, Figures 5 a and b
, c are operation explanatory diagrams of the conventional example. 1... Pot vaporizer 2 - @ Throttle valve 3... Rotating part 7e... Opening adjustment mechanism 8 @ Pot/idle switch 15... Movable contact 16... Stationary contact

Claims (1)

[Claims] A target throttle opening determination means that selects the predicted optimal throttle opening corresponding to the engine operating state at each point in time and sets the selected value as the target throttle opening, and stores the latest of the accepted values as the memory throttle opening. An opening adjustment mechanism that has an opening memory for storing an opening degree and an actuator that locks a rotating part of a throttle valve that self-returns in a closing direction, and adjusts the closed position of the throttle valve by moving the actuator forward and backward. and a movable contact that moves elastically in response to the contact pushing force when the rotating part comes into contact with the actuator of the opening adjustment mechanism, and the moved movable contact elastically contacts the stationary contact. an idle switch that switches to a conductive state when the idle switch becomes conductive; a memory throttle opening updating unit that inputs the same value as the target throttle opening into the opening memory when the idle switch becomes conductive; Presumptive control means that puts the opening adjustment mechanism under control in an operating range in which conduction occurs, and operates the opening adjustment mechanism so that the difference between the memory throttle opening and the target throttle opening falls within a certain range. An engine throttle opening control system comprising: