JP3304123B2 - Engine intake air control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air amount control system for an engine, and more particularly, to an intake system for an engine in which the engine speed does not drop or rise even when the electric load of an alternator or the like fluctuates. The present invention relates to an air amount control device.

[0002]

2. Description of the Related Art For example, during idle operation of an engine (ie, when the throttle valve is substantially fully closed), if the electric load fluctuates due to the start / stop of an air conditioner, power steering, etc., and the power generation amount of the alternator fluctuates, the engine load also decreases. As a result, the idle operation may become unstable.
Therefore, an attempt has been made to stabilize the idling operation by detecting the electric load amount and controlling the intake air amount of the engine in accordance with the fluctuation of the electric load amount.

In such a method, as shown in FIG. 5, an intake air amount correction characteristic X capable of determining an intake air amount Ce for a predetermined electric load amount E in relation to an electric load amount and an intake air amount is determined in advance. For example, when the electric load increases due to the operation of the air conditioner and the power steering,
A predetermined correction value ΔCe for the intake air amount correction characteristic X
Is added to obtain an intake air amount increasing characteristic Y for increasing the amount of intake air (see, for example, Japanese Patent Application Laid-Open No. 62-93453).

[0004]

However, air conditioners,
Even when no external electric load such as power steering is applied (hereinafter referred to as a no-load state), the required intake air amount characteristic X 'actually required due to the power generation characteristics of the alternator or individual differences of the engine itself, and the above-described setting. The inclination from the intake air amount characteristic X may be different.

When the above-mentioned difference in inclination occurs, when an external electric load is applied, the inclination between the intake air amount increasing characteristic Y and the actually required required intake air amount increasing characteristic Y 'is also different. And the engine speed may drop or swell.

[0006] Such a drop or an increase in the engine speed makes the operating state of the engine unstable, and thus its solution is awaited.

The present invention has been made in view of the above points, and is intended to reduce variations in the power generation characteristics of the alternator or individual differences in the engine itself by correcting the intake air amount correction characteristics to those actually required. It is an object of the present invention to obtain an appropriate intake air amount control that is not affected by the influence.

[0008]

According to the present invention, as means for solving the above-mentioned problems, an electric load detecting means for detecting an electric load, and a suction based on a relation between the electric load and an intake air amount of the engine are provided. Correction characteristic setting means for setting an air amount correction characteristic; and intake air amount correction for increasing and correcting the intake air amount of the engine based on the intake air amount correction characteristic when the electric load detected by the electric load detecting means increases. And at least one of an air conditioner and a power steering.
No external electric load caused by the other operation is detected
The intake air amount calculating means for calculating at least two actual intake air amount values corresponding to the electric load amounts having different values, and the actual air amount calculated for the predetermined electric load amount by the intake air amount calculating means. An offset amount for calculating an offset amount between the intake air amount value of the intake air amount value and the intake air amount value corresponding to the same electric load amount as the predetermined electric load amount in the intake air amount correction characteristic set by the correction characteristic setting means. Calculation means and correction means for correcting the inclination of the intake air amount correction characteristic based on at least two offset amounts calculated by the offset amount calculation means are additionally provided.

[0009]

According to the present invention, the following effects can be obtained by the above means.

That is, an external electric load (for example, an air conditioner,
An actual intake air amount value corresponding to a predetermined electric load amount in a no- load state where no power steering is detected ,
The inclination of the intake air amount correction characteristic is based on the offset amount between the predetermined electric load amount and the intake air amount value corresponding to the same electric load amount in the set intake air amount correction characteristic. fixed in a direction approaching to the amount value, when the electric load after the input of external electrical load is increased, the amount of intake air is being increased to the correction intake air amount correction characteristic.

[0011]

According to the present invention, an electric load detecting means for detecting an electric load, and a correction characteristic setting means for setting an intake air amount correction characteristic based on a relationship between an electric load amount and an intake air amount of an engine. An intake air amount control device for increasing the intake air amount of the engine based on the intake air amount correction characteristic when the electric load detected by the electric load detection unit increases. In the above, when the external electric load is not detected, the intake air amount calculating means for calculating at least two actual intake air amount values corresponding to the electric load amounts having different values, and a predetermined amount by the intake air amount calculating means. An actual intake air amount value calculated with respect to the electric load amount is the same as the predetermined electric load amount in the intake air amount correction characteristic set by the correction characteristic setting means. Offset amount calculating means for calculating an offset amount from the intake air amount value corresponding to the load amount, and correcting means for correcting the inclination of the intake air amount correction characteristic based on at least two offset amounts calculated by the offset amount calculating means. To correspond to the actual intake air amount value corresponding to the predetermined electric load amount in the no-load state and the same electric load amount as the predetermined electric load amount in the preset intake air amount correction characteristic. The inclination of the intake air amount correction characteristic is corrected in a direction approaching the actual intake air amount value based on the offset amount with respect to the intake air amount value, and the external electric load (e.g., air conditioner, power steering, etc.) is turned on. When the amount increases, the intake air amount is increased with respect to the corrected intake air amount correction characteristic. Alternatively, even if there is an individual difference of the engine itself, there is an excellent effect that appropriate intake air amount control corresponding to a change in the electric load amount can be easily performed.

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a schematic block diagram showing a configuration of an intake air amount control device for an engine according to an embodiment of the present invention. In the intake passage 2 of the engine 1, an upstream side and a downstream side of a throttle valve 3 are provided. Is provided, and a control valve 5 for controlling the amount of intake air during idle operation when the throttle valve 3 is almost fully closed is provided in the bypass passage 4. The control valve 5 receives a command from a controller 22 described later (that is, a valve drive signal).
Is to be controlled by the opening angle. Reference numeral 6 denotes an airflow sensor for detecting an intake air amount, and a detected intake air amount signal is supplied to a controller 22.

An exhaust passage 7 of the engine 1 is provided with an air-fuel ratio sensor 8 and a catalyst device 9, and a signal from the air-fuel ratio sensor 8 is supplied to a controller 22.

A voltage from an ignition coil 11 is to be applied to a spark plug 10 of the engine 1 via a power distribution device 12. An ignition signal from a controller 22 is supplied to the ignition coil 11, Appliance 1
2, a crank angle signal is supplied to the controller 22. The rotation speed of the engine 1 is calculated based on the crank angle signal.

The fuel injection amount of the fuel injection nozzle 13 of the engine 1 is based on the air-fuel ratio determined by the controller 22 by obtaining the intake air amount from the air flow sensor 6 and the remaining O ₂ amount from the air-fuel ratio sensor 8. The control is to be performed by the fuel injection signal.

The air conditioner sensor 14 supplies an air conditioner operating signal to the controller 22 when the air conditioner is turned on.

The throttle opening sensor 15 supplies an opening signal of the throttle valve 3 to the controller 22.

The power steering sensor 16 supplies a power steering operation signal to the controller 22 during the operation of the power steering.

The alternator 17 generates electric power in conjunction with a crankshaft (not shown) of the engine 1. The electric power generated by the alternator 17 is
F and are supplied to various vehicle electric loads 18. Further, a change in the amount of power generated by the alternator 17 is detected by the E / L sensor 19 acting as an electric load detecting means, and a detection signal is supplied to the controller 22.

The water temperature sensor 21 detects the temperature of the cooling water of the engine 1, and the detection signal is supplied to the controller 22.

The controller 22 is composed of, for example, a microcomputer. As shown in FIG. 1, the controller 22 is in a state where no external electric load (ie, air conditioner, power steering, etc.) is applied. If
In the relationship between the electric load E in the no-load state) and the intake air amount Ce of the engine 1, the intake air amount correction characteristic X
And a correction characteristic setting means 221 for setting the intake air amount correction characteristic X when the electric load E detected by the electric load detecting means (ie, the E / L sensor 19) increases. Intake air amount correction means 222 that outputs a valve drive signal to control valve 5 so as to increase Ce, and at least two actual intake air amount values ΔCe corresponding to electric load amount E in the no-load state are calculated. Correction for correcting the intake air amount correction characteristic X in a direction approaching the intake air amount value ΔCe based on the intake air amount value calculation unit 223 and the actual intake air amount value ΔCe calculated by the intake air amount calculation unit 223 And means 224.

The operation of the engine intake air amount control device configured as described above will be described below with reference to the flowchart shown in FIG.

[0024] In step S _1, the determination of whether an idle operation or not the throttle valve 3 is almost fully closed by a signal from a throttle opening sensor 15, made by the presence or absence of the idle feedback control execution flag F ₁ If it is determined that the vehicle is not idling (that is, F ₁ : nothing), the intake air amount feedback control is not necessary, and the process returns first.

[0025] idling operation in step S ₁ (ie,
F ₁ : Yes), the processing is performed in step S ₂
Proceeds to the presence or absence of the idle learning execution flag F ₂ is determined. The idle learning execution flag F _2, the cooling water temperature detected by the water temperature sensor 21 is 80 ° C. or higher (i.e., the engine 1 is warm operation) the difference between the target value and the actual value of the rotational speed of the set to and the engine 1 Is within a predetermined value (in other words, when the engine 1 is operating in a stable state)
It is to be set up. Here, F _2: If it is determined that no, because the idle learning control is not required, the process proceeds to step S _19, the process returns after reflecting it in the idle feedback control value Ce (fb) .

If it is determined in step S ₂ that F ₂ is present, the process proceeds to step S ₃ , where the electric load E detected by the E / L sensor 19 is changed to the dead zone determination reference value Es (see FIG. 4) is determined. Here, if it is determined that E ≦ Es is because the dead zone, there is no need to correct the tilt of the target suction air amount correction characteristic X shown in FIG. 4, in step S _4, the electrical load amount E at that time the actual intake air amount Ce ₁ corresponding to ₁
When the offset amount DerutaCe ₁ and the point Ce ₁ of the target suction air amount correction characteristic X corresponding to the electrical load amount E ₁ is calculated as the intake air quantity learning value, the inhalation air quantity learning value at step S ₅ ΔCe ₁ is added to the set intake air amount correction characteristic X. Thereafter, the process proceeds to step S _13, increasing control of the intake air amount, which will be described in detail later is executed.

[0027] If it is determined that E> Es in step S _3, the process proceeds to step S _6, this electrical load E ₂ and the gain updating determination reference value Es' (see FIG. 4)
It is determined whether or not the difference from the difference is equal to or greater than a predetermined value ΔEs. That is, it is determined whether or not an increase in the electric load sufficient to obtain the gradient of the correction intake air amount correction characteristic X 'described later has been obtained. Where Es'
If it is determined that -E ₂ <ΔEs is (in other words, the inclination update) the gain update there is no need of, the process proceeds to step S _7, a preset gain .alpha.s (i.e., set (The inclination on the intake air amount correction characteristic X)
Then, in step S ₁₂ to reflect this as electric load learning correction amount Ce (n).

If it is determined in step S ₆ that Es′−E ₂ ≧ ΔE, the processing shifts to step S ₈ , where the set intake air amount correction characteristic X corresponding to the electric load amount E ₂ is determined. offset DerutaCe ₂ the point Ce ₂ is calculated as the intake air quantity learning value, from then the inhalation air amount in step S ₉ learned value DerutaCe ₂ and step S intake air amount calculated in the ₄ learning value DerutaCe ₁ Tokyo, A slope α (in other words, a gain) of the corrected suction correction characteristic X ′ is obtained. The gain α is obtained by the following equation.

Α = (Ce ₂ −Ce ₁ ) / (E ₂ −E ₁ ) In the above processing, the intake air amount learning values ΔCe ₁ and ΔCe ₂ and the gain α are calculated by the intake air amount calculation means 223 in the controller 22. (Here, the intake air amount calculating means 223 of the present embodiment comprises the intake air amount calculating means and the offset amount calculating means according to the first aspect of the present invention).

[0030] Then, in step S _10, the difference between the current gain alpha (i.e., corrected intake air amount correction characteristic X 'inclination) and setting the gain .alpha.s (i.e., the slope of setting the intake air amount correction characteristic X) It is determined whether or not the value is equal to or less than a predetermined value,
If it is determined that alpha> .alpha.s, there is no need to update the setting gain .alpha.s, the process proceeds to step S _7.

[0031] If it is determined that alpha ≦ .alpha.s In step S _10, the the process proceeds to step S _11, is updated with the gain alpha to determined at step S ₉ to set the gain .alpha.s, which in step S ₁₂ This is reflected in the electric load learning correction amount Ce (n). That is, the set intake air amount correction characteristic X is corrected to the corrected intake air amount correction characteristic X '. The correction is executed by the correction unit 224 of the controller 22.

In a step S _13, if the presence or absence (i.e. the signal input from the air conditioner sensor 14, air conditioner
On or not) is determined, if there is a signal input from the air conditioner sensor 14, the process proceeds to step S _14, if the presence or absence (i.e. the signal input from the power steering sensor 16, whether power steering On Is determined.
If there is a signal input from the power steering sensor 16, the process proceeds to step S _15, air conditioning and increase correction value of the intake air amount commensurate with the increase in electric load caused by the operation of the power steering Ce (A / P + P / S)
(See FIG. 4). The increase correction value C obtained here
e (A / P + P / S) is reflected in the idle feedback control value Ce (fb) in step S _16.

[0033] If it is determined that air-off in step S _13, the process proceeds to step S _17,
Presence or absence of signal input from power steering sensor 16
(In other words, power steering, on or not) is determined, if there is a signal input from the power steering sensor 16, the process proceeds to step S _18, the increase in electrical load due to the operation of the power steering An appropriate increase correction value Ce (P / S) of the intake air amount is obtained (see FIG. 4).
The obtained increase correction value Ce (P / S) Step S ₁₆
At the idle feedback control value Ce (fb). Incidentally, when it is determined that the steering-off in step S17, the process proceeds to step S _16, the electric load correction value obtained in step S ₁₂ C
e (n) is set as the idle feedback control value Ce (fb).

[0034] If it is determined that the power steering off in step S _14, the process proceeds to step S _19,
An increase correction value Ce (A / P) of the intake air amount corresponding to the increase in the electric load caused by the operation of the air conditioner is obtained (see FIG. 4). The obtained increase correction value Ce (A / P) is reflected in the idle feedback control value Ce (fb) in step S _16.

The above processing is executed by the intake air amount correcting means 222 in the controller 22.

As described above, according to the present embodiment, actual electric loads E ₁ and E ₂ corresponding to electric load amounts E ₁ and E ₂ in a state where no external electric load (for example, an electric load due to the operation of an air conditioner or power steering) is not applied. Intake air amount correction value ΔCe
₁ , the intake air amount correction characteristic X set in advance based on ΔCe ₂ is corrected, and when the external electric load (for example, air conditioner, power steering, etc.) is turned on, the electric load amount increases,
Since the intake air amount is increased with respect to the corrected intake air amount correction characteristic X ', even if there are variations in the power generation characteristics of the alternator or individual differences in the engine itself, it is possible to cope with changes in the electric load amount. Thus, appropriate intake air amount control can be easily performed.

In this embodiment, the intake air amount is controlled by controlling the opening of a control valve provided in the bypass passage. However, the opening of the throttle valve may be controlled electrically. .

The present invention is not limited to the configuration of the above-described embodiment, and it is needless to say that the design can be appropriately changed without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 is a functional correspondence diagram showing the contents of a controller in an intake air amount control device for an engine of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of an intake air amount control device for an engine according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of the engine intake air amount control device according to the embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between an electric load amount and an intake air amount control value in the intake air amount control device for the engine according to the embodiment of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between an electric load amount and an intake air amount control value in a conventional intake air amount control device for an engine.

[Explanation of symbols]

1 is an engine, 2 is an intake passage, 3 is a throttle valve, 4 is a bypass passage, 5 is a control valve, 14 is an air conditioner sensor,
16 is a power steering sensor, 17 is an alternator, 19 is an electric load detecting means (E / L sensor), 22 is a controller, 221 is a correction characteristic setting means, 222 is an intake air amount correcting means, 223 is an intake air amount calculating means, 22
4 is correction means.

────────────────────────────────────────────────── (5) References JP-A-3-199636 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 45/00 366 F02D 45/00 312 F02D 29/06 F02D 41/34

Claims (1)

(57) [Claims] An electric load detecting means for detecting an electric load; a correction characteristic setting means for setting an intake air amount correction characteristic based on a relationship between the electric load amount and an intake air amount of an engine; electric load which is detected is a intake air quantity control apparatus for an engine comprising a suction air amount correction means for increasing correction of the intake air amount of the engine based on the intake air amount correction characteristics when increased by, air conditioning and At least one of power steering
When the external electric load caused by the motion is not detected,
Intake air amount calculation means for calculating at least two actual intake air amount values corresponding to the electric load amounts having different values; actual intake air calculated for a predetermined electric load amount by the intake air amount calculation means Offset amount calculating means for calculating an offset amount between an air amount value and an intake air amount value corresponding to the same electric load amount as the predetermined electric load amount in the intake air amount correction characteristic set by the correction characteristic setting means. An intake air amount control device for an engine, further comprising correction means for correcting the inclination of the intake air amount correction characteristic based on at least two offset amounts calculated by the offset amount calculation means. .