JPS62178743A - Control device for intake air quantity to engine - Google Patents

Abstract

PURPOSE:To enable a vehicle to be prevented from its spring out, by decreasing an increase rate of a bypass intake quantity immediately after an engine is switched to its non-idle operation when a bypass passage control valve opening is controlled increasing to its initial bypass intake quantity. CONSTITUTION:A controller 45 controls a control valve 27 in such a manner as to gradually decrease a bypass intake quantity from a predetermined value QP by a decrease rate QD, when an engine 1 is in deceleration operation, while to gradually increase the bypass intake quantity QM in a bypass passage 26 to be in the predetermined value QP by an increase rate QI when the engine is in non-idle operation. Here a control is performed in such a manner that the more is an intake air quantity QA, detected by an air flow meter 41, the larger the increase rate QI of the bypass intake quantity QM increases. Accordingly, the bypass intake quantity QM provides less contribution to the total intake air quantity QA immediately after the engine is switched to a non-idle operation region. As the result, an output of the engine 1 comes to increase not abruptly but gradually further smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine intake air amount control device, and in particular,
The present invention relates to an improvement in a device that is equipped with a mechanism that adjusts the amount of bypass intake air that bypasses a throttle valve, and that supplies the above-mentioned bypass intake air during deceleration operation to add a dashpot function.

(Prior Art) Conventionally, as an intake air amount control device for this type of engine, a bypass passage that bypasses a throttle valve in the intake passage of the engine is provided, for example, as disclosed in Japanese Patent Laid-Open No. 55-98629. At the same time, a control valve with a variable opening degree is provided to adjust the passage area of the bypass passage, and during idling operation, the amount of bypass intake air in the bypass passage is controlled by adjusting the opening degree of the 1-li valve, thereby controlling the idle rotation speed. In addition to converging to the target value, during deceleration operation, the opening degree of the control valve is controlled to decrease according to the decrease in engine speed, and the pass intake air ffk is gradually reduced with a bar, so that the intake air amount can be quickly reduced. Adds a buffer and dashpot function (=I) to effectively prevent engine stalling, improve convergence of idle speed to the target value, and suppress the generation of harmful gases during deceleration operation. There are known devices designed to improve emission performance.

(Problem to be solved by the invention) By the way, as mentioned above, when driving at deceleration, the
In the case of multiple JI, it is necessary to expand the opening degree of the Mi control valve to a predetermined opening after the transition from idling operation to non-idling operation, and then when the idling operation transitions, the control valve The bypass intake air amount is gradually reduced by controlling the opening degree of the bypass airflow to be reduced.

However, in that case, in order to increase the opening degree of the control valve to a predetermined injection opening, for example, when the opening degree of the control valve is increased at a set increase rate after the transition from idling operation to non-idling operation, the following method is used. Harmful effects will occur.

? In other words, after the transition to non-idling operation, the amount of intake air gradually increases as the throttle opening increases.
When a considerable amount of time has passed after transitioning to non-idling operation, the amount of intake air is large and the increase in bypass intake air amount does not have much of an effect on drivability and is not a problem, but immediately after transitioning to non-idling operation, the amount of intake air is large. In situations where there is little air flow, an increase in the amount of bypass intake air has a negative effect on the engine, and as a result, the engine output increases dramatically, resulting in a situation where the vehicle jumps out without responding to the will of the driver, and drivability decreases. A drawback arises.

Also, if the set increase rate is made smaller, 11
11) or 0, the initial bypass intake air amount will be small.

Honestly, this was done in consideration of certain points, and the purpose is to install the dash board 1 to IJ with functions when driving at deceleration.
11, when increasing the initial opening of the control valve, that is, the initial bypass intake amount, the increase rate of the bypass intake amount is changed, and after the transition to non-idling operation 0, the bypass intake amount is increased by a small increase*. By gradually increasing the engine output, the engine output is increased smoothly, effectively preventing the vehicle from jumping out immediately after transitioning to non-idling operation,
Therefore, the objective is to improve drivability.

(Means for resolving the problem) In order to achieve the above object, the solution of the present invention provides a bypass passage that bypasses the throttle valve provided in the intake passage and supplies intake air downstream of the throttle valve. , and a control valve that controls bypass intake air m supplied downstream of the throttle valve from the bypass passage,
In response to this, the control valve is controlled so that the bypass intake air amount is gradually reduced from a predetermined value during deceleration operation, and the intake air amount is adjusted so that the bypass intake air amount becomes a predetermined 1st shift during non-idling operation. Accordingly, one control means is provided for controlling the L2 control valve so that the larger the amount of intake air, the greater the rate of increase in bypass intake air m.

(Function) With the above configuration, in the present invention, when the operating state shifts from idling to non-idling operation prior to deceleration operation, the control valve is actuated by the control means, and the bypass intake air flowing through the bypass passage is controlled. The rate of increase in the amount increases sequentially in accordance with the increase in the intake air R1, so immediately after transition to the non-idling operating range where the amount of intake air is small, the amount of bypass intake air m becomes extremely small, and its ratio to the amount of intake air ( Contributing group) becomes smaller. As a result, the engine output increases smoothly even immediately after the transition to this non-idling operating range, and the heavy vehicle accelerates smoothly without jumping out of the way.

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

In FIG. 1, 1 is an engine, 2 is a combustion chamber whose volume is variable by a piston 4 fitted into a cylinder 3 of the engine 1, 5 has one end communicating with the atmosphere via an air cleaner 6, and the other end. opens into combustion chamber 2 and directs intake air to engine 1
7 is an exhaust passage whose one end opens into the combustion chamber 2 and whose other end is open to the atmosphere to discharge exhaust gas. A throttle valve 8 for controlling the amount of fuel, and a fuel injection valve 9 for supplying fuel to the combustion chamber 2 downstream of the throttle valve 8 are arranged. An intake valve 10 is disposed in the section. Further, the fuel injection valve 9 has a fuel supply passage 12 with a fuel pump 11 interposed therebetween.
The exhaust passage 7 is connected to a fuel tank 13 that stores fuel through the combustion chamber 2, and an exhaust valve 15 is disposed at the opening of the exhaust passage 7 to the combustion chamber 2. f17
On the way, there is a touch a to purify the IJI' gas! device 16
A silencer 17 is provided downstream of the silencer 17 to reduce exhaust noise.

A spark plug 20 for igniting the air-fuel mixture in the combustion chamber 2 is disposed at the top of the combustion chamber 2, and a high voltage is distributed to the spark plug 20. A power distribution device 21 functioning as a crank angle sensor is electrically connected to the power distribution device 21, and an ignition timing control device 22 that advances or retards the ignition timing of the spark plug 20; Each is connected to an ignition coil 23 that generates voltage.

Further, in order to adjust and maintain the idle speed of the engine 1 at a set value, a bypass passage 26 is connected to the intake passage 5, which bypasses the throttle valve 8 and a surge tank 25 located downstream thereof. A control valve 27 for variably adjusting the passage area is disposed in the middle of the bypass passage 26, and the passage surface f? By adjusting the magnitude of j, the amount of bypass intake air supplied downstream of the throttle ti8 via the bypass passage 26 is increased or decreased.

In order to improve emission performance, part of the exhaust gas is allowed to flow into the surge tank 25 of the C1 intake passage 5 into the intake system. A flow path 30 is connected to the exhaust gas recirculation passage 30, and an exhaust gas recirculation control valve 31 for allowing or blocking exhaust gas recirculation is disposed in the middle of the exhaust gas recirculation passage 30. Upstream, an exhaust passage 7 is installed in order to improve exhaust gas purification performance.
A secondary air introduction passage 33 of a secondary air introduction device 32 that introduces secondary air into the interior is open. Further, a canister 34 for storing the M source fuel is connected to the fuel tank 13, and the stored evaporative fuel is transferred to the purge valve 35.
The evaporated fuel is supplied to the surge tank 25 of the intake passage 5 via the evaporated fuel supply passage 36 with the evaporated fuel interposed therebetween.

In the figure, numeral 37 is an air introduction valve that introduces the air into the intake passage 5 downstream of the throttle valve 8, numeral 38 is an A alternator, and numeral 3 is an on-vehicle battery.

Further, in the intake passage 5, in order from upstream, there is an intake air temperature sensor 40 that detects the intake air temperature, and an air meter 41 that detects the intake air amount on the upstream side of the connection part of the bypass passage 26.
and a throttle opening sensor 4 that detects throttle opening.
2 is arranged, and there is no contact in the exhaust passage 7.
! ! Oxygen in the exhaust gas +9i1 on the IT device 16-L flow side
An air-fuel ratio sensor 43 for detecting the air-fuel ratio is installed in the engine 1, and a water temperature sensor 44 for detecting the engine cooling water temperature is attached to the engine 1.
4 and the output signal of the power distributor 21 are input to a controller 45 that controls the bypass intake lock control valve 27.

As shown in FIG. 2, inside the controller 45, a bypass passage is provided which receives each output signal from the power distributor 21 and the air flow make 41, and which is set to a bypass path at the time of deceleration operation according to the engine speed and intake air amount. The initial bypass intake area calculation circuit 50 calculates the initial bypass intake air amount Qp of 26, and the initial bypass intake air Fa Q p of the initial bypass intake ffi calculation circuit 50 is sequentially converted into a reduction correction chamber (reduction rate) Qo.
Bypass intake air amount calculation circuit 51 that calculates the bypass intake air mQM during deceleration operation, and the actual bypass of the bypass passage 26 with the bypass intake air mQM of the bypass intake calculation circuit 51 as the target 11α. A drive circuit 52 is provided to drive and control the control valve 27 to reduce the amount of intake air, and also detects that the engine operating state is in a non-idling operating range based on the throttle opening signal from the throttle angle hinger 42. The non-idle operating range detection circuit 53 detects, and after the non-idling operating range detection circuit 53 detects the transition to the non-idling operating range, the bypass intake air amount increase rate (additional correction amount) Q+ is detected by the intake air flow meter 41. An increase rate calculation circuit 54 operates according to the air amount signal and outputs the increase rate Q+ to the drive circuit 52.
iλ has been applied.

Next, the operation of the controller 45 will be explained based on the flowchart of FIG.
■After reading the intake air FfA Q A signal from the aflow meter 41 and the throttle opening signal from the throttle opening sensor 42h, the engine operating state is determined based on the throttle opening in step S2, and the throttle opening is determined. If the engine speed is in the non-idle operating range of NO that is not closed, the bypass intake IQM of the bypass passage 2.6 is adjusted to the initial bypass intake IQ in advance in preparation for deceleration operation from step S3 onwards.
Initialize to P.

That is, in step S3, the initial bypass intake air (5) Qp is shut out based on the intake air mQ8 and the engine speed, and then in step S4, the intake air mQA is set to an arbitrary constant K (however, O<K<1 ) is multiplied by i (XK to Q) to calculate the increase in the bypass intake air ffk Q M by 1 h. After that, in step S5, increase rate Q+ is applied to the bypass intake PQM, and in step S6, this provisional bypass intake 1ft QM is compared in magnitude with the initial bypass intake FnQp, and if YES, QM<QP. In step S7
Bypass intake FP less than this initial bypass intake air amount Qp
The actual bypass intake air amount of the bypass flow t826 is controlled to increase with iQ M as the target value, and the process returns to step S1, and again in steps S4 and S5, the increase +Q+ corresponding to the current intake air amount QA is increased by one bypass intake air amount. Then, in step S6 above, when the bypass intake [g] becomes NO, which is equal to or greater than the initial bypass intake M 111II based on the intake air amount Qp (QM = Qp)
Then, in step SA, the actual bypass intake air 11 is controlled to this initial bypass intake air amount Qp, and the process of returning to step S1 is repeated.

After that, during the deceleration operation when the throttle valves 1 to 1 are fully closed in step S2 (YES), the bypass intake air amount is controlled to decrease Ril over time in step S9 and thereafter, and the stage is shifted to the idle operation range. Control is performed to maintain the idle speed at the target 1st shift. That is, in step S, it is determined whether the bypass intake air ffiQM' has become zero or straight, and if QM≠O is N, O, that is, during deceleration operation, the reduction rate is determined from the bypass intake air FFiQM in step S10. Qo
In step S2, the actual bypass intake air amount is controlled to decrease to this bypass intake mQM, and in step S2
+ is repeated, and if the bypass intake air amount Q- becomes zero value at step S (YES in QM=O), it is determined that the operation has shifted to the idle operating range, and step S is performed.
At u, the bypass intake air amount of the bypass passage 26 is controlled by :Jl in order to maintain the idle speed at the target 1st shift, and the process returns to step S1.

Therefore, in the operation flow shown in FIG. 3 above, step S
10. S7. Through S1 to SLI and S2, the control piece 27 is controlled by IJ so that the bypass intake air amount is gradually reduced from a predetermined value Qp at a reduction rate Qr) during deceleration operation, and the bypass intake air is -1 during non-idling operation. ：Specified li
A fill control means 55 is configured to control the 1li+ control valve 27 according to the intake air ffiQA so that the intake air amount QM becomes l'lQp, and the increase ffi$Q+ of the bypass intake air amount QM becomes larger as the intake air amount QA increases. are doing.

Therefore, in the above embodiment, the da
When adding several layers, the bypass intake air in the bypass passage 26 is darkened and adjusted to the initial bypass intake air ffkQp immediately after the engine operating state shifts from the idle operating range to the non-idle operating range.

In that case, as shown in FIG. 4(a), the throttle opening V
As the engine + expands from fully open to the predetermined opening VTI-1o, the amount of intake air Q through the throttle valve 8 increases as shown in the figure (b).
The amount of bypass intake air flowing through the bypass passage 26 increases as shown in and converges to the predetermined intake air M Q +) corresponding to the predetermined throttle opening degree Vv+o. The first rate Q+ is based on the formula Q+=QAXK, and the total intake air f
jtQA (that is, the sum of the intake air amount Q via the throttle valve 8 and the bypass intake air amount QM in the bypass passage 2G) 81
(D) changes as shown in FIG.

In other words, the increase rate Qr gradually increases from zero immediately after the transition to the non-idle region, that is, when the intake air amount is increasing transiently, and after that, after the intake air amount has reached its maximum level, it becomes approximately the predetermined value Q + o, and the increase rate Compared to the case where the m-rate Q+ is always maintained at a predetermined value fItlQ+a (shown by the dashed line in FIG. As shown in (c), during the transient increase in intake air m, the gradual increase is smaller than when the rate of increase is constant, as shown by the dashed line in the same figure, and the total intake air m Q A is as shown in (e) in the same figure. As shown, the influence of the bypass intake air ffl Q M on the total intake air amount OA immediately after the transition to the non-idling operating range, that is, the contribution, becomes small.As a result, the engine output changes to the non-idling operating range. Even immediately after the transition to the non-idling operating range, the increase is gradual and smooth without increasing dramatically, effectively suppressing the jump of the heavy vehicle that does not correspond to the driver's will, and therefore the operation immediately after the transition to the non-idling operating range. Improves sex.

In addition, when the throttle opening widens greatly during the transition to the non-idling operating range, the increase rate Q+ increases in a short period of time due to a significant increase in intake air ΦQ. Since the increase correction is completed in a short time and preparations for the next deceleration operation are completed quickly,
Even when the next deceleration operation arrives early, the dashpot function can be reliably provided in response to this.

In addition, in the above embodiment, bypass intake! Increase in l = rQ
! is set to increase sequentially according to the increase in the intake air amount 〇A, but it can also be set to increase according to the intake air amount that turns the throttle valve 8 fr, or according to the rate of change in the total intake air amount QA, etc. In other words, the larger the amount of intake air, the larger the increase rate Q1 of the bypass intake air amount.

Further, in the above embodiment, the invention is applied to a device that performs idle adjustment, but the present invention has nothing to do with whether or not idle adjustment is necessary. Of course, the present invention is applicable not only to fuel injection type engines but also to carburetor type engines.

(Effects of the Invention) As explained above, according to the engine intake air amount control device of the present invention, when adding the dashpot function during deceleration operation, the bypass intake air amount in the bypass passage is adjusted to increase in advance to the initial value. In this case, when the intake air amount is low, the increase rate is set small to limit the leakage contribution of the bypass intake air amount to the intake air amount, thereby suppressing the traditional increase in engine output in this condition. As a result, temporary jumping of the vehicle can be effectively prevented, and drivability can be improved.

[Brief explanation of drawings]

The drawings show the * line side of the present invention, Fig. 1 is an overall schematic configuration diagram, Fig. 2 is a block diagram showing the internal configuration of the controller,
Figure 3 is a flowchart showing the operation of the controller;
Figures 4 (a) to (e) are explanatory diagrams for the beginning of the year. DESCRIPTION OF SYMBOLS 1... Engine, 5... Intake passage, 8... Throttle valve, 26... Bypass passage, 27-... Control valve,
41...Air flow meter, 42...Throttle opening degree sensor, 45...Controller, 50...Initial bypass intake air amount calculation circuit, 51...Bypass intake air amount calculation circuit, 53...Non-idle Operating range detection circuit, 54...
- Increase rate calculation circuit, 55...control means.

Claims (1)

[Claims] (1) a bypass passage that bypasses a throttle valve provided in the intake passage and supplies intake air downstream of the throttle valve; and a control valve that controls the amount of bypass intake air supplied downstream of the throttle valve from the bypass passage; The control valve is controlled to gradually reduce the bypass intake air amount from a predetermined value during deceleration operation, and the control valve is controlled according to the intake air amount so that the bypass intake air amount is set to the predetermined value during non-idling operation. An intake air amount control device for an engine, comprising: control means for controlling the increasing rate of bypass intake air amount to increase as the amount of air increases.