JPS6185552A - Controller for throttle valve of engine - Google Patents

Abstract

PURPOSE:To enhance the accuracy of control of the quantity of intake, by providing a means for detecting the time of backward flow of exhaust gas, and a means for altering a compensation limit value to feedback control. CONSTITUTION:An aimed intake quantity Ac1 is determined depending on the operated quantity alpha of an accelerator. The degree thetaR of opening of a throttle valve is feedback-controlled to equalize the actual quantity of intake to the aimed take quantity Ac1. A means 38, which receives the output of an exhaust gas backward flow time detection means 25 so that a compensation limit value to the feedback control of the throttle valve is altered at the time of backward flow of exhaust gas so as to be larger than at the time of stoppage of the backward flow of the exhaust gas, is provided. The feedback control of the throttle valve is thus made appropriated so as to enhance the accuracy of control of the quantity of intake.

Description

[Detailed description of the invention] Industrial application field Akira Kokuoka (Regarding the throttle valve control device of the engine,
11 indicates the required engine output.
This invention relates to an improvement in which the throttle valve opening is feedback-controlled to match a predetermined intake skew.

(Prior Art) Conventionally, as a technique for controlling the amount of intake air supplied to the engine to a predetermined intake number during the accelerator operation indicating the required engine output, there has been proposed a technique as disclosed in Japanese Patent Application Laid-open No. 51-'+38235. , an accelerator detection means for detecting the accelerator (♀r), and a target throttle valve opening setting that receives the output of the accelerator detection means and sets a target value of the throttle valve opening so that a preset air-fuel ratio is achieved. and throttle valve opening control means for receiving the output of the target throttle valve opening setting means and controlling the throttle valve opening to a target value, in response to accelerator operation M. A system is known in which a standard throttle valve opening is determined and the throttle valve opening is controlled with feedback so that the throttle valve opening becomes the target throttle valve opening. By supplying an amount of fuel to the engine so that the air-fuel ratio is set in advance according to the intake air m, the air-fuel ratio of the engine is adjusted to 1st shift.

(Problems to be Solved by the Invention) By the way, instead of using the target throttle valve opening setting means as described above, it is possible to set the number (voice value) of the intake air m so that the air-fuel ratio is set in advance according to the accelerator operation direction. A target air amount setting means may be provided to determine the target intake air amount according to the direction of accelerator operation, and feedback the opening degree of the throttle valve so as to correspond to the target air direction. Control equivalent to the conventional example is possible.

In this way, when the opening degree of the throttle valve is feedback-controlled to bring the intake air amount to the target value, the intake air m
Throttle valve feedback 1ilJ tll in consideration of sudden fluctuations or from a fail-safe perspective.
to the feedback value (correction value)? It is preferable to set a +li positive limit field and prevent the feedback value from exceeding this correction limit value to improve the control accuracy of the feedback control of the throttle valve.

However, for engines that recirculate part of the exhaust gas into the engine's intake passage as part of the engine's exhaust gas purification, there may be variations in the operation of the exhaust recirculation control I valve when air is recirculated to the IJ. Since the exhaust gas recirculation Φ fluctuates depending on the magnitude of the II+ pressure of the fresh air gas, the range of fluctuation in the intake amount of fresh air reduced by this amount of exhaust gas recirculation increases. For this reason, even with one feedback shift, which should originally be adopted, the correction limit is 1.
In this case, there is a problem that the throttle valve feedback t and II groups are not performed accurately.In particular, the target intake amount and the When performing so-called learning correction, the learning correction coefficient as feedback lfD in throttle valve feedback control exceeds its correction limit, and as a result, the learning correction of the target intake air amount is This will not be carried out accurately, and the precision in controlling the intake air m will deteriorate.

The present invention has been made in view of the above, and its purpose is to set the correction limit 1it+ of feedback control during exhaust gas recirculation when the throttle valve is feedback-controlled to adjust the intake air direction to the target intake air amount as described above. Feedback 11 is caused by the vibration being larger than when the exhaust gas recirculation is stopped.
The purpose of this invention is to improve the control accuracy of throttle valve feedback control during IJI air recirculation by appropriately selecting α, thereby improving the control accuracy of the intake air amount regardless of the presence or absence of exhaust gas recirculation.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention are as follows:
J shown in the figure: An engine throttle valve $11 all device that calculates a target intake act according to the accelerator operation direction α and performs feedback control of the throttle valve opening θR so that the target intake air ff1Ac + is reached. In the exhaust gas that detects when exhaust gas is recirculated to the engine;! A correction limit that receives the output of the exhaust gas recirculation detection means 25 and the exhaust gas recirculation detection means 25 to change the correction limit 1itl of the feedback control of the throttle valve during exhaust gas recirculation to a value larger than that when the flow F+ is stopped. The structure includes a Shimahenshi means 38.

(Function) Based on the above configuration, in the present invention, the correction limit 110 of the feed pump is changed to a value b greater than 1 when the exhaust gas recirculation is stopped, compared to 1 during the exhaust gas recirculation when the fluctuation range of the intake air m is large. By doing so, the selection of feedback values is always performed appropriately, and the feedback control of the throttle valve 1' becomes appropriate, and as a result, the control accuracy of the intake air amount is improved.

(Example) Hereinafter, an example of the present invention will be explained based on the drawings from FIG. 2 onwards.

FIG. 2 shows the fill t of an engine according to an embodiment of the present invention.
1 shows the overall configuration of the illumination engine, for example, 1 is a 4-cylinder engine, 2 is air that is taken into the engine 1 with one end opening to the engine via the air cleaner 3 and the other end opening to the engine 1)
4 is an intake passageway which has one end opening into the engine 1 and the other end opening into the atmosphere to discharge exhaust gas from the engine 1.
It is a JI airway. Reference numeral 5 denotes an accelerator pedal that is depressed in response to an engine output request, and reference numeral 6 denotes a throttle valve disposed in the intake passage 2 for controlling the air intake 721'. (, 1, the accelerator pedal 5 is mechanical) and is electrically controlled by the depression m of the accelerator pedal 5, that is, the amount of accelerator operation, as will be described later.

Reference numeral 7 denotes a throttle actuator comprising a step motor or the like for opening and closing the slots 1 to 6.

Reference numeral 8 denotes a catalyst device which is interposed in the exhaust passage 4 and purifies exhaust gas.

Further, 9 has one end opening upstream of the catalyst device 8 in the exhaust passage 4 and the other end opening downstream of the throttle valve 6 in the intake passage 2.
An exhaust recirculation passage that recirculates part of the exhaust gas from the exhaust passage 4 to the intake passage 2; 10 is the exhaust)! Flow passage 9) is interposed therein to control exhaust gas recirculation. The recirculation control valve 11 is a solenoid valve that controls the opening and closing of the recirculation control valve 10, which is a diaphragm-equipped recirculation control valve whose operating source is intake negative pressure.

On the other hand, reference numeral 12 denotes a fuel injection valve disposed downstream of the throttle valve 6 in the intake passage 2 to inject and supply fuel. 15 to a fuel tank 16, and when fuel is supplied from the fuel tank 16, excess fuel is transferred to the fuel tank 16 via a return passage 18 with a fuel pressure regulator 17 interposed therebetween. )! Thus, fuel at a predetermined pressure is supplied to the fuel injection valve 12.

In addition, 19 is an accelerator pedal position sensor that detects the depression of the accelerator pedal 5, that is, the accelerator operation amount α, and 20 is an air meter 70 that is disposed upstream of the throttle valve 6 in the intake passage 2 and detects the intake air ff1QaR. , 21 is also an intake air temperature sensor disposed upstream of the throttle valve 6 in the intake passage 2 and detects the intake air temperature, 22 is a throttle position sensor that detects the opening degree of the throttle valve 6, and 23 is an engine coolant temperature sensor. A water temperature sensor 24 is arranged upstream of the catalyst Vj n 8 in the exhaust passage 4 and detects the air-fuel ratio λ of the engine 1 from the oxygen concentration component in the exhaust gas. 25 is the recirculation control valve 10.
A recirculation sensor is attached to the exhaust recirculation sensor and serves as an exhaust recirculation detecting means for detecting the exhaust recirculation, and these detection signals 19 to 25 are input to a control unit 26 consisting of an analog computer or the like, and the control unit 2
6 controls the throttle actuator 7, solenoid valve 1"l a3, and fuel 1 injection valve 12. Furthermore, the control unit 26 controls the igniter 2.
7 is connected manually, and inputs the signal of the number of ignitions, that is, the engine rotation h x e. Also, the above control [
Dust distributor 28J3 for 1-26
and battery 29 are input connected, and each is ignited! +11115 and battery voltage VB signals are input.

Next, the operation of the control unit 26 is controlled by the 314th
This is explained by: Note that FIG. 3 shows a platform for a four-cylinder engine.

At d5 in FIG. 3, first, to describe the throttle valve opening control system, MAL is set to a target value Qal of air supplied to the engine 1 so that the air-fuel ratio is set in advance for the accelerator operation amount α. the 17th engine which received the output from the accelerator pedal position sensor 19;
Air fl Q al is set to be supplied to the engine 1 according to the accelerator operation amount α. MA2 is engine cold 7J] Minimum air fi Q a to achieve the air-fuel ratio required for idle up with respect to water temperature m T w
rm is set, the water temperature sensor 23
The minimum air amount Q am for water temperature correction is set according to the engine cooling water m a T w.

31 is the first map MAI and the second map MA2.
A maximum of 10 selection circuits receive the respective outputs and select the maximum value Qa2 from the target air ff1Qa+ obtained from the first map M^1 and the minimum water temperature correction air fiQam obtained from the second map M82. and the target air ff1
Qa+ is water bath? When the water temperature is lower than +li most positive minimum air QQm, the water temperature i+fi positive minimum air fiQam is selected to increase the idle to ensure good engine operability. Also, M^3 is the engine rotation speed N
A third map in which the maximum air amount QaM determined by the engine speed Ne is set for C, and the maximum air amount QaM is set to 11QaM according to the engine speed No. 32 is the maximum tITI'r'lU selection circuit 31J3.
and receives each output of the third map MA3 (), which of the maximum air M, Q, and 1M found in the third map IVIA3, such as the maximum 7 found in the maximum j area 1 selection circuit 31 and the maximum air Q112 found in the third map IVIA3. Select the minimum value Qa3 (R Zuru minimum 1iTI selection IR
In the circuit, when the target air amount Qa1 exceeds the maximum air mQax determined by the engine speed Ne,
Since the throttle valve 6 can be fully opened and suction is possible <it is meaningless even if one shift is aimed at seedlings of K air j or more, d], by selecting the maximum air ffiQaM and limiting the maximum value, the throttle valve 6 A fully open signal corresponding to all questions is output to the subsequent stage. As a result of the above, the accelerator operation (6
) for α, the thrower 1 hell valve 6 is determined by the correction for the engine cooling water temperature Tw and the engine speed NC.
The target air ff1QaJ is determined by considering the correction for the maximum air amount at full throttle.

Furthermore, 33 receives the output from the minimum value selection circuit 32, sets the target air mQa3 to 2, and sets the engine speed NO to 2.
Multiplyed by 1a(Nex2)′C, divider f,), 4
The intake air ff1Ac+ per cylinder in a cylinder engine is calculated. MAJIJ3 and MAS are JJi J3 when air recirculation is stopped and IJj J31 when air recirculation is applied to the engine rotational speed Nc, respectively. 4 J3
and the fifth map MAJIMA 11, both of which are switched between when the exhaust gas recirculation is stopped and when the exhaust gas flow port 1 is switched by the signal from the recirculation sensor 25. The throttle valve opening θ1 or θI is selected by the flow switch 34, receives the output from the P1 pipe 33, and is set to the target intake air amount Δc1.
I am trying to set E. 35 is an intake air feedback correction module & learning correction 7 joules, among which the intake air amount feedback correction module 1. L Receives the target intake air ff1Ac+ signal from the divider 33 ()
At the same time, upon receiving the signals of the actual air fftQaR and the engine speed Ne actually measured by the air flow meter 20, the actual intake air amount ACb per cylinder and the target intake mΔ are determined based on the actual air ff1QaR and the engine speed Ne.
The feedback correction coefficient Cap e for performing feedback correction of the C throttle valve opening degree in accordance with the deviation is sequentially eliminated. Further, the learning correction module performs the intake air amount learning correction based on a zone signal from the zone determination module 51 (described later) when, for example, two seconds or more have passed after the intake air amount feedback correction condition is satisfied in the intake air amount feedback correction module. Set the coefficient 5TDY to its initial value=1. 0, then the following formula (% formula % CaFe peak value + past 8 Ca FB bottom values)/16-1.0) is sequentially updated, and the above reflux sensor 25
Based on the output signal from the above intake air amount learning correction coefficient 5T
DY range, exhaust 3! i! 5vov = 1 when the flow stops
．． 0±30%, while 5T for exhaust gas recirculation 0 and r.
The output is limited to DY=1.0±50%,
Receives the output from the reflux sensor 25 [J, 11Zi'Umo
:Ik: Comprises a correction limit value changing means 38 that changes the limit value of the intake ffi science M correction coefficient fiS T ov to a value greater than that when the IJF air recirculation is stopped. Further, 36 indicates the fourth or fifth map MAJ, MA5 and the intake air amount feedback correction module L-L & learning correction module 35.
4. Receive each output from the map MA. MA s is obtained from I; mouth (= 1 throttle valve distance θ1 or θ1ε is obtained by the learning correction module, the intake air amount learning correction coefficient 5
The multiplier 36'C'' multiplies the target throttle valve opening θ2 by multiplying f by the TDV to obtain the target throttle valve opening θ2. A multiplier that multiplies and corrects the intake air amount feedback correction coefficient PilcaFor obtained by the correction module & learning correction module 35, and the number (i) of the target throttle valve opening θ3 corrected by the east exit χ) 37 is the throttle actuator. 7, and the opening degrees of the throttle valves 1 and 6 are controlled to the target throttle valve U; 1 degree θ3 i+J.

As described above, the configuration is such that feedback control is performed on the direct and subex II tour valve 6 for air use.

Next, the fuel supply amount control system in J5 will be described in Fig. 3.
\In particular, Me6 is a sixth map in which a target fuel value Qf+ is set for applying fRt'i; to the engine 1 so that the air-fuel ratio is set in advance for the accelerator operation amount α,
Receives the output from the accelerator pedal position sensor 19 (
), the target fuel amount Qf+ to be supplied to the engine 1 is set according to the accelerator operation amount α. MB7 is the second map M, 82, in which the minimum fuel amount Qfm is set for the engine cooling water temperature Tw so that the air fuel ratio required for idle up is obtained for the air IQam, which is determined by 82. 7 map, receives the output of the water temperature sensor 23, and sets the minimum fuel 1QfIl for water temperature correction according to the engine cooling water t-lean Tw. 39 is the sixth above
Receive each output of map M8G and seventh map MB7,
The target fuel amount Of+ determined by the sixth map Ma6 and the minimum fuel ffl for water temperature correction determined by the seventh map M87
Qfm is a maximum value selection circuit that selects the maximum 11tlQf2, and when the target fuel amount Of+ is lower than the minimum fuel amount IQfz for water temperature correction, it selects the minimum fuel amount Qftn for landing correction to increase the idle. This ensures good engine drivability. In addition, MBs is the maximum air ffiQa set in the third map MA3.
This is the eighth map in which the maximum fuel amount ffi and QfM are set for the engine speed Ne so that the target air-fuel ratio is set in advance for M, and the maximum fuel amount QfM is set according to the engine speed Nc. . 40 receives each output of the maximum value selection circuit 39 and the eighth map Mes, and selects the maximum fuel mQf2 determined by the maximum value selection circuit 39 and the eighth map Mes.
This is a minimum value selection circuit that selects the minimum value Qfa from the maximum fuel ff1QfM determined by the map Me8, and when the target fuel 11fflQf1 exceeds the maximum fuel amount Qfx determined by the engine speed Ne, that is, As shown, the target air ff1Qa+ is the engine rotation speed N
When the target value is m that exceeds the maximum air mQaM determined by e and is greater than the amount of air that can be taken in when the throttle valve 6 is fully open, the maximum air ffiQaM is selected and the maximum fuel ffiQfM is selected, and the engine The target value Qf+ of the sixth map Mes is corrected so that the air-fuel ratio is a preset target air-fuel ratio for the intake air (2) supplied to the engine. From the above, as in the case of air m, engine cooling water '14
11 [Target fuel mQf 3 is determined in consideration of the correction to Tw and the correction to the maximum fuel amount when the throttle valve 6 is fully opened, which is determined by the engine speed NO.

Then, the target fuel m Q from the maximum value selection circuit 40 is
r 34g'? t Ha, except! ? Container 41, ml ~
3rd fl unit 42-44, fuel cut switch 45J
5 and the fuel injection valve 12 via the fuel injection valve correction circuit 46.
is output to. The divider 41 includes a minimum value selection circuit 40
The target fuel mQfz is divided by the engine speed Ne, assuming that fuel is injected into two cylinders at a time, and the fuel supply l'i'1Qfi per cylinder is calculated. In addition, the first power (>) unit 42 converts the target fuel supply f11 Q r i determined by the obstacle remover 41 into the water temperature correction coefficient CTW and the engine cooling water temperature Tw determined by the ninth map M8.3. Enrichment correction coefficient CER obtained by enrichment correction module 47
The target fuel supply ff1Qfi+ is calculated by performing T' multiplication correction. The mouth enrichment correction module 47 is
Based on the zone 18 from the zone determination module 51, which will be described later, when the intake air pressure Δ01 with respect to the engine speed Ne is in the enrich line region, the enrichment correction coefficient CER (for example, 1. 08) is output.

Furthermore, the second multiplier 43 multiplies and corrects the target fuel supply IMQfi+ obtained by the eleventh multiplier 42 by the learning correction coefficient C5TC obtained by the fuel learning correction module 48 to calculate the target fuel supply fiQfi2. This is Surushino. This fuel learning correction module 48 satisfies fuel feedback correction conditions in the four fuel feedback correction modules based on a zone signal from a zone determination module 51 and a fuel feedback correction coefficient CrFe signal from a fuel feedback correction module 49 (described later). For example, when more than 2 seconds have elapsed, the learning supplement i
If the L coefficient C3TD is its initial 'M value - 1, O, then
The following formula % formula % The peak value of CfE[] + the bottom (U) of the past 8 CfFBs/16-1.0 is sequentially updated and output.

Further, the third east stop device 44 multiplies and corrects the target fuel supply ffi Q f i 2 obtained by the second multiplier device 43 by the fuel feedback correction coefficient CfF day obtained by the fuel feedback correction module 49. The target fuel supply ffi Q f i 3 is calculated using the following formula. These four fuel feedback correction modules operate based on the zone signal from the zone determination module 51 and the air-fuel ratio λ signal from the 02 sensor 24, for example, under the following conditions: ■ Engine cooling water temperature Tw>60°C ■ Intake air ff1Ac+ ≧Cylinder stroke volume 10%■
The intake air ff1Ac+ with respect to the engine speed Ne is outside the enrich line and the fuel cut zone. ■ When the 02 sensor 24 is active, the fuel feedback correction coefficient vlCf F B (for example, 0.8≦CfFa≦1.25, proportionality constant P1
= 0.06, integral constant 1 = 0.05/scc).

Further, the above-mentioned Tsuyunil cut switch 45 is activated by the output signal from the Fuconil cut control module 50.
It is controlled by J. This fuconyl cut control module 50 operates based on the zone signal from the zone determination module 51 and the intake air amount AC+ signal, for example, under the following conditions. %■ Engine speed Ne > 1 When QQQrp+++ is satisfied, turn the unit cut switch 4 to cut fuel injection.
5 is controlled to open. Here, the zone determination module 51 uses the respective control modules 35.
7 to 50 condition judgment signals (zone signal 9'3) are created.
It is something that

Furthermore, the fuel injection valve correction circuit 46 includes the third fuel injection valve correction circuit 46.
In response to the target fuel supply ff1Qfi313 from the multiplier 44 and the battery voltage VsI from the battery 29, the pulse signal as the target fuel supply amount signal to the fuel injection valve 12 is corrected according to the battery voltages V and e. It outputs to the fuel injection valve 12. As described above, the fuel injection valve 12 is driven for a predetermined period of time in synchronization with ignition, and the fuel supply 1 is brought to the target value by 2+11111.

Therefore, in the above embodiment, the accelerator operation amount α
A target intake air i1 to be supplied to the engine 1 is determined in accordance with the target intake air amount, and the opening degree of the throttle valve 6 is feedback-controlled so as to reach this target intake air amount, and the target intake air amount is supplied to the engine 1.

In that case, when exhaust gas is recirculated to the engine 1, a continuous flow fil
The amount of exhaust gas recirculation fluctuates due to variations in the operation of the control valve 10 and the magnitude of the exhaust pressure of the recirculated exhaust gas. CaF3 fluctuates greatly, and the fluctuation range of the intake air amount learning correction coefficient 5TDY also increases. However, during this exhaust gas recirculation, the learning correction module 35 has an intake air amount learning correction coefficient of 5vo.
The limit of v is 1 when exhaust gas recirculation is stopped. ○±30% to 1
．． Since the intake air amount learning correction coefficient 5vov, which is the basis of the learning correction, is largely changed to 0±50%, it is output as is to the multiplier 36 without exceeding the limit value, and the multiplier 36 changes it to the target intake air amount Act. Corresponding target throttle valve opening θ)
Or it is subjected to learning correction of θIE, and as a result, the multiplier 3
In step 6, the target throttle valve opening θ1 or θ1E is learned and corrected to an appropriate value, and the degree of control of the intake air amount is improved.

Also, target air m and target fuel r are calculated for the accelerator operation amount α.
31ffi are determined, and based on the determined target values, the intake air amount and the fuel supply amount are controlled simultaneously and in parallel to reach the target values, so that changes in the accelerator operation amount α are controlled. On the other hand, since the intake air amount and the fuel supply m change to the target values at the same time without any time lag between them, there is no delay in fuel response even during transient engine operation, and the engine The fuel ratio can be well controlled by 5 degrees to the target air-fuel ratio, thereby improving the acceleration performance and driving performance of the engine.

(Effects of the Invention) As explained above, according to the present invention, (
j. The correction limit value of the feedback control of the throttle valve has been changed to a larger value than when the air recirculation is stopped, so that the feedback value can be appropriately selected, so the feedback control of the throttle valve can be made appropriate. I can do it,
Therefore, it is possible to improve the control efficiency of the intake air amount.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. ) Fig. 12 and Fig. 3 show an embodiment of the present invention, Fig. 2 is a general schematic diagram, and Fig. 3 is a block diagram showing the operation flow of the control unit. 1...Engine, 5...Accelerator pedal, 6...
Throttle valve, 7... Throttle actuator, 2
6... Control unit, 25... Continuous flow hinger, 38... Correction limit value changing means. Patent applicant Mazda Motor Corporation-17-Z-Mo=1U1″yo;

Claims (1)

[Claims] (1) In an engine throttle valve control device that determines a target intake amount according to the accelerator operation amount and feedback-controls the opening of the throttle valve so as to reach the target intake amount, exhaust gas is recirculated to the engine. Exhaust gas recirculation time detection means for detecting the time; and correction limit value changing means for receiving the output of the exhaust gas recirculation time detection means and changing the correction limit value of the feedback control of the throttle valve during exhaust gas recirculation to a value greater than when the exhaust gas recirculation is stopped. An engine throttle valve control device comprising: