CN1977100A - Controller of internal combustion engine - Google Patents

Abstract

The quantity of air filling a cylinder is divided into a first quantity of air and a second quantity of air. The first quantity of air and the second quantity of air are calculated respectively and summed to calculate the quantity of air filling the cylinder. The first quantity of air is the surplus quantity of air filling the cylinder for the quantity of air passing through a throttle valve resulting from intake stroke. Intake pressure lowering amount, i.e. lowering amount of intake pressure resulting from intake stroke, is detected for each cylinder and total value of lowering amount of intake pressure within the range of 720 DEG crank angle is calculated. The first quantity of air is calculated based on the lowering amount of intake pressure and the total value of lowering amount of intake pressure. With such an arrangement, the quantity of air filling the cylinder can be calculated easily and accurately.

Description

The control gear of internal-combustion engine

Technical field

The present invention relates to the control gear of internal-combustion engine.

Background technique

Have a plurality of cylinders, only the air of closure by air quantity flows into by closure in the suction tude from closure to intake valve, and the air of when carrying out aspirating stroke, only filling air quantity in the cylinder flows out and is filled into the internal-combustion engine in each cylinder from suction tude by corresponding intake valve, is well known that use is by about the mass conservation law of suction tude with calculate about the formula that air state equation in the suction tude obtains in the cylinder of each cylinder and fill air quantity (opening the 2002-70633 communique with reference to the Japan Patent spy).

Fill air quantity in order to use this formula to calculate in cylinder, must obtain the temperature of the air in the suction tude for example and the volume of suction tude.But in order to obtain air temperature, not only for example temperature transducer is essential, even and considering that the serviceability temperature sensor also is difficult to correctly obtain air temperature under the situation of operating lag.And, because foozle is arranged in suction tude, so can not think that the volume of suction tude for example equals design load.Each volume of measuring suction tude is unpractical at all.

And for using formula to infer the situation of filling air quantity in the cylinder, because when using the formula that obtains based on mass conservation law, equation of state same as before, formula complexity, calculated load are big, so formula that will be such is simplified the back utilization usually.In this situation, when intake valve being opened and closed time set to the delay side, intake valve is also opened later in the air inlet lower dead center.At this moment, even piston begins to rise, intake valve also stays open state, so exist the air that sucks in the cylinder to flow back to the interior worry of suction tude.But, fill air quantity in the cylinder when inferring as mentioned above, simplify when utilizing formula, the refluence of this air is not taken into account, can in the cylinder of calculating, fill in the air quantity thus and produce error.

Summary of the invention

Therefore, the object of the present invention is to provide a kind of can be simply and correctly calculate the control gear of filling the internal-combustion engine of air quantity in the cylinder.

As solving the means that above-mentioned problem is used, the invention provides the control gear of the internal-combustion engine in a kind of each claim that is documented in the claim scope.

In order to solve above-mentioned problem, according to the 1st invention, have a plurality of cylinders a kind of, only closure passes through the air of air quantity by in the inlet air pathway part of closure inflow from closure to intake valve, when carrying out aspirating stroke, the air of only filling air quantity in the cylinder flows out by corresponding intake valve and is filled into the internal-combustion engine in each cylinder from this inlet air pathway part, a kind of control gear is provided, wherein, be divided into first air quantity and second air quantity with filling air quantity in the cylinder, this first air quantity is that the closure that carries out the aspirating stroke generation relatively passes through air quantity, fill the overage of air quantity in the cylinder, this control gear has suction pressure and reduces the amount detection machine structure, and it is to the reduction amount of each air cylinder detecting by the suction pressure that carries out the aspirating stroke generation, it is suction pressure reduction amount; First air quantity is calculated mechanism, and it calculates first air quantity of each cylinder according to corresponding suction pressure reduction amount; Closure is by air quantity feeler mechanism, and it detects closure and passes through air quantity; Second air quantity is calculated mechanism, and it calculates second air quantity of each cylinder by air quantity according to closure; Fill air quantity in the cylinder and calculate mechanism, it is by filling air quantity in the cylinder that corresponding first air quantity and second air quantity is added up to, calculates each cylinder; With the control mechanism that carries out internal-combustion engine control according to filling air quantity in the cylinder of each cylinder, this first air quantity is calculated mechanism and in the mode that comprises the aspirating stroke of at least two cylinders of filling air quantity in the cylinder to be calculated the crank shaft angle scope of setting is set, the aggregate value of suction pressure reduction amount of the cylinder of aspirating stroke is carried out in calculating in this setting crank shaft angle scope, calculate first air quantity according to separately suction pressure reduction amount and this suction pressure reduction amount aggregate value.

And, according to the 2nd invention, in the 1st invention, when aspirating stroke produce latter stage air in the cylinder when inlet air pathway partly flows backwards, forbid that above-mentioned second air quantity calculates second air flow meter of mechanism and can be regarded as usefulness.

In order to solve above-mentioned problem, according to the 3rd invention, a kind of control gear is provided, it is as filling the air quantity estimating device in the cylinder of the internal-combustion engine with a plurality of cylinders and a plurality of intake valves, and the interior air quantity of filling of cylinder of each cylinder is divided into basic air quantity and two-part relatively, the above-mentioned air quantity that surpasses surpasses closure and passes through air mass flow for opening owing to intake valve, partly flow into air quantity in the cylinder from inlet air pathway, this control gear has basic air quantity and calculates mechanism, and it opens the basic air quantity of Time Calculation according to the closure that flows into the inlet air pathway part by closure by air mass flow and each intake valve; Surpass air quantity and calculate mechanism, its reduction amount according to the suction pressure that is caused by opening of above-mentioned intake valve is calculated and is surpassed air quantity; The interior air quantity of filling of cylinder is calculated mechanism, and it adds up to above-mentioned basic air quantity with above air quantity, calculates the interior air quantity of filling of cylinder of each cylinder relatively; With the control mechanism that carries out internal-combustion engine control according to filling air quantity in the cylinder of each cylinder, wherein, above-mentioned basic air quantity is calculated the imaginary intake valve that mechanism calculates when the average air flow of all cylinders equates by air mass flow with closure relatively and is opened the time, and this imaginary intake valve time of opening is used as opening the time of above-mentioned intake valve.

According to the 3rd invention, the value when regarding the imaginary intake valve time of opening as relatively the average air flow of all cylinders equates by air mass flow with closure.Therefore, when having the refluence of the air in suction tude in the cylinder, it is short that the intake valve that imaginary intake valve is opened time ratio reality is opened the time, when using this imaginary intake valve time of opening to calculate basic air quantity by basic air quantity calculating mechanism, can correctly calculate basic air quantity.

And, according to the 4th invention, in the 3rd invention, near opening period at intake valve or near IC Intake Valve Closes period, produce when the air of above-mentioned inlet air pathway part flows backwards, above-mentioned basic air quantity is calculated mechanism will be used as opening the time of above-mentioned intake valve the above-mentioned imaginary intake valve time of opening.

According to the present invention, can be simply and correctly calculate and fill air quantity in the cylinder.

Below, can from the description of accompanying drawing and the preferred embodiments of the present invention, understand the present invention more fully.

Description of drawings

Fig. 1 is the overall pattern of internal-combustion engine.

Fig. 2 opens and closes the figure in period for the expression intake valve.

Fig. 3 is the figure of the testing result of expression suction pressure Pm.

Fig. 4 is the time diagram that is used to illustrate suction pressure reduction amount Δ Pmdwni.

Fig. 5 is used to illustrate the figure that fills the computational methods of air quantity Mci in the cylinder.

Fig. 6 A and Fig. 6 B are the time diagram that is used to illustrate the computational methods of parameter K m.

Fig. 7 A and Fig. 7 B are the time diagram of other example that is used to illustrate the computational methods of parameter K m.

Fig. 8 is used to illustrate intake valve is opened and closed the time diagram that valve is set to intake air flow mci in the cylinder when postponing side period.

Fig. 9 is the flow chart of the computer program of expression fuel injection time TAUi.

Figure 10 is the flow chart that relates to computer program first embodiment, the interior filling of expression cylinder air quantity Mci.

Figure 11 is the time diagram that is used to illustrate approximate error.

Figure 12 A and 12B are used to illustrate that imaginary intake valve opens the time diagram of the computational methods of time x.

Figure 13 is used to illustrate that imaginary intake valve opens the time diagram of the computational methods of time x.

Figure 14 is the flow chart that relates to computer program second embodiment, the interior filling of expression cylinder air quantity Mci.

Figure 15 is the flow chart of the computer program of the value of expression variable x.

Embodiment

Below, with reference to accompanying drawing embodiments of the invention are elaborated.Fig. 1 represents the present invention is adapted to situation on the four-stroke cylinder injection spark ignition type internal combustion engine.In addition, the present invention also can be adapted on other spark-ignited internal combustion engine or the compression ignition formula internal-combustion engine.

As shown in Figure 1, in the present embodiment, for example have that the body of the internal-combustion engine 1 of 8 cylinders comprises cylinder block 2, pistons reciprocating 3 and be fixed to cylinder head 4 on the cylinder block 2 in cylinder block 2.Between piston 3 and cylinder head 4, form firing chamber 5.Intake valve 6, suction port 7, exhaust valve 8 and relief opening 9 are being set on each cylinder, on cylinder head 4.In addition, as shown in Figure 1, igniter plug 10 is set, Fuelinjection nozzle 11 is set at the internal face periphery of cylinder head 4 at the central part of the internal face of cylinder head 4.And, the end face of piston 3 form extend to below the Fuelinjection nozzle 11 igniter plug 10 below chamber 12.

The suction port 7 of each cylinder is connected to knock out drum 14 by air intake branch 13, and knock out drum 14 is connected to air-strainer 16 by suction tude 15.The closure 18 that is driven by stepping motor 17 is set in suction tude 15.In addition, in this manual, the part of the inlet air pathway that will constitute by suction tude 15, knock out drum 14, air intake branch 13 and the suction port 7 in closure 18 downstreams, promptly the part of 6 inlet air pathway is called " suction tude part IM " from closure 18 to intake valve.On the other hand, the relief opening 9 of each cylinder is connected to by exhaust branch pipe and outlet pipe 19 on the catalyst converter 21 of built-in Exhaust gas purifying device 20, and this catalyst converter 21 is communicated with atmosphere by the silencing apparatus (not shown).

The intake valve 6 of each cylinder is driven by intake valve drive unit 22 and makes its switching.This intake valve drive unit 22 has camshaft and makes the angle of rotation of the camshaft corresponding with crank shaft angle shift to an earlier date the switching mechanism that selectively switches usefulness between side and the delay side.When the angle of rotation that makes camshaft shifts to an earlier date, shown in the AD among Fig. 2, intake valve 6 the period of opening VO and close period VC in advance, therefore, open and close valve period in advance.On the other hand, when the angle of rotation that makes camshaft postponed, shown in the RT among Fig. 2, therefore the VO and close period VC and postpone in the period of opening of intake valve 6, opened and closed valve and postpones period.In this case, in the lift that keeps intake valve 6 and working angle (valve open during), change phase angle (valve is opened period).In internal-combustion engine as shown in Figure 1, the angle of rotation of camshaft and internal combustion engine operation state are switched in advance side accordingly or postpone side.In addition, the present invention also can be applicable to the continually varying situation in the period of opening that makes intake valve 6, the situation that lift or working angle are changed.

With reference to Fig. 1, electronic control unit (ECU) 31 is made of digital computer, has by bidirectional bus 32 interconnective RAM (random access memory) 33, ROM (ROM (read-only memory)) 34, CPU (microprocessor) 35, input port 36 and output port 37.On the suction tude 15 of closure 18 upstreams, be provided for detecting the Air flow meter 40 of the flow of air (suction gas) by suction tude 15.And, on knock out drum 14, be provided for detecting the pressure transducer 41 of air pressure in the suction tude part IM (below, be called " suction pressure ") Pm.In addition, on accelerator pedal 42, connect to produce the load sensor 43 with the proportional output voltage of the amount of depressing of accelerator pedal 42, on closure 18, be provided for detecting the engine load sensor (not shown) of the aperture of closure 18.The output signal of these sensors 40,41,43 is input to input port 36 by each self-corresponding AD converter 38.In addition, on input port 36, connect crankshaft angle sensor 44, for example 30 ° of the every rotations of bent axle, this sensor produces the output pulse.Calculate internal-combustion engine rotational speed by CPU 35 according to the output pulse of crankshaft angle sensor 44.On the other hand, output port 37 is connected respectively to igniter plug 10, Fuelinjection nozzle 11, stepping motor 17 and intake valve drive unit 22 by the drive circuit 39 of correspondence, controls them according to the output of electronic control unit 31.

In the internal-combustion engine of present embodiment, the i cylinder (i=1,2 ..., 8) fuel injection amount (fuel injection time) TAUi for example calculate according to following formula (1).

TAUi＝TAUb·ηi·k ...(1)

Here, TAUb represents basic fuel injection amount (basic fuel injection time), and η i represents the air quantity offset correction coefficient of i cylinder, and k represents other correction factor.

Basic fuel injection amount TAUb is for making the consistent necessary fuel injection amount with target air-fuel ratio of air fuel ratio.This basic fuel injection amount TAUb is as parameter (for example, engine load and the internal-combustion engine rotational speed NE etc. relevant with the internal combustion engine operation state.Below, be called " operating parameters ") function obtained in advance, and with the mapping form be stored in the ROM 34, perhaps calculate by formula based on operating parameters.And correction factor k is that air fuel ratio correction coefficient, acceleration incremental correction coefficient etc. are blanket to the coefficient of representing together, and when not having correction in case of necessity, this coefficient is 1.0.

Be called in the cylinder and fill air quantity Mci (g) if be filled into the amount of the air in the cylinder when aspirating stroke in the i cylinder is finished, then air quantity offset correction coefficient η i is the coefficient that is used for filling in the compensating cylinder deviation between the cylinder of air quantity Mci.The air quantity offset correction coefficient η i of i cylinder for example calculates according to following formula (2).

ηi＝Mci/Mcave ...(2)

Here, Mcave represents to fill in the cylinder mean value (=∑ Mci/8 of air quantity Mci.Here " 8 " represent cylinder number).

When forming mainly the sediments that is made of carbon on the outer surface of the interior perimeter surface of for example suction tude part IM or intake valve 6, sedimental adhesion amount is all different at each cylinder, fills the worry that produces deviation between cylinder among the air quantity Mci so have in cylinder.And, there is situation to the foozle between the generation cylinders such as volume of firing chamber 5, in this case, also have and in cylinder, fill the worry that produces deviation between cylinder among the air quantity Mci.Exist under the situation of deviation between cylinder, all cylinders are kept the fuel injection amount that equates if in cylinder, fill air quantity Mci, then in air fuel ratio, output torque, can produce the deviation between cylinder.Therefore, in the present embodiment, import air quantity offset correction coefficient η i, with deviation between the cylinder of filling air quantity in the compensating cylinder.

In addition, consider the actual regularly situation of leading a period of time of calculating of carrying out fuel injection timing than fuel injection amount TAUi, can be with the basic fuel injection amount TAUb in the formula (1) as the predicted value that regularly takes the lead a period of time of calculating than the fuel injection amount TAUi of formula (1).

Perhaps, can calculate the fuel injection amount TAUi of i cylinder according to following formula (3).

TAUi＝Mci·kAF·k ...(3)

Here, kAF is the correction factor that air fuel ratio and target air-fuel ratio one are applied.

In this case, consider the actual situation of calculating regularly leading a period of time of carrying out fuel injection timing, also can will fill air quantity Mci in the cylinder in the formula (3) as the predicted value of calculating regularly leading a period of time than fuel injection amount TAU than fuel injection amount TAU.

Like this, under the situation according to formula (1) computing fuel emitted dose TAUi, under situation about calculating according to formula (3), for all cylinders being made air fuel ratio consistent with target air-fuel ratio and do not have deviation between cylinder, be necessary correctly to obtain and fill air quantity Mci in the cylinder.

In the present embodiment, according to the reduction amount of the suction pressure Pm that aspirating stroke produced that carries out the i cylinder, be suction pressure reduction amount Δ Pmdwni, calculate and fill air quantity Mci in the cylinder.Below, with reference to Fig. 3 to Fig. 5 suction pressure reduction amount Δ Pmdwni is described at first.

Fig. 3 for example represents at regular intervals at interval, in 720 ° of crank shaft angle scopes by pressure transducer 41 detected suction pressure Pm.Air inlet in the internal-combustion engine as shown in Figure 3 is #1-#8-#4-#3-#6-#5-#7-#2 in proper order.In Fig. 3, OPi (i=1,2 ..., 8) represent that the intake valve of i cylinder opens and closes period, 0 ° of crank shaft angle is represented the air inlet top dead center of No. 1 cylinder #1.Can know that from Fig. 3 when the aspirating stroke of certain cylinder began, the suction pressure Pm that has risen began to reduce, so, produce peak value upwards in the suction pressure Pm.Suction pressure Pm rises after further reducing once more, so, produces downward peak value in suction pressure Pm.Like this, in suction pressure Pm, alternately produce peak value upwards and downward peak value.In Fig. 3 owing to carry out the aspirating stroke of i cylinder the peak value that makes progress that in suction pressure Pm, produces by UPi represent, downward peak value represented by DNi.

As shown in Figure 4, if the suction pressure Pm among the peak value UPi that makes progress is called maximum value Pmmaxi, suction pressure Pm among the downward peak value DNi is called minimum value Pmmini, then owing to carry out the aspirating stroke of i cylinder, suction pressure Pm is reduced to minimum value Pmmini from maximum value Pmmaxi.Therefore, suction pressure reduction amount Δ Pmdwni is in this case represented by following formula (4).

ΔPmdwni＝Pmmaxi-Pmmini ...(4)

On the other hand, as shown in Figure 4, when intake valve 6 is opened, from suction tude part IM flow out and be inhaled into the air of CYL in the cylinder flow, be that intake air flow mci in the cylinder (Grams Per Second is with reference to Fig. 5) begins to increase.Then, when intake air flow mci in the cylinder than the flow that flows into the air in the suction tude part IM by closure 18, be that closure passes through air mass flow mt (Grams Per Second is with reference to Fig. 5) when big, suction pressure Pm begins to reduce.Then, intake air flow mci reduces and passed through air mass flow mt hour than closure in cylinder, and suction pressure Pm begins to increase.

Promptly, if consider that only closure passes through the air of air mass flow mt by in the closure 18 inflow suction tude part IM, carry out to the air inlet of i cylinder with from the air of suction tude part IM intake air flow mci in each intake valve 6 flows out cylinder only, then temporarily surpass by air mass flow mt as the closure that flows into part as intake air flow mci in the cylinder that flows out part, therefore, the suction pressure Pm as the pressure in the suction tude part IM only reduces suction pressure reduction amount Δ Pmdwni.

In addition, fill the value of air quantity Mci in the cylinder for intake air flow mci in the cylinder being carried out obtain after the time integral.Therefore, open and close OPi in period (with reference to Fig. 3) to filling the influence that repeats of air quantity Mci or air quantity offset correction coefficient η i in the cylinder, then can represent to fill in the cylinder air quantity Mci like that as shown in the formula (5) if can ignore intake valve.

$\mathrm{Mci}={\∫}_{t\max i}^{t\min i}(\mathrm{mci}-\mathrm{mt})\mathrm{dt}+\mathrm{mt}\·\frac{\mathrm{\Δtdwni}+\mathrm{\Δtoc}}{2}---\left(5\right)$

Here, tmaxi is illustrated in air inlet and presses the moment of generation peak value upwards among the Pm, promptly takes place constantly to upward peak, tmini is illustrated in air inlet and presses moment of producing downward peak value among the Pm, is that downward peak value takes place constantly, Δ tdwni represents that tmaxi to downward peak value takes place the time lag (second) the tmini constantly from take place constantly to upward peak, and Δ toc represents that intake valve opens the time (second) (with reference to Fig. 4).

In formula (5), the part of representing by T1 in the 1st presentation graphs 4 in the right (below be called " regional T1 "), that is, and the area of the part that fences up by air mass flow mt by intake air flow mci and closure in the cylinder; The 2nd on the right is with the part represented by T2 in the ladder approximation ground presentation graphs 4 (below be called " regional T2 "), that is, and and the area of the part that fences up by air mass flow mt and straight line mci=0 by intake air flow mci in the cylinder, closure.

As mentioned above, owing to carry out aspirating stroke, intake air flow mci temporarily surpasses closure by air mass flow mt in the cylinder.Therefore, fill air quantity Mci in the cylinder that intake air flow mci in the cylinder is carried out obtaining after the time integral and surpass the time integral value of closure by air mass flow mt.Like this, regional T1 represents to carry out relatively overage closure that aspirating stroke the produces integral value by air mass flow mt, that fill air quantity Mci in the cylinder.

Therefore, generally speaking, with fill in the cylinder air quantity branch serve as reasons regional T1 cartographic represenation of area first air quantity (surpassing air quantity) and by second air quantity (basic air quantity) of the cartographic represenation of area of regional T2, first air quantity is passed through overage air quantity, the interior filling of cylinder air quantity for the closure that carries out the aspirating stroke generation relatively, each cylinder is added up to first air quantity and second air quantity, calculate the interior air quantity of filling of cylinder of each cylinder thus.

On the other hand, use about the air state equation in the suction tude part IM, by the mass conservation law of following formula (6) expression about suction tude part IM.

$\frac{\mathrm{dPm}}{\mathrm{dt}}=\frac{\mathrm{Ra}\·\mathrm{Tm}}{\mathrm{Vm}}\·(\mathrm{mt}-\mathrm{mci})---\left(6\right)$

Here, Vm represents the volume (m of suction tude part IM ³), Ra represents to remove the value that obtains behind the gas constant (below, be called " gas constant " simply) by the mean molecule quantity of air, and Tm represents the temperature (K) (with reference to Fig. 5) of the air in the suction tude part IM.

To the moment tmini, suction pressure Pm only reduces suction pressure reduction amount Δ Pmdwni from moment tmaxi.Therefore,, closure is represented with its mean value mtave by air mass flow mt, then can be used formula (6) that formula (5) is rewritten an accepted way of doing sth (7) like that if Vm/ (RaTm) is represented with parameter K m is unified.

$\mathrm{Mci}=\mathrm{\ΔPmdwni}\·\mathrm{Km}+\mathrm{mtave}\·\frac{\mathrm{\Δtdwni}+\mathrm{\Δtoc}}{2}---\left(7\right)$

Like that, if detect suction pressure Pm and calculate suction pressure reduction amount Δ Pmdwni by pressure transducer 41, obtain above-mentioned parameter Km, detect closure by air mass flow mt and calculate its mean value mtave by Air flow meter 40, and according to suction pressure Pm and closure by air mass flow mean value mtave detect constantly tmaxi, tmini and computing time interval of delta t dwni (=tmini-tmaxi), then can use formula (7) to calculate and fill air quantity Mci in the cylinder.In addition, intake valve is opened time Δ toc and is stored in advance in the ROM 34.

But, as described in starting, be difficult to correctly obtain suction tude volume V m and intake manifold temperature Tm.Therefore, in the present embodiment, under the situation of not asking suction tude volume V m and intake manifold temperature Tm, ask parameter K m.Below, with reference to the computational methods of the parameter K m of Fig. 6 A and 6B explanation present embodiment.

In the present embodiment, in the setting crank shaft angle scope of setting in the mode of the aspirating stroke that comprises in the cylinder to be calculated at least two cylinders of filling air quantity Mci, pay close attention to the air quantity that flows into the air quantity in the suction tude part IM and flow out from suction tude part IM.

Fig. 6 A and Fig. 6 B represent to comprise the aspirating stroke of whole cylinders, for example the air inlet top dead center from No. 1 cylinder is made as the situation of setting the crank shaft angle scope to 720 ° of crank shaft angle scopes the air inlet top dead center of No. 1 cylinder of next time.

The total amount that flows into the air in the suction tude part IM in these 720 ° of crank shaft angle scopes is only rotated 720 ° crank shaft angle needed needed time ts by the closure in these 720 ° of crank shaft angle scopes by air mass flow mean value mtave and bent axle for the area of the part represented by hatching among Fig. 6 A ₇₂₀Product representation (mtavet ₇₂₀).On the other hand, in these 720 ° of crank shaft angle scopes from suction tude part IM flow out and the total amount that is filled into the air in the cylinder for the area of the part represented by hatching Fig. 6 B, represent by the aggregate value ∑ Mci that fills air quantity Mci in the cylinder.

If initial point and destination county suction pressure Pm 720 ° of crank shaft angle scopes are roughly constant, then flow into the total amount of the air in the suction tude part IM during these 720 ° of crank shaft angle and flow out from suction tude part IM and be filled into the total amount of the air in the cylinder should be mutually about equally.Therefore, in this case, following formula (8) is set up.

$\mathrm{mtave}\&CenterDot;{\mathrm{<figure-callout\; id="720"\; label="t"\; filenames="A20068000043300262.png"\; state="\{\{state\}\}">t</figure-callout>}}_{720}=\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{Mci}---\left(8\right)$

When with the right of formula (7) substitution formula (8) and when putting in order, can represent parameter K m like that as shown in the formula (9).

$\mathrm{Km}=\mathrm{mtave}\&CenterDot;\frac{2t_{720}-\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}(\mathrm{\&Delta;tdwni}+\mathrm{\&Delta;toc})}{2\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwni}}---\left(9\right)$

That is, if, calculate needed time t according to the output of crankshaft angle sensor 44 according to calculating closure by air mass flow mean value mtave by air mass flow mt by Air flow meter 40 detected closures ₇₂₀Calculate the aggregate value ∑ Δ tdwni of time lag Δ tdwni (with reference to Fig. 4) or time lag Δ tdwni and intake valve open time Δ toc's (with reference to Fig. 4) and aggregate value ∑ (Δ tdwni+ Δ toc), and calculate the aggregate value ∑ Δ Pmdwni of suction pressure reduction amount Δ Pmdwni, then can calculate parameter K m.Like this, need not ask suction tude volume V m and intake manifold temperature Tm just can simply try to achieve parameter K m, therefore, can be simply and correctly obtain and fill air quantity Mci in the cylinder.

Shown in Fig. 7 A and Fig. 7 B, also can be made as the crank shaft angle scope of setting with for example comprising 360 ° of crank shaft angle scopes of the aspirating stroke of four cylinders.In the example shown in Fig. 7 A and Fig. 7 B, set from first 360 ° of crank shaft angle scopes of the air inlet top dead center of No. 6 cylinders of air inlet top dead center to the of No. 1 cylinder and second 360 ° of crank shaft angle scope from the air inlet top dead center of No. 6 cylinder to the air inlet top dead center of No. 1 cylinder of next time.

For first 360 ° of crank shaft angle scopes, only rotate the needed needed time t of first 360 ° of crank shaft angle scopes by air mass flow mean value mtave, bent axle according to the closure in first 360 ° of crank shaft angle scopes ₃₆₀, and in first 360 ° of crank shaft angle scopes, carry out filling in the cylinder of cylinder of aspirating stroke the aggregate value ∑ Mcj (j=1,2,3,4) of air quantity Mcj, following formula (10) is set up.Here, j represents the aspirating stroke order.Similarly, for second 360 ° of crank shaft angle scope, only rotate second needed needed time t ' of 360 ° of crank shaft angle scopes by air mass flow mean value mtave ', bent axle according to the closure in second 360 ° of crank shaft angle scope ₃₆₀, and in second 360 ° of crank shaft angle scope, carry out filling in the cylinder of cylinder of aspirating stroke the aggregate value ∑ Mcj (j=5,6,7,8) of air quantity Mcj, following formula (11) is set up.

$\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}\mathrm{Mcj}=\mathrm{mtave}\&CenterDot;t_{360}---\left(10\right)$

$\underset{j=5}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{Mcj}=\mathrm{mtav}{e}^{\&prime;}\&CenterDot;{t^{\&prime;}}_{360}---\left(11\right)$

Therefore, can represent like that as shown in the formula (12), can represent like that as shown in the formula (13) about the parameter K m of the second crank shaft angle scope about the parameter K m of the first crank shaft angle scope.

$\mathrm{Km}=\mathrm{mtave}\&CenterDot;\frac{{2t}_{360}-\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}(\mathrm{\&Delta;tdwnj}+\mathrm{\&Delta;toc})}{2\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwnj}}---\left(12\right)$

$\mathrm{Km}=\mathrm{mtav}{e}^{\&prime;}\&CenterDot;\frac{{2t^{\&prime;}}_{360}-\underset{j=5}{\overset{8}{\mathrm{\&Sigma;}}}(\mathrm{\&Delta;tdwnj}+\mathrm{\&Delta;toc})}{2\underset{j=5}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwnj}}---\left(13\right)$

In this case, the parameter K m passing through type (7) that use is calculated by formula (12) calculates in the cylinder of the cylinder that carries out aspirating stroke in the first crank shaft angle scope and fills air quantity Mcj (j=1,2,3,4), use the parameter K m passing through type (7) of calculating to calculate in the cylinder of the cylinder that in the second crank shaft angle scope, carries out aspirating stroke and fill air quantity Mcj (j=5,6 by formula (13), 7,8).

Therefore, generally speaking, in the mode that comprises the aspirating stroke of at least two cylinders of filling air quantity in the cylinder to be calculated the crank shaft angle scope of setting is set, the aggregate value ∑ Δ Pmdwni of suction pressure reduction amount Δ Pmdwni of the cylinder of aspirating stroke is carried out in calculating in this setting crank shaft angle scope, calculate above-mentioned first air quantity based on separately suction pressure reduction amount Δ Pmdwni and this suction pressure reduction amount aggregate value ∑ Δ Pmdwni.Perhaps, can only rotate by air mass flow mt or its mean value, bent axle based on corresponding suction pressure reduction amount Δ Pmdwni, suction pressure reduction amount aggregate value ∑ Δ Pmdwni, closure and set the needed needed time of crank shaft angle scope, produce to upward peak UPi (with reference to Fig. 4) from suction pressure Pm and open time Δ toc or its aggregate value ∑ Δ toc, calculate first air quantity to the time lag Δ tdwni of the downward peak value DNi of generation or its aggregate value ∑ Δ tdwni or intake valve.

, when will be for example the intake valve switching be set to period when postponing side RT (with reference to Fig. 2), IC Intake Valve Closes VC in period becomes after the air inlet lower dead center.At this moment, even piston begins to rise, intake valve 6 also stays open state, therefore exists the air in the suction cylinder to flow back to the interior worry of suction tude part IM.If produce this refluence, then as among Fig. 8 by X represented, intake air flow mci temporarily becomes negative value in the cylinder, regional T2 can not be with ladder approximation.That is,, can not correctly calculate according to formula (7) and fill air quantity Mci in the cylinder when aspirating stroke produces air latter stage from the cylinder during to the refluence of suction tude part IM.

Therefore, in the present embodiment,, forbid filling in the cylinder of formula (7) the calculating effect of air quantity Mci when the intake valve switching being set to period when postponing side RT.In this case, do not carry out filling in the cylinder renewal of air quantity Mci, but calculate air quantity offset correction coefficient η i according to filling air quantity Mci in the cylinder of calculating in the computation cycles in front.

Fig. 9 represents the computer program of fuel injection amount TAUi of the i cylinder of present embodiment.This program is carried out by the interruption of whenever predetermined setting crank shaft angle.

With reference to Fig. 9, in step 101, calculate basic fuel injection amount TAUb according to detected engine load, internal-combustion engine rotational speeds such as load sensor 43 and crankshaft angle sensor 44 etc.Then, in step 102, carry out the computer program of filling air quantity Mci in the cylinder shown in Figure 10, calculate thus and in the cylinder of each cylinder, fill air quantity Mci.Then, in step 103, the mean value Mcave that fills whole cylinders of air quantity in air quantity Mci and this cylinder according in the cylinder of each cylinder, filling of calculating in the step 102, the air quantity offset correction coefficient η i that use formula (2) is calculated the i cylinder (i=1,2 ... 8).Then, in step 104, calculate correction factor k.Then, in step 105, according to the basic fuel injection amount TAUb that calculates in the step 101,103,104, air quantity offset correction coefficient η i and correction factor k, use formula (1) computing fuel emitted dose TAUi.Fuelinjection nozzle 11 by the i cylinder sprays the only fuel of fuel injection amount TAUi.

Figure 10 represents the interior computer program of filling air quantity Mci of cylinder of the i cylinder of present embodiment.

With reference to Figure 10, be set to side AD (with reference to Fig. 2) in advance the period of opening with intake valve 6 of in step 121, judging whether.When be set in advance side AD the period of opening of intake valve 6, advance to next step 122, calculate closure by air mass flow mean value mtave.Then, in step 123, calculate needed time t ₇₂₀Then, in step 124, detect about the i cylinder to upward peak take place constantly tmaxi and downward peak value take place constantly tmini (i=1,2 ... 8).Then, in step 125, calculate the time lag Δ tdwni (Δ tdwni=tmini-tmaxi) of i cylinder.Then, in step 126, calculate ∑ (Δ tdwni+ Δ toc).Then, in step 127, detect maximum value Pmmaxi and minimum value Pmmini about the i cylinder.Then, the suction pressure reduction amount Δ Pmdwni of use formula (4) calculating i cylinder in step 1 28.Then, fall into a trap in step 129 and add atmospheric pressure reduction amount aggregate value ∑ Δ Pmdwni.Then, use formula (9) calculating parameter Km in step 130.Then, in step 131, fill air quantity Mci in the cylinder of use formula (7) calculating i cylinder.Relative therewith, when in step 121, period of opening of intake valve 6 being set to when postponing side RT the end process circulation.Therefore, forbid filling in the cylinder calculating of air quantity Mci.

Among the embodiment shown in before, regional T2 shown in Figure 4 is approximately the top and followingly is respectively the trapezoidal of Δ tdwni and Δ toc.But, for example be the rectangular of Δ tdwni Yi Bian also regional T2 can be approximately.In this case, above-mentioned formula (7) and formula (9) become following formula (14) and (15) respectively.

Mci＝ΔPmdwni·Km+mtave·Δtdwni ...(14)

$\mathrm{Km}=\mathrm{mtave}\&CenterDot;\frac{t_{720}-\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;tdwni}}{\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwni}}---\left(15\right)$

Then, the second embodiment of the present invention is described.If Vm/Ra is represented as parameter K m ', then above-mentioned formula (6) is deformed into formula (16).

$\mathrm{mt}-\mathrm{mci}=\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tm}}\&CenterDot;\frac{\mathrm{dPm}}{\mathrm{dt}}---\left(16\right)$

Because to the moment tmini, suction pressure Pm only reduces suction pressure reduction amount Δ Pmdwni from moment tmaxi, so can use formula (16) above-mentioned formula (5) be rewritten as following formula (17).

$\mathrm{Mci}=\mathrm{\&Delta;Pmdwni}\&CenterDot;\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tm}}+\mathrm{mt}\&CenterDot;\frac{\mathrm{\&Delta;tdwni}+\mathrm{\&Delta;toc}}{2}---\left(17\right)$

Like that, if detect suction pressure Pm and calculate suction pressure reduction amount Δ Pmdwni by pressure transducer 41, obtain above-mentioned parameter Km ', detect closure by air mass flow mt and calculate its mean value mtave by Air flow meter 40, and according to suction pressure Pm detect constantly tmaxi, tmini and computing time interval of delta t dwni (=tmini-tmaxi), then can use formula (17) to calculate and fill air quantity Mci in the cylinder.In addition, in formula (17), intake valve is opened time Δ toc for issue the indicated value of intake valve drive unit 22 from ECU 31, therefore is the 6 actual times of opening of intake valve.

But, as described in starting, owing to suck the refluence of air in suction tude in the cylinder,,, can in cylinder, fill in the air quantity and produce error when calculating like that as mentioned above when filling air quantity in the cylinder perhaps because other main cause.That is second regional T2 in the right of formula (17), with ladder approximation Fig. 4., under the situation of the refluence that produces air etc., compared with regional T2 by second approximate value of calculating in the right of formula (17), can have more the amount of being represented by the oblique line of Figure 11, the result can calculate on the high sidely and fill air quantity in the cylinder, thereby can produce error.In other words, when intake valve being opened time Δ toc and be made as the value that equates with the 6 actual times of opening of intake valve, can in second approximate value of calculating in the right, produce error by formula (17).

Therefore, in the present invention, intake valve is opened time Δ toc adjust to suitable value not to be made as the intake valve 6 actual modes of opening the time, thus, even under the situations such as refluence that produce air, also can calculate regional T2 accurately.Below, with reference to Figure 12 A, Figure 12 B and Figure 13 the computational methods of filling air quantity in the cylinder of the present invention are described.

Figure 12 A and Figure 12 B represent during 720 ° of the crank shaft angle from the air inlet top dead center of No. 1 cylinder to the air inlet top dead center of No. 1 cylinder of next time, about filling air mass flow mci and closure in the cylinder of all cylinders by air mass flow mean value mtave.

The total amount that flows into the air in the suction tude part IM during 720 ° of this crank shaft angle is the area of the part represented by hatching among Figure 12 A, by the closure during 720 ° of this crank shaft angle by air mass flow mean value mtave and bent axle 720 ° of needed needed time t in rotary crankshaft angle only ₇₂₀Product representation (mtavet ₇₂₀).On the other hand, during 720 ° of this crank shaft angle from suction tude part IM flow out and the total amount that is filled into the air in the cylinder for the area of the part represented by hatching Figure 12 B, represent by the aggregate value ∑ Mci that fills air quantity Mci in the cylinder.

If initial point and destination county suction pressure Pm 720 ° of crank shaft angle are roughly constant, then flow into the total amount of the air in the suction tude part IM during 720 ° of this crank shaft angle and flow out from suction tude part IM and be filled into the total amount of the air in the cylinder should be mutually about equally.Therefore, in this case, following formula (18) is set up.

$\mathrm{mtave}\&CenterDot;{\mathrm{<figure-callout\; id="720"\; label="t"\; filenames="A20068000043300262.png"\; state="\{\{state\}\}">t</figure-callout>}}_{720}=\underset{i=8}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{Mci}---\left(18\right)$

And, when with the right of formula (17) substitution formula (18) and when putting in order, can represent like that as shown in the formula (19).

$\mathrm{mtave}\&CenterDot;{\mathrm{<figure-callout\; id="720"\; label="t"\; filenames="A20068000043300262.png"\; state="\{\{state\}\}">t</figure-callout>}}_{720}=\underset{i=8}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwni}\&CenterDot;\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tmave}}+\mathrm{mtave}\&CenterDot;\frac{\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;tdwni}+\mathrm{\&Delta;toc}\&CenterDot;8}{2}---\left(19\right)$

Here, Tmave represents the air temperature mean value in the suction tude part IM during 720 ° of the crank shaft angle.

, formula (19) in fact has invalid possibility.This is because as mentioned above, intake valve is opened time Δ toc be set at the value that equates with the 6 actual times of opening of intake valve, thereby can produce error in second the approximate value of calculating in the right by formula (17).

Therefore, in the present invention,, use variable x to replace intake valve to open time Δ toc for above-mentioned formula (19).At this moment, above-mentioned formula (19) is represented as following formula (20).

$\mathrm{mtave}\&CenterDot;{\mathrm{<figure-callout\; id="720"\; label="t"\; filenames="A20068000043300262.png"\; state="\{\{state\}\}">t</figure-callout>}}_{720}=\underset{i=8}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwni}\&CenterDot;\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tmave}}+\mathrm{mtave}\&CenterDot;\frac{\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;tdwni}+x\&CenterDot;8}{2}---\left(20\right)$

And, about variable x arrangement formula (20), formula (20) can be expressed as formula (21).

$x=\frac{{\mathrm{<figure-callout\; id="720"\; label="t"\; filenames="A20068000043300262.png"\; state="\{\{state\}\}">t</figure-callout>}}_{720}}{4}-\frac{\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;tdwni}}{8}-\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tmave}}\&CenterDot;\frac{\underset{i=1}{\overset{8}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;Pmdwni}}{4\&CenterDot;\mathrm{mtave}}---\left(21\right)$

The variable x that calculates like this is for to open the corresponding value of time Δ toc with intake valve, the total amount that during 720 ° of crank shaft angle of supposition, flows into the air in the suction tude part IM with from suction tude part IM outflow and be filled under the situation that the total amount of the air in each cylinder equates, this variable is the value determined (below, be called " imaginary intake valve is opened the time ").Promptly, imaginary intake valve is opened the value of time x for determining in the following manner, described mode be make among Figure 13 by the area of the part of dotted line (that is, upper base is Δ tdwni, goes to the bottom and open time x, highly be the trapezoidal portions of mtave for imaginary intake valve) with equate by the area of the part (regional T2) of air mass flow mtave and straight line mci=0 encirclement by intake air flow mci, closure in the cylinder.But, 1 cylinder only is shown among Figure 13, and in fact imaginary intake valve is opened time x and determined in the following manner, that is, the aggregate value of area of the part of being surrounded by above-mentioned dotted line of all cylinders is equated with the aggregate value of the area of the regional T2 of all cylinders.

On the other hand, when using variable x to replace Δ toc to come expression (17), obtain following formula (22).

$\mathrm{Mci}=\mathrm{\&Delta;Pmdwni}\frac{{\mathrm{Km}}^{\&prime;}}{\mathrm{Tm}}+\mathrm{mt}\&CenterDot;\frac{\mathrm{\&Delta;tdwni}+x}{2}---\left(22\right)$

And, in the value substitution formula (22) of the variable x that will calculate by formula (21), correctly calculate in the cylinder of each cylinder thus and fill air quantity.

Promptly, according to the present invention, the imaginary intake valve of calculating when the average air flow of all cylinders equates by air mass flow with closure is relatively opened the time, the imaginary intake valve like this time of opening is calculated regional T2 as the time of opening of intake valve, can correctly calculate in the cylinder of each cylinder thus and fill air quantity.

Figure 14 represents according to the computer program of filling air quantity Mci in the cylinder second embodiment, the i cylinder.In a second embodiment, replace computer program shown in Figure 10 among first embodiment, calculate by computer program shown in Figure 14 and fill air quantity Mci in the cylinder of i cylinder.

With reference to Figure 14, the detection closures such as output according to Air flow meter 40 in step 141 pass through air mass flow mt.Then, in step 142 according to the output of pressure transducer 41 detect by the intake valve 6 of i cylinder open the suction pressure that causes to upward peak take place constantly tmaxi and downward peak value take place constantly tmini (i=1,2 ... 8).Then, in step 143, calculate the time lag Δ tdwni (Δ tdwni=tmini-tmaxi) of i cylinder according to the detected peak value generation of step 142 moment tmaxi, tmini.Then, in step 144, obtain by imaginary intake valve shown in Figure 15 and open the variable x that the computer program of time x is calculated.

In step 145, open the maximum value Pmmaxi and the minimum value Pmmini of the suction pressure that causes by the intake valve 6 of i cylinder according to the output detection of pressure transducer 41.Then, in step 146, use formula (4) to calculate the suction pressure reduction amount Δ Pmdwni of i cylinder according to detected maximum value Pmmaxi of step 145 and minimum value Pmmini.In step 147, detect temperature T m in the suction tude part IM according to the output of temperature transducer (not shown) etc.And, in step 148, use formula (22) to calculate according to step 141,143,144,146 and 147 mt that calculate, Δ tdwni, x, Δ Pmdwni and Tm and in the cylinder of each cylinder, fill air quantity Mci.In the cylinder of each cylinder, fill the calculating that air quantity Mci is used for fuel injection amount TAUi to each cylinder shown in Figure 9 with what calculate.

Figure 15 represents the computer program of the variable x of the embodiment of the invention.The every rotation of bent axle is just carried out this computer program for 720 °.

With reference to Figure 15, in step 161, detect the time t of 720 ° of needs of crankshaft rotating according to the output of crankshaft angle sensor 44 etc. ₇₂₀Then, in step 162, calculate the mean value mtave of closure by air mass flow during 720 ° of the crankshaft rotating according to the output of Air flow meter 40 etc.Then, in step 163,, will add up to, calculate ∑ Δ tdwni thus by the time lag Δ tdwni that the step 143 of Figure 14 is calculated about all cylinders.In step 164, about all cylinders, will add up to by the suction pressure reduction amount Δ Pmdwni that the step 146 of Figure 14 is calculated, calculate ∑ Δ Pmdwni thus.Then, in step 165, calculate the mean value Tmave of the temperature in the suction tude part IM according to the output of temperature transducer.Then, in step 166, according to step 161,162,163,164 and 165 t that calculate ₇₂₀, mtave, ∑ Δ tdwni, ∑ Δ Pmdwni and Tmave, use formula (21) is calculated the value of variable x.

In addition, as mentioned above, because the establishment of formula (21) does not roughly become condition with the initial point and the destination county suction pressure Pm of 720 ° of crank shaft angle, fill air quantity Mci in the cylinder so only when running well, calculate, when the transition operation that the initial point and the destination county suction pressure Pm of 720 ° of crank shaft angle are easy to change, preferably end to fill in the cylinder calculating of air quantity Mci.Here, be meant for example engine load or the certain substantially period of operation of internal-combustion engine rotational speed during so-called the normal operation, be meant the period of operation of engine load for example or internal-combustion engine rotational speed change during so-called transition operation.

And, according to the above description,, the intake valve switching postpones side, intake valve is also opened later in the air inlet lower dead center, sucks the situation that the air in the cylinder flows backwards in suction tude thus, also is suitable for the present invention for being set to period.But, the present invention not only is applicable to above-mentioned situation, side, intake valve began to open from the air inlet top dead center in the past for for example the intake valve switching being set to period in advance, though intake valve is opened air and do not flowed into situation in the suction tude thus, also can be suitable for the present invention.

In addition, though based on certain embodiments the present invention is described in detail,,, under the situation that does not break away from claim scope of the present invention and thought, can carry out various changes, correction etc. for those skilled in the art.

Claims (4)

1. the control gear of an internal-combustion engine, this internal-combustion engine has a plurality of cylinders, only closure passes through the air of air quantity by in the inlet air pathway part of closure inflow from closure to intake valve, when carrying out aspirating stroke, only the air of filling air quantity in the cylinder flows out by corresponding intake valve and is filled in each cylinder from this inlet air pathway part

Filling air quantity in the cylinder is divided into first air quantity and second air quantity, and this first air quantity is passed through overage air quantity, the interior filling of cylinder air quantity for the closure that carries out the aspirating stroke generation relatively,

This control gear has suction pressure and reduces the amount detection machine structure, its to each air cylinder detecting by the reduction amount of carrying out the suction pressure that aspirating stroke produces, be suction pressure reduction amount;

First air quantity is calculated mechanism, and it calculates first air quantity of each cylinder according to corresponding suction pressure reduction amount;

Closure is by air quantity feeler mechanism, and it detects closure and passes through air quantity;

Second air quantity is calculated mechanism, and it calculates second air quantity of each cylinder by air quantity according to closure;

Fill air quantity in the cylinder and calculate mechanism, it calculates the interior air quantity of filling of cylinder of each cylinder by corresponding first air quantity and second air quantity are added up to; With

Carry out the control mechanism that internal-combustion engine is controlled according to filling air quantity in the cylinder of each cylinder,

This first air quantity is calculated mechanism and in the mode that comprises the aspirating stroke of at least two cylinders of filling air quantity in the cylinder to be calculated the crank shaft angle scope of setting is set, the aggregate value of suction pressure reduction amount of the cylinder of aspirating stroke is carried out in calculating in this setting crank shaft angle scope, calculate first air quantity according to separately suction pressure reduction amount and this suction pressure reduction amount aggregate value.

2. the control gear of internal-combustion engine as claimed in claim 1, wherein, when aspirating stroke produce latter stage air in the cylinder when inlet air pathway partly flows backwards, forbid that above-mentioned second air quantity calculates second air flow meter of mechanism and can be regarded as usefulness.

3. control gear, it is as filling the air quantity estimating device in cylinder of the internal-combustion engine with a plurality of cylinders and a plurality of intake valves,

Fill air quantity in the cylinder with relative each cylinder and be divided into basic air quantity and surpass air quantity two-part, above-mentioned surpass air quantity for open owing to intake valve surpass closure by air mass flow, partly flow into air quantity in the cylinder from inlet air pathway,

This control gear has basic air quantity and calculates mechanism, and it opens the basic air quantity of Time Calculation according to the closure that flows into the inlet air pathway part by closure by air mass flow and each intake valve;

Surpass air quantity and calculate mechanism, its reduction amount according to the suction pressure that is caused by opening of above-mentioned intake valve is calculated and is surpassed air quantity;

The interior air quantity of filling of cylinder is calculated mechanism, and it adds up to above-mentioned basic air quantity with above air quantity, calculates the interior air quantity of filling of cylinder of each cylinder relatively; With

Carry out the control mechanism that internal-combustion engine is controlled according to filling air quantity in the cylinder of each cylinder,

Wherein, above-mentioned basic air quantity is calculated the imaginary intake valve that mechanism calculates when the average air flow of all cylinders equates by air mass flow with closure relatively and is opened the time, and this imaginary intake valve time of opening is used as opening the time of above-mentioned intake valve.

4. control gear as claimed in claim 3, wherein, near opening period at intake valve or near IC Intake Valve Closes period, produce when the air of above-mentioned inlet air pathway part flows backwards, above-mentioned basic air quantity is calculated mechanism will be used as opening the time of above-mentioned intake valve the above-mentioned imaginary intake valve time of opening.

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