JP2540839B2 - Engine fuel supply control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to fuel supply for a so-called speed-density system (D-Jetronic system) engine, which controls the fuel supply amount based on the pressure in the intake passage of the engine. It relates to a quantity control device.

[Conventional technology]

Conventionally, a negative pressure sensor is provided in the intake passage of the engine,
There has been proposed a fuel supply amount control device for a speed-density (D-Jetronic) engine, which controls a fuel injection amount from an electromagnetic fuel injection valve based on a detection result from the negative pressure sensor. That is, in such a D-Jetronic system, the fuel injection amount Q depends on the pressure in the intake passage.
It is determined by the function f (Pm) of Pm.

[Problems to be Solved by the Invention] By the way, although the pressure in the intake passage changes along with changes in the engine speed and the throttle opening (opening of the throttle valve), since there is a volume in the intake passage, The response is delayed.

Therefore, in the speed-density system (D-Jetronic system), the air-fuel ratio fluctuates immediately after the fluctuations in the rotation speed and the throttle opening, which is considered to be the cause of hunting in the idle state.

Therefore, in order to compensate for this, a predictive control method using a differential value of the pressure in the intake passage as in the expression (1) has been conventionally proposed.

Q = f (Pm) + a ₀ (dPm / dt) (1) where a ₀ indicates a required gain.

However, such means may not be able to completely compensate for the response delay.

It should be noted that Fig. 13 shows the transient response characteristics of the crank rotational speed due to the load fluctuation.From Fig. 13, it can be seen that there is unevenness in the crank rotational speed after the load fluctuation. It turns out that there are cases where it cannot be completed.

By the way, Japanese Unexamined Patent Publication No. 57-88242 discloses a technique in which fuel control is performed by using the amount of change in engine speed (first derivative) or the rate of change in this amount of change (second derivative). ing.

This technique uses fuel control at one of the above engine speeds.
The correction is performed using either one of the second derivative information and the second derivative information to prevent the engine rotation speed from varying during idle operation and low speed running of the vehicle. Even with such a technique, it is difficult to sufficiently suppress the fluctuation of the engine rotation speed.

Therefore, even if the response delay of the pressure change in the intake passage due to the change of the engine rotation speed is sufficiently compensated, and, for example, fuel adheres to the inside of the intake pipe, it is more accurate in anticipation of such a state. There is a desire to be able to perform fuel control.

The present invention is intended to solve such a problem, and in the case where the fuel supply amount is controlled by the D-Jetronic system, the response delay of the pressure change in the intake passage due to the fluctuation of the engine speed is sufficiently delayed. An object of the present invention is to provide a fuel supply amount control device for an engine, which can be compensated.

[Means for solving problems]

Therefore, the engine fuel supply amount control device according to the present invention controls the fuel supply amount by the speed density method (D-Jetronic method), and in the rotation detecting the primary differential information of the engine rotation speed. Speed first-order differential information detecting means and two of the engine rotation speed
The rotational speed secondary differential information detecting means for detecting the secondary differential information, the fuel supply amount by the fuel supply amount control device, the detected value from the rotational speed primary differential information detecting means and the rotational speed secondary differential information detection Compensation means for compensating by the added value with the detection value from the means are provided.

[Work]

In the fuel supply amount control device for an engine according to the present invention described above, the fuel supply amount control based on the pressure information in the intake passage,
It is compensated by the added value of the engine rotational speed first-order differential information and the engine rotational speed second-order differential information.

〔Example〕

Examples of the present invention will be described below according to the present invention. Here, FIGS. 1 to 7 show a fuel supply amount control device for an engine, which was conceived in the process of inventing the present invention.
FIG. 12 is a diagram for explaining an engine fuel supply amount control device as one embodiment of the present invention.

First, a fuel supply amount control device for an engine, which was conceived in the process of creating the present invention, will be described with reference to FIGS. As shown in FIG. 2, the engine 13 having this fuel supply amount control device is an in-line four-cylinder gasoline engine. For this reason, a throttle valve 14a interlocking with an accelerator pedal is provided downstream of the air cleaner in the intake passage 14. The downstream end of the intake passage 14 communicates with the intake port of each cylinder head of the four-cylinder engine via the intake manifold 22.

A bypass air passage 14b that bypasses the throttle valve 14a is provided in the intake passage 14, and a bypass air valve 14c is interposed in the bypass air passage 14b.

Further, a negative pressure sensor (intake passage pressure information detecting means) 20 for detecting the pressure Pm in the intake passage 14 is provided, an intake temperature sensor 25 for detecting the intake temperature Ta is provided, and a throttle valve 14a is also provided. A throttle sensor 21 for detecting the opening degree θ of is provided.

Furthermore, an O ₂ sensor that detects the oxygen concentration in the exhaust is provided in the exhaust passage that communicates with the exhaust port of each cylinder head of the engine through the exhaust manifold, and a water temperature sensor that detects the cooling water temperature Tw of the engine. 26 are provided,
A crank angle sensor 27 and a cylinder discrimination sensor 28, which constitute a rotation speed sensor 10 for detecting an engine rotation speed (engine rotation speed) Ne, are provided.

Then, the respective output signals from these sensors are input to the controller 18.

The crank angle sensor 27 and the cylinder discrimination sensor 28 are provided in a distributor 29, and the crank angle sensor 27 is a rotor 29a of the distributor 29 as shown in FIG.
Protrusions on the outer circumference of the cylinder equidistantly as many as the number of cylinders
30-33 and a pickup 34 that detects these protrusions 30-33 at a fixed position. One revolution of the distributor 29 (two revolutions of the crankshaft) produces the same number of crank phase signals as the number of cylinders (engine revolution). Pick up speed information)
Output from 34.

The cylinder discrimination sensor 28 is the rotor shaft of the distributor 29.
29a, and pickups 36 to 39 arranged at equal intervals around the rotor shaft 29a to detect the projections 35. From this pickup 36 to 39, one revolution (crank) of the distributor 29 is formed. The output signals of the same number as the number of cylinders are sequentially output in two shaft rotations.

As shown in FIG. 2, in each branch passage portion of the intake manifold 22, the electromagnetic fuel injection valves 40 to 40 are provided in the vicinity of each intake port.
43 is provided. These four electromagnetic fuel injection valves 40-43
Has one end communicating with each branch passage portion of the intake manifold 22, and the other end communicating with an open end of a fuel passage communicating with the fuel tank 15 through the fuel pump 16 with the fuel filter 16a and the fuel pressure regulator 17. This fuel passage injection valve 40 ~
Fuel having a constant pressure (low pressure) is constantly supplied to the other end side from the disposition position of 43 by the action of the fuel pump 16 and the fuel pressure regulator 17, and the fuel in this fuel passage is the electromagnetic fuel injection valve 40. Intake manifold when valve bodies ~ 43 are opened based on the injector drive signal from controller 18
It is designed to be injected into each of the 22 branch passage portions. The amount of fuel injected into each branch passage depends on the valve opening time of the electromagnetic fuel injection valves 40 to 43.

The controller 18 has CPU19, ROM44, RA as shown in FIG.
Microcomputer having M45 and plural ports 46a to 46e, external register for cylinder discrimination 47, 16-bit free running counter 48, registers 49 to 52, comparators 53 to 56
And RS flip-flops 57-60 and the like. The crank phase signal from the pickup 34 is shaped into a rectangular wave by the waveform shaping circuit 61 and input to the interrupt terminal INT1 of the CPU 19. The cylinder discriminating signals from the pickups 36 to 39 are shaped into rectangular waves by the waveform shaping circuits 62 to 65 and are registered in the register 47.
The signals from the negative pressure sensor 20, the throttle sensor 21, the intake air temperature sensor 25, the water temperature sensor 26, the DC power source (battery) 74, etc. are adjusted to appropriate levels by the level adjusting circuits 66 to 69, respectively, and then analog / Digital converter (A / D converter) 70,7
Analog / digital converted by 1,72,73,100 port 4
Input to 6a-46e. Further, the microcomputer receives signals from a starter switch, an idle sensor, etc., and the electromagnetic fuel injection valves 40-43 are controlled by the switching transistors 75-78 to turn on / off the power supply from the battery 74 to the valve body opening / closing solenoids 40a-43a. It is opened and closed.

By the way, when the fuel control system based on the D-Jetronic system (speed density system) is shown in a block diagram,
As shown in Fig. 1, the negative pressure sensor 20
A conversion means for receiving a detection signal Pm from the converter and converting it with a required function f (Pm) and outputting it. First intake pressure internal differential information detecting means for detecting first differential information of the intake passage internal pressure Pm.
3, Throttle opening primary differential information detecting means 5 for detecting primary differential information of the detection signal (throttle opening) θ from the throttle sensor 21, detection signal (engine speed) Ne 1 from the rotational speed sensor 10 Engine rotation speed primary differential information detecting means 7 for detecting secondary differential information, gain setting means 2 for multiplying the signal from the negative pressure sensor 20 by the required gain a ₁ , and required gain b ₁ for the signal from the throttle sensor 21. The gain setting means 4 for multiplying and the gain setting means 6 for multiplying the signal from the rotation speed sensor 10 by a required gain c ₁ are provided.

Further, the outputs from the conversion means 1, the intake passage pressure first-order differential information detection means 3, the throttle opening first-order differential information detection means 5, and the engine speed first-order differential information detection means 7 are added to this control system. To an electromagnetic fuel injection valve 40 that receives a fuel injection control signal from the fuel injection amount determining means 9 and the fuel injection amount determining means 9 that determines the fuel injection amount Q based on the addition result from the adding means 8. 43 is provided.

Then, in the adding means 8 and the fuel injection amount determining means 9,
The fuel supply amount control means for controlling the fuel injection amount based on the detection result f (Pm), a ₁ (dPm / dt) from the negative pressure sensor 20 and the fuel injection amount control by the fuel supply amount control means are used for the engine rotation speed. Each detection result c ₁ (dN from the primary differential information detecting means 7 and the throttle opening primary differential information detecting means 5
Compensation means for compensating based on e / dt) and b ₁ (dθ / dt).

That is, in this configuration, as shown in the equation (2), the differential terms dNe / dt, dθ of the engine rotational speed Ne and the throttle opening θ are further added to the equation shown in the above equation (1) as a compensation term.
It is the one with / dt added.

Q = f (Pm) + a ₁ (dPm / dt) + b ₁ (dθ / dt) + c ₁ (dNe / dt) (2) By the way, the basic valve opening time data setting and the actual The setting of the valve opening time data, and further the setting of the correction data based on the various operating states of the engine used when setting the actual valve opening time data are performed by the CPU 19, but in the following, the CPU 19 The operation performed using the RAM 45 according to the program in the ROM 44 will be described.

During this fuel supply control, the main routine shown in FIG. 4 is executed. In this main routine, the operating state is first detected (step a1), and the basic pressure from the manifold negative pressure Pm detected by the negative pressure sensor 20 is detected. driving time Tb is set (step a2), then multiplying the contents of the address DP of RAM45 having a first differential (difference) information in the intake passage pressure Pm and gain a ₁ input to the address TP (step a3),
RA with information on the first derivative (difference) of the throttle valve opening θ
The content of the address Dθ of M45 is multiplied by the gain b ₁ and input to the address Tθ (step a4), and the content of the address DN of the RAM 45 having the first derivative (difference) information of the engine rotation speed Ne and the gain c ₁ are obtained. Multiply and enter in the address TN (step a5).

Further, in step a6, the correction coefficient Kaf is set from the intake passage pressure Pm and the engine rotation speed Ne, and in step a7
Then, the correction coefficient Kw is calculated from the intake passage pressure Pm and the cooling water temperature Tw.
up, and in step a8, the correction coefficient is set according to the intake air temperature Ta.
Set Kat, and then in step a9, throttle opening θ
Differential information Dθ, cooling water temperature Tw, engine speed N
The acceleration increase coefficient Tacl is set according to e, and the deceleration decrease coefficient Tdcl is set according to the first-order differential information Dθ of the throttle opening θ and the cooling water temperature Tw in step a10.
Set the correction coefficient Td according to the voltage of 74 (step a1
1) Finally, in step a12, other correction factors are set as necessary.

In addition, reading the data Pm, θ, Ne from the negative pressure sensor 20, the throttle sensor 21, and the rotation speed sensor 10 and dPm / dt, dθ
The reading of the / dt and dNe / dt information is performed by the timer interrupt routine shown in FIG. That is, this timer interrupt routine updates the data for each timer interrupt signal output at the required interval, but first in step b1, the contents of the address MP of the RAM 45 having the intake passage internal pressure Pm information is stored in the intake passage. The result subtracted from the pressure Pm information is input to the address DP, and RA having the throttle opening θ information is entered in step b2.
The result of subtracting the content of the address Mθ of M45 from the throttle opening θ information is input to the address Dθ, and the result of subtracting the content of the address MN of the RAM45 having the engine speed Ne information from the engine speed Ne information in step b3. The address
Input to DN, then in step b4, input intake passage pressure Pm to address MP, in step b5, input throttle valve opening θ to address Mθ, and in step b6, input engine rotation speed Ne to address MN. input.

That is, in the timer interrupt routine shown in FIG. 5, the difference between the current data and the data one time before is detected in steps b1 to b3, and the current data is detected in steps b4 and b5. There is.

By the way, this timer interrupt routine gives priority to the interrupt processing by the crank phase signal (crank phase interrupt routine) described later, and if the crank phase signal is input during execution of the timer interrupt routine, the timer interrupt routine is temporarily executed at that point. Execution is interrupted and the timer interrupt routine is interrupted after the interrupt processing by the crank phase signal is completed.

The one shown in FIG. 6 has a crank phase signal of CPU19.
This is a crank phase interrupt routine that performs interrupt processing each time it is input to INT1, and when the crank phase signal is input to INT1 from the waveform shaping circuit 61, the CPU 19 first, in step c1, returns various times and time calculated in the main routine. Coefficient Tb, K
From data on af, Kat, Kwup, Tacl, Tdcl, TP, Tθ, TN, TD, Tb × Kaf × Kat × Kwup + Tacl-Tdcl + TP + Tθ + TN + TD
Is calculated and the calculation result is stored in the address TS.

Then, in step c2, the value of the free running counter 48 is read and stored in the address TC. Then step c3
Then, the data of address TS is added to the data of address TC to calculate the sum TO, and it is determined in step c4 whether the content R of the cylinder discrimination external register 47 is 0 or not.

Here, in the four-cylinder engine 13, fuel is to be repeatedly injected by the electromagnetic fuel injection valves 40 to 43 in the order of the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder. The cylinder to be selected is detected by the cylinder discrimination sensor 28 and input to the cylinder discrimination external register 47. And register 47
If the content R is 0 (first cylinder signal), that is, if fuel should be injected into the first cylinder by the electromagnetic fuel injection valve 40, the process proceeds to step c5 and the sum TO is set in the register 49, In step c6, the set signal is output to the flip-flop 57. Therefore, this set signal causes the flip-flop
57 is set, the output signal turns on the transistor 75, the solenoid 40a is activated, and the electromagnetic fuel injection valve 40
The fuel is injected into the first cylinder by opening the. After that, the value of the free running counter 48 is the value TO of the register 49.
When an output signal is output from the comparator 53, the output signal resets the flip-flop 57, turns off the transistor 75, turns off the solenoid 40a, and closes the electromagnetic fuel injection valve 40.

The CPU 19 determines whether the content R of the cylinder discrimination external register 47 is 0 (first cylinder signal) at steps c4, c7, and c10.
Whether or not it is (second cylinder signal) or 2 (third cylinder signal) is determined. If the content R of the register 47 is not 0 in step c4, the process proceeds to step c7. This step c7
If the content R of register 47 is 1 in the judgment of step, step
Go to c8 and set the above TO in register 50, and then step c9
Outputs a set signal to the flip-flop 58. This set signal sets the flip-flop 58, and the output signal turns on the transistor 76, causing the solenoid 40
When a is activated and the electromagnetic fuel injection valve 41 is opened, fuel is injected into the second cylinder. After that, when the value of the free-running counter 48 reaches the value of the register 50 and an output signal is output from the comparator 54, this output signal causes a flip-flop.
58 is reset, the transistor 76 is turned off, the solenoid 41a is turned off, and the electromagnetic fuel injection valve 41 is closed.

The CPU 19 judges that the content R of the register 47 is 1 in the judgment at step c7.
If not, proceed to step c10. When the content of the register 47 is 2 in the judgment at step c10, the routine proceeds to step c11, where the TO is set in the register 51, and at step c12 a set signal is outputted to the flip-flop 59. The flip-flop 59 is set by this set signal, the transistor 77 is turned on by the output signal thereof, the solenoid 42a is actuated, and the electromagnetic fuel injection valve 42 is opened to inject fuel into the third cylinder. After that, when the value of the free-running counter 48 reaches the value of the register 51 and an output signal is output from the comparator 55, the flip-flop 59 is reset by this output signal, the transistor 77 is turned off, the solenoid 42a is turned off, and the electromagnetic type is turned on. The fuel injection valve 42 closes.

The CPU 19 judges that the content R of the register 47 is 2 in the judgment at step c10.
If not, proceed to step c13 and set the above TO to register 5
Set to 2 and output a set signal to the flip-flop 60 in step c14. This set signal sets the flip-flop 60, and the output signal of the flip-flop 60 sets the transistor.
When the solenoid 78a is turned on and the solenoid 43a is operated to open the electromagnetic fuel injection valve 43, fuel is injected into the fourth cylinder.
After that, when the value of the free-running counter 48 reaches the value of the register 52 and an output signal is output from the comparator 56, the flip-flop 60 is reset by this output signal, the transistor 78 is turned off, the solenoid 43a is turned off, and the electromagnetic type is turned on. The fuel injection valve 43 closes.

The cylinder discrimination sensor 28 is the rotor shaft of the distributor 29.
According to the rotation of 29a, the first cylinder signal, the third cylinder signal, the fourth cylinder signal
Since the cylinder signal and the second cylinder signal are sequentially and repeatedly output, the electromagnetic fuel injection valves 40 to 43 are opened in the order of 40, 42, 43, 41 to open the first cylinder, the third cylinder, the fourth cylinder, and the second cylinder. Fuel is injected in the order of cylinders.

In this way, according to the above-described configuration, the differential term of the engine rotational speed Ne and the throttle opening θ is given by the equation (2) as the compensation term for the fuel supply amount control immediately after the change of the engine rotational speed and the throttle opening. Since the fuel prediction control is performed as described above, the fuel prediction control in which only the differential term of the intake passage pressure Pm is used as the compensation term is sufficient even if a sufficient compensation effect cannot be obtained due to the response delay. A compensation effect can be guaranteed, which can eliminate hunting, especially when idling.

FIG. 7 shows the transient response characteristic of the crank rotational speed due to the load change. From FIG. 7, it is found that the crank rotational speed after the load change is uniform, and it can be seen that the hunting phenomenon can be eliminated.

In the above configuration, when the idle switch is on and lower than the fuel cut speed, the engine speed Ne and the throttle opening are used as compensation items for the fuel supply amount control immediately after the engine speed and the throttle opening change. The fuel predictive control may be performed by adding each differential term of the degree θ as shown in equation (2). This case applies to those with an idle speed controller.

Next, a fuel supply amount control device for an engine as an embodiment of the present invention shown in FIGS. 8 to 12 will be described. The configuration described with reference to FIGS. 1 to 7 in FIGS. The same reference numerals indicate almost the same parts.

Also in the case of the engine fuel supply amount control apparatus as one embodiment of the present invention, the entire system of the engine is as shown in FIG. 2, so a detailed description thereof will be omitted, but in this embodiment, the D-Jetronic Compensation of fuel supply control by the method is performed by the sum of the first and second differential terms of the engine speed Ne. That is, the block diagram of the fuel control system according to this embodiment is as shown in FIG. 8. In this control system, the detection signal Pm from the negative pressure sensor 20 is received and the required function f (Pm ) To convert and output the detection signal (engine rotation speed) Ne from the rotation speed sensor 10 to detect the first-order differential information of the engine rotation speed first-order differential information detecting means 7 and the rotation speed sensor 10. Gain setting means 11 for multiplying the signals from the engine rotational speed secondary differential information detecting means 12 for detecting the secondary differential information of the detection signal (engine rotational speed) Ne and the required gains a ₂ and b ₂ respectively. ,
It has thirteen.

Further, in this control system, an adding means 8'for adding outputs from the converting means 1, the engine rotational speed first-order differential information detecting means 7, and the engine rotational speed second-order differential information detecting means 12, and the adding means 8 ' The fuel injection amount determining means 9 for determining the fuel injection amount Q based on the addition result of and the electromagnetic fuel injection valve 40 receiving the fuel injection control signal from the fuel injection amount determining means 9.
~ 43 are provided.

Then, the adding means 8'and the fuel injection amount determining means 9
Then, the fuel supply amount control means for controlling the fuel injection amount based on the detection result f (Pm) from the negative pressure sensor 20 and the fuel injection amount control by this fuel supply amount control means are the engine rotation speed first derivative information detecting means. 7 and engine speed 2
Each detection result a ₂ (dNe / dt), b from the second derivative information detecting means 12
Compensation means for compensation based on ₂ (d ² Ne / dt ² ).

That is, in this embodiment, as shown in the equation (3), the first and second differential terms dNe / d of the engine speed Ne are used as the compensation term.
t, d ² Ne / dt ² is added.

Q = f (Pm) + a ₂ (dNe / dt) + b ₂ (d ² Ne / dt ² ) ...
(3) By the way, in the case of the present embodiment as well, it is used when setting the basic valve opening time data, setting the subsequent actual valve opening time data, and further setting the actual valve opening time data. The setting of correction data based on various operating conditions of the engine is performed by calculation in CPU19.
The operation of 19 using RAM 45 according to the program in ROM 44 will be described.

In this fuel supply control, the main routine shown in FIG. 9 is executed. In this main routine, the operating state is first detected (step d1), and the basic manifold negative pressure Pm detected by the negative pressure sensor 20 is used as the basis. The drive time Tb is set (step d2), the contents of the address DN of the RAM 45 having the first derivative (difference) information of the engine rotation speed Ne and the gain a ₂
Type bets to address TN multiplied by (step d3), 2-order differential of the engine rotational speed Ne is multiplied by the contents of RAM45 address D2N with (differential) information and gain b ₂ input to the address T2N (step d4 ).

Further, at step d5, the correction coefficient Kaf is set from the intake passage pressure Pm and the engine speed Ne, and at step d6
Then, the correction coefficient Kw is calculated from the intake passage pressure Pm and the cooling water temperature Tw.
up, and in step d7, a correction coefficient according to the intake air temperature Ta
Set Kat and then in step d8, throttle opening θ
Differential information Dθ, cooling water temperature Tw, engine speed N
The acceleration increase coefficient Tacl is set according to e, and the deceleration decrease coefficient Tdcl is set according to the first derivative information Dθ of the throttle opening θ and the cooling water temperature Tw in step d9.
Set the correction coefficient Td according to the voltage of (step d10),
Finally, in step d11, other correction coefficients are set as needed.

In addition, reading the data Pm, θ, Ne from the negative pressure sensor 20, the throttle sensor 21, and the rotation speed sensor 10 and dPm / dt, dθ
/ dt, dNe / dt, d ² Ne / dt ² information is read by the timer interrupt routine shown in FIG. In other words, this timer interrupt routine updates the data for each timer interrupt signal that is output at the required intervals.
At e1, the address M of the RAM 45 that holds the information Pm on the intake passage pressure
The result of subtracting the contents of P from the intake passage pressure Pm information is input to the address DP, and in step e2, the address of the RAM M45 having the throttle opening θ information and the result of subtracting the contents of Mθ from the throttle opening θ information to the address. Input to Dθ, in step e3, enter the result obtained by subtracting the content of the address MN of the RAM 45 having the engine speed Ne information from the engine speed Ne information into the address DN, and in step e4 the primary of the engine speed Ne. The result of subtracting the content of the address MDN of RAM45 having differential information from the primary differential information DN of the engine speed Ne is input to address D2N, and then in step e5, the intake passage pressure Pm is input to address MP, and step At e6, input the throttle valve opening θ to address Mθ, and then step e7
Then, the engine rotation speed Ne is input to the address MN, and in step e8, the primary differential information DN of the engine rotation speed Ne is input to the address MDN.

That is, in the timer interrupt routine shown in FIG. 10, the difference between the current data and the previous data is detected in steps e1 to e4, and the current data is detected in steps e5 to e8. There is.

Further, the crank phase interruption routine in this embodiment is the sixth described in the above-mentioned configuration (that is, the engine fuel supply amount control device considered in the process of creating this embodiment).
Since only the step c1 part is different from the crank phase interrupt routine shown in the figure, the description will be given only for step c1 ′ corresponding to step c1, and the other description will be omitted. I will do it.

That is, in step c1 ′ of FIG. 11, various times and coefficients Tb, Kaf, Kat, Kwup, Tacl, Tdc obtained in the main routine are calculated.
From data on l, TN, TDN, TD, Tb x Kaf x Kat x Kwup + T
Calculate acl-Tdcl + TN + TDN + TD and store the result of this operation in address TS. The subsequent processing is the same as the routine of FIG.

In this way, according to the present embodiment, the first and second differential terms of the engine rotation speed Ne are expressed by the equation (3) as the compensation term for the fuel supply amount control immediately after the change of the engine rotation speed and the throttle opening. Since the fuel prediction control is performed as described above, the fuel prediction control in which only the differential term of the intake passage pressure Pm is used as the compensation term is sufficient even if a sufficient compensation effect cannot be obtained due to the response delay. The compensating effect can be compensated, which can eliminate hunting especially during idling.

In addition, Fig. 12 shows the transient response characteristics of the crank rotational speed due to load fluctuation.It is clear from Fig. 12 that the crank rotational speed after load fluctuation is uniform, and it is possible to eliminate the hunting phenomenon from now on. Recognize.

Further, due to the action of the second-order differential term of the engine rotation speed Ne, the fuel supply amount for compensation is increased, and then the fuel consumption amount is decreased. Therefore, the influence of fuel adhesion can also be corrected.

In the present embodiment, when the idle switch is on and lower than the fuel cut speed, the first order of the engine speed Ne is used as a compensation term for the fuel supply amount control immediately after the fluctuation of the engine speed and the throttle opening. Alternatively, the fuel predictive control may be performed by adding the secondary differential term as in the equation (3).

Further, as the compensation term for the fuel supply amount control immediately after the change of the engine speed or the throttle opening, the fuel predictive control in which only the differential term of the engine speed is taken into consideration may be performed. It is possible to assure that the hunting during idling can be eliminated.

〔The invention's effect〕

As described in detail above, according to the engine fuel supply amount control device of the present invention, the following effects and advantages are obtained.

As a compensating term for the fuel supply amount control immediately after the fluctuation of the engine speed or the throttle opening, the first or second engine speed
Since the fuel prediction control is performed with the second derivative term taken into consideration, the fuel predictive control with only the differential term of the intake passage pressure as the compensation term is sufficient even if a sufficient compensation effect cannot be obtained due to its response delay. It is possible to assure a stable compensating effect, so that hunting can be eliminated especially at idling, and due to the action of the second derivative term of the engine rotation speed, the fuel supply amount for compensating is reduced and then the fuel consumption is reduced. Therefore, the influence of fuel adhesion can be corrected.

[Brief description of drawings]

1 to 7 show a fuel supply amount control device for an engine, which was conceived in the process of creating the present invention. FIG. 1 is a fuel control block diagram thereof, FIG. 2 is its overall configuration diagram, and FIG. An electric circuit diagram of its main part, FIG. 4 is a flow chart for explaining its main routine, FIG. 5 is a flow chart for explaining its timer interrupt routine, and FIG. 6 is its crank phase interrupt routine. FIG. 7 is a graph for explaining its operation, FIGS. 8 to 12 show an engine fuel supply amount control apparatus as one embodiment of the present invention, and FIG. The fuel control block diagram, FIG. 9 is a flow chart for explaining the main routine, FIG. 10 is a flow chart for explaining the timer interrupt routine, and FIG. 11 is the crank phase interrupt. Flow chart for explaining a routine, FIG. 12 is a graph illustrating the effect, FIG. 13 is a graph for explaining the operation of the fuel supply amount control apparatus for a conventional engine. 1 ... conversion means, 2 ... gain setting means, 3 ... intake passage pressure primary differential information detecting means, 4 ... gain setting means, 5 ... throttle valve opening primary differential information detecting means, 6
...... Gain setting means, 7 ...... Engine rotation speed first derivative information detecting means, 8, 8 '... Adding means, 9 ...... Fuel injection amount determining means, 10 ...... Rotation speed sensor, 11 ...... Gain setting means , 12 ... Engine rotation speed second derivative information detecting means, 13
...... Gain setting means, 14 ...... Intake passage, 14a ...... Throttle valve, 14b ...... Bypass air passage, 14c ...... Bypass air valve, 15 ...... Fuel tank, 16 ...... Fuel pump, 16a
…… Fuel filter, 17 …… Fuel pressure regulator, 18 …… Controller, 19 …… CPU, 20 …… Negative pressure sensor, 21 …… Throttle sensor, 25 …… Intake air temperature sensor, 26 …… Water temperature sensor, 27 …… Crank angle sensor, 28 ... Cylinder discrimination sensor,
29 …… Distributor, 29a …… Rotor shaft, 30 to 33
…… Protrusion, 34 …… Pickup, 35 …… Protrusion, 36 to 39…
… Pickup, 40-43 …… Electromagnetic fuel injection valve, 40a-4
3a ... solenoid, 44 ... ROM, 45 ... RAM, 46a to 46e ...
… Port, 47 …… External register, 48 …… Free running counter, 49 ～ 52 …… Register, 53 ～ 56 …… Comparator,
57-60 ... RS flip-flop, 61-65 ... wave shaping circuit, 66-69 ... level adjustment circuit, 70A, 70B, 71A, 71B, 72,7
3 …… A / D converter, 74 …… DC power supply (battery), 75 to 78
…… Transistor, 100 …… A / D converter.

Claims (1)

(57) [Claims] Claim: What is claimed is: 1. Intake passage pressure information detecting means for detecting engine intake passage pressure information, and fuel supply amount control means for controlling fuel supply amount based on the detection result from the intake passage pressure information detecting means. And a rotation speed primary differential information detecting means for detecting primary differential information of the rotational speed of the engine, and a rotation detecting secondary differential information of the rotational speed of the engine. The fuel supply amount by the speed secondary differential information detecting means and the fuel supply amount by the fuel supply amount control means is detected by the rotational speed primary differential information detecting means and the rotational speed secondary differential information detecting means. A fuel supply amount control device for an engine, comprising: a compensating means for compensating by an added value.