JPS59194052A - Fuel supply amount control device for internal- combustion engine - Google Patents

Abstract

PURPOSE:To improve the response and the driverability for acceleration by controlling the supply of fuel in accordance with the supply amount of fuel for acceleration previously obtained according to the driving speed of a car when an aceleration driving is demanded. CONSTITUTION:During the peration of an engine, data to indicate a throttle opening ThS in accordance with a pulse signal from a throttle sensor 48 is provided in an MPU in a control circuit 30, and when these data ThS are greater than a fixed value E, it is judged that an acceleration driving is demanded. When this acceleration driving is demanded, whether a car speed VS obtained from the output of a car speed sensor 54 is greater than a fixed value or not is decided. When the decision is NO, an asynchronous injection pulse width TAU' to correspond to the car speed VS is referred and when YES, a comparatively great fixed value F is obtained as he asynchronous injection pulse width. Then, an injection pulse signal in accordance with the said asynchronous injection pulse width is supplied to a fuel injection valve 26 for injecting a proper amount of fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling the amount of fuel supplied to an internal combustion engine.

An acceleration-time valve injection control system is well known, in which fuel is injected each time the internal combustion engine enters an accelerating operation state. According to this method, the response characteristics of the engine during acceleration can be improved. When performing such asynchronous injection, it is already known that the fuel injection amount is controlled according to the opening speed of the throttle valve. However, if the asynchronous injection amount during acceleration is controlled solely according to the opening speed of the throttle valve, it is not possible to provide the optimum injection amount when the engine load condition changes. For example, if the optimal injection amount is used when the vehicle speed is high, but asynchronous injection is performed during acceleration when the vehicle speed is low, a large torque shock will occur.

On the other hand, if asynchronous injection during acceleration is performed when the vehicle speed is high and the optimal injection amount is used when the vehicle speed is low, sluggishness etc. will occur and the response characteristics during acceleration will be significantly deteriorated.

Therefore, the present invention solves the above-mentioned problems of the prior art, and an object of the present invention is to provide a fuel supply amount control device that can improve both drivability and response during acceleration.

The structure of the present invention that achieves the above-mentioned object will be explained using FIG. 1. Means a detects whether acceleration operation is requested or not, and detects the traveling speed of the vehicle C on which the engine is mounted. means d for determining the total fuel supply amount during acceleration in accordance with the detected vehicle running speed; and means e for supplying fuel to the engine in accordance with the determined fuel supply amount during acceleration when acceleration driving is requested. The device of the present invention is equipped with f.

The present invention will be explained in detail with reference to Examples below.

FIG. 2 schematically shows an example of an electronically controlled fuel injection type internal combustion engine as an embodiment of the present invention. The same figure (C
10 represents the entire engine body, 12 represents an intake passage, 14 represents a combustion chamber of one cylinder, and 16 represents an exhaust passage. The air flow sensor 18 detects the flow rate of intake air taken in through an air cleaner (not shown). The intake air θ is controlled by a throttle valve 20 that is linked to an accelerator pedal (not shown). The intake air that has passed through the throttle valve 20 is stratified into the combustion chamber 14 of each cylinder via the surge tank 22 and each intake valve 24.

The fuel injection valve 26 is provided for each fuel injection valve, and is controlled to open and close in response to an electrical drive pulse sent from a control circuit 30 via a valve 28 (not shown). Calorie pressure fuel sent from the fuel supply system is intermittently injected into the intake passage 12 (intake port portion) near the intake valve 24.

After combustion in the combustion chamber 14, the exhaust gas flows through the exhaust valve 3.
2 and the catalytic converter 3 via the exhaust passage 6.
4 to the atmosphere.

The air flow sensor 18 is provided in the intake passage 12 upstream of the throttle valve 2017, and generates a voltage according to the intake air flow line. This output voltage is applied to the control circuit 3 through the output voltage 36.
sent to 0.

A crank angle sensor 4 is installed in the distributor 38 of the engine.
0 and 42 are installed, these sensors 40
, 42 to it, crankshaft is 30'.

A pulse signal is output each time it rotates 360",
These Norse signals are sent to the control circuit 30 via IAs 44 and 46'c, respectively.

A pulse signal is output from the throttle valve 20 interlocked with the throttle valve 20 every time the throttle valve 20 rotates by a minute angle, and this pulse signal is sent to the control circuit 30 via a line 50. be included.

A pulse signal is output from the vehicle speed sensor 54 every time the output shaft of the vehicle rotates by a predetermined angle, and this pulse signal is shown on the line 5.
6 to the control circuit 30.

FIG. 3 is a block diagram showing an example of the configuration of the control circuit 30 shown in FIG.

The voltage signal from the air 20-sensor 18 is fed into an analog-to-digital (A/D) converter 70 with analog multiplexer functionality and is sent to the microprocessor unit (
iVIPU) 72, it is converted into two communication signals.

The signal from the crank angle sensor 40 at every 30 degrees of crank angle is sent to the M
The signal is sent to the PU 72 and becomes an interrupt request signal for the 30° crank angle processing routine, and also serves as a clock for incrementing the timing counter provided in the I10 circuit 74. A pulse signal every 360° of crank angle from the crank angle sensor 42 acts as a reset signal for the timing counter. The injection start timing signal obtained from this timing counter is sent to the MPU 72 and becomes an interrupt request signal for the injection processing routine for synchronous sounding.

The nose signal from the vehicle speed sensor 54 is connected to the Ilo circuit 7.
4 to the MPU 72, and becomes an interrupt request signal for the vehicle speed calculation processing routine.

The pulse signal from the throttle position sensor 48 is also I
The signal is sent to the MPU 72 via the lo circuit 74 and becomes an interrupt request signal for the processing routine for calculating throttle opening speed.

In the input/output circuit (I10 circuit) 76, there is a drive circuit that receives a 1-bit injection pulse signal having a duration corresponding to the injection pulse width TAU' sent from the MPU 72 and converts it into a drive signal. is provided. A drive signal from this drive circuit is sent to the fuel injection valves 26a to 26d to energize them. As a result, an amount of fuel corresponding to the pulse width TAU is injected.

The A/D converter 70 and the I10 circuits 74 and 76 are connected to the MPU 72, which is the main component of the microconbeater.
, a random access memory (RAM) 78, and a read only memory (ROM) 80 via a path 82, and data transfer is performed via this bus 82.

The ROM 80 contains a main processing routine program to be described later, an interrupt processing routine program for every 30 degrees of crank angle, an interrupt processing routine program for calculating vehicle speed, an interrupt processing program for calculating throttle opening speed, and Other programs, as well as data and tables used in their calculation processes, are stored in advance as a storage source.

Next, the operation of the above-mentioned microcomputer will be explained using the flowcharts in FIGS. 4 to 18.

When the MPU 72 receives a pulse signal every 30 degrees of crank angle from the crank angle sensor 40, it executes the interrupt processing routine shown in FIG. 4 and forms data representing the rotational speed NE of the engine. 1. At step 90, the MPU 7
Read the contents of the free run counter provided in 2 and set the value to 030. In the next step 91, the value 03g read at the previous interrupt and the current value C
The difference △C from so is △C=C. -Cs5, and in the next step 92, the reciprocal of the difference ΔC is calculated to obtain the rotational speed NE. That is, the calculations NE-Z and C are performed. However, A is a constant. The NE thus obtained is stored at a predetermined location in the RAIVI 78. The next step 93 is to use the current counter content C9 as the previous read value at the next interrupt processing.
Perform C3o processing. Carry out other necessary processing from now on.
'After Lfc, the interrupt processing routine returns to the main routine.

Further, when the MPU 72 receives a pulse signal from the vehicle speed sensor 54, it executes the interrupt processing routine shown in FIG. 5 to form data representing the vehicle speed VS. The processing routine shown in FIG. 5 is almost the same as that shown in FIG. 4, so a description thereof will be omitted. However, in the figure, B is a constant.

Furthermore, the MPU 72 has a slot position sensor 48.
When a pulse signal is sent from , the interrupt processing routine shown in FIG. 6 is executed to form data representing the throttle opening speed Th5k. The processing routine shown in FIG. 6 is also substantially the same as that shown in FIG. 4, so the explanation thereof will be omitted. In the figure, it is the Dfd constant.

Note that when an A/D conversion completion interrupt occurs from the A/D converter 70, the MPU 72 takes in data representing the intake air flow XQ of the engine and stores it in a predetermined location in the RAM 78.

On the other hand, the MPU 72 executes the process shown in FIG. 7 during the main processing routine. That is, the throttle opening ? created by the interrupt processing routine shown in FIG. 6 and stored in Fl and AM78. The data represented by Ths * is compared with a constant value E to determine whether accelerated driving is requested. ThS
If ≦E, it is determined that the accelerator pedal depression speed is slow and acceleration operation is not required, and the main routine continues.

If ThS>E, it is assumed that the accelerator pedal depression speed is high and accelerated driving is required, and all acceleration interrupt processing is requested.

FIG. 8 shows this accelerated interrupt processing routine. As described above, the MPU 72 executes the entire acceleration interrupt process when the throttle opening speed change ThS is larger than the constant value E. First, in step 100, data representing the vehicle speed VS created in the interrupt processing routine of FIG.
Read M78.

In the next step 10, this vehicle speed VS is 2 Km/
It is determined whether or not it is smaller than h. VS (2Km
/ h, it is assumed that racing is taking place, and the process proceeds to stage 1102, where the asynchronous fuel injection and pulse width TAU' are performed.
A relatively large constant value F is given as . This is because during racing there is no load, so even if a certain amount of fuel is injected, no torque shock will occur.

On the other hand, if VS≧2Km/h: rf step 103
Proceed to the asynchronous injection pulse width TAU corresponding to the vehicle speed VS.
'Seek.' ROM80 contains T A U for VS.
' A one-dimensional function table is stored in advance, and in step 103, an interpolation method or the like is used to calculate T for VS.
AU”z is determined. In the next step 104, this T A
An injection pulse signal having a duration corresponding to U' is generated and an asynchronous injection of fuel is carried out. As a method for creating the injection pulse signal, for example, in step 104, the injection pulse signal 7-. 1' and 1#, the contents of the free run counter at that time are known, and the value of this counter after T AU' has elapsed is set in the total conveyor counter.

When the content of the free run counter becomes equal to the content of the conveyor counter, an interrupt is generated and the injection pulse signal sound is inverted to "0#". As a result, an asynchronous injection pulse signal having a pulse width corresponding to TAU' is generated at each acceleration.

Note that the MPU 72 operates at a predetermined crank angle, for example, 180°C.
A or 360℃A1 every rotation speed) l, intake air flow rate, etc. for synchronous injection! All injection pulse signals are generated and the fuel injection is controlled accordingly.

FIG. 9 shows the relationship of the asynchronous pulse width TA' with respect to the vehicle speed vs. S% calculated as described above.

If the vehicle speed is less than 2 km/h, a relatively large amount of fuel is injected asynchronously, assuming that racing is taking place.
If the vehicle speed is 2 km/h or more, fuel is injected asynchronously in an amount corresponding to the vehicle speed at that time.

In this case, a larger amount of fuel is injected asynchronously when the vehicle speed is higher than when the vehicle speed is lower. As a result, when the vehicle speed is high, the rotational speed and torque are quickly increased during acceleration, and the response characteristics during acceleration are improved. Furthermore, when the vehicle speed is low, the amount of asynchronously injected fuel is small, so it is possible to prevent torque shock from occurring during acceleration.

In addition, in the above-mentioned embodiment, the amount of asynchronously injected fuel during acceleration is controlled to a value that corresponds only to the full vehicle speed, but in the present invention,
This may be controlled according to both the vehicle speed and the throttle opening speed.

As described above in detail, according to the present invention, the amount of fuel supplied during acceleration is variably controlled in accordance with the vehicle speed, so that it is possible to improve response during acceleration and reduce torque shock.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 2 is a schematic diagram of an embodiment of the present invention, FIG. 3 is a block diagram showing the control circuit in FIG. 2 in detail, and FIGS. 4 to 8 is a flowchart of a part of the control program of the control circuit in FIG. 3, and FIG.
FIG. 3 is a characteristic diagram of the amount of asynchronously injected fuel in the embodiment shown in the figure. 18... Air flow sensor, 2o... Throttle valve, 26... Fuel injection valve, 30... Control circuit, 40
, 42... Crank angle sensor, 48... Throttle motion sensor, 54... Vehicle speed sensor, 72...
M.P.U. 74, 76-I10 circuit, 78・RAM, 80-・
・ROM. Patent Applicant Toyota Motor Corporation Patent Application Agent Patent Attorney Akira Aoki Patent Attorney Kazuyuki Nishidate Patent Attorney Akira Yamaguchi 6th Patent Attorney

Claims (1)

[Claims] 1. Means for detecting whether accelerated driving is requested;
means for detecting the running speed of a vehicle in which the engine is mounted; means for determining the fuel supply amount during acceleration according to the detected vehicle running speed; and means for determining the determined fuel supply amount during acceleration when acceleration driving is requested. k'f! A fuel supply amount control device for an I71 fuel engine with the following characteristics.