JP2672824B2 - Electronic fuel supply amount control device for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic fuel supply amount control device for an internal combustion engine,
More specifically, the fuel supply amount signal is generated according to the operating parameter, and the fuel supply amount error for each cylinder (deviation from the average value of the fuel amount supplied to each cylinder) is obtained from the fluctuation signal obtained from the engine speed signal. The present invention relates to an electronic fuel supply amount control device for an internal combustion engine, which is provided with an electronic control device that determines a fuel supply amount by superimposing a correction signal for correcting the error on the fuel supply amount signal.

[Prior Art] In an automobile, low frequency vibration (sway) frequently occurs in the entire automobile in a low rotational speed region during idling operation. This vibration is caused by a deviation between the mechanical energy generated in each cylinder for each work stroke (combustion stroke) and the mechanical energy for each cylinder and work stroke obtained through the camshaft cycle. To do. That is, this deviation is caused, for example, by a fuel supply error with respect to the cylinder or a different cylinder efficiency.

This causes a torque fluctuation with a basic waveform corresponding to the camshaft period, which causes vibrations about the longitudinal axis throughout the vehicle via the suspension.

This phenomenon called “sway” (hereinafter, simply referred to as vibration) often actually occurs at the camshaft frequency.

DE-A 33 36 028 describes a device for suppressing vibrations in motor vehicles. For this purpose, first, a signal is taken out from the segment wheel attached to the crankshaft, and the fuel supply amount error for the cylinder of the internal combustion engine is obtained from this signal. Vibration can be reduced by varying the amount of fuel to be supplied to the cylinder as desired. The amount of fuel supplied to the individual cylinders is adjusted to some common average value. The correction signal required for that purpose must have an average value of almost zero. The average value of the correction signal is set to approximately zero so that the correction device does not affect the control of the basic fuel supply amount.

[Problems to be Solved by the Invention] In the known device as described above, since the amount of fuel supplied to each cylinder is individually corrected, it is complicated and too expensive.

The present invention aims at providing a device of the kind mentioned at the outset which is able to eliminate the vibrations mentioned above in a simpler and cheaper way.

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, an electronic fuel supply amount of an internal combustion engine equipped with an electronic control device that generates a fuel supply amount signal (QK) according to an operating parameter. In the control device, the engine speed signal to the engine speed fluctuation signal (S
Means (18) for obtaining Q), means (20) for forming a periodic correction signal (SK) whose cycle corresponds to one rotation of the camshaft, and fuel supplied to each cylinder from the rotation speed fluctuation signal. Calculate the deviation from the average value of the amount for each cylinder,
Means for determining the phase position of the correction signal so that the position of the minimum value of the correction signal corresponds to the fuel supply amount signal of the cylinder in which the fuel supply amount exceeds the average value and shifts to the maximum (19,
22), and a configuration is adopted in which the periodic correction signal having the determined phase is superimposed on the fuel supply amount signal to compensate the rotation speed fluctuation.

[Operation] With such a configuration, the control of the amount of fuel supplied to each cylinder can be performed not for each cylinder but for all cylinders.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

In FIG. 1, the reference numeral 10 indicates a crankshaft or a camshaft, and one of the plurality of teeth mounted on the crankshaft is indicated by the reference numeral 11. Reference numeral 12 denotes two teeth which are closely arranged in front and back. Reference numeral 13 denotes a sensor for detecting a rotation speed signal or a rotation fluctuation signal, which is connected to the signal processing device 14. The output signal of the signal processing device 14 is applied to the rotation speed signal generator 15 and the fluctuation signal generator 18. The output signal of the fluctuation signal generator 18 is connected to the maximum value selection circuit 19, and the output signal of the maximum value selection circuit 19 is supplied to the signal generator 20. The output signal of the rotation speed signal generator 15 is supplied to the data generator 16 and further to the signal generator 20 via the lead wire 23. The signal from the signal generator 20 is output to the amplifier 21. The phase detection processing circuit indicated by reference numeral 22 is connected to the maximum value selection circuit 19 via a lead wire 25,
Further, it is connected to the amplifier 21 via the lead wire 24. Other operating parameters are shown at 17 and are input to the data generator 16 to form the fuel supply signal QK. The signal of the data generator 16 and the signal of the amplifier 21 are added at an addition point 26 to form a corrected fuel supply amount signal, which is supplied to an operating device (actuator) 27.
The fuel pump 28 is operated by the operating device 27, and the reference numeral 29 is given.
Combustion is supplied to the individual fuel chambers of the internal combustion engine via routes indicated by.

The operation of the device corresponding to the block circuit diagram of FIG. 1 will be described in detail with reference to FIGS. 2, 3, and 4. When the crankshaft 10 rotates, the teeth 13 or 12 provided on the crankshaft generate pulses in the sensor 13. The signal processing device indicated by reference numeral 14 detects the time between two pulses. Depending on the amount of fuel delivered to an individual cylinder, there will be variations in the time elapsed between individual pulses. From this time, the rotation speed signal is generated in the rotation speed signal generator 15. Similarly, in the fluctuation generator 18 supplied with a signal from the signal processing device 14, a fluctuation signal indicating the smoothness of rotation is formed. How to obtain this signal is
Known from DE-A 33 86 028,
No detailed description is given here. From the fluctuation signal, the deviation from the average value of the fuel amount supplied to each cylinder is obtained for each cylinder. The example shown in FIG. 2 shows changes in the fuel supply amount (injection amount) for a four-cylinder engine.

Reference numeral 40 relates to the cylinder supplied with the maximum amount of fuel. The value indicated by reference numeral 40 is particularly important. The maximum value selection circuit indicated by reference numeral 19 in FIG. 1 operates the signal generator 20 so that the signal of the signal generator 20 takes the minimum value when the fuel supply amount signal reaches the maximum value. The frequency of the signal generator 20, which generates a sine wave signal, a triangular wave signal or a rectangular wave signal, is changed by the rotation speed n via the lead wire 23. The signal generator 20 must generate a signal having a camshaft frequency, because the vehicle vibrates due to the camshaft frequency and the vehicle vibrates at the camshaft frequency. From the rotational speed n and other parameters such as the accelerator pedal position, the outside air temperature and the air pressure, a fuel supply amount signal QK is generated via the data generator 16. This fuel supply amount signal is led to the addition point 26. At the same time, the correction signal of the signal generator 20 is added to the addition point 26 via the amplifier 21.
SK is guided. As the output of the addition point 26, a combination of QK and the correction signal SK is generated. This signal causes the operating device 27
Are activated to control the amount of fuel supplied to the pump 28.

The circuit indicated by the reference numeral 22 has a function of minimizing the fluctuation of the rotation or torque according to the rotation speed and the fluctuation signal, and is used for performing the phase detection processing described later. In an automobile equipped with a microprocessor-controlled control device, the phase detection process is generally realized by a program.

As already mentioned, the phase of the signal of the signal generator 20 is
The minimum value of the signal from the signal generator 20 and the maximum value of the fuel supply amount are adjusted to overlap. Next, the amplitude of the signal from the signal generator 20 is adjusted by the phase detection processing circuit 22 so that the fluctuation signal takes the minimum value. At this time, if a change in the phase position occurs, the phase is equalized to a new phase position, and then the amplitude is adjusted. In principle, this series of steps can be repeated arbitrarily many times. A correction signal is shown in FIG. 3, and the large deviation shown in FIG. 2 is corrected using this correction signal. It should be noted that the correction signal has an average value of almost zero, as shown in FIG. 3, in order not to change the basic fuel supply formed by the fuel supply controller. Otherwise, the corrected fuel supply amount will increase or decrease as a whole, leading to an increase or decrease in the rotational speed. A correction signal having a camshaft frequency (cycle) and an average value of which is substantially zero is suitable for error compensation as described above. FIG. 4 shows the change in the corrected fuel injection amount. As can be seen from the figure, the variation in the amount of fuel supplied to the cylinder is clearly reduced. Since the device shown is simplified,
It is not possible to precisely adjust the amount of fuel in individual cylinders to the average value. However, the reduction in fluctuations caused by the different amounts of fuel in the individual cylinders reduces the sources of vibration of the motor vehicle and the associated reduction in sway.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the periodic correction signal is used, and the fuel supply amount to all the cylinders is corrected by this correction signal. In this case, the cycle of the periodic correction signal is adjusted to one rotation of the camshaft, and the phase thereof is set to a predetermined cylinder, so that the correction of the fuel supply amount to all cylinders can be performed by one periodic correction signal. Therefore, it is possible to effectively carry out the operation, and it is possible to effectively suppress the unpleasant vibration of the vehicle caused by the difference in the amount of fuel supplied to each cylinder with a simple structure.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of the device of the present invention, FIG. 2 is a diagram showing changes in the amount of fuel supplied to individual cylinders with respect to time, FIG. 3 is a diagram showing correction signals, and FIG. It is a diagram which shows the change with respect to the corrected amount of fuel over time. 13 …… Sensor, 16 …… Data generator 20 …… Signal generator, 21 …… Amplifier 22 …… Detection processing device, 27 …… Operating device 28 …… Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Max Strauber Germany 7000 Stuttgart 61 Ontario Strasse 30b (56)

Claims (4)

(57) [Claims] 1. An electronic fuel supply amount control device for an internal combustion engine, comprising an electronic control device for generating a fuel supply amount signal (QK) according to an operating parameter, and means for obtaining a rotational speed fluctuation signal (SQ) from an engine rotational speed signal. (18), means for forming a periodic correction signal (SK) whose cycle corresponds to one rotation of the camshaft, and (20) an average value of the amount of fuel supplied to each cylinder from the rotation speed fluctuation signal. Is determined for each cylinder, and the phase position of the correction signal is determined so that the position of the minimum value of the correction signal corresponds to the fuel supply amount signal of the cylinder in which the fuel supply amount exceeds the average value and shifts to the maximum. Means (19, 22) for superimposing the periodic correction signal having the determined phase on the fuel supply amount signal to compensate for the rotational speed fluctuation, and an electronic fuel supply amount control device for an internal combustion engine. . 2. The apparatus according to claim 1, wherein the average value of the correction signal is substantially zero. 3. A correction signal having a sine wave shape, a rectangular wave shape, or a triangle shape.
The device according to item. 4. A device according to claim 1, further comprising means for adjusting the amplitude of the periodic correction signal having the defined phase. apparatus.