JPS58176424A - Correction of irregularities of fuel controlling amount by engine cylinders - Google Patents

Abstract

PURPOSE:To make it possible to correct the amount of fuel injection by cylinders by a method wherein in the case of a fuel injection device for an internal- combustion engine, the amount of fuel injection by cylinders is corrected in proportion to the difference between the average engine rotation speed and the engine rotation speed corresponding to each of the cylinders. CONSTITUTION:When the amount (e) of fuel injection by cylinders becomes irregular as a result of irregularities of the surface areas of the openings of fuel injection valves among the cylinders occurring due to a manufacturing tolerance or a secular change, the engine rotation speed becomes irregular as shown by the left hand side graph (a). To overcome such difficulties, a study amount K1 is first obtained on the base of the difference between the average value N of the engine rotation speed and the actual engine rotation speed N1 as shown by the right hand side graph (c) and then the fuel controlling amount T1 is corrected for each of the cylinders as shown by the right hand side graph (d). As a consequence, the amount (q1) of fuel supply becomes equal for each of the cylinders as shown by the graph (e).

Description

[Detailed description of the invention]

The present invention provides a method for correcting engine cylinder fuel adjustment variation 4, especially between cylinder phases Ti of a multi-cylinder engine.

[Is the variation in fuel injection amount based on engine speed? The present invention relates to a method for correcting fuel metering variation for each engine cylinder. BACKGROUND ART In electronic engine control systems for automobiles and the like, there is fuel injection control that controls the amount of fuel injected from a fuel injection valve. Conventionally, fuel injection control for multi-cylinder engines uniformly controls the fuel injection amount to all cylinders. -2- In other words, the opening time of the fuel injection valve of each cylinder is the same for all cylinders.
It was controlled by a control amount. However, due to manufacturing tolerances or changes in the rod section, variations occur in the opening area of the fuel injector between cylinders, resulting in variations in the fuel flow rate of each cylinder, resulting in stable combustion. This tends to cause problems such as an increase in harmful components in the exhaust gas and a loss of drivability during engine rotation, especially when idling.
, ``The present invention aims to solve the above-mentioned problems, and determines an appropriate fuel injection amount for each cylinder so as to improve the transmission as described above and improve drivability. be. Therefore, the method of correcting the fuel adjustment variation for each cylinder of a T-engine according to the present invention is a method of adjusting the fuel adjustment of the fuel injection valve based on the engine rotational speed corresponding to each cylinder of a multi-cylinder engine. It is characterized in that the fuel injection +3J@ for each cylinder is corrected according to the difference (9i) between the average rotational speed corresponding to all cylinders of the engine and the rotational speed corresponding to each cylinder.
- The present invention 4 will be explained with reference to the drawings below. Figure 1 shows an engine control system to which the present invention is applied.
1 shows a schematic configuration diagram of a four-cylinder gasoline engine system, which is an example of the system. In FIG. 1, a carrot 1 inhales air for roasting sardines, which is known in the art and is carried in an automobile, through an air reach 2, an intake pipe 3, and a throttle valve 4. Further, fuel is supplied from a fuel system (not shown) through electromagnetic fuel injection valves 5 provided corresponding to each cylinder. Exhaust gas after combustion goes to exhaust manifold 6
, exhaust pipe 7, catalyst] inverter 8, etc., and is released into the atmosphere. The intake pipe 3 is equipped with a meter-type opening sensor 1 that outputs the engine load signal that corresponds to the throttle opening. A thermistor-type intake temperature sensor 2 is installed, which detects the intake temperature and outputs an analog voltage (analog detection signal@) according to the intake temperature. Further, the engine 1 is equipped with a one-noise, one-mister type water temperature sensor 13 that detects the temperature of the coolant water and outputs an analog voltage (analog detection signal) -4- corresponding to the coolant temperature. The rotational speed (number) sensor 15 detects the rotation of the crankshaft of the engine 1 (in degrees) (rotational speed) and outputs a pulse signal with a frequency corresponding to the rotational speed. The cylinder discrimination sensor 16 outputs a pulse signal to the injection tAIIW of the first cylinder, which is a reference signal, in order to specify each cylinder to which fuel is to be supplied according to the combustion order of each cylinder. The control circuit 20 is a circuit that manipulates the fuel injection amount based on the detection signals of the sensors 11 to 16, and adjusts the fuel injection amount by controlling the opening time of the electromagnetic fuel injection valve 5 for each cylinder. do. The control circuit 20 will be explained with reference to FIG. 100 is a fuel injection 0" microphone [1 processor υ
(CPU). Reference numeral 101 denotes a rotation number counter that counts the engine rotation number based on a signal from the rotation speed (number) sensor 15hs+ro. Further, this rotation number counter 101 sends an interrupt command signal -5- to the interrupt control section 102 in synchronization with the engine rotation. When the interrupt control unit 102 receives this signal, it interrupts the microprocessor 100 via the common bus 150.
Outputs an interrupt signal to. 103 is a digital input port indicating the cylinder to which fuel is supplied
The forward signal is transmitted to the microprocessor 100. 104
is an analog input coupler consisting of an analog multiplexer and an A-D converter.
It has a function of converting the data and sequentially reading it into the microprocessor 100. Each of these units 101.102.103
．． The output information of 104 is communicated to microprocessor 100 via common bus 150. Reference numeral 105 is a power supply circuit which supplies power to the RAM 107 which will be described later. 17 is a battery, and 18 is a key switch, but the power supply circuit 105 is directly connected to the battery 17 without passing through the key switch 18. Therefore, the RAM 107, which will be described later, is the key switch 1.
Power is always applied regardless of 8. -6- 106 is also a power supply circuit, but it is connected to the battery 17 through the key switch 18. The power supply circuit 106 supplies power to parts other than the RAM 107 (see below). 107 is a temporary memory gA unit (RAM) that is used temporarily during program operation, but the key switch 1 is
8, the power is always applied regardless of the system, and the key switch 18 is turned OFF to stop the engine operation.
8 is a read-only memory (ROM) for storing programs and various constants, etc. 109 is a fuel injection time control counter including registers, which consists of a down counter, The digital signal representing the opening time of the electromagnetic fuel injection valve 5 calculated in , that is, the amount of fuel injector is converted into a pulse signal with a pulse time width of I corresponding to the actual opening time of the electromagnetic fuel injection valve 5. Convert. 110 is a power amplification unit that drives the electromagnetic fuel injection valve 5; 111 measures the elapsed time with a timer, and
Transfer to 00. The rotation number counter 101 is the rotation number sensor 4.
The engine rotation speed is measured once every half rotation of the engine based on the -7- output of f15, and an interrupt command signal is supplied to the interrupt control unit 102 at the end of the measurement in (a). The interrupt control unit 102 generates an interrupt signal from the signal and sends it to the microprocessor 10.
0 to execute an interrupt processing routine that performs fuel injection calculation. FIG. 3 does not show a schematic 70-day diagram of microprocessor 100. Hereinafter, the functions of the microprocessor 100 will be explained based on this flowchart, and the operation of the entire configuration will also be explained. At the same time as the key switch 18 is turned on, a program prepared in advance in the ROM 108 starts, and first, in step 100, initialization processing is executed prior to subsequent processing. In step 101, the engine rotational speed Ni and throttle opening degree α are taken in, and from step Ni1α to step 102, the basic injection side amount TO is determined and overturned. Next, in step 103, the cooling water temperature T HW and the intake temperature T
11A, and from the THW and THA, in step 104, the correction coefficients f (THW) and f (THA
)−8= and set the basic injection MTO obtained in step 102 to T
Correction is performed as oXf(T)-1△)xf(TI-(W). In step 105, it is determined whether the basic injection amount tA is for that cylinder by checking the rotational speed after the G signal is input from the cylinder discrimination sensor 16. The judgment is reversed depending on the number of inputs of the Ne signal from the sensor 15. In step 106, the learning correction amount Ki in the non-volatile memory 107 is retrieved, and in step 107, the basic injection 69 hours TO is corrected by using the learning correction amount Ki. Set the output injection time 1-i to ToX (1+Ki), and step 108
Output with . Between steps 109 and 110, it is determined whether the engine load and engine rotational speed are in a stable state, and the process proceeds to step 111 only when the engine load and engine rotational speed are in a stable state. Step 1 when in unstable state
25, the engine rotational speed integrated value ΣNi, which will be described later, in the memory 107 is cleared to prevent learning correction from being performed using biased cylinder engine rotational speed data. The above-mentioned stable state determination is performed as follows. -9- That is, in step 109, the engine rotational speed change amount and J
, and the engine load change amount (ΔN=Ni−+−Ni−Ni and Δα−αi l−αi) are each below a predetermined value. If the change amount is below a predetermined value, the process further proceeds to step 110. For reliable learning, a delay is determined from when the load change disappears until the engine condition becomes stable. After a predetermined delay, the process proceeds to step 111. During seven steps 111 to 115, the T engine rotational speed Ni for each cylinder is taken in for learning and a comparison standard in step 116, which will be described later, is calculated. That is, in step 111, the fuel after fuel injection is delivered to the engine [
Taking into consideration the delay until it is reflected in the HERC, the routine exits from this routine and proceeds to step 125 during a predetermined delay, but proceeds to step 112 after the predetermined delay. In step 112, the engine rotational speed Ni when the fuel is reflected as the engine output is added to the engine rotational speed integrated value ΣN1 in the memory 107, and is set as a new ΣNi. -10- In step 113, the engine rotational speed integrated value ΣNi obtained in the previous step 112 is stored in the memory 107. In step 114, it is determined whether the number of times the engine rotation speed Ni is captured matches a predetermined number of times (an integral multiple of the number of cylinders), and if it is less than the predetermined number, the routine is exited and the next engine rotation speed N1 is sampled. If the jump is executed a predetermined number of times in step 101, the process proceeds to step 115. In step 115, the average value of the engine rotational speed integrated value ΣNi after being captured a predetermined number of times is calculated, and step 1
In step 16, it is determined whether the difference between the average value & and the current engine rotational speed Ni (ΔN=Ni−艮) is positive, negative, or equal, and if the engine rotational speed Ni is larger than the average value, then It is determined that there is a large number of fuel injection failures in the relevant cylinder, and the process proceeds to step 117. However, if the engine rotational speed N1 is smaller than the average value &, it is determined that there is little fuel injection failure in the relevant cylinder, and the process proceeds to step 118, in which the engine rotation speed is determined to be low. Speed-11 Once N1 is equal to the average value N, the process proceeds to step 119. In step 117, the output injection time T in step 108 is
Subtract the unit correction iE suspension ΔT from i, and in step 118 add the unit correction amount Δt to the output injection time Ti, and in step 11
In step 9, the output injection time Ti is left as is, and the corrected output injection time Ti - is set respectively. In step 120, the difference between the corrected output injection time T1- and the basic injection time To after temperature correction obtained in step 104 is calculated to obtain a unit correction amount integrated value (ΣΔT)i. In step 121, we want to find ΣΔT in step 120)
It is determined whether i is greater than or equal to a predetermined value, and if it is greater than or equal to the predetermined value, it is determined that there is some abnormality and the process proceeds to step 123, where the student value Ki is cleared. On the other hand, in the case of a predetermined number of vortices, it is assumed that it is normal and the ratio of the unit correction amount integrated value (ΣΔ lower) i and the basic injection time To obtained in step 104, that is, the character spacing correction value Ki, is determined in step 122, and the basic injection time To It is written so that it can be corrected at a constant ratio of m-12. In step 124, the learning correction IKi is stored in the non-volatile memory 1.
07, and use it for the next output injection time Ti numbing when the resin is in operation. The functions of the microprocessor are as described above. As described above, the character spacing value Ki is corrected for each cylinder to eliminate the fuel difference between the cylinders. 4 and 5 show time charts for specifically explaining the embodiment as described above in comparison with the conventional example. FIG. 4 corresponds to the conventional example, and FIG. It is shown as corresponding to the example. In the conventional method, as shown in FIG. 4, even if the engine speed Ni varies between cylinders as shown in (a) due to variations in the amount of fuel supplied between cylinders, the basic control amount To and (1))
And since it is set constant as shown in (C), the fuel control ITi (-To*(1→-Ki)) becomes constant as shown in (d), and -13- Therefore, the supplied fuel amount qi is As shown in (e), there are still variations among the cylinders, and as a result, the engine speed N
i is not corrected and remains in a state with variations. On the other hand, in this embodiment, when the engine speed Ni varies as shown in FIG. 4(a), the learning amount Ki becomes < In order to make a separate correction, the fuel control unit 7i becomes as shown in (d), and as a result, the supplied fuel amount qi becomes (e
), the dispersion between the cylinders is eliminated and the gold cylinders have the same value. Therefore, as shown in <a>, the engine rotational speed Ni eliminates the dispersion among the cylinders and becomes the same value for all cylinders, resulting in an operating state with no rotational unevenness. Fig. 6 shows another example of setting the unit correction amount ∆t in -1-), and Fig. 6<A) shows the unit correction amount ∆t by integrating the engine rotation speed. An example is shown in which the value is proportional to the difference ΔN between the average value of the value ΣNi and the current engine rotational speed Ni. On the other hand, Figure 1 14-6 (B) shows the value ΣNi as a value proportional to the difference ΔN between the average value ΣNi and the current engine rotational speed Ni. An example is shown in which the value is set to be larger as the value increases. By setting the unit complement i1:@8T in this way, it is possible to perform a highly accurate and quick variation correction. As explained above, the present invention is a method for adjusting the fuel injection opening of a fuel injection valve based on the engine rotational speed corresponding to each cylinder of a multi-cylinder engine, which comprises: The amount of fuel injection Di for each cylinder is corrected according to the deviation between the speed and the rotational speed corresponding to each cylinder. Therefore, according to the present invention, it is possible to correct the unevenness of fuel injection speed between cylinders and to make appropriate corrections to achieve a uniform fuel injection speed for all cylinders.
It becomes possible to sufficiently improve emissions and drivability. Furthermore, it is possible to improve fuel efficiency by improving the stability of eye 1 mill operation. -15- Furthermore, although the above embodiment is an example in which the present invention is applied to a gasoline engine, it goes without saying that the present invention is not limited thereto and can also be applied to a diesel engine.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of an engine control system to which the present invention is applied, FIG. 2 shows its electric block configuration, and FIG. 3 shows a flowchart showing an example of the processing of this embodiment.
FIG. 4 is an explanatory diagram of a conventional example, FIG. 5 is an explanatory diagram of the present invention, and FIG. 6 is an explanatory diagram of another embodiment of the present invention. 1...Multi-engine cylinder 5...Fuel injection valve 11...Throttle opening sensor 12...
・Intake temperature sensor 13...Cooling water temperature sensor 15...Rotation speed sensor 16...Cylinder discrimination sensor 20...Control circuit agent Patent attorney Tsutomu Seitachi 16-

Claims (1)

[Claims] 1. A method for adjusting the fuel injection amount of a fuel injection valve based on the engine rotational speed corresponding to each cylinder of a multi-cylinder engine, the method comprising: adjusting the fuel injection amount of a fuel injection valve based on the engine rotational speed corresponding to each cylinder of a multi-cylinder engine, 1. A method for correcting fuel adjustment variations for individual engine cylinders, characterized in that the fuel injection amount for each cylinder is corrected according to the deviation from the rotational speed corresponding to each cylinder. 2. For each engine cylinder according to claim 1, the arithmetic mean value of one sampling city obtained by multiplying the engine rotation speed by 1J with a sampling number that is an integral multiple of the number of cylinders is used as the average rotation speed. Method for correcting variations in fuel tone silk. 3. The fuel PI metering variation correction method for each engine cylinder according to claim 1 or 2, wherein the fuel injection amount for each cylinder is corrected by a constant correction amount regardless of the deviation. -1- Claim 1 or 2, wherein the fuel injection amount for each of the four cylinders is corrected according to the magnitude of the deviation.
] - Method for correcting variations in combustion angle adjustment for each engine cylinder. 5. The fuel adjustment for each engine cylinder according to any one of claims 1 to 4, wherein the correction of the fuel injection amount for each cylinder is performed after the engine rotation is stabilized and the engine load is stabilized. How to correct hanging variations.