JPS5946352A - Method of reducing engine roughness by way of air-fuel ratio control - Google Patents

Abstract

PURPOSE:To improve the driving performance of an engine and to keep the specific fuel consumption of the engine low, by preventing occurrence of engine roughness with high accuracy by detecting variation of the indicated mean effective pressure of each cylinder during one cycle of engine operation and deviation of the indicated mean effective pressures of a plurality of cylinders, and controlling the air-fuel ratio of each cylinder on the basis of the above two factors. CONSTITUTION:Output signal of a crank signal sensor 3 and combustion pressure signals of each cylinder produced by respective combustion pressure sensors 4 are furnished to a Pi-meter 9, which calculates the indicated mean effective pressure Pi of each cylinder from these signals. These signals are also furnished to a control circuit 10 together with the crank signal. Further, a signal relating to the flow rate of intake air is furnished from an air-flow meter 7 to the control circuit 10. In the control circuit 10, the engine speed N is calculated from the crank signal and an air-fuel ratio necessary for the actual operational conditions of an engine is determined from the indicated mean effective pressure calculated by the Pi-meter 9, the flow rate Q of intake air detected by the air-flow meter 7, etc. Further, in controlling the air-fuel ratio, engine roughness is judged to be within a tolerable range if variation of the indicated mean effective pressure Pi during one cycle of engine operation is smaller than a prescribed tolerable value or deviation of the indicated mean effective pressure of the cylinders is lower than a prescribed tolerable value.

Description

[Detailed description of the invention]

The present invention is directed to a method for reducing engine roughness, or more specifically, a method for reducing engine roughness by controlling the air-fuel ratio. In recent years, the development of automatic fuel related technology (
Extinguish I! Improvement of ratio, 1) Reduction of (j harmful components in 1 gas,
Ease of driving and stability of driving, etc., have been investigated.
J. The first automatic medium is being offered. In addition, one way to improve drivability is to reduce engine roughness (representing slightly unstable engine rotation and engine vibration) caused by fluctuations in the output of each cylinder of the engine and variations in output between cylinders. As shown in Figure 1, it is known that engine roughness increases as the air-fuel ratio becomes leaner (lower fuel ratio), but fuel efficiency improves and indicated average effectiveness 1) decreases. Conventionally, a lux sensor or the like is used to detect the hr lux from the output shaft of the engine and control the engine output on all cylinders.
11 Methods have been used to reduce engine roughness by reducing engine roughness, but it is not possible to perform precise control of each cylinder f0, and in the end it is possible to reduce engine roughness by a certain amount. It is impossible to do so, and there is a problem in that if the problem is forcibly reduced, the fuel efficiency will decrease. The indicated mean effective pressure PI3, which is correlated to the engine output, is the area 3a c, which is used as the output in the same figure. ,”,Reponbu (one thing-
(3b'("The value obtained by subtracting the surface area and dividing this by the stroke volume 1 Formula C is 1") If 1'i - (Sa-3
1+)/Vl+ and 4'. However, \/h Cr!. Represents the traveling volume, 1°1 for each cylinder, each -r Cr fo k
-8 cylinders 111 from the detected indicated average effective It
It is characterized by determining the cycle-to-cycle variation in the indicated mean effective pressure and the cylinder-to-cylinder difference in the indicated mean effective pressure, and controlling the air-fuel ratio of each cylinder based on the cycle-to-cycle variation and the cylinder-to-cylinder difference. The present invention will be described below with reference to the drawings and an example of the present invention. FIG. 3 shows an example of a JIl example to which the method of the present invention is applied.
Outline of Carrot (/I4 Neucle, 4-cylinder case) and all peripheral equipment 1 1%q 11. Figure (There is. In the same figure, J3 and C11 are shown) Engine, 2 G; ``Magnets 1~ are arranged at equal intervals!, : represents something. 3 is a crank signal sensor consisting of, for example, a pickup 1, which generates a crank signal in synchronization with the rotation of the crank signal generating disk 2. 4 represents the combustion IJ which is integrated with the spark plug of each cylinder or is installed separately from the spark plug and detects the combustion pressure in the cylinder: 5 represents the input data manifold, 6 is attached to the data manifold 5 (J is attached to the data manifold 5, and the du-eye ratio of the pulse signal is J:).
The fuel injectors are turned and rolled, and 7 represents a load indicator meter for detecting the engine load. Furthermore, 8 is a combustion pressure wrench 4 and a crank signal line 1) 3
9 is a Pi meter that calculates the indicated average effective JT from the combustion r- signal outputted through amplifier 8 and the crank signal; 10 is a microb [11L7 υ included]; Each shows a control circuit. The control circuit 10 also includes an input port 1 as shown in FIG.
0a, output ports 1-10b, input/output data points) Temporarily stores oil cylinder data, ΔM (random access memory)'IOC, control ports 11 ROM (reads) stores genome and control data. A) 10d, data oil cylinder processing, control f I within 1<0M10d
II Gusi lXk IY, -,) 'l t-J')
'? -fri[1b[]re()-1 i.e. CPU (tn1~ralb11:] L?SingniLnitsl")10e
, these elements are connected (pass line 1'Or which is a transmission line of one bow, and output capo) to amplify the Fukuno. .. In the tree ffd configured as above + example l'l river -
To explain, the engine 1 starts, the crankshaft rotates, and the crank iM, Fb series 3J
, the crank signal 2) is output along with the combustion signal 4.
The combustion pressure signals of each cylinder such as hs l are sent to amplifier B,
Each amplified signal is transferred to a Pi meter 9cr: r″A
The indicated mean effective pressure Pi of each cylinder is falsified, and furthermore, the crank signal is transmitted to the control circuit 1.
Sent to 0. MaiE 11111 God Circuit 10, -
[1) The intake air amount signal from the meter 7 is )'A and (
There is. Then, in the control circuit 10, a crank signal QJ, engine rotational speed N is generated according to the control program in the ROM 10d, and furthermore, the calculated indicated mean effective pressure is displayed on the i meter 9, and the air flow meter 7 Based on the intake air ff1Q detected by
lj, the necessary air-fuel ratio is set, and based on the set value, a predetermined amount of fuel is supplied to the fuel Il! in synchronization with the crank angle signal.
! It is injected through the injection valve 6 and sent into the cylinder. Thereafter, the same control is repeated while the resin is in operation. In addition, when controlling the air-fuel ratio, check whether the cycle-to-cycle variation in the indicated mean effective pressure Pi is smaller than the predetermined tolerance value S1, as shown in FIG. 5, or the indicated average as shown in FIG. The cylinder-to-cylinder difference in effective pressure Pi is determined in advance and is smaller than i=tolerance value S2.

If [), then () of the indicated mean effective pressure Pi
-Since engine roughness caused by cycle-to-cycle fluctuations or cylinder-to-cylinder differences is considered to be within an acceptable range, air-fuel ratio control focuses on reducing fuel efficiency (improving fuel efficiency). In addition, l) In the i meter 9, the indicated average
When fraudulently overturning the I-T Pi, quantitative changes in the culm ratio of each cylinder (for example, the culm fV product of 7200 minutes of 1 recycle is changed to 1
Crank signal for every 00 division l, : value)>:1.1. If the Iha signal is outputted from the y-series 3, and this 1m signal is used as a ringing signal, the C combustion n-lens 4J and the detected combustion 11 are non-bringed by 4, as shown in Figure 2. The indicated 'l'l' = J effective pressure ()i obtained from the curved parts 3a and 3b of the acupressure scale diagram C is (11: fj culm volume, Δv: volume 1i'i f conversion, l) 0
: '/ Combustion at non-point angle O)'j('cAs shown, the simple act of adjusting 04 and moving to the center becomes possible, and the acting speed becomes faster.Next. The control which is the main part of this embodiment] 1111g will be explained. Fig. 7 (for each cylinder, January) 7 [" - Buki - 1 ~ of the judgment control between ruri and rcru] will be explained. .This diagram [.. The processes shown in this figure (a part of the various judgment control 1+1 processes of the control circuit 10 are expressed in the form of a rib blue f.Here, 31 is - ■ that 1] meter) 7 and a step of determining an increase/decrease in the engine load Q/N obtained based on the signal of the crank signal sensor 3; 32 is the step of determining the indicated average effective o+pi of the m-th cylinder (hereinafter referred to as n1). G3 to recycle the variable rib S between recycles n times
Pi (Pi, i) of each of the 4 noicles and 1 of the m-th cylinder
] Step 33 is S calculated in step 32 from the total recycling average of i 1l11.
34 is a step of gradually decreasing the fuel injection regulation IT-value τlTl0 of the relevant cylinder by a constant amount α; Step 0 is gradually increased by α, and the 36μ base fuel injection amount τis is obtained from a map (not shown) in the ROM at that time, for example, intake? Search for τms corresponding to the engine load determined by 11+ air volume and engine rotation speed, or negative, /+! Step 37 is to derive and determine τms according to a predetermined formula. 37 calculates the sum τm of τmO, etc., and controls the fuel injection well according to the height of 1m.
] By controlling the air-fuel ratio to a value corresponding to 1 m4
Shows a slap. If C1 car is (1) at constant f1 x 1j, then '
// is entered into the tree routine, ;Lzusj°tsu f31 part'-Af U meter 7 etc. part f'3)i,
4. Is the load negative for the previous tree routine processing? 81
It is determined whether there is an increase or decrease in η compared to the constant load l
'i Td, so it is determined that the change in load is h < NO, leading to S) ° tube 332. Step 32
The cycle-to-cycle variation of 3 m between the specified number of cycles of i in the Yi cylinder is calculated from the above equation (1). Next C. Su1
j) Compare the ¥1 volume value 531 and Sm 4, and if Sm is 81 or less, decrease 1m (+ by 17 minutes, and conversely exceed 81 4; L: r vPlo α separation 1
111 u, next step) Tuzo: Move on to 17. However, τmO
The first IUJ setting is OC: Yes. In this step 37, the fuel sentinel z'm is set to τms+τmO, and the process skips this routine. Then, it is processed by this routine in the same way as other cylinders. As long as the load does not change, the processing in this loopoon will proceed with steps 31.32.33.34 and 37, or with steps 31.32.33.35 and 3.
7. I get hit. As a result, the cylinder quickle fluctuation Sm is maintained near 31 without exceeding Sl, and J,
The engine is operated with increased output and fuel efficiency up to the V1 range of engine roughness. Next, the load changes due to acceleration/deceleration operations, etc. , : In the case, the process is determined as YES in step 31 and the process proceeds to step 3.
Move on to 6. Next, the process moves to step 37, where 1 m, which is the sum of τms and τmO already calculated in step 34 or 35, is determined, and the fuel injection length is set to 1 m. (If the load fluctuations are large, it is also good to set τmo to "0" and reset l-L'U.) In this way, the air-fuel ratio will be within the range that allows engine roughness depending on the load on each cylinder side. It is controlled to fit within. Next, the J-dilation rate for judgment control between cylinders is shown in Figure 8. The processing shown in this figure is expressed in the form of a 4-knob routine consisting of a series of various judgment controls 93 and 1, similar to the flowchart shown in FIG. r-play 1~(This is executed in the 1st step of the process. Here, ゛(, 111 is the highest [)i and the lowest 1]i from the Pi of each cylinder in a certain recycle. The step of calculating which difference i' is, /12 is the step of comparing and determining the value of the difference between the cylinders W1, S2 and 1 i,)i'', and 433 is the step of calculating the difference between all cylinders σ-)l. ) i total average giant i
4.1 is the indicated average effective II' P i m of cylinder m [1] and comparison judgment J
step, 45G, the fuel injection amount for each cylinder is 2m by β 1) Gradually decreases by 10 m by β ()
Indicates the snoop that will be gradually increased (j,. Here, when the process is added to this routine, first, step)
After l'f') i - has been calculated in the tube 41, then (
Compare S7 and 1) i −, which are applied to the tube 42, and if [)i − is less than or equal to 82 (゛, then the difference between the cylinders is J, and the engine roughness is fine ( l "It is determined that it is 1 or more, and no processing is performed, or (currently elf
The current processing is called t+, and this routine is skipped. At step 42, 1) i' exceeds $2 λ (If there is, 100 i is calculated in the next step /13, and then step) It reaches 1 tube 44. In step 44, determination processing is performed every (Aiki 1j). For example, the indicated mean effective pressure pim of the 1st cylinder II is compared with Pi, and if it is determined that Pim exceeds i, the process moves to step 45 and the fuel injection of the mth cylinder is performed. Gradually decrease the amount τm by β to lower Pim. Also, 1) If it is determined that im and Pi are equal, perform the process (4) or maintain the status quo. , t'tm is determined to be less than 11, the process moves to the suittub 46, and gradually increases τm of the m-th cylinder by β minutes to raise Pi31.Then, the process moves to the m+1-th cylinder, and the same process is performed. In this way, the air-fuel ratio is controlled by adjusting the fuel injection amount of all cylinders starting from the first cylinder, and then this routine is exited. In this way, by bringing the Pi of each cylinder close to 101, the engine is controlled so that Pi' is 82 or less, and the engine roughness caused by the difference between the cylinders is minimized, and moreover, within the limit of It becomes possible to maintain the highest output and fuel efficiency.Furthermore, as shown in Figures 7 and 8, the treatment is InI;
) In order to maintain maximum output and fuel efficiency within the IQ limit of engine roughness, each engine runs smoothly. I can do that. 1-nT' iJi The method of reducing engine run-downs according to the present invention and fuel ratio control is as follows:
The indicated average effective 11 for each cycle of each cylinder fij of a multi-cylinder engine is detected, and the detected indicated average effective) Tj is calculated, and the indicated average effective IN for each cylinder is calculated between cycles and the indicated average The air-fuel ratio of each cylinder is controlled based on the cylinder-to-cylinder variation and the cylinder-to-cylinder difference.
It is characterized by: . Therefore, if the method of the present invention is used, it is possible to suppress the variation between cylinders IFj and the balun A of the small ψ average Tlr effect 1 between the cylinders. The main objective is to suppress the C driver, direct the C driver, and maintain the fuel efficiency low.
From engine roughness! 1: ni r1'] It becomes possible to prevent wear and tear on the engine and its peripheral parts.

[Brief explanation of the drawings] Figure 1 shows the air-fuel ratio and fuel efficiency, as shown in the figure.
Figure 2 is a Shiatsu diagram, Figure 3 is a schematic diagram of the engine and its peripheral equipment to which the method of the present invention is applied,
Figure 1) is a block diagram showing the control circuit, Figure 1) is an explanatory diagram showing the correlation between engine roughness and indicated average effective pressure → inter-vehicle variation, and Figure 6 is an explanatory diagram showing the correlation between engine roughness and indicated average effective pressure j1 between cylinders. Indicates the correlation between the differences・Control circuit ioe-cpu Fig. 1 12 18 懺Burn Accent Fig. 2 Flea, Side-/7"$-AI-mushi. Fig. 5 Mouth Kitten Y Sentm1's Gaifle Usage Pressure V peak Karusuke figure 7

Claims (1)

[Claims] Multi-cylinder - ``The name of each cylinder of the engine (illustrated on the river) 17
Detecting the equalized effective pressure, the detected figure No. 1-11 equalized right effect/Tg
Calculate the inter-quickle variation of the indicated average rightward movement J1- and the cylinder-to-cylinder difference in the indicated average effective pressure for each quickle-to-quickle variation and cylinder-to-cylinder difference for each quickle Fl, and control the air-fuel ratio of each cylinder based on the quickle-to-quickle variation and inter-cylinder difference. The method of reducing engine roughness by controlling the air-fuel ratio.