JPS6093151A - Fuel control device upon deceleration of engine - Google Patents

Abstract

PURPOSE:To accurately control the supply amount of fuel upon deceleration to make it possible to smoothly carry out deceleration, by compensating the supply amount of fuel upon deceleration in accordance with the engine operating condition before deceleration and the time length of engine running in this running condition. CONSTITUTION:The amount of fuel F fed into an intake-air passage 12 in an engine 11, is controlled by a fuel supply means 13. The deceleration of the engine 11 is detected by a deceleration detecting means 14, and the running time in a predetermined running condition is detected by a running time detecting means 15. Further a first memory means 16 stores therein data relating to the amount of fuel adhering to the wall surface 12 of the intake-air passage 12 upon engine steady state running condition, and a second memory means stores therein data relating to variations in the amount of fuel adhering to the wall surface of the intake-air passage 12, corresponding to the running time of the engine. A supplied fuel compenasating means 18 receives the outputs of the detecting means 14, 15 and compensates the amount of fuel fed form the fuel supply means 13 in accordance with the data from the memory means 16, 17, thereby the supply amount of fuel upon deceleration is accurately controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine deceleration fuel control device that appropriately supplies fuel to the engine during deceleration.

(Prior art) Generally, when the throttle is suddenly tightened during deceleration, the intake passage downstream of the throttle becomes negative pressure, and the fuel adhering to the intake passage wall evaporates and is sucked into the engine, resulting in overconcentration of fuel. There is a problem that the speed cannot be decelerated smoothly.

In an attempt to solve this problem, the engine operating state before sudden deceleration was detected, and based on the assumption that this operating state was a steady state, the fuel # (evaporation) adhering to the wall was calculated from pre-prepared data. Conventionally, a method is known in which the fuel supply amount is reduced by the estimated amount of fuel adhering to the wall during sudden deceleration (see Japanese Patent Laid-Open No. 58-8238).

However, the actual amount of fuel adhering to the wall surface is determined not only by the engine operating state before deceleration begins, but is also influenced by the length of the operating time in that operating state. For example, even if the state is in a high-load operating state with a large amount of fuel injection before deceleration, if this state continues for a long time in a steady state, the actual amount of fuel Fl adhering to the wall will increase, but in a high-load operating state was continued for only a short time, and 111 was under low load condition 7
．． 1, the actual amount of fuel deposited on the wall would be small. Therefore, method 11, which does not take into consideration the operating time of the engine operating state before deceleration, has the disadvantage that the amount of fuel supplied cannot be accurately controlled.

(Object 1-1 of the invention) This invention was made in order to eliminate the drawbacks of L-kijoto, and it is based on the engine operating state of +iF+ that enters deceleration and the length of the operating time in that operating state. It is an object of the present invention to provide a fuel control device during deceleration of an engine that accurately controls the fuel cost N during deceleration by compensating the fuel cost M g during deceleration, thereby achieving smooth deceleration. shall be.

(Structure of the Invention) The structure of this invention for achieving the above object is shown in FIG.

In FIG. 1, an engine 11 has a fuel inlet IF supplied to an intake passage 12 thereof by a fuel supply means 13 according to the operating state of the engine 11. Further, the deceleration of the engine 11 is detected by the deceleration detecting means 14, and the operating time at the predetermined 4U diversion 4 is detected by the operating time detecting means 15.

On the other hand, the first notation t1 means 16 controls the intake passage 1 in each operating region when the engine 11 is in a steady operating state.
The second storage means 17 stores first data related to the amount of fuel adhering to the wall of the intake passage 12 corresponding to the operating time indicated in -. I remember the data from 2. Reference numeral 18 denotes a supplied fuel correction means, which receives the outputs of the stall speed detection means 14 and the cartwheel time detection stage 15, and adjusts the output of the above-mentioned first t0 stage 16 during deceleration.
Based on the first data in the operating region immediately before the -1- deceleration recorded in t0 and the second data stored in the t0 memory stage 17 of the -I-memory 2, the 1-memory fuel The fuel meter supplied from the first supply stage 13 is corrected, thereby accurately controlling the amount of fuel supplied during deceleration.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, an engine 11 has an intake passage 12 and an exhaust passage 21, and a fuel injection valve 22, a throttle valve 23, an air flow meter 24, and a pressure sensor 25 are installed in the intake passage 12. . Further, a rotation sensor 27 is provided near the crankshaft 26 of the engine 11.

28 is a control unit consisting of a microcomputer, which sends an injection pulse 29 to the fuel injection valve 22 to control the fuel injected from the fuel injection valve 22 as part of the fuel supply means 13 (FIG. 1). Control the amount of F. This control unit 28 includes a fuel injection valve 2
Fuel supply means 13 and deceleration detection means 14 in FIG. 1 except for 2.
, an operating time detection means 15, a first storage means 16, a second storage means 17, and a supplied fuel correction means 18 are built in. The control unit 28 uses its fuel supply means 13 (FIG. 1) to determine the amount of fuel supplied based on the intake air amount signal 31 from the air flow meter 24 and the rotation speed signal 32 from the rotation sensor 27. The deceleration detection means 14 (FIG. 1) detects the deceleration state of the engine 1 based on the throttle opening signal 33 from the throat valve 23, and the operating time detection means 15 (FIG. 1) detects After determining the operating state based on the suction pressure signal from the pressure sensor 25, that is, the engine load signal 34, and the rotational speed signal 32, the operating time in the predetermined operating state is detected.

The control unit 28 is a first storage means 16 (FIG. 1) in its storage device, and stores first data Tm as shown in FIG. 3. This first data Tm is data corresponding to the amount of fuel Fa sticking to the wall surface 12a of the intake passage 12 when the engine 11 is in a steady operating state. is expressed as the time it takes to cut the fuel supply. In other words,
Dark surface adhesion fuel oil IF a ensures that engine 11 is in good condition during deceleration.
Therefore, the fuel supply from the fuel injection valve 22 is canted to maintain an appropriate level of fuel 1 entering the engine 11. The amount of time it takes to shut down the fuel supply from the fuel valve 22 is increasing.

The first data Tm in section 1- is obtained by dividing a large number of operating ranges based on the engine load and rotation, and then experimentally estimating the cut time in section 1- for each of the divided operating ranges. This is what is called mapping data.In this data, the higher the load and the higher the rotation speed, the longer the cant time, that is, the greater the amount of fuel adhering to the wall surface.

Further, the control unit 28 stores second data f (t) as shown in FIG. 4 in the second storage means 17 (FIG. 1) in its storage device. This second
The data f (t) is determined by the first data T depending on how long the operation time continues to exist in the Jl + rotation area of the deceleration straight 11i7 (divided operation area in Fig. 3).
Modify m 11: It is something that cannot be done, and it increases with the lotus roll time t, and if the cartwheel time t becomes longer than a certain point, it becomes l.

The reason why the above-mentioned second data f (t) is set to 1 or more is that the operating region immediately before deceleration continues as a steady state F; or the operating region of the above-mentioned deceleration value rir+ The previous 4i was in a low-load driving range with less fuel and 71 size! This is because it excludes the case where there is a high-load operating region in which more fuel sticking j11 occurs before the operating region immediately before deceleration. If you were in a higher load operation area at +iij when you transition to the operation area immediately before deceleration, it is determined that deceleration is occurring at the time of the transition. After all, it is impossible for the vehicle to have been in a higher load operating region before shifting to the operating region immediately before deceleration, so this case can be excluded.

Furthermore, the amount of fuel adhering to the wall surface is determined by adjusting the throttle 23 to J! !
・Since it is also related to the speed of creation, this example
The third data g (-dθ/dt) as shown in FIG. ]-The first data Tm is modified. In other words, the operating speed of the throttle valve 23 in the valve closing direction -
As d O/d t increases, a sudden negative pressure acts on the intake passage and the amount of fuel adhering to the wall evaporates increases.
When the throttle operation speed dθ/dt is a predetermined value -a, that is, when -d O/dt is a predetermined value a, g (-dθ
/dt) is set to 1, and as -d O/dt becomes hotter, g'(-dθ/dt) becomes thicker.Here, the above throttle operation speed dθ/dt is set to This is derived from the throttle opening signal 33, and the opening of the throttle valve 23 is O in the fully closed state, and has a positive sign in the opening direction, so if the throttle valve 23 is operated in the closing direction during deceleration, the throttle operation will be The speed dO/dt takes a negative value.

In this way, the first data Tm is converted into T m X f (
t) Complement 1 in the form of X g (-dθ/d t'). That is, the supply fuel supplementary means 18 (FIG. 1) in the control I/roll unit 28 calculates T m,, f (
t), g (-c+θ/d),) and multiplying them to perform a fuel cut. By correcting the amount of `l, we determine the fuel supplying star that is ＼(E).

Next, a flowchart that executes the control described above!・6th
As shown in the figure. In addition, Pl to P18 in the figure are flowchart 1.
・Indicates each step.

The control shown in FIG. 6 is always performed while the engine 11 is operating. 'First, the first routine starts at Pl by starting JlΦIζ of the engine 11, and initial values 0 are entered into the symbols -FLAG and t at P2. Next, in P3, the operating range is determined from the engine load and rotational speed, and in P4, the first data Tm of the corresponding operating range is searched from the mapping data of FIG. 3.

At P5 in FIG. 6, it is determined whether the operating region is not the same between the previous determination and the current determination, and if NO,
In other words, if they are the same, proceed to P6 and count up by putting t+l into t to calculate the operating time t. If the determination in P5 is YES, that is, there is a change in the driving q1 region, the process proceeds to P7, and t is set to 0 during driving 111f. Proceeding to P7 means that an acceleration or deceleration operation has been performed.

At P8, the throttle operation speed dθ/dt is set to a predetermined value (i(
Determine whether it is larger than j − a, and if NO,
In other words, if it is in a deceleration state, proceed to P9, and at P9 mark F
Check whether T, A, and G are 1. In this first routine, FLAG is O, so proceed to PLO, and calculate the value of the second data f(j) in Fig. 4 from the operating time t, and the third data f(j) in Fig. 5 from the throttle operation speed lid Data g(
-dθ/dt), and then calculate the fuel cut time TO as To=TmX f (t)
θ/dt). Next, FLAG is set to 1 at the pH shown in FIG.

Next, PI4 determines whether the -1- fuel cut time TO is O or not, and if it is not 0, PI3 subtracts 1 from TO and sets it as a new To, and PI3 executes the fuel cut. do. After finishing this first cut in PI3, I'R to P3 and start the second routine.

In this 2 times 1 routine, from P3 to P4. ,I'5
, P6, P8, and since FLAG is 1 at P9, P
The program jumps to 14, and a fuel cut is executed via 111, PI3, and PI-6. 3 times [The routine after 1 is continued in the same way, and when TO=0, P , 14 to PI
Proceed to step 3 and set FLAG to 0 to end the fuel cut. After the fuel cut ends, the process returns to P3 to prepare for control during the next deceleration.

On the other hand, if the judgment result in P8 is YES, that is, if it is not in a deceleration state, the process proceeds to PI3, where the throttle operation speed dθ is
/dt is positive), I; 71. ! i (lri Determine whether it is smaller than b, and if it is not smaller, it is assumed that it is in an accelerated state and proceed to PI3. After setting TO to O, proceed to PI3. Here, since To=O, 1P178 is entered, F
Set LAG to O and end the routine with PI3. Therefore, if it is determined in the first routine that the deceleration is not 1 and proceeds to PI3, fuel cut will not be performed at all from the beginning, and if in the second and subsequent routines it is determined that the deceleration is not 1 and proceeds to PI3, the fuel will be cut at that point. will be cancelled.

Furthermore, if the throttle operation speed dθ/dL in PI3 is smaller than the positive reference value, that is, if the throttle operation is continued for deceleration or if the throttle operation is terminated midway, it will not pass through PI3. Then, proceed directly from PI3 to P14, and continue the fuel cut through the steps from P14 onwards. In other words, if the throttle operation for deceleration is continued, or if the throttle operation is terminated midway, the fuel cut is continued based on the fuel cut time TO initially set in PLO.

In this way, appropriate fuel cut is performed during deceleration, so that the wall surface 12a of the intake passage 12 in FIG. 2 (-1-1;
Even if the fuel Fa that was being used evaporates and is sucked into the engine, the fuel will not become overly concentrated, and an appropriate amount of fuel supply will be ensured.

2. In the above embodiments, the lower fuel supply stage 13 is constructed of a fuel injection device, but the present invention can also be applied to a fuel supply means 13 equipped with a carburetor.

(Effects of the Invention) As explained above, according to the present invention, fuel supply during deceleration takes into consideration not only the engine operating state before deceleration, but also the length of the operating time in that operating state. Since the amount is corrected, the amount of fuel supplied during deceleration can be accurately controlled to ensure smooth deceleration.

[Brief explanation of the drawing]

FIG. 1 shows the configuration of this invention 411 (schematic configuration diagram, second
3 is a graph showing the first data, FIG. 4 is a graph showing the second data, and FIG. 5 is a graph showing the third data. The graph shown in FIG. 6 is a flowchart 1 for explaining the operation of the embodiment.
・It is. 11...Engine, 12...Intake passage, 13...
Fuel supply means, 14... Deceleration detection means, 15... Operating time detection lower stage, ]6... First storage means, 17...
・Second record, 10th stage, 18...supply fuel replenishment means,
Tm...first data, f(t)...second data, Fa...wall surface fuel, t...operating time. To Figure 1 1 5 343-” dQ t

Claims (1)

[Claims] (1) A fuel supply means for supplying an amount of fuel according to the operating state of the engine, a deceleration detecting means for detecting deceleration of the engine, an operating time detecting means for detecting the operating time in a predetermined operating state; a first storage means for storing first data related to the amount of fuel adhering to the wall of the intake passage in each operating region when in a steady operating state; a second storage means for storing second data related to a change in quantity; -4-
Receives the output of the deceleration detection means and the operation time detection means,
-1-Ration 1 stored in the storage means during deceleration -1-Ration 1 first data in the operating region immediately before deceleration and -1-Ration 2
and second data stored in the storage means of the fuel supply correction means for correcting the amount of fuel supplied from the fuel supply means based on the second data stored in the storage means. Device.