JPS61279756A - Engine operating range detecting device - Google Patents

Abstract

PURPOSE:To enhance the accuracy of detection of the operation of an engine, by setting a first deceleration boundary in accordance with the volume of intake- air, and a second deceleration boundary in accordance with the opening degree of a throttle valve, and by detecting the deceleration of the engine in accordance with these boundaries. CONSTITUTION:There is provided a memory means 23 in which are stored a first deceleration boundary set in accordance with the volume of intake-air and the rotational speed of an engine and a secondary deceleration boundary set in accordance with the opening degree of a throttle valve and the engine rotational speed in the vicinity of the intake-air volume decreasing side of the afore-mentioned first deceleration boundary. Further, there are provided first and second deceleration detecting means 24, 25 for detecting the deceleration of the engine in view of the first and second deceleration boundaries and in accordance with the outputs of an intake-air volume detecting means 20 and an engine rotational speed detecting means 21, and the outputs of a throttle valve opening degree detecting means 22 and the engine rotational speed detecting means 21, respectively. An output means 26 issues a detection signal in accordance with the outputs of the detecting means 24, 25.

Description

[Detailed description of the invention] 1: [Industrial application field] (: ′″(7)Q q cat, “7′yoilti:*
l&m”94 ;
), [prior art]
II
In a vehicle engine, fuel is consumed during deceleration.
If I;1 is supplied, it will be caused by high intake pipe negative pressure.
Since misfires are likely to occur at 1°, which is unfavorable in terms of fuel efficiency and exhaust gas purification, the deceleration operating range is detected as shown in, for example, Japanese Patent Application Laid-open No. 57-1265', □32.
Although efforts are being made to cut fuel supplies,
, :In case of fuel co-supply"y) (7) Control accuracy 2
-1'';-+6', it is necessary to accurately detect the deceleration driving range.
:i: 8″-4・1′
1. As an example of such a driving range detection device,
' Conventionally, for example, there is a method disclosed in Japanese Patent Application Laid-Open No. 60-47830, in which the value of the throttle opening for determining the deceleration operation area is set as the first deceleration operation boundary line, and the value of the throttle opening for determining the deceleration operation area is set as the first deceleration operation boundary line The intake negative pressure for determining the second deceleration operation boundary line is set directly below the first deceleration operation boundary line, and the output of the throttle opening sensor or negative pressure sensor is set as the second deceleration operation boundary line. When the line is reached, it is determined that deceleration operation is in progress. This operating range detection device detects deceleration operation when the output of at least one of the throttle opening sensor or the negative pressure sensor reaches the deceleration operation boundary line. The responsiveness of deceleration range detection during deceleration operation can be ensured, and detection based on the negative pressure sensor eliminates the problem of decreased detection accuracy due to engine individual differences and installation errors of the throttle opening sensor. There is an advantage that this problem can be resolved below the driving boundary line.

However, with the device described in the above-mentioned conventional publication, the problem of reduced detection accuracy due to engine individual differences and installation errors of the throttle opening sensor above the first deceleration operation boundary line has not been solved, and the problem of reduced detection accuracy due to negative pressure Because it uses a sensor,
Since it is difficult for this negative pressure sensor to accurately detect minute changes in the intake negative pressure, there is still concern that detection accuracy in the deceleration operation range may deteriorate due to detection errors by the negative pressure sensor.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide an engine operating range detection device that can guarantee detection accuracy during deceleration.

[Structure of the invention]

In the conventional driving range detection device described above, one possible way to ensure detection accuracy during deceleration is to use an intake air amount sensor that can detect minute intake air amounts with relatively high accuracy in place of the throttle opening sensor. However, with this intake air amount sensor, there is a delay in detecting the deceleration operating range during sudden deceleration, so it is not sufficient as a method to reliably guarantee detection accuracy.
i,・9 First, we will consider the detection responsiveness and detection accuracy when detecting deceleration operation according to the intake air amount or throttle opening. This is an ideal detection method because the change in amount matches the required characteristics of the engine, but it requires the use of an intake air amount sensor such as an air flow meter as a detection means, which poses a problem in terms of transient response. On the other hand, when detecting the throttle opening and performing region determination, the detection operation of the throttle opening sensor is a mechanical operation, so the transient response is good, but
Detection errors are large due to individual engine differences and sensor installation errors.

Furthermore, since the above-mentioned intake air amount sensor detects air through the air, it is difficult to improve its transient response.On the other hand, individual engine differences and throttle opening sensor installation errors may occur due to the actual manufacturing process. Above, it is difficult to reduce this to zero.

Therefore, area determination is performed based on the intake air amount sensor to ensure detection accuracy, and the detection delay of the intake air amount sensor during sudden deceleration can be avoided by adjusting the throttle opening.
'4 area judgment 2°'''-7 resolved 61 marks °1
; it is expected that detection accuracy and detection responsiveness can be ensured both during slow deceleration and sudden deceleration.
: To be done.

Therefore, the present invention sets a first deceleration operation boundary line according to the intake air amount, and sets a second deceleration operation boundary line directly below this first deceleration operation boundary line according to the throttle opening,
When the output of the intake air amount sensor reaches the first deceleration operation boundary line or the output of the throttle opening sensor reaches the second deceleration operation boundary line, it is determined that deceleration operation is occurring.

That is, the present invention, as shown in the functional block diagram of FIG. While the throttle opening detection means 22 and the rotation speed detection means 21 are provided, the storage means 2
3, a first deceleration operation boundary line preset according to the intake air amount and engine speed, and a first deceleration operation boundary line set in advance according to the intake air amount and engine speed, and a first deceleration operation boundary line that is set in advance in accordance with the intake air amount decreasing direction of the boundary line, and a first deceleration operation boundary line that is set in advance according to the intake air amount and engine speed. The second deceleration operation boundary line set in advance is stored, and the first deceleration operation detection means 24 detects both the outputs of the intake air amount detection means 20 and the rotation speed detection means 21 and the first deceleration operation boundary line of the storage means 23. The time of deceleration operation of the engine is detected based on the boundary line, and the deceleration operation detection means 25 of Collection 2 detects both the outputs of the throttle opening detection means 22 and the rotation speed detection means 21 and the second deceleration operation boundary line of the storage means 23. The deceleration operation detection signal output means 26 detects the deceleration operation of the engine based on the first. Second deceleration operation detection means 24゜2
5 outputs a deceleration detection signal when at least one of the engines detects that the engine is decelerating.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

2 to 4 show an engine operating range detection device according to an embodiment of the present invention, which is an example commonly used in a fuel injection control device for a fuel injection type engine. In the figure, 1
is an engine, a throttle valve 3 is disposed in the middle of an intake passage 2 of the engine 1, and an air flow meter (intake air quantity detection means) 4 is provided in the intake passage 2 on the upstream side of the throttle valve 3. The upstream end of the intake passage 2 reaches an air cleaner 5, while a fuel injection valve 6 is disposed in the intake passage 2 on the downstream side of the throttle valve 3.

In addition, in the figure, 7 is a throttle opening sensor (throttle opening detection means) that detects the opening of the throttle valve 3, and 8 is a rotation speed sensor (rotation speed detection means) that detects the engine rotation speed.
, 9 is a control unit that controls the fuel injection amount of the fuel injection valve 6, 10-18 is a hardware representation of the functions of the control unit 9, and 10 is a control unit that controls fuel injection according to the intake air amount and engine speed. A control circuit that creates a pulse and applies it to the fuel injection valve 6; 11 is a switching circuit that connects and disconnects the control circuit IO and the fuel injection valve 6; 12 is a first to third deceleration operation boundary line a; A memory circuit 13 stores maps b and c (see Fig. 4), and a memory circuit 13 detects the deceleration operation of the engine from the intake air amount, the engine rotation speed, and the first deceleration operation boundary line a in the memory circuit 12. a first deceleration operation detection circuit,
14.15 is the throttle opening, engine speed, and the second or third deceleration operation boundary line in the memory circuit 12, c
2nd to detect when the engine is running at deceleration. The third deceleration operation detection circuit, 16, is the first. Second deceleration operation detection circuit 1
3. An OR circuit that makes the output of 14 a two-man power, 17 is the output of the rotation speed sensor 8 and the set rotation speed, for example, 1100 rpm+
A comparison circuit 18 is an AN that controls the switching circuit 11 by using the output of the OR circuit 16, the output of the third deceleration operation detection circuit 15, and the output of the comparison circuit 17.
This is the D circuit.

Note that in the above configuration, the control unit 9 has the storage means 23. as shown in FIG. 1st. The functions of the second deceleration operation detection means 24, 25 and the deceleration operation detection signal output means 26 are realized.

Next, the operation will be explained using FIGS. 3 and 4.

Here, FIG. 3 shows a flowchart of the arithmetic processing of the control unit 9, and FIG. 4 shows the first to third deceleration operation boundary lines a, b,
The map of c is shown. The first deceleration operation boundary line a is set using the intake air amount per rotation and the engine rotation speed as parameters, and the second deceleration operation boundary line a is set using the intake air amount per rotation and the engine rotation speed as parameters. The third deceleration operation boundary lines (a) and (c) are set close to the intake air amount decreasing direction and intake air amount increasing direction of the first deceleration operation boundary line (a) using the throttle opening degree and engine rotational speed as parameters, and both of them are In the low engine speed range, the engine speed increases as the throttle opening increases, and the engine speed increases as the throttle opening increases.
The throttle opening remains constant in the high rotation range. In addition, the second. Third deceleration operation boundary line S, c J.
is the installation error of the throttle opening sensor (bl, b in Fig. 4)
2)), the second deceleration operation boundary
The upper limit b1 of the 1-line or the lower limit of the third deceleration operation boundary line is
: It is necessary to set it so that it is not located above or below the first deceleration operation boundary line a.
・、.

When the engine is running, the air flow meter 4.
・-;, 1 Output j of throttle opening sensor 7 and rotation speed sensor 8, 1
The force is input to the control unit 9 (steps 30-
1.1: 32), in this control unit 9, the control circuit
::10, a fuel injection pulse is calculated and created according to the intake air amount and engine speed, and this is output at a predetermined timing l:□' (step 36). At that time, the first deceleration operation detection circuit 13 detects the intake air amount and the engine rotation speed and the memory circuit 12
It is determined whether the engine is in non-deceleration operation based on the first deceleration operation boundary line a in (step 33), and
The deceleration operation detection circuit 14 determines whether or not the engine is in non-deceleration operation based on the throttle opening, the engine speed, and the second deceleration operation boundary line in the memory circuit 12 (
Steps 34 and 35), deceleration operation detection circuit 15 of Collection 3
Now, throttle opening, engine speed and memory circuit 12
It is determined whether or not the engine is in deceleration operation based on the third deceleration operation boundary line C (steps 37 and 38).
). When the engine is in a non-deceleration state, the output of the first deceleration detection circuit 13 is "0", so no deceleration detection signal is applied to the switching circuit 11, and the fuel injection pulse of the control circuit 10 is is added to the fuel injection valve 6 at a predetermined timing, and fuel is supplied to the engine (steps 33 to 36).

When the engine is slowly decelerated from such a non-deceleration state and the intake air amount reaches the first deceleration operation boundary IKa, the first
The output of the deceleration operation detection circuit 13 becomes "1", and the throttle opening reaches the third deceleration operation boundary line C, and the output of the third deceleration operation detection circuit 15 becomes ``1'', so that the AND circuit 1 day, and the first deceleration operation detection circuit 13 “
1” signal is used as a deceleration operation detection signal by OR circuit 16 and A.
is added to the switching circuit 11 via the ND circuit 18,
This cuts the fuel supply (step 3).
3, 37-39).

Furthermore, when the engine is suddenly decelerated from a non-decelerating state, there will be a delay in detection during deceleration operation due to the detection delay of the air flow meter 4. In this case, when the engine is in deceleration operation, the air flow meter 4 (The throttle opening reaches the second deceleration operation boundary line a, and the second deceleration operation detection circuit 14
The signal "1"'""su・,=h"'<deceleration operation detection signal'!"67 is applied to the switching circuit 11 via the 10R circuit 16 and the AND circuit 18, thereby cutting off the fuel supply. (Steps 33 to 35.39).

On the other hand, when the engine is slowly accelerated from such a deceleration operation state and the intake air amount exceeds the first deceleration operation boundary line a,
The output of the first deceleration operation detection circuit becomes "0", and the application of the deceleration operation detection signal to the switching circuit 11 is stopped, thereby returning to the above-mentioned fuel supply state (step 33
~36).

Furthermore, if the engine is suddenly accelerated from a decelerating state, there will be a delay in detection during non-decelerating operation due to the detection delay of the air flow meter 4. Then, the throttle opening becomes 3rd.
reaches the deceleration operation boundary line C, and the third deceleration operation detection circuit 1
Since the output of step 5 becomes "0" and the AND circuit 18 is immediately closed, the output of the deceleration operation detection signal is stopped and fuel supply is started without delay (step 33.
37.38.36).

Note that when the engine speed is below the set speed, the output of the comparison circuit 17 becomes "0", the AND circuit 18 is closed, and the fuel cut is not performed. This is because even if the engine is in a deceleration operating state, it is necessary to supply fuel when the engine is rotating at low speeds to prevent the engine from stalling.

In the device of this embodiment as described above, deceleration is determined based on changes in the amount of intake air, so the deceleration operating range and non-decelerating operating range can be determined with high precision during slow deceleration and m acceleration of the engine. As a result, the control accuracy of fuel cut or start of fuel supply can be improved, and good fuel efficiency and deceleration feeling or acceleration can be ensured.

Additionally, if deceleration is determined based on the amount of intake air, there will be a delay in detecting deceleration or non-deceleration operation due to the air flow meter's detection delay during sudden deceleration or sudden acceleration. However, in this case, this device determines deceleration based on the output of the throttle opening sensor, so it can detect the deceleration operation range during sudden deceleration, or the non-deceleration operation range during sudden acceleration without delay, and the fuel Good control accuracy for cutting or starting fuel supply can be guaranteed.

In addition, this device uses two types of sensors, the air flow meter and the throttle opening sensor, to determine deceleration, so even if one sensor fails or is damaged, engine deceleration can be determined based on the remaining sensor. This makes it possible to make the device fail-safe.

In the above embodiment, a case has been described in which the engine operating range detection device is installed in a fuel injection control device of a fuel injection type engine, but this can of course be applied to other devices. Further, the third deceleration operation boundary line C does not necessarily need to be provided.

〔Effect of the invention〕

As described above, according to the engine operating range detection device according to the present invention, the first deceleration operation boundary line is set according to the intake air amount, and the throttle opening is set directly below the first deceleration operation boundary line. A second deceleration operation boundary line is set according to the following, and when the output of the intake air amount sensor reaches the first deceleration operation boundary line or the output of the throttle opening sensor reaches the second deceleration operation boundary line. Since it is determined that the vehicle is in deceleration operation, there is an effect that detection accuracy and detection responsiveness can be guaranteed during slow deceleration and sudden deceleration.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a schematic configuration diagram of an engine operating range detection device according to an embodiment of the present invention, and FIG. 3 is a functional block diagram showing the operation processing of the control unit 9 in the above device. FIG. 4, which is a diagram showing a flowchart, is a diagram showing first to third deceleration operation boundary lines a-c in the above device. '20...Intake air amount detection means, 21...Rotational speed detection means, 22...Throttle opening detection means, 23...Storage means, 24.25...First. Second deceleration operation detection means, 26...Deceleration operation detection signal output means, 4...Air flow meter, 7...Throttle opening sensor, 8.
...Rotation speed sensor, 9...Control unit. Patent applicant: Mazda Motor Corporation agent, patent attorney Ken Hayase - Figure 1 Figure 3

Claims (1)

[Claims] (1) An intake air amount detection means for detecting the intake air amount of the engine, a throttle opening detection means for detecting the opening of a throttle valve disposed in the intake passage, and a rotation speed detection means for detecting the engine rotation speed. , a first deceleration operation boundary line preset according to the engine intake air amount and the engine rotation speed;
and a storage means for storing a second deceleration operation boundary line which is set in advance in accordance with the throttle opening degree and the engine rotational speed in proximity to the intake air amount decreasing direction side of the boundary line, and the intake air amount detection device. a first decelerating operation detecting means for detecting when the engine is decelerating based on both outputs of the means and the rotation speed detecting means and a first decelerating operation boundary line of the storage means; a second deceleration operation detection means for detecting when the engine is decelerating based on both outputs of the number detection means and a second deceleration operation boundary line of the storage means; and the first and second deceleration operation detection means. 1. An engine operating range detection device comprising: deceleration operation detection signal output means for outputting a deceleration operation detection signal when at least one of the devices detects that the engine is in deceleration operation.