JP2873736B2 - Engine idle speed control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an idle speed control device for an engine.

(Prior Art) In recent years, the demand for higher engine output has led to an increase in the number of cylinders in engines. However, in engines such as eight-cylinders and twelve-cylinders, sufficient intake can be obtained with only one intake system. Since it cannot be done, the cylinder is divided into two blocks,
An engine having two systems of intake systems in which intake is performed independently for each block is being used.

Incidentally, some engines are provided with idle speed control means in order to adjust the engine speed during idling operation. This idle speed control means is generally provided, for example, in Japanese Patent Laid-Open No. 1-2776.
As disclosed in Japanese Patent Publication No. 50, a control valve which is an electromagnetic solenoid valve is provided in a bypass intake passage connected in parallel with the intake passage so as to bypass a throttle valve provided in the intake passage of the engine, and a predetermined idle When the condition is satisfied, the control valve is adjusted to control the flow rate of air passing through the bypass intake passage, thereby controlling the rotation speed of the engine when the throttle valve is in the idle position. .

In an engine having two intake systems as described above, it is conceivable to provide each intake system with an idle speed control means in addition to an air flow meter and a throttle valve.

(Problems to be Solved by the Invention) However, in an engine having two intake systems, when each intake system is provided with idle speed control means, the feedback control condition of only one idle speed control means is not satisfied. It is possible to arrange. Specifically, the above determination is made by idle switches provided in the respective intake systems. However, it is conceivable that the start timing of the feedback control of both idle speed control means is shifted due to mounting errors or the like. In such a case, a phenomenon occurs in which only one of the two idle speed control means performs the feedback control and the other does not perform the feedback control, resulting in a difference in the number of revolutions in each bank of the engine. That is not desirable.

(Means for Solving the Problems) Therefore, the present invention has two independent intake systems,
In an idle speed control device for an engine having idle speed control means in each of these two intake systems, a determination means for determining whether feedback control conditions of the idle speed control means are satisfied is provided for each intake system. When one of the determination means determines that the feedback control condition of one of the idle speed control means is satisfied, feedback control start means for performing feedback control of both of the idle speed control means is provided. .

Regarding the idle speed control means in which the feedback control is started without depending on the judgment of the self-judgment means, the idle speed control is accurately performed until the self-judgment means judges that the feedback control condition is satisfied. It is desirable to prohibit learning control for performing.

The idle speed control means preferably includes a bypass exhalation passage having a throttle valve as a bypass, an electromagnetic solenoid valve for opening and closing the bypass exhalation passage, and control means for controlling the solenoid valve.

The determining means determines that the feedback control condition is satisfied when, for example, an idle switch that detects the fully closed state of the throttle valve detects a fully closed state.

(Operation / Effect of the Invention) In the engine idle speed control device of the present invention, because of the above-described configuration, only one of the idle speed control means is feedback-controlled, and both of the engine speeds are reduced during the idle operation. It is possible to prevent a deviation in the rotation speed of the bank.

The learning is prohibited until the feedback control condition in the self-determining means is satisfied, so that erroneous learning can be prevented.

(Embodiment) Hereinafter, an idle speed control device for an engine according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an entire idle speed control device according to an embodiment of the present invention.

In this figure, reference numeral 1 denotes an engine, and the engine 1 is configured as a V-type 8-cylinder engine having four cylinders in right and left banks 1R and 1L. Each bank 1R, 1L
Independently, the intake passages 2R and 2L and the exhaust passage
3R and 3L are provided. The structures of the intake passages 2R and 2L are the same, and they include, in order from the upstream side, hot-wire air flow meters 4R and 4L for detecting intake air amount, throttle valves 5R and 5L, and injectors for injecting fuel.
6R and 6L are provided.

In the intake passages 2R, 2L, the throttle valve 5R,
The bypass intake passages 7R and 7L that bypass 5L are provided. The bypass intake passage 11 is provided with electromagnetic solenoid valves 8R and 8L for adjusting the amount of air flowing through the bypass intake passages 7R and 7L to adjust the idle speed. The electromagnetic solenoid valves 8R and 8L are connected to a control unit 9 composed of a microcomputer, for example.
The control unit 9 controls the duty of the opening and closing of the control unit 9 to adjust the amount of air flowing through the bypass intake passages 7R and 7L.

The control unit 9 includes an engine speed sensor 10 (outputs a signal Ne), an engine cooling water temperature sensor 11 in addition to the air flow meters 4R and 4L (outputs signals Q _aR and Q _aL ).
(Output signal Tw), an exhaust passage 3R, respectively provided in 3L, to detect the oxygen concentration in the exhaust gas, the signal S _OR, O ₂ sensor 12R for outputting the S _OL, 12L, and the throttle valve 5
The idle switches 13R and 13L that detect the fully closed state of R and 5L and output idle signals S _SR and S _SL are connected, and the control unit 9 receives output signals from these sensors and the like, In addition to controlling the fuel supply by the injectors 6R and 6L, the idle speed of the engine 1 is controlled by the electromagnetic solenoid valves 8R and 8L during idling operation. The control of the fuel supply by the injectors 6R and 6L may be the same as the conventional control, and therefore, further description of the control will be omitted here.

Next, control of the idling speed of the engine 1 by the electromagnetic solenoid valves 8R and 8L during idling of the engine 1 by the control unit 9 will be described with reference to the flowchart of FIG. In this control, the electromagnetic solenoid valves 8R and 8R, which are ISC bubbles, are used.
Even if control is performed with the same control amount due to the individual difference of L, since the amount of air flowing through the solenoid valve varies,
It is assumed that learning control for compensating for this is also being performed.

In this control, first, in step S1, and inputs the engine speed ne, the idle signal S _SR, S _SL, various signals such as coolant temperature Tw. Next, in step S2, it is determined whether or not the actual engine speed ne is smaller than a predetermined engine start zone determination speed NA.If the determination is YES, the engine is being started, so in step S3, Start zone control for controlling the electromagnetic solenoid valves 8R and 8L, which are ISC valves, with a fixed duty ratio is performed, and the process returns to step S1. On the other hand, if the determination in the step S2 is NO, in a step S4, it is determined whether or not the test terminal indicating that the terminal is in the initial set zone for performing the idle adjustment after the assembly is ON. If this determination is YES, step S5
Then, the initial set zone control for controlling the electromagnetic solenoid valves 8R and 8L, which are ISC bubbles, with a fixed duty ratio is executed, and the process returns to step S1.

On the other hand, if the determination in step S4 is NO, it is not the initial set zone control, so in step S6,
It is determined whether or not the actual engine speed ne is smaller than the idle zone (that is, the feedback control zone for idle speed) NB, and it is determined whether the engine is in the idle zone. When this determination is NO, it is not the idle zone, so in step S7, the electromagnetic solenoid valve 8R,
Execute open zone control to open control 8L,
It returns to step S1.

If the above determination is YES and the vehicle is in the idle zone,
In step S8, the idle switch (Idle Sw) or flag is established, i.e., determines to close its idle switch, an idle signal S _SR, or S _SL has been issued. When the determination is NO, in step S9, the idle switch of the other bank is closed, and the idle signal S
_SR, it determines whether the S _SL has been issued. This judgment is NO
At this time, since the idle condition is not satisfied in both banks, the process shifts to the open control in step S7. on the other hand,
When the determination in step S9 is YES and the feedback control is performed in the other bank, that is, the electromagnetic solenoid valves 8R and 8L, in step S10, a flag for forcibly performing feedback control also in this bank (hereinafter simply referred to as a flag). In this case, the flag is set to “1”, and the process proceeds to step S11. On the other hand, if the determination in step S8 is YES,
In step S12, the flag is set to “0”, and the process proceeds to step S11.

In step S11, an electromagnetic solenoid valve which is an ISC valve
A feedback compensation amount GFB for 8R and 8L feedback control is calculated. This feedback correction amount GFB
_In the calculation of _(i) , the deviation Δne between the target engine speed and the actual engine speed ne set by illuminating the engine cooling water temperature on the target engine speed map shown in FIG. 4 is shown in FIG. ΔGFB is set in light of such a ΔGFB characteristic map, and is calculated by the following equation.

GFB _(i) = GFB _(i−1) + ΔGFB Here, GFB _(i−1) indicates the previous feedback correction amount.

After calculating the feedback correction amount CFB, step S13
It is determined whether the flag is 0. When the determination is NO, the feedback control is not performed when the own condition is satisfied. Therefore, in step S14, the previous learning value is set as the learning value GLRN. On the other hand, if the determination in step S13 is YES,
Since the feedback control is performed when the own condition is satisfied, the learning value is updated in step S15 and subsequent steps.

In updating the learning value, the feedback correction amount GFB is sampled. This sampling is performed a set number of times Gnx, for example, 32 times. Therefore, in step S15, the feedback correction amount GFB is sampled, and in step S16, a predetermined value Gn1 is subtracted from the remaining number of sampling times GnxA (which is initially set to Gnx), and a sample countdown is performed. The latest value Gna is calculated, and these are calculated in step S17.
Is performed until 0 is determined. Until the sample countdown number becomes 0, the process proceeds to step S14, where the learning value GLR
The previous learning value is set as N. On the other hand, when the sampling of the feedback correction amount GFB is completed, the average value GLRNA of the sampled feedback correction amount GFB is calculated in step S18, and the update value GLRN _(i) of the learning value GLRN is calculated in step S19. . The calculation of the update value GLRN _(i) is performed by, for example, the following equation.

GLRN _(i) = GLRN _(i-1) + (GLRNA ÷ 2) Thus, the previous learning value GLRN _(i-1) is equal to the average value GLRNA of 2
The reason why the learning value is updated by adding one-half is to prevent erroneous learning due to noise or the like.

Thereafter, in order to prevent the control amount from becoming too large, in step S20, (GLRNA か ら 2) is subtracted from the feedback correction amount GFB _(i) calculated in step S11, and the value is newly added to the feedback correction amount. Set as GFB _(i) . When the calculation of the feedback correction amount GFB is completed, the final control amount G of the ISC valves, which are the electromagnetic solenoid valves 8R and 8L, is set by the following equation.

G = GB + GFB + GLRN Here, GB is a basic control amount, which is set in the basic control amount map of FIG. 5 by illuminating the engine cooling water temperature.

Finally, in step S21, the operation of the ISC valve is actually controlled by the final control amount G, and the control of one routine is ended.

As described above, according to the present invention, it is possible to prevent a situation in which only one of the idle speed control means is feedback-controlled and the rotational speeds of both banks of the engine are deviated during idling operation. .

Further, the learning of the feedback control is prohibited until the feedback control condition in the self-judgment means is satisfied, so that erroneous learning can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an engine incorporating an idle speed control device according to an embodiment of the present invention. FIG. 2 is a flowchart for explaining control of the idle speed by the idle speed control device. 3 is a diagram showing a ΔGFB characteristic map, FIG. 4 is a diagram showing an idle target rotation speed map, and FIG. 5 is a diagram showing a basic control amount map of the ISC valve. 1 ... Engine 1R, 1L ... Bank 2R, 2L ... Intake passage 4R, 4L ... Air flow meter 5R, 5L ... Throttle valve 7R, 7L ... Bypass intake passage 8R, 8L ... Solenoid solenoid valve 9 ... control unit

Continued on the front page (72) Inventor Hirohide Abe 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 41/16 F02D 41 / 14 310 F02D 45/00 340

Claims (4)

(57) [Claims] An idle speed control device for an engine having two independent exhalation systems and each of these two exhalation systems having an idle speed control means. A determination means for determining whether the feedback control condition of the control means is satisfied is provided.
An engine speed control device, comprising: feedback control starting means for performing feedback control of both idle speed control means when it is determined that feedback control conditions of one of the idle speed control means are satisfied. 2. The idle speed control means for which feedback control has been started without depending on the judgment of its own judgment means, until the self-judgment means judges that the feedback control condition is satisfied. 2. The engine idle speed control device according to claim 1, further comprising learning control prohibiting means for prohibiting learning control for accurately performing the control of the engine. 3. The method according to claim 1, wherein the idle speed control means includes a bypass exhalation passage bypassing the throttle valve.
2. The engine speed control device according to claim 1, further comprising an electromagnetic solenoid valve for opening and closing the bypass expiration passage, and control means for controlling the solenoid valve. 4. The engine speed control device according to claim 1, wherein said judging means judges that the feedback control condition is satisfied when a fully closed state is detected by an idle switch for detecting a fully closed throttle valve.