JP3103206B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to prevent the supply of fuel during a shift operation of an engine with an automatic transmission, for example, in order to prevent a shift torque shock which occurs during a shift operation of an automatic transmission. The present invention relates to a control device for an engine.

[0002]

2. Description of the Related Art Conventionally, as an engine control device of the above-mentioned example, there is, for example, a device described in Japanese Patent Publication No. 2-20817. That is, in order to prevent the occurrence of a shift torque shock in an AT vehicle, this is an apparatus configured to stop fuel supply at the time of a shift (at the time of speed change).

However, this conventional apparatus has the following problems. In other words, the fuel injected from the injector has a portion directly entering the combustion chamber and a portion adhering to the intake pipe wall, and the fuel adhering to the intake pipe wall is vaporized and taken to the combustion chamber during the intake stroke. Therefore, even if the fuel supply is stopped at the time of the above-mentioned AT vehicle shift to prevent the occurrence of the shift torque shock, the combustion may be continued due to the above-mentioned carried-off fuel amount. However, there is a problem that it is difficult to reduce the torque.

[0004]

According to the first aspect of the present invention, when the amount of fuel removed from the fuel attached to the wall of the intake pipe and carried away to the combustion chamber becomes a combustible value, By switching from the fuel supply stop to the torque down control by the ignition timing control, it is possible to reliably prevent the combustion from being continued due to the amount of fuel removed even when the fuel supply is stopped and the torque down cannot be performed. It is intended to provide a control device.

In addition to the object of the first aspect of the present invention, when the combustion at the above-mentioned removed amount is possible, the invention according to the second aspect of the present invention anticipates the combustion at the removed amount. It is an object of the present invention to provide an engine control device capable of reducing the carry-out amount early by making the execution time of the torque reduction due to the stop of the fuel supply early, and performing the torque reduction reliably.

According to a third aspect of the present invention, in addition to the object of the first aspect, when the combustion at the above-mentioned removed amount is possible, torque reduction control by stopping fuel supply, and ignition An object of the present invention is to provide an engine control device capable of surely performing torque reduction by using together with torque reduction control by retarding the timing (retard).

According to a fourth aspect of the present invention, in addition to the object of the first, second or third aspect of the present invention, it is possible to reliably prevent a shift torque shock occurring during a shift in an engine with an automatic transmission. The purpose of the present invention is to provide a control device for an engine that can be used.

[0008]

According to the first aspect of the present invention, when a predetermined torque-down execution condition is satisfied,
A control device for an engine having a fuel supply stopping means for stopping the supply of fuel, comprising: a calculating means for calculating a removal amount which is vaporized from fuel adhering to an intake pipe wall surface and removed to a combustion chamber; and Determining means for determining whether combustion at the carry-off amount is possible based on the calculation result of the means, retarding means for executing torque down by retarding the ignition timing, and determining result of the determining means Switching means for switching from the torque-down control by the fuel supply stopping means to the torque-down control by the retarding means when combustion at the carry-out amount is possible based on .

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the fuel supply is stopped when the removal amount can be burned based on the determination result of the determining means. The control device is an engine control device including an execution time advance means for advancing the torque down execution time by the means.

According to a third aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the fuel supply is stopped when the removal amount can be burned based on the determination result of the determining means. This is a control device for an engine that uses both torque down control by means and torque down control by the retarding means.

According to a fourth aspect of the present invention, in addition to the configuration of the first, second or third aspect of the present invention, the control of the engine in which the torque-down execution condition is set at the time of shifting of the engine with the automatic transmission is set. The device is characterized in that:

[0012]

According to the first aspect of the present invention, as shown in the claim correspondence diagram of FIG. 7, the arithmetic means P1 is vaporized from the fuel adhering to the intake pipe wall surface and removed to the combustion chamber. The above-mentioned determination means P2 determines whether or not combustion at the above-mentioned removal amount is possible based on the calculation result of the calculation means, and when a predetermined torque-down execution condition is satisfied ( PO), and when the removal amount can be burned based on the determination result of the determination means P2, the change means P3 retards the ignition timing from the torque down control by the fuel supply stop means P4. The control is switched to the torque-down control by the retarding means P5 for executing the torque-down (including both the case where the fuel supply stop is executed and the case where the fuel supply stop is not executed). As a result, there is an effect that even if the fuel supply is stopped, it is possible to reliably prevent the combustion from being continued and the torque from being unable to be reduced due to the removed fuel amount.

According to the invention described in claim 2 of the present invention,
In addition to the effect of the first aspect of the present invention, when the combustion at the carry-out amount is possible based on the determination result of the determination means, the execution timing advance means sets the torque reduction execution timing by the fuel supply stop means. Hasten. In other words, the timing of stopping the fuel supply by the fuel supply stopping means is advanced. For this reason, the amount of carry-out can be reduced early, and there is an effect that the torque can be reliably reduced.

According to the third aspect of the present invention,
In addition to the effect of the first aspect of the present invention, when the combustion at the above-mentioned removed amount is possible based on the determination result of the determination means,
Since the torque-down control by the fuel supply stopping means and the torque-down control by the retarding means for retarding the ignition timing are used together, there is an effect that the torque can be reliably reduced.

According to the invention described in claim 4 of the present invention,
In addition to the effects of the first, second or third aspect of the present invention, the torque-down execution condition is set at the time of shifting of the engine with the automatic transmission. There is an effect that can be done.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a control device for the engine. In FIG. 1, an air flow sensor 2 is connected to the rear of an air cleaner 1 for purifying intake air, and the air flow sensor 2 detects the intake air amount Q.

A throttle body 3 is connected to the rear of the above-mentioned airflow sensor 2, and a throttle valve 5 for controlling the amount of intake air is provided in a throttle chamber 4 in the throttle body 3. And this throttle valve 5
A surge tank 6 as an expansion chamber having a predetermined capacity is connected to the downstream intake passage, an intake manifold 8 communicating with an intake port 7 is connected downstream of the surge tank 6, and an injector 9 is connected to the intake manifold 8. Is arranged.

On the other hand, the above-described intake port 7 and exhaust port 11 which are appropriately communicated with the combustion chamber 23 of the engine 10 have:
Intake valve 12 that is opened and closed by a valve operating mechanism (not shown)
And an exhaust valve 13 respectively, and a spark plug 14 having a spark gap facing the above-described combustion chamber 23 is mounted on the cylinder head 24.

An O2 sensor 16 is provided in an exhaust passage 15 communicating with the above-described exhaust port 11, and a catalytic converter, a so-called catalyst, for detoxifying harmful gas is connected to the rear of the exhaust passage 15.

A bypass passage 17 for bypassing the throttle valve 5 is provided. An ISC valve 18 as an ISC (idle speed control) mechanism is provided in the bypass passage 17, while a downstream side of the element 19 of the air cleaner 1 is provided. , An intake air temperature sensor 20, a throttle sensor 21 in the throttle body 3, and a water temperature sensor 22 in the water jacket.

FIG. 2 is an explanatory diagram showing the state of the fuel injected from the injector 9 and the fuel flowing into the combustion chamber 23. The fuel T injected from the injector 9 is shown in FIG.
Is the amount of adhesion TA adhering to the intake pipe wall surface and the direct combustion chamber 2
3 and is divided into the direct input A sucked in. Further, the fuel (in-mani-wet amount) Tm attached to the intake pipe wall surface is vaporized and carried away in the combustion chamber 23, and remains as it is without vaporizing, and is vaporized and sucked in the next injection. And remaining fuel.

FIG. 3 shows a control circuit of the engine control device. The CPU 30 includes an intake air amount Q from the air flow sensor 2, an engine water temperature t from the water temperature sensor 22, a throttle opening TVO from the throttle sensor 21, and a distributor 25. Various input signals such as an engine speed Ne from a crank angle sensor, a turbine speed Nt from a turbine speed sensor 26, a shift signal Sh from an inhibitor switch 27, and an air-fuel ratio A / F from an O2 sensor 16. In accordance with the program stored in the ROM 28, the injector 9 and the spark plug 14
And the RAM 29 accelerates the turbine rotation speed Nt2 (see FIG. 4) and the torque reduction execution time when the normal fuel supply is stopped (the fuel cut is simply abbreviated as fuel cut). Necessary data such as data corresponding to the turbine speed Nt1 in the case (see FIG. 4) and a map are stored. Normal fuel cut is performed at the time when the turbine speed Nt starts to decrease after the turbine speed Nt increases as shown in FIG. This is performed at t2.

Here, the CPU 30 determines that a predetermined torque-down execution condition is satisfied (in this embodiment, at the time of shifting of the AT vehicle, the engine water temperature is equal to or higher than a predetermined value, and the throttle opening TVO is further increased by a predetermined opening). (When the above conditions are satisfied), the fuel cut means for stopping the supply of fuel (see the seventh step S7 in the flowchart of FIG. 5).
From the fuel adhering to the wall of the intake pipe,
Means (refer to the third step S3 in the flowchart of FIG. 5) for calculating the removed amount B (see FIG. 2), and combustion at the removed amount B based on the calculation result of the above-described calculating means. Determining means for determining whether or not ignition is possible (refer to a sixth step S6 in the flowchart of FIG. 5), and retarding means for executing a torque down by retarding the ignition timing (a fourteenth step S1 in the flowchart of FIG. 5).
4) and changing means for switching from torque-down control by the fuel-cut means to torque-down control by the retarding means when the combustion at the carry-out amount B is possible based on the judgment result of the judgment means (CPU 30 itself)
And also.

The operation of the thus configured engine control device will be described in detail below with reference to the flowchart shown in FIG. The contents indicated by various symbols used in the following description are as follows. Fa: retard flag for retarding the ignition timing (retard) Ta: basic injection amount of fuel α: direct injection rate at which fuel directly enters the combustion chamber 23 β: vaporization from fuel attached to the intake pipe wall surface and combustion chamber 2
3. Removal ratio SA: ignition timing Tm: intake manifold amount (see FIG. 2) T: final injection amount of fuel A: direct injection (T × α) B: removal amount (Tm × β) In step S1, the CPU 30 executes reading of various necessary signals, and in the next second step S2, the CPU 30 executes a normal operation and sets the retard flag Fa to zero.

In the next third step S3, the CPU 30 determines the basic fuel injection amount Ta, the direct injection rate α, the removal rate β, and the ignition timing S.
A are calculated respectively, and in the next fourth step S4, the CPU
30 determines whether the fuel cut signal is ON, and when the fuel cut signal is OFF, the tenth step S
While skipping to 10, the fuel cut signal is ON
In the case of, the process proceeds to the next fifth step S5.

In the fifth step S5, the CPU 30 next obtains a control A / F based on an arithmetic expression represented by [Equation 1]. That is, this is an arithmetic expression for determining whether or not combustion is possible at the air-fuel ratio of the carry-out amount B shown in FIG.

[0027]

(Equation 1)

Next, in a sixth step S6, the CPU 30 determines whether or not the combustion at the above-mentioned removal amount B is possible. If the combustion is not possible, the process proceeds to the next seventh step S7. The process proceeds to the ninth step S9.

In the above-described seventh step S7, the CPU 30 executes a fuel cut to prevent a shift shock of the AT vehicle. The processing in the seventh step S7 is a normal torque-down control in a case where combustion at the carry-out amount B is impossible.
Next, in an eighth step S8, the CPU 30
Is driven at a predetermined ignition timing SA.

On the other hand, when it is determined in the above-described sixth step S6 that the combustion at the carry-out amount B is possible, the process proceeds to a ninth step S9, and in this ninth step S9, the CPU 3
0 sets a retard flag Fa in a predetermined area of the RAM 29.

Next, in a tenth step S10, the CPU 30
Calculates the final injection amount T of the fuel based on the following equation.

T = (Ta−Tm · β) / α Next, in an eleventh step S11, the CPU 30 drives the injector 9 to inject fuel corresponding to the above-described final injection amount T.

The above-described tenth step S10 and eleventh step
Since the process of step S11 is a process used both when the fuel cut signal is ON and when the fuel cut signal is OFF, in the next twelfth step S12, the CPU 30 determines whether or not the retard flag Fa is set. It is determined that when Fa = 0, the process proceeds to the above-described eighth step S8, and the ignition is executed. On the other hand, when Fa = 1, the process proceeds to the next thirteenth step S13.

In the thirteenth step S13, the CPU 30
Calculates the retard amount (retard amount) of the ignition timing required for the torque down control.
A step 30 obtains the current ignition timing SA by subtracting the retard amount from the ignition timing SA.
Performs ignition at the above-described ignition timing SA.

In short, when the predetermined torque-down execution condition is satisfied, the above-described determination means (the sixth step S
When the combustion at the above-mentioned removal amount B is possible on the basis of the determination result of (6), the changing means (see CPU 30) delays the ignition timing from the torque down control by the fuel cut means (see the seventh step S7). Switching to torque-down control by retarding means (refer to a fourteenth step S14) that executes torque-down by turning.

As a result, even if the fuel is cut, there is an effect that it is possible to reliably prevent the combustion from being continued and the torque from being unable to be reduced due to the removed fuel amount.

FIG. 6 is a flowchart showing another embodiment of the engine control device. In this embodiment, the circuit devices shown in FIGS. 1, 2 and 3 are used. The contents indicated by various symbols used in the following description are as follows.

Ta: Basic injection amount of fuel α: Direct injection rate at which fuel directly enters the combustion chamber 23 β: Vaporization of fuel adhering to the intake pipe wall surface and combustion chamber 2
3. Removal ratio SA: ignition timing Tm: intake manifold amount (see FIG. 2) T: final injection amount of fuel Fb: fuel cut request flag A: direct entry (T × α) B: removal amount ( Tm × β) The operation of the engine control device will be described below with reference to the flowchart of FIG.

In a first step C1, the CPU 30 executes reading of various necessary signals, and in a next second step C2,
The CPU 30 executes the normal calculation, and further in a next third step C3, the CPU 30 calculates the basic fuel injection amount Ta, the direct injection rate α, the removal rate β, and the ignition timing SA, respectively.

Next, at a fourth step C4, the CPU 30 determines the speed based on the speed change signal Sh from the inhibitor switch 27.
It is determined whether or not the shift signal Sh is ON, and Sh = OFF
, While returning to the first step C1, while Sh =
When it is ON, the process proceeds to the next fifth step C5.

In this fifth step C5, the CPU 30 determines whether or not the fuel cut request flag Fb is set. When Fb = 0 (when fuel cut is not necessary even during shifting), the first step is performed. While returning to C1, when Fb = 1, the process proceeds to the next sixth step C6.

In the sixth step C6, the CPU 30 next obtains a control A / F based on an arithmetic expression represented by [Equation 1]. That is, a calculation is performed to determine whether or not combustion is possible at the air-fuel ratio of the carry-out amount B shown in FIG.

[0043]

(Equation 1)

Next, in a seventh step S7, the CPU 30 determines whether or not the combustion at the above-mentioned removal amount B is possible. If the combustion is not possible, the process proceeds to the next eighth step C8. The process moves to the tenth step C10.

In the above-described eighth step C8, the CPU 30 determines whether or not the fuel cut signal is ON. When the fuel cut signal is ON, the CPU 30 executes the fuel cut in the next ninth step C9. The injector 9 is driven by C12 to inject fuel. Here, the process in the ninth step C9 is a process for preventing the shift torque shock of the AT vehicle as in the related art.

On the other hand, when it is determined in the above-described seventh step C7 that the combustion at the carry-out amount B is possible, the process proceeds to the tenth step C10, and in this tenth step C10,
The CPU 30 determines whether or not the fuel cut signal is ON. When the fuel cut signal is ON, the process proceeds to a thirteenth step C13, and when it is OFF, the process proceeds to an eleventh step C11.

In the above-described eleventh step C11, it is necessary to cut the fuel.
The PU 30 sets the basic injection amount Ta to zero, and in the next twelfth step C12, the CPU 30 drives the injector C9. In this case, since Ta = 0, fuel cut is substantially performed.

On the other hand, in the above-mentioned thirteenth step C13, C
The PU 30 advances the timing of executing the torque down from the time t2 shown in FIG. 4 to the time t1. Next, the fourteenth step C1
At 4, the CPU 30 retards the ignition timing for the purpose of torque down control.

In short, when the predetermined torque-down execution condition is satisfied (see Fb = 1 in the fifth step C5),
In addition, based on the determination result of the determination means (refer to the seventh step C7), when the combustion at the above-mentioned removal amount B is possible, the changing means (C
The PU 30) activates the retarding means (refer to the fourteenth step C14) for executing the torque down by retarding the ignition timing, and also advances the torque cut execution timing by the fuel cut (refer to the thirteenth step C13). Therefore, there is an effect that the removal amount B can be reduced at an early stage, and the torque can be reliably reduced by retarding the ignition timing.

In correspondence with the configuration of the present invention and the above-described embodiment, the fuel supply stopping means (fuel cut means) of the present invention is provided in the seventh step S7 (see FIG. 5) and the ninth step C9 ( In the same manner, the calculating means corresponds to the third step S3 (see FIG. 5) and the third step C3 (see FIG. 6), and the determining means corresponds to the sixth step S6 (see FIG. 5). 7), the seventh step C7 (FIG. 6)
), The retarding means performs the operation in the fourteenth step S14.
(See FIG. 5), the fourteenth step C14 (see FIG. 6), the changing means corresponds to the CPU 30, and the execution timing advance means corresponds to the thirteenth step C13. It is not limited to only the configuration of the example.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an engine control device of the present invention.

FIG. 2 is an explanatory diagram showing a fuel injection state and a carry-out amount.

FIG. 3 is a control circuit block diagram.

FIG. 4 is a time chart.

FIG. 5 is a flowchart showing an embodiment of torque down control.

FIG. 6 is a flowchart showing another embodiment of the torque down control.

FIG. 7 is a diagram corresponding to claims.

[Explanation of symbols]

 23: Combustion chamber B: Removal amount S3, C3 ... Calculation means S6, C7 ... Determination means S7, C9 ... Fuel cut means S14, C14 ... Retardation means C13 ... Execution timing advance means 30 ... CPU (change means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-22153 (JP, A) JP-A-3-92560 (JP, A) JP-A-3-121224 (JP, A) JP-A-3-3 124237 (JP, A) JP-A-3-124924 (JP, A) JP-A-55-69738 (JP, A) JP-A-1-211649 (JP, A) JP-A-2-19633 (JP, A) JP-A-2-45628 (JP, A) JP-A-2-157448 (JP, A) JP-A-64-66436 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/04 330 F02D 41/12 330 F02P 5/15

Claims (4)

(57) [Claims] An engine control device having a fuel supply stopping means for stopping fuel supply when a predetermined torque-down execution condition is satisfied. Calculating means for calculating the amount of carry-off, determining means for determining whether or not combustion at the amount of carry-off is possible based on the result of calculation by the means for calculating, and retarding the ignition timing. Retarding means for executing torque down;
An engine control device comprising: changing means for switching from the torque-down control by the fuel supply stopping means to the torque-down control by the retarding means when the removal amount can be burned based on the determination result of the determining means. 2. An engine according to claim 1, further comprising an execution timing advance means for advancing a torque reduction execution timing by said fuel supply stopping means when the fuel can be burned at the carry-out amount based on a determination result of said determination means. Control device. 3. The torque reduction control by the fuel supply stopping means and the torque reduction control by the retarding means when the combustion at the carry-out amount is possible based on the determination result of the determination means. An engine control device according to any one of the preceding claims. 4. The engine control device according to claim 1, wherein the torque-down execution condition is set at the time of shifting of an engine with an automatic transmission.