JPH02248641A - Control device of vehicle internal combustion engine - Google Patents

Abstract

PURPOSE:To execute ignition cut only to a cylinder in which no fuel is present and prevent welding loss of catalyst by sending a current to an ignition plug at following ignition timing only when a valve opening signal is outputted to a fuel injection valve. CONSTITUTION:When a vehicle is made into a determined driving state such as deceleration driving, a fuel cut control means M5 prohibits the output of valve opening signal to a fuel injection valve M1 from a fuel injection executing means M2, and executes fuel cut control. At that time, a judging means M6 provided every cylinder judges whether the valve opening signal is outputted to the fuel injection valve M1 of this cylinder from the fuel injection executing means M2 or not, and when the signal is not outputted, the current sending to the ignition plug M3 of this cylinder executed at following ignition timing by an ignition executing means M4 is prohibited by an ignition cut control means M7. Hence, inconveniences such as welding loss of catalyst and breakdown of ignition plug caused according to fuel cut control and ignition cut control can be completely prevented.

Description

[Detailed description of the invention] [Industrial field of application] The present invention (companion) During vehicle deceleration Stopping the fuel supply to the internal combustion engine under predetermined operating conditions of the vehicle and cylinders with 1:% fuel supply stopped The present invention relates to a control device between internal combustion engines for a vehicle that cuts off power to a spark plug of a vehicle.

[Prior Art] Conventionally, as one type of control device for a vehicle internal combustion engine, there is a device that executes so-called fuel cut control, which improves fuel efficiency by stopping the fuel supply to the internal combustion engine when the vehicle is decelerating, etc. There is. In addition, fuel cut control can suppress the output torque of the internal combustion engine, so even if acceleration slip occurs in the drive shaft during vehicle acceleration, such fuel cut control can reduce the drive torque of the drive wheels. It has also been considered to suppress acceleration slip (for example, Japanese Patent Application Laid-open No. 1983-
No. 8436).

By the way, when fuel cut control is executed, fuel is no longer supplied to the cylinders of the internal combustion engine, so the required voltage required to discharge the spark plugs provided in each cylinder of the internal combustion engine is higher than when fuel is supplied. do. Further, when fuel cut control is executed, even if the spark plug is discharged, no fuel combustion occurs in the cylinder, so the temperature of the spark plug decreases and the required voltage further increases. On the other hand, spark plugs are designed based on the required voltage that can be discharged when fuel is supplied into the cylinder, and the withstand voltage is set slightly higher than this required voltage. Therefore, when the required voltage of the spark plug increases due to the fuel cut control as described above, the voltage applied to the spark plug via the igniter or the like exceeds the withstand voltage, and the spark plug may be destroyed.

In order to solve this problem, it has been considered in the past to execute so-called ignition cut control, which cuts off the power to one spark plug at the same time when fuel cut control is executed.

[Problem to be solved by the invention] However, in the past, the ignition cut control was simply executed in synchronization with the fuel cut control, so there was no fuel supplied to the cylinder after the ignition cut control started. In other words, the fuel supply to the internal combustion engine is carried out in the intake passage of the internal combustion engine by the fuel injector or carburetor, so that the gas is directly discharged into the exhaust passage. Since fuel is inhaled during the intake stroke after fuel supply, fuel supplied before the start of the fuel cut control may be inhaled into the cylinder after the start of the fuel cut control. By simply synchronizing the 1A cylinder and the ignition cut control, the ignition cut may be executed even though there is fuel in the 1A cylinder, and unburned gas may be discharged as is into the exhaust passage.

If unburned gas is discharged into the exhaust passage as it is, it will react with the catalyst for exhaust purification installed in the exhaust passage and burn, causing the catalyst to deteriorate.
In some cases, problems such as the catalyst being eroded and lost occur.

Furthermore, if the fuel cut control and ignition cut control are simply executed in synchronization as described above, energization to the spark plug may be restarted even though there is no fuel in the cylinder, and the spark plug There is also the problem of deterioration or damage. This is because, as mentioned above, 1: there is a time lag between the fuel supply and the inflow of fuel into the cylinder.

Therefore, the present invention has the advantage that when executing the ignition cut control during the fuel cut control, the start and end timings of the ignition cut control are suitably controlled to completely eliminate the above-mentioned problems such as catalyst melting and spark plug damage. Means for Solving the Problems [Means for Solving the Problems] That is, the present invention 1 for achieving the above objects is as illustrated in FIG.

Fuel injection valve M of each cylinder of the internal combustion engine at a predetermined injection timing
1, a fuel injection execution means M2 that outputs a valve opening signal to the engine 1, and a spark plug M2 for each cylinder of the internal combustion engine at a predetermined ignition timing.
ignition execution means M4 that energizes the fuel injection valve M1; and fuel cut control means M5 that prohibits output of a valve opening signal from the fuel injection execution means M2 to the fuel injection valve M1 under predetermined operating conditions of the vehicle. In the control equipment of internal combustion engines for vehicles,
For each cylinder of the internal combustion engine, from the fuel injection execution means M2 to the fuel injection valve M of the cylinder
Judgment means M for judging whether or not a valve opening signal is output to 1.
6, based on the judgment result of the judgment means M6, when a valve opening signal is output from the fuel injection execution means M2 to the fuel injection valve M1 of the cylinder concerned, the ignition execution means M4 performs the following ignition at the next ignition timing. Spark plug M3 of the cylinder to be executed
If the fuel injection execution means M2 does not output a valve opening signal to the fuel injection valve M1 of the cylinder, the ignition of the cylinder is executed at the next ignition timing by the ignition execution means M4. The gist of the present invention is a control device for a vehicle internal combustion engine, which is characterized by being provided with: an ignition cut control means M7 that prohibits energization to the plug 3;

[Function] In the control device for a vehicle internal combustion engine of the present invention configured as described above, the fuel injection executing means M2 outputs a valve opening signal to the fuel injection valve M1 of each cylinder of the internal combustion engine to control the internal combustion engine. Fuel is supplied, and the ignition execution means M4 energizes the spark plugs M3 of each cylinder of the internal combustion engine to ignite the fuel supplied to each cylinder, thereby operating the internal combustion engine. Further, when the vehicle enters a predetermined operating state such as deceleration driving, the fuel cut control means M5 causes the fuel injection execution means M2 to control the fuel injection valve M1.
Fuel cut control is executed by prohibiting the output of the valve open signal to the Furthermore, determination means M provided for each cylinder
6 determines whether a valve opening signal has been output from the fuel injection execution means M2 to the fuel injection valve Mll2 of the cylinder;
When the valve opening signal is not output to the fuel injection valve M1 of the relevant cylinder, the ignition cut control means M7 causes the ignition execution means M4 to cut off the ignition cut to the spark plug 3 of the relevant cylinder, which is executed at the next ignition timing. Prohibit energization.

Therefore, in the present invention, the ignition is cut only to the spark plug M3 of the cylinder to which fuel supply has actually been stopped by the fuel cut control, and the fuel supply is executed during normal operation of the internal combustion engine or when the fuel cut is resumed. Therefore, according to the present invention, the ignition is cut off for the cylinder to which fuel has been supplied, thereby preventing unburned gas from flowing into the exhaust passage. It is possible to completely prevent problems such as the catalyst being eroded due to fuel being discharged or, conversely, the spark plug being damaged by energizing the spark plug in a cylinder where no fuel is present.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

First, Fig. 2 (a) is a schematic diagram showing the overall configuration of a vehicle internal combustion engine opening control system according to an embodiment of the present invention applied to a front engine rear drive (FR) vehicle using a four-cylinder internal combustion engine 2 as a power source. It is a diagram.

As shown in the figure, the vehicle of this embodiment includes an acceleration slip control circuit 4 that detects acceleration slip occurring in the driving wheels when the vehicle accelerates and calculates a control amount of the internal combustion engine 2 to suppress the acceleration slip. An internal combustion engine control circuit 6 is provided that performs fuel injection control and ignition timing control of the internal combustion engine based on the control amount for acceleration slip control calculated by the acceleration slip control circuit 4 and the operating state of the internal combustion engine 2. .

Here, first, as is well known, on the internal combustion engine control circuit 61, C
It is configured as a logic operation circuit centered on PU6a, ROM6b, RAM6c, etc., and inputs detection signals from various sensors that detect the operating state of internal combustion engine 2 and control amount data output from acceleration slip control circuit 4. The fuel injection amount and ignition timing of the internal combustion engine 2 are inputted via the interface 6d, and the fuel injection valve 8 and igniter 10 of each cylinder are controlled via the output interface 6e based on these inputs. control.

As a sensor for detecting the operating state of the internal combustion engine 2, an intake air temperature sensor 14 that detects the temperature of intake air flowing into the intake passage 2a (intake air ff1) near the air cleaner 12, and an accelerator pedal 16 are used. a throttle opening sensor 20 that detects the opening degree (throttle opening degree) of the throttle valve 18 that is opened and closed by the engine; an intake pressure sensor 24 that detects the pressure in the surge tank 22 (intake pipe pressure) that suppresses intake pulsation; 2b, the air-fuel ratio sensor 28 detects the oxygen concentration in the exhaust gas on the upstream side of the three-way catalyst 26 for purifying the exhaust gas, the water temperature sensor 30 detects the cooling water temperature, and the spark plug 32 of each cylinder is connected to a high voltage. The temperature of the internal combustion engine 2 increases to 30°C depending on the rotation of the distributor 34 that distributes
The rotation angle sensor 36 outputs a signal every eight revolutions, and the distributor 34 has a rotation angle I: 1 time (i.e. internal combustion I).
A cylinder discrimination sensor 38, etc., which outputs a signal every two rotations of iI open 2) is provided, and the detection signals from these sensors are input into the internal combustion engine control circuit 6 via the input interface 6d. be done.

Next, on the acceleration slip control circuit 41, similar to the internal combustion engine control circuit 6, E, CPU 4 a, ROM
4 b.

It is configured as a logic operation circuit centered on the RAM 4c, etc., and includes the above-mentioned throttle opening sensor 20, intake pressure sensor 24. and left and right idle wheel speed sensors 42 FL, which detect the detection signals from the rotation angle sensor 36 and the rotation speeds of the left and right front wheels (idle wheels) 40FL and 40FR, respectively.
42 FR, and the rotation of the crankshaft 2C of the internal combustion engine 2 is controlled by the transmission 44. Left and right drive shaft speed sensors 42 detect the rotational speeds of the left and right rear wheels (drive shafts) 40RL and 40RR, which are transmitted via differential gears 46 and the like.
The detection signals from the RL, 42 RR, etc. are input through the input interface 4d, the acceleration slip of the drive shaft is detected based on these input data, the control amount of the internal combustion engine 2 is calculated, and the control amount is calculated according to the calculation result. The controlled variable data is output to the internal combustion engine control circuit 6 via the output interface 4e.

Next, various control processes for acceleration slip control and engine control executed by the acceleration slip control circuit 4 and the internal combustion engine control circuit 6 configured as described above are performed according to the flowcharts shown in FIGS. 3 to 6. explain.

First, FIG. 3 shows acceleration slip control processing in which acceleration slip control circuit 4 detects acceleration slip and calculates a control amount for internal combustion engine 2 according to the detection result.

This acceleration slip control process is a process executed as an interrupt process at predetermined time intervals in the acceleration slip control circuit 4. When the process is started, step 110 is first executed, and the left and right drive wheel speed sensors 42RL, 42RR and left and right idle wheel speed sensors 42FL.

Based on the detection signal from 42FR, drive wheel speed VR and vehicle body speed VF are calculated, respectively. Furthermore, driving wheel speed VRI friend
The rotational speeds VRL and VRR of the left and right drive shafts 40RL and 40RR are determined based on the detection signals from the left and right drive wheel speed sensors 42RL and 42RR, respectively, and the vehicle speed is set by selecting the larger one.
Left and right driven wheel speed sensors 42FL, 42FR
Based on the detection signal from the left and right driven wheels 40FL, 40
FR (7) The rotational speed is set by determining the rotational speed VFL and VFR and selecting the larger one.

Next, in step 120, the drive shaft 40RL is
A target slip amount Vo of 40RR is calculated. In the following step 130, the difference between the vehicle body speed VF and the drive shaft speed VR (: VR - VF) is calculated,
Calculate the actual slip amount Vj of RL and 40 RR,
Proceeding to step 140, this actual slip amount Vj
The deviation ΔV between this and the target slip amount Vo obtained in step 120 is calculated.

Next, in step 150, it is determined whether or not the slip control execution flag FS, which is set at the start of acceleration slip control, is in the reset state in the process described later, and if the slip control execution flag FS is in the reset state, That is, if acceleration slip control is not currently being executed ('L), proceed to the following step 160, and check whether the deviation ΔV (=V j -V o) between the target slip amount Vo and the actual slip amount Vj is a positive value. Depending on whether or not, the drive shaft 40RL,
It is determined whether acceleration slip has occurred in 40RR.

If ΔV>O, it is determined that acceleration slip has occurred on the drive shafts 40RL and 40RR, and the process proceeds to step 170, where the slip control execution flag FS is set. , drive shaft 40RL, 40
RR1: determines that no acceleration slip has occurred,
The process moves to step 320, which will be described later.

If the slip control execution flag FS is set in step 170, or if it is determined that the slip control execution flag FS has already been set in step 150, (
Then, proceeding to step 180, the average speed VR of the left and right drive shafts 40RL, 40RH is determined based on the detection signals of the left and right drive shaft speed sensors 42RL, 42RRh%, etc.
In addition to calculating O, the rotational speed N of the internal combustion engine 2 is calculated based on the detection signals from the rotational angle sensor 36 and the intake pressure sensor 24.
Calculate E and intake pipe pressure PM. Then, in the subsequent step 190, the reduction ratio γ in the power transmission system from the internal combustion engine 2 to the drive shaft (
=NE/VRO) and proceeds to the following step 20Q.

In step 200, an integral constant 01 and a proportionality constant GP are used to calculate the target torque of the internal combustion engine 2 in the next step 210 and subsequent processes based on the calculated reduction ratio γ and the rotational speed NE of the internal combustion engine 2. To calculate the integral constant 01 and the proportionality constant GP, a map preset using the internal combustion engine's rotational speed NE and reduction ratio γ as parameters is used.
The larger the gear ratio is, the larger the integral constant 01 and the proportional constant GP are set.

That is, the inertia of the vehicle drive system is inversely proportional to the square of the gear ratio γ, and the larger the gear ratio γ, the higher the responsiveness of the acceleration slip control system from the internal combustion engine 2 to the drive wheels, and the output torque of the internal combustion engine 2 is The response speed of the acceleration slip control system changes depending on the rotational speed of the internal combustion engine 2, and the higher the rotational speed NE of the internal combustion engine 2, the higher the responsiveness of the acceleration slip control system. By setting the constants, that is, the integral constant G1 and the proportionality constant GP, it is possible to perform torque control of the internal combustion engine 2 for acceleration slip control with optimal responsiveness without hunting the control.

In this way, the integral constant 01 and the proportional constant GP are set in step 200, and the process moves to the following step 210, where the set integral constant G1, the target slip amount Vo and the actual slip amount Vj obtained in step 140 are calculated. From the deviation ΔV and the current target drive shaft torque integral term TSI, the following formula (
1) to update the target drive shaft torque integral term TSI.

TSI:TSI-Gl-ΔV (1) Next, in step 220, the proportional constant GP set in step 200 and the target slip amount V obtained in step 140 are calculated.
From the deviation ΔV between o and the actual slip amount v3, the following formula (2
) to calculate the target drive shaft torque proportional term TSP.

TSP knee GP - ΔV - (2) Then, in the following step 230, LL Determine the drive shaft torque TS, step 240
to move to.

In step 240, the target driving wheel torque T obtained above is
By dividing by the reduction ratio γ obtained in SI & step 200, the output torque of the internal combustion engine 2 necessary to control the rotational torque of the drive wheels to the target drive shaft torque TS is calculated as the target engine torque TE. And then step 2
At 50, the internal combustion engine is The output torque of internal combustion engine 2 is calculated as the maximum engine torque TMAX, and the process proceeds to step 260, where the output torque of the internal combustion engine 2 is calculated from the maximum engine torque TMAX and the target engine torque TE using the following equation (3). Number of cylinders to which fuel supply should be stopped in order to control the target engine torque TE (hereinafter referred to as the number of cylinders cut)
Calculate NC.

NC:KC-INT (KC-TE/TMAX)
(3) In the above formula (3), KC represents the number of cylinders of the internal combustion engine 2, and INT represents an integer obtained by rounding down the decimal point of the calculated value in parentheses.

In this way, the number of cylinder cuts NC for acceleration slip control is
Once calculated, the process proceeds to step 270, where the calculated cylinder cut number data is output to the internal combustion engine control circuit 6 as control amount data for the internal combustion engine 2, and the process proceeds to step 280. When the cylinder cut number data is output, the internal combustion engine control circuit 6 performs fuel cut control using the number of cylinders according to this data through the control amount calculation process and crank angle interrupt process (described later), and reduces the output of the internal combustion engine 2. Suppress torque.

In step 280, it is determined whether the deviation ΔV between the target slip amount vO obtained in step 140 and the actual slip amount Vj is less than 0, that is, whether acceleration slip is suppressed. Even if ΔV〉0, the CfS acceleration slip continues, so the process is temporarily terminated and ΔV〉0.
If V≦0 (L), proceed to the following step 290, and Δ
A counter Ct for counting the state of V≦0 is incremented, and the process proceeds to step 300.

In step 300, it is determined whether the value of the counter C1 exceeds a predetermined value Co, that is, whether the state of ΔV≦0 has been maintained for a predetermined period of time or more. If a negative determination is made in step 300, the process is temporarily terminated. Otherwise, it is determined that acceleration slip will no longer occur in the driving wheels 40RL and 40RR, and step 310
, and the output of the cylinder cut number data to the internal combustion engine control circuit 6 is stopped. Then, in the following steps 320 to 340, 1:% is applied for the next acceleration slip control.
Initialization processing for initializing the counter C1, slip control execution flag FS, and target torque integral term TSI is executed, and the processing is temporarily terminated.

In this initialization process C, the value of the counter C1 is set to 0 in step 320, the slip control execution flag FS is reset in step 330, and the initial value TSlo is set to the target torque integral term TSI in step 340. executed in steps.

Also, in step 160 of this initialization process,
Deviation ΔV is 0 or less, driving wheels 40 RL, 40 R
It is also executed when it is determined that no acceleration slip has occurred in R.

Next, FIG. 4 is a flowchart showing a fuel cut determination process for determining whether or not the internal combustion engine control circuit 6 executes fuel cut control for the gold cylinder as the internal combustion engine 2 decelerates.

This fuel cut determination process 1 is a process executed as an interrupt process at predetermined time intervals in the internal combustion engine control circuit 6. When the process is started, step 400 is first executed, and a detection signal from the throttle opening sensor 20 is detected. Based on this, it is determined whether the throttle valve 18 is fully open. If it is determined in this step 400 that the throttle valve 18 is in the fully closed state, the process moves to the following step 410, and from the amount of change in the intake pipe pressure PM obtained based on the detection signal from the intake pressure sensor 24, etc. It is determined whether the internal combustion engine 2 is currently in a deceleration state.

On the other hand, if it is determined in step 400 that the throttle valve 18 is not in a fully closed state, or if it is determined in step 410 that the internal combustion engine 2 is not in a deceleration state, the process moves to step 420, and the process described below is performed. A fuel cut execution flag F that is set when it is determined that the execution conditions for the fuel cut control of the gold cylinder due to the deceleration of the internal combustion engine 2 are satisfied.
When C is reset, the value of counter C2 for determining whether to start the fuel cut control is reset in step 1''-430, and the process is temporarily terminated.

Next, if it is determined in step 410 that the internal combustion engine 2 is in a deceleration state, the process moves to the following step 440, where it is determined whether or not the fuel cut execution flag FC is in a reset state. If it is determined in this step 440 that the fuel cut execution flag FC is in the reset state, the process moves to the following step 450, and the rotation angle sensor 36
It is determined whether the rotational speed NE of the internal combustion engine 2 obtained based on the detection signal from
Step 430 is executed and the process ends.

On the other hand, if it is determined in step 450 that NE≧NCK, the process moves to the following step 460, and the counter C2 is
is incremented, and in subsequent step 470, the counter C
Depending on whether the value of 2 is greater than or equal to the predetermined value Cx, NE≧
It is determined whether the state of NCK has passed for a predetermined period of time. Then, C2≧CX, and in step 470, NE≧NC
If it is determined that the state of K has passed for a predetermined period of time, it is assumed that the execution condition for the fuel cut control is satisfied, and the process proceeds to step 48.
When the flag is 0, the post-processing after setting the fuel cut execution flag FC is temporarily terminated, and conversely, when C2<Cx, the processing is temporarily terminated.

Next, in step 440, if it is determined that the fuel cut execution flag FC has been set and the execution conditions for the fuel cut control have already been met, the process moves to step 490L, in which the rotational speed NE of the internal combustion engine 2 is set. It is determined whether or not the fuel cut return determination speed is equal to or higher than a preset fuel cut return determination speed NCF.

If NE≧NCF, it is 1'L. It is determined that the execution conditions for the fuel cut control are still satisfied, and the process is temporarily terminated. Otherwise, E, that is, NE<NC.
F or 1'L Assuming that the execution condition for fuel cut control is not established, steps 420 and 430 are executed.
After executing the process, the process is temporarily terminated.

Note that this fuel cut return judgment speed NCF is set to a value that is equal to or smaller than the fuel cut start judgment speed NCK at every predetermined rotation angle.

Next, in the internal combustion engine control circuit 6 shown in FIG. 3 is a flowchart showing a control amount calculation process.

This control amount calculation process is a process that is repeatedly executed after starting the internal combustion engine 2 in the internal combustion engine control circuit 6. When the process is started, step 500 is executed first, and the set/reset is performed in the fuel cut determination process. It is determined whether the fuel cut execution flag FC is set, that is, whether the execution conditions for fuel cut control are satisfied.

In this step 500, the fuel cut execution flag FC is
If it is determined that is set, the process proceeds to step 510, in which all cylinders are set as fuel cut cylinders in order to execute fuel cut control on the gold cylinders of the internal combustion engine 2,
The process moves to step 570, which will be described later.

On the other hand, if it is determined in step 500 that the fuel cut execution flag FC is not set (step 520
, the rotational speed NE of the internal combustion engine 2 and the intake pipe pressure P
Based on M, the basic fuel injection amount τ0 is calculated using a preset map. In the following step 530 (friends: intake temperature sensor 14, air-fuel ratio sensor 28, water temperature sensor 3)
Based on the detection signal from 0, etc., warm-up supplement L of the fuel injection amount
τ is calculated for various well-known fuel correction coefficients for performing air-fuel ratio correction and the like. Then, in step 540, the amount of fuel injection from the fuel injection valve 8, which is the control target, is calculated by multiplying the calculated various fuel correction coefficients by τ by the basic fuel injection amount τ0 obtained in step 520. do.

Once the fuel injection amount τ is set in this way, the process moves to step 550, and it is determined whether the cylinder cut number data for acceleration slip control output from the acceleration slip control circuit 4 has been input. do. Then the cylinder cut number data is input 1'L.Continued step 560
The program then moves to step 570 to set the cylinder to which fuel cut control is to be performed based on this input data NC, and then moves to step 570. If the cylinder cut number data has not been input, the process directly moves to step 570.

In step 570, a basic ignition timing θ0 is calculated using a preset map based on the rotational speed NE of the internal combustion engine 2 and the intake pipe pressure PM. And then step 5
Based on the detection signals from the intake air temperature sensor 14, the water temperature sensor 30, etc., various well-known ignition correction amounts θX for warming up the ignition timing, etc. are calculated, and the process proceeds to step 590. This calculated various ignition correction amount θX
is added to the basic ignition timing θ0 calculated in step 570 to determine the ignition timing θ of the internal combustion engine 2 that is the control target,
The process moves to step 500 again.

Next, FIG. 6 shows the internal combustion engine control circuit 6 and the rotation angle sensor 36.
This represents a crank angle interrupt process executed every predetermined rotation angle of the internal combustion engine 2 based on a detection signal from the internal combustion engine 2. In this process 1, based on the control variables of the internal combustion engine 2 calculated in the above-mentioned control variable calculation process, that is, the fuel injection amount τ and the ignition timing θ, a timer circuit 1 (not shown) provided in the ratio regulator face 6e is activated for each cylinder. The opening and closing times of the fuel injection valve 8 are set, and the output start and stop times of the ignition signal to the igniter 10 are set, and the fuel injection valve 8 and the igniter 10 are actually operated via a drive circuit (not shown). This is the process for driving the

As shown in the figure, when this crank angle interrupt process is started,
First, step 600 is executed to determine whether or not it is the current fuel injection amount setting timing. - It is determined whether the cylinder in which the fuel injection amount is currently being set is the fuel cut cylinder set in step 560 or step 510 described above.In step 610, the cylinder in which the fuel injection amount is currently set is determined to be the cylinder in which the fuel injection amount is currently set. If it is determined that the cylinder is not a fuel cut cylinder, the process moves to step 620, and the opening and closing times of the fuel injection valve 8 of the specific cylinder are set based on the fuel injection amount τ calculated in the control amount calculation process. , step 620
to move to.

Step 620 it, if it is determined in step 600 that it is not the current fuel injection amount setting timing,
This process is also executed when it is determined in step 610 that the cylinder for which the fuel injection amount is set is a fuel cut cylinder, and it is determined whether the current ignition timing is set. Then, if the current ignition timing is set, the process moves to step 630.
Based on the ignition timing θ calculated in the control amount calculation process, the output start and stop times of the ignition signal to the igniter 10 are set, and the process is temporarily ended.

2, the internal combustion engine control circuit 6 of this embodiment calculates the fuel injection amount τ and the ignition timing θ according to the operating state of the internal combustion engine 2, and the fuel injection valve 8 and the igniter 10 are adjusted according to the calculation results. At the same time, when the execution conditions for fuel cut control due to deceleration of the internal combustion engine 2 are satisfied, driving of the fuel injection valve 8 of the gold cylinder is stopped, fuel supply to all cylinders of the internal combustion engine is stopped, and further acceleration slip control is performed. When the cylinder cut number data for acceleration slip control is output from the circuit 4, the fuel injection valve 8 of the cylinder corresponding to the cylinder cut number data is prohibited from being driven and the fuel supply to that cylinder is stopped. It has been stopped.

By the way, when fuel cut control is executed for all cylinders or a specific cylinder of internal combustion g1 function 2 by such engine control (see table), if normal ignition control is executed for the fuel cut cylinders, the distributor 34 is The voltage applied to the spark plug 32 through the spark plug 32 becomes significantly higher than normal, causing problems such as damage to the spark plug 32.

Therefore, in this embodiment, 1: in the output interface 6e of the internal combustion engine control circuit 6 processes the ignition signal output from the drive circuit (not shown) using the timer set, and prohibits energization to the spark plug of the fuel cut cylinder. An ignition cut control circuit 50 is provided.

Ignition cut control circuit 501 table As shown in FIG. 7, there are a plurality of ignition control circuits 51 to 50 provided for each cylinder of the internal combustion engine 2 (in this embodiment, there are four internal combustion II! engine 2 cylinders, so there are four). 54, and an OR circuit OR for outputting the ignition signals output from each of these ignition control circuits 51 to 54 to the igniter To. In addition, the fuel injection signals for each cylinder output to the fuel injection valves 8 of each cylinder are respectively input to each ignition control circuit 51 to 54, and the internal combustion The 30° C. Hasshin output from the engine 2 every 30° C.A is inputted respectively. It should be noted that each of these ignition control circuits 51 to 541 includes the aforementioned determination means M6 and ignition cut control means M7.

The configuration and operation of each of these ignition control circuits 51 to 54 will be explained below based on the circuit configuration diagram in FIG. 8 and the time chart in FIG. 9.

As shown in FIG. 8, each ignition control circuit 51 to 54 (like
First, the fuel injection signal is transmitted through flip-flop circuits FFI and F.
Inverting input to set terminal S of F2 respectively lt'lA 30
'CA signal is reset terminal R of flip-flop FF1
and is input to the AND circuit ANDI, respectively. Also, the output signal from flip-flop FF2 is output from the AND circuit ANDI.
The output signal from the AND circuit ANDI and the output signal from the flip-flop FFI are input to the clock terminal CLOCK and reset terminal R of the binary counter CNT, respectively.

Next, the count value of the binary counter CNT is compared in magnitude with a preset reference value input to the comparators CMPI and CMP2, respectively.

The output signals from these comparators CMPI and CMP2 are respectively input to the set terminal S and reset terminal R of the flip-flop circuit FF3. It is input to the AND circuit AND2. Note that the output signal from the comparator CMP2 is also input to the reset terminal R of the flip-flop FF2.

Here, comparator CM1 [friend binary counter CN
This is to detect the rise timing of the ignition signal when the ignition timing is overadvanced based on the count result of T.
The comparator CM2 is used to detect the fall timing of the ignition signal when the ignition timing is at its most retarded.
A count value corresponding to each timing is set.

Further, each of the comparators CMPI and CMP2 is configured to output a pulse signal with a constant pulse width at each of the above-mentioned timings.

In each of the ignition control circuits 51 to 54 configured in this way, 1,
1. As shown in FIG. 9, when the fuel injection signal is input, the flip-flop circuit FF is activated at the falling time t1.
The output terminal Q of I becomes High level, and then the temperature rises to 30°C.
Until time t2 when the A signal rises, a pulse signal is output from the flip-flop circuit FFI. Since this output pulse is input to the reset terminal of the binary counter CNT, the binary counter CNT is reset at time t2.

On the other hand, since the fuel injection signal is also invertedly input to the set terminal S of the flip-flop circuit FF2, at the same time as the pulse signal is output from the flip-flop circuit FFI, the output terminal Q of the flip-flop circuit FF2 is g
h level. The output pulse from this flip-flop circuit FF2 (with the upper 30°C A signal and the AND circuit AND
Since the output from the AND circuit ANDI is input to the clock terminal CLOC of the binary counter CNT, the clock terminal CLO of the binary counter CNT
1 up on CK Flip-flop circuit FF2 from time t2
A 30°C A signal is input up to the time t3 when is reset.

Therefore, the binary counter CN T is 3 at time t2.
The 0°C A signal starts to be counted, and the count value C of the binary counter CNT becomes a value representing the rotation angle of the internal combustion engine a2 after fuel injection.

Next, the output from this binary counter CNT (is input to the companion comparators CMPI and CMP2, but as mentioned above, the output from each comparator CMPI and CMP is used as a reference value for the rise timing of the ignition signal when the ignition timing is overadvanced and Since the value for detecting the fall timing of the ignition signal at the time of the most retarded ignition timing is set, the output from each comparator CMPI and the CM P2 m binary counter CNT can be compared with each reference value. Each of these timings is detected and a pulse signal is output.

Furthermore, since the output pulses from each of these comparators CMPI and CMP2 are input to the set terminal S and reset terminal R of the flip-flop circuit FF3, respectively, the flip-flop circuit FF3 outputs a pulse signal representing the output range of the ignition signal for the relevant cylinder. will be output.

Furthermore, since the output signal from this flip-flop circuit FF3 is input to the AND circuit AND2 together with the ignition signal, the AND circuit A N D 21t outputs the ignition signal input within the output range of the ignition signal of the cylinder concerned. The ignition signal is output to the above-mentioned OR circuit ORI.

Note that since the output pulse from the comparator CMP2 is input to the reset terminal of the flip-flop FF2, the output terminal of the flip-flop FF2 is input to the output terminal of the flip-flop FF2.
After the fall timing of the ignition signal at the time of the most retarded ignition timing is detected at time t2, it becomes low level, and at time t3, the 30@CA signal is input to the binary counter CNT, that is, the counting operation of the binary counter CNT is stopped.

Next, when the cylinder in question is a fuel cut cylinder, the flip-flop circuit F
The output terminals Q of FI and FF2 remain at Low level, and the counting operation by the binary counter CNT is not executed. Therefore, no pulse signal is output from the comparators CMPI and CMP2. Therefore, the ignition signal for the relevant cylinder is input. Even if the ignition is performed, the AND circuit AND2 does not output a large ignition signal, and ignition of the relevant cylinder is prohibited.

In this way, each ignition control circuit 51 to 54 receives the fuel injection signal output to the fuel injection valve 8 of the corresponding cylinder.
The ignition signal for the cylinder is passed only when a fuel injection signal is input, and the ignition signal is cut if no fuel injection signal is input. For this reason, in this embodiment, when fuel cut control is executed, ignition cut control is performed for each cylinder when fuel no longer flows into the cylinder due to fuel cut control, and when fuel cut control is restored, the ignition cut control is performed for each cylinder. Ignition can be restarted after fuel has actually been supplied to the engine.

Therefore, according to this embodiment, the ignition is cut off for the cylinder to which fuel is supplied, thereby deteriorating the three-way catalyst 26, or conversely, the spark plug of the cylinder to which fuel is not supplied is energized. , the spark plug does not deteriorate, and the conventional problems associated with the execution of fuel cut control can be satisfactorily solved.

In addition, residual fuel in the intake passage may enter the fuel cut cylinder immediately after the fuel cut starts, and if ignition is performed by mistake at this time, combustion will continue until the next intake stroke due to the lean mixture in the cylinder, resulting in a so-called backfire. However, in this embodiment, since the ignition cut can be accurately executed for the fuel cut cylinders in which fuel injection is not performed, it is possible to prevent such backfire from occurring.

[Effects of the Invention] As described in detail above, in the control device for a vehicle internal combustion engine of the present invention, it is determined whether or not a valve opening signal is output to the fuel injection valve for each cylinder of the internal combustion engine. , the spark plug is energized at the next ignition timing only when a valve open signal is output to the fuel injection valve, and the ignition plug is prohibited from being energized at the next ignition timing if there is no valve open signal. has been done. Therefore, according to the present invention, LL
The fuel supply is actually stopped by the fuel cut control.Ignition cut can be executed only for the spark plug of the cylinder in which there is no fuel in the cylinder at the time of ignition. Traditional problems such as spark plug damage can be completely prevented. In addition, it is possible to accurately perform ignition cut on the fuel cut cylinder, and it is also possible to completely prevent backfires caused by igniting the fuel cut cylinder immediately after the start of fuel cut.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. FIG. 2 is a schematic diagram showing the overall configuration of a vehicle internal combustion engine control device according to an embodiment. FIG. 3 is a block diagram showing the acceleration slip control process executed in the acceleration slip control circuit. FIG. 4 is a flowchart showing the fuel cut determination process executed in the internal combustion engine control circuit, FIG. 5 is a flowchart showing the control amount calculation process, and FIG. 6 is a flowchart showing the crank angle interrupt process. Figure 7 shows the configuration of the ignition cut control circuit provided in the output interface of the internal combustion engine control circuit. Figure 8 shows the configuration of the ignition cut control circuit provided for each cylinder of the internal combustion engine in the ignition cut control circuit. FIG. 9 is a time chart illustrating the operation of each ignition control circuit. Ml, 8...Fuel injection valve M2...Fuel injection execution means M3, 32...Ignition plug M4...Ignition execution means M5...Fuel cut control means M6...Judgment means Ml... Ignition cut control means 2...Internal combustion engine 1$f14...Acceleration slip control circuit 6...Internal combustion engine control circuit 10...Igniter 5
0...Ignition cut control circuit 51-54...Ignition control circuit agent Tsutomu Sadate, patent attorney (and 2 other people) Fig. 1 Fig. Fig. Fig.

Claims (1)

[Scope of Claims] Fuel injection execution means that outputs a valve opening signal to the fuel injection valve of each cylinder of the internal combustion engine at a predetermined injection timing, and ignition execution means that energizes the spark plug of each cylinder of the internal combustion engine at a predetermined ignition timing. A control device for an internal combustion engine for a vehicle, comprising: and a fuel cut control means for prohibiting output of a valve opening signal from the fuel injection execution means to the fuel injection valve under predetermined operating conditions of the vehicle. determining means for determining, for each cylinder of the engine, whether or not a valve opening signal has been output from the fuel injection execution means to the fuel injection valve of the cylinder; and based on the determination result of the determination means, the fuel injection execution means When a valve opening signal is output to the fuel injection valve of the cylinder concerned, the ignition execution means permits energization to the spark plug of the cylinder concerned at the next ignition timing, and the fuel injection execution means ignition cut control means for prohibiting energization to the spark plug of the cylinder, which is executed by the ignition execution means at the next ignition timing, when a valve opening signal is not output to the fuel injection valve of the cylinder; A control device for a vehicle internal combustion engine, characterized in that: