JPH03202642A - Output control method of engine - Google Patents

Abstract

PURPOSE:To prevent any excessive decrease in output by determining the maximum number of inoperative cylinders in response to engine speed or load, and stopping fuel supply in the range in the case of decreasing the output of the engine when racing is generated at a driving wheel. CONSTITUTION:Racing(slip) of a driving wheel 17 is detected based on respective detection results 18 and 20 of driving wheel speed and driven wheel speed by a slip detection means 25 in an ECU while a vehicle is in operation so as to set a target torque at which the slip is not generated at the driving wheel 17 by a target torque setting means 26. A target torque and a present driving torque detected by a driving torque detection means 27 are inputted to a number of inoperative cylinder calculation means 30 by an engine speed detection means 28 according to an engine speed together with the maximum number of inoperative cylinders set by a maximum number of inoperative cylinder setting means 29. A fuel injection stop control means 30 and an ignition stop control means 32 are controlled according to the number of inoperative cylinders calculated according to a slip quantity by the calculation means 30 so as to make some cylinders inoperative.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an output control method for reducing the output of an engine when a drive wheel spins.

<Prior Art> Generally, when the road surface conditions change suddenly while the vehicle is running, or when the vehicle is traveling on a slippery surface such as a snowy or frozen road, the driver must take precautions to prevent the drive wheels from spinning. Even if you are not an expert, it is very difficult to delicately control the engine output by pressing the accelerator pedal to the wR11 level. Similarly, if the speed of the vehicle relative to the turning path is too high, the wheels may skid, creating a dangerous situation.
In such cases, in order to reduce the engine output appropriately and drive the vehicle safely with a turning radius that corresponds to the turning path, it is necessary to In cases where vehicles are gradually becoming smaller, advanced driving skills are required.

For this reason, an output control (traffic engine control) that detects the wheel slip state and forcibly reduces the engine output regardless of the amount the driver presses the accelerator pedal has been considered. A model has been announced that allows the driver to select between driving using Traxian Control as needed, and normal driving, which controls the engine output according to the amount of depression of the accelerator pedal.

Traction control methods that reduce engine output include a throttle control system that closes the throttle valve regardless of how much the accelerator pedal is pressed, and a brake system that forcibly applies the brake. 11111
Common methods include the E1 system, the ignition retard system that retards the ignition timing, and the A/FJ-on system that reduces the amount of fuel relative to the amount of intake air.

<Problems to be Solved by the Invention> The conventional means for controlling mushrooms described above includes the following IQIII. That is, the throttle control method has poor responsiveness because the intake air amount is not immediately restricted even when the throttle valve is closed, and is expensive because it requires an independent driving means. In addition, the brake control method causes a lot of brake wear and is expensive. Furthermore, the ignition retard system and the A/FIJ-con system have a narrow output range that can be restricted, which leads to deterioration of combustion efficiency, resulting in poor exhaust gas performance.

Means for Solving the Problems> The engine output control method of the present invention for solving the above problems reduces the output of the two engines when the drive wheels spin. E1 method, wherein a maximum number of cylinders to which fuel supply is to be discontinued is determined according to at least one of the engine speed and engine load, and fuel supply is discontinued within the range of the determined maximum number of cylinders. It is characterized by

Embodiment Hereinafter, an embodiment of the method of the present invention will be described based on the drawings.

First, an outline of an engine for carrying out the method of the present invention will be explained based on FIGS. 1 and 2.

A base end of an intake pipe 4 is connected to the combustion chamber 2 of the engine 1 via an intake valve 3, and an exhaust pipe 6 is connected to the combustion chamber 2 via an exhaust valve 5. Intake If! ! : An air cleaner 7 is attached to the tip of the air cleaner 7.
An air cleaner element 8 is housed inside.

A butterfly-type throttle valve 10 is provided in the middle of the intake pipe 4 and changes the opening degree of the intake passage 9 formed by the intake pipe 4 to control the amount of intake air supplied into the combustion chamber 2. The valve 10 is opened and closed by the throttle drive motor 11 . Throttle drive motor 11
is driven based on a command from an electronic control unit (ECU) 12, and is linked to an accelerator pedal (not shown).

A spark plug 13 is provided in the combustion chamber 2 of the engine 1,
The ignition timing of the spark plug 13 is controlled based on commands from the ECU 12. Further, the intake pipe 4 is provided with an injector 14 for fuel injection, and the injector 14 is provided for each intake pipe 4 of each cylinder, and the basic driving time is controlled based on commands from the ECU 12.

ECU12 is an engine control computer (EC
C) 15 and the traction control computer (T
CC) 16, a drive command for the throttle drive motor 11 is output from TeCl4, and a drive command for the spark plug 13 and injector 14 is output from ECCl3. Detection signals from a driving wheel speed detection sensor 18 that detects the rotational speed of the driving wheel 17 and a driven wheel speed detection sensor 20 that detects the rotational speed of the driven wheel 19 are input to TeCl4.

Engine information 21 such as cooling water temperature and intake air amount is input to the ECC 15 . Further, the drive signal 22 of the throttle drive motor 11 is inputted to TeCl4 from ECCl3, and the ignition stop signal 23 of the spark plug 13 is input to ECCl3.
and the fuel injection stop signal 24 of the injector 14 is TCC
It is input from 16.

The control block of the ECU 12 will be explained based on FIG.

The slip amount detection means 25 detects the amount of idling (slip amount) of the drive wheels 17 based on the signals from the drive wheel speed detection sensor 18 and the driven wheel speed detection sensor 20. The target torque setting means 26 sets a torque at which no slip occurs in the driving wheels 17, and the driving torque detecting means 27 detects the current driving torque. The engine rotational speed detection means 28 detects the rotational speed of the engine 1, and the maximum number of cylinders setting means 29 sets the maximum number of cylinders according to the rotational speed of the engine 1. The number of cylinders in the cylinder calculation means 30 calculates the number of cylinders to be cylindered according to the amount of slip, and the fuel injection stop control means 31 performs control to stop the fuel injection of the injector 14 of the cylinder in which the cylinder is to be cylindered.
The ignition stop control means 32 performs control to stop the ignition of the spark plug of the cylinder that performs the body cylinder.

Next, an embodiment of the output control method of the present invention will be described based on FIG.

As shown in FIG. 3 (al), in step S, the driving wheel speed VF is detected by the driving wheel speed detection sensor 18, and the driven wheel speed 8 is detected by the driven wheel speed detection sensor 20.
Andlli! The slip amount Dv(V, -V, ) of the driving wheels 17 is calculated based on the driving wheel speed V. In step S, it is determined whether the slip amount Dv is larger than the body cylinder judgment slip amount D, and if the slip amount Dv is small, the body cylinder control is stopped (the number of body cylinders is set to zero), and the body cylinder control flag is 0
3F and the slip amount Dv is large, Fig. 3(b)
The process moves on to the body cylinder control routine shown in . After stopping the body cylinder control, it is determined in step S whether the slip amount Dv is larger than the throttle control judgment slip amount DvTH, and if the slip amount DV is small, the throttle control is ended and the process returns to step S1. If the slip amount DV is large, the third
The process moves to the throttle control routine shown in FIG.

As shown in FIG. 3 [b], in step S the slip amount D
After it is determined that v is large, it is determined in step S4 whether or not the body cylinder control flag is ON. When the cylinder control flag is ON, the maximum allowable number of cylinders N is determined from the engine rotation speed N and the unit intake air amount (amount of air taken in per engine rotation) A/N based on the map shown in Fig. 4. When the body cylinder flag is OFF, the body cylinder control flag is turned ON and the maximum body cylinder integration timer Te.

, and calculate the maximum allowable number of cylinders N1.8.

Maximum allowable number of body cylinders N, 1. is calculated, step S5
The maximum cylinder integration timer Te, , is the maximum set value 're,
Determine whether it is larger than m6M and set the maximum setting value Tey
1. If it is larger than sy, the number of cylinders Ne in the body is calculated based on the slip amount Dv based on the map shown in FIG. As shown in FIG. 5, the number of cylinders in the body Nc, is set in stages according to the slip amount Dv, and is set with a slight hysteresis h for each case when the slip amount DV is increasing and decreasing. ing. In step S6, the maximum cylinder integration timer Tey reaches the maximum set value TCV ffi@. If it is determined that the number of cylinders is smaller than , the number of cylinders in the cylinder is set to the maximum allowable number of cylinders, N, and the injector 1 of the corresponding cylinder is
At the same time, the fuel injection according to step 4 is stopped, and the ignition of the spark plug 13 is also stopped to carry out the cylinder operation. On the other hand, after the number of body cylinders N, , is calculated from the slip amount Dv, this number of body cylinders Nc is compared with the maximum allowable number of body cylinders N□8, and the number of body cylinders Ne, , If there are many cylinders, the maximum allowable cylinder N,... In addition to carrying out the body cylinder at the maximum allowable cylinder N. , if the number of cylinders is smaller than
The process returns to step S indicated by al.

In other words, the maximum allowable number of body cylinders N7.8, which is the maximum number of body cylinders, is set based on the engine speed N6 and the unit intake air amount A/N, and if slip occurs in the drive wheel 17, the slip amount Dv
When the value of the number of body cylinders Nc, calculated according to , is large, the body cylinder is carried out with the maximum allowable number of cylinders N7.8 set based on the engine rotation speed N5. Therefore, excessive torque reduction can be prevented even when the engine speed is low.

In the above embodiment, the engine rotation speed N and the air-fuel ratio A/
The maximum allowable number of body cylinders N7.8 was calculated with N, but the engine load can be calculated from the intake pipe internal pressure, the intake air amount or fuel supply amount and the engine rotation speed NI! It is also possible to find it from

As shown in FIG. 3(e), after it is determined that the slip amount DV is large in step S3, the vehicle body acceleration GV is calculated from the driven wheel speed v8, and the vehicle acceleration GV is calculated from the vehicle body acceleration Gv1 vehicle weight, wheel radius R, The target vehicle body drive torque TVTo is calculated, and the target engine torque T is calculated from the target vehicle body drive torque TvT0 and the reduction ratio RG.

Calculate. In step S, it is determined whether the body cylinder flag is ON or not. If it is not ON (after the body cylinder is released), in step SA, the target engine torque T, T and the engine speed [aN, from the fourth target throttle opening θTO.
The opening degree of the throttle valve 10 is controlled to the target throttle opening degree θTG by calculating based on the map shown in the figure.
Return to step S1 at t. If the body cylinder flag is determined to be ON in step S6, the target engine torque T5a is set based on the body cylinder aNc, .

is corrected and the process moves to step S7. To correct the target engine torque T, change the total number of cylinders NALL to the number of cylinders NALL.
Target engine torque T1 before correction to the value divided by
7. Multiply by

By executing this, the drive torque can be finely controlled only by throttle control after the cylinder is closed.

Here, a method of calculating the target engine torque T0° will be explained.

■ Calculate the vehicle speed v9 from the driven wheel speed and the wheel radius tag using equation (1).

V=V

GV=dvv/dt (2) ■ The target vehicle body drive torque TVTo is calculated from the vehicle body acceleration Gv and the vehicle weight Mv using equation (3).

TVT o =MvX GV (31) However, MV is set in advance or detected by a suspension sensor's stroke sensor, air pressure sensor, etc.

■Target vehicle body drive torque TVTo1 transmission reduction ratio ρa and differential reduction ratio ρ. (Reduction ratio R
6) Calculate target engine torque TETQ from torque converter torque ratio t (in case of A/T) using equation (4).

T1a. =TVTO"ρ7×ρoxt) - (4) However, ρ1 is determined based on the memory table by detecting the reshift position by the shift position sensor, ρ0 is set in advance, and t is determined by the torque from the engine speed and vehicle speed. The converter input/output shaft speed ratio is determined based on the memory table.

On the other hand, in order to obtain the actual driving torque for calculating the body cylinder judgment slip amount and the throttle control judgment slip amount DvTH, it is necessary to directly detect it with a torque sensor installed on the output shaft of the transmission, or to calculate the amount of intake air and the engine Calculate based on the memory table from the rotational speed, or back-calculate the above-mentioned formula (41).

According to the above-mentioned output control method, the maximum allowable number of cylinders N7.8 is calculated based on the engine speed N and the unit intake air amount A/N, and when the drive wheels 17 slip, the slip amount Dv
If the number of body cylinders Nc2 determined according to the above exceeds the maximum allowable number of body cylinders Nma, the maximum allowable number of body cylinders N71.
Since the body cylinder is installed at the same time, it is possible to prevent excessive torque reduction. Furthermore, since the drive torque is finely controlled only by throttle control after the cylinder is finished, smooth output reduction control can be performed.

<Effects of the Invention> The engine output control method of the present invention determines the maximum number of body cylinders according to at least one of engine speed and engine load, and adjusts the body cylinders within the determined maximum number of cylinders. As a result, output control can be performed with good responsiveness, and excessive reduction in output can be prevented, and there is no risk of engine stalling even when the engine speed is low.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an engine implementing the method of the present invention;
Fig. 2 is a control block diagram, Fig. 3 is a flowchart of an output control method according to an embodiment of the present invention, Fig. 4 is a map for determining the maximum allowable number of cylinders, and Fig. 5 is a map for calculating the number of cylinders. The map shown in FIG. 6 is a map for determining the target throttle opening. In the drawing, 1 is the engine, 4 is the intake pipe, 10 is the throttle valve, and 12 is the ECU. 14 is an injector, 15 is an engine control computer, 16 is a traction control computer, 17 is a driving wheel, 18 is a driving wheel speed detection sensor, 19 is a driven wheel, and 20 is a driven wheel speed detection sensor.

Claims (1)

[Claims] An engine output control method for reducing engine output when a drive wheel idles, the method comprising: reducing the maximum number of cylinders to which fuel supply is stopped depending on at least one of the engine rotation speed and the engine load; 1. A method for controlling an engine output, comprising: determining a maximum number of cylinders; and stopping fuel supply within the determined maximum number of cylinders.