JPH0370835A - Output control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To precisely control the output of an internal combustion engine by providing a means for reading the throttle sensor output of a second throttle valve full-closed position to learn the full-closed position of the second throttle valve in the state where a driver does not operate an accelerator and the output of the internal combustion engine does not take part in the running of a vehicle. CONSTITUTION:When the idling state of an engine and the neutral position of a transmission are detected, the full-closed position of a second throttle valve is learnt by a full-closed position learning means by the throttle sensor output of the second throttle valve full-closed position. At this time, a driver does not operate an accelerator, and the output of the internal combustion engine does not take part in the running of a vehicle. Consequently, the full- closed position of the second throttle valve is learnt without causing an unpleasant feeling in driving.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to an internal combustion engine which is equipped with a second throttle valve for traction control in the engine intake passage in addition to a normal first throttle valve that is linked to an accelerator pedal. This invention relates to an output control device.

<Prior art> In order to prevent the wheels from slipping and the vehicle from swinging laterally when the vehicle accelerates on icy or snowy roads, a second throttle valve is installed in series with the first throttle valve that is linked to the accelerator pedal. is provided, and when a slip state of the wheel is detected, that is, when a slip state is detected by determining the difference between the rotational speed of the driving wheel and the rotational speed of the driven wheel detected by the wheel rotational speed sensor, the traction control request signal is generated. A device has been proposed that is equipped with a device (hereinafter referred to as a traction control device) that controls the second throttle valve to close when the engine is activated, thereby reducing the torque of the engine and reducing the driving force. (Refer to Publication No. 61-60331, etc.).

Here, the second throttle valve for traction control is always in the fully open position when no traction control request occurs, and is controlled to the closed position according to the request (slip ratio) only when a traction control request occurs. Ru.

<Problem to be Solved by the Invention> Here, in the tandem throttle chamber used in the conventional output control device, the second throttle valve for traction control is rotated by a stamp motor attached to one end of the valve shaft, The opening degree TVO of the second throttle valve is detected by the throttle sensor of potentiometer 2 attached to the other end.

Here, the present applicant has proposed an invention that prevents the deterioration of the combustion state during traction control by stopping feedback control of the air-fuel ratio during traction control operation so that the air-fuel ratio is appropriate when the internal combustion engine is in a transient state. (see Japanese Patent Application No. 63-25957), but the control has become complicated and detailed as described above.

Therefore, when the second throttle valve, which is fully open when there is no traction control request, shifts to the closed side when a traction control request occurs, a throttle sensor measures the actual movement amount in response to the request. Well, second
Inputting the absolute opening of the throttle valve from the fully closed position into the control unit is necessary for accurate control, but it is necessary to input the absolute opening degree of the throttle valve from the fully closed position to the control unit. Due to installation errors, etc., if the opening degree of the second throttle valve is calculated backwards from the fully open position, the various errors may cause a decrease in detection accuracy.

Therefore, it is conceivable to calibrate the throttle sensor using the output of the throttle sensor at the fully closed position when the second throttle valve is fully open, but since the intake air flow rate is O, the driver Even if the driver operates the accelerator pedal, the amount of intake air will not increase, and unless the calibration is performed with timing taken into consideration, drivability may feel strange.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an output control device for an internal combustion engine that learns the fully closed position of the second throttle valve so that the output control of the internal combustion engine can be performed accurately without causing any discomfort in drivability. do.

Means for Solving the Problems> For this reason, as shown in FIG. 1, the present invention provides a first throttle valve in the engine intake passage, which is connected to the accelerator pedal, and which is installed in the engine intake passage under predetermined operating conditions of the vehicle. An output control device for an internal combustion engine including a second throttle valve that is controlled in a fully closed direction in response to an output traction control request signal,
It is equipped with an idle operating state detection means for detecting an idle operating state of an internal combustion engine, and a neutral detection means for detecting a neutral position of a transmission. The configuration further includes fully closed position learning means for reading the throttle sensor output at the fully closed position of the second throttle valve when the second throttle valve is in the neutral position and learning the fully closed position of the second throttle valve.

<Operation> With this configuration, when it is detected that the engine is in an idling state and the transmission is in the neutral position, the second throttle valve is fully closed by the throttle sensor output at the fully closed position of the second throttle valve. Although the position is learned, at this time the driver is not operating the accelerator, and the output of the internal combustion engine is not involved in driving the vehicle. As a result, the fully closed position of the second throttle valve can be learned without causing any discomfort in drivability.

<Example> Embodiments of the present invention will be described below with reference to the drawings.

First, the system configuration of an output control device for an internal combustion engine will be explained with reference to FIG.

In the engine 1, intake air is supplied to each cylinder through an intake passage 2 and a throttle chamber 3, and fuel is injected and supplied by a fuel injection valve 4. Then, the air-fuel mixture in the cylinder is ignited and exploded by the discharge action of a spark plug (not shown), and is discharged to the outside through an exhaust pipe.

Here, the flow of intake air is controlled by a first throttle valve 11 in the throttle chamber 3, which is controlled to open and close in conjunction with the depression operation of the accelerator pedal IO. A second throttle valve 1 is provided in the intake passage 2 upstream of the first throttle valve 11.
The opening degree of the second throttle valve 12 is controlled by a step motor 14 connected via a rod 13. The second throttle valve 12 is normally in a fully open state, and when a current is supplied to the step motor 14 by a control signal from a traction control unit 43, which will be described later, the step motor 14 rotates by a predetermined angle. to close the second throttle valve 12.

The intake air flow rate Q is detected by the air flow meter 20, the opening degree TVO of the first throttle valve 11 is detected by the throttle opening degree sensor 21, and the fully closed position of the first throttle valve 11 is detected by the idle switch 25. , these detection signals are sent to the control unit 4, which will be described later.
1 and 43.

Furthermore, the opening degree TVO□ of the second throttle valve 12 is detected by the throttle opening sensor 22, and during this time, the degree TVO signal is input to the motor control unit 15 and output to the control unit 41, which will be described later, via the buffer 15a. has been done.

Furthermore, a crank angle signal (corresponding to the engine rotation speed) from the crank angle sensor 23, a vehicle speed signal from the vehicle speed sensor 24, and a water temperature signal from the water temperature sensor 27 are input to the control unit 41. . Further, a detection signal from a neutral switch 26 that detects the neutral position of the transmission is also input to the control unit 41.

Further, wheel speed sensors 31 to 34 are provided to detect the rotational speeds of the front, rear, left and right wheels of the vehicle, and these detection signals are input to the traction control unit 43, which detects the rotational speeds of the wheels. Detects a slip condition. Further, the on/off detection signal from the brake switch 36 that detects the depression state of the brake pedal 35 is also manually inputted to the traction control unit 43, and the traction control can be turned on/off manually by the driver using the traction switch 37. select.

The control unit 41 receives the aforementioned various sensor information and a traction control signal from a traction control unit 43 (described later), and performs engine combustion control (air-fuel ratio control and ignition timing control).

On the other hand, the neutral switch 26, the wheel speed sensor 31~
34, the signals from the brake switch 36 and the traction switch 37 are input to the traction control unit 43, and the traction control unit 43 reduces the output torque of the engine based on these sensor information to suppress the slip of the drive wheels. It performs brake control to prevent slippage by reducing the driving force to the wheels.

The traction control unit 43 includes a microcomputer, etc., and includes the above-mentioned sensors 25.
Signals from 26.31 to 34.35.37, the actual opening signal of the throttle valve 12 from the motor control unit 15, the engine speed from the control unit 4, etc. are input manually, while the signals from the traction control unit 43 are input manually. A control signal for controlling the opening degree TVO2 of the second throttle valve 12 is sent to the motor control unit 15, an operation signal for notifying the control unit 41 of the operating state of traction control, and an operation signal is sent to the brake hydraulic actuator 46 for brake control. The signals are output respectively.

Control unit for trafsilane) 43 odor,
The second throttle valve 12 is controlled according to the routine shown in FIG. 3 while communicating with the control unit 41 by inputting and outputting each of the signals.

Next, control in the traction control unit 43 will be explained with reference to FIGS. 3 and 4.

In step (denoted as S in the figure; the same applies hereinafter) 1, a learned flag F is determined, and if the flag F is 1, learning has already been performed, and this routine is ended.

If the learned flag F is O, the process proceeds to step 2, where it is determined whether the first throttle valve 11 is in the fully closed position by turning on/off the idle switch 25, and if it is on, the process proceeds to step 3. That is, the idle switch 25 constitutes idle operation state detection means.

In step 3, it is determined whether the neutral switch 26 is on or off. If it is on, the gear position of the Q cushion is in the neutral position, the output of engine 1 is not being transmitted to the drive wheels, and the engine brake etc. are not working, so the vehicle will not be able to drive. is internal combustion engine I
Assuming that the output of is not involved, proceed to step 4. That is, the neutral switch 26 constitutes neutral detection means.

In step 4, the driver is not operating the accelerator 10 and the output of the internal combustion engine 1 is not involved in the running of the vehicle, so even if the second throttle valve 12 is fully closed, the drivability may feel strange. In order to fully close the second throttle valve 12, the step motor 14 is activated by a control signal from the traction control unit 43 to completely close the second throttle valve 12.
A current is supplied to the step motor 14, and the step motor 14 rotates by a predetermined angle.

In step 5, the detection output TV of the throttle opening sensor 22 is determined when current is supplied to the step motor 14 to fully close the second throttle valve 12 in step 4.
Load O2.

That is, the detection output TVO of the throttle opening sensor 22 read in step 5 is the throttle opening sensor 2 when the second throttle valve 12 is actually in the fully closed position.
2 is the opening degree output.

In step 6, the learned flag F is set to F=1 and the routine ends. Incidentally, this flag F is set to O by the initialization routine shown in FIG. 4, which is executed when the engine key switch (or start switch) is turned on.

That is, the traction control unit 43 constitutes a fully closed position learning means.

As a result, the flag F, which is cleared by the initialization routine when the engine key switch is turned on, is used, so that the throttle opening sensor 22 is calibrated once every time the engine key switch is turned on, so that the output control of the internal combustion engine is performed accurately. will only be carried out.

In addition, since the calibration is performed by the idle switch 25 and neutral switch 26 when the driver is not operating the accelerator and the output of the internal combustion engine is not involved in driving the vehicle, it may cause discomfort in drivability. Calibration is performed and the fully closed position is learned without causing any damage.

Therefore, the second throttle valve 1
2 fully closed position is learned.

In this embodiment, the idle switch 25 constitutes the idle operating state detection means, but only the throttle opening sensor 21 that detects the opening TV○ of the first throttle valve 11 is used to detect the output by software. The idle operating state may be detected by performing arithmetic processing.

<Effects of the Invention> As explained above, according to the present invention, when the driver is not operating the accelerator and the output of the internal combustion engine is not involved in driving the vehicle, the second throttle valve is fully activated. Since the fully closed position of the second throttle valve is learned by reading the throttle sensor output in the closed position, learning is performed without causing any discomfort in drivability, and the output of the internal combustion engine can be accurately controlled. can.

[Brief explanation of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a system configuration diagram of an embodiment of the present invention, and FIGS. 3 and 4 are flowcharts showing the output control program.

Claims (1)

[Claims] In addition to the normal first throttle valve that is connected to the accelerator pedal in the engine intake passage, the internal combustion engine is equipped with a second throttle valve that is controlled in the fully closed direction in response to a traction control request signal that is output under predetermined vehicle operating conditions. An engine output control device, comprising an idling state detection means for detecting an idling state of an internal combustion engine, and a neutral detection means for detecting a neutral position of a transmission,
Based on the signals output from both of the detection means, the throttle sensor output at the second throttle valve fully closed position when the internal combustion engine is in an idling state and the transmission is in the neutral position is read, and the second throttle valve is fully closed. An output control device for an internal combustion engine, comprising a fully closed position learning means for learning a closed position.