JPH11107817A - Throttle controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the unprepared increase of an engine speed at the time of starting an internal combustion engine in an electronic throttle system wherein a valve return spring for energizing a throttle valve to a closed side is abolished. SOLUTION: For stopping the control of an electronic throttle system, a throttle valve 5 is set equal to a specified opening degree or lower (specifically, in the vicinity of an opening degree during idling) before stopping by driving of a torque motor 19. Thus, since the excessive increase of an engine speed is prevented at the time of starting the internal combustion engine next time and it does not take much time until the throttle valve 5 is set to a proper opening position, even if a failure occurs in the electronic throttle system, the unprepared increase of the engine speed of the internal combustion engine is prevented and thereby a highly reliable system is configured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control device for an internal combustion engine that controls an opening degree of a throttle valve by driving an actuator according to an accelerator operation amount or the like.

[0002]

2. Description of the Related Art Conventionally, an internal combustion engine called an "electronic throttle system" for controlling a throttle valve opening (hereinafter also referred to as "throttle opening") by driving a motor as an actuator in accordance with an accelerator operation amount or the like. Throttle control devices are known. In such a throttle control device, for example, a current is supplied to a motor in accordance with a signal from an accelerator opening sensor that detects an opening corresponding to the amount of depression of an accelerator pedal (hereinafter, referred to as “accelerator opening”), When the motor is driven, the throttle valve is opened and closed to control the amount of air supplied to the internal combustion engine.
At this time, a proportional / integral / differential control (Proportional Integral Differential Control) is performed on the motor so that the deviation between the signal from the throttle opening sensor for detecting the opening of the throttle valve and the signal from the accelerator opening sensor is eliminated.
trol; hereinafter, simply referred to as “PID control”).

[0003]

Here, when a failure occurs in the electronic throttle system, the motor is turned off, and the throttle valve is forcibly forced by the valve return spring which is constantly biased to the closing side. The opening degree is set to be equal to or less than a predetermined opening degree. Thus, the engine speed of the internal combustion engine at the time of the system failure does not exceed the predetermined speed.

If the above-mentioned spring is simply abolished for cost reduction, the opening of the throttle valve will not be less than the predetermined opening even if the motor is turned off. And the ignition switch is turned off when the throttle valve is larger than the specified opening.
In such a case, there has been a problem that the engine speed at the next start of the internal combustion engine becomes too high, or that it takes too much time to bring the throttle valve to an appropriate opening position thereafter.

Accordingly, the present invention has been made to solve such a problem, and can cope with a failure of an electronic throttle system in which a valve return spring for biasing a throttle valve to a closing side is abolished. It is an object of the present invention to provide a throttle control device for an internal combustion engine capable of shortening the time required for setting the throttle valve to an appropriate opening position after the engine speed at the time does not become too high.

[0006]

According to the first aspect of the present invention, when the drive control of the throttle valve is stopped, the throttle valve is driven to a predetermined opening or less by the drive of the actuator before the stop control. By doing so, the engine speed does not become too high at the next start of the internal combustion engine, and it does not take much time to bring the throttle valve to the appropriate opening position. As a result, even if a failure occurs in the electronic throttle system, the engine speed of the internal combustion engine is prevented from being carelessly increased, and a highly reliable system can be constructed.

In the throttle control device for an internal combustion engine according to the second aspect, the throttle valve is always returned to a set position near the opening during idling regardless of the opening of the throttle valve when the drive control of the throttle valve is stopped. By being
At the next start of the internal combustion engine, the engine speed can be set to a value near the idling time, and a system can be constructed without any inconvenience even if a failure occurs in the electronic throttle system.

According to a third aspect of the present invention, when the opening of the throttle valve deviates from an allowable opening range based on various sensor signals detected corresponding to the control amount supplied to the actuator. Since the failure of the throttle drive mechanism is considered and the supply of fuel to the internal combustion engine is stopped, safety can be ensured.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples.

FIG. 1 is a schematic diagram showing an internal combustion engine to which a throttle control device for an internal combustion engine according to a first embodiment of the present invention is applied, and peripheral devices thereof.

In FIG. 1, an internal combustion engine 1 is configured as a V-type six-cylinder four-cycle engine. Internal combustion engine 1
An air cleaner 3 is provided on the upstream side of the intake passage 2 of
An air flow meter 4 for detecting an intake air amount (intake air amount) is provided downstream of the air cleaner 3. Further, a throttle valve 5 is provided downstream of the air flow meter 4 in the intake passage 2, and the opening degree of the throttle valve 5 (actual throttle) is controlled by the driving force of a torque motor 19 connected to a rotation shaft 5 a of the throttle valve 5. Is controlled, and the amount of intake air supplied to the internal combustion engine 1 is adjusted. The actual throttle opening of the throttle valve 5 is detected by a throttle opening sensor 16. Note that, even during idling, the actual throttle opening is controlled by the driving force of the torque motor 19, whereby the intake air amount GN is controlled, and feedback control is performed so that the engine speed NE matches the target idle speed. . Further, the intake passage 2 is connected to each cylinder of the internal combustion engine 1 via an intake manifold 6, and intake air from the intake passage 2 is distributed and supplied to each cylinder via the inside of the intake manifold 6.

Intake manifolds 6 are provided with injectors 7 corresponding to the respective cylinders, and the fuel injected from the respective injectors 7 is mixed with intake air and supplied to the respective cylinders. This air-fuel mixture is introduced into the combustion chamber 9 of each cylinder as the intake valve 8 opens and closes, is burned by the ignition of a spark plug 10, pushes down a piston 11, and applies torque to a crankshaft 12. The exhaust gas after combustion is discharged to the outside via an exhaust passage 14 with opening and closing of an exhaust valve 13. A crank angle sensor 15 is provided at a position close to the crankshaft 12, and a pulse signal is output from the crank angle sensor 15 at every 30 ° CA (Crank Angle).

Reference numeral 20 denotes an ECU (Electronic Control Unit).
The ECU 20 controls the driving of the injector 7 based on the intake air amount GN signal detected by the air flow meter 4 and the engine speed NE signal detected by the crank angle sensor 15, and controls the throttle opening sensor The CPU controls the opening / closing of the throttle valve 5 based on the throttle opening TA signal detected by the accelerator pedal 16 and the accelerator opening Ap signal detected by the accelerator opening sensor 18 based on the amount of depression of the accelerator pedal 17.
The microcomputer mainly comprises a microcomputer 21, a ROM 22, a RAM 23, and the like.

Next, the configuration of the ECU 20 and its surroundings will be described in more detail with reference to FIG.

In the ECU 20, a CPU 21 reads an intake air amount GN signal, an engine speed NE signal, a throttle opening degree TA signal, an accelerator opening degree Ap signal, and the like, and is requested each time according to the operating state of the internal combustion engine 1. This is a well-known central processing unit that calculates a fuel injection amount of the injector 7, a throttle opening of the throttle valve 5, and the like.

The ROM 22 is a so-called program memory in which various control programs for controlling the operating state of the internal combustion engine 1, that is, a fuel injection control program, a throttle control program, and the like are stored in advance.
The CPU 21 executes various arithmetic processes in accordance with the program stored in the ROM 22. Also, RA
M23 is a so-called data memory that temporarily stores input / output data of various sensors, calculation processing data by the CPU 21, and the like.

The injector drive circuit 24 has an intake air amount GN
This is a circuit for driving the injector 7 by forming a signal of a predetermined pulse width corresponding to the fuel injection amount calculated through the CPU 21 based on the signal and the engine speed NE signal. As a result, an amount of fuel corresponding to the calculated fuel injection amount is injected and supplied from the injector 7 to each cylinder of the internal combustion engine 1.

The A / D conversion circuit 27 performs A / D (analog-digital) conversion of the read intake air amount GN signal, throttle opening degree TA signal, accelerator opening degree Ap signal, cooling water temperature THW signal, and the like. This is a circuit for outputting to the CPU 21. Further, the D / A conversion circuit 28 is
The command value TTP of the throttle opening of the throttle valve 5 by the torque motor 19 described later calculated by
/ A (digital-analog) conversion and output to the motor drive circuit 30. Motor drive circuit 30
Is a PID (proportional / integral / differential) control circuit 31, PWM
(Pulse Width Modulation) A command value TTP for driving a motor from the CPU 21 which is constituted by a circuit 32 and a driver 33.
This is a circuit for driving the torque motor 19 according to a signal.

Here, the command value T calculated by the CPU 21
The TP is converted into an analog value by the D / A conversion circuit 28 and input to the PID control circuit 31. PID control circuit 3
In P1, the PID calculation is executed to reduce the deviation based on the deviation between the command value TTP and the throttle opening TA signal from the throttle opening sensor 16, and the torque motor 19
Is calculated. In the PWM circuit 32, the control amount calculated by the PID control circuit 31 is input, and the control amount corresponds to a control current DUTY as a duty ratio signal.
And the driver 3 according to the control current DUTY
3, the torque motor 19 is driven, and the actual throttle opening TA signal detected by the throttle opening sensor 16 is adjusted so that it finally matches the throttle opening command value TTP (throttle target opening). You.

Next, the configuration of the throttle control device for the internal combustion engine will be described with reference to FIGS.

2 and 3, the accelerator pedal 1
An accelerator opening sensor 18 is provided in 7, and the accelerator pedal 17 is connected to an accelerator lever 41. The accelerator lever 41 is connected to the accelerator return spring 4
The accelerator pedal 17 is urged in the return direction (clockwise direction) by the accelerator pedals 2a and 42b. Accelerator pedal 1
7 is not operated (accelerator OFF), the accelerator lever 41 is pressed by the accelerator return springs 42a, 4b.
2b, it is held in a state of contact with the accelerator fully closed stopper 43. While the internal combustion engine 1 is operating, the position of the accelerator lever 41 based on the operation amount of the accelerator pedal 17 is detected by the accelerator opening sensor 18 as the accelerator opening Ap.

On the other hand, a connection spring 5 is connected to a valve lever 44 connected to a rotation shaft 5a of the throttle valve 5.
0 (motor OFF shown in FIG. 2B (power OFF to torque motor 19))
At times, it is stopped at the intermediate stopper position abutting on the intermediate stopper 49. At this time, the valve lever 44 does not contact the throttle fully closed stopper 46. This intermediate stopper position is, for example, an engine speed slightly higher than an idle speed at which the vehicle can retreat when the throttle drive mechanism is normal, but there is some abnormality and there is a request to turn off the motor as described later. (Throttle opening = approx. 3
°).

On the other hand, during normal control (when the motor is ON) shown in FIG. 2A, the torque motor 19 rotates forward or backward according to the operation amount of the accelerator pedal 17, and the throttle opening of the throttle valve 5 is adjusted. The throttle opening TA of the throttle valve 5 at that time is detected by the throttle opening sensor 16. At this time, when opening the throttle opening, the torque motor 19 is rotated forward to
As shown in FIG.
, The throttle valve 5 is driven in the opening direction. Conversely, when closing the throttle opening,
The throttle valve 5 is driven in the closing direction while the torque motor 19 is reversed to lower the valve lever 44, and when the throttle valve 5 is closed to the fully closed stopper position (throttle opening = 0 °), the valve lever 44 is The stopper abuts on the throttle fully closed stopper 46, and further rotation is prevented.

Next, based on a flowchart of FIG. 4 showing a processing procedure of a motor stop control in the CPU 21 in the ECU 20 used in the throttle control device for the internal combustion engine according to the first embodiment of the present invention. explain. This motor stop control routine is repeatedly executed by the CPU 21 in the ECU 20 at predetermined time intervals.

In FIG. 4, first, it is determined in step S101 whether there is an OFF request for the torque motor 19 or not. If the determination condition of step S101 is satisfied, that is, if the stop of the torque motor 19 is instructed for some reason, the process proceeds to step S102, and the throttle valve 5 is set to the preset intermediate stopper position (open during idling at which limp-home travel is possible. (Throttle opening near the degree). Next, the process proceeds to step S103, where the torque motor 19 is turned off, and the present routine ends. On the other hand, when the determination condition of step S101 is not satisfied and there is no OFF request to the torque motor 19, this routine ends without performing any operation.

As described above, the throttle control device for an internal combustion engine according to the present embodiment controls the control current DUTY to convert the opening of the throttle valve 5 to the target opening set based on various sensor signals. ECU to calculate quantity
A control amount calculating means achieved by the CPU 21 in 20;
The control amount DUTY calculated by the control amount calculating means is used to drive the torque motor 19 as an actuator by the control current DUTY, and the CPU 21 and the motor drive circuit 30 in the ECU 20 for controlling the opening degree of the throttle valve 5 are achieved. When the control by the throttle control means and the control by the throttle control means are stopped, the torque motor 19
Control stop means achieved by the CPU 21 in the ECU 20 which stops after the opening degree of the throttle valve 5 is reduced to a predetermined opening degree or less by the drive of.

That is, when the control of the electronic throttle system is stopped, the throttle valve 5 is set to a predetermined opening or less by driving the torque motor 19 before the stop.
For this reason, at the next start of the internal combustion engine, the engine speed does not become too high, and it does not take time to bring the throttle valve 5 to the appropriate opening position.
Even if a failure occurs in the electronic throttle system, the engine speed of the internal combustion engine is prevented from being carelessly increased, and a highly reliable system can be constructed.

Further, in the throttle control device for an internal combustion engine according to the present embodiment, the predetermined opening when the drive control of the throttle valve 5 is stopped is set to be close to the opening when the internal combustion engine 1 is idling. That is, when the control by the electronic throttle system is stopped, regardless of the opening of the throttle valve 5 at that time, the throttle valve 5 is always returned to the intermediate stopper position set near the opening during idling. As a result, when the internal combustion engine is started next time, the engine speed becomes close to the idling time. Therefore, even if a failure occurs in the electronic throttle system, a system that is not inconvenient can be constructed.

<Embodiment 2> FIG. 5 is a flowchart showing a processing procedure of a motor stop control in a CPU 21 in an ECU 20 used in a throttle control device for an internal combustion engine according to a second embodiment of the present invention. is there. This motor stop control routine is executed every predetermined time by the ECU.
20 is repeatedly executed by the CPU 21. Further, the configurations of the internal combustion engine to which the throttle control device for an internal combustion engine according to the present embodiment is applied and the peripheral devices thereof are the same as those in FIGS. 1 to 3 in the above-described first embodiment. Omitted.

In FIG. 5, in step S201, it is determined whether a failure has occurred in the throttle drive mechanism. If the determination condition in step S201 is not satisfied, that is, if no failure has occurred in the throttle drive mechanism, step S201 is executed.
The process proceeds to 202, and it is determined whether there is a failure other than the throttle drive mechanism. If the determination condition of step S202 is not satisfied, that is, if there is no failure other than the throttle drive mechanism, the process proceeds to step S203, and it is determined whether there is an OFF request to the torque motor 19.

If the determination condition of step S203 is satisfied, that is, if the stop of the torque motor 19 is instructed for some reason, or if the determination condition of step S202 is satisfied, that is, if there is a failure other than the throttle drive mechanism, step S204 is performed. To the throttle valve 5
Is driven to a preset intermediate stopper position (throttle opening near the opening during idling at which limp-home traveling is possible). Next, the process proceeds to step S205, where the torque motor 19 is turned off, and the present routine ends. On the other hand, when the determination condition of step S203 is not satisfied, that is, when there is no OFF request to the torque motor 19, this routine ends without performing any operation because there is no failure in the throttle drive mechanism and other failures.

Here, when the determination condition of step S201 is satisfied, that is, when a failure has occurred in the throttle drive mechanism, the process proceeds to step S206, and after performing the fuel cut process for the internal combustion engine 1, the process proceeds to step S205. Then, the torque motor 19 is turned off, and this routine ends.

As described above, the throttle control device for an internal combustion engine according to the present embodiment sets the predetermined opening when the drive control of the throttle valve 5 is stopped close to the opening when the internal combustion engine 1 is idling. . That is, when the control of the electronic throttle system is stopped, the throttle valve 5 is always returned to the intermediate stopper position set near the opening during idling irrespective of the opening of the throttle valve 5 at that time. As a result, when the internal combustion engine is started next time, the engine speed becomes close to the idling time. Therefore, even if a failure occurs in the electronic throttle system, a system that is not inconvenient can be constructed.

In the throttle control device for an internal combustion engine according to the present embodiment, the opening degree of the throttle valve 5 is obtained by converting the control amount by the control stop means achieved by the CPU 21 in the ECU 20 and the motor drive circuit 30. Control current DUT
When deviating from the allowable opening range corresponding to Y, the supply of fuel to the internal combustion engine 1 is stopped. That is, when the throttle opening TA detected by the throttle opening sensor 16 corresponding to the control current DUTY obtained by converting the control amount supplied to the torque motor 19 is out of the allowable opening range, the torque motor 19 and a failure of the motor drive circuit 30 are considered. For this reason, safety is ensured by stopping the supply of fuel to the internal combustion engine 1.

In the above-described embodiment, the intermediate stopper position is set by contacting the intermediate lever 47 with the intermediate stopper 49. However, the present invention is not limited to this. However, the intermediate stopper position does not necessarily need to be set mechanically, and the intermediate stopper position may be set based on the throttle opening TA detected by the throttle opening sensor 16.

In the above embodiment, the torque motor 19 is used as the actuator. However, the present invention is not limited to this, and a DC motor or the like may be used. In particular, when the present invention is applied to an electronic throttle system using a torque motor, the effect that the accuracy and responsiveness to the throttle opening can be improved is remarkable.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an internal combustion engine to which a throttle control device for an internal combustion engine according to a first example and a second example of an embodiment of the present invention is applied, and peripheral devices thereof.

FIG. 2 is a schematic diagram illustrating a main configuration of a throttle control device for an internal combustion engine according to a first example and a second example of the embodiment of the present invention.

FIG. 3 is a perspective view showing a main configuration of a throttle control device for an internal combustion engine according to a first example and a second example of the embodiment of the present invention.

FIG. 4 is a diagram showing E used in a throttle control device for an internal combustion engine according to a first example of the embodiment of the present invention.
9 is a flowchart illustrating a processing procedure of motor stop control in a CPU in a CU.

FIG. 5 is a diagram showing E used in a throttle control device for an internal combustion engine according to a second example of the embodiment of the present invention.
9 is a flowchart illustrating a processing procedure of motor stop control in a CPU in a CU.

[Explanation of symbols]

 Reference Signs List 1 internal combustion engine 5 throttle valve 16 throttle opening sensor 18 accelerator opening sensor 19 torque motor (actuator) 20 ECU (electronic control unit) 30 motor drive circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/22 330 F02D 41/22 330S

Claims (3)

[Claims] 1. A control amount calculating means for calculating a control amount for making an opening of a throttle valve coincide with a target opening set based on various sensor signals, and the control amount calculated by the control amount calculating means. By driving the actuator by, throttle control means for controlling the opening of the throttle valve, when stopping the control by the throttle control means,
A throttle control device for stopping the throttle valve after the opening degree of the throttle valve is reduced to a predetermined opening degree or less by driving the actuator. 2. The system according to claim 1, wherein the predetermined opening is set near an opening when the internal combustion engine is idling.
3. The throttle control device for an internal combustion engine according to claim 1. 3. The control stopping means stops the supply of fuel to the internal combustion engine when the opening of the throttle valve deviates from an allowable opening range corresponding to the control amount. 3. The throttle control device for an internal combustion engine according to claim 1 or 2.