JP2001323821A - Throttle control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excessiveness of an output and the engine stall of an internal combustion engine in the abnormal of an accelerator opening sensor. SOLUTION: In the abnormal of the accelerator opening sensor 18, a throttle opening TA of a throttle valve 5 is controlled so as to provide an intake amount GN required for keeping an accelerator opening Ap set to a predetermined opening and an idling speed of the internal combustion engine 1. The throttle opening TA of the throttle valve 5 is corrected according to a coolant temperature THW of the internal combustion engine 1. Thus, the throttle opening TA is adequately controlled even if the accelerator opening sensor 18 becomes abnormal, and stable evacuation running is allowed without getting in excess of an output of the internal combustion engine 1. Even during cooling the internal combustion engine, the throttle opening TA is corrected to keep the idling speed optimal and prevent engine stall.

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, as a prior art document relating to a throttle control device for an internal combustion engine, Japanese Patent Application Laid-Open No.
The one disclosed in Japanese Patent Application Publication No. HEI 10-203 (1995) is known. In this technology, there is disclosed a technology for improving the reliability of diagnosis of a sensor failure related to an electronic throttle system, such as an accelerator opening sensor for detecting an amount of depression of an accelerator pedal, a throttle opening sensor for detecting an opening of a throttle valve, and the like. ing.

[0003]

By the way, in the above-mentioned system, when it is diagnosed that a sensor related to the electronic throttle system has failed, the power supply to the actuator for driving the throttle valve constituting the electronic throttle system is stopped, and the throttle valve is stopped. Is fixed to a predetermined mechanical opening to achieve limp-home running. At this time,
It is necessary to limit the opening of the throttle valve so that the output of the internal combustion engine according to the predetermined opening of the throttle valve does not become too large.

However, according to the opening degree of the throttle valve in which the output of the internal combustion engine is suppressed, for example, at the time of cold start of the internal combustion engine, the intake air amount (the intake air amount) required to maintain the idle speed. Therefore, there is a possibility that engine stall may occur due to failure to achieve a stable starting state of the internal combustion engine.

SUMMARY OF THE INVENTION The present invention has been made to solve the problem of predictability of such a problem, and it is possible to prevent an excessive increase in the output of the internal combustion engine when the accelerator opening sensor is abnormal or an engine stall in a cold state. It is an object to provide an engine throttle control device.

[0006]

According to the first aspect of the present invention, when the accelerator opening sensor detects an abnormal state by the abnormality detecting means, the opening setting means sets the throttle opening to a predetermined opening. The throttle opening of the throttle valve is controlled by the throttle control means so that the set accelerator opening and the amount of intake air necessary to maintain the idling speed of the internal combustion engine are maintained. Thereby, even if the accelerator opening sensor becomes abnormal, the throttle opening of the throttle valve is appropriately controlled, and the idling speed is appropriately maintained without excessively increasing the output of the internal combustion engine, thereby stabilizing the engine. Evacuation traveling becomes possible.

According to the second aspect of the present invention, when the accelerator opening sensor detects an abnormal state by the abnormality detecting means, the target engine speed of the internal combustion engine is set by the speed setting means. The throttle opening of the throttle valve is controlled by the throttle control means so that the intake air amount is required to maintain the predetermined rotation speed as described above and the idle rotation speed of the internal combustion engine. Thereby, even if the accelerator opening sensor becomes abnormal, the throttle opening of the throttle valve is appropriately controlled, and the idling speed is appropriately maintained without excessively increasing the output of the internal combustion engine, thereby stabilizing the engine. Evacuation traveling becomes possible.

According to the third aspect of the present invention, the throttle opening of the throttle valve is corrected in accordance with the temperature of the cooling water of the internal combustion engine. The idle speed is optimally maintained by the throttle opening to prevent engine stall.

[0009]

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

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 an embodiment of the present invention is applied, and peripheral devices thereof.

In FIG. 1, an air cleaner 3 is provided upstream of an intake passage 2 of an internal combustion engine 1.
An air flow meter 4 for detecting an intake air amount is installed downstream of the air flow meter. The air flow meter 4 in the intake passage 2
The throttle valve 5 is provided further downstream, and the throttle opening TA which is the actual opening of the throttle valve 5 is controlled by the driving force of the electric motor 19 connected to the rotary shaft 5a of the throttle valve 5, The amount of intake air supplied to the internal combustion engine 1 is adjusted. The throttle opening TA of the throttle valve 5 is detected by a throttle opening sensor 16. Even during idling, the throttle opening TA is controlled by the driving force of the electric motor 19, whereby the intake air amount GN is controlled and the engine speed NE is controlled.
Is feedback-controlled such that is equal to 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 (fuel injection valves) 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, and the ignition plug 1
The combustion is caused by the ignition of 0, the piston 11 is pushed down, and a torque is applied to the 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, the engine speed NE signal detected by the crank angle sensor 15, and the like. CPU that controls opening and closing of the throttle valve 5 based on the throttle opening degree TA signal detected by the sensor 16 and the accelerator opening Ap signal detected by the accelerator opening degree 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. A target throttle opening TT which is a target command value of the throttle valve 5 by the electric motor 19 and a fuel injection amount of the injector 7.
It is a well-known central processing unit that calculates P 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.

Further, the motor drive circuit 25 includes a CPU 21
(PWM) conversion in order to reduce the deviation according to the deviation between the target throttle opening TTP of the throttle valve 5 by the electric motor 19 and the throttle opening TA from the throttle opening sensor 16 by the electric motor 19 Output DUT calculated as the duty ratio signal obtained
This is a circuit that forms an output current DUTY from Y (control amount) and outputs it to the electric motor 19. As a result, a driving force corresponding to the output current DUTY is generated in the electric motor 19, and the throttle opening TA of the throttle valve 5 detected by the throttle opening sensor 16 finally matches the target throttle opening TTP. Adjusted.

The A / D conversion circuit 27 reads various signals such as a read intake air amount GN signal, a throttle opening degree TA signal, an accelerator opening degree Ap signal, and a cooling water temperature THW signal from a water temperature sensor (not shown). This is a circuit for A / D (analog-digital) conversion of sensor information and outputting it to the CPU 21.

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 valve lever 44 is connected to the rotary shaft 5a of the throttle valve 5, and this valve lever 44
Is urged in the opening direction of the throttle valve 5 (upward in FIG. 2) by the retreat running spring 45. Therefore, when the motor is turned off (power to the electric motor 19 is turned off) shown in FIG. 2B, the valve lever 44 is held at the intermediate stopper position where the valve lever 44 abuts on the intermediate lever 47 by the retreat traveling spring 45. At this time, the intermediate lever 47
Is biased by the valve return spring 48 in the closing direction of the throttle valve 5 (downward in FIG. 2), and is in contact with the intermediate stopper 49.

That is, the pulling force of the valve return spring 48 is set to be larger than the pulling force of the retreat running spring 45. Therefore, when the motor is turned off as shown in FIG. 2B, the pulling force of the valve return spring 48 overcomes the pulling force of the retreat running spring 45, and the intermediate lever 47 abuts on the intermediate stopper 49 and is held. Of the throttle opening TA at the intermediate stopper position (throttle opening T
A = about 7 °).

On the other hand, during normal control (motor ON) shown in FIG. 2A, the electric motor 19 rotates forward or reverse according to the operation amount of the accelerator pedal 17, and the throttle opening degree TA of the throttle valve 5 becomes smaller. The throttle opening TA of the throttle valve 5 at that time is adjusted by the throttle opening sensor 16. At this time, when the throttle opening TA is increased, the positive motor current is supplied to the electric motor 19 and the electric motor 19 is rotated forward, so that the valve lever 44 is moved as shown in FIG. The intermediate lever 4 against the pulling force of the valve return spring 48
7, the throttle valve 5 is driven in the opening direction. Conversely, when the throttle opening TA is reduced, the negative motor current is supplied to the electric motor 19, and the electric motor 19 is rotated in the reverse direction.
And the throttle valve 5 is driven in the closing direction.
When the throttle lever 5 is driven in the closing direction after the intermediate lever 47 is brought into contact with the intermediate stopper 49, the valve lever 44 is lowered against the pulling force of the retreating spring 45, and the throttle valve 5 is fully closed. When the valve lever 44 is closed to the stopper position (throttle opening TA = 0 °), the valve lever 44 comes into contact with the throttle fully closed stopper 46, and further rotation is prevented.

As shown in FIGS. 2 and 3, the throttle opening sensor 16 and the accelerator opening sensor 18 are both configured as a double system. Therefore, as is well known, when the difference between the two throttle opening degree TA signals or the difference between the two accelerator opening degree Ap signals deviates from a predetermined value, it is determined to be abnormal.

Next, E used in a throttle control device for an internal combustion engine according to an embodiment of the present invention will be described.
A description will be given based on a flowchart of FIG. 4 showing a processing procedure of the required accelerator operation amount calculation in the CPU 21 in the CU 20. It should be noted that the required accelerator opening degree calculation routine is approximately 8
It is repeatedly executed by the CPU 21 every ms.

In FIG. 4, in step S101, it is determined whether the accelerator opening sensor 18 is normal. When the determination condition of step S101 is satisfied, that is, when the accelerator opening sensor 18 is normal, the process proceeds to step S102, and the accelerator opening is determined according to the output from the accelerator opening sensor 18 (the accelerator opening Ap signal). Is set to
This routine ends.

On the other hand, if the determination condition of step S101 is not satisfied, that is, if the accelerator opening sensor 18 is abnormal, the process proceeds to step S103, and the accelerator opening sensor 1
Regardless of the output from 8, the accelerator opening at this time is set to a predetermined opening of {(fully closed) + (several degrees)}, and this routine ends. As described above, the accelerator opening sensor 1
The accelerator opening set at the time of abnormality 8 corresponds to a throttle opening TA that takes into account the engine output of the internal combustion engine 1 and the limp-home running without causing abnormal acceleration in the vehicle.

As described above, the throttle control apparatus for an internal combustion engine according to the present embodiment drives the electric motor 19 as an actuator based on various sensor information to control the throttle opening TA of the throttle valve 5. An accelerator opening sensor 18 for detecting an accelerator opening Ap corresponding to an amount of depression of an accelerator pedal 17; an abnormality detecting means achieved by a CPU 21 in an ECU 20 for detecting an abnormal state of the accelerator opening sensor 18; When the detecting means detects an abnormal state of the accelerator opening sensor 18, the opening setting means achieved by the CPU 21 in the ECU 20 sets the accelerator opening Ap to a predetermined opening regardless of the depression amount of the accelerator pedal 17. When the accelerator opening sensor 18 is abnormal, the predetermined opening set by the opening setting means and the idle Throttle opening degree TA of the throttle valve 5 based on the intake air amount GN needed to maintain the rotational speed
And a throttle control means achieved by the CPU 21 in the ECU 20 that controls the ECU. The throttle control means achieved by the CPU 21 in the ECU 20 of the internal combustion engine throttle control device of the present embodiment corrects the throttle opening degree TA of the throttle valve 5 in accordance with the cooling water temperature THW of the internal combustion engine 1. is there.

That is, when the accelerator opening sensor 18 is abnormal, the accelerator opening Ap set to a predetermined opening,
The throttle opening TA of the throttle valve 5 is controlled so that the intake air amount GN required to maintain the idle speed of the internal combustion engine 1 is maintained. At this time, the cooling water temperature TH of the internal combustion engine 1
The throttle opening TA of the throttle valve 5 is corrected according to W.

Thus, even if the accelerator opening sensor 18 is in an abnormal state, the throttle opening TA of the throttle valve 5 is appropriately controlled, so that the output of the internal combustion engine 1 does not become excessively large and the limp-home operation is stable. Becomes possible. At this time, even when the internal combustion engine is cold, the idle speed can be optimally maintained by correcting the throttle opening TA of the throttle valve 5 to prevent engine stall.

Next, E used in a throttle control device for an internal combustion engine according to an embodiment of the present invention will be described.
A description will be given based on a flow chart of FIG. The required accelerator operation amount calculation routine is repeatedly executed by the CPU 21 about every 8 ms.

In FIG. 5, in step S201, it is determined whether the accelerator opening sensor 18 is normal. When the determination condition in step S201 is satisfied, that is, when the accelerator opening sensor 18 is normal, the process proceeds to step S202, and the accelerator opening is output from the accelerator opening sensor 18 (the accelerator opening degree), as in the above-described embodiment. The opening degree is set according to the (Ap signal), and this routine ends.

On the other hand, when the condition of step S201 is not satisfied, that is, when the accelerator opening sensor is abnormal, the process proceeds to step S203, and the target engine speed at this time is determined regardless of the output from the accelerator opening sensor 18. The number is set to a predetermined rotation speed of {(idling rotation speed) + (several hundred rotation speeds)}. Next, the process proceeds to step S204, where it is determined whether the engine speed NE detected by the crank angle sensor 15 exceeds the target engine speed set in step S203. When the determination condition of step S204 is satisfied, that is, when the engine speed NE is higher than the target engine speed, the process proceeds to step S205, and the present throttle opening is obtained by subtracting a predetermined opening from the previous throttle opening. The opening is set, and this routine ends.

When the condition of step S204 is not satisfied, that is, when the engine speed NE is lower than the target engine speed, the process proceeds to step S206, where the current throttle opening is set to the previous throttle opening. Is set to a value obtained by adding a predetermined opening to the routine, and this routine is terminated. Thus, when the accelerator opening sensor 18 becomes abnormal, the throttle opening TA is gradually corrected so that the engine speed NE approaches the target engine speed. In this correction calculation process, for example, the well-known PID control (Proportional Int
egral Differential Control; proportional / integral / differential control)
May be used. The feedback control is not limited to the PID control, but may be a PI control, a PD control, or a P control, and various other methods based on the control theory can be appropriately used. As described above, the throttle opening TA set when the accelerator opening sensor 18 is abnormal corresponds to the engine output of the internal combustion engine 1 in which abnormal acceleration does not occur in the vehicle and the opening in consideration of the limp-home mode. ing.

As described above, the throttle control device for an internal combustion engine according to this modification drives the electric motor 19 as an actuator based on various types of sensor information to control the throttle opening TA of the throttle valve 5. A crank angle sensor 15 as a rotation speed sensor for detecting the engine speed NE of the internal combustion engine 1, an accelerator opening sensor 18 for detecting an accelerator opening Ap corresponding to the depression amount of an accelerator pedal 17, and an accelerator opening sensor 18 An abnormality detecting means achieved by the CPU 21 in the ECU 20 for detecting an abnormal state of the ECU 20. When the abnormality detecting means detects an abnormal state of the accelerator opening sensor 18, the target engine speed of the internal combustion engine 1 is changed to a predetermined engine speed. CPU 21 in ECU 20 set to
In the case where the rotation speed setting means achieved by the above and the accelerator opening sensor 18 is abnormal, the intake air amount GN necessary for maintaining the predetermined rotation speed set by the rotation speed setting means and the idle rotation speed of the internal combustion engine 1. And a throttle control means achieved by the CPU 21 in the ECU 20 for controlling the throttle opening degree TA of the throttle valve 5 based on the above. The throttle control means achieved by the CPU 21 in the ECU 20 of the throttle control device for an internal combustion engine according to the present modification corrects the throttle opening degree TA of the throttle valve 5 in accordance with the cooling water temperature THW of the internal combustion engine 1. is there.

That is, when the accelerator opening sensor 18 is abnormal, the target engine speed set to a predetermined speed,
The throttle opening TA of the throttle valve 5 is controlled so that the intake air amount GN required to maintain the idle speed of the internal combustion engine 1 is maintained. At this time, the cooling water temperature TH of the internal combustion engine 1
The throttle opening TA of the throttle valve 5 is corrected according to W.

Thus, even if the accelerator opening sensor 18 is in an abnormal state, the throttle opening TA of the throttle valve 5 is appropriately controlled. Becomes possible. At this time, even when the internal combustion engine is cold, the idle speed can be optimally maintained by correcting the throttle opening TA of the throttle valve 5 to prevent engine stall.

[Brief description of the drawings]

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

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

FIG. 4 is an EC used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.
9 is a flowchart illustrating a processing procedure of a requested accelerator opening calculation in a CPU in U.

FIG. 5 is an EC used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.
15 is a flowchart illustrating a modified example of a processing procedure of a requested accelerator opening calculation in the CPU in U.

[Explanation of symbols]

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

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G065 AA04 CA39 DA05 DA06 DA15 EA03 EA09 FA12 GA05 GA09 GA10 GA41 GA46 HA19 HA21 HA22 JA04 JA09 JA11 KA02 KA15 KA16 3G084 AA03 BA05 CA03 DA30 EA05 EA11 EB14 EB03 FA01 FA20 FA33 3G301 HA06 JB01 KA07 KA08 LA03 LB02 LC03 MA12 NA03 NA04 NA05 NA08 NB15 ND02 ND05 PA01Z PA11A PE01Z PE04Z PE08Z PF03Z

Claims (3)

[Claims] An accelerator opening sensor for detecting an accelerator opening according to an amount of depression of an accelerator pedal in a throttle control device for an internal combustion engine that controls an opening of a throttle valve by driving an actuator based on various sensor information. Abnormality detecting means for detecting an abnormal state of the accelerator opening sensor, and when the abnormality detecting means detects an abnormal state of the accelerator opening sensor, the accelerator opening is opened by a predetermined amount regardless of the accelerator pedal depression amount. Opening degree setting means for setting the degree of opening, and when the accelerator opening degree sensor is abnormal, the intake air amount necessary to maintain the predetermined opening degree set by the opening degree setting means and the idle speed of the internal combustion engine. Throttle control means for controlling an opening degree of the throttle valve based on the throttle control of the internal combustion engine. Apparatus. 2. A throttle control device for an internal combustion engine that controls an opening of a throttle valve by driving an actuator based on various types of sensor information, wherein: a speed sensor for detecting an engine speed of the internal combustion engine; An accelerator opening sensor that detects an accelerator opening according to the amount, an abnormality detecting unit that detects an abnormal state of the accelerator opening sensor, and an abnormality detecting unit that detects an abnormal state of the accelerator opening sensor. Rotation speed setting means for setting a target engine rotation speed of the internal combustion engine to a predetermined rotation speed; and when the accelerator opening sensor is abnormal, the predetermined rotation speed set by the rotation speed setting means and an idle rotation speed of the internal combustion engine. Throttle control means for controlling the opening degree of the throttle valve based on the amount of intake air required to maintain the number. Throttle control apparatus for an internal combustion engine, characterized in that. 3. The throttle control device for an internal combustion engine according to claim 1, wherein the throttle control means corrects an opening degree of the throttle valve according to a cooling water temperature of the internal combustion engine. .