JP3477857B2 - Throttle control device for internal combustion engine - Google Patents

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 which drives a DC motor according to the amount of depression of an accelerator pedal to control the opening of a throttle valve. At times, the internal combustion engine that can reliably switch to the escape travel mode (a function that enables safe traveling from the place where the abnormality occurred to the repair shop etc. instead of stopping the internal combustion engine at the same time as the abnormality occurred) The present invention relates to a throttle control device.

[0002]

2. Description of the Related Art Conventionally, as a prior art document related to a throttle control device for an internal combustion engine, there is Japanese Patent Laid-Open No. 63-2464.
The one disclosed in Japanese Patent Publication No. 49 is known. This device is provided with main control means for controlling the throttle valve and sub control means for controlling the throttle valve when the main control means is abnormal, and outputs a pseudo signal to the sub control means when the main control means is normal. , A technique for detecting an abnormality of the sub-control unit from the operating state of the throttle valve is shown.

Further, the one disclosed in Japanese Patent Laid-Open No. 59-190441 is known. This document discloses a technique for detecting an abnormality in the throttle control system by monitoring a switch that is turned on when the accelerator is not operated and a switch that is turned on in the initial state of the throttle valve.

Further, the one disclosed in Japanese Patent Application Laid-Open No. 2-204642 is known. This one detects the opening of each accelerator pedal and throttle valve,
In addition to U, an analog circuit is used to compare outputs to detect an abnormality in the throttle control system and to disconnect an electromagnetic clutch provided between the motor and the throttle valve.

[0005]

By the way, Japanese Patent Laid-Open No. Sho 63-63
According to Japanese Patent Laid-Open No. 246449, since a pseudo signal is issued to the output of the accelerator opening sensor, for example, the operation is such that the accelerator pedal is not depressed and the throttle valve holds a predetermined opening like during cruise control. There was a problem that the abnormality of the throttle control system could not be judged in the state.

Further, in JP-A-59-190441, since the CPU detects an abnormality, it cannot be detected when the CPU is out of order, and it is impossible to switch to the retracting traveling mechanism by disengaging the electromagnetic clutch. there were.

Further, in Japanese Patent Laid-Open No. 2-204642, it is possible to disengage the electromagnetic clutch by the analog circuit even when the CPU fails, but as a countermeasure when an abnormality occurs in the throttle control system when the analog circuit fails. There was a problem that the reliability was not sufficient.

Therefore, the present invention has been made to solve such a problem, and it is highly reliable that the operation of the throttle control system can be surely checked in accordance with various operating states and an abnormality can be judged. An object is to provide a throttle control device for an internal combustion engine.

[0009]

In a throttle control device for an internal combustion engine according to a first aspect of the present invention, as shown in the concept of FIG. 14, the opening degree of the throttle valve 5 of the internal combustion engine is equivalent to the depression operation of the accelerator pedal 20. Throttle drive means G1 which independently controls based on a predetermined throttle opening command value
A biasing means G2 for biasing the throttle valve 5 in the closing direction when the throttle driving means G1 is not operating, an accelerator opening sensor G3 for detecting the depression amount of the accelerator pedal 20, and the throttle valve 5. A throttle opening sensor G4 for detecting the opening and a cruise control detecting means G for detecting whether the cruise control is being performed.
5, a brake detecting means G6 for detecting a depression operation of the brake pedal 21, and a clutch means G for connecting and disconnecting the throttle driving means G1 and the throttle valve 5.
7, the output values of the accelerator opening sensor G3 and the throttle opening sensor G4 are compared with predetermined values based on the selection of the cruise control detecting means G5 and the brake detecting means G6, and the throttle control system is abnormal. Circuit G8 for detecting the
When the abnormality of the throttle control system is detected in 8,
The clutch means G7 is driven to disconnect the throttle drive means G1 from the throttle valve 5, and the accelerator pedal 20 and the throttle valve 5 are connected.
And a switching means G9 for switching to a retreat traveling mode in which one or more of a fuel supply amount, an ignition timing, and an intake air amount are mechanically connected to each other, and a switching means G9 for switching to a retreat traveling mode according to an operating state at a predetermined timing. And a check means G10 for checking whether or not the analog circuit G8 for detecting an abnormality in the throttle control system normally operates by using a predetermined pseudo signal.

According to a second aspect of the throttle control device for an internal combustion engine, in addition to the means of the first aspect, when the analog circuit is abnormal, the throttle drive means controls the throttle valve to the closing side. The clutch means is operated to disconnect the connection between the throttle drive means and the throttle valve, and at least one of the processes for issuing an alarm to the driver is performed to switch to the escape traveling mode.

[0011]

According to the first aspect of the present invention, the analog circuit compares the respective outputs of the accelerator opening sensor and the throttle opening sensor with predetermined values based on the selection of the cruise control detecting means and the brake detecting means, and the abnormality of the throttle control system is detected. Is detected. When an abnormality in the throttle control system is detected by the analog circuit, the switching means drives the clutch means to disconnect the throttle drive means from the throttle valve and mechanically connect the accelerator pedal to the throttle valve. The vehicle is switched to the retreat traveling mode in which one or more of the traveling state or the fuel supply amount, the ignition timing, and the intake air amount are adjusted. Furthermore, the throttle control system is controlled by the check means at a predetermined timing using a predetermined pseudo signal according to the operating state.
Whether the analog circuit that detects the abnormality in the
One of the operation check is performed.

In the analog circuit of the throttle control device for an internal combustion engine according to a second aspect, in addition to the action of the first aspect, when the abnormality occurs, the throttle driving means controls the throttle valve to the closing side to operate the clutch means to operate the throttle driving means. Then, the connection between the throttle valve and the throttle valve is cut off, and one or more of the processes for issuing a warning to the driver are executed to switch to the escape mode.

[0013]

EXAMPLES The present invention will be described below based on specific examples.

FIG. 1 is a schematic configuration diagram showing a throttle control device for an internal combustion engine according to an embodiment of the present invention.

First, a schematic structure of an internal combustion engine to which the throttle control device for an internal combustion engine of this embodiment is applied will be described. In FIG. 1, an internal combustion engine 1 is configured as a V-type 6-cylinder 4-cycle internal combustion engine. An air cleaner 3 is provided on the upstream side of the intake passage 2 of the internal combustion engine 1.
On the downstream side of the air flow meter 4 for detecting the amount of intake air
Is installed. A throttle valve 5 is provided downstream of the air flow meter 4 in the intake passage 2, and the amount of intake air supplied to the internal combustion engine 1 is adjusted according to the opening / closing of the throttle valve 5. 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 to each cylinder via the intake manifold 6.

An injector 7 is installed in the intake manifold 6 corresponding to each cylinder, and the fuel injected from each injector 7 is mixed with intake air and supplied to each cylinder. This air-fuel mixture is introduced into the combustion chamber 9 of each cylinder as the intake valve 8 is opened and closed, and is burned by the ignition of the spark plug 10 to push down the piston 11 and apply torque to the crankshaft 12. The exhaust gas after combustion is discharged to the outside through the exhaust passage 14 as the exhaust valve 13 is opened and closed. A crank angle sensor 15 is installed near the crankshaft 12 and outputs a pulse signal every 30 degrees at the crank angle.

Next, the configuration around the throttle valve to which the throttle control device for an internal combustion engine according to one embodiment of the present invention is applied will be described with reference to the schematic diagrams of FIGS.
2 and 3, the upper side is the opening side of the throttle valve 5 and the lower side is the closing side, as indicated by the arrow.

FIG. 2 is a throttle structure with a link in which the accelerator pedal 20 and the throttle valve 5 can be mechanically connected, and FIG. 3 is the accelerator pedal 20 and the throttle valve 5.
This is a throttle control device for an internal combustion engine in a linkless throttle configuration in which and are completely independent.

First, in FIG. 2, when the driver operates the accelerator pedal 20, the amount of depression is detected by the accelerator opening sensor 100, and the opening of the throttle valve 5 at that time is detected by the throttle opening sensor 34. Both sensor outputs are input to an ECU (Electronic Control Unit) 61. Reference numerals 102 and 103 denote full-close stoppers that regulate the fully closed positions of the accelerator pedal 20 and the throttle valve 5. The throttle valve 5 is biased to the open side by the spring 113, and the DC motor 3
The opening side drive of 1 opens the throttle valve 5 against the biasing force of the return spring 112. On the contrary, the throttle valve 5 is closed against the biasing force of the spring 113 by driving the DC motor 31 on the closing side.

During normal running, the accelerator plate 110
There is a constant gap between the intermediate plate 111 and the intermediate plate 111. However, when the throttle control system (including the microcomputer) is abnormal, the DC motor 31 is driven to the close side or the electromagnetic clutch 80 is disengaged to disconnect the DC motor 31 and the throttle valve 5. At this time, the biasing force of the return spring 112 overcomes the biasing force of the spring 113 to mechanically close the throttle valve 5. After that, instead of keeping the vehicle stationary, the vehicle is operated in the evacuation mode (limp home) mode, and the accelerator pedal 20 and the throttle valve 5 are mechanically connected to each other, whereby self-driving to a repair shop becomes possible.

Next, the configuration of FIG. 3 will be described focusing on the differences from FIG.

In the configuration shown in FIG. 3, the return spring 107 applied to the throttle valve 5 is the only biasing force. By driving the DC motor 31, the throttle valve 5 is opened against the biasing force of the return spring 107. On the contrary, the drive of the DC motor 31 or the energization of the DC motor 31 is cut off, and the return spring 107 mechanically closes the throttle valve 5.

The full-closed stopper 106 is usually an ISC (Idle
(Speed Control: idle speed control), the throttle valve 5 is controlled by the DC motor 31, so the convex portion 106a of the fully closed stopper 106 is pushed down to control the idle opening. Further, when the throttle control system is abnormal, the electromagnetic clutch 80 is disengaged so that the throttle valve 5 is held at a fixed opening by the full-closed stopper 106 so that the throttle valve 5 is adjusted to reduce the fuel supply amount and the ignition timing is delayed. This is possible by setting the traveling state to satisfy at least one of the adjustment in the direction and the adjustment in the direction to reduce the intake air amount. The reduction gear 105 common to FIGS. 2 and 3 plays a role of amplifying the rotational torque generated by the DC motor 31 and transmitting it to the throttle valve 5.

Next, the electrical construction of the throttle control device for the internal combustion engine of this embodiment will be described.

As shown in FIG. 1, the ECU 61 mainly includes a CPU 62, a ROM 63, a RAM 64, an injector drive circuit 65, an electromagnetic clutch drive circuit 68, an A / D conversion circuit 66, a D / A conversion circuit 67, an analog circuit 69 and It is composed of a lamp drive circuit 70. ROM 63
Various programs for controlling the operation of the internal combustion engine 1, for example, programs for controlling the opening of the throttle valve 5 and controlling the fuel injection of the injector 7 are stored in the CP.
U62 executes processing according to those programs.
Further, the RAM 64 temporarily stores processing data executed by the CPU 62.

The CPU 62 has an intake air amount Qa detected by the air flow meter 4 and a throttle opening sensor 34.
Of the output voltage Vth (= throttle opening θth) and the accelerator opening signal Ap of the accelerator opening sensor 100 are A
It is converted into a digital value by the / D conversion circuit 66 and input. Further, the CPU 62 has a Ne pulse signal from the crank angle sensor 15, a vehicle speed signal from a vehicle speed sensor (not shown), a C / C (Cruise Control) set SW (switch) C / C set SW signal, and a brake pedal. A brake SW signal interlocked with the depression of 21 is input.

Then, the CPU 62, for example, calculates the engine speed N calculated from the pulse signal of the crank angle sensor 15.
Based on e and the intake air amount Qa, the current internal combustion engine 1
Calculates the fuel injection amount required by the fuel injection amount and outputs a control signal having a pulse width corresponding to the fuel injection amount to the injector drive circuit 65. On the other hand, the CPU 62, based on the guard opening degree θmg corresponding to the accelerator operation amount and the engine speed Ne, is a throttle opening degree command value θ which is a target value for throttle opening degree control.
cmd is determined, and the throttle opening command value θcmd
The throttle command voltage Vcmd corresponding to the above is determined. Furthermore, the CPU 62 outputs a clutch control signal to the electromagnetic clutch drive circuit 68, and the electromagnetic clutch drive circuit 68 turns on / off the electromagnetic clutch 80.

The DC motor drive circuit 71 is a PID
It is composed of a (proportional / integral / derivative) control circuit 72, a PWM (pulse width modulation) circuit 73, and a driver 74.
The throttle command voltage V calculated by the CPU 62 in this way
The cmd is converted into an analog value by the D / A conversion circuit 67 and input to the PID control circuit 72. The PID control circuit 72 executes a proportional / integral / derivative operation to reduce the deviation based on the throttle command voltage Vcmd and the output voltage Vth from the throttle opening sensor 34, and the DC motor 3
The control amount of 1 is calculated. The PWM circuit 73 inputs the control amount calculated by the PID control circuit 72, converts the control amount into a corresponding duty ratio signal, and the driver 74 drives the DC motor 31 in accordance with the duty ratio signal to generate an actual duty ratio signal. Adjust the throttle opening θth to the throttle opening command value θcmd. The duty ratio signal of the PWM circuit 73 is C
It is also input to the PU 62.

Next, the processing procedure of the CPU 62 used in the throttle control device for the internal combustion engine according to the embodiment of the present invention will be described with reference to the flow charts of FIGS. 4, 5 and 6.

<< Analog Circuit Abnormality Detection Main Routine: See FIG. 4 >> FIG. 4 is a flowchart showing an abnormality detection process of the analog circuit 69.

First, in step S101, a determination process as to whether or not the operation check execution of the analog circuit 69 is permitted is executed by a permission determination subroutine described later.
Next, the process proceeds to step S102, and it is determined whether the check permission flag XCHK = 1. Step S102
When the determination condition of is not satisfied, this routine is ended without doing anything. Here, when the determination condition of step S102 is satisfied, the process proceeds to step S103,
Accelerator opening sensor 100, throttle opening sensor 3
4. Each signal from the vehicle speed, C / C set SW, and brake SW is read.

Next, in step S104, the C / C
It is determined whether the set SW is ON. Step S1
If the determination condition of 04 is satisfied and the C / C is being performed, the process proceeds to step S105, and the C / C in-use test signal XTEST is performed.
= 1. If the determination condition of step S104 is not satisfied, the process proceeds to step S106, the accelerator is fully closed (the output of the accelerator opening sensor 100 is equal to or less than the initial value), and the brake pedal 21 is being depressed (the brake SW is ON). ) Determines whether the vehicle is decelerating. When the determination condition of step S106 is satisfied, step S
The process proceeds to 107, and the deceleration test signal XTEST = 2.

On the other hand, when the determination condition of step S106 is not satisfied, the routine proceeds to step S108, where it is determined whether the accelerator is fully closed and the vehicle speed = 0. When the determination condition of step S108 is satisfied,
The process proceeds to step S109, and the idle test signal XT
EST = 3. On the other hand, when the determination condition of step S108 is not satisfied and the vehicle is traveling normally, step S1
10, the test signal XTEST = 4 during normal running is set.

Steps S105, S107, S109,
After the process of S110, the process proceeds to step S111, and a pseudo signal is output by a pseudo signal output subroutine described later, and the circuit check process is executed. That is, a pseudo signal is output to the analog circuit 69 according to each operating state (C / C, deceleration, idle, normal running). Next step S1
12, the output of the analog circuit 69 is monitored, and the process proceeds to step S113 to determine whether the output of the analog circuit 69 is Hi. Here, step S
At 111, a pseudo signal that causes the analog circuit 69 to make a fail determination according to the operating state is output.
When is normally operating, it outputs Hi (fail signal).

When the determination condition of step S113 is not satisfied and the output is Lo and it is determined that there is an abnormality, step S113 is performed.
The process proceeds to 114, and the fail process is executed. As the fail processing, a signal is output to the driver 74 of the DC motor drive circuit 71 to control the DC motor 31 to the close side or a signal is output to the electromagnetic clutch drive circuit 68 to disconnect the electromagnetic clutch 80, and Throttle valve 5
Is disconnected or a signal is output to the lamp drive circuit 70 to turn on the warning lamp 90 to warn the driver and switch to the escape traveling mode. Step S113
When it is determined that the condition is satisfied and the condition is normal, and after the process of step S114, the process proceeds to step S115, the check permission flag XCHK = 0 is reset, and this routine ends.

<Analog Circuit Operation Check Execution Permission Subroutine: See FIG. 5> FIG. 5 is a flowchart showing the analog circuit operation check execution permission processing in step S101 of FIG.

In step S201, the fail flag XF
It is determined whether AIL = 1. If the determination condition of step S201 is not satisfied and the state is not failing, the process proceeds to step S202, and the check permission flag XCHK = 1.
Is determined. If the determination condition of step S202 is not satisfied and the check is not in progress, step S203
Then, the check permission flag XCHK = 1 is set, and this routine is finished. It should be noted that when the determination condition of step S201 is satisfied and the condition is failing, the step S20 is performed again.
When the determination condition 2 is satisfied and the check is in progress, the routine is terminated without doing anything.

<Pseudo Signal Output Subroutine: See FIGS. 6 to 11> FIG. 6 is a flowchart showing the pseudo signal output process of step S111 of FIG. In the analog circuit 69 of FIGS. 8, 9, 10 and 11, the output switching unit 6 shown in FIG.
9a is omitted.

In step S301, it is determined whether or not the C / C mid test signal XTEST = 1. Step S30
If the determination condition of 1 is satisfied and C / C is in progress, step S3
02, and operate the C / C set SW to C / CO
Generate an FF signal. At this time, as shown in FIG. 7, the pseudo signal output unit 62a of the CPU 62 outputs C / C O
The FF signal is output to the analog circuit 69. Then, as shown in FIG. 8, the output Ap of the accelerator opening sensor 100 is smaller than a preset initial value A0 because it is in C / C, and the output θth of the throttle opening sensor 34 is preset. Since the value is larger than the initial value B and is C / C OFF from the pseudo signal output unit 62a, the abnormality determination of the portion surrounded by the broken line is established as shown by the thick line, and the output of the analog circuit 69 becomes Hi. At this time, the initial value B, which is a comparison value with the output θth of the throttle opening sensor 34, is a value corresponding to the maximum opening during idling.

As shown in FIG. 7, this judgment output is input to the output switching section 69a of the analog circuit 69. The output switching unit 69a sends the output of the analog circuit 69 to the CPU 62 when the pseudo signal output unit 62a of the CPU 62 is operating (during the check of the analog circuit 69), and when the test is not in progress (during failure), the analog circuit 69 The output is output to the DC motor drive circuit 71, the lamp drive circuit 70, and the electromagnetic clutch drive circuit 68. That is, during the test, the DC motor 3
This is for avoiding the drivability defect due to the control of the closing side of No. 1 and the electromagnetic clutch 80 being disengaged. If the output of the analog circuit 69 is Low, it is determined that the circuit is abnormal, and the fail process described above is executed. Then, after the processing of step S302, this routine is ended.

When the determination condition of step S301 is not satisfied, the process proceeds to step S303 and it is determined whether the deceleration test signal XTEST = 2. Step S3
If the determination condition of 03 is satisfied and the vehicle is decelerating, step S3
04, the brake is ON, but C / C is OFF because it is not in C / C, but the same C / C ON signal as when the C / C set SW is operated by the pseudo signal output unit 62a of the CPU 62. Is emitted. Then, as shown in FIG. 9, since the brake is ON and the C / C is ON, the C / C cancel determination of the portion surrounded by the broken line is established as shown by the bold line, and the output of the analog circuit 69 becomes Hi. To be done. The following processing is the C / C in step S302.
The description is omitted because it is the same as when the middle test signal XTEST = 1. Then, after the processing of step S304, this routine is ended.

When the determination condition of step S303 is not satisfied, the routine proceeds to step S305, where it is determined whether or not the idle test signal XTEST = 3. If the determination condition of step S305 is satisfied and the engine is idling, the process proceeds to step S306, the output of the throttle opening sensor 34 is operated, and the output when the throttle valve 5 is opened is transmitted. As shown in FIG. 10, because the engine is idling, the output Ap of the accelerator opening sensor 100 is smaller than a preset initial value A0 and C / COFF, and the output θth of the throttle opening sensor 34 is originally Although it is smaller than the preset initial value B, θth> B because the output of the throttle opening sensor 34 is operated to the open side by the pseudo signal output unit 62a, and therefore the abnormality determination of the portion surrounded by the broken line is performed. Is established as indicated by a thick line, and the output of the analog circuit 69 is Hi. The following processing is performed during the C / C test signal XTEST =
Since it is the same as the case of 1, it is omitted. And step S3
After the processing of 06, this routine is ended.

When the determination condition of step S305 is not satisfied, the routine proceeds to step S307, where the output of the accelerator opening sensor 100 is operated during normal traveling, and the output when the accelerator pedal 20 is fully closed is transmitted. Figure 11
As shown in (1), because the vehicle is traveling normally, the output θth of the throttle opening sensor 34 is larger than a preset initial value B and C / C OFF, and originally the output Ap of the accelerator opening sensor 100 is Ap. Is a preset initial value A0
Although it is larger, the pseudo signal output unit 62a causes the output of the accelerator opening sensor 100 to be fully closed,
Since Ap <A0, the abnormality judgment of the portion surrounded by the broken line is established as shown by the thick line, and the output of the analog circuit 69 becomes H level.
i. The subsequent processing is the same as that in the C / C mid test signal XTEST = 1 in step S302, and will be omitted. Then, after the processing of step S307, this routine is ended.

As described above, the throttle control device for the internal combustion engine according to the present embodiment determines the opening degree of the throttle valve 5 of the internal combustion engine 1 based on the predetermined throttle opening degree command value independently of the depression operation of the accelerator pedal 20. DC motor 3 controlled by
Throttle driving means composed of 1; biasing means composed of return springs 112 and 107 for biasing the throttle valve 5 in the closing direction when the throttle driving means is not operating; and accelerator opening degree for detecting the depression amount of the accelerator pedal 20. The sensor 100, the throttle opening sensor 34 for detecting the opening of the throttle valve 5, the cruise control detecting means achieved by the CPU 62 for detecting whether cruise control is being performed, and the depression operation of the brake pedal 21 are detected. Brake detection means achieved by the CPU 62, the throttle drive means, and the throttle valve 5
The accelerator opening sensor 10 based on the clutch means including the electromagnetic clutch 80 that connects and disconnects with the cruise control detecting means and the brake detecting means.
The analog circuit 69 for comparing the output values of 0 and the throttle opening sensor 34 with predetermined values to detect an abnormality in the throttle control system including the CPU 62, and the analog circuit 6
When the abnormality of the throttle control system is detected in 9,
Of the running state or the fuel supply amount, the ignition timing, and the intake air amount in which the clutch means is driven to disconnect the throttle drive means and the throttle valve 5 and the accelerator pedal 20 and the throttle valve 5 are mechanically connected. A CPU 62 that checks the operation of the analog circuit 69 by using a switching unit that is achieved by the CPU 62 that switches to the evacuation traveling mode that includes one or more traveling states and a predetermined pseudo signal that corresponds to the operating state at a predetermined timing. The check means achieved in 1. is provided, and this can be the embodiment of claim 1.

Therefore, the abnormality of the throttle control system including the CPU 62 is detected by the analog circuit 69, and the operation check of the analog circuit 69 is performed by the CPU 62 by C /
It is performed according to each operating state during C, during deceleration, during idling, and during normal running, and mutual abnormal states can be monitored by each other.
Therefore, it is possible to construct a highly reliable throttle control device for an internal combustion engine in which the occurrence of abnormality is reliably detected.

Further, the analog circuit 69 of the throttle control device for the internal combustion engine of this embodiment controls the throttle valve 5 to the closing side by the throttle driving means and operates the clutch means to operate the throttle driving means and the throttle when the abnormality occurs. The connection with the valve 5 is cut off, and one or more processes of generating an alarm to the driver are performed to switch to the escape travel mode, which can be the embodiment of claim 2.

Therefore, the throttle control system including the CPU 62 and the analog circuit 69 are monitored by each other, and it is possible to surely switch to the escape traveling mode when an abnormality occurs on the analog circuit 69 side, so that the reliability can be greatly improved.

By the way, in the above-mentioned embodiment, the output Ap of the accelerator opening sensor 100 is smaller than the initial value A0, the output θth of the throttle opening sensor 34 is larger than the predetermined value B, and C / C set. SW signal is OFF
The analog circuit 69 is determined to be abnormal when it is, but it is turned on when the accelerator pedal 20 returns to the fully closed position.
The accelerator fully closed SW is ON, the throttle fully closed SW that is ON when the throttle valve 5 returns to the fully closed position is OFF, and the C / C set SW signal is OFF.
The same operation check can be performed even with the analog circuit 69A as shown in FIG.

Further, the accelerator fully closed SW which is turned on when the accelerator pedal 20 returns to the fully closed position is ON, and
The output θth of the throttle opening sensor 34 is larger than a preset initial value B, and the C / C set SW signal is O.
A similar operation check can be performed even with the analog circuit 69B as shown in FIG. 13, which is determined to be abnormal when it is an FF.

[0050]

As described above, according to the throttle control device for an internal combustion engine of the first aspect, the accelerator opening sensor and the throttle opening sensor can be selected based on the selection of the cruise control detecting means and the brake detecting means in the analog circuit. When each output is compared with a predetermined value and an abnormality of the throttle control system is detected, and when an abnormality of the throttle control system is detected by the analog circuit, the switching means drives the clutch means to operate the throttle drive means and the throttle valve. When the connection is cut off, the vehicle is switched to a retreat mode in which the accelerator pedal and the throttle valve are mechanically connected to each other, or one or more of the fuel supply amount, the ignition timing, and the intake air amount are adjusted. , Using a predetermined pseudo signal according to the driving condition at a predetermined timing by the checking means Whether the operation check <br/> analog circuit for detecting an abnormality of the throttle control system operates normally is performed. In other words, an abnormality in the throttle control system is reliably detected by the analog circuit, and safety can be secured by switching to the escape travel mode. Also, the operation check of the analog circuit is performed by digital C / C such as CPU of throttle control system
It is carried out according to each operating state during C, during deceleration, during idling, and during normal traveling, and it is possible to reliably function on the safe side. That is, since the throttle control system and the analog circuit are monitored by each other, it is possible to reliably detect the occurrence of an abnormality, improve safety, and improve reliability.

According to the throttle control device of the internal combustion engine of the second aspect, in addition to the effect of the first aspect, when the analog circuit is abnormal, the throttle driving means controls the throttle valve to the closing side to operate the clutch means to drive the throttle. The connection between the means and the throttle valve is cut off, and one or more processes of issuing an alarm to the driver are executed to switch to the escape traveling mode. As described above, when the abnormality occurs on the analog circuit side, it is possible to reliably switch to the retreat traveling mode, so that the reliability can be greatly improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an operation principle around a throttle valve to which a throttle control device for an internal combustion engine according to an embodiment of the present invention is applied.

FIG. 3 is a schematic diagram showing another operating principle around a throttle valve to which a throttle control device for an internal combustion engine according to an embodiment of the present invention is applied.

FIG. 4 is a flowchart showing a processing procedure of analog circuit abnormality detection of a CPU used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a processing procedure for permitting execution of analog circuit operation check of a CPU used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 6 is a flowchart showing a pseudo signal output processing procedure of a CPU used in a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram showing an abnormality determination process in an analog circuit of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a fail determination condition during C / C in an analog circuit of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a fail determination condition during deceleration in an analog circuit of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a fail determination condition during idling in an analog circuit of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a fail determination condition during normal running in an analog circuit of a throttle control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram showing another fail determination condition in the analog circuit of the throttle control device for the internal combustion engine according to the embodiment of the present invention.

FIG. 13 is an explanatory diagram showing still another fail determination condition in the analog circuit of the throttle control device for the internal combustion engine according to the embodiment of the present invention.

FIG. 14 is a block diagram showing the concept of the present invention.

[Explanation of symbols]

1 Internal combustion engine 5 Throttle valve 20 accelerator pedal 31 DC motor 34 Throttle opening sensor 61 ECU (electronic control unit) 62 CPU 69 analog circuit 80 electromagnetic clutch 100 Accelerator position sensor

Continued front page       (56) References JP-A-5-99002 (JP, A)                 JP-A-5-263693 (JP, A)                 JP-A-2-204642 (JP, A)                 JP-A-63-246449 (JP, A)                 JP-A-59-16011 (JP, A)                 JP-A-56-6134 (JP, A)                 Japanese Patent Publication 5-31663 (JP, B2)

Claims (3)

(57) [Claims] 1. A throttle driving means for controlling an opening of a throttle valve of an internal combustion engine based on a predetermined throttle opening command value independently of a depression operation of an accelerator pedal, and a throttle driving means when the throttle driving means is not operating. Energizing means for urging the throttle valve in the closing direction, an accelerator opening sensor for detecting the depression amount of the accelerator pedal, a throttle opening sensor for detecting the opening of the throttle valve, and whether the cruise control is being performed. A cruise control detecting means for detecting the brake pedal, a brake detecting means for detecting a depression operation of a brake pedal, a clutch means for connecting and disconnecting the throttle driving means and the throttle valve, a cruise control detecting means and the brake detecting means. The accelerator opening sensor and the throttle based on the selection of An analog circuit for comparing each output value of the throttle opening sensor with a predetermined value to detect an abnormality in the throttle control system, and driving the clutch means when the analog circuit detects an abnormality in the throttle control system. The connection between the throttle driving means and the throttle valve is cut off, and at least one of a running state or a fuel supply amount, an ignition timing, and an intake air amount for mechanically connecting the accelerator pedal and the throttle valve is adjusted. Switching means for switching to the evacuation traveling mode depending on the traveling state, and operation of whether or not the analog circuit for detecting abnormality of the throttle control system using a predetermined pseudo signal according to the operating state at a predetermined timing operates normally A throttle control device for an internal combustion engine, comprising: checking means for checking. 2. The analog circuit generates an alarm when the analog circuit is abnormal, by controlling the throttle valve to be closed by the throttle driving means and operating the clutch means to disconnect the connection between the throttle driving means and the throttle valve. The throttle control device for an internal combustion engine according to claim 1, wherein at least one of the processes is performed to switch to the escape travel mode. 3. A throttle drive means for controlling an opening of a throttle valve of an internal combustion engine based on a predetermined throttle opening command value independently of a depression operation of an accelerator pedal, and a throttle drive means when the throttle drive means is inoperative. Energizing means for urging the throttle valve in the closing direction, an accelerator opening sensor for detecting the depression amount of the accelerator pedal, a throttle opening sensor for detecting the opening of the throttle valve, and whether the cruise control is being performed. A cruise control detecting means for detecting the brake pedal, a brake detecting means for detecting a depression operation of the brake pedal, and outputs of the accelerator opening sensor and the throttle opening sensor based on the selection of the cruise control detecting means and the brake detecting means. Detects an abnormality in the throttle control system by comparing each value with a predetermined value An analog circuit for controlling the throttle control system, and a switching means for switching to a retreat traveling mode including a traveling state in which one or more of a fuel supply amount, an ignition timing, and an intake air amount are adjusted when an abnormality is detected in the throttle control system. A check unit for checking whether or not the analog circuit for detecting an abnormality of the throttle control system operates normally by using a predetermined pseudo signal according to an operating state at a predetermined timing. A throttle control device for an internal combustion engine.